Intervertebral disc degeneration(IVDD)is the primary contributor to a range of spinal diseases.Dynamin-related protein 1(Drp1)-mediated mitochondrial fission has recently been identified as a new cause of nucleus pulp...Intervertebral disc degeneration(IVDD)is the primary contributor to a range of spinal diseases.Dynamin-related protein 1(Drp1)-mediated mitochondrial fission has recently been identified as a new cause of nucleus pulposus cell(NPC)death and IVDD,but the underlying mechanisms remain unclear.Although the effects of Drp1 phosphorylation in IVDD have been studied,it is currently unknown if small ubiquitin-like modifications(SUMOylation)of Drp1 regulate IVDD.This study aimed to investigate the functions and mechanisms of mitochondria-anchored protein ligase(MAPL),a mitochondrial SUMO E3 ligase,during IVDD progression.The expression of genes related to SUMOylation and mitochondrial dynamics in TNF-α-stimulated NPCs was analysed via RNA sequencing.展开更多
BACKGROUND Diabetic cognitive dysfunction(DCD)is one of the chronic complications of diabetes,but its mechanism is currently unknown.Studies have shown that mitochondrial fission mediated by calcium overload is an imp...BACKGROUND Diabetic cognitive dysfunction(DCD)is one of the chronic complications of diabetes,but its mechanism is currently unknown.Studies have shown that mitochondrial fission mediated by calcium overload is an important mechanism of DCD.Blocking calcium overload and restoring calcium homeostasis are key steps in treatment.Transient receptor potential melastatin 7(TRPM7)is a novel player in causing calcium overload.Our previous studies have shown that genetic silencing of TRPM7 in type 1 diabetic rats leads to significant improvements in cognitive function,but the specific mechanism remains unclear.Troxerutin,extracted from the flowers of Sophora japonica,is one of the derivatives of rutin and has been shown to have neuroprotective effects.However,its association with TRPM7 remains unclear.AIM To use animal and cellular models,we investigated whether TRPM7 mediated mitochondrial fission by upregulation of calcineurin(CaN)/dynamin-related protein 1(Drp1)ser637 in DCD,and whether Troxerutin improved DCD by inhibiting TRPM7-mediated mitochondrial division.METHODS In this study,we used db/db mice and hippocampal neuronal cell lines(HT22)treated with high-concentration glucose as our study subjects.We evaluated cognitive function using Morris water maze,novel object recognition tasks,and Nesting tests.We observed mitochondrial morphology using transmission electron microscopy and measured mitochondrial energy metabolism indicators using a spectrophotometer.We also detected mRNA and protein expression of TRPM7,CaN,p-Drp1^(ser637),caspase-3,B-cell lymphoma 2 associated X protein,and B-cell lymphoma 2 using quantitative real-time polymerase chain reaction,western blotting,and immunofluorescence.RESULTS In the db/db diabetic mice with cognitive dysfunction,as well as in hippocampal neurons exposed to high-concentration glucose,TRPM7 and CaN expression were upregulated,phosphorylated Drp1^(ser637)expression was downregulated,and mitochondrial fission was increased.By modulating(inhibiting or overexpressing)TRPM7,it was further validated that TRPM7 activates the CaN/Drp1^(ser637)pathway,resulting in an increase in mitochondrial fission and neuronal cell apoptosis.Troxerutin downregulated TRPM7/CaN/Drp1^(ser637),reduced mitochondrial fission,and improved DCD.CONCLUSION TRPM7 promotes mitochondrial fission via the CaN/Drp1^(ser637)pathway.Troxerutin improves mitochondrial function and reduces neuronal damage by inhibiting this pathway,suggesting TRPM7 as a potential therapeutic target for DCD.展开更多
Increasing evidence indicates that mitochonarial lission imbalance plays an important role in derayed neuronal cell death. Our previous study round that photo biomodulation improved the motor function of rats with spi...Increasing evidence indicates that mitochonarial lission imbalance plays an important role in derayed neuronal cell death. Our previous study round that photo biomodulation improved the motor function of rats with spinal cord injury.However,the precise mechanism remains unclear.To investigate the effect of photo biomodulation on mitochondrial fission imbalance after spinal cord injury,in this study,we treated rat models of spinal co rd injury with 60-minute photo biomodulation(810 nm,150 mW) every day for 14 consecutive days.Transmission electron microscopy results confirmed the swollen and fragmented alte rations of mitochondrial morphology in neurons in acute(1 day) and subacute(7 and 14 days) phases.Photo biomodulation alleviated mitochondrial fission imbalance in spinal cord tissue in the subacute phase,reduced neuronal cell death,and improved rat posterior limb motor function in a time-dependent manner.These findings suggest that photobiomodulation targets neuronal mitochondria,alleviates mitochondrial fission imbalance-induced neuronal apoptosis,and thereby promotes the motor function recovery of rats with spinal cord injury.展开更多
OBJECTIVE To elucidate the molecular mechanism and the anti-breast cancer effect of polyphyllinⅠ,which is a natural compound extracted from Rhizoma of Paris polyphyllin.METHODS Human breast cancer cells were treated ...OBJECTIVE To elucidate the molecular mechanism and the anti-breast cancer effect of polyphyllinⅠ,which is a natural compound extracted from Rhizoma of Paris polyphyllin.METHODS Human breast cancer cells were treated with polyphyllinⅠ,after which DRP1-dependent mitochondrial fission and apoptosis,mitophagy and PINK1/PARK2 pathway were evaluated.A genetic approach was employed to determine how knockdown of PINK1 with sh RNA regulates polyphyllinⅠ-induced mitophagy and apoptosis.The inhibitory effect of polyphyllinⅠon tumor growth in a breast cancer cell xenograft mouse model was also examined.RESULTS PolyphyllinⅠenhanced the stabilization of full-length PINK1at the mitochondrial surface,leading to PARK2 recruitment to mitochondria,and culminating in mitophagy.PolyphyllinⅠalso induced dephosphorylation of DRP1 at Ser637 and mitochondrial translocation of DRP1,leading to mitochondrial fission and apoptosis.Knockdown of PINK1 evidently suppressed mitophagy stimulated by polyphyllinⅠ,and markedly enhanced DRP1-dependent mitochondrial fission and apoptosis induced by polyphyl inⅠ.Furthermore,suppression of DRP1 by mdivi-1 or sh RNA inhibits PINK1 knockdown-mediated mitochondrial fragmentation and apoptosis in response to polyphyllinⅠtreatment,suggesting that depletion of PINK1 lead to mitochondrial fragmentation due to excessive fission.Our in vivo study also showed that knockdown of PINK1potentiated polyphyllinⅠ-mediated inhibition of tumor growth in a breast cancer cell xenograft mouse model.CONCLUSION Our study provides a mechanism to support the role of PINK1 in the regulation of polyphyl inⅠ-induced mitophagy and apoptosis,and suggest polyphylinⅠas a potential drug for treatment of breast cancer.展开更多
Polycystic ovarian syndrome(PCOS)is the most principal reason for infertility in reproductive women,but no versatile treatment is feasible.Although trans-10-hydroxy-2-decenoic acid(10H2DA)exhibits the anti-inflammator...Polycystic ovarian syndrome(PCOS)is the most principal reason for infertility in reproductive women,but no versatile treatment is feasible.Although trans-10-hydroxy-2-decenoic acid(10H2DA)exhibits the anti-inflammatory,anti-cancerous and immunomodulatory properties,its role in improving PCOS remains elusive.This present study examined the effects of 10H2DA on the estrous cycle,ovarian morphology,reproductive hormone,glucose and insulin tolerances of PCOS mice,analyzed the binding between 10H2DA and free fatty acid receptor 4(FFAR4),and explored the regulation of 10H2DA on the c-Jun N-terminal kinase(JNK)/JUN(Jun proto-oncogene)signaling,cytosolic calcium ion(Ca^(2+)),endoplasmic reticulum(ER)Ca^(2+) release,mitochondrial Ca^(2+),mitochondrial function,autophagy,lysosomal acidification,mitochondrial fission,secretion function and apoptosis of ovarian granulosa cells(GCs)using enzyme-linked immunosorbent assay,flow cytometry,Western blotting,molecular docking,various fluorescent probes or plasmid,etc.The results showed that 10H2DA alleviated the symptom of PCOS mice through improving the secretion dysfunction of GCs and protecting GCs against apoptosis.After binding to FFAR4 and inactivation of JNK/JUN signaling,10H2DA restricted the release of ER Ca^(2+)through targeting ryanodine receptors(RYRs)which had been identified as the downstream targets of JUN,diminished cytosolic Ca^(2+) accumulation and prevented Ca^(2+) influx into mitochondria via adjusting the mitochondrial calcium uptake 1 and mitochondrial calcium uniporter.Concurrently,10H2DA kept the integrity of mitochondrial function through maintaining mitochondrial Ca2 homeostasis and suppressed the discharge of mitochondrial reactive oxygen species into the cytosol through blocking the mitochondrial permeability transition pore opening to avoid the lipid peroxidation and ameliorate the secretory function and apoptosis of GCs.Furthermore,1OH2DA rescued the defective autophagic flux along with the decline of autophagosomes and sequestosome 1 aggregation,restored the mitophagy flux with the abatement of mitophagosomes and Parkin recruitment to mitochondria,and accelerated the lysosomal degradation for depolarized mitochondria with the recovery of lysosomal acidification,whereas activation of JNK antagonized the amelioration of 10H2DA on above effectiveness,but this antagonism was counteracted by the attenuation of intracellular Ca^(2+).After application of 10H2DA,dynamin-related protein 1 phosphorylation was diminished and its recruitment to mitochondrial surface was impeded concomitant with the improvement of mitochondrial fragmentation,whereas inhibition of late-stage autophagy caused the failure of 10H2DA in improving mitochondrial fission.Collectively,10H2DA might ameliorate PCOS mice through modulating autophagy-mediated mitochondrial fission dependent on the maintenance of Ca^(2+) homeostasis between ER and mitochondria.展开更多
Objective To observe the effect of electroacupuncture(EA)pretreatment of"biaoben acupoint combination"on cardiomyocyte mitochondrial fission in the rats with myocardial ischemia-reperfusion injury(MIRI)and e...Objective To observe the effect of electroacupuncture(EA)pretreatment of"biaoben acupoint combination"on cardiomyocyte mitochondrial fission in the rats with myocardial ischemia-reperfusion injury(MIRI)and explore its mechanism.Methods Fifty male SD rats were randomly divided into a sham-operation group,a model group,an EA pretreatment group,an EA pretreatment+Compound C group and an EA pretreatment+ML385 group,10 rats in each group.In the EA pretreatment,the EA pretreatment+Compound C group and the EA pretreatment+ML3855 group,EA was delivered at bilateral“Neiguan”(PC6),“Zusanli”(ST36)and"Guanyuan"(CV4)for 20 min,with continuous wave and 2 Hz of frequency,1 mA of current,once daily for consecutive 7 days.On day 8,in the EA pretreatment+Compound C group and the EA pretreatment+ML385 group,30 minbeforemodel preparation,the intraperitoneal injection with Compound C(0.3 mg/kg)and ML385(30 mg/kg)was administered respectively.Except in the sham-operation group,the ligation of the left anterior descending coronary artery was performed to prepare MIRI rat model in the rest groups.In the shamoperation group,the thread was not ligated.After modeling,the content of reactive oxygen species(ROS)in the ischemic area was measured by flow cytometry,superoxide dismutase(SOD)was detected using xanthine oxidase method,and malondialdelyde(MDA)was detected using thiobarbituric acid(TBA)chromatometry.The morphology of myocardial tissue in the ischemic area was observed with HE staining,and the mitochondria ultrastructure of cardiomyocytes observed under transmission electron microscopy.Using immunofluorescence analysis,the positive expression of mitochondrial fission factor(MFF),mitochondrial fission 1 protein antibody(Fis1)and dynamin-related protein 1(Drpl)was detected;and with immunohistochemical method used,the protein expression of adenosine monophosphate-activated protein kinase(AMPK),nuclear factor E2-associated factor2(Nrf2)and Drpl in the ischemic area was detected.Results Compared with the sham-operation group,the content of ROS and MDA in the myocardial tissue of the ischemic area,and the positive expression of MFF,Fisl and Drpl increased in the model group(P<0.01);the content of SOD and the protein expression of AMRK and Nrf2 decreased(P<0.01),and the protein expression of Drpl elevated(P<0.01).Compared with the model group,the content of ROS and MDA in the myocardial tissue of the ischemic area,and the positive expression of MFF,Fisl and Drpl were dropped in the EA pretreatment group(P<0.01);the content of SOD and the protein expression of AMRK and Nrf2 rose(P<0.01),and the protein expression of Drpl declined(P<0.01);and in the EA pretreatment+Compound C group and the EA pretreatment+ML385 group,the positive expression of MFF,Fisl and Drpl,and the protein expression of Drpl were all reduced(P<0.01).When compared with the EA pretreatment+Compound C group and the EA pretreatment+ML385 group,the content of ROS and MDA in the myocardial tissue of the ischemic area,and the positive expression of MFF,Fisl and Drpl were dropped in the EA pretreatment group(P<0.01);the content of SOD and the protein expression of AMRK and Nrf2 rose(P<0.01,P<0.05),and the protein expression of Drpl decreased(P<0.05).In comparison with the model group,the EA pretreatment+Compound C group and the EA pretreatment+ML385 group,the cardiac muscle fiber rupture,cell swelling and mitochondrial disorders were obviously alleviated in the EA pretreatment group.The morphological changes were similar among the model group,the EA pretreatment+Compound C group and the EA pretreatment+ML385 group.Conclusion Electroacupuncture pretreatment of"biaoben acupoint combination"attenuates myocardial injury in MIRI rats,probably through promoting the phosphorylation of AMPK and Nrf2,inhibiting the excessive mitochondrial fission induced by Drpl,and reducing mitochondrial dysfunction caused by mitochondrial fragmentation and vacuolation.展开更多
Chronic diabetic wounds remain a globally recognized clinical challenge.They occur due to high concentrations of reactive oxygen species and vascular function disorders.A promising strategy for diabetic wound healing ...Chronic diabetic wounds remain a globally recognized clinical challenge.They occur due to high concentrations of reactive oxygen species and vascular function disorders.A promising strategy for diabetic wound healing is the delivery of exosomes,comprising bioactive dressings.Metformin activates the vascular endothelial growth factor pathway,thereby improving angiogenesis in hyperglycemic states.However,multifunctional hydrogels loaded with drugs and bioactive substances synergistically promote wound repair has been rarely reported,and the mechanism of their combinatorial effect of exosome and metformin in wound healing remains unclear.Here,we engineered dual-loaded hydrogels possessing tissue adhesive,antioxidant,self-healing and electrical conductivity properties,wherein 4-armed SH-PEG cross-links with Ag^(+),which minimizes damage to the loaded goods and investigated their mechanism of promotion effect for wound repair.Multiwalled carbon nanotubes exhibiting good conductivity were also incorporated into the hydrogels to generate hydrogen bonds with the thiol group,creating a stable three-dimensional structure for exosome and metformin loading.The diabetic wound model of the present study suggests that the PEG/Ag/CNT-M+E hydrogel promotes wound healing by triggering cell proliferation and angiogenesis and relieving peritraumatic inflammation and vascular injury.The mechanism of the dual-loaded hydrogel involves reducing the level of reactive oxygen species by interfering with mitochondrial fission,thereby protecting F-actin homeostasis and alleviating microvascular dysfunction.Hence,we propose a drug-bioactive substance combination therapy and provide a potential mechanism for developing vascular function-associated strategies for treating chronic diabetic wounds.展开更多
Background:Sirtuin-3(Sirt3)has been documented to protect against mitochondrial dysfunction and apoptosis.Honokiol(HKL)is a Sirt3 pharmacological activator with reported neuroprotective effects in multiple neurologica...Background:Sirtuin-3(Sirt3)has been documented to protect against mitochondrial dysfunction and apoptosis.Honokiol(HKL)is a Sirt3 pharmacological activator with reported neuroprotective effects in multiple neurological disorders.The present study aimed to explore the neuroprotective effects of HKL and the role of Sirt3 following intracerebral hemorrhage(ICH).Methods:An in vivo ICH model in rats was established by injecting autologous blood into the right basal ganglia.PC12 cells were stimulated with hemin.For the in vivo investigation,the modified Neurological Severity Scores and the Morris water maze test were performed to assess neurological deficits.Hematoxylin-Eosin and Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining were employed to evaluate the histopathology and apoptosis.Immunohistochemical staining was used to investigate the expression of Sirt3.Adenosine triphosphate(ATP)levels were quantified to assess mitochondrial dysfunction.Cell counting kit-8,lactate dehydrogenase assay,and flow cytometry were used to analyze cell vitality and apoptosis in vitro.Immunofluorescence staining was performed to observe mitochondrial morphology and dynamin-related protein 1(Drp1)localization to mitochondria.Western blot was applied to quantify the expression of Sirt3,Bax,Bcl-2,cleaved-caspase-3,Drp1,phosphorylation of Drp1 at serine-616,and phosphorylation of Drp1 at serine-637 in vivo and in vitro.Results:HKL treatment alleviated neurological deficits,attenuated the histopathological damage and cell apoptosis,and restored the decreased ATP levels in ICH rats.HKL improved cell survival rate,reduced cell apoptosis,and inhibited mitochondrial fission in PC12 cells.Moreover,both in vivo and in vitro models showed increased phosphorylation of Drp1 at Ser616,and reduced phosphorylation of Drp1 at Ser637.Meanwhile,immunofluorescence co-localization analysis revealed that hemin increased the overlap of Drp1 and mitochondria in PC12 cells.The phosphorylation and mitochondrial translocation of Drp1 were effectively reversed by HKL treatment.Importantly,the selective Sirt3 inhibitor 3-(1H-1,2,3-triazol-4-yl)pyridine suppressed these effects.Conclusion:Our findings demonstrated that HKL ameliorated ICH-induced apoptosis and mitochondrial fission by Sirt3,suggesting that HKL has immense prospects for the treatment of ICH.展开更多
Mitochondria are morphologically dynamic organelles which undergo fission and fusion processes. Our previous study found that arterial constriction was always accompanied by increased mitochondrial fission in smooth m...Mitochondria are morphologically dynamic organelles which undergo fission and fusion processes. Our previous study found that arterial constriction was always accompanied by increased mitochondrial fission in smooth muscle cells, whereas inhibition of mitochondrial fission in smooth muscle cells was associated with arterial relaxation. Here, we used the typical vasorelaxants, verapamil and phentolamine, to further confirm the coupling between arterial constriction and mitochondrial fission in rat aorta. Results showed that phentolamine but not verapamil induced vasorelaxation in phenylephrine(PE)-induced rat thoracic aorta constriction. Verapamil, but not phentolamine, induced vasorelaxation in high K^+(KPSS)-induced rat thoracic aorta constriction. Pre-treatment with phentolamine prevented PEbut not KPSS-induced aorta constriction and pre-treatment with verapamil prevented both PE-and KPSSinduced aorta constriction. Transmission electron microscopy(TEM) results showed that verapamil but not phentolamine inhibited KPSS-induced excessive mitochondrial fission in aortic smooth muscle cells,and verapamil prevented both PE-and KPSS-induced excessive mitochondrial fission in aortic smoothmuscle cells. Verapamil inhibited KPSS-induced excessive mitochondrial fission in cultured vascular smooth muscle cells(A10). These results further demonstrate that arterial relaxation is coupled to inhibition of mitochondrial fission in arterial smooth muscle cells.展开更多
Mitochondrial shape rapidly changes by dynamic balance of fusion and fission to adjust to constantly changing energy demands of cancer cells.Mitochondrial dynamics balance is exactly regulated by molecular motor consi...Mitochondrial shape rapidly changes by dynamic balance of fusion and fission to adjust to constantly changing energy demands of cancer cells.Mitochondrial dynamics balance is exactly regulated by molecular motor consisted of myosin and actin cytoskeleton proteins.Thus,targeting myosin eactin molecular motor is considered as a promising strategy for anti-cancer.In this study,we performed a proof-of-concept study with a natural-derived small-molecule J13 to test the feasibility of anti-cancer therapeutics via pharmacologically targeting molecular motor.Here,we found J13 could directly target myosin-9(MYH9)eactin molecular motor to promote mitochondrial fission progression,and markedly inhibited cancer cells survival,proliferation and migration.Mechanism study revealed that J13 impaired MYH9 eactin interaction to inactivate molecular motor,and caused a cytoskeleton-dependent mitochondrial dynamics imbalance.Moreover,stable isotope labeling with amino acids in cell culture(SILAC)technology-coupled with pulldown analysis identified HSPA9 as a crucial adaptor protein connecting MYH9 eactin molecular motor to mitochondrial fission.Taken together,we reported the first natural small-molecule directly targeting MYH9 eactin molecular motor for anti-cancer translational research.Besides,our study also proved the conceptual practicability of pharmacologically disrupting mitochondrial fission/fusion dynamics in human cancer therapy.展开更多
Graft-versus-host disease (GVHD) significantly contributes to patient morbidity and mortality after allogeneic hematopoietic cell transplantation (allo-HSCT). Sphingosine-1-phosphate (S1P) signaling is involved in the...Graft-versus-host disease (GVHD) significantly contributes to patient morbidity and mortality after allogeneic hematopoietic cell transplantation (allo-HSCT). Sphingosine-1-phosphate (S1P) signaling is involved in the biogenetic processes of different immune cells. In the current study, we demonstrated that recipient sphingosine kinase 1 (Sphk1), but not Sphk2, was required for optimal S1PR1-dependent donor T-cell allogeneic responses by secreting S1P. Using genetic and pharmacologic approaches, we demonstrated that inhibition of Sphk1 or S1PR1 substantially attenuated acute GVHD (aGVHD) while retaining the graft-versus-leukemia (GVL) effect. At the cellular level, the Sphk1/S1P/S1PR1 pathway differentially modulated the alloreactivity of CD4+ and CD8+ T cells;it facilitated T-cell differentiation into Th1/Th17 cells but not Tregs and promoted CD4+ T-cell infiltration into GVHD target organs but was dispensable for the CTL activity of allogeneic CD8+ T cells. At the molecular level, the Sphk1/S1P/S1PR1 pathway augmented mitochondrial fission and increased mitochondrial mass in allogeneic CD4+ but not CD8+ T cells by activating the AMPK/AKT/mTOR/Drp1 pathway, providing a mechanistic basis for GVL maintenance when S1P signaling was inhibited. For translational purposes, we detected the regulatory efficacy of pharmacologic inhibitors of Sphk1 and S1PR1 in GVHD induced by human T cells in a xenograft model. Our study provides novel mechanistic insight into how the Sphk1/S1P/S1PR1 pathway modulates T-cell alloreactivity and validates Sphk1 or S1PR1 as a therapeutic target for the prevention of GVHD and leukemia relapse. This novel strategy may be readily translated into the clinic to benefit patients with hematologic malignancies and disorders.展开更多
Abnormal mitochondrial dynamics can lead to seizures,and improved mitochon-drial dynamics can alleviate seizures.Vacuolar protein sorting 13D(VPS13D)is closely associ-ated with regulating mitochondrial homeostasis and...Abnormal mitochondrial dynamics can lead to seizures,and improved mitochon-drial dynamics can alleviate seizures.Vacuolar protein sorting 13D(VPS13D)is closely associ-ated with regulating mitochondrial homeostasis and autophagy.However,further investigation is required to determine whether VPS13D affects seizures by influencing mitochondrial dy-namics and autophagy.We aimed to investigate the influence of VPS13D on behavior in a rat model of acute epileptic seizures.Hence,we established an acute epileptic seizure rat model and employed the CRISPR/CAS9 technology to construct a lentivirus to silence the Vps13d gene.Furthermore,we used the HT22 mouse hippocampal neuron cell line to establish a stable strain with suppressed expression of Vps13d in vitro.Then,we performed quantitative prote-omic and bioinformatics analyses to confirm the mechanism by which VPS13D influences mito-chondrial dynamics and autophagy,both in vitro and in vivo using the experimental acute epileptic seizure model.We found that knockdown of Vps13d resulted in reduced seizure la-tency and increased seizure frequency in the experimental rats.Immunofluorescence staining and western blot analysis revealed a significant increase in mitochondrial dynamin-related pro-tein 1 expression following Vps13d knockdown.Moreover,we observed a significant reduction in LC3Il protein expression levels and the LC31/LC3l ratio(indicators for autophagy)accompa-nied by a significant increase in P62 expression(an autophagy adaptor protein).The proteomic analysis confirmed the up-regulation of P62 protein expression.Therefore,we propose that VPS13D plays a role in modulating seizures by influencing mitochondrial dynamics and autophagy.展开更多
Objective:Capsaicin(CPS)is a major component of the red pepper,and its anti-tumor property has been confirmed.However,the underlying mechanism of this anti-tumor effect has not been fully clarified,so we conducted thi...Objective:Capsaicin(CPS)is a major component of the red pepper,and its anti-tumor property has been confirmed.However,the underlying mechanism of this anti-tumor effect has not been fully clarified,so we conducted this study to evaluate the role of mitochondrial fission and subsequent mitochondrial dysfunction in CPS-induced apoptosis of melanoma cells.Methods:Two melanoma cell lines and melanocytes were treated with CPS alone or in combination with ruthenium red(a transient receptor potential vanilloid 1[TRPV]antagonist),Z-VAD-FMK(a pan-caspase inhibitor),or N-acetyl-Lcysteine(an antioxidant).Cell vitality was tested using a cell counting kit-8 assay.The expression levels of related proteins were examined by Western blotting.Apoptosis,intracellular reactive oxygen species,mitochondrial membrane potential,adenosine triphosphate levels,and mitochondrial dynamics were analyzed by flow cytometry,luminometry,and confocal laser microscopy,respectively,and compared between groups.Results:CPS treatment significantly inhibited the vitality of melanoma cells(For A2058 cells:0 vs.120 mmol/L:[100.00%±0%]vs.[51.02%±6.40%],P<0.05;For WM35 cells:0 vs.120 mmol/L:[100.00%±0%]vs.[51.80%±3.45%],P<0.05)but exerted less impact on normal melanocytes.CPS promoted melanoma cell apoptosis through TRPV channels and the caspase cascade.CPS treatment then led to TRPV channel-dependent mitochondrial dysfunction with an increase in reactive oxygen species generation(For A2058 cells:CPS vs.CPS+RR:[2.34±0.30]vs.[1.34±0.12],P<0.05;For WM35 cells:CPS vs.CPS+RR:[2.25±0.25]vs.[1.65±0.13],P<0.05),dissipation of the mitochondrial membrane potential(Control vs.CPS:[1.00±0]vs.[0.61±0.08],P<0.05),and adenosine triphosphate reduction(P<0.05).In addition,reactive oxygen species generation contributed to CPS-induced melanoma cell apoptosis.Mitochondrial fission was subsequently proved to connect CPS treatment to mitochondrial dysfunction,which was also TRPV channel-dependent,thereby inducing melanoma cell apoptosis.Conclusion:Our study highlights the role of mitochondrial fission and its related mitochondrial dysfunction in mediating the pro-apoptotic effect of CPS in melanoma.These findings deepen our understanding of the mechanisms underlying the anti-tumor activity of CPS and indicate the clinical relevancy of extending the use of this agent for cancer therapy.展开更多
This paper aimed to explore the mechanism of tetrapeptide Val-Thr-Pro-Tyr(VTPY)in improving alcoholic gastric injury.VTPY has the potential to enhance the growth and movement of normal human gastric epithelial cells(G...This paper aimed to explore the mechanism of tetrapeptide Val-Thr-Pro-Tyr(VTPY)in improving alcoholic gastric injury.VTPY has the potential to enhance the growth and movement of normal human gastric epithelial cells(GES-1).Following ethanol-induced impairment,VTPY effectively improved migration of GES-1 and human umbilical vein endothelial cells(HUVEC)cells,enhanced angiogenesis,eliminated cellular and mitochondrial reactive oxygen species(ROS),inhibited excessive mitochondrial division,enhanced F-actin polymerization and mitochondrial respiratory capacity.To counteract excessive mitochondrial fission,VTPY primarily restores the mitochondria dynamics by reducing the expression of Drpl and Fis1,while increasing Mfn2.Further studies utilizing inhibitors clarifies that the inhibition of excessive mitochondrial fission can markedly reduce F-actin depolymerization,consequently enhancing cell migration.Additionally,VTPY can inhibit the apoptosis pathway by maintaining potential of mitochondrial membrane,preventing the release of mitochondrial cytochrome C,bolstering the levels of Bcl-XL,while reducing the levels of Bax and cleaved-Caspase-3.Further investigations using inhibitors demonstrates that excessive mitochondrial fission could activate apoptotic pathway.However,VTPY counteracts this effect and enhance cells viability.Further evidence suggests that VTPY effectively improves ulcer index and pathologic changes,relieves inflammation,enhances the balance of oxidation and anti-oxidation,promotes angiogenesis,improves the expression of mitochondrial dynamics factors,blocks apoptotic pathway,and subsequently ameliorates gastric damage in mice through Fis-1/Bcl-2 pathway.展开更多
The dramatic increase in intracranial pressure after subarachnoid hemorrhage leads to a decrease in cerebral perfusion pressure and a reduction in cerebral blood flow.Mitochondria are directly affected by direct facto...The dramatic increase in intracranial pressure after subarachnoid hemorrhage leads to a decrease in cerebral perfusion pressure and a reduction in cerebral blood flow.Mitochondria are directly affected by direct factors such as ischemia,hypoxia,excitotoxicity,and toxicity of free hemoglobin and its degradation products,which trigger mitochondrial dysfunction.Dysfunctional mitochondria release large amounts of reactive oxygen species,inflammatory mediators,and apoptotic proteins that activate apoptotic pathways,further damaging cells.In response to this array of damage,cells have adopted multiple mitochondrial quality control mechanisms through evolution,including mitochondrial protein quality control,mitochondrial dynamics,mitophagy,mitochondrial biogenesis,and intercellular mitochondrial transfer,to maintain mitochondrial homeostasis under pathological conditions.Specific interventions targeting mitochondrial quality control mechanisms have emerged as promising therapeutic strategies for subarachnoid hemorrhage.This review provides an overview of recent research advances in mitochondrial pathophysiological processes after subarachnoid hemorrhage,particularly mitochondrial quality control mechanisms.It also presents potential therapeutic strategies to target mitochondrial quality control in subarachnoid hemorrhage.展开更多
Temperature tolerance restricts the distribution of a species. However, the molecular and cellular mechanisms that set the thermal tolerance limits of an organism are poorly understood. Here, we report on the function...Temperature tolerance restricts the distribution of a species. However, the molecular and cellular mechanisms that set the thermal tolerance limits of an organism are poorly understood. Here, we report on the function of dual-specificity phosphatase 1(DUSP1) in thermal tolerance regulation. Notably, we found that dusp1-/- zebrafish grew normally but survived within a narrowed temperature range. The higher susceptibility of these mutant fish to both cold and heat challenges was attributed to accelerated cell death caused by aggravated mitochondrial dysfunction and over-production of reactive oxygen species in the gills. The DUSP1-MAPK-DRP1 axis was identified as a key pathway regulating these processes in both fish and human cells. These observations suggest that DUSP1 may play a role in maintaining mitochondrial integrity and redox homeostasis. We therefore propose that maintenance of cellular redox homeostasis may be a key mechanism for coping with cellular thermal stress and that the interplay between signaling pathways regulating redox homeostasis in the most thermosensitive tissue(i.e., gills) may play an important role in setting the thermal tolerance limit of zebrafish.展开更多
Huntington’s disease is a genetic disease caused by expanded CAG repeats on exon 1 of the huntingtin gene located on chromosome 4.Compelling evidence implicates impaired mitochondrial energetics,altered mitochondrial...Huntington’s disease is a genetic disease caused by expanded CAG repeats on exon 1 of the huntingtin gene located on chromosome 4.Compelling evidence implicates impaired mitochondrial energetics,altered mitochondrial biogenesis and quality control,disturbed mitochondrial trafficking,oxidative stress and mitochondrial calcium dyshomeostasis in the pathogenesis of the disorder.Unfortunately,conventional mitochondrial-targeted molecules,such as cysteamine,creatine,coenzyme Q10,or triheptanoin,yielded negative or inconclusive results.However,future therapeutic strategies,aiming to restore mitochondrial biogenesis,improving the fission/fusion balance,and improving mitochondrial trafficking,could prove useful tools in improving the phenotype of Huntington’s disease and,used in combination with genome-editing methods,could lead to a cure for the disease.展开更多
There is no clear consensus regarding how cells respond to hydrostatic pressure. This is largely attributable to the high heterogeneity among cell types and the diverse custom-made devices used in previous studies. Th...There is no clear consensus regarding how cells respond to hydrostatic pressure. This is largely attributable to the high heterogeneity among cell types and the diverse custom-made devices used in previous studies. The aim of this work was to develop a facile device that could mimic various pressure environments and then delineate the cellular response to pressure stimulus. The device described here achieved both stable and periodic pressurization without oxygen deprivation. The biological utility of the device was assessed using human umbilical vein endothelial cells. We found more stereoscopic nuclear morphology and re-distribution of lamin A/C under high hydrostatic pressure compared to control cells. Mass spectrometry-based proteomics analysis showed significant changes in mitochondria-related pathways. Western blot analysis confirmed that high hydrostatic pressure induced a tendency toward mitochondrial fusion. Increased mitochondrial activity was observed as well. In conclusion, this device can be readily applied in biological research and extend our understanding of cellular mechano-sensation and the associated changes in mitochondrial behaviors.展开更多
At the present,association of mitochondrial dysfunction and progression of neurological disorders has gained significant attention.Defects in mitochondrial network dynamics,point mutations,deletions,and interaction of...At the present,association of mitochondrial dysfunction and progression of neurological disorders has gained significant attention.Defects in mitochondrial network dynamics,point mutations,deletions,and interaction of pathogenomic proteins with mitochondria are some of the possible underlying mechanisms involved in these neurological disorders.Mitochondrial genetics,defects in mitochondrial oxidative phosphorylation machinery,and reactive oxygen species production might share common crosstalk in the progression of these neurological disorders.It is of significant interests to explore and develop therapeutic strategies aimed at correcting mitochondrial abnormalities.This review provided insights on mitochondrial dysfunction/mutations involved in the progression of Alzheimer’s disease,Huntington’s disease,and epilepsy with a special focus on Parkinson’s disease pathology.Along with the deleterious effects of mitochondrial mutations in aforesaid neurological disorders,this paper unraveled the available therapeutic strategy,specifically aiming to improve mitochondrial dysfunction,drugs targeting mitochondrial proteins,gene therapies aimed at correcting mutant mtDNA,peptide-based approaches,and lipophilic cations.展开更多
Divisions at the periphery and midzone of mitochondria are two fission signatures that determine the fate of mitochondria and cells.Pharmacological induction of excessively asymmetric mitofissionassociated cell death(...Divisions at the periphery and midzone of mitochondria are two fission signatures that determine the fate of mitochondria and cells.Pharmacological induction of excessively asymmetric mitofissionassociated cell death(MFAD)by switching the scission position from the mitochondrial midzone to the periphery represents a promising strategy for anticancer therapy.By screening a series of paninhibitors,we identified pracinostat,a pan-histone deacetylase(HDAC)inhibitor,as a novel MFAD inducer,that exhibited a significant anticancer effect on colorectal cancer(CRC)in vivo and in vitro.Pracinostat increased the expression of cyclin-dependent kinase 5(CDK5)and induced its acetylation at residue lysine 33,accelerating the formation of complex CDK5/CDK5 regulatory subunit 1 and dynaminrelated protein 1(Drp1)-mediated mitochondrial peripheral fission.CRC cells with high level of CDK5(CDK5-high)displayed midzone mitochondrial division that was associated with oncogenic phenotype,but treatment with pracinostat led to a lethal increase in the already-elevated level of CDK5 in the CRC cells.Mechanistically,pracinostat switched the scission position from the mitochondrial midzone to the periphery by improving the binding of Drp1 from mitochondrial fission factor(MFF)to mitochondrial fission 1 protein(FIS1).Thus,our results revealed the anticancer mechanism of HDACi pracinostat in CRC via activating CDK5-Drp1 signaling to cause selective MFAD of those CDK5-high tumor cells,which implicates a new paradigm to develop potential therapeutic strategies for CRC treatment.展开更多
基金supported by National Natural Science Foundation of China(82272549,82472505,and 82472498)National key Research and Development plan,Ministry of Science and Technology of the People’s Republic of China(2022YFC2407203)+2 种基金the Young Health Talents of Shanghai Municipal Health Commission,China(2022YQ011)China Medical Education Association(3030537245)The Youth Talent Project of Huashan Hospital(30302164006).
文摘Intervertebral disc degeneration(IVDD)is the primary contributor to a range of spinal diseases.Dynamin-related protein 1(Drp1)-mediated mitochondrial fission has recently been identified as a new cause of nucleus pulposus cell(NPC)death and IVDD,but the underlying mechanisms remain unclear.Although the effects of Drp1 phosphorylation in IVDD have been studied,it is currently unknown if small ubiquitin-like modifications(SUMOylation)of Drp1 regulate IVDD.This study aimed to investigate the functions and mechanisms of mitochondria-anchored protein ligase(MAPL),a mitochondrial SUMO E3 ligase,during IVDD progression.The expression of genes related to SUMOylation and mitochondrial dynamics in TNF-α-stimulated NPCs was analysed via RNA sequencing.
基金Supported by the Natural Science Foundation of Hebei Province,No.H2021206187 and No.H2021206452.
文摘BACKGROUND Diabetic cognitive dysfunction(DCD)is one of the chronic complications of diabetes,but its mechanism is currently unknown.Studies have shown that mitochondrial fission mediated by calcium overload is an important mechanism of DCD.Blocking calcium overload and restoring calcium homeostasis are key steps in treatment.Transient receptor potential melastatin 7(TRPM7)is a novel player in causing calcium overload.Our previous studies have shown that genetic silencing of TRPM7 in type 1 diabetic rats leads to significant improvements in cognitive function,but the specific mechanism remains unclear.Troxerutin,extracted from the flowers of Sophora japonica,is one of the derivatives of rutin and has been shown to have neuroprotective effects.However,its association with TRPM7 remains unclear.AIM To use animal and cellular models,we investigated whether TRPM7 mediated mitochondrial fission by upregulation of calcineurin(CaN)/dynamin-related protein 1(Drp1)ser637 in DCD,and whether Troxerutin improved DCD by inhibiting TRPM7-mediated mitochondrial division.METHODS In this study,we used db/db mice and hippocampal neuronal cell lines(HT22)treated with high-concentration glucose as our study subjects.We evaluated cognitive function using Morris water maze,novel object recognition tasks,and Nesting tests.We observed mitochondrial morphology using transmission electron microscopy and measured mitochondrial energy metabolism indicators using a spectrophotometer.We also detected mRNA and protein expression of TRPM7,CaN,p-Drp1^(ser637),caspase-3,B-cell lymphoma 2 associated X protein,and B-cell lymphoma 2 using quantitative real-time polymerase chain reaction,western blotting,and immunofluorescence.RESULTS In the db/db diabetic mice with cognitive dysfunction,as well as in hippocampal neurons exposed to high-concentration glucose,TRPM7 and CaN expression were upregulated,phosphorylated Drp1^(ser637)expression was downregulated,and mitochondrial fission was increased.By modulating(inhibiting or overexpressing)TRPM7,it was further validated that TRPM7 activates the CaN/Drp1^(ser637)pathway,resulting in an increase in mitochondrial fission and neuronal cell apoptosis.Troxerutin downregulated TRPM7/CaN/Drp1^(ser637),reduced mitochondrial fission,and improved DCD.CONCLUSION TRPM7 promotes mitochondrial fission via the CaN/Drp1^(ser637)pathway.Troxerutin improves mitochondrial function and reduces neuronal damage by inhibiting this pathway,suggesting TRPM7 as a potential therapeutic target for DCD.
基金supported by the National Natural Science Foundation of China,Nos.81070996 (to ZW) and 815 72151 (to XYH)Shaanxi Provincial Key R&D Program,Nos.2020ZDLSF02-05 (to ZW),2021ZDLSF02-10 (to XYH)。
文摘Increasing evidence indicates that mitochonarial lission imbalance plays an important role in derayed neuronal cell death. Our previous study round that photo biomodulation improved the motor function of rats with spinal cord injury.However,the precise mechanism remains unclear.To investigate the effect of photo biomodulation on mitochondrial fission imbalance after spinal cord injury,in this study,we treated rat models of spinal co rd injury with 60-minute photo biomodulation(810 nm,150 mW) every day for 14 consecutive days.Transmission electron microscopy results confirmed the swollen and fragmented alte rations of mitochondrial morphology in neurons in acute(1 day) and subacute(7 and 14 days) phases.Photo biomodulation alleviated mitochondrial fission imbalance in spinal cord tissue in the subacute phase,reduced neuronal cell death,and improved rat posterior limb motor function in a time-dependent manner.These findings suggest that photobiomodulation targets neuronal mitochondria,alleviates mitochondrial fission imbalance-induced neuronal apoptosis,and thereby promotes the motor function recovery of rats with spinal cord injury.
基金The project supported by National Natural Science Foundation of China(81402970,81402202,81402013,81202869)
文摘OBJECTIVE To elucidate the molecular mechanism and the anti-breast cancer effect of polyphyllinⅠ,which is a natural compound extracted from Rhizoma of Paris polyphyllin.METHODS Human breast cancer cells were treated with polyphyllinⅠ,after which DRP1-dependent mitochondrial fission and apoptosis,mitophagy and PINK1/PARK2 pathway were evaluated.A genetic approach was employed to determine how knockdown of PINK1 with sh RNA regulates polyphyllinⅠ-induced mitophagy and apoptosis.The inhibitory effect of polyphyllinⅠon tumor growth in a breast cancer cell xenograft mouse model was also examined.RESULTS PolyphyllinⅠenhanced the stabilization of full-length PINK1at the mitochondrial surface,leading to PARK2 recruitment to mitochondria,and culminating in mitophagy.PolyphyllinⅠalso induced dephosphorylation of DRP1 at Ser637 and mitochondrial translocation of DRP1,leading to mitochondrial fission and apoptosis.Knockdown of PINK1 evidently suppressed mitophagy stimulated by polyphyllinⅠ,and markedly enhanced DRP1-dependent mitochondrial fission and apoptosis induced by polyphyl inⅠ.Furthermore,suppression of DRP1 by mdivi-1 or sh RNA inhibits PINK1 knockdown-mediated mitochondrial fragmentation and apoptosis in response to polyphyllinⅠtreatment,suggesting that depletion of PINK1 lead to mitochondrial fragmentation due to excessive fission.Our in vivo study also showed that knockdown of PINK1potentiated polyphyllinⅠ-mediated inhibition of tumor growth in a breast cancer cell xenograft mouse model.CONCLUSION Our study provides a mechanism to support the role of PINK1 in the regulation of polyphyl inⅠ-induced mitophagy and apoptosis,and suggest polyphylinⅠas a potential drug for treatment of breast cancer.
基金supported by Natural Science Foundation of Jilin Province(20220101287JC)National Natural Science Foundation of China(31873003 and 31472158)Graduate Innovation Fund of Jilin University(2022140).
文摘Polycystic ovarian syndrome(PCOS)is the most principal reason for infertility in reproductive women,but no versatile treatment is feasible.Although trans-10-hydroxy-2-decenoic acid(10H2DA)exhibits the anti-inflammatory,anti-cancerous and immunomodulatory properties,its role in improving PCOS remains elusive.This present study examined the effects of 10H2DA on the estrous cycle,ovarian morphology,reproductive hormone,glucose and insulin tolerances of PCOS mice,analyzed the binding between 10H2DA and free fatty acid receptor 4(FFAR4),and explored the regulation of 10H2DA on the c-Jun N-terminal kinase(JNK)/JUN(Jun proto-oncogene)signaling,cytosolic calcium ion(Ca^(2+)),endoplasmic reticulum(ER)Ca^(2+) release,mitochondrial Ca^(2+),mitochondrial function,autophagy,lysosomal acidification,mitochondrial fission,secretion function and apoptosis of ovarian granulosa cells(GCs)using enzyme-linked immunosorbent assay,flow cytometry,Western blotting,molecular docking,various fluorescent probes or plasmid,etc.The results showed that 10H2DA alleviated the symptom of PCOS mice through improving the secretion dysfunction of GCs and protecting GCs against apoptosis.After binding to FFAR4 and inactivation of JNK/JUN signaling,10H2DA restricted the release of ER Ca^(2+)through targeting ryanodine receptors(RYRs)which had been identified as the downstream targets of JUN,diminished cytosolic Ca^(2+) accumulation and prevented Ca^(2+) influx into mitochondria via adjusting the mitochondrial calcium uptake 1 and mitochondrial calcium uniporter.Concurrently,10H2DA kept the integrity of mitochondrial function through maintaining mitochondrial Ca2 homeostasis and suppressed the discharge of mitochondrial reactive oxygen species into the cytosol through blocking the mitochondrial permeability transition pore opening to avoid the lipid peroxidation and ameliorate the secretory function and apoptosis of GCs.Furthermore,1OH2DA rescued the defective autophagic flux along with the decline of autophagosomes and sequestosome 1 aggregation,restored the mitophagy flux with the abatement of mitophagosomes and Parkin recruitment to mitochondria,and accelerated the lysosomal degradation for depolarized mitochondria with the recovery of lysosomal acidification,whereas activation of JNK antagonized the amelioration of 10H2DA on above effectiveness,but this antagonism was counteracted by the attenuation of intracellular Ca^(2+).After application of 10H2DA,dynamin-related protein 1 phosphorylation was diminished and its recruitment to mitochondrial surface was impeded concomitant with the improvement of mitochondrial fragmentation,whereas inhibition of late-stage autophagy caused the failure of 10H2DA in improving mitochondrial fission.Collectively,10H2DA might ameliorate PCOS mice through modulating autophagy-mediated mitochondrial fission dependent on the maintenance of Ca^(2+) homeostasis between ER and mitochondria.
文摘Objective To observe the effect of electroacupuncture(EA)pretreatment of"biaoben acupoint combination"on cardiomyocyte mitochondrial fission in the rats with myocardial ischemia-reperfusion injury(MIRI)and explore its mechanism.Methods Fifty male SD rats were randomly divided into a sham-operation group,a model group,an EA pretreatment group,an EA pretreatment+Compound C group and an EA pretreatment+ML385 group,10 rats in each group.In the EA pretreatment,the EA pretreatment+Compound C group and the EA pretreatment+ML3855 group,EA was delivered at bilateral“Neiguan”(PC6),“Zusanli”(ST36)and"Guanyuan"(CV4)for 20 min,with continuous wave and 2 Hz of frequency,1 mA of current,once daily for consecutive 7 days.On day 8,in the EA pretreatment+Compound C group and the EA pretreatment+ML385 group,30 minbeforemodel preparation,the intraperitoneal injection with Compound C(0.3 mg/kg)and ML385(30 mg/kg)was administered respectively.Except in the sham-operation group,the ligation of the left anterior descending coronary artery was performed to prepare MIRI rat model in the rest groups.In the shamoperation group,the thread was not ligated.After modeling,the content of reactive oxygen species(ROS)in the ischemic area was measured by flow cytometry,superoxide dismutase(SOD)was detected using xanthine oxidase method,and malondialdelyde(MDA)was detected using thiobarbituric acid(TBA)chromatometry.The morphology of myocardial tissue in the ischemic area was observed with HE staining,and the mitochondria ultrastructure of cardiomyocytes observed under transmission electron microscopy.Using immunofluorescence analysis,the positive expression of mitochondrial fission factor(MFF),mitochondrial fission 1 protein antibody(Fis1)and dynamin-related protein 1(Drpl)was detected;and with immunohistochemical method used,the protein expression of adenosine monophosphate-activated protein kinase(AMPK),nuclear factor E2-associated factor2(Nrf2)and Drpl in the ischemic area was detected.Results Compared with the sham-operation group,the content of ROS and MDA in the myocardial tissue of the ischemic area,and the positive expression of MFF,Fisl and Drpl increased in the model group(P<0.01);the content of SOD and the protein expression of AMRK and Nrf2 decreased(P<0.01),and the protein expression of Drpl elevated(P<0.01).Compared with the model group,the content of ROS and MDA in the myocardial tissue of the ischemic area,and the positive expression of MFF,Fisl and Drpl were dropped in the EA pretreatment group(P<0.01);the content of SOD and the protein expression of AMRK and Nrf2 rose(P<0.01),and the protein expression of Drpl declined(P<0.01);and in the EA pretreatment+Compound C group and the EA pretreatment+ML385 group,the positive expression of MFF,Fisl and Drpl,and the protein expression of Drpl were all reduced(P<0.01).When compared with the EA pretreatment+Compound C group and the EA pretreatment+ML385 group,the content of ROS and MDA in the myocardial tissue of the ischemic area,and the positive expression of MFF,Fisl and Drpl were dropped in the EA pretreatment group(P<0.01);the content of SOD and the protein expression of AMRK and Nrf2 rose(P<0.01,P<0.05),and the protein expression of Drpl decreased(P<0.05).In comparison with the model group,the EA pretreatment+Compound C group and the EA pretreatment+ML385 group,the cardiac muscle fiber rupture,cell swelling and mitochondrial disorders were obviously alleviated in the EA pretreatment group.The morphological changes were similar among the model group,the EA pretreatment+Compound C group and the EA pretreatment+ML385 group.Conclusion Electroacupuncture pretreatment of"biaoben acupoint combination"attenuates myocardial injury in MIRI rats,probably through promoting the phosphorylation of AMPK and Nrf2,inhibiting the excessive mitochondrial fission induced by Drpl,and reducing mitochondrial dysfunction caused by mitochondrial fragmentation and vacuolation.
基金supported by National Natural Science Foundation of China Youth Science Fund Project(No.82002039)National Natural Science Foundation of China(81530064)+1 种基金National Natural Science Foundation of China(81772071)National Natural Science Foundation of China(No.82172210).
文摘Chronic diabetic wounds remain a globally recognized clinical challenge.They occur due to high concentrations of reactive oxygen species and vascular function disorders.A promising strategy for diabetic wound healing is the delivery of exosomes,comprising bioactive dressings.Metformin activates the vascular endothelial growth factor pathway,thereby improving angiogenesis in hyperglycemic states.However,multifunctional hydrogels loaded with drugs and bioactive substances synergistically promote wound repair has been rarely reported,and the mechanism of their combinatorial effect of exosome and metformin in wound healing remains unclear.Here,we engineered dual-loaded hydrogels possessing tissue adhesive,antioxidant,self-healing and electrical conductivity properties,wherein 4-armed SH-PEG cross-links with Ag^(+),which minimizes damage to the loaded goods and investigated their mechanism of promotion effect for wound repair.Multiwalled carbon nanotubes exhibiting good conductivity were also incorporated into the hydrogels to generate hydrogen bonds with the thiol group,creating a stable three-dimensional structure for exosome and metformin loading.The diabetic wound model of the present study suggests that the PEG/Ag/CNT-M+E hydrogel promotes wound healing by triggering cell proliferation and angiogenesis and relieving peritraumatic inflammation and vascular injury.The mechanism of the dual-loaded hydrogel involves reducing the level of reactive oxygen species by interfering with mitochondrial fission,thereby protecting F-actin homeostasis and alleviating microvascular dysfunction.Hence,we propose a drug-bioactive substance combination therapy and provide a potential mechanism for developing vascular function-associated strategies for treating chronic diabetic wounds.
基金Natural Science Foundation of Hebei Province(No.H2019105137)
文摘Background:Sirtuin-3(Sirt3)has been documented to protect against mitochondrial dysfunction and apoptosis.Honokiol(HKL)is a Sirt3 pharmacological activator with reported neuroprotective effects in multiple neurological disorders.The present study aimed to explore the neuroprotective effects of HKL and the role of Sirt3 following intracerebral hemorrhage(ICH).Methods:An in vivo ICH model in rats was established by injecting autologous blood into the right basal ganglia.PC12 cells were stimulated with hemin.For the in vivo investigation,the modified Neurological Severity Scores and the Morris water maze test were performed to assess neurological deficits.Hematoxylin-Eosin and Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining were employed to evaluate the histopathology and apoptosis.Immunohistochemical staining was used to investigate the expression of Sirt3.Adenosine triphosphate(ATP)levels were quantified to assess mitochondrial dysfunction.Cell counting kit-8,lactate dehydrogenase assay,and flow cytometry were used to analyze cell vitality and apoptosis in vitro.Immunofluorescence staining was performed to observe mitochondrial morphology and dynamin-related protein 1(Drp1)localization to mitochondria.Western blot was applied to quantify the expression of Sirt3,Bax,Bcl-2,cleaved-caspase-3,Drp1,phosphorylation of Drp1 at serine-616,and phosphorylation of Drp1 at serine-637 in vivo and in vitro.Results:HKL treatment alleviated neurological deficits,attenuated the histopathological damage and cell apoptosis,and restored the decreased ATP levels in ICH rats.HKL improved cell survival rate,reduced cell apoptosis,and inhibited mitochondrial fission in PC12 cells.Moreover,both in vivo and in vitro models showed increased phosphorylation of Drp1 at Ser616,and reduced phosphorylation of Drp1 at Ser637.Meanwhile,immunofluorescence co-localization analysis revealed that hemin increased the overlap of Drp1 and mitochondria in PC12 cells.The phosphorylation and mitochondrial translocation of Drp1 were effectively reversed by HKL treatment.Importantly,the selective Sirt3 inhibitor 3-(1H-1,2,3-triazol-4-yl)pyridine suppressed these effects.Conclusion:Our findings demonstrated that HKL ameliorated ICH-induced apoptosis and mitochondrial fission by Sirt3,suggesting that HKL has immense prospects for the treatment of ICH.
基金supported by the National Natural Science Foundation of China(Grant Nos.81373406 and 81421063)
文摘Mitochondria are morphologically dynamic organelles which undergo fission and fusion processes. Our previous study found that arterial constriction was always accompanied by increased mitochondrial fission in smooth muscle cells, whereas inhibition of mitochondrial fission in smooth muscle cells was associated with arterial relaxation. Here, we used the typical vasorelaxants, verapamil and phentolamine, to further confirm the coupling between arterial constriction and mitochondrial fission in rat aorta. Results showed that phentolamine but not verapamil induced vasorelaxation in phenylephrine(PE)-induced rat thoracic aorta constriction. Verapamil, but not phentolamine, induced vasorelaxation in high K^+(KPSS)-induced rat thoracic aorta constriction. Pre-treatment with phentolamine prevented PEbut not KPSS-induced aorta constriction and pre-treatment with verapamil prevented both PE-and KPSSinduced aorta constriction. Transmission electron microscopy(TEM) results showed that verapamil but not phentolamine inhibited KPSS-induced excessive mitochondrial fission in aortic smooth muscle cells,and verapamil prevented both PE-and KPSS-induced excessive mitochondrial fission in aortic smoothmuscle cells. Verapamil inhibited KPSS-induced excessive mitochondrial fission in cultured vascular smooth muscle cells(A10). These results further demonstrate that arterial relaxation is coupled to inhibition of mitochondrial fission in arterial smooth muscle cells.
基金supported by the National Key Technology R&D Program“New Drug Innovation”of China[Nos.2019YFC1711000 and 2019YFC1708902]the National Natural Science Foundation of China[Nos.81973505 and 81773932]
文摘Mitochondrial shape rapidly changes by dynamic balance of fusion and fission to adjust to constantly changing energy demands of cancer cells.Mitochondrial dynamics balance is exactly regulated by molecular motor consisted of myosin and actin cytoskeleton proteins.Thus,targeting myosin eactin molecular motor is considered as a promising strategy for anti-cancer.In this study,we performed a proof-of-concept study with a natural-derived small-molecule J13 to test the feasibility of anti-cancer therapeutics via pharmacologically targeting molecular motor.Here,we found J13 could directly target myosin-9(MYH9)eactin molecular motor to promote mitochondrial fission progression,and markedly inhibited cancer cells survival,proliferation and migration.Mechanism study revealed that J13 impaired MYH9 eactin interaction to inactivate molecular motor,and caused a cytoskeleton-dependent mitochondrial dynamics imbalance.Moreover,stable isotope labeling with amino acids in cell culture(SILAC)technology-coupled with pulldown analysis identified HSPA9 as a crucial adaptor protein connecting MYH9 eactin molecular motor to mitochondrial fission.Taken together,we reported the first natural small-molecule directly targeting MYH9 eactin molecular motor for anti-cancer translational research.Besides,our study also proved the conceptual practicability of pharmacologically disrupting mitochondrial fission/fusion dynamics in human cancer therapy.
基金This work is supported in part by SmartState Cancer Stem Cell Biology&Therapy Program and by R01 grants from the National Institutes of Health,including AI118305,HL140953 and CA258440(X.-Z.Y.).
文摘Graft-versus-host disease (GVHD) significantly contributes to patient morbidity and mortality after allogeneic hematopoietic cell transplantation (allo-HSCT). Sphingosine-1-phosphate (S1P) signaling is involved in the biogenetic processes of different immune cells. In the current study, we demonstrated that recipient sphingosine kinase 1 (Sphk1), but not Sphk2, was required for optimal S1PR1-dependent donor T-cell allogeneic responses by secreting S1P. Using genetic and pharmacologic approaches, we demonstrated that inhibition of Sphk1 or S1PR1 substantially attenuated acute GVHD (aGVHD) while retaining the graft-versus-leukemia (GVL) effect. At the cellular level, the Sphk1/S1P/S1PR1 pathway differentially modulated the alloreactivity of CD4+ and CD8+ T cells;it facilitated T-cell differentiation into Th1/Th17 cells but not Tregs and promoted CD4+ T-cell infiltration into GVHD target organs but was dispensable for the CTL activity of allogeneic CD8+ T cells. At the molecular level, the Sphk1/S1P/S1PR1 pathway augmented mitochondrial fission and increased mitochondrial mass in allogeneic CD4+ but not CD8+ T cells by activating the AMPK/AKT/mTOR/Drp1 pathway, providing a mechanistic basis for GVL maintenance when S1P signaling was inhibited. For translational purposes, we detected the regulatory efficacy of pharmacologic inhibitors of Sphk1 and S1PR1 in GVHD induced by human T cells in a xenograft model. Our study provides novel mechanistic insight into how the Sphk1/S1P/S1PR1 pathway modulates T-cell alloreactivity and validates Sphk1 or S1PR1 as a therapeutic target for the prevention of GVHD and leukemia relapse. This novel strategy may be readily translated into the clinic to benefit patients with hematologic malignancies and disorders.
基金supported by the Science and Technology Fund Project of the Guizhou Provincial Health Commission (China) (No.gzwkj2023-109,gzwkj2021.017,gzwjkj2020-1-010)the Science and Technology Plan Project of Zunyi City,Guizhou,China (No.ZSKHZC-HZ (2020)172)+1 种基金the Science and Technology Project in Guizhou Province,China (No.QKHJC-ZK[2021]NO.408)the National Natural Science Foundation of China (No.82101527).
文摘Abnormal mitochondrial dynamics can lead to seizures,and improved mitochon-drial dynamics can alleviate seizures.Vacuolar protein sorting 13D(VPS13D)is closely associ-ated with regulating mitochondrial homeostasis and autophagy.However,further investigation is required to determine whether VPS13D affects seizures by influencing mitochondrial dy-namics and autophagy.We aimed to investigate the influence of VPS13D on behavior in a rat model of acute epileptic seizures.Hence,we established an acute epileptic seizure rat model and employed the CRISPR/CAS9 technology to construct a lentivirus to silence the Vps13d gene.Furthermore,we used the HT22 mouse hippocampal neuron cell line to establish a stable strain with suppressed expression of Vps13d in vitro.Then,we performed quantitative prote-omic and bioinformatics analyses to confirm the mechanism by which VPS13D influences mito-chondrial dynamics and autophagy,both in vitro and in vivo using the experimental acute epileptic seizure model.We found that knockdown of Vps13d resulted in reduced seizure la-tency and increased seizure frequency in the experimental rats.Immunofluorescence staining and western blot analysis revealed a significant increase in mitochondrial dynamin-related pro-tein 1 expression following Vps13d knockdown.Moreover,we observed a significant reduction in LC3Il protein expression levels and the LC31/LC3l ratio(indicators for autophagy)accompa-nied by a significant increase in P62 expression(an autophagy adaptor protein).The proteomic analysis confirmed the up-regulation of P62 protein expression.Therefore,we propose that VPS13D plays a role in modulating seizures by influencing mitochondrial dynamics and autophagy.
基金This work was supported by grants from the National Natural Science Foundation of China(Nos.81625020,81402736,and 81902791)the Key Research and Development Program of Shaanxi Province(No.2019sf-079).
文摘Objective:Capsaicin(CPS)is a major component of the red pepper,and its anti-tumor property has been confirmed.However,the underlying mechanism of this anti-tumor effect has not been fully clarified,so we conducted this study to evaluate the role of mitochondrial fission and subsequent mitochondrial dysfunction in CPS-induced apoptosis of melanoma cells.Methods:Two melanoma cell lines and melanocytes were treated with CPS alone or in combination with ruthenium red(a transient receptor potential vanilloid 1[TRPV]antagonist),Z-VAD-FMK(a pan-caspase inhibitor),or N-acetyl-Lcysteine(an antioxidant).Cell vitality was tested using a cell counting kit-8 assay.The expression levels of related proteins were examined by Western blotting.Apoptosis,intracellular reactive oxygen species,mitochondrial membrane potential,adenosine triphosphate levels,and mitochondrial dynamics were analyzed by flow cytometry,luminometry,and confocal laser microscopy,respectively,and compared between groups.Results:CPS treatment significantly inhibited the vitality of melanoma cells(For A2058 cells:0 vs.120 mmol/L:[100.00%±0%]vs.[51.02%±6.40%],P<0.05;For WM35 cells:0 vs.120 mmol/L:[100.00%±0%]vs.[51.80%±3.45%],P<0.05)but exerted less impact on normal melanocytes.CPS promoted melanoma cell apoptosis through TRPV channels and the caspase cascade.CPS treatment then led to TRPV channel-dependent mitochondrial dysfunction with an increase in reactive oxygen species generation(For A2058 cells:CPS vs.CPS+RR:[2.34±0.30]vs.[1.34±0.12],P<0.05;For WM35 cells:CPS vs.CPS+RR:[2.25±0.25]vs.[1.65±0.13],P<0.05),dissipation of the mitochondrial membrane potential(Control vs.CPS:[1.00±0]vs.[0.61±0.08],P<0.05),and adenosine triphosphate reduction(P<0.05).In addition,reactive oxygen species generation contributed to CPS-induced melanoma cell apoptosis.Mitochondrial fission was subsequently proved to connect CPS treatment to mitochondrial dysfunction,which was also TRPV channel-dependent,thereby inducing melanoma cell apoptosis.Conclusion:Our study highlights the role of mitochondrial fission and its related mitochondrial dysfunction in mediating the pro-apoptotic effect of CPS in melanoma.These findings deepen our understanding of the mechanisms underlying the anti-tumor activity of CPS and indicate the clinical relevancy of extending the use of this agent for cancer therapy.
基金support from the Science and Technology Innovation Foundation of Dalian City(2019J11CY005)the Graduate Innovation Fund of Dalian Polytechnic University。
文摘This paper aimed to explore the mechanism of tetrapeptide Val-Thr-Pro-Tyr(VTPY)in improving alcoholic gastric injury.VTPY has the potential to enhance the growth and movement of normal human gastric epithelial cells(GES-1).Following ethanol-induced impairment,VTPY effectively improved migration of GES-1 and human umbilical vein endothelial cells(HUVEC)cells,enhanced angiogenesis,eliminated cellular and mitochondrial reactive oxygen species(ROS),inhibited excessive mitochondrial division,enhanced F-actin polymerization and mitochondrial respiratory capacity.To counteract excessive mitochondrial fission,VTPY primarily restores the mitochondria dynamics by reducing the expression of Drpl and Fis1,while increasing Mfn2.Further studies utilizing inhibitors clarifies that the inhibition of excessive mitochondrial fission can markedly reduce F-actin depolymerization,consequently enhancing cell migration.Additionally,VTPY can inhibit the apoptosis pathway by maintaining potential of mitochondrial membrane,preventing the release of mitochondrial cytochrome C,bolstering the levels of Bcl-XL,while reducing the levels of Bax and cleaved-Caspase-3.Further investigations using inhibitors demonstrates that excessive mitochondrial fission could activate apoptotic pathway.However,VTPY counteracts this effect and enhance cells viability.Further evidence suggests that VTPY effectively improves ulcer index and pathologic changes,relieves inflammation,enhances the balance of oxidation and anti-oxidation,promotes angiogenesis,improves the expression of mitochondrial dynamics factors,blocks apoptotic pathway,and subsequently ameliorates gastric damage in mice through Fis-1/Bcl-2 pathway.
基金supported by the National Natural Science Foundation of China,Nos.82130037(to CH),81971122(to CH),82171323(to WL)the Natural Science Foundation of Jiangsu Province of China,No.BK20201113(to WL)。
文摘The dramatic increase in intracranial pressure after subarachnoid hemorrhage leads to a decrease in cerebral perfusion pressure and a reduction in cerebral blood flow.Mitochondria are directly affected by direct factors such as ischemia,hypoxia,excitotoxicity,and toxicity of free hemoglobin and its degradation products,which trigger mitochondrial dysfunction.Dysfunctional mitochondria release large amounts of reactive oxygen species,inflammatory mediators,and apoptotic proteins that activate apoptotic pathways,further damaging cells.In response to this array of damage,cells have adopted multiple mitochondrial quality control mechanisms through evolution,including mitochondrial protein quality control,mitochondrial dynamics,mitophagy,mitochondrial biogenesis,and intercellular mitochondrial transfer,to maintain mitochondrial homeostasis under pathological conditions.Specific interventions targeting mitochondrial quality control mechanisms have emerged as promising therapeutic strategies for subarachnoid hemorrhage.This review provides an overview of recent research advances in mitochondrial pathophysiological processes after subarachnoid hemorrhage,particularly mitochondrial quality control mechanisms.It also presents potential therapeutic strategies to target mitochondrial quality control in subarachnoid hemorrhage.
基金supported by the National Key Research and Development Program of China(2018YFD0900601)National Natural Science Foundation of China(32130109)。
文摘Temperature tolerance restricts the distribution of a species. However, the molecular and cellular mechanisms that set the thermal tolerance limits of an organism are poorly understood. Here, we report on the function of dual-specificity phosphatase 1(DUSP1) in thermal tolerance regulation. Notably, we found that dusp1-/- zebrafish grew normally but survived within a narrowed temperature range. The higher susceptibility of these mutant fish to both cold and heat challenges was attributed to accelerated cell death caused by aggravated mitochondrial dysfunction and over-production of reactive oxygen species in the gills. The DUSP1-MAPK-DRP1 axis was identified as a key pathway regulating these processes in both fish and human cells. These observations suggest that DUSP1 may play a role in maintaining mitochondrial integrity and redox homeostasis. We therefore propose that maintenance of cellular redox homeostasis may be a key mechanism for coping with cellular thermal stress and that the interplay between signaling pathways regulating redox homeostasis in the most thermosensitive tissue(i.e., gills) may play an important role in setting the thermal tolerance limit of zebrafish.
文摘Huntington’s disease is a genetic disease caused by expanded CAG repeats on exon 1 of the huntingtin gene located on chromosome 4.Compelling evidence implicates impaired mitochondrial energetics,altered mitochondrial biogenesis and quality control,disturbed mitochondrial trafficking,oxidative stress and mitochondrial calcium dyshomeostasis in the pathogenesis of the disorder.Unfortunately,conventional mitochondrial-targeted molecules,such as cysteamine,creatine,coenzyme Q10,or triheptanoin,yielded negative or inconclusive results.However,future therapeutic strategies,aiming to restore mitochondrial biogenesis,improving the fission/fusion balance,and improving mitochondrial trafficking,could prove useful tools in improving the phenotype of Huntington’s disease and,used in combination with genome-editing methods,could lead to a cure for the disease.
基金supported by grants from the National Key R&D Program of China(No.2018YFC1005002)the National Natural Science Foundation of China(Nos.82070482,81772007,21734003 and 51927805)+1 种基金the Shanghai Municipal Science and Technology Major Project(No.2017SHZDZX01)the Shanghai Municipal Education Commission(Innovation Program No.2017-01-07-00-07E00027)。
文摘There is no clear consensus regarding how cells respond to hydrostatic pressure. This is largely attributable to the high heterogeneity among cell types and the diverse custom-made devices used in previous studies. The aim of this work was to develop a facile device that could mimic various pressure environments and then delineate the cellular response to pressure stimulus. The device described here achieved both stable and periodic pressurization without oxygen deprivation. The biological utility of the device was assessed using human umbilical vein endothelial cells. We found more stereoscopic nuclear morphology and re-distribution of lamin A/C under high hydrostatic pressure compared to control cells. Mass spectrometry-based proteomics analysis showed significant changes in mitochondria-related pathways. Western blot analysis confirmed that high hydrostatic pressure induced a tendency toward mitochondrial fusion. Increased mitochondrial activity was observed as well. In conclusion, this device can be readily applied in biological research and extend our understanding of cellular mechano-sensation and the associated changes in mitochondrial behaviors.
文摘At the present,association of mitochondrial dysfunction and progression of neurological disorders has gained significant attention.Defects in mitochondrial network dynamics,point mutations,deletions,and interaction of pathogenomic proteins with mitochondria are some of the possible underlying mechanisms involved in these neurological disorders.Mitochondrial genetics,defects in mitochondrial oxidative phosphorylation machinery,and reactive oxygen species production might share common crosstalk in the progression of these neurological disorders.It is of significant interests to explore and develop therapeutic strategies aimed at correcting mitochondrial abnormalities.This review provided insights on mitochondrial dysfunction/mutations involved in the progression of Alzheimer’s disease,Huntington’s disease,and epilepsy with a special focus on Parkinson’s disease pathology.Along with the deleterious effects of mitochondrial mutations in aforesaid neurological disorders,this paper unraveled the available therapeutic strategy,specifically aiming to improve mitochondrial dysfunction,drugs targeting mitochondrial proteins,gene therapies aimed at correcting mutant mtDNA,peptide-based approaches,and lipophilic cations.
基金supported by the National Natural Science Foundation of China(Grant Nos.:82103208,and 82002948)the Guangdong Basic and Applied Basic Research Foundation(Grant Nos.:2022A1515220212,and 2023A1515030115)+1 种基金National Key R&D Program of China(Grant No.:2020YFE0202200)Jinan University National College Students'Innovation and Entrepreneurship Training Program(Program No.:202110559085).
文摘Divisions at the periphery and midzone of mitochondria are two fission signatures that determine the fate of mitochondria and cells.Pharmacological induction of excessively asymmetric mitofissionassociated cell death(MFAD)by switching the scission position from the mitochondrial midzone to the periphery represents a promising strategy for anticancer therapy.By screening a series of paninhibitors,we identified pracinostat,a pan-histone deacetylase(HDAC)inhibitor,as a novel MFAD inducer,that exhibited a significant anticancer effect on colorectal cancer(CRC)in vivo and in vitro.Pracinostat increased the expression of cyclin-dependent kinase 5(CDK5)and induced its acetylation at residue lysine 33,accelerating the formation of complex CDK5/CDK5 regulatory subunit 1 and dynaminrelated protein 1(Drp1)-mediated mitochondrial peripheral fission.CRC cells with high level of CDK5(CDK5-high)displayed midzone mitochondrial division that was associated with oncogenic phenotype,but treatment with pracinostat led to a lethal increase in the already-elevated level of CDK5 in the CRC cells.Mechanistically,pracinostat switched the scission position from the mitochondrial midzone to the periphery by improving the binding of Drp1 from mitochondrial fission factor(MFF)to mitochondrial fission 1 protein(FIS1).Thus,our results revealed the anticancer mechanism of HDACi pracinostat in CRC via activating CDK5-Drp1 signaling to cause selective MFAD of those CDK5-high tumor cells,which implicates a new paradigm to develop potential therapeutic strategies for CRC treatment.
