Summary:Ranolazine,a late sodium current inhibitor,has been demonstrated to be effective on heart failure.18B-glycyrrhetinic acid(18β-GA)has the similar inhibitory effect on late sodium currents.However,its effect on...Summary:Ranolazine,a late sodium current inhibitor,has been demonstrated to be effective on heart failure.18B-glycyrrhetinic acid(18β-GA)has the similar inhibitory effect on late sodium currents.However,its effect on diastolic function is still unknown.This study aimed to determine whether 18β-GA can improve the diastolic function and to explore the underlying mechanisms.Eighty male Sprague Dawley(SD)rats of Langendorff model were randomly divided into the following groups:group A,normal cardiac perfusion group;group B,ischemia-reperfusion group;group C,ischemia-reperfusion with anemoniasulcata toxinⅡ(ATX-Ⅱ);group D,ranolazine group;and group E,18β-GA group with four different concentrations.Furthermore,a pressure-overloaded rat model induced by trans-aortic constriction(TAC)was established.Echocardiography and hemodynamics were used to evaluate diastolic function at 14th day after TAC.Changes of free intracellular calcium(Ca27)concentration was indirectly detected by laser scanning confocal microscope to confirm the inhibition of late sodium currents.With the intervention of ATX-Ⅱon ischemia reperfusion injury group,5 umol/L ranolazine,and 5,10,20,40μmol/L 18β-GA could improve ATX-I-induced cardiac diastolic dysfunction.630 mg/kg glycyrrhizin tablets could improve cardiac diastolic function in the pressure-overloaded rats.18B-GA and ranolazine had similar effects on reducing the free calcium in cardiomyocytes.The study demonstrates that 18B-GA and glycyrrhizin could improve diastolic dysfunction induced by ischemia-reperfusion injury in Langendorff-perfused rat hearts and pressure-overloaded rats.The mechanism may be attributed to the inhibition of enhanced late sodium currents.展开更多
Cervical cancer stands is a formidablemalignancy that poses a significant threat towomen’s health.Calcium overload,a minimally invasive tumor treatment,aims to accumulate an excessive concentration of Ca^(2+)within m...Cervical cancer stands is a formidablemalignancy that poses a significant threat towomen’s health.Calcium overload,a minimally invasive tumor treatment,aims to accumulate an excessive concentration of Ca^(2+)within mitochondria,triggering apoptosis.Copper sulfide(CuS)represents a photothermal mediator for tumor hyperthermia.However,relying solely on thermotherapy often proves insufficient in controlling tumor growth.Curcumin(CUR),an herbal compound with anti-cancer properties,inhibits the efflux of exogenous Ca^(2+)while promoting its excretion from the endoplasmic reticulum into the cytoplasm.To harness these therapeutic modalities,we have developed a nanoplatform that incorporates hollow CuS nanoparticles(NPs)adorned with multiple CaCO_(3) particles and internally loaded with CUR.This nanocomposite exhibits high uptake and easy escape from lysosomes,along with the degradation of surrounding CaCO3,provoking the generation of abundant exogenous Ca^(2+)in situ,ultimately damaging the mitochondria of diseased cells.Impressively,under laser excitation,the CuS NPs demonstrate a photothermal effect that accelerates the degradation of CaCO_(3),synergistically enhancing the antitumor effect through photothermal therapy.Additionally,fluorescence imaging reveals the distribution of these nanovehicles in vivo,indicating their effective accumulation at the tumor site.This nanoplatform shows promising outcomes for tumor-targeting and the effective treatment in a murine model of cervical cancer,achieved through cascade enhancement of calcium overload-based dual therapy.展开更多
Objective: To investigate the mechanism of Cornus officinalis Total Glycosides (COTG) on myocardial protection, by studying effects of COTG on cardiomyocyte apoptosis induced by hypoxia/reoxygenation and calcium conce...Objective: To investigate the mechanism of Cornus officinalis Total Glycosides (COTG) on myocardial protection, by studying effects of COTG on cardiomyocyte apoptosis induced by hypoxia/reoxygenation and calcium concentration in rats. Methods: The myocardial cells of born 1-3d SD rats were isolated by enzyme digestion, cultured for 3 days. Cells were divided into five groups: Control group, H/R group, Cornus officinalis Total Glycosides low-dose group (LDG), Cornus officinalis Total Glycosides middle-dose group (MDG) and Cornus officinalis Total Glycosides high-dose group (HDG). Three drug groups were pretreated with different doses of Cornus officinalis Total Glycosides before hypoxia/reoxygenation treatment. The apoptotic rate was determined by flow cytometry assay, the intracellular free calcium concentration was examined by flow cytometry, and the ultrastructure of myocardial cells was observed under transmission electron microscope. Results: The results revealed that Cornus officinalis Total Glycosides pretreatment decreased apoptosis rate, but the effect of lower dosage is not significant. Furthermore, Cornus officinalis Total Glycosides can attenuate mitochondrial calcium overload, improve mitochondrial morphology and inhibit cardiomyocyte apoptosis caused by H/R. Conclusion: Cornus officinalis Total Glycosides pretreatment can inhibit cardiomyocyte apoptosis and calcium overload during H/R injury. However, the underlying mechanisms require us to further study.展开更多
Diabetic cardiomyopathy(DCM)is a medical condition characterized by cardiac remodeling and dysfunction in individuals with diabetes mellitus.Sarcoplasmic reticulum(SR)and mitochondrial Ca^(2+)overload in cardiomyocyte...Diabetic cardiomyopathy(DCM)is a medical condition characterized by cardiac remodeling and dysfunction in individuals with diabetes mellitus.Sarcoplasmic reticulum(SR)and mitochondrial Ca^(2+)overload in cardiomyocytes have been recognized as biological hallmarks in DCM;however,the specific factors underlying these abnormalities remain largely unknown.In this study,we aimed to investigate the role of a cardiac-specific long noncoding RNA,D830005E20Rik(Trdn-as),in DCM.Our results revealed the remarkably upregulation of Trdn-as in the hearts of the DCM mice and cardiomyocytes treated with high glucose(HG).Knocking down Trdn-as in cardiac tissues significantly improved cardiac dysfunction and remodeling in the DCM mice.Conversely,Trdn-as overexpression resulted in cardiac damage resembling that observed in the DCM mice.At the cellular level,Trdn-as induced Ca^(2+)overload in the SR and mitochondria,leading to mitochondrial dysfunction.RNA-seq and bioinformatics analyses identified calsequestrin 2(Casq2),a primary calcium-binding protein in the junctional SR,as a potential target of Trdn-as.Further investigations revealed that Trdn-as facilitated the recruitment of METTL14 to the Casq2 mRNA,thereby enhancing the m6A modification of Casq2.This modification increased the stability of Casq2 mRNA and subsequently led to increased protein expression.When Casq2 was knocked down,the promoting effects of Trdn-as on Ca^(2+)overload and mitochondrial damage were mitigated.These findings provide valuable insights into the pathogenesis of DCM and suggest Trdn-as as a potential therapeutic target for this condition.展开更多
Hydrogen sulfide(H_(2)S)-based mitochondrial energy metabolism blockade is an attractive tumor therapeutic modality.However,it is limited owing to metabolic plasticity,which allows tumors to shift their metabolic phen...Hydrogen sulfide(H_(2)S)-based mitochondrial energy metabolism blockade is an attractive tumor therapeutic modality.However,it is limited owing to metabolic plasticity,which allows tumors to shift their metabolic phenotype between oxidative phosphorylation and glycolysis for energy compensation.Herein,a hollow-hierarchical H_(2)S-multistage blasting nanomedicine was designed for a dual-pathway strategy targeting the blockade of energy metabolism and the imbalance of redox homeostasis.The tetrasulfide bond-modified hollow-hierarchical structure presents in-situ H_(2)S long-term bursting under the intracellular overexpressed glutathione(GSH),which inhibits the expression of the electron transport chain complex cytochrome C(COX IV)for restraining mitochondrial bioenergy supply and causes the energy metabolism blockade.Meanwhile,the Prussian blue in the home position,with thermal-enhanced peroxidase enzymatic activity,could simultaneously generate highly toxic hydroxyl radicals and exacerbate the GSH depletion process,thus further disrupting intracellular redox homeostasis.Mainly,externally encapsulated calcium can induce intracellular acidification and calcium overload,which aggravates mitochondrial dysfunction.The loaded glucose oxidase competes for intracellular glycolytic substrates,generating endogenous H_(2)O_(2) while inhibiting COX IV activity and rapidly depleting intracellular adenosine in triphosphate,thus completely blocking the energy supply of tumor cells.This dual-pathway strategy utilizes H_(2)S gas-bloomed calcium overload to block energy metabolism and induce redox imbalance,providing new insights into exploring energy metabolism blockade as a therapeutic tool for tumor treatment.展开更多
Background:Sarcoplasmic reticulum calcium ATPase 2a(SERCA2a)is a key protein that maintains myocardial Ca2+homeostasis.The present study aimed to investigate the mechanism underlying the SERCA2a-SUMOylation(small ubiq...Background:Sarcoplasmic reticulum calcium ATPase 2a(SERCA2a)is a key protein that maintains myocardial Ca2+homeostasis.The present study aimed to investigate the mechanism underlying the SERCA2a-SUMOylation(small ubiquitinlike modifier)process after ischemia/reperfusion injury(I/RI)in vitro and in vivo.Methods:Calcium transient and systolic/diastolic function of cardiomyocytes isolated from Serca2a knockout(KO)and wildtype mice with I/RI were compared.SUMO-relevant protein expression and localization were detected by quantitative real-time PCR(RT-qPCR),Western blotting,and immunofluorescence in vitro and in vivo.Serca2a-SUMOylation,infarct size,and cardiac function of Senp1 or Senp2 overexpressed/suppressed adenovirus infected cardiomyocytes,were detected by immunoprecipitation,triphenyltetrazolium chloride(TTC)-Evans blue staining,and echocardiography respectively.Results:The results showed that the changes of Fura-2 fluorescence intensity and contraction amplitude of cardiomyocytes decreased in the I/RI groups and were further reduced in the Serca2a KO+I/RI groups.Senp1 and Senp2 messenger ribose nucleic acid(mRNA)and protein expression levels in vivo and in cardiomyocytes were highest at 6 h and declined at 12 h after I/RI.However,the highest levels in HL-1 cells were recorded at 12 h.Senp2 expression increased in the cytoplasm,unlike that of Senp1.Inhibition of Senp2 protein reversed the I/RI-induced Serca2a-SUMOylation decline,reduced the infarction area,and improved cardiac function,while inhibition of Senp1 protein could not restore the above indicators.Conclusion:I/RI activated Senp1 and Senp2 protein expression,which promoted Serca2a-deSUMOylation,while inhibition of Senp2 expression reversed Serca2a-SUMOylation and improved cardiac function.展开更多
Background： Acute lung injury （ALI） is a common complication of sepsis that is associated with high mortality, lntracellular Ca^2＋ overload plays an important role in the pathophysiology of sepsis-induced ALl, and...Background： Acute lung injury （ALI） is a common complication of sepsis that is associated with high mortality, lntracellular Ca^2＋ overload plays an important role in the pathophysiology of sepsis-induced ALl, and cyclic adenosine diphosphate ribose （cADPR） is an important regulator of intracellular Ca^2＋ mobilization. The cluster of differentiation 38 （CD38）/cADPR pathway has been found to play roles in multiple inflammatory processes but its role in sepsis-induced ALl is still unknown. This study aimed to investigate whether the CD38/cADPR signaling pathway is activated in sepsis-induced ALl and whether blocking cADPR-mediated calcium overload attenuates ALl. Methods： Septic rat models were established by cecal ligation and puncture （CLP）. Rats were divided into the sham group, the CLP group, and the CLP＋ 8-bromo-cyclic adenosine diphosphate ribose （8-Br-cADPR） group. Nicotinamide adenine dinucleotide （NAD＋）, cADPR, CD38, and intracellular Ca^2＋ levels in the lung tissues were measured at 6, 12, 24, and 48 h after CLP surgery. Lung histologic injury, tumor necrosis factor （TNF）-a, malondialdehyde （MDA） levels, and superoxide dismutase （SOD） activities were measured. Results： NAD＋, cADPR, CD38, and intracellular Ca-＋ levels in the lungs of septic rats increased significantly at 24 h after CLP surgery. Treatment with 8-Br-cADPR, a specific inhibitor of cADPR, significantly reduced intracellular Ca^2＋ levels （P = 0.007）, attenuated lung histological injury （P = 0.023）, reduced TNF-a and MDA levels （P 〈 0.001 and P = 0.002, respectively） and recovered SOD activity （P = 0.031） in the lungs of septic rats. Conclusions： The CD38/cADPR pathway is activated in the lungs of septic rats, and blocking cADPR-mediated calcium overload with 8-Br-cADPR protects against sepsis-induced ALl.展开更多
Objective：To assess any direct effect of extract of Paris polyphylla Simth（EPPS）,a Chinese plant,on a cardiomyocyte subject to ischemia-reperfusion injury and to further elucidate its protective effect against myoc...Objective：To assess any direct effect of extract of Paris polyphylla Simth（EPPS）,a Chinese plant,on a cardiomyocyte subject to ischemia-reperfusion injury and to further elucidate its protective effect against myocardium ischemia on the cellular level.Methods：Neonatal rat cardiomyocytes were isolated and subjected to an anoxia-reoxia injury simulating the ischemia-reperfusion injury in vivo in the presence or absence of EPPS or diltizem,a positive control.The lactate dehydrogenase（LDH） activities in culture supematants and cell viabilities were analyzed using the enzymatic reaction kinetics monitoring-method and MTT method, respectively.Free intracellular calcium concentrations and activities of Na~＋-K~＋ ATPase and Ca^（2＋） ATPase in cells were also measured with laser confocal microscopy and the inorganic phosphorus-transformation method,respectively.Results：In cardiomyocytes subject to anoxia-reoxia injury,EPPS at 50-400 mg/L showed a concentration-dependent inhibition on LDH leakage and maintenance of cell viability,and the effect was significant at 275 and 400 mg/L（both P0.01）.In addition,EPPS at 275 and 400 mg/L significantly inhibited the increase in intracellular free calcium（both P0.01） as well as decreased the activities of Na~＋-K~＋ ATPase and Ca^（2＋） ATPase（P0.01,P0.05）.Conclusions：EPPS prevents anoxia-reoxia injury in neonatal rat cardiomyocytes in vitro by preservation of Na~＋-K~＋ ATPase and Ca^（2＋） ATPase activities and inhibition of calcium overload.The direct protective effect on cardiomyocytes may be one of the key mechanisms that underlie the potential therapeutic benefit of EPPS against myocardium ischemia.展开更多
Background Liraglutide is glucagon-like peptide-1 receptor agonist for treating patients with type 2 diabetes mellitus. Our previous studies have demonstrated that liraglutide protects cardiac function through improvi...Background Liraglutide is glucagon-like peptide-1 receptor agonist for treating patients with type 2 diabetes mellitus. Our previous studies have demonstrated that liraglutide protects cardiac function through improving endothelial function in patients with acute myocardial infarction undergoing percutaneous coronary intervention. The present study will investigate whether liraglntide can perform direct protective effects on cardiomyocytes against reperfusion injury. Methods In vitro experiments were performed using H9C2 cells and neonatal rat ventricular cadiomyocytes undergoing simulative hypoxia/reoxygenation （H/R） induction. Cardiomyocytes apoptosis was detected by fluorescence TUNEL. Mitochondrial membrane potential （AWm） and intracellular reactive oxygen species （ROS） was assessed by JC-1 and DHE, respectively. Fura-2/AM was used to measure intracellular Ca2＋ concentration and calcium transient. Immtmofluorescence staining was used to assess the expression level of sarcoplasmic reticulum Ca2＋-ATPase （SERCA2a）. In vivo experiments, myocardial apoptosis and expression of SERCA2a were detected by colorimetric TUNEL and by immunofluorescence staining, respectively. Results In vitro liraglutide inhibited cardiomyotes apoptosis against H/R. △mψ of cardiomyocytes was higher in liraglntide group than H/R group. H/R increased ROS production in H9C2 cells which was attenuated by liraglutide. Liraglutide significantly lowered Ca2＋ overload and improved calcium transient compared with H/R group, lmmunofluorescence staining results showed liraglutide promoted SERCA2a expression which was decreased in H/R group. In ischemia/reperfusion rat hearts, apoptosis was significantly attenuated and SERCA2a expression was increased by liraglutide compared with H/R group. Conclusions Liraglutide can directly protect cardiomyocytes against reperfusion injury which is possibly through modulation of intracellular calcium homeostasis.展开更多
Early pathogenesis of ischemia-reperfusion(I/R)-induced acute kidney injury(AKI)is dominated by intracellular calcium overload,which induces oxidative stress,intracellular energy metabolism disorder,inflammatory activ...Early pathogenesis of ischemia-reperfusion(I/R)-induced acute kidney injury(AKI)is dominated by intracellular calcium overload,which induces oxidative stress,intracellular energy metabolism disorder,inflammatory activation,and a series of pathologic cascaded reactions that are closely intertwined with self-amplifying and interactive feedback loops,ultimately resulting in cell damage and kidney failure.Currently,most nanomedicines originate from the perspective of antioxidant stress,which can only quench existing reactive oxide species(ROS)but cannot prevent the continuous production of ROS,resulting in insufficient efficacy.As a safe and promising drug,BAPTA-AM is hydrolyzed into BAPTA by intracellular esterase upon entering cells,which can rapidly chelate with overloaded Ca^(2+),restoring intracellular calcium homeostasis,thus inhibiting ROS regeneration at the source.Here,we designed a KTP-targeting peptide-modified yolk-shell structure of liposome–poly(ethylene glycol)methyl ether-block-poly(L-lactide-co-glycolic)(mPLGA)hybrid nanoparticles(<100 nm),with the characteristics of high encapsulation rate,high colloid stability,facile modification,and prolonged blood circulation time.Once the BA/mPLGA@Lipo-KTP was targeted to the site of kidney injury,the cholesteryl hemisuccinate(CHEMS)in the phospholipid bilayer,as an acidic cholesterol ester,was protonated in the simulated inflammatory slightly acidic environment(pH 6.5),causing the liposomes to rupture and release the BA/mPLGA nanoparticles,which were then depolymerized by intracellular esterase.The BAPTA-AM was diffused and hydrolyzed to produce BAPTA,which can rapidly cut off the malignant loop of calcium overload/ROS generation at its source,blocking the endoplasmic reticulum(ER)apoptosis pathway(ATF4–CHOP–Bax/Bcl-2,Casp-12–Casp-3)and the inflammatory pathway(TNF-α–NF-κB–IL-6 axes),thus alleviating pathological changes in kidney tissue,thereby inhibiting the expression of renal tubular marker kidney injury molecule 1(Kim-1)(reduced by 82.9%)and also exhibiting prominent anti-apoptotic capability(TUNEL-positive ratio decreased from 40.2%to 8.3%),significantly restoring renal function.Overall,this research holds huge potential in the treatment of I/R injury-related diseases.展开更多
Iron overload can lead to iron deposits in many tissues,particularly in the heart.It has also been shown to be associated with elevated oxidative stress in tissues.Elevated cardiac iron deposits can lead to iron overl...Iron overload can lead to iron deposits in many tissues,particularly in the heart.It has also been shown to be associated with elevated oxidative stress in tissues.Elevated cardiac iron deposits can lead to iron overload cardiomyopathy,a condition which provokes mortality due to heart failure in iron-overloaded patients.Currently,the mechanism of iron uptake into cardiomyocytes is still not clearly understood.Growing evidence suggests L-type Ca2+channels(LTCCs)as a possible pathway for ferrous iron(Fe2+)uptake into cardiomyocytes under iron overload conditions.Nevertheless,controversy still exists since some findings on pharmacological interventions and those using different cell types do not support LTCC’s role as a portal for iron uptake in cardiac cells.Recently,T-type Ca2+channels (TTCC)have been shown to play an important role in the diseased heart.Although TTCC and iron uptake in cardiomyocytes has not been investigated greatly,a recent finding indicated that TTCC could be an important portal in thalassemic hearts.In this review,comprehensive findings collected from previous studies as well as a discussion of the controversy regarding iron uptake mechanisms into cardiomyocytes via calcium channels are presented with the hope that understanding the cellular iron uptake mechanism in cardiomyocytes will lead to improved treatment and prevention strategies,particularly in iron-overloaded patients.展开更多
The plasma membrane Ca2+-ATPase(PMCA)is an ATPdriven pump that is critical for the maintenance of low resting[Ca2+]i in all eukaryotic cells.Metabolic stress, either due to inhibition of mitochondrial or glycolytic me...The plasma membrane Ca2+-ATPase(PMCA)is an ATPdriven pump that is critical for the maintenance of low resting[Ca2+]i in all eukaryotic cells.Metabolic stress, either due to inhibition of mitochondrial or glycolytic metabolism,has the capacity to cause ATP depletion and thus inhibit PMCA activity.This has potentially fatal consequences,particularly for non-excitable cells in which the PMCA is the major Ca2+efflux pathway.This is because inhibition of the PMCA inevitably leads to cytosolic Ca2+ overload and the consequent cell death.However,the relationship between metabolic stress,ATP depletion and inhibition of the PMCA is not as simple as one would have originally predicted.There is increasing evidence that metabolic stress can lead to the inhibition of PMCA activity independent of ATP or prior to substantial ATP depletion.In particular,there is evidence that the PMCA has its own glycolytic ATP supply that can fuel the PMCA in the face of impaired mitochondrial function.Moreover, membrane phospholipids,mitochondrial membrane potential,caspase/calpain cleavage and oxidative stress have all been implicated in metabolic stress-induced inhibition of the PMCA.The major focus of this review is to challenge the conventional view of ATP-dependent regulation of the PMCA and bring together some of the alternative or additional mechanisms by which metabolic stress impairs PMCA activity resulting in cytosolic Ca2+ overload and cytotoxicity.展开更多
基金This project was supported by the National Natural Science Foundation of China(No.81600317 and No.81700345)the Open Foundation of Hubei Key Laboratory of Biological Targeted Therapy(No.02.03.2014-10).
文摘Summary:Ranolazine,a late sodium current inhibitor,has been demonstrated to be effective on heart failure.18B-glycyrrhetinic acid(18β-GA)has the similar inhibitory effect on late sodium currents.However,its effect on diastolic function is still unknown.This study aimed to determine whether 18β-GA can improve the diastolic function and to explore the underlying mechanisms.Eighty male Sprague Dawley(SD)rats of Langendorff model were randomly divided into the following groups:group A,normal cardiac perfusion group;group B,ischemia-reperfusion group;group C,ischemia-reperfusion with anemoniasulcata toxinⅡ(ATX-Ⅱ);group D,ranolazine group;and group E,18β-GA group with four different concentrations.Furthermore,a pressure-overloaded rat model induced by trans-aortic constriction(TAC)was established.Echocardiography and hemodynamics were used to evaluate diastolic function at 14th day after TAC.Changes of free intracellular calcium(Ca27)concentration was indirectly detected by laser scanning confocal microscope to confirm the inhibition of late sodium currents.With the intervention of ATX-Ⅱon ischemia reperfusion injury group,5 umol/L ranolazine,and 5,10,20,40μmol/L 18β-GA could improve ATX-I-induced cardiac diastolic dysfunction.630 mg/kg glycyrrhizin tablets could improve cardiac diastolic function in the pressure-overloaded rats.18B-GA and ranolazine had similar effects on reducing the free calcium in cardiomyocytes.The study demonstrates that 18B-GA and glycyrrhizin could improve diastolic dysfunction induced by ischemia-reperfusion injury in Langendorff-perfused rat hearts and pressure-overloaded rats.The mechanism may be attributed to the inhibition of enhanced late sodium currents.
基金This research was sponsored by the key research program of Ningbo(No.2023Z210)funded by Ningbo Natural Science Foundation(No.202003N4006)the Joint Research Funds of Department of Science&Technology of Shaanxi Province,Northwestern Polytechnical University(No.2020GXLH-Z-017).
文摘Cervical cancer stands is a formidablemalignancy that poses a significant threat towomen’s health.Calcium overload,a minimally invasive tumor treatment,aims to accumulate an excessive concentration of Ca^(2+)within mitochondria,triggering apoptosis.Copper sulfide(CuS)represents a photothermal mediator for tumor hyperthermia.However,relying solely on thermotherapy often proves insufficient in controlling tumor growth.Curcumin(CUR),an herbal compound with anti-cancer properties,inhibits the efflux of exogenous Ca^(2+)while promoting its excretion from the endoplasmic reticulum into the cytoplasm.To harness these therapeutic modalities,we have developed a nanoplatform that incorporates hollow CuS nanoparticles(NPs)adorned with multiple CaCO_(3) particles and internally loaded with CUR.This nanocomposite exhibits high uptake and easy escape from lysosomes,along with the degradation of surrounding CaCO3,provoking the generation of abundant exogenous Ca^(2+)in situ,ultimately damaging the mitochondria of diseased cells.Impressively,under laser excitation,the CuS NPs demonstrate a photothermal effect that accelerates the degradation of CaCO_(3),synergistically enhancing the antitumor effect through photothermal therapy.Additionally,fluorescence imaging reveals the distribution of these nanovehicles in vivo,indicating their effective accumulation at the tumor site.This nanoplatform shows promising outcomes for tumor-targeting and the effective treatment in a murine model of cervical cancer,achieved through cascade enhancement of calcium overload-based dual therapy.
文摘Objective: To investigate the mechanism of Cornus officinalis Total Glycosides (COTG) on myocardial protection, by studying effects of COTG on cardiomyocyte apoptosis induced by hypoxia/reoxygenation and calcium concentration in rats. Methods: The myocardial cells of born 1-3d SD rats were isolated by enzyme digestion, cultured for 3 days. Cells were divided into five groups: Control group, H/R group, Cornus officinalis Total Glycosides low-dose group (LDG), Cornus officinalis Total Glycosides middle-dose group (MDG) and Cornus officinalis Total Glycosides high-dose group (HDG). Three drug groups were pretreated with different doses of Cornus officinalis Total Glycosides before hypoxia/reoxygenation treatment. The apoptotic rate was determined by flow cytometry assay, the intracellular free calcium concentration was examined by flow cytometry, and the ultrastructure of myocardial cells was observed under transmission electron microscope. Results: The results revealed that Cornus officinalis Total Glycosides pretreatment decreased apoptosis rate, but the effect of lower dosage is not significant. Furthermore, Cornus officinalis Total Glycosides can attenuate mitochondrial calcium overload, improve mitochondrial morphology and inhibit cardiomyocyte apoptosis caused by H/R. Conclusion: Cornus officinalis Total Glycosides pretreatment can inhibit cardiomyocyte apoptosis and calcium overload during H/R injury. However, the underlying mechanisms require us to further study.
基金supported by the National Natural Science Foundation of China(Nos.82273919,82270396,and U21A20339)the HMU Marshal Initiative Funding(No.HMUMIF-21022)the Science Foundation for the Excellent Youth Scholars of Heilongjiang Province(No.JJ2023YX0509).
文摘Diabetic cardiomyopathy(DCM)is a medical condition characterized by cardiac remodeling and dysfunction in individuals with diabetes mellitus.Sarcoplasmic reticulum(SR)and mitochondrial Ca^(2+)overload in cardiomyocytes have been recognized as biological hallmarks in DCM;however,the specific factors underlying these abnormalities remain largely unknown.In this study,we aimed to investigate the role of a cardiac-specific long noncoding RNA,D830005E20Rik(Trdn-as),in DCM.Our results revealed the remarkably upregulation of Trdn-as in the hearts of the DCM mice and cardiomyocytes treated with high glucose(HG).Knocking down Trdn-as in cardiac tissues significantly improved cardiac dysfunction and remodeling in the DCM mice.Conversely,Trdn-as overexpression resulted in cardiac damage resembling that observed in the DCM mice.At the cellular level,Trdn-as induced Ca^(2+)overload in the SR and mitochondria,leading to mitochondrial dysfunction.RNA-seq and bioinformatics analyses identified calsequestrin 2(Casq2),a primary calcium-binding protein in the junctional SR,as a potential target of Trdn-as.Further investigations revealed that Trdn-as facilitated the recruitment of METTL14 to the Casq2 mRNA,thereby enhancing the m6A modification of Casq2.This modification increased the stability of Casq2 mRNA and subsequently led to increased protein expression.When Casq2 was knocked down,the promoting effects of Trdn-as on Ca^(2+)overload and mitochondrial damage were mitigated.These findings provide valuable insights into the pathogenesis of DCM and suggest Trdn-as as a potential therapeutic target for this condition.
基金supported by the National Natural Science Foundation of China(Nos.22205048 and U22A20347)the China Postdoctoral Science Foundation(No.2023T160154)+2 种基金the Heilongjiang Postdoctoral Science Foundation(No.LBH-TZ2406)the Young Elite Scientists Sponsorship Program of Heilongjiang(No.2024QNTJ001)the Fundamental Research Funds for the Central Universities.
文摘Hydrogen sulfide(H_(2)S)-based mitochondrial energy metabolism blockade is an attractive tumor therapeutic modality.However,it is limited owing to metabolic plasticity,which allows tumors to shift their metabolic phenotype between oxidative phosphorylation and glycolysis for energy compensation.Herein,a hollow-hierarchical H_(2)S-multistage blasting nanomedicine was designed for a dual-pathway strategy targeting the blockade of energy metabolism and the imbalance of redox homeostasis.The tetrasulfide bond-modified hollow-hierarchical structure presents in-situ H_(2)S long-term bursting under the intracellular overexpressed glutathione(GSH),which inhibits the expression of the electron transport chain complex cytochrome C(COX IV)for restraining mitochondrial bioenergy supply and causes the energy metabolism blockade.Meanwhile,the Prussian blue in the home position,with thermal-enhanced peroxidase enzymatic activity,could simultaneously generate highly toxic hydroxyl radicals and exacerbate the GSH depletion process,thus further disrupting intracellular redox homeostasis.Mainly,externally encapsulated calcium can induce intracellular acidification and calcium overload,which aggravates mitochondrial dysfunction.The loaded glucose oxidase competes for intracellular glycolytic substrates,generating endogenous H_(2)O_(2) while inhibiting COX IV activity and rapidly depleting intracellular adenosine in triphosphate,thus completely blocking the energy supply of tumor cells.This dual-pathway strategy utilizes H_(2)S gas-bloomed calcium overload to block energy metabolism and induce redox imbalance,providing new insights into exploring energy metabolism blockade as a therapeutic tool for tumor treatment.
基金supported by grants from the Natural Science Foundation of Jiangsu Province(No.BK20190988)the Scientific Research Project of Jiangsu Health Committee(No.H2018005)+1 种基金the Key Research and Development Program of Xuzhou(No.KC20097)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX21_2671).
文摘Background:Sarcoplasmic reticulum calcium ATPase 2a(SERCA2a)is a key protein that maintains myocardial Ca2+homeostasis.The present study aimed to investigate the mechanism underlying the SERCA2a-SUMOylation(small ubiquitinlike modifier)process after ischemia/reperfusion injury(I/RI)in vitro and in vivo.Methods:Calcium transient and systolic/diastolic function of cardiomyocytes isolated from Serca2a knockout(KO)and wildtype mice with I/RI were compared.SUMO-relevant protein expression and localization were detected by quantitative real-time PCR(RT-qPCR),Western blotting,and immunofluorescence in vitro and in vivo.Serca2a-SUMOylation,infarct size,and cardiac function of Senp1 or Senp2 overexpressed/suppressed adenovirus infected cardiomyocytes,were detected by immunoprecipitation,triphenyltetrazolium chloride(TTC)-Evans blue staining,and echocardiography respectively.Results:The results showed that the changes of Fura-2 fluorescence intensity and contraction amplitude of cardiomyocytes decreased in the I/RI groups and were further reduced in the Serca2a KO+I/RI groups.Senp1 and Senp2 messenger ribose nucleic acid(mRNA)and protein expression levels in vivo and in cardiomyocytes were highest at 6 h and declined at 12 h after I/RI.However,the highest levels in HL-1 cells were recorded at 12 h.Senp2 expression increased in the cytoplasm,unlike that of Senp1.Inhibition of Senp2 protein reversed the I/RI-induced Serca2a-SUMOylation decline,reduced the infarction area,and improved cardiac function,while inhibition of Senp1 protein could not restore the above indicators.Conclusion:I/RI activated Senp1 and Senp2 protein expression,which promoted Serca2a-deSUMOylation,while inhibition of Senp2 expression reversed Serca2a-SUMOylation and improved cardiac function.
文摘Background： Acute lung injury （ALI） is a common complication of sepsis that is associated with high mortality, lntracellular Ca^2＋ overload plays an important role in the pathophysiology of sepsis-induced ALl, and cyclic adenosine diphosphate ribose （cADPR） is an important regulator of intracellular Ca^2＋ mobilization. The cluster of differentiation 38 （CD38）/cADPR pathway has been found to play roles in multiple inflammatory processes but its role in sepsis-induced ALl is still unknown. This study aimed to investigate whether the CD38/cADPR signaling pathway is activated in sepsis-induced ALl and whether blocking cADPR-mediated calcium overload attenuates ALl. Methods： Septic rat models were established by cecal ligation and puncture （CLP）. Rats were divided into the sham group, the CLP group, and the CLP＋ 8-bromo-cyclic adenosine diphosphate ribose （8-Br-cADPR） group. Nicotinamide adenine dinucleotide （NAD＋）, cADPR, CD38, and intracellular Ca^2＋ levels in the lung tissues were measured at 6, 12, 24, and 48 h after CLP surgery. Lung histologic injury, tumor necrosis factor （TNF）-a, malondialdehyde （MDA） levels, and superoxide dismutase （SOD） activities were measured. Results： NAD＋, cADPR, CD38, and intracellular Ca-＋ levels in the lungs of septic rats increased significantly at 24 h after CLP surgery. Treatment with 8-Br-cADPR, a specific inhibitor of cADPR, significantly reduced intracellular Ca^2＋ levels （P = 0.007）, attenuated lung histological injury （P = 0.023）, reduced TNF-a and MDA levels （P 〈 0.001 and P = 0.002, respectively） and recovered SOD activity （P = 0.031） in the lungs of septic rats. Conclusions： The CD38/cADPR pathway is activated in the lungs of septic rats, and blocking cADPR-mediated calcium overload with 8-Br-cADPR protects against sepsis-induced ALl.
基金Supported by the Major Scientific and Technological Specialized Project for"Significant New Formulation of New Drugs(No. 2009ZX09301,2009ZX09303-003)"
文摘Objective：To assess any direct effect of extract of Paris polyphylla Simth（EPPS）,a Chinese plant,on a cardiomyocyte subject to ischemia-reperfusion injury and to further elucidate its protective effect against myocardium ischemia on the cellular level.Methods：Neonatal rat cardiomyocytes were isolated and subjected to an anoxia-reoxia injury simulating the ischemia-reperfusion injury in vivo in the presence or absence of EPPS or diltizem,a positive control.The lactate dehydrogenase（LDH） activities in culture supematants and cell viabilities were analyzed using the enzymatic reaction kinetics monitoring-method and MTT method, respectively.Free intracellular calcium concentrations and activities of Na~＋-K~＋ ATPase and Ca^（2＋） ATPase in cells were also measured with laser confocal microscopy and the inorganic phosphorus-transformation method,respectively.Results：In cardiomyocytes subject to anoxia-reoxia injury,EPPS at 50-400 mg/L showed a concentration-dependent inhibition on LDH leakage and maintenance of cell viability,and the effect was significant at 275 and 400 mg/L（both P0.01）.In addition,EPPS at 275 and 400 mg/L significantly inhibited the increase in intracellular free calcium（both P0.01） as well as decreased the activities of Na~＋-K~＋ ATPase and Ca^（2＋） ATPase（P0.01,P0.05）.Conclusions：EPPS prevents anoxia-reoxia injury in neonatal rat cardiomyocytes in vitro by preservation of Na~＋-K~＋ ATPase and Ca^（2＋） ATPase activities and inhibition of calcium overload.The direct protective effect on cardiomyocytes may be one of the key mechanisms that underlie the potential therapeutic benefit of EPPS against myocardium ischemia.
基金This work is supported by grants from National Natural Science Foundation of China （No. 81102079） and China Postdoctoral Science Foundation （No. 201003776）. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors report no conflict of interest. The authors are responsible for the content and writing of the paper.
文摘Background Liraglutide is glucagon-like peptide-1 receptor agonist for treating patients with type 2 diabetes mellitus. Our previous studies have demonstrated that liraglutide protects cardiac function through improving endothelial function in patients with acute myocardial infarction undergoing percutaneous coronary intervention. The present study will investigate whether liraglntide can perform direct protective effects on cardiomyocytes against reperfusion injury. Methods In vitro experiments were performed using H9C2 cells and neonatal rat ventricular cadiomyocytes undergoing simulative hypoxia/reoxygenation （H/R） induction. Cardiomyocytes apoptosis was detected by fluorescence TUNEL. Mitochondrial membrane potential （AWm） and intracellular reactive oxygen species （ROS） was assessed by JC-1 and DHE, respectively. Fura-2/AM was used to measure intracellular Ca2＋ concentration and calcium transient. Immtmofluorescence staining was used to assess the expression level of sarcoplasmic reticulum Ca2＋-ATPase （SERCA2a）. In vivo experiments, myocardial apoptosis and expression of SERCA2a were detected by colorimetric TUNEL and by immunofluorescence staining, respectively. Results In vitro liraglutide inhibited cardiomyotes apoptosis against H/R. △mψ of cardiomyocytes was higher in liraglntide group than H/R group. H/R increased ROS production in H9C2 cells which was attenuated by liraglutide. Liraglutide significantly lowered Ca2＋ overload and improved calcium transient compared with H/R group, lmmunofluorescence staining results showed liraglutide promoted SERCA2a expression which was decreased in H/R group. In ischemia/reperfusion rat hearts, apoptosis was significantly attenuated and SERCA2a expression was increased by liraglutide compared with H/R group. Conclusions Liraglutide can directly protect cardiomyocytes against reperfusion injury which is possibly through modulation of intracellular calcium homeostasis.
基金supported by the Taishan Scholar Foundation of Shandong Province(No.tsqn202211065)Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(No.2021JJLH0037)+1 种基金the Natural Science Foundation of China(No.82003673)the Fundamental Research Funds for the Central Universities(No.202113049)。
文摘Early pathogenesis of ischemia-reperfusion(I/R)-induced acute kidney injury(AKI)is dominated by intracellular calcium overload,which induces oxidative stress,intracellular energy metabolism disorder,inflammatory activation,and a series of pathologic cascaded reactions that are closely intertwined with self-amplifying and interactive feedback loops,ultimately resulting in cell damage and kidney failure.Currently,most nanomedicines originate from the perspective of antioxidant stress,which can only quench existing reactive oxide species(ROS)but cannot prevent the continuous production of ROS,resulting in insufficient efficacy.As a safe and promising drug,BAPTA-AM is hydrolyzed into BAPTA by intracellular esterase upon entering cells,which can rapidly chelate with overloaded Ca^(2+),restoring intracellular calcium homeostasis,thus inhibiting ROS regeneration at the source.Here,we designed a KTP-targeting peptide-modified yolk-shell structure of liposome–poly(ethylene glycol)methyl ether-block-poly(L-lactide-co-glycolic)(mPLGA)hybrid nanoparticles(<100 nm),with the characteristics of high encapsulation rate,high colloid stability,facile modification,and prolonged blood circulation time.Once the BA/mPLGA@Lipo-KTP was targeted to the site of kidney injury,the cholesteryl hemisuccinate(CHEMS)in the phospholipid bilayer,as an acidic cholesterol ester,was protonated in the simulated inflammatory slightly acidic environment(pH 6.5),causing the liposomes to rupture and release the BA/mPLGA nanoparticles,which were then depolymerized by intracellular esterase.The BAPTA-AM was diffused and hydrolyzed to produce BAPTA,which can rapidly cut off the malignant loop of calcium overload/ROS generation at its source,blocking the endoplasmic reticulum(ER)apoptosis pathway(ATF4–CHOP–Bax/Bcl-2,Casp-12–Casp-3)and the inflammatory pathway(TNF-α–NF-κB–IL-6 axes),thus alleviating pathological changes in kidney tissue,thereby inhibiting the expression of renal tubular marker kidney injury molecule 1(Kim-1)(reduced by 82.9%)and also exhibiting prominent anti-apoptotic capability(TUNEL-positive ratio decreased from 40.2%to 8.3%),significantly restoring renal function.Overall,this research holds huge potential in the treatment of I/R injury-related diseases.
基金Supported by Thailand Research Fund grants RTA5280006 (Chattipakorn N)BRG5480003(Chattipakorn S)+1 种基金the National Research Council of Thailand(Chattipakorn N)the Thai-land Research Fund Royal Golden Jubilee project(Kumfu S and Chattipakorn N)
文摘Iron overload can lead to iron deposits in many tissues,particularly in the heart.It has also been shown to be associated with elevated oxidative stress in tissues.Elevated cardiac iron deposits can lead to iron overload cardiomyopathy,a condition which provokes mortality due to heart failure in iron-overloaded patients.Currently,the mechanism of iron uptake into cardiomyocytes is still not clearly understood.Growing evidence suggests L-type Ca2+channels(LTCCs)as a possible pathway for ferrous iron(Fe2+)uptake into cardiomyocytes under iron overload conditions.Nevertheless,controversy still exists since some findings on pharmacological interventions and those using different cell types do not support LTCC’s role as a portal for iron uptake in cardiac cells.Recently,T-type Ca2+channels (TTCC)have been shown to play an important role in the diseased heart.Although TTCC and iron uptake in cardiomyocytes has not been investigated greatly,a recent finding indicated that TTCC could be an important portal in thalassemic hearts.In this review,comprehensive findings collected from previous studies as well as a discussion of the controversy regarding iron uptake mechanisms into cardiomyocytes via calcium channels are presented with the hope that understanding the cellular iron uptake mechanism in cardiomyocytes will lead to improved treatment and prevention strategies,particularly in iron-overloaded patients.
基金Supported by A New Investigator Award from the BBSRC
文摘The plasma membrane Ca2+-ATPase(PMCA)is an ATPdriven pump that is critical for the maintenance of low resting[Ca2+]i in all eukaryotic cells.Metabolic stress, either due to inhibition of mitochondrial or glycolytic metabolism,has the capacity to cause ATP depletion and thus inhibit PMCA activity.This has potentially fatal consequences,particularly for non-excitable cells in which the PMCA is the major Ca2+efflux pathway.This is because inhibition of the PMCA inevitably leads to cytosolic Ca2+ overload and the consequent cell death.However,the relationship between metabolic stress,ATP depletion and inhibition of the PMCA is not as simple as one would have originally predicted.There is increasing evidence that metabolic stress can lead to the inhibition of PMCA activity independent of ATP or prior to substantial ATP depletion.In particular,there is evidence that the PMCA has its own glycolytic ATP supply that can fuel the PMCA in the face of impaired mitochondrial function.Moreover, membrane phospholipids,mitochondrial membrane potential,caspase/calpain cleavage and oxidative stress have all been implicated in metabolic stress-induced inhibition of the PMCA.The major focus of this review is to challenge the conventional view of ATP-dependent regulation of the PMCA and bring together some of the alternative or additional mechanisms by which metabolic stress impairs PMCA activity resulting in cytosolic Ca2+ overload and cytotoxicity.
