AIM: To develop a method for studying myocardial area at risk(AAR) in ischemic heart disease in correlation with cardiac magnetic resonance imaging(c MRI). METHODS: Nine rabbits were anesthetized, intubated and subjec...AIM: To develop a method for studying myocardial area at risk(AAR) in ischemic heart disease in correlation with cardiac magnetic resonance imaging(c MRI). METHODS: Nine rabbits were anesthetized, intubated and subjected to occlusion and reperfusion of the left circumflex coronary artery(LCx) to induce myocardial infarction(MI). ECG-triggered c MRI with delayed en-hancement was performed at 3.0 T. After euthanasia, the heart was excised with the LCx re-ligated. Bifunctional staining was performed by perfusing the aorta with a homemade red-iodized-oil(RIO) dye. The heart was then agar-embedded for ex vivo magnetic resonance imaging and sliced into 3 mm-sections. The AAR was defined by RIO-staining and digital radiography(DR). The perfusion density rate(PDR) was derived from DR for the AAR and normal myocardium. The MI was measured by in vivo delayed enhancement(i DE) and ex vivo delayed enhancement(e DE) c MRI. The AAR and MI were compared to validate the bifunctional straining for cardiac imaging research. Linear regression with Bland-Altman agreement, one way-ANOVA with Bonferroni's multiple comparison, and paired t tests were applied for statistics.RESULTS: All rabbits tolerated well the surgical procedure and subsequent c MRI sessions. The openchest occlusion and close-chest reperfusion of the LCx, double suture method and bifunctional staining were successfully applied in all animals. The percentage MI volumes globally(n = 6) and by slice(n = 25) were 36.59% ± 13.68% and 32.88% ± 12.38% on i DE, and 35.41% ± 12.25% and 32.40% ± 12.34% on e DE. There were no significant differences for MI determination with excellent linear regression correspondence(r global = 0.89; r slice = 0.9) between i DE and e DE. The percentage AAR volumes globally(n = 6) and by slice(n = 25) were 44.82% ± 15.18% and 40.04% ± 13.64% with RIO-staining, and 44.74% ± 15.98% and 40.48% ± 13.26% by DR showing high correlation in linear regression analysis(r global = 0.99; r slice = 1.0). The mean differences of the two AAR measurements on BlandAltman were almost zero, indicating RIO-staining and DR were essentially equivalent or inter-replaceable. The AAR was significantly larger than MI both globally and slice-by-slice(P < 0.01). After correction with the background and the blank heart without bifunctional staining(n = 3), the PDR for the AAR and normal myocardium was 32% ± 15% and 35.5% ± 35%, respectively,which is significantly different(P < 0.001), suggesting that blood perfusion to the AAR probably by collateral circulation was only less than 10% of that in the normal myocardium.CONCLUSION: The myocardial area at risk in ischemic heart disease could be accurately determined postmortem by this novel bifunctional staining, which may substantially contribute to translational cardiac imaging research.展开更多
Free radicals in ischemic and reperfused rat brain were measured by electron spinresonance(ESR) spectrometer.The inhibitory effect of allopurinol on the free radical genera-tion in reperfused rat brain was observed.Th...Free radicals in ischemic and reperfused rat brain were measured by electron spinresonance(ESR) spectrometer.The inhibitory effect of allopurinol on the free radical genera-tion in reperfused rat brain was observed.The experimental results revealed that the free radi-cal content of the brain in the ischemia group was markedly higher than that in the control group(P【0.01),that in the reperfusion group was markedly higher than that in the ischemia group(P【0.01)and that in the allopurinol group was markedly lower than that in the reperfusiongroup(P【0.01).These results suggest that free radicals increase.greatly after cerebralischemia-reperfusion and that allopurinol plays a certain inhibitory role in the free radical genera-tion in the reperfused rat brain.展开更多
Objective To assess the effects of Dy DTPA BMA (sprodiamide) on ex vivo MR imaging of reperfused acute myocardial infarction Methods Eighteen dogs were subjected to 2 hour coronary artery occlusion followed by...Objective To assess the effects of Dy DTPA BMA (sprodiamide) on ex vivo MR imaging of reperfused acute myocardial infarction Methods Eighteen dogs were subjected to 2 hour coronary artery occlusion followed by 24 hour reperfusion Dysprosium chelate (Dy DTPA BMA) was injected into 16 dogs Twenty minutes before their sacrifice Two dogs did not receive the contrast medium and were used as controls Excised hearts were imaged on T2 weighted spin echo sequence (T2W SE) and T2 * weighted gradient recalled echo sequence (T2 *W GRE), then sectioned and double perfused for planimetric comparison Results Dy DTPA BMA induced myocardial signal loss was detected on T2W SE and on T2 *W GRE images The signal loss was observed at the subendocardial location of the myocardial wall inducing an apparent enlargement of the left ventricle cavity and a thinning appearance of the anterior myocardial wall Conclusions Myocyte necrosis diminishes the potency of dysprosium to cause MR imaging signal intensity loss in reperfused myocardial infarction Pre infarcted myocardium with potentially reversible viability may be responsible for the effect of the contrast medium展开更多
Ischemia–reperfusion injury is a common pathophysiological mechanism in retinal degeneration.PANoptosis is a newly defined integral form of regulated cell death that combines the key features of pyroptosis,apoptosis,...Ischemia–reperfusion injury is a common pathophysiological mechanism in retinal degeneration.PANoptosis is a newly defined integral form of regulated cell death that combines the key features of pyroptosis,apoptosis,and necroptosis.Oligomerization of mitochondrial voltage-dependent anion channel 1 is an important pathological event in regulating cell death in retinal ischemia–reperfusion injury.However,its role in PANoptosis remains largely unknown.In this study,we demonstrated that voltage-dependent anion channel 1 oligomerization-mediated mitochondrial dysfunction was associated with PANoptosis in retinal ischemia–reperfusion injury.Inhibition of voltage-dependent anion channel 1 oligomerization suppressed mitochondrial dysfunction and PANoptosis in retinal cells subjected to ischemia–reperfusion injury.Mechanistically,mitochondria-derived reactive oxygen species played a central role in the voltagedependent anion channel 1-mediated regulation of PANoptosis by promoting PANoptosome assembly.Moreover,inhibiting voltage-dependent anion channel 1 oligomerization protected against PANoptosis in the retinas of rats subjected to ischemia–reperfusion injury.Overall,our findings reveal the critical role of voltage-dependent anion channel 1 oligomerization in regulating PANoptosis in retinal ischemia–reperfusion injury,highlighting voltage-dependent anion channel 1 as a promising therapeutic target.展开更多
Recent studies have shown that fibrotic scar formation following cerebral ischemic injury has varying effects depending on the microenvironment.However,little is known about how fibrosis is induced and regulated after...Recent studies have shown that fibrotic scar formation following cerebral ischemic injury has varying effects depending on the microenvironment.However,little is known about how fibrosis is induced and regulated after cerebral ischemic injury.Sonic hedgehog signaling participates in fibrosis in the heart,liver,lung,and kidney.Whether Shh signaling modulates fibrotic scar formation after cerebral ischemic stroke and the underlying mechanisms are unclear.In this study,we found that Sonic Hedgehog expression was upregulated in patients with acute ischemic stroke and in a middle cerebral artery occlusion/reperfusion injury rat model.Both Sonic hedgehog and Mitofusin 2 showed increased expression in the middle cerebral artery occlusion rat model and in vitro fibrosis cell model induced by transforming growth factor-beta 1.Activation of the Sonic hedgehog signaling pathway enhanced the expression of phosphorylated Smad 3 and Mitofusin 2 proteins,promoted the formation of fibrotic scars,protected synapses or promoted synaptogenesis,alleviated neurological deficits following middle cerebral artery occlusion/reperfusion injury,reduced cell apoptosis,facilitated the transformation of meninges fibroblasts into myofibroblasts,and enhanced the proliferation and migration of meninges fibroblasts.The Smad3 phosphorylation inhibitor SIS3 reversed the effects induced by Sonic hedgehog signaling pathway activation.Bioinformatics analysis revealed significant correlations between Sonic hedgehog and Smad3,between Sonic hedgehog and Mitofusin 2,and between Smad3 and Mitofusin 2.These findings suggest that Sonic hedgehog signaling may influence Mitofusin 2 expression by regulating Smad3 phosphorylation,thereby modulating the formation of early fibrotic scars following cerebral ischemic stroke and affecting prognosis.The Sonic Hedgehog signaling pathway may serve as a new therapeutic target for stroke treatment.展开更多
Objective:Leucine-rich alpha-2 glycoprotein 1(Lrg1)could regulate diverse cells in cerebral ischemiareperfusion.Our study seeks to uncover Lrg1’s impact on endothelial cell heterogeneity via differentiation pathways ...Objective:Leucine-rich alpha-2 glycoprotein 1(Lrg1)could regulate diverse cells in cerebral ischemiareperfusion.Our study seeks to uncover Lrg1’s impact on endothelial cell heterogeneity via differentiation pathways and transcription factors.Method:The CSOmap model measured cell-to-brain-center distances using single-cell RNA sequencing(scRNA-seq)data in middle cerebral artery occlusion reperfusion(MCAO/R).Monocle2 mapped endothelial differentiation paths.Gene set enrichment analysis(GSEA)analyzed endothelial subcluster variations.Database searches revealed a zinc finger MIZ-type containing 1 protein-frizzled 3(Zmiz1-Fzd3)promoter interaction.Endothelial cells were transfected with a Fzd3 promoter-luciferase plasmid.Polymerase chain reaction(PCR)and western blotting assessed MCAO/R or Zmiz1 overexpression effects on Fzd3-related mRNA and proteins.A retroviral vector carrying Zmiz1 was injected into the brains of mice to study its effect on Fzd3.Result:Lrg1−/−mice exhibited elevated cell adhesion proteins and decreased microvascular leakage after MCAO/R.CSOmap showed widened astrocyte spacing in thesemice.RSS revealed Zmiz1 overexpression inMCAO/R+Lrg1−/−mice.MCAO/R and pcDNA3-Zmiz1 transfection both enhanced luciferase activity with Fzd3,indicating Zmiz1 binding to Fzd3.Retroviral Zmiz1 injection or knockdown disrupted ischemic brain tight junctions,highlighting Zmiz1’s key role in blood-brain barrier protection,likely through Fzd3 pathway modulation.Conclusion:The findings indicate Lrg1 knockout induces endothelial differentiation by activating Zmiz1,which is crucial for maintaining blood-brain barrier function,possibly via modulating the Fzd3 pathway.展开更多
Background Our previous studies have demonstrated that Tongxinluo （TXL）, a traditional Chinese medicine, can protect hearts against no-reflow and reperfusion injury in a protein kinase A （PKA）-dependent manner. Th...Background Our previous studies have demonstrated that Tongxinluo （TXL）, a traditional Chinese medicine, can protect hearts against no-reflow and reperfusion injury in a protein kinase A （PKA）-dependent manner. The present study was to investigate whether the PKA-mediated cardioprotection of TXL against no-reflow and reperfusion injury relates to the inhibition of myocardial inflammation, edema, and apoptosis. Methods In a 90-minute ischemia and 3-hour reperfusion model, minipigs were randomly assigned to sham, control, TXL （0.05 g/kg, gavaged one hour prior to ischemia）, and TXL ＋ H-89 （a PKA inhibitor, intravenously and continuously infused at 1.0 μg/kg per minute） groups. Myocardial no-reflow, necrosis, edema, and apoptosis were determined by pathological and histological studies. Myocardial activity of PKA and myeloperoxidase was measured by colorimetric method. The expression of PKA, phosphorylated cAMP response element-binding protein （p-CREB） （Ser133）, tumor necrosis factor a （TNF-a）, P-selectin, apoptotic proteins, and aquaporins was detected by Western blotting analysis. Results TXL decreased the no-reflow area by 37.4% and reduced the infarct size by 27.0% （P〈0.05）. TXL pretreatment increased the PKA activity and the expression of Ser133 p-CREB in the reflow and no-reflow myocardium （P 〈0.05）. TXL inhibited the ischemia-reperfusion-induced elevation of myeloperoxidase activities and the expression of TNF-a and P-selectin, reduced myocardial edema in the left ventricle and the reflow and no-reflow areas and the expression of aquaporin-4, -8, and -9, and decreased myocytes apoptosis by regulation of apoptotic protein expression in the reflow and no-reflow myocardium. However, addition of the PKA inhibitor H-89 counteracted these beneficial effects of TXL. Conclusion PKA-mediated cardioprotection of TXL against no-reflow and reperfusion injury relates to the inhibition of myocardial inflammation, edema, and apoptosis in the reflow and no-reflow myocardium.展开更多
Background Myocardial perfusion associates with clinical syndromes and prognosis. Adenosine could improve myocardial perfusion of acute myocardial infarction within 6 hours, but few data are available on late perfusio...Background Myocardial perfusion associates with clinical syndromes and prognosis. Adenosine could improve myocardial perfusion of acute myocardial infarction within 6 hours, but few data are available on late perfusion of myocardial infarction （MI）. This study aimed at quantitatively evaluating the value of intracoronary adenosine improving myocardial perfusion in late reperfused MI with myocardial contrast echocardiography （MCE）. Methods Twenty-six patients with anterior wall infarcts were divided randomly into 2 groups： adenosine group （n=12） and normal saline group （n=-14）. Their history of myocardial infarction was about 3-12 weeks. Adenosine or normal saline was given when the guiding wire crossed the lesion through percutaneous coronary intervention （PCI）, then the balloon was dilated and stent （Cypher/Cypher select） was implanted at the lesion. Contrast pulse sequencing MCE with Sonovue contrast via the coronary route was done before PCI and 30 minutes after PCI. Video densitometry and contrast filled-blank area were calculated with the CUSQ off-line software. Heart function and cardiac events were followed up within 30 days. Results Perfusion in the segments of the criminal occlusive coronary artery in the adenosine group was better than that in the saline group （5.71：L-0.29 VS 4.95±1.22, P〈0.05）. Ischemic myocardial segment was deminished significantly after PCI, but the meliorated area was bigger in the adenosine group than in the saline group （（1.56±0.60） cm^2 vs （1.02±0.56） cm^2, P〈0.05）. The video densitometry in cntical segments was also improved significantly in the adenosine group （5.53±0.36 VS 5.26±0.35, P〈0.05）. Left ventricular ejection fraction （LVEF） was improved in all patients after PCI, but EF was not significant between the two groups （（67±6）% vs （62±7）%, P〉0.05）. There was no in-hospital or 30-day major adverse cardiac event （MACE） in the adenosine group but 3 MACE in the saline group in 30 days after PCI. Conclusions Adenosine could improve myocardial microvascular perfusion in the late reopening of an occluded infarct related artery （3 to 12 weeks after AMI） and clinical outcome in the follow-up period, and myocardial microvascular perfusion is a powerful predictor of clinical events.展开更多
Objective: To investigate the modulation of nitric oxide synthase (NOS) isoenzymes in skeletal muscle during 3 h ischemia/reperfusion (I/R, 3 h ischemia followed by 3 h reperfusion). Methods: The extensor digitorum lo...Objective: To investigate the modulation of nitric oxide synthase (NOS) isoenzymes in skeletal muscle during 3 h ischemia/reperfusion (I/R, 3 h ischemia followed by 3 h reperfusion). Methods: The extensor digitorum longuses (EDLs) from 20 adult rats were divided into 4 groups: the normal, the sham operation, the ischemia (3 h), and the ischemia/reperfusion group. One normal EDL from each rat was used as the non operated control, and the opposite ones are distributed into the 3 remaining groups. All the samples were studied with Western blotting technique and immunohistochemistry staining. Results: Three sizes of protein bands verified with the proteins of relative molecule to be of 155?000, 140?000 and 135?000, were detected in the EDL homogenate by Western blotting, which were comparable with the positive controls for nNOS, eNOS and iNOS, respectively. Immunostaining demonstrated that nNOS was present in the muscle fiber, with a similar location of the muscle stria, eNOS was found apparently in microvascular endothelia, but not found in muscle fibers, and iNOS was found in the leukocytes around the muscle fiber and some endothelia cells. Immunostaining paralleled the Western blotting results. Conclusions: It suggests that the constitutive nNOS and eNOS protein can be regulated by I/R, and I/R results in a down regulation of nNOS and up regulation of eNOS and iNOS in reperfused skeletal muscle. The fact that nNOS is present around stria suggests that nNOS may have a close relationship with muscle function. The localization of eNOS in endothelial cell indicates its role in regulating blood supply of the muscle. Based on these findings, it is possible that NO produced by distinct NOS may play a different role in I/R injury.展开更多
Objective: To observe effects of arginine on arterial endothelium injured by ischemia reperfusion (IR), and explore its possible mechanism. Methods: Fifty four rats were divided into 3 groups and treated in respective...Objective: To observe effects of arginine on arterial endothelium injured by ischemia reperfusion (IR), and explore its possible mechanism. Methods: Fifty four rats were divided into 3 groups and treated in respective ways: (1) drinking tap water as the control; (2) drinking tap water containing 2.5 % L arginine; (3) drinking tap water containing 2.5 % L arginine together with intraperitoneal injection of N G nitro L arginine methylester 5 mg·kg -1 ·d -1 . A segment of the common carotid artery was occluded for 1 h, and then reperfused. Samples taken at different post IR time from the segment were prepared for the ultrastructural and Ce H 2O 2 cytochemical observation. The naked index (NI) of internal elastic lamina (IEL) was measured for comparing the endothelial injure extent and its repair process. Results: Less damage of endothelial cells (EC), more platelets adhering to naked IEL and more regenerating EC were observed in Group 2. The NI values of samples taken at 1, 2, 3 d after the IR were respectively 0.92 ± 0.08 , 0.88 ± 0.03 and 0.41 ± 0.02 in Group 1, and reduced to 0.52 ± 0.05 , 0.19 ± 0.08 and 0.06 ± 0.01 in Group 2 (P< 0.05 0.01 ). In Group 3, the endothelium damage was not alleviated, and so were the NI. The Ce H 2O 2 particles deposited on the lumen surface of endothelium were much less in Group 2 than in Groups 1 and 3. Conclusions: L arginine promotes the repair process of IR injured endothelium probably through the removal of oxygen free radicals by NO.展开更多
Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cereb...Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cerebral ischemia,but the relationship between ER stress and autophagy remains unclear.In this study,we established experimental models using oxygen-glucose deprivation/reoxygenation in PC12 cells and primary neurons to simulate cerebral ischemia/reperfusion injury.We found that prolongation of oxygen-glucose deprivation activated the ER stress pathway protein kinase-like endoplasmic reticulum kinase(PERK)/eukaryotic translation initiation factor 2 subunit alpha(e IF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP),increased neuronal apoptosis,and induced autophagy.Furthermore,inhibition of ER stress using inhibitors or by si RNA knockdown of the PERK gene significantly attenuated excessive autophagy and neuronal apoptosis,indicating an interaction between autophagy and ER stress and suggesting PERK as an essential target for regulating autophagy.Blocking autophagy with chloroquine exacerbated ER stress-induced apoptosis,indicating that normal levels of autophagy play a protective role in neuronal injury following cerebral ischemia/reperfusion injury.Findings from this study indicate that cerebral ischemia/reperfusion injury can trigger neuronal ER stress and promote autophagy,and suggest that PERK is a possible target for inhibiting excessive autophagy in cerebral ischemia/reperfusion injury.展开更多
Neurotoxic astrocytes are a promising therapeutic target for the attenuation of cerebral ischemia/reperfusion injury.Low-density lipoprotein receptor,a classic cholesterol regulatory receptor,has been found to inhibit...Neurotoxic astrocytes are a promising therapeutic target for the attenuation of cerebral ischemia/reperfusion injury.Low-density lipoprotein receptor,a classic cholesterol regulatory receptor,has been found to inhibit NLR family pyrin domain containing protein 3(NLRP3)inflammasome activation in neurons following ischemic stroke and to suppress the activation of microglia and astrocytes in individuals with Alzheimer’s disease.However,little is known about the effects of low-density lipoprotein receptor on astrocytic activation in ischemic stroke.To address this issue in the present study,we examined the mechanisms by which low-density lipoprotein receptor regulates astrocytic polarization in ischemic stroke models.First,we examined low-density lipoprotein receptor expression in astrocytes via immunofluorescence staining and western blotting analysis.We observed significant downregulation of low-density lipoprotein receptor following middle cerebral artery occlusion reperfusion and oxygen-glucose deprivation/reoxygenation.Second,we induced the astrocyte-specific overexpression of low-density lipoprotein receptor using astrocyte-specific adeno-associated virus.Low-density lipoprotein receptor overexpression in astrocytes improved neurological outcomes in middle cerebral artery occlusion mice and reversed neurotoxic astrocytes to create a neuroprotective phenotype.Finally,we found that the overexpression of low-density lipoprotein receptor inhibited NLRP3 inflammasome activation in oxygen-glucose deprivation/reoxygenation injured astrocytes and that the addition of nigericin,an NLRP3 agonist,restored the neurotoxic astrocyte phenotype.These findings suggest that low-density lipoprotein receptor could inhibit the NLRP3-meidiated neurotoxic polarization of astrocytes and that increasing low-density lipoprotein receptor in astrocytes might represent a novel strategy for treating cerebral ischemic stroke.展开更多
Reperfusion following cerebral ischemia causes both structural and functional damage to brain tissue and could aggravate a patient's condition;this phenomenon is known as cerebral ischemia-reperfusion injury.Curre...Reperfusion following cerebral ischemia causes both structural and functional damage to brain tissue and could aggravate a patient's condition;this phenomenon is known as cerebral ischemia-reperfusion injury.Current studies have elucidated the neuroprotective role of the sirtuin protein family(Sirtuins)in modulating cerebral ischemia-reperfusion injury.However,the potential of utilizing it as a novel intervention target to influence the prognosis of cerebral ischemia-reperfusion injury requires additional exploration.In this review,the origin and research progress of Sirtuins are summarized,suggesting the involvement of Sirtuins in diverse mechanisms that affect cerebral ischemia-reperfusion injury,including inflammation,oxidative stress,blood-brain barrier damage,apoptosis,pyroptosis,and autophagy.The therapeutic avenues related to Sirtuins that may improve the prognosis of cerebral ischemia-reperfusion injury were also investigated by modulating Sirtuins expression and affecting representative pathways,such as nuclear factor-kappa B signaling,oxidative stress mediated by adenosine monophosphate-activated protein kinase,and the forkhead box O.This review also summarizes the potential of endogenous substances,such as RNA and hormones,drugs,dietary supplements,and emerging therapies that regulate Sirtuins expression.This review also reveals that regulating Sirtuins mitigates cerebral ischemia-reperfusion injury when combined with other risk factors.While Sirtuins show promise as a potential target for the treatment of cerebral ischemiareperfusion injury,most recent studies are based on rodent models with circadian rhythms that are distinct from those of humans,potentially influencing the efficacy of Sirtuinstargeting drug therapies.Overall,this review provides new insights into the role of Sirtuins in the pathology and treatment of cerebral ischemia-reperfusion injury.展开更多
Nitric oxide(NO)is a gaseous molecule produced by 3 different NO synthase(NOS)isoforms:Neural/brain NOS(nNOS/bNOS,type 1),endothelial NOS(eNOS,type 3)and inducible NOS(type 2).Type 1 and 3 NOS are constitutively expre...Nitric oxide(NO)is a gaseous molecule produced by 3 different NO synthase(NOS)isoforms:Neural/brain NOS(nNOS/bNOS,type 1),endothelial NOS(eNOS,type 3)and inducible NOS(type 2).Type 1 and 3 NOS are constitutively expressed.NO can serve different purposes:As a vasoactive molecule,as a neurotransmitter or as an immunomodulator.It plays a key role in cerebral ischemia/reperfusion injury(CIRI).Hypoxic episodes simulate the production of oxygen free radicals,leading to mitochondrial and phospholipid damage.Upon reperfusion,increased levels of oxygen trigger oxide synthases;whose products are associated with neuronal damage by promoting lipid peroxidation,nitrosylation and excitotoxicity.Molecular pathways in CIRI can be altered by NOS.Neuroprotective effects are observed with eNOS activity.While nNOS interplay is prone to endothelial inflammation,oxidative stress and apoptosis.Therefore,nNOS appears to be detrimental.The interaction between NO and other free radicals develops peroxynitrite;which is a cytotoxic agent.It plays a main role in the likelihood of hemorrhagic events by tissue plasminogen activator(t-PA).Peroxynitrite scavengers are currently being studied as potential targets to prevent hemorrhagic transformation in CIRI.展开更多
Cerebral ischemia/reperfusion(I/R)injury is an important pathophysiological condition of ischemic stroke that involves a variety of physiological and pathological cell death pathways,including autophagy,apoptosis,necr...Cerebral ischemia/reperfusion(I/R)injury is an important pathophysiological condition of ischemic stroke that involves a variety of physiological and pathological cell death pathways,including autophagy,apoptosis,necroptosis,and phagoptosis,among which autophagy is the most studied.We have reviewed studies published in the past 5 years regarding the association between autophagy and cerebral I/R injury.To the best of our knowledge,this is the first review article summarizing potential candidates targeting autophagic pathways in the treatment of I/R injury post ischemic stroke.The findings of this review may help to better understand the pathogenesis and mechanisms of I/R events and bridge the gap between basic and translational research that may lead to the development of novel therapeutic approaches for I/R injury.展开更多
Ferroptosis is a novel form of non-apoptotic cell death that has been widely studied in recent years and is involved in a variety of pathophysiological processes.The core treatment goal of ischemic stroke is to restor...Ferroptosis is a novel form of non-apoptotic cell death that has been widely studied in recent years and is involved in a variety of pathophysiological processes.The core treatment goal of ischemic stroke is to restore blood flow as early as possible,while the pathological mechanism of reperfusion injury after restoring blood flow is complex,involving oxidative stress,calcium overload,and inflammatory response.In recent years,more and more studies have found that ferroptosis mediation is involved in the occurrence and development of cerebral ischemia-reperfusion injury.This paper elaborates on the concept,mechanisms,and regulation of ferroptosis,detailing its role in cerebral ischemia-reperfusion injury and potential inhibition strategies.The aim is to deepen the understanding of ferroptosis in this pathological process and provide insights for possible targeted therapies.展开更多
Myocardial ischemia(MI)is a pathophysiological condition in which the myocardium is unable to maintain normal cardiac function due to insufficient coronary artery blood and oxygen supply,as well as abnormal myocardial...Myocardial ischemia(MI)is a pathophysiological condition in which the myocardium is unable to maintain normal cardiac function due to insufficient coronary artery blood and oxygen supply,as well as abnormal myocardial energy metabolism[1].Ginsenoside Rbi(Rbi),one of the most abundant natural ingredients in ginseng and Panax notoginseng,has been proven to protect the heart from MI/reperfusion injury(RI)[2].展开更多
It has been shown clinically that continuous removal of ischemia/reperfusion-induced reactive oxygen species is not conducive to the recovery of late stroke.Indeed,previous studies have shown that excessive increases ...It has been shown clinically that continuous removal of ischemia/reperfusion-induced reactive oxygen species is not conducive to the recovery of late stroke.Indeed,previous studies have shown that excessive increases in hypochlorous acid after stroke can cause severe damage to brain tissue.Our previous studies have found that a small amount of hypochlorous acid still exists in the later stage of stroke,but its specific role and mechanism are currently unclear.To simulate stroke in vivo,a middle cerebral artery occlusion rat model was established,with an oxygen-glucose deprivation/reoxygenation model established in vitro to mimic stroke.We found that in the early stage(within 24 hours)of ischemic stroke,neutrophils produced a large amount of hypochlorous acid,while in the recovery phase(10 days after stroke),microglia were activated and produced a small amount of hypochlorous acid.Further,in acute stroke in rats,hypochlorous acid production was prevented using a hypochlorous acid scavenger,taurine,or myeloperoxidase inhibitor,4-aminobenzoic acid hydrazide.Our results showed that high levels of hypochlorous acid(200μM)induced neuronal apoptosis after oxygen/glucose deprivation/reoxygenation.However,in the recovery phase of the middle cerebral artery occlusion model,a moderate level of hypochlorous acid promoted the proliferation and differentiation of neural stem cells into neurons and astrocytes.This suggests that hypochlorous acid plays different roles at different phases of cerebral ischemia/reperfusion injury.Lower levels of hypochlorous acid(5 and 100μM)promoted nuclear translocation ofβ-catenin.By transfection of single-site mutation plasmids,we found that hypochlorous acid induced chlorination of theβ-catenin tyrosine 30 residue,which promoted nuclear translocation.Altogether,our study indicates that maintaining low levels of hypochlorous acid plays a key role in the recovery of neurological function.展开更多
Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug deliv...Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.展开更多
Objective:Acute kidney injury(AKI)is a clinical syndrome characterized by sudden deterioration of renal function,with ischemia reperfusion injury(IRI)being the most common cause.Long noncoding RNA(lncRNA)regulate cell...Objective:Acute kidney injury(AKI)is a clinical syndrome characterized by sudden deterioration of renal function,with ischemia reperfusion injury(IRI)being the most common cause.Long noncoding RNA(lncRNA)regulate cell fate through interactions with microRNA(miRNA)and messenger RNAs(mRNA),but the mechanisms and regulatory networks underlying lncRNA AK154753(AK154753)in IRI-induced AKI remain unclear.This study aims to investigate the role of AK154753 in acute renal IRI and to elucidate the molecular mechanism of the AK154753 via miR-345-3p/Bcl-2 homologous antagonist/killer(Bak)and miR-708-5p/Bcl-2 interacting mediator of cell death(Bim)axis.Methods:A bilateral renal artery ischemia model was established in mice(30 minutes ischemia followed by 24 hours and 48 hours reperfusion).Kidney tissues were analyzed using microarray-based transcriptomic sequencing to identify differentially expressed lncRNAs,miRNAs,and mRNAs.RNA levels of AK154753,miR-345-3p,miR-708-5p,Bak,and Bim were validated using real-time reverse transcription PCR(real-time RTPCR).Oxygen and glucose deprivation/reperfusion(OGD/R)models were constructed in mouse proximal renal tubular epithelial BUMPT cells to simulate in vitro IRI conditions.Adeno-associated virus(AAV)-mediated shRNA was used to silence AK154753 in vivo.Apoptosis was assessed using TUNEL staining and flow cytometry.Protein levels of Bak,Bim,and cleaved-caspase-3 were measured using Western blotting.Fluorescence in situ hybridization(FISH)was used to determine intracellular localization of AK154753.Binding relationships between AK154753 and miR-345-3p/Bak and miR-708-5p/Bim were verified using dual-luciferase reporter assays.MiRNA mimics and inhibitors were used to evaluate regulatory-network integrity.Results:IRI significantly elevated serum blood urea nitrogen(BUN)and serum creatinine(Scr),accompanied by tubular-structure damage and increased cell apoptosis(all P<0.05).Transcriptome profiling and real-time RT-PCR validation demonstrated that lncRNA AK154753,along with the pro-apoptotic proteins Bak and Bim,was significantly upregulated after IRI,whereas miR-345-3p and miR-708-5p were markedly downregulated(P<0.01).In vitro,OGD/R treatment significantly induced AK154753 expression in renal tubular epithelial cells and suppressed the expression of miR-345-3p and miR-708-5p,while markedly increasing the protein levels of Bak,Bim,and cleaved-caspase 3,resulting in a significant increase in apoptosis(all P<0.01).Silencing AK154753 significantly attenuated OGD/R-induced apoptosis,reduced the expression of Bak,Bim,and cleaved caspase 3,and decreased cell apoptosis(all P<0.01),while significantly upregulating miR-345-3p and miR-708-5p expression(P<0.01).In vivo,adeno-associated virus(AAV)-mediated knockdown of AK154753 significantly improved renal function in IRI mice,alleviated tubular injury,and suppressed renal tissue apoptosis,as evidenced by reduced BUN and Scr levels,improved histopathological injury scores,and decreased expression of Bak,Bim,and cleaved caspase-3(all P<0.01),accompanied by significant upregulation of miR-345-3p and miR-708-5p(all P<0.01).Luciferase reporter assays further confirmed that miR-345-3p directly binds to the 3'-untranslated region(3'-UTR)of AK154753 and Bak,whereas miR-708-5p directly binds to the 3'-UTRs of AK154753 and Bim.Inhibition of miR-345-3p or miR-708-5p abolished the anti-apoptotic effects induced by AK154753 silencing and restored Bak and Bim expression levels(all P<0.01).Conclusion:AK154753 is upregulated in acute renal IRI and promotes apoptosis by suppressing miR-345-3p and miR-708-5p,thereby upregulating Bak and Bim,and participates in the initiation and progression of acute renal IRI.展开更多
基金Supported by The awarded grants of the KU Leuven Molecular Small Animal Imaging Center Mo SAIC(KUL EF/05/08)the Center of Excellence in vivo Molecular Imaging Research(IMIR)of KU Leuven+1 种基金a EU Project Asia-Link Cf P 2006-Europe Aid/123738/C/ACT/Multi-Proposal,No.128-498/111Jiangsu Province Natural Science Foundation,China,No.BK2010594
文摘AIM: To develop a method for studying myocardial area at risk(AAR) in ischemic heart disease in correlation with cardiac magnetic resonance imaging(c MRI). METHODS: Nine rabbits were anesthetized, intubated and subjected to occlusion and reperfusion of the left circumflex coronary artery(LCx) to induce myocardial infarction(MI). ECG-triggered c MRI with delayed en-hancement was performed at 3.0 T. After euthanasia, the heart was excised with the LCx re-ligated. Bifunctional staining was performed by perfusing the aorta with a homemade red-iodized-oil(RIO) dye. The heart was then agar-embedded for ex vivo magnetic resonance imaging and sliced into 3 mm-sections. The AAR was defined by RIO-staining and digital radiography(DR). The perfusion density rate(PDR) was derived from DR for the AAR and normal myocardium. The MI was measured by in vivo delayed enhancement(i DE) and ex vivo delayed enhancement(e DE) c MRI. The AAR and MI were compared to validate the bifunctional straining for cardiac imaging research. Linear regression with Bland-Altman agreement, one way-ANOVA with Bonferroni's multiple comparison, and paired t tests were applied for statistics.RESULTS: All rabbits tolerated well the surgical procedure and subsequent c MRI sessions. The openchest occlusion and close-chest reperfusion of the LCx, double suture method and bifunctional staining were successfully applied in all animals. The percentage MI volumes globally(n = 6) and by slice(n = 25) were 36.59% ± 13.68% and 32.88% ± 12.38% on i DE, and 35.41% ± 12.25% and 32.40% ± 12.34% on e DE. There were no significant differences for MI determination with excellent linear regression correspondence(r global = 0.89; r slice = 0.9) between i DE and e DE. The percentage AAR volumes globally(n = 6) and by slice(n = 25) were 44.82% ± 15.18% and 40.04% ± 13.64% with RIO-staining, and 44.74% ± 15.98% and 40.48% ± 13.26% by DR showing high correlation in linear regression analysis(r global = 0.99; r slice = 1.0). The mean differences of the two AAR measurements on BlandAltman were almost zero, indicating RIO-staining and DR were essentially equivalent or inter-replaceable. The AAR was significantly larger than MI both globally and slice-by-slice(P < 0.01). After correction with the background and the blank heart without bifunctional staining(n = 3), the PDR for the AAR and normal myocardium was 32% ± 15% and 35.5% ± 35%, respectively,which is significantly different(P < 0.001), suggesting that blood perfusion to the AAR probably by collateral circulation was only less than 10% of that in the normal myocardium.CONCLUSION: The myocardial area at risk in ischemic heart disease could be accurately determined postmortem by this novel bifunctional staining, which may substantially contribute to translational cardiac imaging research.
文摘Free radicals in ischemic and reperfused rat brain were measured by electron spinresonance(ESR) spectrometer.The inhibitory effect of allopurinol on the free radical genera-tion in reperfused rat brain was observed.The experimental results revealed that the free radi-cal content of the brain in the ischemia group was markedly higher than that in the control group(P【0.01),that in the reperfusion group was markedly higher than that in the ischemia group(P【0.01)and that in the allopurinol group was markedly lower than that in the reperfusiongroup(P【0.01).These results suggest that free radicals increase.greatly after cerebralischemia-reperfusion and that allopurinol plays a certain inhibitory role in the free radical genera-tion in the reperfused rat brain.
文摘Objective To assess the effects of Dy DTPA BMA (sprodiamide) on ex vivo MR imaging of reperfused acute myocardial infarction Methods Eighteen dogs were subjected to 2 hour coronary artery occlusion followed by 24 hour reperfusion Dysprosium chelate (Dy DTPA BMA) was injected into 16 dogs Twenty minutes before their sacrifice Two dogs did not receive the contrast medium and were used as controls Excised hearts were imaged on T2 weighted spin echo sequence (T2W SE) and T2 * weighted gradient recalled echo sequence (T2 *W GRE), then sectioned and double perfused for planimetric comparison Results Dy DTPA BMA induced myocardial signal loss was detected on T2W SE and on T2 *W GRE images The signal loss was observed at the subendocardial location of the myocardial wall inducing an apparent enlargement of the left ventricle cavity and a thinning appearance of the anterior myocardial wall Conclusions Myocyte necrosis diminishes the potency of dysprosium to cause MR imaging signal intensity loss in reperfused myocardial infarction Pre infarcted myocardium with potentially reversible viability may be responsible for the effect of the contrast medium
基金supported by the National Natural Science Foundation of China,Nos.82172196(to KX),82372507(to KX)the Natural Science Foundation of Hunan Province,China,No.2023JJ40804(to QZ)the Key Laboratory of Emergency and Trauma(Hainan Medical University)of the Ministry of Education,China,No.KLET-202210(to QZ)。
文摘Ischemia–reperfusion injury is a common pathophysiological mechanism in retinal degeneration.PANoptosis is a newly defined integral form of regulated cell death that combines the key features of pyroptosis,apoptosis,and necroptosis.Oligomerization of mitochondrial voltage-dependent anion channel 1 is an important pathological event in regulating cell death in retinal ischemia–reperfusion injury.However,its role in PANoptosis remains largely unknown.In this study,we demonstrated that voltage-dependent anion channel 1 oligomerization-mediated mitochondrial dysfunction was associated with PANoptosis in retinal ischemia–reperfusion injury.Inhibition of voltage-dependent anion channel 1 oligomerization suppressed mitochondrial dysfunction and PANoptosis in retinal cells subjected to ischemia–reperfusion injury.Mechanistically,mitochondria-derived reactive oxygen species played a central role in the voltagedependent anion channel 1-mediated regulation of PANoptosis by promoting PANoptosome assembly.Moreover,inhibiting voltage-dependent anion channel 1 oligomerization protected against PANoptosis in the retinas of rats subjected to ischemia–reperfusion injury.Overall,our findings reveal the critical role of voltage-dependent anion channel 1 oligomerization in regulating PANoptosis in retinal ischemia–reperfusion injury,highlighting voltage-dependent anion channel 1 as a promising therapeutic target.
基金supported by the National Natural Science Foundation of China,Nos.82171456(to QY)and 81971229(to QY)the Natural Science Foundation of Chongqing,Nos.CSTC2021JCYJ-MSXMX0263(to QY)and CSTB2023NSCQ-MSX1015(to XL)Doctoral Innovation Project of The First Affiliated Hospital of Chongqing Medical University,Nos.CYYY-BSYJSCXXM-202318(to JW)and CYYY-BSYJSCXXM-202327(to HT).
文摘Recent studies have shown that fibrotic scar formation following cerebral ischemic injury has varying effects depending on the microenvironment.However,little is known about how fibrosis is induced and regulated after cerebral ischemic injury.Sonic hedgehog signaling participates in fibrosis in the heart,liver,lung,and kidney.Whether Shh signaling modulates fibrotic scar formation after cerebral ischemic stroke and the underlying mechanisms are unclear.In this study,we found that Sonic Hedgehog expression was upregulated in patients with acute ischemic stroke and in a middle cerebral artery occlusion/reperfusion injury rat model.Both Sonic hedgehog and Mitofusin 2 showed increased expression in the middle cerebral artery occlusion rat model and in vitro fibrosis cell model induced by transforming growth factor-beta 1.Activation of the Sonic hedgehog signaling pathway enhanced the expression of phosphorylated Smad 3 and Mitofusin 2 proteins,promoted the formation of fibrotic scars,protected synapses or promoted synaptogenesis,alleviated neurological deficits following middle cerebral artery occlusion/reperfusion injury,reduced cell apoptosis,facilitated the transformation of meninges fibroblasts into myofibroblasts,and enhanced the proliferation and migration of meninges fibroblasts.The Smad3 phosphorylation inhibitor SIS3 reversed the effects induced by Sonic hedgehog signaling pathway activation.Bioinformatics analysis revealed significant correlations between Sonic hedgehog and Smad3,between Sonic hedgehog and Mitofusin 2,and between Smad3 and Mitofusin 2.These findings suggest that Sonic hedgehog signaling may influence Mitofusin 2 expression by regulating Smad3 phosphorylation,thereby modulating the formation of early fibrotic scars following cerebral ischemic stroke and affecting prognosis.The Sonic Hedgehog signaling pathway may serve as a new therapeutic target for stroke treatment.
基金supported by the Foundation Project:National Natural Science.Foundation of China(Nos.:82460249,82100417,81760094)The Foundation of Jiangxi Provincial Department of Science and Technology Outstanding Youth Fund Project(20212BAB206022,20242BAB23080).
文摘Objective:Leucine-rich alpha-2 glycoprotein 1(Lrg1)could regulate diverse cells in cerebral ischemiareperfusion.Our study seeks to uncover Lrg1’s impact on endothelial cell heterogeneity via differentiation pathways and transcription factors.Method:The CSOmap model measured cell-to-brain-center distances using single-cell RNA sequencing(scRNA-seq)data in middle cerebral artery occlusion reperfusion(MCAO/R).Monocle2 mapped endothelial differentiation paths.Gene set enrichment analysis(GSEA)analyzed endothelial subcluster variations.Database searches revealed a zinc finger MIZ-type containing 1 protein-frizzled 3(Zmiz1-Fzd3)promoter interaction.Endothelial cells were transfected with a Fzd3 promoter-luciferase plasmid.Polymerase chain reaction(PCR)and western blotting assessed MCAO/R or Zmiz1 overexpression effects on Fzd3-related mRNA and proteins.A retroviral vector carrying Zmiz1 was injected into the brains of mice to study its effect on Fzd3.Result:Lrg1−/−mice exhibited elevated cell adhesion proteins and decreased microvascular leakage after MCAO/R.CSOmap showed widened astrocyte spacing in thesemice.RSS revealed Zmiz1 overexpression inMCAO/R+Lrg1−/−mice.MCAO/R and pcDNA3-Zmiz1 transfection both enhanced luciferase activity with Fzd3,indicating Zmiz1 binding to Fzd3.Retroviral Zmiz1 injection or knockdown disrupted ischemic brain tight junctions,highlighting Zmiz1’s key role in blood-brain barrier protection,likely through Fzd3 pathway modulation.Conclusion:The findings indicate Lrg1 knockout induces endothelial differentiation by activating Zmiz1,which is crucial for maintaining blood-brain barrier function,possibly via modulating the Fzd3 pathway.
文摘Background Our previous studies have demonstrated that Tongxinluo （TXL）, a traditional Chinese medicine, can protect hearts against no-reflow and reperfusion injury in a protein kinase A （PKA）-dependent manner. The present study was to investigate whether the PKA-mediated cardioprotection of TXL against no-reflow and reperfusion injury relates to the inhibition of myocardial inflammation, edema, and apoptosis. Methods In a 90-minute ischemia and 3-hour reperfusion model, minipigs were randomly assigned to sham, control, TXL （0.05 g/kg, gavaged one hour prior to ischemia）, and TXL ＋ H-89 （a PKA inhibitor, intravenously and continuously infused at 1.0 μg/kg per minute） groups. Myocardial no-reflow, necrosis, edema, and apoptosis were determined by pathological and histological studies. Myocardial activity of PKA and myeloperoxidase was measured by colorimetric method. The expression of PKA, phosphorylated cAMP response element-binding protein （p-CREB） （Ser133）, tumor necrosis factor a （TNF-a）, P-selectin, apoptotic proteins, and aquaporins was detected by Western blotting analysis. Results TXL decreased the no-reflow area by 37.4% and reduced the infarct size by 27.0% （P〈0.05）. TXL pretreatment increased the PKA activity and the expression of Ser133 p-CREB in the reflow and no-reflow myocardium （P 〈0.05）. TXL inhibited the ischemia-reperfusion-induced elevation of myeloperoxidase activities and the expression of TNF-a and P-selectin, reduced myocardial edema in the left ventricle and the reflow and no-reflow areas and the expression of aquaporin-4, -8, and -9, and decreased myocytes apoptosis by regulation of apoptotic protein expression in the reflow and no-reflow myocardium. However, addition of the PKA inhibitor H-89 counteracted these beneficial effects of TXL. Conclusion PKA-mediated cardioprotection of TXL against no-reflow and reperfusion injury relates to the inhibition of myocardial inflammation, edema, and apoptosis in the reflow and no-reflow myocardium.
文摘Background Myocardial perfusion associates with clinical syndromes and prognosis. Adenosine could improve myocardial perfusion of acute myocardial infarction within 6 hours, but few data are available on late perfusion of myocardial infarction （MI）. This study aimed at quantitatively evaluating the value of intracoronary adenosine improving myocardial perfusion in late reperfused MI with myocardial contrast echocardiography （MCE）. Methods Twenty-six patients with anterior wall infarcts were divided randomly into 2 groups： adenosine group （n=12） and normal saline group （n=-14）. Their history of myocardial infarction was about 3-12 weeks. Adenosine or normal saline was given when the guiding wire crossed the lesion through percutaneous coronary intervention （PCI）, then the balloon was dilated and stent （Cypher/Cypher select） was implanted at the lesion. Contrast pulse sequencing MCE with Sonovue contrast via the coronary route was done before PCI and 30 minutes after PCI. Video densitometry and contrast filled-blank area were calculated with the CUSQ off-line software. Heart function and cardiac events were followed up within 30 days. Results Perfusion in the segments of the criminal occlusive coronary artery in the adenosine group was better than that in the saline group （5.71：L-0.29 VS 4.95±1.22, P〈0.05）. Ischemic myocardial segment was deminished significantly after PCI, but the meliorated area was bigger in the adenosine group than in the saline group （（1.56±0.60） cm^2 vs （1.02±0.56） cm^2, P〈0.05）. The video densitometry in cntical segments was also improved significantly in the adenosine group （5.53±0.36 VS 5.26±0.35, P〈0.05）. Left ventricular ejection fraction （LVEF） was improved in all patients after PCI, but EF was not significant between the two groups （（67±6）% vs （62±7）%, P〉0.05）. There was no in-hospital or 30-day major adverse cardiac event （MACE） in the adenosine group but 3 MACE in the saline group in 30 days after PCI. Conclusions Adenosine could improve myocardial microvascular perfusion in the late reopening of an occluded infarct related artery （3 to 12 weeks after AMI） and clinical outcome in the follow-up period, and myocardial microvascular perfusion is a powerful predictor of clinical events.
文摘Objective: To investigate the modulation of nitric oxide synthase (NOS) isoenzymes in skeletal muscle during 3 h ischemia/reperfusion (I/R, 3 h ischemia followed by 3 h reperfusion). Methods: The extensor digitorum longuses (EDLs) from 20 adult rats were divided into 4 groups: the normal, the sham operation, the ischemia (3 h), and the ischemia/reperfusion group. One normal EDL from each rat was used as the non operated control, and the opposite ones are distributed into the 3 remaining groups. All the samples were studied with Western blotting technique and immunohistochemistry staining. Results: Three sizes of protein bands verified with the proteins of relative molecule to be of 155?000, 140?000 and 135?000, were detected in the EDL homogenate by Western blotting, which were comparable with the positive controls for nNOS, eNOS and iNOS, respectively. Immunostaining demonstrated that nNOS was present in the muscle fiber, with a similar location of the muscle stria, eNOS was found apparently in microvascular endothelia, but not found in muscle fibers, and iNOS was found in the leukocytes around the muscle fiber and some endothelia cells. Immunostaining paralleled the Western blotting results. Conclusions: It suggests that the constitutive nNOS and eNOS protein can be regulated by I/R, and I/R results in a down regulation of nNOS and up regulation of eNOS and iNOS in reperfused skeletal muscle. The fact that nNOS is present around stria suggests that nNOS may have a close relationship with muscle function. The localization of eNOS in endothelial cell indicates its role in regulating blood supply of the muscle. Based on these findings, it is possible that NO produced by distinct NOS may play a different role in I/R injury.
文摘Objective: To observe effects of arginine on arterial endothelium injured by ischemia reperfusion (IR), and explore its possible mechanism. Methods: Fifty four rats were divided into 3 groups and treated in respective ways: (1) drinking tap water as the control; (2) drinking tap water containing 2.5 % L arginine; (3) drinking tap water containing 2.5 % L arginine together with intraperitoneal injection of N G nitro L arginine methylester 5 mg·kg -1 ·d -1 . A segment of the common carotid artery was occluded for 1 h, and then reperfused. Samples taken at different post IR time from the segment were prepared for the ultrastructural and Ce H 2O 2 cytochemical observation. The naked index (NI) of internal elastic lamina (IEL) was measured for comparing the endothelial injure extent and its repair process. Results: Less damage of endothelial cells (EC), more platelets adhering to naked IEL and more regenerating EC were observed in Group 2. The NI values of samples taken at 1, 2, 3 d after the IR were respectively 0.92 ± 0.08 , 0.88 ± 0.03 and 0.41 ± 0.02 in Group 1, and reduced to 0.52 ± 0.05 , 0.19 ± 0.08 and 0.06 ± 0.01 in Group 2 (P< 0.05 0.01 ). In Group 3, the endothelium damage was not alleviated, and so were the NI. The Ce H 2O 2 particles deposited on the lumen surface of endothelium were much less in Group 2 than in Groups 1 and 3. Conclusions: L arginine promotes the repair process of IR injured endothelium probably through the removal of oxygen free radicals by NO.
基金supported by the National Natural Science Foundation of China,Nos.82260245(to YX),81660207(to YX),81960253(to YL),82160268(to YL),U1812403(to ZG)Science and Technology Projects of Guizhou Province,Nos.[2019]1440(to YX),[2020]1Z067(to WH)+1 种基金Cultivation Foundation of Guizhou Medical University,No.[20NSP069](to YX)Excellent Young Talents Plan of Guizhou Medical University,No.(2022)101(to WH)。
文摘Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cerebral ischemia,but the relationship between ER stress and autophagy remains unclear.In this study,we established experimental models using oxygen-glucose deprivation/reoxygenation in PC12 cells and primary neurons to simulate cerebral ischemia/reperfusion injury.We found that prolongation of oxygen-glucose deprivation activated the ER stress pathway protein kinase-like endoplasmic reticulum kinase(PERK)/eukaryotic translation initiation factor 2 subunit alpha(e IF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP),increased neuronal apoptosis,and induced autophagy.Furthermore,inhibition of ER stress using inhibitors or by si RNA knockdown of the PERK gene significantly attenuated excessive autophagy and neuronal apoptosis,indicating an interaction between autophagy and ER stress and suggesting PERK as an essential target for regulating autophagy.Blocking autophagy with chloroquine exacerbated ER stress-induced apoptosis,indicating that normal levels of autophagy play a protective role in neuronal injury following cerebral ischemia/reperfusion injury.Findings from this study indicate that cerebral ischemia/reperfusion injury can trigger neuronal ER stress and promote autophagy,and suggest that PERK is a possible target for inhibiting excessive autophagy in cerebral ischemia/reperfusion injury.
基金supported by the National Natural Science Foundation of China,No.82201460(to YH)Nanjing Medical University Science and Technology Development Fund,No.NMUB20210202(to YH).
文摘Neurotoxic astrocytes are a promising therapeutic target for the attenuation of cerebral ischemia/reperfusion injury.Low-density lipoprotein receptor,a classic cholesterol regulatory receptor,has been found to inhibit NLR family pyrin domain containing protein 3(NLRP3)inflammasome activation in neurons following ischemic stroke and to suppress the activation of microglia and astrocytes in individuals with Alzheimer’s disease.However,little is known about the effects of low-density lipoprotein receptor on astrocytic activation in ischemic stroke.To address this issue in the present study,we examined the mechanisms by which low-density lipoprotein receptor regulates astrocytic polarization in ischemic stroke models.First,we examined low-density lipoprotein receptor expression in astrocytes via immunofluorescence staining and western blotting analysis.We observed significant downregulation of low-density lipoprotein receptor following middle cerebral artery occlusion reperfusion and oxygen-glucose deprivation/reoxygenation.Second,we induced the astrocyte-specific overexpression of low-density lipoprotein receptor using astrocyte-specific adeno-associated virus.Low-density lipoprotein receptor overexpression in astrocytes improved neurological outcomes in middle cerebral artery occlusion mice and reversed neurotoxic astrocytes to create a neuroprotective phenotype.Finally,we found that the overexpression of low-density lipoprotein receptor inhibited NLRP3 inflammasome activation in oxygen-glucose deprivation/reoxygenation injured astrocytes and that the addition of nigericin,an NLRP3 agonist,restored the neurotoxic astrocyte phenotype.These findings suggest that low-density lipoprotein receptor could inhibit the NLRP3-meidiated neurotoxic polarization of astrocytes and that increasing low-density lipoprotein receptor in astrocytes might represent a novel strategy for treating cerebral ischemic stroke.
文摘Reperfusion following cerebral ischemia causes both structural and functional damage to brain tissue and could aggravate a patient's condition;this phenomenon is known as cerebral ischemia-reperfusion injury.Current studies have elucidated the neuroprotective role of the sirtuin protein family(Sirtuins)in modulating cerebral ischemia-reperfusion injury.However,the potential of utilizing it as a novel intervention target to influence the prognosis of cerebral ischemia-reperfusion injury requires additional exploration.In this review,the origin and research progress of Sirtuins are summarized,suggesting the involvement of Sirtuins in diverse mechanisms that affect cerebral ischemia-reperfusion injury,including inflammation,oxidative stress,blood-brain barrier damage,apoptosis,pyroptosis,and autophagy.The therapeutic avenues related to Sirtuins that may improve the prognosis of cerebral ischemia-reperfusion injury were also investigated by modulating Sirtuins expression and affecting representative pathways,such as nuclear factor-kappa B signaling,oxidative stress mediated by adenosine monophosphate-activated protein kinase,and the forkhead box O.This review also summarizes the potential of endogenous substances,such as RNA and hormones,drugs,dietary supplements,and emerging therapies that regulate Sirtuins expression.This review also reveals that regulating Sirtuins mitigates cerebral ischemia-reperfusion injury when combined with other risk factors.While Sirtuins show promise as a potential target for the treatment of cerebral ischemiareperfusion injury,most recent studies are based on rodent models with circadian rhythms that are distinct from those of humans,potentially influencing the efficacy of Sirtuinstargeting drug therapies.Overall,this review provides new insights into the role of Sirtuins in the pathology and treatment of cerebral ischemia-reperfusion injury.
文摘Nitric oxide(NO)is a gaseous molecule produced by 3 different NO synthase(NOS)isoforms:Neural/brain NOS(nNOS/bNOS,type 1),endothelial NOS(eNOS,type 3)and inducible NOS(type 2).Type 1 and 3 NOS are constitutively expressed.NO can serve different purposes:As a vasoactive molecule,as a neurotransmitter or as an immunomodulator.It plays a key role in cerebral ischemia/reperfusion injury(CIRI).Hypoxic episodes simulate the production of oxygen free radicals,leading to mitochondrial and phospholipid damage.Upon reperfusion,increased levels of oxygen trigger oxide synthases;whose products are associated with neuronal damage by promoting lipid peroxidation,nitrosylation and excitotoxicity.Molecular pathways in CIRI can be altered by NOS.Neuroprotective effects are observed with eNOS activity.While nNOS interplay is prone to endothelial inflammation,oxidative stress and apoptosis.Therefore,nNOS appears to be detrimental.The interaction between NO and other free radicals develops peroxynitrite;which is a cytotoxic agent.It plays a main role in the likelihood of hemorrhagic events by tissue plasminogen activator(t-PA).Peroxynitrite scavengers are currently being studied as potential targets to prevent hemorrhagic transformation in CIRI.
基金Shanghai Rehabilitation Medical Association,Grant/Award Number:2023JGKT24China Rehabilitation Medical Association,Grant/Award Number:KFKT-2023Shanghai“14th Five-Year Plan”Traditional Chinese Medicine Specialty and Traditional Chinese Medicine Emergency Capacity Improvement Project,Grant/Award Number:ZYTSZK2-7。
文摘Cerebral ischemia/reperfusion(I/R)injury is an important pathophysiological condition of ischemic stroke that involves a variety of physiological and pathological cell death pathways,including autophagy,apoptosis,necroptosis,and phagoptosis,among which autophagy is the most studied.We have reviewed studies published in the past 5 years regarding the association between autophagy and cerebral I/R injury.To the best of our knowledge,this is the first review article summarizing potential candidates targeting autophagic pathways in the treatment of I/R injury post ischemic stroke.The findings of this review may help to better understand the pathogenesis and mechanisms of I/R events and bridge the gap between basic and translational research that may lead to the development of novel therapeutic approaches for I/R injury.
基金Natural Science Basic Research Program of Shaanxi Province(Project No.:2021JM-554)。
文摘Ferroptosis is a novel form of non-apoptotic cell death that has been widely studied in recent years and is involved in a variety of pathophysiological processes.The core treatment goal of ischemic stroke is to restore blood flow as early as possible,while the pathological mechanism of reperfusion injury after restoring blood flow is complex,involving oxidative stress,calcium overload,and inflammatory response.In recent years,more and more studies have found that ferroptosis mediation is involved in the occurrence and development of cerebral ischemia-reperfusion injury.This paper elaborates on the concept,mechanisms,and regulation of ferroptosis,detailing its role in cerebral ischemia-reperfusion injury and potential inhibition strategies.The aim is to deepen the understanding of ferroptosis in this pathological process and provide insights for possible targeted therapies.
文摘Myocardial ischemia(MI)is a pathophysiological condition in which the myocardium is unable to maintain normal cardiac function due to insufficient coronary artery blood and oxygen supply,as well as abnormal myocardial energy metabolism[1].Ginsenoside Rbi(Rbi),one of the most abundant natural ingredients in ginseng and Panax notoginseng,has been proven to protect the heart from MI/reperfusion injury(RI)[2].
基金supported by the Natural Science Foundation of Jiangsu Province of China,No.BK20211348(to SHQ)Xuzhou Basic Research Program,No.KC21030(to LYH)+1 种基金Leadership Program of Xuzhou Medical University,No.JBGS202203(to SHQ)Research Grant Council GRF of Hong Kong Special Administrative Region of China,No.17105220(to JGS)。
文摘It has been shown clinically that continuous removal of ischemia/reperfusion-induced reactive oxygen species is not conducive to the recovery of late stroke.Indeed,previous studies have shown that excessive increases in hypochlorous acid after stroke can cause severe damage to brain tissue.Our previous studies have found that a small amount of hypochlorous acid still exists in the later stage of stroke,but its specific role and mechanism are currently unclear.To simulate stroke in vivo,a middle cerebral artery occlusion rat model was established,with an oxygen-glucose deprivation/reoxygenation model established in vitro to mimic stroke.We found that in the early stage(within 24 hours)of ischemic stroke,neutrophils produced a large amount of hypochlorous acid,while in the recovery phase(10 days after stroke),microglia were activated and produced a small amount of hypochlorous acid.Further,in acute stroke in rats,hypochlorous acid production was prevented using a hypochlorous acid scavenger,taurine,or myeloperoxidase inhibitor,4-aminobenzoic acid hydrazide.Our results showed that high levels of hypochlorous acid(200μM)induced neuronal apoptosis after oxygen/glucose deprivation/reoxygenation.However,in the recovery phase of the middle cerebral artery occlusion model,a moderate level of hypochlorous acid promoted the proliferation and differentiation of neural stem cells into neurons and astrocytes.This suggests that hypochlorous acid plays different roles at different phases of cerebral ischemia/reperfusion injury.Lower levels of hypochlorous acid(5 and 100μM)promoted nuclear translocation ofβ-catenin.By transfection of single-site mutation plasmids,we found that hypochlorous acid induced chlorination of theβ-catenin tyrosine 30 residue,which promoted nuclear translocation.Altogether,our study indicates that maintaining low levels of hypochlorous acid plays a key role in the recovery of neurological function.
基金supported by the Natural Science Foundation of Shandong Province,No.ZR2023MC168the National Natural Science Foundation of China,No.31670989the Key R&D Program of Shandong Province,No.2019GSF107037(all to CS).
文摘Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.
基金supported by the National Natural Science Foundation of China(81770692)。
文摘Objective:Acute kidney injury(AKI)is a clinical syndrome characterized by sudden deterioration of renal function,with ischemia reperfusion injury(IRI)being the most common cause.Long noncoding RNA(lncRNA)regulate cell fate through interactions with microRNA(miRNA)and messenger RNAs(mRNA),but the mechanisms and regulatory networks underlying lncRNA AK154753(AK154753)in IRI-induced AKI remain unclear.This study aims to investigate the role of AK154753 in acute renal IRI and to elucidate the molecular mechanism of the AK154753 via miR-345-3p/Bcl-2 homologous antagonist/killer(Bak)and miR-708-5p/Bcl-2 interacting mediator of cell death(Bim)axis.Methods:A bilateral renal artery ischemia model was established in mice(30 minutes ischemia followed by 24 hours and 48 hours reperfusion).Kidney tissues were analyzed using microarray-based transcriptomic sequencing to identify differentially expressed lncRNAs,miRNAs,and mRNAs.RNA levels of AK154753,miR-345-3p,miR-708-5p,Bak,and Bim were validated using real-time reverse transcription PCR(real-time RTPCR).Oxygen and glucose deprivation/reperfusion(OGD/R)models were constructed in mouse proximal renal tubular epithelial BUMPT cells to simulate in vitro IRI conditions.Adeno-associated virus(AAV)-mediated shRNA was used to silence AK154753 in vivo.Apoptosis was assessed using TUNEL staining and flow cytometry.Protein levels of Bak,Bim,and cleaved-caspase-3 were measured using Western blotting.Fluorescence in situ hybridization(FISH)was used to determine intracellular localization of AK154753.Binding relationships between AK154753 and miR-345-3p/Bak and miR-708-5p/Bim were verified using dual-luciferase reporter assays.MiRNA mimics and inhibitors were used to evaluate regulatory-network integrity.Results:IRI significantly elevated serum blood urea nitrogen(BUN)and serum creatinine(Scr),accompanied by tubular-structure damage and increased cell apoptosis(all P<0.05).Transcriptome profiling and real-time RT-PCR validation demonstrated that lncRNA AK154753,along with the pro-apoptotic proteins Bak and Bim,was significantly upregulated after IRI,whereas miR-345-3p and miR-708-5p were markedly downregulated(P<0.01).In vitro,OGD/R treatment significantly induced AK154753 expression in renal tubular epithelial cells and suppressed the expression of miR-345-3p and miR-708-5p,while markedly increasing the protein levels of Bak,Bim,and cleaved-caspase 3,resulting in a significant increase in apoptosis(all P<0.01).Silencing AK154753 significantly attenuated OGD/R-induced apoptosis,reduced the expression of Bak,Bim,and cleaved caspase 3,and decreased cell apoptosis(all P<0.01),while significantly upregulating miR-345-3p and miR-708-5p expression(P<0.01).In vivo,adeno-associated virus(AAV)-mediated knockdown of AK154753 significantly improved renal function in IRI mice,alleviated tubular injury,and suppressed renal tissue apoptosis,as evidenced by reduced BUN and Scr levels,improved histopathological injury scores,and decreased expression of Bak,Bim,and cleaved caspase-3(all P<0.01),accompanied by significant upregulation of miR-345-3p and miR-708-5p(all P<0.01).Luciferase reporter assays further confirmed that miR-345-3p directly binds to the 3'-untranslated region(3'-UTR)of AK154753 and Bak,whereas miR-708-5p directly binds to the 3'-UTRs of AK154753 and Bim.Inhibition of miR-345-3p or miR-708-5p abolished the anti-apoptotic effects induced by AK154753 silencing and restored Bak and Bim expression levels(all P<0.01).Conclusion:AK154753 is upregulated in acute renal IRI and promotes apoptosis by suppressing miR-345-3p and miR-708-5p,thereby upregulating Bak and Bim,and participates in the initiation and progression of acute renal IRI.
