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Abstract The incidence of non-alcoholic fatty liver (NAFLD) remains high, and many NAFLD patients suffer from severe ischemia-reperfusion injury (IRI). Currently, no practical approach can be used to treat IRI. Puerarin plays a vital role in treating multiple diseases, such as NAFLD, stroke, diabetes, and high blood pressure. However, its role in the IRI of the fatty liver is still unclear. We aimed to explore whether puerarin could protect the fatty liver from IRI. C57BL/6J mice were fed with a high‐fat diet (HFD) followed by ischemia reperfusion injury. We showed that hepatic IRI was more severe in the fatty liver compared with the normal liver, and puerarin could significantly protect the fatty liver against IRI and alleviate oxidative stress. The PI3K-AKT signaling pathway was activated during IRI, while liver steatosis decreased the level of activation. Puerarin significantly protected the fatty liver from IRI by reactivating the PI3K-AKT signaling pathway. However, LY294002, a PI3K-AKT inhibitor, attenuated the protective effect of puerarin. In conclusion, puerarin could significantly protect the fatty liver against IRI by activating the PI3K-AKT signaling pathway.
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Objective To investigate the potential effect and mechanism of curcumin in inhibiting synaptic injury in the cortex of rats with cerebral ischemia-reperfusion. Methods Sprague-Dawley rats were divided into sham-operated group, model group, low-dose curcumin (50 mg/kg) group, and high-dose curcumin (100 mg/kg) group. A model of middle cerebral artery occlusion for 2 hours and reperfusion for 24 hours was constructed, and curcumin was administered. Based on the neurological function score, the effects of curcumin on cerebral infarct volume, synaptic ultrastructure changes, inflammatory cell infiltration, and the expression of NLRP3, Caspase-1, Synapsin1, and CAMKⅡ were observed after the end of the animal treatment. Results The neurological function scores were 0, 3.25±0.43, 2.50±0.50, and 1.50±0.50 for the sham-operated group, model group, low-dose curcumin group, and high-dose curcumin group, respectively. The percentage of cerebral infarct volume was 0, (38.89±2.21)%, (33.48±1.77)%, and (23.69±2.19)%, respectively. Compared with the sham operation group, the model group had severe synaptic ultrastructure damage, extensive inflammatory cell infiltration, significantly increased expression of Caspase-1 and NLRP3 (P < 0.5), and significantly decreased expression of Synapsin1 and CAMKⅡ (P < 0.5). Curcumin treatment significantly inhibited synaptic damage, reduced inflammatory cell infiltration, decreased the expression of Caspase-1 and NLRP3 (P < 0.5), and increased the expression of Synapsin1 and CAMKII (P < 0.5), when compared with the model group. Conclusion Ischemia-reperfusion-mediated synaptic injury in rat brain triggers an inflammatory response in cortical nerve cells, and curcumin alleviates synaptic damage and reduces brain injury by inhibiting inflammatory factor levels.
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ObjectiveTo investigate the mechanism of modified Shenhong Tongluo prescription on cell apoptosis in rats with myocardial ischemia-reperfusion injury （MIRI）. MethodSixty Sprague-Dawley （SD） rats were randomly divided into a blank group， a model group， low-， medium-， and high-dose groups of modified Shenhong Tongluo prescription， and a simvastatin group. Except for the blank group， a rat model of MIRI was prepared by ligating the left anterior descending coronary artery. Starting from the first day after successful modeling， the blank group （1.0 mL·kg-1 physiological saline）， model group （1.0 mL·kg-1 physiological saline）， low-， medium-， and high-dose groups of modified Shenhong Tongluo prescription （1.031， 2.063， and 4.126 g·kg-1 Shenhong Tongluo prescriptiona standard concentrate）， and simvastatin group （0.71 mg·kg-1 simvastatin） were orally administered once daily for 2 weeks. Hematoxylin-eosin （HE） staining was used to observe the pathological changes of cardiomyocytes. Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of serum creatine kinase isoenzyme （CK-MB）， interleukin-6 （IL-6）， and tumor necrosis factor-α （TNF-α）. TdT-mediated dUTP nick-end labeling（TUNEL） staining was used to detect the apoptosis rate of rat cardiomyocytes. Western blot was used to detect the expression levels of apoptosis-related proteins B-cell lymphoma-2 （Bcl-2）， Bcl-2-associated X protein （Bax）， and caspase-3. ResultCompared with the blank group， in the model group， HE staining showed disturbed arrangement of cardiomyocytes， incomplete fibers， focal necrosis of cardiomyocytes， and inflammatory cell infiltration； serum CK-MB， IL-6， and TNF-α levels were significantly increased （P<0.05）； apoptosis rate of cardiomyocytes was significantly increased （P<0.01）， with significantly increased expression levels of Bax and Caspase-3 proteins， and significantly decreased Bcl-2 expression （P<0.05）. Compared with the model group， the low-， medium-， and high-dose groups of modified Shenhong Tongluo prescription significantly reduced CK-MB， IL-6， and TNF-α levels （P<0.05）， significantly downregulated cardiomyocyte apoptosis rate （P<0.05）， significantly decreased Bax and Caspase-3 proteins， and significantly increased Bcl-2 expression levels （P<0.01）. In the modified Shenhong Tongluo prescription groups， the expression levels of Bax and Caspase-3 proteins significantly decreased with increasing dosage， while the expression level of Bcl-2 significantly increased with increasing dosage of modified Shenhong Tongluo prescription （P<0.05）. ConclusionShenhong Tongluo prescription can alleviate myocardial tissue pathological damage and reduce myocardial cell apoptosis， possibly by inhibiting Caspase-3 and Bax expression and promoting Bcl-2 expression.
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Liver transplantation is the optimal treatment for end-stage liver disease and hepatocellular carcinoma, which can significantly improve clinical prognosis and quality of life of patients. However, multiple challenges, such as rejection, immune tolerance, shortage of donor liver, preservation of donor liver, ischemia-reperfusion injury and postoperative complications, <i>etc.</i>, limit the efficacy of liver transplantation in clinical practice. Research teams in China have made significant contributions to the basic research related to liver transplantation by making continuous efforts and combining the development of emerging technologies, interdisciplinary integration and other emerging fields. In this article, the frontier progress in the basic research of liver transplantation in 2023 was reviewed, highlighting the progress made by Chinese research teams in the basic research of liver transplantation, aiming to provide reference for promoting the integration of Chinese characteristics into the research of liver transplantation, accelerate the integration of Chinese liver transplantation research with international community, and promote further advancement of liver transplantation in China.
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As a mature organ transplantation, liver transplantation has become the optimal treatment for end-stage liver disease, which can improve the quality of life of recipients. However, liver transplantation still faces multiple challenges, such as rejection, infection, biliary complications, delayed graft function, ischemia-reperfusion injury, recurrence of hepatocellular carcinoma after liver transplantation, kidney-related diseases after transplantation, and donor shortage, <i>etc.</i>, which remain to be improved and urgently resolved. With persistent attempts and experience accumulated by Chinese experts and scholars, these problems related to liver transplantation have been gradually resolved year by year. In 2023, liver transplantation teams in China have achieved a series of significant progresses in the field of clinical research. In this article, clinical frontiers and novel technological progresses in the field of liver transplantation in 2023 were reviewed, and the achievements of clinical liver transplantation in China in 2023 were summarized, aiming to provide novel ideas for promoting further development of liver transplantation in China.
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Kidney transplantation has achieved significant success in treating end-stage renal disease. Nevertheless, it still faces a series of complex and significant challenges after surgery, such as infection, rejection, ischemia-reperfusion injury and chronic renal allograft dysfunction, <i>etc.</i> With the development of science and technology, including biomaterials, gene sequencing and other emerging technologies, Chinese researchers have launched a series of remarkable research in the field of kidney transplantation, aiming to solve these thorny issues. In 2023, relevant research of kidney transplantation in China not only focused on resolving the above challenges, but also highlighting on expanding novel technologies and concepts to build a brighter future of kidney transplantation. In this article, academic achievements of Chinese research teams in the field of kidney transplantation in 2023 were systematically reviewed, covering the frontiers of basic and clinical research and the application of emerging technologies, aiming to provide novel ideas and strategies for major clinical problems in the field of kidney transplantation from the local perspective and accelerate the advancement of kidney transplantation in China to a higher peak.
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<b>Objective</b> To evaluate the effect of glycogen synthase kinase 3β (GSK3β) on hypoxia/reoxygenation (H/R)-induced injury of senescent renal tubular epithelial cell (RTEC) in aged mice and its regulatory mechanism. <b>Methods</b> RTEC were divided into the Young group (young RTEC with normal growth), Old group (aged RTEC induced by Etoposide), Old+Ad-shNC+H/R group [aged RTEC induced by Etoposide and then transfected with adenovirus negative control (Ad-shNC) for H/R treatment], and Old+Ad-shGSK3β+H/R group (aged RTEC induced by Etoposide and then transfected with short-hairpin RNA-expressing adenovirus with targeted silencing GSK3β for H/R treatment), respectively. Apoptosis level and mitochondrial reactive oxygen species level were detected by flow cytometry. Calcium ion level was determined by immunofluorescence staining. The expression and phosphorylation levels of GSK3β, mitochondria-associated endoplasmic reticulum membrane (MAM)-related proteins of inositol 1,4,5-trisphosphate receptor1 (ITPR1), voltage dependent anion-selective channel 1(VDAC1) and glucose-regulated protein 75 (GRP75) were detected by Western blot. The interaction between GSK3β and MAM-related proteins was analyzed by immunoprecipitation. <b>Results</b> Compared with the Young group, the apoptosis, mitochondrial reactive oxygen species and mitochondrial calcium ion levels were higher in the Old group. Compared with the Old group, the apoptosis, mitochondrial reactive oxygen species and mitochondrial calcium ion levels were higher in the Old+Ad-shNC+H/R group. Compared with the Old+Ad-shNC+H/R group, the apoptosis, mitochondrial reactive oxygen species and mitochondrial calcium ion levels were lower in the Old+Ad-shGSK3β+H/R group, and the differences were statistically significant (all <i>P</i><0.05). Compared with the Young group, the expression levels of ITPR1, GRP75 and GSK3β proteins were up-regulated, the phosphorylation levels of ITPR1 and GRP75 were increased, whereas the total protein and phosphorylation levels of VDAC1 were decreased in the Old group. Compared with the Old group, the expression level of GSK3β protein was unchanged, the total protein and phosphorylation levels of ITPR1 and GRP75 were increased, the expression level of total VDAC1 protein remained unchanged and the phosphorylation level was increased in the Old+Ad-shNC+H/R group. Compared with the Old+Ad-shNC+H/R group, the expression level of GSK3β protein was decreased, the expression levels of total ITPR1, GRP75 and VDAC1 proteins were unchanged, whereas the phosphorylation levels were decreased in the Old+Ad-shGSK3β+H/R group. Immunoprecipitation showed that GSK3β could interact with ITPR1, GRP75 and VDAC1 proteins. <b>Conclusions</b> The expression level of GSK3β is up-regulated in senescent RTEC. Down-regulating GSK3β expression may reduce the phosphorylation level of ITPR1-GRP75-VDAC1 complex, constrain the overload of mitochondrial calcium ion, protect mitochondrial function and mitigate cell damage during reperfusion.
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Objective To investigate whether discontinuous sleep supplementation can reduce myocardial ischemia-reperfusion injury in diabetic rats aggravated by circadian rhythm disorder.Methods The rats were injected intra-peritoneal with 1％streptozotocin(STZ)30 mg/kg combined with high-fat and high-glucose diet to replicate diabetic model.Forty diabetic rats were randomly divided into four groups with 10 in each:sham surgery group(Sham group),ischemia-reperfusion group(I/R group),in which the left anterior descending coronary artery(LDA)was ligated for thirty minutes and reperfusion for 2 h,circadian rhythm disorder group(Crd group,24 h daily light and food),discontinuous sleep supplementation group(Dss group,every 3 hours of illumination and 1.5 hours break at night).We analyzed the myocardial infarct size(by 2,3,5-triphenyltetrazolium chloride stai-ning),determined serum creatine kinase-myoglobin(CK-MB)activity and cardiac troponinⅠ(cTnⅠ)concentrations;the expression level of BMAL1 and REV-ERBα was determined by Western blot.Results Compared to the sham group,the I/R group showed a significantly increased in myocardial infarct size,serum CK-MB activity and cTnⅠ concentration.The expression of the myocardial biological clock gene BMAL1 was down-regulated,while the ex-pression of REV-ERBα was up-regulated(P<0.05).Compared to the I/R group,the Crd group showed a signifi-cantly increase in myocardial infarct size,serum CK-MB activity and cTnⅠ concentration.The expression of the myocardial biological clock gene BMAL1 was down-regulated,while the expression of REV-ERBα was up-regulated(P<0.05).Compared to the Crd group,Dss group showed a significantly decrease in the myocardial infarct size,serum cTn concentration and CK-MB activity.Furthermore,there was an increased protein expression of BMAL1 and a decrease of REV-ERBα(P<0.05).Conclusions Discontinuous sleep supplementation can reduce myocardial is-chemia-reperfusion injury in diabetic rats aggravated by circadian rhythm disorder.
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Objective To analyze the role of NOD-like receptor thermal protein domain associated protein 3(NLRP3)inflammasome in a therapeutic mild hypothermia(34℃)treated isolated rat myocardial ischemia-reperfusion model and explore its mechanism.Methods Sixty clean grade adult male SD rats,aged 7-10 weeks,weighing 250-300 g.Using a random number table method,the rats were divid-ed into five groups:blank control group(group S),myocardial ischemia-reperfusion group(group IR),34℃mild hypothermia post-treated myocardial ischemia-reperfusion group(group MH),34℃mild hypother-mia post-treated myocardial ischemia-reperfusion+3-TYP group(group HT),and 34℃mild hypothermia post-treated myocardial ischemia-reperfusion+3-TYP+MCC950 group(group HTM),12 rats in each group.Group S perfused the rat heart at 37℃with a balanced perfusion solution for 180 minutes.Group IR re-ceived balanced perfusion of the rat heart at 37℃for 30 minutes,followed by ischemia for 30 minutes and reperfusion with 37℃perfusion for 120 minutes.Group MH perfused the rat heart at 37℃for 30 minutes,followed by ischemia for 30 minutes and reperfusion with 34℃perfusion solution for 120 minutes.Group HT perfused the hearts of rats at 37℃for 30 minutes,followed by ischemia for 30 minutes,silent mating type information regulation 2 homolog 3(sirt3)inhibitor 3-TYP was added to the perfusate,and then per-fused at 34℃for 120 minutes.Group HTM perfused the hearts of rats at 37℃for 30 minutes,followed by ischemia for 30 minutes,sirt3 inhibitor 3-TYP and NLRP3 inhibitor MCC950 were added to the perfusate,and then perfused at 34℃for 120 minutes.The isolated heart was obtained 120 minutes after reperfusion,and the concentrations of IL-6 and IL-1β in the perfused cardiac fluid was measured using ELISA method,Western blot method for detecting the relative content of NLRP3 and sirt3 proteins in myocardial tissue,1%triphenyl tetrazolium chloride staining for calculating myocardial infarction area,and HE staining for observ-ing myocardial pathological changes.Results Compared with group S,HR were significantly slowed down,LVSP,±dp/dtmax were significantly decreased,and LVEDP were significantly increased 30,60,90,and 120 minutes after reperfusion,the concentrations of IL-6 and IL-1β in cardiac fluid leakage,and the per-centage of myocardial infarction area were significantly increased in groups IR,MH,HT,and HTM(P＜0.05),the content of sirt3 protein in myocardial tissue were significantly reduced,while the content of NLRP3 protein were significantly increased in groups IR,HT,and HTM(P＜0.05),the contents of sirt3 and NLRP3 protein in the myocardial tissue were significantly increased in group MH(P＜0.05).Com-pared with group IR,HR were significantly increased,LVSP,±dp/dtmax were significantly increased,and LVEDP were significantly decreased 30,60,90,and 120 minutes after reperfusion,the concentrations of IL-6 and IL-1β in cardiac fluid leakage and the percentage of myocardial infarction area were significantly decreased in groups MH and HTM(P＜0.05),the content of sirt3 protein in myocardial tissue was signifi-cantly increased,while the content of NLRP3 protein was significantly decreased in group MH(P＜0.05),the content of NLRP3 protein in myocardial tissue was significantly reduced in group HTM(P＜0.05).Compared with group MH,HR were significantly slowed down,LVSP,±dp/dtmax were significantly de-creased,and LVEDP were significantly increased 30,60,90,and 120 minutes after reperfusion,the con-centrations of IL-6 and IL-1β in cardiac fluid leakage,the percentage of myocardial infarction area,and the content of NLRP3 protein in myocardial tissue were significantly increased in group HT(P＜0.05),the content of sirt3 protein in myocardial tissue was significantly reduced in groups HT and HTM(P＜0.05).Compared with group HT,HR were significantly increased,LVSP,±dp/dtmax were significantly increased,and LVEDP were significantly decreased 30,60,90,and 120 minutes after reperfusion,the concentrations of IL-6 and IL-1β in cardiac fluid leakage,the percentage of myocardial infarction area,and the content of NLRP3 protein in myocardial tissue were significantly reduced in group HTM(P＜0.05).Conclusion Therapeutic mild hypothermia(34℃)can improve hemodynamic parameters of isolated hearts and reduce the concentrations of IL-6 and IL-1β,NLRP3 protein content in myocardial tissue,percentage of myocardial infarction area,improve myocardial pathological changes,and reduce myocardial ischemia-reperfusion injury in rats,the mechanism may be related to the mitochondrial mediated sirt3 pathway inhibiting the high expres-sion of inflammatory corpuscle NLRP3.
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Objective:To explore the role and mechanism of neurotrophin-3(NT-3)in promoting neurological func-tion recovery after cerebral ischemia-reperfusion injury in rats.Methods:Twenty-four SD rats were randomly divided into sham operation group(Sham),middle cerebral artery occlusion/reperfusion(MCAO/R)group,and MCAO/R+NT-3 group.The neurological function scores of rats in each group were evaluated using the modified Garcia score.Western Blot was used to detect the expression of NT-3 and LC3B in brain tissues of rats.Culture dishes with the same density of neurons were randomly divided into normal group(Normal),oxygen-glucose deprivation(OGD)group,OGD+NT-3 group,OGD+NT-3+PF-06273340(TrkC inhibitor)group,OGD+NT-3+ZSTK474(PI3K inhibitor)group,and OGD+NT-3+CCT128930(AKT inhibitor)group.Western Blot was used to detect the expression of TrkC,the phosphorylation of PI3K/AKT,and LC3B in neurons.The morphological changes of neurons and the phenomenon of neuronal autophagy were observed using autophagy-specific fluorescent staining.Results:The animal experiment found that the expression of NT-3 increased in the brain tissue with ischemia-reperfusion injury(P＜0.05),and after the treatment with exogenous NT-3,the modified Garcia score increased(P＜0.05),and the level of autophagy weakened(P＜0.05).The cell experiment found that NT-3 can inhibit neuronal autophagy under ischemic hypoxia and maintain the neuronal morphology to the maximum extent.After using PF-06273340,the expression of p-PI3K and p-AKT de-creased(P＜0.05).After using ZSTK474 and CCT128930,the autophagy-inhibiting effect of NT-3 weakened(P＜0.05).Conclusion:NT-3 inhibits autophagy via the PI3K/AKT signaling pathway to maintain neuronal survival,thereby promoting the recovery of neurological function after cerebral ischemia-reperfusion injury in rats.
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Acute kidney injury(AKI)is a global public health problem with high morbidity,high mortality and costly treatment cost.The pathogenesis of AKI is very complex,and the treatment strategies for AKI are lim-ited,then it is very matter to explore the pathophysiological mechanism and potential therapeutic targets of acute kidney injury.N6-methyladenosine(m6A)is the most abundant and extremely conservative epigenetic modification in eukaryotic,which is a dynamic and reversible process involving in splicing,nuclear export,translation,stabil-ity,and higher structure of RNA,and regulated by three regulatory factors:methyltransferase,demethylase and methylated reading protein.Current studies have found that m6A plays an important regulatory role in AKI and can be a potential therapeutic target for AKI.In this review,we provide a brief description of m6A and summarize the impact of m6A on AKI and possible future study directions for this research.
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Objective To investigate the effects of puerarin on myocardial ischemia-reperfusion injury and its mecha-nism.Methods Molecular docking and dynamics simulation were utilized to predict the binding potential of puerarin and SIRT1.A myocardial ischemia-reperfusion model was established in SD rats by ligating the anterior descending branch of the left coronary artery.The protective effect of puerarin on myocardial injury was observed,and the therapeutic effect of puerarin was compared after inhibition of SIRT1 expression.The infarct volume was detected using 2,3,5-triphenyltetrazolium chloride(TTC)staining.The apoptosis rate and SIRT1 expression of cardiomyocytes were detected by using TUNEL combined with im-munofluorescence.Transmission electron microscope was used to observe the myocardial ultrastructure.Western blot was per-formed to detect the expression of ferroptosis-related proteins.Results Molecular docking studies confirmed the formation of stable complexes between puerarin and SIRT1.Puerarin treatment significantly increased myocardial ischemia-reperfusion injury through upregulation of SIRT1,SLC7A11 and GPX4 expression,and downregulation of IREB2 expression in rats.The protec-tive effect of puerarin on myocardium was abolished once SIRT1 protein expression was inhibited.Conclusion Molecular doc-king and molecular dynamics simulation techniques can accurately predict the interaction of puerarin,and the main target SIRT1.Puerarin inhibits ferroptosis by activating SIRT1 pathway,thereby alleviating myocardial ischemia-reperfusion injury.
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BACKGROUND:The mechanism,manifestation,prevention and treatment of ischemia-reperfusion injury have been reported in the past.However,there are few studies on the ischemia-reperfusion injury of lower limb skeletal muscle caused by total knee arthroplasty.This article focuses on the pathogenesis,clinical impact,prevention and treatment of the ischemia-reperfusion injury of lower limb caused by total knee arthroplasty. OBJECTIVE:To summarize the related literature of lower limb ischemia-reperfusion injury caused by total knee arthroplasty,analyze the mechanism and significance,and give hints for further research on skeletal muscle ischemia-reperfusion injury. METHODS:The relevant articles on PubMed,CNKI,WanFang and VIP databases published from January 1,2000 to April 30,2022 were searched by computer with the Chinese and English search terms of"ischemia-reperfusion injury,total knee arthroplasty,tourniquet,mechanism,pathophysiology,skeletal muscle,treatment".After excluding repetitive research and some basic articles with low correlation,68 articles were finally selected for review. RESULTS AND CONCLUSION:(1)The pathogenesis of ischemia-reperfusion injury is related to oxygen free radicals,intracellular calcium overload,neutrophil activation,as well as high concentration of nitric oxide,no reflow phenomenon,apoptosis and other mechanisms.More detailed mechanism research can provide basis for future prevention and treatment.(2)Ischemia-reperfusion injury of lower limbs will cause local skeletal muscle injury,which may be caused by the trauma of the operation itself or the role of ischemia-reperfusion injury.More targeted research is needed to distinguish the relationship between the two.(3)Ischemia-reperfusion injury of lower limbs may even affect the distal organs,causing kidney and lung damage.It also affects local and systemic circulation.(4)To clarify the effect of ischemia-reperfusion injury can point out the direction for future prevention and treatment.The current prevention and treatment measures mainly include ischemic preconditioning,anesthetic,antioxidant and other drug prevention.(5)The detailed review of ischemia-reperfusion injury of lower limb skeletal muscle caused by total knee arthroplasty can provide basis for future diagnosis and treatment decisions.
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BACKGROUND:Croton cream can activate ERK pathways and have anti-apoptotic effects on neuronal cells.It is not clear whether it synergistically exerts anti-apoptotic effects by inhibiting the activation of JNK and p38 pathways. OBJECTIVE:To explore the effects and mechanisms of croton cream on neuronal damage and apoptosis in the ischemic cortex of rats with cerebral ischemia-reperfusion injury. METHODS:(1)Ninety Sprague-Dawley rats were randomly divided into sham operation group,model group,croton cream low-dose group,croton cream medium-dose group,croton cream high-dose group and nimodipine group,with 15 rats in each group.Except for the sham operation group,animal models of middle cerebral artery occlusion were prepared in rats by the thread method.Rats in the three croton cream groups were given 20,40,and 60 mg/kg croton cream,respectively.Rats in the sham operation and model groups were given the same amount of normal saline,once a day,for 7 consecutive days.The optimal concentration of croton cream,namely the high dose of croton cream,was selected based on neurological deficit score,TTC staining,brain tissue water content,hematoxylin-eosin staining and Nissl staining.(2)Another 120 Sprague-Dawley rats were randomly divided into sham operation group,model group,croton cream group,JNK inhibitor group,croton cream+JNK inhibitor group,p38 MAPK inhibitor group,croton cream+p38 MAPK inhibitor group,and nimodipine group,with 15 rats in each group.Animal models of middle cerebral artery occlusion were prepared using the thread method in all the groups except in the sham operation group.Thirty minutes before modeling,10 μL of SP600125(JNK inhibitor)and 10 μL of SB203580(p38 MAPK inhibitor)were injected into the lateral ventricle of the rats,respectively.Rats in croton cream groups were intragastrically given 60 mg/kg croton cream.Seven days later,the JNK/p38 MAPK signaling pathway,apoptosis-related proteins and cell apoptosis were detected by western blot,TUNEL staining and flow cytometry,respectively. RESULTS AND CONCLUSION:(1)Compared with the sham operation group,neurological deficit score,cerebral water content,cerebral infarction volume and apoptosis rate were significantly increased in the model group(P<0.05),where nerve cells showed scattered distribution.Compared with the model group,neurological deficit score,water content of brain tissue and cerebral infarction volume were significantly decreased in the croton cream medium-dose group,high-dose group and nimodipine group(P<0.05),and the pathological morphology of nerve cells was significantly improved.(2)Compared with the JNK inhibitor group,p-JNK/JNK,p-p38/p38 and Bax expressions in rat brain tissue and the apoptotic rate were significantly decreased in the croton cream+inhibitor groups(P<0.05),while the expression of and Bcl-2 was significantly increased(P<0.05).To conclude,croton cream may inhibit the activation of JNK/p38 MAPK signaling pathway and reduce neuronal apoptosis to achieve neuroprotective effects in rats with cerebral ischemia-reperfusion injury.
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BACKGROUND:Exercise is an effective strategy to prevent and treat various cardiovascular diseases and protect the heart from ischemia-reperfusion injury.Its mechanism of action needs to be studied in depth. OBJECTIVE:To observe the effect of aerobic exercise preconditioning on myocardial ischemia-reperfusion injury and to explore the effect of endothelial nitric oxide synthase(eNOS)activation(including coupling and phosphorylation). METHODS:Eighty adult Wistar rats were randomly divided into sedentary(n=40)and exercise(n=40)groups.The rats in the exercise group were subjected to aerobic exercise for 8 weeks while those in the sedentary group were quietly fed and caged.After 8 weeks of intervention,three experiments were performed.(1)Experiment 1:After the last training,cardiac function,cardiac nitric oxide metabolite content and cardiac eNOS,phosphorylated eNOS-S1177,eNOS dimer and eNOS monomer protein expression levels were detected.(2)Experiment 2:Rats were divided into sedentary control group,exercise control group,sedentary+eNOS inhibitor group,exercise+eNOS inhibitor group,all of which were subjected to an in vitro myocardial ischemia-reperfusion injury experiment.eNOS inhibitor was continuously infused into the sedentary+eNOS inhibitor group and exercise+eNOS inhibitor group 10 minutes before reperfusion,and cardiac function and myocardial infarction area were detected 3 hours after reperfusion.(3)Experiment 3:Rats were divided into sedentary control group,exercise control group,sedentary+eNOS coupler group and exercise+eNOS coupler group,all of which were subjected to an in vitro myocardial ischemia-reperfusion injury experiment.The rats in the sedentary+eNOS coupler group and exercise+eNOS coupler group were treated with eNOS coupler.Myocardial infarct area,cardiac nitric oxide metabolite content,cardiac protein expression of eNOS,phosphorylated eNOS-S1177,eNOS dimer,eNOS monomer and 3-nitrotyrosine were detected 3 hours after reperfusion.The phosphorylated eNOS-S1177/eNOS ratio reflected the phosphorylated/dephosphorylated level of eNOS and eNOS dimer/monomer ratio reflected eNOS coupling/uncoupling level. RESULTS AND CONCLUSION:Experiment 1:Compared with the sedentary group,the exercise group had increased cardiac output and left ventricular ejection fraction(P<0.05),increased nitrite and S-nitrosothiol contents(P<0.05),upregulated phosphorylated eNOS-S1177,eNOS protein expression and phosphorylated eNOS-S1177/eNOS ratio(P<0.05),eNOS dimer protein expression and eNOS dimer/monomer ratios were elevated(P<0.05).Experiment 2:Compared with the sedentary control group,left ventricular development pressure increased(P<0.05)and myocardial infarct area decreased(P<0.05)in the exercise control group.Compared with the exercise control group,left ventricular development pressure decreased(P<0.05)and myocardial infarct area increased(P<0.05)in the exercise+eNOS inhibitor group.Experiment 3:Compared with the sedentary control group,the exercise control group had increased left ventricular developmental pressure(P<0.05),decreased myocardial infarct area(P<0.05),decreased phosphorylated eNOS-S1177/eNOS ratio(P<0.05),decreased eNOS dimer/monomer ratio(P<0.05),increased S-nitrosothiol content(P<0.05),and decreased 3-nitrotyrosine protein expression(P<0.05).Compared with the exercise control group,the exercise+eNOS coupler group had decreased left ventricular developmental pressure(P<0.05),increased myocardial infarct area(P<0.05),increased phosphorylated eNOS-S1177/eNOS ratio(P<0.05),increased eNOS dimer/monomer ratio(P<0.05),and elevated 3-nitro tyrosine protein expression(P<0.05).To conclude,aerobic exercise preconditioning could induce cardioprotection,which is related to uncoupling and dephosphorylation of eNOS during cardiac ischemia-reperfusion,thereby inhibiting the excessive production of nitric oxide and reducing nitro-oxidative stress.
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BACKGROUND:Dexmedetomidine has the effect of anti-ischemia-reperfusion injury,but the comprehensive and systematic review of its signaling pathway is less. OBJECTIVE:To focus on the review of dexmedetomidine's signaling pathway in the mechanisms of antioxidant stress,inhibition of inflammation,anti-apoptosis,autophagy,and so on. METHODS:The relevant articles on PubMed,CNKI,WanFang,and VIP databases were searched by computer with the key words"ischemia-reperfusion inquiry;dexmedetomidine;signal path;oxidative stress;inflammation;apoptosis"in Chinese and English.After excluding repetitive research and some basic articles with low correlation,57 articles were finally included for review. RESULTS AND CONCLUSION:(1)Dexmedetomidine plays an important role in organ protection through many mechanisms,such as anti-oxidative stress injury,anti-inflammation,anti-apoptosis and autophagy.This involves many pathways,including Nrf2 and its downstream protein antioxidant stress pathway,Toll-like receptor 4 family and nuclear factor-κB-related anti-inflammatory pathway,JAK2/STAT3-related anti-inflammatory pathway,and cholinergic anti-inflammatory pathway,and the cholinergic pathway is the upstream mechanism of many nuclear factor-κB signaling pathways.(2)PI3K/Akt pathway plays different roles according to its activated downstream signals,inhibiting the activation of NLRP3 inflammatory body,activating signal molecules endothelial nitric oxide synthase,mammalian target of rapamycin,and hypoxia-inducible factor 1α to play an anti-inflammatory role,and activate Bad or Bax residues to play an anti-apoptotic role,and PI3K/Akt activates glycogen synthetase kinase-3β.It can also play an anti-inflammatory and anti-apoptotic role.(3)Dexmedetomidine activates SIRT3 to mediate anti-apoptosis and inhibit endoplasmic reticulum stress to produce anti-apoptosis.(4)The detailed review of the anti-ischemia-reperfusion injury signaling pathway of dexmedetomidine can provide a basis for future mechanism research and diagnosis and treatment decisions.
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BACKGROUND:Ischemic postconditioning is one of the effective ways to reduce ischemia-reperfusion injury and has been more and more widely used in clinical practice in recent years,but its specific molecular mechanism has yet to be studied. OBJECTIVE:To investigate the role and mechanism of piRNA-005854 in the aging cardiomyocytes caused by hypoxic postconditioning. METHODS:In vitro,cardiomyocytes were administered 8 mg/mL D-galactose for 9 days to induce their aging.β-Galactosidase staining was used to observe the aging of cardiomyocytes.Senescent cells were treated with hypoxia/reoxygenation and hypoxic postconditioning.ELISA was utilized to detect changes in myocardial injury markers creatine kinase isoenzyme MB and lactate dehydrogenase levels.Western blot assay was applied to detect the expression changes of autophagy-related proteins LC3II,p62,ULK1 and phosphorylated ULK1 in aging cardiomyocytes.qRT-PCR was employed to determine the expression level of piRNA-005854.piRNA-005854 inhibitor and piRNA-005854 mimics were transferred into aging cardiomyocytes and followed with hypoxic postconditioning.Western blot assay was used to examine the expression of LC3II,p62,ULK1 and phosphorylated ULK1. RESULTS AND CONCLUSION:(1)D-galactose induced obvious senescence of cardiomyocytes 9 days later.(2)Compared with the normoxia group,creatine kinase isoenzyme MB and lactate dehydrogenase levels increased in the hypoxia/reoxygenation group(P<0.01);LC3 II/I expression was increased;p62 expression was decreased;ULK1 phosphorylation level was increased,and piRNA-005854 expression was increased(P<0.01).(3)Compared with the hypoxia/reoxygenation group,creatine kinase isoenzyme MB and lactate dehydrogenase levels significantly reduced in the hypoxic postconditioning group(P<0.01);LC3 II/I expression significantly decreased(P<0.05);p62 expression increased(P<0.01);ULK1 phosphorylation level decreased(P<0.05),and piRNA-005854 expression decreased(P<0.01).(4)After transfection of piRNA-005854 inhibitor,LC3II/I expression was decreased(P<0.01);the expression of p62 was increased significantly(P<0.05);the phosphorylation level of ULK1 was decreased significantly(P<0.01).After transfection of piRNA-005854 mimics,LC3II/I expression was increased significantly;the expression of p62 was decreased,and the phosphorylation level of ULK1 was increased significantly(P<0.01).(5)The results show that piRNA-005854-mediated reduction of ULK1-dependent autophagy level is a possible mechanism that hypoxic postconditioning exerts its protective effect on aging cardiomyocytes.
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BACKGROUND:Inflammation is one of the important factors that induce cerebral ischemia-reperfusion injury.Studies have shown that electroacupuncture can effectively reduce inflammation after ischemic stroke and improve the symptoms of neurological deficits,but the mechanism is not clear. OBJECTIVE:To observe the effect of electroacupuncture on Toll-like receptor 4/nuclear factor-κB in rats with cerebral ischemia-reperfusion injury. METHODS:Forty-eight male Sprague-Dawley rats were randomly divided into sham operation group,model group and electroacupuncture group,with 16 rats in each group.The rat model of cerebral ischemia-reperfusion injury was prepared by middle cerebral artery occlusion.At 24 hours after modeling,the rats in the electroacupuncture group were treated with electroacupuncture,once a day,20 minutes each time,for a total of 5 days.The sham operation group and the model group did not do any intervention.After 5 days of intervention,Longa method was used to evaluate the degree of neurological injury in rats.Triphenyl tetrazolium chloride staining and hematoxylin-eosin staining were used to measure the volume of cerebral infarction and the pathological changes of brain tissue in rats.Serum interleukin-6,interleukin-18 and tumor necrosis factor-α were detected by ELISA.Expressions of Toll-like receptor 4 and nuclear factor-κB in the cerebral cortex at mRNA and protein levels were detected by fluorescence quantitative PCR and western blot,respectively. RESULTS AND CONCLUSION:Compared with the sham operation group,the neurological function scores,serum interleukin-6,interleukin-18,and tumor necrosis factor-α levels,Toll-like receptor 4 and nuclear factor-κB mRNA and protein expression levels were significantly higher in the model group(P＜0.01).Compared with the model group,electroacupuncture significantly reduced the neurological function scores,serum interleukin-6,interleukin-18,and tumor necrosis factor-α levels,Toll-like receptor 4 and nuclear factor-κB mRNA and protein expression levels(P＜0.05,P＜0.01).Compared with the sham operation group,the volume of cerebral infarction in the model group increased significantly(P＜0.01).Compared with the model group,the volume of cerebral infarction in the electroacupuncture group decreased(P＜0.05).In the model group,the arrangement of neurons was disordered,some nerve cells disappeared,nuclei presented with pyknosis and incomplete structure.After electroacupuncture intervention,the degree of neuronal degeneration and neuronal loss in the cerebral cortex of rats were reduced compared with those in the model group.To conclude,electroacupuncture can significantly improve the neurobehavior of rats with cerebral ischemia-reperfusion injury,reduce brain tissue injury,and effectively reduce the level of serum inflammatory factors.The mechanism may be related to the inhibition of Toll-like receptor 4/nuclear factor-κB signaling pathway.
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BACKGROUND:Conductive biomaterials are considered potential candidates for transmitting electrical signals for myocardial repair.Combining cell-based or cell-free strategies with conductive biomaterials to replenish cardiomyocytes and/or restore electrical signaling pathways is a promising approach for cardiac repair. OBJECTIVE:To evaluate the effect of polypyrrole-chitosan conductive composite hydrogel on cardiac function in rats with myocardial ischemia-reperfusion injury. METHODS:The polypyrrole-chitosan conductive composite hydrogel was prepared by chemical oxidative polymerization.The micromorphology,biocompatibility and conductivity of the hydrogels were characterized.Thirty adult SD rats were selected to establish a myocardial ischemia-reperfusion injury model by clamping the left anterior descending branch of the heart and then releasing it.After 21 days of modeling,the rats were divided into three groups by the random number table method:Normal saline was injected into the left ventricular infarction area and infarction margin area in the blank group.Chitosan hydrogel was injected into the left ventricular infarction area and infarction margin area in the ordinary hydrogel group.The polypyrrole-chitosan conductive composite hydrogel was injected into the left ventricular infarction area and infarction margin area,with 10 rats in each group.The corresponding time points after modeling were set,and cardiac mechanical function(echocardiogram,pressure-volume analysis),cardiac electrophysiology(electrocardiogram,programmed electrical stimulation,optical mapping technology,microelectrode array technology,eight-lead electrocardiogram,and electrical resistivity of the scar area)and cardiac histology were detected. RESULTS AND CONCLUSION:(1)There were a lot of pores on the surface of the conductive composite hydrogel,and the conductivity was(3.19±0.03)×10-3 mS/cm,which had good biocompatibility co-cultured with smooth muscle cells.(2)After 105 days of modeling,echocardiogram and pressure-volume analysis showed that compared with the blank group and the ordinary hydrogel group,the conductive composite hydrogel could significantly improve the contractile function of the heart of rats with myocardial ischemia-reperfusion injury.The results of electrocardiogram,programmed electrical stimulation,optical mapping technology,microelectrode array technology,eight-lead electrocardiogram,and electrical resistivity of the scar area examination at 105 days after modeling displayed that,compared with the blank group and the ordinary hydrogel group,the conductive composite hydrogel could significantly improve the electrical conduction function of the heart of rats with myocardial ischemia-reperfusion injury and reduce the occurrence of arrhythmia.Masson staining of heart tissue at 105 days after modeling exhibited that there were different degrees of fibrosis in the myocardial infarction area of the three groups.Compared with the normal saline group and the ordinary hydrogel group,the conductive hydrogel group had more normal myocardial tissue and less fibrosis in the myocardial infarction area.(3)The results verify that polypyrrole-chitosan conductive composite hydrogel may promote the repair of infarcted heart after ischemia-reperfusion injury by increasing the electrical conduction velocity of infarct scar area tissue,increasing scar thickness,enhancing synchronous cardiac contraction,and reducing damaged tissue.
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BACKGROUND:Pretreatment with moxibustion is a preventive treatment in traditional Chinese medicine.Pretreatment with moxibustion at the onset of prodromal symptoms can significantly reduce the symptoms and delay the onset of many diseases,but the exact mechanism remains to be studied. OBJECTIVE:To investigate the mechanism of SIRT1/FoxO3 pathway in moxibustion pretreatment to ameliorate oxidative stress injury in cerebral ischemia-reperfusion model rats. METHODS:Forty-eight Sprague-Dawley rats were randomly divided into sham-operated group,model group,moxibustion pretreatment group,and moxibustion pretreatment+EX527(SIRT1 inhibitor)group,with 12 rats in each group.The moxibustion pretreatment group was given moxibustion with seed-sized moxa cone at Baihui,Dazhui,and Zusanli before modeling,three moxa-cones per acupoint,once a day for 7 days.In the model group,moxibustion pretreatment group and moxibustion pretreatment+EX527 group,the rat model of middle cerebral artery occlusion was made by suturing of the middle cerebral artery 30 minutes after the last moxibustion.After 2 hours of cerebral ischemia,the middle artery suture was removed and the rats were reperfused for 12 hours.In the sham-operated group,only the common carotid artery,internal carotid artery,and external carotid artery were dissected without suturing the middle cerebral artery.In the moxibustion pretreatment+EX527 group,EX527(15 mg/kg)was given intraperitoneally 30 minutes before each moxibustion.After 12 hours of reperfusion,the rats were scored for neurological deficits,and the cerebral infarct volume was calculated by 2,3,5-triphenyltetrazolium chloride staining method.The levels of oxidative stress factors in the infarcted tissues were detected by the kit method,and western-blot method was used to detect the expression levels of SIRT1,FoxO3,p-FoxO3 and brain-derived neurotrophic factor in the ischemic area of the cerebral cortex. RESULTS AND CONCLUSION:After 12 hours of reperfusion,the neurobehavioral score in the model group was significantly higher than that in the sham-operated group(P＜0.01),while the score in the moxibustion pretreatment group was significantly lower than that in the model group(P＜0.01)and moxibustion pretreatment+EX527 group(P＜0.05).There were no obvious infarct foci in the brain tissue of the sham-operated rats,but obvious ischemic foci were observed in the right side of the brain tissue of the rats in the model group(P＜0.01).The right infarct volume in the moxibustion pretreatment group was significantly reduced compared with the model group(P＜0.01),while the right infarct volume in the moxibustion pretreatment+EX527 group was significantly enlarged compared with the moxibustion pretreatment group.After 12 hours of reperfusion,the level of malondialdehyde was significantly elevated(P＜0.01)and the expression of superoxide dismutase was significantly decreased(P＜0.01)in the model group compared with the sham-operated group.The levels of malondialdehyde was significantly decreased(P＜0.01,P＜0.05)and the expression of superoxide dismutase was significantly increased(P＜0.01,P＜0.05)in the moxibustion pretreatment group compared with the model group and the moxibustion pretreatment+EX527 group.Western blot results showed that the expression levels of SIRT1,FoxO3,p-FoxO3,and brain-derived neurotrophic factor proteins were significantly higher in the model group compared with the sham-operated group(P＜0.01);compared with the model group,the expression levels of SIRT1,FoxO3,and brain-derived neurotrophic factor were significantly higher in the moxibustion pretreatment group(P＜0.01),and p-FoxO3 expression was significantly lower(P＜0.01);compared with the moxibustion pretreatment+EX527 group,the expression levels of SIRT1,FoxO3,and brain-derived neurotrophic factor were elevated in the moxibustion pretreatment group(P＜0.05),and no statistically significant difference was found in the p-FoxO3 expression(P＞0.05).To conclude,moxibustion pretreatment can significantly improve neurological function in rats after cerebral ischemia-reperfusion,and the mechanism may be related to the activation of SIRT1/FoxO3 pathway to reduce oxidative stress injury in the rat model of cerebral ischemia-reperfusion.