Puerarin protects the fatty liver from ischemia-reperfusion injury by regulating the PI3K/AKT signaling pathway

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.

Breviscapine alleviates myocardial ischemia-reperfusion injury in diabetes rats

Purpose: To investigate the protective effect of breviscapine on myocardial ischemia-reperfusion injury (MIRI) in diabetes rats. Methods: Forty rats were divided into control, diabetes, MIRI of diabetes, and treatment groups. The MIRI of diabetes model was established in the latter two groups. Then, the treatment group was treated with 100 mg/kg breviscapine by intraperitoneal injection for 14 consecutive days. Results: After treatment, compared with MIRI of diabetes group, in treatment group the serum fasting blood glucose, fasting insulin, homeostasis model assessment of insulin resistance, and glycosylated hemoglobin levels decreased, the serum total cholesterol, triacylglycerol, and low-density lipoprotein cholesterol levels decreased, the serum high-density lipoprotein cholesterol level increased, the heart rate decreased, the mean arterial pressure, left ventricular ejection fraction, and fractional shortening increased, the serum cardiac troponin I, and creatine kinase-MB levels decreased, the myocardial tumor necrosis factor α and interleukin-6 levels decreased, the myocardial superoxide dismutase level increased, and the myocardial malondialdehyde level decreased (all P < 0.05). Conclusions: For treating MIRI of diabetes in rats, the breviscapine can reduce the blood glucose and lipid levels, improve the cardiac function, reduce the myocardial injury, and decrease the inflammatory response and oxidative stress, thus exerting the alleviating effect.

Identification of potential crucial cuproptosis-related genes in myocardial ischemia-reperfusion injury through the bioinformatic analysis

Abstract Background: Cuproptosis is known to regulate diverse physiological functions in many diseases, but its role in regulating Myocardial Ischemia-Reperfusion Injury (MI/RI) remains unclear. Methods: For this purpose, the MI/RI microarray datasets GSE61592 were downloaded from the Gene Expression Omnibus (GEO) database, and the Differently Expressed Genes (DEGs) in MI/RI were identified using R software. Moreover, the MI/RI mice model was established to confirm further the diagnostic value of Pyruvate Dehydrogenase B (Pdhb), Dihydrolipoamide S-acetyltransferase (Dlat), and Pyruvate dehydrogenase E1 subunit alpha 1 (Pdhα1). Results: The analysis of microarray datasets GSE61592 revealed that 798 genes were upregulated and 768 were downregulated in the myocardial tissue of the ischemia-reperfusion injury mice. Furthermore, Dlat, Pdhb, Pdhα1, and cuproptosis-related genes belonged to the downregulated genes. The receiver operating characteristics curve analysis results indicated that the Dlat, Pdhb, and Pdhα1 levels were downregulated in MI/RI and were found to be potential biomarkers for MI/RI diagnosis and prognosis. Similarly, analysis of Dlat, Pdhb, and Pdhα1 levels in the MI/RI mice revealed Pdhb being the key diagnostic marker. Conclusions: This study demonstrated the prognostic value of cuproptosis-related genes (Dlat, Pdhb, and Pdhα1), especially Pdhb, MI/RI, providing new insight into the MI/RI treatment.

Protective effect of extracorporeal cardiac shock wave combined with ultrasound microbubble post-conditioning on myocardial ischemia-reperfusion injury in rats / 中华超声影像学杂志

Objective:To investigate the myocardial protective effect of extracorporeal cardiac shock wave therapy (CSWT) combined with sulfur hexafluoride microbubble post-conditioning on myocardial ischemia-reperfusion injury (MI/RI) in rats, and to provide theoretical support for clinical treatment of MI/RI.Methods:A total of 32 male SD rats were randomly divided into 4 groups: sham operation group (Sham group), MI/RI group (IR group), CSWT group (IR+ SW group), and CSWT combined with sulfur hexafluoride microbubble treatment group (IR+ SW+ MB group), with 8 rats in each group. Therapeutic intervention was performed in IR+ SW group and IR+ SW+ MB group on the 1st, 3rd and 5th day after modeling. The left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) of the rats were measured by echocardiography before and after treatment. On the 7th day, myocardial fibrosis was assessed by Masson staining, and cardiomyocyte apoptosis was observed by TUNEL staining. The myocardial apoptotic proteins Bcl-2, BAX, Cleaved-Caspase-3 and Cleaved-Caspase-9 in the infarct boundary area were detected by Western blot. The differences of the above indexes among different groups were compared.Results:①There was no significant change in heart rhythm and heart rate among the groups before and after treatment, and there was no significant difference in heart rate ( P>0.05). ②The echocardiographic results after treatment showed that, compared with IR group, LVEDD and LVESD in IR+ SW group and IR+ SW+ MB group decreased in turn, while LVEF and LVFS increased in turn with significant differences between each two groups (all P<0.05). ③Compared with IR group, the degrees of myocardial fibrosis and apoptosis in IR+ SW group and IR+ SW+ MB group were alleviated in turn, and the relief in IR+ SW+ MB group was the most obvious. Quantitative analysis showed that compared with IR group, the proportions of cardiomyocyte apoptosis in IR+ SW group and IR+ SW+ MB group decreased in turn, and there were significant differences between each two groups (all P<0.05). ④The results of Western blot detection showed that compared with IR group, the levels of Bcl-2 in IR+ SW group and IR+ SW+ MB group increased in turn, while the levels of BAX and the activation level of Caspase-3 and Caspase-9 protein decreased in turn. These differences were all statistically significant between each two groups (all P<0.05) except for the activation level of Caspase-3 protein between IR+ SW group and IR+ SW+ MB group ( P>0.05). Conclusions:CSWT combined with sulfur hexafluoride microbubble therapy can improve left ventricular remodeling and left ventricular systolic function by inhibiting cardiomyocyte apoptosis.

Effects of Buyang Huanwu Decoction on mitochondrial oxidative damage and PKCε-Nampt pathway in rats following cerebral ischemia-reperfusion / 中成药

AIM To explore the effects of Buyang Huanwu Decoction on mitochondrial oxidative damage and PKCε-Nampt pathway in rats following cerebral ischemia reperfusion(I/R).METHODS The rats were randomly divided into the sham operation group,the model group,Buyang Huanwu Decoction group(14.3 g/kg)and edaravone group(3 mg/kg).Except those of the sham operation group,SD rats of other groups were induced into models of brain I/R injury by MCAO method,followed by corresponding drug administration 24 hours after operation.After 7 days of administration,the rats had their neurological deficit evaluated by neurological function scoring;thier expression of neuron marker MAP-2 detected by immunofluorescence staining;their neuron damage observed and the oxidative damage evaluated through assessment of their ROS levels and MDA and SOD activities;their changes of mitochondrial membrane potential detected by fluorescent probe JC-1;their ratio of NAD+/NADH detected using modified enzyme circulation method;their expressions of PKCε,p-PKCε and Nampt proteins detected with Western blot;and their positive expressions of p-PKCε and Nampt proteins detected with immunohistochemistry method.RESULTS Compared with the model group,Buyang Huanwu Decoction group shared decreased cerebral infarction volume and neurological function score(P<0.05);increased cerebral fluorescence intensity of MAP-2(P<0.05);reduced neuronal damage,decreased cerebral levels of ROS and MDA(P<0.05);increased SOD activity,mitochondrial membrane potential and NAD+/NADH ratio(P<0.05);and increased protein expressions of p-PKCε and Nampt(P<0.05).CONCLUSION Buyang Huanwu Decoction can improve mitochondrial function and reduce brain I/R injury in rats by activating their PKCε-Nampt signaling pathway.

Effects of Zhuangyao Shuanglu Tongnao Formula on neuronal apoptosis of rats with ischemia-reperfusion induced injury / 中成药

AIM To investigate the effects of Zhuangyao Shuanglu Tongnao Formula on neuronal apoptosis in rats with cerebral ischemia-reperfusion injury based on the study of oxidative stress and inflammatory response.METHODS The rats were randomly divided into the sham operation group,the model group,the edaravone group(3.0 mg/kg),the low,medium and high dose groups(9.0,18.0,36.0 g/kg)of Zhuangyao Shuanglu Tongnao Formula,with 18 rats in each group.The middle cerebral artery occlusion/reperfusion was conducted by thread embolism method to simulate cerebral ischemia reperfusion injury in rats followed by 6 days corresponding drugs administration.Subsequently,the rats had their neurological function deficit scored by Zeal Longa scoring method;their sizes of cerebral infarction areas measured by TTC staining;their pathological damage and apoptosis of neurons in hippocampal CA1 area of ischemic penumbra of the brain tissue detected by HE staining and TUNEL staining;their SOD activity and levels of GSH,MDA,IL-6,IL-1β,TNF-α in brain tissue detected by kits;and their protein expressions of Bax,Bcl-2,caspase-3,cleaved-capase-3,TLR4,NF-κB p65,Nrf2,HO-1 in rat brain tissue determined by Western blot.RESULTS Compared with the model group,the groups intervened with edaravone,medium and high dose of Zhuangyao Shuanglu Tongnao Formula displayed improvements in the scores of nerve function defects,the rate of cerebral infarction,the rate of neuronal apoptosis,the levels of IL-6,IL-1β,TNF-α and MDA in the ischemic penumbra of brain tissues,the protein expressions of Bax and TLR4,the ratio of cleaved-capase-3/caspase-3 and p-NF-κB p65/NF-κB p65(P＜0.05),the levels of GSH,the activity of SOD and the protein expressions of Bcl-2,Nrf2 and HO-1(P＜0.05).CONCLUSION Being an inhibitor of oxidative stress and inflammatory response,Zhuangyao Shuanglu Tongnao Formula can alleviate brain injury in rats with cerebral ischemia reperfusion injury through the inhibition of neuronal apoptosis and improvement of neural function mediated by the inhibition of TLR4/NF-κB signal pathway and activation of Nrf2/HO-1 signal pathway.

Effect of Modified Shenhong Tongluo Prescription on Cell Apoptosis in Rats with Myocardial Ischemia-reperfusion Injury by Bcl-2/Bax/Caspase-3 Signaling Pathway / 中国实验方剂学杂志

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.

Summary of basic research on liver transplantation in China of 2023 / 器官移植

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.

Highlights of clinical research on liver transplantation in China of 2023 / 器官移植

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.

Research progress on domestic kidney transplantation of 2023 / 器官移植

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.

Down-regulating GSK3β alleviates hypoxia/reoxygenation-induced injury of senescent renal tubular epithelial cells by inhibiting the function of ITPR1-GRP75-VDAC1 complex / 器官移植

<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.

Neurotrophin-3 promotes the recovery of neurological function after cerebral ischemia-reperfusion injury in rats / 神经解剖学杂志

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.

Ischemia-reperfusion injury in total knee arthroplasty / 中国组织工程研究

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.

Effects of croton cream on JNK/p38 MAPK signaling pathway and neuronal apoptosis in cerebral ischemia-reperfusion injury rats / 中国组织工程研究

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.

Role of endothelial nitric oxide synthase in exercise preconditioning-induced improvement of myocardial ischemia-reperfusion injury / 中国组织工程研究

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.

Signaling pathway of dexmedetomidine against ischemia-reperfusion injury / 中国组织工程研究

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.

Hypoxic postconditioning protects myocardium by regulating autophagy in aging cardiomyocytes through piRNA-005854 / 中国组织工程研究

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.

Electroacupuncture reduces inflammatory factor expression by suppressing Toll-like receptor 4/nuclear factor-kappa B signaling in rats with cerebral ischemia-reperfusion injury / 中国组织工程研究

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.

Polypyrrole-chitosan conductive composite hydrogel promotes recovery of cardiac function after ischemia-reperfusion injury / 中国组织工程研究

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.

Improving the strategy of mesenchymal stem cells in treatment of flap ischemia-reperfusion injury / 中国组织工程研究

BACKGROUND:Mesenchymal stem cells have great potential in the treatment of ischemia-reperfusion injury of skin flaps.However,their defects and the decline of their role in the treatment of ischemia-reperfusion injury of skin flaps restrict their wide application. OBJECTIVE:To review the strategies for improving the treatment of ischemia-reperfusion injury of skin flaps with mesenchymal stem cells,and provide a reference for its further theoretical research and clinical application. METHODS:Relevant documents included in CNKI,WanFang and PubMed were searched.The Chinese and English search terms were"mesenchymal stem cell,ischemia-reperfusion adjustment of skin flap,mesenchymal stem cells,stem cells,skin flap,ischemia-reperfusion injury,pretreatment,gene modification,biomaterial packaging,joint application".The relevant documents since 2007 were retrieved,and the documents with little relationship between the research content and the article theme,poor quality and outdated content were eliminated through reading the article,and finally 75 documents were included for summary. RESULTS AND CONCLUSION:(1)Mesenchymal stem cells can inhibit inflammatory reactions,resist oxidative stress and induce angiogenesis,which has great potential in the treatment of skin flap ischemia-reperfusion injury.(2)Although mesenchymal stem cells have shown great potential in the treatment of skin flap ischemia-reperfusion injury,their shortcomings in treatment have limited their widespread clinical application.Through pre-treatment(cytokines,hypoxia,drugs,and other pre-treatment mesenchymal stem cells),gene-modified mesenchymal stem cells,biomaterial encapsulation of mesenchymal stem cells,as well as the combined use of mesenchymal stem cells and other drugs or therapeutic methods,can not only overcome the shortcomings of mesenchymal stem cells in treatment,but also improve their therapeutic effectiveness in skin flap ischemia-reperfusion injury.(3)Therefore,further improving the effectiveness of mesenchymal stem cells in treating skin flap ischemia-reperfusion injury and exploring its therapeutic potential are of great significance for the research of mesenchymal stem cells and the treatment of skin flap ischemia-reperfusion injury.