Gamma-aminobutyric acid enhances miR-21-5p loading into adipose-derived stem cell extracellular vesicles to alleviate myocardial ischemia-reperfusion injury via TXNIP regulation

BACKGROUND Myocardial ischemia-reperfusion injury(MIRI)poses a prevalent challenge in current reperfusion therapies,with an absence of efficacious interventions to address the underlying causes.AIM To investigate whether the extracellular vesicles(EVs)secreted by adipose mesenchymal stem cells(ADSCs)derived from subcutaneous inguinal adipose tissue(IAT)underγ-aminobutyric acid(GABA)induction(GABA-EVs^(IAT))demonstrate a more pronounced inhibitory effect on mitochondrial oxidative stress and elucidate the underlying mechanisms.METHODS We investigated the potential protective effects of EVs derived from mouse ADSCs pretreated with GABA.We assessed cardiomyocyte injury using terminal deoxynucleotidyl transferase dUTP nick end-labeling and Annexin V/propidium iodide assays.The integrity of cardiomyocyte mitochondria morphology was assessed using electron microscopy across various intervention backgrounds.To explore the functional RNA diversity between EVs^(IAT)and GABA-EVs^(IAT),we employed microRNA(miR)sequencing.Through a dual-luciferase reporter assay,we confirmed the molecular mechanism by which EVs mediate thioredoxin-interacting protein(TXNIP).Western blotting and immunofluorescence were conducted to determine how TXNIP is involved in mediation of oxidative stress and mitochondrial dysfunction.RESULTS Our study demonstrates that,under the influence of GABA,ADSCs exhibit an increased capacity to encapsulate a higher abundance of miR-21-5p within EVs.Consequently,this leads to a more pronounced inhibitory effect on mitochondrial oxidative stress compared to EVs from ADSCs without GABA intervention,ultimately resulting in myocardial protection.On a molecular mechanism level,EVs regulate the expression of TXNIP and mitigating excessive oxidative stress in mitochondria during MIRI process to rescue cardiomyocytes.CONCLUSION Administration of GABA leads to the specific loading of miR-21-5p into EVs by ADSCs,thereby regulating the expression of TXNIP.The EVs derived from ADSCs treated with GABA effectively ameliorates mitochondrial oxidative stress and mitigates cardiomyocytes damage in the pathological process of MIRI.

Protective Effect of Naringenin on Acute Myocardial Ischemia-reperfusion Injury in Rats

[Objectives]To investigate the protective mechanism of naringenin on acute myocardial ischemia-reperfusion injury(AMI-RI)in Sprague-Dawley(SD)rats.[Methods]A total of 32 SD rats with AMI-RI model construction were randomly divided into AMI-RI model control group and citrus pigment A/B/C groups(n=8).The naringenin A,B,and C groups were administrated 20,40 and 80 mg/(kg•d)for 10 d.The AMI group served as the negative control and was not treated.At the conclusion of the treatment regimen,a sample of intraventricular blood was collected for the purpose of measuring lactate dehydrogenase(LDH),glutathione peroxidase(GLH-PX),nitric oxide(NO),and superoxide dismutase(SOD)levels.Additionally,myocardial tissue was identified within the ischemic region.The content of malondialdehyde(MDA)was determined by inducing nitric oxide synthase(iNOS)and endodermal nitric oxide synthase(eNOS)positive cells in the left anterior descending coronary artery.[Results]Following citrus treatment,the contents of GLH-PX and SOD in ventricular blood of the citrus B group were found to be significantly elevated,while the contents of NO and LDH in myocardial MDA and ventricle were observed to be significantly reduced.The number of eNOS-positive cells was significantly increased,while the number of iNOS-positive cells was significantly decreased.The difference was statistically significant when compared with the AMI-RI group(P<0.05).The changes observed in the above indicators in the citrus C group were more pronounced than those observed in the citrus B group.The difference between the citrus C and the B group was statistically significant(P<0.05),indicating that this effect is concentration dependent.[Conclusions]In addition to its ability to inhibit myocardial lipid peroxidation during AMI-RI by increasing SOD activity,naringenin may also affect the synthesis and release of NO by regulating eNOS and iNOS,thereby achieving protection against AMI-RI.One effect is enhanced as the dose of the drug increases.

Preliminary study on the protective effect of electroacupuncture Neiguan acupoint pretreatment on rats with myocardial ischemia-reperfusion injury:role of the miR-214-3p/NCX1 axis

Background:Ischemia-reperfusion can worsen myocardial damage and increase the risk of death.Studies have revealed that ischemic preconditioning provides the best endogenous protection against myocardial ischemia-reperfusion injury(MIRI),and the principle of electroacupuncture(EA)preconditioning is comparable to that of myocardial ischemic preconditioning adaption.Our earlier research demonstrated that EA pretreatment inhibits the expression of calmodulin-dependent protein kinase IIδ(CaMKIIδ),sodium/calcium exchanger 1(NCX1),and cyclophilin D,hence providing protection against MIRI.However,the exact mechanism is still unknown.The expression of NCX1 mRNA is directly regulated by microRNA-214(miR-214).Moreover,it suppresses the levels of CaMKIIδand cyclophilin D.Whether these variables contribute to EA preconditioning to improve MIRI needs to be investigated,though.This study aimed to preliminarily determine whether EA pretreatment ameliorates MIRI by modulating the miR-214-3p/NCX1 axis.Methods:We used a rat MIRI model to investigate the effect of EA pretreatment on MIRI and the expression of miR-214-3p.In addition,adenovirus injection inhibited miR-214-3p expression in the rat MIRI model,and the influence of EA pretreatment towards MIRI was observed in the context of blocked miR-214-3p expression.Both the myocardial histological abnormalities and the alterations in the ST segment of the rat electrocardiogram were analyzed.NCX1 mRNA,cyclophilin D,and CaMKIIδexpression levels were also analyzed.Results:EA pretreatment improved MIRI.In rats with MIRI,EA administration increased miR-214-3p expression while decreasing NCX1 mRNA,cyclophilin D,and CaMKIIδproteins in cardiac tissues.The beneficial effect of EA pretreatment against MIRI was reversed,coupled with elevated levels of NCX1 mRNA,cyclophilin D,and CaMKIIδprotein expression,when an adenovirus injection disrupted the expression of miR-214-3p.Conclusions:Our findings preliminarily show that EA pretreatment inhibits the expression of NCX1 mRNA,cyclophilin D,and CaMKIIδproteins via miR-214-3p,hence exerting MIRI protection.

Liqi Huoxue dripping pill protects against myocardial ischemia-reperfusion injury via the PI3K/Akt/GSK-3β signaling pathway in rats

Background:Liqi Huoxue dripping pill(LQHXDP),a traditional Chinese drug for coronary heart disease,has a protective effect on the heart of rats with myocardial ischemia-reperfusion injury(MIRI)in previous studies;however,its mechanism of action remains unclear.The purpose of this study was to investigate the protective mechanism of LQHXDP on MIRI in rats and its relationship with the PI3K/Akt signaling pathway.Methods:In this study,Sprague-Dawley rats were pre-infused with LQHXDP(175 mg/kg/d)for 10 days.PI3K inhibitor LY294002(0.3 mg/kg)was intravenously injected 15 minutes before ischemia.The rat model of MIRI was established by ligating the left anterior descending coronary artery.Subsequently,cardiac hemodynamics,serum myocardial injury markers,inflammatory factors,myocardial infarct size,antioxidant indexes,myocardial histopathology,and phosphorylation levels of key proteins of PI3K/Akt signaling pathway were assessed in rats.Results:LQHXDP was found to improve cardiac hemodynamic indexes,reduce serum creatine kinase MB isoenzyme activity and cardiac troponin and heart-type fatty acid binding protein levels,lower serum interleukin-1 beta,interleukin-6 and tumour necrosis factorαlevels,reduce the myocardial infarct size and enhance the antioxidant capacity of myocardial tissue in MIRI rats.Pathological analysis revealed that LQHXDP attenuated the extent of myocardial injury and protected mitochondria from damage in MIRI rats.Immunoblot analysis revealed that LQHXDP increased the expression levels of p-Akt and p-GSK-3βin MIRI rat cardiomyocytes.PI3K inhibitor LY294002 could impair these effects of LQHXDP.Conclusion:LQHXDP attenuated myocardial injury,attenuated oxidative stress injury and reduced inflammatory response in MIRI rats,and its protective effects were mediated by activating of PI3K/Akt/GSK-3βsignaling pathway.

Improved methodology for efficient establishment of the myocardial ischemia-reperfusion model in pigs through the median thoracic incision

To investigate the feasibility and effectiveness of establishing porcine ischemia-reperfusion models by ligating the left anterior descending(LAD)coronary artery,we first randomly divided 16 male Bama pigs into a sham group and a model group.After anesthesia,we separated the arteries and veins.Subsequently,we rapidly located the LAD coronary artery at the beginning of its first diagonal branch through a mid-chest incision.Then,we loosened and released the ligation line after five minutes of pre-occlusion.Finally,we ligated the LAD coronary artery in situ two minutes later and loosened the ligature 60 min after ischemia.Compared with the sham group,electrocardiogram showed multiple continuous lead ST-segment elevations,and ultrasound cardiogram showed significantly lower ejection fraction and left ventricular fractional shortening at one hour and seven days post-operation in the model group.Twenty-four hours after the operation,cardiac troponin T and creatine kinase-MB isoenzyme levels significantly increased in the model group,compared with the sham group.Hematoxylin and eosin staining showed the presence of many inflammatory cells infiltrating the interstitium of the myocardium in the model group but not in the sham group.Masson staining revealed a significant increase in infarct size in the ischemia/reperfusion group.All eight pigs in the model group recovered with normal sinus heart rates,and the survival rate was 100%.In conclusion,the method can provide an accurate and stable large animal model for preclinical research on ischemia/reperfusion with a high success rate and homogeneity of the myocardial infarction area.

Effect of salvianolic acid B-loaded mesoporous silica nanoparticles on myocardial ischemia-reperfusion injury

Background:Currently,no drugs can specifically improve clinical cardiac ischemia-reperfusion injury or the prognosis of hemodialysis.Salvianolic acid B(SalB)is a widely used cardiac protectant;however,its clinical application is limited by its low oral bioavailability and poor intestinal absorption.The exploration of its preparation and clinical applications has become a research hotspot in recent years.Methods:To determine whether mesoporous silica nanoparticles(MSNs)efficiently delivered SalB to the heart and SalB@MSNs-RhB reduced myocardial ischemia-reperfusion injury,we constructed a myocardial ischemia-reperfusion male rat model,hypoxia/reoxygenation cardiomyocytes,and treated them with SalB@MSNs-RhB.Results:SalB@MSNs-RhB showed improved bioavailability,therapeutic effect,heightened JAK2/STAT3-dependent pro-survival signaling,and antioxidant responses,thereby protecting cardiomyocytes from ischemia-reperfusion injury-induced oxidative stress and apoptosis.Conclusion:This use of SalB-loaded nanoparticles and investigation of their mechanism of action may provide a new strategy for treating cardiomyocytes.Thus,hypoxia/reoxygenation promotes the clinical application of SalB.

Atorvastatin Alleviates Myocardial Ischemia-Reperfusion Injury via miR-26a-5p/FOXO1

Purpose: Ischemia-reperfusion (I/R) injury exacerbates myocardial cell death (including apoptosis and necrosis), leading to complications such as arrhythmias, myocardial stenosis, microvascular obstruction and heart failure, and it is particularly important to seek new strategies to mitigate reperfusion injury. In this paper, we will investigate whether atorvastatin can alleviate myocardial ischemia-reperfusion injury and verify its molecular mechanism. Methods: We successfully constructed a hypoxia-reperfusion (H/R) H9c2 cell model and transfected miR-26a-5p mimic, miR-26a-5p inhibitor and its negative control NC-mimic or NC-inhibitor into H9c2 cells using a transfection kit. The expression of miR-26a-5p and FOXO1 were detected by RT-qPCR assay, the expression of related proteins by Western blot assay, the cell viability of H9c2 cells by CCK-8 assay, the apoptosis rate of H9c2 cells by flow cytometry, the CK and LDH activity in cells by CK and LDH assay kits. The targeting relationship between miR-26a-5p and FOXO1 was verified by dual luciferase reporter gene assay. Results: MiR-26a-5p expression was decreased in H/R-induced cells and FOXO1 expression was increased in H/R-induced cells. Atorvastatin alleviated H/R injury in cardiomyocytes and was most effective at a concentration of 1 μM. Atorvastatin alleviated H/R injury in cardiomyocytes by upregulating miR-26a-5p expression, miR-26a-5p and FOXO1 were negatively regulated by targeting. Conclusion: Atorvastatin can alleviate H/R injury in cardiomyocytes by regulating miR-26a-5p/FOXO1.

Myocardial ischemia-reperfusion injury:Possible role of melatonin

Our knowledge and understanding of the pathophysiology of coronary atherosclerosis has increased enormously over the last 20 years.Reperfusion through thrombolysis or percutaneous coronary angioplasty is the standard treatment for preventing acute myocardial infarction.Early reperfusion is an absolute prerequisite for survival of the ischemic myocardium,but reperfusion itself may lead to accelerated and additional myocardial injury beyond that generated by ischemia alone.These outcomes,in a range of reperfusion-associated pathologies,are collectively termed "reperfusion injuries".Reactive oxygen species are known to be produced in large quantities in the first few minutes of the post-ischemia reperfusion process.Similarly,scientific evidence from the last 15 years has suggested that melatonin has beneficial effects on the cardiovascular system.The presence of vascular melatoninergic receptor binding sites has been demonstrated;these receptors are functionally linked to vasoconstrictor or vasodilatory effects of melatonin.It has been shown that patients with coronary heart disease have a low melatonin production rate,especially those with higher risk of cardiac infarction and/or sudden death.Melatonin attenuates molecular and cellular damage resulting from cardiac ischemia-reperfusion in which destructive free radicals are involved.

Effect of Minocycline Postconditioning and Ischemic Postconditioning on Myocardial Ischemia-reperfusion Injury in Atherosclerosis Rabbits

This study examined the protective effect of ischemic postconditioning(IPoC) and minocycline postconditioning(MT) on myocardial ischemia-reperfusion(I/R) injury in atherosclerosis(AS) animals and the possible mechanism.Forty male healthy rabbits were injected with bovine serum albumin following feeding on a high fat diet for 6 weeks to establish AS model.AS rabbits were randomly divided into 3 groups:(1) I/R group,the rabbits were subjected to myocardial ischemia for 35 min and then reperfusion for 12 h;(2) IPoC group,the myocardial ischemia lasted for 35 min,and then reperfusion for 20 s and ischemia for 20 s [a total of 3 cycles(R20s/I20s×3)],and then reperfusion was sustained for 12 h;(3) MT group,minocycline was intravenously injected 10 min before reperfusion.The blood lipids,malondialdehyde(MDA),superoxide dismutase(SOD),soluble cell adhesion molecule(sICAM),myeloperoxidase(MPO),and cardiac troponin T(cTnT) were biochemically determined.The myocardial infarction size(IS) and apoptosis index(AI) were measured by pathological examination.The expression of bcl-2 and caspase-3 was detected in the myocardial tissue by using reverse transcription-polymerase chain reaction(RT-PCR).The results showed that the AS models were successfully established.The myocardial IS,the plasma levels of MDA,sICAM,MPO and cTnT,and the enzymatic activity of MPO were significantly decreased,and the plasma SOD activity was significantly increased in IPoC group and MT group as compared with I/R group(P<0.05 for all).The myocardial AI and the caspase-3 mRNA expression were lower and the bcl-2 mRNA expression was higher in IPoC and MT groups than those in I/R group(all P<0.05).It is concluded that the IPoC and MT can effectively reduce the I/R injury in the AS rabbits,and the mechanisms involved anti-oxidation,anti-inflammation,up-regulation of bcl-2 expression and down-regulation of caspase-3 expression.Minocycline can be used as an effective pharmacologic postconditioning drug to protect myocardia from I/R injury.

The therapeutic effect of Jiawei Danshen Decoction on myocardial ischemia-reperfusion injury by inhibiting H_(2)S-mediated autophagy signaling pathway

Objective To investigate the protective effects of Jiawei Danshen Decoction(加味丹参饮,JWDSD)on myocardial ischemia-reperfusion injury(MIRI)via the regulation of serum Hydrogen sulfide(H2S)and cardiac Beclin1,light Chain 3 A/B(LC3 A/B),p62,and autophagy protein5(ATG5).Methods Seventy specific pathogen free(SPF)Sprague-Dawley(SD)rats were randomly assigned to seven groups(n=10 in each group),including normal control,sham operation,MIRI model(model),ischemic preconditioning,Na HS,JWDSD,and JWDSD+CSE inhibitor(JWDSD+PPG)groups,and orally administered the indicated drugs for 14 d.Two hours after the last administration,the left anterior decreased branch of the coronary artery of each rat in model,Na HS,JWDSD,and JWDSD+PPG groups was ligated for 30 min and subsequently reperfused for 90 min to establish the MIRI model,and the rats in the sham operation group were only exposed to the thorax after surgery without coronary ligation.Blood samples were collected to detect H2S levels using an enzyme-linked immunosorbent assay(ELISA).Heart tissues were harvested for histopathological and immunohistochemical examination and quantitative reverse transcription polymerase chain reaction analysis of Beclin1 and ATG5 m RNA expression and Western blot analysis of Beclin1,LC3 A/B,and p62 protein expression.Results(1)The serum H2S content in model group rats was significantly reduced(P<0.01),JWDSD significantly increased the serum H2S content of model group rats(P<0.01),and the CSE inhibitor(PPG)significantly reduced H2S levels in the JWDSD group rats(P<0.01).(2)Compared with the normal control group,the myocardial tissue necrosis and cell destruction occurred in the MIRI model group,and JWDSD could alleviate the myocardial tissue necrosis of model rats,but the ameliorative effect of JWDSD could be reversed by PPG.(3)Beclin1,LC3 A/B,and p62 expression levels in the heart tissues of the model group were significantly increased(P<0.001),whereas decreased by JWDSD(P<0.05,P<0.01,and P<0.001,respectively),and the inhibitory effects of JWDSD on Beclin1,LC3 A/B,and p62 expression were partially reversed by PPG(P<0.01,P<0.05,and P<0.01,respectively).(4)The expression levels of autophagy-related genes Beclin1 and ATG5 were significantly increased in the model group(P<0.001).JWDSD clearly downregulated the expression levels of Beclin1 and ATG5(P<0.05 and P<0.001,respectively),which were reversed by PPG(P<0.001).Conclusion Our experimental data show that JWDSD can exhibit an anti-MIRI role by increasing endogenous H2S generation,and downregulating the expression of Beclin1,LC3 A/B,p62 and ATG5,which are related to inhibiting autophagy signaling.

Experimental study of miRNA-210 modified MSCs in the treatment of myocardial ischemia-reperfusion injury in rats

Objective:To investigate the therapeutic effect of microRNA210(miRNA-210)modified mesenchymal stem cells(MSCs)on myocardial ischemia-reperfusion injury(MIRI)model rats.Methods:One SD rat was sacrificed,and the lower extremity tibia and femur were isolated.MSCs were cultured by whole bone marrow adherence method to construct miRNA-210 modified MSCs.40 SD rats were divided into the sham operation group,model group,MSCs group,and miRNA-210+MSCs group,with 10 rats in each group.The left anterior descending coronary artery was ligated to prepare a model of myocardial ischemia and reperfusion.After successful modeling,50μl of MSCs suspension was injected into the tail vein of the MSCs group,and 50μl of miRNA-210 modified MSCs suspension was injected into the tail vein of the miRNA-210+MSCs group.The sham operation group and the model group were injected with the same amount of normal saline.On the 10th day after modeling,the area of myocardial infarction,morphological changes of myocardial tissue,myocardial cell apoptosis rate,and miRNA-210 expression were compared in each group.Results:The area of myocardial infarction and the rate of myocardial cell apoptosis in the model group were significantly higher than those in the sham operation group(<0.05);The area of myocardial infarction and the rate of myocardial cell apoptosis in the MSCs group were significantly lower than those in the sham operation group(P<0.05);The area of myocardial infarction and the rate of myocardial cell apoptosis in the miRNA-210+MSCs group were significantly higher than those in the MSCs group(P<0.05);The area of myocardial infarction and the rate of myocardial cell apoptosis in the miRNA-210+MSCs group were significantly lower than those in the sham operation group(P<0.05).The expression level of miRNA-210 in the myocardial tissue of the model group was significantly higher than that in the sham operation group(P<0.05);There were no significantly different in the expression level of miRNA-210 in the myocardial tissue between the MSCs group and model group(P>0.05);The expression level of miRNA-210 in the myocardial tissue of MSCs group was significantly higher than in the MSCs group,model group and sham operation group(P<0.05).HE staining showed that the miRNA-210+MSCs group had normal morphology of myocardial tissues,more uniform cytoplasmic staining,and arranged neatly myocardial fibers.The inflammatory cell infiltration and interstitial edema of the miRNA-210+MSCs group were significantly improved compared with the model group and MSCs group.Conclusion:MiRNA-210 modified MSCs can inhibit myocardial cell apoptosis in myocardial ischemia-reperfusion injury model rats,reduce the area of myocardial infarction,and improve pathological damage of myocardial tissue in rats,which has a certain therapeutic effect on myocardial ischemia-reperfusion injury.

Effect of dexmedetomidine on monophasic action potential amplitude in myocardial ischemia-reperfusion and its correlation with myocardial injury

Objective: To study the effect of dexmedetomidine on monophasic action potential amplitude (MAPA) in myocardial ischemia-reperfusion and its correlation with myocardial injury. Methods: SD rats were selected as the experimental animals and randomly divided into control group, ischemia reperfusion group (I/R group) and dexmedetomidine group (Dex group);I/R group and Dex group were made into myocardial ischemia-reperfusion injury models, and Dex group were given exmedetomidine intervention;the MAPA of myocardial tunica intima layer, tunica media layer and tunica externa layer were measured in Langendorff perfusion system;myocardial tissue was collected to determine the contents of oxidative stress molecules and the expression of apoptosis genes. Results: The MAPA levels of myocardial tunica intima layer, tunica media layer and tunica externa layer as well as Klotho and SOD contents in myocardial tissue of I/R group were significantly lower than those of control group whereas CaMKII, NOX2, NOX4 and MDA contents as well as CaSR, USP14, JNK, Bax, Fas and Caspase-3 mRNA expression in myocardial tissue were significantly higher than those of control group;the MAPA levels of myocardial tunica intima layer, tunica media layer and tunica externa layer as well as Klotho and SOD contents in myocardial tissue of Dex group were significantly higher than those of I/R group whereas CaMKII, NOX2, NOX4 and MDA contents as well as CaSR, USP14, JNK, Bax, Fas and Caspase-3 mRNA expression in myocardial tissue were significantly lower than those of I/R group;Pearson test showed that the MAPA levels of myocardial tunica intima layer, tunica media layer and tunica externa layer were negatively correlated with CaMKII, NOX2, NOX4 and MDA contents as well as CaSR, USP14, JNK, Bax, Fas and Caspase-3 mRNA expression in myocardial tissue, and positively correlated with Klotho and SOD contents. Conclusion: Dexmedetomidine can increase the MAPA in myocardial ischemia-reperfusion process, and is closely related to the inhibition of oxidative stress response and apoptosis.

Correlation between myocardial ischemia-reperfusion-induced monophasic action potential amplitude change and myocardial damage

Objective:To study the correlation between myocardial ischemia-reperfusion-induced monophasic action potential amplitude (MAPA) change and myocardial damage.Methods:New Zealand rabbits were selected as experimental animals and randomly divided into control group and ischemia-reperfusion group (I/R group), myocardial ischemia-reperfusion injury models were established, then the heart was separated and the MAPA of myocardial intima layer, media layer and outer layer were determined in Langendorff perfusion system;serum samples and myocardial tissue were collected to determine the contents of myocardial injury molecules.Results: MAPA levels of myocardial intima layer, media layer and outer layer of I/R group were significantly lower than those of control group;CK-MB, cTnI, cTnT and MDA contents in serum as well as Bax, Caspase-3 and Caspase-9 mRNA expression in myocardial tissue of I/R group were significantly higher than those of control group and negatively correlated with MAPA levels of myocardial intima layer, media layer and outer layer while SOD, GSH-Px and HO-1 contents in serum as well as Bcl-2 and Bcl-xL mRNA expression in myocardial tissue were significantly lower than those of control group and positively correlated with MAPA levels of myocardial intima layer, media layer and outer layer.Conclusion:Myocardial ischemia - reperfusion can induce the decrease of MAPA and is closely related to myocardial oxidative stress injury and apoptosis.

Tongxinluo Activates PI3K/AKT Signaling Pathway to Inhibit Endothelial Mesenchymal Transition and Attenuate Myocardial Fibrosis after Ischemia-Reperfusion in Mice

Objective To investigate the potential role of Tongxinluo(TXL)in attenuating myocardial fibrosis after myocardial ischemia-reperfusion injury(MIRI)in mice.Methods A MIRI mouse model was established by left anterior descending coronary artery ligation for 45 min.According to a random number table,66 mice were randomly divided into 6 groups(n=11 per group):the sham group,the model group,the LY-294002 group,the TXL group,the TXL+LY-294002 group and the benazepril(BNPL)group.The day after modeling,TXL and BNPL were administered by gavage.Intraperitoneal injection of LY-294002 was performed twice a week for 4 consecutive weeks.Echocardiography was used to measure cardiac function in mice.Masson staining was used to evaluate the degree of myocardial fibrosis in mice.Qualitative and quantitative analysis of endothelial mesenchymal transition(EndMT)after MIRI was performed by immunohistochemistry,immunofluorescence staining and flow cytometry,respectively.The protein expressions of platelet endothelial cell adhesion molecule-1(CD31),α-smoth muscle actin(α-SMA),phosphatidylinositol-3-kinase(PI3K)and phospho protein kinase B(p-AKT)were assessed using Western blot.Results TXL improved cardiac function in MIRI mice,reduced the degree of myocardial fibrosis,increased the expression of CD31 and inhibited the expression ofα-SMA,thus inhibited the occurrence of EndMT(P<0.05 or P<0.01).TXL significantly increased the protein expressions of PI3K and p-AKT(P<0.05 or P<0.01).There was no significant difference between TXL and BNPL group(P>0.05).In addition,the use of the PI3K/AKT pathway-specific inhibitor LY-294002 to block this pathway and combination with TXL intervention,eliminated the protective effect of TXL,further supporting the protective effect of TXL.Conclusion TXL activated the PI3K/AKT signaling pathway to inhibit EndMT and attenuated myocardial fibrosis after MIRI in mice.

Hepatic ischemia-reperfusion syndrome and its effect on the cardiovascular system: The role of treprostinil, a synthetic prostacyclin analog

Hepatic ischemia-reperfusion syndrome has been the subject of intensive study and experimentation in recent decades since it is responsible for the outcome of several clinical entities,such as major hepatic resections and liver transplantation.In addition to the organ’s post reperfusion injury,this syndrome appears to play a central role in the dysfunction of distant tissues and systems.Thus,continuous research should be directed toward finding effective therapeutic options to improve the outcome and reduce the postoperative morbidity and mortality rates.Treprostinil is a synthetic analog of prostaglandin I2,and its experimental administration has shown encouraging results.It has already been approved by the Food and Drug Administration in the United States for pulmonary arterial hypertension and has been used in liver transplantation,where preliminary encouraging results showed its safety and feasibility by using continuous intravenous administration at a dose of 5 ng/kg/min.Treprostinil improves renal and hepatic function,diminishes hepatic oxidative stress and lipid peroxidation,reduces hepatictoll-like receptor 9 and inflammation,inhibits hepatic apoptosis and restores hepatic adenosine triphosphate(ATP)levels and ATP synthases,which is necessary for functional maintenance of mitochondria.Treprostinil exhibits vasodilatory properties and antiplatelet activity and regulates proinflam-matory cytokines;therefore,it can potentially minimize ischemia-reperfusion injury.Additionally,it may have beneficial effects on cardiovascular parameters,and much current research interest is concentrated on this compound.

Investigation on the mechanisms of Wuling Powder in treating myocardial ischemia-reperfusion injury based on network pharmacology and molecular docking with experiment verification

Background Myocardial ischemia-reperfusion injury is characterized by the inability of tissue and organ function to recover after the perfusion blood flow is restored followed by myocardial ischemia.Previous studies have shown that many Chinese herbal compounds can reduce myocardial ischemia-reperfusion injury,but the efficacy of Wuling Powder in treating myocardial ischemia-reperfusion injury has not been reported.The present study aimed to investigate the mechanism of Wuling Powder in treating myocardial ischemia-reperfusion injury by network pharmacology and molecular docking.Methods The active constituents of Wuling Powder were obtained by the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP),and the related targets of active constituents of Wuling Powder were screened by the Swiss Target Prediction database.Disease targets of myocardial ischemia-reperfusion injury were obtained by Gene Cards,Dis Ge NET and OMIM gene databases.The active compound-target network of Wuling Powder was constructed using Cytoscape software.The drug prediction targets were mapped to the disease target set,and the intersection targets were obtained.The Gene Ontology(GO)function and Kyoto Encyclopedia of Genes anf Genomes(KEGG)pathway enrichment analysis were performed on the intersection targets obtained by using String database.Auto Dock Vina was used for molecular docking of core targets and the top 3 key active ingredients with degree values.Results Through screening,56 active ingredients and 116 targets of Wuling Powder were obtained.There were 27 common targets of Wuling Powder and myocardial ischemia-reperfusion injury in Myocardial ischemia-reperfusion injury(MIRI).Protein-Protein Interaction(PPI)network analysis in this study showed that CASP3,PTGS2,CAT,JUN,ESR1,CASP8,CASP9 and RELA may be the key targets of Wuling Powder to exert the protective effect of MIRI.GO functional analysis and KEGG pathway enrichment analysis showed that biological processes such as apoptosis,lipopolysaccharide response,steroid hormone response and signal transduction pathways such as PTGS2,TNF-α,nuclear transcription factor-κB(NF-κB),MAPK,PI3K/AKT,NLRP3,and autophagy play an important role in the occurrence and development of MIRI.Molecular docking results showed thatβ-sitosterol and hederagenin had good binding activities with key targets such as PTGS2,CASP3,and CAT.Conclusions Wuling Powder may act on CASP3,PTGS,CAT,JUN,ESR1,CASP8,CASP9 and other targets throughβ-sitosterol,hederagenin,3β-acetoxyatractylone,taxifolin and other active ingredients.[S Chin J Cardiol 2024;25(3):179-192]

Effect and mechanism of salvianolic acid B on the myocardial ischemiareperfusion injury in rats

Objective:To investigate the effect of salvianolic acid B on rats with myocardial ischemiareperfusion injury.Methods:SD rats were randomly divided into five groups(n=10 in each group):A sham operation group,B ischemic reperfusion group model group,C low dose salvianolic acid B group,D median dose salvianolic acid B group,E high dose salvianolic acid B group.One hour after establishment of the myocardial ischemia-reperfusion model,the concentration and the apoptotic index of the plasma level of myocardial enzymes(CTnⅠ,CKMB),SOD,MDA,NO,ET were,measured.Heart tissues were obtained and micro-structural changes were observed.Results:Compared the model group,the plasma CTnⅠ,CK-MB,MDA and ET contents were significantly increased,NO,T-SOD contents were decreased in the treatment group(group C,D,and E)(P<0.05);compared with group E,the plasma CTnⅠ,CKMB,MDA and ET levels were increased,the NO,T-SOD levels were decreased in groups C and D(P<0.05).Infarct size was significantly reduced,and the myocardial ultrastructural changes were improved significantly in treatment group.Conclusions:Salvianolic acid B has a significant protective effect on myocardial ischemia-reperfusion injury.It can alleviate oxidative stress,reduce calcium overload,improve endothelial function and so on.

Neuroprotection of Erythropoietin and Methylprednisolone against Spinal Cord Ischemia-Reperfusion Injury

Recent research based on various animal models has shown the neuroprotective effects of erythropoietin （EPO）. However, few studies have examined such effects of EPO in the clinic. In this study we enrolled patients with spinal cord ischemia-reperfusion （I-R） injury to investigate the clinical application of EPO and methylprednisolone （MP） for the neuroprotection against spinal cord I-R injury. Retrospective analysis of 63 cases of spinal cord I-R injury was performed. The Frankel neurological performance scale was used to evaluate the neurological function after spinal cord injury （SCI）, including 12 cases of scale B, 30 cases of scale C, and 21 cases of scale D. These cases were divided into 2 groups： group A （27 cases） got treatment with both EPO and MP; group B （36 cases） got treatment with MP only. The neurological function of patients after treatment was evaluated by American Spinal Cord Injury Association （ASIA） index score, and activity of daily living （ADL） of the patients was also recorded. All patients got follow-up and the follow-up period ranged from 24 to 39 months （mean 26 months）. There was no significance difference in neurological function between groups A and B before the treatment （P〉0.05）. However, the neurological function and ADL scores were significantly improved 1 week, 1 year or 2 years after the treatment compared to those before the treatment （P〈0.05）, and the improvement was more significant in group A than in group B （P〈0.05）. It is suggested that the clinical application of EPO and MP provides the neuroprotection against spinal cord I-R injury.

Effects of glucagon-like peptide 1 analogs in combination with insulin on myocardial infarct size in rats with type 2 diabetes mellitus

AIM To evaluate the effects of glucagon-like peptide-1 analogs(GLP-1 a) combined with insulin on myocardial ischemiareperfusion injury in diabetic rats.METHODS Type 2 diabetes mellitus(T2 DM) was induced in maleWistar rats with streptozotocin(65 mg/kg) and verified using an oral glucose tolerance test. After anesthesia, the left coronary artery was occluded for 40 min followed by 80 min reperfusion. Blood glucose level was measured during surgery. Rats were randomized into six groups as follows:(1) control rats;(2) insulin(0.1 U/kg) treated rats prior to ischemia;(3) insulin(0.1 U/kg) treated rats at reperfusion;(4) GLP-1 a(140 mg/kg) treated rats prior to ischemia;(5) GLP-1 a(140 mg/kg) treated rats at reperfusion; and(6) rats treated with GLP-1 a(140 mg/kg) prior to ischemia plus insulin(0.1 U/kg) at reperfusion. Myocardial area at risk and infarct size was measured planimetrically using Evans blue and triphenyltetrazolium chloride staining, respectively.RESULTS There was no significant difference in the myocardial area at risk among groups. Insulin treatment before ischemia resulted in a significant increase in infarct size(34.7% ± 3.4% vs 18.6% ± 3.1% in the control rats, P < 0.05). Post-ischemic administration of insulin or GLP-1 a had no effect on infarct size. However, pre-ischemic administration of GLP-1 a reduced infarct size to 12% ± 2.2%(P < 0.05). The maximal infarct size reduction was observed in the group treated with GLP-1 a prior to ischemia and insulin at reperfusion(8% ± 1.6%, P < 0.05 vs the control and GLP-1 a alone treated groups).CONCLUSION GLP-1 a pre-administration results in myocardial infarct size reduction in rats with T2 DM. These effects are maximal in rats treated with GLP-1 a pre-ischemia plus insulin at reperfusion.

A review of potential mechanisms and uses of SGLT2 inhibitors in ischemia-reperfusion phenomena

Recently added to the therapeutic arsenal against chronic heart failure as a first intention drug,the antidiabetic drug-class sodium-glucose cotransporter-2 inhibitors(SGLT2i)showed efficacy in decreasing overall mortality,hospitalization,and sudden death in patients of this very population,in whom chronic or acute ischemia count among the first cause.Remarkably,this benefit was observed independently from diabetic status,and benefited both preserved and altered ventricular ejection fraction.This feature,observed in several large randomized controlled trials,suggests additional effects from SGLT2i beyond isolated glycemia control.Indeed,both in-vitro and animal models suggest that inhibiting the Na+/H+exchanger(NHE)may be key to preventing ischemia/reperfusion injuries,and by extension may hold a similar role in ischemic damage control and ischemic preconditioning.Yet,several other mechanisms may be explored which may help better target those who may benefit most from SGLT2i molecules.Because of a large therapeutic margin with few adverse events,ease of prescription and potential pharmacological efficacity,SGLT2i could be candidate for wider indications.In this review,we aim to summarize all evidence which link SGLT2i and ischemia/reperfusion injuries modulation,by first listing known mechanisms,including metabolic switch,prevention of lethal arrythmias and others,which portend the latter,and second,hypothesize how the former may interact with these mechanisms.