Network-pharmacology-based research on protective effects and underlying mechanism of Shuxin decoction against myocardial ischemia/reperfusion injury with diabetes

BACKGROUND Patients with diabetes mellitus are at higher risk of myocardial ischemia/reperfusion injury(MI/RI).Shuxin decoction(SXT)is a proven recipe modification from the classic herbal formula"Wu-tou-chi-shi-zhi-wan"according to the traditional Chinese medicine theory.It has been successfully used to alleviate secondary MI/RI in patients with diabetes mellitus in the clinical setting.However,the underlying mechanism is still unclear.AIM To further determine the mechanism of SXT in attenuating MI/RI associated with diabetes.METHODS This paper presents an ensemble model combining network pharmacology and biology.The Traditional Chinese Medicine System Pharmacology Database was accessed to select key components and potential targets of the SXT.In parallel,therapeutic targets associated with MI/RI in patients with diabetes were screened from various databases including Gene Expression Omnibus,DisGeNet,Genecards,Drugbank,OMIM,and PharmGKB.The potential targets of SXT and the therapeutic targets related to MI/RI in patients with diabetes were intersected and subjected to bioinformatics analysis using the Database for Annotation,Visualization and Integrated Discovery.The major results of bioinformatics analysis were subsequently validated by animal experiments.RESULTS According to the hypothesis derived from bioinformatics analysis,SXT could possibly ameliorate lipid metabolism disorders and exert anti-apoptotic effects in MI/RI associated with diabetes by reducing oxidized low density lipoprotein(LDL)and inhibiting the advanced glycation end products(AGE)-receptor for AGE(RAGE)signaling pathway.Subsequent animal experiments confirmed the hypothesis.The treatment with a dose of SXT(2.8 g/kg/d)resulted in a reduction in oxidized LDL,AGEs,and RAGE,and regulated the level of blood lipids.Besides,the expression of apoptosis-related proteins such as Bax and cleaved caspase 3 was down-regulated,whereas Bcl-2 expression was up-regulated.The findings indicated that SXT could inhibit myocardial apoptosis and improve cardiac function in MI/RI in diabetic rats.CONCLUSION This study indicated the active components and underlying molecular therapeutic mechanisms of SXT in MI/RI with diabetes.Moreover,animal experiments verified that SXT could regulate the level of blood lipids,alleviate cardiomyocyte apoptosis,and improve cardiac function through the AGE-RAGE signaling pathway.

Progress in protective effect and mechanism of 6-gingerol on myocardial ischemia/reperfusion injury

The morbidity and mortality of cardiovascular diseases are very high,which has attracted more and more attention all over the world.Common treatment methods for clinical treatment of acute myocardial infarction include direct percutaneous coronary intervention and coronary artery bypass grafting,which can quickly restore blocked coronary blood flow and reduce the infarct size.However,the inevitable ischemia/reperfusion injury will occur during the recovery of coronary blood flow,its pathological mechanism is complicated,and the Western medicine countermeasures are very limited.Among the current drugs for the treatment of cardiovascular diseases,traditional Chinese medicine has become a research hotspot due to its multiple targets,safety,and low side effects.Ginger is the fresh rhizome of Zingiber officinale Rosc.,a perennial herbaceous plant in the ginger family.It is a dual-purpose resource of medicine and food.Ginger has the functions of relieving the appearance and dispelling cold,warming up and relieving vomiting,resolving phlegm and relieving cough,and relieving fish and crab poison.The chemical components of ginger mainly include volatile oil,gingerol,diphenylheptane,etc..Among them,6-gingerol,as the main active component of gingerols,has obvious pharmacological effects in myocardial protection,anti-oxidation,anti-inflammatory,etc..Studies have shown that 6-gingerol protects myocardium mainly through anti-oxidative stress,anti-inflammatory,inhibiting cell apoptosis,and preventing calcium influx.①Anti-oxidative stress:oxidative stress is a state where oxidation and anti-oxidation in the body are out of balance,and it is also an important factor leading to myocardial damage.Many studies have confirmed that 6-gingerol has an antioxidant effect,and it is considered a natural antioxidant.6-gingerol can significantly reduce the degree of oxidative stress and the level of reactive oxygen species caused by cardiomyocyte damage,and has a significant cardioprotective effect.②Anti-inflammatory:inflammation can cause substantial cell damage and organ dysfunction,which is another important cause of myocardial damage.6-gingerol can reduce the levels of inflammatory factors such as interleukin-6,interleukin-1β,and tumor necrosis factor-αin cardiomyocytes,and at the same time inhibit the TLR4/NF-κB signaling pathway,an important regulatory pathway of inflammation,showing that it may improve myocardial damage through anti-inflammatory effects.③Inhibition of apoptosis:apoptosis is a complex and orderly process in the autonomous biochemical process of cells,and one of the main mechanisms of myocardial injury.This process can be roughly divided into three pathways:mitochondria,endoplasmic reticulum,and death receptors.Among them,the mitochondrial pathway plays an important role,and Bcl-2 and Bax located upstream of this pathway can regulate the entire process of cell apoptosis by regulating the permeability of the mitochondrial membrane.Studies have found that the preventive application of 6-gingerol can reduce cell damage,reduce the number of apoptotic cells,reduce the activity of Bax and caspase-3,and increase the expression of Bcl-2.Therefore,6-gingerol pretreatment can reduce the damage of cardiomyocytes,and its mechanism may be related to the inhibition of apoptosis.④Prevent calcium influx:calcium overload is involved in the pathogenesis of myocardial ischemic injury,which may be related to excessive contracture,arrhythmia,and mitochondrial Ca2+accumulation that impairs myocardial function.6-gingerol inhibits the increase of intracellular Ca2+concentration by inhibiting L-type calcium current,thereby reducing extracellular Ca2+influx,thereby avoiding calcium overload and playing a cardioprotective effect.In summary,6-gingerol can effectively treat and improve myocardial ischemia/reperfusion injury,and it has great development potential in the fields of medicine and health products.

Activation of epidermal growth factor receptor mediates myocardial ischemia/reperfusion arrhythmias in anaesthetized rats

Objectives Epidermal growth factor receptor （EGFR）is a receptor protein tyrosine kinase and plays a critical role in the development and function of the heart.Previous studies have demonstrated that EGFR is involved in regulating electrical excitability of the heart.The present study was designed to investigate whether EGFR activation would mediate myocardial arrhythmias induced by ischemia/reperfu- sion in anaesthetized rats.Methods and results Myocardial ischemia/reperfusion arrhythmias were induced by 10 min ligation of the left anterior descending coronary artery,followed by a 30 min reperfusion in anaesthetized rats.Incidence and severity of cardiac arrhythmias were significantly reduced by pretreatment with the EGFR kinase inhibitor AG556.Phosphorylation level of myocardial EGFR was increased during ischemia and at early reperfusion.Intramyocardial transfection of EGFR siRNA reduced EGFR mRNA and protein,and decreased the incidence of ventricular fibrillation induced by reperfusion.Interestingly,tyrosine phosphorylation levels of cardiac Na+ channel(INa) and L-type Ca2+ channel(ICa.l) were significantly increased at corresponding time points to the alteration of phosphorylated EGFR level during reperfusion.AG556 pretreatment countered the increased tyrosine phosphorylation level of Na+ and L-type Ca2+ channels induced by reperfusion.No significant alteration was observed in tyrosine phosphorylation levels of cardiac Kv4.2 and Kir2.1 channels during the cardiac ischemia/reperfusion. Conclusions These results demonstrate for the first time that EGFR plays an important role in the genesis of myocardial ischemia/reperfusion arrhythmias,which is likely mediated at least in part by enhancing tyrosine phosphorylation of cardiac Na+ and L-type Ca2+ channels.

Effect of peroxisome proliferator-activated receptor gamma agonist on heart of rabbits with acute myocardial ischemia/reperfusion injury

Objective:To explore protective effect of rosiglitazone on myocardial ischemia reperfusion injury.Methods:A total of 48 male SD rats were randomly divided into control group(A),I/R group(B),high dose of rosiglitazone(C),low dose of rosiglitazone(D).Plasm concentration of creatine kinase(CK),CK-MB,hsCRP,Superoxide dismutase(SOD),malondialdehyde(MDA),glutathione peroxidase(GSH-Px),nitric oxide(NO)and endothelin(ET)were measured 1 h later after I/R.24 h after I/R hearts were harvested to observe pathological and ultrastructural changes.Immunohistochemistry and western blotting was used to test CD40 expression in myocardial tissue.Area of myocardial infarction were tested,arrhythmia rate during I/R was recorded.Results:Plasm concentration of creatine kinase(CK),CK-MB,hsCRP,NO,MDA and ET were decreased in group C,D compared with group B.Plasm concentration of T-SOD and GSHPx was increased significantly in group C,D compared with group B.Compared with group B,pathological and ultrastructural changes in group C,D were slightly.Myocardial infarction area and arrhythmia rate were lower in group C,D compare with group B.Conclusions:Rosiglitazone can protect myocardium from I/R injury by enhancing T-SOD and GSH-Px concentration,inhibit inflammatory reaction,improve endothelial function,reduce oxidative stress and calcium overload.

Comparative analysis of different cyclosporine A doses on protection after myocardial ischemia/reperfusion injury in rat

Objective:To investigate the protective effect of different cyclosporin A(CsA)doses on myocardial ischemia/reperfusion injury in rat models.Methods:A rat model of myocardial ischemia/reperfusion injury was established in vivo and the rats were randomly divided into four groups:placebo(PBS;T1),low-dose(CsA dose:1.0 mg/kg:T2),medium-dose(CsA dose:2.5 mg/kg:T3),and high-dose(CsA dose:5.0 mg/kg;T4)groups.Heart function indexes were monitored at different time points,the extent of myocardial infarction was assessed by Evans Blue-TTC staining,and creatine kinase MB mass and cardiac troponin 1 values were measured by biochemical assays.Results:Compared with the T1 and T2 groups,both the creatine kinase MB mass and cardiac troponin 1 were significantly lower in the T3 and T4 groups(P<0.05).The mean arterial pressure(MAP)and left ventricular systolic pressure(LVSP)decreased sequentially in each group,with the extending reperfusion time.Significant decreases in LVSP and MAP were observed in the T3 and T4 groups as compared to the T1 and T2 group(P<0.05)and the T2 group showed a significantly lower LVSP and MAP decline than the T1 group(P<0.05).Compared with the Tl group,the rats from the T2.T3,and T4 groups suffered from a significantly lower extent of myocardial infarction(P<0.05).Also,the a animals in the T3 and T4 groups had a significantly smaller extent of myocardial infarction than those in the T2 group(P<0.05).Conclusions:Various CsA doses exert different degrees of protection against ischemia/reperfusion injury,and this protective effect peaks at approximately 2.5 mg/kg in rat models.

MicroRNA-15a/b are up-regulated in response to myocardial ischemia/reperfusion injury

ObjectiveSeveral 研究显示了 miR-15a， miR-15b 和 miR-16 可以是 apoptosis 的重要管理者。后来稀释 apoptosis 能保护心肌层和还原剂梗塞尺寸，现在的学习被瞄准发现是否这些 miRNAs 参予调整心肌的局部缺血灌注( I/R )在受到 I/R 的老鼠心的 injury.MethodsApoptosis 被 TUNEL 试金在 vivo 检测，当流动 cytometry 分析由 Annexin V/PI 列在后面时，在 vitro 的两倍污点被用来在受到 hypoxia/reoxygenation ( H/R )的有教养的 cardiomyocytes 检测 apoptosis 。Taqman 即时量的 PCR 被用来证实 miR-15a/15b/16 是否涉及心脏的 I/R 的规定，控制， I/R 或 H/R 的到那些的 H/R.ResultsCompared 导致了 cardiomyocytes 的 apoptosis 显著地在 vivo 两个都被增加(24.4%&#x000b1；9.4% 对 2.2%&#x000b1；1.9% ， P &#x0003c；0.01， n = 5 ) 并且在 vitro (14.12%&#x000b1；0.92% 对 2.22%&#x000b1；0.08%) 。 miR-15a 和 miR-15b 的表达式，然而并非 miR-16 ，在鼠标 I/R 模型，和结果被增加在 H/R model.ConclusionsOur 数据是一致的显示因此， miR-15 和 miR-15b 响应心脏的 I/R 损害是起来调整的 miR-15a/b 的下面规定可以是有希望的策略减少心脏的 I/R 损害导致的心肌的 apoptosis 。

A Selective TRPC3 Inhibitor Pyr3 Attenuates Myocardial Ischemia/Reperfusion Injury in Mice

An emerging body of evidence indicates that transient receptor potential TRP channels act as important mediators for a wide variety of physiological functions and are potential targets for drug discovery.Our previous study has identified transient receptor potential channel 3(TRPC3)and TRPC6 as cation channels through which most of the damaging calcium enters,aggravates pathological changes in vivo and increases ischemia/reperfusion(I/R)injury in mice.This study aimed to verify the effects of TRPC3 inhibitor Pyr3 on myocardial I/R injury in mice.C57BL/6J wild-type male mice(8 to 12 weeks old)were anesthetized with 3.3%chloral hydrate.A murine I(30 min)/R(24 h)injury model was established by temporary occlusion of the left anterior descending(LAD)coronary artery.Pyr3 was administered at concentrations of 0,2.5,5,or 10 mg/kg via the right jugular vein 5 min before reperfusion.We observed that the selective TRPC3 inhibitor,10 mg/kg Pyr3,significantly decreased the infarct size of left ventricle,and reduced the myocardial cell apoptosis rate and inflammatory response in mice.In a conclusion,TRPC3 can function as a candidate target for I/R injury prevention,and Pyr3 may directly bind to TRPC3 channel protein,inhibit TRPC3 channel activity,and improve TRPC3-related myocardial I/R injury.Pyr3 may be used for clarification of TRPC3 functions and for treatments of TRPC3-mediated diseases.

The role of glycogen synthase kinase 3 beta in brain injury induced by myocardial ischemia/reperfusion injury in a rat model of diabetes mellitus

Myocardial ischemia/reperfusion injury can lead to severe brain injury.Glycogen synthase kinase 3 beta is known to be involved in myocardial ischemia/reperfusion injury and diabetes mellitus.However,the precise role of glycogen synthase kinase 3 beta in myocardial ischemia/reperfusion injury-induced brain injury is unclear.In this study,we observed the effects of glycogen synthase kinase 3 beta on brain injury induced by myocardial ischemia/reperfusion injury in diabetic rats.Rat models of diabetes mellitus were generated via intraperitoneal injection of streptozotocin.Models of myocardial ischemia/reperfusion injury were generated by occluding the anterior descending branch of the left coronary artery.Post-conditioning comprised three cycles of ischemia/reperfusion.Immunohistochemical staining and western blot assays demonstrated that after 48 hours of reperfusion,the structure of the brain was seriously damaged in the experimental rats compared with normal controls.Expression of Bax,interleukin-6,interleukin-8,terminal deoxynucleotidyl transferase d UTP nick end labeling,and cleaved caspase-3 in the brain was significantly increased,while expression of Bcl-2,interleukin-10,and phospho-glycogen synthase kinase 3 beta was decreased.Diabetes mellitus can aggravate inflammatory reactions and apoptosis.Ischemic post-conditioning with glycogen synthase kinase 3 beta inhibitor lithium chloride can effectively reverse these changes.Our results showed that myocardial ischemic post-conditioning attenuated myocardial ischemia/reperfusion injury-induced brain injury by activating glycogen synthase kinase 3 beta.According to these results,glycogen synthase kinase 3 beta appears to be an important factor in brain injury induced by myocardial ischemia/reperfusion injury.

C-reactive protein aggravates myocardial ischemia/reperfusion injury through activation of extracellular-signal-regulated kinase 1/2

当组织被重新酒跟随局部缺血的延长经期时， BackgroundIschemia/reperfusion 损害(IRI ) 是发生的煽动性的回答。几研究显示了那 C 反应的蛋白质(CRP ) 可能在导致 IRI 起一个重要作用。然而，心肌的 IRI 和内在的机制上的 CRP 的效果充分没被阐明。试图调查在 CRP 和心肌的 IRI 和内在的 mechanisms.MethodsWe 之间的协会的这研究在新生的 Sprague-Dawley 老鼠 cardiomyocytes 用氧葡萄糖 deprivation/ 氧化(OGD/R ) 模仿了 ischemia/reperfusion；灌注损害与到一小时灌注跟随的葡萄糖和浆液剥夺到三小时组织缺氧被导致。房间生存能力与山试金被测试，并且 cardiomyocyte 损坏被评估由喂奶脱氢酶(LDH ) 漏。Mitochondrial 膜潜力用 tetramethylrhodamine 乙醇酉旨(TMRE ) 被测量， mitochondrial 渗透转变毛孔(mPTP ) 洞用 calcein/AM 被测量；TMRE 和 caocein/AM 与扫描共焦的显微镜学的激光被设想。另外，我们学习了与简单 OGD/R 组一起经由西方的污点 analysis.ResultsCompared 位于 调停CRP 的 ischemia/reperfusion 损害下面的发信号的小径，吗在有 10 的干预以后?????????传???????????圠卍????????????椠'諗珮I???????????????????？？

Mechanism of hesperidin improving myocardial ischemia/reperfusion injury in type 2 diabetic rats through SIRT1/Nrf2/HO-1 signaling pathway

Objective:To observe the protective effect of hesperidin on myocardial ischemia/reperfusion injury in type 2 diabetes mellitus and its effect on SIRT1/Nrf2/HO-1 signaling pathway.Methods:50 Sprague-Dawley(SD)rats were randomly assigned to the normal control group(NC),model group,ischemia-reperfusion group(IR),hesperidin group,SIRT1 inhibitor group and hesperidin plus SIRT1 inhibitor group.In addition to NC,the rats in the remaining groups were replicated by intraperitoneal of high-fat diet combined with injection of streptozotocin for type 2 diabetic rats.After then,the myocardial ischemia/reperfusion injury(MIRI)rat model was established by LAd for 30 minutes with 2 hours reperfusion.He staining was used to observe the pathological changes of myocardial tissue,and the levels of serum LDH,CK-MB and SOD,GSH and MDA in myocardial tissue were detected by kit methods,and the expression abundance of related proteins in 4-HNE and SIRT1/Nrf2/HO-1 signal pathway were detected by immunohistochemistry and Western blot;Results:Hesperidin could significantly inhibit cardiomyocyte necrosis and inflammatory cell infiltration,reduce LDH activity,CK-MB and MDA level,and increase SOD activity,GSH and 4-HNE level,the differences were statistically significant when compared with IR group(P<0.01).In addition,compared with the ischemia-reperfusion group,the expressions of SIRT1,Nrf2 and HO-1 proteins in hesperidin group were significantly up-regulated,the differences were statistically significant(P<0.01);Conclusion:Hesperidin inhibits oxidative stress by activating SIRT1/Nrf2/HO-1 signaling pathway,and play a protective effect of myocardial ischemia reperfusion injury in diabetic rats.

Acupuncture preconditioning protects against myocardial ischemia/reperfusion injury mediated apoptosis through miR-214/NCX1 activation: a hypothesis

Early reperfusion of ischemic cardiac tissue is usually the best option to improve clinical outcome of angina pectoris, especially of acute myocardial infarction. However, myocardial reperfusion may cause an abnormal increase of intracellular Ca^2+-mediated cardiomyocyte death and consequent loss of cardiac function, which is referred to myocardial ischemia/reperfusion (I/R) injury. Recently, the microRNA-214 (miR-214)/Na^+/Ca^2+ exchanger (NCX) 1 co-expression is a key factor in cellular protection against myocardial apoptosis for myocardial I/R injury. Once activated, miR-214/NCX1 axis can inhibit several Ca^2+ downstream signaling effectors that mediate cell death simultaneously. Studies have shown that acupuncture preconditioning has a protective effect on myocardial I/R injury, but its mechanism deserves further research. It has been proved that acupuncture preconditioning for ischemic myocardium successfully inhibit multiple Ca2+ handling related microRNAs that mediate cell death pathways, and miR-214 is one of its targets. In terms of clinical practice, coronary heart disease (CHD) patients benefit a lot from this intervention. However, there is barely no study correlating acupuncture preconditioning to the miR-214/NCX1 co-expression in patients with CHD. This review aims to discuss whether there is some evidence to justify a recommendation of acupuncture preconditioning in CHD patients as a non-pharmacological therapeutic method to activate the miR-214/NCX1 co-expression network model.

CHANGES IN NEUROPEPTIDES AFTER MUSIC EXPOSURE 429Cardioprotective effect of ivabradine via the AMPK/SIRT1/PGC-1αsignaling pathway in myocardial ischemia/reperfusion injuryinduced in H9c2 cell

Post-resuscitation myocardial dysfunction(PRMD)is the most severe myocardial ischemia-reperfusion injury(MIRI)and is characterized by difficult treatment and poor prognosis.Research has shown the protective effects of the rational use of ivabradine(IVA)against PRMD,however,the molecular mechanisms of IVA remain unknown.In this study,an ischemia-reperfusion injury(IRI)model was established using hypoxic chambers.The results demonstrated that pretreatment with IVA reduced IRI-induced cytotoxicity and apoptosis.IVA attenuated mitochondrial damage,eliminated excess reactive oxygen species(ROS),suppressed IRI-induced ATP and NAD+,and increased the AMP/ATP ratio.We further found that IVA increased the mRNA levels of sirtuin 1(SIRT1)and peroxisome proliferator-activated receptor-γcoactivator 1α(PGC-1α)and upregulated the expression levels of phosphorylated AMP-activated protein kinase(p-AMPK)/AMPK,SIRT1,and PGC-1αproteins.Interestingly,no change in AMPK mRNA levels was observed.Cardiomyocyte energy metabolism significantly changed after IRI.The aim of this study was to demonstrate the cardioprotective effect of Ivabradine via the AMPK/SIRT1/PGC-1αsignaling pathway in myocardial ischemia/reperfusion injury-induced in H9c2 cell.

Cardioprotective effects of Salvia miltiorrhiza Bunge and Lignum dalbergiae odoriferae on rat myocardial ischemia/reperfusion injury

Aim Salvia miltiorrhiza Bunge （SM） and lignum dalbergiae odoriferae （DO） are both traditional Chi- nese medicine that have cardioprotective effects. Here, we further examined the combined effects of SM and DO on rat myocardial ischemia/reperfusion injury. The possible mechanism of SM and DO also were elucidated. Methods DO was divided into aqueous extract of lignum dalbergiae odoriferae （DOW） and lignum dalbergiae odoriferae oil （DOO）. Sprague-Dawley rats were randomized to seven groups： sham group, model group, treatment groups inclu- ding SM （10 g · kg^-1）, DOW （5 g · kg^-1）, DOO （0.5 ml · kg^-1）, SM ＋ DOW （10 g · kg^-1 ＋ 5 g · kg^-1）, SM ＋ DOO （ 10 g · kg^-1 ＋ 0. 5 ml · kg^-1）. Rats were pretreated with homologous drug for 7 days and then subjec- ted to 30 rain of ischemia followed by 180 rain of reperfusion. Electrocardiogram （ECG） and heart rate were moni- tored and recorded continuously. At the end of reperfusion, blood samples were collected to determine the serum levels of creatine kinase-MB （CK-MB） and lactate dehydrogenase （LDH）. Hearts were harvested to assess heart- body rate, infarct size and histopathological changes as well. Maximum and minimum effective points were deter- mined by measuring indicators associate with myocardial injury at different time-points of reperfusion （Smin, 15min, 30min, 45rain, 60min, 120min, 180min）. The potential therapeutic mechanism of SM and SM ＋ DOO were carried out by detecting superoxide dismutase （SOD）, malondialdehyde （MDA）, tumor necrosis factor-alpha （TNF-alpha） and interleukin 6 （IL-6）. Results The results showed SM and DO can ameliorate cardiac function respectively, and this cardioprotective effect was further strengthened by their combinations. Among all the combi- nations, SM ＋ DOO showed predominant potential to improve ECG and heart rate, reduce heart-body rate （28.5% ＋ 1.4% , P 〈 0.01 vs model） and myocardial infarct size （ 20.96% ＋ 1.61% , P 〈 0.01 vs model, P 〈 0.05 vs SM） , attenuate histopathological damage, decrease the levels of CK-MB and LDH （P 〈 0.01 vs model, P 〈 0.05 vs SM）. The maximum effective points of SM and SM ＋ DOO were 15min and 30rain respectively, and the minimum effective points of them were 180rain. In reducing serum level of MDA, TNF-alpha, IL-6 and increasing SOD activ- ity, SM ＋ DOO was similar to SM. Conclusion The results of this study indicated that SM ＋ DOO have combined effects that are highly effective than single pretreatment against myocardial ischemie reperfusion injury in rats. The possible mechanism of SM and DO were likely through its anti-oxidant and anti-inflammatory properties, and thus may be an effective and promising medicine for both prophylaxis and treatment of ischemic heart disease.

Blocking the Aryl Hydrocarbon Receptor Alleviates Myocardial Ischemia/Reperfusion Injury in Rats

Objective Restoring the blood perfusion of ischemic heart tissues is the main treatment for myocardial ischemia.However,the accompanying myocardial ischemia reperfusion injury(IRI)would aggravate myocardial damage.Previous studies have confirmed that aryl hydrocarbon receptor(AhR)is closely correlated to kidney and intestinal IRI.The present study aimed to explore the relationship between AhR and myocardial IRI.Methods An oxygen glucose deprivation/reoxygenation(OGD/R)model of H9c2 cells and an ischemia/reperfusion(I/R)model of Sprague-Dawley rat myocardium were established.OGD/R cells and myocardial IRI rats were treated with different concentrations of the AhR antagonist CH-223191 or agonist 6-formylindolo[3,2-b]carbazole(FICZ).Under the conditions of normoxia and hypoxia/reoxygenation,the activity of cardiomyocytes,lactate dehydrogenase(LDH)and cell reactive oxygen species(ROS)were detected.In rats,myocardial pathological damage and markers of myocardial injury were detected.Results According to the results of the cell viability,LDH and ROS tests in vitro,both CH-223191 and FICZ showed no myocardial protection under OGD/R conditions.However,the histological staining and analysis of myocardial injury marker LDH in vitro revealed that CH-223191 could significantly reduce the myocardial IRI.Conclusion AhR exhibited a different effect on myocardial IRI in vitro and in vivo.In vivo,CH-223191 could significantly alleviate the myocardial IRI,suggesting that inhibition of AhR may play a role in myocardial protection,and AhR may serve as a potential treatment target for myocardial IRI.

Advances in molecular mechanism of myocardial ischemia/reperfusion injury

Myocardial ischemia/reperfusion(I/R)injury is a pathological change that occurs during the restoration of blood supply to ischemic or occluded coronary arteries after coronary heart disease,stroke,cardiac arrest and resuscitation,organ transplantation,shock and other events.Myocardial I/R injury is often accompanied by cardiovascular adverse events,which seriously affect the prognosis of myocardial ischemia.The potential mechanism of myocardial I/R injury is complex,involving many pathological processes,such as oxygen free radical injury,calcium overload,inflammation,apoptosis,activation,immune imbalance,endoplasmic reticulum stress,autophagy,myocardial energy metabolism disorder,myocardial microvascular endothelial cell injury and so on.Ischemic preconditioning is an effective preventive and therapeutic measure to reduce ischemia-reperfusion(I/R)injury.At present,there are many experimental studies on the pathogenesis and prevention and treatment measures,but the clinical application is still limited,so the prevention and treatment of I/R injury is still a major challenge.The pathogenesis of myocardial I/R injury is not completely clear,and the treatment methods and drugs are limited,so this paper summarizes the molecular mechanism and related signal pathways involved in its injury,as well as the emerging targeted therapy,to provide strategy and theoretical basis for clinical prevention and treatment of myocardial I/R injury.

Effect of remifentanil on toll-like receptor 4, NF-κB and IL-6 in rabbit myocardial ischemia/reperfusion model

Objective:To investigate whether remifentanil induced cardioprotecting effect is associated with expression of toll-like receptor 4(TLR4),nuclear factor κB(NF-κB) and serum interleukin-6(IL-6).Methods:Fifty rabbits were randomly divided into 5 groups(n=10) according to the treatment:sham operation group(group A),ischemia-reperfusion group(group B),low-dose remifentanil group(group C),mediate-dose remifentanil group(group D),and high-dose remifentanil group(group E).Myocardial TLR4 mRNA levels,NF-κB protein expression and serum levels of IL-6 were observed in 120 min after reperfusion.Results:The myocardial expressions of TLR4 mRNA,NF-κB protein and IL-6 level in sera of groups B,C,D and E were elevated compared with group A.However,remifentanil significantly reduced the levels of TLR4 mRNA,NF-κB protein expression and serum IL-6 in groups C,D and E compared with group B.There were remarkable differences between the groups(P<0.01).Conclusion:Intravenous remifentanil has protective effect against rabbit myocardial ischemia/reperfusion injury.This effect may be associated with TLR4,NF-κB expressions on myocytes and serum level of IL-6 in a dose-dependent manner.

Epac1/Rap1 signaling pathway is involved in the pathogenesis of myocardial ischemia/reperfusion injury in rats

OBJECTIVE In this study we explored the role of Epac1-Rap1 pathway in the acute myocardial ischemia/reperfusion injury(MIRI) in vitro and in vivo.METHODS An acute myocardial ischemia/reperfusion injury model was established by the ligation of left anterior descending coronary.Myocardial architecture,fibers and apoptosis was evaluated by the Masson trichrome staining,Sirius red staining and TUNEL assay.H9c2 cells were subjected to hypoxia for 5 h followed by 1-h reoxygen.ation in vitro.Cell viability was measured by MTT assay and cellular injury was evaluated by measuring the release of lactate dehydrogenase(LDH).Western blot,real-time PCR and immunofluorescence were used to detect the expressions of Epac1 and relative downstream molecules.RESULTS Myocardial IR-induced cardiac apoptosis and accumulation of Epac1 and Rap1 in rat IR injury model.Direct Epac activation by 8-CPT(8-(4-chlorophenylthio)-2′-O-methyl-cAMP) exacerbated cardiomyocyte death and dysfunction following hypoxia-reoxygenation(H/R),selective activation of Epac in response to H/R was evident which enriched for cytosolic/membrane proteins and mRNA.Harmacological inhibitor of Epac(ESI-09) significantly ameliorated myocardial injury with the decline of Epac expression.Epac inhibitor and agonist studies also implicated the effect of Rap1,which is downstream of Epac in this pathway.The expression of Rap1 elevated when activated by Epac agonist and was blocked by Epac inhibitor.The same result was true for myocyte CaMK-II and intracellular calcium ions activation.Moreover,ESI-09 also increased ERK1/2 phosphorylation.CONCLUSION Our study reveal that Epac1/Rap1 signaling pathway is involved in the pathogenesis of myocardial I/R injury in rats,which provides evidence on the development of therapeutic strategies target this pathway for myocardial I/R injury.

Cardioprotective Effects of Diazoxide on Myocardial Ischemia/Reperfusion Injury in Rats

In order to study the cardioprotective effects of diazoxide on the myocardial ische-mia/reperfusion injury of rats and mechanisms, the healthy SD rats were randomly divided into 2 groups: the rats in the experimental group were injected with diazoxide for preconditioning with the dosage of 12.5 mg/kg through the right femoral vein and those in the control group was only admin-istered with the equal volume of media. After 10 min, a left thoracotomy was performed and the left anterior descending branch was occluded for 2 h. Two h later, the left anterior descending branch was reperfused for 2 h and then the heart was quickly excised to be used for measurement of MDA, SOD and the infarct size, in situ cell apoptosis detection and observation of the cell ultrastructure by electron microscopy. The results showed that as compared with the control group, MDA, the infarct size and cell apoptosis in the experimental group were greatly reduced (P<0.05). And the cell ultrastructure was obviously improved. But the activity of SOD had no change (P>0.05). It was concluded that diazoxide could protect the rats from myocardial ischemia/reperfusion injury, which might be contributed to the reduction of lipid peroxidation and cell apoptosis.

Efficacy of Danlou tablet(丹蒌片)on myocardial ischemia/reperfusion injury assessed by network pharmacology and experimental verification

OBJECTIVE:To investigate the potential pharmacological mechanism of Danlou tablet(丹蒌片,DLT)with a long-term clinical application in the treatment of myocardial ischemia/reperfusion(I/R)injury through network pharmacology,molecular docking and experimental verification.METHODS:The main chemical ingredients in DLT were retrieved from the Traditional Chinese Medicine(TCM)System Pharmacology Database,the TCM information database,the bioinformatics analysis tool for molecular mechanism of TCM,and HERB database.Disease targets of I/R were accessed from the databases of Online Mendelian Inheritance in Man,Gene Cards,Therapeutic Target Database,and Dis Ge NET database.The overlaying genes of DLT and I/R were obtained from the Venny online platform.The core targets and proteinprotein interaction network were constructed and analyzed via the Search Tool for the Retrieval of Interacting Genes Proteins database and Cytoscape software.Furthermore,Gene Ontology(GO)analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analysis were performed by the Metascape platform.Based on the results,the component-target-pathway network was constructed and drafted via the Cytoscape software and the platform of Bioinformatics.Furthermore,we performed molecular docking to predict the binding information between chemical molecules and target proteins.Finally,oxygenglucose deprivation/recovery(OGD/R)-induced H9c2 cardiomyocytes were used to validate the results of network pharmacology in vitro.RESULTS:A total of 189 active chemical components in DLT and 849 correlative targets of I/R were screened.Of note,133 overlaying genes found from the Venny online platform were concentrated into 28 core genes.Furthermore,the GO and KEGG pathway enrichment analysis presented that DLT might participate in 42 types of GO molecular functions,747 types of GO biological processes,19 types of GO cellular components,and 140 kinds of pathways to treat I/R.In the component-targetpathway network,the indirect relationship between herbs and their possible effective pathways was clarified.Based on the molecular docking,we speculated that Baicalein-prostaglandin G/H synthase 2(PTGS2)with-3.24 kcal/mol,Luteolin-heat shock protein 90 alpha family class A member 1(HSP90AA1)with-3.22 kcal/mol,Baicalein-HSP90AA1 with-3.13 kcal/mol,and QuercetinHSP90AA1 with-3.05 kcal/mol possessed the strongest binding force of less than-3 kcal/mol,sequentially.Experimental verification showed that Quercetin,Luteolin,and Baicalein could increase the relative cell viability of OGD/R-stimulated cardiomyocytes,probably by suppressing PTGS2,and activating HSP90AA1 and estrogen receptor 1 expression.CONCLUSIONS:We predicted the potential active compounds as the material basis of DLT that may provide a new approach to elucidate the novel pharmacological mechanism underlying the treatment of cardiac I/R damage.

Role of Mitophagy in Myocardial Ischemia/Reperfusion Injury and Chinese Medicine Treatment

Mitophagy is one of the important targets for the prevention and treatment of myocardial ischemia/reperfusion injury(MIRI).Moderate mitophagy can remove damaged mitochondria,inhibit excessive reactive oxygen species accumulation,and protect mitochondria from damage.However,excessive enhancement of mitophagy greatly reduces adenosine triphosphate production and energy supply for cell survival,and aggravates cell death.How dysfunctional mitochondria are selectively recognized and engulfed is related to the interaction of adaptors on the mitochondrial membrane,which mainly include phosphatase and tensin homolog deleted on chromosome ten(PTEN)-induced kinase 1/Parkin,hypoxia-inducible factor-1α/Bcl-2 and adenovirus e1b19k Da interacting protein 3,FUN-14 domain containing protein 1 receptor-mediated mitophagy pathway and so on.In this review,the authors briefly summarize the main pathways currently studied on mitophagy and the relationship between mitophagy and MIRI,and incorporate and analyze research data on prevention and treatment of MIRI with Chinese medicine,thereby provide relevant theoretical basis and treatment ideas for clinical prevention of MIRI.