Humans ; Myocardial Reperfusion Injury/genetics* ; RNA, Long Noncoding/genetics* ; Myocytes, Cardiac ; Apoptosis ; Myocardial Ischemia

Humans ; Myocardial Reperfusion Injury/genetics* ; RNA, Long Noncoding/genetics* ; Myocytes, Cardiac ; Apoptosis ; Myocardial Ischemia

OBJECTIVE: To observe the effects of electroacupuncture (EA) pretreatment on cardiac function, sympathetic nerve activity, indexes of myocardial injury and GABA_A receptor in fastigial nucleus in rats with myocardial ischemia reperfusion injury (MIRI), and to explore the neuroregulatory mechanism of EA pretreatment in improving MIRI. METHODS: A total of 60 male SD rats were randomly divided into a sham operation group, a model group, an EA group, an agonist group and an agonist+EA group, 12 rats in each group. The MIRI model was established by ligation of the left anterior descending coronary artery. EA was applied at bilateral "Shenmen" (HT 7) and "Tongli" (HT 5) in the EA group and the agonist+EA group, with continuous wave, in frequency of 2 Hz and intensity of 1 mA, 30 min each time, once a day for 7 consecutive days. After intervention, the MIRI model was established. In the agonist group, the muscone (agonist of GABA_A receptor, 1 g/L) was injected in fastigial nucleus for 7 consecutive days before modeling, 150 μL each time, once a day. In the agonist+EA group, the muscone was injected in fastigial nucleus 30 min before EA intervention. The data of electrocardiogram was collected by PowerLab standard Ⅱ lead, and ST segment displacement and heart rate variability (HRV) were analyzed; the serum levels of norepinephrine (NE), creatine kinase isoenzyme MB (CK-MB) and cardiac troponin I (cTnI) were detected by ELISA; the myocardial infarction area was measured by TTC staining; the morphology of myocardial tissue was observed by HE staining; the positive expression and mRNA expression of GABA_A receptor in fastigial nucleus were detected by immunohistochemistry and real-time PCR. RESULTS: Compared with the sham operation group, in the model group, ST segment displacement and ratio of low frequency to high frequency (LF/HF) of HRV were increased (P<0.01), HRV frequency domain analysis showed enhanced sympathetic nerve excitability, the serum levels of NE, CK-MB and cTnI were increased (P<0.01), the percentage of myocardial infarction area was increased (P<0.01), myocardial fiber was broken and interstitial edema was serious, the positive expression and mRNA expression of GABA_A receptor in fastigial nucleus were increased (P<0.01). Compared with the model group, in the EA group, ST segment displacement and LF/HF ratio were decreased (P<0.01), HRV frequency domain analysis showed reduced sympathetic nerve excitability, the serum levels of NE, CK-MB and cTnI were decreased (P<0.01), the percentage of myocardial infarction area was decreased (P<0.01), myocardial fiber breakage and interstitial edema were lightened, the positive expression and mRNA expression of GABA_A receptor in fastigial nucleus were decreased (P<0.01). Compared with the EA group, in the agonist group and the agonist+EA group, ST segment displacement and LF/HF ratio were increased (P<0.01), HRV frequency domain analysis showed enhanced sympathetic nerve excitability, the serum levels of NE, CK-MB and cTnI were increased (P<0.01), the percentage of myocardial infarction area was increased (P<0.01), myocardial fiber breakage and interstitial edema were aggravated, the positive expression and mRNA expression of GABA_A receptor in fastigial nucleus were increased (P<0.01). CONCLUSION EA pretreatment can improve the myocardial injury in MIRI rats, and its mechanism may be related to the inhibition of GABA_A receptor expression in fastigial nucleus, thereby down-regulating the excitability of sympathetic nerve.
Male ; Animals ; Rats ; Rats, Sprague-Dawley ; Cerebellar Nuclei ; Electroacupuncture ; Myocardial Reperfusion Injury/therapy* ; Receptors, GABA-A/genetics* ; RNA, Messenger

BACKGROUND: Dysfunction of the gap junction channel protein connexin 43 (Cx43) contributes to myocardial ischemia/reperfusion (I/R)-induced ventricular arrhythmias. Cx43 can be regulated by small ubiquitin-like modifier (SUMO) modification. Protein inhibitor of activated STAT Y (PIASy) is an E3 SUMO ligase for its target proteins. However, whether Cx43 is a target protein of PIASy and whether Cx43 SUMOylation plays a role in I/R-induced arrhythmias are largely unknown. METHODS: Male Sprague-Dawley rats were infected with PIASy short hairpin ribonucleic acid (shRNA) using recombinant adeno-associated virus subtype 9 (rAAV9). Two weeks later, the rats were subjected to 45 min of left coronary artery occlusion followed by 2 h reperfusion. Electrocardiogram was recorded to assess arrhythmias. Rat ventricular tissues were collected for molecular biological measurements. RESULTS: Following 45 min of ischemia, QRS duration and QTc intervals statistically significantly increased, but these values decreased after transfecting PIASy shRNA. PIASy downregulation ameliorated ventricular arrhythmias induced by myocardial I/R, as evidenced by the decreased incidence of ventricular tachycardia and ventricular fibrillation, and reduced arrythmia score. In addition, myocardial I/R statistically significantly induced PIASy expression and Cx43 SUMOylation, accompanied by reduced Cx43 phosphorylation and plakophilin 2 (PKP2) expression. Moreover, PIASy downregulation remarkably reduced Cx43 SUMOylation, accompanied by increased Cx43 phosphorylation and PKP2 expression after I/R. CONCLUSION PIASy downregulation inhibited Cx43 SUMOylation and increased PKP2 expression, thereby improving ventricular arrhythmias in ischemic/reperfused rats heart.
Rats ; Male ; Animals ; Myocardial Reperfusion Injury/metabolism* ; Connexin 43/genetics* ; Sumoylation ; Down-Regulation ; Rats, Sprague-Dawley ; Arrhythmias, Cardiac/drug therapy* ; Myocardial Ischemia/metabolism* ; RNA, Small Interfering/metabolism*

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-1 α/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.
Humans ; Mitochondria/metabolism* ; Mitophagy/genetics* ; Myocardial Reperfusion Injury ; Protein Kinases/metabolism*

BACKGROUND: Sarcoplasmic reticulum calcium ATPase 2a (SERCA2a) is a key protein that maintains myocardial Ca 2+ homeostasis. The present study aimed to investigate the mechanism underlying the SERCA2a-SUMOylation (small ubiquitin-like modifier) process after ischemia/reperfusion injury (I/RI) in vitro and in vivo . METHODS: Calcium transient and systolic/diastolic function of cardiomyocytes isolated from Serca2a knockout (KO) and wild-type mice with I/RI were compared. SUMO-relevant protein expression and localization were detected by quantitative real-time PCR (RT-qPCR), Western blotting, and immunofluorescence in vitro and in vivo . Serca2a-SUMOylation, infarct size, and cardiac function of Senp1 or Senp2 overexpressed/suppressed adenovirus infected cardiomyocytes, were detected by immunoprecipitation, triphenyltetrazolium chloride (TTC)-Evans blue staining, and echocardiography respectively. RESULTS: The results showed that the changes of Fura-2 fluorescence intensity and contraction amplitude of cardiomyocytes decreased in the I/RI groups and were further reduced in the Serca2a KO + I/RI groups. Senp1 and Senp2 messenger ribose nucleic acid (mRNA) and protein expression levels in vivo and in cardiomyocytes were highest at 6 h and declined at 12 h after I/RI. However, the highest levels in HL-1 cells were recorded at 12 h. Senp2 expression increased in the cytoplasm, unlike that of Senp1. Inhibition of Senp2 protein reversed the I/RI-induced Serca2a-SUMOylation decline, reduced the infarction area, and improved cardiac function, while inhibition of Senp1 protein could not restore the above indicators. CONCLUSION I/RI activated Senp1 and Senp2 protein expression, which promoted Serca2a-deSUMOylation, while inhibition of Senp2 expression reversed Serca2a-SUMOylation and improved cardiac function.
Animals ; Mice ; Calcium/metabolism* ; Cysteine Endopeptidases/metabolism* ; Myocardial Reperfusion Injury/metabolism* ; Myocardium/metabolism* ; Myocytes, Cardiac/metabolism* ; Proteins/metabolism* ; Sarcoplasmic Reticulum Calcium-Transporting ATPases/genetics*

Objective To explore the role and mechanism of microRNA-204(miR-204) carried by the exosomes of human umbilical cord-derived mesenchymal stem cells(hUC-MSC) in regulating the polarization of macrophages in a mouse model of myocardial ischemia-reperfusion(I/R) injury. Methods After the hUC-MSCs were isolated,cultured,and identified,their adipogenic and osteogenic differentiation capabilities were determined.The exosomes of hUC-MSCs were separated by ultracentrifugation,and the expression of CD81,CD63,tumor susceptibility gene 101(Tsg101),and calnexin in the exosomes was determined by Nanoparticle Tracking Analysis software,transmission electron microscopy,and Western blotting.Three groups(hUC-MSC,miR-204 mimic,and negative control) were designed for the determination of the expression of miR-204 in the cells and their exosomes by qRT-PCR.The C57BL/6J mice were randomly assigned into a sham operation group,an I/R group,a hUC-MSC exosomes group,a negative control group,and a miR-204 mimic group.Except the sham operation group,the I/R model was established by ligating the left anterior descending artery.The echocardiography system was employed to detect the heart function of mice.HE staining was employed to observe the pathological changes of mouse myocardium.ELISA was employed to determine the levels of interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),arginase 1(Arg-1),and IL-10 in the myocardial tissue.After the macrophages of mouse myocardial tissue were isolated,flow cytometry was employed to determine the expression of CD11c and CD206,and ELISA to measure the levels of IL-1β,TNF-α,Arg-1,and IL-10 in the macrophages. Results hUC-MSCs had adipogenic and osteogenic differentiation capabilities,and the exosomes were successfully identified.Compared with the negative control group,the miR-204 mimic group showed up-regulated expression of miR-204 in hUC-MSCs and their exosomes(P<0.001,P<0.001).Compared with the sham operation group,the modeling of I/R increased the left ventricular end-diastolic diameter(LVEDD)(P<0.001),left ventricular end-systolic diameter(LVESD)(P<0.001),myocardial injury score(P<0.001),and the levels of IL-1β(P<0.001),TNF-α(P<0.001),and CD11c(P<0.001).Meanwhile,it lowered the left ventricular ejection fraction(LVEF)(P<0.001),left ventricular fractional shortening(LVFS)(P<0.001),Arg-1(P<0.001),IL-10(P<0.001),and CD206(P<0.001).Compared with those in the I/R group,the LVEDD(P<0.001),LVESD(P<0.001),myocardial injury score(P<0.001),and the levels of IL-1β(P<0.001),TNF-α(P=0.010),and CD11c(P<0.001) reduced,while LVEF(P<0.001),LVFS(P<0.001),and the levels of Arg-1(P<0.001),IL-10(P=0.028),and CD206(P=0.022) increased in the hUC-MSC exosomes group.Compared with those in the negative control group,the LVEDD(P<0.001),LVESD(P<0.001),myocardial injury score(P=0.001),and the levels of IL-1β(P=0.048),TNF-α(P<0.001),and CD11c(P=0.007) reduced,while the LVEF(P<0.001),LVFS(P<0.001),and the levels of Arg-1(P<0.001),IL-10(P=0.001),and CD206(P=0.001) increased in the miR-204 mimic group. Conclusion The hUC-MSC exosomes overexpressing miR-204 can inhibit the polarization of macrophages in the I/R mouse model to M1-type and promote the polarization to M2-type.
Animals ; Humans ; Mice ; Disease Models, Animal ; Exosomes/pathology* ; Interleukin-10/metabolism* ; Macrophages ; Mesenchymal Stem Cells ; Mice, Inbred C57BL ; MicroRNAs/genetics* ; Myocardial Reperfusion Injury ; Osteogenesis ; Stroke Volume ; Tumor Necrosis Factor-alpha/metabolism* ; Umbilical Cord/pathology* ; Ventricular Function, Left

Animals ; Apoptosis ; Bridged Bicyclo Compounds, Heterocyclic/pharmacology* ; Cell Line ; Hypoxia ; MicroRNAs/genetics* ; Myocardial Reperfusion Injury/drug therapy* ; Myocytes, Cardiac ; Oxidative Stress ; Rats ; Reperfusion Injury ; Tetrahydronaphthalenes/pharmacology*

The study aims to investigate the effect of the compatibility of paeonol and paeoniflorin(hereinafter referred to as the compatibility) on the expression of myocardial proteins in rats with myocardial ischemia injury and explore the underlying mechanism of the compatibility against myocardial ischemia injury. First, the acute myocardial infarction rat model was established by ligation of the anterior descending branch of the left coronary artery. The model rats were given(ig) paeonol and paeoniflorin. Then protein samples were collected from rat cardiac tissue and quantified by tandem mass tags(TMT) to explore the differential proteins after drug intervention. The experimental results showed that differential proteins mainly involved phagocytosis engulfment, extracellular space, and antigen binding, as well as Kyoto encyclopedia of genes and genomes(KEGG) pathways of complement and coagulation cascades, syste-mic lupus erythematosus, and ribosome. In this study, the target proteins and related signaling pathways identified by differential proteomics may be the biological basis of the compatibility against myocardial ischemia injury in rats.
Acetophenones ; Animals ; Glucosides ; Monoterpenes ; Myocardial Ischemia/genetics* ; Myocardial Reperfusion Injury ; Proteomics ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To study the effect of silencing LncRNA SNHG7 on hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury and its targeted regulation on miR-181b-5p. METHODS: Rat cardiomyocytes H9c2 were cultured in vitro and randomly divided into control group, H/R group, H/R + si-NC group, H/R + si-SNHG7 group, H/R + si-SNHG7 + anti-miR-NC group and H/R + si-SNHG7 + anti-miR-181b-5p group. The content of lactate dehydrogenase (LDH), malondialedhyde (MDA) and the activity of superoxide dismutase (SOD) were detected. Flow cytometry was carried out to detect the rate of apoptosis. qRT-PCR was used to detect the expression of SNHG7 and miR-181b-5p. Dual luciferase report experiment was used to verify the targeting relationship between SNHG7 and miR-181b-5p. Western blotting was used to detect the expression of Bax and Bcl-2. RESULTS: Compared with the control group, the H/R group showed significantly increased SNHG7 expression in cardiomyocytes, reduced miR-181b-5p expression, higher levels of LDH and MDA, reduced activity of SOD, increased cell apoptosis rate, higher level of Bax protein, and reduced level of Bcl-2 protein (all P< 0.05). Compared with the H/R and H/R + si-NC groups, the H/R + si-SNHG7 group had significantly reduced level of LDH and MDA, increased activity of SOD, reduced apoptosis rate, reduced level of Bax protein, increased level of Bcl-2 protein (all P< 0.05). The dual luciferase report experiment confirmed that SNHG7 could target miR-181b-5p. Interference with the expression of miR-181b-5p could reduce the effect of silencing SNHG7 on H/R-induced cardiomyocyte oxidative stress and apoptosis. CONCLUSION Silencing SNHG7 may inhibit H/R-induced cardiomyocyte oxidative stress and apoptosis by up-regulating the expression of miR-181b-5p, thereby exerting a protective effect on cardiomyocytes.
Animals ; Apoptosis ; Hypoxia ; MicroRNAs/genetics* ; Myocardial Reperfusion Injury ; Myocytes, Cardiac ; RNA, Long Noncoding/genetics* ; Rats