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*

OBJECTIVE: To explore the effect of Kuanxiong Aerosol (KXA) on isoproterenol (ISO)-induced myocardial injury in rat models. METHODS: Totally 24 rats were radomly divided into control, ISO, KXA low-dose and high-dose groups according to the randomized block design method, and were administered by intragastric administration for 10 consecutive days, and on the 9th and 10th days, rats were injected with ISO for 2 consecutive days to construct an acute myocardial ischemia model to evaluate the improvement of myocardial ischemia by KXA. In addition, the diastolic effect of KXA on rat thoracic aorta and its regulation of ion channels were tested by in vitro vascular tension test. The influence of KXA on the expression of calcium-CaM-dependent protein kinase II (CaMK II)/extracellular regulated protein kinases (ERK) signaling pathway has also been tested. RESULTS: KXA significantly reduced the ISO-induced increase in ST-segment, interventricular septal thickness, cardiac mass index and cardiac tissue pathological changes in rats. Moreover, the relaxation of isolated thoracic arterial rings that had been precontracted using norepinephrine (NE) or potassium chloride (KCl) was increased after KXA treatment in an endothelium-independent manner, and was attenuated by preincubation with verapamil, but not with tetraethylammonium chloride, 4-aminopyridine, glibenclamide, or barium chloride. KXA pretreatment attenuated vasoconstriction induced by CaCl₂ in Ca²⁺-free solutions containing K⁺ or NE. In addition, KXA pretreatment inhibited accumulation of Ca²⁺ in A7r5 cells mediated by KCl and NE and significantly decreased p-CaMK II and p-ERK levels. CONCLUSION KXA may inhibit influx and release of calcium and activate the CaMK II/ERK signaling pathway to produce vasodilatory effects, thereby improving myocardial injury.
Aerosols ; Animals ; Aorta, Thoracic ; Calcium/metabolism* ; Endothelium, Vascular/metabolism* ; Myocardial Ischemia/metabolism* ; Rats ; Vasodilation

OBJECTIVE: To observe the effect of electroacupuncture (EA) on vascular endothelial growth factor-C (VEGF-C), vascular endothelial growth factor receptor-3 (VEGFR-3), proinflammatory factors and apoptosis in myocardial tissue in mice with acute myocardial ischemia (AMI), and to explore the mechanism of EA for AMI. METHODS: Fifty male C57BL/6 mice were randomly divided into a sham operation group, a model group, an EA group, an inhibitor group and an inhibitor+EA group, 10 mice in each group. Except for the sham operation group, the mice in the remaining groups were intervented with ligation at the left anterior descending (LAD) coronary artery to establish AMI model. The mice in the sham operation group were intervented without ligation after thoracotomy. The mice in the EA group were intervented with EA at "Shenmen" (HT 7) and "Tongli" (HT 5), disperse-dense wave, 2 Hz/15 Hz in frequency, 1 mA in current intensity, 30 min each time, once a day, for 3 d. The mice in the inhibitor group were treated with intraperitoneal injection of SAR 131675 (12.5 mg•kg^-1•d^-1, once a day for 3 d). The mice in the inhibitor+EA group were injected intraperitoneally with SAR 131675 30 min before EA. The ECG before modeling, 30 min after modeling and 3 d after intervention was detected, and the ST segment displacement was recorded; after the intervention, the ELISA method was applied to measure the contents of serum creatine kinase isoenzyme (CK-MB), aspartate aminotransferase (AST) as well as tumor necrosis factor-α (TNF-α) and interleukin-23 (IL-23) in myocardial tissue; the HE staining method was used to observe the morphological changes of myocardial tissue; the immunofluorescence double labeling method was applied to measure the number of co-expression positive cells of VEGF-C/VEGFR-3 in myocardial tissue; the TUNEL method was used to detect the level of cardiomyocyte apoptosis; the Western blot method was applied to measure the protein expressions of VEGF-C, VEGFR-3, b-lymphoma-2 (Bcl-2), activated caspase-3 (Cleaved Caspase-3) and activated poly adenosine diphosphate ribose polymerase-1 (Cleaved PARP-1). RESULTS: Compared with the sham operation group, in the model group the ST segment displacement was increased (P<0.01); the contents of CK-MB, AST, TNF-α and IL-23 were increased (P<0.01); the arrangement of myocardial fibers was disordered, and interstitial inflammatory cell infiltration was obvious; the number of co-expression positive cells of VEGF-C/VEGFR-3 was decreased (P<0.01); the number of cardiomyocyte apoptosis was increased (P<0.01); the expressions of VEGF-C, VEGFR-3 and Bcl-2 were decreased (P<0.01); the expressions of Cleaved Caspase-3 and Cleaved PARP-1 were increased (P<0.01). Compared with the model group, in the EA group the ST segment displacement was decreased (P<0.01); the contents of CK-MB, AST, TNF-α, IL-23 were decreased (P<0.01); the severity of myocardial pathological injury was reduced; the number of co-expression positive cells of VEGF-C/VEGFR-3 was increased (P<0.01); the number of cardiomyocyte apoptosis was reduced (P<0.01); the expressions of VEGF-C, VEGFR-3 and Bcl-2 were increased (P<0.01); the expressions of Cleaved Caspase-3 and Cleaved PARP-1 were reduced (P<0.01). There was no significant difference in all the indexes between the model group and the inhibitor group (P>0.05). Compared with the model group, the protein expression of VEGF-C was increased in the inhibitor+EA group (P<0.01). Compared with the inhibitor group, in the EA group the ST segment displacement was decreased (P<0.01); the contents of CK-MB, AST, TNF-α, IL-23 were decreased (P<0.01); the severity of myocardial pathological injury was reduced; the number of co-expression positive cells of VEGF-C/VEGFR-3 was increased (P<0.05); the number of cardiomyocyte apoptosis was reduced (P<0.01); the expressions of VEGF-C, VEGFR-3 and Bcl-2 were increased (P<0.01); the expressions of Cleaved Caspase-3 and Cleaved PARP-1 were reduced (P<0.01). Compared with the inhibitor+EA group, all the indexes in the EA group were improved except the protein expression of VEGF-C (P<0.01). CONCLUSION EA could relieve the inflammatory reaction and apoptosis in AMI mice, and its mechanism may be related to activating VEGF-C/VEGFR-3 pathway and promoting lymphangion genesis.
Mice ; Male ; Animals ; Electroacupuncture ; Vascular Endothelial Growth Factor Receptor-3 ; Caspase 3 ; Vascular Endothelial Growth Factor C ; Tumor Necrosis Factor-alpha/genetics* ; Vascular Endothelial Growth Factor A/genetics* ; Poly(ADP-ribose) Polymerase Inhibitors ; Mice, Inbred C57BL ; Myocardial Ischemia/metabolism* ; Apoptosis ; Interleukin-23 ; Proto-Oncogene Proteins c-bcl-2

This study established the EA.hy926 cell myocardial ischemia model to compare the effects of two Kaixin Powder prescriptions, Buxin Decoction(BXD) and Dingzhi Pills(DZP), at three dosages(500, 200, and 100 μg·mL~(-1)) on the cell viability. Further, the public databases(TCMSP, TCMID, SYMMAP, and STRING) and the network pharmacology methods such as KEGG pathway enrichment were employed to decipher the possible molecular mechanism of BXD in exerting the cardioprotective effect. The pharmacological effect of BXD was evaluated with the rat model of isoprenaline(ISO)-induced myocardial ischemia. The expression levels of proteins involved in the phosphatidylinositol-3-kinase/protein kinase B(PI3 K/AKT) signaling pathway were measured by Western blot. BXD significantly increased the viability of EA.hy926 cells, showing the performance superior to DZP. The network pharmacology analysis predicted that BXD might exert cardiac protection through the PI3 K/AKT signaling pathway. The in vivo experiment on rats showed that BXD treatment significantly increased the cardiac ejection fraction(EF), fractional shortening(FS), diastolic left ventricular anterior wall(LVAWd), systolic left ventricular anterior wall(LVAWs), and diastolic left ventricular posterior wall(LVPWd), significantly decreased the beat per minute(BPM) and diastolic left ventricular internal diameter(LVIDd), and significantly improved the ST segment in the electrocardiogram. The pathological results(Masson staining) showed that BXD restored the myocardial thickness, decreased the collagen fiber, increased the muscle fiber, and reduced the infarct area to alleviate myocardial ischemia. Furthermore, BXD lowered the serum levels of inflammatory cytokines [tumor necrosis factor-α(TNF-α) and interleukin-6(IL-6)] and myocardial enzymes [creatine kinase(CK) and lactate dehydrogenase(LDH)], increased the p-AKT/AKT ratio, up-regulated the protein levels of PI3 K, NF-κB, IKK-α, and Bcl-xl, and down-regulated that of the apoptotic protein Bax. In conclusion, BXD may exert cardiac protection effect by regulating the PI3 K/AKT signaling pathway.
Rats ; Animals ; Proto-Oncogene Proteins c-akt/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Powders ; Network Pharmacology ; Signal Transduction ; Myocardial Ischemia ; Myocardium/pathology* ; Creatine Kinase ; Interleukin-6/metabolism* ; Tumor Necrosis Factor-alpha/metabolism* ; Prescriptions

OBJECTIVE: To examine the effect of Shenmai Injection (SMJ) on ferroptosis during myocardial ischemia reperfusion (I/R) injury in rats and the underlying mechanism. METHODS: A total of 120 SPF-grade adult male SD rats, weighing 220-250 g were randomly divided into different groups according to a random number table. Myocardial I/R model was established by occluding the left anterior descending artery for 30 min followed by 120 min of reperfusion. SMJ was injected intraperitoneally at the onset of 120 min of reperfusion, and erastin (an agonist of ferroptosis), ferrostatin-1 (Fer-1, an inhibitor of ferroptosis) and ML385 (an inhibitor of nuclear factor erythroid-2 related factor 2 (Nrf2)) were administered intraperitoneally separately 30 min before myocardial ischemia as different pretreatments. Cardiac function before ischemia, after ischemia and after reperfusion was analysed. Pathological changes in the myocardium and the ultrastructure of cardiomyocytes were observed, and the myocardial infarction area was measured. Additionally, the concentration of Fe²⁺ in heart tissues and the levels of creatine kinase-MB (CK-MB), troponin I (cTnl), malondialdehyde (MDA) and superoxide dismutase (SOD) in serum were measured using assay kits, and the expressions of Nrf2, glutathione peroxidase 4 (GPX4) and acyl-CoA synthetase long-chain family member 4 (ACSL4) were examined by Western blot. RESULTS: Compared with the sham group, I/R significantly injured heart tissues, as evidenced by the disordered, ruptured and oedematous myocardial fibres; the increases in infarct size, serum CK-MB, cTnI and MDA levels, and myocardial Fe²⁺ concentrations; and the decreases in SOD activity (P<0.05). These results were accompanied by ultrastructural alterations to the mitochondria, increased expression of ACSL4 and inhibited the activation of Nrf2/GPX4 signalling (P<0.05). Compared with I/R group, pretreatment with 9 mL/kg SMJ and 2 mg/kg Fer-1 significantly reduced myocardial I/R injury, Fe²⁺ concentrations and ACSL4 expression and attenuated mitochondrial impairment, while 14 mg/kg erastin exacerbated myocardial I/R injury (P<0.05). In addition, cardioprotection provided by 9 mL/kg SMJ was completely reversed by ML385, as evidenced by the increased myocardial infarct size, CK-MB, cTnI, MDA and Fe²⁺ concentrations, and the decreased SOD activity (P<0.05). CONCLUSIONS Ferroptosis is involved in myocardial I/R injury. Pretreatment with SMJ alleviated myocardial I/R injury by activating Nrf2/GPX4 signalling-mediated ferroptosis, thereby providing a strategy for the prevention and treatment of ischemic heart diseases.
Animals ; Male ; Rats ; Coenzyme A ; Creatine Kinase ; Ferroptosis ; Ligases ; Malondialdehyde ; Myocardial Infarction/drug therapy* ; Myocardial Ischemia/drug therapy* ; Myocardial Reperfusion Injury/pathology* ; Myocytes, Cardiac/metabolism* ; NF-E2-Related Factor 2/metabolism* ; Phospholipid Hydroperoxide Glutathione Peroxidase ; Rats, Sprague-Dawley ; Superoxide Dismutase/metabolism* ; Troponin I

OBJECTIVE: To observe the effects of electroacupuncture (EA) pretreatment on the cardiac ejection fraction (EF), the number of macrophages in spleen and heart, and the expression of nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3) and interleukin-1β (IL-1β) in myocardium in mice with acute myocardial ischemia, and to explore the possible mechanism of EA pretreatment on promoting myocardial protection. METHODS: A total of 30 male C57BL/6J mice were randomly divided into a control group, a model group and an EA pretreatment group, 10 rats in each group. The acute myocardial ischemia model was established by ligating the left anterior descending branch of the coronary artery in the model group and EA pretreatment group, while threading but no ligating at left anterior descending branch of the coronary artery was applied in the control group. In the EA pretreatment group, mice were intervented with EA at bilateral "Neiguan" (PC 6), disperse-dense wave, frequency of 2 Hz/15 Hz, intensity of 2 mA; each EA treatment last for 20 min, once a day, and 3-day treatment was given before model establishment. The EF value was evaluated by ultrasonic cardiogram; the number of macrophages in spleen and heart was measured by flow cytometry; the expression level of NLRP3 and IL-1β in myocardium was measured by Western blot. RESULTS: Compared with the control group, the EF value was decreased in the model group (<0.001), the number of macrophages in the heart and spleen was increased (<0.001), and the expression level of NLRP3 and IL-1β in the myocardium was increased (<0.001, <0.01). Compared with the model group, the EF value was increased in the EA pretreatment group (<0.01), the number of macrophages in the heart and spleen was decreased (<0.01), and the expression level of NLRP3 and IL-1β in the myocardium was decreased (<0.01, <0.05). CONCLUSION EA pretreatment could reduce the number of macrophages in spleen and heart, down-regulate the expression of NLRP3 and IL-1β in myocardial tissue in mice with acute myocardial ischemia, which could relieve the local inflammatory response and achieve the myocardial protective effect.
Acupuncture Points ; Animals ; Electroacupuncture ; Heart ; physiology ; Inflammation ; immunology ; Interleukin-1beta ; metabolism ; Macrophages ; cytology ; Male ; Mice ; Mice, Inbred C57BL ; Myocardial Ischemia ; immunology ; therapy ; Myocardium ; NLR Family, Pyrin Domain-Containing 3 Protein ; metabolism ; Random Allocation ; Spleen

BACKGROUND: High on-treatment platelet reactivity (HTPR) has been suggested as a risk factor for patients with ischemic vascular disease. We explored a predictive model of platelet reactivity to clopidogrel and the relationship with clinical outcomes. METHODS: A total of 441 patients were included. Platelet reactivity was measured by light transmittance aggregometry after receiving dual antiplatelet therapy. HTPR was defined by the consensus cutoff of maximal platelet aggregation >46% by light transmittance aggregometry. CYP2C19 loss-of-function polymorphisms were identified by DNA microarray analysis. The data were compared by binary logistic regression to find the risk factors. The primary endpoint was major adverse clinical events (MACEs), and patients were followed for a median time of 29 months. Survival curves were constructed with Kaplan-Meier estimates and compared by log-rank tests between the patients with HTPR and non-HTPR. RESULTS: The rate of HTPR was 17.2%. Logistic regression identified the following predictors of HTPR: age, therapy regimen, body mass index, diabetes history, CYP2C192, or CYP2C193 variant. The area under the curve of receiver operating characteristic for the HTPR predictive model was 0.793 (95% confidence interval: 0.738-0.848). Kaplan-Meier analysis showed that patients with HTPR had a higher incidence of MACE than those with non-HTPR (21.1% vs. 9.9%; χ = 7.572, P = 0.010). CONCLUSIONS Our results suggest that advanced age, higher body mass index, treatment with regular dual antiplatelet therapy, diabetes, and CYP2C192 or CYP2C193 carriers are significantly associated with HTPR to clopidogrel. The predictive model of HTPR has useful discrimination and good calibration and may predict long-term MACE.
Aged ; Blood Platelets ; drug effects ; Clopidogrel ; pharmacology ; therapeutic use ; Coronary Artery Disease ; metabolism ; prevention & control ; Cytochrome P-450 CYP2C19 ; metabolism ; Female ; Genotype ; Glycated Hemoglobin A ; metabolism ; Humans ; Kaplan-Meier Estimate ; Logistic Models ; Male ; Middle Aged ; Multivariate Analysis ; Myocardial Ischemia ; metabolism ; prevention & control ; Regression Analysis

Syringa pinnatifolia Hemsl.( SP) is a representative Mongolian folk medicine with the effects of inhibiting Heyi related diseases,clearing heat and relieving pain. It has been used for the treatment of Heyi-induced heart tingling,heart palpitations,upset,insomnia and other symptoms. Total ethanol extract( T) and major fraction( M) of SP have been evaluated its anti-ischemic effects,and the mechanism was related to the regulation of cyclooxygenase( COX)-mediated inflammatory pathway and p53-mediated apoptosis pathway in our previous studies. This study reports the chemical fractionation on M by which to obtain subfractions( I and M_3),and the pharmacological evaluation of M,I,and M_3 against myocardial ischemia in mice. The result showed that I and M reduced the values of LVEDd and LVEDs,significantly increased EF and FS values,increased serum CK-MB and LDH levels in mice,and reduced in inflammatory cells infiltration and collagen deposition in the infarcted myocardial tissue,suggesting that M and I possess the same degree anti-myocardial is chemia equally whereas M_3 has no this effect. Related mechanism studies suggested that I can reduce the expression of COX-1,COX-2 and p53 protein in myocardial tissue in a dose-dependent manner. This study lays the foundation for further chemical segmentation and clarification of pharmacological substance groups,paving the way for the full use and benefits to be use of systematic biological methods to analyze the pharmacological basis of SP against myocardial ischemia.
Animals ; Cyclooxygenase 1/metabolism* ; Cyclooxygenase 2/metabolism* ; Heart/drug effects* ; Medicine, Mongolian Traditional ; Membrane Proteins/metabolism* ; Mice ; Myocardial Ischemia/drug therapy* ; Myocardium/metabolism* ; Plant Extracts/therapeutic use* ; Syringa/chemistry* ; Tumor Suppressor Protein p53/metabolism*

OBJECTIVETo observe the effects of electroacupuncture (EA) on inflammatory reaction of acute myocardial ischemia (MI) in mice, and to explore its action mechanism.

METHODSForty adult male C57BL/6 mice were randomly divided into a control group, a sham operation group, a model group and an EA group, 10 mice in each one. The model was established in the model group and EA group by ligating the left anterior descending branch of coronary artery. The mice in the EA group were treated with EA at "Neiguan" (PC 6) with 2 mA of intensity and 2 Hz /100 Hz of frequency; EA was given 30 min per treatment, once a day for totally 5 days. The mice in the control group and model group were treated with immobilization and no EA was given. The mice in the sham operation group were not treated with ligating at the left anterior descending branch of coronary artery, but the remaining procedure was identical to the model group. The electrocardiogram was recorded and △ST was calculated to evaluate the model. TTC and HE staining methods were applied to evaluate the infarct size and pathologic change of myocardial tissue, respectively. Western blot method was applied to test the protein expression levels of tumor necrosis factor-α (TNF-α), nuclear factor-κB p65 (NF-κB p65), interleukin-1β (IL-1β) and interleukin-8 (IL-8).

RESULTSCompared with the sham operation group, the S-T segments in the model group and EA group were increased obviously after modeling (both <0.01), indicating the MI model was established successfully. The TTC and HE staining results indicated, compared with the sham operation group, the model group had larger infarction size (<0.01), more myocardial fibers injury and inflammatory infiltration; compared with the model group, the infarction size of the EA group was significantly reduced (<0.01), and the myocardial fibers injury and inflammatory infiltration were improved. Compared with the control group, the protein expression levels in the sham operation group were similar (all >0.05); compared with the sham operation group, the expression levels of TNF-α, NF-κB p65, IL-1β and IL-8 were significantly increased in the model group (<0.01, <0.05); compared with the model group, the expression levels of TNF-α, NF-κB p65, IL-1β and IL-8 were significantly reduced in the EA group (all <0.05).

CONCLUSIONEA might reduce the protein expression levels of TNF-α, NF-κB p65, IL-1β and IL-8 in cardiac muscle tissue to inhibit inflammatory reaction and achieve myocardial protective effect in mice with acute myocardial ischemia.

Animals ; Electroacupuncture ; Inflammation ; therapy ; Interleukin-1beta ; metabolism ; Interleukin-8 ; metabolism ; Male ; Mice ; Mice, Inbred C57BL ; Myocardial Ischemia ; therapy ; Myocardium ; pathology ; Random Allocation ; Transcription Factor RelA ; metabolism ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVES: To observe the expression changes of hypoxia inducible factor-1α（HIF-1α） and vascular endothelial growth factor-A （VEGF-A） in rats with arrhythmias, and to explore the differences of the expression pattern in the two indicators of acute myocardial ischemia caused by arrhythmias and coronary insufficiency. METHODS: The arrhythmia was induced by CaCl₂, and the expression changes of HIF-1α and VEGF-A were detected by immunohistochemistry, Western blotting and real-time PCR within 6 h after the arrhythmia in rats. RESULTS: The expression of HIF-1α and VEGF-A showed diffuse in the myocardial tissue of rats died from arrhythmias. Both of them increased in the early arrhythmia, then decreased. Extensive myocardial ischemia happened at the beginning of arrhythmia occurrence and its range didn't expand with time. CONCLUSIONS The expressions of HIF-1α and VEGF-A in myocardium of the rats with arrhythmia can provide evidence for the differential diagnosis of acute myocardial ischemia caused by fatal arrhythmia and coronary insufficiency.
Animals ; Arrhythmias, Cardiac/metabolism* ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Myocardial Ischemia/metabolism* ; Myocardium/metabolism* ; Rats ; Vascular Endothelial Growth Factor A/metabolism*