Jiming Powder is a traditional ancient prescription with good therapeutic effect in the treatment of heart failure, but its mechanism lacks further exploration. In this study, a mouse model of coronary artery ligation was used to evaluate the effect and mechanism of Jiming Powder on myocardial fibrosis in mice with myocardial infarction. The study constructed a mouse model of heart failure after myocardial infarction using the method of left anterior descending coronary artery ligation. The efficacy of Jiming Powder was evaluated from multiple angles, including ultrasound imaging, hematoxylin-eosin(HE) staining, Masson staining, Sirius Red staining, and serum myocardial enzyme spectrum detection. Western blot analysis was performed to detect key proteins involved in ventricular remodeling, including transforming growth factor-β1(TGF-β1), α-smooth muscle actin(α-SMA), wingless-type MMTV integration site family member 3a(Wnt3a), β-catenin, matrix metallopeptidase 2(MMP2), matrix metallopeptidase 3(MMP3), TIMP metallopeptidase inhibitor 1(TIMP1), and TIMP metallopeptidase inhibitor 2(TIMP2). The results showed that compared with the model group, the high and low-dose Jiming Powder significantly reduced the left ventricular internal diameter in systole(LVID;s) and diastole(LVID;d), increased the left ventricular ejection fraction(LVEF) and left ventricular fractional shortening(LVFS), effectively improved cardiac function in mice after myocardial infarction, and effectively reduced the levels of myocardial injury markers such as creatine kinase(CK), creatine kinase isoenzyme(CK-MB), and lactic dehydrogenase(LDH), thus protecting ischemic myocardium. HE staining showed that Jiming Powder could attenuate myocardial inflammatory cell infiltration after myocardial infarction. Masson and Sirius Red staining demonstrated that Jiming Powder effectively inhibited myocardial fibrosis, reduced the collagen Ⅰ/Ⅲ ratio in myocardial tissues, and improved collagen remodeling after myocardial infarction. Western blot results showed that Jiming Powder reduced the expression of TGF-β1, α-SMA, Wnt3a, and β-catenin, decreased the levels of MMP2, MMP3, and TIMP2, and increased the level of TIMP1, suggesting its role in inhibiting cardiac fibroblast transformation, reducing extracellular matrix metabolism in myocardial cells, and lowering collagen Ⅰ and α-SMA content, thus exerting an anti-myocardial fibrosis effect after myocardial infarction. This study revealed the role of Jiming Powder in improving ventricular remodeling and treating myocardial infarction, laying the foundation for further research on the pharmacological effect of Jiming Powder.
Mice ; Animals ; Transforming Growth Factor beta1/metabolism* ; Matrix Metalloproteinase 2/metabolism* ; beta Catenin/metabolism* ; Matrix Metalloproteinase 3/therapeutic use* ; Powders ; Ventricular Remodeling ; Stroke Volume ; Ventricular Function, Left ; Myocardial Infarction/drug therapy* ; Myocardium/pathology* ; Heart Failure/metabolism* ; Collagen/metabolism* ; Creatine Kinase ; Fibrosis

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 investigate the therapeutic effect of Yixin Ningshen Tablet (YXNS) on comorbidity of myocardial infarction (MI) and depression in rats and explore the underlying mechanism. METHODS: The Sprague-Dawley rats were randomly divided into 5 groups with 7 rats in each group according to their weights, including control, model, fluoxetine (FLXT, 10 mg/kg), low-dose YXNS (LYXNS, 100 mg/kg), and high-dose YXNS (HYXNS, 300 mg/kg) groups. All rats were pretreated with corresponding drugs for 12 weeks. The rat model of MI and depression was constructed by ligation of left anterior descending coronary artery and chronic mild stress stimulation. The echocardiography, sucrose preference test, open field test, and forced swim test were performed. Myocardial infarction (MI) area and myocardial apoptosis was also detected. Serum levels of interleukin (IL)-6, IL-1β, tumor necrosis factor-α (TNF-α), 5-hydroxytryptamine (5-HT), adrenocorticotrophic hormone (ACTH), corticosterone (CORT), and norepinephrine (NE) were determined by enzyme linked immunosorbent assay. The proteins of adenosine 5'-monophosphate -activated protein kinase (AMPK), p-AMPK, peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), and nuclear respiratory factor 1 (NRF1) in heart were detected by Western blot analysis. The expression levels of TNF-α, IL-6, indoleamine 2,3-dioxygenase (IDO1), kynurenine 3-monooxygenase (KMO), and kynureninase (KYNU) in hippocampus were detected by real-time quantitative polymerase chain reaction. RESULTS: Compared with the model group, the cardiac function of rats treated with YXNS improved significantly (P<0.01). Meanwhile, YXNS effectively reduced MI size and cardiomyocytes apoptosis of rats (P<0.01 or P<0.05), promoted AMPK phosphorylation, and increased PGC-1α protein expression (P<0.01 or P<0.05). HYXNS significantly increased locomotor activity of rats, decreased the levels of TNF-α, IL-6 and IL-1β, and increased the serum levels of 5-HT, NE, ACTH, and CORT (all P<0.05). Moreover, HYXNS decreased the mRNA expressions of IDO1, KMO and KYNU (P<0.05). CONCLUSIONS YXNS can relieve MI by enhancing myocardial energy metabolism. Meanwhile, YXNS can alleviate depression by resisting inflammation and increasing availability of monoamine neurotransmitters. It may be used as a potential drug to treat comorbidity of MI and depression.
AMP-Activated Protein Kinases/metabolism* ; Adrenocorticotropic Hormone ; Animals ; Comorbidity ; Depression/drug therapy* ; Energy Metabolism ; Interleukin-6/metabolism* ; Myocardial Infarction/pathology* ; Neurotransmitter Agents ; Rats ; Rats, Sprague-Dawley ; Serotonin/metabolism* ; Tablets ; Tumor Necrosis Factor-alpha/metabolism*

OBJECTIVE: To investigate whether Lingbao Huxin Pill (LBHX) protects against acute myocardial infarction (AMI) at the infarct border zone (IBZ) of myocardial tissue by regulating apoptosis and inflammation through the sirtuin 1 (SIRT1)-mediated forkhead box protein O1 (FOXO1) and nuclear factor-κ B (NF-κ B) signaling pathways. METHODS: Six-week-old Wistar rats with normal diet were randomized into the sham, the model, Betaloc (0.9 mg/kg daily), LBHX-L (0.45 mg/kg daily), LBHX-M (0.9 mg/kg daily), LBHX-H (1.8 mg/kg daily), and LBHX+EX527 (0.9 mg/kg daily) groups according to the method of random number table, 13 in each group. In this study, left anterior descending coronary artery (LADCA) ligation was performed to induce an AMI model in rats. The myocardial infarction area was examined using a 2,3,5-triphenyltetrazolium chloride solution staining assay. A TdT-mediated dUTP nick-end labeling (TUNEL) assay was conducted to assess cardiomyocyte apoptosis in the IBZ. The histopathology of myocardial tissue at the IBZ was assessed with Heidenhain, Masson and hematoxylineosin (HE) staining assays. The expression levels of tumor necrosis factor α (TNF-α), interleukin (IL)-6, IL-1 β, and intercellular adhesion molecule-1 were measured using enzyme-linked immunosorbent assays (ELISAs). The mRNA expressions of SIRT1 and FOXO1 were detected by real-time qPCR (RT-qPCR). The protein expressions of SIRT1, FOXO1, SOD2, BAX and NF- κ B p65 were detected by Western blot analysis. RESULTS: The ligation of the LADCA successfully induced an AMI model. The LBHX pretreatment reduced the infarct size in the AMI rats (P<0.01). The TUNEL assay revealed that LBHX inhibited cardiomyocyte apoptosis at the IBZ. Further, the histological examination showed that the LBHX pretreatment decreased the ischemic area of myocardial tissue (P<0.05), myocardial interstitial collagen deposition (P<0.05) and inflammation at the IBZ. The ELISA results indicated that LBHX decreased the serum levels of inflammatory cytokines in the AMI rats (P<0.05 or P<0.01). Furthermore, Western blot analysis revealed that the LBHX pretreatment upregulated the protein levels of SIRT1, FOXO1 and SOD2 (P<0.05) and downregulated NF- κ B p65 and BAX expressions (P<0.05). The RT-qPCR results showed that LBHX increased the SIRT1 mRNA and FOXO1 mRNA levels (P<0.05). These protective effects, including inhibiting apoptosis and alleviating inflammation in the IBZ, were partially abolished by EX527, an inhibitor of SIRT1. CONCLUSION LBHX could protect against AMI by suppressing apoptosis and inflammation in AMI rats and the SIRT1-mediated FOXO1 and NF- κ B signaling pathways were involved in the cardioprotection effect of LBHX.
Animals ; Apoptosis ; Drugs, Chinese Herbal ; Inflammation/metabolism* ; Myocardial Infarction/pathology* ; NF-kappa B/metabolism* ; Nerve Tissue Proteins ; Rats ; Rats, Wistar ; Sirtuin 1/genetics*

BACKGROUNDMyocardial infarction (MI) is a major disease burden. Wild-type p53-induced phosphatase 1 (Wip1) has been studied extensively in the context of cancer and the regulation of different types of stem cells, but the role of Wip1 in cardiac adaptation to MI is unknown. We investigated the significance of Wip1 in a mouse model of MI.

METHODSThe study began in June 2014 and was completed in July 2016. We compared Wip1-knockout (Wip1-KO) mice and wild-type (WT) mice to determine changes in cardiac function and survival in response to MI. The heart weight/body weight (HW/BW) ratio and cardiac function were measured before MI. Mouse MI was established by ligating the left anterior descending (LAD) coronary artery under 1.5% isoflurane anesthesia. After MI, survival of the mice was observed for 4 weeks. Cardiac function was examined by echocardiography. The HW/BW ratio was analyzed, and cardiac hypertrophy was measured by wheat germ agglutinin staining. Hematoxylin and eosin (H&E) staining was used to determine the infarct size. Gene expression of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) was assessed by quantitative real-time polymerase chain reaction (qPCR), and the levels of signal transducers and activators of transcription 3 (stat3) and phosphor-stat3 (p-stat3) were also analyzed by Western blotting. Kaplan-Meier survival analysis, log-rank test, unpaired t-test, and one-way analysis of variance (ANOVA) were used for statistical analyses.

RESULTSWip1-KO mice had a marginally increased HW/BW ratio and slightly impaired cardiac function before LAD ligation. After MI, Wip1-deficient mice exhibited increased mortality (57.14% vs. 29.17%; n = 24 [WT], n = 35 [Wip1-KO], P< 0.05), increased cardiac hypertrophy (HW/BW ratio: 7 days: 7.25 ± 0.36 vs. 5.84 ± 0.18, n = 10, P< 0.01, and 4 weeks: 6.05 ± 0.17 vs. 5.87 ± 0.24, n = 10, P > 0.05; cross-sectional area: 7 days: 311.80 ± 8.29 vs. 268.90 ± 11.15, n = 6, P< 0.05, and 4 weeks: 308.80 ± 11.26 vs. 317.00 ± 13.55, n = 6, P > 0.05), and reduced cardiac function (ejection fraction: 7 days: 29.37 ± 1.38 vs. 34.72 ± 1.81, P< 0.05, and 4 weeks: 19.06 ± 2.07 vs. 26.37 ± 2.95, P< 0.05; fractional shortening: 7 days: 13.72 ± 0.71 vs. 16.50 ± 0.94, P< 0.05, and 4 weeks: 8.79 ± 1.00 vs. 12.48 ± 1.48, P< 0.05; n = 10 [WT], n = 15 [Wip1-KO]). H&E staining revealed a larger infarct size in Wip1-KO mice than in WT mice (34.79% ± 2.44% vs. 19.55% ± 1.48%, n = 6, P< 0.01). The expression of IL-6 and p-stat3 was downregulated in Wip1-KO mice (IL-6: 1.71 ± 0.27 vs. 4.46 ± 0.79, n = 6, P< 0.01; and p-stat3/stat3: 1.15 ± 0.15 vs. 1.97 ± 0.23, n = 6, P< 0.05).

CONCLUSIONThe results suggest that Wip1 could protect the heart from MI-induced ischemic injury.

Animals ; Echocardiography ; Interleukin-1beta ; metabolism ; Interleukin-6 ; metabolism ; Male ; Mice ; Mice, Knockout ; Myocardial Infarction ; genetics ; metabolism ; pathology ; Myocytes, Cardiac ; metabolism ; Protein Phosphatase 2C ; deficiency ; genetics ; metabolism ; Real-Time Polymerase Chain Reaction ; Tumor Necrosis Factor-alpha ; metabolism ; Ventricular Remodeling

Previous studies have indicated that the Ilex genus exhibits antioxidant, neuroprotective, hepatoprotective, and anti-inflammatory activities. However, the pharmacologic action and mechanisms of Ilex cornuta against cardiac diseases have not yet been explored. The present study was designed to investigate the antioxidant and cardioprotective effects of Ilex cornuta root with in vitro and in vivo models. The anti-oxidative effects of the extract of Ilex cornuta root (ICR) were measured by 2, 2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging and MTT assays as well as immunoassay. Furthermore, a rat model of myocardial ischemia was established to investigate the cardioprotective effect of ICR in vivo. Eight compounds were isolated and identified from ICR and exhibited DPPH free-radical scavenging activities. They also could increase cell viability and inhibit morphological changes induced by HO or NaSO in H9c2 cardiomyocytes, followed by increasing the SOD activities and decreasing the MDA and ROS levels. In addition, it could suppress the apoptosis of cardiomyocytes. In the rat model of myocardial ischemia, ICR decreased myocardial infarct size and suppressed the activities of LDH and CK. Furthermore, ICR attenuated histopathological alterations of heart tissues and the MDA levels, while increasing SOD activities in serum. In conclusion, these results suggest that ICR has cardioprotective activity and could be developed as a new food supplement for the prevention of ischemic heart disease.
Animals ; Antioxidants ; metabolism ; pharmacology ; therapeutic use ; Apoptosis ; Cardiovascular Agents ; pharmacology ; therapeutic use ; Cell Survival ; drug effects ; Hydrogen Peroxide ; metabolism ; Ilex ; Malondialdehyde ; metabolism ; Myocardial Infarction ; Myocardial Ischemia ; drug therapy ; metabolism ; pathology ; Myocardium ; cytology ; pathology ; Myocytes, Cardiac ; drug effects ; Oxidative Stress ; drug effects ; Phytotherapy ; Plant Extracts ; pharmacology ; therapeutic use ; Plant Roots ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism ; Superoxide Dismutase ; metabolism

The traditional Chinese medicine Shensong Yangxin (SSYX) can improve the clinical symptoms of arrhythmia in an integrated manner. This study aimed to investigate the electrophysiological effect of SSYX on the hearts of myocardial-infarcted rabbits and further explore the mechanism by which SSYX alleviates myocardial fibrosis. Myocardial infarction (MI) was established in rabbits by ligation of the left circumflex coronary. The rabbits were treated with SSYX (0.5 g/kg/d) or saline for 8 weeks by oral administration. Microelectrode array (MEA) technology was used in vivo for extracellular electrophysiological recordings of the infarct border zone. Masson's trichrome staining was used to observe myocardial fibrosis. Western blotting was performed to evaluate the protein expression levels of collagen I (COL I) and collagen III (COL III). Quantitative real-time polymerase chain reaction (real-time PCR) was performed to evaluate the TGF-β1 and MMP-2 mRNA expression levels. The results showed that the total activation time (TAT) and the dispersion of TAT were significantly increased and the excitation propagation markedly disordered after MI. SSYX could significantly decrease TAT and the dispersion of TAT, and significantly ameliorate the chaotic spread pattern of excitation. Furthermore, SSYX treatment could significantly decrease COL I and COL III protein levels and down-regulate TGF-β1 and MMP-2 mRNA expression levels in MI rabbits. It was concluded that SSYX may ameliorate cardiac electrophysiological abnormalities in infarcted hearts by decreasing the protein levels of COL I and COL III, down-regulating the mRNA expression levels of TGF-β1 and MMP2, and thereby reducing adverse cardiac remodeling.
Animals ; Collagen Type I ; genetics ; metabolism ; Collagen Type III ; genetics ; metabolism ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; therapeutic use ; Female ; Heart Rate ; drug effects ; Hyperplasia ; Male ; Matrix Metalloproteinase 2 ; genetics ; metabolism ; Myocardial Infarction ; drug therapy ; pathology ; Myocardium ; metabolism ; pathology ; Rabbits ; Transforming Growth Factor beta ; genetics ; metabolism

OBJECTIVETo investigate the microRNAs (miRNAs) expression profile of acute myocardial infarction (AMI) rats and the regulating effects of Huoxue Anxin Recipe (, HAR) on angiogenesis-related miRNAs and genes.

METHODSForty-five Wistar rats were randomly assigned to 3 groups according to a random number table: sham, AMI, and AMI+HAR groups (15 in each group). AMI rats were established by ligation of the left descending coronary artery. HAR was intragastrically administered to rats of the AMI+HAR group for successive 21 days since modeling, meanwhile the same volume of 0.9% normal saline was administered to rats of the sham and AMI groups. Doppler echocardiography was used for noninvasive cardiac function test. Hematoxylin and eosin staining was used to observe the histopathological change. miRNAs expression profile was detected by quantitative realtime polymerase chain reaction (qRT-PCR). The mRNA and protein expressions of vascular endothelial growth factor (VEGF), and a target gene of miR-210 was further detected by qRT-PCR and Western blot, respectively. The microvessels density of myocardium was evaluated by CD31 immunostaining.

RESULTSCompared with the sham group, ejection fraction (EF) and fractional shortening (FS) values were decreased significantly in the AMI group (P<0.01), while the infarction area and the interstitial collagen deposition were increased obviously. As for the AMI+HAR group, EF and FS values were increased significantly (P<0.05 vs. AMI group), and the infarction area was reduced and the interstitial collagen deposition were alleviated significantly. Total of 23 miRNAs in the AMI group expressed differently by at least 1.5 folds compared with those in the sham group; 5 miRNAs in the AMI+HAR group expressed differently by at least 1.5 folds compared with those in the AMI group. Among them, miR-210 was low in the AMI group and high in the AMI+HAR group. The relative mRNA and protein expressions of VEGF were decreased significantly in the AMI group (P<0.05 vs. sham group), and increased significantly in the AMI+HAR group (P<0.01 vs. AMI group). CD31 expression area and optical intensity were decreased significantly in the AMI group (P<0.05 vs. sham group), and increased significantly in the AMI+HAR group (P<0.01 vs. AMI group).

CONCLUSIONSHAR could reduce the infarction area, alleviate the interstitial fibrosis and improve the cardiac function of AMI rats. Those effects could be related to promoting myocardium angiogenesis of HAR by up-regulating miR-210 and VEGF.

Animals ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Heart Function Tests ; Male ; MicroRNAs ; genetics ; metabolism ; Microvessels ; pathology ; Myocardial Infarction ; drug therapy ; genetics ; physiopathology ; Myocardium ; pathology ; Neovascularization, Physiologic ; drug effects ; genetics ; RNA, Messenger ; genetics ; metabolism ; Rats, Wistar ; Up-Regulation ; drug effects ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

OBJECTIVES: To explore the value of mast cell tryptase and brain natriuretic peptide（BNP） in the differential diagnostic of sudden death due to hypersensitivity and coronary atherosclerotic heart disease. METHODS: Totally 30 myocardial samples were collected from the autopsy cases in the Department of Forensic Pathology, Shanxi Medical University during 2010-2015. All samples were divided into three groups： death of craniocerebral injury group, sudden death of hypersensitivity group and sudden death of coronary atherosclerotic heart disease group, 10 cases in each group. Mast cell tryptase and BNP in myocardium were detected by immunofluorescence staining and Western Blotting. RESULTS: Immunofluorescence staining showed that the positive staining mast cell tryptase appeared in myocardium of sudden death of hypersensitivity group and coronary atherosclerotic heart disease group. Among the three groups, the expression of mast cell tryptase showed significantly differences through pairwise comparison （P<0.05）; The expression level of BNP in sudden death of coronary atherosclerotic heart disease group were significantly higher than the sudden death of hypersensitivity group and death of craniocerebral injury group （P<0.05）. The difference of the expression level of BNP between the sudden death of hypersensitivity group and the death of craniocerebral injury group had no statistical significance （P>0.05）. CONCLUSIONS The combined detection of the mast cell tryptase and BNP in myocardium is expected to provide help for the forensic differential diagnosis of sudden death due to hypersensitivity and coronary atherosclerotic heart disease.
Anaphylaxis ; Autopsy ; Blotting, Western ; Case-Control Studies ; Coronary Artery Disease/complications* ; Death, Sudden, Cardiac/etiology* ; Diagnosis, Differential ; Fluorescent Antibody Technique ; Forensic Pathology ; Humans ; Male ; Myocardial Infarction ; Myocardium/metabolism* ; Natriuretic Peptide, Brain/metabolism* ; Tryptases/metabolism*

OBJECTIVETo establish a flow cytometric method to detect the alteration of phenotypes and concentration of circulating microvesicles (MVs) from myocardial ischemic preconditioning (IPC) treated rats (IPC-MVs), and to investigate the effects of IPC-MVs on ischemia/reperfusion (I/R) injury in rats.

METHODSMyocardial IPC was elicited by three.cycles of 5-min ischemia and 5-min reperfusion of the left anterior descending (LAD) coronary artery. Platelet-free plasma (PFP) was isolated through two steps of centrifugation at room temperature from the peripheral blood, and IPC-MVs were isolated by ultracentrifugation from PFR PFP was incubated with anti-CD61, anti-CD144, anti-CD45 and anti-Erythroid Cells, and added 1, 2 µm latex beads to calibrate and absolutely count by flow cytometry. For functional research, I/R injury was induced by 30-min ischemia and 120-min reperfusion of LAD. IPC-MVs 7 mg/kg were infused via the femoral vein in myocardial I/R injured rats. Mean arterial blood pressure (MAP), heart rate (HR) and ST-segment of electro-cardiogram (ECG) were monitored throughout the experiment. Changes of myocardial morphology were observed after hematoxylin-eosin (HE) staining. The activity of plasma lactate dehydrogenase (LDH) was tested by Microplate Reader. Myocardial infarct size was measured by TTC staining.

RESULTSTotal IPC-MVs and different phenotypes, including platelet-derived MVs (PMVs), endothelial cell-derived MVs (EMVs), leucocyte-derived MVs (LMVs) and erythrocyte-derived MVs (RMVs) were all isolated which were identified membrane vesicles (<1 Vm) with corresponding antibody positive. The numbers of PMVs, EMVs and RMVs were significantly increased in circulation of IPC treated rats (P<0.05, respectively). In addition, at the end of 120-min reperfusion in I/R injured rats, IPC-MVs markedly increased HR (P<0.01), decreased ST-segment and LDH activity (P < 0.05, P < 0.01). The damage of myocardium was obviously alleviated and myocardial infarct size was significantly lowered after IPC-MVs treatment (P < 0.01).

CONCLUSIONThe method of flow cytometry was successfully established to detect the phenotypes and concentration alteration of IPC-MVs, including PMVs, EMVs, LMVs and RMVs. Furthermore, circulating IPC-MVs protected myocardium against I/R injury in rats.

Animals ; Cell-Derived Microparticles ; metabolism ; Coronary Vessels ; pathology ; Flow Cytometry ; Heart Rate ; Ischemic Preconditioning, Myocardial ; Myocardial Infarction ; physiopathology ; Myocardial Reperfusion Injury ; physiopathology ; Myocardium ; pathology ; Phenotype ; Rats