MI Rats Research Articles

Qingxin Jieyu Granule alleviates myocardial infarction through inhibiting neutrophil extracellular traps via activating ANXA1/FPR2 axis

BackgroundMyocardial infarction (MI), representing the most severe manifestation of coronary artery disease (CAD), stands as a primary concern in the prevention and management of cardiovascular diseases. Clinical evidence demonstrates that Qingxin Jieyu Granule (QXJYG) is efficacious in treatment of MI patients. However, the mechanisms underlying its therapeutic effects remain to be elucidated. PurposeThis study aimed to evaluate the effects of QXJYG on MI and investigate its underlying mechanisms. Materials and methodsThe MI model in rats was developed through ligating the left anterior descending (LAD) artery. The effect of QXJYG on cardiac function impairment in MI rats was assessed by echocardiography, while the improvement of cardiomyocyte morphology and myocardial fibrosis after treatment with QXJYG was evaluated through hematoxylin-eosin (H&E) staining and Masson staining. The chemical constituents of QXJYG in blood were identified by using the UPLC-Q-TOF/MS technique. Furthermore, the molecular mechanism underlying the QXJYG therapeutic effect in MI was postulated based on the disease gene-drug target network analysis. Other technical methods such as ELISA, immunohistochemical staining, Western Blot analysis and application of pharmacological inhibitors were employed to verify the effectiveness of QXJYG in treating MI and explore its potential molecular targets. ResultsThe cardiac function in experimental rats post-MI was significantly impaired, as evidenced by an enlarged infarction area, disordered arrangement of cardiomyocytes, and aggravated myocardial fibrosis. QXJYG treatment significantly enhanced the cardiac function and reduced the pathological damage of the cardiac tissue in MI rats. Through the network pharmacology analysis, we identified that FPR2 might be a potential target of QXJYG in its cardiac protection role. QXJYG markedly downregulated the level of neutrophil extracellular traps (NETs) in MI rats, specifically manifested as a significant reduction in the Histone-DNA level and expression of myeloperoxidase (MPO) and citrullinated histone H3 (CitH3) proteins. Furthermore, QXJYG upregulated the levels of ANXA1 and FPR2 proteins in MI rats. The level of FPR2 was markedly reduced in MI rats upon administration of WRW4, a specific inhibitor of FPR2, which was associated with exacerbated MI injury and an elevated level of NETs. When WRW4 was co-administered with QXJYG, the cardioprotective effects of QXJYG on MI were significantly diminished. However, the addition of DNase I did not result in significant changes of the outcomes in MI rats after QXJYG intervention. ConclusionQXJYG treatment alleviates cardiac tissue injury in MI rats by inhibiting NETs through activating the ANXA1/FPR2 axis. The findings extend our understanding of the therapeutic effectiveness of QXJYG and offer a scientific foundation for the clinical utilization of QXJYG.

Analysis of Differentially Expressed Murine miRNAs in Acute Myocardial Infarction and Target Genes Related to Heart Rate.

This study aims to investigate the expression profile of miRNAs significantly dysregulated after acute myocardial infarction (AMI) and their potential targets. After the establishment of a mouse model of AMI, RNA was extracted from mouse infarcted myocardium. Paired-end sequencing was then performed using the Illumina NovaSeq 6000 system to explore the expression profile of miRNAs. Target genes of downregulated differentially expressed miRNAs (DEmiRNAs) were predicted with miRanda (version 3.3a) and TargetScan (version 6.0). Cytoscape was used to construct a DEmiRNA-mRNA regulatory network to show the regulatory relationship. RT-qPCR was performed to measure miR-142a-3p expression in H2O2-treated rat cardiomyocyte H9c2 cells and heart tissues of MI rats. Cell counting kit-8 and TUNEL assays were conducted to detect H9c2 cell viability and apoptosis. There were 33 differentially expressed miRNAs, of which 3 were significantly upregulated and the rest 30 were significantly downregulated. Target genes of these miRNAs were identified, and their functional enrichment was analyzed using gene ontology (GO) analysis. Importantly, target genes that can regulate heart rate and their paired upstream miRNAs attracted attention. Significant expression correlation between heart rate-related targets (Epas1, Bves, Hcn4, Cacna1e, Ank2, Slc8a1, Pde4d) and paired miRNAs (miR-142a-5p, miR-7b-5p, miR-144-3p, miR-34c-5p, miR-223-3p, miR-18a-5p) in mouse myocardial tissues was identified. MiR-142a-3p was downregulated in H9c2 cells and rat infarct tissues, and overexpressing miR-142a-3p restrains H2O2-induced H9c2 cell apoptosis. Cardioprotective miRNAs, such as miR-142a-3p, were identified in mouse myocardial tissues, and some specific miRNA-target pairs are associated with heart rate regulation.

Interval training suppresses nod-like receptor protein 3 inflammasome activation to improve cardiac function in myocardial infarction rats by hindering the activation of the transforming growth factor-β1 pathway

ObjectiveMyocardial infarction (MI) -induced cardiac dysfunction can be attenuated by aerobic exercises. This study explored the mechanism of interval training (IT) regulating cardiac function in MI rats, providing some theoretical basis for clarifying MI pathogenesis and new ideas for clinically treating MI.MethodsRats were subjected to MI modeling, IT intervention, and treatments of the Transforming growth factor-β1 (TGF-β1) pathway or the nod-like receptor protein 3 (NLRP3) activators. Cardiac function and hemodynamic indicator alterations were observed. Myocardial pathological damage and fibrosis, reactive oxygen species (ROS) level, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities, MDA content, inflammasome-associated protein levels, and inflammatory factor levels were assessed. The binding between TGF-β1 and receptor was detected.ResultsMI rats exhibited decreased left ventricle ejection fraction (LVEF), left ventricle fractional shortening (LVFS), left ventricular systolic pressure (LVSP), positive and negative derivates max/min (dP/dt max/min) and increased left ventricular end-systolic pressure (LVEDP), a large number of scar areas in myocardium, disordered cell arrangement and extensive fibrotic lesions, increased TGF-β1 and receptor binding, elevated ROS level and MDA content and weakened SOD, CAT and GSH-Px activities, and up-regulated NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC) and cleaved-caspase-1 levels, while IT intervention caused ameliorated cardiac function. IT inactivated the TGF-β1 pathway to decrease oxidative stress in myocardial tissues of MI rats and inhibit NLRP3 inflammasome activation. Activating NLRP3 partially reversed IT-mediated improvement on cardiac function in MI rats.ConclusionIT diminished oxidative stress in myocardial tissues and suppressed NLRP3 inflammasome activation via inactivating the TGF-β1 pathway, thus improving the cardiac function of MI rats.

Methanolic extract of Cleome droserifolia mitigates epinephrine-induced cardiac injury

Ethnopharmacological relevanceCleome droserifolia treatment has potent antioxidant, antimicrobial, and immunomodulatory potentials, which can help recover the general health status. Aim of the studyThis research aims to estimate the potential cardioprotective properties of the methanolic extract of Cleome droserifolia (MEC) against epinephrine-induced cardiac injury (MI) in rats. Materials and methodsThirty-six male Wistar rats were separated equally into 6 groups. The control group (Cont) received oral distilled water for 30 uninterrupted days and was administered subcutaneous saline on the 31st and 32nd days. The MEC 100 group received MEC 100 mg/kg, P.O., for 30 uninterrupted days and administered subcutaneous saline on the 31st and 32nd days. The MEC 200 group received MEC 200 mg/kg, P.O. for 30 uninterrupted days and subcutaneous saline was administered on the 31st and 32nd days. The epinephrine group (EP) received distilled water orally for 30 uninterrupted days and administered subcutaneous epinephrine (2 mg/kg, s.c.) divided into two doses (1 mg/kg, s.c) each on the 31st and 32nd days. MEC 100+Ep group received MEC 100 mg/kg, P.O., for 30 uninterrupted days and administered subcutaneous epinephrine (2 mg/kg, s.c.) divided into two doses (1 mg/kg, s.c) each on the 31st and 32nd days. The MEC 200+EP received MEC 200 mg/kg, P.O. for 30 uninterrupted days and administered subcutaneous epinephrine (2 mg/kg, s.c.) divided into two doses (1 mg/kg, s.c) each on the 31st and 32nd days. Electrocardiography (ECG), biochemical, oxidative stress, inflammatory mediators, histopathological, immunohistochemical analysis and the expression of phosphoinositide 3-kinases (PI3K) and protein kinase B (AKT) were assessed. ResultsMEC reversed epinephrine-induced lessening of heart rate, prolonged QT interval and ST displacement. Pretreatment with MEC significantly reduced serum aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB) levels in MI rats. The MEC pretreatment promoted total antioxidant capacity (TAC), glutathione (GSH), and total oxidant status (TOS). In addition, it reduced interleukin-1β (IL-1β), interleukin-6 (IL-6), malondialdehyde (MDA), and tumour necrosis factor (TNF-α) in MI rats. Furthermore, MEC statistically reduced immunohistochemical promotion of nuclear factor–κB (NF-κB) and expression of AKT and PI3K in cardiac tissue and perfected histopathological changes. ConclusionThe MEC, rich in phenolic and flavonoid contents, had a cardioprotective effect on rats suffering from epinephrine-induced MI. Such effect was achieved via improving cardiac function, antioxidant status, attenuating ECG pattern and histological picture, as well as reducing IL-6, IL-1β, TNF-α and NF-κB, which its antioxidant and anti-inflammatory potential may partly arbitrate.

Sfrp1 as a Pivotal Paracrine Factor in the Trained Pericardial Stem Cells that Foster Reparative Activity.

Tissue damage often induces local inflammation that in turn dictates a series of subsequential responses, such as stem cell activation and growth, to maintain tissue homeostasis. The aim of the study is to testify the possibility of using inflammation-trained stem cells as optimal donor cells to augment the efficacy of cell therapy. The pericardial stem/stromal cells derived from the animals after myocardial infarction (MI-pSC) showed an enhanced myogenic potential and augmented reparative activity after transplantation in the injured hearts, as compared to the Sham-pSC. Bulk RNA-Seq analysis revealed significant upregulation of a panel of myogenic and trophic genes in the MI-pSC and, notably, Sfrp1 as an important anti-apoptotic factor induced robustly in the MI-pSC. Injection of the MI-pSC yielded measurable numbers of surviving cardiomyocytes (Tunel and Casp-3 negative) within the infarct area, but the effects were significantly diminished by siRNA-based silence of Sfrp1 gene in the pSC. Primed Sham-pSC with pericardial fluid from MI rats mimicked the upregulation of Sfrp1 and enhanced myogenic potential and reparative activity of pSC. Taken together, our results illustrated the inflammation-trained pSC favor a reparative activity through upregulation of Sfrp1 gene that confers anti-apoptotic activity in the injured cardiomyocytes. Therefore, the active form of stem cells may be used as a cardiac protective agent to boost therapeutical potential of stem cells.

Integrating network pharmacology and experimental verification to explore the mechanisms of salidroside against myocardial fibrosis

Myocardial fibrosis (MF) is the manifestation of a variety of cardiovascular diseases. Salidroside (SAL) has been proved to have a certain effect on anti-fibrosis in various organs. However, the mechanism of SAL in the treatment of MF remains unclear. Network pharmacology showed that there were 1228 SAL-related target genes and 2793 MF-related target genes. The intersection of these genes resulted in 271 drug-disease interactions, and 15 core active targets were filtered from protein-protein interaction mapping. The top 20 Gene ontology biological processes analysis showed that the involved processes were close to the pathogenesis of MF. Among the top 20 enriched KEGG pathways, Wnt/β-catenin and TGF-β1/Smad3 signaling pathways were identified. In vivo, MI rats exhibited thinning of the myocardial region and the formation of fibrous scars, the expression of smad3 and β-catenin were increased. After SAL treatment, there was a significant reduction in collagen area and a decrease in the ratio of collagen type I to type III. The expression of smad3 and β-catenin was suppressed and positively correlated with the dosage of SAL. SAL may contribute to the progression of MF through the TGF-β1/Smad3 and Wnt/β-catenin signaling pathways.

Extracellular Vesicles from NMN Preconditioned Mesenchymal Stem Cells Ameliorated Myocardial Infarction via miR-210-3p Promoted Angiogenesis

Mesenchymal stem cell-derived extracellular vesicles (MSCs-EVs) possess cardioprotection in acute myocardial infarction. Nevertheless, the therapeutic intervention potential and the molecular mechanism of EVs from NMN (Nicotinamide mononucleotide) preconditioned hUCMSCs (N-EVs) in acute myocardial infarction remains unknown. In the present study, EVs from hUCMSCs (M-EVs) and N-EVs were identified by electron microscopy, immunoblotting and nanoparticle tracking analysis. Compared with M-EVs, N-EVs significantly increased the proliferation, migration, and angiogenesis of HUVECs. Meanwhile, N-EVs markedly reduced apoptosis and cardiac fibrosis and promoted angiogenesis in the peri-infarct region in the MI rats. A high-throughput miRNA sequencing and qPCR methods analysis revealed that miR-210-3p was abundant in N-EVs and the expression of miR-210-3p was obviously upregulated in HUVECs after N-EVs treated. Overexpression of miR-210-3p in HUVECs significantly enhanced the tube formation, migration and proliferative capacities of HUVECs. However, downregulation of miR-210-3p in HUVECs markedly decreased the tube formation, migration and proliferative capacities of HUVECs. Furthermore, bioinformatics analysis and luciferase assays revealed that EphrinA3 (EFNA3) was a direct target of miR-210-3p. Knockdown of miR-210-3p in N-EVs significantly impaired its ability to protect the heart after myocardial infarction. Altogether, these results indicated that N-EVs promoted the infarct healing through improvement of angiogenesis by miR-210-3p via targeting the EFNA3. Graphical Created with Biorender.com.

Modified Linggui Zhugan Decoction protects against ventricular remodeling through ameliorating mitochondrial damage in post-myocardial infarction rats.

Modified Linggui Zhugan Decoction (MLZD) is a Traditional Chinese Medicine prescription developed from Linggui Zhugan Decoction (LZD) that has been used for the clinical treatment of ischemic cardiovascular diseases. However, the cardioprotective mechanism of MLZD against post-myocardial infarction (MI) ventricular remodeling remains unclear. We explored the effects of MLZD on ventricular remodeling and their underlying mechanisms, respectively, in SD rats with MI models and in H9c2 cardiomyocytes with oxygen-glucose deprivation (OGD) models. The cardiac structure and function of rats were measured by echocardiography, HE staining, and Masson staining. Apoptosis, inflammation, mitochondrial structure and function, and sirtuin 3 (SIRT3) expression were additionally examined. MLZD treatment significantly ameliorated cardiac structure and function, and thus reversed ventricular remodeling, compared with the control. Further research showed that MLZD ameliorated mitochondrial structural disruption, protected against mitochondrial dynamics disorder, restored impaired mitochondrial function, inhibited inflammation, and thus inhibited apoptosis. Moreover, the decreased expression level of SIRT3 was enhanced after MLZD treatment. The protective effects of MLZD on SIRT3 and mitochondria, nevertheless, were blocked by 3-TYP, a selective inhibitor of SIRT3. These findings together revealed that MLZD could improve the ventricular remodeling of MI rats by ameliorating mitochondrial damage and its associated apoptosis, which might exert protective effects by targeting SIRT3.

Investigation of Cardioprotective Effect of 2, 4-thiazolidinedione Derivative Using HFD-STZ Fed Rats

Abstract: Background: Myocardial infarction is a 2nd most important origin of universal death and after coronary revascularization, cardiovascular events occurs further a lot in subjects through DM: 3.5- as well as 2-fold fatality ranks correspondingly behind percutaneous coronary intervention or coronary bypass graft surgery. Objectives: The aim of an attendance research was to discover usefulness of 2, 4- thiazolidinedione derivatives lying on diabetic MI and HFD-STZ diabetic rats. Materials and Methods: In in-vivo investigation, Type-2 diabetes was elicited by higher fatty meal plus little dosage for streptozotocin and MI was provoked by LAD Coronary artery ligation model. The rats were divided into a variety of groups, including treatment groups (Composite An epalrestat, Composite B pioglitazone). And after 15 days of treatment a variety of factors were evaluated, i.e. serum glucose, total cholesterol, serum triglycerides, lipid profile antioxidant enzymes, ECG analysis, and Histopathological examination of heart were done. Results: In in-vivo investigation, levels of serum glucose, triglycerides, LDL level, LDH level, CK-MB, Troponin I, malondialdehyde (MDA), total cholesterol, infarct area, were considerably decreased in composite A and B treated animals. Whereas the HDL level, antioxidant enzymes, had drastically risen in composite, treated animals balanced to disease control rats. In ECG analysis ST elevation was restored in drug treated animals. Composite treated heart indicated mild congestion and inflammation in histopathological examination. Homogenate of drug treated animals indicated less apoptotic signals and nearer to normal animals. Conclusion: The treatment with Composite A and Composite B notably ameliorated the alterations in MI in a dose dependant manner. Keywords: 2, 4-Thiazolidinedione, Myocardial infarction, Diabetic MI, Type-2 diabetes, LAD, Macrovascular complication.

β-catenin ameliorates myocardial infarction by preventing YAP-associated apoptosis

ObjectiveTo explore whether the effect of β-catenin on MI and MI-induced cardiomyocyte apoptosis is YAP-dependent. MethodsThe authors established an MI rat model by ligating the anterior descending branch of the left coronary artery, and an MI cell model by treating cardiomyocytes with H2O2. Resultsβ-catenin downregulation was observed in MI cardiac tissues and in H2O2-treated cardiomyocytes. Lentiviral-CTNNB1 was administered to MI rats to upregulate β-catenin expression in MI cardiac tissue. β-catenin recovery reduced the myocardial infarct area, fibrosis, and apoptotic cell death in MI rats. H2O2 treatment attenuated cell viability and induced cell death in cardiomyocytes, whereas β-catenin overexpression partially reversed these changes. Moreover, H2O2 treatment caused the deactivation of Yes-Associated Protein (YAP), as detected by increased YAP phosphorylation and reduced the nuclear localization of YAP. Upregulation of β-catenin expression reactivated YAP in H2O2-treated cardiomyocytes. Reactivation of YAP was achieved by administration of Mitochonic Acid-5 (MA-5) to H2O2-treated cardiomyocytes, and deactivation of YAP by CIL56 treatment in β-catenin-overexpressing H2O2-treated cardiomyocytes. MA-5 administration increased cell viability and repressed apoptosis in H2O2-treated cardiomyocytes, whereas CIL56 treatment counteracted the effects of β-catenin overexpression on cell survival and apoptosis. ConclusionsThe present data indicate that β-catenin and YAP are effective treatment targets for MI, blocking the apoptotic death of cardiomyocytes.

The role of Vav3 expression for inflammation and cell death during experimental myocardial infarction

ObjectivesMyocardial Infarction (MI) is the leading cause of chronic heart failure. Previous studies have suggested that Vav3, a receptor protein tyrosine kinase signal transducer, is associated with a variety of cellular signaling processes such as cell morphology regulation and cell transformation with oncogenic activity. However, the mechanism of Vav3-mediated MI development requires further investigation. MethodHere, The authors established an MI rat model by ligating the anterior descending branch of the left coronary artery, and an MI cell model by treating cardiomyocytes with H2O2. Microarray analysis was conducted to identify genes with differential expression in heart tissues relevant to MI occurrence and development. Vav3 was thus selected for further investigation. ResultsVav3 downregulation was observed in MI heart tissue and H2O2-treated cardiomyocytes. Administration of Lentiviral Vav3 (LV-VAV3) in MI rats upregulated Vav3 expression in MI heart tissue. Restoration of Vav3 expression reduced infarct area and ameliorated cardiac function in MI rats. Cardiac inflammation, apoptosis, and upregulation of NFκB signal in heart tissue of MI animals were assessed using ELISA, TUNEL staining, real-time PCR, and WB. Vav3 overexpression reduced cardiac inflammation and apoptosis and inhibited NFκB expression and activation. Betulinic Acid (BA) was then used to re-activate NFκB in Vav3-overexpressed and H2O2-induced cardiomyocytes. The expression of P50 and P65, as well as nuclear P65, was significantly increased by BA exposure. ConclusionsVav3 might serve as a target to reduce ischemia damage by suppressing the inflammation and apoptosis of cardiomyocytes.

Electroacupuncture Treats Myocardial Infarction by Influencing the Regulation of Substance P in the Neurovascular to Modulate PGI2/TXA2 Metabolic Homeostasis via PI3K/AKT Pathway: A Bioinformatics-Based Multiomics and Experimental Study.

Acute myocardial infarction (AMI) is the most severe form of coronary heart disease caused by ischemia and hypoxia. The study is aimed at investigating the role of neuropeptides and the mechanism of electroacupuncture (EA) in acute myocardial infarction (AMI) treatment. Compared with the normal population, a significant increase in substance P (SP) was observed in the serum of patients with AMI. PGI2 expression was increased in the SP-treated AMI mouse model, and TXA2 expression was decreased. And PI3K pathway-related genes, including Pik3ca, Akt, and Mtor, were upregulated in myocardial tissue of SP-treated AMI patients. Human cardiomyocyte cell lines (HCM) treated with SP increased mRNA and protein expression of PI3K pathway-related genes (Pik3ca, Pik3cb, Akt, and Mtor). Compared to MI control and EA-treated MI rat models, Myd88, MTOR, Akt1, Sp, and Irak1 were differentially expressed, consistent with in vivo and in vitro studies. EA treatment significantly enriched PI3K/AKT signaling pathway genes within MI-associated differentially expressed genes (DEGs) according to Kyoto Encyclopedia of Genes and Genomes (KEGG). Furthermore, it was confirmed by molecular docking analysis that PIK3CA, AKT1, and mTOR form stable dockings with neuropeptide SP. PI3K/AKT pathway activity may be affected directly or indirectly by EA via SP, which corrects the PGI2/TXA2 metabolic imbalance in AMI. MI treatment is now better understood as a result of this finding.

Cardioprotection Attributed to Aerobic Exercise-Mediated Inhibition of ALCAT1 and Oxidative Stress-Induced Apoptosis in MI Rats.

Cardiolipin (CL) plays a pivotal role in mitochondria-mediated apoptosis. Acyl-CoA: lysocardiolipin acyltransferase 1 (ALCAT1) can accelerate CL reactive oxygen production and cause mitochondrial damage. Although we have demonstrated that aerobic exercise significantly reduced ALCAT1 levels in MI mice, what is the temporal characteristic of ALCAT1 after MI? Little is known. Based on this, the effect of exercise on ALCAT1 in MI rats needs to be further verified. Therefore, this paper aimed to characterize ALCAT1 expression, and investigate the possible impact of exercise on ALCAT1 and its role in fibrosis, antioxidant capacity, and apoptosis in MI rats. Our results indicated that the potential utility of MI increased ALCAT1 expression within 1–6 h of MI, and serum CK and CKMB had significant effects in MI at 24 h, while LDH exerted an effect five days after MI. Furthermore, ALCAT1 expression was upregulated, oxidative capacity and excessive apoptosis were enhanced, and cardiac function was decreased after MI, and aerobic exercise can reverse these changes. These findings revealed a previously unknown endogenous cardiac injury factor, ALCAT1, and demonstrated that ALCAT1 damaged the heart of MI rats, and aerobic exercise reduced ALCAT1 expression, oxidative stress, and apoptosis after MI-induced cardiac injury in rats.

The application of proteomics and metabolomics to reveal the molecular mechanism of Nutmeg-5 in ameliorating cardiac fibrosis following myocardial infarction

BackgroundNutmeg-5, an ancient and classic formula in traditional Mongolian medicine comprising five kinds of traditional Chinese medicine, is widely used in the treatment of myocardial infarction (MI, called heart “Heyi” disease in Mongolian medicine). Cardiac fibrosis plays a critical role in the development and progression of heart failure after MI. However, the material basis and pharmacological mechanisms of the effect of Nutmeg-5 on cardiac fibrosis after MI remain unclear. ObjectiveThe aim of this study was to first explore the potential material basis and molecular mechanism of action of Nutmeg-5 in improving cardiac fibrosis after MI via a multiomics approach. MethodsThe constituents in Nutmeg-5 were identified by ultra-performance liquid chromatography coupled with tandem mass spectrometry (UPLC–MS/MS). High-performance liquid chromatography (HPLC) and gas chromatography (GC)-based fingerprints of Nutmeg-5 were analysed, and characteristic peaks were identified by comparison to standard samples. A rat MI model was created by permanent ligation of the left anterior descending artery. The protective effect of Nutmeg-5 on cardiac fibrosis after MI was evaluated by tissue histology and measurement of the serum biomarkers of myocardial injury. Cardiac fibrosis levels were evaluated by Sirius red staining. Differentially expressed proteins in the myocardium and metabolites in the serum were explored by proteomic and untargeted metabolome analyses, respectively. Pearson correlation analysis was performed to explore the association between serum metabolites and myocardial proteins. ResultsA total of 67 constituents were identified in Nutmeg-5 by UPLC–MS/MS.Sixteen components were identified in the fingerprint of Nutmeg-5 by comparison with a standard sample. Six lactones were isolated from Nutmeg-5 and quantified by HPLC and GC. MI was significantly alleviated in Nutmeg-5-treated rats compared to MI rats, as demonstrated by their decreased mortality, improved cardiac function, and attenuated cardiac fibrosis and myocardial injury. A total of 252 significant differential metabolites were identified in plasma between model and Nutmeg-5-treated rats by untargeted metabolome analysis. Among these, 36 critical metabolites were associated with Nutmeg-5 activity. Proteomic analysis identified 338 differentially expressed proteins in the rat myocardium between MI and Nutmeg-5-treated rats, including 204 upregulated and 134 downregulated proteins. Protein set enrichment analysis revealed that Nutmeg-5 treatment significantly inhibited the extracellular matrix (ECM)-receptor interaction pathway, which was activated in the myocardium of MI rats. A significant decrease in collagen and alpha smooth muscle actin expression levels was found in the myocardium of Nutmeg-5-treated rats compared to MI rats. These results illustrated that Nutmeg-5 had a significant protective effect on cardiac fibrosis after MI. A significant correlation was found between the ECM-receptor interaction pathway in the myocardium and critical metabolites in the serum. In addition, there were positive correlations between the levels of critical metabolites and the expression levels of transforming growth factor (TGF)-β1 and Smad2 in the rat myocardium. ConclusionsNutmeg-5 alleviated cardiac fibrosis after MI in rats by inhibiting the myocardial ECM-receptor interaction pathway and TGF-β1/Smad2 signalling, which was achieved by regulating plasma metabolites.

CLOFIBRATE TREATMENT IMPROVED THE STRUCTURAL DAMAGE ELICITED BY MYOCARDIAL ISCHEMIA THROUGH MODULATION OF RENIN-ANGIOTENSIN SYSTEM

Objective: Myocardial ischemia is an acute condition that, if not treated in a timely manner, produces the loss of heart tissue which can lead to heart failure or death of the patients. Our group has studied fibrates, exogenous ligands of PPAR, as an alternative to reduce processes associated with inflammation and we interested to know the exogenous ligand effect over damage in the cardiac tissue by RAS system. To study the effect of PPAR alpha ligand; clofibrate, on renin angiotensin system and on the structural morphology of the heart in myocardial infarcted subjects. Design and method: Male Wistar rats were separated in two groups: 1.- Sham, 2.- Myocardial infarct by coronary artery ligation. Seven days after, the rats were subdivided in vehicle (Vh)- or clofibrate treatment (Clof 100 mg/kg/day) administered for seven more days. At the end of the treatment (14 days in total), serum and left ventricle were analyzed. Results: Angiotensin converting enzyme (ACE), AT1 receptor and Ang II decreased in MI-Clof vs. MI-Vh, whereas non-classic RAS system components: ACE2, AT2 receptor, bradykinin, and Ang-(1–7) augmented in MI-Clof with respect to MI-Vh. VEGF also raised in clofibrate-treated animals. Clofibrate treatment preserved the structure of the sarcomere (fiber). Conclusions: Clofibrate treatment to MI rats exerts an antifibrotic effect and augmented the expression of non-classical axis of RAS system.

Danqi soft caspule prevents atrial fibrillation by ameliorating left atrial remodeling through inhibiting cardiac fibroblasts differentiation and function

BackgroundDanqi soft capsule (DQ) is a Chinese herb medicine with a remarkable protective effect on cardio‐cerebrovascular diseases. PurposeThe study aimed to investigate the role and mechanism of DQ on left atrial (LA) remodeling and atrial fibrillation (AF) occurrence in rats with post-myocardial infarction (MI) induced heart failure (HF). MethodsMI in rats was established by ligation of the left anterior descending coronary artery. DQ was administered to the post-MI induced HF rats over a 4-week period. AF inducibility was detected using the transesophageal programmed electrical stimulation technology. Echocardiogram, histology, and western blot analysis were performed. Meanwhile, cardiac fibroblasts (CFs) were performed to determine the effects of DQ on CFs function by 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT), flow cytometry, transwell assay and ELISA. ResultsThe DQ-treated rats showed lower rates of AF inducibility and shorter AF durations than the MI rats. Moreover, DQ inhibited fibrosis and increased the expression of Cx43 in the left atrium; it also inhibited the myofibroblasts differentiation by reducing the expression of cytokines TNF-α, IL-6, and TGF-β1 via the TGF-β1/Smad 3 pathway. In addition, DQ inhibited the proliferation, migration, and collagen secretion of CFs in vitro. ConclusionsDQ reduces the risk of AF in post-MI HF rats by ameliorating LA arrhythmogenic substrate via inhibiting the function of proliferation, migration, collagen secretion, and myofibroblasts differentiation of CFs. Together, these results indicate the therapeutic potential of DQ in AF by delaying the progression of LA remodeling in post-MI-induced HF. Targeting CFs may be a novel prospective therapeutic avenue for AF after MI.

MiR-223-3p affects myocardial inflammation and apoptosis following myocardial infarction via targeting FBXW7.

BackgroundMyocardial infarction (MI) is one of the main causes of disability and death in the world, leading to myocarditis and cardiomyocyte apoptosis. Studies have shown that microRNA (miRNA) is involved in myocarditis and apoptosis. The main purpose of this study was to explore the regulatory mechanism of miR-223-3p on myocarditis and apoptosis after MI.MethodsWe cultured H9c2 cells and detected the expression of miR-223-3p in cells treated with different concentrations of H2O2. Sprague Dawley (SD) rats were fed with normal diet, constructed an MI model and detect the expression of miR-223-3p in heart tissue. Overexpression or inhibition of miR-223-3p was conducted in MI model cells in vitro, and the contents of the inflammatory factors tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and interleukin-10 (IL-10) in cell supernatant were detected by enzyme-linked immunosorbent assay (ELISA). Cell apoptosis was detected by flow cytometry. Luciferase activity assay was used to detect the targeting relationship between miR-223-3p and FBXW7, and the expression of FBXW7 in cells was also detected. Overexpression of miR-223-3p was performed in MI rats to detect the expression of inflammatory factors, FBXW7, and apoptosis in rat cardiac tissue.ResultsThe expression of miR-223-3p was down regulated in MI models established in vitro and in vivo. Overexpression of miR-223-3p can inhibit inflammatory response and apoptosis in H9c2 cells and cardiac tissues. It was revealed that miR-223-3p can inhibit the expression of FBXW7, reduce myocarditis and apoptosis after MI, and improve cardiac function.ConclusionsIt is possible that miR-223-3p reduces myocarditis and apoptosis after MI and improves cardiac function by targeted inhibition of FBXW7 expression.

Naoxintong capsule limits myocardial infarct expansion by inhibiting platelet activation through the ERK5 pathway

BackgroundIn the clinic, Naoxintong capsule (NXT) has been applied in two level prevention of ischemic disease. However, its mechanism of action requires further study. PurposeThis study investigated whether NXT could affect platelet function and activation under ischemic pathological conditions. Materials and methodsWistar rats were divided into six groups, sham, saline, NXT (250, 500, 1000 mg/kg), and aspirin group (10 mg/kg). For the pre-treatment assays, MI model was established after pre-administration of saline, NXT-L, NXT-M, NXT-H, and aspirin respectively for 14 days, and after surgery, there were no continuous treatments. For the post-treatment assay, rats were orally administered for 3 days after MI. FeCl3-induced thrombosis model was applied to determine the thrombus wet weight. Bleeding time was used to assess the ability of the platelets to develop a hemostatic plug. ResultsNXT decreased infarct size, decreased LDH, CK, and CK-MB values, and improved cardiac function. NXT inhibited platelets activation through reducing CD62P-positive platelets and inhibited infarct expansion by decreasing the number of CD45-positive cells and the amount of MMP9 secreted into the heart tissue. Mechanistically, NXT inhibited platelets activation through decreasing ROS levels, decreasing ERK5 phosphorylation, and increasing RAC1 phosphorylation in MI rats. Pre-treatment with NXT decreased thrombus formation and had normal bleeding times. ConclusionNXT showed obviously preventive effects, which was associated with negative control of platelet activation. The above results provide a basis for clinically expanding application of NXT.

Noninvasive Prognosis of Postmyocardial Infarction Using Urinary miRNA Ultratrace Detection Based on Single-Target DNA-Functionalized AuNPs.

Urine is the most appropriate body fluid for analysis because it is easily and less-invasively obtained than blood; thus, urinary miRNAs can better represent the local stage of the disease and might grow up to be a new class of noninvasive biomarkers of postmyocardial infarction (MI). Monofunctionalized Au nanoparticles (AuNPs) with only one selective DNA at a specific location are more promising in nanotechnology. This study developed a urinary miRNA ultratrace detection strategy based on single-target DNA-functionalized AuNPs for the noninvasive prognosis of post-MI. The AuNPs were designed with only single-stranded biotinylated DNA complementary to the target miRNA through a ratio-optimized stoichiometric method for the first time. Combined with the duplex specific nuclease-assisted target recycling amplification, the single-target DNA-functionalized AuNPs for the first time were used in inductively coupled plasma-mass spectrometry for the determination of urinary miRNA with high sensitivity. After optimizing the reaction conditions, a linear detection range between 1 fM and 10 pM for miR-155 and a detection limit of 0.47 fM were obtained. Finally, the target miR-155 in urine samples collected from MI rats was quantified and the level of miR-155 in MI groups was 30 times higher than in the control groups. The results suggest that urinary miR-155 could be a novel biomarker for the noninvasive diagnosis of MI.

Applying Vasopressin-Pre-Conditioned Human Adipose Mesenchymal Stem Cells Improves Heart Condition after Transplantation into Infarcted Myocardium.

Transplantation of H-AdMSCs may improve heart function after MI. AVP is a neurohypophyseal hormone that reduces cardiovascular damage. This study investigated the role of AVP preconditioning in the survival of MSCs and their effect on myocardial repair in the MI rats. H-AMSCs were isolated and incubated for 3 days. The expression of oxytocin and vasopressin receptors was evaluated by Real-time-PCR. Forty male Wistar rats were divided into 4 groups: control, sham, ASC and AVP-ASC. Ischemia was established by ligation of LAD coronary artery. Electrocardiography, fibrosis, angiogenesis, and apoptosis in myocardium were determined after 7 days. Results showed that preconditioned MSCs significantly increased cardiac function when compared with group that received non-preconditioned MSCs. This was associated with significantly reduced fibrosis, increased vascular density, and decreased resident myocyte apoptosis. Results indicate that AVP preconditioned MSCs can be consider a novel approach to management of MI.