MicroRNA-1 and Circulating Microvesicles Mediate the Protective Effects of Dantonic in Acute Myocardial Infarction Rat Models

Metabolomics analysis reveals the effects of Salvia Miltiorrhiza Bunge extract on ameliorating acute myocardial ischemia in rats induced by isoproterenol

Salvia miltiorrhiza Bunge (SM) is a widespread herbal therapy for myocardial ischemia (MI). Nevertheless, the therapeutic signaling networks of SM extract on MI is yet unknown. Emerging evidences suggested that alterations in cardiac metabolite influences host metabolism and accelerates MI progression. Herein, we employed an isoproterenol (ISO)-induced acute myocardial ischemia (AMI) rat model to confirm the pharmacological effects of SM extract (0.8, 0.9, 1.8 g/kg/day) via assessment of the histopathological alterations that occur within the heart tissue and associated cytokines; we also examined the underlying SM extract-mediated signaling networks using untargeted metabolomics. The results indicated that 25 compounds with a relative content higher than 1 % in SM aqueous extract were identified using LC-MS/MS analysis, which included salvianolic acid B, lithospermic acid, salvianolic acid A, and caffeic acid as main components. An in vivo experiment showed that pretreatment with SM extract attenuated ISO-induced myocardial injury, shown as decreased myocardial ischemic size, transformed electrocardiographic, histopathological, and serum biochemical aberrations, reduced levels of proinflammatory cytokines, inhibited oxidative stress (OS), and reversed the trepidations of the cardiac tissue metabolic profiles. Metabolomics analysis shows that the levels of 24 differential metabolites (DMs) approached the same value as controls after SM extract therapy, which were primarily involved in histidine; alanine, aspartate, and glutamate; glycerophospholipid; and glycine, serine, and threonine metabolisms through metabolic pathway analysis. Correlation analysis demonstrated that the levels of modulatory effects of SM extract on the inflammation and OS were related to alterations in endogenous metabolites. Overall, SM extract demonstrated significant cardioprotective effects in an ISO-induced AMI rat model, alleviating myocardial injury, inflammation and oxidative stress, with metabolomics analysis indicating potential therapeutic pathways for myocardial ischemia.

Storax Attenuates Cardiac Fibrosis following Acute Myocardial Infarction in Rats via Suppression of AT1R-Ankrd1-P53 Signaling Pathway

Myocardial fibrosis following acute myocardial infarction (AMI) seriously affects the prognosis and survival rate of patients. This study explores the role and regulation mechanism of storax, a commonly used traditional Chinese medicine for treatment of cardiovascular diseases, on myocardial fibrosis and cardiac function. The AMI rat model was established by subcutaneous injection of Isoproterenol hydrochloride (ISO). Storax (0.1, 0.2, 0.4 g/kg) was administered by gavage once/d for 7 days. Electrocardiogram, echocardiography, hemodynamic and cardiac enzyme in AMI rats were measured. HE, Masson, immunofluorescence and TUNEL staining were used to observe the degree of pathological damage, fibrosis and cardiomyocyte apoptosis in myocardial tissue, respectively. Expression of AT1R, CARP and their downstream related apoptotic proteins were detected by WB. The results demonstrated that storax could significantly improve cardiac electrophysiology and function, decrease serum cardiac enzyme activity, reduce type I and III collagen contents to improve fibrosis and alleviate myocardial pathological damage and cardiomyocyte apoptosis. It also found that storax can significantly down-regulate expression of AT1R, Ankrd1, P53, P-p53 (ser 15), Bax and cleaved Caspase-3 and up-regulate expression of Mdm2 and Bcl-2. Taken together, these findings indicated that storax effectively protected cardiomyocytes against myocardial fibrosis and cardiac dysfunction by inhibiting the AT1R-Ankrd1-P53 signaling pathway.

Cardioprotective Effects of Tetrahydropalmatine on Acute Myocardial Infarction in Rats

Tetrahydropalmatine (THP) is an active component of Corydalis yanhusuo W. T. Wang. The current study investigates the possible cardioprotective effects of tetrahydropalmatine in acute myocardial ischemia (AMI) rats. The anterior descending coronary artery of SD rats was ligated to establish an AMI model. After two weeks of gavage of THP, cardiac function was determined by echocardiography. The organ index and the infarct size were assessed after the experiment, and the histopathological myocardial tissue changes were observed. In addition, the apoptosis index of myocardial cells was detected by the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. The levels of SOD, MDA, CAT, GSH-Px, BNP, and cTn-I were measured by enzyme-linked immunosorbent assay. To determine relevant proteins, the Western blot and molecular docking were applied. Compared with the model group, THP could enhance rat cardiac ejection function to improve cardiac function, drastically lessen the infarct size, reduce myocardial cell damage and inflammatory cell infiltration. THP might also prevent ischemic myocardial damage by inhibiting myocardial cell apoptosis and efficiently reducing oxidative stress. Specifically, THP could decrease MDA, BNP, c-TnI activities, as well as the expression of Bax and Caspase-3 protein, while increasing SOD, GSH-Px, CAT activities, and Bcl-2 level. Furthermore, THP could significantly promote the phosphorylation of PI3K and Akt proteins. The involved pathways and proteins have also been verified through molecular docking. According to these findings, THP may preserve the myocardium due to its anti-oxidant and anti-apoptotic properties.

miR-3113-5p, miR-223-3p, miR-133a-3p, and miR-499a-5p are sensitive biomarkers to diagnose sudden cardiac death

Background

Sudden cardiac death (SCD) remains a great health threat and diagnostic challenge, especially those cases without positive autopsy findings. Molecular biomarkers have been urgently needed for the diagnosis of SCD displaying negative autopsy results. Due to their nature of stability, microRNAs (miRNAs) have emerged as promising diagnostic biomarkers for cardiovascular diseases.

Methods

This study investigated whether specific cardio-miRNAs (miR-3113-5p, miR-223-3p, miR-499a-5p, and miR-133a-3p) could serve as potential biomarkers for the diagnosis of SCD. Thirty-four SCD cases were selected, 18 categorized as SCD with negative autopsy (SCD-negative autopsy) findings and 16 as SCD with positive autopsy (SCD-positive autopsy) findings such as coronary atherosclerosis and gross myocardial scar. Carbon monoxide (CO) intoxication (n = 14) and fatal injury death (n = 14) that displayed no pathological changes of myocardium were selected as control group, respectively. Histological analyses were performed to reveal the pathological changes and real-time quantitative polymerase chain reaction (RT-qPCR) was used to determine the expression of those miRNAs.

Results

It showed that heart samples from the SCD-negative autopsy group displayed no remarkable difference with regard to the expression of cleaved-caspase3, CD31, and CD68 and the extent of fibrotic tissue accumulation when compared with control samples. The four cardio-miRNAs were significantly up-regulated in the SCD samples as compared with control. When discriminating SCD from controls, receiver operating characteristic (ROC) curve analysis revealed that the areas under the curve (AUC) of these 4 miRNAs were from 0.7839 to 0.9043 with sensitivity of 64.71–97.06% and specificity of 70–100%. Moreover, when discriminating the specific causes of SCD, the four miRNA expressions increased in the heart from the SCD-negative autopsy group as relative to that from the SCD-positive autopsy group, and a combination of two miRNAs presented higher diagnostic value (AUC = 0.7407–0.8667).

Conclusion

miR-3113-5p, miR-223-3p, miR-499a-5p, and miR-133a-3p may serve as independent diagnostic biomarkers for SCD, and a combination of two of these miRNAs could further discriminate detailed causes of SCD.

Evaluation of Oxidative Stress, Apoptosis, and Expression of MicroRNA-208a and MicroRNA-1 in Cardiovascular Patients

BACKGROUND

MicroRNA expression signature and reactive oxygen species (ROS) production have been associated with the development of cardiovascular diseases (CVDs). This study aimed to evaluate oxidative stress, inflammation, apoptosis, and the expression of miRNA-208a and miRNA-1 in cardiovascular patients.

METHODS

The study population included four types of patients (acute coronary syndromes (ACS), myocardial infarction (MI), arrhythmia, and heart failure (HF)), with 10 people in each group, as well as a control group. Quantitative real-time PCR was performed to measure mir-208 and miR-1 expression, the mRNAs of inflammatory mediators (TNFα, iNOS/eNOS), and apoptotic factors (Bax and Bcl2). XOX, MDA, and antioxidant enzymes (CAT, SOD, and GPx) were measured by ZellBio GmbH kits by an ELISA Reader.

RESULTS

The results showed significant decreases in the activity of antioxidant enzymes (CAT, SOD, and Gpx) and a significant increase in the activity of the MDA and XOX in cardiovascular patients. Significant increases in IL-10, iNos, iNOS / eNOS, and TNF-α in cardiovascular patients were also observed. Also, a significant increase in the expression of miR-208 (HF> arrhythmia> ACS> MI) and a significant decrease in the expression of miR-1 (ACS> arrhythmia> HF> MI) were found in all four groups in cardiovascular patients.

CONCLUSION

The results showed increases in oxidative stress, inflammation, apoptotic factors, and in the expression of miR-208a in a variety of cardiovascular patients (ACS, MI, arrhythmia, and HF). It is suggested that future studies determine the relationships that miR-1, miR-208, and oxidative stress indices have with inflammation and apoptosis.

An ultrasound activated oxygen generation nanosystem specifically alleviates myocardial hypoxemia and promotes cell survival following acute myocardial infarction

Hypoxemia after acute myocardial infarction (AMI) causes severe damage to cardiac cells and induces cardiac dysfunction. Protection of cardiac cells and reconstruction of cardiac functions by re-introducing oxygen into the infarcted myocardium represents an efficient approach for the treatment of AMI. However, the established methods for oxygen supplementation mainly focus on systemic oxygen delivery, which always results in inevitable oxidative stress on normal tissues. In this work, an ultrasound (US) activated oxygen generation nanosystem has been developed, which specifically releases oxygen in the infarcted myocardium and alleviates the hypoxemic myocardial microenvironment to protect cardiac cells after AMI. The nanosystem was constructed through the formation of calcium peroxide in the mesopores of biocompatible mesoporous silica nanoplatforms, followed by the assembly of the thermosensitive material heneicosane and polyethyleneglycol. The mild hyperthermia induced by US irradiation triggered the phase change of heneicosane, thus achieving US responsive diffusion of water and release of oxygen. The US-activated oxygen release significantly alleviated the hypoxia and facilitated the mitigation of oxidative stress after AMI. Consequently, the survival of cardiac cells under hypoxic conditions was substantially improved and the damage in the infarcted myocardial tissue was minimized. This US-activated oxygen generation nanosystem may provide an efficient modality for the treatment of AMI.

Changes of cardiac troponin I and hypersensitive C-reactive protein prior to and after treatment for evaluating the early therapeutic efficacy of acute myocardial infarction treatment

The present study aimed to evaluate the utility of the extent of change (C) and change rate (Cr) of cardiac troponin I (cTnI) and hypersensitive C-reactive protein (hs-CRP) prior to and after treatment in evaluating the early therapeutic efficacy of acute myocardial infarction (AMI) treatment. A total of 145 patients with AMI who received regular MI treatment were enrolled in the present study. Patients were divided into the effective group and the ineffective group based on the early therapeutic efficacy. The values of two parameters, namely the serum levels of cTnI and hs-CRP, were collected prior to and after AMI treatment. Data were analyzed by using the t-test, Chi-squared test, logistic regression and receiver operating characteristic (ROC) curve analysis. Compared with those in the ineffective group, the values of cTnI and hs-CRP after treatment [cTnI_(post) and hs-CRP_(post)], as well as their C and Cr values, were significantly decreased in the effective group (P<0.01). Furthermore, the positive rates (PR) of cTnI_(post), hs-CRP_(post), (cTnI+hs-CRP)_(post), C_(cTnI), C_(hs-CRP) and C_{(cTnI+hs-CRP)} were significantly lower in the effective group compared with those in the ineffective group (P<0.01). It was indicated that hs-CRP_(post) and C_(hs-CRP), as well as the PR-cTnI_(post) and the PR-C_(cTnI), may be used as independent factors for early therapeutic efficacy evaluation (P<0.05). In addition, the area under the ROC curve, as well as the associated sensitivity and specificity analysis for cTnI_(post), hs-CRP_(post), C_{(cTnI or hs-CRP)} and Cr_{(cTnI or hs-CRP)}, all indicated that these parameters were able to distinguish between the effective and the ineffective groups. The present study revealed that compared with the cTnI_(post) and hs-CRP_(post), the C and the Cr of cTnI and hs-CRP may have enhanced value for evaluating the early therapeutic efficacy of AMI treatment.

Metoprolol protects against myocardial infarction by inhibiting miR-1 expression in rats

OBJECTIVES

Metoprolol is regarded as a first-line medicine for the treatment of myocardial infarction (MI). However, the underlying mechanisms remain largely unknown. This study aimed to investigate the involvement of miR-1 in the pharmacological function of metoprolol.

METHODS

In vivo MI model was established by left anterior descending coronary artery (LAD) ligation. The effects of metoprolol on infarct size and cardiac dysfunction were determined by triphenyltetrazolium chloride staining and cardiac echocardiography, respectively. In vitro oxidative stress cardiomyocyte model was established by H₂ O₂ treatment. The effect of metoprolol on the expression of miR-1 and connexin43 (Cx43) was quantified by real-time PCR and western blot, respectively. The intercellular communication was evaluated by lucifer yellow dye diffusion.

KEY FINDINGS

Left anterior descending ligation-induced MI injury was markedly attenuated by metoprolol as shown by reduced infarct size and better cardiac function. Metoprolol reversed the up-regulation of miR-1 and down-regulation of Cx43 in MI heart. Moreover, in H₂ O₂ -stimulated cardiomyocytes, overexpression of miR-1 abolished the effects of metoprolol on Cx43 up-regulation and increased intercellular communication, indicating that miR-1 may be a necessary mediator for the cardiac protective function of metoprolol.

CONCLUSIONS

Metoprolol relieves MI injury via suppression miR-1, thus increasing its target protein Cx43 and improving intercellular communication.

Circulating microRNA-1 in the diagnosis and predicting prognosis of patients with chest pain: a prospective cohort study

Background

To investigate the early diagnostic and prognostic value of microRNA-1 in patients with acute chest pain.

Methods

This study enrolled 341 patients attacked by chest pain within 3 h, and another 100 volunteers as control group. Circulating microRNA-1 was collected and determined by real-time quantitative reverse transcription-polymerase chain reaction. The clinical follow-up period was 720 days.

Results

There were 174 patients in acute myocardial infarction (AMI) group, 167 in non-AMI group. The relative expression of microRNA-1 was significantly increased within 3 h in AMI group, and it continued rising within 12 h, lower at 24 h than that 12 h in AMI group without reperfusion therapy. Otherwise, microRNA-1 concentration was markedly low at 12 h after primary percutaneous coronary intervention in AMI group. The 95% reference range of circulating microRNA-1 was 0.171–0.653. It was significantly available for microRNA-1 to early diagnose AMI with an optimal cutoff value of 2.215 and diagnostic accuracy could be improved when combined with cardiac troponin I. It was not statistically significant for microRNA-1 to forecast future AMI but might prognose mortality of 720 days in chest pain patients. In patients with chest pain, microRNA-1 concentration was high with major adverse cardiac events within 30 days, low with high overall survival within 720 days.

Conclusions

Circulating microRNA-1 might diagnose early AMI and predict the prognosis of patients with chest pain.