Tongxinluo Attenuates Myocardiac Fibrosis after Acute Myocardial Infarction in Rats via Inhibition of Endothelial-to-Mesenchymal Transition

A review regarding the article 'Traditional Chinese medicine compound (Tongxinluo) and clinical outcomes of patients with acute myocardial infarction the CTS-AMI randomized clinical trial'

Tongxinluo, a traditional Chinese medicine compound, has shown promise in improving outcomes for patients with ST-segment elevation myocardial infarction (STEMI). This randomized, double-blind, placebo-controlled trial investigated the efficacy of Tongxinluo in reducing major adverse cardiac and cerebrovascular events (MACCEs) in STEMI patients. The study enrolled 3777 patients from 124 hospitals in China, all of whom received standard STEMI treatments in addition to either Tongxinluo or placebo for 12 months. The primary endpoint was the occurrence of MACCEs at 30 days, with secondary endpoints including individual components of MACCEs, severe STEMI complications, major bleeding, and all-cause mortality at 1 yr. Results showed that Tongxinluo significantly reduced the 30-day MACCE rate compared to placebo (3.4 % vs 5.2 %), and this benefit persisted at 1 year (5.3 % vs 8.3 %). Cardiac death and myocardial reinfarction rates were also significantly lower in the Tongxinluo group. These findings underscore the importance of integrating traditional Chinese medicine with conventional Western medical treatments, providing significant evidence to support the development of evidence-based practices in traditional Chinese medicine. This study represents a pivotal advancement in the field of TCM, demonstrating its potential to contribute meaningfully to modern clinical practice and highlighting the necessity for further high-quality research in this area.

Tongxinluo capsule as a multi-functional traditional Chinese medicine in treating cardiovascular disease: A review of components, pharmacological mechanisms, and clinical applications

Cardiovascular diseases (CVDs) are one of the most significant diseases that pose a threat to human health. The innovative traditional Chinese medicine Tongxinluo Capsule, developed under the guidance of the theory of traditional Chinese medicine, has good clinical efficacy in various cardiovascular diseases, this medicine has effects such as blood protection, vascular protection, myocardial protection, stabilizing vulnerable plaques, and vasodilation. However, CVDs are a multifactorial disease, and their underlying mechanisms are not fully understood. Therefore, exploring the mechanism of action and clinical application of Tongxinluo Capsule in the treatment of various cardiovascular diseases is beneficial for exerting its therapeutic effect from multiple components, targets, and pathways. At the same time, it provides broader treatment ideas for other difficult to treat diseases in the cardiovascular event chain, and has significant theoretical and clinical significance for improving the treatment of cardiovascular diseases with traditional Chinese medicine.

Tongxinluo Activates PI3K/AKT Signaling Pathway to Inhibit Endothelial Mesenchymal Transition and Attenuate Myocardial Fibrosis after Ischemia-Reperfusion in Mice

OBJECTIVE

To investigate the potential role of Tongxinluo (TXL) in attenuating myocardial fibrosis after myocardial ischemia-reperfusion injury (MIRI) in mice.

METHODS

A MIRI mouse model was established by left anterior descending coronary artery ligation for 45 min. According to a random number table, 66 mice were randomly divided into 6 groups (n=11 per group): the sham group, the model group, the LY-294002 group, the TXL group, the TXL+LY-294002 group and the benazepril (BNPL) group. The day after modeling, TXL and BNPL were administered by gavage. Intraperitoneal injection of LY-294002 was performed twice a week for 4 consecutive weeks. Echocardiography was used to measure cardiac function in mice. Masson staining was used to evaluate the degree of myocardial fibrosis in mice. Qualitative and quantitative analysis of endothelial mesenchymal transition (EndMT) after MIRI was performed by immunohistochemistry, immunofluorescence staining and flow cytometry, respectively. The protein expressions of platelet endothelial cell adhesion molecule-1 (CD31), α-smoth muscle actin (α-SMA), phosphatidylinositol-3-kinase (PI3K) and phospho protein kinase B (p-AKT) were assessed using Western blot.

RESULTS

TXL improved cardiac function in MIRI mice, reduced the degree of myocardial fibrosis, increased the expression of CD31 and inhibited the expression of α-SMA, thus inhibited the occurrence of EndMT (P<0.05 or P<0.01). TXL significantly increased the protein expressions of PI3K and p-AKT (P<0.05 or P<0.01). There was no significant difference between TXL and BNPL group (P>0.05). In addition, the use of the PI3K/AKT pathway-specific inhibitor LY-294002 to block this pathway and combination with TXL intervention, eliminated the protective effect of TXL, further supporting the protective effect of TXL.

CONCLUSION

TXL activated the PI3K/AKT signaling pathway to inhibit EndMT and attenuated myocardial fibrosis after MIRI in mice.

Chinese patent medicine Tongxinluo: A review on chemical constituents, pharmacological activities, quality control, and clinical applications

BACKGROUND

Cardiovascular and cerebrovascular disease (CCVD) is the leading cause of morbidity and mortality worldwide, imposing a significant economic burden on individuals and societies. For the past few years, Traditional Chinese Medicine (TCM) has attracted much attention due to its advantages such as fewer side effects in the treatment of CCVD. TXL has shown great promise in the treatment of CCVD.

PURPOSE

This paper aims to provide a comprehensive introduction to TXL, covering its chemical constituents, quality control, pharmacological properties, adverse reactions, and clinical applications through an extensive search of relevant electronic databases while discussing its current challenges and provides opinions for future study.

METHODS

The following electronic databases were searched up to 2023: "TXL", "CCVD", "Chemical constituents", "Quality control" and "Pharmacological properties" were entered as keywords in PubMed, Web of Science, Google Scholar and China National Knowledge Infrastructure Database and WANFANG DATA databases. The PRISMA guidelines were followed in this review process.

RESULTS

Studies have confirmed that TXL is effective in treating patients with CCVD and has fewer adverse effects. The aim of this review is to explore TXL anti-CCVD effects in relation to oxidative stress, lipid metabolism and enhanced cardiac function. This review also provides additional information on safety issues.

CONCLUSION

TXL plays a key role in the treatment of CCVD by regulating various pathways such as lipid metabolism, oxidative stress and inflammation. However, further clinical trials and animal experiments are needed to provide more evidence and recommendations for its clinical application. This article provides an overview of TXL research to inform and inspire future studies.

Clinical effects and mechanisms of a Chinese patent medicine, Tongxinluo capsule, as an adjuvant treatment in coronary heart disease

Coronary heart disease (CHD) is the leading cause of death globally, posing a serious threat to human health. However, the current treatment approaches available for CHD fall short of the ideal results. Tongxinluo (TXL) is a traditional Chinese medicine (TCM) that has been employed in the clinical treatment of cardiovascular and cerebrovascular diseases (such as angina pectoris, stroke, etc.) in China for many years and holds great potential as a prospective treatment. TXL either as a standalone treatment or in combination with interventions recommended in CHD guidelines has been shown to be effective and well tolerated in clinical trials for CHD. Drawing on the evidence from clinical trials and experimental studies, this review will focus on the cardiovascular protective properties and related mechanisms of TXL. By searching 8 Chinese and English databases, more than 4000 articles were retrieved. These articles were categorized, then read, and finally written into this review. In this review, the pharmacological properties of TXL include regulation of blood lipids, improvement of endothelial function, anti-inflammatory, antioxidant, inhibition of apoptosis and regulation of autophagy, anti-fibrosis, promotion of angiogenesis, and modulation of exosome communication. The information provided in this review will help the reader to comprehend better the insights that TCM has developed over time in practice and provide new perspectives for the treatment of CHD.

Non-coding RNAs: targets for Chinese herbal medicine in treating myocardial fibrosis

Cardiovascular diseases have become the leading cause of death in urban and rural areas. Myocardial fibrosis is a common pathological manifestation at the adaptive and repair stage of cardiovascular diseases, easily predisposing to cardiac death. Non-coding RNAs (ncRNAs), RNA molecules with no coding potential, can regulate gene expression in the occurrence and development of myocardial fibrosis. Recent studies have suggested that Chinese herbal medicine can relieve myocardial fibrosis through targeting various ncRNAs, mainly including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). Thus, ncRNAs are novel drug targets for Chinese herbal medicine. Herein, we summarized the current understanding of ncRNAs in the pathogenesis of myocardial fibrosis, and highlighted the contribution of ncRNAs to the therapeutic effect of Chinese herbal medicine on myocardial fibrosis. Further, we discussed the future directions regarding the potential applications of ncRNA-based drug screening platform to screen drugs for myocardial fibrosis.

Tongxinluo enhances the effect of atorvastatin on the treatment of atherosclerosis with chronic obstructive pulmonary disease by maintaining the pulmonary microvascular barrier

Atherosclerosis (AS) is a common comorbidity of chronic obstructive pulmonary disease (COPD), and systemic inflammation is an important mechanism of COPD with AS. Tongxinluo (TXL) improves the function of vascular endothelial cells. We aimed to prove that impairment of pulmonary microvascular barrier function is involved in COPD-mediated aggravation of AS and investigate whether TXL enhances the effect of Ato (atorvastatin) on COPD with AS by protecting pulmonary microvascular endothelial barrier function. In vivo, a COPD with atherosclerotic apolipoprotein E knockout (AS ApoE^-/-) mouse model was established by cigarette smoke combined with a high-fat diet. The animals were administered TXL, Ato, and TXL + Ato once a day for 20 weeks. Lung function, lung microvascular permeability, lung inflammation, systemic inflammation, serum lipid levels, atheromatous plaque formation, and endothelial damage biomarkers were measured. In vitro, human pulmonary microvascular endothelial cells (HPMECs) were pretreated with TXL and incubated with cigarette smoke extract to establish the model. The permeability of the endothelial monolayer, inflammatory cytokines, endothelial damage biomarkers, and tight junction (Tj) proteins were determined. Cigarette smoking significantly exacerbated the high-fat diet-induced pulmonary function decline, pulmonary microvascular endothelial barrier dysfunction, inflammation, and atherosclerotic plaques. These changes were reversed by TXL-Ato; the combination was more effective than Ato alone. Furthermore, TXL protected the HPMEC barrier and inhibited inflammation in HPMECs. COPD aggravates AS, possibly through the destruction of pulmonary microvascular barrier function; thus, lung inflammation triggers systemic inflammation. In treating COPD with AS, TXL enhances the antiatherosclerotic effect of Ato, protecting the pulmonary microvascular barrier.

Dioscin alleviates myocardial infarction injury via regulating BMP4/NOX1-mediated oxidative stress and inflammation

BACKGROUND

Dioscin, a steroidal saponin natural product, has various pharmacological activities, such as anti-inflammatory, antioxidant, lipid-lowering. However, little is known about its effects on myocardial infarction (MI) injury. Thus, the study aimed to investigate the protective effects and possible mechanisms of dioscin.

METHODS

We evaluated protective effects of Dioscin on HL-1 cells after hypoxia based on MTT and ROS in vitro. In vivo, we ligated left anterior descending (LAD) of C57BL/6 mice to establish MI model and assess serum levels of LDH, CK-MB, cTnI, SOD, MDA and CAT treated by dioscin. In addition, myocardial damages were reflected by H&E, masson and ultrastructural examination and Electrocardiograph (ECG) was detected in MI mice. And the BMP4/NOX1 pathway was measured by western blotting, immunofluorescence assay and Real-time PCR. Furthermore, to investigate cardio-protective effects of dioscin via targeting BMP4, we transfected siBMP4 into HL-1 cells in vitro and injected BMP4 siRNA though tail veins in vivo.

RESULTS

In vitro, dioscin significantly increased the viability of HL-1 cells and inhibited ROS level under hypoxia. In vivo, dioscin markedly reduced the elevation of ST segment and alleviated myocardial infarct area in mice. In terms of serology, dioscin evidently decreased LDH, CK-MB, cTnI, MDA levels, and increased SOD level. In addition, dioscin improved the pathological status of myocardial tissue and restrained the production of collagen fibers. Mechanism study proved that dioscin notablely regulated the levels of Nrf2, Keap1, HO-1, p-NF-κB, nNF-κB, TNF-α, IL-1β and IL-6 by down-regulating the protein levels of BMP4 and NOX1 against oxidative stress and inflammation. Further investigation showed that siBMP4 transfection diminished hypoxia and MI-induced oxidative and inflammation injury. The transfection decreased LDH, CK-MB and cTnI levels, improved ischemia T-wave inversion and reduced striated muscle necrosis, nucleus dissolution, collagen fibrosis and mitochondrial swelling in mice. In addition, siBMP4 decreased ROS and MDA levels, increased SOD and CAT levels and down-regulated mRNA levels of TNF-α, IL-1β and IL-6. Moreover, BMP4, NOX1 and nNF-κB protein levels were decreased and Nrf2 levels were increased by siBMP4.

CONCLUSION

Our study confirmed that dioscin showed an outstanding anti-myocardial infarction effect via regulating BMP4/NOX1-mediated oxidative stress and inflammation, which has a promising application value and development prospect against MI injury in the future.

Guanxin V alleviates acute myocardial infarction by restraining oxidative stress damage, apoptosis, and fibrosis through the TGF-β1 signalling pathway

BACKGROUND

Oxidative stress, apoptosis, and fibrosis have important roles in acute myocardial infarction, which is the main cause of global morbidity and mortality. Guanxin V significantly ameliorates acute myocardial infarction, the underlying mechanism, however, is still unclear.

PURPOSE

In this study, we detected the anti-oxidative, anti-apoptotic, and anti-fibrosis effects of Guanxin V on acute myocardial infarction.

METHODS

We used left anterior descending coronary artery ligation to construct an acute myocardial infarction model. Cardiac function, heart weight, infarction size, and histopathology were measured. Cardiomyocytes were treated with hydrogen peroxide to build an in vitro model. Cell apoptosis, fibrosis, and reactive oxygen species-related markers were tested. We observed the mitochondrial ultrastructure through transmission electron microscopy. The levels of collagens and TGF-β1 signalling were measured. The lentiviral vector containing the full-length TGF-β1 sequence was administered to investigate the rescue role of Guanxin V.

RESULTS

Guanxin V significantly decreased apoptosis and inhibited oxidative stress damage and fibrosis in acute myocardial infarction. Hydrogen peroxide could stimulate cardiomyocytes to produce reactive oxygen species and Guanxin V could significantly reverse hydrogen peroxide-induced cell damage, inhibit oxidative stress damage, apoptosis, and fibrosis, and enhance mitochondrial dynamic balance. Mechanistically, Guanxin V attenuated oxidative stress damage, apoptosis, and fibrosis induced by the TGF-β1 signalling pathway activation.

CONCLUSIONS

Guanxin V effectively relieved apoptosis, oxidative stress damage, and fibrosis through down-regulating the TGF-β1 signalling pathway, which enhances the knowledge of the cellular and molecular mechanism of Guanxin V in treating acute myocardial infarction.

Efficacy and Safety of Different Courses of Tongxinluo Capsule as Adjuvant Therapy for Coronary Heart Disease after Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Tongxinluo capsule (TXLC) is a widely used traditional Chinese medicine for coronary heart disease (CHD). However, the efficacy and safety of different courses of TXLC for CHD after percutaneous coronary intervention (PCI) have not been systematically evaluated yet. The Cochrane Library, PubMed, Embase, China National Knowledge Infrastructure, Wanfang Database, and Chinese Scientific Journal Database were searched from the inception to 26 August 2021. A meta-analysis was performed using a fixed- or random-effects model. The risk of adverse cardiovascular events, mortality, or adverse effects was evaluated by risk ratio (RR) with 95% confidence interval (CI). Thirty-four studies involving 3652 patients were finally included. After the 6-month treatment, compared with conventional treatment alone, TXLC combined with conventional treatment achieved better efficacy in lowering the risk of angiographic restenosis (RR = 0.37, 95% CI = 0.28−0.48, p < 0.001), myocardial infarction (RR = 0.38, 95% CI = 0.25−0.60, p < 0.001), heart failure (RR = 0.32, 95% CI = 0.18−0.56, p < 0.001), angina (RR = 0.26, 95% CI = 0.17−0.38, p < 0.001), revascularization (RR = 0.20, 95% CI = 0.09−0.46, p < 0.001), all-cause mortality (RR = 0.24, 95% CI = 0.10−0.58, p = 0.001), and mortality due to any cardiovascular event (RR = 0.27, 95% CI = 0.09−0.80, p = 0.018). After the 12-month treatment, TXLC reduced the recurrence risk of angina (RR = 0.40, 95% CI = 0.20−0.80, p = 0.009). However, there was no difference in any outcomes after the 3-month treatment. Besides, no difference was found in the incidence of adverse effects after the 3-month and 6-month treatments (3 months: RR = 0.73, 95% CI = 0.35−1.56, p = 0.418; 6 months: RR = 1.71, 95% CI = 0.74−3.93, p = 0.209). The certainty of evidence ranged from very low to moderate due to the risk of bias, inconsistency, and imprecision. TXLC showed beneficial effects on reducing the adverse cardiovascular events without compromising safety for CHD patients after PCI on the 6-month course. However, due to the unavoidable risk of bias, more high-quality and long-term studies are still needed to further evaluate the efficacy and safety of TXLC in many countries, not only in China.

Tongxinluo capsule as supplementation and cardiovascular endpoint events in patients with coronary heart disease: A systematic review and meta-analysis of randomized, double-blind, placebo-controlled trials

ETHNOPHARMACOLOGICAL RELEVANCE

Tongxinluo Capsule(TXLC) is a well-known traditional Chinese medicine prescription with effects of tonifying Qi and activating blood based on the Chinese herbal medicine theory that has been recommended as routine adjuvant treatment in patients with coronary heart disease (CHD) in China.

AIM OF THE STUDY

This meta-analysis aimed to evaluate the efficacy and safety of TXLC as supplementation in the prevention of adverse cardiovascular events in patients with CHD.

MATERIALS AND METHODS

We performed a literature search in Pubmed, Cochrane Library, China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Database (VIP), Wan Fang Database, and Chinese Biomedical Database (CBM) from their inceptions to March 2020. Only randomized controlled trials (RCTs) that assessed supplementation with TXLC or placebo and with adverse cardiovascular outcomes, were included in this meta-analysis. Primary end points were myocardial infarction (MI), target vessel revascularization (TVR) or in-stent restenosis (ISR), and cardiovascular death. Secondary end points included cerebrovascular accidents, heart failure (HF), and unscheduled readmission for cardiovascular diseases (CVDs). Adverse drug events were also evaluated. Trial sequential analysis (TSA) was conducted to reduce random errors introduced by possible insufficient sample size.

RESULTS

Eleven RCTs involving 1505 patients were analyzed. The mean(SD) age of included patients were 59.03(9.7) years. Treatment duration varied from 2 months to 12 months. Compared with placebo, TXLC supplementation showed significant effects on reducing the risk of MI (RR = 0.44, [95% CI, 0.24-0.80]), TVR or ISR (RR = 0.43, [95% CI, 0.31-0.58]), cerebrovascular accidents(RR = 0.17, [95% CI, 0.06-0.46]), HF (RR = 0.41, [95% CI, 0.21-0.79]), and unscheduled readmission for CVDs (RR = 0.72, [95% CI], P = 0.04), but did not have associations with incidence of cardiovascular death (RR = 0.53, [95% CI, 0.15-1.91]). Subgroups of trials with 2-month (MI: RR = 0.44, [95% CI, 0.13-1.53]; cardiovascular death: RR = 0.30, [95% CI, 0.01-7.67]; cerebrovascular accidents: RR = 0.04, [95% CI, 0.01-0.26]; unscheduled readmission for CVDs: RR = 0.43, [95% CI, 0.20-0.94]) and 12-month (MI: RR = 0.42, [95% CI, 0.20-0.89]; TVR or ISR: RR = 0.42, [95% CI, 0.31-0.58]; HF: RR = 0.34, [95% CI, 0.14-0.78]; unscheduled readmission for CVDs: RR = 0.85, [95% CI, 0.59-1.22]) intervention period were analyzed. The adverse drug reactions were mild with no significant difference between TXLC and placebo.

CONCLUSIONS

This meta-analysis indicated that TXLC supplementation had beneficial effects on the prevention of cardiovascular adverse events, especially in TVR or ISR after coronary revascularization and may possibly lower the incidence of first or recurrent MI and HF within 12 months in patients with CHD, while insufficient sample size implied that these results lacked certain stability. And the effects of TXLC on cardiovascular mortality, cerebrovascular events, and unscheduled readmission for CVDs could not be confirmed due to insufficient cases. Clinical trials with large-sample sizes and extended follow-up time are of interest in the future researches.

Application of vascular endothelial cells in stem cell medicine

Stem cell medicine is gaining momentum in the development of therapy for various end-stage diseases. The search for new seed cells and exploration of their application prospects are topics of interest in stem cell medicine. In recent years, vascular endothelial cells (VECs) have attracted wide attention from scholars. VECs, which form the inner lining of blood vessels, are critically involved in many physiological functions, including permeability, angiogenesis, blood pressure regulation, immunity, and pathological development, such as atherosclerosis and malignant tumors. VECs have significant therapeutic effects and broad application prospects in stem cell medicine for the treatment of various refractory diseases, including atherosclerosis, myocardial infarction, diabetic complications, hypertension, coronavirus disease 2019, and malignant tumors. On the one hand, VECs and their extracellular vesicles can be directly used for the treatment of these diseases. On the other hand, VECs can be used as therapeutic targets for some diseases. However, there are still some obstacles to the use of VECs in stem cell medicine. In this review, advances in the applications and challenges that come with the use of these cells are discussed.

Tongxinluo prevents chronic obstructive pulmonary disease complicated with atherosclerosis by inhibiting ferroptosis and protecting against pulmonary microvascular barrier dysfunction

Cardiovascular comorbidities are pervasive in chronic obstructive pulmonary disease (COPD) and often result in serious adverse cardiovascular events. Tongxinluo (TXL) has been clinically verified to treat atherosclerosis (AS), improve lung function and alleviate dyspnoea. The present study aimed to explore the effect of lung microvascular barrier dysfunction on AS in COPD and the potential pulmonary protective mechanisms of TXL in COPD complicated with AS. COPD complicated with AS was induced in mice by cigarette smoke (CS) exposure and high-fat diet (HFD) feeding. The mice were treated with atorvastatin (ATO), TXL or combination therapy (ATO+TXL) for 20 weeks. Pulmonary function, lung pathology, serum lipid levels, atherosclerotic plaque area and indicators of barrier function, oxidative stress and ferroptosis in lung tissue were evaluated. In vitro, human pulmonary microvascular endothelial cells (HPMECs) were pretreated with TXL for 4 h and then incubated with cigarette smoke extract (CSE) and homocysteine (Hcy) for 36 h to induce barrier dysfunction. Then the indicators of barrier function, oxidative stress and ferroptosis were measured. The results demonstrate that CS aggravated dyslipidaemia, atherosclerotic plaque formation, pulmonary function decline, pathological injury, barrier dysfunction, oxidative stress and ferroptosis in the HFD-fed mice. However, these abnormalities were partially reversed by ATO and TXL. Similar results were observed in vitro. In conclusion, pulmonary microvascular barrier dysfunction plays an important role by which COPD affects the progression of AS, and ferroptosis may be involved. Moreover, TXL delays the progression of AS and reduces cardiovascular events by protecting the pulmonary microvascular barrier and inhibiting ferroptosis.

Traditional Chinese medicine for acute coronary syndrome: A meta-analysis of clinical manifestations and objective indicators

BACKGROUND

Modern clinical trials and experimental researches of traditional Chinese medicine (TCM) have been conducted for decades and provided support for the prevention and treatment of acute coronary syndrome (ACS). However the level of evidence and the proper application of TCM were still barely satisfactory.

METHODS

In this study, we divided ACS into 3 different stages, including unstable angina, acute myocardial infarction, and post myocardial infarction. Then we systematically reviewed and meta-analyzed the existing randomized controlled trials on both clinical manifestations and objective indicators, in these 3 aspects.

RESULTS

The results indicate that TCM can both improve the clinical manifestations and ameliorate the objective parameters in different courses of ACS, including C-reactive protein in unstable angina, left ventricular ejection fraction in acute myocardial infarction and post myocardial infarction. And the incidence of short-term cardiovascular events are lower in TCM intervention group. Some of the improvements lead to potential long-term benefits.

CONCLUSION

TCM treatment is beneficial to different courses of ACS. To acquire more solid and comprehensive evidence of TCM in treating ACS, more rigorously designed randomized controlled trials with longer follow-up duration are warranted.

miR-16-5p Regulates PTPN4 and Affects Cardiomyocyte Apoptosis and Autophagy Induced by Hypoxia/Reoxygenation

Objectives

To explore the effects of miR-16-5p and PTPN4 on the apoptosis and autophagy of AC16 cardiomyocytes after hypoxia/reoxygenation treatment.

Methods

AC16 cells were divided into the control group (NC), hypoxia/reoxygenation group (H/R), knockdown miR-16-5p negative control group (NC inhibitor), knockdown miR-16-5p group (miR-16-5p inhibitor), overexpression miR-16-5p negative control group (NC mimics), overexpression miR-16-5p group (miR-16-5p mimics), silent PTPN4 negative control group (sh-NC), silent PTPN4 group (sh-PTPN4), and silent PTPN4 + knockdown miR-16-5p group (sh-PTPN4 + miR-16-5p inhibitor). Real-time fluorescent quantitative PCR (RT-qPCR) and western blotting (WB) were used to measure the expression level of miR-16-3p, miR-16-5p, protein tyrosine phosphatase nonreceptor type 4 (PTPN4), and autophagy-related proteins (beclin-1, LC3 II/I, and P26) in AC16 cells. The apoptosis level of AC16 cells in each group was measured by flow cytometry and TUNEL. The dual-luciferase reporter gene experiment was also used to verify the targeting relationship between miR-16-5p and PTPN4.

Results

After H/R treatment, the levels of myocardial injury markers including LDH and CK-MB in AC16 cells were increased significantly (P < 0.05), and the levels of cell apoptosis and autophagy also increased significantly (P < 0.05). The level of miR-16-3p in AC16 cells did not change significantly after H/R treatment, whereas the level of miR-16-5p was increased significantly (P < 0.05). After miR-16-5p was knocked down, the levels of LDH and CK-MB in AC16 cells treated with H/R were significantly reduced (P < 0.05), and the rates of cell apoptosis and autophagy were also significantly reduced (P < 0.05). miR-16-5p negatively regulated the expression level of PTPN4 protein in AC16 cells (P < 0.05), and the dual-luciferase reporter gene experiment confirmed that PTPN4 was the downstream target of miR-16-5p. Silencing of PTPN4 significantly increased the damage of AC16 cells induced by H/R treatment (P < 0.05), but simultaneously inhibiting the expression of PTPN4 and miR-16-5p reversed the protective effect of miR-16-5p knockdown on AC16 cells (P < 0.05).

Conclusions

The expression of miR-16-5p is upregulated in AC16 cells after H/R treatment and the knockdown which can protect AC16 cells from H/R-induced cell damage that may be due to its regulation on the expression of PTPN4.

Metformin Attenuates Hypoxia-induced Endothelial Cell Injury by Activating the AMP-Activated Protein Kinase Pathway

ABSTRACT

Metformin reduces the incidence of cardiovascular diseases, and potential underlying mechanisms of action have been suggested. Here, we investigated the role of metformin in endothelial cell injury and endothelial-mesenchymal transition (EndMT) induced by hypoxia. All experiments were performed in human cardiac microvascular endothelial cells (HCMECs). HCMECs were exposed to hypoxic conditions for 24, 48, 72, and 96 hours, and we assessed the cell viability by cell counting kit 8; metformin (2, 5, 10, and 20 mmol/L) was added to the cells after exposure to the hypoxic conditions for 48 hours. The cells were randomly divided into the control group, hypoxia group, hypoxia + metformin group, hypoxia + control small interfering RNA group, hypoxia + small interfering Prkaa1 (siPrkaa1) group, and hypoxia + siPrkaa1 + metformin group. Flow cytometry and cell counting kit 8 were used to monitor apoptosis and assess cell viability. Immunofluorescence staining was used to identify the CD31+/alpha smooth muscle actin+ double-positive cells. Quantitative real-time-PCR and Western blot were used for mRNA and protein expression analyses, respectively. Hypoxia contributed to endothelial injuries and EndMT of HCMECs in a time-dependent manner, which was mainly manifested as decreases in cell viability, increases in apoptotic rate, and changes in expression of apoptosis-related and EndMT-related mRNAs and proteins. Furthermore, metformin could attenuate the injuries and EndMT caused by hypoxia. After metformin treatment, phosphorylated-AMPK (pAMPK) and p-endothelial nitric oxide synthase expression increased, whereas p-mammalian target of rapamycin expression decreased. However, results obtained after transfection with siPrkaa1 were in contrast to the results of metformin treatment. In conclusion, metformin can attenuate endothelial injuries and suppress EndMT of HCMECs under hypoxic conditions because of its ability to activate the AMPK pathway, increase p-AMPK/AMP-activated protein kinase, and inhibit mammalian target of rapamycin.

Long non-coding RNA XIST promotes the proliferation of cardiac fibroblasts and the accumulation of extracellular matrix by sponging microRNA-155-5p

Acute myocardial infarction (AMI) is characterized by cardiomyocyte death followed by myocardial fibrosis, eventually leading to heart failure. Long non-coding (lnc)RNA X-inactive specific transcript (XIST) serves a vital role in the regulation of fibrosis. The aim of the present study was to determine whether myocardial fibrosis may be regulated by XIST and to elucidate the underlying mechanism. The relative mRNA expression levels of the target genes were evaluated using reverse transcription-quantitative polymerase chain reaction. Cell viability and apoptosis were determined using a Cell Counting Kit-8 assay and flow cytometry, respectively. The apoptosis and fibrosis-related protein expression levels were detected using western blot analysis. Finally, the interaction between XIST and microRNA (miR)-155-5p was analyzed using a luciferase reporter assay. XIST-overexpression increased proliferation and the expression level of the fibrosis-related proteins in the human cardiac fibroblast cells (HCFs). XIST directly targeted miR-155-5p and downregulated its expression, while miR-155-5p downregulation abolished the effect of XIST-silencing on cell viability and the expression level of the fibrosis-related proteins in the HCFs. XIST promoted cell proliferation and the expression level of fibrosis-related proteins by sponging miR-155-5p. Therefore, XIST may represent a novel effective target for AMI treatment.

miR-325-3p Overexpression Inhibits Proliferation and Metastasis of Bladder Cancer Cells by Regulating MT3

BACKGROUND miRNAs have been widely used in cancer treatment. Our study was designed to explore the effects of miR-325-3p in bladder cancer cells. MATERIAL AND METHODS Levels ofd miR-325-3p and MT3 in bladder cancer tissues and cells were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). miR-325-3p mimics were transfected into bladder cancer T24 cells, and cell migration and invasion rates and cell proliferation were assessed by transwell assay and Cell Counting Kit-8 (CCK-8). The target mRNA for miR-325-3p was predicted by Targetscan7.2 and confirmed by dual-luciferase reporter assay. More experiments were performed to confirm the effects of miR-325-3p and MT3 in T24 cells. Additionally, the levels of TIMP-2, MMP9, and E-cadherin were assessed by Western blotting to identify the effects of miR-325-3p and MT3 on epithelial-mesenchymal transition (EMT). RESULTS miR-325-3p expression was reduced and MT3 was increased in bladder cancer tissues and bladder cancer cells. miR-325-3p mimics suppressed cell proliferation ability and invasion and migration rates of T24 cells. Moreover, miR-325-3p was confirmed to target MT3. Further experiments showed that the effects of increased cell proliferation, invasion, migration, and EMT promoted by MT3 overexpression were abolished by miR-325-3p mimics, proving that miR-325-3p is a tumor suppressor through targeting MT3 in bladder cancer cells. CONCLUSIONS Downregulation of miR-325-3p in bladder cancer regulates cell proliferation, migration, invasion, and EMT by targeting MT3. Furthermore, miR-325-3p is a potential therapeutic target in treating bladder cancer.