Protective effect of microRNA-30b on hypoxia/reoxygenation-induced apoptosis in H9C2 cardiomyocytes

Silencing of Long Noncoding RNA TUG1 Ameliorates Atherosclerosis-Induced Myocardial Injury by Upregulating microRNA-30b-3p and Downregulating Brd4

ABSTRACT

Long noncoding RNAs and microRNAs (miRNAs) are emerging biomarkers involved in human diseases, and we focused on the roles of long noncoding RNA taurine upregulated gene 1 (TUG1) and miR-30b-3p in the related mechanisms of atherosclerosis-induced myocardial injury. ApoE-deficient mice were fed with high-fat diet to establish atherosclerotic models and then were subjected to either TUG1 downregulation or miR-30b-3p upregulation treatment. The serum myocardial enzymes, inflammatory biomarkers, pathological changes, intramyocardial macrophage infiltration, and apoptosis of cardiomyocytes in atherosclerotic mice were determined. The expression of TUG1, miR-30b-3p, and bromodomain protein 4 (Brd4) in atherosclerotic models was evaluated. Moreover, the correlations of TUG1, miR-30b-3p, and Brd4 were verified. TUG1 and Brd4 were increased while miR-30b-3p was decreased in atherosclerotic mice. The silenced TUG1 or elevated miR-30b-3p attenuated atherosclerosis-induced myocardial injury mainly by reducing serum myocardial enzyme content and inflammatory response, improving pathological changes, and preventing macrophage infiltration and cardiomyocyte apoptosis in atherosclerotic mice. Mechanistically, TUG1 could competitively bind with miR-30b-3p to prevent the degradation of its target gene Brd4. This study reveals that the silencing of TUG1 ameliorates atherosclerosis-induced myocardial injury by upregulating miR-30b-3p and downregulating Brd4, which may provide novel targets for atherosclerosis treatment.

Wildfires and extracellular vesicles: Exosomal MicroRNAs as mediators of cross-tissue cardiopulmonary responses to biomass smoke

INTRODUCTION

Wildfires are a threat to public health world-wide that are growing in intensity and prevalence. The biological mechanisms that elicit wildfire-associated toxicity remain largely unknown. The potential involvement of cross-tissue communication via extracellular vesicles (EVs) is a new mechanism that has yet to be evaluated.

METHODS

Female CD-1 mice were exposed to smoke condensate samples collected from the following biomass burn scenarios: flaming peat; smoldering peat; flaming red oak; and smoldering red oak, representing lab-based simulations of wildfire scenarios. Lung tissue, bronchoalveolar lavage fluid (BALF) samples, peripheral blood, and heart tissues were collected 4 and 24 h post-exposure. Exosome-enriched EVs were isolated from plasma, physically characterized, and profiled for microRNA (miRNA) expression. Pathway-level responses in the lung and heart were evaluated through RNA sequencing and pathway analyses.

RESULTS

Markers of cardiopulmonary tissue injury and inflammation from BALF samples were significantly altered in response to exposures, with the greatest changes occurring from flaming biomass conditions. Plasma EV miRNAs relevant to cardiovascular disease showed exposure-induced expression alterations, including miR-150, miR-183, miR-223-3p, miR-30b, and miR-378a. Lung and heart mRNAs were identified with differential expression enriched for hypoxia and cell stress-related pathways. Flaming red oak exposure induced the greatest transcriptional response in the heart, a large portion of which were predicted as regulated by plasma EV miRNAs, including miRNAs known to regulate hypoxia-induced cardiovascular injury. Many of these miRNAs had published evidence supporting their transfer across tissues. A follow-up analysis of miR-30b showed that it was increased in expression in the heart of exposed mice in the absence of changes to its precursor molecular, pri-miR-30b, suggesting potential transfer from external sources (e.g., plasma).

DISCUSSION

This study posits a potential mechanism through which wildfire exposures induce cardiopulmonary responses, highlighting the role of circulating plasma EVs in intercellular and systems-level communication between tissues.

LncRNA KCNQ1OT1 Regulates Endoplasmic Reticulum Stress to Affect Cerebral Ischemia-Reperfusion Injury Through Targeting miR-30b/GRP78

Endoplasmic reticulum stress (ERS) plays an important role in cerebral ischemia-reperfusion injury (CIRI) by regulating apoptosis. Although the role of long non-coding RNA (LncRNA) KCNQ1OT1 in CIRI has been reported, the specific mechanism is still unclear. In this paper, the regulation of ERS by LncRNA KCNQ1OT1 in CIRI and its mechanism were studied. Transient middle cerebral artery occlusion (tMCAO) model was established in SD rats with KCNQ1OT1 intervention. PC12 cells were used to construct the OGD/R cell model. The expressions of LncRNA KCNQ1OT1 and miR-30b were detected by RT-qPCR. TCC staining was used to detect the extent of cerebral ischemia. TUNEL staining was used to detect apoptosis level, and Western blot was used to detect the expressions of ERS and apoptosis-related proteins. The targeted binding of LncRNA KCNQ1OT1, miR-30b, and GRP78 was detected by double luciferase assay. The expressions of LncRNA KCNQ1OT1 and miR-30b were interfered by cell transfection. Cell proliferation was detected by CCK-8. The level of LncRNA KCNQ1OT1 was increased and that of miR-30b was decreased in the blood samples of patients with CIRI. In tMCAO rats with KCNQ1OT1 intervention, the expression of miR-30b was increased, and the ischemic range of brain tissues was decreased. What's more, the level of ERS was decreased, and the apoptosis of brain tissues was decreased. LncRNA KCNQ1OT1 could regulate miR-30b/GRP78 in OGD/R cells in a targeted way. Intervention of KCNQ1OT1 could promote the proliferation of OGD/R cells, inhibiting the level of ERS and cell apoptosis. Further inhibition of miR-30b could reverse the effect of intervention of KCNQ1OT1. LncRNA KCNQ1OT1 regulates ERS to affect CIRI through targeting miR-30b/GRP78.

Overexpression of miR-431 attenuates hypoxia/reoxygenation-induced myocardial damage via autophagy-related 3

Myocardial injury is still a serious condition damaging the public health. Clinically, myocardial injury often leads to cardiac dysfunction and, in severe cases, death. Reperfusion of the ischemic myocardial tissues can minimize acute myocardial infarction (AMI)-induced damage. MicroRNAs are commonly recognized in diverse diseases and are often involved in the development of myocardial ischemia/reperfusion injury. However, the role of miR-431 remains unclear in myocardial injury. In this study, we investigated the underlying mechanisms of miR-431 in the cell apoptosis and autophagy of human cardiomyocytes in hypoxia/reoxygenation (H/R). H/R treatment reduced cell viability, promoted cell apoptotic rate, and down-regulated the expression of miR-431 in human cardiomyocytes. The down-regulation of miR-431 by its inhibitor reduced cell viability and induced cell apoptosis in the human cardiomyocytes. Moreover, miR-431 down-regulated the expression of autophagy-related 3 (ATG3) via targeting the 3'-untranslated region of ATG3. Up-regulated expression of ATG3 by pcDNA3.1-ATG3 reversed the protective role of the overexpression of miR-431 on cell viability and cell apoptosis in H/R-treated human cardiomyocytes. More importantly, H/R treatments promoted autophagy in the human cardiomyocytes, and this effect was greatly alleviated via miR-431-mimic transfection. Our results suggested that miR-431 overexpression attenuated the H/R-induced myocardial damage at least partly through regulating the expression of ATG3.

Roles and regulatory mechanisms of miR-30b in cancer, cardiovascular disease, and metabolic disorders (Review)

MicroRNAs (miRNAs) are non-coding RNAs 21-23 nucleotides in length that regulate gene expression, and thereby modulate signaling pathways and protein synthesis in both physiological and pathogenic processes. miR-30b inhibits cell proliferation, migration, invasion and epithelial-mesenchymal transformation in multiple types of cancer. In addition to its role in several types of neoplasias, miR-30b has been shown to exhibit essential roles in cardiovascular and metabolic diseases. In the present review, an overview of the biological functions of miR-30b and its role in the pathogenesis of neoplastic, cardiovascular and metabolic diseases is provided. miR-30b is a potential candidate for clinical development as a diagnostic and prognostic biomarker, therapeutic agent and drug target. However, further research is required to elucidate its role in health and disease and to harness its potential clinical utility.

Kaempferol Regulates miR-15b/Bcl-2/TLR4 to Alleviate OGD-Induced Injury in H9c2 Cells

Ischemic heart disease (IHD) is one of the world's leading causes of human death. Kaempferol (Kae) was proved to have anti-inflammatory, antioxidant, and anticancer effects. Such properties suggested that it might play protective roles in IHD. In this study, we have attempted to disclose the potential regulating mechanisms of Kae in primary cardiomyocytes and H9c2 cells.Cells were first stimulated by oxygen-glucose deprivation (OGD) and then exposed to Kae. CCK-8 assay and flow cytometry were used to examine cell characteristics. Quantitative reverse-transcription polymerase chain reaction was utilized to test the expression levels of miR-15b and TLR4. Afterward, cell transfection, dual-luciferase activity assay, and western blot were used to explore the potential mechanisms.OGD treatment suppressed cell viability, whereas it enhanced cell apoptosis. Besides, OGD treatment enhanced the expression of apoptosis-associated proteins. Kae exposure, however, attenuated the effects that OGD-induced. Further experiments showed that Kae exposure promoted down-regulation of miR-15b, Bcl-2 and TLR4 were a target of miR-15b. Moreover, Kae enhanced the expression of key factors involved in PI3K/AKT and Wnt/β-catenin pathways, whereas miR-15b mimic reversed the Kae-triggered effects.This investigation revealed that Kae diminished OGD-triggered cell damage through down-regulating miR-15b expression via activating PI3K/AKT and Wnt3a/β-catenin pathways.

Up-regulation of microRNA-30b/30d cluster represses hepatocyte apoptosis in mice with fulminant hepatic failure by inhibiting CEACAM1

Recently, impacts of microRNAs have been unraveled in human diseases, and we aimed to confirm the role of miR-30b/30d in fulminant hepatic failure (FHF). Expression of miR-30b/30d and CEACAM1 in serum of FHF patients and healthy people was measured by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. Mice FHF models were established by injection of D-Galn and lipopolysaccharide, and were treated with miR-30b/30d mimics. Oxidative stress, liver injury, and inflammatory reaction in mouse liver tissues were measured using oxidative stress-related factor kits, hematoxylin-eosin staining and enzyme-linked immunosorbent assay, respectively. Moreover, cell cycle distribution and apoptosis of hepatocytes of mice were determined by flow cytometry, and the target relation between miR-30b/30d and CEACAM1 was confirmed by bioinformatic method and dual luciferase reporter gene assay. MiR-30b/30d expression was positively, and CEACAM1 expression was negatively related to prognosis of FHF patients. Up-regulation of miR-30b/30d attenuated oxidative stress, liver injury, and inflammatory reaction, and improved survival rate of FHF mice. Furthermore, elevated miR-30b/30d ameliorated apoptosis and cell cycle arrest of hepatocytes of FHF mice. CEACAM1 was a target gene of miR-30b/30d. This study highlights that up-regulated miR-30b/30d attenuates the progression of FHF by targeting CEACAM1, which may be helpful to FHF treatment.

Anti-apoptotic effect of microRNA-30b in early phase of rat myocardial ischemia-reperfusion injury model

This study aimed to investigate the effect of microRNA-30b (miR-30b) in rat myocardial ischemic-reperfusion (I/R) injury model. We randomly divided Sprague-Dawley (SD) rats (n = 80) into five groups: 1) control group; 2) miR-30b group; 3) sham-operated group; 4) I/R group, and 5) I/R+miR-30b group. Real-time quantitative polymerase chain reaction, immunohistochemical staining and Western blot analysis were conducted. TUNEL assay was employed for testing cardiomyocyte apoptosis. Our results showed that miR-30b levels were down-regulated in I/R group and I/R + miR-30b group compared with sham-operated group (both P < 0.05). However, miR-30b level in I/R + miR-30b group was higher than I/R group (P < 0.05). Markedly, the apoptotic rate in I/R group showed highest in I/R group (P < 0.05). Additionally, the results illustrated that protein levels of Bcl-2, Bax, and caspase-3 were at higher levels in ischemic regions in I/R group, comparing to sham-operated group (all P < 0.05), while Bcl-2/Bax was reduced (P < 0.05). Bcl-2 level and Bcl-2/Bax were obviously increased in I/R + miR-30b group by comparison with I/R group, and expression levels of Bax and caspase-3 were down-regulated (all P < 0.05). We also found that in I/R + miR-30b group, KRAS level was apparently lower and p-AKT level was higher by comparing with I/R group (both P < 0.05). Our study indicated that miR-30b overexpression had anti-apoptotic effect on early phase of rat myocardial ischemia injury model through targeting KRAS and activating the Ras/Akt pathway.

Sarco"MiR" friend or foe: a perspective on the mechanisms of doxorubicin-induced cardiomyopathy

Anthracyclines are a class of chemotherapeutics used to treat a variety of human cancers including both solid tumors such as breast, ovarian, and lung, as well as malignancies of the blood including leukemia and lymphoma. Despite being extremely effective anti-cancer agents, the application of these drugs is offset by side effects, most notably cardiotoxicity. Many patients treated with doxorubicin (DOX), one of the most common anthracyclines used in oncology, will develop radiographic signs and/or symptoms of cardiomyopathy. Since more and more patients treated with these drugs are surviving their malignancies and manifesting with heart disease, there is particular interest in understanding the mechanisms of anthracycline-induced injury and developing ways to prevent and treat its most feared complication, heart failure. MicroRNAs (miRNAs) are small noncoding RNAs that regulate the expression of mRNAs. Since miRNAs can regulate many mRNAs in a single network they tend to play a crucial role in the pathogenesis of several diseases, including heart failure. Here we present a perspective on a recent work by Roca-Alonso and colleagues who demonstrate a cardioprotective function of the miR-30 family members following DOX-induced cardiac injury. They provide evidence for direct targeting of these miRNAs on key elements of the β-adrenergic pathway and further show that this interaction regulates cardiac function and apoptosis. These experiments deliver fresh insights into the biology of toxin-induced cardiomyopathy and suggest the potential for novel therapeutic targets.

MiR-30b Is Involved in the Homocysteine-Induced Apoptosis in Human Coronary Artery Endothelial Cells by Regulating the Expression of Caspase 3

Homocysteine (Hcy) is an independent risk factor for a variety of cardiovascular diseases, such as coronary heart disease, hypertension, stroke, etc. There is a close relationship between the vascular endothelial cell apoptosis and these diseases. Recent studies have shown homocysteine can induce apoptosis in endothelial cells, which may be an important mechanism for the development of theses cardiovascular diseases. Although there are several reports about how the Hcy induces apoptosis in endothelial cells, the exact mechanism is not fully understood. MicroRNAs are small, non-coding RNA. Previous studies have shown that there is a close relationship between several microRNAs and cell apoptosis. However, there are no studies about the role of microRNAs in Hcy-induced apoptosis in endothelial cells so far. In this study, we constructed the model of homocysteine-induced apoptosis in human coronary artery endothelial cells (HCAECs) and found miR-30b was significantly down-regulated by 1 mmol/L Hcy. In addition, overexpression of miR-30b can improve the Hcy-induced apoptosis in HCAECs by downregulating caspase-3 expression. Therefore, miR-30b may play an important role in Hcy-induced apoptosis in endothelial cells.