The role of microRNA in modulating myocardial ischemia-reperfusion injury

β stimulator induces upregulation of miR-27a in the rat heart one hour after the injection

MicroRNAs (miRs) are non-coding small RNA containing 18 to 22 nucleotides, that post-transcriptionally regulates mRNA expression. Chronic injection of β stimulator is known to induce cardiac injury and change of miRs expression level in the heart with some pathological changes such as fibrosis, heart failure, myocardial infarction. We investigated the changes in the expression level of miRs in the rat heart one hour after isoproterenol (a β stimulator) injection. Male Sprague-Dawley rats were assigned into three groups and received subcutaneous injection of normal sarin (NS) or 0.1 mg/kg isoproterenol (ISO-0.1) or 10 mg/kg isoproterenol (ISO-10). After one hour, we collected their heart and plasma. Total RNA was extracted from the left ventricle and used for deep miRNA sequencing. Based on the results of miRNA sequencing, we performed real-time polymerase chain reaction (RT-PCR) using 8 miR primers. Cardiac injury was evaluated by hematoxylin and eosin, and phosphotungstic acid-hematoxylin staining and measuring troponin-I levels in plasma. Troponin-I was significantly increased in ISO-0.1 and ISO-10 groups, but histological observation did not show any cardiac necrosis. miRNA sequencing identified 14 upregulated miRs and 12 downregulated miRs. Of the 26 miRs, RT-PCR confirmed miR-144-3p/5p and miR-451-5p were decreased, and that 5 miRs (miR-27a-5p, miR-30b-3p, miR-92a-1-5p, miR-132-5p, miR-582-3p) were upregulated. This study showed that β stimulus causes downregulation of miR-144/451 cluster and increases expression of five 5 miRs in the heart, especially 6.5-fold upregulation of miR-27a-5p as early as one hour after isoproterenol injection. Therefore, these miRs might be good biomarkers for cardiac injury.

CIRC-MARC2 SILENCING PROTECTS HUMAN CARDIOMYOCYTES FROM HYPOXIA/REOXYGENATION-INDUCED INJURY BY MODULATING MIR-335-5P/TRPM7 AXIS

ABSTRACT

Myocardial ischemia-reperfusion injury (MIRI) is a vital risk factor for cardiovascular diseases. Some circular RNAs have been identified as modulators of MIRI. However, the effects of circ-mitochondrial amidoxime reducing component 2 (circ-MARC2) in MIRI are unclear. Our results showed that circ-MARC2 was overexpressed in hypoxia/reoxygenation (H/R)-treated AC16 cells. Circ-MARC2 silencing reversed the inhibitory effect of H/R treatment on cell proliferation and promoting effects on lactate dehydrogenase activity, creatine kinase activity, and cell apoptosis in AC16 cells. Moreover, circ-MARC2 served as the sponge for miR-335-5p and ameliorated H/R-induced AC16 cell damage by decoying miR-335-5p. In addition, transient receptor potential cation channel subfamily M member 7 (TRPM7) was identified as the target gene of miR-335-5p. Overexpression of miR-335-5p relieved H/R-induced AC16 cell damage, whereas TRPM7 elevation abolished the effect. Circ-MARC2 knockdown was able to relieve H/R-induced AC16 cell injury through miR-335-5p/TRPM7 axis.

miR-133a-3p/TRPM4 axis improves palmitic acid induced vascular endothelial injury

Background: Vascular endothelial injury is a contributing factor to the development of atherosclerosis and the resulting cardiovascular diseases. One particular factor involved in endothelial cell apoptosis and atherosclerosis is palmitic acid (PA), which is a long-chain saturated fatty acid. In addition, transient receptor potential melastatin 4 (TRPM4), a non-selective cation channel, plays a significant role in endothelial dysfunction caused by various factors related to cardiovascular diseases. Despite this, the specific role and mechanisms of TRPM4 in atherosclerosis have not been fully understood. Methods: The protein and mRNA expressions of TRPM4, apoptosis - and inflammation-related factors were measured after PA treatment. The effect of TRPM4 knockout on the protein and mRNA expression of apoptosis and inflammation-related factors was detected. The changes of intracellular Ca2+, mitochondrial membrane potential, and reactive oxygen species were detected by Fluo-4 AM, JC-1, and DCFH-DA probes, respectively. To confirm the binding of miR-133a-3p to TRPM4, a dual luciferase reporter gene assay was conducted. Finally, the effects of miR-133a-3p and TRPM4 on intracellular Ca2+, mitochondrial membrane potential, and reactive oxygen species were examined. Results: Following PA treatment, the expression of TRPM4 increases, leading to calcium overload in endothelial cells. This calcium influx causes the assemblage of Bcl-2, resulting in the opening of mitochondrial calcium channels and mitochondrial damage, ultimately triggering apoptosis. Throughout this process, the mRNA and protein levels of IL-1β, ICAM-1, and VCAM1 significantly increase. Database screenings and luciferase assays have shown that miR-133a-3p preferentially binds to the 3'UTR region of TRPM4 mRNA, suppressing TRPM4 expression. During PA-induced endothelial injury, miR-133a-3p is significantly decreased, but overexpression of miR-133a-3p can attenuate the progression of endothelial injury. On the other hand, overexpression of TRPM4 counteracts the aforementioned changes. Conclusion: TRPM4 participates in vascular endothelial injury caused by PA. Therefore, targeting TRPM4 or miR-133a-3p may offer a novel pharmacological approach to preventing endothelial injury.

Depletion of microRNA-92a Enhances the Role of Sevoflurane Treatment in Reducing Myocardial Ischemia-Reperfusion Injury by Upregulating KLF4

OBJECTIVE

As some articles have highlighted the role of microRNA-92a (miR-92a) in myocardial ischemia-reperfusion injury (MI/RI), this article aimed to investigate the effect of miR-92a on Sevoflurane (Sevo)-treated MI/RI via regulation of Krüppel-like factor 4 (KLF4).

METHODS

An MI/RI rat model was established by ligating the left anterior descending coronary artery. The cardiac function, pathological changes of myocardial tissues, inflammatory response, oxidative stress and cardiomyocyte apoptosis in MI/RI rats were determined. KLF4 and miR-92a expression was detected in the myocardial tissue of rats, and the target relationship between miR-92a and KLF4 was confirmed.

RESULTS

Sevo treatment alleviated myocardial damage, inflammatory response, oxidative stress response, and cardiomyocyte apoptosis, and improved cardiac function in MI/RI rats. miR-92a increased and KLF4 decreased in the myocardial tissue of MI/RI rats. KLF4 was targeted by miR-92a. Downregulation of miR-92a or upregulation of KLF4 further enhanced the effect of Sevo treatment on MI/RI.

CONCLUSION

This study suggests that depletion of miR-92a promotes upregulation of KLF4 to improve cardiac function, reduce cardiomyocyte apoptosis and further enhance the role of Sevo treatment in alleviating MI/RI.

Inhibition of MicroRNA-122-5p Relieves Myocardial Ischemia-Reperfusion Injury via SOCS1

OBJECTIVE

 Evidence has shown that microRNA (miR)-122-5p is a diagnostic biomarker of acute myocardial infarction. Here, we aimed to uncover the functions of miR-122-5p in the pathological process of myocardial ischemia-reperfusion injury (MI/RI).

METHODS

 An MI/RI model was established by left anterior descending coronary artery ligation in mice. The levels of miR-122-5p, suppressor of cytokine signaling-1 (SOCS1), phosphorylation of Janus kinase 2 (p-JAK2), and signal transducers and activators of transcription (p-STAT3) in the myocardial tissues of mice were measured. Downregulated miR-122-5p or upregulated SOCS1 recombinant adenovirus vectors were injected into mice before MI/RI modeling. The cardiac function, inflammatory response, myocardial infarction area, pathological damage, and cardiomyocyte apoptosis in the myocardial tissues of mice were evaluated. Cardiomyocytes were subjected to hypoxia/reoxygenation (H/R) injury and cardiomyocyte biological function was tested upon transfection of miR-122-5p inhibitor. The target relation between miR-122-5p and SOCS1 was evaluated.

RESULTS

 miR-122-5p expression and p-JAK2 and p-STAT3 expression were high, and SOCS1 expression was low in the myocardial tissues of MI/RI mice. Decreasing miR-122-5p or increasing SOCS1 expression inactivated the JAK2/STAT3 pathway to alleviate MI/RI by improving cardiac function and reducing inflammatory reaction, myocardial infarction area, pathological damage, and cardiomyocyte apoptosis in mice. Silencing of SOCS1 reversed depleted miR-122-5p-induced cardioprotection for MI/RI mice. In vitro experiments revealed that the downregulation of miR-122-5p induced proliferative, migratory, and invasive capabilities of H/R cardiomyocytes while inhibiting apoptosis. Mechanically, SOCS1 was a target gene of miR-122-5p.

CONCLUSION

 Our study summarizes that inhibition of miR-122-5p induces SOCS1 expression, thereby relieving MI/RI in mice.

Roles of non-coding RNAs in cell death pathways involved in the treatment of resistance and recurrence of cancer

Considering the burden of cancer, a number of methods have been applied to control or stop it. However, because of drug resistance or cancer recurrence, these treatments usually face failure. Combination of modulation of expression of non-coding RNAs (ncRNAs) with other treatments can increase treatment-sensitivity of tumors but these approaches still face some challenges. Gathering information in this field is a prerequisite to find more efficient cures for cancer. Cancer cells use ncRNAs to enhance uncontrolled proliferation originated from inactivation of cell death routs. In this review article, the main routes of cell death and involved ncRNAs in these routes are discussed. Moreover, extant information in the role of different ncRNAs on cell death pathways involved in the treatment resistance and cancer recurrence is summarized.

Granulosa cells undergo BPA-induced apoptosis in a miR-21-independent manner

Bisphenol A (BPA) is a harmful endocrine disrupting compound that alters not only classical cellular mechanisms but also epigenetic mechanisms. Evidence suggests that BPA-induced changes in microRNA expression can explain, in part, the changes observed at both the molecular and cellular levels. BPA is toxic to granulosa cells (GCs) as it can activate apoptosis, which is known to contribute to increased follicular atresia. miR-21 is a crucial antiapoptotic regulator in GCs, yet the exact function in a BPA toxicity model remains unclear. BPA was found to induce bovine GC apoptosis through the activation of several intrinsic factors. BPA reduced live cells counts, increased late apoptosis/necrosis, increased apoptotic transcripts (BAX, BAD, BCL-2, CASP-9, HSP70), increased the BAX/Bcl-2 ratio and HSP70 at the protein level, and induced caspase-9 activity at 12 h post-exposure. miR-21 inhibition increased early apoptosis and, while it did not influence transcript levels or caspase-9 activity, it did elevate the BAX/Bcl-2 protein ratio and HSP70 in the same manner as BPA. Overall, this study shows that miR-21 plays a molecular role in regulating intrinsic mitochondrial apoptosis; however, miR-21 inhibition did not make the cells more sensitive to BPA. Therefore, apoptosis induced by BPA in bovine GCs is miR-21 independent.

Circadian system microRNAs - Role in the development of cardiovascular diseases

Circadian rhythm regulates numerous physiological processes, and disruption of the circadian clock can lead to cardiovascular disease. Cardiovascular disease is the leading cause of morbidity and mortality worldwide. Small non-coding RNAs, microRNAs (miRNAs), are involved in regulating gene expression, both those important for the cardiovascular system and key circadian clock genes. Epigenetic mechanisms based on miRNAs are essential for fine-tuning circadian physiology. Indeed, some miRNAs depend on circadian periodicity, others are under the influence of light, and still others are under the influence of core clock genes. Dysregulation of miRNAs involved in circadian rhythm modulation has been associated with inflammatory conditions of the endothelium and atherosclerosis, which can lead to coronary heart disease and myocardial infarction. Epigenetic processes are reversible through their association with environmental factors, enabling innovative preventive and therapeutic strategies for cardiovascular disease. Here, is a review of recent findings on how miRNAs modulate circadian rhythm desynchronization in cardiovascular disease. In the era of personalized medicine, the possibility of treatment with miRNA antagomirs should be time-dependent to correspond to chronotherapy and achieve the most significant efficacy.

MicroRNA‑194‑5p attenuates hypoxia/reoxygenation‑induced apoptosis in H9C2 cardiomyocytes by inhibiting the over‑activation of RAC1 protein

Ras‑related C3 botulinum toxin substrate 1 (RAC1), a member of the Rac family of guanosine triphosphate phosphohydrolases, has been suggested to be a regulator of myocardial injury during ischemia and reperfusion (I/R). Whether microRNAs (miRs) are involved in the regulation of the aforementioned process remains to be elucidated. In the present study, an in vitro model of H9C2 cardiomyocytes was used to establish the overexpression of RAC1 following hypoxia and reoxygenation (H/R). Overexpression of RAC1 in H/R‑cultured cardiomyocytes could lead to cellular accumulation of reactive oxygen species (ROS) and facilitate the induction of apoptosis of H9C2 cardiomyocytes during H/R. Subsequent bioinformatic analysis indicated that RAC1 was the target of miRNA‑194‑5p. Further experiments showed that miR‑194‑5p attenuated the accumulation of cellular ROS and alleviated the induction of apoptosis of H9C2 cardiomyocytes caused by H/R, which was accompanied by the reduction in the expression levels of the RAC1 protein. Taken together, these results indicated that upregulation of miR‑194‑5p may function as a self‑regulated cardioprotective response against RAC1‑mediated ROS accumulation and cardiomyocyte apoptosis. Exogenous administration of miR‑194‑5p may be a novel target to ameliorate I/R injury‑induced myocardial apoptosis.

Modified mRNA Therapeutics for Heart Diseases

Cardiovascular diseases (CVD) remain a substantial global health problem and the leading cause of death worldwide. Although many conventional small-molecule treatments are available to support the cardiac function of the patient with CVD, they are not effective as a cure. Among potential targets for gene therapy are severe cardiac and peripheral ischemia, heart failure, vein graft failure, and some forms of dyslipidemias. In the last three decades, multiple gene therapy tools have been used for heart diseases caused by proteins, plasmids, adenovirus, and adeno-associated viruses (AAV), but these remain as unmet clinical needs. These gene therapy methods are ineffective due to poor and uncontrolled gene expression, low stability, immunogenicity, and transfection efficiency. The synthetic modified mRNA (modRNA) presents a novel gene therapy approach which provides a transient, stable, safe, non-immunogenic, controlled mRNA delivery to the heart tissue without any risk of genomic integration, and achieves a therapeutic effect in different organs, including the heart. The mRNA translation starts in minutes, and remains stable for 8-10 days (pulse-like kinetics). The pulse-like expression of modRNA in the heart induces cardiac repair, cardiomyocyte proliferation and survival, and inhibits cardiomyocyte apoptosis post-myocardial infarction (MI). Cell-specific (cardiomyocyte) modRNA translation developments established cell-specific modRNA therapeutics for heart diseases. With these laudable characteristics, combined with its expression kinetics in the heart, modRNA has become an attractive therapeutic for the treatment of CVD. This review discusses new developments in modRNA therapy for heart diseases.

Role of miRNA-1 and miRNA-21 in Acute Myocardial Ischemia-Reperfusion Injury and Their Potential as Therapeutic Strategy

Coronary artery disease remains the leading cause of death. Acute myocardial infarction (MI) is characterized by decreased blood flow to the coronary arteries, resulting in cardiomyocytes death. The most effective strategy for treating an MI is early and rapid myocardial reperfusion, but restoring blood flow to the ischemic myocardium can induce further damage, known as ischemia-reperfusion (IR) injury. Novel therapeutic strategies are critical to limit myocardial IR injury and improve patient outcomes following reperfusion intervention. miRNAs are small non-coding RNA molecules that have been implicated in attenuating IR injury pathology in pre-clinical rodent models. In this review, we discuss the role of miR-1 and miR-21 in regulating myocardial apoptosis in ischemia-reperfusion injury in the whole heart as well as in different cardiac cell types with special emphasis on cardiomyocytes, fibroblasts, and immune cells. We also examine therapeutic potential of miR-1 and miR-21 in preclinical studies. More research is necessary to understand the cell-specific molecular principles of miRNAs in cardioprotection and application to acute myocardial IR injury.

Flow-Responsive Noncoding RNAs in the Vascular System: Basic Mechanisms for the Clinician

The vascular system is largely exposed to the effect of changing flow conditions. Vascular cells can sense flow and its changes. Flow sensing is of pivotal importance for vascular remodeling. In fact, it influences the development and progression of atherosclerosis, controls its location and has a major influx on the development of local complications. Despite its importance, the research community has traditionally paid scarce attention to studying the association between different flow conditions and vascular biology. More recently, a growing body of evidence has been accumulating, revealing that ncRNAs play a key role in the modulation of several biological processes linking flow-sensing to vascular pathophysiology. This review summarizes the most relevant evidence on ncRNAs that are directly or indirectly responsive to flow conditions to the benefit of the clinician, with a focus on the underpinning mechanisms and their potential application as disease biomarkers.

The Regulation Mechanisms and Clinical Application of MicroRNAs in Myocardial Infarction: A Review of the Recent 5 Years

Myocardial infarction (MI) is the most frequent end-point of cardiovascular pathology, leading to higher mortality worldwide. Due to the particularity of the heart tissue, patients who experience ischemic infarction of the heart, still suffered irreversible damage to the heart even if the vascular reflow by treatment, and severe ones can lead to heart failure or even death. In recent years, several studies have shown that microRNAs (miRNAs), playing a regulatory role in damaged hearts, bring light for patients to alleviate MI. In this review, we summarized the effect of miRNAs on MI with some mechanisms, such as apoptosis, autophagy, proliferation, inflammatory; the regulation of miRNAs on cardiac structural changes after MI, including angiogenesis, myocardial remodeling, fibrosis; the application of miRNAs in stem cell therapy and clinical diagnosis; other non-coding RNAs related to miRNAs in MI during the past 5 years.

Locked Nucleic Acid AntimiR Therapy for the Heart

Coronary heart disease is one of the leading causes of death in industrialized nations. Even though revascularization strategies improved the outcome of patients after acute myocardial infarction, about 30% of patients develop chronic heart failure. Ischemic heart disease and heart failure are characterized by an adverse remodeling of the heart, featuring cardiomyocyte hypertrophy, increased fibrosis, and capillary rarefaction. Therefore, novel therapeutic approaches for the treatment of heart failure, such as reducing ischemia/reperfusion injury, fibrosis, or hypertrophy, are needed. Here microRNAs (miRNAs) come into play. For heart failure, cardiac stress and several cardiovascular diseases, individual miRNAs, and whole miRNA clusters have been implicated as disease relevant and dysregulated. miRNAs are short non-coding RNA molecules of about 22 nucleotides, and their inhibitors are 8-15 nucleotides long plus a sugar-ring (LNA, locked nucleid acid) or cholesterol ending (AntagomiR). Modulation of miRNAs might serve as therapeutic targets through miRNA knockdown or overexpression via miRNA mimics. Due to their pleiotropic mode of action and the presence of individual miRNAs in a variety of tissues and cells, a local, target region-oriented application is important to achieve therapeutic effects and at the same time reducing adverse effects in other off-target organs and tissues. Due to their small size, the miRNA inhibitors are able to pass endothelial barrier at both arterial and venous sides of the bloodstream vessels. For these reasons, the gold standard administration route of miRNA modulators for therapeutic approaches of the left ventricle is the anterograde application into one or both coronary arteries via an over-the-wire (OTW) balloon. In this chapter we provide a comprehensive description of the anterograde application procedure in a large animal model such as pig. Of a particular note, this methodology is a standard procedure in catheter laboratories, a key characteristic that allows therapeutic translation from large animals to patients.

MiR-21-5p-expressing bone marrow mesenchymal stem cells alleviate myocardial ischemia/reperfusion injury by regulating the circRNA_0031672/miR-21-5p/programmed cell death protein 4 pathway

BACKGROUND

For patients with coronary heart disease, reperfusion treatment strategies are often complicated by ischemia/reperfusion (I/R) injury (IRI), leading to serious organ damage and malfunction. The miR-21/programmed cell death protein 4 (PDCD4) pathway is involved in the IRI of cardiomyocytes; however, the aberrant miR-21 expression remains unexplained. Therefore, this study aimed to explore whether circRNA_0031672 downregulates miR-21-5p expression during I/R and to determine whether miR-21-5p-expressing bone marrow mesenchymal stem cells (BMSCs) reduce myocardial IRI.

METHODS

CircRNA_0031672, miR-21-5p, and PDCD4 expressions were evaluated in the I/R rat model and hypoxia/re-oxygenation (H/R)-treated H9C2 cells. Their interactions were subsequently investigated using luciferase reporter and RNA pulldown assays. Methyltransferase-like 3, a methyltransferase catalyzing N6-methyladenosine (m6A), was overexpressed in H9C2 cells to determine whether m6A modification influences miR-21-5p targeting PDCD4. BMSCs stably expressing miR-21 were co-cultured with H9C2 cells to investigate the protective effect of BMSCs on H9C2 cells upon H/R.

RESULTS

I/R downregulated miR-21-5p expression and upregulated circRNA_0031672 and PDCD4 expressions. CircRNA_0031672 knockdown increased miR-21-5p expression, but repressed PDCD4 expression, indicating that circRNA_0031672 competitively bound to miR-21-5p and prevented it from targeting PDCD4 mRNA. The m6A modification regulated PDCD4 expression, but had no effect on miR-21-5p targeting PDCD4. The circRNA_0031672/miR-21-5p/PDCD4 axis regulated myocardial cells viability and apoptosis after H/R treatment; co-culture with miR-21-5p-expressing BMSCs restored miR-21-5p abundance in H9C2 cells and further reduced H9C2 cells apoptosis induced by H/R.

CONCLUSIONS

We identified a novel circRNA_0031672/miR-21-5p/PDCD4 signaling pathway that mediates the apoptosis of cardiomyocytes and successfully alleviates IRI in myocardial cells by co-culture with miR-21-5p-expressing BMSCs, offering novel insights into the IRI pathogenesis in cardiovascular diseases.

Diagnostic and Prognostic Value of miRNAs after Coronary Artery Bypass Grafting: A Review

MiRNAs are noncoding, 21-24 nucleotide-long RNA particles that control over 60% of genes. MiRNAs affect gene expression through binding to the 3'-untranslated region of messenger RNA (mRNA), thus inhibiting mRNA translation or inducing mRNA degradation. MiRNAs have been associated with various cardiovascular diseases, including heart failure, hypertension, left ventricular hypertrophy, or ischemic heart disease. In addition, miRNA expression alters during coronary artery bypass grafting (CABG) surgery, which could be used to predict perioperative outcomes. CABG is an operation in which complex coronary arteries stenosis is treated by bypassing atherosclerotic lesions with venous or arterial grafts. Despite a very low perioperative mortality rate and excellent long-term survival, CABG is associated with postoperative complications, including reperfusion injury, graft failure, atrial fibrillation and perioperative myocardial infarction. So far, no reliable diagnostic and prognostic tools to predict prognosis after CABG have been developed. Changes in the perioperative miRNA expression levels could improve the diagnosis of post-CABG myocardial infarction and atrial fibrillation and could be used to stratify risk after CABG. Herein, we describe the expression changes of different subtypes of miRNAs during CABG and review the diagnostic and prognostic utility of miRNAs in patients undergoing CABG.

MicroRNA-21-5p Reduces Hypoxia/Reoxygenation-Induced Neuronal Cell Damage through Negative Regulation of CPEB3

Objectives

To explore the role of microRNA-21-5p (miR-21-5p) in hypoxia/reoxygenation- (H/R-) induced HT22 cell damage.

Methods

The hypoxia/reoxygenation (H/R) model was established in mouse neuronal cells HT22. Cell Counting Kit-8 (CCK-8) and qRT-PCR were used to determine the effects of H/R treatment on cell viability and miR-21-5p expression. HT22 cells were transfected with miR-21-5p mimic or negative control (NC) followed by the induction of H/R; cell viability, apoptosis, and SOD, MDA, and LDH activities were detected. Besides, the apoptosis-related proteins including BAX, BCL2, cleaved caspase-3, and caspase-3 as well as proteins of EGFR/PI3K/AKT signaling pathways were measured by Western blot. To verify the target relation between cytoplasmic polyadenylation element binding protein 3 (CPEB3) and miR-21-5p, luciferase reporter gene experiment was performed. After cotransfection with miR-21-5p mimic and CPEB3 plasmids, the reversal effects of CPEB3 on miR-21-5p in H/R damage were studied.

Results

H/R treatment could significantly reduce the cell viability (P < 0.05) and miR-21-5p levels (P < 0.05) in HT22 cells. After overexpressing miR-21-5p, cell viability was increased (P < 0.05) under H/R treatment, and the apoptosis rate and the levels of apoptosis-related proteins were suppressed (all P < 0.05). Furthermore, SOD activity was increased (P < 0.05), while MDA and LDH activity was decreased (both P < 0.05). Besides, miR-21-5p could restore the activation of the EGFR/PI3K/AKT signaling pathway inhibited by H/R treatment (all P < 0.05). The luciferase reporter gene experiment verified that CPEB3 is the target of miR-21-5p (P < 0.05). When coexpressing miR-21-5p mimic and CPEB3 in the cells, the protective effects of miR-21-5p under H/R were reversed (all P < 0.05), and the activation of the EGFR/PI3K/AKT pathway was also inhibited (all P < 0.05).

Conclusion

This study showed that miR-21-5p may regulate the EGFR/PI3K/AKT signaling pathway by targeting CPEB3 to reduce H/R-induced cell damage and apoptosis.

Novel Role of miR-18a-5p and Galanin in Rat Lung Ischemia Reperfusion-Mediated Response

Lung ischemia reperfusion (IR) is known to occur after lung transplantation or cardiac bypass. IR leads to tissue inflammation and damage and is also associated with increased morbidity and mortality. Various receptors are known to partake in activation of the innate immune system, but the downstream mechanism of tissue damage and inflammation is yet unknown. MicroRNAs (miRNAs) are in the forefront in regulating ischemia reperfusion injury and are involved in inflammatory response. Here, we have identified by high-throughput approach and evaluated a distinct set of miRNAs that may play a role in response to IR in rat lung tissue. The top three differentially expressed miRNAs were validated through quantitative PCRs in the IR rat lung model and an in vitro model of IR of hypoxia and reoxygenation exposed type II alveolar cells. Among the miRNAs, miR-18a-5p showed consistent downregulation in both the model systems on IR. Cellular and molecular analysis brought to light a crucial role of this miRNA in ischemia reperfusion. miR-18a-5p plays a role in IR-mediated apoptosis and ROS production and regulates the expression of neuropeptide Galanin. It also influences the nuclear localization of transcription factor: nuclear factor-erythroid 2-related factor (Nrf2) which in turn may regulate the expression of the miR-18a gene. Thus, we have not only established a rat model for lung IR and enumerated the important miRNAs involved in IR but have also extensively characterized the role of miR-18a-5p. This study will have important clinical and therapeutic implications for and during transplantation procedures.

MicroRNA-30c-5p protects against myocardial ischemia/reperfusion injury via regulation of Bach1/Nrf2

MicroRNAs (miRNAs) are critical regulatory factors in myocardial ischemia/reperfusion (I/R) injury. The miRNA miR-30c-5p has been reported as a key mediator in several myocardial abnormalities. However, the precise roles and mechanisms of miR-30c-5p in myocardial I/R injury remain not well-studied. This project aimed to explore the potential function of this miRNA in mediating myocardial I/R injury. Significant induction of miR-30c-5p was observed in myocardial tissue of rats with myocardial I/R injury in vivo and cardiomyocytes with hypoxia/re‑oxygenation (H/R) injury in vitro. Functional studies elucidated that forced expression of miR-30c-5p in rats effectively reduced infarct area, cardiac apoptosis, oxidative stress and inflammation induced by myocardial I/R injury. Moreover, in vitro cardiomyocytes with forced expression of miR-30c-5p were also protected from H/R-induced apoptosis, oxidative stress and inflammation. Importantly, BTB domain and CNC homology 1 (Bach1) was identified as a new target of miR-30c-5p. miR-30c-5p was shown to promote the activation of nuclear factor (erythroid-derived 2)-like 2 (Nrf2) via the inhibition of Bach1. The re-expression of Bach1 reversed miR-30c-5p-mediated-cardioprotective effects against myocardial I/R injury in vivo or H/R injury in vitro. Overall, our results demonstrate that forced expression of miR-30c-5p exhibited beneficial effects against myocardial I/R injury through enhancement of Nrf2 activation via inhibition of Bach1. This work reveals a novel molecular mechanism for myocardial I/R injury at the miRNA level and suggests a therapeutic value of miR-30c-5p in treatment of myocardial I/R injury.

MiR-518a-5p Targets GZMB to Extenuate Vascular Endothelial Cell Injury Induced by Hypoxia-Reoxygenation and Thereby Improves Myocardial Ischemia

To probe the function of miR-518a-5p/Granzyme B (GZMB) in hypoxia/reoxygenation (H/R) -induced vascular endothelial cell injury.The key genes of myocardial infarction were screened by bioinformatic methods. The upstream micro RNAs (miRNAs) of GZMB were predicted by TargetScan. The binding of miR-518a-5p to GZMB was verified with luciferase reporter assay. The H/R model was constructed with human vascular endothelial cell (HUVEC) in vitro. Cell Counting Kit-8 (CCK8) assay was performed to detect cell proliferation. Western blot was utilized to evaluate the levels of indicated proteins.GZMB was up-regulated in patients with myocardial infarction and identified as the key gene by the bioinformatics analysis. Then the prediction from TargetScan indicated that miR-518a-5p, which is down-regulated in myocardial infarction patients, might be the potential upstream miRNA for GZMB. The following experiments verified that miR-518a-5p could bind to the 3'UTR of GZMB and negatively modulates GZMB expression. More importantly, the miR-518a-5p mimic enhanced cell proliferation and repressed apoptosis of H/R-injured HUVEC cells by inhibiting GZMB expression.We proved that miR-518a-5p could partly attenuate H/R-induced HUVEC cell injury by targeting GZMB, and perhaps the miR-518a-5p/GZMB axis could be potential therapeutic targets for myocardial infarction.

Restoration of NRF2 attenuates myocardial ischemia reperfusion injury through mediating microRNA-29a-3p/CCNT2 axis

Accumulated studies have been implemented for comprehending the mechanism of myocardial ischemia reperfusion injury (MI/RI). Nuclear factor erythroid-2 related factor 2 (NRF2)-mediated transcription activity in MI/RI has not been completely interpreted from the perspective of microRNA-29a-3p (miR-29a-3p) and cyclin T2 (CCNT2). Therein, this study intends to decode the mechanism of NRF2/miR-29a-3p/CCNT2 axis in MI/RI. Rat MI/RI models were established by left anterior descending artery ligation. Rats were injected with NRF2 or CCNT2 overexpression plasmids or miR-29a-3p agomir to explore their effects on MI/RI. Hypoxia/reoxygenation (H/R) cardiomyocytes were established and transfected with restored NRF2 or miR-29a-3p or CCNT2 for further exploration of their roles. NRF2, miR-29a-3p, and CCNT2 expression in myocardial tissues in rats with MI/RI and in cardiomyocytes in H/R injury were detected. ChIP assay verified the relationship between miR-29a-3p and NRF2, and the bioinformatics software and dual-luciferase reporter experiment verified the interaction between miR-29a-3p and CCNT2. NRF2 and miR-29a-3p were down-regulated while CCNT2 was up-regulated in myocardial tissues in rats with MI/RI and in H/R-treated cardiomyocytes. Restoration of NRF2 or miR-29a-3p improved hemodynamics and myocardial injury and suppressed serum inflammation and cardiomyocyte apoptosis via CCNT2 in rats with MI/RI. Upregulation of NRF2 or miR-29a-3p inhibited LDH and CK-MB activities, oxidative stress, and apoptosis and promoted viability of cardiomyocytes with H/R injury. NRF2 bound to the promoter of miR-29a-3p and CCNT2 was targeted by miR-29a-3p. This study elucidates that up-regulating NRF2 or miR-29a-3p attenuates MI/RI via inhibiting CCNT2, which may renew the existed knowledge of MI/RI-related mechanism and provide a novel guidance toward MI/RI treatment.

MicroRNA-132 attenuated cardiac fibrosis in myocardial infarction-induced heart failure rats

The aim of the present study was to determine the effect of microRNA (miR)-132 on cardiac fibrosis in myocardial infarction (MI)-induced heart failure and angiotensin (Ang) II-treated cardiac fibroblasts (CFs). Experiments were carried out in Sprague-Dawley rat treatment with ligation of left coronary artery to induce heart failure, and in CFs administration of Ang II to induce fibrosis. The level of miR-132 was increased in the heart of rats with MI-induced heart failure and the Ang II-treated CFs. In MI rats, left ventricle (LV) ejection fraction, fractional shortening, the maximum of the first differentiation of LV pressure (LV +dp/dtmax) and decline (LV -dp/dtmax) and LV systolic pressure (LVSP) were reduced, and LV end-systolic diameter (LVESD), LV end-diastolic diameter (LVEDD), LV volumes in systole (LVVS) and LV volumes in diastole (LVVD) were increased, which were reversed by miR-132 agomiR but deteriorated by miR-132 antagomiR. The expression levels of collagen I, collagen III, transforming growth factor-β (TGF-β), and α-smooth muscle actin (α-SMA) were increased in the heart of rat with MI-induced heart failure and CFs administration of Ang II. These increases were inhibited by miR-132 agomiR but enhanced by miR-132 antagomiR treatment. MiR-132 inhibited PTEN expression, and attenuated PI3K/Akt signal pathway in CFs. These results indicated that the up-regulation of miR-132 improved the cardiac dysfunction, attenuated cardiac fibrosis in heart failure via inhibiting PTEN expression, and attenuating PI3K/Akt signal pathway. Up-regulation of miR-132 may be a strategy for the treatment of heart failure and cardiac fibrosis.

Randomized controlled clinical study on Yiqi Liangxue Shengji prescription for intervention cardiac function of acute myocardial infarction with ischemia-reperfusion injury

INTRODUCTION

The morbidity and mortality of acute myocardial infarction patients still remains high after percutaneous coronary intervention (PCI). Myocardial ischemia-reperfusion (MIR) injury is one of the important reasons. Although the phenomenon of MIR injury can paradoxically reduce the beneficial effects of myocardial reperfusion, there currently remains no effective therapeutic agent for preventing MIR. Previous studies have shown that Yiqi Liangxue Shengji prescription (YLS) is effective in improving clinical symptoms and ameliorating the major adverse cardiovascular events of coronary heart disease patients undergoing PCI. This study aims to evaluate the effectiveness and safety of YLS in patients with acute myocardial infarction (AMI) after PCI.

METHODS

This study is a randomized, double-blinded, placebo-controlled, single-central clinical trial. A total of 140 participants are randomly allocated to 2 groups: the intervention group and the placebo group. Based on routine medications, the intervention group will be treated with YLS and the placebo group will be treated with YLS placebo. All participants will receive a 8-week treatment and then be followed up for another 12 months. The primary outcome measures are N terminal pro B type natriuretic peptide (NT-proBNP) and left ventricular ejection fraction. Secondary outcomes are plasma levels of microRNA-145, plasma cardiac enzyme, and Troponin I levels in blood samples, changes in ST-segment in ECG, Seattle Angina Questionnaire, the efficacy of angina symptoms, and occurrence of major adverse cardiac events. All the data will be recorded in case report forms and analyzed by SPSS V.17.0.

DISCUSSION

The trial will investigate whether the postoperative administration of YLS in patients with AMI after PCI will improve cardiac function. And it explores microRNAs (miRNA)-145 as detection of blood-based biomarkers for AMI by evaluating the relation between miRNAs in plasma and cardiac function.

TRIAL REGISTRATION

Chinese Clinical Trials Registry identifier ChiCTR2000038816. Registered on October 10, 2020.

MiRNA-26a inhibits myocardial infarction-induced apoptosis by targeting PTEN via JAK/STAT pathways

INTRODUCTION

Acute myocardial infarction (MI) is a common cause of the morbidity and mortality of cardiovascular diseases in the world. Acute MI lead to cardiovascular output after formation of myocardial ischemia and circulatory arrest in coronary heart diseases. However, the mechanisms underlying MI injury are poorly understood. We explored the part played by miR-26a in myocardial infarction (MI).

MATERIAL AND METHODS

Decreased miR-26a expression in H2O2-treated newborn murine ventricular cardiomyocytes (NMVCs) was observed, as well as in the infarcted heart of MI mouse model, compared to untreated NMVCs and healthy mouse heart tissue, respectively. Conversely, the upregulation of phosphatase and tensin homolog (PTEN) was observed in H2O2-treated NMVCs, and in infarcted hearts. An MTT assay and BrdU staining showed that H2O2 treatment attenuated cell viability in NMVCs, whereas miR-26a overexpression increased cell viability. Both TUNEL assay and flow cytometry (FC) displayed that miR-26a expression suppressed H2O2-induced cell apoptosis. Besides, miR-26a overexpression suppressed the upregulation of PTEN expression in H2O2-treated NMVCs by directly binding to PTEN 3'-UTR.

RESULTS

PI3K/Akt and JAK/STAT signal transduction pathways were found to be regulated through cross-talk between miR-26a and PTEN. Furthermore, agomiR-26a treatment in MI mouse model considerably suppressed the size of the infarcted regions, and improved cardiac activity.

CONCLUSIONS

MiR-26a expression in MI cardiac tissues was downregulated in response to H2O2 stress, whereas it could still protect against cell death by modulation of the PI3K/Akt and JAK/STAT signal transduction pathways by directly targeting PTEN.

miR-19a-3p containing exosomes improve function of ischaemic myocardium upon shock wave therapy

AIMS

As many current approaches for heart regeneration exert unfavourable side effects, the induction of endogenous repair mechanisms in ischaemic heart disease is of particular interest. Recently, exosomes carrying angiogenic miRNAs have been described to improve heart function. However, it remains challenging to stimulate specific release of reparative exosomes in ischaemic myocardium. In the present study, we sought to test the hypothesis that the physical stimulus of shock wave therapy (SWT) causes the release of exosomes. We aimed to substantiate the pro-angiogenic impact of the released factors, to identify the nature of their cargo, and to test their efficacy in vivo supporting regeneration and recovery after myocardial ischaemia.

METHODS AND RESULTS

Mechanical stimulation of ischaemic muscle via SWT caused extracellular vesicle (EV) release from endothelial cells both in vitro and in vivo. Characterization of EVs via electron microscopy, nanoparticle tracking analysis and flow cytometry revealed specific exosome morphology and size with the presence of exosome markers CD9, CD81, and CD63. Exosomes exhibited angiogenic properties activating protein kinase b (Akt) and extracellular-signal regulated kinase (ERK) resulting in enhanced endothelial tube formation and proliferation. A miRNA array and transcriptome analysis via next-generation sequencing were performed to specify exosome content. miR-19a-3p was identified as responsible cargo, antimir-19a-3p antagonized angiogenic exosome effects. Exosomes and target miRNA were injected intramyocardially in mice after left anterior descending artery ligation. Exosomes resulted in improved vascularization, decreased myocardial fibrosis, and increased left ventricular ejection fraction as shown by transthoracic echocardiography.

CONCLUSION

The mechanical stimulus of SWT causes release of angiogenic exosomes. miR-19a-3p is the vesicular cargo responsible for the observed effects. Released exosomes induce angiogenesis, decrease myocardial fibrosis, and improve left ventricular function after myocardial ischaemia. Exosome release via SWT could develop an innovative approach for the regeneration of ischaemic myocardium.

Alcoholic and Non-Alcoholic Beer Modulate Plasma and Macrophage microRNAs Differently in a Pilot Intervention in Humans with Cardiovascular Risk

Beer is a popular beverage and some beneficial effects have been attributed to its moderate consumption. We carried out a pilot study to test if beer and non-alcoholic beer consumption modify the levels of a panel of 53 cardiometabolic microRNAs in plasma and macrophages. Seven non-smoker men aged 30–65 with high cardiovascular risk were recruited for a non-randomised cross-over intervention consisting of the ingestion of 500 mL/day of beer or non-alcoholic beer for 14 days with a 7-day washout period between interventions. Plasma and urine isoxanthohumol were measured to assess compliance with interventions. Monocytes were isolated and differentiated into macrophages, and plasma and macrophage microRNAs were analysed by quantitative real-time PCR. Anthropometric, biochemistry and dietary parameters were also measured. We found an increase in plasma miR-155-5p, miR-328-3p, and miR-92a-3p after beer and a decrease after non-alcoholic beer consumption. Plasma miR-320a-3p levels decreased with both beers. Circulating miR-320a-3p levels correlated with LDL-cholesterol. We found that miR-17-5p, miR-20a-5p, miR-145-5p, miR-26b-5p, and miR-223-3p macrophage levels increased after beer and decreased after non-alcoholic beer consumption. Functional analyses suggested that modulated microRNAs were involved in catabolism, nutrient sensing, Toll-like receptors signalling and inflammation. We concluded that beer and non-alcoholic beer intake modulated differentially plasma and macrophage microRNAs. Specifically, microRNAs related to inflammation increased after beer consumption and decreased after non-alcoholic beer consumption.

MicroRNA regulation in hypoxic environments: differential expression of microRNAs in the liver of largemouth bass (Micropterus salmoides)

Environmental changes in intensive aquaculture commonly lead to hypoxic stress for cultured largemouth bass (Micropterus salmoides). To better to understand the hypoxic stress response mechanisms, the miRNA expression profiles of the livers of largemouth bass exposed for 24 h to three different dissolved oxygen levels (7.0 ± 0.2 mg/L as control, 3.0 ± 0.2 mg/L and 1.2 ± 0.2 mg/L) were compared. In this study, a total of 266 known miRNAs were identified, 84 of which were differentially expressed compared with the control group. Thirteen of the differentially expressed miRNAs (miR-15b-5p, miR-30a-3p, miR-133a-3p, miR-19d-5p, miR-1288-3p, miR456, miR-96-5p, miR-23a-3p, miR-23b-5p, miR-214, miR-24, miR-20a-3p, and miR-2188-5p) were significantly enriched in VEGF signaling pathway, MAPK signaling pathway, and phosphatidylinositol signaling system. These miRNAs were significantly downregulated during stress, especially after a 4-h exposure to hypoxia. In contrast, their target genes (vegfa, pla2g4a, raf1a, pik3c2a, clam2a, inpp1, pi4k2b, mtmr14, ip6k, itpkca, map3k7, and Jun) were significant upregulated after 4 h of hypoxic stress. Moreover, two potential hypoxia-tolerance signal transduction pathways (MAPK signaling pathway and phosphatidylinositol signaling system) were revealed, both of which may play important roles in responding to acute hypoxic stress. We see that miRNAs played an important role in regulating gene expression related to physiological responses to hypoxia. Potential functional network regulated by miRNAs under hypoixic stress in the liver of largemouth bass (Micropterus salmoides). Blue boxes indicated that the expression of miRNA or target genes were down-regulated. Red boxes indicated that the expression of miRNA or target genes wasere up-regulated.

MicroRNA-200a represses myocardial infarction-related cell death and inflammation by targeting the Keap1/Nrf2 and β-catenin pathways

BACKGROUND

Acute myocardial infarction (MI) is a main cause of emergency death in the world. MicroRNAs (miRs/miRNAs) are a series of small non-coding RNA molecules, which regulate cardiovascular disorders that involve MI. In this study, we explored the function of miR-200a in MI treatment.

METHODS

We observed down-regulation of miR-200a levels and up-regulation of Keap1 and β-catenin levels in H₂O₂-treated newborn murine ventricular cardiomyocytes (NMVCs) and the infarcted heart tissues of MI mouse models, compared to the non-treated NMVCs and normal heart tissues of healthy mice.

RESULTS

CCK-8 and colony formation assays indicated the reduction in NMVC vitality due to H₂O₂ treatment and the recovery of cell vitality due to miR-200a overexpression, respectively. Flow cytometry with Annexin and PI staining indicated the inhibition of H₂O₂-triggered cell apoptosis through ectopically expressed miR-200a. Western blotting and ELISA analyses that detected pro-inflammatory cell factors [interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α] confirmed that miR-200a prevented H₂O₂-induced NMVC inflammation. Moreover, miR-200a inhibited up-regulation of Keap1 and β-catenin expression in H₂O₂-treated NMVCs by directly binding with the 3'-UTR regions of both Keap1 and β-catenin. Furthermore, overexpression of Keap1 and β-cateninin in H₂O₂-treated NMVCs with recovered miR-200a elevated inflammation and apoptosis, respectively.

CONCLUSION

The results showed that miR-200a expression was inhibited in murine cardiomyocytes due to H₂O₂ stress in MI cardiac tissues and overexpressed miR-200a could protect the cells from death by regulating the Keap1/Nrf2 and β-catenin signal transduction pathways.

MiR-21 mediates the protection of kaempferol against hypoxia/reoxygenation-induced cardiomyocyte injury via promoting Notch1/PTEN/AKT signaling pathway

Kaempferol, a natural flavonoid compound, possesses potent myocardial protective property in ischemia/reperfusion (I/R), but the underlying mechanism is not well understood. The present study was aimed to explore whether miR-21 contributes to the cardioprotective effect of kaempferol on hypoxia/reoxygenation (H/R)-induced H9c2 cell injury via regulating Notch/phosphatase and tensin homologue (PTEN)/Akt signaling pathway. Results revealed that kaempferol obviously attenuates H/R-induced the damages of H9c2 cells as evidence by the up-regulation of cell viability, the down-regulation of lactate dehydrogenase (LDH) activity, the reduction of apoptosis rate and pro-apoptotic protein (Bax) expression, and the increases of anti-apoptotic protein (Bcl-2) expression. In addition, kaempferol enhanced miR-21 level in H9c2 cells exposed to H/R, and inhibition of miR-21 induced by transfection with miR-21 inhibitor significantly blocked the protection of kaempferol against H/R-induced H9c2 cell injury. Furthermore, kaempferol eliminated H/R-induced oxidative stress and inflammatory response as illustrated by the decreases in reactive oxygen species generation and malondialdehyde content, the increases in antioxidant enzyme superoxide dismutase and glutathione peroxidase activities, the decreases in pro-inflammatory cytokines interleukin (IL)-1β, IL-8 and tumor necrosis factor-alpha levels, and an increase in anti-inflammatory cytokine IL-10 level, while these effects of kaempferol were all reversed by miR-21 inhibitor. Moreover, results elicited that kaempferol remarkably blocks H/R-induced the down-regulation of Notch1 expression, the up-regulation of PTEN expression, and the reduction of P-Akt/Akt, indicating that kaempferol promotes Notch1/PTEN/AKT signaling pathway, and knockdown of Notch1/PTEN/AKT signaling pathway induced by Notch1 siRNA also abolished the protection of kaempferol against H/R-induced the damage of H9c2 cells. Notably, miR-21 inhibitor alleviated the promotion of kaempferol on Notch/PTEN/Akt signaling pathways in H9c2 cells exposed to H/R. Taken together, these above findings suggested thatmiR-21 mediates the protection of kaempferol against H/R-induced H9c2 cell injuryvia promoting Notch/PTEN/Akt signaling pathway.

Emerging roles of microRNAs in intestinal ischemia/reperfusion-induced injury: a review

Intestinal ischemia/reperfusion (II/R) injury is a serious pathological phenomenon in underlying hemorrhagic shock, trauma, strangulated intestinal obstruction, and acute mesenteric ischemia which associated with high morbidity and mortality. MicroRNAs (miRNAs, miRs) are endogenous non-coding RNAs that regulate post-transcriptionally target mRNA translation via degrading it and/or suppressing protein synthesis. This review discusses on the role of some miRNAs in underlying II/R injury. Some of these miRNAs can have protective action through agomiR or specific antagomiR, and others can have destructive effects in the basal level of II/R insult. Based on these literature reviews, II/R injury affects several miRNAs and their specific target genes. Some miRNAs upregulate under condition of II/R injury, and multiple miRNAs downregulate following II/R damage. Data of this review have been collected from the scientific articles published in databases such as Science Direct, Scopus, PubMed, Web of Science, and Scientific Information Database from 2000 to 2020. It is shown a correlation between changes in the expression of miRNAs and autophagy, inflammation, oxidative stress, apoptosis, and epithelial barrier function. Taken together, agomiR or antagomiR of some miRNAs can be considered as one new target for the research and development of innovative drugs to the prevention or treatment of II/R damage.

miR-708 affords protective efficacy in anoxia/reoxygenation-stimulated cardiomyocytes by blocking the TLR4 signaling via targeting HMGB1

Ischemic heart disease is a proverbial and common cardiovascular disease, and constitutes a leading cause of disability and mortality globally. Myocardial ischemic/reperfusion (MI/R) injury is a highly orchestrated phenomenon that involves the excessive activation of high mobility group box 1 (HMGB1) signaling. In the present study, we sought to investigate the function of miR-708 in MI/R injury due to the predicted binding to HMGB1. Intriguingly, down-regulation of miR-708 and up-regulation of HMGB1 were observed in MI/R rat model and H9c2 cardiomyocytes exposed to hypoxia/reoxygenation (H/R) conditions. Dual luciferase reporter assays substantiated that HMGB1 was a direct target of miR-708. Moreover, miR-708 overexpression suppressed the mRNA and protein expression of HMGB1. Noticeably, elevation of miR-708 antagonized H/R-induced inhibition in cell viability; whilst, increased cell apoptosis evoked by H/R was restrained after miR-708 up-regulation. Simultaneously, miR-708 elevation suppressed H/R exposure-increased lactate dehydrogenase (LDH) release and reactive oxygen species (ROS) generation, but elevated the activity of anti-oxidative stress superoxide dismutase (SOD). Additionally, H/R-increased production of pro-inflammatory cytokine TNF-α and IL-6 was offset following miR-708 overexpression. Moreover, enhancement of miR-708 inhibited H/R-evoked activation of the HMGB1-TLR4-NF-κB pathway by inhibiting the protein levels of HMGB1, TLR4 and p-p65 NF-κB. Specially, restoring this pathway offset the protective effects of miR-708 on H/R-induced cardiomyocyte injury. Together, these data indicate that miR-708 may protect against H/R-induced cardiomyocyte damage by directing targeting HMGB1 signaling, implying a promising therapeutic agent against ischemic heart disease including myocardial infarction.

MiR-24 Protects Cardiomyocytes Against Hypoxia/Reoxygenation-Induced Injury Through Regulating Mitogen-Activated Protein Kinase 14

This study aimed to explore the function of miR-24 in hypoxia/reoxygenation (H/R) -induced cardiomyocyte injury.We constructed a cardiomyocyte model of H/R using the primary cardiomyocytes isolated from Sprague-Dawley rats. To explore the role of miR-24, cells were transfected with a miR-24 mimic or miR-24 inhibitor. The RNA expression levels of miR-24 and Mapk14 were determined using qRT-PCR. The proliferation and apoptosis of cells were determined using a CCK8 assay and a flow cytometer. The TargetScan website was used to predict the targets of miR-24. A dual-luciferase reporter gene assay was conducted to verify whether Mapk14 is indeed a target of miR-24. A Western blot was applied for protein detection.H/R exposure decreased the expression of miR-24 in rat cardiomyocytes. Transfection of the miR-24 mimic into cardiomyocytes reduced H/R-induced injury as evidenced by an increase in proliferation and a decrease in the apoptotic rate. By contrast, transfection of the miR-24 inhibitor aggravated H/R-induced injury. The expression of Bcl-2 was increased while the levels of Bax and Active-caspase 3 were reduced in the H/R+miR-24 mimic group compared to those in the H/R group. H/R+miR-24 inhibitor group showed the opposite results. Mapk14 was identified as a target of miR-24. The mRNA level of Mapk14 and its protein (p38 MAPK) level were negatively affected by miR-24. Furthermore, we discovered that depletion of Mapk14 reduced the promoting effect of the miR-24 inhibitor on cell apoptosis.Overall, our results illustrated that miR-24 could attenuate H/R-induced injury partly by regulating Mapk14.

Circulating miR-1 as a potential predictor of left ventricular remodeling following acute ST-segment myocardial infarction using cardiac magnetic resonance

Background

The identification of patients with a high likelihood of left ventricular (LV) remodeling with a high-risk prognosis has critical implications for risk stratification after acute ST-segment elevation myocardial infarction (STEMI). This study aimed to evaluate the relationship between circulating miR-1 and 6-month post-infarct LV remodeling based on cardiac magnetic resonance (CMR) imaging.

Methods

A total of 80 patients with a first STEMI treated with primary percutaneous coronary intervention (PCI) who underwent CMR imaging 1 week and 6 months after STEMI were evaluated. The percentage changes of LV ejection fraction (LVEF), LV end-diastolic volume (LVEDV), LV end-systolic volume index (LVESV) at 1 week and 6 months after PCI (%ΔLVEF, %ΔLVEDV and %ΔLVESV) were calculated. miR-1 was measured using polymerase chain reaction (PCR)-based technologies in plasma samples that were collected at admission. The study group was divided into two groups based on a 10% cutoff value for the percentage of change in the LV end-diastolic volume (%ΔLVEDV): remodeling at high risk of major adverse cardiac events (MACEs) (%ΔLVEDV ≥10%, termed the LV remodeling group) and remodeling at lower risk of MACEs (%ΔLVEDV <10%, termed the non-LV remodeling group). The associations of miR-1 expression with the %ΔLVEDV, percentage change in the LV end-systolic volume (%ΔLVESV), and percentage change in the LV ejection fraction at follow-up were estimated.

Results

Twenty-two patients (27.5%) showed adverse LV remodeling, and 58 patients (72.5%) did not show adverse LV remodeling at the 6-month follow-up of CMR. The mean LVEF, LVEDV index, and LVESV index values at 1 week were 50.6%±8.2%, 74.6±12.8 mL/m², and 37.2±10.2 mL/m², respectively. Mean LVEF at follow-up (53.5%±10.6%) was increased compared with baseline (P<0.001). There were significant decreases in LVEDV index and LVESV index values at follow-up (72.0±14.9 mL/m² and 33.7±11.0 mL/m², respectively; P=0.009 and P<0.001, respectively). The expression of miR-1 at admission was positively correlated with the %ΔLVEDV (r=0.611, P<0.001) and %ΔLVESV (r=0.268, P=0.016). Receiver operating characteristic (ROC) analysis showed that miR-1 expression predicted LV remodeling with an area under the curve (AUC) value of 0.68 (95% CI: 0.56-0.78). Compared with the clinical factors of peak creatine kinase-myocardial band (CK-MB) and peak troponin T level, peak logNT-proBNP showed the highest predictive power, with an AUC value of 0.75 (95% CI: 0.64-0.84). A model including the clinical, CMR, and miR-1 factors showed greater predictive power (P=0.034) than a model including only clinical and CMR factors, with AUCs of 0.89 (95% CI: 0.80-0.95) and 0.81 (95% CI: 0.71-0.89), respectively.

Conclusions

Circulating miR-1 at admission is an independent predictor of LV remodeling 6 months after STEMI. miR-1 showed incremental value in predicting LV remodeling compared with the clinical and CMR measurements.

The Role of Non-coding RNAs in Ischemic Myocardial Reperfusion Injury

MicroRNAs (miRNA) are non-coding RNAs that regulate gene expression in up to 90% of the human genome through interactions with messenger RNA (mRNA). The expression of miRNAs varies and changes in diseased and healthy states, including all stages of myocardial ischemia-reperfusion and subsequent ischemia-reperfusion injury (IRI). These changes in expression make miRNAs an attractive potential therapeutic target. Herein, we review the differences in miRNA expression prior to ischemia (including remote ischemic conditioning and ischemic pre-conditioning), the changes during ischemia-reperfusion, and the changes in miRNA expression after IRI, with an emphasis on inflammatory and fibrotic pathways. Additionally, we review the effects of manipulating the levels of certain miRNAs on changes in infarct size, inflammation, remodeling, angiogenesis, and cardiac function after either ischemia-reperfusion or permanent coronary ligation. Levels of target miRNA can be increased using molecular mimics ("agomirs"), or can be decreased by using "antagomirs" which are antisense molecules that act to bind and thus inactivate the target miRNA sequence. Other non-coding RNAs, including long non-coding RNAs and circular RNAs, also regulate gene expression and have a role in the regulation of IRI pathways. We review the mechanisms and downstream effects of the miRNAs that have been studied as therapy in both permanent coronary ligation and ischemia-reperfusion models.

Exosome Derived from Coronary Serum of Patients with Myocardial Infarction Promotes Angiogenesis Through the miRNA-143/IGF-IR Pathway

Purpose

Myocardial ischemia-reperfusion injury primarily causes myocardial infarction (MI), which is manifested by cell death. Angiogenesis is essential for repair and regeneration in cardiac tissue after MI. In this study, we aimed to investigate the effect of exosomes derived from the serum of MI patients in angiogenesis and its related mechanism.

Patients and Methods

Exosomes, isolated from serum, were collected from MI (MI-exosome) and control (Con-exosome) patients. After coculturing with human umbilical vein endothelial cells, MI-exosome promoted cell proliferation, migration, and tube formation.

Results

The results revealed that the production and release of MI-exosome were associated with cardiomyocytes. Moreover, microarray assays demonstrated that miRNA-143 was significantly decreased in MI-exosome. Meanwhile, the overexpression and knockdown of miRNA-143 could inhibit and enhance angiogenesis, respectively. Furthermore, the effect of exosomal miRNA-143 on angiogenesis was mediated by its targeting gene, insulin-like growth factor 1 receptor (IGF-IR), and was associated with the production of nitric oxide (NO).

Conclusion

Taken together, exosomes derived from the serum of patients with MI promoted angiogenesis through the IGF-IR/NO signaling pathway. The results provide novel understanding of the function of exosomes in MI.

Circulating miR-320a as a Predictive Biomarker for Left Ventricular Remodelling in STEMI Patients Undergoing Primary Percutaneous Coronary Intervention

Restoration of epicardial coronary blood flow, achieved by early reperfusion with primary percutaneous coronary intervention (PPCI), is the guideline recommended to treat patients with ST-segment-elevation myocardial infarction (STEMI). However, despite successful blood restoration, increasing numbers of patients develop left ventricular adverse remodelling (LVAR) and heart failure. Therefore, reliable prognostic biomarkers for LVAR in STEMI are urgently needed. Our aim was to investigate the role of circulating microRNAs (miRNAs) and their association with LVAR in STEMI patients following the PPCI procedure. We analysed the expression of circulating miRNAs in blood samples of 56 patients collected at admission and after revascularization (at 3, 6, 12 and 24 h). The associations between miRNAs and left ventricular end diastolic volumes at 6 months were estimated to detect LVAR. miRNAs were also analysed in samples isolated from peripheral blood mononuclear cells (PBMCs) and human myocardium of failing hearts. Kinetic analysis of miRNAs showed a fast time-dependent increase in miR-133a, miR-133b, miR-193b, miR-499, and miR-320a in STEMI patients compared to controls. Moreover, the expression of miR-29a, miR-29b, miR-324, miR-208, miR-423, miR-522, and miR-545 was differentially expressed even before PPCI in STEMI. Furthermore, the increase in circulating miR-320a and the decrease in its expression in PBMCs were significantly associated with LVAR and correlated with the expression of miR-320a in human failing myocardium from ischaemic origin. In conclusion, we determined the time course expression of new circulating miRNAs in patients with STEMI treated with PPCI and we showed that miR-320a was positively associated with LVAR.

Circulating miRNAs expression as potential biomarkers of mild traumatic brain injury

TBI is the main cause of death and disability in individuals aged 1-45 in Western countries. One of the main challenges of TBI at present is the lack of specific diagnostic biomarkers, especially for mild TBI (mTBI), which remains currently difficult to value in clinical practice. In this context MiRNAs may be important mediators of the profound molecular and cellular changes that occur after TBI in both the short and the long term. Recently, plasma miRNAs profiling in human TBI, have revealed dynamic temporal regulation of miRNA expression within the cortex. Aim of this study was to select a specific miRNAs panel for mTBI, by focusing the research on the prognostic meaning of miRNAs in the hours following the trauma, in order to be able to use this MIRNAs as potential biomarkers useful for monitoring the follow up of mild TBI. Serum levels of 17 miRNAs were measured by RT-quantitative polymerase chain reaction (qPCR) in 20 patients with mTBI at three different time-points (0 h, 24 h, 48 h) and in 10 controls. For 15 miRNAs we found a significant differences in the comparison among the three time points: for each of these miRNAs the values were greater at baseline and progressively reduced at 24 h and 48 h. These data allow us to consider the miRNAs included in panel as sensitive and specific biomarkers for mTBI, useful in monitoring the post-trauma period.

Inhibition of microRNA-199a-5p ameliorates oxygen-glucose deprivation/reoxygenation-induced apoptosis and oxidative stress in HT22 neurons by targeting Brg1 to activate Nrf2/HO-1 signalling

MicroRNAs (miRNAs) have emerged as critical regulators of neuronal survival during cerebral ischaemia/reperfusion injury. Accumulating evidence has shown that miR-199a-5p plays a crucial role in regulating apoptosis and survival in various cell types. However, whether miR-199a is involved in regulating neuronal survival during cerebral ischaemia/reperfusion injury remains unknown. In this study, we aimed to explore the biological role of miR-199a-5p in regulating neuronal injury induced by oxygen-glucose deprivation/reoxygenation (OGD/R), an in vitro cellular model of cerebral ischaemia and reperfusion injury. We found that miR-199a-5p expression was significantly altered in neurons in response to OGD/R treatment. Overexpression of miR-199a-5p facilitated OGD/R-induced apoptosis and reactive oxygen species (ROS) production, whereas miR-199a-5p inhibition alleviated OGD/R-induced apoptosis and ROS production. Notably, our results identified Brahma-related gene 1 (Brg1) as a target gene of miR-199a-5p. Moreover, inhibition of miR-199a-5p promoted the activation of nuclear factor-erythroid-2-related factor-2 (Nrf2)/heme oxygenase-1 (HO-1) signalling via targeting Brg1. However, silencing of Brg1 markedly reversed the miR-199a-5p inhibition-mediated neuroprotective effect. Taken together, our results suggest that downregulation of miR-199a-5p protects neurons from OGD/R-induced neuronal injury through upregulating Brg1 to activate Nrf2/HO-1 signalling. The miR-199a-5p/Brg1/Nrf2/HO-1 regulation axis may play an important role in regulating neuronal survival during cerebral ischaemic/reperfusion injury in vivo.

Oxidative Stress-Responsive MicroRNAs in Heart Injury

Reactive oxygen species (ROS) are important molecules in the living organisms as a part of many signaling pathways. However, if overproduced, they also play a significant role in the development of cardiovascular diseases, such as arrhythmia, cardiomyopathy, ischemia/reperfusion injury (e.g., myocardial infarction and heart transplantation), and heart failure. As a result of oxidative stress action, apoptosis, hypertrophy, and fibrosis may occur. MicroRNAs (miRNAs) represent important endogenous nucleotides that regulate many biological processes, including those involved in heart damage caused by oxidative stress. Oxidative stress can alter the expression level of many miRNAs. These changes in miRNA expression occur mainly via modulation of nuclear factor erythroid 2-related factor 2 (Nrf2), sirtuins, calcineurin/nuclear factor of activated T cell (NFAT), or nuclear factor kappa B (NF-κB) pathways. Up until now, several circulating miRNAs have been reported to be potential biomarkers of ROS-related cardiac diseases, including myocardial infarction, hypertrophy, ischemia/reperfusion, and heart failure, such as miRNA-499, miRNA-199, miRNA-21, miRNA-144, miRNA-208a, miRNA-34a, etc. On the other hand, a lot of studies are aimed at using miRNAs for therapeutic purposes. This review points to the need for studying the role of redox-sensitive miRNAs, to identify more effective biomarkers and develop better therapeutic targets for oxidative-stress-related heart diseases.

MicroRNA-21 mediates the protective effects of salidroside against hypoxia/reoxygenation-induced myocardial oxidative stress and inflammatory response

Myocardial ischemia-reperfusion (I/R) injury is the oxidative stress and inflammatory response that occurs when a tissue is reperfused following a prolonged period of ischemic injury. Growing evidence has demonstrated that microRNAs (miRs) are essential in the development of myocardial I/R injury. Salidroside, a phenylpropanoid glycoside isolated from a traditional Chinese medicinal plant, Rhodiola rosea, possesses multiple pharmacological functions and protects against myocardial I/R injury in vitro and in vivo. However, the role of miRs in the cardioprotective effects of salidroside against myocardial I/R injury has not been studied, to the best of our knowledge. In the present study, the role of miR21 in the underlying mechanism of salidroside-induced protection against oxidative stress and inflammatory injuries in hypoxia/reoxygenation (H/R)-treated H9c2 cardiomyocytes was determined. The cell viability was assessed with an MTT assay. Lactate dehydrogenase (LDH) release, caspase-3 activity, malondialdehyde (MDA) level, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were determined by commercial kits. Cell apoptosis was measured by flow cytometry. Intracellular reactive oxygen species (ROS) generation was monitored by DCFH-DA. The miR-21 level was quantified by reverse transcription-quantitative (RT-q)PCR. The interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α levels were measured by RT-qPCR and ELISA. The results showed that salidroside pretreatment significantly increased cell viability and decreased the release of LDH, accompanied by an increase in miR-21 expression in H/R-treated H9c2 cells and a miR-21 inhibitor reversed these effects. In addition, the miR-21 inhibitor also abrogated the inhibition of salidroside on H/R-induced increases in apoptosis and caspase-3 activity in H9c2 cells. Salidroside mitigated H/R-induced oxidative stress as illustrated by the downregulation of ROS generation and MDA level and increased the activities of the antioxidant enzymes, SOD and GSH-Px, all of which were abrogated in cells transfected with the miR-21 inhibitor. Salidroside induced a decrease in the expression and levels of the pro-inflammatory cytokines, IL-6, IL-1β and TNF-α, which were prevented by the miR-21 inhibitor. Together, these results provide evidence of the beneficial effects of salidroside against myocardial I/R injury by reducing myocardial oxidative stress and inflammation which are enhanced by increasing miR-21 expression.

Bone marrow mesenchymal stem cell-secreted exosomes carrying microRNA-125b protect against myocardial ischemia reperfusion injury via targeting SIRT7

MicroRNA-125b (miR-125b) reduces myocardial infarct area and restrains myocardial ischemia reperfusion injury (I/R). In this study, we aimed to investigate the effect of bone marrow mesenchymal stem cell (BMSC)-derived exosomes carrying miR-125b on I/R rats. The myocardial I/R model in rats was constructed by ligation of the left anterior descending coronary artery (LAD). Rats were randomly divided into I/R and Sham group. Lv-cel-miR-67 (control) or Lv-miR-125b was transfected into BMSCs. Exosomes were extracted from transfected BMSCs, and separately named BMSC-Exo-67, BMSC-Exo-125b, and BMSC-Exo. MTT assay and flow cytometry were used to detect the viability and apoptosis of I/R myocardium cells, respectively. The expression of cell apoptosis proteins and the levels of inflammatory factors were examined by Western blot and ELISA assay, respectively. The target relationship between miR-125b and SIRT7 was predicted by using StarBase3.0, and was confirmed by using dual-luciferase reporter gene assay. qRT-PCR, immunohistochemistry staining, and Western blot were used to evaluate the expression of SIRT7 in myocardium tissues in I/R rats. BMSC-derived exosomes were successfully isolated and identified by TEM and positive expression of CD9 and CD63. The expression of miR-125b was down-regulated in I/R myocardium tissues and cells. BMSC-Exo-125b significantly up-regulated miR-125b in I/R myocardium cells. The intervention of BMSC-Exo-125b significantly increased the cell viability, decreased the apoptotic ratio, down-regulated Bax and caspase-3, up-regulated Bcl-2, and decreased the levels of IL-1β, IL-6, and TNF-α in I/R myocardium cells. SIRT7 was a target of miR-125b, and BMSC-Exo-125b significantly down-regulated SIRT7 in myocardium cells. In addition, the injection of BMSC-Exo-125b alleviated the pathological damages and down-regulated SIRT7 in myocardium tissues of I/R rats. BMSC-derived exosomes carrying miR-125b protected against myocardial I/R by targeting SIRT7.

Propofol-mediated cardioprotection dependent of microRNA-451/HMGB1 against myocardial ischemia-reperfusion injury

Administration of propofol at the time of reperfusion has shown to protect the heart from ischemia and reperfusion (I/R) injury. The aim of the present study was to investigate the molecular mechanism underling the cardioprotective effect of propofol against myocardial I/R injury (MIRI) in vivo and in vitro. Rat heart I/R injury was induced by ligation of the left anterior descending (LAD) artery for 30 min followed by 2-hr reperfusion. Propofol pretreatment (0.01 mg/g) was performed 10 min before reperfusion. In vitro MIRI was investigated in cultured cardiomyocytes H9C2 following hypoxia/reoxygenation (H/R) injuries. Propofol pretreatment in vitro was achieved in the medium supplemented with 25 μmol/L propofol before H/R injuries. Propofol pretreatment significantly increased miRNA-451 expression, decreased HMGB1 expression, reduced infarct size, and I/R-induced cardiomyocyte apoptosis in rat hearts undergoing I/R injuries. Knockdown of miRNA-451 48 hr before I/R injury was found to increase HMGB1 expression, infarct size, and I/R-induced cardiomyocyte apoptosis in rat hearts in the presence of propofol pretreatment. These in vivo findings were reproduced in vivo that knockdown of miRNA-451 48 hr before H/R injuries increased HMGB1 expression and H/R-induced apoptosis in cultured H9C2 supplemented with propofol. In addition, luciferase activity assays and gain-of-function studies found that propofol could decrease HMGB1, the target of miRNA-541. Taken together our findings provide a first demonstration that propofol-mediated cardioprotection against MIRI is dependent of microRNA-451/HMGB1. The study provides a novel target to prevent I/R injury during propofol anesthesia.

Bilobalide protects H9c2 cell from oxygen-glucose-deprivation-caused damage through upregulation of miR-27a

Background: Myocardial ischemia is a troublesome disease. Bilobalide possesses multiple biological functions. We researched the consequents of bilobalide in OGD-irritated H9c2 cells. Methods: OGD-stimulated H9c2 cells were treated by bilobalide, and/or transfected with miR-27a inhibitor or negative control. Use CCK-8 and flow cytometry to test cell activity and apoptosis, respectively. Luciferase activity experiment was to test targeting link between miR-27a and Tmub1. Levels of cell-cycle and apoptosis relative proteins and phosphorylation of PI3K/AKT and Wnt/β-catenin related proteins were detected through western blot. Results: OGD stimulation reduced cell activity and negatively regulated the expression of CDK4, CDK6 and CyclinD1. Cell apoptosis was increased and its related proteins were affected by OGD. Bilobalide administration reversed all the results above caused by OGD. OGD negatively regulated miR-27a while bilobalide upregulated miR-27a. miR-27a's target gene was Tmub1. The protection consequents of bilobalide were suppressed when cells were transfected with a miR-27a inhibitor that cell activity was reduced and apoptosis was raised. Attenuation in the phosphorylation level of PI3K, AKT and β-catenin by OGD was reversed by bilobalide, whereas there were opposite results after transfected with miR-27a inhibitor. Conclusion: Bilobalide relieved OGD-caused H9c2 cell damage, raising cell activity and attenuating apoptosis via upregulating miR-27a and activating of PI3K/AKT and Wnt/β-catenin signal pathway. Highlights Bilobalide alleviates OGD-induced H9c2 cell injury. Bilobalide upregulates miR-27a expression in OGD-stimulated H9c2 cells. Bilobalide alleviates cell injury by upregulation of miR-27a. Bilobalide actuates PI3K/AKT and Wnt/β-catenin pathways.

MicroRNA-146a protects against myocardial ischaemia reperfusion injury by targeting Med1

BACKGROUND

Myocardial ischaemia reperfusion injury (MIRI) is a difficult problem in clinical practice, and it may involve various microRNAs. This study investigated the role that endogenous microRNA-146a plays in myocardial ischaemia reperfusion and explored the possible target genes.

METHODS

MIRI models were established in microRNA-146a deficient (KO) and wild type (WT) mice. MicroRNA-146a expression was evaluated in the myocardium of WT mice after reperfusion. The heart function, area of myocardium infarction and in situ apoptosis were compared between the KO and WT mice. Microarray was used to explore possible target genes of microRNA-146a, while qRT-PCR and dual luciferase reporter assays were used for verification. Western blotting was performed to detect the expression levels of the target gene and related signalling molecules. A rescue study was used for further testing.

RESULTS

MicroRNA-146a was upregulated 1 h after reperfusion. MicroRNA-146a deficiency decreased heart function and increased myocardial infarction and apoptosis. Microarray detected 19 apoptosis genes upregulated in the KO mice compared with the WT mice. qRT-PCR and dual luciferase verified that Med1 was one target gene of microRNA-146a. TRAP220, encoded by Med1 in the KO mice, was upregulated, accompanied by an amplified ratio of Bax/Bcl2 and increased cleaved caspase-3. Inhibition of microRNA-146a in H9C2 cells caused increased TRAP220 expression and more apoptosis under the stimulus of hypoxia and re-oxygenation, while knockdown of the increased TRAP220 expression led to decreased cell apoptosis.

CONCLUSIONS

MicroRNA-146a exerts a protective effect against MIRI, which might be partially mediated by the target gene Med1 and related to the apoptosis signalling pathway.

Tumor Necrosis Factor-alpha (TNF-α) Enhances miR-155-Mediated Endothelial Senescence by Targeting Sirtuin1 (SIRT1)

Background

Sirtuin1 (SIRT1) participates in a wide variety of cellular processes, but the molecular mechanism remains largely unknown. miR-155 is an element of the inflammatory signaling pathway in atherosclerosis. Therefore, we tested the hypothesis that TNF-α stimulates miR-155 to target SIRT1 and thereby regulates endothelial senescence, and we also explored the function of miR-155 as a regulator of cardiovascular diseases.

Material/Methods

TNF-α was used to stimulate human umbilical vein endothelial cells (HUVECs), after which protein and gene expression were assessed via Western blotting and RT-qPCR. miR-155 targeting of SIRT1 was confirmed via luciferase reporter assays, while MTT and senescence-associated β-galactosidase (SA-β-gal) assays were used for quantifying cellular proliferation and senescence.

Results

We found that miR-155 was upregulated in response to TNF-α treatment, in addition to inducing marked changes in SIRT1/FoxO-1/p21 pathway protein level. When we overexpressed miR-155 mimics, SIRT1 was markedly reduced, whereas miR-155 inhibition had the opposite effect in TNF-α-treated cells. We additionally confirmed that miR-155 was able to directly bind to SIRT1 3′-UTR, and that inhibition of miR-155 reduced the ability of TNF-α to induce senescence in HUVECs, thereby leading to their enhanced proliferation.

Simvastatin was associated with suppression of miR-155 expression in HUVECs following TNF-α treatment, and with a corresponding reduction in TNF-α-induced senescence, whereas miR-155 overexpression had the opposite effect.

Conclusions

Our findings suggest that TNF-α upregulates miR-155, which then targets SIRT1, suppressing its expression and driving HUVEC apoptosis. Simvastatin disrupted this senescence mechanism via the miR-155/SIRT1/FoxO-1/p21 pathway signaling. Hence, miR-155 is a possible therapeutic approach to endothelial senescence in the development of cardiovascular diseases.

MiR-149 Aggravates Pyroptosis in Myocardial Ischemia-Reperfusion Damage via Silencing FoxO3

BACKGROUND MicroRNAs (miRNAs), which modulate the expression of their target genes, are commonly involved in stimulating and adjusting of many processes that result in cardiovascular diseases, contain cardiac ischemia/reperfusion (I/R) damage. However, the expression and role of miR-149 in pyroptosis mediated myocardial I/R damage remains unclear. MATERIAL AND METHODS Real-time polymerase chain reaction was performed to measure the miR-149 and FoxO3 expression in I/R stimulated H9C2 cells. The cell proliferation, pyroptosis-related inflammatory genes in I/R-treated H9C2 cells transfected miR-149 mimics or miR-149 inhibitor were both explored. We predicted and confirmed miR-149 targets by using bioinformatics analyses and luciferase reporter assay. In addition, the potential relationship between miR-149 and FoxO3 in pyroptosis from I/R treated H9C2 cells was analyzed. RESULTS Our results showed that miR-149 was upregulated, while FoxO3 was downregulated in I/R stimulated H9C2 cells. Over-expression of miR-149 inhibited cell viability and promote pyroptosis, however, down-expression of miR-149 had an opposite effect in I/R treated H9C2 cells. Furthermore, miR-149 could negatively regulate FoxO3 expression by binding 3'UTR, whereas silencing of FoxO3 attenuated the effect of miR-149-mimics on cell proliferation and pyroptosis in I/R treated H9C2 cells. CONCLUSIONS Our study found that miR-149 played a critical role in pyroptosis during cardiac I/R injury, and thus, might provide a novel therapeutic target.

MicroRNA-29a-3p Reduces TNFα-Induced Endothelial Dysfunction by Targeting Tumor Necrosis Factor Receptor 1

miR-29a-3p has been shown to be associated with cardiovascular diseases; however, the effect of miR-29a-3p on endothelial dysfunction is unclear. This study aimed to reveal the effects and mechanisms of miR-29a-3p on endothelial dysfunction. The levels of vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1), and E-selectin were determined by real-time PCR and immunofluorescence staining to reveal the degree of tumor necrosis factor alpha (TNFα)-induced endothelial dysfunction. A luciferase activity assay and cell transfection with a miR-29a-3p mimic or an inhibitor were used to reveal the underlying mechanisms of miR-29a-3p action. Furthermore, the effects of miR-29a-3p on endothelial dysfunction were assessed in C57BL/6 mice injected with TNFα and/or a miR-29a-3p agomir. The results showed that the expression of TNFα-induced adhesion molecules in vascular endothelial cells (EA.hy926 cells, human aortic endothelial cells [HAECs], and primary human umbilical vein endothelial cells [pHUVECs]) and smooth muscle cells (human umbilical vein smooth muscle cells [HUVSMCs]) was significantly decreased following transfection with miR-29a-3p. This effect was reversed by cotransfection with a miR-29a-3p inhibitor. As a key target of miR-29a-3p, tumor necrosis factor receptor 1 mediated the effect of miR-29a-3p. Moreover, miR-29a-3p decreased the plasma levels of TNFα-induced VCAM-1 (32.62%), ICAM-1 (38.22%), and E-selectin (39.32%) in vivo. These data indicate that miR-29a-3p plays a protective role in TNFα-induced endothelial dysfunction, suggesting that miR-29a-3p is a novel target for the prevention and treatment of atherosclerosis.