MiR-101 Attenuates Myocardial Infarction-induced Injury by Targeting DDIT4 to Regulate Autophagy

Ssc-miR-101-3p inhibits hypoxia-induced apoptosis and inflammatory response in alveolar type-II epithelial cells of Tibetan pigs via targeting FOXO3

Tibetan pigs are a unique swine strain adapted to the hypoxic environment of the plateau regions in China. The unique mechanisms underlying the adaption by Tibetan pigs, however, are still elusive. Only few studies have investigated hypoxia-associated molecular regulation in the lung tissues of animals living in the plateau region of China. Our previous study reported that ssc-miR-101-3p expression significantly differed in the lung tissues of Tibetan pigs at different altitudes, suggesting that ssc-miR-101-3p plays an important role in the adaptation of Tibetan pigs to high altitude. To understand the underlying molecular mechanism, in this study, the target genes of ssc-miR-101-3p and their functions were analyzed via various methods including qRT-PCR and GO and KEGG pathway enrichment analyses. The action of ssc-miR-101-3p was investigated by culturing alveolar type-II epithelial cells (ATII) of Tibetan pigs under hypoxic conditions and transfecting ATII cells with vectors overexpressing or inhibiting ssc-miR-101-3p. Overexpression of ssc-miR-101-3p significantly increased the proliferation of ATII cells and decreased the expression of inflammatory and apoptotic factors. The target genes of ssc-miR-101-3p were significantly enriched in FOXO and PI3K-AKT signaling pathways required to mitigate lung injury. Further, FOXO3 was identified as a direct target of ssc-miR-101-3p. Interestingly, ssc-miR-101-3p overexpression reversed the damaging effect of FOXO3 in the ATII cells. In conclusion, ssc-miR-101-3p targeting FOXO3 could inhibit hypoxia-induced apoptosis and inflammatory response in ATII cells of Tibetan pigs. These results provided new insights into the molecular mechanisms elucidating the response of lung tissues of Tibetan pigs to hypoxic stress.

H3K27ac acts as a molecular switch for doxorubicin-induced activation of cardiotoxic genes

BACKGROUND

Doxorubicin (Dox) is an effective chemotherapeutic drug for various cancers, but its clinical application is limited by severe cardiotoxicity. Dox treatment can transcriptionally activate multiple cardiotoxicity-associated genes in cardiomyocytes, the mechanisms underlying this global gene activation remain poorly understood.

METHODS AND RESULTS

Herein, we integrated data from animal models, CUT&Tag and RNA-seq after Dox treatment, and discovered that the level of H3K27ac (a histone modification associated with gene activation) significantly increased in cardiomyocytes following Dox treatment. C646, an inhibitor of histone acetyltransferase, reversed Dox-induced H3K27ac accumulation in cardiomyocytes, which subsequently prevented the increase of Dox-induced DNA damage and apoptosis. Furthermore, C646 alleviated cardiac dysfunction in Dox-treated mice by restoring ejection fraction and reversing fractional shortening percentages. Additionally, Dox treatment increased H3K27ac deposition at the promoters of multiple cardiotoxic genes including Bax, Fas and Bnip3, resulting in their up-regulation. Moreover, the deposition of H3K27ac at cardiotoxicity-related genes exhibited a broad feature across the genome. Based on the deposition of H3K27ac and mRNA expression levels, several potential genes that might contribute to Dox-induced cardiotoxicity were predicted. Finally, the up-regulation of H3K27ac-regulated cardiotoxic genes upon Dox treatment is conservative across species.

CONCLUSIONS

Taken together, Dox-induced epigenetic modification, specifically H3K27ac, acts as a molecular switch for the activation of robust cardiotoxicity-related genes, leading to cardiomyocyte death and cardiac dysfunction. These findings provide new insights into the relationship between Dox-induced cardiotoxicity and epigenetic regulation, and identify H3K27ac as a potential target for the prevention and treatment of Dox-induced cardiotoxicity.

Construction of ferroptosis-related prediction model for pathogenesis, diagnosis and treatment of ruptured abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a dangerous cardiovascular disease, which often brings great psychological burden and economic pressure to patients. If AAA rupture occurs, it is a serious threat to patients' lives. Therefore, it is of clinical value to actively explore the pathogenesis of ruptured AAA and prevent its occurrence. Ferroptosis is a new type of cell death dependent on lipid peroxidation, which plays an important role in many cardiovascular diseases. In this study, we used online data and analysis of ferroptosis-related genes to uncover the formation of ruptured AAA and potential therapeutic targets. We obtained ferroptosis-related differentially expressed genes (Fe-DEGs) from GSE98278 dataset and 259 known ferroptosis-related genes from FerrDb website. Enrichment analysis of differentially expressed genes (DEGs) was performed by gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG). Receiver Operating characteristic (ROC) curve was employed to evaluate the diagnostic abilities of Fe-DEGs. Transcription factors and miRNAs of Fe-DEGs were identified through PASTAA and miRDB, miRWalk, TargetScan respectively. Single-sample gene set enrichment analysis (ssGSEA) was used to observe immune infiltration between the stable group and the rupture group. DGIdb database was performed to find potential targeted drugs of DEGs. GO and KEGG enrichment analysis found that DEGs mainly enriched in "cellular divalent inorganic cation homeostasis," "cellular zinc ion homeostasis," "divalent inorganic cation homeostasis," "Mineral absorption," "Cytokine - cytokine receptor interaction," "Coronavirus disease - COVID-19." Two up-regulated Fe-DEGs MT1G and DDIT4 were found to further analysis. Both single and combined applications of MT1G and DDIT4 showed good diagnostic efficacy (AUC = 0.8254, 0.8548, 0.8577, respectively). Transcription factors STAT1 and PU1 of MT1G and ARNT and MAX of DDIT4 were identified. Meanwhile, has_miR-548p-MT1G pairs, has_miR-53-3p/has_miR-181b-5p/ has_miR-664a-3p-DDIT4 pairs were found. B cells, NK cells, Th2 cells were high expression in the rupture group compared with the stable group, while DCs, Th1 cells were low expression in the rupture group. Targeted drugs against immunity, GEMCITABINE and INDOMETHACIN were discovered. We preliminarily explored the clinical significance of Fe-DEGs MT1G and DDIT4 in the diagnosis of ruptured AAA, and proposed possible upstream regulatory transcription factors and miRNAs. In addition, we also analyzed the immune infiltration of stable and rupture groups, and found possible targeted drugs for immunotherapy.

Clinical Variables Influence the Ability of miR-101, miR-150, and miR-21 to Predict Ventricular Remodeling after ST-Elevation Myocardial Infarction

Left ventricle remodeling (LVR) after acute myocardial infarction (MI) leads to impairment of both systolic and diastolic function, a significant contributor to heart failure (HF). Despite extensive research in the field, predicting post-MI LVR and HF is still a challenge. Several circulant microRNAs have been proposed as LVR predictors; however, their clinical value is controversial. Here, we used real-time quantitative PCR to quantify the plasma levels of hsa-miR-101, hsa-miR-150, and hsa-miR-21 on the first day of hospital admission of MI patients with ST-elevation (STEMI). We analyzed their correlation to the patient's clinical and paraclinical variables and evaluated their ability to discriminate between post-MI LVR and non-LVR. We show that, despite being excellent MI discriminators, none of these microRNAs can distinguish between LVR and non-LVR patients. Furthermore, we found that diabetes mellitus (DM), Hb level, and the number of erythrocytes significantly influence all three plasma microRNA levels. This suggests that plasma microRNAs' diagnostic and prognostic value in STEMI patients should be reevaluated and interpreted in the context of associated pathologies.

miRNAs Epigenetic Tuning of Wall Remodeling in the Early Phase after Myocardial Infarction: A Novel Epidrug Approach

Myocardial infarction (MI) is one of the leading causes of death in Western countries. An early diagnosis decreases subsequent severe complications such as wall remodeling or heart failure and improves treatments and interventions. Novel therapeutic targets have been recognized and, together with the development of direct and indirect epidrugs, the role of non-coding RNAs (ncRNAs) yields great expectancy. ncRNAs are a group of RNAs not translated into a product and, among them, microRNAs (miRNAs) are the most investigated subgroup since they are involved in several pathological processes related to MI and post-MI phases such as inflammation, apoptosis, angiogenesis, and fibrosis. These processes and pathways are finely tuned by miRNAs via complex mechanisms. We are at the beginning of the investigation and the main paths are still underexplored. In this review, we provide a comprehensive discussion of the recent findings on epigenetic changes involved in the first phases after MI as well as on the role of the several miRNAs. We focused on miRNAs function and on their relationship with key molecules and cells involved in healing processes after an ischemic accident, while also giving insight into the discrepancy between males and females in the prognosis of cardiovascular diseases.

Signs and signals limiting myocardial damage using PICSO: a scoping review decoding paradigm shifts toward a new encounter

Background

Inducing recovery in myocardial ischemia is limited to a timely reopening of infarct vessels and clearing the cardiac microcirculation, but additional molecular factors may impact recovery.

Objective

In this scoping review, we identify the paradigm shifts decoding the branching points of experimental and clinical evidence of pressure-controlled intermittent coronary sinus occlusion (PICSO), focusing on myocardial salvage and molecular implications on infarct healing and repair.

Design

The reporting of evidence was structured chronologically, describing the evolution of the concept from mainstream research to core findings dictating a paradigm change. All data reported in this scoping review are based on published data, but new evaluations are also included.

Results

Previous findings relate hemodynamic PICSO effects clearing reperfused microcirculation to myocardial salvage. The activation of venous endothelium opened a new avenue for understanding PICSO. A flow-sensitive signaling molecule, miR-145-5p, showed a five-fold increase in porcine myocardium subjected to PICSO.Verifying our theory of "embryonic recall," an upregulation of miR-19b and miR-101 significantly correlates to the time of pressure increase in cardiac veins during PICSO (r2 = 0.90, p < 0.05; r2 = 0.98, p < 0.03), suggesting a flow- and pressure-dependent secretion of signaling molecules into the coronary circulation. Furthermore, cardiomyocyte proliferation by miR-19b and the protective role of miR-101 against remodeling show another potential interaction of PICSO in myocardial healing.

Conclusion

Molecular signaling during PICSO may contribute to retroperfusion toward deprived myocardium and clearing the reperfused cardiac microcirculation. A burst of specific miRNA reiterating embryonic molecular pathways may play a role in targeting myocardial jeopardy and will be an essential therapeutic contribution in limiting infarcts in recovering patients.

Targeting Epigenetics and Non-coding RNAs in Myocardial Infarction: From Mechanisms to Therapeutics

Myocardial infarction (MI) is a complicated pathology triggered by numerous environmental and genetic factors. Understanding the effect of epigenetic regulation mechanisms on the cardiovascular disease would advance the field and promote prophylactic methods targeting epigenetic mechanisms. Genetic screening guides individualised MI therapies and surveillance. The present review reported the latest development on the epigenetic regulation of MI in terms of DNA methylation, histone modifications, and microRNA-dependent MI mechanisms and the novel therapies based on epigenetics.

miR‑101a‑3p overexpression prevents acetylcholine‑CaCl2‑induced atrial fibrillation in rats via reduction of atrial tissue fibrosis, involving inhibition of EZH2

Atrial fibrillation (AF), a clinically common heart arrhythmia, can result in left ventricular hypofunction, embolism and infarction. MicroRNA (miR)‑101a‑3p is lowly expressed in atrial tissues of patients with AF, but its role in AF remains unknown. In the present study, an AF model in rats was established via intravenous injection of acetylcholine (Ach)‑CaCl2. The downregulation of miR‑101a‑3p and upregulation of enhancer of zeste 2 homolog 2 (EZH2) were observed in AF model rats, indicating the involvement of miR‑101a‑3p and EZH2 in AF development. To study the effect of miR‑101a‑3p on AF in vivo, AF model rats were intramyocardially injected with lentivirus expressing miR‑101a‑3p. Electrocardiogram analysis identified that miR‑101a‑3p overexpression restored disappeared P wave and R‑R interphase changes in Ach‑CaCl2‑induced rats. Overexpression of miR‑101a‑3p also increased the atrial effective refractory period, reduced AF incidence and shortened duration of AF. Histological changes in atrial tissues were observed after H&E and Masson staining, which demonstrated that miR‑101a‑3p reduced atrial remodeling and fibrosis in AF model rats. Moreover, EZH2 expression was downregulated in atrial tissues by miR‑101a‑3p induction. Immunohistochemistry for collagen Ⅰ and collagen III revealed a reduction in atrial collagen synthesis following miR‑101a‑3p overexpression in AF model rats. Additionally, miR‑101a‑3p lowered the expression of pro‑fibrotic biomarkers, including TGF‑β1, connective tissue growth factor, fibronectin and α‑smooth muscle actin. The luciferase reporter assay results also indicated that EZH2 was a target gene of miR‑101a‑3p. Taken together, it was found that miR‑101a‑3p prevented AF in rats possibly via inhibition of collagen synthesis and atrial fibrosis by targeting EZH2, which provided a potential target for preventing AF.

Overexpression of miR-365a-3p relieves sepsis-induced acute myocardial injury by targeting MyD88/NF-κB pathway

Sepsis often leads to systemic multiple organ dysfunction, with the majority of deaths attributable to acute myocardial injury (AMI). In this study, we aimed to explore the functional role of miR-365a-3p in sepsis-induced AMI. The sepsis myocardial injury model was constructed using lipopolysaccharide (LPS) both in vitro and in vivo with selective regulation of miR-365a-3p expression. Real-time PCR or Western blot was employed to detect the expressions of miR-365a-3p, inflammatory cytokines (tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β), and IL-6), and inflammation-related proteins (nuclear factor-κB (NF-κB), I-κB, myeloid differentiation factor 88 (MyD88)) in myocardial tissues and cells. Also, cell counting kit-8 (CCK8) and flow cytometry assays were used to measure cardiomyocyte proliferation and apoptosis, respectively. Furthermore, the targeting relationship between miR-365a-3p and MyD88 was verified with the dual luciferase activity assay. miR-365a-3p was downregulated in LPS-induced myocardial injury model. miR-365a-3p overexpression attenuated cardiomyocyte apoptosis and suppressed the expressions of inflammatory cytokines and proteins. Inhibiting miR-365a-3p, however, produced the opposite effects. Mechanistically, miR-365a-3p targeted the 3'-untranslated region of MyD88, thereby inactivating MyD88-mediated NF-κB pathway. miR-365a-3p overexpression mitigated sepsis-mediated myocardial injury by inhibiting MyD88-mediated NF-κB activation.

Autophagy in cardiovascular diseases: role of noncoding RNAs

Cardiovascular diseases (CVDs) remain the world's leading cause of death. Cardiomyocyte autophagy helps maintain normal metabolism and functioning of the heart. Importantly, mounting evidence has revealed that autophagy plays a dual role in CVD pathology. Under physiological conditions, moderate autophagy maintains cell metabolic balance by degrading and recycling damaged organelles and proteins, and it promotes myocardial survival, but excessive or insufficient autophagy is equally deleterious and contributes to disease progression. Noncoding RNAs (ncRNAs) are a class of RNAs transcribed from the genome, but most ncRNAs do not code for functional proteins. In recent years, increasingly, various ncRNAs have been identified, and they play important regulatory roles in the physiological and pathological processes of organisms, as well as in autophagy. Thus, determining whether ncRNA-regulated autophagy plays a protective role in CVDs or promotes their progression can help us to develop ncRNAs as therapeutic targets in autophagy-related CVDs. In this review, we briefly summarize the regulatory roles of several important ncRNAs, including microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), in the autophagy of various CVDs to provide a theoretical basis for the etiology and pathogenesis of CVDs and develop novel therapies to treat CVDs.

Is REDD1 a metabolic double agent? Lessons from physiology and pathology

The Akt/mechanistic target of rapamycin (mTOR) signaling pathway governs macromolecule synthesis, cell growth, and metabolism in response to nutrients and growth factors. Regulated in development and DNA damage response (REDD)1 is a conserved and ubiquitous protein, which is transiently induced in response to multiple stimuli. Acting like an endogenous inhibitor of the Akt/mTOR signaling pathway, REDD1 protein has been shown to regulate cell growth, mitochondrial function, oxidative stress, and apoptosis. Recent studies also indicate that timely REDD1 expression limits Akt/mTOR-dependent synthesis processes to spare energy during metabolic stresses, avoiding energy collapse and detrimental consequences. In contrast to this beneficial role for metabolic adaptation, REDD1 chronic expression appears involved in the pathogenesis of several diseases. Indeed, REDD1 expression is found as an early biomarker in many pathologies including inflammatory diseases, cancer, neurodegenerative disorders, depression, diabetes, and obesity. Moreover, prolonged REDD1 expression is associated with cell apoptosis, excessive reactive oxygen species (ROS) production, and inflammation activation leading to tissue damage. In this review, we decipher several mechanisms that make REDD1 a likely metabolic double agent depending on its duration of expression in different physiological and pathological contexts. We also discuss the role played by REDD1 in the cross talk between the Akt/mTOR signaling pathway and the energetic metabolism.