MicroRNA-29b reduces myocardial ischemia-reperfusion injury in rats via down-regulating PTEN and activating the Akt/eNOS signaling pathway

Circulating Small Extracellular Vesicles Involved in Systemic Regulation Respond to RGC Degeneration in Glaucoma

Glaucoma is a leading cause of irreversible blindness worldwide and is characterized by progressive retinal ganglion cell (RGC) degeneration and vision loss. Since irreversible neurodegeneration occurs before diagnosable, early diagnosis and effective neuroprotection are critical for glaucoma management. Small extracellular vesicles (sEVs) are demonstrated to be potential novel biomarkers and therapeutics for a variety of diseases. In this study, it is found that intravitreal injection of circulating plasma-derived sEVs (PDEV) from glaucoma patients ameliorated retinal degeneration in chronic ocular hypertension (COH) mice. Moreover, it is found that PDEV-miR-29s are significantly upregulated in glaucoma patients and are associated with visual field defects in progressed glaucoma. Subsequently, in vivo and in vitro experiments are conducted to investigate the possible function of miR-29s in RGC pathophysiology. It is showed that the overexpression of miR-29b-3p effectively prevents RGC degeneration in COH mice and promotes the neuronal differentiation of human induced pluripotent stem cells (hiPSCs). Interestingly, engineered sEVs with sufficient miR-29b-3p delivery exhibit more effective RGC protection and neuronal differentiation efficiency. Thus, elevated PDEV-miR-29s may imply systemic regulation to prevent RGC degeneration in glaucoma patients. This study provides new insights into PDEV-based glaucoma diagnosis and therapeutic strategies for neurodegenerative diseases.

A bibliometric analysis of myocardial ischemia/reperfusion injury from 2000 to 2023

Background

Myocardial ischemia/reperfusion injury (MIRI) refers to the more severe damage that occurs in the previously ischemic myocardium after a short-term interruption of myocardial blood supply followed by restoration of blood flow within a certain period of time. MIRI has become a major challenge affecting the therapeutic efficacy of cardiovascular surgery.

Methods

A scientific literature search on MIRI-related papers published from 2000 to 2023 in the Web of Science Core Collection database was conducted. VOSviewer was used for bibliometric analysis to understand the scientific development and research hotspots in this field.

Results

A total of 5,595 papers from 81 countries/regions, 3,840 research institutions, and 26,202 authors were included. China published the most papers, but the United States had the most significant influence. Harvard University was the leading research institution, and influential authors included Lefer David J., Hausenloy Derek J., Yellon Derek M., and others. All keywords can be divided into four different directions: risk factors, poor prognosis, mechanisms and cardioprotection.

Conclusion

Research on MIRI is flourishing. It is necessary to conduct an in-depth investigation of the interaction between different mechanisms and multi-target therapy will be the focus and hotspot of MIRI research in the future.

Myocardial ischemia-reperfusion injury; Molecular mechanisms and prevention

Cardiovascular diseases are one of the leading causes of mortality in developed countries. Among cardiovascular disorders, myocardial infarction remains a life-threatening problem predisposing to the development and progression of ischemic heart failure. Ischemia/reperfusion (I/R) injury is a critical cause of myocardial injury. In recent decades, many efforts have been made to find the molecular and cellular mechanisms underlying the development of myocardial I/R injury and post-ischemic remodeling. Some of these mechanisms are mitochondrial dysfunction, metabolic alterations, inflammation, high production of ROS, and autophagy deregulation. Despite continuous efforts, myocardial I/R injury remains a major challenge in medical treatments of thrombolytic therapy, heart disease, primary percutaneous coronary intervention, and coronary arterial bypass grafting. The development of effective therapeutic strategies to reduce or prevent myocardial I/R injury is of great clinical significance.

An updated review on cell signaling pathways regulated by candidate miRNAs in coronary artery disease

MicroRNAs (miRNAs) are small endogenous non-coding RNA, size range from 17 to 25 nucleotides that regulate gene expression at the post-transcriptional level. More than 2000 different types of miRNAs have been identified in humans which regulate about 60% of gene expression, since the discovery of the first miRNA in 1993. MicroRNA performs many functions such as being involved in the regulation of various biological pathways for example cell migration, cell proliferation, cell differentiation, disease progression, and initiation. miRNAs also play an important role in the development of atherosclerosis lesions, cardiac fibroblast, cardiac hypertrophy, cancer, and neurological disorders. Abnormal activation of many cell signaling pathways has been observed in the development of coronary artery disease. Abnormal expression of these candidate miRNA genes leads to up or downregulation of specific genes, these specific genes play an important role in the regulation of cell signaling pathways involved in coronary artery disease. Many studies have found that miRNAs play a key role in the regulation of crucial signaling pathways that are involved in the pathophysiology of coronary artery disease. This review is designed to investigate the role of cell signaling pathways regulated by candidate miRNAs in Coronary artery disease.

MiR-199a-5p promotes ferroptosis-induced cardiomyocyte death responding to oxygen-glucose deprivation/reperfusion injury via inhibiting Akt/eNOS signaling pathway

Myocardial ischemia/reperfusion (I/R) injury is associated with the poor outcome and higher mortality after myocardial infarction. Recent studies have revealed that miR-199a-5p participates in the process of myocardial I/R injury, but the precise roles and molecular mechanisms of miR-199a-5p in myocardial I/R injury remain not well-studied. Ferroptosis has been proposed to promote cardiomyocyte death, closely associated with myocardial I/R injury. Herein, the present study aimed to explore the function and mechanisms by which miR-199a-5p regulates whether miR-199a-5p contributes to ferroptosis-induced cardiomyocyte death responding to oxygen-glucose deprivation/reoxygenation (OGD/R) injury, an in vitro model of myocardial I/R injury focusing on Akt/eNOS signaling pathway. The results found that ferroptosis-induced cardiomyocyte death occurs and is accompanied by an increase in miR-199a-5p level in OGD/R-treated H9c2 cells. MiR-199a-5p inhibitor ameliorated ferroptosis-induced cardiomyocyte death as evidenced by the increased cell viability, the reduced reactive oxygen species (ROS) generation, lactate dehydrogenase (LDH) activity, malondialdehyde (MDA) and Fe²⁺ contents, and the up-regulated glutathione (GSH)/glutathione disulphide (GSSG) ratio as well as glutathione peroxidase 4 (Gpx4) protein expression in H9c2 cells-exposed to OGD/R, while miR-199a-5p mimic had the opposite effects. In addition, OGD/R led to the inhibition of Akt/eNOS signaling pathway, which was also blocked by miR-199a-5p inhibitor and aggravated by miR-199a-5p mimic. Furthermore, LY294002, an inhibitor of Akt/eNOS signaling pathway, abrogated miR-199a-5p inhibitor-induced the reduction of ferroptosis-induced cardiomyocyte death. In summary, our findings demonstrated that miR-199a-5p plays a central role in stimulating ferroptosis-induced cardiomyocyte death during ischemic/hypoxic injury via inhibiting Akt/eNOS signaling pathway.

miR-29b-3p Inhibitor Alleviates Hypomethylation-Related Aberrations Through a Feedback Loop Between miR-29b-3p and DNA Methylation in Cardiomyocytes

As a member of the miR-29 family, miR-29b regulates global DNA methylation through target DNA methyltransferases (DNMTs) and acts as both a target and a key effector in DNA methylation. In this study, we found that miR-29b-3p expression was inversely correlated with DNMT expression in the heart tissues of patients with congenital heart disease (CHD), but whether it interacts with DNMTs in cardiomyocytes remains unknown. Further results revealed a feedback loop between miR-29b-3p and DNMTs in cardiomyocytes. Moreover, miR-29b-3p inhibitor relieved the deformity of hypomethylated zebrafish and restored the DNA methylation patterns in cardiomyocytes, resulting in increased proliferation and renormalization of gene expression. These results suggest mutual regulation between miR-29b-3p and DNMTs in cardiomyocytes and support the epigenetic normalization of miRNA-based therapy in cardiomyocytes.

Propofol postconditioning alleviates diabetic myocardial ischemia‑reperfusion injury via the miR‑200c‑3p/AdipoR2/STAT3 signaling pathway

Myocardial ischemia/reperfusion (MI/RI) syndrome is one of the leading causes of mortality and disability. Propofol postconditioning is known to improve myocardial ischemia/reperfusion injury (MI/RI). The present study aimed to explore the mechanism of propofol postconditioning in diabetic MI/RI. Diabetic MI/RI rat models were established and the rats were treated via propofol postconditioning. Staining with 2,3,5-triphenyl-2H-tetrazolium chloride, H&E staining, TUNEL staining and ELISA were applied to detect infarct size, pathological changes, apoptosis and oxidative stress-related factor and apoptotic factor levels, respectively. Subsequently, the effect of propofol on H9C2 cells was also assessed using the Cell Counting Kit-8 assay. High-glucose hypoxia/reperfusion (H/R) models of H9C2 cardiomyocytes were established. miR-200c-3p overexpression or AdipoR2 silencing combined with propofol postconditioning was performed in H/R-induced H9C2 cells and STAT3 protein expression levels were determined. Propofol postconditioning significantly reduced myocardial infarct size, oxidative stress and apoptosis in diabetic MI/RI models. Furthermore, propofol postconditioning significantly reduced the oxidative stress and apoptosis of H9C2 cells in high-glucose H/R models. Propofol postconditioning also significantly downregulated miR-200c-3p expression levels and promoted AdipoR2 expression levels. miR-200c-3p overexpression or AdipoR2 downregulation significantly reversed the effects of propofol postconditioning on its antioxidation and anti-apoptotic effects in H9C2 cells and on decreasing STAT3 phosphorylation levels. Together, the results of the present study demonstrated that propofol postconditioning inhibited miR-200c-3p, upregulated AdipoR2 and activated the STAT3 signaling pathway, thus alleviating diabetic MI/RI and therefore highlighting its potential as a treatment of diabetic MI/RI.