MiR-183-5p overexpression in bone mesenchymal stem cell-derived exosomes protects against myocardial ischemia/reperfusion injury by targeting FOXO1.

Exosomes have been suggested to serve as possible drug delivery vehicles due to their nanometer-size range and capability of transferring biological materials to recipient cells. Thus, whether miR-183-5p-overexpressing bone marrow mesenchymal stem cell-derived exosomes (BMSC-Exos) could protect against myocardial ischemia/reperfusion (MI/R) injury by targeting FOXO1 was investigated. Exosomes were isolated from rat BMSCs, and ischemia/reperfusion (I/R) rat models were established. I/R rats were treated with Exo/NC-Exo/miR-183-5p-Exo/anti-miR-183-5p-Exo. Cardiac function, serum biochemical indices, apoptosis, myocardial infarction size, and the expression of miR-183-5p, FOXO1 and cleaved caspase 3 were assessed. Primary cardiomyocytes were isolated to establish hypoxia/reoxygenation (H/R) models to observe the function of miR-183-5p-Exo in vitro. Rats in the I/R group exhibited a decreased left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS) and left ventricular systolic pressure (LVSP) but an increased left ventricular end-diastolic pressure (LVEDP), myocardial infarct size and apoptosis index (AI). In addition, in I/R rats, miR-183-5p expression was decreased, but FOXO1 and cleaved caspase 3 expression was increased. Both Exo and miR-183-5p-Exo improved the above indices in I/R rats, but miR-183-5p-Exo showed better effects. However, anti-miR-183-5p-Exo reversed the protective effect of Exo. FOXO1 was a target gene of miR-183-5p. Experiments in vitro revealed that Exo and miR-183-5p-Exo suppressed apoptosis and oxidative stress injury in H/R-induced cardiomyocytes, whereas overexpressed FOXO1 reversed the protective role of miR-183-5p-Exo. BMSC-derived exosomal miR-183-5p could target FOXO1 to reduce apoptosis and oxidative stress in I/R cardiomyocytes and improve cardiac function, thereby protecting against MI/R injury.

Mao S ，Zhao J ，Zhang ZJ ，Zhao Q ... -  《-》

Exosomes of bone-marrow stromal cells inhibit cardiomyocyte apoptosis under ischemic and hypoxic conditions via miR-486-5p targeting the PTEN/PI3K/AKT signaling pathway.

Myocardial ischemia-reperfusion injury (MIRI) is a major obstacle in the treatment of ischemic heart disease. Recent studies have shown that exosomes-small membrane vesicles secreted by most cell types-could have a protective effect on the ischemic myocardium. In this study we explored the effect of exosomes derived from bone-marrow stromal cells (BMSC-exo) on cardiomyocyte apoptosis and MIRI. Exosomes were purified from culture media using the ExoQuick kit and observed using transmission electron microscopy. Cell viability was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Cell apoptosis was analyzed by flow cytometry using the Annexin-V/PI stain. The expression levels of microRNA (miRNA), messenger RNA (mRNA) and PTEN/PI3K/AKT-pathway-related proteins were detected by qRT-PCR and western blot, respectively. Myocardial ischemia was simulated by incubating H9C2 cells in a hypoxia/reoxygenation (H/R) conditioned rat MIRI model. BMSC-exo induced the proliferation of H9C2 cells and rescued H9C2 cells from apoptosis in the H/R model, indicating that BMSC-exo has a protective effect on cardiomyocyte injury caused by H/R. Using transgenic H9C2 cells, we found that miR-486-5p in BMSC-exo suppressed the H/R-triggered apoptosis of H9C2 cells. In addition, BMSC-exo repressed the expression of PTEN in H9C2 cells via miR-486-5p, and subsequently activated the PI3K/AKT pathway in vitro. Moreover, the myocardial injury caused by ischemia/reperfusion was repaired by BMSC-exo which activates the PI3K/AKT pathway via miR-486-5p in vivo. Our results suggested that exosomes from BMSCs have a protective effect on myocardium ischemic injury. MiR-486-5p carried by BMSC-exo plays a pivotal role in the regulatory process by suppressing PTEN expression, activating the PI3K/AKT signaling pathway, and subsequently inhibiting the apoptosis of injured cardiomyocytes.

Sun XH ，Wang X ，Zhang Y ，Hui J ... -  《-》

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

Chen Q ，Liu Y ，Ding X ，Li Q ，Qiu F ，Wang M ，Shen Z ，Zheng H ，Fu G ... -  《-》

Mesenchymal Stem Cell-Originated Exosomal Lnc A2M-AS1 Alleviates Hypoxia/Reperfusion-Induced Apoptosis and Oxidative Stress in Cardiomyocytes.

Mesenchymal stem cell (MSC)-derived exosomes play significant roles in ameliorating cardiac damage after myocardial ischemia-reperfusion (I/R) injury. Long non-coding RNA alpha-2-macroglobulin antisense RNA 1 (Lnc A2M-AS1) was found that might protect against myocardial I/R. However, whether Lnc A2M-AS1 delivery via MSC-derived exosomes could also regulate myocardial I/R injury remains unknown. Exosomes were isolated by ultracentrifugation, and qualified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blot. Hypoxia/reoxygenation (H/R) treatment in human cardiomyocytes was used to mimic the process of myocardial I/R in vitro. The viability and apoptosis of cardiomyocytes were detected using cell counting kit-8, flow cytometry, and Western blot assays. The contents of lactate dehydrogenase (LDH), malondialdehyde (MDA), and superoxide dismutase (SOD) were evaluated using corresponding commercial kits. The quantitative real-time polymerase chain reaction and Western blot were used to determine the expression levels of Lnc A2M-AS1, microRNA (miR)-556-5p, and X-linked inhibitor of apoptosis protein (XIAP). The binding interaction between miR-556-5p and Lnc A2M-AS1 or XIAP was confirmed by the dual-luciferase reporter, RIP and pull-down assays. Exosomes isolated from hMSCs (hMSCs-exo) attenuated H/R-induced apoptosis and oxidative stress in cardiomyocytes. Lnc A2M-AS1 was lowly expressed in AMI patients and H/R-induced cardiomyocytes. Besides, Lnc A2M-AS1 was detectable in hMSCs-exo, exosomes derived from Lnc A2M-AS1-transfected hMSCs weakened H/R-induced apoptosis and oxidative stress, and enhanced the protective action of hMSCs-exo on H/R-induced cardiomyocytes. Further mechanism analysis showed that Lnc A2M-AS1 acted as a sponge for miR-556-5p to increase XIAP expression level. Importantly, miR-556-5p overexpression or XIAP knockdown reversed the action of exosomal Lnc A2M-AS1 on H/R-induced cardiomyocytes. Lnc A2M-AS1 delivery via MSC-derived exosomes ameliorated H/R-induced cardiomyocyte apoptosis and oxidative stress via regulating miR-556-5p/XIAP, opening a new window into the pathogenesis of myocardial I/R injury.

Yu H ，Pan Y ，Dai M ，Wang X ，Chen H ... -  《-》

Exosomal miR-455-3p from BMMSCs prevents cardiac ischemia-reperfusion injury.

Wang Y ，Shen Y 《-》