Bone marrow stromal cell-derived exosomes improve oxidative stress and pyroptosis in doxorubicin-induced myocardial injury in vitro by regulating the transcription of GSDMD through the PI3K-AKT-Foxo1 pathway.

Doxorubicin (DOX) can contribute to severe myocardial injury, and bone marrow stromal cells (BMSC)-exosomes (Exos) improves acute myocardial infarction. Hence, this research investigated whether BMSC-Exos alleviated DOX-induced myocardial injury. BMSC-derived Exos were isolated and identified, and the optimal concentration of DOX was confirmed. H9C2 cells were treated with DOX and BMSC-Exos or in combination with the protein kinase B (AKT) inhibitor. Reactive oxygen species (ROS) and JC-1 were detected to assess oxidative stress (OS) and mitochondrial membrane damage, respectively. In addition, the expression of pyroptosis-related molecules was measured. The expression of phosphatidylinositol 3 kinase (PI3K)-AKT pathway-related proteins and the phosphorylation and acetylation of forkhead box O1 (Foxo1) in the cell nucleus and cytoplasm were tested. Last, interactions between Foxo1 and gasdermin D (GSDMD) were assessed. BMSC-Exo treatment increased viability and mitochondrial membrane potential and reduced lactic dehydrogenase release and ROS levels in DOX-treated H9C2 cells. Furthermore, the addition of BMSC-Exos suppressed DOX-induced activation and upregulation of NLRP3 and apoptosis-associated speck-like protein containing A CARD (ASC) and in vitro cleavage of caspase-1, GSDMD, interleukin (IL)-1β, and IL-18 proteins. Additionally, BMSC-Exo treatment enhanced the expression of phosphorylated (p)-PI3K, p-AKT, and p-mTOR in DOX-treated H9C2 cells and the levels of phosphorylated Foxo1 in the cytoplasm of DOX-treated H9C2 cells. Foxo1 was enriched in the promoter region of GSDMD. Moreover, the AKT inhibitor API-2 annulled the effects of BMSC-Exos on OS, pyroptosis, and Foxo1 phosphorylation in DOX-treated H9C2 cells. BMSC-Exos phosphorylated Foxo1 and inactivated Foxo1 transcription via the PI3K-AKT pathway to diminish GSDMD expression, thus restraining DOX-induced pyroptosis and OS of myocardial cells.

Zeng H ，Yang Y ，Tou F ，Zhan Y ，Liu S ，Zou P ，Chen Y ，Shao L ... -  《Immunity Inflammation and Disease》

Embryonic stem cell-derived exosomes inhibit doxorubicin-induced TLR4-NLRP3-mediated cell death-pyroptosis.

Tavakoli Dargani Z ，Singla DK 《-》

Exosomal miR-27b-3p Derived from Hypoxic Cardiac Microvascular Endothelial Cells Alleviates Rat Myocardial Ischemia/Reperfusion Injury through Inhibiting Oxidative Stress-Induced Pyroptosis via Foxo1/GSDMD Signaling.

Exosomes derived from cardiac microvascular endothelial cells (CMECs) under hypoxia can mediate cardiac repair functions and alleviate pyroptosis and oxidative stress during ischemia-reperfusion (I/R) injury. This study is aimed at investigating the effect and mechanism of miR-27b-3p underlying hypoxic CMECs-derived exosomes against I/R injury. CMECs were isolated from the left ventricle of Sprague-Dawley rats, followed by culturing under hypoxic conditions or pretreatment with the miR-27b-3p inhibitor. CMECs-derived exosomes were added into H9C2 cells before hypoxia/reoxygenation (H/R) or injected into the rat heart before I/R injury. An in vivo I/R injury model was established by ligating and releasing the left anterior descending coronary artery. Expression of pyroptosis-related factors was detected using Western blot, and heart infarcted size was determined by the 2,3,5-triphenyl-2H-tetrazpinolium chloride staining method. Dual-Luciferase Reporter assays were performed to analyze the interactions of nmiR-27b-3p-forkhead box O1 (Foxo1) and Gasdermin D- (GSDMD-) Foxo1. Chromatin-immunoprecipitation (ChIP) assays were performed to validate the interactions between forkhead box O1 (Foxo1) and Gasdermin D (GSDMD) and Foxo1-mediated histone acetylation of GSDMD. CMECs were successfully identified from left ventricle of Sprague-Dawley rats. The expressions of Foxo1 and pyroptosis-related proteins (GSDMD, NLPR3, cleaved caspase 1, IL-1β, and IL-18) were upregulated in the rat heart after I/R injury. Treatment of CMEC-derived exosomes, especially that under hypoxic conditions, significantly reduced pyroptosis in the rat heart. miR-27b-3p was significantly upregulated in CMEC-derived exosomes under hypoxic conditions, and miR-27b-3p inhibition in exosomes alleviated its cytoprotection and inhibited oxidative stress in H9C2 cells. Treatment with Foxo1 overexpression plasmids aggravated in vitro H/R and in vivo I/R injury by upregulating pyroptosis-related proteins. Further experiments validated that miR-27b-3p negatively targeted Foxo1, which bound to the promoter region of GSDMD. These results demonstrated a great therapeutic efficacy of miR-27b-3p overexpression in hypoxic CMEC-derived exosomes in preventing the development of myocardial damage post I/R injury through inhibiting Foxo1/GSDMD signaling-induced oxidative stress and pyroptosis.

Zhang B ，Sun C ，Liu Y ，Bai F ，Tu T ，Liu 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 ... -  《-》

M2 Macrophage-Derived Exosomes Regulate Myocardial Ischemia-Reperfusion And Pyroptosis Via ROS/NLRP3 Pathway.

Hu H ，Qi L ，Ren C ，Yan S ... -  《-》