Published online Feb 26, 2022. doi: 10.4252/wjsc.v14.i2.183
Peer-review started: October 13, 2021
First decision: November 8, 2021
Revised: November 29, 2021
Accepted: January 25, 2022
Article in press: January 25, 2022
Published online: February 26, 2022
Processing time: 134 Days and 20.8 Hours
Previous studies have demonstrated that extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) reveal the cardioprotective effects against myocardial infarction (MI). Hypoxia-preconditioned EVs (HP-EVs) derived from MSCs are thought to have better cardioprotective effects, and the underlying mechanisms have garnered increasing attention from scholars.
Although some scholars have focused on the effect of hypoxia preconditioning on MSCs, the underlying mechanisms remain unclear. Thus, this study focused on the mechanism underlying the cardioprotective effect of HP-EVs from MSCs.
We explored the cardioprotective mechanism of HP-EVs from MSCs.
HP-EVs from mouse adipose-derived MSCs (ADSCs) were extracted, and their cardioprotective effect on improving the survival of cardiomyocytes (CMs) and ameliorating cardiac function were evaluated by Evans Blue/2,3,5-triphenyltetrazolium chloride staining and echocardiography. Mechanistically, microRNA (miRNA) sequencing was adopted to investigate the functional RNA diversity between HP-EVs or normoxic EVs (NC-EVs) from mouse ADSCs. Subsequently, the molecular mechanism of EVs in mediating thioredoxin-interacting protein (TXNIP) and TXNIP-mediated hypoxia-inducible factor-1 alpha (HIF-1α) ubiquitination were verified by the dual-luciferase reporter assay, immunoprecipitation, western blotting, and immunofluorescence.
HP-EVs reduced both infarct size (necrosis area) and the degree of apoptosis to a greater extent than NC-EVs in CMs subjected to hypoxia in vitro and mice suffering from MI in vivo. We showed that EV miRNA224-5p directly bound to the 3’-untranslated region of TXNIP and had a critical protective role against hypoxia-associated CM injury. Our results suggested that MI triggered TXNIP-mediated HIF-1α ubiquitination and degradation via the chromosomal region maintenance 1-dependent nuclear transport pathway in CMs, which led to aggravated injury and hypoxia tolerance in CMs in the early stage of MI.
The anti-apoptotic effect of HP-EVs, which improves tolerance toward MI or hypoxic conditions and alleviates the degree of CM apoptosis until reperfusion therapy, may partly result from EV miR-224-5p targeting TXNIP.
This study partly reveals the mechanism underlying the cardioprotective effect of HP-EVs and provides insights into potential therapies against MI.