MicroRNA-141-3p reduces pulmonary hypoxia/reoxygenation injury through suppression of Beclin-1-dependent autophagy

Alterations in autophagy are involved in pulmonary hypoxia/reoxygenation (H/R)-induced injury. Here, we intended to explain the function of microRNA-141-3p (miR-141-3p) in regulating autophagy under the H/R condition. Rat pulmonary microvascular endothelial cells (PMVECs) were applied for H/R cell model establishment, followed by tracing of autophagy formation. SIRT1 plays a critical role in controlling the lifespan of yeast, flies, and mice. Interaction between SIRT1 and Beclin-1, an indicator protein for autophagy, and between miR-141-3p and SIRT1 was assayed with their roles in PMVEC injury. Autophagy of PMVECs was activated after hypoxia treatment and further activated after H/R treatment. The binding of miR-141-3p and SIRT1 was verified. In H/R-treated PMVECs, the binding of miR-141-3p and SIRT1 was reduced. Furthermore, SIRT1 acted as a deacetylase to stabilize the Beclin-1 protein, promoting autophagy and PMVEC injury. H/R rat models were established, and in vivo, experiments further confirmed that miR-141-3p regulated autophagy and lung injury in H/R rats through SIRT1/Beclin-1 axis. The current study highlighted that reduced miR-141-3p in H/R-treated PMVECs promoted deacetylation of Beclin-1 by SIRT1, thus causing PMVEC injury.