LncRNA OIP5-AS1 knockdown or miR-223 overexpression can alleviate LPS-induced ALI/ARDS by interfering with miR-223/NLRP3-mediated pyroptosis.

Abstract

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are life-threatening diseases and endothelial barrier injury is an important contributor to the pathogenesis of ALI/ARDS. Long non-coding (lncRNA) has been shown to participate in the progression of ALI/ARDS. The present study aimed to investigate the function of lncRNA opa-interacting protein 5 antisense RNA 1 (OIP5-AS1) in lipopolysaccharide (LPS)-induced ALI/ARDS. OIP5-AS1 and miR-223 levels were detected by a polymerase chain reaction in the serum of ALI/ARDS patients or healthy donors. An 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay was performed to detect the proliferation of human pulmonary microvascular endothelial cells (HPMECs). Flow cytometry were performed to detect the apoptosis of HPMECs. The protein levels of NLRP3, ASC, GSDMD-N and caspase-1 were measured by western blotting to detect the pyroptosis of HPMECs. Interleukin (IL)-1β, IL-6, IL-18 and IL-10 were detected by an enzyme-linked immunosorbent assay to measure the inflammatory response of HPMECs. The production of reactive oxygen species, superoxide dismutase and malondialdehyde was measured to determine the oxidative stress of HPMECs. Targets of OIP5-AS1 and miR-223 were predicted by StarBase and confirmed by a dual-luciferase reporter assay. We found that OIP5-AS1 was up-regulated and miR-223 was down-regulated in the serum of ALI/ARDS patients and LPS-treated HPMECs. Functionally, knockdown of OIP5-AS1 induced proliferation and inhibited apoptosis, pyroptosis, inflammatory response and oxidative stress of LPS-treated HPMECs. Interestingly, miR-223 was a target of OIP5-AS1 and miR-223 inhibition abolished the effects of si-OIP5-AS1 on LPS-induced HPMECs. More importantly, miR-223 directly targeted NLRP3, and miR-223 overexpression promoted proliferation and inhibited apoptosis, pyroptosis, inflammatory response and oxidative stress of LPS-treated HPMECs, with this being abolished by NLRP3 overexpression. Finally, we found that OIP5-AS1 knockdown and miR-223 overexpression could both alleviate LPS-induced ALI/ARDS in vivo. Taken together, we find that lncRNA OIP5-AS1 aggravates LPS-induced ALI/ARDS via miR-223/NLRP3 axis and provides new targets for ALI/ARDS therapy.