RESUMO
Long noncoding RNAs (lncRNAs) are related to the development of atherosclerosis (AS). However, the role of lncRNA metastasis associated lung adenocarcinoma transcript 1 (MALAT1) in tumor necrosis factorα (TNFα)induced rat aortic endothelial cell (RAOEC) pyroptosis, as well as the underlying mechanisms, remain unclear. RAOEC morphology was assessed using an inverted microscope. The mRNA and/or protein expression levels of MALAT1, microRNA(miR)30c5p and connexin 43 (Cx43) were assessed using reverse transcriptionquantitative PCR (RTqPCR) and/or western blotting, respectively. The relationships among these molecules were validated by dualluciferase reporter assays. Biological functions, such as LDH release, pyroptosisassociated protein levels and the proportion of PIpositive cells, were evaluated using a LDH assay kit, western blotting and Hoechst 33342/PI staining, respectively. The present study demonstrated that compared with the control group, the mRNA expression levels of MALAT1 and protein expression levels of Cx43 were significantly upregulated, whereas miR30c5p mRNA expressions levels were significantly decreased in TNFαtreated RAOEC pyroptosis. Knockdown of MALAT1 or Cx43 significantly attenuated the increase in LDH release, pyroptosisassociated protein expression and PIpositive cell numbers among RAOEC treated using TNFα, whereas an miR30c5p mimic exerted the opposite effect. Furthermore, miR30c5p was demonstrated to be a negative regulator of MALAT1 and could also target Cx43. Finally, cotransfection with siMALAT1 and miR30c5p inhibitor could attenuate the protective effect of MALAT1 knockdown against TNFαmediated RAOEC pyroptosis by upregulation of Cx43 expression. In conclusion, MALAT1 might serve an important role in TNFαmediated RAOEC pyroptosis by regulating the miR30c5p/Cx43 axis, which would provide a potential novel diagnostic and therapeutic target for AS.