Knockdown of the long non‑coding RNA MALAT1 ameliorates TNF‑α‑mediated endothelial cell pyroptosis via the miR‑30c‑5p/Cx43 axis

Abstract

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 factor-α (TNF-α)-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)-30c-5p and connexin 43 (Cx43) were assessed using reverse transcription-quantitative PCR (RT-qPCR) and/or western blotting, respectively. The relationships among these molecules were validated by dual-luciferase reporter assays. Biological functions, such as LDH release, pyroptosis-associated protein levels and the proportion of PI-positive 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 up-regulated, whereas miR-30c-5p mRNA expressions levels were significantly decreased in TNF-α-treated RAOEC pyroptosis. Knockdown of MALAT1 or Cx43 significantly attenuated the increase in LDH release, pyroptosis-associated protein expression and PI-positive cell numbers among RAOEC treated using TNF-α, whereas an miR-30c-5p mimic exerted the opposite effect. Furthermore, miR-30c-5p was demonstrated to be a negative regulator of MALAT1 and could also target Cx43. Finally, co-transfection with siMALAT1 and miR-30c-5p inhibitor could attenuate the protective effect of MALAT1 knockdown against TNF-α-mediated RAOEC pyroptosis by upregulation of Cx43 expression. In conclusion, MALAT1 might serve an important role in TNF-α-mediated RAOEC pyroptosis by regulating the miR-30c-5p/Cx43 axis, which would provide a potential novel diagnostic and therapeutic target for AS.

Long non‑coding RNA DANCR aggravates breast cancer through the miR‑34c/E2F1 feedback loop

“…Previous research has indicated that lncRNAs are involved in the epigenetic modification of multiple diseases, including via both transcriptional and post-transcriptional regulation (25,26). Notably, it has been reported that lncRNAs serve a crucial role in the etiology, proliferation, metastasis and recurrence of tumors (27)(28)(29)(30).…”

Identification of a Novel lncRNA LNC_001186 and Its Effects on CPB2 Toxin-Induced Apoptosis of IPEC-J2 Cells

“…For example, Zhang et al [31] found that lncRNA TTTY15 knockdown suppressed hypoxia-induced apoptosis and the dysfunction of mitochondrial energy metabolism in cardiomyocytes in vitro through the let-7i-5p/TLR3/NF-kappa B pathway. Zhang et al [32] demonstrated that the lncRNA MALAT1 attenuated TNF-α-induced endothelial cell pyroptosis through the miR-30c/Cx43 axis.…”

Perspective and Therapeutic Potential of the Noncoding RNA–Connexin Axis

“…Antagomirs to miR-221/222 [ 21 ], miR-205 [ 22 ], and miR-224 [ 27 ] can upregulate Cx43 protein levels in glial cells and have anti-neuroinflammatory potential. Carefully designed siRNAs and antisense oligonucleotides can suppress upstream ncRNAs, such as lncRNA ANRIL [ 61 ] to rescue Cx43 or to reduce Cx43 levels by suppressing lncRNA CCRR [ 44 ] and lncRNA MALAT1 [ 62 ]. More directly, CRISPR-Cas9 technology can be employed to edit ncRNAs, such as lncRNA Pnky, to regulate connexin gene expression.…”