Knockdown of long noncoding RNA growth arrest-specific transcript 5 regulates forkhead box O3 to inhibit lipopolysaccharide-induced human bronchial epithelial cell pyroptosis.

Pyroptosis is a novel proinflammatory programmed cell death process. This study was designed to investigate the functional mechanisms of long noncoding RNA growth arrest-specific transcript 5 (lncRNA GAS5) on lipopolysaccharide (LPS)-induced human bronchial epithelial cell (HBEC) pyroptosis. LPS was used to induce pyroptosis in HBECs, followed by the detection of the expression of GAS5, forkhead box O3 (FOXO3), and nuclear factor E2-related factor 2/heme oxygenase 1 (Nrf2/HO-1) signaling pathway-related factors. Cell viability was evaluated using CCK-8 assay, lactate dehydrogenase (LDH) release was assessed by LDH assay kit and caspase-1 activity by flow cytometry. Furthermore, expression of NOD-like receptor family pyrin domain containing 3 and pyroptosis-related proteins was evaluated using Western blot analysis, while enzyme-linked immunosorbent assay was used to determine the levels of inflammatory factors. The interaction between GAS5 and FOXO3 was confirmed using bioinformatic prediction, RNA immunoprecipitation assay, RNA pull-down, and dual-luciferase reporter gene assay. Treatment of HBECs with LPS upregulated the expression of GAS5 and FOXO3, resulting in the inactivation of the Nrf2/HO-1 signaling pathway. On the other hand, inhibition of both GAS5 and FOXO3 promoted cell viability, reduced LDH release, pyroptosis, and inflammatory response in LPS-induced HBECs. Furthermore, FOXO3 could interact with GAS5, while FOXO3 overexpression reversed the inhibitory effect of GAS5 knockdown on cell pyroptosis. Thus, mechanistically, inhibition of FOXO3 activates the Nrf2/HO-1 pathway to suppress LPS-induced pyroptosis in HBECs. This study revealed that GAS5 knockdown attenuates FOXO3 expression thereby activating the Nrf2/HO-1 pathway to inhibit LPS-induced pyroptosis in HBECs. These findings may contribute to identifying novel targets that inhibit pyroptosis in HBECs.

LncRNA SNHG1 regulates vascular endothelial cell proliferation and angiogenesis via miR-196a.

Inflammatory cytokines are important protagonists in the formation of atherosclerotic plaques, triggering effects throughout the atherosclerotic vessels due to the destruction in proliferation, migration and angiogenesis of endothelial cells. In this study, we found SNHG1 is upregulated in TNF-α-treated HUVECs. We silenced SNHG1 and found it inhibited vascular endothelial cell proliferation and angiogenesis. In the other hand, exogenetic overexpression of SNHG1 promotes proliferation, migration and angiogenesis. Then we demonstrated that SNHG1 may interact directly with miR-196a to act as a miR-196a sponge. Further, MAPK6 were predicted to be the target of miR-196a. So we blocked miR-196a, which increased expression level of MAPK6, enhanced cell proliferation, migration and angiogenesis. These data indicated that SNHG1/miR-196a/MAPK6 axis may take a part in autophagy regulation in TNF-α-treated HUVECs. The subsequent rescue experiments come to the results ascertained the specificity of SNHG1/miR-196a/MAPK6 axis in regulating MAPK6. Overall, our findings demonstrate a novel mechanism by which SNHG1 overexpression protects the function of HUVECs, which may delay the progression of AS. SNHG1/miR-196a/MAPK6 axis may be of therapeutic significance in AS.