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Hirschsprung disease (HSCR) is a congenital disorder attributed to the failure of the neural crest derivatives migrating and/or differentiating along the hindgut. The most frequent complication in Hirschsprung disease patients is Hirschsprung-associated enterocolitis (HAEC). However, its pathogenesis has not been fully understood. This study investigated miRNAs influenced by Lipopolysaccharide (LPS) in postoperative HAEC patients, their effect on enterocolitis and the underlying mechanism. MiR-132 and miR-212 were up-regulated in HAEC dilated tissues and LPS-treated mice enteritis samples. LPS-stimulated HT29 cells showed a high expression of miR-132 and miR-212. QRT-PCR analysis, western blotting, luciferase reporter assay, and flow cytometric analysis were carried out in vitro, showing that miR-132 and miR-212 could directly inhibit Sirtuin 1 (SIRT1) expression. Consequently, SIRT1 deficiency in LPS-stimulated HT29 cell line and LPS-treated mice activated NLRP3 inflammasome and Caspase-1-mediated pyroptosis. Furthermore, the above inflammation activation was reversed by miR-132/212 inhibitor or SIRT1 overexpression plasmid transfection. In conclusion, LPS upregulated miR-132 and miR-212 expression in HAEC, suppressing SIRT1 and facilitating NLRP3 inflammasome activation, which induced pyroptosis. Our findings illustrated the role of LPS/miR-132/-212/SIRT1/NLRP3 regulatory network in the occurrence and progression of HAEC and proposed a new molecular pathway for LPS-mediated cell pyroptosis.

Previous studies have shown that PCB1254 has an adverse effect on zebrafish retinal development, but the basic mechanism behind it is not clear. The purpose of this study was to investigate the molecular mechanisms of PCB-induced retinal dysplasia. RT-qPCR, immunoblotting, HE staining and immunofluorescence were adopted to detect the expression at mRNA and protein level. Functional experiments were carried out in 661w cells including CCK-8 assay, caspase-3 assay, and the flow cytometry, while the functional role of miR - 20b was further investigated by using the zebrafish model. The result showed that PCB1254 exposure inhibited cell proliferation and increased the apoptosis of the 661w cells, and the dose-response relationship between the retinal development-related genes (SWS1, CRX, Rho), miR-20b expression and PCB1254 exposure was also discovered. We confirmed that miR-20b targeted FGF2 and GRB2 by constructing a dual luciferase reporter gene and suppressed the cell function as well as PCB1254. In the miR-20b overexpression zebrafish model, we found abnormal retinal morphology characterized by sparse and irregular photoreceptor cells and the thick photoreceptor cell layers. Our results demonstrate for the first time that PCBs target the MAPK/ERK signaling through miR-20b, affecting retinal cell development and leading to visual impairment.

Previous studies have shown that PCB1254 has an adverse effect on zebrafish retinal development, but the basic mechanism behind it is not clear. The purpose of this study was to investigate the molecular mechanisms of PCB-induced retinal dysplasia. RT-qPCR, immunoblotting, HE staining and immunofluorescence were adopted to detect the expression at mRNA and protein level. Functional experiments were carried out in 661w cells including CCK-8 assay, caspase-3 assay, and the flow cytometry, while the functional role of miR - 20b was further investigated by using the zebrafish model. The result showed that PCB1254 exposure inhibited cell proliferation and increased the apoptosis of the 661w cells, and the dose–response relationship between the retinal development-related genes (SWS1, CRX, Rho), miR-20b expression and PCB1254 exposure was also discovered. We confirmed that miR-20b targeted FGF2 and GRB2 by constructing a dual luciferase reporter gene and suppressed the cell function as well as PCB1254. In the miR-20b overexpression zebrafish model, we found abnormal retinal morphology characterized by sparse and irregular photoreceptor cells and the thick photoreceptor cell layers. Our results demonstrate for the first time that PCBs target the MAPK/ERK signaling through miR-20b, affecting retinal cell development and leading to visual impairment.