ZENG Haiwen, XU Jisong, SU Wanting, CHEN Yazheng
Abstract (
)
Download PDF (
)
Knowledge map
Save
Objective To examine the impact of LncRNA KCNQ1OT1 on acute lung injury (ALI) in septic mice by targeting the miR-34a/SIRT1 axis. Methods The HSAEC cells were assigned to the control group or LPS group (treated with 10 mg/L LPS for 24 hours). RT-qPCR was used to detect the levels of LncRNA KCNQ1OT1, miR-34a and SIRT1 mRNA in the cells. The dual luciferase reporter assay and RNA pull-down assay were used to detect the targeting relationship between LncRNA KCNQ1OT1/SIRT1 and miR-34a. The experimental mice were randomly assigned to the control group, model group, NC group, KCNQ1OT1 group, KCNQ1OT1 + NC group, and KCNQ1OT1 + miR-34a group. Except for the control group, all the mice in other groups were induced to develop sepsis-induced ALI models by intraperitoneal injection of 10 mg/kg LPS. RT-qPCR was used to detect the levels of LncRNA KCNQ1OT1, miR-34a, SIRT1 mRNA, TNF-α mRNA, IL-6 mRNA, IL-1β mRNA, caspase-3 mRNA and Bax mRNA in lung tissue. ELISA was used to measure the levels of inflammatory factors in lung tissue. The lung wet/dry weight ratio (W/D ratio) was measured in each group of mice. HE staining was used to observe the pathological changes of the lung tissue. TUNEL staining was used to observe the apoptosis of lung tissue cells. Western blot was used to detect the level of apoptosis-related proteins. Results Cell experiments revealed that compared with the control group, the levels of LncRNA KCNQ1OT1 and SIRT1 mRNA decreased, while the level of miR-34a increased significantly in LPS group (P < 0.05). The dual luciferase reporter assay and RNA pull-down experiment revealed that there were targeting relationships between LncRNA KCNQ1OT1/SIRT1 and miR-34a. Animal experiments revealed that compared with the control group, the alveoli of mice collapsed, the number of alveoli decreased, and the alveoli and pulmonary interstitium were congested and edematous in the model group. The alveoli were infiltrated by a large number of inflammatory cells, associated with punctate or patchy hemorrhagic foci. The levels of LncRNA KCNQ1OT1 and SIRT1 mRNA decreased, while the level of miR-34a, mRNA levels of TNF-α, IL-6, and IL-1β, protein level of TNF-α, IL-6, and IL-1β, mRNA and protein levels of caspase-3 and Bax, W/D ratio, apoptosis rate and protein level of C-caspase-3 increased significantly (P < 0.05). Compared with the NC group, the pathological damage of lung tissue in the KCNQ1OT1 group improved significantly. The levels of LncRNA KCNQ1OT1 and SIRT1 mRNA increased, while the level of miR-34a, mRNA levels of TNF-α, IL-6, and IL-1β, protein level of TNF-α, IL-6, and IL-1β, mRNA and protein levels of caspase-3 and Bax, W/D ratio, apoptosis rate and protein level of C-caspase-3 decreased significantly (P < 0.05). Compared with the KCNQ1OT1 + NC group, the pathological damage of lung tissue was more severe in the KCNQ1OT1 + miR-34a group. The SIRT1 mRNA level was lower, and the level of miR-34a, mRNA and protein levels of TNF-α, IL-6, and IL-1β, mRNA and protein levels of caspase-3 and Bax, W/D ratio, apoptosis rate and protein level of C-caspase-3 all increased significantly (P < 0.05). Conclusions LncRNA KCNQ10T1 can improve ALI in septic mice, probably by targeted inhibition of the miR-34a/SIRT1 axis.
