Effect And Its Mechanism Of MiRNA-1 On Hepatocyte Injury Under Intermittent Hypoxia

OBJECTIVE: OSAHS(sleep apnea hypopnea syndrome)is a common and frequently-occurring disease.It is also one of the hotspots in the research of respiratory diseases in recent years.Its pathophysiological characteristics are due to airway collapse and airflow limitation during sleep.It causes repeated intermittent hypoxia and sleep fragmentation,which leads to changes in neuromodulation,endocrine dysfunction,hemodynamic changes and microcirculation abnormalities,which ultimately leads to functional damage of multiple systemic systems.The main feature of OSAHS is intermittent hypoxia,which is a hypoxic sensitive organ.Sustained severe hypoxia or ischemia can lead to hypoxic hepatitis.Severe hypoxia or ischemia can lead to apoptosis of liver cells.Studies have shown that MiRNA-1 is a highly correlated factor of apoptosis,and our previous experiments have also shown that MiRNA-1 may be associated with apoptosis.Therefore,this article focuses on the effects of MiRNA-1 on hepatocyte injury after intermittent hypoxia-stimulated hepatocytes,and explores its related mechanisms from the perspective of hepatocyte apoptosis to discover a new approach to the treatment of OSAHS liver injury.METHODS: Rats were randomly divided into intermittent hypoxia group and normoxia group.After 8 weeks of intermittent hypoxia treatment,rat liver tissues were taken for HE staining and TUNEL staining,and Western blot was used to detect apoptosis-related protein expression.Realtime-The amount of MiRNA-1 expression was detected by PCR.The intermittent hypoxia model of liver LO-2 cells was constructed.The expression of MiRNA-1 and apoptosis-related genes were detected by Realtime-PCR.The expression of apoptosis-related proteins was detected by Western Blot.Apoptosis was detected by flow cytometry.Cell proliferation was detected by MTT.The intermittent hypoxia model of hepatic LO-2 cells knockdown MiRNA-1 was constructed.The knockdown efficiency and expression of apoptosis-related genes were detected by Realtime-PCR.The expression of apoptosis-related proteins was detected by Western Blot.Flow cytometry was performed.Apoptosis,MTT assay for cell proliferation.RESULTS: HE staining experiments showed that the structure of the portal group in the intermittent hypoxia group was disordered and the inflammatory cells were aggregated(P<0.05).TUNEL experiments showed that hepatocyte apoptosis was increased in the intermittent hypoxia group compared with the normoxia group(P<0.05).Rat liver Realtime-PCR results showed that the intermittent hypoxia group was significantly up-regulated compared with the normoxia group(P<0.05).The results of Western Blot in rat liver showed that the expression of Bax,Caspase3 and Caspase9 in the hypoxic group was significantly up-regulated(P<0.05),and the expression of anti-apoptotic protein Bcl-2 was down-regulated(P<0.05).The results of Realtime-PCR of liver LO-2 cells showed that the microRNAs in the intermittent hypoxia group were significantly up-regulated compared with the normoxia group(P<0.05);the expressions of apoptosis-related genes Bax,Caspase3 and Caspase9 were significantly up-regulated(P<0.05);The expression of the apoptotic gene Bcl-2 was significantly down-regulated(P<0.05).The results of Western Blot of liver LO-2 cells showed that the expression of Bax,Caspase3 and Caspase9 in the hypoxic group was significantly up-regulated(P<0.05),and the expression of anti-apoptotic protein Bcl-2 was down-regulated(P< 0.05).MTT experiments showed that hepatocyte proliferation was inhibited in the intermittent hypoxia group compared with the normoxia group.Flow cytometry experiments showed that the apoptosis rate of hepatocytes in the intermittent hypoxia group was significantly higher than that in the normoxia group(P<0.05).MTT assay after MiRNA-1 knockdown showed that the proliferation ability of MiRNA-1 knockdown was significantly increased(P<0.05).Flow cytometry experiments showed that the apoptosis ability of MiRNA-1 knockdown cells decreased significantly(P< 0.05).Western Blot results showed that the expression of proapoptotic and apoptosis-related proteins Bax,Caspase3 and Caspase9 were down-regulated after MiRNA-1 knockdown(P<0.05);the expression of anti-apoptotic protein Bcl-2 was significantly up-regulated(P<0.05)..Realtime-PCR results showed that the expression of apoptosis-inducing genes and apoptosis-related genes Bax,Caspase3 and Caspase9 were down-regulated after MiRNA-1 knockdown(P<0.05);the expression of anti-apoptotic gene Bcl-2 was significantly up-regulated(P<0.05).Conclusion:(1)Intermittent hypoxia can induce the increase of MiRNA-1expression in the liver.(2 MiRNA-1 may control the apoptosis of liver cells under intermittent hypoxia by regulating the balance of Bax/Bcl-2 and up-regulating the expression of Caspase-3 and Caspase-9 proteins,thereby causing liver damage and hepatocyte proliferation.decline.(3)After MiRNA-1 knockdown,the apoptosis of liver cells was reduced under intermittent hypoxia,and the cell proliferation ability was restored.The apoptosis of hepatocytes caused by intermittent hypoxia and the decrease of hepatocyte proliferation ability of MiRNA-1.