Effects Of LSD1 On Renal Fibrosis After Acute Kidney Injury

Objective: To investigate the protective role of LSD1(histone lysine specific demethylation enzyme 1)in the development of renal fibrosis after acute kidney injury(AKI).Methods: 30 SD rats were randomly divided into six groups: the control group,the AKI 1-day group,the AKI 1-week,2-week group,4-week and 8-week groups,with 5 in each group;the control group of SD rats underwent the resection of left kidneys,right kidneys without any treatment;for the AKI 1-day,1-week,2-week,4-week and 8-week groups SD rats,after the left kidneys were excised,the right kidneys pedicles were clipped for 40 minutes,after 1day,1 week,2 weeks,4 weeks and 8 weeks,the rats were sacrificed and the kidneys were harvested respectively.The human renal tubular epithelial cells(HK-2)were divided into control group,AKI group,AKI+empty plasmid group,AKI+LSD1 overexpression group.Control group: normal cultured HK-2 cells;AKI group: HK-2 cells were anaerobic cultured for 12 hours and then normal cultured for 1 hours;AKI+ empty plasmid group: HK-2 cells transfected with blank plasmid were anaerobic cultured for 12 hours and then normal cultured for 1 hours;AKI+LSD1 overexpression group: HK-2 cells transfected with LSD1 plasmid were anaerobic cultured for 12 hours and then normal cultured for 1 hours;the expression of LSD1,H3K4me1,H3K4me2,TGF-?1 and fibrosis markers were detected by PCR and Western blotting in each group;Chromosomal immunoprecipitation(Ch IP)technique was applied to detect the expression of H3K4me1 and H3K4me2 on the promoter of TGF-?1 in HK-2 cells,and to explore the specific mechanism of LSD1 on renal fibrosis.Results: In animal experiments,compared with the control group,fibrosis indexes Col3?1??-SMA of AKI 1-week,2-week,4-week and 8-week groups were higher(P < 0.05),TGF-?1,LSD1 and H3K4 methylation marker H3K4me1 expression were increased(P < 0.05)also,H3K4me2 only increased in AKI 2-week and 4-week groups and there was no significant differences between AKI 1-day and control group(P > 0.05);In cell experiments,compared with group AKI and AKI+ empty plasmid group,fibrosis indexes Col3?1 and ?-SMA decreased significantly,TGF-?1,H3K4me1 and H3K4me2 expression decreased in AKI+LSD1 overexpression group(all P < 0.05);In cell experiments,compared with the control group,the expression of H3K4me1 and H3K4me2 increased on TGF-?1 promoter in AKI group and AKI+ plasmid group(P < 0.05).Compared with AKI group and AKI+ plasmid group,the expression of H3K4me1 and H3K4me2 on TGF-?1 promoter in AKI+LSD1 overexpression group was decreased(P < 0.05).Conclusions: LSD1 plays a protective role in renal fibrosis after AKI by inducingdemethylation of H3K4me1 and H3K4me2 to decrease the expression of TGF-?1.