Expression And Significance Of Mitochondrial Transcription Factor A In Hepatocytes Of Infant With Cholestatic Jaundice

Objective: To investigate the expression of mitochondrial transcri ption factor A(mtTFA)in hepatocytes of infant with cholestatic jaundice and explore the possible regulatory mechanism.Methods: The liver samples and clinical data of patients were collected;The cholestatic model of glycochenodeoxycholic acid(GCDCA)-induced human normal hepatocyte(LO2)was constructed;HE staining was used to detect morphological change of the liver;CCK-8showed changes in viability of LO2 treated with different treatment factors;Real-time PCR and qRT-PCR were adopted to detect the mitochondral DNA(mtDNA)copy number,mtDNA transcription level and changes in mRNA levels of mtTFA and silent mating type information regulator 2homolog 1(SIRT1)pathway;IHC was adopted to detect the localization and expression of mtTFA protein;Western blotting showed changes in mtTFA and SIRT1 pathway protein levels.Results: Clinical statistics presented that liver function of the jaundice group was significantly lower than control group(P <0.0001).HE staining showed that the jaundice group had hepatocyte morphology disorder,bile pigmentation and intracellular cholestasis.CCK-8 analysis showed that the activity of LO2 decreased gradually with the increase of GCDCA concentration(P<0.01),and the activity of LO2 increased after SIRT1 agonist activated cholestasis group(P<0.01).The results of Real-time PCR and qRT-PCR demonstrated that the mtDNA copy number and the level of mtDNA transcription of hepatocytes were significantly lower in jaundice group(P<0.01);the mRNA levels of mtTFA,SIRT1 and peroxisome proliferator-activated receptor gamma coactivator-1?(PGC-1?)were significantly decreased in jaundice group(P<0.05);The result of IHC showed that mtTFA was mainly located in the cytoplasm of hepatocytes,and mtTFA was widely expressed in the control group but less in the experimental group.Western blot analysis showed that the levels of the mtTFA and SIRT1 proteins were significantly decreased in jaundice group and GCDCA-induced LO2 than contorls(P<0.001),while PGC-1? was no statistical difference(P>0.05).Treatment of SRT1720 resulted in increased expression level of mtTFA protein(P<0.05).Conclusion: The expression level of mtTFA is obviously decreased in hepatocytes of infant with cholestatic jaundice,and SIRT1 signaling pathway may play a regulatory role in the expression of mtTFA.