ABSTRACT
Objective To investigate the effect of high fat diet feeding on mitochondrial structure and function. Methods Male C57BL/6J mice at the age of 4 weeks were used in this study. After 6 weeks of regular diet(RD)or high-fat diet(HF)feeding, the high fat-induced obesity phenotype was confirmed by body weight measurement and liver histopathology. RNA was isolated from the liver tissue of RD and HF mice and the expression profiles were detected using RNA-seq. Differentially expressed genes between RD and HF mice were analyzed using BRB-ArrayTools. DAVID online tools were applied to analyze the GO and KEGG pathways. Transmission electron microscopy and western blotting were performed to observe the mitochondrial ultrastructure and quantified the expression of function-related proteins. Results Compared with the RD mice,the body weight gain was faster in the HF mice. The size of the lipid droplets was bigger in the HF-fed mouse liver tissue. Multiple pathway analysis all identified that these major gene changes were related to mitochondria. The mitochondrial deformation,enlarged or even destruction was observed in the high fat diet group observed by transmission electron microscopy. This observation was further confirmed by detecting of the expression of genes in the HF liver mitochondria. The levels of MFN1 and PHB1 were significantly increased, while the level of FKBP51 was significantly decreased. Conclusions FKBP51 is involved in the high-fat-induced mitochondrial damage via morphological and structural damages of mitochondria.
ABSTRACT
Objective To study the function of Fkbp51 in the heart and liver by analyzing the differential RNA expression profiles in the wild-type mice (WT) and Fkbp51 knockout (KO) mice, and to elucidate the role of Fkbp51 gene in metabolic pathways in the heart and liver.Methods Using the second generation of high-throughput gene sequencing technology, the mRNA expression profiles of heart and liver were sequenced in WT and Fkbp51 KO mice.The data of sequencing of heart tissues were analyzed by DEGseq, and the results of sequencing of liver tissues were analyzed by BRB-Array Tools.The differential genes of the heart and liver in the mice were screened respectively.Gene ontology (GO) analysis and KEGG pathway analysis were performed to analyze the differentially expressed genes using the online tool DAVID.In addition, the differential genes of the two organ tissues were analyzed by Venn diagram.The interaction network of proteins was analyzed using the STRING database.Results (1) The absence of Fkbp51 led to changes in mRNA expressions of heart-related signal pathways such as vascular smooth muscle contraction, chemokine, retinol, and MAPK signaling pathways.(2) The lack of Fkbp51 mostly induced changes in cholesterol synthesis and metabolism, lipid metabolism, redox and other related genes and pathways in the liver.(3) In the heart and liver, Fkbp51 deletionresult ed in four co-differential genes, among them, down-regulation of Rnaset2b, Hmga1 and Fkbp51, while Cyp2b10 was down-regulated in the heart but up-regulated in the liver.All these proteins may interact with HSP90 protein and participat in the metabolism of heart and liver tissues.Conclusions Fkbp51 is involved in different metabolic and gene expression regulation pathways of heart and liver, and the roles are both independent and interrelated.
ABSTRACT
Objective The goal of this study is to understand the function of FKBP51 in resistant to high fat diet-induced obesity using FKBP51 knockout ( KO) mice and in vitro adipocyte differentiation.Methods Four-week old male FKBP51 KO and wild type ( WT) mice were fed separately with regular or high fat diet for 6 weeks.The body weight and food consumption were recorded weekly, the energy expenditure differences ( O2 consumption, CO2 production, respiratory exchange ratio, and heat production) of each group were monitored using the MM-100 metabolism cages system for 24 hours, then the liver from the above animals were stained with the Oil red-O to detect the lipid accumulation and the expression of metabolic genes.In addition, induction of adipocyte differentiation of immortalized MEF cells from WT and FKBP51 KO mice were used to observe the effect of FKBP51 gene on lipogenesis.Results Compared to WT mice, FKBP51 KO mice has less weight increment, and less lipid accumulation in the liver, but with no difference on food consumption during high-fat diet fed.Moreover, FKBP51 KO mice exhibited more O2 consumption, CO2 production and heated production under both RD and HF diet conditions.The PEPCK, G6Pase and UCP-1 genes up-regulation.In addition, lipid content was reduced in FKBP51 gene deficient MEF cells after adipocyte differentiation.Conclusions The FKBP51 gene plays an important role in high fat diet-induced obesity through the energy metabolism enhancement and lipogenesis inhibition.