Changes in metabolic capacity and gene expression of brown adipose tissue in the first and third trimester of pregnancy / 中华内分泌代谢杂志

ABSTRACT

Objective:To explore gene expression and metabolic capacity changes of brown adipose tissue(BAT)during different gestation periods.Methods:A normal pregnancy model was established using C57BL/6J mice, while infertile mice of the same age were served as the control group. The morphological alteration of BAT during pregnancy as well as the gene expression of uncoupling protein 1(UCP1) and other fat browning and mitochondrial marker genes were detected. Moreover, BATs from early and late gestation were selected to screen differentially expressed genes in relation to pregnancy progressing by RNA sequencing(RNA-seq), and gene ontology(GO) and Kyoto gene and gene sequencing(KEGG)were performed.Results:With pregnancy progressing, the size of BAT lipid droplets was substantially enlarged, UCP1 protein expression was decreased( P<0.01), and the fat browning marker genes(Ucp1, Dio2, and Pgc1α)and the mitochondrial marker gene CytC were downregulated( P<0.001). Additionally, a total of 1 298 distinct genes were identified by RNA-seq, 906 of which were upregulated and 392 were downregulated at later stage of pregnancy. GO and KEGG analyses revealed that the differentially expressed genes were mainly enriched in bioregulatory functional pathways such as lipid metabolism, sex steroid hormones, and inflammatory factors. Conclusion:BAT in mice showed larger lipid droplets and reduced thermogenic and metabolic capacity during late gestation, and BAT gene expression was significantly different in different periods of gestation, so reduced metabolic capacity of BAT may contribute to metabolic abnormality during pregnancy.