Ovariectomy May be Responsible for Subcutaneous Fat Deposition by Altering Hepatic Lipid Metabolism in Female Pigs

Background: Emerging experimental and human evidence has linked decreased ovary-origin hormones and obesity and various metabolic diseases through affecting homeostasis of glucose and lipid metabolism, but the underlying mechanisms remain unclear. Methods: To investigate the effect removal of ovary on the growth and fat deposition of female pigs. In this work, we compared the average backfat thickness, hepatic lipid metabolism indexes and hepatic transcriptome between ovariectomized (OVX) and sham-operated (Sham) female pigs. Result: Results showed that the OVX females had remarkably increased backfat thickness, total cholesterol and triglyceride levels in the liver, whereas serum estradiol levels and hepatic high-density lipoprotein-cholesterol levels presented significantly lower levels compared with those in the sham females. A total of 414 differentially expressed genes (DEGs) identified by transcriptome analysis between the OVX and Sham livers, of which 130 and 314 genes were up-and down-regulated in the OVX livers, respectively. Pathway analysis showed that these DEGs were mainly involved in PPAR signaling pathway, insulin signaling pathway, insulin resistance, hippo signaling pathway. Besides, twelve DEGs involved in glucose and lipid metabolism were screened out, including PCK1, FDPS, HMGCR, HMGCS1, HMGCS2, PPP1R3B, PPP1R3C, ACAT2, SIK1, OGDHL, SOCS2 and IGFBP1. These results indicate that hormones generated by ovaries may play important roles in subcutaneous fat deposition by mediating hepatic glucose and lipid metabolism in female pigs.