TPT1 promotes the adipogenic differentiation of stromal vascular fractions via the PI3K/AKT pathway and FOXO1 in sheep

ABSTRACT The functions of tumour protein, translationally controlled 1 (TPT1), have been extensively researched in various cell types. Although TPT1 was reported to have accelerating effects on the lipid deposition of mouse hepatocytes, and the activation roles in phosphatidylinositol 3 kinase (PI3K/AKT) pathway, its role in the differentiation of ovine stromal vascular fractions (SVFs) and their underlying mechanisms have not been addressed. Therefore, the objective of this study was to explore whether TPT1 participates in the adipogenic differentiation regulation of ovine SVFs and the underlying mechanisms. The results from this study revealed that TPT1 was abundant in the tail fat of sheep and the protein was located in the nucleus of C3H10T1/2 cell line and ovine SVFs. Moreover, TPT1 expression was up-regulated during the adipogenic differentiation of SVFs. The overexpression of TPT1 dramatically accelerated the adipogenic differentiation of SVFs, accompanied by the up-regulation of adipogenic marker genes, while TPT1 inhibition had opposite effects. TPT1 also had a negative effect on forkhead box O1 (FOXO1). The PI3K/AKT pathway was involved in the promotion of adipogenesis induced by overexpressing TPT1. We concluded that TPT1 promotes the adipogenic differentiation of ovine SVFs through PI3K/AKT-dependent pathway and attenuates the expression of FOXO1 in ovine SVFs.