Porcine G₀/G₁ Switch Gene 2 (G0S2) Expression is Regulated During Adipogenesis and Short‐Term In‐Vivo Nutritional Interventions

Abstract

Adipose triglyceride lipase (ATGL), catalyzing the initial step of hydrolysis of triacylglycerol (TAG) in adipocytes, has been known to be inhibited by G0/G1 switch gene 2 (G0S2). In this study, we report the porcine G0S2 cDNA and amino acid sequences as well as the expression level of porcine G0S2. The porcine G0S2 mRNA was abundantly expressed in adipose tissue and liver among various tissues. In adipose tissue, porcine G0S2 expression was 16-fold higher in the fat cell fraction than the stromal vascular fraction. The G0S2 level increased significantly during adipogenesis in vitro and in vivo. These data indicate that G0S2 expression is closely associated with lipid accumulation and adipogenesis. Considering G0S2 as an inhibitor of cell proliferation, the relatively low levels of G0S2 in preadipocytes and adipose tissues of fetal and neonatal pigs compared to adipocytes and adipose tissues of adult pigs may allow the fast cell proliferation rates. Further studies showed that a short-term 24-h fast down-regulated G0S2 expression and increased ATGL expression in adipose tissue; however, a long-term calorie restriction for 8 days had no influence on the level of G0S2 but increased ATGL expression. Therefore, porcine G0S2, which is both a negative regulator of ATGL-mediated lipolysis and cell proliferation in adipose tissue, can be down-regulated in vivo by a short-term 24-h fast followed by increased ATGL-mediated lipolysis.

Defective Adipose Lipolysis and Altered Global Energy Metabolism in Mice with Adipose Overexpression of the Lipolytic Inhibitor G0/G1 Switch Gene 2 (G0S2)

“…The mechanism by which G0S2 increases lipid content in adipocytes and promotes adipocyte hypertrophy is presumably through the restriction of TG turnover. Although G0S2 expression has been shown previously to increase during both TG accumulation and adipogenesis (29,30), changes in fat mass seen in aP2-G0S2 mice are more characteristic of increased adipocyte size.…”

Dissecting adipose tissue lipolysis: molecular regulation and implications for metabolic disease

“…4C; Yang et al 2010). Notably, G0S2 protein and mRNA expression is dramatically reduced in human AT by prolonged physiological stimulation of lipolysis with a 72-h fast (Nielsen et al 2011) and similar effects have been observed in birds (Oh et al 2011) and pigs (Ahn et al 2013). However, it is currently not known if the association between ATGL and G0S2 is dynamic and subject to regulation or if G0S2-mediated ATGL inhibition primarily depends on the intracellular levels of G0S2.…”

Inhibition of Lipolysis in the Novel Transgenic Quail Model Overexpressing G0/G1 Switch Gene 2 in the Adipose Tissue during Feed Restriction

“…Another regulator of ATGL is the G 0 /G 1 switch gene 2 (G0S2), which was recently identified as an inhibitor of ATGL in 3T3-L1 adipocytes [3]. Comparative analysis of G0S2 amino acid sequences among animals and humans revealed a conservation of the hydrophobic domain, which is required for binding directly to the patatin domain of ATGL [3], [13], [14]. Similar to ATGL, G0S2 expression is mainly found in adipose tissues and is greatly up-regulated during preadipocyte differentiation in humans, mice, pigs, and avian species [3], [13]–[17].…”