Involvement of protein tyrosine phosphatases in adipogenesis: New anti-obesity targets?

Abstract

Obesity is a worldwide epidemic as well as being a major risk factor for diabetes, cardiovascular diseases and several types of cancers. Obesity is mainly due to the overgrowth of adipose tissue arising from an imbalance between energy intake and energy expenditure. Adipose tissue, primarily composed of adipocytes, plays a key role in maintaining whole body energy homeostasis. In view of the treatment of obesity and obesity-related diseases, it is critical to understand the detailed signal transduction mechanisms of adipogenic differentiation. Adipogenic differentiation is tightly regulated by many key signal cascades, including insulin signaling. These signal cascades generally transfer or amplify the signal by using serial tyrosine phosphorylations. Thus, protein tyrosine kinases and protein tyrosine phosphatases are closely related to adipogenic differentiation. Compared to protein tyrosine kinases, protein tyrosine phosphatases have received little attention in adipogenic differentiation. This review aims to highlight the involvement of protein tyrosine phosphatases in adipogenic differentiation and the possibility of protein tyrosine phosphatases as drugs to target obesity. [BMB Reports 2012; 45(12): 700-706]

Phosphoprotein phosphatase 1CB (PPP1CB), a novel adipogenic activator, promotes 3T3-L1 adipogenesis

“…The differentiation of preadipocytes into mature fat cells is regulated by a highly orchestrated gene An increasing number of obesity studies have reported the involvement of several types of protein phosphatases in adipogenesis, including serine/threonine and tyrosine phosphatases [16], and they are increasingly considered as biochemical "on" or "off" switches and key regulators in intracellular signaling cascades during adipogenic differentiation [16]. To date, it has been shown that several protein phosphatases are up-regulated in and promote adipocyte differentiation [17].…”

Set7/9, a methyltransferase, regulates the thermogenic program during brown adipocyte differentiation through the modulation of p53 acetylation

“…There are two distinct types of adipocytes, white and brown adipocytes, which have opposite functions with regard to the energy balance (Bae et al, 2012;Kim et al, 2015a). White adipocytes store excess energy as triglycerides in lipid droplets, whereas brown adipocytes release energy in the form of heat through thermogenesis.…”

Distinction of white, beige and brown adipocytes derived from mesenchymal stem cells

“…Adipose tissue, which is composed mostly of adipocytes, is a major endocrine organ and plays a key role in energy homeostasis. Two types of adipose tissue, white adipose tissue (WAT) and brown adipose tissue (BAT), have been identified [1] . In practice, obesity does not depend on body weight but depends on either the number of white adipocytes or the amount of WAT.…”