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]

Brown adipocytes have an important role in the regulation of energy balance through uncoupling protein‐1 (UCP‐1)‐mediated nonshivering thermogenesis. Although brown adipocytes have been highlighted as a new therapeutic target for the treatment of metabolic diseases, such as obesity and type 2 diabetes in adult humans, the molecular mechanism underlying brown adipogenesis is not fully understood. We recently found that protein tyrosine phosphatase receptor type B (PTPRB) expression dramatically decreased during brown adipogenic differentiation. In this study, we investigated the functional roles of PTPRB and its regulatory mechanism during brown adipocyte differentiation. Ectopic expression of PTPRB led to a reduced brown adipocyte differentiation by suppressing the tyrosine phosphorylation of VEGFR2, whereas a catalytic inactive PTPRB mutant showed no effects on differentiation and phosphorylation. Consistently, the expression of brown adipocyte‐related genes, such as UCP‐1, PGC‐1α, PRDM16, PPAR‐γ and CIDEA, were significantly inhibited by PTPRB overexpression. Overall, these results suggest that PTPRB functions as a negative regulator of brown adipocyte differentiation through its phosphatase activity‐dependent mechanism and may be used as a target protein for the regulation of obesity and diabetes. Support or Funding Information This work was supported by grants from the KRIBB and from the Research Program (grants 2016R1C1B2013430, 2015M3A9B5030308, 2015M3A7B6027948, and 2015M3A9D7029882) through the National Research Foundation of Korea. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.