Leptin and Insulin Act on POMC Neurons to Promote the Browning of White Fat (Cell. 2015 Jan 15;160(1-2):88-104.)

報告日期: 2015/11/20
報告時間: 3:10/4:00
報告學生: 阮瀞萱
講評老師: 蔡耀聲
附件下載: 下載[1525-1443055285-1.pdf] 

Leptin And Insulin Act On POMC Neuron To Promote The Browning Of White Fat

Cell(2015)160: 88-104

Speaker: Jing-Syuan Ruan

Commentator: Dr. Yau-Sheng Tsai

Date: 3:00-3:50 pm, Friday, November 20, 2015

Place: Room 602

Abstract

In mammals, there are two major types of adipose tissue could be found: white adipose tissue (WAT) and brown adipose tissue (BAT). WAT is responsible for energy storage. In contrast, BAT contains substantial uncoupling protein-1 (UCP-1) in mitochondria which can dissipate the stored energy to generate heat without ATP production. Therefore, BAT has been considered an attractive target to promote weight loss. Interestingly, ’beige’ adipocytes can develop in WAT to increase UCP-1 mediated thermogenesis and energy expenditure in response to various activators. Many genes and pathways that regulate brown and beige adipocyte biology have now been identified, providing a variety of promising therapeutic targets for metabolic disease. To date, the studies on WAT browning still limited to factors that directly promote the development of beige preadipocytes, but the connections between WAT browning and central nervers system (CNS) is still undiscovered. The author identified that the two peripheral factors, insulin and leptin, and their signaling can be sensitized in hypothalamic proopiomelanocortin (POMC) neurons by deletion two phosphatases: TCPTP and PTP1B respectively. Moreover, double knockout of phosphatases TCPTP and PTP1B enhances both insulin and leptin mediated signaling in POMC neurons that promote WAT browning through sympathetic innervations and then increase energy expenditure and prevent diet-induced obesity. Taken together, this study provides an insight into energy homeostasis mechanism of the synergistic effect of insulin and leptin on WAT browning controlled by CNS and may be applied to combat obesity.

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