分子途径mTORC1控制脂肪的转换

Scientists have reported that a molecular¹ pathway called mTORC1 controls the conversion² of unhealthy white fat into beige（浅褐色的） fat, an appealing target for increasing energy expenditure³ and reducing obesity⁴. The team, led by researchers from the School of Medicine at The University of Texas Health Science Center at San Antonio, also found that a protein, Grb10, serves as the on-off switch for mTORC1 signaling and the "beigeing" of fat. The finding could inform development of novel diabetes⁵ and obesity drugs, the scientists said. The study is reported in this month's issue of Cell Metabolism⁶ and was selected as the highlighted featured article. Heat in response to cold   Grb10 is stimulated⁷ by cold stress, which causes the body to burn energy. ""We know that if we want to keep our body lean, we have to get rid of extra nutrients⁸ in the body, which means burning more energy," said senior author Feng Liu, Ph.D., professor of pharmacology at the UT Health Science Center and director of the Metabolic⁹ Syndrome¹⁰ Research Center at Xiangya Second Hospital, Central South University, in Changsha, China.   "Understanding how beigeing is controlled is so very important because if we can improve energy expenditure, we can reduce obesity," Dr. Liu said.   Undesirable¹¹ storage   Adipose¹² (fat) tissues, which include white adipose tissue（白色脂肪组织） and brown adipose tissue, are important regulators of metabolism. Having too much white adipose tissue and not burning it off through exercise or other energy expenditure is associated with obesity and metabolic diseases such as type 2 diabetes.   "Normally when we eat something, we store it in white fat," said co-author Lily Dong, Ph.D., professor of cellular¹³ and structural¹⁴ biology at the UT Health Science Center. "For the extra food we eat, it is better to release it, not store it. So finding a way to turn the white fat into beige and burn the energy that normally we store would have high therapeutic¹⁵ potential for the treatment of obesity and its related diseases. Dr. Liu has identified the pathway to do this."   Broader application   The mTORC1 pathway is also involved in aging, cardiovascular disease and cancer, so identifying the regulator of this pathway, Grb10, should be very informative¹⁶ for researching other fields, Dr. Liu said.   Drs. Liu and Dong also are members of the Health Science Center's Barshop Institute for Longevity#p#分页标题#e#¹⁷ and Aging Studies.