Protein molecules that help maintain a healthy body temperature, electrolyte balance, respiration, heart rate, and other critical functions, also appear to regulate weight and fertility, according to Yale researchers. STAT3 proteins are regulatory molecules that signal cell functions for activating genes. When the STAT3 molecules are disrupted in mice, the animals either die before they are born, or overeat and become obese, diabetic and infertile, according to the study published in the Proceedings of the National Academy of Sciences. Mice with disrupted STAT3 begin to gain weight at six to eight weeks old and weigh twice as much as normal mice by adulthood. The excess body mass was almost exclusively fat. Livers of the mice also were severely enlarged with fat deposits. The senior author, Xin-Yuan Fu, of the Department of Pathology at Yale School of Medicine, said the study contradicts previous research that concluded STAT3 plays no role in reproduction and growth and only a marginal role in glucose regulation.
