The adipose-derived hormone, leptin, acts via its receptor (LRb) to convey the status of body energy stores to the brain, decreasing feeding and potentiating neuroendocrine energy expenditure. The failure of high levels of leptin in most obese individuals to promote weight loss defines a state of diminished responsiveness to increased leptin, termed leptin resistance. Leptin stimulates the phosphorylation of several tyrosine residues on LRb to mediate leptin action. We homologously replaced LRb in mice with a receptor with a mutation in one of these sites (Tyr985) in order to examine its role in leptin action and signal attenuation in vivo. Mice homozygous for this mutation are neuroendocrinologically normal, but females demonstrate decreased feeding, decreased expression of orexigenic neuropeptides, protection from high-fat diet–induced obesity, and increased leptin sensitivity in a sex-biased manner. Thus, leptin activates autoinhibitory signals via LRb Tyr985 to attenuate the anti-adiposity effects of leptin, especially in females, potentially contributing to leptin insensitivity in obesity.
Marie Björnholm, Heike Münzberg, Rebecca L. Leshan, Eneida C. Villanueva, Sarah H. Bates, Gwendolyn W. Louis, Justin C. Jones, Ryoko Ishida-Takahashi, Christian Bjørbaek, Martin G. Myers Jr.
This file is in Adobe Acrobat (PDF) format. If you have not installed and configured the Adobe Acrobat Reader on your system.
PDFs are designed to be printed out and read, but if you prefer to read them online, you may find it easier if you increase the view size to 125%.
Many versions of the free Acrobat Reader do not allow Save. You must instead save the PDF from the JCI Online page you downloaded it from. PC users: Right-click on the Download link and choose the option that says something like "Save Link As...". Mac users should hold the mouse button down on the link to get these same options.