Role of hypothalamic proopiomelanocortin neuron autophagy in the control of appetite and leptin response

W Quan, HK Kim, EY Moon, SS Kim, CS Choi… - …, 2012 - academic.oup.com
W Quan, HK Kim, EY Moon, SS Kim, CS Choi, M Komatsu, YT Jeong, MK Lee, KW Kim…
Endocrinology, 2012academic.oup.com
Autophagy is a catabolic cellular process involving the degradation of the cell's own
components. Although the role of autophagy of diverse tissues in body metabolism has been
investigated, the importance of autophagy in hypothalamic proopiomelanocortin (POMC)
neurons, key regulators of energy balance, has not been addressed. The role of autophagy
in leptin sensitivity that is critical for the control of body weight and appetite has also not
been investigated. We produced mice with specific deletion of autophagy-related 7 (Atg7) …
Autophagy is a catabolic cellular process involving the degradation of the cell's own components. Although the role of autophagy of diverse tissues in body metabolism has been investigated, the importance of autophagy in hypothalamic proopiomelanocortin (POMC) neurons, key regulators of energy balance, has not been addressed. The role of autophagy in leptin sensitivity that is critical for the control of body weight and appetite has also not been investigated. We produced mice with specific deletion of autophagy-related 7 (Atg7), an essential autophagy gene, in hypothalamic POMC neurons (Atg7ΔPOMC mice). Atg7 expression was deficient in the arcuate nucleus of the hypothalamus of Atg7ΔPOMC mice. p62, a specific substrate of autophagy, accumulated in the hypothalamus of Atg7ΔPOMC mice, which colocalized with ubiquitin. Atg7ΔPOMC mice had increased body weight due to increased food intake and decreased energy expenditure. Atg7ΔPOMC mice were not more prone to diet-induced obesity compared with control mice but more susceptible to hyperglycemia after high-fat diet. The ability of leptin to suppress fasting-elicited hyperphagia and weight gain during refeeding was attenuated in Atg7ΔPOMC mice. Deficient autophagy did not significantly affect POMC neuron number but impaired leptin-induced signal transducer and activation of transcription 3 activation. Our findings indicate a critical role for autophagy of POMC neurons in the control of energy homeostasis and leptin signaling.
Oxford University Press