Obesity leads to an increased risk for type 2 diabetes, heart attack, many types of cancer, hypertension, stroke, and is estimated to soon be the leading cause of death in the US. Through twin and family studies, obesity has been found to have a 40-70% heritability rate, pointing to a strong genetic etiology. The general objective of our research is to understand the cellular and molecular basis of long-term regulation of energy homeostasis in order to identify genes in which mutations cause obesity in humans and to discover new targets for the treatment of obesity. This research proposal focuses on the G-protein coupled Melanocortin-4 Receptor (MC4R), a gene expressed in the central nervous system and implicated in the regulation of food intake. Different mutations in the coding sequence of MC4R cause severe obesity in humans. In this proposal, we will extend our recent novel findings related to the genetic and cellular biology of MC4R. Specifically, we will study the disease consequences of the observation that only one copy of the Mc4r gene is active in each neuron expressing this receptor. We will also study the importance of the observation that MC4R localizes to the primary cilia, a cellular organelle that serves as a signaling hub for eukaryotic cells in general and neurons in particular.

Public Health Relevance

Obesity has become a major public health concern as it increases the risk for type 2 diabetes, heart attack, certain forms of cancer, hypertension and stroke. Obesity results from the interaction between the environment and genetic predisposition. This research proposal is aimed at understanding better how mutations in the Melanocortin-4 receptor, a brain expressed gene that controls food intake in response to peripheral cues, cause severe obesity in humans. This research could lead to a better understanding on how people become obese and could lead to new treatments for this condition.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
2R01DK060540-14A1
Application #
9972579
Study Section
Integrative Physiology of Obesity and Diabetes Study Section (IPOD)
Program Officer
Karp, Robert W
Project Start
2002-02-15
Project End
2025-08-31
Budget Start
2020-09-01
Budget End
2021-08-31
Support Year
14
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of California San Francisco
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94118
Siljee, Jacqueline E; Wang, Yi; Bernard, Adelaide A et al. (2018) Subcellular localization of MC4R with ADCY3 at neuronal primary cilia underlies a common pathway for genetic predisposition to obesity. Nat Genet 50:180-185
Vaisse, Christian; Reiter, Jeremy F; Berbari, Nicolas F (2017) Cilia and Obesity. Cold Spring Harb Perspect Biol 9:
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Ionova-Martin, S S; Wade, J M; Tang, S et al. (2011) Changes in cortical bone response to high-fat diet from adolescence to adulthood in mice. Osteoporos Int 22:2283-93

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