The goal of our research program is to determine molecular mechanisms whereby extracellular signals regulate adipocyte differentiation and metabolism. In the past funding period, we have performed novel studies demonstrating an important role for Wnt10b signaling as an inhibitor of adipogenesis in cultured preadipocytes and in transgenic mice. Our studies have demonstrated that Wnt10b is expressed in preadipocytes and stromal vascular cells and that Wnt10b decreases rapidly upon induction of adipogenesis. Wnt10b blocks adipogenesis by inhibiting expression of C/EBPa and PPAR?, and neutralization of endogenous Wnt10b with antisera stimulates adipogenesis of preadipocytes. Transgenic mice expressing Wnt10b in adipose tissue (FABP4-Wnt10b) have ~50% less total body fat and a ~60% reduction in visceral fat depots. FABP4-Wnt10b mice are resistant to diet-induced and genetic-obesity, and these mice are more glucose-tolerant and insulin-sensitive than controls. Our studies have expanded the role for Wnt10b from simple inhibition of preadipocyte differentiation to modulating fate of multipotent stem cells. Thus, FABP4-Wnt10b mice not only have less adipose tissue, but they have a four-fold increase in trabecular bone. In addition to a direct effect of Wnt10b to stimulate osteoblastogenesis and decrease adipogenesis of resident mesenchymal progenitor cells in marrow, increased osteoblast activity also appears to be mediated by a novel mechanism through mammalian target of rapamycin and protein translation. Further support for a critical role for Wnt10b in governing fate of mesenchymal precursors comes from our observations that Wnt10b -/- mice have ~30% less trabecular bone and a corresponding decrease in serum osteoblast markers. While our focus to date has been on how Wnt/?-catenin influences developmental processes, our studies suggest that Wnt signaling has additional roles in functions of the mature adipocyte. These studies have led us to hypothesize that Wnts signal in adipocyte through the Wnt receptor frizzled 4 to regulate adipocyte and whole body metabolism. The experiments proposed in this application will systematically build on our past studies to understand in greater detail the molecular, cellular and whole animal biology of Wnt signaling in adipocytes and adipose tissue.

Public Health Relevance

Obesity and weight gain are associated with diabetes and many other medical problems including cardiovascular disease and certain cancers. Obesity is characterized by an increase in adipose tissue due to increase in size of existing fat cells, and recruitment of new progenitors. Wnt signaling is involved in both of these processes;however, the mechanisms are not well understood. Thus, the proposed research will provide important insights into adipocyte and whole body metabolism, and potentially provide insight into the medical problems of obesity and type II diabetes, two major health risks in the United States.

National Institute of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Research Project (R01)
Project #
Application #
Study Section
Cellular Aspects of Diabetes and Obesity Study Section (CADO)
Program Officer
Haft, Carol R
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of Michigan Ann Arbor
Schools of Medicine
Ann Arbor
United States
Zip Code
Ma, Xiaoya; Pham, Vinh T; Mori, Hiroyuki et al. (2017) Iron elevation and adipose tissue remodeling in the epididymal depot of a mouse model of polygenic obesity. PLoS One 12:e0179889
Ge, Chunxi; Cawthorn, William P; Li, Yan et al. (2016) Reciprocal Control of Osteogenic and Adipogenic Differentiation by ERK/MAP Kinase Phosphorylation of Runx2 and PPAR? Transcription Factors. J Cell Physiol 231:587-96
Chen, Yii-Shyuan; Wu, Rui; Yang, Xiaosong et al. (2016) Inhibiting DNA methylation switches adipogenesis to osteoblastogenesis by activating Wnt10a. Sci Rep 6:25283
Mori, Hiroyuki; Yao, Yao; Learman, Brian S et al. (2016) Induction of WNT11 by hypoxia and hypoxia-inducible factor-1? regulates cell proliferation, migration and invasion. Sci Rep 6:21520
Chkourko Gusky, H; Diedrich, J; MacDougald, O A et al. (2016) Omentum and bone marrow: how adipocyte-rich organs create tumour microenvironments conducive for metastatic progression. Obes Rev 17:1015-1029
Qiang, Guifen; Whang Kong, Hyerim; Xu, Shanshan et al. (2016) Lipodystrophy and severe metabolic dysfunction in mice with adipose tissue-specific insulin receptor ablation. Mol Metab 5:480-90
Alexander, Caroline M; Kasza, Ildiko; Yen, C-L Eric et al. (2015) Dermal white adipose tissue: a new component of the thermogenic response. J Lipid Res 56:2061-9
Zhang, Jing; Motyl, Katherine J; Irwin, Regina et al. (2015) Loss of Bone and Wnt10b Expression in Male Type 1 Diabetic Mice Is Blocked by the Probiotic Lactobacillus reuteri. Endocrinology 156:3169-82
Liu, Shannon; Sheng, Liang; Miao, Hongzhi et al. (2014) SRA gene knockout protects against diet-induced obesity and improves glucose tolerance. J Biol Chem 289:13000-9
Kasza, Ildiko; Suh, Yewseok; Wollny, Damian et al. (2014) Syndecan-1 is required to maintain intradermal fat and prevent cold stress. PLoS Genet 10:e1004514

Showing the most recent 10 out of 42 publications