More than one-third of U.S. population is obese. The prevalence of obesity-related comorbidities such as type-2 diabetes and heart diseases emphasizes the need for concerted efforts to prevent and treat obesity. A decrease in ?5% of the body weight significantly reduces cardiovascular risk in humans which clearly demonstrates the urgency of weight management. Lifestyle intervention is primary albeit not sufficient in long term weight management. Thus, we need anti-obesity drugs. Due to partial effects of the current anti-obesity drugs that inhibit food intake or absorption, recent focus has shifted towards enhancing energy expenditure in metabolic tissues. Adipose tissue is a major regulator of energy metabolism. Therefore, adipose tissue function in normal and obese conditions are being extensively studied. Because of the complexity of the adipose tissue, a complete understanding of the mechanism and regulation of its metabolism is still lacking. Discovery of all the major components of adipose tissue metabolism will certainly help to design therapeutic strategies. In this proposal, we introduce IP6K1 as one such component with therapeutic potential. Our laboratory is interested in understanding the mechanism and regulation of adipose tissue metabolism in normal and obese conditions using mouse models. Utilizing the inositol hexakisphosphate kinase 1 (IP6K1) knockout (K1-KO) mice, we previously discovered that these mice are resistant to weight gain and insulin resistance, despite their unaltered food intake. The objective of the current proposal is to determine the mechanisms by which IP6K1 promotes lipid accumulation in the adipose tissue using whole body and adipose tissue specific IP6K1 mouse models. The central hypothesis is that IP6K1 is a major regulator of energy metabolism in the adipose tissue. To test this hypothesis, role of IP6K1 in; 1) adipose tissue browning and thermogenesis; 2) lipolysis and; 3) adipogenesis will be determined and underlying mechanisms by which IP6K1 regulates these processes will be identified. The proposed research is conceptually innovative, because it represents a new and substantive departure from the status quo, namely determining the mechanisms by which IP6K1 regulates adipose mass. The contribution is significant because it is the first step in a continuum of research that is expected to lead to development of novel pharmacologic strategies in obesity. Therefore, the proposed project is expected to have significant impacts on improving quality of life.

Public Health Relevance

Obesity is associated with health risks such as type-2 diabetes, hypertension, cardiovascular diseases, dyslipidemia, arthritis and certain cancers which significantly decrease quality of life and reduce life expectancy. Extensive research is ongoing to identify the ideal protein or pathway which can be pharmacologically targeted to ameliorate obesity and associated diseases. This project investigates the role of inositol hexakisphosphate kinase 1 (IP6K1) in obesity and diabetes. The project proposes to identify the underlying mechanisms by which IP6K1 facilitates increase in adipose mass. By generating novel mouse and cellular models, this project demonstrates pleiotropic actions of IP6K1 on fat accumulation and proposes that targeting IP6K1 has significant anti-obesity and anti-diabetic potential.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK103746-05
Application #
9450508
Study Section
Cellular Aspects of Diabetes and Obesity Study Section (CADO)
Program Officer
Haft, Carol R
Project Start
2015-04-15
Project End
2020-03-31
Budget Start
2018-04-01
Budget End
2019-03-31
Support Year
5
Fiscal Year
2018
Total Cost
Indirect Cost
Name
Saint Louis University
Department
Pharmacology
Type
Schools of Medicine
DUNS #
050220722
City
Saint Louis
State
MO
Country
United States
Zip Code
63103
Chakraborty, Anutosh (2018) The inositol pyrophosphate pathway in health and diseases. Biol Rev Camb Philos Soc 93:1203-1227
Boregowda, Siddaraju V; Ghoshal, Sarbani; Booker, Cori N et al. (2017) IP6K1 Reduces Mesenchymal Stem/Stromal Cell Fitness and Potentiates High Fat Diet-Induced Skeletal Involution. Stem Cells 35:1973-1983
Zhu, Qingzhang; Ghoshal, Sarbani; Tyagi, Richa et al. (2017) Global IP6K1 deletion enhances temperature modulated energy expenditure which reduces carbohydrate and fat induced weight gain. Mol Metab 6:73-85
Zhu, Qingzhang; Ghoshal, Sarbani; Rodrigues, Ana et al. (2016) Adipocyte-specific deletion of Ip6k1 reduces diet-induced obesity by enhancing AMPK-mediated thermogenesis. J Clin Invest 126:4273-4288
Ghoshal, Sarbani; Tyagi, Richa; Zhu, Qingzhang et al. (2016) Inositol hexakisphosphate kinase-1 interacts with perilipin1 to modulate lipolysis. Int J Biochem Cell Biol 78:149-155
Ghoshal, Sarbani; Zhu, Qingzhang; Asteian, Alice et al. (2016) TNP [N2-(m-Trifluorobenzyl), N6-(p-nitrobenzyl)purine] ameliorates diet induced obesity and insulin resistance via inhibition of the IP6K1 pathway. Mol Metab 5:903-17