There is a dire need for new technologies to address the obesity epidemic and its associated sequellae, including Type II Diabetes. Increasing caloric output through expansion and activation of brown adipose tissue (BAT), which ?burns? metabolic fuels to produce heat, is garnering increasing interest as a novel mechanism to trigger weight loss in adults. However, the technological translation of this approach, including the engineering of biomaterial platforms to support BAT in vitro and in vivo, has been limited by a poor understanding of how cues from the physical microenvironment regulate BAT activation. Our preliminary data hint at a novel and unexpected model in which beta-adrenergic (-AR) stimulation triggers BAT activation through a myosin- and YAP/TAZ-dependent mechanotransductive signaling network, ultimately enhancing expression of the heat- generating mitochondrial protein UCP1. This model has profound implications, because it would suggest that incorporation of mechanical cues within the microenvironment could be leveraged to activate BAT and promote caloric output as a strategy to combat obesity. Thus, the goal of this proposal is to critically test the hypothesis that -AR and mechanotransductive signaling collude to stimulate BAT activation and enhanced cellular respiration. We have three aims: (1) To dissect the mechanisms through which actomyosin tension acutely activates BAT; (2) To determine how mechanical activation of YAP/TAZ regulates expression of UCP1; and (3) To investigate the role of mechanosensitive YAP/TAZ-dependent signals in white/beige adipose fate determination. In addition to detailed dissection of signaling events, our approach features an innovative combination of engineered materials, mechanical stimulation, advanced mouse genetic models, inducible expression of myosin-activating proteins, and measurements of cell and tissue mechanics. Successful completion of this work would substantially advance our mechanistic understanding of BAT activation while informing the design of materials technologies to stimulate BAT activation to reduce obesity.

Public Health Relevance

Activating brown adipose tissue holds the promise of burning excess calories and thus might lead to new strategies for fighting obesity-related disorders. We have uncovered evidence for a new mechanism of brown adipose tissue activation that involves the creation and sensing of intracellular tension, which we want to characterize further by identifying its molecular components.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
1R01DK118940-01A1
Application #
9746962
Study Section
Integrative Physiology of Obesity and Diabetes Study Section (IPOD)
Program Officer
Haft, Carol R
Project Start
2019-06-01
Project End
2023-05-31
Budget Start
2019-06-01
Budget End
2020-05-31
Support Year
1
Fiscal Year
2019
Total Cost
Indirect Cost
Name
University of California Berkeley
Department
Nutrition
Type
Earth Sciences/Resources
DUNS #
124726725
City
Berkeley
State
CA
Country
United States
Zip Code
94710