Lipolysis of bone marrow adipocytes is required to fuel bone and the marrow niche during energy deficits
- University of Michigan-Ann Arbor, United States
- Maine Medical Center Research Institute, United States
Abstract
To investigate roles for bone marrow adipocyte (BMAd) lipolysis in bone homeostasis, we created a BMAd-specific Cre mouse model in which we knocked out adipose triglyceride lipase (ATGL, Pnpla2 gene). BMAd-Pnpla2-/- mice have impaired BMAd lipolysis, and increased size and number of BMAds at baseline. Although energy from BMAd lipid stores is largely dispensable when mice are fed ad libitum, BMAd lipolysis is necessary to maintain myelopoiesis and bone mass under caloric restriction. BMAd-specific Pnpla2 deficiency compounds the effects of caloric restriction on loss of trabecular bone in male mice, likely due to impaired osteoblast expression of collagen genes and reduced osteoid synthesis. RNA sequencing analysis of bone marrow adipose tissue reveals that caloric restriction induces dramatic elevations in extracellular matrix organization and skeletal development genes, and energy from BMAd is required for these adaptations. BMAd-derived energy supply is also required for bone regeneration upon injury, and maintenance of bone mass with cold exposure.
Data availability
The accession number for the BMAT bulk RNA seq data reported in this paper is GEO: GSE183784.
Article and author information
Author details
Kanakadurga Singer
Funding
National Institutes of Health (R01 DK62876)
- Ormond MacDougald
National Institutes of Health (T32 DK071212)
- Kenneth T Lewis
National Institutes of Health (F32 DK122654)
- Kenneth T Lewis
National Institutes of Health (T32 DK101357)
- Rebecca L Schill
National Institutes of Health (F32 DK123887)
- Rebecca L Schill
National Institutes of Health (R01AR066028)
- Kurt D Hankenson
National Institutes of Health (R24DK092759)
- Clifford J Rosen
American Diabetes Association (1-18-PDF-087)
- Ziru Li
American Heart Association (20-PAF00361)
- Emily Bowers
National Institutes of Health (R24 DK092759)
- Ormond MacDougald
National Institutes of Health (R01 DK126230)
- Ormond MacDougald
National Institutes of Health (R01 AG069795)
- Ormond MacDougald
National Institutes of Health (T32 GM835326)
- Steven M Romanelli
National Institutes of Health (F31 DK12272301)
- Steven M Romanelli
National Institutes of Health (T32 HD007505)
- Devika P Bagchi
National Institutes of Health (T32 GM007863)
- Devika P Bagchi
National Institutes of Health (R01DK115583)
- Kanakadurga Singer
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All procedures were approved by the University of Michigan Committee on the Use and Care of Animals with the protocol number as PRO00009687.
Copyright
© 2022, Li et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Lipolysis of bone marrow adipocytes is required to fuel bone and the marrow niche during energy deficits
eLife 11:e78496.
https://doi.org/10.7554/eLife.78496
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