Bone marrow fat accumulation accelerated by high fat diet is suppressed by exercise.
Marrow adipose tissue (MAT), associated with skeletal fragility and hematologic insufficiency, remains poorly understood and difficult to quantify. We tested the response of MAT to high fat diet (HFD) and exercise using a novel volumetric analysis, and compared it to measures of bone quantity. We hypothesized that HFD would increase MAT and diminish bone quantity, while exercise would slow MAT acquisition and promote bone formation. Eight week-old female C57BL/6 mice were fed a regular (RD) or HFD, and exercise groups were provided voluntary access to running wheels (RD-E, HFD-E). Femoral MAT was assessed by μCT (lipid binder osmium) using a semi-automated approach employing rigid co-alignment, regional bone masks and was normalized for total femoral volume (TV) of the bone compartment. MAT was 2.6-fold higher in HFD relative to RD mice. Exercise suppressed MAT in RD-E mice by more than half compared with RD. Running similarly inhibited MAT acquisition in HFD mice. Exercise significantly increased bone quantity in both diet groups. Thus, HFD caused significant accumulation of MAT; importantly running exercise limited MAT acquisition while promoting bone formation during both diets. That MAT is exquisitely responsive to diet and exercise, and its regulation by exercise appears to be inversely proportional to effects on exercise induced bone formation, is relevant for an aging and sedentary population.
Department of Medicine, University of North Carolina, Chapel Hill, NC, USA. Electronic address: mstyner@med.unc.edu.
Maya
M
Styner
Department of Medicine, University of North Carolina, Chapel Hill, NC, USA.
William R
WR
Thompson
Department of Medicine, University of North Carolina, Chapel Hill, NC, USA.
Kornelia
K
Galior
Department of Medicine, University of North Carolina, Chapel Hill, NC, USA.
Gunes
G
Uzer
Department of Medicine, University of North Carolina, Chapel Hill, NC, USA.
Xin
X
Wu
Department of Medicine, University of North Carolina, Chapel Hill, NC, USA.
Sanjay
S
Kadari
Department of Medicine, University of North Carolina, Chapel Hill, NC, USA.
Natasha
N
Case
Department of Medicine, University of North Carolina, Chapel Hill, NC, USA.
Zhihui
Z
Xie
Department of Medicine, University of North Carolina, Chapel Hill, NC, USA.
Buer
B
Sen
Department of Psychiatry and Computer Science, University of North Carolina, Chapel Hill, NC, USA.
Andrew
A
Romaine
Department of Biomedical Engineering, State University of New York, Stony Brook, NY, USA.
Gabriel M
GM
Pagnotti
Department of Biomedical Engineering, State University of New York, Stony Brook, NY, USA.
Clinton T
CT
Rubin
Department of Computer Science, University of North Carolina, Chapel Hill, NC, USA; Department of Psychiatry and Computer Science, University of North Carolina, Chapel Hill, NC, USA.
Martin A
MA
Styner
Department of Orthopedics and Rehabilitation, Yale University, New Haven, CT, USA.
Mark C
MC
Horowitz
Department of Medicine, University of North Carolina, Chapel Hill, NC, USA.
Janet
J
Rubin
D000273:Adipose Tissue / Q000378:metabolism*; D000818:Animals; D001853:Bone Marrow / Q000378:metabolism*; D059305:Diet, High-Fat; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D010805:Physical Conditioning, Animal; D055114:X-Ray Microtomography
Bone micro architecture; Exercise; Lipid; Marrow adipose tissue; Micro-CT; Quantitative image analysis