Exercise Degrades Bone in Caloric Restriction, Despite Suppression of Marrow Adipose Tissue (MAT).

Autor: McGrath C; Department of Medicine, Division of Endocrinology, University of North Carolina, Chapel Hill, NC, USA., Sankaran JS; Department of Medicine, Division of Endocrinology, University of North Carolina, Chapel Hill, NC, USA., Misaghian-Xanthos N; Department of Medicine, Division of Endocrinology, University of North Carolina, Chapel Hill, NC, USA., Sen B; Department of Medicine, Division of Endocrinology, University of North Carolina, Chapel Hill, NC, USA., Xie Z; Department of Medicine, Division of Endocrinology, University of North Carolina, Chapel Hill, NC, USA., Styner MA; Department of Computer Science, University of North Carolina, Chapel Hill, NC, USA.; Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA., Zong X; Biomedical Research Imaging Center, University of North Carolina, Chapel Hill, NC, USA., Rubin J; Department of Medicine, Division of Endocrinology, University of North Carolina, Chapel Hill, NC, USA., Styner M; Department of Medicine, Division of Endocrinology, University of North Carolina, Chapel Hill, NC, USA.
Jazyk: angličtina
Zdroj: Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research [J Bone Miner Res] 2020 Jan; Vol. 35 (1), pp. 106-115. Date of Electronic Publication: 2019 Oct 25.
DOI: 10.1002/jbmr.3872
Abstrakt: Marrow adipose tissue (MAT) and its relevance to skeletal health during caloric restriction (CR) is unknown: It remains unclear whether exercise, which is anabolic to bone in a calorie-replete state, alters bone or MAT in CR. We hypothesized that response of bone and MAT to exercise in CR differs from the calorie-replete state. Ten-week-old female B6 mice fed a regular diet (RD) or 30% CR diet were allocated to sedentary (RD, CR, n = 10/group) or running exercise (RD-E, CR-E, n = 7/group). After 6 weeks, CR mice weighed 20% less than RD, p < 0.001; exercise did not affect weight. Femoral bone volume (BV) via 3D MRI was 20% lower in CR versus RD (p < 0.0001). CR was associated with decreased bone by μCT: Tb.Th was 16% less in CR versus RD, p < 0.003, Ct.Th was 5% less, p < 0.07. In CR-E, Tb.Th was 40% less than RD-E, p < 0.0001. Exercise increased Tb.Th in RD (+23% RD-E versus RD, p < 0.003) but failed to do so in CR. Cortical porosity increased after exercise in CR (+28%, p = 0.04), suggesting exercise during CR is deleterious to bone. In terms of bone fat, metaphyseal MAT/ BV rose 159% in CR versus RD, p = 0.003 via 3D MRI. Exercise decreased MAT/BV by 52% in RD, p < 0.05, and also suppressed MAT in CR (-121%, p = 0.047). Histomorphometric analysis of adipocyte area correlated with MAT by MRI (R 2 = 0.6233, p < 0.0001). With respect to bone, TRAP and Sost mRNA were reduced in CR. Intriguingly, the repressed Sost in CR rose with exercise and may underlie the failure of CR-bone quantity to increase in response to exercise. Notably, CD36, a marker of fatty acid uptake, rose 4088% in CR (p < 0.01 versus RD), suggesting that basal increases in MAT during calorie restriction serve to supply local energy needs and are depleted during exercise with a negative impact on bone. © 2019 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.
(© 2019 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.)
Databáze: MEDLINE
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