Format

Send to

Choose Destination
Calcif Tissue Int. 2016 May;98(5):511-9. doi: 10.1007/s00223-015-0097-z. Epub 2016 Jan 12.

Palmitic Acid Reduces Circulating Bone Formation Markers in Obese Animals and Impairs Osteoblast Activity via C16-Ceramide Accumulation.

Author information

1
Division of Periodontics, College of Dental Medicine, Columbia University, 630 W 168th St, PH7C-200B, New York, NY, 10032, USA.
2
Irving Institute for Clinical and Translational Research, Columbia University Medical Center, New York, NY, USA.
3
Division of Periodontics, College of Dental Medicine, Columbia University, 630 W 168th St, PH7C-200B, New York, NY, 10032, USA. us2141@cumc.columbia.edu.

Abstract

Obesity and impaired lipid metabolism increase circulating and local fatty acid (FA) levels. Our previous studies showed that a high high-saturated -fat diet induced greater bone loss in mice than a high high-unsaturated-fat diet due to increased osteoclast numbers and activity. The impact of elevated FA levels on osteoblasts is not yet clear. We induced obesity in 4 week old male mice using a palmitic acid (PA)- or oleic acid (OA)-enriched high fat high-fat diet (HFD) (20 % of calories from FA), and compared them to mice on a normal (R) caloric diet (10 % of calories from FA). We collected serum to determine FA and bone metabolism marker levels. Primary osteoblasts were isolated; cultured in PA, OA, or control (C) medium; and assessed for mineralization activity, gene expression, and ceramide levels. Obese animals in the PA and OA groups had significantly lower serum levels of bone formation markers P1NP and OC compared to normal weight animals (*p < 0.001), with the lowest marker levels in animals on an PA-enriched HFD (*p < 0.001). Accordingly, elevated levels of PA significantly reduced osteoblast mineralization activity in vitro (*p < 0.05). Elevated PA intake significantly increased C16 ceramide accumulation. This accumulation was preventable through inhibition of SPT2 (serine palmitoyl transferase 2) using myriocin. Elevated levels of PA reduce osteoblast function in vitro and bone formation markers in vivo. Our findings suggest that saturated PA can compromise bone health by affecting osteoblasts, and identify a potential mechanism through which obesity promotes bone loss.

KEYWORDS:

Ceramides; Mineralization; Obesity; Osteoblast; Palmitic acid

PMID:
26758875
DOI:
10.1007/s00223-015-0097-z
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Springer
Loading ...
Support Center