Fatty acids in bone matrix offer clue to pathophysiology
MedWire News: Fatty acids in the bone matrix are remarkably diverse and vary according to underlying pathophysiologic processes, a clinical study indicates.
Julia Humphries (The University of Adelaide, Australia) and team used gas chromatography to evaluate in situ fatty acid profiles (n-3, n-6, saturated, monounsaturated, and polyunsaturated) of cancellous bone.
This is the first study to focus solely on the cancellous subchondral bone mineral matrix, note Humphries et al, since previous studies have always included the bone marrow.
The team collected bone matrix samples from the femoral heads of 27 women undergoing orthopedic surgery (n=8 for osteoarthritis, n=19 for fractured neck of femur) and from four cadavers at autopsy (controls).
Reporting their findings in Bone, Humphries et al reveal that a total of 42 distinct fatty acids were identified across the bone specimens, although not all were detected in every specimen.
The most abundant fatty acids were palmitic acid, oleic acid, and linoleic acid, which accounted for 25%, 42%, and 9.5%, respectively, of the total tissue mass.
The relative content of saturated, monounsaturated, and polyunsaturated fats across the groups was comparable among the osteoarthritis, fracture, and control groups.
Also, the percent fat did not differ between the superior principal compression and the superior principal tensile regions of the femoral head.
However, the total fat percent was significantly lower in subchondral bone from women with osteoarthritis than in controls and fracture patients, at 11%, 24%, and 19%, respectively.
Finally, the saturated fats pelargonic acid and lauric acid were detected only in the superior principal tensile region of subchondral bone from fracture patients and in subchondral bone from controls, but were absent in the osteoarthritis samples.
Noting that bone health and remodeling are known to be influenced by changes in the concentration of individual fatty acids, Humphries and team conclude: "There are differences in the bone matrix-level profile of fatty acids that may have a central role in modulating bone remodelling and inflammatory processes involved in [osteoarthritis].
"This study forms the basis for further investigations into the implications of varying in situ fatty acid profiles on the metabolic relationships between adiposity and subchondral bone remodelling and osteoarthritis."
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By Joanna Lyford