Altered fatty acid composition of skeletal muscle phospholipid in mdx mice

Abstract

Mdx mice are a model for Duchenne muscular dystrophy (DMD) and exhibit increased oxidative stress and inflammation. We sought to determine if the profile of fatty acids (FAs) in muscle phospholipid (PL) is altered in manners that could impact anti-inflammatory status or other aspects of muscular function. 8 mdx mice and 8 C57BL/10 control mice (con), on the same standard diet, were tested with a grip strength meter and then skeletal muscle was collected. The FA profile of quadriceps PL was determined by HPLC, assessing the abundance of 22 FAs as percentage of total FAs in PL. Compared to con, mdx PL contained less of the ω-3 FA docosahexaenoic acid (DHA) (20.3±1.2% vs. 24.0±1.8%, P<0.05) and more linoleic acid (13.4±0.5% vs. 11.7±0.9%, P<0.05). Mdx PL also contained more oleic acid (6.1±1.2% vs. 3.4±0.4%, P<0.05) with no significant difference for stearic acid; thus, Δ-9 desaturase activity may have been accentuated in mdx mice. In addition, α-linolenic acid content in PL was positively correlated with muscular strength in mdx mice (R=0.83, P<0.05) but not in control mice (R=−0.66, P=0.08), indicating a potential benefit of ω-3 FAs to diseased muscle. In conclusion, ω-3 FAs in muscle could be of importance for coping with the disease process in DMD. Furthermore, we discovered potential evidence for altered desaturase activity that requires further study to indicate a physiological role. Supported by Rutgers University