Vitamin D supplementation down-regulates interleukin-6 and myosin heavy chain gene expression in skeletal muscle cells isolated from Vitamin-D deficient CKD patients

Skeletal muscle wasting is a common co-morbidity associated with chronic kidney disease (CKD), adversely affecting quality of life, physical function, morbidity and mortality. Patients are often Vitamin-D deficient, which has been correlated with frailty in elderly populations. Recent evidence also suggests that Vitamin-D supplementation regulates myogenic and inflammatory processes skeletal muscle. This study investigated the effect of Vitamin-D supplementation on myogenic and inflammatory gene expression in primary cultures derived from Vitamin-D deficient CKD patient donors. Supplementation of 10nmol 1α,25(OH)2D3 for 5-days significantly reduced inflammatory (IL-6) and myogenic (MyHC1 and MyHC8) gene expression in human primary myotubes derived from Vitamin-D deficient CKD patients. There was a strong trend for down-regulation of myostatin and MyHC3 expression, with no effect on mRNA of MRFs or VDR. This suggests Vitamin-D deficiency may play a role in intramuscular inflammation and muscle wasting, both of which are prevalent in CKD.