lalpha,25(OH)_2-Vitamin D_3 and 17beta-Estradiol: Two Steroid Partners Acting in Skeletal Muscle

摘要

1alpha,25(OH)_2-vitamin D_3 and 17P-estradiol regulate skeletal muscle cell proliferation, differentiation, apoptosis and contractility through receptor-mediated transcriptional and non-genomic mechanisms. This review focuses on recent advances on signal transduction pathways activated by both steroid hormones. Data are given on the participation of the VDR and ERs (a and |3) in activation of MAPKs in muscle cells. Likewise, we describe novel evidence supporting non-classical localizations of the VDR in the plasma membrane and ER beta in mitochondria. 1alpha,25(OH)_2D_3 promotes DNA synthesis in skeletal muscle cells implicating c-Src/ERK1/2, whereas 17beta-estradiol inhibits apoptosis through ERK2 and p38 MAPKs. This study provides basis for the understanding of vitamin D- and estrogen-dependent myopathies.