La vitamina D induce apoptosis en células musculares lisas

Resumo

Background Degeneration of the arterial medial layer is one of the characteristic features of arteriosclerosis and affects the elastic laminae, as well as the muscle cells and extracellular matrix. Among other factors, vitamin D induces arterial calcification and when administered in combination with a high cholesterol diet, contributes to cholesterol deposition and to the advance of the vascular lesion. This study was designed to evaluate the effect of different vitamin D2 concentrations on the growth of cultured smooth muscle cells. Method Different vitamin D2 concentrations (0-200.000 U/ml) were applied to 2h - 4 day cultures of muscle cells from rat abdominal artery. Cell proliferation was estimated through 3Hthymidine incorporation, and cell damage, assessed as DNA fragmentation was determined using the TUNEL technique. Results Smooth muscle cells incubated in the absence of vitamin D2 proliferated throughout the study period. The presence of vitamin D2 in the culture medium induced changes in the proliferation rate and led to growth cessation at the highest vitamin concentration used. These findings were concurrent with an enhanced apoptosis that was noted in the same cells. Conclusions Vitamin D2 inhibits the proliferation of smooth muscle cells and enhances cell death via apoptosis in a concentration- and time-dependent manner.