Systemic lupus erythematosus (SLE), is a systemic autoimmune disease, can cause chronic inflammation and damage in several tissues and organs.
Vitamin D, as a steroid hormone, exhibits regulatory effects on growth, proliferation, apoptosis and function of the immune system cells. Vitamin D is associated with pathophysiology of SLE.
The discovery of vitamin D receptor expression by cells of the immune system has spurred more research on the immunomodulatory properties of vitamin D over the past decade.
Vitamin D deficiency is highly prevalent in SLE patients due to the avoidance of sunshine, photoprotection, renal insufficiency and the use of medications such as glucocorticoids, anticonvulsants which alter the metabolism of vitamin D or down regulate the functions of the vitamin D receptor.
The human VDR gene is located inchromosome 12 and contains 14 exons and spans approximately 75 kb. The promoter of the VDR gene is embedded in a GC-rich island with five binding motifs for the transcription factors.The transcriptional activity of VDR could be affected also by epigenetic mechanisms such as DNA methylation which regulate gene expression and chromatin structure.