Retinoic acid alters metalloproteinase action in red deer antler stem cells.

Metalloproteinases (MMP)s regulate developmental processes, control angiogenesis and wound healing, participate in the formation of immune receptors, and are expressed in stem cells. Retinoic acid (RA) is a potential modulator of these proteinases. The aim was to determine (1) MMPs' action in antler stem cells (ASCs) before and after differentiation into adipo-, osteo-, and chondrocytes and (2) the effect of RA on modifying MMP action in ASCs. Antler tissue from pedicle was collected approximately 40 days after antler casting, post mortem from healthy breeding five year old males (N = 7). The cells were isolated from the pedicle layer of periosteum after skin separation and cultured. The pluripotency of the ASCs was evaluated by mRNA expression for NANOG, SOX2, and OCT4. ASCs were stimulated with RA (100nM) and differentiated for 14 days. The MMP (1-3) and TIMP(1-3) (tissue inhibitor of MMPs) mRNA expression was determined in the ASCs, their concentrations in the ASCs and the medium after RA stimulation as well as profiles of mRNA expression for MMPs: 1-3 and TIMPs: 1-3 during differentiation of ASC to osteocytes, adipocytes and chondrocytes. RA increased MMP-3 and TIMP-3 mRNA expression and output (P < 0.05) and not influenced on MMP-1 and TIMP-1 mRNA expression and output in ASC (P > 0.05). Depending on differentiation of ASC to osteocytes, adipocytes or chondrocytes, MMPs`and TIMPs`expression profile fluctuates for all studied proteases and its inhibitors. The studies demand continuation considering the role of proteases in stem cells physiology and differentiation. The results may be relevant for the study of cellular processes during the cancerogenesis of tumor stem cells.