Induction Of Antler Mesenchymal Stem Cell Chondrogenic Differentiation And Gene Expression Profile Of C-myc In The Differentiation

The antler possesses very high value for human health care. Tarim wapiti is one of the important economic animal in the southern of Xinjiang for its antler with a desirable quality. Deer antlers are the only mammalian appendages that are subject to an annual cycle of epimorphic regeneration, and its features and mechanisms draws more and more attention. c-myc gene is a transcription factor of proto-oncogene family.The study found that it is up-regulated in many cancer tissues. c-myc gene have many function for normal cells that, it can regulate the proliferation, differentiation and apoptosis. The aim of the study was to construct culture model of antler mesenchyma stem cells（MSCs） and cartilage differentiation by inducing TGFβ₁ in vitro, and investigated c-myc’s expression patterns in its differentiation using realtime PCR. This can provide the basis for antler growth and human development of cartilage and bone diseases, also provide theoretical support for study the rapid growth mechanism of antler.1、the antler mesenchymal stem cells were successful obtained using an enzyme digestion andtissue method. The results showed that the sample tissues completely adhered on the culture flask on 1^thd. A few on cellsgrown out of tissues block were observed on 2^thd. Cells reached confluency after 6^thd. The cells of the second passage to the sixth passage reached growth peak at 4^thd. The spindle-shaped original antler mesenchymal stem cells and nucleus with oval-shaped were observed, while the passage cells were triangle. DMSO（5%） as a frozen liquid made cells been long-term frozen.2、Join 10 ng/mL TGFβ₁,10^-7 M dexamethasone and 50 μg/mL ascorbic acid in the culture medium as induction medium to inducted antler mesenchymal stem cells in to chondrocytes. The results show that Cells were detected to express little CoLâ…¡ onthe 7（th）day,but don’t detected Proteoglycans. Alcian blue staining and to luidnedine blue staining revealed heavy positive staining in the cellular matrix from the 21^thday. In the21^thday cells’ expression of Co Lâ…¡ is significantly higher than other days cells’（p<0.05）, and the amount of extracellular collagen type â…¡ was identified by immunohistochemistry. After 28^thd the cells’ expression of Co Lâ…¡ is reduce,expression of Co LΙ is sig nificantly increased（p<0.05）. Now cells matured and differentiate into bone cells. After35^thd the cells’ expression of Co Lâ…¡ and Co LΙ are reduce, the positive cell rate in each stage of the immunohistochemical and alizarin red staining’s results showed significant difference, respectively（p<0.05）.3、In process of the antler mesenchymal stem cells differentiation, c-myc expression was low level, induced 7^thd get highest, expression has been declining until 21^thd and get the lowest. After 21^thd the c-myc expression increased, but there was no significant difference in the expression of 7^thd. In conclusion Tarim wapiti antler’ mesenchymal stem cells can be induced to chondrocyte differentiation by 10 ng/mL TGFβ₁,and differentiated cells had can secrete cartilage markers of COLâ…¡and proteoglycan. It was proposed that the down-regulate expression of c-myc affected the process of antler MSCs cartilage differentiation.