Effect Of Age On Proliferation Of Rat Bone Marrow Stromal Cells And Differentiation Of Them Into GAD And ChAT Immunoreactive Cells

Bone marrow stromal cells (BMSCs) are multipotential and have the ability to self-renew. In addition, BMSCs are easy to be obtained and good for self-transplantation. Therefore BMSCs are considered as one kind of promising candidates for tissue-engineering and cell therapy. To achieve better efficiency of cell therapy , the problems such as, to get enough BMSCs, and to induce them into specified neurons, should be solved before transplantation. In present study, cell culture, immunohistochemistry and hematoxylin stainning were used to detect the effect of age (neonatal, adult and aged) on proliferation of BMSCs; BDNF and BME were used to induce the adult BMSCs' differentiation. In the proliferation study, BMSCs were isolated from femurs marrow of neonatal (1-2 days after born), adult (2-3months old) and aged rats (>18 months old), planted on plastic flask respectively and cultured with DMEM media containing 20% PCS at 37癈 and with 5%CO2. In different time point, BrdU was added to the cultures and then the proliferation rates were calculated. In the differentiation study, the BMSCs were induced to differentiate by BDNF and BME, then specific antibodiesagainst NF-200, NeuN, GFAP , GAD and ChAT were used to characterize the differentiated BMCs. The results indicated: 1. at day 5, 7 and 9, the BMSCs grew quickly. At day 5,the proliferation rates of BMCs from neonatal, adult and aged rats were 78.7±5.3%, 72.0±3.3% and 65.4±3.9% respectively. At day 7, they were 78.3±3.2%, 67.3±3.9% and 52.6±6.0% respectively; At day 9, they were 66.9 ± 3.3%, 46.4 ± 3.9%,39.1 ± 2.2% respectively. Statistical analysis showed that the differences of proliferation rates among three different groups of age were significant (P<0.05). 2. After induced, some BMSCs exhibited neuron-like characteristics morphologically and were immunopositive for NF-200, MAP-2 and NeuN, but negative for GFAP. And some cells expressed GAD and ChAT . The results demonstrated that the proliferation capability of BMSCs was decreased with aging and they can be induced to differentiate into neuron-like cells and some of the induced cells expressed GAD and ChAT.