Abstract: Objective To investigate the possible mechanism of CB-MSCs differentiated into DA neuron-like cells induced by PTN. Method Preparation of the mononuclear cell fraction was performed by the Ficoll gradient technique according to the manufacturer’s instructions. rPTN was added as inducing group (rPTN group), passage 1 CB-MSCs with H-DMEM as control group (CON group). 48hours later, RT-PCR and immunofluorescence were employed to indentify the expression of PTN and its receptors SDC3、ALK, also to indentify the expression of TH、DAT and NSE. Results During the induction, cell morphology changed obviously, the expression of TH, DAT, and NSE increased .The ratio of positive cells were: TH(CON group): 3.77±0.42，（rPTN group）: 7.91±0.55；DAT(CON group): 1.89±0.28，（rPTN group）: 为6.21±0.77；NSE(CON group): 4.35±0.76，（rPTN group）: 7.67±0.97；The expression of SDC3 also increased comparing with the CON group. Our study discovered PTN can promote the PTN secretion of CB-MSCs. The ratio of positive cells were: PTN(CON group): 14.38±0.54，（rPTN group）: 20.21±1.51；SDC3(CON group): 5.70±0.78，（rPTN group）: 10.02±1.45；ALK(CON group): 4.87±0.34，（rPTN group）:5.01±0.99; Conclusion PTN could induce CB-MSCs differentiate into DA neuron-like cells by prompting CB-MSCs express PTN and its receptor SDC3.

Key words: CB-MSCs, PTN, dopaminergic neuron cells