Objective To observe the effect of intercellular adhesion molecule on neuronal differentiation of P19 cells in vitro.Methods Monolayer P19 cells were cultured on the plates coated with 0.1% gelatin, 2.5 mg/L and 10 mg/L N-cad-Fc (a fusion protein of the N-cadherin extracellular domain and the IgG Fc domain), and then 5 × 10-7mol/L retinoic acid (RA) was used to induce neuronal differentiation of P19 cells. Neuron-specific class Ⅲβ-tubulin (Tuj-1) antibody was examined by immunofluorescence staining. The protein expressions of oct3/4 in stem cells, nestin in precursor cells, ngnl and map2 in neurons and gfap in glial cells were detected by reverse transcription-polymerase chain reaction (RT-PCR).Results RA at 5 × 10-7mol/L could induce P19 cells to differentiate into neurons. The average differentiation rates on 0. 1% gelatin, 2. 5 mg/L and 10 mg/L N-cad-Fc were 7. 8%, 28. 6% and 26.8%, respectively. Cells cultured on N-cad-Fc coated plates dramatically up-regulated the expressions of neural-specific proteins ngnl and map2. The expression of stem cell specific protein oct3/4 was decreased ahead of schedule and the expression of glial cell specific protein gfap could not be found by RT-PCR. Conclusions RA can induce P19 cells to differentiate into neuronal cells. Intercellular adhesion molecule has promotional effect on cell differentiation.

Objective Evaluating important factors which have effects on cardiomyocyte differentiation and to optimize differentiation efficiency.Methods Hanging drop method or 96-well plate method were used to produce aggregates.DMSO was used to induce cardiomyocyte differentiation of P19 cells.Beating cells were detected with microscopy and cardiomyocyte specific protein Troponin T was examined by immunostaining.RT-PCR was applied to evaluate the expression of cardiomyocyte related genes.Results Compared with Hanging drop method,96-well plate method facilitated aggregate formation and adhesion.Adding DMSO improved aggregates integrity.Seeding concentration of 1?107～2?108L-1 caused the most effective differentiation.Troponin T immunostaining was observed before cells started beating.Conclusion By optimizing the method for aggregates formation,differentiation inducing chemicals and cell seeding concentration,it is possible to improve cardiomyocyte differentiation effect of P19 cells.This might provide us a way for cardiomyocyte differentiation with high efficiency.