OBJECTIVETo study whether the nuclear factor-kappa B (NF-kappaB) play a role in differentiation of marrow stroma cells (MSCs) into neuron-like cells induced by Ciwujia injection in vitro.

METHODRats were randomly divided into control group and Ciwujia induced group. Cell morphology was observed with invert microscope; MSCs phenotype, expression of neural marker protein and nucleus translocation of NF-kappaB subunit RelA (p65) after induction were observed by immunofluorescence; Expression of IkappaBalpha in Ciwujia induced group and control group was detected by Western blot.

RESULTThe decreased volume of some MSCs, strengthened three-dimensional structure and shrinkage of cell body with formation of spire or round was observed after induction by Ciwujia for 1 hour. After 5-hour exposure to Ciwujia, changes in the morphology of MSCs were as follows: appearance of more triangular or round shapes cells, retraction of microfilament in MSCs, formation of slender process from pseudopod with reticular structure, exfoliation and necrosis. After 7-day induction, most MSCs became triangular and round shapes, exhibiting a typical neuronal structure. Immunofluorescence method showed that nestin expression displayed intensively positive in Ciwujia group at 1 hour, and still remain positive at 7 day. However, beta-III Tubulin expression was weakly positive at 1 hour and intensive positive at 3 and 5 hour. It was still positive at 7 day. NSE expression was weakly positive at 3 hour and intensive positive at 5 hour and 7 day. GFAP expression was negative. However, in the control group, every expression of marker protein was negative or weakly positive. Expression of p65 was in cytoplasm. Western blot method showed IkappaBalpha protein relative IA was 1.000 before induction. It was 0.4556 +/- 0.1008 after induction in Ciwujia group and decreased significantly than before induction (P < 0.01). It was 0.0296 +/- 0.0099 after induction in control group and decreased significantly than before induction and in Ciwujia group (P < 0.01).

CONCLUSIONThe data showed that MSCs can induce differentiation into neuron-like cells by Ciwujia, and Ciwujia could inhibit the translocation of NF-kappaB from the cytoplasm to the nucleus, which may be relate to the differentiation of MSCs into neuron-like cells.