OBJECTIVETo explore the differentiation and the variant expression of protein of the bone marrow stromal stem cells (BMSCs) when the BMSCs differentiated into the neuronal cells in the analogous micro-environment of spinal cord injury.

METHODSBMSCs were isolated from bone marrow of Wistar rats and labeled with PKH26 (control group), and then were cocultured with neural cells, which were isolated from the spinal cord of the fetal rats, in the same plate well (co-culture group) or in the two-layer Petri well (two-layer group). Eight days later, the BMSCs were identified by immunofluorescence staining of NSE and GFAP respectively. The apparently changing proteins were analyzed by SELDI-TOF-MS while the BMSCs differentiated into neurons.

RESULTSEight days after co-culturing with neural cells in the same plate well or in the two-layer Petri well, BMSCs appeared more similar with neural cells. The immunofluorescence identification showed that, NSE and GFAP of which the BMSCs of the two-layer group expressed were obviously higher than control group (P < 0.05); and these two proteins of co-culture group were also obviously higher than the other two groups (P < 0.05). Five proteins in the co-culture group changed obviously as followed: TIP39_RAT and CALC_RAT were 5.360 and 2.807 times of that in the control group; INSL6_RAT, PNOC_RAT and PCSK1_RAT were 38.0, 49.9 and 43.8 percent of those in the control group.

CONCLUSIONSBMSCs could differentiate into neural cells in vitro, and the differentiation ratio of BMSCs in the co-culture group is higher than that of the two-layer group. Five proteins, including TIP39_RAT, CALC_RAT, INSL6_RAT, PNOC_RAT and PCSK1_RAT, are correlated closely to the mechanisms of which the BMSCs differentiated into neurons.