Substance P stimulates differentiation of mice osteoblast through up-regulating Osterix expression.
OBJECTIVE
To investigate the molecular pathway of substance P (SP) to induce osteoblastic differentiation.


METHODS
Mesenchymal stem cells were isolated and cultured. The cultures were divided into four groups with Group A (control group) cultured without any factors, Group B cultured with SP, Group C cultured with SP and SP receptor neurokinin-1 (NK1) antagonist, and Group D cultured with SP NK1 antagonist respectively to induce osteoblastic cells differentiation. Osterix gene expression was detected by reverse transcription-polymerase chain reaction (RT-PCR) for three times after 1-2 weeks of cultivation and the results were analyzed by one-way analysis of variance (ANOVA).


RESULTS
The log phase of bone marrow stromal cells appeared at 4-6 days. ALP staining revealed that the majority of cells, more than 95%, were positive and small blue-purple granules were found in the cytoplasm. And Group B, treated with SP, showed a higher level of ALP activity than the other three groups. Meanwhile, RT-PCR found that Osterix expression in Group B was obviously up-regulated, compared with other groups. But Osterix expression in Group D had no remarkable differences, compared with the controls.


CONCLUSIONS
SP can up-regulate Osterix gene expression to stimulate differentiation of mesenchymal stem cells into osteoblastic cells at the final stage. The regulatory effect of SP on Osterix expression was dependant on SP NK1 receptors.
Sun
Hai-biao
HB
Department of Orthopedics, First Affiliated Hospital, Shanxi Medical University, Taiyuan, China. suny0607@163.com
Chen
Jun-chang
JC
Liu
Qiang
Q
Guo
Min-feng
MF
Zhang
Hua-ping
HP
D000469:Alkaline Phosphatase / Q000032:analysis; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013373:Substance P / Q000494:pharmacology*; D014157:Transcription Factors / Q000235:genetics*; D015854:Up-Regulation
C495181:Sp7 protein, rat; D014157:Transcription Factors; D013373:Substance P; D000469:Alkaline Phosphatase