Substance P promotes expression of bone morphogenetic protein 2 in bone marrow stromal cells and its relationship with Wnt pathway

Abstract

Objective To explore how substance P(SP) regulates expression of bone morphogenetic protein 2 (BMP-2) in bone marrow stromal cells (BMSCs) in the respects of time and concentration effects and relationship with Wnt signaling pathway. Methods The third passage of BMSCs from SD rats were divided into 4 groups (n = 3) which were added respectively with: phosphate buffered saline (PBS) (control), SP (10-8 mol/L), SP (10-10 mol/L), and SP (10-12 mol/L). At 7, 14 and 21 days after culture, cellular morphology was observed by light microscopy, expression of alkaline phosphatase (ALP) and BMP-2 was detected using Western blot. After the best concentration of SP was determined, the third passage BMSCs from SD rats were then divided into 3 groups (n = 3) which were added respectively with: PBS (control), SP, and SP + DKK1 (dickkopf 1). Protein expression of BMP-2 and β-catenin was detected using western blot. Results At 14 days, ALP protein was significantly more in SP (10-8 mol/L) group (1.428±0.166) and SP (10-10 mol/L) group (1.742±0.221) than in control group (P < 0.05). At 14 days, BMP-2 was significantly more in SP(10-8 mol/L) group(1.801±0.239), SP (10-10 mol/L) group (4.070±0.297) and SP (10-12 mol/L) group (1.943±0.196) than in control group(P < 0.05). At 21 days, BMP-2 was significantly more in SP (10-10 mol/L) group (2.960±0.324) and SP (10-12 mol/L) group (2.652±0.265) than in control group(P < 0.05). The best concentration of SP was 10-10 mol/L. BMP-2 at 7, 14 and 21 days (4.300±0.297, 2.290±0.175 and 3.160±0.234) was significantly more in SP group than in control group and SP + DKK1 group(P < 0.05). β-catenin at 14 and 21 days in SP group (1.553±0.210 and 1.471±0.170) was significantly more than in SP + DKK1 group and control group (P < 0.05). Conclusions SP can promote expression of BMP-2 in BMSCs. The regulation of BMP-2 expression in BMSCs by SP has time and concentration effects and may be associated with the Wnt signaling pathway. Key words: Substance P; Bone marrow cells; Mesenchymal stem cells; Bone morphogenetic proteins; Signaling transduction