Novel function of mTOR in inducing intervertebral disc degeneration

Research Project

Project/Area Number	25861303
Research Category	Grant-in-Aid for Young Scientists (B)
Allocation Type	Multi-year Fund
Research Field	Orthopaedic surgery
Research Institution	University of Yamanashi
Principal Investigator	WAKO Masanori 山梨大学, 総合研究部, 助教 (30402077)
Research Collaborator	HARO Hirotaka 山梨大学, 総合研究部, 教授 (10313264) ANDO Takashi 山梨大学, 総合研究部, 助教 (10377492) SATO Nobutaka 山梨大学, 総合研究部, 助教 (00418716)
Project Period (FY)	2013-04-01 – 2015-03-31
Project Status	Completed (Fiscal Year 2014)
Budget Amount *help	¥4,160,000 (Direct Cost: ¥3,200,000、Indirect Cost: ¥960,000) Fiscal Year 2014: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000) Fiscal Year 2013: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Keywords	トロンビン / PAR-1 / MCP-1 / migration / 骨折 / 組織因子 / 椎間板 / mTOR
Outline of Final Research Achievements	We herein report various effects of thrombin on mouse osteoblastic MC3T3-E1 cells. MC3T3-E1 cells expressed PAR1, also known as the coagulation factor II receptor. They also produced MCP-1, tissue factor (TF), MCSF and IL-6 upon thrombin stimulation through PI3K-Akt and MEK-Erk1/2 but not the MKK-p38 pathway. Furthermore, MCP-1 obtained from thrombin-stimulated MC3T3-E1 cells induced migration by macrophage RAW264 cells. All these effects of thrombin on MC3T3-E1 cells were abolished by the selective non-peptide thrombin receptor inhibitor SCH79797. We also found that thrombin, PAR-1, MCP-1, TF as well as phosphorylated AKT and p42/44 were significantly expressed at the fracture site of mouse femoral bone. Collectively, thrombin/PAR-1 interaction regulated MCP-1, TF, MCSF and IL-6 production by MC3T3-E1 cells. Furthermore, MCP-1 induced RAW264 cell migration. Thrombin may thus be a novel cytokine that regulates several aspects of osteoblast function and fracture healing.