Contribution of membrane skeletal protein in osteoblast for bone remodeling

Research Project

Project/Area Number	10671388
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Orthopaedic surgery
Research Institution	Tokyo Women's Medical University
Principal Investigator	HORIKOSHI Mariko (1999) Tokyo Women's Medical University, Dep.of Orthopaedic Surgery, Assistant Professer, 医学部, 講師 (00287400) 堀越万里子 (1998) 東京女子医科大学, 医学部, 講師
Co-Investigator(Kenkyū-buntansha)	INOUE Kazuhiko Tokyo Women's Medical University, Dep.of Orthopaedic Surgery, Professer, 医学部, 教授 (70095024) TAKAKUWA Yuichi Tokyo Women's Medical University, Dep.of Biochemistry, Professer, 医学部, 教授 (40113740)
Project Period (FY)	1998 – 1999
Project Status	Completed (Fiscal Year 1999)
Budget Amount *help	¥3,000,000 (Direct Cost: ¥3,000,000) Fiscal Year 1999: ¥600,000 (Direct Cost: ¥600,000) Fiscal Year 1998: ¥2,400,000 (Direct Cost: ¥2,400,000)
Keywords	bone remodeling / osteoblast / membrane skeleton / protein 4.1 / CD44 / CO44 / 骨リモデーリング / 骨芽細胞(正常ヒト) / CD44 / 骨 / 細胞膜裏打ち構造 / 刺激分泌連関 / 細胞接着
Research Abstract	Remodeling of bone tissue is maintained by bone formation and absorption which are regulated by osteoblasts and osteclasts, respectively. This remodeling is affected by systematic and local factors secreted from these cells as well as cell adhesion. Membrane skeleton has been shown to be involved in secretion of local factors and cell adhesion in other tissues, however, little information is available concerning the skeletal proteins in osteoblasts. In the present experiments we aimed to show the presence and distribution of membrane skeletal proteins in cultured osteoblasts. Analysis of membrane proteins obtained from mouse cultured osteoblasts (MC3T3-E1) by SDS-PAGE and immunobloting using anti-membrane skeletal proteins such as protein 4.1 as well as transmembrane proteins such as CD44 indicated presence of protein 4.1 and CD44. mRNA of these proteins were identified by analysis of cDNA amplified using RT-PCR of total mRNA obtained from the cultured cells. Immunostaining showed distribution of protein 4.1 in the cytoplasm as well as membranes of these cells. These results were basiccaly confirmed using human cultured osteoblasts (Cryo NHOst). Taken together these relults suggest that the membrane skeletal organization is present in the osteoblasts and that this system may be involved in regulation of secretion and adhesion of osteoblasts.