title: Distribution of type VI collagen in association with osteoblast lineages in the groove of Ranvier during rat postnatal development.
abstract: In the groove of Ranvier (GOR), osteoblast lineages form bone bark, which develops into endosteal cortical bone. This ossification process is thought to be regulated by the microenvironment in the GOR. Type VI collagen (Col VI), an extracellular matrix (ECM) protein found in the periosteum/perichondrium, mediates osteoblast differentiation via the cell-surface receptor neural/glial antigen 2 (NG2) chondroitin sulfate proteoglycan. In order to clarify the function of Col VI during osteoblast differentiation in the GOR, in the present study, we examined the distribution of Col VI and osteoblast lineages expressing NG2 in the rat tibia proximal end during postnatal growing periods by immunohistochemistry. Our data revealed that Col VI accumulated in the ECM of the GOR middle layer and that Col VI accumulation was reduced and disappeared in the inner and middle lower regions. Runt-related transcription factor 2-immunoreactive pre-osteoblasts expressed NG2 in Col VI-immunopositive areas. However, Osterix-immunoreactive mature osteoblasts were only found in the Col VI-immunonegative area. These findings indicate that Col VI provided a characteristic microenvironment in the GOR and that NG2-Col VI interactions may regulate the differentiation of osteoblast lineages prior to terminal maturation.
authors: Laboratory of Veterinary Anatomy, Nippon Veterinary and Life Science University, Tokyo, Japan.
authors: Yukihiro
authors: Y
authors: Kohara
authors: Laboratory of Veterinary Anatomy, Nippon Veterinary and Life Science University, Tokyo, Japan. Electronic address: s-soeta@nvlu.ac.jp.
authors: Satoshi
authors: S
authors: Soeta
authors: Department of Molecular Pharmacology, Medical Research Institute, Tokyo Medical and Dental University, Tokyo, Japan.
authors: Yayoi
authors: Y
authors: Izu
authors: Laboratory of Veterinary Surgery, Nippon Veterinary and Life Science University, Tokyo, Japan.
authors: Kiyotaka
authors: K
authors: Arai
authors: Laboratory of Veterinary Anatomy, Nippon Veterinary and Life Science University, Tokyo, Japan.
authors: Hajime
authors: H
authors: Amasaki
mesh_terms: D000375:Aging / Q000378:metabolism / Q000473:pathology; D000818:Animals; D000941:Antigens / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D019070:Cell Lineage / Q000502:physiology; D024142:Collagen Type VI / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology; D006132:Growth Plate / Q000166:cytology* / Q000378:metabolism*; D008297:Male; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism*; D011509:Proteoglycans / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014018:Tissue Distribution; D000099216:Chondroitin Sulfate Proteoglycan 4
chemical_list: D000941:Antigens; D024142:Collagen Type VI; D011509:Proteoglycans; D000099216:Chondroitin Sulfate Proteoglycan 4
keywords: Bone bark; NG2; Osteoblast; Osterix; Runx2; Type VI collagen