title: Homeoprotein Hex is expressed in mouse developing chondrocytes.
abstract: Endochondral ossification is a complex process involving the formation of cartilage and the subsequent replacement by mineralized bone. Although the proliferation and differentiation of chondrocytes are strictly regulated, the molecular mechanisms involved are not completely understood. Here, we show that a divergent-type homeobox gene, hematopoietically expressed homeobox gene (HEX), is expressed in mouse chondrogenic cell line ATDC5. The expression of Hex protein drastically increased during differentiation. The chondrogenic differentiation-enhanced expression of Hex protein was also observed in chondrocytes in the tibia of embryonic day 15.5 (E15.5) mouse embryos. The localization of Hex protein in the chondrocytes of the tibia changed in association with maturation; namely, there was Hex protein in the cytoplasm near the endoplasmic reticulum (ER) in resting chondrocytes, which moved to the nucleus in prehypertrophic chondrocytes, and thereafter entered the ER in hypertrophic chondrocytes. These results suggest Hex expression and subcellular localization are associated with chondrocyte maturation.
authors: Department of Physiological Chemistry II, Faculty of Pharmaceutical Science, Teikyo University, Kanagawa, Japan. r-morimo@pharm.teikyo-u.ac.jp
authors: Riyo
authors: R
authors: Morimoto
authors: Akitsugu
authors: A
authors: Yamamoto
authors: Yoshihiro
authors: Y
authors: Akimoto
authors: Akiko
authors: A
authors: Obinata
mesh_terms: D000818:Animals; D002356:Cartilage / Q000254:growth & development / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics*; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism*; D020219:Chondrogenesis / Q000235:genetics*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics*; D017403:In Situ Hybridization / Q000379:methods; D051379:Mice; D014157:Transcription Factors / Q000235:genetics*
chemical_list: C513080:Hhex protein, mouse; D018398:Homeodomain Proteins; D014157:Transcription Factors