title: Identification of estrogen-regulated genes during fracture healing, using DNA microarray.
abstract: Estrogen deficiency impairs fracture healing, while estrogen treatment of ovariectomized rats accelerates fracture healing. To identify genes regulated by estrogen during fracture healing, we evaluated gene expression in calluses from three groups of rats: sham-operated, ovariectomized, and ovariectomized and treated with estrogen. RNA from calluses harvested 10 days after fracture was subjected to DNA microarray-based analysis of 5147 genes. In total, 52 genes were identified whose mRNA expressions were found to be downregulated by ovariectomy but restored with estrogen. Differential mRNA expression of 4 genes (collagen type 2, extracellular superoxide dismutase, urokinase-type plasminogen activator [ u-PA], and ptk-3) was confirmed by reverse transcription polymerase chain reaction. Further, chondrocytes and chondroclasts were positive for u-PA in the junction between cartilage and bone, implying its importance in resorption and remodeling of callus. Identification of these genes is a prerequisite to understanding the mechanism by which estrogen influences the complex metabolic process of fracture repair.
authors.affiliation: Department of Orthopedic Research, Mayo Clinic and Foundation MSB3-69, 200 First Street SW, Rochester, MN 55905, USA.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hatano
authors.forename: Herrick J
authors.initials: HJ
authors.lastname: Siegel
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamagiwa
authors.forename: James T
authors.initials: JT
authors.lastname: Bronk
authors.forename: Russell T
authors.initials: RT
authors.lastname: Turner
authors.forename: Mark E
authors.initials: ME
authors.lastname: Bolander
authors.forename: Gobinda
authors.initials: G
authors.lastname: Sarkar
mesh_terms: D000818:Animals; D002146:Bony Callus / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D015536:Down-Regulation / Q000187:drug effects; D004967:Estrogens / Q000378:metabolism* / Q000494:pharmacology; D020224:Expressed Sequence Tags; D005260:Female; D017102:Fracture Healing / Q000235:genetics*; D050723:Fractures, Bone / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D020869:Gene Expression Profiling; D020411:Oligonucleotide Array Sequence Analysis; D010052:Ovariectomy; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D015203:Reproducibility of Results; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014568:Urokinase-Type Plasminogen Activator / Q000378:metabolism
chemical_list: D004967:Estrogens; D012333:RNA, Messenger; D014568:Urokinase-Type Plasminogen Activator