title: Leptin receptors and beta2-adrenergic receptor mRNA expression in brain injury-related heterotopic ossification.
abstract: Heterotopic ossification (HO) frequently occurs after brain injury. Recently, we found that leptin levels were decreased in the serum of patients with HO. Data suggest two mechanisms mediating leptin effects: a central suppressive mechanism acting via the beta(2)-adrenergic system and a direct stimulatory action starting when leptin binds to its receptors in osteoblastic cells. In this study, we analyzed leptin and beta(2)-adrenergic receptors mRNA expression in osteocytes originated from normal or heterotopic bone biopsies to investigate whether direct or indirect pathway signaling might be implicated in this pathological bone formation. We report for the first time the mRNA expression of the leptin receptor isoforms in osteocytes isolated from all biopsies. Moreover, quantitative reverse transcription-polymerase chain reaction allowed us to measure a significant decrease in the level of beta(2)-adrenergic receptor mRNA in cells isolated from heterotopic bone biopsies. These results could suggest an association between hypothalamic leptin signaling and brain injury-related HO.
authors.affiliation: LBCM-Laboratoire de Biologie Cellulaire et Moleculaire, EA2603-IFR114 IMPRT, Universite Lille Nord de France, Boulogne-sur-mer, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Chauveau
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Devedjian
authors.forename: Christophe
authors.initials: C
authors.lastname: Delecourt
authors.forename: Joseph
authors.initials: J
authors.lastname: Jeanfils
authors.forename: Pierre
authors.initials: P
authors.lastname: Hardouin
authors.forename: Odile
authors.initials: O
authors.lastname: Broux
mesh_terms: D000328:Adult; D001930:Brain Injuries / Q000150:complications* / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D006801:Humans; D020738:Leptin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000209:etiology / Q000378:metabolism*; D010011:Osteocytes / Q000166:cytology / Q000378:metabolism*; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018343:Receptors, Adrenergic, beta-2 / Q000235:genetics / Q000378:metabolism*; D054411:Receptors, Leptin / Q000235:genetics / Q000378:metabolism*
chemical_list: D020738:Leptin; D016760:Proto-Oncogene Proteins c-fos; D012333:RNA, Messenger; D018343:Receptors, Adrenergic, beta-2; D054411:Receptors, Leptin