title: Imbalance of RANK, RANKL and OPG expression during tibial fracture repair in diabetic rats.
abstract: To clarify the mechanisms of altered bone repair in the diabetic state, we investigated RANK, RANKL and OPG expression by immunohistochemistry and RT-PCR in the fracture sites of rats that were either healthy or made diabetic by alloxan. Histomorphometric analysis of the fracture site at 7 days after fracture revealed that diabetic rats (db) have significantly less hard tissue formation at the fracture site, compared to controls. The number of RANK, RANKL and OPG positive cells was decreased in the db group; however, the RANKL/OPG ratio was similar in controls and db at this time. At day 14, numbers of RANKL and OPG positive cells and the mRNA expression for these markers were higher in the control group than in db (P = 0.008). The RANKL/OPG ratio in the db group was greater than in controls. Our results demonstrate an imbalance of RANKL/OPG expression associated with diabetes that may contribute to the delay of fracture repair during the course of diabetes.
authors.affiliation: Department of Pathology, Faculty of Medicine, University of Brasília, Brasilia, Distrito Federal, Brazil.
authors.forename: Fernanda Penna Lima Guedes
authors.initials: FP
authors.lastname: de Amorim
authors.forename: Sócrates Souza
authors.initials: SS
authors.lastname: Ornelas
authors.forename: Sandoval Felicíssimo
authors.initials: SF
authors.lastname: Diniz
authors.forename: Aline Carvalho
authors.initials: AC
authors.lastname: Batista
authors.forename: Tarcília Aparecida
authors.initials: TA
authors.lastname: da Silva
mesh_terms: D000496:Alloxan / Q000494:pharmacology; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000139:chemically induced / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D008297:Male; D053244:Osteoprotegerin / Q000235:genetics / Q000378:metabolism*; D053245:RANK Ligand / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000235:genetics / Q000378:metabolism*; D013978:Tibial Fractures / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*
chemical_list: D001786:Blood Glucose; D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; D000496:Alloxan