RESUMO
Liver receptor homologue 1 (Lrh-1) is a member of the nuclear receptor belonging to the second subfamily of the nuclear receptor family 5A (NR5A), also named NR5A2, which is important for lipid homeostasis, embryogenesis, and regulation of aromatics. The present study aimed to understand the sequence of ovine Lrh-1 and the expression traits in reproductive organ tissues. Initially, we cloned Lrh-1 from the liver of Hu sheep through degenerate primer of reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends. Characteristic functional domains of DNA binding and ligand binding, conserved among transcription factors of the nuclear receptor superfamily, were identified in Lrh-1 of Hu sheep. The Lrh-1 protein levels in the tissues detected by Western blotting correlated significantly with the transcript levels measured by quantitative real-time polymerase chain reaction (qRT-PCR). To understand the Lrh-1 expression change in the hypothalamus and hypophysis during the estrous cycle, we analyzed the expression pattern of Lrh-1 mRNA and protein by qRT-PCR and Western blotting, respectively. This analysis revealed that Lrh-1 expression in the hypothalamus was highest during the metestrus phase, while the Lrh-1 level was similar during other phases. In the hypophysis, the expression was significantly different during the 4 phases of the estrous cycle but highest during the estrus phase, significantly correlating with FSH concentration. These results indicate that Lrh-1 expression is correlated with gonadotropic hormone secretion, influencing follicular formation in the ovary.
Assuntos
Regulação da Expressão Gênica , Receptores Citoplasmáticos e Nucleares/genética , Ovinos/genética , Sequência de Aminoácidos , Animais , China , Clonagem Molecular , Ciclo Estral , Feminino , Perfilação da Expressão Gênica , Sistema Hipotálamo-Hipofisário/metabolismo , Fígado/metabolismo , Dados de Sequência Molecular , Oviductos/metabolismo , Receptores Citoplasmáticos e Nucleares/sangue , Receptores Citoplasmáticos e Nucleares/química , Alinhamento de Sequência , Ovinos/sangue , Ovinos/classificaçãoRESUMO
In the present study, we systematically examined telmisartan, an angiotensin AT(1) receptor antagonist, on rosiglitazone-induced bone loss in ovariectomized spontaneously hypertensive rats. Telmisartan (5 mg/kg/d, 90 days) was found to be able to significantly alleviate rosiglitazone (10 mg/kg/d, 90 days)-induced decrease in BMD of femur and lumbar vertebrae. The BMD changes were associated with positive biomechanical changes of lumbar vertebrae, improvements in microarchitecture of tibial metaphysic and normalized serum osteocalcin (OC) levels and urinary deoxypyridinoline/creatinine (DPD/Cr) ratio. MicroCT analysis of the tibial metaphysis showed that telmisartan significantly prevented the decreases in bone volume/tissue volume (BV/TV), connect density (Conn. D.), trabecular number (Tb. N.) and trabecular thickness (Tb. Th.), and increase in trabecular separation (Tb. Sp.) induced by rosiglitazone. Histomorphometric analysis also showed that telmisartan had protective effects on rosiglitazone-reduced bone formation indices such as histomorphometric bone volume fraction (BV/TV-Histo), mineralizing surface/bone surface (MS/BS), mineral apposition rate (MAR) and bone formation rate (BFR/BS). Our study clearly showed that telmisartan alleviated rosiglitazone-induced bone loss in ovariectomized spontaneous hypertensive rats. The relief of bone loss provides a possible therapeutic application of telmisartan with rosiglitazone for the treatment of elderly women patients afflicted with metabolic syndrome.