Opg/Rankl mRNA dynamic expression in the bone tissue of ovariectomized rats with osteoporosis

Abstract

ABSTRACT.We established animal models of osteoporosis in ovariectomized rats to detect osteoprogerin (Opg)/receptor activator of nuclear factor-kB ligand (Rankl) mRNA expression levels in the tibias and serum estradiol concentrations at different time points. Sixty Sprague-Dawley female rats were randomly selected and divided into an ovariectomized (OVX) group and sham-operated (SHAM) group. In the SHAM group, only a small amount of abdominal fat and tissues was removed from the rats. Ten rats in each group were sacrificed at 0, 6, and 12 months after establishing the animal models (12 weeks). Opg mRNA expression and serum estradiol concentration in the OVX group were significantly lower than those in the SHAM group (P < 0.05). In contrast, Rankl mRNA expression in the OVX group was significantly higher than that in the SHAM group (P < 0.05). In the OVX group, Opg mRNA expression and serum estradiol concentrations decreased C. Li et al. 9216©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (3): 9215-9224 (2015) significantly from 0 to 12 months (P < 0.05), whereas Rankl mRNA expression increased significantly (P < 0.05). Opg mRNA expression and serum estradiol concentrations in the OVX group continually decreased, whereas Rankl mRNA expression continually increased. The Opg/Rankl ratio showed a decrease. The OPG/RANKL ratio may be a key factor affecting the osteoblast-mediated reaction.

Protective Effect of Oxytocin Against Bone Loss in a Female Rat Model of Osteoporosis

“…A negative correlation was seen between RANKL mRNA and OT levels in groups II and III rats. These results were in agreement with those of previous studies (20,23). OPG and RANKL proteins are thought to influence postmenopausal osteoporosis; RANKL stimulates osteoclast differentiation, while OPG acts as a decoy receptor for RANKL, thus downregulating RANKL signaling through RANK and acting as an inhibitor of bone resorption (27).…”

Heartwood extract from Dalbergia sissoo promotes fracture healing and its application in ovariectomy-induced osteoporotic rats

“…Osteoclast differentiation and activation is associated with reduction in the OPG/RANKL ratio . Ovx favours reduced OPG/RANKL ratio in the bones of rats and promotes bone loss . Enhanced expression of OPG/RAKL ratio in osteoblasts was observed in E2 or selective estrogen receptor modulator (Raloxifene) treatments .…”

Genistein prevents bone loss in type 2 diabetic rats induced by streptozotocin

“…Osteoblasts and bone marrow stromal cells express RANKL, which can bind with the RANK on osteoclasts to stimulate osteoclast maturation and increase bone resorption. Simultaneously, osteoblasts also secrete OPG, which competitively combines with RANK and inhibits formation and maturation of osteoclasts (39). Numerous studies showed that hyperglycemia and enhanced inflammation caused by diabetes might lead to an increased RANKL/OPG ratio or affect osteoblasts through other mechanisms to aggravate bone resorption, and ultimately increase the fracture risk (10,(40)(41)(42)(43).…”