Effect of adiponectin on the expression of osteoprotegerin and receptor activator of nuclear factor-kappa B ligand in osteoblasts

Qun LI; Bi HUANG; Hui XIE; Lingqing YUAN

ABSTRACT

BACKGROUND:

The main role that the osteoprotegedn (OPG) plays in bone tissues is to inhibilate the formation and the activity of osteoclast, while as for the receptor activator of nuclear factor-κB ligand (RANKL), it is to stimulate the differentiation and the activity of osteoclast. Both OPG and RANKL are important for the regulation of osteoclastic function. Recent studies have found the stimulative effects of adiponectin on the proliferation and the differentiation of osteoblast, as well as the coupling between adiponectin and bone metabolism. But effects of adiponectin on osteoclast remain unclear.

OBJECTIVE:

To investigate the effect of adiponectin on the expression of OPG and RANKL in osteoblast, and to further analyze its effects on the formation of osteoclast. DESIGN, TIME AND

SETTING:

A contrast observational experiment was conducted in the laboratory of Institute of 2008.MATERIALS Cancellous bone in anterior superior lilac spine was obtained from adult normal by surgery for cell incubation. Clinical samples were provided by the Xiangya Hospital.

METHODS:

Human osteoblast was incubated with different doses of adiponcetin (0, 3, 10 and 30 mg/L) for 48 hours, after which OPG and RANKL mRNA and protein expression level was determined. In addition, adiponcetin was added into the co-culture system of osteoblast and peripheral blood monouclear cells for examing its effects on osteoclast formation. MAIN OUTCOME

MEASURES:

OPG and RANKL mRNA and protein expression in human osteoblast was determined using fluorescent quantitative polymerase chain reaction (PCR) and enzyme linked immunosorbent assay (ELISA). Osteoclast was detected by antitartaric acid acid phosphatase staining.

RESULTS:

Adiponcetin inhibited osteoblast OPG mRNA and protein expression in a dose-dependent way (P < 0.05). Adiponcetin promoted osteoblast RANKL mRNA and protein expression in a dose-dependent way (P < 0.05). Adiponectin induced the osteoclasts formation in the co-culture system of osteoblast and peripheral blood monouclear cells.

CONCLUSION:

Adiponectin has the effect of inducing osteoclast formation via stimulating RANKL expression and inhibiting OPG