OPG

Osteoprotegerin, which is a member of the tumor necrosis factor receptor superfamily and is involved in the regulation of bone metabolism. OPGand its ligand (OPGL) are cytokines regulating osteoclasto-genesis. OPGL binds to receptors on the surface of preosteoclasts and stimulates their differentiation into active osteoclasts. This leads to osteoresorption. OPG inhibits this osteoclasto-genesis (OPG is secreted by osteoblasts, and binds to OPGL, thus inhibiting maturation of osteoclasts and osteoresorption). The degree and activity of osteoresorption depend mainly on the balance between OPG and its ligand (OPGL); factors increasing OPGL expression mostly reduce OPG expression and vice versa.

Reference:

1. Effects of hypolipemic drugs on the osteoprotegerin - sRANKL system in patients with coronary artery disease. Thromb Haemost 2007 May;97(5):868-70
2. Plasma osteoprotegerin levels in the general population: relation to indices of left ventricular structure and function. Hypertension 2007 Jun;49(6):1392-8
3. The sex-specific association of serum osteoprotegerin and receptor activator of nu clear factor kappaB legend with bone mineral density in older adults: the Rancho Bernardo study. Eur J Endocrinol 2007 May;156(5):555-62
4. Thyroid hormone deficiency and postmenopausal status independently increase serum osteoprotegerin concentrations in women. Eur J Endocrinol 2007 May;156(5):539-45
5. Abnormal bone remodeling process is due to an imbalance in the receptor activator of nuclear factor-kappaB ligand (RANKL)/osteoprotegerin (OPG) axis in patients with solid tumors metastatic to the skeleton.
Acta Oncol 2007;46(2):221-9
6. Inhibition of tooth movement by osteoprotegerin vs. pamidronate under conditions of constant orthodontic force. Eur J Oral Sci 2007 Apr;115(2):131-6