Receptor activator of nuclear factor-κB ligand (RANKL) (RANKL)

Receptor activator of nuclear factor-κB ligand (RANKL) is a type II transmembrane protein and a member of the tumor necrosis factor (TNF) cytokine superfamily that serves as a critical regulator of bone remodeling and immune system function [1, 2]. It is primarily produced by osteoblasts, osteocytes, and activated T-cells, and it functions by binding to its cognate receptor, RANK, located on the surface of osteoclast precursors and mature osteoclasts [1, 3]. This binding interaction stimulates the differentiation, activation, and survival of osteoclasts, which are the primary cells responsible for bone resorption [2, 3]. Dysregulation of the RANKL/RANK signaling pathway, often characterized by an imbalance between RANKL and its natural decoy receptor osteoprotegerin (OPG), is a central mechanism in the pathogenesis of bone loss disorders such as osteoporosis, rheumatoid arthritis, and bone metastases [3, 4]. Therapeutically, RANKL is targeted by the monoclonal antibody denosumab, which binds to RANKL with high affinity, preventing its interaction with RANK and thereby inhibiting osteoclast-mediated bone destruction [4]. Beyond its skeletal roles, RANKL is also involved in lymph node organogenesis, mammary gland development during pregnancy, and the regulation of body temperature [1, 2].

Other names

TNFSF11Tumor necrosis factor ligand superfamily member 11TRANCETNF-related activation-induced cytokineOPGLOsteoprotegerin ligandODFOsteoclast differentiation factorCD254

RANKL inhibition prevents the binding of RANKL to its receptor RANK, thereby inhibiting osteoclast formation, function, and survival, which leads to decreased bone resorption [3, 4].