Description
Ciliary neurotrophic factor (CNTF), also known as HCNTF, is a cytokine that supports survival and/or differentiation of a variety of neuronal cell types including sensory, sympathetic and motoneurons (1). It is structurally related to IL-6, IL-11, LIF and OSM. CNTF is expressed in glial cells within the central and peripheral nervous systems. It lacks the classical signal peptide sequence of a secreted protein, but is thought to convey its cytoprotective effects after release by some mechanism induced by injury. The receptors for CNTF are CNTF Rα subunit and gp130, which are expressed exclusively in the nervous system and skeletal muscle. In addition to its neuronal actions, CNTF also acts on non-neuronal cells such as glia, hepatocytes, skeletal muscle, embryonic stem cells and bone marrow stromal cells. Because CNTF is predominantly expressed in the nervous system, its modulation may have implications for Parkinson's disease, ALS and cell-replacement therapies for other disorders (2-3). CNTF mimics the biological actions of leptin while overcoming "leptin resistance" and appears to reduce inflammatory signaling cascades associated with lipid accumulation in liver and skeletal muscle (4). Therefore, it may be a therapeutic target for obesity-related metabolic disease. CNTF is highly conserved across species and exhibits cross-species bioactivity