Complement C1q and tumor necrosis factor-related protein 9 (CTRP9)

Complement C1q and tumor necrosis factor-related protein 9 (CTRP9) is a secreted glycoprotein belonging to the CTRP family, closely related to adiponectin. It is composed of a signal peptide, an N-terminal variable domain, a collagen-like domain, and a C-terminal C1q globular domain homologous to complement component C1q. CTRP9 is mainly produced by adipose tissue and circulates in plasma both as a full-length protein and as a proteolytically cleaved globular form (gCTRP9), with the globular form being the dominant circulating isoform. CTRP9 exerts pleiotropic biological functions, including regulation of glucose and lipid metabolism, modulation of vasodilation (through endothelial nitric oxide synthase activation), suppression of vascular inflammation, protection against oxidative stress and apoptosis, and promotion of angiogenesis. It signals through adiponectin receptor 1 (AdipoR1), N-cadherin, and potentially other membrane receptors, activating pathways such as AMP-activated protein kinase (AMPK), Akt, and endothelial nitric oxide synthase (eNOS). Abnormal CTRP9 levels are implicated in cardiovascular disease, diabetes, obesity, and other inflammation-mediated conditions. As a result, it is being explored as both a disease biomarker and a potential therapeutic target in these disorders. However, the full spectrum of drugs targeting CTRP9 or modulating its activity is not defined, nor are specific mechanisms of action for drugs directed at this protein currently established in clinical medicine.

Other names

C1q and TNF related protein 9Complement C1q and tumor necrosis factor-related protein 9AC1QTNF9C1QTNF9AUNQ6503/PRO21380MGC48915AQL1complement C1q tumor necrosis factor-related protein 9C1q/Tumor Necrosis Factor-Related Protein 9

Not established