[Tyr]-CNP22, Human – Other Categories

C-type natriuretic peptide (CNP) is a novel urinary biomarker which is part of the natriuretic peptide family. CNP is produced in the kidney and the endothelium and has been localised to renal tubules. CNP expression has also been detected in cardiomyocytes, vascular endothelium, and bone. CNP is synthesized as the precursor 103 amino acid (AA) protein, proCNP (AA 1-103), which is then cleaved into NT-proCNP (AA 1-50) and CNP53 (AA 51-103) by the intracellular endoprotease furin. CNP53 is then cleaved to give the biologically active mature form CNP22 (AA 82-103) and inactive form NT-CNP53 (51-81). CNP primarily acts as an autocrine or paracrine factor and has anti-proliferative and anti-fibrotic properties, including suppression of fibroblast proliferation and collagen production, inhibition of vascular smooth muscle cell proliferation and accelerated regeneration of endothelial cells. CNP is a vasodilator and potent venodilator and slightly elevated levels have been detected in heart failure and renal disease states. CNP has renoprotective properties and is activated during renal injury, where it helps preserve glomerular function and suppress pro-fibrotic processes. Hypoxia, cytokines and fibrotic growth factors, are stimuli for CNP production and release. CNP selectively activates the cell surface particulate guanylyl cyclase receptor B (GC-B), catalysing the conversion of GTP to the downstream second messenger, cyclic guanosine monophosphate (cGMP).