Fig. 11
From: Fibrosis and bone marrow: understanding causation and pathobiology
Role of exogenous proline in regulating HIF1 alpha and collagen synthesis in culture. Proline plays an important role in regulation of gene expression, transcription factors, mTOR cell signaling, cellular redox reactions, synthesis of ornithine, arginine, polyamines, glutamate and collagen. Proline is formed via glutamine metabolism from amino acid pool or via tricarboxylic acid cycle via alpha keto-glutarate. Proline is hydroxylated into hydroxyproline by proline hydroxylase. Hydroxyproline is the key amino acid of collagen biosynthesis. Copper ions and vitamin C are required for collagen biosynthesis. [POX, proline hydroxylase; CDP, cytidine diphosphate; HIF1a, hypoxia inducing factor 1alpha; red line with sidebar indicates inhibition]