Ascorbate Modulation of Collagen Gene Expression

Genes Ascorbic acid-enhanced increase in mRNA (fold) Cells Reference 

The collagens are the most abundant proteins found in various connective tissues of all multicellular animals. A typical collagen molecule has a long, flexible, and triple-stranded helical structure, in which three collagen polypeptide chains, so-called a-chains, are coiled in a rope-like helix. Among the 15 types of mature collagen molecules composed of different a-chains, the primary types are I, II, IV, and IX. 

The two- to threefold increase in the transcription level induced by ascorbic acid is too small to identify the ascorbic acid regulatory sequence(s) on the procollagen gene by conventional analysis methods. Further work is required to develop cell culture systems in which the procollagen gene can be induced at much higher levels. 

The definite mechanism by which ascorbic acid stimulates transcription of the procollagen gene remains unknown. However, an alternative hypothesis as to the role of ascorbic acid as a peroxidant is that ascorbic acid stimulates lipid peroxidation with the formation of reactive aldehydes, which up-regulate expression of the procollagen gene. This is based on the following observations  

Recently, the role of ascorbic acid as a peroxidant in collagen synthesis has been opposed, by the following arguments (Darr et at., 1994)  

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