Ascorbate deficiency results in decreased collagen production: under-hydroxylation of proline leads to increased intracellular degradation.
| Publication Type | Academic Article |
| Authors | Berg R, Steinmann B, Rennard S, Crystal R |
| Journal | Arch Biochem Biophys |
| Volume | 226 |
| Issue | 2 |
| Pagination | 681-6 |
| Date Published | 10/15/1983 |
| ISSN | 0003-9861 |
| Keywords | Ascorbic Acid Deficiency, Collagen, Lung, Proline |
| Abstract | Collagen production by cultured human lung fibroblasts was examined when the cells were made deficient in ascorbate. Cells grown in the absence of ascorbate produced 30% less collagen during a 6-h labeling period than cells incubated with as little as 1 microgram/ml ascorbate during the labeling period. Cells grown without ascorbate produced under-hydroxylated collagen which was subject to increased intracellular degradation from a basal level of 16% to an enhanced level of 49% of all newly synthesized collagen. The likely mechanism for increased intracellular degradation is the inability of under-hydroxylated collagen to assume a triple-helical conformation causing it to be susceptible to intracellular degradation. Measurement of collagen production by enzyme linked immunoassay (ELISA) using antibodies directed against triple-helical determinants of collagen showed that both types I and III collagens were affected. In contrast, another connective tissue component, fibronectin, was not affected. Analysis by ELISA showed a greater decrease in collagen production than did analysis by the collagenase method, suggesting that some non-helical collagen chains (detected by collagenase but not by ELISA) were secreted in the absence of ascorbate. These results provide a mechanism to account, in part, for the deficiency of collagen in connective tissues which occurs in a state of ascorbate deficiency. |
| DOI | 10.1016/0003-9861(83)90338-7 |
| PubMed ID | 6639074 |