Cortisol decreases the concentration of translatable type-I procollagen mRNA species in the developing chick-embryo calvaria

Abstract

The calvarial mRNA species of chick embryos were translated in the rabbit reticulocyte-lysate cell-free translation system. The amount of procollagen type-I mRNA species was determined by digestion with bacterial collagenase and by fluorography of the cell-free translation products. Administration of cortisol resulted in a specific decrease in the cellular concentration of translatable procollagen type-I mRNA species in the calvaria of developing chick embryos. There was a lag period of up to 12 h before the response, which was dose-dependent. The data suggest that the decrease in amounts of procollagen mRNA species is the main reason for the lower amount of tissue collagen after topical or systemic administration of glucocorticoids, although other factors may contribute to the response.

Transforming growth factor-beta increases steady state levels of type I procollagen and fibronectin messenger RNAs posttranscriptionally in cultured human dermal fibroblasts.

“…Both positive and negative regulation has been shown to take place depending on the inducer (1 1,[13][14][15][16][17][18][19][20][21][22][23][24]. For example, cortisol and other antiinflammatory steroids, parpthyroid hormone, and y-interferon all cause a specific decrease in the cellular concentration of translatable type I procollagen mRNA (16, 18, genes with a consequent decrease in the levels of type I procollagen mRNAs (20)(21)(22)(23).…”

Age Differences in the Effect of Hydrocortisone on the Synthesis of Insoluble Elastin in Aortic Tissue of Growing Chicks

“…The slow disappearance of hydrocortisone from the serum of glucocorticoid-treated chicks embryos as compared to 14 day old chicks suggests that the metabolic pathways for the removal of this steroid from the serum are not yet developed at this stage in the embryo chick, but have appeared by two weeks after hatching. Although the dose levels and schedules for administration of hydrocortisone to embryos and chicks were chosen to ensure both an adequate period of exposure to the steroid (16,18) and comparable serum levels at the time of sacrifice, identical exposure conditions in embryos and chicks of all ages could not be achieved in these experiments, particularly because of the fact that the mechanisms for removal of the glucocorticoid from serum are apparently developing in the chick over this period of time. Thus it remains possible that these results may be related not to development directly, but rather to changes in the metabolism of this steroid in chicks at difference stages of development.…”

“…In the case of collagen, this inhibition of synthesis is, at least in part, due to decreased levels of procollagen mRNA (18,(25)(26)(27)(28), suggested to result from an increased degradation rate of the message (28). There are, however, several reports in the literature of apparent increases in collagen synthesis with glucocorticoid treatment (29)(30)(31)(32)(33) under a variety of cell culture conditions.…”

Altered steady-state ratio of type I/III procollagen mRNAs correlates with selectively increased type I procollagen biosynthesis in cultured keloid fibroblasts.

“…For isolation of mRNA, the medium was removed and cells were scraped in 10 mM Tris HCl (pH 7.4) containing 1 mM EDTA and 1% NaDodSO4. The samples were digested with 100 ,ug of proteinase K (Boehringer) per ml for 90 min at 50°C (21). Poly(A)+ RNA was isolated by oligo(dT)-cellulose column chromatography (22), and the recovery of poly(A)+ RNA was determined by a technique utilizing rabbit globin mRNA as an internal standard during the isolation procedure, as described elsewhere (15).…”