EurekaMag.com logo
+ Site Statistics
References:
52,725,316
Abstracts:
28,411,598
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Regulation of glycosamino glucan synthesis by thyroid hormone in vitro


Journal of Clinical Investigation 70(5): 1066-1073
Regulation of glycosamino glucan synthesis by thyroid hormone in vitro
Human skin fibroblasts synthesize and accumulate glycosaminoglycans (GAG). Fibroblasts incubated in thyroid hormone-deficient media accumulate more GAG than do cultures incubated in the same media enriched with 0.1 .mu.M triiodothyronine (T3). The current study characterizes that enhanced accumulation. Confluent cultures were maintained in thyroid hormone-deficient media without or with added T3, labeled with [3H]acetate and analyzed for total [3H]GAG and [3H]hyaluronic acid content. Addition of T3 to thyroid hormone-depleted media consistently inhibited the incorporation of [3H]acetate into GAG by 28-60% in fibroblast cultures from 4 different normal human donors. Maximal inhibitory effect was observed within 3 d after hormone addition at concentrations >n 1 nM. Of the maximal inhibitory effect, 73% was observed in the presence of physiologic concentrations of T3 (0.16 nM total T3 or 1.4 pM free T3). T3 inhibition of [3H]GAG accumulation is most likely due to a decrease in GAG synthesis rather than to changes in the acetate pool or GAG degradation; addition of 0, 100, 500 and 2500 .mu.M unlabeled acetate progressively decreased [3H]acetate incorporation into GAG, up to 80%, without altering the further inhibitory effect of T3 (35-40%); a similar effect of T3 on GAG (32% inhibition) was observed using [3H]glucosamine as substrate; T3 decreased hyaluronate synthetase activity by 32%; and there was no effect of T3 on GAG degradation in a pulse-chase experiment. The effect of T3 on [3H]GAG accumulation appears to be quite specific, since the hormone had no effect on the incorporation of [3H]leucine into trichloroacetic acid-precipitable material. Thyroid hormone inhibits GAG accumulation in a dose-, time-dependent and reversible manner. This inhibition is apparently due to specific effects on the rate of macromolecular synthesis.


Accession: 006288223

PMID: 6813355



Related references

Regulation of glycosaminoglycan synthesis by thyroid hormone in vitro. Journal of Clinical Investigation 70(5): 1066-1073, 1982

Yeast b-glucan synthesis: KRE6 encodes a predicted type II membrane protein required for glucan synthesis in vivo and for glucan synthase activity in vitro. Proceedings of the National Academy of Sciences of the United States of America 88: 295-9, 1991

Yeast beta-glucan synthesis: KRE6 encodes a predicted type II membrane protein required for glucan synthesis in vivo and for glucan synthase activity in vitro. Proceedings of the National Academy of Sciences of the United States of America 88(24): 11295-9, 1991

A novel thyroid hormone receptor that is pituitary specific down regulation of its messenger rna by thyroid hormone is dependent upon new protein synthesis. Clinical Research 37(2): 533A, 1989

Thyroid hormone regulation of prohormone convertase 1 (PC1): regional expression in rat brain and in vitro characterization of negative thyroid hormone response elements. Journal of Molecular Endocrinology 33(1): 21-33, 2004

Regulation by thyroid hormone of the synthesis of a cytosolic thyroid hormone binding protein during liver regeneration. Biochemical & Biophysical Research Communications 189(1): 257-263, 1992

Investigations on myelination in vitro. Regulation of sulfolipid synthesis by thyroid hormone in cultures of dissociated brain cells from embryonic mice. Journal of Biological Chemistry 256(3): 1167-1171, 1981

Thyroid hormone action in pituitary cells. Differences in the regulation of thyrotropin-releasing hormone receptors and growth hormone synthesis. Journal of Biological Chemistry 254(10): 3907-3911, 1979

Dominant inhibition of thyroid hormone action selectively in the pituitary of thyroid hormone receptor-beta null mice abolishes the regulation of thyrotropin by thyroid hormone. Molecular Endocrinology 17(9): 1767-1776, 2003

Regulation of thyroid hormone synthesis in cultured ovine thyroid follicles. Endocrinology 130(5): 2789-2794, 1992