Browse by author
Lookup NU author(s): Professor William Dunlop, Emeritus Professor Nick Europe-Finner, Professor James Gillespie
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
As term approaches, a number of key proteins [contraction-associated proteins (CAPs)] are expressed within the human myometrium that are essential for the activation of powerful coordinated contractions during labor. The nature of the signals that switch on the synthesis of CAPs in vivo is not known. The ryanodine-sensitive intracellular Ca2+ release channel (RyR2) is a CAP whose expression in vitro is activated by transforming growth factor- β (TGFβ). The present experiments were performed to determine whether TGFβ and TGFβ receptors are present in the human myometrium at term and to explore the idea that they might form part of a signaling system in vivo. TGFβ receptor types I and II, but not III, were demonstrated in myometrial smooth muscle in tissue taken from nonpregnant, pregnant nonlaboring, and spontaneous laboring women. Western blotting was used subsequently to determine the relative expression of TGFβ receptor types I and II. Using nonpregnant myometrium as a baseline control the levels of expression of receptor types I and II were significantly increased by 168 ± 19% (n = 6) and 162 ± 22% (n = 7) in pregnant nonlaboring myometrium. In spontaneous laboring myometrium the levels of TGFβ receptor type I and II expression were 93 ± 12% (n = 6) and 85 ± 11% (n = 7), respectively, compared to nonpregnant control values and were significantly lower than levels in pregnant nonlaboring tissues. The total TGFβ1 levels in the myometrial tissues were 334 ± 10,534 ± 73, and 674 ± 106 pg/g tissue wet wt in nonpregnant, pregnant nonlaboring, and spontaneous laboring myometrium (n = 3 in each group), respectively. Thus, the TGFβ signaling system appears to be up-regulated in the myometrium before the onset of parturition. The apparent loss of receptors in the spontaneous laboring samples in the presence of elevated total levels of TGFβ may be indicative of agonist-induced receptor downregulation. These observations support the idea that cytokines, in particular TGFβ1, may play a role in the normal processes that prepare the myometrium for parturition at term.
Author(s): Hatthachote P, Morgan J, Dunlop W, Europe-Finner GN, Gillespie JI
Publication type: Article
Publication status: Published
Journal: Journal of Clinical Endocrinology and Metabolism
Year: 1998
Volume: 83
Issue: 8
Pages: 2987-2992
ISSN (print): 0021-972X
ISSN (electronic): 1945-7197
Publisher: The Endocrine Society
URL: http://dx.doi.org/10.1210/jc.83.8.2987
DOI: 10.1210/jc.83.8.2987
PubMed id: 9709980
Altmetrics provided by Altmetric
