Uterine fibroid cell cytoskeletal organization is affected by altered G protein-coupled estrogen receptor-1 and phosphatidylinositol 3-kinase signaling.

OBJECTIVE: To determine whether cyclic strain affects fibroid cell cytoskeletal organization, proliferation, and collagen synthesis differently than myometrial cells. DESIGN: A basic science study using primary cultures of patient-matched myometrial and fibroid cells. SETTING: Academic laboratory. PATIENT(S): Premenopausal women undergoing myomectomy or hysterectomy for the treatment of symptomatic uterine fibroids. INTERVENTION(S): Application of uniaxial strain patterns mimicking periovulation, menses, or dysmenorrhea using the Flexcell tension system or static control. Secondarily, inhibition of G protein-coupled estrogen receptor-1 and phosphatidylinositol 3-kinase. MAIN OUTCOME MEASURE(S): Cell alignment, cell number, and collagen content. RESULT(S): Menses-strained cells demonstrated the most variation in cell alignment, cell proliferation, and procollagen content between myometrial and fibroid cells. Procollagen content decreased in myometrial cells with increasing strain amplitude and decreasing frequency. G protein-coupled estrogen receptor-1 inhibition decreases cellular alignment in the presence of strain. CONCLUSION(S): Mechanotransduction affecting cytoskeletal arrangement through the G protein-coupled estrogen receptor-1-phosphatidylinositol 3-kinase pathway is altered in fibroid cells. These results highlight the importance of incorporating mechanical stimulation into the in vitro study of fibroid pathology.

Cyclic Adenosine Monophosphate Eliminates Sex Differences in Estradiol-Induced Elastin Production from Engineered Dermal Substitutes.

Lack of adult cells' ability to produce sufficient amounts of elastin and assemble functional elastic fibers is an issue for creating skin substitutes that closely match native skin properties. The effects of female sex hormones, primarily estrogen, have been studied due to the known effects on elastin post-menopause, thus have primarily included older mostly female populations. In this study, we examined the effects of female sex hormones on the synthesis of elastin by female and male human dermal fibroblasts in engineered dermal substitutes. Differences between the sexes were observed with 17ß-estradiol treatment alone stimulating elastin synthesis in female substitutes but not male. TGF-ß levels were significantly higher in male dermal substitutes than female dermal substitutes and the levels did not change with 17ß-estradiol treatment. The male dermal substitutes had a 1.5-fold increase in cAMP concentration in the presence of 17ß-estradiol compared to no hormone controls, while cAMP concentrations remained constant in the female substitutes. When cAMP was added in addition to 17ß-estradiol and progesterone in the culture medium, the sex differences were eliminated, and elastin synthesis was upregulated by 2-fold in both male and female dermal substitutes. These conditions alone did not result in functionally significant amounts of elastin or complete elastic fibers. The findings presented provide insights into differences between male and female cells in response to female sex steroid hormones and the involvement of the cAMP pathway in elastin synthesis. Further explorations into the signaling pathways may identify better targets to promote elastic fiber synthesis in skin substitutes.