The PKA Pathway of Endometrial Stromal Fibroblasts Reveals Differentiation and Proliferative Potential in Endometriosis

Intrinsic abnormalities in transplanted eutopic endometrium are believed to contribute to the pathogenesis of pelvic endometriosis. Herein, we investigated transcriptomic differences in human endometrial stromal fibroblasts (hESF) from women with (hESFendo) versus without (hESFnon-endo) endometriosis, in response to activation of the PKA pathway with 8-Br-cAMP. hESFnon-endo (n=4) and hESFendo (mild endometriosis, n=4) were isolated from eutopic endometrium and treated +/- 0.5mM 8-Br-cAMP for 96 hours. Purified total RNA was subjected to microarray analysis using the whole genome Gene 1.0 ST Affymetrix platform. 733 genes were regulated in cAMP-treated hESFnon-endo versus 172 genes in hESFendo, suggesting a blunted response to cAMP/PKA pathway activation in women with disease. Real-time PCR and ELISA validated the decreased expression of decidualization markers in hESFendo compared to hESFnon-endo. In the absence of disease, 8-Br-cAMP down-regulated progression through the cell-cycle due to a decrease in Cyclin D1, cyclin-dependent kinase 6 and cell division cycle 2, and an increase in cyclin-dependent kinase inhibitor 1A. However, cell cycle components in hESFendo were not responsive to 8-Br-cAMP, resulting in persistence of a proliferative phenotype. hESFendo treated with 8-Br-cAMP exhibited altered expression of immune response, extracellular matrix, cytoskeleton, and apoptosis genes. Changes in phosphodiesterase expression and activity were not different among experimental groups. Thus, eutopic hESF with increased proliferative potential may seed the pelvic cavity via retrograde menstruation and promote establishment, survival, and proliferation of endometriosis lesions, independent of hydrolysis of cAMP and likely due to an inherent abnormality in the PKA pathway in the presence of disease.

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Aghajanova L, Horcajadas JA, Weeks JL, Esteban FJ, Nezhat CN, Conti M, Giudice LC