Activin-A secretion is increased in the eutopic endometrium from women with endometriosis.
BACKGROUND
Activin is a well-characterised growth and differentiation factor and an important inflammatory mediator. Activin is secreted by normal endometrial glands and stroma and is expressed by endometrial leucocytes. It is also known that the eutopic endometrium from women with endometriosis is functionally different to that from women without endometriosis. In this study, we hypothesise that the endometrial secretion of activin is altered in women with endometriosis.


OBJECTIVE
To determine whether the expression of inhibin/activin subunits and the secretion of activin-A is different in eutopic endometrium from women with and without endometriosis.


METHODS
Endometrial biopsies were obtained from premenopausal, regularly menstruating women with and without endometriosis. Staining intensity for the different inhibin/activin subunits was compared in endometrial and endometriotic biopsies. Activin-A secretion was studied using endometrial explants and endometrial glandular and stromal monolayer cell cultures.


RESULTS
The alpha- and betaA-subunits of inhibin/activin were more abundant in eutopic glandular cells from patients with minimal to mild endometriosis compared to women without endometriosis. In patients with endometriosis, the betaB-subunit was more abundant in eutopic stromal cells and endometrial leucocytes. Comparison of paired endometrial and endometriotic biopsies from the same patient did not reveal significant differences for any of the inhibin/activin subunits or activin receptors. Activin-A secretion by glandular and stromal endometrial cells was sevenfold and threefold higher, respectively, in women with endometriosis compared to women without endometriosis.


CONCLUSIONS
The expression of inhibin/activin subunits in eutopic endometrium is altered in women with endometriosis, leading to higher levels of activin-A secretion by both glandular cells and stromal cells.
Rombauts
Luk
L
Centre for Women's Health Research, Department of Obstetrics and Gynaecology, Monash University, Melbourne, Victoria, Australia. lukrombauts@hotmail.com
Donoghue
Jacqui
J
Cann
Leonie
L
Jones
Rebecca L
RL
Healy
David L
DL
D028341:Activins / Q000032:analysis / Q000096:biosynthesis*; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D016022:Case-Control Studies; D002478:Cells, Cultured; D004715:Endometriosis / Q000175:diagnosis* / Q000378:metabolism; D004717:Endometrium / Q000378:metabolism / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D028322:Inhibin-beta Subunits / Q000032:analysis / Q000096:biosynthesis*; D007265:Inhibins / Q000032:analysis / Q000096:biosynthesis; D011336:Probability; D012016:Reference Values; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D046509:Tissue Culture Techniques; D014591:Uterine Diseases / Q000473:pathology*
D015415:Biomarkers; C422405:activin A; D028341:Activins; D007265:Inhibins; D028322:Inhibin-beta Subunits