Related Experiment Video
Updated: May 8, 2026
Isolation of Human Endometrial Stromal Cells for In Vitro Decidualization
Published on: September 1, 2018
Endometrial Intracrinology--generation of an estrogen-dominated microenvironment in the secretory phase of women
D A Gibson1, K J McInnes, H O D Critchley
1Medical Research Council (MRC) Centre for Reproductive Health, The University of Edinburgh, Queen's Medical Research Institute, 47 Little France Crescent, Edinburgh, EH16 4TJ, UK. p.saunders@ed.ac.uk.
Context:
The human endometrium is a complex multicellular tissue subject to cyclical fluctuations in ovarian-derived steroid hormones. Fertile cycles are characterized by differentiation (decidualization) of endometrial stromal cells (ESC).
Objective:
To determine the impact of human stromal cell decidualization on biosynthesis and secretion of estrogens.
Design:
Primary cell culture was used. Cells were decidualized in vitro. Some cultures were treated with an aromatase inhibitor.
Setting:
A University Research Institute.
Patients:
Primary ESC were derived from women with normal menstrual cycles (n = 12). None of the women were receiving hormonal therapy or suffering from endometriosis.
Main Outcome Measurements:
Expression of mRNA and protein encoded by the aromatase (CYP19A1) and 3-β-hydroxysteroid dehydrogenase (HSD3B1) genes was assessed. Aromatase activity was measured using a tritiated water assay; steroid metabolism was determined using thin layer chromatography. Estrone (E1) and estradiol (E2) in cell culture media were measured by ELISA.
Results:
Decidualization induced a two-fold increase in aromatase mRNA. Aromatase protein was only detected in decidualized ESC. 3-β-Hydroxysteroid dehydrogenase protein was present in ESC both before and after decidualization; concentrations appeared unchanged. The existence of functional aromatase in decidualized ESC was confirmed; E1 and E2 were secreted into culture media in decidualized ESC and concentrations were reduced when cells were incubated with an aromatase inhibitor. Decidualization resulted in reduced metabolism of E2 and an increase in the ratio of E2:E1.
Conclusions:
Decidualization is characterized by an increase in aromatase expression/activity favoring the generation of an E2-dominated estrogen microenvironment within the endometrial stroma.
Related Concept Videos
01:19Secretory Phase
Following ovulation, the corpus luteum, a temporary endocrine structure, produces progesterone and estrogens. These hormones stimulate the growth and coiling of endometrial...
02:07Oogenesis
01:22Hormonal Regulation of the Menstrual Cycle
At puberty, GnRH begins a pulsatile release pattern, which triggers the anterior pituitary gland to secrete follicle-stimulating hormone (FSH) and luteinizing hormone (LH). The frequency and amplitude of GnRH pulses vary across the menstrual cycle, with faster pulses favoring LH release and slower pulses favoring FSH release.
01:30Hormonal Control of the Ovarian Cycle
Before puberty, the hypothalamus releases GnRH in a low frequency, low amplitude pulsatile manner. This along with the immature hypothalamic-pituitary-gonadal axis activity, results in low estrogen levels and the absence of a fully functional ovarian cycle. At puberty, GnRH secretion increases in both frequency and...
01:18Menses Phase
When fertilization does not occur, the corpus luteum deteriorates, causing a significant drop in the levels of estrogen and progesterone in the body. This hormonal decrease triggers the release of prostaglandins, which cause the uterine...
01:20Proliferative Phase
Notably, the stratum basale, the basal layer of the endometrium, including the basal parts of the uterine glands, remains unaffected by menstruation. Stem cells in this layer undergo mitosis, regenerating the stratum functionalis and thickening the...