Erika Johnston-MacAnanny

Endometrial Stromal Decidualization Responds Reversibly to Hormone Stimulation and Withdrawal

Human endometrial stromal decidualization is required for embryo receptivity, angiogenesis, and placentation. Previous studies from our laboratories established that connexin (Cx)-43 critically regulates endometrial stromal cell (ESC) differentiation, whereas gap junction blockade prevents it. The current study evaluated the plasticity of ESC morphology and Cx43 expression, as well as other biochemical markers of cell differentiation, in response to decidualizing hormones. Primary human ESC cultures were exposed to 10 nM estradiol, 100 nM progesterone, and 0.5 mM cAMP for up to 14 days, followed by hormone withdrawal for 14 days, mimicking a biphasic ovulatory cycle. Reversible differentiation was documented by characteristic changes in cell shape. Cx43 was reversibly up- and down-regulated after the estradiol, progesterone, and cAMP treatment and withdrawal, respectively, paralleled by fluctuations in prolactin, vascular endothelial growth factor, IL-11, and glycodelin secretion. Markers of mesenchymal-epithelial transition (MET), and its counterpart epithelial-mesenchymal transition, followed reciprocal patterns corresponding to the morphological changes. Incubation in the presence of 18α-glycyrrhetinic acid, an inhibitor of gap junctions, partially reversed the expression of decidualization and MET markers. In the absence of hormones, Cx43 overexpression promoted increases in vascular endothelial growth factor and IL-11 secretion, up-regulated MET markers, and reduced N-cadherin, an epithelial-mesenchymal transition marker. The combined results support the hypothesis that Cx43-containing gap junctions and endocrine factors cooperate to regulate selected biomarkers of stromal decidualization and MET and suggest roles for both phenomena in endometrial preparation for embryonic receptivity.

Gap junction blockade induces apoptosis in human endometrial stromal cells.

One of the most dynamic adult human tissues is the endometrium. Through coordinated, cyclical proliferation, differentiation, leukocyte recruitment, apoptosis, and desquamation, the uterine lining is expanded and shed monthly, unless pregnancy is established. Errors in these steps potentially cause endometrial dysfunction, abnormal uterine bleeding, failed embryonic implantation, infertility, or endometrial carcinoma. Our prior studies showed that gap junctions comprised of Gap junction alpha‐1 (GJA1) protein, also known as connexin 43 (CX43), subunits are critical to endometrial stromal cell differentiation. The current studies were undertaken to explore the mechanism of endometrial dysfunction when gap junction intercellular communication (GJIC) is disrupted. Gap junction blockade by two distinct GJIC inhibitors, 18α‐glycyrrhetinic acid (AGA) and octanol (OcOH), suppressed proliferation and induced apoptosis in endometrial stromal cells, as manifested by reduced biomarkers of cell viability, increased TUNEL staining, caspase‐3 activation, sub‐G1 chromosomal DNA complement, as well as shortened telomere length. Unexpectedly, we also observed that the chemical inhibitors blocked CX43 gene expression. Moreover, when endometrial stromal cells were induced to undergo hormonal decidualization, following a 7‐day exposure to 10 nM 17β‐estradiol + 100 nM progesterone + 0.5 mM dibutyryl cAMP, characteristic epithelioid changes in cell shape and secretion of prolactin were blunted in the presence of AGA or OcOH, recapitulating effects of RNA interference of CX43. Our findings indicate that endometrial stromal cell proliferation and maintenance of decidualized endometrial function are GJIC‐dependent, and that disruption of gap junctions induces endometrial stromal cell apoptosis. These observations may have important implications for several common clinical endometrial pathologies. Mol. Reprod. Dev. 81: 666–675, 2014.

Stress and Implantation Failure

The cornerstone of female reproduction is the hypothalamic-pituitary-ovarian (HPO) axis. This term is incomplete in that it omits reference to the uterus and endometrium, which are clearly critical to the most important step in reproduction, namely, implantation. Implantation requires that the endometrium become receptive to a healthy blastocyst. Thus, folliculogenesis must result not only in ovulation but also in the secretion of estradiol and progesterone in a pattern that prepares the endometrium for implantation. While implantation failure can be defined as absent hCG production after ovulation that is signaled by menstrual bleeding, the definition also encompasses transient hCG production that is not sustained, which is often called “chemical” pregnancy.

Infectious Risk Based on Contraceptive Method in Women With New Cancer Diagnoses: Are Indwelling Methods Riskier? [6O]

INTRODUCTION: To determine if indwelling contraceptive methods such as long-acting reversible contraceptives (LARC) contribute to increased incidence of infectious sequelae as compared to non-indwelling methods (oral contraceptives, transdermal methods) in women with new diagnosis of hematologic cancers such as leukemia and lymphoma. METHODS: Retrospective case review of new cancer diagnoses registered to the institutional tumor registry between November 20, 2012 and May 27, 2014 were evaluated. Patients reporting breast and gynecologic malignancies were excluded. The main outcome assessment was neutropenic fever, which was considered representative of infectious sequelae. Results were stratified based on type of cancer. Chi-square test was used to evaluate statistical significance. RESULTS: A total of 197 patients were identified. Sixty six patients were excluded for incomplete records, and 22 were gynecologic cancers. Seventy two patients reported solid cancer; 37 reported hematologic cancer. Of these women with hematologic cancers, 22 women used short-acting hormonal methods of contraception. Of these, 10/22 were noted to have treatment-related infectious complication. Twelve women were identified as using LARC; 6/22 were noted to have treatment-related infectious complication. Two patients in this group reported hysterectomy and had treatment-related infectious complication. CONCLUSION: Critics of indwelling LARC propose that indwelling contraceptive methods may pose increased risk of infectious sequelae in patients who are undergoing leukemia and lymphoma treatment and anticipate neutropenia. Our data supports no increased risk of infectious complication in women undergoing chemotherapy for leukemia and lymphoma based on the contraceptive method used. Given these data, a provider should consider the use of LARC in this high-risk, specialized population.