High stretch cycling inhibits the morphological and biological decidual process in human endometrial stromal cells.

Purpose: Subendometrial myometrium exerts wave-like activity throughout the menstrual cycle, and uterine peristalsis is markedly reduced during the implantation phase. We hypothesized that abnormal uterine peristalsis has an adverse effect on the endometrial decidualization process. We conducted an in vitro culture experiment to investigate the effect of cyclic stretch on the morphological and biological endometrial decidual process.
Methods: Primary human endometrial stromal cells (HESCs) were isolated from hysterectomy specimens and incubated with or without 8-bromo-cyclic adenosine monophosphate (8-br-cAMP) and medroxyprogesterone acetate (MPA) for 3 days. After decidualization, cultures were continued for 24 hours with or without cyclic stretch using a computer-operated cell tension system.
Results: Cyclic stretch significantly repressed expression of decidual markers including insulin-like growth factor-binding protein 1 ( IGFBP1 ), prolactin ( PRL ), forkhead box O1 ( FOXO1 ), and WNT4 on decidualized HESCs. In addition, cyclic stretch of decidualized HESCs affected the decidual morphological phenotype to an elongated shape. The alternation of F-actin localization in decidualized HESCs was not observed in response to cyclic stretch.
Conclusions: These data suggest that cyclic stretch inhibits the morphological and biological decidual process of HESCs. Our findings imply that uterine abnormal contractions during the implantation period impair endometrial decidualization and contribute to infertility.
Competing Interests: Conflict of interest: The authors declare no conflict of interest. Human rights statement and informed consent: All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institution and national) and with the Helsinki Declaration of 1964 and its later amendments. Informed consent was obtained from all patients included in the study. The Institutional Review Board of the Saitama Medical University Hospital approved this study.
(© 2020 The Authors. Reproductive Medicine and Biology published by John Wiley & Sons Australia, Ltd on behalf of Japan Society for Reproductive Medicine.)