Cycle Physiology · Luteal Phase
Evans J et al., 2012 · Rev Endocr Metab Disord
Menstruation has many of the features of an inflammatory process. The complexity and sequence of inflammatory-type events leading to the final tissue breakdown and bleeding are slowly being unravelled. Progesterone has anti-inflammatory properties, and its rapidly declining levels (along with those of estrogen) in the late secretory phase of each non-conception cycle, initiates a sequence of interdependent events of an inflammatory nature involving local inter-cellular interactions within the endometrium. Intracellular responses to loss of progesterone (in decidualized stromal, vascular and epithelial cells) lead to decreased prostaglandin metabolism and loss of protection from reactive oxygen species (ROS). Increased ROS results in release of NFκB from suppression with activation of target gene transcription and increased synthesis of pro-inflammatory prostaglandins, cytokines, chemokines and matrix metalloproteinases (MMP). The resultant leukocyte recruitment, with changing phenotypes and activation, provide further degradative enzymes and MMP activators, which together with a hypoxic environment induced by prostaglandin actions, lead to the tissue breakdown and bleeding characteristic of menstruation. In parallel, at sites where shedding is complete, microenvironmentally-induced changes in phenotypes of neutrophils and macrophages from proto anti-inflammatory, in addition to induction of growth factors, contribute to the very rapid re-epithelialization and restoration of tissue integrity.
Endometrial Assessment · Receptivity Testing
Lessey BA et al., 1995 · Fertil Steril
To assess uterine receptivity in women with unexplained infertility using integrin cell adhesion molecules as markers. Prospective, controlled study design. Eighty-seven nulliparous women with unexplained infertility and 32 fertile and infertile parous controls. Immunohistochemical staining for alpha 1, alpha 4, and beta 3 integrin subunits in endometrial biopsies obtained during the window of implantation (days 20 to 24), using the semiquantitative HSCORE by two observers in a blinded fashion. All endometrial biopsies from parous controls contained positive immunostaining for the alpha 1, and beta 3 integrin subunits in glandular epithelium. Some samples from parous controls were missing the alpha 4 subunit. In contrast, compared with parous controls, biopsies from women with unexplained infertility had reduced significantly beta 3 expression, with similar expression of alpha 1 and alpha 4. Two distinct defects in integrin expression were identified: "out-of-phase" samples that lacked beta 3 because of histologic lag (type I defects) and "in-phase" endometrium that still failed to express this integrin (type II defects). These subclassifications accounted for 26% and 39% of the total unexplained infertility group, respectively. Abnormal endometrial integrin expression was a frequent finding in women with unexplained infertility. These data suggest that defective uterine receptivity may be an unrecognized cause of infertility in this population of women.
Endometrial Assessment · Receptivity Testing
Lessey BA et al., 1996 · Fertil Steril
To compare the expression of endometrial P receptors (PR) levels with markers of endometrial receptivity during the window of implantation. Prospective, controlled study to examine endometrial PR and three cycle-specific integrins in endometrial biopsies obtained during the window of implantation. An academic teaching hospital. One hundred seventy-five endometrial biopsies from regularly cycling women with luteal phase defect (LPD; group 1; n = 80), medically treated LPD (group 2; n = 16), minimal and mild endometriosis with aberrant alpha v beta 3 expression (group 3; n = 21), fertile controls (group 4; n = 26), and infertile controls (group 5; n = 32). Immunohistochemical staining intensity of each antigen using the semi-quantitative grading system (HSCORE), compared using analysis of variance with Scheffe's correction. Among the five groups studied, nuclear PR expression was significantly elevated in glandular epithelial cells from tissue samples with histologic delay > or = 3 days consistent with luteal phase deficiency (LPD; group 1). Failure of PR down-regulation was associated with aberrant alpha v beta 3 integrin expression. Medical correction of LPD was associated with return of normal endometrial histology, normal integrin expression, and the loss of epithelial PR, similar to controls. The other two cycle-dependent integrin markers, alpha 1 beta 1 and alpha 4 beta 1, were not different between groups. In women with aberrant alpha v beta 3 and "in phase" endometrium, epithelial PR expression was not different from controls. The establishment of normal endometrial receptivity appears to be tightly associated with the down-regulation of epithelial PR. Histologic delay, consistent with LPD, is associated with a failure of PR down-regulation and the lack of normal markers of endometrial receptivity. Occult uterine receptivity defects (aberrant beta 3 expression in otherwise normal histology) are regulated differently, suggesting alternate mechanisms also exist which influence endometrial receptivity.
Endometrial Assessment · Receptivity Testing
Petousis S et al., 2016 · J Matern Fetal Neonatal Med
To compare the expression of progesterone receptors (A + B) and type-B progesterone receptors in the epithelial and stromal cells of fertile and infertile women. Women were divided into two groups, the group of fertile controls (group 1) and the group of infertile women (group 2) and were set on regular ultrasound imaging in order to detect ovulation. An endometrial biopsy was obtained on the seventh or eighth post-ovulatory day. Immunohistochemistry was performed to measure percentage of positive nuclei, intensity of staining and h-score for progesterone receptors (PgR) (A + B) as well as type-B progesterone receptors in epithelial and stromal cells. Secondary outcomes included endometrial tissue dating, the rate of tissues being out-of-phase and endometrial thickness. Endometrial issue was obtained from 15 fertile and 30 infertile women. Expression of PgR (A + B) and PgR type-B was significantly lower in the epithelial cells of infertile women. PgR (A + B) h-score was 220.0 ± 18.5 for fertile versus 147.3 ± 18.0 for infertile women (p = 0.02). PgR type-B h-score in epithelial cells was 166.8 ± 30.7 for fertile versus 90.8 ± 20.6 for infertile (p = 0.04). No significant difference was observed in stromal cells. Expression levels of PgR (A + B) as well as type-B receptors are significantly lower in the epithelial cells of infertile women during implantation window.