Apoptosis, proliferation, and sex hormone receptors in superficial parts of human endometrium at the end of the secretory phase

Evaluation of the Ki-67 Proliferation Index and Urocortin Expression in Women with Ovarian Endometriomas

OBJECTIVE

The reasons why endometriosis is more aggressive and invasive in some patients are unknown. Despite the importance of population-based clinically defined risk factors in the prediction of recurrence, biochemical markers obtained from the patient are more valuable for prediction on an individual basis. Therefore, the discovery of significant potential biomarkers could be useful to clinicians for shedding light on the pathogenesis of endometriosis and in the monitoring recurrence.

MATERIALS AND METHODS

This study included 50 patients who underwent surgery for ovarian cysts that were diagnosed as endometrioma. The age of the patients, stage of the endometriosis, diameter and localization of endometriomas, type of surgery, and pre- and postoperative cancer antigen 125 (CA125) levels were compared between patients with and without recurrence. The archived pathology slides were stained with Ki-67 and anti-urocortin antibodies for reevaluation. By comparing the pathology parameters of the patients with and without recurrence, the association between these parameters and recurrence was investigated.

RESULTS

The median Ki-67 proliferation index of the patients with recurrence (7.5±6.5) was statistically significant compared with that of the patients without recurrence (1±4) (p=0.003). The urocortin epithelial staining intensity and percentage were not found to be statistically significant in comparison. A statistically significant difference was determined between postoperative CA125 median levels of patients without recurrence (10±17.6) and those of patients with recurrence (29.9±18.1) (p=0.003).

CONCLUSION

The Ki-67 proliferation index may be useful for predicting prognosis and recurrence risk.

Noninvasive imaging of cell death using an Hsp90 ligand

Cell death plays a central role in normal physiology and in disease. Common to apoptotic and necrotic cell death is the eventual loss of plasma membrane integrity. We have produced a small organoarsenical compound, 4-(N-(S-glutathionylacetyl)amino)phenylarsonous acid, that rapidly accumulates in the cytosol of dying cells coincident with loss of plasma membrane integrity. The compound is retained in the cytosol predominantly by covalent reaction with the 90 kDa heat shock protein (Hsp90), the most abundant molecular chaperone of the eukaryotic cytoplasm. The organoarsenical was tagged with either optical or radioisotope reporting groups to image cell death in cultured cells and in murine tumors ex vivo and in situ. Tumor cell death in mice was noninvasively imaged by SPECT/CT using an (111)In-tagged compound. This versatile compound should enable the imaging of cell death in most experimental settings.

Global analysis of genes regulated by HOXA10 in decidualization reveals a role in cell proliferation

Homeobox (HOX) A10 is essential for fertility as demonstrated in transgenic mice, specifically affecting implantation and decidualization. Its role in human decidualization, however, remains unknown. In this study, we used gene silencing followed by microarray analysis to decipher the role of HOXA10 during decidualization of human endometrial stromal cells (HESCs). HOXA10 was knocked down using siRNA oligonucleotide transfection and cells were treated with estradiol, medroxyprogesterone acetate and dibutyryl cAMP (H + cAMP) to induce decidualization. Genes significantly regulated were identified using the Affymetrix microarray chip. With this method, 2361 transcripts were significantly altered by 1.5-fold or higher (P < 0.05) with H + cAMP treatment only. Of these genes, 258 were significantly up-regulated by HOXA10 knockdown and 236 transcripts were significantly down-regulated by more than 1.5-fold, totaling 494 genes that were regulated by HOXA10 during decidualization. Data analysis using the Ingenuity System revealed that many of the genes regulated by HOXA10 knockdown during H + cAMP treatment were associated with cell cycle. Real-time PCR was used to confirm that HOXA10 knockdown decreased expression of the cell cycle genes CDC2 and CCNB2. In addition, a higher percentage of cells were arrested in the G2/M phase. Next, we observed that cell proliferation as measured by BrdU incorporation was decreased upon HOXA10 knockdown and H + cAMP treatment. Apoptosis, on the other hand, as measured by Annexin V staining was not influenced by siHOXA10 in decidualizing cells. Together, these data demonstrate that during decidualization of HESC, HOXA10 is actively involved in promoting cell proliferation through the regulation of hundreds of genes.

Hormonal and histological study on irregular genital bleeding in patients with endometriosis during treatment with dienogest, a novel progestational therapeutic agent

Aim:  Dienogest, a novel progestational 19-norsteroid, has been shown to have a therapeutic effect on endometriosis with its major side-effect being irregular genital bleeding. This study aimed to investigate the mechanism responsible for the bleeding seen during dienogest therapy. Methods:  For this multicenter, single-dose, open-label study, dienogest at a daily oral dose of 2 mg was administered for 16 weeks to nine patients with endometriosis showing regular menstrual cycles. Weekly determinations of serum endocrine hormone levels during the course of the treatment period and histological endometrial biopsies at the onset of genital bleeding were undertaken. Results:  All cases showed genital bleeding irregularly during the treatment period. Endometrial histological findings at the time of presentation of the bleeding revealed a secretory, inert or atrophic appearance of the epithelium, pseudo-decidualization in the stroma, and local hemorrhage around the regions of desquamation of epithelium and lysis in the subepithelial stromal tissue, which are characteristics of breakthrough bleeding known to occur with progestational agents. In contrast, no association with the course of genital bleeding was found with respect to changes in serum estradiol, progesterone, follicle stimulating hormone and luteinizing hormone concentrations, plasma dienogest concentration, endometrial thickness or follicular diameter. Conclusion:  These results suggest that the genital bleeding seen in the period of medication with dienogest originated from breakthrough bleeding from the pseudodecidua, which reflects a direct progestational effect of dienogest on the endometrium. (Reprod Med Biol 2007; 6: 223-228).

Importance of uterine cell death, renewal, and their hormonal regulation in hamsters that show progesterone-dependent implantation

This study was initiated to investigate the significance of uterine cell death and proliferation during the estrous cycle and early pregnancy and their correlation with sex steroids in hamsters where blastocyst implantation occurs in only progesterone-primed uteri. The results obtained in hamsters were also compared with mice where blastocyst implantation occurs in progesterone-primed uteri if estrogen is provided. Apoptotic cells in the uterus were detected by using terminal deoxynucleotide transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) technique. Uterine cell proliferation was determined by 5-bromo-2'-deoxyuridine labeling followed by immunohistochemistry and methyl-tritiated [(3)H]thymidine labeling. Active caspase-3, an executor protein of cell death, expression was assayed by immunohistochemistry/immunofluorescence. Our results demonstrate that epithelial proliferation on the second day after mating marks the initiation of pregnancy-related uterine changes in both species despite their differences in hormonal requirements. Hamsters and mice showed subtle differences in uterine proliferative and apoptotic patterns during early pregnancy and in response to steroids. There existed almost a direct correlation between apoptosis and caspase-3 expression, suggesting uterine cell death mostly involves the caspase pathway. Consistent with these findings, we showed, for the first time, that execution of uterine epithelial cell apoptosis by caspase-3 is important for blastocyst implantation because a caspsase-3 inhibitor N-acetyl-DEVD-CHO when instilled inside the uterine lumen on d 3 of pregnancy inhibits implantation in hamsters and mice. The overall results indicate that uterine cell apoptosis and proliferation patterns are highly ordered cell-specific phenomena that play an important role in maintaining the sexual cycle and pregnancy-associated uterine changes.

Stage-variations of anandamide hydrolase activity in the mouse uterus during the natural oestrus cycle

Recent studies have demonstrated that the endogenous cannabinoids are important modulators of fertility in mammals. In particular, a role of the endocannabinoid system in early stages of embryo development, oviductal transport of embryos, pregnancy maintenance and labour has been demonstrated in rodents and/or in humans. In the present paper, we report the analysis of FAAH activity and protein content in the mouse uterus as a function of the natural oestrus cycle stages. Variations of FAAH activity are discussed in relationship to changes in sex steroid levels and to the possible action of AEA on remodelling of uterine tissues.

Potential action of androstenedione on the proliferation and apoptosis of stromal endometrial cells

Background

Hyperandrogenic conditions have been associated with a high prevalence of endometrial pathologies related to cell survival. However, the action of androgens on proliferation and apoptosis in endometrial cells is poorly understood. Therefore, the aim of the present study was to evaluate the effect of androstenedione on cell proliferation, cell death and expression of estrogen receptor (ER) isoforms and proteins related to apoptosis in endometrial cells using two in vitro experimental approaches.

Methods

The endometrial tissue was obtained from 20 eumenorrheic women [28.7 (25 – 35) years] during the early secretory phase. We analyzed cell proliferation (immunohistochemistry of Ki-67 and spectrophotometric assay); apoptosis (DNA fragmentation (TUNEL) and Annexin V-FITC binding); ER-alpha, ER-beta bcl-2 and bax mRNA abundance (RT-PCR) in explants and isolated endometrial epithelial (EEC) and stromal cells (ESC) incubated with androstenedione 1 micro mol/l (A4) or A4 plus hydroxyflutamide 10 micro mol/l (F) for 24 h.

Results

In explants, A4 induced an increase of cell proliferation and a decrease on apoptosis in the stromal compartment (p < 0.05). In isolated ESC, proliferation augmented with A4 (p < 0.05), whereas, no significant modifications in the expression of ER-alpha, ER-beta bcl-2 and bax nor in the apoptotic index were observed. In EEC, A4 increase the ER-beta mRNA abundance (p < 0.05) and a decrease of the bcl-2/bax ratio (p < 0.05), without an increase in the apoptotic index. Hydroxyflutamide reverted the effect of androstenedione on the parameters described.

Conclusions

These results indicate that androstenedione may modulate cell survival, expression of ER-beta and proteins related to apoptosis, suggesting a potential mechanism that associates the effect of hyperandrogenemia on the endometrial tissue.