M. Cecilia Johnson

Augmented cell survival in eutopic endometrium from women with endometriosis: Expression of c-myc, TGF-beta1 and bax genes

BackgroundEndometriosis is a common gynaecological disorder characterized by the presence of endometrial tissue outside of the uterus. The fragments in normal menstruation are composed of necrotic and living cells, which do not survive in ectopic locations because of programmed cell death. The aim of this study was to evaluate if the balance between cell proliferation and apoptosis is changed in eutopic endometrium from women with endometriosis throughout the menstrual cycle by studying bax (pro-apoptotic), c-myc (regulator of cell cycle) and TGF-beta1 (involved in cell differentiation) genes.MethodsEutopic endometrium was obtained from: 30 women with endometriosis (32.8 +/- 5 years) and 34 fertile eumenorrheic women (36 +/- 5.3 years). We analyzed apoptosis (TUNEL: DNA fragmentation); cell proliferation (immunohistochemistry (IHC) for Ki67); c-myc, bax and TGF-beta1 mRNA abundance (RT-PCR) and TGF-beta1 protein (IHC) in endometrial explants.ResultsCell proliferation strongly decreased from proliferative to late secretory phases in glands, but not in stroma, in both endometria. Positive staining in glands and stroma from proliferative endometrium with endometriosis was 1.9- and 2.2-fold higher than control endometrium, respectively (p < 0.05). Abundance of c-myc mRNA was 65% higher in proliferative endometrium from endometriosis than normal tissue (p < 0.05). TGF-beta1 (mRNA and protein) augmented during mid secretory phase in normal endometrium, effect not observed in endometrium with endometriosis. In normal endometrium, the percentage of apoptotic epithelial and stromal cells increased more than 30-fold during late secretory phase. In contrast, in endometrium from endometriosis, not only this increase was not observed, besides bax mRNA decreased 63% versus normal endometrium (p < 0.05). At once, in early secretory phase, apoptotic stromal cells increased 10-fold with a concomitant augment of bax mRNA abundance (42%) in endometria from endometriosis (p < 0.05).ConclusionAn altered expression of c-myc, TGF-beta1 and bax was observed in eutopic endometrium from endometriosis, suggesting its participation in the regulation of cell survival in this disease. The augmented cell viability in eutopic endometrium from these patients as a consequence of a reduction in cell death by apoptosis, and also an increase in cell proliferation indicates that this condition may facilitate the invasive feature of the endometrium.

Nuclear factor κB pathway and interleukin-6 are affected in eutopic endometrium of women with endometriosis

In order to investigate the role of the nuclear factor kappaB (NFKB) pathway on gene expression in the eutopic endometrium in endometriosis, and in particular of interleukin-6 (IL6), we evaluated RELA, IkappaB kinase (CHUK), NFKBIA and IL6 expressions and NFKB DNA binding in eutopic endometrium from women with endometriosis. Eutopic endometrium was obtained from 37 women with endometriosis and 42 fertile women during laparoscopy. We analysed RELA, CHUK, NFKBIA and IL6 mRNA levels (RT-PCR); RELA, CHUK and NFKBIA proteins and p-NFKBIA/NFKBIA ratio (western blot); and NFKB binding (DNA shift assay) and IL6 concentration (ELISA) in endometrial explants. Our results indicate that mRNA and cytoplasmic proteins of RELA and CHUK exhibit constant levels in normal endometrium during the menstrual cycle. A dramatic increase (P<0.05) in NFKBIA mRNA expression, RELA nuclear presence and the mRNA and the protein of IL6 during late secretory phase was also observed in this tissue. By contrast, in eutopic endometrium from endometriosis patients, a decrease (P<0.05) in IL6 mRNA and protein (61%), NFKBIA mRNA (46%), p-NFKBIA/NFKBIA ratio (42%), RELA nuclear stromal (68%) and CHUK (48%) proteins were found exclusively during the late secretory phase compared with normal endometrium. In conclusion, the canonical activation of NFKB pathway is deregulated and may have reduced transcriptional function affecting NFKBIA and IL6 expression, genes related local proinflammatory processes. These molecular alterations observed during the late secretory phase in eutopic endometrium from endometriosis patients constitute a NFKB system dysfunction, suggesting that NFKB could be an important factor in endometriosis aetiology.

hCG activates Epac-Erk1/2 signaling regulating Progesterone Receptor expression and function in human endometrial stromal cells

STUDY QUESTION How does hCG signal in human endometrial stromal cells (ESCs) and what is its role in regulating ESC function? SUMMARY ANSWER hCG signaling in ESCs activates the extracellular signal-regulated protein kinases 1 and 2 (Erk1/2) pathway through exchange protein activated by cyclic AMP (cAMP) (Epac) and transiently increases progesterone receptor (PR) transcript and protein expression and its transcriptional function. WHAT IS KNOWN ALREADY hCG is one of the earliest embryo-derived secreted signals in the endometrium, which abundantly expresses LH/hCG receptors. hCG signals through cAMP/protein kinase A (PKA) in gonadal cells, but in endometrial epithelial cells, hCG induces Erk1/2 activation independent of the cAMP/PKA pathway. Few data exist concerning the signal transduction pathways triggered by hCG in ESCs and their role in regulation of ESC function. STUDY DESIGN, SIZE, DURATION This is an in vitro study comprising patients undergoing benign gynecological surgery (n = 46). PARTICIPANTS/MATERIALS, SETTING, METHODS Endometrial samples were collected from normal cycling women during the mid-secretory phase for ESCs isolation. The study conducted in an academic research laboratory within a tertiary-care hospital. The activation of the Erk1/2 signal transduction pathway elicited by hCG was evaluated in ESC. Signaling pathway inhibitors were used to examine the roles of PKA, PI3K, PKC, adenylyl cyclase and Epac on the hCG-stimulated up-regulation of phospho-Erk1/2 (pErk1/2). Erk1/2 phosphorylation was determined by immunoblot. siRNA targeting Epac was used to investigate the molecular mechanisms. To assess the role of Erk1/2 signaling induced by hCG on ESC function, gene expression regulation was examined by immunofluorescence and real-time quantitative PCR. The role of PR on the regulation of transcript levels was studied using progesterone and the PR antagonist RU486. All experiments were conducted using at least three different cell culture preparations in triplicate. MAIN RESULTS AND THE ROLE OF CHANCE Addition of hCG to ESCs in vitro induced the phosphorylation of Erk1/2 through cAMP accumulation. Such induction could not be blocked by inhibitors for PKA, PKC and PI3K. Epac inhibition and knockdown with siRNA prevented pErk1/2 induction by hCG. ESCs stimulated with hCG for up to 72 h showed a significant increase in PR mRNA and immunofluorescent label at 48 h only; an effect that was abrogated with the mitogen-activated protein kinase kinase inhibitor UO126. In addition, the hCG-activated Erk1/2 pathway significantly decreased the mRNA levels for secreted frizzled-related protein 4 (SFRP4) at 24 h, whereas it increased those for homeobox A10 (HOXA10) at 48 h (P = 0.041 and P = 0.022 versus control, respectively). Prolactin mRNA levels were not significantly modified. HOXA10 mRNA up-regulation by hCG was not enhanced by co-stimulation with progesterone; however, it was completely abolished in the presence of RU486 (P = 0.036 hCG versus hCG + RU486). LARGE SCALE DATA N/A. LIMITATIONS, REASONS FOR CAUTION This is an in vitro study utilizing stromal cell cultures from human endometrial tissues. Furthermore, results obtained should also be confirmed in vivo in the context of the whole human endometrial tissue and hormonal milieu. The in vitro experiments using hCG have been conducted without other hormones/factors that may also modulate the ESCs response to hCG. WIDER IMPLICATIONS OF THE FINDINGS We have determined that hCG induces the PR through the Erk1/2 pathway in ESCs which may render them more sensitive to progesterone, increasing our understanding about the effects of hCG at the embryo-maternal interface. The activation of such a pathway in the context of the hormonal milieu during the window of implantation might contribute to a successful dialog between the embryo and the uterus, leading to appropriate endometrial function. Defective hCG signaling in the endometrial stromal tissue may lead to an incomplete uterine response, compromising embryo implantation and early pregnancy. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the National Fund for Scientific and Technological Development, Government of Chile (FONDECYT) grants 11100443 and 1140614 (A.T.-P.). The authors have no conflicts of interest to declare.

Acid-Labile Subunit (ALS) Gene Expression and Protein Content in Human Placentas: Differences According to Birth Weight

CONTEXT In humans, IGF-I and -II have an important role in pre- and postnatal growth. The IGFs circulate in plasma principally as a ternary complex with the IGF binding protein-3 and an acid-labile subunit (ALS), which increases their half life. OBJECTIVES The objectives of the study were to determine whether the human placenta expresses the mRNA and protein for ALS and to evaluate any possible differences in the mRNA and protein for ALS in placentas from small (SGA) and appropriate (AGA) or gestational age newborns. SUBJECTS/METHODS We studied the placentas from 47 AGA and 42 SGA pregnancies. IGF-I, IGF-II, IGF binding protein-3, and ALS placental mRNA and protein contents were determined in both the basal and the chorionic plates of the placenta. RESULTS We observed that the human placenta expresses the gene and protein for ALS. The ALS mRNA in SGA was higher compared with AGA placentas (0.15 ± 0.01 vs. 0.12 ± 0.01 arbitrary units, respectively, P < 0.05). In addition, the ALS protein content in SGA (31.7 ± 3.3 pmol/g) was higher compared with AGA (22.1 ± 2.3 pmol/g, P < 0.05) placentas. CONCLUSION We describe that the human placenta expresses the mRNA and the protein for ALS, and we observed an increase in ALS mRNA expression and protein content in SGA compared with AGA placentas.

P450Arom induction in isolated control endometrial cells by peritoneal fluid from women with endometriosis

OBJECTIVE To study the effect of peritoneal fluid from women with (PF-E) and without (PF-C) endometriosis on P(450)Arom expression in endometrial cells. DESIGN Experimental study. SETTING University research unit. PATIENT(S) Forty women of reproductive age with (n = 22) or without (control; n = 18) endometriosis. INTERVENTION(S) Peritoneal fluid and eutopic endometrial samples were obtained during surgery from women with (n = 13 and 9, respectively) and without (n = 4 and 14, respectively) endometriosis. MAIN OUTCOME MEASURE(S) Expression study for P(450)Arom, steroid factor 1 (SF-1), chicken ovalbumin upstream transcription factor I (COUP-TFI), and COUP-TFII messenger RNA (reverse transcriptase-polymerase chain reacion) and/or protein (immunoblot) in isolated endometrial epithelial cells transfected or not with expression vector containing SF-1, COUP-TFI, or COUP-TFII complementary DNAs. RESULT(S) Basal messenger RNA and/or protein expression of P(450)Arom and SF-1 were augmented in endometriosis, and that of COUP-TF was diminished. In control cells, (Bu)(2)cAMP and PF-E increased P(450)Arom and SF-1 expression (but not COUP-TF expression) in a dose-dependent way, an effect not observed with PF-C, adsorbed PF-E, or 10(-5) M indomethacin. Transfected cells confirmed these results. Any treatments modified the studied molecules in endometriosis cells. CONCLUSION(S) These data indicate that molecules contained in PF-E favor an estrogenic microenvironment, suggesting a role in the etiopathogenesis of endometriosis enabling the survival, maintenance, and growth of endometrial implants in the ectopic locations.

IGF-IR signal transduction protein content and its activation by IGF-I in human placentas: relationship with gestational age and birth weight.

Introduction The human placenta expresses the IGF-I and IGF-IR proteins and their intracellular signal components (IRS-1, AKT and mTOR). The aim of this study was to assess the IGF-IR content and activation of downstream signaling molecules in placentas from newborns who were classified by gestational age and birth weight. We studied placentas from 25 term appropriate (T-AGA), 26 term small (T-SGA), 22 preterm AGA (PT-AGA), and 20 preterm SGA (PT-SGA) newborns. The total and phosphorylated IGF-IR, IRS-1, AKT, and mTOR contents were determined by Western Blot and normalized by actin or with their respective total content. The effect of IGF-I was determined by stimulating placental explants with recombinant IGF-I 10-8 mol/L for 15, 30, and 60 minutes. Results The IGF-IR content was higher in T-SGA compared to T-AGA placentas, and the IRS-1 content was higher in PT-placentas compared with their respective T-placentas. The effect of IGF-I on the phosphorylated forms of IGF-IR was increased in T-SGA (150%) and PT-SGA (300%) compared with their respective AGA placentas. In addition, AKT serine phosphorylation was higher in PT-SGA compared to PT-AGA and T-SGA placentas (90% and 390% respectively). Conclusion The higher protein content and response to IGF-I of IGF-IR, IRS-1, and AKT observed in SGA placentas may represent a compensatory mechanism in response to fetal growth restriction.

Prevalencia de la endometriosis en mujeres sometidas a esterilización quirúrgica laparoscópica en un hospital de Santiago de Chile

BACKGROUND The clinical manifestations of endometriosis are infertility, dysmenorrhea, sexuality disturbances, and chronic pelvic pain. It is the cause of 30 to 50% of infertility cases. In developed countries, the prevalence of endometriosis among women undergoing surgical sterilization is approximately 6%. AIM To determine the prevalence of endometriosis among women with proven fertility in Santiago de Chile. MATERIAL AND METHODS Review of surgical protocols of 287 women aged 25 to 49 years, subjected to a surgical sterilization between 2007 and 2011. RESULTS Endometriosis was found in 14 of the 287 women (4.9%). In spite of being asymptomatic, five of the 14 women with endometriosis were classified as severe, due to the presence of at least one endometrioma. In order of frequency, the most commonly affected anatomical sites were the ovary, the peritoneum, the posterior cul-de-sac and uterosacral ligaments. CONCLUSIONS Our findings are very similar to those found elsewhere and suggest that fertile women could better tolerate endometriosis than their infertile counterparts.