Uterine Cervical Inflammatory Cytokines, Interleukin-6 and -8, as Predictors of Miscarriage in Recurrent Cases

Changes in cytokine and sequestosome-1 levels during twin pregnancy progression: Association with outcome

BACKGROUND

Twin pregnancies are associated with complications and adverse outcomes. The number of twin pregnancies has increased in the last decades, due to the use of assisted reproductive techniques and delayed childbearing. Analysis of changes that occur during twin pregnancy progression and their association with outcome will lead to improved clinical interventions.

OBJECTIVE

We evaluated if the plasma concentration of select cytokines and the level of sequestosome-1 (p62) in peripheral blood mononuclear cells (PBMCs) during each trimester of twin gestations was predictive of pregnancy outcome.

STUDY DESIGN

This prospective, observational study was conducted at Careggi University Hospital, Florence, Italy. Plasma from 82 women with twin pregnancies was collected in each trimester for measurement of interleukin (IL)-1β, IL-6, IL-10, IL-12 and tumor necrosis factor (TNF)-α. The intracellular PBMC concentration of p62, a protein involved in autophagy, kinase activity and cell differentiation, was also determined.

RESULTS

IL-1β (p < 0.001), IL-6 (p < 0.001), TNF-α (p < 0.001) and p62 (p < 0.05) increased from the 1st to the 2nd to the 3rd trimester. The TNF-α level was correlated with the IL-1β concentration in the 1st and 3rd trimesters p < 0.01) and with the IL-6 concentration in each of the three trimesters (p < 0.01). The intracellular p62 level in PBMCs was negatively correlated with the concentration of IL-1β in the 2nd trimester (p < 0.05) and negatively correlated with the IL-6 level in the 3rd trimester (p < 0.05). The TNF-α level was significantly higher in the 2nd (p < 0.05) and 3rd (p < 0.001) trimester in women with a spontaneous preterm delivery. The TNF-α concentrations in the 2nd (p < 0.05) and 3rd (p < 0.01) trimester, respectively, and 3rd trimester IL-6 (p < 0.01), were negatively associated with gestational age at delivery. The concentration of IL-6 was highest in the 2nd (p < 0.05) and 3rd (p < 0.05) trimesters in women who utilized assisted reproductive technologies. An elevated IL-1β level in the 3rd trimester was associated with gestational diabetes mellitus (p < 0.05).

CONCLUSION

Variations in cytokine levels between individual women during the three trimesters of twin gestations are predictive of spontaneous preterm delivery and the onset of gestational diabetes.

A Narrative Review Discussing the Obstetric Repercussions Due to Alterations of Personalized Bacterial Sites Developed within the Vagina, Cervix, and Endometrium

BACKGROUND

The reproductive tract microbiota that evolved as an integrative component has been studied intensively in the last decade. As a result, novel research, clinical opportunities, and perspectives have been derived following the close investigation of this microecological environment. This has paved the way for an update to and improvement of the management strategies and therapeutic approaches. However, obscurities, contradictions, and controversies arise regarding the ascension route from the vagina to the endometrium via the cervix, with finality in adverse obstetric outcomes.

METHODS

Starting from these considerations, we aimed to gather all existing data and information from four major academic databases (PubMed, ISI Web of Knowledge, Scopus, and ScienceDirect) published in the last 13 years (2010-2023) using a controlled vocabulary and dedicated terminology to enhance the coverage, identification, and sorting of potentially eligible studies.

RESULTS

Despite the high number of returned entries (n = 804), only a slight percentage (2.73%) of all manuscripts were deemed eligible following two rounds of evaluation. Cumulatively, a low level of Lactobacillus spp. and of other core microbiota members is mandatory, with a possible eubiosis-to-dysbiosis transition leading to an impairment of metabolic and endocrine network homeostasis. This transposes into a change in the pro-inflammatory landscape and activation of signaling pathways due to activity exerted by the bacterial lipopolysaccharides (LPSs)/endotoxins that further reflect a high risk of miscarriage in various stages. While the presence of some pathogenic entities may be suggestive of an adverse obstetric predisposition, there are still pros and cons of the role of specific strains, as only the vagina and cervix have been targeted as opposed to the endometrium, which recently started to be viewed as the key player in the vagina-cervix-endometrium route. Consequently, based on an individual's profile, diet, and regime, antibiotics and probiotics might be practical or not.

CONCLUSIONS

Resident bacteria have a dual facet and are beneficial for women's health, but, at the same time, relaying on the abundance, richness, and evenness that are definitory indexes standing as intermediaries of a miscarriage.

Cervicovaginal microbiome in patients with recurrent pregnancy loss

There have been few studies concerning an association between unexplained recurrent pregnancy loss (RPL) and the microbiome. A recent study including 67 patients demonstrated that an increase in Ureaplasma species in the endometrium raised the risk of miscarriage with an euploid karyotype. While endometrial sampling is invasive, cervicovaginal sampling is not. We compared vaginal and cervical microbiomes with a 16 S ribosomal RNA sequence between 88 patients with unexplained RPL and 17 healthy women with no history of miscarriage. We prospectively assessed risk factors for maternal colonization at a subsequent miscarriage without an aneuploid karyotype in patients. Cervicovaginal bacteria were dominated by Lactobacillus iners, Gardnerella vaginalis, Atopobium vaginae and Bifidobacterium breve in Japanese population. The proportions of Delftia and unknown bacteria in the cervix were significantly higher in patients with RPL than in controls. Streptococcus, Microbacterium, Delftia, Anaerobacillus and Chloroplast in the cervix were significantly higher in patients with a history of chorioamnionitis compared to the controls. The abundance of Cutibacterium and Anaerobacillus in the cervix was significantly higher in patients who had subsequently miscarried compared to those who gave birth. The miscarriage rate in patients with higher proportions of both Cutibacterium and Anaerobacillus (66.7%, 2/3) was significantly greater than that of patients who lacked these bacteria (9.2%, 6/65, adjusted odds ratio 16.90, 95% confidence interval 1.27-225.47, p = 0.032). The presence of certain bacteria could be a predictor of subsequent miscarriage without an aneuploid karyotype. The cervicovaginal microbiome might be useful for investigating a possible cause of RPL.

Role of Inflammaging on the Reproductive Function and Pregnancy

During female lifetime and pregnancy, inflammation and cellular senescence are implicated in physiological processes, from ovulation and menstruation, to placental homeostasis and delivery. Several lifestyles, nutritional, and environmental insults, as well as long-lasting pregestational inflammatory diseases may lead to detrimental effects in promoting and sustaining a chronic excessive inflammatory response and inflammaging, which finally contribute to the decay of fertility and pregnancy outcome, with a negative effect on placental function, fetal development, and future health risk profile in the offspring. Maladaptation to pregnancy and obstetric disease may in turn increase maternal inflammaging in a feedback loop, speeding up aging processes and outbreak of chronic diseases. Maternal inflammaging may also impact, through transgenerational effects, on future adult health. Hence, efficacious interventions should be implemented by physicians and healthcare professionals involved in prevention activities to reduce the modifiable factors contributing to the inflammaging process in order to improve public health.

IL-6 and IL-8: An Overview of Their Roles in Healthy and Pathological Pregnancies

Interleukin-6 (IL-6) is an acknowledged inflammatory cytokine with a pleiotropic action, mediating innate and adaptive immunity and multiple physiological processes, including protective and regenerative ones. IL-8 is a pro-inflammatory CXC chemokine with a primary function in attracting and activating neutrophils, but also implicated in a variety of other cellular processes. These two ILs are abundantly expressed at the feto-maternal interface over the course of a pregnancy and have been shown to participate in numerous pregnancy-related events. In this review, we summarize the literature data regarding their role in healthy and pathological pregnancies. The general information related to IL-6 and IL-8 functions is followed by an overview of their overall expression in cycling endometrium and at the feto-maternal interface. Further, we provide an overview of their involvement in pregnancy establishment and parturition. Finally, the implication of IL-6 and IL-8 in pregnancy-associated pathological conditions, such as pregnancy loss, preeclampsia, gestational diabetes mellitus and infection/inflammation is discussed.

Diminished miR-374c-5p negatively regulates IL (interleukin)-6 in unexplained recurrent spontaneous abortion

Unexplained recurrent spontaneous abortion (URSA) is commonly observed, and seriously affects women's reproductive health. Excessive interleukin-6 (IL-6) production has been shown to frequently occur and relate to URSA pathogenesis. In this study, the miRNA expression profile in peripheral blood mononuclear cells (PBMCs) from URSA patients and normal pregnant (NP) women was assessed by miRNA microarray and real-time quantitative reverse-transcription polymerase chain reaction (qPCR). MiRNA target prediction tools and luciferase reporter assay were used to detect direct binding between miRNAs and IL6. Functional study of administering anti-IL-6 neutralizing antibody and miR-374c-5p mimics to an URSA animal model was performed to evaluate embryo resorption rates. In the results, compared with NP women, the expression of IL-6 increased markedly in PBMCs and decidual tissues at both mRNA and protein levels, while miR-374c-5p expression decreased significantly. Prediction software and luciferase reporter assay showed that miR-374c-5p binds with IL6 3'UTR via the complementary bases. Transfection of miR-374c-5p mimics into an in vitro HeLa cell line significantly downregulated the expression of IL-6, while transfection of the miR-374c-5p inhibitor induced an opposite result. In the URSA mouse model, miR-374c-5p overexpression reduced the embryo resorption rate significantly, accompanied with decreased expression of IL-6 in the decidua. To sum up, downregulated miR-374c-5p was involved in the pathogenesis of URSA by enhancing IL-6 expression. Modulation of miR-374c-5p expression may be used to regulate IL-6 production for the treatment of URSA.

Grim-19 deficiency promotes decidual macrophage autophagy in recurrent spontaneous abortion

Dysregulation of decidual macrophages leads to the occurrence of recurrent spontaneous abortion (RSA). However, the role of macrophages in RSA occurrence remains unclear. In this study, we found that the expression of Grim-19 was decreased, and the expression of autophagy related proteins Beclin1, LC3B II/I and BNIP3 was markedly upregulated in decidual macrophages of RSA patients compared with the normal pregnancy group. Furthermore, we demonstrated that downregulation of GRIM-19 increased the expression of autophagy related proteins Beclin1, LC3B II/I, BNIP3 and the proinflammatory cytokines IL1B, IL6 and TNFa in uterine mononuclear cells of GRIM-19^+/- mice. The proportion of CD45+CD11b+F4/80+LC3B+ cells in GRIM-19^+/- mouse uteri was significantly higher than that in WT mouse uteri. In addition, we confirmed that inhibition of Grim-19 by siRNA enhanced the expression of autophagy related proteins in RAW264.7 cells and THP-1 cells. More importantly, downregulation of Grim-19 in RAW264.7 cells promoted the release of proinflammatory cytokines and promoted phagocytic activity, which could be reversed by autophagy blockade. For THP-1-derived macrophages, the results of RNA-seq suggested that Grim-19 mainly modulates immune and inflammatory-related pathways, leading to cytokine production, and thus contributing to inflammation. Therefore, our data reveal that Grim-19 deficiency influences macrophage function, characterized by enhanced proinflammatory cytokines and phagocytic activity, and this might be regulated by autophagy. This may represent a novel mechanism for the occurrence of RSA.

Identification of key molecules in recurrent miscarriage based on bioinformatics analysis

BACKGROUND

Recurrent miscarriage (RM) affects 1% to 5% of couples, and the mechanisms still stay unclear. In this study, we explored the underlying molecular mechanism and potential molecular biomarkers of RM as well as constructed a miRNA-mRNA regulation network.

METHODS

The microarray datasets GSE73025 and GSE22490, which represent mRNA and miRNA profiles, respectively, were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) with p-value < 0.05 and fold-change > 2 were identified while the miRNAs with p-value < 0.05 and fold-change > 1.3 were considered as significant differentially expressed miRNAs (DEMs).

RESULTS

A total of 373 DEGs, including 218 up-regulated genes and 155 down-regulated genes, were identified, while 138 up-regulated and 68 down-regulated DEMs were screened out. After functional enrichment analysis, we found GO biological process (BP) terms significantly enriched in the Fc-gamma receptor signaling pathway involved in phagocytosis. Moreover, signaling pathway analyses indicated that the neurotrophin signaling pathway (hsa04722) was the top KEGG enrichment. 6 hub genes (FPR1, C5AR1, CCR1, ADCY7, CXCR2, NPY) were screened out to construct a complex regulation network in RM because they had the highest degree of affecting the network. Besides, we constructed miRNA-mRNA network between DEMs target genes and DEGs in RM, including hsa-miR-1297- KLHL24 and hsa-miR-548a-5p-KLHL24 pairs.

CONCLUSIONS

In conclusion, the novel differentially expressed molecules in the present study could provide a new sight to explore the pathogenesis of RM as well as potential biomarkers and therapeutic targets for RM diagnosis and treatment.

Does tumour necrosis factor alpha-induced cyclooxygenase-2 expression lead to spontaneous abortion in Chlamydia trachomatis-infected women

Cytokines might be involved in spontaneous abortion by triggering inflammatory mediators (Cyclooxygenases (Cox)) leading to spontaneous abortion in Chlamydia trachomatis (Ct)-infected women. Study aimed to quantitate the expression of pro-inflammatory cytokines (TNF-α, IFN-γ, IL-8) and Cox-2 in endometrial curettage tissue (ECT) of Spontaneous Aborters (SA). SA (n = 135) and 120 age-matched controls were enrolled from SJH, New Delhi, India. PCR was performed for detection of Ct MOMP gene (537 bp) in ECT. mRNA expression of pro-inflammatory cytokines and Cox-2 was assessed by real-time qPCR. Data was statistically evaluated. 14.8% SA were diagnosed as Ct-positive. Elevated expression of TNF-α, IFN-γ, IL-8 and Cox-2 was observed in Ct-infected SA. Ct-positive recurrent aborters showed significantly higher cytokine expression. Significant positive correlation was found between expression of Cox-2 and TNF-α in infected SA. Data suggested an increased expression of Th-1 cytokines, particularly TNF-α that induced Cox-2 expression in ECT, leading to spontaneous abortion in Ct-infected pregnant women.

Weathering the storm; a review of pre-pregnancy stress and risk of spontaneous abortion

The Weathering Effect is a theory that links stress exposure, over the life-course, with racial disparities in reproductive outcomes, through the effects of social adversity on a woman's body. The concept of maternal "weathering" captures cumulative somatic and psychological adversities that can exacerbate the effects of aging. Much of the evidence for weathering comes from observational studies linking self-report measures with reproductive outcomes. The purpose of this review is to explore biological mechanisms that underlie these observations. We focus on spontaneous abortion because this event is understudied despite evidence of racial disparities in this outcome. Spontaneous abortion is the most common pregnancy failure, and it happens early in pregnancy. Early pregnancy is a time most susceptible to the harmful effects of immune dysregulation that may, in part, result from adversities experienced before pregnancy begins. In exploring these mechanisms, we draw on well-defined signaling processes observed in the stressor-depression relationship. Pro-inflammatory dysregulation, for example, has particular relevance to immunological control occurring early in pregnancy. Early pregnancy immunologic changes affect the trajectories of pregnancy via control of trophoblastic invasion. Within the first few weeks of pregnancy, uterine derived cytokines operate within cytokine networks and play a critical role in this invasion. Programming for pro-inflammatory dysregulation can occur before conception. This dysregulation, brought into early pregnancy, has implications for viability and success of the index pregnancy. These patterns suggest early pregnancy health is susceptible to stress processing pathways that influence this immunologic control in the first six to eight weeks of pregnancy. In this review, we discuss the known mediating role of immune factors in the stressor-depression relationship. We also discuss how adversity experienced before the index pregnancy, or "pre-pregnancy" may influence these pathways, and subsequently influence early pregnancy health. There is a need to understand adversity, experienced before pregnancy, and mechanisms driving the effects of these experiences on pregnancy outcomes. This approach is a useful entry point for understanding racial inequities in pregnancy health through an understanding of differences in exposures to adversity. We hypothesize that spontaneous abortion involves cyclical changes within a woman's reproductive tract in response to stressors that are established well before a woman enters into pregnancy. Furthermore, we propose mechanisms that potentially drive weathering processes relevant to reproductive disparities. We also examine what is known about pre-pregnancy stress exposures associated with race, inequity, and adversity, and their potential impact on neuroendocrine and immune changes affecting early pregnancy risk.

Differential expression of circulating Th1/ Th2/ Th17 cytokines in serum of Chlamydia trachomatis-infected women undergoing incomplete spontaneous abortion

The study aimed to elucidate role of Th1/Th2/Th17 cytokines in the immunopathogenesis of spontaneous abortion in Chlamydia trachomatis (Ct)-positive first-trimester aborters. Endometrial curettage tissue and serum were collected from 145 aborters (spontaneous abortion (SA) group, n = 85; recurrent miscarriage (RM) group, n = 60) and 120 controls attending Department of Obstetrics & Gynecology at Safdarjung hospital, New Delhi (India). Polymerase chain reaction was used to detect Ct plasmid/MOMP, while commercial cytometric bead array kit was utilized to estimate circulating serum cytokines. 13.7% aborters were Ct-positive, however, none was found to be infected among controls. IFN-γ, TNF-α, IL-2, IL-6 and IL-17A cytokines were significantly increased in SA group/RM group (Ct-infected) versus controls. IL-4 showed no difference between groups, while IL-10 was significantly elevated in controls versus Ct-infected subjects in SA group/RM group. Furthermore, IFN-γ, TNF-α, IL-6, IL-17A cytokines were significantly elevated in Ct-positive RM group versus Chlamydia-infected SA group. However, IL-2, IL-4 and IL-10 cytokines showed no significant difference between Ct-positive SA group versus infected RM group. Positive correlation was found between few cytokines (TNF-α and IFN-γ/IL-17A; IL-17A and IFN-γ/IL-6) in Ct-positive aborters. Our study clearly established the role of Th1/Th2/Th17 cytokines in the pathogenesis of spontaneous abortion in Ct-infected subjects and found that Chlamydia-positive recurrent aborters had a predominant Th1/Th17 bias.

Partnered sexual activity moderates menstrual cycle-related changes in inflammation markers in healthy women: an exploratory observational study

OBJECTIVE

To examine differences in inflammation markers in sexually active versus abstinent women and observe changes in inflammation markers across the menstrual cycle. Cycle-related immune fluctuations may have evolved to reduce interference with conception. If so, reproductively active (i.e., sexually active) women should show the most variability in cytokine expression.

DESIGN

Participants provided serum samples at menses and ovulation (from which cytokines were assayed) and saliva samples at menses and during follicular, ovulation, and luteal phases (from which C-reactive protein [CRP] was assayed). Participants self-reported intercourse frequency during the study.

SETTING

Academic research laboratory.

PATIENT(S)

Thirty-two healthy, naturally cycling premenopausal women (sexually active, n = 15; abstinent, n = 17).

INTERVENTION(S)

Observational study.

MAIN OUTCOME MEASURE(S)

Levels of proinflammatory cytokines (interleukin-6 [IL-6], interferon γ [IFN-γ], tumor necrosis factor-α [TNF-α]), an anti-inflammatory cytokine (interleukin-4 [IL-4]), and a marker of total inflammation (CRP).

RESULT(S)

Sexually active women had higher levels of all of the immune markers measured, including both pro- and anti-inflammatory cytokines, than abstinent women. Relative to sexually active women, abstinent women had less change across the menstrual cycle in levels of CRP. Among sexually active women, higher intercourse frequency predicted greater midcycle decreases in CRP, IL-6, and IFN-γ and midcycle increases in IL-4.

CONCLUSION(S)

Sexual activity may stimulate a complex interaction between pro- and anti-inflammatory cytokines that subsequently drives midcycle declines in inflammation.

Association between Serum TNF-α Levels and Recurrent Spontaneous Miscarriage: A Meta-analysis

Most recurrent spontaneous miscarriages (RSMs) are attributed to 'unexplained' factors, the majority of which are immune factors. Furthermore, clinically, only a small number of RSM patients get early diagnosis by testing for antiphospholipid antibodies, whereas most of the patients, present no specific diagnostic indicators. We performed a meta-analysis of observational studies to detect the association between RSM and TNF-α levels. We searched PubMed, EMBase, ScienceDirect, Web of Science, and Chinese databases (including: Wanfang Data, CNKI, and VIP databases) for articles published up to 2014. Of the 151 initially identified studies, 11 case-control studies with 1371 patients were finally analyzed. Overall, baseline TNF-α levels were higher in patients than in controls. The standardized mean difference of the TNF-α levels of the patients was 2.82 units (95% confidence interval 1.57-4.06) and the overall effect z-score was 4.42 (P < 0.0001). The heterogeneity test revealed significant differences among individual studies (P = 0.000, I(2)  = 98.7%). Serum TNF-α levels were significantly increased in patients relative to those in controls. The heterogeneity could be attributed to the differences in the detection methods and sampling times used in the different studies.

Elevation of soluble form of receptor for advanced glycation end products (sRAGE) in recurrent pregnancy losses (RPL): possible participation of RAGE in RPL

OBJECTIVE

To determine whether the soluble receptor for advanced glycation end products (sRAGE) and immune inflammatory markers are associated with recurrent pregnancy losses (RPL).

DESIGN

Prospective case-control study.

SETTING

University clinic.

PATIENT(S)

A total of 93 women (age 35.8±4.6 years) were enrolled including 63 women with three or more recurrent pregnancy losses (RPL), and age-matched fertile controls with a history of at least one live birth and no history of pregnancy losses (n=30).

INTERVENTION(S)

Peripheral blood collection.

MAIN OUTCOME MEASURE(S)

Assessment of anthropometric, metabolic, and inflammatory immune variables.

RESULT(S)

Levels of sRAGE were statistically significantly higher in RPL patients than in control patients (1,528.9±704.5 vs. 1,149.9±447.4 pg/mL). In the multivariate analysis, the levels of insulin, plasminogen activator inhibitor-1, the resistance index of the uterine radial artery, and the ratio of tumor necrosis factor-α/interleukin-10 producing T helper cells were statistically significantly associated with the serum sRAGE level.

CONCLUSION(S)

Elevated levels of serum sRAGE are associated with RPL. The soluble receptor for advanced glycation end products might contribute to RPL by reducing uterine blood flow and subsequently causing ischemia in the fetus via inflammatory and thrombotic reactions.

Role of cathepsin E in decidual macrophage of patients with recurrent miscarriage

In a previous study, we reported that the cathepsin-cystatin system caused endometrial dysfunction in early pregnancy. Here, we investigated the existence and contribution of cathepsin E in early pregnancy in patients with recurrent miscarriage (RM). The effect of cathepsin deficiency on fertility and female reproductive organs were also analyzed in CatE(-/-) mice. Human studies were conducted in a hospital setting, with informed consent. Cervical mucus was collected from RM patients in early pregnancy (4-6 gestational weeks, n = 21), and the pregnancy outcome was compared prospectively. The cathepsin E expression in decidua of RM patients (n = 49) and normal pregnant women undergoing elective surgical abortion (n = 24) was measured using SDS-PAGE, and western blot analysis. Decidual macrophages were isolated from RM patients (n = 6) and stimulated by lipopolysaccharide (LPS) and interferon gamma (IFN-γ). Results from the mouse model showed that CatE(-/-) mice were fertile, but the litter number was significantly smaller. The uterus of CatE(-/-) mice showed granulation tissue. In human samples, protease activity of cathepsin E measured with Fluorescence-Quenching Substrate (KYS-1) in cervical mucus of patients who developed miscarriage was markedly decreased compared with patients without RM. The expression of cathepsin E in decidua, semi-quantified by SDS-PAGE, western blot analysis was significantly lower in RM patients compared with patients without RM. By double staining immunofluorescence, the staining of cathepsin E was observed in CD14 or CD68 positive cells in all deciduas. Upon stimulation with LPS and IFN-γ, the expression of cathepsin E in cell lysate of decidual macrophages was markedly reduced in RM patients compared with controls. The results suggested that decreased activity of cathepsin E produced by decidual macrophages might be responsible for the induction of miscarriages in some RM patients.

Proinflammatory cytokines induced altered expression of cyclooxygenase-2 gene results in unreceptive endometrium in women with idiopathic recurrent spontaneous miscarriage

OBJECTIVE

To investigate the expression pattern of proinflammatory, anti-inflammatory, and angiogenic cytokines and their effect on various mediators of endometrial receptivity in women with idiopathic recurrent spontaneous miscarriage (IRSM).

DESIGN

A prospective study.

SETTING

Tertiary care hospital and reproductive health research unit.

PATIENT(S)

Thirty-six women with IRSM (<35 years) and 30 fertile women as controls matched by age and body mass index undergoing sterilization.

INTERVENTION(S)

Endometrial biopsies in all women corresponding to the window of implantation.

MAIN OUTCOME MEASURE(S)

Assessment of endometrial expression of proinflammatory, anti-inflammatory, and angiogenic cytokines, mediators of matrix turnover and angiogenesis, markers of receptivity.

RESULT(S)

A statistical significantly higher level of proinflammatory cytokines, mediators of matrix turnover and angiogenesis, and a reduced expression of anti-inflammatory and angiogenic cytokines were observed in women with IRSM. Additionally, the markers of endometrial receptivity were poorly expressed in women with IRSM.

CONCLUSION(S)

Aberrant expression of proinflammatory, anti-inflammatory, and angiogenic cytokines during implantation window in women with IRSM is one of the key factors that adversely affect endometrial development, as evidenced by the inadequate expression of various endometrial receptivity markers.

Interleukin-6 in pregnancy and gestational disorders

IL6 is a multifunctional cytokine with pivotal roles in the inflammatory response and in directing T cell differentiation in adaptive immunity. IL6 is widely expressed in the female reproductive tract and gestational tissues, and exerts regulatory functions in embryo implantation and placental development, as well as the immune adaptations required to tolerate pregnancy. Here, we summarise the current understanding of how membrane-bound and soluble receptors mediate IL6 signalling to regulate leukocytes and non-haemopoietic cells. We review the published literature regarding the expression and actions of IL6 in the uterus, decidua and placenta, and studies implicating this cytokine in pregnancy disorders. Elevated IL6 is frequently evident in the altered cytokine profiles characteristic of unexplained infertility, recurrent miscarriage, preeclampsia and preterm delivery. Notably, there is compelling evidence indicating altered systemic IL6 trans-signalling in women prone to recurrent miscarriage, with excessive IL6 bioavailability potentially inhibiting generation of CD4+ T regulatory cells required for pregnancy tolerance. Insufficient local IL6 may also contribute to fetal loss, since IL6 expression is reduced in the endometrium of women with recurrent miscarriage, and in the fetal-placental tissue of CBA×DBA/2 mice. Consistent with the role of IL6 in key reproductive events, Il6 null mutant mice exhibit elevated fetal resorption and delayed parturition. Investigation of the association between IL6 signalling components and T cell responses in pregnant women, as well as detailed analysis of the maternal immune response in IL6-deficient mice, is now required to define the mechanisms by which this cytokine exerts influence on reproductive success.

Global alteration in gene expression profiles of deciduas from women with idiopathic recurrent pregnancy loss

Recurrent pregnancy loss (RPL) occurs in ∼5% of women. However, the etiology is still poorly understood. Defects in decidualization of the endometrium during early pregnancy contribute to several pregnancy complications, such as pre-eclampsia and intrauterine growth restriction (IUGR), and are believed to be important in the pathogenesis of idiopathic RPL. We performed microarray analysis to identify gene expression alterations in the deciduas of idiopathic RPL patients. Control patients had one antecedent term delivery, but were undergoing dilation and curettage for current aneuploid miscarriage. Gene expression differences were evaluated using both pathway and gene ontology (GO) analysis. Selected genes were validated using quantitative reverse transcription-polymerase chain reaction (qRT-PCR). A total of 155 genes were found to be significantly dysregulated in the deciduas of RPL patients (>2-fold change, P < 0.05), with 22 genes up-regulated and 133 genes down-regulated. GO analysis linked a large percentage of genes to discrete biological functions, including immune response (23%), cell signaling (18%) and cell invasion (17.1%), and pathway analysis revealed consistent changes in both the interleukin 1 (IL-1) and IL-8 pathways. All genes in the IL-8 pathway were up-regulated while genes in the IL-1 pathway were down-regulated. Although both pathways can promote inflammation, IL-1 pathway activity is important for normal implantation. Additionally, genes known to be critical for degradation of the extracellular matrix, including matrix metalloproteinase 26 and serine peptidase inhibitor Kazal-type 1, were also highly up-regulated. In this first microarray approach to decidual gene expression in RPL patients, our data suggest that dysregulation of genes associated with cell invasion and immunity may contribute significantly to idiopathic recurrent miscarriage.

Evaluation of Cytokines in Endocervical Secretion and Vaginal pH from Women with Bacterial Vaginosis or Human Papillomavirus

Objective. To verify the relationship between vaginal pH and human papillomavirus (HPV) infection and to measure cytokine levels in endocervical secretions of women with bacterial vaginosis (BV) or HPV. Methods. 173 women (16-48 years old) were enrolled and divided into groups: BV, HPV, and controls. Microbiological culture and vaginal pH were measured. HPV detect by PCR, and cytokines by ELISA (IL-2, IL-6, IL-10, IL-12, TNF-α, and IFN-γ cytokines). Results. Of 173 women, 60 were control group (34.7%) and 113 were distributed in HPV (n=36, 20.8%), BV (n=36, 20.8%), vaginitis (n=30, 17.3%) and, BV and HPV-associated groups (n=11, 6.4%). Vaginal pH > 4.5 was related with HPV infection. IL-2 and IL-12 were increased in BV and HPV groups, and IL-6 (only BV group), compared to control group. IL-12 and IFN-γ were higher in HPV than BV group. Conclusion. The increase of vaginal pH was associated with HPV infection; BV and HPV groups had a Th1 cytokines immune response.

Understanding the link between the IL-6 cytokine family and pregnancy: implications for future therapeutics

Cytokines are involved in almost all processes during the menstrual cycle, the fertilization period and pregnancy. They are expressed in numerous reproduction-related body fluids and tissues. Disorders of cytokine expression patterns may cause pregnancy pathologies. Therefore, cytokines have the potential as new biomarkers in different body compartments for a variety of such pathologies. Furthermore, cytokines may also serve to treat fertility and pregnancy disorders. The IL-6-like family of cytokines is an intensively investigated group of cytokines with well-accepted functions in fertility and pregnancy. This article summarizes current knowledge on IL-6-like cytokines in regard of their role in reproduction and their potential for new strategies in the treatment of reproductive pathologies.

Metformin modulates IL-8, IL-1β, ICAM and IGFBP-1 expression in human endometrial stromal cells

To evaluate the effects of metformin on endometrial stromal cell gene expression and on the decidualization process, endometrial biopsies were collected from five healthy, regularly cycling women. Stromal cell culture was performed and decidualized with oestrogen/progesterone in the presence or absence of metformin and thereafter stimulated with insulin. The effect of metformin on decidualization was analysed by prolactin determination in the cell culture supernatant. Gene expression of insulin-like growth factor binding protein 1 (IGFBP-1), interleukin (IL) 8 and 1β and intercellular adhesion molecule (ICAM) was analysed by real-time PCR. Decidualization was significantly diminished in cells incubated with metformin (P<0.05) accompanied by a significant reduction of prolactin secretion in the supernatant (day 10: 2.2 fold, P<0.05; day 15: 3.1 fold, P<0.05). IGFBP-1 gene expression was reduced after long-term metformin exposure (7.7 fold, P<0.05). The negative effect of insulin on IL-8 (4.8 fold) and IL-1β (9.3 fold) gene expression was similarly found in cells incubated with metformin. As far as is known, this is the first demonstration of a change in endometrial gene and protein expression after in-vitro stimulation with metformin, including a diminished decidualization process and changes in genes relevant to implantation.

ITI-H4, as a biomarker in the serum of recurrent pregnancy loss (RPL) patients

Recurrent pregnancy loss (RPL) is defined as at least three pregnancy losses in series prior to the 20-28 weeks of pregnancy. There are several etiological factors associated with immunology, anatomy, endocrinology, genetic, infection, chromosomal abnormalities, and environmental factors contributing to the condition. The aim of this study was to identify RPL associated factors in human blood using proteomics. Since it is difficult to obtain tissues or follicular fluids, we used blood samples from normal and RPL patients to conduct a comparative proteomic study. Three RPL blood samples and one cocktailed blood sample from 3 normal women were used. We performed 2-DE and selected spots were analyzed with MALDI-TOF/MS. In the three RPL blood samples, 2-DE analysis revealed 549, 563 and 533 spots to be differentially expressed, respectively. Through a comparative analysis between the control and RPL, 21 spots were shown to be differentially expressed. Of these, 5 proteins were confirmed by Western blot analysis. One of these proteins, ITI-H4 (inter-α trypsin inhibitor-heavy chain 4), was weakly expressed at a molecular weight of 120 kDa, but was highly expressed at a modified molecular weight of 36 kDa in RPL patients. These findings suggest that ITI-H4 expression may be used as a biomarker, which could facilitate the development of novel diagnostic and therapeutic tools.

Serum proinflammatory cytokine - interleukin-8 as possible infection site marker in preterm deliveries

AIM

To evaluate serum level of proinflammatory cytokine interleukin-8 as a biochemical marker of local infections in patients with clinical symptoms of preterm deliveries.

METHODS

We studied 74 pregnant women at 24-36 gestational weeks (GW) with preterm delivery. Serum interleukin-8 was measured.

RESULTS

The mean value of interleukin-8 in the study group (n=36) was 19.13 pg/mL vs. 5.02 pg/mL in the controls (n=38).

CONCLUSIONS

The results indicate that serum level of interleukin-8 might be used as non-invasive marker of infections in pregnancy, as well as a marker of preterm deliveries.

Cytokine networks and the regulation of uterine function in pregnancy and parturition

Complex cytokine networks play an important role in a wide range of reproductive and pregnancy related processes. Here, we review the current knowledge concerning the impact of cytokines on uterine physiology and pathophysiology. Cytokines influence a range of uterine functions during the menstrual cycle, implantation, pregnancy and labour. The synergistic interactions between individual cytokines are intricate and dynamic, and modulated by pregnancy hormones. It is not surprising therefore, that perturbations to cytokine signalling are associated with adverse pregnancy outcomes, such as miscarriage, pre-eclampsia, preterm labour and foetal brain injury. Further insight into the complexity of cytokine networks will be required to develop novel therapeutic strategies for the treatment of cytokine imbalances in pregnancy.