Inflammatory cytokines differentially up-regulate human endometrial haptoglobin production in women with endometriosis

Molecular Mechanisms of Endometriosis Revealed Using Omics Data

Endometriosis is a gynecological disorder prevalent in women of reproductive age. The primary symptoms include dysmenorrhea, irregular menstruation, and infertility. However, the pathogenesis of endometriosis remains unclear. With the advent of high-throughput technologies, various omics experiments have been conducted to identify genes related to the pathophysiology of endometriosis. This review highlights the molecular mechanisms underlying endometriosis using omics. When genes identified in omics experiments were compared with endometriosis disease genes identified in independent studies, the number of overlapping genes was moderate. However, the characteristics of these genes were found to be equivalent when functional gene set enrichment analysis was performed using gene ontology and biological pathway information. These findings indicate that omics technology provides invaluable information regarding the pathophysiology of endometriosis. Moreover, the functional characteristics revealed using enrichment analysis provide important clues for discovering endometriosis disease genes in future research.

Feeding rumen-protected lysine altered immune and metabolic biomarkers in dairy cows during the transition period

This experiment was conducted to determine the effects of feeding rumen-protected lysine (RPL; AjiPro-L Generation 3, Ajinomoto Health and Nutrition North America Inc.) from -26 ± 4.6 d prepartum (0.54% RPL of dietary dry matter intake) to 28 d postpartum (0.39% RPL of dietary dry matter intake) on immunometabolic status and liver composition in dairy cows. Seventy-five multiparous Holstein cows, blocked by parity, previous 305-d mature-equivalent milk production, expected calving date, and body condition score during the far-off dry period were assigned to 1 of 4 dietary treatments in a randomized, complete block design with a 2 × 2 factorial arrangement of treatments. Treatments prepartum consisted of total mixed ration top dressed with RPL (PRE-L) or without RPL (PRE-C), and postpartum treatments consisted of total mixed ration top dressed PRE-L prepartum and postpartum, PRE-L prepartum and PRE-C postpartum, PRE-C prepartum and PRE-L postpartum, and PRE-C prepartum and postpartum in 300 g of molasses. Blood samples were taken on -7 ± 0.5, 0 ± 0.5, 7 ± 0.9, 14 ± 0.9, and 28 ± 0.5 d relative to calving. Whole blood samples were taken on -14 ± 0.5, -7 ± 0.5, 7 ± 0.9, and 14 ± 0.9 d relative to calving for oxidative burst and phagocytic capacity of monocytes and neutrophils. Liver samples were collected via a biopsy on -12 ± 4.95 and 13 ± 2.62 d relative to calving and analyzed for liver composition (triacylglyceride and carnitine concentrations), mRNA expression of hepatic genes, and protein abundance. Protein abundance was calculated by normalizing intensity bands for a specific protein with glyceraldehyde-3-phosphate dehydrogenase. Concentrations of haptoglobin and glutathione peroxidase activity in plasma were lower at d 0 for cows in PRE-L (102 µg/mL and 339 nmol/min per mL, respectively) compared with cows in PRE-C (165 µg/mL and 405 nmol/min per mL, respectively). Oxidative burst capacity in monocytes tended to be greater on d 7 postpartum for cows in PRE-L (65.6%) than cows in PRE-C (57.5%). Additionally, feeding RPL altered the mRNA expression in liver tissue prepartum [decreased INSR (insulin receptor), CPT1A (carnitine palmitoyltransferase 1A), and IL1B (interleukin 1 β)] and postpartum [increased IL8 (interleukin 8), EHMT2 (euchromatic histone lysine methyltransferase 2), TSPO (translocator protein), and SLC3A2 (solute carrier family 3 member 2); and decreased SLC7A1 (solute carrier family 7 member 1), SOD1 (superoxide dismutase 1), and SAA3 (serum amyloid A 3)] compared with cows not consuming RPL]. Additionally, cows in the PRE-C prepartum and PRE-L postpartum treatment tended to have greater protein abundance of mTOR postpartum compared with the PRE-C prepartum and postpartum treatment. Protein abundance of SLC7A7 (solute carrier family 7 member 7) pre- and postpartum tended to be greater and BBOX1 (gamma-butyrobetaine dioxygenase 1) tended to be less when RPL was consumed prepartum. In conclusion, cows that consumed RPL during the transition period had molecular changes related to liver composition, enhanced liver function indicated by greater total protein and albumin concentrations in plasma, and improved immune status indicated by decreased haptoglobin, glutathione peroxidase activity, and immune related mRNA expression.

The Risk of Endometrial Cancer and Uterine Sarcoma Following Endometriosis or Pelvic Inflammatory Disease

The relationship between uterine corpus cancer and endometriosis was conflicting. We aimed to determine the risk of uterine cancer in patients with endometriosis or pelvic inflammatory disease (PID). In this population-based cohort study, a total of 135,236 females with endometriosis (n = 20,510) or PID (n = 114,726), as well as 135,236 age-matched controls, were included. Cox regression models estimated the risk of uterine cancer in each group. Sub-outcomes of risk for uterine corpus cancer included endometrial cancer and uterine sarcoma were analyzed. An age subgroup analysis was performed to determine the moderator effect of age. A landmark analysis depicted the time varying effect of endometriosis and PID. A propensity score matching analysis was conducted to validate the findings. Patients with endometriosis had significantly higher risk of endometrial cancer (adjusted hazard ratio, aHR = 2.92; 95% CI = 2.12-4.03) and uterine sarcoma (aHR = 5.83; 95% CI = 2.02-16.89), while PID was not associated with the risk of uterine cancer. The increased risk of uterine cancer in patients with endometriosis persisted after propensity score matching (aHR = 2.83, 95%CI = 1.70-4.71). The greatest risk of endometrial cancer occurred in patients who had endometriosis for 37 to 60 months (adjusted relative risk, aRR = 9.15, 95% CI = 4.40-19.02). Females aged 12 to 35 years were at the greatest risk of endometriosis-associated uterine cancer (RR = 6.97, 95% CI = 3.41-14.26). In conclusion, patients with endometriosis were at great risk of uterine cancer, including endometrial cancer and uterine sarcoma, compared with propensity score-matched populations and compared with patients of PID. Younger females with endometriosis and patients who had endometriosis for three to five years were at the greatest risk of endometriosis-associated uterine cancer.

Molecular mechanisms in IL-1β-mediated decorin production by decidual cells

Decorin, a small leucine-rich proteoglycan produced by decidual cells restrains trophoblast differentiation, migration and invasiveness of extra-villous trophoblast cells. Decidual overproduction of decorin is associated with preeclampsia, and elevated decorin levels in maternal plasma are a predictive biomarker of preeclampsia. Furthermore, decorin plays an autocrine role in maturation of human endometrial stromal cells into decidual cells. Thus, a balanced decorin production by the decidua is critical for healthy pregnancy. However, the molecular mechanisms regulating decorin production by the decidua are unclear. Interleukin-1 beta is an inflammation-associated multi-functional cytokine, and is reported to induce decidualization in primates. Hence, the present study was designed: (i) to test if exogenous Interleukin-1 beta stimulated decorin production by human endometrial stromal cells; and if so, (ii) to identify the cellular source of Interleukin-1 beta in first trimester decidual tissue; (iii) to identify the downstream molecular partners in Interleukin-1 beta mediated decorin production by human endometrial stromal cells. Results revealed that (i) amongst multiple pro-inflammatory cytokines tested, Interleukin-1 beta alone stimulated decorin production by these cells; (ii) both macrophages and decidual cells in first trimester decidua produced Interleukin-1 beta; (iii) Interleukin-1 beta mediated decorin production was dependent on Interleukin-1 receptor activation, followed by activation and nuclear translocation of nuclear factor kappa B and its binding to the decorin promoter. These results reveal that Interleukin-1 beta plays a novel role in inducing decorin production by human endometrial stromal cells by activating nuclear factor kappa B.

Serum Proteomic Analysis of Cannabis Use Disorder in Male Patients

Cannabis use has been growing recently and it is legally consumed in many countries. Cannabis has a variety of phytochemicals including cannabinoids, which might impair the peripheral systems responses affecting inflammatory and immunological pathways. However, the exact signaling pathways that induce these effects need further understanding. The objective of this study is to investigate the serum proteomic profiling in patients diagnosed with cannabis use disorder (CUD) as compared with healthy control subjects. The novelty of our study is to highlight the differentially changes proteins in the serum of CUD patients. Certain proteins can be targeted in the future to attenuate the toxicological effects of cannabis. Blood samples were collected from 20 male individuals: 10 healthy controls and 10 CUD patients. An untargeted proteomic technique employing two-dimensional difference in gel electrophoresis coupled with mass spectrometry was employed in this study to assess the differentially expressed proteins. The proteomic analysis identified a total of 121 proteins that showed significant changes in protein expression between CUD patients (experimental group) and healthy individuals (control group). For instance, the serum expression of inactive tyrosine protein kinase PEAK1 and tumor necrosis factor alpha-induced protein 3 were increased in CUD group. In contrast, the serum expression of transthyretin and serotransferrin were reduced in CUD group. Among these proteins, 55 proteins were significantly upregulated and 66 proteins significantly downregulated in CUD patients as compared with healthy control group. Ingenuity pathway analysis (IPA) found that these differentially expressed proteins are linked to p38MAPK, interleukin 12 complex, nuclear factor-κB, and other signaling pathways. Our work indicates that the differentially expressed serum proteins between CUD and control groups are correlated to liver X receptor/retinoid X receptor (RXR), farnesoid X receptor/RXR activation, and acute phase response signaling.

The pathogenesis of endometriosis: clues from the immunological evidence

INTRODUCTION

Endometriosis pathogenesis is still a matter of debate. It is now agreed that a complex cooperation of genetic, hormonal, immune and environmental factors is implicated. However, no consensus has been reached yet on what firstly is responsible for the initiation, promotion and survival of endometrial-like tissue outside the uterine cavity. Since consistent evidence have found immunological alterations in women with the disease, the impairment of immune system has been considered for decades one of the possible causes of endometriosis. The aim of this literature review is to summarize the available findings on a particular aspect of this topic represented by the inhibition of natural killer (NK) cell activity in women affected as a paradigmatic example of the complexity in studying the pathogenesis of endometriosis.

EVIDENCE ACQUISITION

Advanced search of PubMed for English articles published between 1990 and September 2020 using the keywords "endometriosis" or "endometrioma" or "endometriotic" or "ectopic endometrium" in combination with "natural killer cells" (NK).

EVIDENCE SYNTHESIS

Consistent studies have found an impairment in NK cell activity in women with endometriosis especially in advanced stages of disease (stage III/IV). Reports to explain these findings support the phenomenon as a consequence of the disease establishment. Evidence from genetic studies have questioned the role of these dysfunctions in the pathogenesis of the disease.

CONCLUSIONS

Immunological dysfunctions and the decreased NK cell cytotoxicity may only represent consequence of endometriosis, although the underlining mechanisms still need to be elucidated.

Progress on haptoglobin and metabolic diseases

Haptoglobin (Hp) is an acidic glycoprotein, existing in the serum and other body fluids of human beings and a variety of mammals. Hp is produced in the liver, white adipose tissue, and the kidney. The genetic polymorphisms and different phenotypes of Hp have different biological functions. Hp has antibacterial, antioxidant, and angiogenic effects and is associated with multiple diseases including simple obesity, vascular complications of diabetes mellitus, nonalcoholic fatty liver disease, hypertension, blood diseases, autoimmune diseases, and malignant tumors. Hp also participates in many life activities, indicating the importance of Hp in further studies. Previously, we found that the expression of serum Hp changed after treatment of simple obesity patients in clinical trials. However, the specific mechanism of Hp in patients with simple obesity is still unclear. The purpose of this article is to introduce recent research progress on Hp, emphasizing the relationship between Hp and the development of metabolic disease, which will improve the understanding of the functions of Hp underlying metabolic diseases and discuss future research directions.

Evaluation of IL-3, IL-5, and IL-6 concentration in the follicular fluid of women with endometriosis: A cross-sectional study

Background

Endometriosis is associated with abnormal immunologic responses and combined inflammatory and anti-inflammatory conditions.

Objective

This study aims to investigate follicular fluid (FF) concentration of interleukin (IL)-3, IL-5, and IL-6 in women with and without endometriosis.

Materials and Methods

In this cross-sectionalstudy 68 women who were referred to the in vitro fertilization center of Imam Reza hospital in Mashhad during 2018 were selected randomly. Leaves of cytokines in the FF samples were evaluated in the endometriosis and the control group (n = 34/each). The diagnostic accuracy of cytokines and clinical characteristics were evaluated.

Results

IL-3 and IL-6 were significantly changed in the FF of the women with endometriosis compared with the control group (p = 0.04, and p < 0.01, respectively), and the mean concentration of IL-5 in the endometriosis group was lower than in the control group (p = 0.5), but this was not significant. There were significant differences in the menstrual cycle, dyspareunia, and dysmenorrhea between the groups (p < 0.01, p = 0.04, and p = 0.02, respectively). The diagnostic accuracy of IL-3 and IL-6 in the FF was low, with the area under the curve of 0.614 and 0.645, respectively.

Conclusion

Although none of the cytokines had a predictive value for endometriosis, the decreased levels of IL-3 and increased levels of IL-6 in the FF samples of women with endometriosis, and risk factors, including irregular menstrual cycle, dyspareunia, and dysmenorrhea, could be associated with the pathogenesis of this painful disease.

Systematic review of genome-wide association studies on susceptibility to endometriosis

Endometriosis is a complex and heterogeneous disease in which extrinsic and intrinsic factors, such as genetics, provide to the disease development. Genome-wide association (GWA) studies may be essential to recognize genetic variants associated with the endometriosis risk. However, in the current literature there are some conflicting results between these studies. The aim of the present study was to undertake a systematic review about endometriosis GWA studies, to describe the disease-associated genes and single nucleotide polymorphisms (SNPs) to try to understand the endometriosis etiopathogenesis, besides to discuss possible bias of conflicting results among these studies. This study is a systematic review of GWA studies in endometriosis published until December 31^th, 2019 by PubMed database, considering the following descriptors: endometriosis and ("polymorphism" or "SNP" or "genetic polymorphism" or "variants" or "locus") and ("GWA" or "Genome-wide" or "Genome wide" or "Genetic association study"). The included studies were analyzed with methodological rigor (STROBE and PRISMA) to enable better quality of case-control and meta-analysis studies, respectively. Of the 88 articles found, only 15 were eligible. All articles had appropriate quality evaluated by STROBE and PRISMA checklists (77% and 81%, respectively). Overall, 35,022 endometriosis cases and 181,760 controls were analyzed. The number of participants in each study was quite different (171 to 17,045 for the cases and 308 to 150,021 for the controls), with a predominance of European ethnicity. Most endometriosis cases (86%) were diagnosed by surgery, while selection of the control group was different among studies. About 47% performed only one stage (discovery stage) and 53% performed both the discovery and replication analyses. Eleven genes/SNPs were associated with endometriosis risk in more than one article (chromosome 1, 2, 6, 7, 9 and 12; WNT4, GREB1, FN1, IL1A, ETAA1, RND3, ID4, NFE2L3, CDKN2B-AS1 and VEZT). SNPs were localized in intergenic and intronic regions, their risk allele frequencies varied among the studies and their results were conflicting. In summary, WNT4 rs7521902, GREB1 rs13394619, FN1 rs1250248, IL1A rs6542095 and VEZT rs10859871 variants are highlighted due to high frequency and pathways and function that each gene influences in the development of endometriosis. However, the replication and validation of these variants in different populations are necessary for a better understanding of the endometriosis etiopathogenesis, in order to optimize the diagnosis and improve the efficiency of clinical treatment of the disease.

Types of acute phase reactants and their importance in vaccination

Vaccines are considered to be one of the most cost-effective life-saving interventions in human history. The body's inflammatory response to vaccines has both desired effects (immune response), undesired effects [(acute phase reactions (APRs)] and trade-offs. Trade-offs are more potent immune responses which may be potentially difficult to separate from potent acute phase reactions. Thus, studying acute phase proteins (APPs) during vaccination may aid our understanding of APRs and homeostatic changes which can result from inflammatory responses. Depending on the severity of the response in humans, these reactions can be classified as major, moderate or minor. In this review, types of APPs and their importance in vaccination will be discussed.

Short communication: Assessment of biomarkers of inflammation in the vaginal discharge of postpartum dairy cows diagnosed with clinical metritis

Clinical metritis, characterized by the presence of an enlarged uterus and abnormal red-brownish foul-smelling vaginal discharge (VD), is a prevalent condition that causes important economic losses to dairy operations. The accurate diagnosis and treatment of this disease can help decrease its negative effects on the well-being and performance of dairy cows. The objectives of this study were to assess (1) the concentration of haptoglobin (Hp) and neutrophil-derived haptoglobin-matrix metalloproteinase 9 (Hp-MMP 9) in the VD of postpartum cows; and (2) the correlation between Hp and Hp-MMP 9 concentrations in serum and VD. Fifty-three dairy cows from 4 farms in central Pennsylvania were enrolled in this observational study.. Postpartum cows (7 ± 3 DIM) were screened using a Metricheck device to assess VD score (VDS): 1, clear fluid (n = 4); 2, < 50% white purulent fluid (n = 14); 3, > 50% white purulent fluid (n = 8); 4, red-brownish watery fluid without fetid smell (n = 22); and 5, fetid red-brownish watery fluid (n = 5). Blood and VD samples were collected for assessment of Hp and Hp-MMP 9 concentrations. Cows with a VDS of 4 or 5 (VDS4/5) had higher serum Hp concentrations than cows with a VDS of 1, 2, or 3 (VDS1/3; 93 ± 187 µg/mL vs. 59 ± 106 µg/mL, respectively). Similarly, cows with VDS4/5 had higher VD Hp concentrations than cows with VDS1/3 (73 ± 56 µg/mL vs. 17 ± 16 µg/mL, respectively). We found a significant correlation (0.37) between Hp levels in serum and in VD. We found no difference in serum Hp-MMP 9 between VDS4/5 and VDS1/3 cows. The VD concentrations of Hp-MMP 9 were higher in VDS4/5 cows than in VDS1/3 cows (7,629 ± 9,847 ng/mL vs. 1,567 ± 2,165 ng/mL, respectively). The correlation between Hp-MMP 9 in serum and VD was 0.22; nevertheless, it was not statistically significant. Interestingly, Hp and Hp-MMP 9 concentrations were higher in VD samples than in serum, regardless of VDS. Results from this study suggest that inflammatory biomarkers may be increased in cows with a VDS of 4 or 5. Further research should be aimed at elucidating the processes involved in inflammatory biomarker production and transportation in the uterus, as well as the effect of these biomarkers on endometrial cells.

Overexpression of TGF-β enhances the migration and invasive ability of ectopic endometrial cells via ERK/MAPK signaling pathway

Endometriosis is a common gynecological disease with manifestations of endometrial-like tissue outside the uterus. Transforming growth factor-β (TGF-β) is known to facilitate a series of biological events in many cells, including migration. However, the roles of TGF-β in endometriosis still remain largely unknown. The aim of the present study was to discover the role of TGF-β1 in endometriosis development and progression and its associated mechanisms. It was demonstrated that the expression of TGF-β1 was significantly elevated in endometriosis in comparison with that in normal tissue. Overexpression of TGF-β increased the proliferation and upregulated proliferating cell nuclear antigen and cyclin D1 in endometrial stromal cells (ESCs). Furthermore, TGF-β overexpression also triggered a series of biological events occurring in ESCs, including cell migration and invasion, and activated the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) signaling pathway. The inhibition of the ERK/MAPK pathway reversed the previous effects of TGF-β overexpression. Collectively, the present results indicate that overexpression of TGF-β enhances the migration and invasion of ectopic ESCs via the ERK/MAPK signaling pathway, providing theoretical evidence for the development of new treatment methods targeting the TGF-β-ERK/MAPK signaling pathway for prophylaxis of endometriosis.

Sphingosine 1 Phosphate (S1P) Increased IL-6 Expression and Cell Growth in Endometriotic Cells

OBJECTS

There is growing evidence that sphingosine 1-phosphate (S1P) is involved in inflammatory diseases. As endometriosis is known as an inflammatory disease, we investigated the role of S1P system in the development of endometriosis.

METHODS

The expression of sphingosine kinase (SphK) 1 in endometriosis lesions was examined by immunohistochemistry. The cystic fluid of ovarian cysts/tumors were obtained to measure S1P concentrations. Endometriotic stromal cells (ESC) derived from endometrioma were used for in vitro experiments.

RESULTS

Sphingosine kinase 1 was detected in epithelium and stromal cells of endometriotic lesions. The mean S1P concentration in the cystic fluid of endometriomas was higher than that in nonendometriomas significantly (98.2 nM vs less than 1.5 nM, P < .01). Interleukin-1β (IL-1β) or transforming growth factor-β exhibited 2.7-fold and 11.5-fold increase in SphK1 messenger RNA (mRNA) expression in ESC, respectively (P < .01). Higher dose of S1P (125nM) increased the cell number of ESC by 20%, and low dose of S1P (1.25 nM and 12.5 nM) induced IL-6 mRNA production and IL-6 secretion by ESC dose-dependently. JTE013, an antagonist for S1PR2, partially suppressed IL-6 induction by S1P (P < .05). JTE013 and VPC23019, an antagonist for S1PR1 and S1PR3, suppressed the ESC proliferation induced by S1P.

CONCLUSION

The present study for the first time proved that the SphK-S1P-S1PR axis play a role of accelerating inflammation and growth of endometriotic cells.

Genetic Variation at Chromosome 2q13 and Its Potential Influence on Endometriosis Susceptibility Through Effects on the IL-1 Family

Endometriosis is characterized by the growth of epithelial and stromal cells outside the uterine cavity. It has a complex etiology and affects ∼10% of reproductive age women. It is accompanied by a chronic inflammatory response with substantial evidence to indicate genetic susceptibility. The causal genes and their pathways leading to endometriosis, however, are still unknown. Recently, genomewide association studies on endometriosis identified 14 genomic risk loci in women of European and Japanese ancestry. It is becoming increasingly clear that these risk regions are intergenic and thus contribute to disease susceptibility through regulatory mechanisms, most likely mediated through regulation of genes within a restricted distance from the risk variants. One endometriosis risk locus has been detected at chromosome 2q13 within an inflammatory-rich region of gene transcripts and thus may play a role in the inflammation component of the disease. We carried out detailed analysis of the genomic region 250 kb on either side of sentinel SNP rs10167914 and identified 21 transcripts which contained 6 interleukin (IL)-1 family genes, 3 previously reported coding genes that have a relationship to inflammation, 4 novel coding, or pseudogenes, and 8 noncoding RNA transcripts. Through an extensive literature search, we examined the roles these genes and their resultant proteins play in endometriosis pathogenesis. The results suggest alteration in the expression the IL-1 family transcripts either alone or as a complex milieu could have a significant influence on endometriosis and should be prioritized for future study on the implications of inflammation on endometriotic lesions.

Endometriosis, especially mild disease: a risk factor for miscarriages

OBJECTIVE

To investigate the prevalence of miscarriage in women with endometriosis (WwE) compared with disease-free control women (CW).

DESIGN

Cross-sectional analysis nested in a retrospective observational study (n = 940).

SETTING

Hospitals and associated private practices.

PATIENT(S)

Previously pregnant women (n = 268) within reproductive age in matched pairs.

INTERVENTION(S)

Retrospective analysis of surgical reports and self-administered questionnaires.

MAIN OUTCOME MEASURE(S)

Rate of miscarriage, subanalysis for fertility status (≤12 vs. >12 months' time to conception), endometriosis stages (revised American Society of Reproductive Medicine classification [rASRM] I/II vs. III/IV) and phenotypic localizations (superficial peritoneal, ovarian, and deep infiltrating endometriosis).

RESULT(S)

The miscarriage rate was higher in WwE (35.8% [95% confidence interval 29.6%-42.0%]) compared with CW (22.0% [16.7%-27.0%]); adjusted incidence risk ratio of 1.97 (95% CI 1.41-2.75). This remained significant in subfertile WwE (50.0% [40.7%-59.4%]) vs. CW (25.8% [8.5%-41.2%]) but not in fertile WwE (24.5% [16.3%-31.6%]) vs. CW (21.5% [15.9%-26.8%]). The miscarriage rate was higher in women with milder forms (rASRM I/II 42.1% [32.6%-51.4%] vs. rASRM III/IV 30.8% [22.6%-38.7%], compared with 22.0% [16.7%-27.0%] in CW), and in women with superficial peritoneal endometriosis (42.0% [32.0%-53.9%]) compared with ovarian endometriosis (28.6% [17.7%-38.7%]) and deep infiltrating endometriosis (33.9% [21.2%-46.0%]) compared with CW (22.0% [16.7%-27.0%]).

CONCLUSION(S)

Mild endometriosis, as in superficial lesions, is related to a great extent of inflammatory disorder, possibly leading to defective folliculogenesis, fertilization, and/or implantation, presenting as increased risk of miscarriage.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02511626.

Glycyrrhizin inhibits LPS-induced inflammatory mediator production in endometrial epithelial cells

Endometriosis is a continuous inflammation of uterine endometrium that usually affects women of reproductive age. Glycyrrhizin, a triterpene isolated from the roots and rhizomes of licorice (Glycyrrhiza glabra), has been known to have anti-inflammatory effect. The purpose of this study was to investigate the anti-inflammatory effect of glycyrrhizin on LPS-stimulated mouse endometrial epithelial cells (MEEC). The levels of TNF-α, IL-1β, and PGE₂ were measured by ELISA. The expression of COX-2, iNOS, TLR4, and NF-ĸB were detected by western blot analysis. The results showed that glycyrrhizin significantly suppressed LPS-induced TNF-α, IL-1β, NO, and PGE₂ production. Also, LPS-induced iNOS and COX-2 expression were attenuated by glycyrrhizin. Furthermore, glycyrrhizin significantly attenuated TLR4 expression and NF-κB activation induced by LPS in MEEC. In conclusion, the present study demonstrated that glycyrrhizin inhibited LPS-induced inflammatory response by inhibiting TLR4 signaling pathway in MEEC. Glycyrrhizin may be used as a potential agent for the treatment of endometriosis.

Hp: an inflammatory indicator in cardiovascular disease

Over the past decade significant advancement has occurred in the biological and pathological role that Hp has in cardiovascular disease. Hp is an acute-phase protein with a role in the neutralization and clearance of free heme. Iron has tremendous potential for initiating vascular oxidation, inflammation and exacerbating coronary atherosclerosis. Hp genotype has been linked as a prognostic biomarker of acute myocardial infarction, heart failure, restenosis and cardiac transplant rejection. The increased understanding of Hp as a biomarker has provided new insights into the mechanisms of inflammation after cardiac injury and support the concept that Hp is not only an important antioxidant in vascular inflammation and atherosclerosis, but also an enhancer of inflammation in cardiac transplant.

Potential scenarios leading to ovarian cancer arising from endometriosis

OBJECTIVES

The aim of this review was to highlight recent advances in our understanding of the pathogenesis of malignant transformation of endometriosis.

METHODS

This study reviewed the English-language literature concerning basic science studies of the potential promotion of carcinogenesis.

RESULTS

Repeated episodes of hemorrhage occur in endometriosis at the onset of menstruation. Extracellular hemoglobin, heme, and iron derivatives in endometriosis cause DNA damage and mutations, which create increased cellular susceptibility to oxidant-mediated cell killing. Excess DNA damage and mutations are linked to cell death, but not carcinogenesis. In response to an oxidative and inflammatory microenvironment, endometriotic cells and macrophages secrete antioxidants that control excess oxidative stress in the surrounding environment. Exposure of endometriotic cells to a sublethal level of oxidative stress may lead to carcinogenesis. Macrophages also secrete immunosuppressive factors that lead to promotion of malignant transformation.

DISCUSSION

At least two potential scenarios could result in ovarian cancer arising from endometriosis. The first step: extracellular hemoglobin, heme, and iron cause cellular oxidative damage by promoting reactive oxygen species formation, which results in DNA damage and mutations (ovarian cancer initiation from endometriosis). The second step: cancer progression may be associated with persistent antioxidant production favoring a protumoral microenvironment.

Time-dependent behavioral, neurochemical, and metabolic dysregulation in female C57BL/6 mice caused by chronic high-fat diet intake

High-fat diet (HFD) induced obesity is associated not only with metabolic dysregulation, e.g., impaired glucose homeostasis and insulin sensitivity, but also with neurological dysfunction manifested with aberrant behavior and/or neurotransmitter imbalance. Most studies have examined HFD's effects predominantly in male subjects, either in the periphery or on the brain, in isolation and after a finite feeding period. In this study, we evaluated the time-course of selected metabolic, behavioral, and neurochemical effects of HFD intake in parallel and at multiple time points in female (C57BL/6) mice. Peripheral effects were evaluated at three feeding intervals (short: 5-6 weeks, long: 20-22 weeks, and prolonged: 33-36 weeks). Central effects were evaluated only after long and prolonged feeding durations; we have previously reported those effects after the short (5-6 weeks) feeding duration. Ongoing HFD feeding resulted in an obese phenotype characterized by increased visceral adiposity and, after prolonged HFD intake, an increase in liver and kidney weights. Peripherally, 5 weeks of HFD intake was sufficient to impair glucose tolerance significantly, with the deleterious effects of HFD being greater with prolonged intake. Similarly, 5 weeks of HFD consumption was sufficient to impair insulin sensitivity. However, sensitivity to insulin after prolonged HFD intake was not different between control, low-fat diet (LFD) and HFD-fed mice, most likely due to age-dependent decrease in insulin sensitivity in the LFD-fed mice. HFD intake also induced bi-phasic hepatic inflammation and it increased gut permeability. Behaviorally, prolonged intake of HFD caused mice to be hypoactive and bury fewer marbles in a marble burying task; the latter was associated with significantly impaired hippocampal serotonin homeostasis. Cognitive (short-term recognition memory) function of mice was unaffected by chronic HFD feeding. Considering our prior findings of short-term (5-6 weeks) HFD-induced central (hyperactivity/anxiety and altered ventral hippocampal neurochemistry) effects and our current results, it seems that in female mice some metabolic/inflammatory dysregulations caused by HFD, such as gut permeability, appear early and persist, whereas others, such as glucose intolerance, are exaggerated with continuous HFD feeding; behaviorally, prolonged HFD consumption mainly affects locomotor activity and anxiety-like responses, likely due to the advanced obesity phenotype; neurochemically, the serotonergic system appears to be most sensitive to continued HFD feeding.

rhTNFR: Fc Suppresses the Development of Endometriosis in a Mouse Model by Downregulating Cell Proliferation and Invasiveness

Tumor necrosis factor α (TNF-α), a proinflammatory cytokine, may play an important role in the pathogenesis of endometriosis; therefore, TNF-α inhibitors potentially have an effect on endometriosis. To investigate the effect of anti-TNF-α treatment on endometriosis, 2 TNF-α inhibitors: recombinant human TNF receptor: Fc fusion protein (rhTNFR: Fc) and TNF-α monoclonal antibody (TNF-α mAb) were used to treat human eutopic endometrial stromal cells (hESCs), and the effects on cell survival, cell cycle, and invasiveness were compared. It was found that rhTNFR: Fc suppressed the TNF-α-induced hESC survival and invasiveness but not TNF-α mAb. Recombinant human TNF receptor: Fc fusion protein decreased the S phase of hESC compared with the TNF-α-treated group. Then, we used a surgically induced mouse model of endometriosis to study the effect of rhTNFR: Fc treatment in vivo. The fluorescence intensity and the size of implanted endometriotic lesions in the mouse model were decreased by rhTNFR: Fc. In conclusion, rhTNFR: Fc suppresses hESC survival and invasiveness and decreases the fluorescence intensity and implant size in the mouse model of endometriosis.

The complementary and alternative medicine for endometriosis: a review of utilization and mechanism

Endometriosis (EM) is one of the common gynecological conditions causing menstrual and pelvic pain and affects 10%-15% of women of reproductive age. In recent years, the complementary and alternative medical (CAM) treatment for EM has become popular due to the few adverse reactions reported. The CAM therapy for EM includes several different treatments such as herbs (herbal prescription, extract, and patent), acupuncture, microwave physiotherapy, and Chinese herb medicine enema (CHM enema). These CAM therapies are effective at relieving dysmenorrhoea, shrinking adnexal masses, and promoting pregnancy, with less unpleasant side effects when compared to hormonal and surgical treatments. In this review, we focus on the status quo of CAM on EM and try to identify therapeutic efficacy and mechanisms based on some clinical and experimental studies. We hope to provide some instructive suggestions for clinical treatment and experimental research in the future.

Atypical Expression of COX-2, StAR, CYP19A1 and Apoptotic Regulators in CD90 Positive Endometrial Stromal Cells from Women with Endometriosis

Purpose

Endometriosis is an invasive gynecologic disease characterized by diminished apoptosis, sustained ectopic survival of dysfunctional endometrial cells and implantation of endometriotic lesions outside of the uterus. The purpose of this investigation was to determine the expression pattern of apoptotic and steroidogenic genes in the progenitor stem cell population of eutopic tissues from women with endometriosis and compare them to controls. The expression of these genes was determined in a subpopulation of endometrial cells that displayed CD90 positivity (CD+ve90) and colony forming capacity.

Methods

We obtained endometrial samples from women with or without endometriosis. Endometrial stromal cells (ESCs) were isolated and cultured for 15 days. Purified ESCs were sorted by using a multipotent mesenchymal stromal cell multi-color flow cytometry kit. Single cell cloning was performed by serial dilution in 96-micro well plates. Fifteen days later, colonies were identified (CFUs). The colonies were chosen and cultured. mRNA expression of apoptotic genes, mitogen activated kinase 14 (MAPK14), nuclear factor kappa B (NFkB), steroidogenic acute regulatory protein (StAR), aromatase (CYP19A1) and cyclo-oxygenase-2 (COX-2) were determined by qRT-PCR. Protein levels of StAR, CYP19A1 and COX-2 were determined by western blotting.

Results

A subset of stromal cells derived from women with endometriosis were isolated and identified as progenitor stem cells based on their CD90 positivity and colony forming ability. The cells displayed increased levels of MAPK14, NFkB, COX-2, StAR and CYP19A1 both at the mRNA and protein level compared to stromal cells derived from controls. Similarly, pro-apoptotic molecules such as Bax were decreased whereas anti-apoptotic molecules such as Bcl2 were decreased at the mRNA level compared to stromal cells derived from controls.

Conclusions

CD90+ve ESCs derived from women with endometriosis displayed markers suggesting stem cell-like properties and aberrant expression of apoptotic and steroidogenic enzymes which may contribute to sustained survival of these cells.

Defining future directions for endometriosis research: workshop report from the 2011 World Congress of Endometriosis In Montpellier, France

Endometriosis, defined as estrogen-dependent lesions containing endometrial glands and stroma outside the uterus, is a chronic and often painful gynecological condition that affects 6% to 10% of reproductive age women. Endometriosis has estimated annual costs of US $12 419 per woman (approximately €9579), comprising one-third of the direct health care costs with two-thirds attributed to loss of productivity. Decreased quality of life is the most important predictor of direct health care and total costs. It has been estimated that there is a mean delay of 6.7 years between onset of symptoms and a surgical diagnosis of endometriosis, and each affected woman loses on average 10.8 hours of work weekly, mainly owing to reduced effectiveness while working. To encourage and facilitate research into this debilitating disease, a consensus workshop to define future directions for endometriosis research was held as part of the 11th World Congress on Endometriosis in September 2011 in Montpellier, France. The objective of this workshop was to review and update the endometriosis research priorities consensus statement developed following the 10th World Congress on Endometriosis in 2008.(1) A total of 56 recommendations for research have been developed, grouped under 6 subheadings: (1) diagnosis, (2) classification and prognosis, (3) clinical trials, treatment, and outcomes, (4) epidemiology, (5) pathophysiology, and (6) research policy. By producing this consensus international research priorities statement, it is the hope of the workshop participants that researchers will be encouraged to develop new interdisciplinary research proposals that will attract increased funding support for work on endometriosis.

Endometriosis, a modern syndrome

The identification of endometriosis has been a subject of intense debate over the last decade. There is, however, no doubt that Thomas Cullen was the first to describe endometriosis and adenomyosis as one disease characterized by the presence of endometrium-like tissue outside the uterine cavity. With the introduction of laparoscopy in the early 1960s three different clinical presentations of endometriosis were distinguished: peritoneal, deep adenomyotic and cystic ovarian. As soon as synthetic steroids became available, pioneer clinicians started utilizing these in an attempt to replace radical surgery by a medical treatment. While medical therapy may resort in relief, in most cases the current approach consists of a combination of medical and surgical therapy. While the pathogenesis of endometriosis is still enigmatic and complex, there is increasing evidence that endometriosis is part of a uterine reproductive dysfunction syndrome. For prevention of complications, it is very important that diagnosis is made as early as possible in a woman's life.

TGF-β1 induces proteinase-activated receptor 2 (PAR2) expression in endometriotic stromal cells and stimulates PAR2 activation-induced secretion of IL-6

BACKGROUND

Proteinase-activated receptor 2 (PAR2) is a G-protein-coupled receptor that is activated by several serine proteases. PAR2 activation in endometriotic stromal cells (ESCs) has been implicated in the development of endometriosis but the regulatory mechanism of PAR2 expression in ESC is unknown. Our objective was to study the mechanism by which PAR2 expression may be regulated in endometriotic lesions.

METHODS

Primary cultures of ESCs were treated with transforming growth factor-β (TGF-β) 1, tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β), and the expression of PAR2 was examined by real-time quantitative PCR. ESCs pretreated with or without TGF-β1 were treated with PAR2 agonist peptide (PAR2AP) and the secretion of the pro-endometriotic cytokine, IL-6, was measured using a specific enzyme-linked immunosorbent assay. Effects of TGF-β type 1 inhibitor, SB431542, and PAR2 small interfering RNA (siRNA) on the TGF-β1 stimulation of PAR2 gene expression and PAR2AP-induced IL-6 secretion were also evaluated. To study intracellular signaling, effects of inhibitors of mitogen-activated protein kinases (MAPKs) and phosphoinositide 3-kinase (PI3K) and of Smad4 siRNA on the TGF-β1-induced PAR2 gene expression were studied.

RESULTS

Only TGF-β1, but neither TNF-α nor IL-1β, increased gene expression of PAR2. Activation of PAR2 with PAR2AP increased the secretion of IL-6 from ESCs. As expected, TGF-β1 pretreatment dose-dependently enhanced the PAR2AP-induced increase in IL-6 secretion from ESCs. Treatment of ESCs with the TGF-β type 1 inhibitor, SB431542, inhibited both TGF-β1-stimulation of PAR2 gene expression and PAR2AP-induced IL-6 secretion. Transfection of ESCs with PAR2 siRNA produced a similar inhibition of IL-6 secretion. The TGF-β1-induced increase in PAR2 gene expression was repressed by inhibition of p38 MAPK, p42/44 MAPK or PI3K, but not by knockdown of Smad4 expression.

CONCLUSIONS

In view of significant roles of PAR2 and IL-6 in endometriosis, the TGF-β1-induced increase in PAR2 expression may be an elaborate mechanism that augments the progression of the disease.

Proteolytic tailoring of the heat shock protein 70 and its implications in the pathogenesis of endometriosis

OBJECTIVE

To investigate the mechanism underlying the appearance of a 20-kd HSP70 fragment and its consequences in the ectopic endometrium of endometriosis patients.

DESIGN

Experimental study.

SETTING

Research institute and obstetrics and gynecology clinic.

PATIENT(S)

Participants with (n = 18) and without (n = 20) endometriosis.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Reverse-transcription polymerase chain reaction, protease assays, and in silico tools were used to investigate the origin of the 20-kd HSP70 fragment. Immunocolocalization studies were carried out to determine whether subtilisin/kexin isozyme 1 (SKI-1) and HSP70 are colocalized. Expression and localization of surrogate markers of inflammation, such as nuclear factor NF-κB and interleukin IL-6 were examined by immunoblotting and in situ studies.

RESULT(S)

HSP70 is posttranslationally processed into a 20-kd fragment by SKI-1, a protease of the subtilisin family, in ectopic endometrium (ECE). Immunocolocalization studies revealed spatial proximity of SKI-1 and HSP70 in ECE. Furthermore, ECE demonstrated nuclear localization of the transcription factor, NF-κB and high expression of its target protein, IL-6.

CONCLUSION(S)

This study hints at the possible mechanisms underlying the trimming of HSP70 in ECE and also at the role of proteases in the pathogenesis of endometriosis. The possible repercussions of HSP70 fragmentation include dysregulation of key regulatory proteins, resulting in the escalation of inflammatory events in endometriotic lesions.