G-Protein-Coupled Receptor CXCR7 Is Overexpressed in Human and Murine Endometriosis

A narrative review: CXC chemokines influence immune surveillance in obesity and obesity-related diseases: Type 2 diabetes and nonalcoholic fatty liver disease

Adipose tissue develops lipids, aberrant adipokines, chemokines, and pro-inflammatory cytokines as a consequence of the low-grade systemic inflammation that characterizes obesity. This low-grade systemic inflammation can lead to insulin resistance (IR) and metabolic complications, such as type 2 diabetes (T2D) and nonalcoholic fatty liver disease (NAFLD). Although the CXC chemokines consists of numerous regulators of inflammation, cellular function, and cellular migration, it is still unknown that how CXC chemokines and chemokine receptors contribute to the development of metabolic diseases (such as T2D and NAFLD) during obesity. In light of recent research, the objective of this review is to provide an update on the linkage between the CXC chemokine, obesity, and obesity-related metabolic diseases (T2D and NAFLD). We explore the differential migratory and immunomodulatory potential of CXC chemokines and their mechanisms of action to better understand their role in clinical and laboratory contexts. Besides that, because CXC chemokine profiling is strongly linked to leukocyte recruitment, macrophage recruitment, and immunomodulatory potential, we hypothesize that it could be used to predict the therapeutic potential for obesity and obesity-related diseases (T2D and NAFLD).

CXC chemokines influence immune surveillance in immunological disorders: Polycystic ovary syndrome and endometriosis

Reproductive health is a worldwide challenge, but it is of particular significance to women during their reproductive age. Several female reproductive problems, including polycystic ovary syndrome (PCOS) and endometriosis, affect about 10 % of women and have a negative impact on their health, fertility, and quality of life. Small, chemotactic, and secreted cytokines are CXC chemokines. Both PCOS and endometriosis demonstrate dysregulation of CXC chemokines, which are critical to the development and progression of both diseases. Recent research has shown that both in humans and animals, CXC chemokines tend to cause inflammation. It has also been found that CXC chemokines are necessary for promoting angiogenesis and inflammatory responses. CXC chemokine overexpression is frequently associated with poor survival and prognosis. CXC chemokine levels in PCOS and endometriosis patients impact their circumstances significantly. Hence, CXC chemokines have significant potential as diagnostic and prognostic biomarkers and therapeutic targets. The molecular mechanisms through which CXC chemokines promote inflammation and the development of PCOS and endometriosis are currently unknown. This article will discuss the functions of CXC chemokines in the promotion, development, and therapy of PCOS and endometriosis, as well as future research directions. The current state and future prospects of CXC chemokine -based therapeutic strategies in the management of PCOS and endometriosis are also highlighted.

Uterine administration of C-X-C motif chemokine ligand 12 increases the pregnancy rates in mice with induced endometriosis

OBJECTIVE

To study the effect of intrauterine injection of C-X-C motif chemokine ligand 12 (CXCL12), also known as a stem cell chemoattractant (stromal cell-derived factor 1), on fertility and endometrial receptivity in mice with endometriosis.

DESIGN

Laboratory study.

SETTING

Academic Medical Center.

ANIMAL(S)

Fifty-six mice underwent chemotherapy and bone marrow transplantation. Thirty-six of these mice underwent either surgery to induce endometriosis (n = 20) or sham surgery (n = 16).

INTERVENTION(S)

Injection of CXCL12 as a potential therapeutic agent to improve fertility in endometriosis.

MAIN OUTCOME MEASURE(S)

Pregnancy rate, bone marrow-derived cell (BMDC) recruitment and endometrial receptivity markers.

RESULT(S)

The mice with or without endometriosis received a single uterine injection of either CXCL12 or placebo. Uterine injection of CXCL12 increased the pregnancy rates in a mouse model of endometriosis. Mice were euthanized after delivery, and implantation markers homeobox A11, alpha-v beta-3 integrin, and progesterone receptor were analyzed by immunohistochemistry, whereas green fluorescent protein positive BMDC recruitment was quantified by immunohistochemistry and immunofluorescence. The sham surgery groups without endometriosis had the highest cumulative pregnancy rate (100%) regardless of CXCL12 treatment. The endometriosis group treated with placebo had the lowest pregnancy rate. An increased pregnancy rate was noted in the endometriosis group after treatment with CXCL12. There was also an increase in BMDC recruitment and endometrial expression of progesterone receptor and alpha-v beta-3 integrin in the endometriosis group that received CXCL12 compared with that in the endometriosis group that received placebo.

CONCLUSION(S)

Uterine injection of CXCL12 increased the pregnancy rates in a mouse model of endometriosis. These results suggest that CXCL12 has a potential role as a therapeutic agent in women with infertility related to endometriosis and potentially other endometrial receptivity defects.

Potential link between the nerve injury-induced protein (Ninjurin) and the pathogenesis of endometriosis

Endometriosis remains a widespread but severe gynecological disease in women of reproductive age, with an unknown etiology and few treatment choices. The menstrual reflux theory is largely accepted as the underlying etiology but does not explain the morbidity or unpleasant pain sensations of endometriosis. The neurological and immune systems are both involved in pain mechanisms of endometriosis, and interlinked through a complex combination of cytokines and neurotransmitters. Numerous pieces of evidence suggest that the nerve injury-inducible protein, Ninjurin, is actively expressed in endometriosis lesions, which contributes to the etiology and development of endometriosis. It may be explored in the future as a novel therapeutic target. The aim of the present review was to elucidate the multifaceted role of Ninjurin. Furthermore, we summarize the association of Ninjurin with the pain mechanism of endometriosis and outline the future research directions. A novel therapeutic pathway can be discovered based on the potential pathogenic variables.

Inhibition of Angiogenesis by MiR-524-5p through Suppression of AKT and ERK Activation by Targeting CXCR7 in Colon Cancer Cells

Increasing evidence shows that alterations in microRNA (miRNA) expression are involved in the occurrence and development of various malignant tumors, including colon cancer. MiRNA-524-5p has been reported to have anticancer activity in colon cancer. This study explored the influence of the miRNA-524-5p/CXCR7 axis on angiogenesis using colon cancer cells and further studied the mechanisms involved. We found that changing the expression of miRNA-524-5p can affect colonic proliferation, migration, and angiogenesis. Furthermore, angiogenesis induced by miRNA-524-5p overexpression was reversed by overexpression of CXCR7 in HT-29 cells, while the opposite was observed in Caco-2 cells. Furthermore, miRNA-524-5p inhibited the activation of AKT and ERK signaling by targeting CXCR7. Overall, our results indicated that the miRNA-524-5p/CXCR7 axis regulated angiogenesis in colon cancer cells through the AKT and ERK pathways.

MALAT1 accelerates proliferation and inflammation and suppresses apoptosis of endometrial stromal cells via the microRNA-142-3p/CXCR7 axis

MALAT1, microRNA (miR)-142-3p, and CXCR7 are critical molecules mediating endometriosis progression, and their correlation in endometriosis has been barely discussed. Thus, this research sought to survey the impact of MALAT1 on endometrial stromal cell (ESC) proliferation, apoptosis, and inflammation via miR-142-3p/CXCR7 axis to promote explorations on endometriosis. In endometrial tissues and ESCs, CXCR7 expression was determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot analysis and miR-142-3p and MALAT1 expression by qRT-PCR. Then, ESC proliferation was assessed by CCK-8 and EdU labeling assays, apoptosis by flow cytometry, and levels of inflammatory factors tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6 in ESC supernatant by enzyme linked immunosorbent assay. The interactions among CXCR7, miR-142-3p, and MALAT1 were evaluated by dual luciferase reporter gene, RNA pull-down, and Argonaute 2- RNA immunoprecipitation assays. At last, the relevance of miR-142-3p to MALAT1 and that of miR-142-3p to CXCR7 in ectopic endometrial tissues were analyzed using Pearson correlation analysis. CXCR7 and MALAT1 were overexpressed whilst miR-142-3p was lowly expressed in ectopic endometrial tissues. CXCR7 silencing or miR-142-3p overexpression reduced proliferative ability and enhanced apoptosis rate in ESCs and decreased TNF-α, IL-1β, and IL-6 levels in cell supernatant. miR-142-3p negatively targeted CXCR7 while MALAT1 negatively targeted miR-142-3p. However, MALAT1 silencing diminished ESC proliferation and TNF-α, IL-1β, and IL-6 levels in ESC supernatant and elevated ESC apoptosis, which was counterweighed by inhibiting miR-142-3p. Conclusively, MALAT1 promoted ESC proliferation and inflammatory factor expression and inhibited ESC apoptosis via miR-142-3p/CXCR axis.

Tofacitinib alters STAT3 signaling and leads to endometriosis lesion regression

Endometriosis is a widespread gynecologic condition affecting up to 15% of women of reproductive age. The Janus kinase/signal transducer and activator of transcription (JAK/STAT3) pathway is upregulated in endometriosis and is a therapeutic target. Here we sought to determine the effect of Tofacitinib, a JAK inhibitor in widespread clinical use, on JAK/STAT signaling in endometriosis and lesion growth. Endometriosis was surgically induced in C57BL/6 mice using homologous uterine horn transplantation. Lesions were allowed to form over 4 weeks followed by Tofacitinib (10 mg/kg) or vehicle administered by oral gavage over 4 weeks. Tofacitinib treatment in vivo led to endometriosis lesion regression and reduced adhesion burden compared to vehicle treatment. In vitro studies on Ishikawa cells showed that Tofacitinib reduced hypoxia-inducible factor 1α and vascular endothelial growth factor mRNA levels at 12 and 24 h. Western blot analysis showed that Tofacitinib effectively reduced STAT3 phosphorylation in Ishikawa cells and human primary stromal and epithelial cells from eutopic endometrium of patients with and without endometriosis. This study suggests that the inhibition of JAK/STAT signaling using Tofacitinib may be a viable method for the treatment of endometriosis.

Inflammatory Mediators and Pain in Endometriosis: A Systematic Review

BACKGROUND

pain is one of the main symptoms of endometriosis and it has a deleterious effect on a patients' personal and social life. To date, the clinical management of pain includes prolonged medication use and, in some cases, surgery, both of which are disruptive events for patients. Hence, there is an urgency for the development of a sufficient non-invasive medical treatment. Inflammation is one of the causative factors of pain in endometriosis. It is well established that inflammatory mediators promote angiogenesis and interact with the sensory neurons inducing the pain signal; the threshold of pain varies and it depends on the state and location of the disease. The inhibition of inflammatory mediators' synthesis might offer a novel and effective treatment of the pain that is caused by inflammation in endometriosis.

OBJECTIVES

patients with endometriosis experience chronic pelvic pain, which is moderate to severe in terms of intensity. The objective of this systematic review is to highlight the inflammatory mediators that contribute to the induction of pain in endometriosis and present their biological mechanism of action. In addition, the authors aim to identify new targets for the development of novel treatments for chronic pelvic pain in patients with endometriosis.

DATA SOURCES

three databases (PubMed, Scopus, and Europe PMC) were searched in order to retrieve articles with the keywords 'inflammation, pain, and endometriosis' between the review period of 1 January 2016 to 31 December 2020. This review has been registered with PROSPERO (registry number: CRD42020171018). Eligibility Criteria: only original articles that presented the regulation of inflammatory mediators and related biological molecules in endometriosis and their contribution in the stimulation of pain signal were included.

DATA EXTRACTION

two authors independently extracted data from articles, using predefined criteria.

RESULTS

the database search yielded 1871 articles, which were narrowed down to 56 relevant articles of interest according to the eligibility criteria.

CONCLUSIONS

inflammatory factors that promote angiogenesis and neuroangiogenesis are promising targets for the treatment of inflammatory pain in endometriosis. Specifically, CXC chemokine family, chemokine fractalkine, and PGE2 have an active role in the induction of pain. Additionally, IL-1β appears to be the primary interleukin (IL), which stimulates the majority of the inflammatory factors that contribute to neuroangiogenesis along with IL-6. Finally, the role of Ninj1 and BDNF proteins needs further investigation.

Mouse model of menstruation: An indispensable tool to investigate the mechanisms of menstruation and gynaecological diseases (Review)

Abnormal menstruation may result in several pathological alterations and gynaecological diseases, including endometriosis, menstrual pain and miscarriage. However, the pathogenesis of menstruation remains unclear due to the limited number of animal models available to study the menstrual cycle. In recent years, an effective, reproducible, and highly adaptive mouse model to study menstruation has been developed. In this model, progesterone and oestrogen were administered in cycles following the removal of ovaries. Subsequently, endometrial decidualisation was induced using sesame oil, followed by withdrawal of progesterone administration. Vaginal bleeding in mice is similar to that in humans. Therefore, the use of mice as a model organism to study the mechanism of menstruation and gynaecological diseases may prove to be an important breakthrough. The present review is focussed ond the development and applications of a mouse model of menstruation. Furthermore, various studies have been described to improve this model and the research findings that may aid in the treatment of menstrual disorders in women are presented.

Shear stress improves the endothelial progenitor cell function via the CXCR7/ERK pathway axis in the coronary artery disease cases

BACKGROUND

Dysfunction in the late Endothelial Progenitor Cells (EPCs) is responsible for endothelial repair in patients with Coronary Artery Disease (CAD), and the shear stress is beneficial for EPCs function. However, the impact of shear stress on the capacity of EPCs in CAD patients has not been elucidated yet. The C-X-C chemokine receptor 7/extracellular signal-regulated kinase (CXCR7)/(ERK) pathways are identified to regulate EPCs function in CAD patients. Here, we hypothesize that shear stress upregulates the CXCR7/ERK pathways, which restore the EPCs function in CAD patients.

METHODS

The human Peripheral Blood Mononuclear Cells (PBMCs) were collected from healthy adults and CAD patients and then used for EPCs cultivation. The Lv-siRNA for human CXCR7 was transfected into induced EPCs isolated from the CAD patients. Meanwhile, the EPCs from CAD patients were subjected to shear stress generated by a biomimetic device. Next, the cell viability, migration, tube formation, and apoptosis were detected by CCK-8, Transwell assay, Matrigel, and flow cytometry, respectively. Also, the CXCR7/ERK pathways in human EPCs were analyzed by Western blotting and qRT-PCR.

RESULT

Compared to the EPCs collected from normal adults, the CAD patient-derived EPCs showed reduced in vitro vasculogenic capacity. Also, the level of CXCR7 in CAD patient-derived EPCs was significantly reduced compared to the EPCs of healthy subjects. Meanwhile, the extracellular signal-regulated kinase (ERK), which represents a CXCR7 downstream signaling pathway, had decreased phosphorylation level. The shear stress treatment augmented the CXCR7 expression and also elevated ERK phosphorylation, which is comparable to the up-regulation of CAD patient-derived EPCs function. Further, the small interfering RNA (siRNA)-mediated CXCR7 knockdown diminished the enhanced migration, adhesion, and tube formation capacity of shear stress treated CAD patient-derived EPCs.

CONCLUSION

Up-regulation of the CXCR7/ERK pathways by shear stress can be a promising new target in enhancing the vasculogenic ability of CAD patient-derived EPCs.

The extracellular matrix in development

As the crucial non-cellular component of tissues, the extracellular matrix (ECM) provides both physical support and signaling regulation to cells. Some ECM molecules provide a fibrillar environment around cells, while others provide a sheet-like basement membrane scaffold beneath epithelial cells. In this Review, we focus on recent studies investigating the mechanical, biophysical and signaling cues provided to developing tissues by different types of ECM in a variety of developing organisms. In addition, we discuss how the ECM helps to regulate tissue morphology during embryonic development by governing key elements of cell shape, adhesion, migration and differentiation.

Summary: This Review discusses our current understanding of how the extracellular matrix helps guide developing tissues by influencing cell adhesion, migration, shape and differentiation, emphasizing the biophysical cues it provides.

Bioinformatic analysis reveals the importance of epithelial-mesenchymal transition in the development of endometriosis

Background: Endometriosis is a frequently occurring disease in women, which seriously affects their quality of life. However, its etiology and pathogenesis are still unclear. Methods: To identify key genes/pathways involved in the pathogenesis of endometriosis, we recruited 3 raw microarray datasets (GSE11691, GSE7305, and GSE12768) from Gene Expression Omnibus database (GEO), which contain endometriosis tissues and normal endometrial tissues. We then performed in-depth bioinformatic analysis to determine differentially expressed genes (DEGs), followed by gene ontology (GO), Hallmark pathway enrichment and protein-protein interaction (PPI) network analysis. The findings were further validated by immunohistochemistry (IHC) staining in endometrial tissues from endometriosis or control patients. Results: We identified 186 DEGs, of which 118 were up-regulated and 68 were down-regulated. The most enriched DEGs in GO functional analysis were mainly associated with cell adhesion, inflammatory response, and extracellular exosome. We found that epithelial-mesenchymal transition (EMT) ranked first in the Hallmark pathway enrichment. EMT may potentially be induced by inflammatory cytokines such as CXCL12. IHC confirmed the down-regulation of E-cadherin (CDH1) and up-regulation of CXCL12 in endometriosis tissues. Conclusions: Utilizing bioinformatics and patient samples, we provide evidence of EMT in endometriosis. Elucidating the role of EMT will improve the understanding of the molecular mechanisms involved in the development of endometriosis.

Advances in CXCR7 Modulators

CXC chemokine receptor 7 (CXCR7) is a G-protein-coupled receptor that signals through the β-arrestin pathway. Its ligands include interferon-inducible T cell α chemoattractant (CXCL11) and stromal cell-derived factor-1 (CXCL12). It interacts with CXCR4, and the two are associated with various cancers, as well as other disease states such as coronary artery disease, stroke, inflammation and human immunodeficiency virus (HIV). Antibodies and small interfering RNA (siRNA) have shown the utility of antagonists of CXCR7 in these disease states. Although some small molecules were initially reported as antagonists due to their displayed activity, many function as agonists while still producing the desired pharmacologic effects. A potential reason for this contradiction is that effects may be due to elevated extracellular CXCL12 levels.

The CXL12/CXCR4/CXCR7 axis in female reproductive tract disease: Review

Initial studies on the chemokine stromal derived factor 1 (now referred to as CXCL12) were proposed to be enhanced in several diseases including those which affect the female reproductive tract. These include endometriosis, Asherman's syndrome, endometrial cancers, and ovarian cancers. Additionally, recent studies from our laboratory suggest that CXCL12 signaling is involved in leiomyomas (fibroids). These diseases present an inflammatory/hypoxic environment which further promotes pathology. At first, studies focused on signaling by CXCL12 via its well-known receptor, CXCR4. However, the discovery of CXCR7 as another receptor for CXCL12 with rather high binding affinity and recent reports about its involvement in endometrial disease and cancer progression has questioned the potential of "selective blockade"' of CXCR4 to treat these ailments. This review will focus on the signaling and effects of the potent chemokine CXCL12, and its long-known G protein-coupled receptor CXCR4, as well as the alternate receptor CXCR7 on the female reproductive tract and related diseases such as endometriosis, Asherman's syndrome, leiomyomas, endometrial cancer, and ovarian cancer. Although several other mechanisms are inherent to these diseases such as gene mutations, differential expression of miRNAs and epigenetics, for this review, we will focus on the CXCL12/CXCR4/CXCR7 axis as a novel target.