Endometriosis-related ceRNA network to identify predictive biomarkers of endometrial receptivity

A comprehensive overview of exosome lncRNAs: emerging biomarkers and potential therapeutics in endometriosis

Endometriosis is a gynecological condition that significantly impacting women's daily lives. In recent years, the incidence of endometriosis has been rising yearly and is now an essential contributor to female infertility. Exosomes are extracellular vesicles (EVs) that carry long noncoding RNA (lncRNA) and shield lncRNA from the outside environment thanks to their vesicle-like structure. The role of exosome-derived lncRNAs in endometriosis is also receiving more study as high-throughput sequencing technology develops. Several lncRNAs with variable expression may be crucial to the emergence and growth of endometriosis. The early diagnosis of endometriosis will be considerably improved by further high specificity and sensitivity Exosome lncRNA screening. Exosomes assist lncRNAs in carrying out their roles, offering a new target for creating endometriosis-specific medications. In order to serve as a reference for clinical research on the pathogenesis, diagnosis, and treatment options of endometriosis, this paper covers the role of exosome lncRNAs in endometriosis and related molecular mechanisms.

Combined proteomics and transcriptomics identifies serpin family C member 1 associated protein as a biomarker of endometriosis

OBJECTIVE

To explore potential biomarkers indicating endometriosis (EM).

MATERIALS AND METHODS

A proteomics method and combined quantitative transcriptomics were adopted to highlight markers in the EM. Venn analysis was used to integrate the ribonucleic acid sequencing (RNA-seq) and protein profiles. Promising candidate markers were tested by enzyme-related immunosorbent assay.

RESULTS

A sum of 979 mRNAs and 39 proteins were tested to be significantly differentially expression in the standard cluster compared with the EM cluster. Venn analysis showed a filtered signature of only two down-regulated molecules in the EM group, i.e. fetuin B (FETUB) and serpin family C member 1 (SERPINC1); the latter showed a big variance between the control category and the EM set in the authentication test.

CONCLUSION

SERPINC1 may be a useful possible biomarker for the analysis of EM.

Interleukin-33 Derived from Endometriotic Lesions Promotes Fibrogenesis through Inducing the Production of Profibrotic Cytokines by Regulatory T Cells

In endometriosis, it has been widely believed that the local immunological milieu is Th2-skewed. Regulatory T cells (Tregs) promote fibrogenesis of endometriosis through the transforming growth factor β1 (TGF-β1) and platelet-derived growth factor (PDGF) signaling pathways. We aimed to explore whether Tregs in endometriotic lesions acquire increased production of effector cytokines under the influence of lesion-derived interleukin (IL)-33. We extracted lymphocytes from normal endometrium and ovarian endometrioma to evaluate the expression of IL-4, IL-13, interferon-γ (IFN-γ), TGF-β1, and the IL-33 receptor (ST2) by Tregs from these tissues. Colocalization of IL-33 and FOXP3 in normal endometrium and ovarian endometrioma was evaluated by immunofluorescence. Tregs and endometriotic stromal cells were co-cultured and treated with anti-IL-33 antibody, and the cytokines produced by Tregs were analyzed by flow cytometry and enzyme-linked immunosorbent assay (ELISA). Tregs in ovarian endometrioma produced significant amounts of IL-4, IL-13, TGF-β1, and ST2. Colocalization of IL-33 and FOXP3 was detected in ovarian endometrioma. IL-33 from endometriotic stromal cells caused the differentiation of lesional Tregs into type 2 T helper (Th2)-like cells, along with increased production of TGF-β1 by Tregs. Thus, Tregs and endometriotic lesions engage active crosstalk through IL-33 to promote fibrogenesis in endometriosis, and, as such, this finding opens up new avenues to identify novel therapeutic targets for endometriosis.

Non-coding RNAs and their cross-talks impacting reproductive health of women

Non-coding RNAs (ncRNAs) work as crucial posttranscriptional modulators of gene expression regulating a wide array of biological processes that impact normal physiology, including reproductive health. The health of women, especially reproductive health, is now a prime focus of society that ensures the females' overall physical, social, and mental well-being. Furthermore, there has been a growing cognizance of ncRNAs' possible applications in diagnostics and therapeutics of dreaded diseases. Hence, understanding the functions and mode of actions of ncRNAs in the context of women's health will allow us to develop effective prognostic and therapeutic strategies that will enhance the quality of life of women. Herein, we summarize recent progress on ncRNAs, such as microRNAs (miRNAs) and long ncRNAs (lncRNAs), and their implications in reproductive health by tying the knot with lifestyle factors that affect fertility complications, pregnancy outcomes, and so forth. We also discourse the interplay among the RNA species, especially miRNAs, lncRNAs, and protein-coding RNAs, through the competing endogenous RNA regulations in diseases of women associated with maternal and fetal health. This review provides new perspectives correlating ncRNAs, lifestyle, and reproductive health of women, which will attract future studies to improve women's lives. This article is categorized under: RNA in Disease and Development > RNA in Disease Regulatory RNAs/RNAi/Riboswitches > Regulatory RNAs.

Association of embryo transfer type with infertility in endometriosis: a systematic review and meta-analysis

PURPOSE

The study aims to evaluate whether frozen embryo transfer can restore optimal receptivity leading to better assisted reproductive technology outcomes in women with endometriosis.

METHODS

This systematic review and meta-analysis, conducted from January 10, 2021 to July 1, 2021, searched the Cochrane Library, PubMed, Embase, Web of Science, OVID, and Clinicaltrials.gov databases from inception to January 10, 2021. The search strategy combined search terms as follows: ("endometriosis" OR "deep endometriosis" OR "endometrioma") AND ("frozen-thawed embryo transfer" OR "frozen embryo transfer" OR "freeze-all strategy") AND ("pregnancy outcome" OR "live birth rate" OR "clinical pregnancy rate" OR "miscarriage rate"). No publication time or language limits were set during the searches. In addition, references of the related articles were searched by hand. Patients were included if they had a history of endometriosis and had received fresh or frozen embryo transfer. Only the first transfer cycle was included. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to express outcomes, and data synthesis was conducted using RevMan, version 5.4 software.

RESULTS

A total of six studies with moderate methodologic quality were retrieved in the meta-analysis. The studies included 3010 women with endometriosis who wanted to conceive; 1777 (59.0%) had frozen embryo transfer, and 1233 (41.0%) had fresh embryo transfer. There was a significantly higher frequency of live births in the frozen embryo group than in the fresh embryo group (OR, 1.53; 95% CI, 1.13-2.08; P = .007). Despite a similar clinical pregnancy rate in the two groups (OR, 1.26; 95% CI, 0.95-1.69; P = .11), the difference in miscarriage rate was significant (OR, 0.70; 95% CI, 0.50-0.97; P = .03). Evidence quality was considered moderate.

CONCLUSION

Cryopreserved embryo transfer has resulted in preferable reproduction outcomes when compared with fresh embryo transfer in patients with endometriosis, but the evidence is not yet abundant. More strictly designed research is needed to evaluate whether frozen embryo transfer leads to better reproductive outcomes in women with endometriosis compared with those receiving fresh embryo transfer.

REGISTRATION NUMBER

PROSPERO CRD42021248313.

Long noncoding RNA ADAMTS9-AS1 represses ferroptosis of endometrial stromal cells by regulating the miR-6516-5p/GPX4 axis in endometriosis

Endometriosis (EMs) is one of the most frequent diseases of reproductive-age women and is characterized by the growth of endometrial tissues beyond the uterus. The enhanced proliferative and migratory potential of endometrial stromal cells (ESCs) plays an important role in the progression of EMs. Mounting studies have demonstrated that long noncoding RNAs (lncRNAs) exert an important role in regulating the development and progression of EMs. Given the aberrant expression of lncRNA ADAMTS9-AS1 in ectopic endometrium (ecEM), we investigated the biological effect of ADAMTS9-AS1 on ESC proliferation and migration and explored the underlying mechanism. The current data showed that ADAMTS9-AS1 expression was significantly upregulated in ecEM compared with eutopic endometrium (euEM) in patients with EMs and in a murine model of EMs. Functionally, ADAMTS9-AS1 knockdown in ectopic ESCs (EESCs) decreased cell viability and migration, whereas ADAMTS9-AS1 overexpression in normal ESCs (NESCs) enhanced cell viability and migration. More importantly, the effect of ADAMTS9-AS1 inhibition on decreasing ESC viability was significantly blocked by ferrostatin-1 (Fer-1, a ferroptosis inhibitor), and ADAMTS9-AS1 overexpression repressed erastin (a ferroptosis activator)-induced cell death. Furthermore, the regulatory role of ADAMTS9-AS1 in ferroptosis was defined and evidenced by increased reactive oxygen species (ROS) levels and malonyl dialdehyde (MDA) content and decreased expression of glutathione peroxidase 4 (GPX4) after ADAMTS9-AS1 inhibition. Mechanistically, ADAMTS9-AS1 functioned as a competing endogenous RNA (ceRNA) by sponging miR-6516-5p to derepress the expression of GPX4, the critical repressor of ferroptosis. Taken together, these results demonstrate that upregulated ADAMTS9-AS1 accelerates ESC proliferation and migration by regulating miR-6516-5p/GPX4-dependent ferroptosis and may be a potential target for the treatment of EMs.

The Role of Long Non-Coding RNAs in Endometriosis

Endometriosis is a chronic gynecological disorder affecting the quality of life and fertility of many women around the world. Heterogeneous and non-specific symptoms may lead to a delay in diagnosis, with treatment options limited to surgery and hormonal therapy. Hence, there is a need to better understand the pathogenesis of the disease to improve diagnosis and treatment. Long non-coding RNAs (lncRNAs) have been increasingly shown to be involved in gene regulation but remain relatively under investigated in endometriosis. Mutational and transcriptomic studies have implicated lncRNAs in the pathogenesis of endometriosis. Single-nucleotide polymorphisms (SNPs) in lncRNAs or their regulatory regions have been associated with endometriosis. Genome-wide transcriptomic studies have identified lncRNAs that show deregulated expression in endometriosis, some of which have been subjected to further experiments, which support a role in endometriosis. Mechanistic studies indicate that lncRNAs may regulate genes involved in endometriosis by acting as a molecular sponge for miRNAs, by directly targeting regulatory elements via interactions with chromatin or transcription factors or by affecting signaling pathways. Future studies should concentrate on determining the role of uncharacterized lncRNAs revealed by endometriosis transcriptome studies and the relevance of lncRNAs implicated in the disease by in vitro and animal model studies.

Transcriptomic analysis and competing endogenous RNA network in the human endometrium between proliferative and mid-secretory phases

Successful embryo implantation is the first step for establishing natural pregnancy and is dependent on the crosstalk between the embryo and a receptive endometrium. However, the molecular signaling events for successful embryo implantation are not entirely understood. To identify differentially expressed transcripts [long-noncoding RNAs (lncRNAs), microRNAs (miRNAs) and mRNAs] and competing endogenous RNA (ceRNA) networks associated with endometrial receptivity, the current study analyzed gene expression profiles between proliferative and mid-secretory endometria in fertile women. A total of 247 lncRNAs, 67 miRNAs and 2,154 mRNAs were identified as differentially expressed between proliferative and mid-secretory endometria. Kyoto Encyclopedia of Genes and Genomes pathway analysis indicated that these differentially expressed genes were significantly enriched for 'cell adhesion molecules.' Additionally, 98 common mRNAs were significantly involved in tryptophan metabolism, metabolic pathways and FoxO signaling. From the differentially expressed lncRNA/miRNA/mRNA ceRNA network, hub RNAs that formed three axes were identified: The DLX6-AS1/miR-141 or miR-200a/OLFM1 axis, the WDFY3-AS2/miR-135a or miR-183/STC1 axis, and the LINC00240/miR-182/NDRG1 axis. These may serve important roles in the regulation of endometrial receptivity. The hub network of the current study may be developed as a candidate marker for endometrial receptivity.

Regulatory effect of LncRNA DRAIC/miR-149-5p/NFIB molecular network on autophagy of esophageal cancer cells and its biological behavior

OBJECTIVE

This experiment will explore the effect of LncRNA DRAIC/miR-149-5p/NFIB molecular network on esophageal cancer (EC) cells' biological behavior and autophagy.

METHODS

We bought human EC cells and normal esophageal epithelial cells HEEC. DRAIC, miR-149-5p and NFIB protein expression were tested. The low expression plasmid of DRAIC and empty vector of DRAIC, miR-149-5p miR-mimics, miR-149-5p inhibitors and negative control groups, NFIB high expression plasmid, NFIB low expression plasmid and empty vector were transfected into EC cells (Eca-109 and EC9706) to detect changes in cell biological behavior and autophagy protein expression. The targeted relationship between DRAIC/miR-149-5p/NFIB was verified through dual-luciferase report and pull-down experiment.

RESULTS

DRAIC and NFIB showed high expression in EC cells, while miR-149-5p showed low expression. Down-regulating DRAIC, NFIB and over-expressing miR-149-5p can inhibit EC cells' proliferation and invasion, and improve apoptosis and autophagy. Dual-luciferase report and pull-down experiment confirmed that DRAIC targeted miR-149-5p regulation, and down-regulating DRAIC could reverse miR-149-5p inhibitor's effect on the biological behavior of EC cells. However, dual-luciferase report revealed that miR-149-5p directly targeted NFIB, and miR-149-5p inhibitor could weaken the effect of down-regulating NFIB on apoptosis and autophagy of EC cells. Moreover, DRAIC has an effect on the autophagy of EC cells through miR-149-5p/NFIB.

CONCLUSION

LncRNA DRAIC is relevant to cell biology and autophagy of EC. In the future, DRAIC may be developed as a key gene for EC diagnosis and treatment.