MicroRNA variants in endometriosis and its severity

Genetic variants in miR-146a and miR-196a2 in endometriosis: a Brazilian study

OBJECTIVE

The aim of this study was to determine the allelic and genotypic frequencies of the polymorphisms, rs2910164 miR-146a and rs11614913 miR-196a2, by investigating their association with endometriosis.

METHODS

This is a case-control study performed with approximately 120 women. The polymorphisms were determined by real-time polymerase chain reaction. For the statistical analysis, the chi-square and logistic regression tests were used.

RESULTS

There were no significant differences in the genotype and allele frequencies of rs2910164 and rs11614913 between cases and controls. The frequencies in both polymorphisms are in accordance with Hardy-Weinberg equilibrium regarding miR-146a (patients: χ2=1.64, p=0.20; controls: χ2=0.25, p=0.62) and miR-196a2 (patients: χ2=0.58, p=0.44; controls: χ2=2.78, p=0.10). No relationship was observed between rs2910164 and rs11614913 and endometriosis in the inheritance models analyzed.

CONCLUSION

In this study, our results show that the studied polymorphisms are not implicated in the development of endometriosis.

Exosomes from ectopic endometrial stromal cells promote M2 macrophage polarization by delivering miR-146a-5p

BACKGROUND

Ectopic endometrial stromal cells (ESCs) and M2 macrophages co-exist in the lesions of endometriosis and participate in the occurrence and progression of endometriosis. However, the interaction between ectopic ESCs and M2-type macrophage polarization is poorly understood. This study aims to investigate the effect of exosomes released from ectopic ESCs on M2 macrophage polarization and the potential mechanism.

METHODS

Human THP-1 monocytic cells induced macrophage differentiation (M0) and M2 polarization. Ectopic ESCs and their exosomes were used to stimulate M2 macrophages. M2 macrophage polarization was examined by detecting CD163 and ARG1 expression. Exosomal microRNAs were analyzed by small-RNA sequencing.

RESULTS

Our in vitro results suggest that exosomes of ectopic ESCs promoted M2 macrophage polarization. Meanwhile, The miR-146a-5p level was highly increased in ectopic ESCs and their exosomes and promoted the role of exosomes in M2 macrophage polarization. As a target, TRAF6 overexpression inhibits the function of miR-146a-5p mimic on M2 macrophage polarization. In the rat model, exosomes from ectopic ESCs contribute to the development of endometriosis.

CONCLUSIONS

It was suggested that exosomes derived from ectopic ESCs promote the M2 macrophage polarization by delivering miR-146a-5p targeting TRAF6 in the pathological process of endometriosis.

The effect of MicroRNAs variants on idiopathic recurrent pregnancy loss

BACKGROUND

Although the importance of miRNA variants in female reproductive disorders has been frequently reported, the association between miRNA polymorphisms and recurrent pregnancy loss (RPL) has been poorly studied. In this study, we aimed to assess the correlation of four different miRNA variants to unexplained RPL.

METHODS AND RESULTS

The prevalence of four SNPs including miR-21 rs1292037, miR-155-5p rs767649, miR-218-2 rs11134527, and miR-605 rs2043556 in 280 cases with iRPL and 280 controls was performed. The DNA was extracted from all subjects and the SNPs were genotyped using RFLP-PCR methods. The data revealed that rs1292037 and rs767649 were significantly associated with higher rates of iRPL in patients compared with controls while rs11134527 and rs2043556 showed no association with increased rates of iRPL among patients. The haplotypes T-A-G-G and T-A-G-A were the most frequent in both cases and controls. Three haplotypes including T-T-G-A, C-T-G-G, and T-A-A-A showed significantly different frequencies in patients in comparison to healthy females.

CONCLUSION

This study suggests that rs1292037 and rs767649 could be risk factors for increased rates of iRPL.

Liquid Biopsy in Endometriosis: A Systematic Review

Despite laparoscopy being a standardized option to diagnose pelvic endometriotic implants, non-invasive biomarkers are necessary to avoid the discomfort of invasive procedures. Recent evidence suggests a potential role of microRNAs (miRNAs) as feasible biomarkers for the early diagnosis of endometriosis. Following the recommendations in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, we systematically searched PubMed, EMBASE, Scopus, Cochrane Library, and Science Direct in January 2023. We provided no restriction on the country and year of publication, and considered English published articles. We selected studies including patients with endometriosis and describing miRNA regulation in the context of endometriosis. Overall, 45 studies fulfilled the inclusion criteria, and 2045 patients with endometriosis and 1587 controls were screened. Patients were analyzed concerning miRNAs expression and sources, stage of disease, and symptoms, and compared to controls. Among DEMs, the ones with the widest delta between endometriosis patients and controls-Relative Expression ≥ 4 Log2(ratio)-were miR-145, miR-191, miR-195, miR-21-5p, miR-106b-5p, miR-195-5p, miR-451a, miR-200c, miR-20a-5p, and miR-15a-5p. Although the epigenetic regulation is partially unclear, miRNAs are valid biomarkers to diagnose endometriotic lesions in symptomatic and non-symptomatic women. MiRNAs modulation should be clarified, especially during therapies or relapse, to plan targeted management protocols.

Study of association between different microRNA variants and the risk of idiopathic recurrent pregnancy loss

AIM

Recurrent pregnancy loss (RPL) is a common reproductive disorder among women and a major cause of infertility among them; however, the underlying causes of RPL remain unknown which have led to great difficulties and complications in the treatment. MicroRNAs (miRNA) have been shown to be a potential diagnosis tools in different reproductive disorders. This study aimed to investigate the association of four different miRNA variants with the risk of idiopathic RPL (iRPL).

METHODS

A total of 450 women including 225 patients and 225 controls were recruited in this study. DNA was extracted, and genotyped by PCR method. Haplotype analysis, as well as linkage disequilibrium between SNPs, was performed.

CONCLUSION

This study suggested that rs4636297, rs41291957, and rs353292, but not rs531564 can play a risk factor role for iRLP.

Genetic Variants miR-126, miR-146a, miR-196a2, and miR-499 in Polycystic Ovary Syndrome

Introduction: Alterations in certain microRNAs (miRNAs) and their target genes have reported in polycystic ovary syndrome (PCOS) and other disease of the female reproductive system, and so may be potential biomarkers. We hypothesised alterations in the prevalence of four miRNAs single nucleotide polymorphism (SNP) variants miR-126 rs4636297, miR-146a rs2910164, miR-196a2 rs11614913, and miR-499 rs3746444 in women with PCOS in comparison to healthy controls.

Methods: SNPs in the four miRNAs were determined in 385 patients and 385 controls by standard RT-PCR techniques.

Results: SNPs in miR-126 and miR-246a were significant linked with PCOS under the allelic, dominant, co-dominant, and recessive models (all p ≤ 0.01). The SNP in miR-499 was linked to PCOS in allelic (T, p = 0.002), dominant (p = 0.035) and recessive (p = 0.003) models. The SNPs -196a was significant linked to PCOS only in the recessive model (p = 0.037). Combining these SNPs in miR-499, mi146a, miR-196a and miR-126 respectively into allele haplotypes found highly significant odds ratios (95% CI) of 0.40 (0.29–0.54) (p < 0.001) for the C-G-C-G haplotype, and 0.46 (0.30–0.70) (p = 0.002) for the C-C-C-A haplotype (p = 0.002) for PCOS.

Conclusion: Single SNPs and haplotype combinations in certain SNPs in miR-126, miR-146a, miR-196a2 and miR-499 are strongly linked to PCOS, and so may be useful predictors of this condition.

MicroRNA Variants miR-27a rs895819 and miR-423 rs6505162, but not miR-124-1 rs531564, are Linked to Endometriosis and its Severity

Background: While different studies have investigated the association of SNPs with female reproductive disorders, a limited number of studies have investigated the effect of microRNAs variants in endometriosis. In this study, we evaluated the prevalence and the association of three different miRNAs variants including, miR-27a rs895819, miR-124-1 rs531564, and miR-423 rs6505162 with endometriosis to help further elucidate the importance of these variants in female reproductive disorders.

Methods: A total number of 440 women (220 cases and 220 controls) were included. DNA was extracted and genotyping of the SNPs was carried out by PCR.

Results: The results showed that rs895819 and rs6505162 had a significant association with endometriosis under the dominant, recessive, co-dominant, and allelic model, but rs531564 was not linked to endometriosis. Our results also imply a protective effect on endometriosis severity for AG genotype and G allele in rs895819 (p < 0.001), and also for AA and AC genotypes in rs6505162 with severity in endometriosis (p < 0.001). Moreover, Hardy–Weinberg equilibrium, haplotype frequency, and linkage disequilibrium between SNPs were performed.

Conclusion: miR-27a rs895819 and miR-423 rs6505162, but not miR-124-1 rs531564, are linked to endometriosis.

Endometriosis: Epidemiology, Classification, Pathogenesis, Treatment and Genetics (Review of Literature)

Endometriosis is a “mysterious” disease and its exact cause has not yet been established. Among the etiological factors, congenital, environmental, epigenetic, autoimmune and allergic factors are listed. It is believed that the primary mechanism of the formation of endometriosis foci is retrograde menstruation, i.e., the passage of menstrual blood through the fallopian tubes into the peritoneal cavity and implantation of exfoliated endometrial cells. However, since this mechanism is also observed in healthy women, other factors must also be involved in the formation of endometriosis foci. Endometriosis is in many women the cause of infertility, chronic pain and the deterioration of the quality of life. It also represents a significant financial burden on health systems. The article presents a review of the literature on endometriosis—a disease affecting women throughout the world.

CD44 polymorphisms and its variants, as an inconsistent marker in cancer investigations

Among cell surface markers, CD44 is considered the main marker for identifying and isolating the cancer stem cells (CSCs) among other cells and has attracted significant attention in a variety of research areas. Many studies have shown the essential roles of CD44 in initiation, metastasis, and tumorigenesis in different types of cancer; however, the validity of CD44 as a therapeutic or diagnostic target has not been fully confirmed in some other studies. Whereas the association of specific single nucleotide polymorphisms (SNPs) in the CD44 gene and related variants with cancer risk have been observed in clinical investigations, the significance of these findings remains controversial. Here, we aimed to provide an up-to-date overview of recent studies on the association of CD44 polymorphisms and its variants with different kinds of cancer to determine whether or not it can be used as an appropriate candidate for cancer tracking.