Silencing of AFAP1-AS1 lncRNA impairs cell proliferation and migration by epigenetically promoting DUSP5 expression in pre-eclampsia

Roles of AFAP1-AS1 in Gynecology and Urogenital System

BACKGROUND

Human disease onset and progression are strongly associated with aberrant long noncoding RNA (lncRNA) expression, highlighting the functional regulatory role of lncRNA. Actin filament-associated protein 1-antisense RNA 1 (AFAP1-AS1), a member of lncRNAs, is located on the antisense strand of Actin filament-associated protein 1 (AFAP1).

METHODS

We conducted a comprehensive review of AFAP1-AS1's functions in gynecology and urogenital systems using the "PubMed" database.

RESULTS

Our analysis reveals that AFAP1-AS1 is overexpressed and engages in the initiation and process of gynecological and urogenital diseases. The regulatory mechanisms employed by AFAP1-AS1 involve four major strategies: gene-level effects, competition for microRNA (miRNA) repression, protein binding, participation in signaling networks that influence cellular processes such as proliferative phenotype, migration, invasiveness, epithelial-mesenchymal transition (EMT), cycle regulation, drug resistance, and more. Furthermore, AFAP1-AS1 is implicated in guiding clinicopathological characteristics.

CONCLUSION

AFAP1-AS1 holds promise as a potent diagnostics and treatment option for gynecological and genitourinary systems in the future.

Interaction of lncRNA Gm2044 and EEF2 promotes estradiol synthesis in ovarian follicular granulosa cells

The functions and molecular mechanisms of long noncoding RNA (lncRNA) in reproduction have been widely studied at present. However, lncRNA regulating hormone synthesis in ovarian follicular granulosa cells has not been sufficiently studied. Our previous research demonstrated that lncRNA Gm2044 could promote estradiol synthesis in follicular granulosa cells. In this study, we identified 21 binding proteins of lncRNA Gm2044 in ovarian follicles using comprehensive identification of RNA-binding proteins by mass spectrometry (ChIRP-MS). RNA immunoprecipitation (RNA IP) and reverse transcription PCR (RT-PCR) confirmed that lncRNA Gm2044 can interact with eukaryotic translation elongation factor 2 (EEF2) protein. Furthermore, we constructed lncRNA Gm2044 knockout mice using the CRISPR/Cas9 method. Although the follicular development and fertility of female lncRNA Gm2044 knockout mice were not affected, the serum estradiol concentration in female lncRNA Gm2044 knockout mice significantly decreased. Western blotting and ELISA revealed that lncRNA Gm2044 may promote the binding of EEF2 to Nr5a1 mRNA and then enhance the Nr5a1 mRNA translation, and the upregulated NR5A1 protein can strengthen estradiol synthesis. To determine the potential signaling pathway of lncRNA Gm2044 regulating estradiol synthesis, transcriptome sequencing was performed for ovaries of adult lncRNA Gm2044 knockout mice, which identified 565 significant up-regulated genes and 303 significant down-regulated genes, which were then analyzed with Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) and validated by molecular experiments. Understanding how lncRNA Gm2044/EEF2 protein regulates estradiol synthesis will help treat estrogen-related reproductive diseases.

IGF2BP2 enhances LincRNA01116 stability via m6 A: A potential biomarker and therapeutic target for patients with pre-eclampsia

Pre-eclampsia (PE) is a serious complication in pregnant women characterized by failure of placental remodeling and is one of the primary causes of changes in the placental structure and function. The aberrant expression of long noncoding RNA is associated with the occurrence and progression of PE. This study found that linc01116 expression was significantly downregulated in PE patients and was related to poor uterine spiral artery remodeling. Knockdown of linc01116 remarkably decreased the angiogenesis of trophoblast cells in vitro and in vivo. Mechanistically, IGF2BP2 regulated linc01116 RNA stability via m⁶ A methylation. Bioinformatics and other experiments further revealed that linc01116 upregulates AAMP expression by adsorbing miR-210-3p in trophoblast cells. In conclusion, this study revealed the critical role of linc01116 in regulating trophoblast angiogenesis. Furthermore, the study provides new clues for detecting placental pathology in PE.

Regulatory roles of non-coding RNAs and m6A modification in trophoblast functions and the occurrence of its related adverse pregnancy outcomes

Adverse pregnancy outcomes, such as preeclampsia, gestational diabetes mellitus, fetal growth restriction, and recurrent miscarriage, occur frequently in pregnant women and might further induce morbidity and mortality for both mother and fetus. Increasing studies have shown that dysfunctions of human trophoblast are related to these adverse pregnancy outcomes. Recent studies also showed that environmental toxicants could induce trophoblast dysfunctions. Moreover, non-coding RNAs (ncRNAs) have been reported to play important regulatory roles in various cellular processes. However, the roles of ncRNAs in the regulation of trophoblast dysfunctions and the occurrence of adverse pregnancy outcomes still need to be further investigated, especially with exposure to environmental toxicants. In this review, we analyzed the regulatory mechanisms of ncRNAs and m6A methylation modification in the dysfunctions of trophoblast cells and the occurrence of adverse pregnancy outcomes and also summarized the harmful effects of environmental toxicants. In addition to DNA replication, mRNA transcription, and protein translation, ncRNAs and m6A modification might be considered as the fourth and fifth elements that regulate the genetic central dogma, respectively. Environmental toxicants might also affect these processes. In this review, we expect to provide a deeper scientific understanding of the occurrence of adverse pregnancy outcomes and to discover potential biomarkers for the diagnosis and treatment of these outcomes.

EZH2 enhances proliferation and migration of trophoblast cell lines by blocking GADD45A-mediated p38/MAPK signaling pathway

Impaired activity of the trophoblasts is a major contributor to the progression of pregnancy pathologies including preeclampsia (PE). This research probed the function of enhancer of zeste homolog 2 (EZH2) in activity of trophoblast cells and its correlation with growth arrest and DNA damage inducible alpha (GADD45A). EZH2 was predicted to be downregulated in placental tissues in PE according to a gene chip analysis, and reduced expression of EZH2 was detected in the placental tissues of patients with PE. Overexpression of EZH2 augmented proliferation and invasiveness of two trophoblast cell lines HTR-8/SVneo and JEG3 cells. EZH2 catalyzed trimethylation of lysine 27 on histone 3 (H3K27me3) in GADD45A promoter to suppress its transcription. GADD45A silencing increased the activity of the trophoblast cell lines and inactivated the p38/mitogen-activated protein kinase (MAPK) signaling pathway. Rescue experiments confirmed that either inhibition of GADD45A or p38 restored the proliferation, migration, and invasiveness of the trophoblast cell lines suppressed by EZH2 silencing. In conclusion, this work suggests that EZH2 enhances activity of trophoblast cell lines by suppressing GADD45A-mediated p38/MAPK signaling pathway.

Human Papillomavirus Type 16 Early Protein E7 Activates Autophagy through Inhibition of Dual-Specificity Phosphatase 5

Consistent high-risk human papillomavirus (HPV) infection leads to various malignant cancers. Autophagy can promote cancer progression by helping cancer cells survive under stress or induce oncogenic effects when mutations or abnormalities occur. Mitogen activated protein kinases (MAPKs) can transduce various external or intrinsic stimuli into cellular responses, including autophagy, and dual-specificity phosphates (DUSPs) contribute to the direct regulation of MAPK activities. Previously, we showed that expression of DUSP5 was repressed in HPV16 E7-expressing normal human epidermal keratinocytes (NHEKs). Here we show that clinical HPV16 E7-positive precancerous and cancerous tissues also demonstrate low DUSP5 levels compared with control tissues, indicating that the inverse correlation between HPV16 E7 and DUSP5 is clinically relevant. We furthermore investigated the autophagy response in both DUSP5-deficient and HPV16 E7-expressing NHEKs. Confocal microscopy and Western analysis showed induction of LC3-II levels, autophagosome formation and autophagy fluxes in DUSP5-deficient NHEKs. Furthermore, Western analysis demonstrated specific induction of phosphorylated ERK in DUSP5-deficient and HPV16 E7-expressing NHEKs, indicating that HPV16 E7-mediated repression of DUSP5 results in induced MAPK/ERK signaling. Finally, phosphorylated mTOR and ULK (S757) were reduced in DUSP5-deficient NHEKs, while phosphorylated ULK (S555) and AMPK were increased, thereby inducing canonical autophagy through the mTOR and AMPK pathways. In conclusion, our results demonstrate that HPV16 E7 expression reduces DUSP5 levels, which in turn results in active MAPK/ERK signaling and induction of canonical autophagy through mTOR and MAPK regulation. Given its demonstrated inverse correlation with clinical cancerous tissues, DUSP5 may serve as a potential therapeutic target for cervical cancer.

A novel regulatory mechanism network mediated by lncRNA TUG1 that induces the impairment of spiral artery remodeling in Preeclampsia

Preeclampsia (PE) is associated with maternal and fetal perinatal morbidity and mortality, which brings tremendous suffering and imposes an economic burden worldwide. The failure of uterine spiral artery remodeling may be related to the abnormal function of trophoblasts and lead to the occurrence and progression of PE. Aberrant expression of long non-coding RNAs (lncRNAs) is involved in the failure of uterine spiral artery remodeling. However, the regulation of lncRNA expression in PE is poorly characterized. Here, we reported that hypoxia-induced microRNA (miR)-218 inhibited the expression of lncRNA TUG1 by targeting FOXP1. Further RNA sequencing and mechanism analysis revealed that silencing of TUG1 increased the expression of DNA demethylase TET3 and proliferation-related DUSP family, including DUSP2, DUSP4, and DUSP5, via binding to SUV39H1 in the nucleus. Moreover, TUG1 modulated the DUSP family in vitro through a TET3-mediated epigenetic mechanism. Taken together, our results unmask a new regulatory network mediated by TUG1 as an essential determinant of the pathogenesis of PE, which regulates cell growth and possibly the occurrence and development of other diseases.

SNHG22 promotes migration and invasion of trophoblasts via miR-128-3p/PCDH11X axis and activates PI3K/Akt signaling pathway

OBJECTIVES

Long non-coding RNAs (LncRNAs) act as an indispensable role in the Preeclampsia (PE)-related trophoblast function, while its relationship with Small Nucleolar RNA Host Gene 22 (SNHG22) remains unknown. Hence, this study aimed to investigate the roles of lncRNA SNHG22 in the Preeclampsia (PE)-related trophoblasts function and the underlying mechanism.

METHOD

Normal placentas and placentas from PE patients were collected to detect the expression of lncRNA SNHG22. Then, trophoblasts HTR-8/Svneo and JEG-3 were purchased, cultured, and treated to investigate the roles of lncRNA SNHG22 on cell migration and invasion as well as its underlying regulatory mechanism.

RESULTS

The SNHG22 was downregulated in PE patients, and it was found that SNHG22 overexpression could drive migration and invasion of trophoblasts, while SNHG22 depletion exerted a suppressive effect. Mechanistically, SNHG22 was validated to regulate microRNA-128-3p (miR-128-3p), and Protocadherin 11 X-Linked (PCDH11X) was identified as the target gene of miR-128-3p. Furthermore, it was found that SNHG22 acted as a promoter in the migration and invasion of trophoblast cells in a miR-128-3p/PCDH11X dependent manner, and SNHG22 silencing weakened the activation of PCDH11X-mediated PI3K/Akt signaling pathways through inhibiting miR-128-3p, thereby preventing migration and invasion of trophoblasts.

CONCLUSION

SNHG22 acted as a driver in the migration and invasion of trophoblasts and may be considered a candidate for the amelioration of PE.