LncRNA and mRNA Expression Profiling in the Periurethral Vaginal Wall Tissues of Postmenopausal Women with Stress Urinary Incontinence

Small Extracellular Vesicles Secreted by Peri-urethral Tissues Regulate Fibroblast Function and Contribute to the Pathogenesis of Female Stress Urinary Incontinence

OBJECTIVE

This study aimed to explore the existence of small extracellular vesicles (sEVs) in peri-urethral tissues and the role of abnormal expression of sEVs in the pathogenesis of female stress urinary incontinence (SUI).

METHODS

sEVs were extracted from peri-urethral vaginal wall tissues using differential centrifugation and were observed by transmission electron microscopy (TEM). The number of sEVs and their protein contents were compared between SUI and control groups using nanoparticle tracking analysis (NTA) and bicinchoninic acid (BCA) protein assay. Fibroblasts were cultured separately with SUI (SsEVs group) and normal tissue sEVs (NsEVs group). Proliferation and migration of fibroblasts were compared between groups using CCK-8 and wound healing assays, respectively. Expression levels of collagen I and III were compared among blank control (BC), NsEVs, and SsEVs groups using real-time PCR. Protein mass spectrometry was used to test the differentially expressed proteins contained in sEVs between groups.

RESULTS

sEVs were extracted and found under the electron microscope. There were significantly more sEVs extracted from the SUI group compared to the normal group. Fibroblasts showed increased proliferative and decreased migratory abilities, and expressed more collagen in the SsEVs group compared to the NsEVs and BC groups. Protein spectrum analysis demonstrated several differentially expressed targets, including components of microfibrils, elastin polymer, and anti-inflammatory factors.

CONCLUSION

sEVs were detected in the peri-urethral tissues. SUI tissues expressed more sEVs than control. The abnormal expression of sEVs and their protein contents may contribute to the pathogenesis and progression of SUI.

Molecular Processes in Stress Urinary Incontinence: A Systematic Review of Human and Animal Studies

Stress urinary incontinence (SUI) is a common and burdensome condition. Because of the large knowledge gap around the molecular processes involved in its pathophysiology, the aim of this review was to provide a systematic overview of genetic variants, gene and protein expression changes related to SUI in human and animal studies. On 5 January 2021, a systematic search was performed in Pubmed, Embase, Web of Science, and the Cochrane library. The screening process and quality assessment were performed in duplicate, using predefined inclusion criteria and different quality assessment tools for human and animal studies respectively. The extracted data were grouped in themes per outcome measure, according to their functions in cellular processes, and synthesized in a narrative review. Finally, 107 studies were included, of which 35 used animal models (rats and mice). Resulting from the most examined processes, the evidence suggests that SUI is associated with altered extracellular matrix metabolism, estrogen receptors, oxidative stress, apoptosis, inflammation, neurodegenerative processes, and muscle cell differentiation and contractility. Due to heterogeneity in the studies (e.g., in examined tissues), the precise contribution of the associated genes and proteins in relation to SUI pathophysiology remained unclear. Future research should focus on possible contributors to these alterations.

Transcriptome profiling of lncRNA and co-expression network in the vaginal epithelial tissue of women with lubrication disorders

Background

Vaginal lubrication is a crucial physiological response that occurs at the beginning of sexual arousal. However, research on lubrication disorders (LD) is still in its infancy, and the role of long non-coding RNAs (lncRNAs) in LD remains unclear. This study aimed to explore the function of lncRNAs in the pathogenesis of vaginal LD.

Methods

The expression profiles of LD and normal control (NC) lncRNAs were examined using next-generation sequencing (NGS), and eight selected differentially expressed lncRNAs were verified by quantitative real-time PCR. We conducted GO annotation and KEGG pathway enrichment analyses to determine the principal functions of significantly deregulated genes. LncRNA-mRNA co-expression and protein-protein interaction (PPI) networks were constructed and the lncRNA transcription factors (TFs) were predicted.

Results

From the results, we identified 181,631 lncRNAs and 145,224 mRNAs in vaginal epithelial tissue. Subsequently, our preliminary judgment revealed a total of 499 up-regulated and 337 down-regulated lncRNAs in LD. The top three enriched GO items of the dysregulated lncRNAs included the following significant terms: “contractile fiber part,” “actin filament-based process,” and “contractile fiber”. The most enriched pathways were “cell-extracellular matrix interactions,” “muscle contraction,” “cell-cell communication,” and “cGMP-PKG signaling pathway”. Our results also showed that the lncRNA-mRNA co-expression network was a powerful platform for predicting lncRNA functions. We determined the three hub genes, ADCY5, CXCL12, and NMU, using PPI network construction and analysis. A total of 231 TFs were predicted with RHOXF1, SNAI2, ZNF354C and TBX15 were suspected to be involved in the mechanism of LD.

Conclusion

In this study, we constructed the lncRNA-mRNA co-expression network, predicted the lncRNA TFs, and comprehensively analyzed lncRNA expression profiles in LD, providing a basis for future studies on LD clinical biomarkers and therapeutic targets. Further research is also needed to fully determine lncRNA’s role in LD development.