Regulatory effect of miR-144-3p on the function of human trabecular meshwork cells and fibronectin-1

Identification and validation of key biomarkers and potential therapeutic targets for primary open-angle glaucoma

Primary open-angle glaucoma (POAG) is a prevalent cause of blindness worldwide, resulting in degeneration of retinal ganglion cells and permanent damage to the optic nerve. However, the underlying pathogenetic mechanisms of POAG are currently indistinct, and there has been no effective nonsurgical treatment regimen. The objective of this study is to identify novel biomarkers and potential therapeutic targets for POAG. The mRNA expression microarray datasets GSE27276 and GSE138125, as well as the single-cell high-throughput RNA sequencing (scRNA-seq) dataset GSE148371 were utilized to screen POAG-related differentially expressed genes (DEGs). Functional enrichment analyses, protein-protein interaction (PPI) analysis, and weighted gene co-expression network analysis (WGCNA) of the DEGs were performed. Subsequently, the hub genes were validated at a single-cell level, where trabecular cells were annotated, and the mRNA expression levels of target genes in different cell clusters were analyzed. Immunofluorescence and quantitative real-time PCR (qPCR) were performed for further validation. DEGs analysis identified 43 downregulated and 32 upregulated genes in POAG, which were mainly enriched in immune-related pathways, oxidative stress, and endoplasmic reticulum (ER) stress. PPI networks showed that FN1 and DUSP1 were the central hub nodes, while GPX3 and VAV3 were screened out as hub genes through WGCNA and subsequently validated by qPCR. Finally, FN1, GPX3, and VAV3 were determined to be pivotal core genes via single-cell validation. The relevant biomarkers involved in the pathogenesis of POAG, may serve as potential therapeutic targets. Further studies are necessary to unveil the mechanisms underlying the expression variations of these genes in POAG.

Circ_0047835 Combines with miR-144-3p to Promote the Proliferation, Invasion, Migration, and Fibrosis of TGF-β1-Treated Human Tenon's Capsule Fibroblasts by Upregulating SP1

PURPOSE

Glaucoma is the leading cause of blindness worldwide with complex pathogenesis. Circular RNAs (circRNAs) play critical roles in various diseases, including glaucoma. The purpose of this study was to investigate the role of circ_0047835 and underlying mechanisms in the development of fibrosis after glaucoma filtration surgery.

METHODS

Human Tenon's capsule fibroblasts (HTFs) were stimulated using transforming growth factor-β1 (TGF-β1) to mimic a cellular model of glaucoma in vitro. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8) assay and 5-ethynyl-2'-deoxyuridine (EdU) assay. Cell invasion and migration were detected by transwell assay and wound healing assay, respectively. Western blot assay was used to measure protein levels. The expression levels of circ_0047835, microRNA-144-3p (miR-144-3p) and specific protein 1 (SP1) mRNA were determined by real-time quantitative polymerase chain reaction (RT-qPCR). The interaction between miR-144-3p and circ_0047835 or SP1 was confirmed by dual-luciferase reporter assay and RNA Immunoprecipitation (RIP) assay.

RESULTS

Circ_0047835 expression was elevated in glaucoma tissues and TGF-β1-treated HTFs. Circ_0047835 or SP1 knockdown suppressed the proliferation, migration, invasion, and fibrosis of TGF-β1-treated HTFs. MiR-144-3p was a target of circ_0047835, and miR-144-3p inhibition reversed the effects of circ_0047835 knockdown in TGF-β1-treated HTFs. Moreover, SP1 was identified as a target of miR-144-3p, and miR-144-3p overexpression weakened TGF-β1-induced proliferation, migration, invasion, and fibrosis by targeting SP1 in HTFs. Furthermore, circ_0047835 combined with miR-144-3p to regulate SP1 expression.

CONCLUSION

Circ_0047835 might contribute to fibrosis progression after glaucoma surgery by regulating the miR-144-3p/SP1 axis.

Identification of the potential biological target molecules related to primary open-angle glaucoma

Background

To identify the potential biological target molecules and the corresponding interaction networks in primary open-angle glaucoma (POAG) development.

Methods

The microarray datasets of GSE138125 and GSE27276 concerning lncRNA and mRNA expression profiles in trabecular meshwork of POAG were downloaded from the Gene Expression Omnibus database. The R software was applied to identify differentially expressed (DE) lncRNAs and mRNAs in POAG, and to perform GO and KEGG functional enrichment analysis. Protein–protein interaction (PPI) network and module analysis, and lncRNA-miRNA-mRNA competing endogenous RNA (ceRNA) network were performed by Cytoscape software.

Results

A total of 567 DE-mRNAs were identified from GSE138125 and GSE27276, including 298 up-regulated and 269 down-regulated mRNAs, which were found enriching in biological processes of extracellular matrix organization and epidermis development, respectively. KEGG pathway enrichment analysis further revealed that module genes in PPI network were primarily involved in the AGE-PAGE, PI3K-Akt and TGF-β signaling pathways. Moreover, 897 up-regulated and 1036 down-regulated DE-lncRNAs were identified from GSE138125. Through literature review and databases searching, we obtained 712 lncRNA-miRNA and 337 miRNA-mRNA pairs based on the selected eight POAG-related miRNAs. After excluding 702 lncRNAs and 284 mRNAs that were not comprised in the DE-lncRNA and DE-mRNAs, a total of 53 lncRNA nodes, eight miRNA nodes, 10 mRNA nodes, and 78 edges were included in the final ceRNA network.

Conclusions

This study demonstrated the lncRNA and mRNA expression profiles of trabecular meshwork in POAG patients and the normal controls, and identified potentially ceRNAs and pathways which might improve the pathogenic understanding of this ocular disease.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-022-02368-0.

miR-486-5p Restrains Extracellular Matrix Production and Oxidative Damage in Human Trabecular Meshwork Cells by Targeting TGF-β/SMAD2 Pathway

Background

Glaucoma is characterized by elevated intraocular pressure caused by aqueous outflow dysfunction. Trabecular meshwork plays a key role in controlling intraocular pressure by modulating aqueous outflow. This study investigated the protective effects of miR-486-5p in H₂O₂-stimulated human trabecular meshwork cells (TMCs).

Methods

TMCs were disposed with 300 μM H₂O₂ to establish oxidative damage models in vitro. miR-486-5p mimics and its controls were transfected into TMCs, and cell apoptosis and extracellular matrix production (ECM) genes were measured by flow cytometry, western blotting, and immunofluorescence staining. Activities of superoxide dismutase (SOD) and malondialdehyde (MDA) were also assayed. Online tools and luciferase reporter assays were used to uncover the relationship between miR-486-5p and the TGF-β/SMAD2 pathway.

Results

We found that H₂O₂-induced oxidative damage in TMCs and miR-486-5p was downregulated in H₂O₂-stimulated TMCs. Overexpression of miR-486-5p mitigated H₂O₂-induced oxidative damage by inhibiting apoptosis, reducing cleaved caspase-3/9 expression, reducing MDA levels, and increasing SOD levels as well as downregulating ECM genes. SMAD2 was demonstrated to be targeted by miR-486-5p, and miR-486-5p inhibited TGF-β/SMAD2 signaling in H₂O₂-stimulated TMCs. Additionally, SMAD2 was upregulated by H₂O₂, and SMAD2 upregulation abrogated the protective effects of miR-486-5p against H₂O₂-induced injury.

Conclusion

miR-486-5p restrains H₂O₂-induced oxidative damage in TMCs by targeting the TGF-β/SMAD2 pathway.

Suppression of LINC00460 mediated the sensitization of HCT116 cells to ionizing radiation by inhibiting epithelial-mesenchymal transition

Radiation resistance is the most common challenge for improving radiotherapy. The mechanisms underlying the development of radioresistance remain poorly understood. This study aims to explore the role of LINC00460 in ionizing radiation-induced radioresistance as well as the mechanisms by which LINC00460 is regulated by radiation exposure. The expression of LINC00460 was measured. Cell proliferation and colony formation were measured in HCT116 cells after treatment by radiation. The development of epithelial-mesenchymal transition (EMT) was determined with or without knockdown LINC00460 expression using western blot analysis. Transcription activity was determined using a series of LINC00460-promoter luciferase reporter gene vectors. LINC00460 expression was significantly higher in HCT116 cells, relative to other cell types, with LINC00460 expression significantly affecting HCT116 cell proliferation. Suppression of LINC00460 inhibits EMT development in HCT116 cells via regulation of ZEB1 expression. Furthermore, LINC00460 expression was induced by irradiation via the activation of c-jun transcription factor-binding element located on the LINC00460 promoter. LINC00460 was shown to play a crucial role in EMT-associated progression of colorectal cancer, indicating that LINC00460 may be an indicator or new potential therapeutic target for colorectal cancer radiosensitization.

Oxidative stress and antioxidants in the trabecular meshwork

Glaucoma is an age-dependent disease closely related to oxidative stress and is regarded as the second leading cause of irreversible blindness worldwide. In recent years, many studies have shown that morphological and functional abnormalities of the trabecular meshwork (TM) are closely related to glaucoma, especially with respect to oxidative stress. In this review, the mechanisms of oxidative stress in the TM and treatment strategies for this condition, including strategies involving antioxidants, noncoding RNAs and exogenous compounds, are discussed. Although many questions remain to be answered, the reviewed findings provide insights for further research on oxidative stress alleviation in glaucoma and suggest new targets for glaucoma prevention.