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Meng F, Ren S. Identification of hub genes and molecular pathways in keratoconus by integrating bioinformatics and literature mining at the RNA level. Int Ophthalmol 2024; 44:244. [PMID: 38904678 DOI: 10.1007/s10792-024-03071-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 02/16/2024] [Indexed: 06/22/2024]
Abstract
OBJECTIVE Keratoconus (KC) is a condition characterized by progressive corneal steepening and thinning. However, its pathophysiological mechanism remains vague. We mainly performed literature mining to extract bioinformatic and related data on KC at the RNA level. The objective of this study was to explore the potential pathological mechanisms of KC by identifying hub genes and key molecular pathways at the RNA level. METHODS We performed an exhaustive search of the PubMed database and identified studies that pertained to gene transcripts derived from diverse corneal layers in patients with KC. The identified differentially expressed genes were intersected, and overlapping genes were extracted for further analyses. Significantly enriched genes were screened using "Gene Ontology" (GO) and "Kyoto Encyclopedia of Genes and Genomes" (KEGG) analysis with the "Database for Annotation, Visualization, and Integrated Discovery" (DAVID) database. A protein-protein interaction (PPI) network was constructed for the significantly enriched genes using the STRING database. The PPI network was visualized using the Cytoscape software, and hub genes were screened via betweenness centrality values. Pathways that play a critical role in the pathophysiology of KC were discovered using the GO and KEGG analyses of the hub genes. RESULTS 68 overlapping genes were obtained. Fifty genes were significantly enriched in 67 biological processes, and 16 genes were identified in 7 KEGG pathways. Moreover, 14 nodes and 32 edges were identified via the PPI network constructed using the STRING database. Multiple analyses identified 4 hub genes, 12 enriched biological processes, and 6 KEGG pathways. GO enrichment analysis showed that the hub genes are mainly involved in the positive regulation of apoptotic process, and KEGG analysis showed that the hub genes are primarily associated with the interleukin-17 (IL-17) and tumor necrosis factor (TNF) pathways. Overall, the matrix metalloproteinase 9, IL-6, estrogen receptor 1, and prostaglandin-endoperoxide synthase 2 were the potential important genes associated with KC. CONCLUSION Four genes, matrix metalloproteinase 9, IL-6, estrogen receptor 1, and prostaglandin endoperoxide synthase 2, as well as IL-17 and TNF pathways, are critical in the development of KC. Inflammation and apoptosis may contribute to the pathogenesis of KC.
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Affiliation(s)
- Feiying Meng
- Henan Eye Hospital, Henan Provincial People's Hospital/People's Hospital of Zhengzhou University, Zhengzhou, 450003, China
- Eye Institute, Henan Academy of Innovations in Medical Science, Zhengzhou, China
| | - Shengwei Ren
- Henan Eye Hospital, Henan Provincial People's Hospital/People's Hospital of Zhengzhou University, Zhengzhou, 450003, China.
- Eye Institute, Henan Academy of Innovations in Medical Science, Zhengzhou, China.
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Xia Y, Chen K, Yang Q, Chen Z, Jin L, Zhang L, Yu X, Wang L, Xie C, Zhao Y, Shen Y, Tong J. Methylation in cornea and corneal diseases: a systematic review. Cell Death Discov 2024; 10:169. [PMID: 38589350 PMCID: PMC11002037 DOI: 10.1038/s41420-024-01935-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 03/24/2024] [Accepted: 03/25/2024] [Indexed: 04/10/2024] Open
Abstract
Corneal diseases are among the primary causes of blindness and vision loss worldwide. However, the pathogenesis of corneal diseases remains elusive, and diagnostic and therapeutic tools are limited. Thus, identifying new targets for the diagnosis and treatment of corneal diseases has gained great interest. Methylation, a type of epigenetic modification, modulates various cellular processes at both nucleic acid and protein levels. Growing evidence shows that methylation is a key regulator in the pathogenesis of corneal diseases, including inflammation, fibrosis, and neovascularization, making it an attractive potential therapeutic target. In this review, we discuss the major alterations of methylation and demethylation at the DNA, RNA, and protein levels in corneal diseases and how these dynamics contribute to the pathogenesis of corneal diseases. Also, we provide insights into identifying potential biomarkers of methylation that may improve the diagnosis and treatment of corneal diseases.
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Affiliation(s)
- Yutong Xia
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, China
| | - Kuangqi Chen
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, China
| | - Qianjie Yang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, China
| | - Zhitong Chen
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, China
| | - Le Jin
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, China
| | - Liyue Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, China
| | - Xin Yu
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, China
| | - Liyin Wang
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, China
| | - Chen Xie
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, China
| | - Yuan Zhao
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, China
| | - Ye Shen
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, China.
| | - Jianping Tong
- Department of Ophthalmology, The First Affiliated Hospital of Zhejiang University, Hangzhou, 310003, China.
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Nowak-Malczewska DM, Swierkowska J, Gajecka M. Differentially expressed microRNAs targeting genes in key pathways in keratoconus. Front Genet 2024; 15:1301676. [PMID: 38469119 PMCID: PMC10925626 DOI: 10.3389/fgene.2024.1301676] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 02/12/2024] [Indexed: 03/13/2024] Open
Abstract
Introduction: Keratoconus (KTCN) is a corneal ectasia, characterized by a progressive thinning and protrusion of the cornea, with a complex etiology involving genetic, behavioral, lifestyle, and environmental factors. Previous studies indicated that microRNAs (miRNAs) could be involved in KTCN pathogenesis. This in silico study aimed to identify precursor microRNAs (pre-miRNAs) differentially expressed in KTCN corneas and to characterize mature miRNAs and their target genes. Materials and methods: Expression levels of pre-miRNAs were retrieved from our previously obtained RNA sequencing data of 25 KTCN and 25 non-KTCN human corneas (PMID:28145428, PMID:30994860). Differential expression with FDR ≤0.01 and ≥1.5-fold changes were considered significant. Lists of target genes (target score ≥90) of mature miRNAs were obtained from miRDB. Revealed up-/downregulated miRNAs and their target genes were assessed in databases and literature. Enrichment analyses were completed applying the DAVID database. Results: From a total of 47 pre-miRNAs, six were remarkably upregulated (MIR184, MIR548I1, MIR200A, MIR6728, MIR429, MIR1299) and four downregulated (MIR6081, MIR27B, MIR23B, MIR23A) in KTCN corneas. Out of the 1,409 target genes, 220 genes with decreased and 57 genes with increased expression levels in KTCN samples vs non-KTCN samples were found. The extracellular matrix (ECM) organization, response to mechanical stimulus, regulation of cell shape, and signal transduction processes/pathways were identified as distinctive in enrichment analyses. Also, processes associated with the regulation of transcription and DNA binding were listed. Conclusion: Indicated miRNAs and their target genes might be involved in KTCN pathogenesis via disruption of crucial molecular processes, including ECM organization and signal transduction.
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Affiliation(s)
- Dorota M. Nowak-Malczewska
- Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
| | | | - Marzena Gajecka
- Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
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Jaskiewicz K, Maleszka-Kurpiel M, Kabza M, Karolak JA, Gajecka M. Sequence variants contributing to dysregulated inflammatory responses across keratoconic cone surface in adolescent patients with keratoconus. Front Immunol 2023; 14:1197054. [PMID: 37483635 PMCID: PMC10359427 DOI: 10.3389/fimmu.2023.1197054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Accepted: 06/09/2023] [Indexed: 07/25/2023] Open
Abstract
Background Keratoconus (KTCN) is the most common corneal ectasia resulting in a conical shape of the cornea. Here, genomic variation in the corneal epithelium (CE) across the keratoconic cone surface in patients with KTCN and its relevance in the functioning of the immune system were assessed. Methods Samples from four unrelated adolescent patients with KTCN and two control individuals were obtained during the CXL and PRK procedures, respectively. Three topographic regions, central, middle, and peripheral, were separated towards the whole-genome sequencing (WGS) study embracing a total of 18 experimental samples. The coding and non-coding sequence variation, including structural variation, was assessed and then evaluated together with the previously reported transcriptomic outcomes for the same CE samples and full-thickness corneas. Results First, pathway enrichment analysis of genes with identified coding variants pointed to "Antigen presentation" and "Interferon alpha/beta signaling" as the most overrepresented pathways, indicating the involvement of inflammatory responses in KTCN. Both coding and non-coding sequence variants were found in genes (or in their close proximity) linked to the previously revealed KTCN-specific cellular components, namely, "Actin cytoskeleton", "Extracellular matrix", "Collagen-containing extracellular matrix", "Focal adhesion", "Hippo signaling pathway", and "Wnt signaling" pathways. No genomic heterogeneity across the corneal surface was found comparing the assessed topographic regions. Thirty-five chromosomal regions enriched in both coding and non-coding KTCN-specific sequence variants were revealed, with a most representative 5q locus previously recognized as involved in KTCN. Conclusion The identified genomic features indicate the involvement of innate and adaptive immune system responses in KTCN pathogenesis.
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Affiliation(s)
| | - Magdalena Maleszka-Kurpiel
- Optegra Eye Health Care Clinic in Poznan, Poznan, Poland
- Chair of Ophthalmology and Optometry, Poznan University of Medical Sciences, Poznan, Poland
| | - Michał Kabza
- Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
| | - Justyna A. Karolak
- Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
| | - Marzena Gajecka
- Institute of Human Genetics, Polish Academy of Sciences, Poznan, Poland
- Chair and Department of Genetics and Pharmaceutical Microbiology, Poznan University of Medical Sciences, Poznan, Poland
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Zhu Y, Li Y, Wang Y, Wang L, Shi P, Du X, Zhang Y, Song Y, Zhu Z. Mitochondrial DNA polymorphisms in COX1 affect the lifespan of Caenorhabditis elegans through nuclear gene dct-15. Gene 2022; 845:146776. [PMID: 36063972 DOI: 10.1016/j.gene.2022.146776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/28/2022] [Accepted: 07/28/2022] [Indexed: 11/04/2022]
Abstract
Mutations in the mitochondrial DNA (mtDNA) are closely related to age and age-related complex diseases, but the exact regulatory mechanism of mtDNA natural variation or polymorphism and ageing remains unclear. Recently, nuclear genes that regulate mitochondrial functions and thereby influence ageing have been widely studied. In this study, the relationship between the retrograde communication from the mitochondria to the nucleus and its ultimate effect on ageing has been elucidated. This study found that the natural variations in COX1 of the mitochondria in the Caenorhabditis elegans population do not correlate with multiple phenotypes, except for a mild correlation with lifespan. After excluding the differences in the nuclear genome, the correlation between natural mitochondrial variation and lifespan increased significantly. Moreover, mtDNA variation downregulated the nuclear dct-15 gene expression, which consequently reduced the lifespan, development rate and motility of C. elegans. dct-15 mutations decreased mitochondria copy number but increased ATP content and mitochondrial ultrastructure. Thus, the results indicated that dct-15 interacted with the mitochondrial DNA polymorphisms in COX1 and is associated with ageing. Finally, bioinformatic analyses revealed that mtDNA variation regulated the structural constituent of the cuticle via dct-15 and suggested that the structural constituent of the cuticle could have an important role in the development and ageing processes. These results provide insights into the mtDNA mechanism that can alter the nuclear gene and thereby regulate ageing and ageing-related diseases.
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Affiliation(s)
- Yao Zhu
- Xuzhou Engineering Research Center of Medical Genetics and Transformation, Key Laboratory of Genetic Foundation and Clinical Application, Department of Genetics, Xuzhou Medical University, Xuzhou, China
| | - Ying Li
- Medical Technology College, Xuzhou Medical University, Xuzhou, China
| | | | - Liang Wang
- Department of Bioinformatics, School of Medical Informatics and Engineering, Xuzhou Medical University, Xuzhou, China
| | - Peng Shi
- School of Anesthesiology, Xuzhou Medical University, Xuzhou, China
| | - Xinze Du
- The First Clinical College, Xuzhou Medical University, Xuzhou, China
| | - Yingchun Zhang
- Xuzhou Engineering Research Center of Medical Genetics and Transformation, Key Laboratory of Genetic Foundation and Clinical Application, Department of Genetics, Xuzhou Medical University, Xuzhou, China
| | - Yuanjian Song
- Xuzhou Engineering Research Center of Medical Genetics and Transformation, Key Laboratory of Genetic Foundation and Clinical Application, Department of Genetics, Xuzhou Medical University, Xuzhou, China.
| | - Zuobin Zhu
- Xuzhou Engineering Research Center of Medical Genetics and Transformation, Key Laboratory of Genetic Foundation and Clinical Application, Department of Genetics, Xuzhou Medical University, Xuzhou, China.
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Stachon T, Nastaranpour M, Seitz B, Meese E, Latta L, Taneri S, Ardjomand N, Szentmáry N, Ludwig N. Altered Regulation of mRNA and miRNA Expression in Epithelial and Stromal Tissue of Keratoconus Corneas. Invest Ophthalmol Vis Sci 2022; 63:7. [PMID: 35816043 PMCID: PMC9284461 DOI: 10.1167/iovs.63.8.7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Evaluation of mRNA and microRNA (miRNA) expression in epithelium and stroma of patients with keratoconus. Methods The epithelium and stroma of eight corneas of eight patients with keratoconus and eight corneas of eight non-keratoconus healthy controls were studied separately. RNA was extracted, and mRNA and miRNA analyses were performed using microarrays. Differentially expressed mRNAs and miRNAs in epithelial and stromal keratoconus samples compared to healthy controls were identified. Selected genes and miRNAs were further validated using RT-qPCR. Results We discovered 170 epithelial and 1498 stromal deregulated protein-coding mRNAs in KC samples. In addition, in epithelial samples 180 miRNAs and in stromal samples 379 miRNAs were significantly deregulated more than twofold compared to controls. Pathway analysis revealed enrichment of metabolic and axon guidance pathways for epithelial cells and enrichment of metabolic, mitogen-activated protein kinase (MAPK), and focal adhesion pathways for stromal cells. Conclusions This study demonstrates significant differences in the expression and regulation of mRNAs and miRNAs in the epithelium and stroma of Patients with KC. Also, in addition to the well-known target candidates, we were able to identify further genes and miRNAs that may be associated with keratoconus. Signaling pathways influencing metabolic changes and cell contacts are affected in epithelial and stromal cells of patients with keratoconus.
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Affiliation(s)
- Tanja Stachon
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Homburg (Saar), Germany
| | - Mahsa Nastaranpour
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Homburg (Saar), Germany
| | - Berthold Seitz
- Department of Ophthalmology, Saarland University Medical Center, Homburg (Saar), Germany
| | - Eckart Meese
- Department of Human Genetics and Center for Human and Molecular Biology, Saarland University, Homburg (Saar), Germany
| | - Lorenz Latta
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Homburg (Saar), Germany
| | - Suphi Taneri
- Center for Refractive Surgery, Eye Department at St. Francis Hospital, Muenster, Germany
| | | | - Nóra Szentmáry
- Dr. Rolf M. Schwiete Center for Limbal Stem Cell and Aniridia Research, Homburg (Saar), Germany.,Department of Ophthalmology, Semmelweis University, Budapest, Hungary
| | - Nicole Ludwig
- Department of Human Genetics and Center for Human and Molecular Biology, Saarland University, Homburg (Saar), Germany
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Wang Y, Cao H. Corneal and Scleral Biomechanics in Ophthalmic Diseases: An Updated Review. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2022. [DOI: 10.1016/j.medntd.2022.100140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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