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Project description:PurposeEvaluation of mRNA and microRNA (miRNA) expression in epithelium and stroma of patients with keratoconus.MethodsThe 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.ResultsWe 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.ConclusionsThis 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.
| S-EPMC9284461 | biostudies-literature
Project description:Purpose: To evaluate conjunctival cell microRNA and mRNA expression in relation to observed phenotype and genotype of aniridia-associated keratopathy (AAK) in a cohort of subjects with congenital aniridia. Methods: Using impression cytology, bulbar conjunctival cells were sampled from 20 subjects with congenital aniridia and 20 age and sex-matched healthy control subjects. RNA was extracted and microRNA and mRNA analysis was performed using microarrays. Results were related to the presence and severity of AAK determined by a standardized clinical grading scale and to the genotype (PAX6 mutation?) determined by clinical genetics. Results: Of the 2549 microRNAs analyzed, 21 were differentially expressed relative to controls. Among these miR-204-5p, an inhibitor of corneal neovascularization, was downregulated 26.8-fold, while miR-5787 and miR-224-5p were upregulated 2.8 and 2.4-fold relative to controls, respectively. At the mRNA level, 539 transcripts were differentially expressed, among these FOSB and FOS were upregulated 17.5 and 9.7-fold respectively, and JUN by 2.9-fold, all components of the AP-1 transcription factor complex. Pathway analysis revealed dysregulation of several enriched pathways including PI3K-Akt, MAPK, and Ras signaling pathways in aniridia. For several microRNAs and transcripts, expression levels aligned with AAK severity, while in very mild cases with missense or non-PAX6 coding mutations, gene expression was only minimally altered. Conclusion: In aniridia, specific factors and pathways are strongly dysregulated in conjunctival cells, suggesting that the conjunctiva in aniridia is abnormally maintained in a pro-angiogenic and proliferative state, promoting the aggressivity of AAK in a mutation-dependent manner. Transcriptional profiling of conjunctival cells at the microRNA and mRNA levels presents a powerful, minimally-invasive means to assess the regulation of cell dysfunction at the ocular surface.
2022-07-20 | GSE204838 | GEO
Project description:Purpose: To evaluate conjunctival cell microRNA and mRNA expression in relation to observed phenotype and genotype of aniridia-associated keratopathy (AAK) in a cohort of subjects with congenital aniridia. Methods: Using impression cytology, bulbar conjunctival cells were sampled from 20 subjects with congenital aniridia and 20 age and sex-matched healthy control subjects. RNA was extracted and microRNA and mRNA analysis was performed using microarrays. Results were related to the presence and severity of AAK determined by a standardized clinical grading scale and to the genotype (PAX6 mutation?) determined by clinical genetics. Results: Of the 2549 microRNAs analyzed, 21 were differentially expressed relative to controls. Among these miR-204-5p, an inhibitor of corneal neovascularization, was downregulated 26.8-fold, while miR-5787 and miR-224-5p were upregulated 2.8 and 2.4-fold relative to controls, respectively. At the mRNA level, 539 transcripts were differentially expressed, among these FOSB and FOS were upregulated 17.5 and 9.7-fold respectively, and JUN by 2.9-fold, all components of the AP-1 transcription factor complex. Pathway analysis revealed dysregulation of several enriched pathways including PI3K-Akt, MAPK, and Ras signaling pathways in aniridia. For several microRNAs and transcripts, expression levels aligned with AAK severity, while in very mild cases with missense or non-PAX6 coding mutations, gene expression was only minimally altered. Conclusion: In aniridia, specific factors and pathways are strongly dysregulated in conjunctival cells, suggesting that the conjunctiva in aniridia is abnormally maintained in a pro-angiogenic and proliferative state, promoting the aggressivity of AAK in a mutation-dependent manner. Transcriptional profiling of conjunctival cells at the microRNA and mRNA levels presents a powerful, minimally-invasive means to assess the regulation of cell dysfunction at the ocular surface.
2022-07-20 | GSE204791 | GEO
Project description:Keratoconus (KC) is an ectatic corneal disease characterized by progressive thinning and irregular astigmatism, and a leading indication for corneal transplantation. KC-associated changes have been demonstrated for the entire cornea, but the pathological thinning and mechanical weakening is usually localized. We performed quantitative proteomics using Sequential Windowed Acquisition of All Theoretical Fragment Ion Mass Spectrometry (SWATH-MS) to analyze epithelial and stromal changes between the topographically-abnormal cone and topographically-normal non-cone regions of advanced KC corneas, compared to age-matched normal corneas. Expression of 20 epithelial and 14 stromal proteins was significantly altered (?2 or ?0.5-fold) between cone and non-cone in all 4 KC samples. Ingenuity pathway analysis illustrated developmental and metabolic disorders for the altered epithelial proteome with mitochondrion as the significant gene ontology (GO) term. The differential stromal proteome was related to cellular assembly, tissue organization and connective tissue disorders with endoplasmic reticulum protein folding as the significant GO term. Validation of selected protein expression was performed on archived KC, non-KC and normal corneal specimens by immunohistochemistry. This is the first time to show that KC-associated proteome changes were not limited to the topographically-thinner and mechanically-weakened cone but also non-cone region with normal topography, indicating a peripheral involvement in KC development.
| S-EPMC6393548 | biostudies-literature
Project description:PurposeKeratoconus (KC) is a multifactorial disease where progressive thinning and weakening of the cornea leads to loss of visual acuity. Although the underlying etiology is poorly understood, a major endpoint is a dysfunctional stromal connective tissue matrix. Using multiple individual KC corneas, we determined that matrix production by keratocytes is severely impeded due to an altered stress response program.MethodsKC and donor (DN) stromal keratocytes were cultured in low glucose serum-free medium containing insulin, selenium and transferrin. Fibronectin, collagens and proteins related to their chaperone, processing and export, matrix metalloproteinase, and stress response related proteins were investigated by immunoblotting, immunocytochemistry, hydroxyproline quantification, and gelatin zymography. Multiplexed mass spectrometry was used for global proteomic profiling of 5 individual DN and KC cell culture. Transcription of selected proteins was assayed by qPCR.ResultsDN and KC cells showed comparable survival and growth. However, immunoblotting of selected ECM proteins and global proteomics showed decreased fibronectin, collagens, PCOLCE, ADAMTS2, BMP1, HSP47, other structural and cytoskeletal proteins in KC. Phosphorylated (p) eIF2?, a translation regulator and its target, ATF4 were increased in KC cultured cells and corneal sections.ConclusionsThe profound decrease in structural proteins in cultured KC cells and increase in the p-eIF2?, and ATF4, suggest a stress related blockade in structural proteins not immediately needed for cell survival. Therefore, this cell culture system reveals an intrinsic aggravated stress response with consequent decrease in ECM proteins as potential pathogenic underpinnings in KC.
| S-EPMC5995483 | biostudies-literature
Project description:AIM:To identify changes in the expression of genes coding for extracellular matrix (ECM) proteins in patients with non-inflammatory corneal disorder keratoconus (KC), patients with corneal scarring, and normal controls. MATERIALS AND METHODS:Total RNA extracted from corneal tissue of 13 KC patients, 2 patients with corneal scaring and 4 normal controls was analyzed using Human Extracellular Matrix & Adhesion Molecules Profiler PCR Array. Statistically significant changes in gene expression were identified using the Data Analysis software. RESULTS:Comparison of KC and control corneas with thresholds of 1.5 or greater fold change and a p-value of 0.05 or lower, revealed 21 differentially expressed genes, 16 genes were downregulated and 5 were upregulated. Among transcripts downregulated in KC patients we identified THBS1, ADAMTS1, SPP1, several collagens and integrins. We found TGFBI (BIGH3) gene was the most significantly upregulated transcript. CONCLUSION:Development of keratoconus results in deregulation of gene expression of extracellular matrix and adhesion molecules. CLINICAL SIGNIFICANCE:Downregulation of collagens and upregulation of TGFBI repeatedly identified in KC patients may be used as clinical markers of the disease.
| S-EPMC5627975 | biostudies-literature
Project description:The purpose of this study was to investigate the expression and localization of transforming growth factor (TGF) β1 and TGFβ2 in rabbit corneas that healed with and without stromal fibrosis, and to further study defective perlecan incorporation in the epithelial basement membrane (EBM) in corneas with scarring fibrosis. A total of 120 female rabbits had no surgery, -4.5D PRK, or -9D PRK. Immunohistochemistry (IHC) was performed at time points from unwounded to eight weeks after surgery, with four corneas at each time point in each group. Multiplex IHC was performed for TGFβ1 or TGFβ2, with Image-J quantitation, and keratocan, vimentin, alpha-smooth muscle actin (SMA), perlecan, laminin-alpha 5, nidogen-1 or CD11b. Corneas at the four-week peak for myofibroblast and fibrosis development were evaluated using Imaris 3D analysis. Delayed regeneration of both an apical epithelial growth factor barrier and EBM barrier function, including defective EBM perlecan incorporation, was greater in high injury -9D PRK corneas compared to -4.5D PRK corneas without fibrosis. Defective apical epithelial growth factor barrier and EBM allowed epithelial and tear TGFβ1 and tear TGFβ2 to enter the corneal stroma to drive myofibroblast generation in the anterior stroma from vimentin-positive corneal fibroblasts, and likely fibrocytes. Vimentin-positive cells and unidentified vimentin-negative, CD11b-negative cells also produce TGFβ1 and/or TGFβ2 in the stroma in some corneas. TGFβ1 and TGFβ2 were at higher levels in the anterior stroma in the weeks preceding myofibroblast development in the -9D group. All -9D corneas (beginning two to three weeks after surgery), and four -4.5D PRK corneas developed significant SMA + myofibroblasts and stromal fibrosis. Both the apical epithelial growth factor barrier and/or EBM barrier functions tended to regenerate weeks earlier in -4.5D PRK corneas without fibrosis, compared to -4.5D or -9D PRK corneas with fibrosis. SMA-positive myofibroblasts were markedly reduced in most corneas by eight weeks after surgery. The apical epithelial growth factor barrier and EBM barrier limit TGFβ1 and TGFβ2 entry into the corneal stroma to modulate corneal fibroblast and myofibroblast development associated with scarring stromal fibrosis. Delayed regeneration of these barriers in corneas with more severe injuries promotes myofibroblast development, prolongs myofibroblast viability and triggers stromal scarring fibrosis.
| S-EPMC7856119 | biostudies-literature
Project description:Although microRNAs are being extensively studied for their involvement in cancer and development, little is known about their roles in Alzheimer's disease (AD). In this study, we used microarrays for the first joint profiling and analysis of miRNAs and mRNAs expression in brain cortex from AD and age-matched control subjects. These data provided the unique opportunity to study the relationship between miRNA and mRNA expression in normal and AD brains. Using a non-parametric analysis, we showed that the levels of many miRNAs can be either positively or negatively correlated with those of their target mRNAs. Comparative analysis with independent cancer datasets showed that such miRNA-mRNA expression correlations are not static, but rather context-dependent. Subsequently, we identified a large set of miRNA-mRNA associations that are changed in AD versus control, highlighting AD-specific changes in the miRNA regulatory system. Our results demonstrate a robust relationship between the levels of miRNAs and those of their targets in the brain. This has implications in the study of the molecular pathology of AD, as well as miRNA biology in general.
| S-EPMC2813862 | biostudies-literature
Project description:We investigated the expression of the secreted frizzled-related proteins (SFRPs) in keratoconus (KC) and control corneas. KC buttons (∼8 mm diameter) (n = 15) and whole control corneas (n = 7) were fixed in 10% formalin or 2% paraformaldehyde and subsequently paraffin embedded and sectioned. Sections for histopathology were stained with hematoxylin and eosin, or Periodic Acid Schiff's reagent. A series of sections was also immunolabelled with SFRP 1 to 5 antibodies, visualised using immunofluorescence, and examined with a Zeiss LSM700 scanning laser confocal microscope. Semi-quantitative grading was used to compare SFRP immunostaining in KC and control corneas. Overall, KC corneas showed increased immunostaining for SFRP1 to 5, compared to controls. Corneal epithelium in all KC corneas displayed heterogeneous moderate to strong immunoreactivity for SFRP1 to 4, particularly in the basal epithelium adjacent to cone area. SFRP3 and 5 were localised to epithelial cell membranes in KC and control corneas, with increased SFRP3 cytoplasmic expression observed in KC. Strong stromal expression of SFRP5, including extracellular matrix, was seen in both KC and control corneas. In control corneas we observed differential expression of SFRP family proteins in the limbus compared to more central cornea. Taken together, our results support a role for SFRPs in maintaining a healthy cornea and in the pathogenesis of epithelial and anterior stromal disruption observed in KC.
| S-EPMC3688946 | biostudies-literature
Project description:Keratoconus (KTCN, OMIM 148300) is a degenerative eye disorder characterized by progressive stromal thinning that leads to a conical shape of the cornea, resulting in optical aberrations and even loss of visual function. The biochemical background of the disease is poorly understood, which motivated us to perform RNA-Seq experiment, aimed at better characterizing the KTCN transcriptome and identification of long non-coding RNAs (lncRNAs) that might be involved in KTCN etiology. The in silico functional studies based on predicted lncRNA:RNA base-pairings led us to recognition of a number of lncRNAs possibly regulating genes with known or plausible links to KTCN. The lncRNA sequences and data regarding their predicted functions in controlling the RNA processing and stability are available for browse, search and download in KTCNlncDB (http://rhesus.amu.edu.pl/KTCNlncDB/), the first online platform devoted to KTCN transcriptome.Database URL: http://rhesus.amu.edu.pl/KTCNlncDB/.
| S-EPMC5225396 | biostudies-literature