Effect of Thyroxine on Transforming Growth Factor β1, Collagen I, and V Expression in Keratoconus Corneal Fibroblasts and Keratocytes, in Vitro

Changes in PEDF, MMP-2, and TGF-β2 levels in the aqueous humor of cataract patients and their correlation with disease severity

OBJECTIVE

To explore the changes of Pigment Epithelium-Derived Factor (PEDF), Matrix Metalloproteinase-2 (MMP-2), and Transforming Growth Factor-β2 (TGF-β2) levels in the aqueous humor of cataract patients and their correlation with disease severity.

METHODS

93 cataract patients and 56 healthy subjects were study objects. PEDF, MMP-2, and TGF-β2 levels of aqueous humor were compared, and the correlation between each index and Lens Opacity Classification System (LOCS) III classification was analyzed. ROC curve was used to analyze the evaluation value of the combined detection of each index on cataract development, and logistic regression to analyze the influence of the changes of each index on cataract development.

RESULTS

PEDF levels were lower and MMP-2 and TGF-β2 levels were higher in the aqueous humor of cataract patients than in healthy subjects. PEDF levels in the aqueous humor were negatively correlated with LOCS III classification, while MMP-2 and TGF-β2 levels were positively correlated with LOCS III classification. The AUC value of combined detection was higher than that of PEDF, MMP-2, and TGF-β2 in the aqueous humor alone. MMP-2 ≥ 15.13 pg/mL, TGF-β2 ≥ 385.91 pg/mL and PEDF < 198.85 ng/mL were risk factors for cataract development.

CONCLUSION

The changes in PEDF, MMP-2, and TGF-β2 levels in the aqueous humor of cataract patients are related to LOCS III classification. The combined detection is valuable in evaluating cataract development.

In Vitro Expression Analysis of Cytokines and ROS-Related Genes in Human Corneal Fibroblasts and Keratocytes of Healthy and Keratoconus Corneas

PURPOSE

To investigate expression of cytokines and ROS-related genes in stromal cells of healthy and keratoconus (KC) corneas.

METHODS

Expression analysis was performed for cytokines including several interleukins (IL), Tumor necrosis factor-α (TNF-α), Transforming growth factor-β1 (TGF-β1), Interferon-γ (IFN-γ) and ROS-related genes such as Catalase, Glutathione peroxidase 1, NADPH oxidase 1, superoxide dismutase 1 in corneal fibroblasts (HCFs/KC-HCFs) or keratocytes (Keratocytes/KC-Keratocytes) by qPCR and ELISA.

RESULTS

Gene and protein expression of most inflammatory markers was decreased in keratocytes compared to fibroblasts, whereas no differences were found between healthy and keratoconus cells for the majority of cytokines measured. TNF-α expression was increased at gene (KC keratocytes) and protein levels (supernatant of Keratocytes/KC-Keratocytes) compared to corneal fibroblasts. No differential expression of ROS-related genes was detected between healthy and diseased cells in both fibroblasts and keratocytes.

CONCLUSION

Increased expression of several inflammatory markers described as altered in KC was not evident in KC cells in vitro.

Corneal Morphological and Biomechanical Changes in Thyroid-Associated Ophthalmopathy

PURPOSE

This study aimed to evaluate corneal morphological and biomechanical changes in patients with thyroid-associated ophthalmopathy (TAO) and their correlations with activity and severity.

METHODS

Patients diagnosed with TAO were recruited and divided into groups by activity and severity. All subjects underwent a complete ophthalmic examination, including magnetic resonance imaging. Corneal topography was measured using a Pentacam device, and biomechanical parameters were obtained using a CorVis ST tonometer. Correlations among the corneal parameters, clinical activity score, and NOSPECS score were analyzed. Areas under the receiver operating characteristic curves were calculated to evaluate the diagnostic accuracy of corneal changes for active and severe TAO.

RESULTS

Fifty-three eyes with TAO and 16 healthy eyes were enrolled in our study. The back elevation, CorVis biomechanical index, tomographic and biomechanical index, stiffness parameter at the first applanation, deviation from normality in back elevation, relational thickness, and overall deviation from normality were significantly increased in patients with TAO (all P <0.05), whereas the smallest corneal thickness, maximum Ambrósio relational thickness, and deformation amplitude (DA) ratio were significantly decreased (all P <0.05). The clinical activity score was strongly positively correlated with back elevation (γ = 0.515, P <0.001). The NOSPECS score was strongly positively correlated with relational thickness and tomographic and biomechanical index (γ = 0.429 and 0.515, P <0.001) and negatively correlated with maximum Ambrósio relational thickness (γ = -0.53, P <0.001). Moreover, maximum Ambrósio relational thickness and the Ambrósio relational thickness through the horizontal meridian showed desirable diagnostic capacity in distinguishing mild TAO from moderate-severe TAO (areas under the receiver operating characteristic curve, 0.799 and 0.769).

CONCLUSIONS

Corneal morphological and biomechanical changes were found in patients with TAO, which might be related to the presence of inflammation. Measurements of corneal morphological and biomechanical parameters could serve as references in evaluating TAO.

Investigation of Potential Crucial Genes and Key Pathways in Keratoconus: An Analysis of Gene Expression Omnibus Data

Keratoconus is one of the most common causes leading to visual impairment in young adult population. The pathogenesis of keratoconus remains poorly understood. The aim of this study was to identify the potential key genes and pathways associated with keratoconus and to further analyze its molecular mechanism. Two RNA-sequencing datasets of keratoconus and paired normal corneal tissues from the Gene Expression Omnibus database were obtained. Differentially expressed genes (DEGs) were identified, and the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted. The protein-protein interaction (PPI) network of the DEGs was established, and the hub genes and significant gene modules of PPI were further constructed. Lastly, the GO and KEGG analyses of the hub gene were performed. In total, 548 common DEGs were identified. GO enrichment analysis showed that the DEGs were primarily associated with regulation of cell adhesion, the response to molecule of bacterial origin, lipopolysaccharide and biotic stimulus, collagen-containing extracellular matrix, extracellular matrix, and structure organization. KEGG pathway analysis showed that these DEGs were mainly involved in the TNF signaling pathway, IL-17 signaling pathway, Rheumatoid arthritis, Cytokine-cytokine receptor interaction. The PPI network was constructed with 146 nodes and 276 edges, and 3 significant modules are selected. Finally, top 10 hub genes were identified from the PPI network. The results revealed that extracellular matrix remodeling and immune inflammatory response could be the key links of keratoconus, TNF, IL6, IL1A, IL1B, CCL3, MMP3, MMP9, MMP1, and TGFB1 may be potential crucial genes, and TNF signaling pathway and IL-17 signaling pathway were the potential pathways accounting for pathogenesis and development of keratoconus.

Different mRNA expression patterns in keratoglobus and pellucid marginal degeneration keratocytes

PURPOSE

Alike keratoconus (KC), keratoglobus (KG) and pellucid marginal degeneration (PMD) belong to ectatic corneal diseases. While there are numerous studies on keratoconus pathophysiology, there is no exact knowledge on genetic and pathophysiological background of KG and PMD, so far. It is not yet clarified, whether KG and PMD are independent clinical entities or represent different stages of the same disease. Our purpose was to investigate key parameters concerning collagen synthesis, intracellular LOX expression and inflammation in corneal stromal cells of KG and PMD subjects, in vitro.

METHODS

Normal human keratocytes of corneas from the LIONS Cornea Bank Saar-Lor-Lux, Trier/Westpfalz and human keratocytes of KG and PMD patients were isolated and cultured as keratocytes. To examine Collagen I and V (Col I, Col V), heat shock protein 47 (Hsp47), Lysyl Oxidase (LOX), nuclear factor kappa B (NF-κB) mRNA and protein expression in all cell types, quantitative PCR and Western blot analysis has been performed.

RESULTS

Col5A1 mRNA expression was significantly lower in KG and PMD keratocytes and LOX mRNA expression was significantly higher in KG-keratocytes, compared to controls. Col1A1, Hsp47 and NF-κB mRNA expression and the analyzed protein expressions did not differ from controls, in KG or PMD.

CONCLUSIONS

Col5A1 mRNA expression is decreased in KG and PMD and LOX mRNA expression is increased in KG. Therefore, the pathophysiology of KG and PMD differs from KC and these seem to be from KC independent entities. The explanation of the peripheral corneal thinning in KG and PMD must be investigated in further studies.