scholarly journals Lower Fractions of TCF4 Transcripts Spanning over the CTG18.1 Trinucleotide Repeat in Human Corneal Endothelium

Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 2006
Author(s):  
Ida Maria Westin ◽  
Andreas Viberg ◽  
Berit Byström ◽  
Irina Golovleva
Keyword(s):  
Endothelial Cells ◽  
Corneal Endothelium ◽  
Trinucleotide Repeat ◽  
Late Onset ◽  
Corneal Dystrophy ◽  
Digital Pcr ◽  
Corneal Endothelial Cells ◽  
Transcription Start Sites ◽  
Gradual Loss ◽  
Transcription Factor 4

Fuchs’ endothelial corneal dystrophy (FECD) is a bilateral disease of the cornea caused by gradual loss of corneal endothelial cells. Late-onset FECD is strongly associated with the CTG18.1 trinucleotide repeat expansion in the Transcription Factor 4 gene (TCF4), which forms RNA nuclear foci in corneal endothelial cells. To date, 46 RefSeq transcripts of TCF4 are annotated by the National Center of Biotechnology information (NCBI), however the effect of the CTG18.1 expansion on expression of alternative TCF4 transcripts is not completely understood. To investigate this, we used droplet digital PCR for quantification of TCF4 transcripts spanning over the CTG18.1 and transcripts with transcription start sites immediately downstream of the CTG18.1. TCF4 expression was analysed in corneal endothelium and in whole blood of FECD patients with and without CTG18.1 expansion, in non-FECD controls without CTG18.1 expansion, and in five additional control tissues. Subtle changes in transcription levels in groups of TCF4 transcripts were detected. In corneal endothelium, we found a lower fraction of transcripts spanning over the CTG18.1 tract compared to all other tissues investigated.

scholarly journals Regulation of Oxidative Stress in Corneal Endothelial Cells by Prdx6

Antioxidants ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 180 ◽  
Author(s):  
Matthew Lovatt ◽  
Khadijah Adnan ◽  
Gary Peh ◽  
Jodhbir Mehta
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Corneal Endothelium ◽  
Corneal Dystrophy ◽  
The Body ◽  
Corneal Endothelial Cells ◽  
Functional Studies ◽  
Age Dependent ◽  
Cellular Integrity

The inner layer of the cornea, the corneal endothelium, is post-mitotic and unable to regenerate if damaged. The corneal endothelium is one of the most transplanted tissues in the body. Fuchs’ endothelial corneal dystrophy (FECD) is the leading indication for corneal endothelial transplantation. FECD is thought to be an age-dependent disorder, with a major component related to oxidative stress. Prdx6 is an antioxidant with particular affinity for repairing peroxidised cell membranes. To address the role of Prdx6 in corneal endothelial cells, we used a combination of biochemical and functional studies. Our data reveal that Prdx6 is expressed at unusually high levels at the plasma membrane of corneal endothelial cells. RNAi-mediated knockdown of Prdx6 revealed a role for Prdx6 in lipid peroxidation. Furthermore, following induction of oxidative stress with menadione, Prdx6-deficient cells had defective mitochondrial membrane potential and were more sensitive to cell death. These data reveal that Prdx6 is compartmentalised in corneal endothelial cells and has multiple functions to preserve cellular integrity.

scholarly journals Energy Shortage in Human and Mouse Models of SLC4A11-Associated Corneal Endothelial Dystrophies

2019 ◽  
Author(s):  
Wenlin Zhang ◽  
Ricardo Frausto ◽  
Doug D. Chung ◽  
Christopher G. Griffis ◽  
Liyo Kao ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Mitochondrial Dysfunction ◽  
Corneal Endothelium ◽  
Cell Metabolism ◽  
Corneal Dystrophy ◽  
Pcr Analysis ◽  
Corneal Endothelial Cells ◽  
Atp Production ◽  
Functional Changes ◽  
Molecular Events

PurposeTo elucidate the molecular events in solute carrier family 4 member 11 (SLC4A11)-deficient corneal endothelium that lead to the endothelial dysfunction that characterizes the dystrophies associated with SLC4A11 mutations, congenital hereditary endothelial dystrophy (CHED) and Fuchs endothelial corneal dystrophy 4.MethodsComparative transcriptomic analysis (CTA) was performed in primary human corneal endothelial cells (pHCEnC) and murine corneal endothelial cells (MCEnC) with normal and reduced levels of SLC4A11 (SLC4A11 KD pHCEnC) and Slc4a11 (Slc4a11−/− MCEnC), respectively. Validation of differentially expressed genes was performed using immunofluorescence staining of CHED corneal endothelium, as well as western blot and quantitative PCR analysis of SLC4A11 KD pHCEnC and Slc4a11−/− MCEnC. Functional analyses were performed to investigate potential functional changes associated with the observed transcriptomic alterations.ResultsCTA revealed inhibition of cell metabolism and ion transport function as well as mitochondrial dysfunction, leading to reduced adenosine triphosphate (ATP) production, in SLC4A11 KD pHCEnC and Slc4a11−/− MCEnC. Co-localization of SNARE protein STX17 with mitochondria marker COX4 was observed in CHED corneal endothelium, as was activation of AMPK–p53/ULK1 in both SLC4A11 KD pHCEnC and Slc4a11−/− MCEnC, providing additional evidence of mitochondrial dysfunction and mitophagy. Reduced Na+-dependent HCO3− transport activity and altered NH4Cl-induced membrane potential changes were observed in Slc4a11−/− MCEnC.ConclusionsReduced steady-state ATP levels and subsequent activation of the AMPK–p53 pathway provide a link between the metabolic functional deficit and transcriptome alterations, as well as evidence of insufficient ATP to maintain the Na+/K+-ATPase corneal endothelial pump as the cause of the edema that characterizes SLC4A11-associated corneal endothelial dystrophies.

scholarly journals Reversal of the Inflammatory Responses in Fabry Patient iPSC-Derived Cardiovascular Endothelial Cells by CRISPR/Cas9-Corrected Mutation

2021 ◽  
Vol 22 (5) ◽  
pp. 2381
Author(s):  
Hui-Yung Song ◽  
Yi-Ping Yang ◽  
Yueh Chien ◽  
Wei-Yi Lai ◽  
Yi-Ying Lin ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Inflammatory Responses ◽  
Late Onset ◽  
Critical Role ◽  
Vascular Complications ◽  
Digital Pcr ◽  
Mapk Signaling ◽  
Autophagic Flux ◽  
Fabry Patient ◽  
Genomic Editing

The late-onset type of Fabry disease (FD) with GLA IVS4 + 919G > A mutation has been shown to lead to cardiovascular dysfunctions. In order to eliminate variations in other aspects of the genetic background, we established the isogenic control of induced pluripotent stem cells (iPSCs) for the identification of the pathogenetic factors for FD phenotypes through CRISPR/Cas9 genomic editing. We adopted droplet digital PCR (ddPCR) to efficiently capture mutational events, thus enabling isolation of the corrected FD from FD-iPSCs. Both of these exhibited the characteristics of pluripotency and phenotypic plasticity, and they can be differentiated into endothelial cells (ECs). We demonstrated the phenotypic abnormalities in FD iPSC-derived ECs (FD-ECs), including intracellular Gb3 accumulation, autophagic flux impairment, and reactive oxygen species (ROS) production, and these abnormalities were rescued in isogenic control iPSC-derived ECs (corrected FD-ECs). Microarray profiling revealed that corrected FD-derived endothelial cells reversed the enrichment of genes in the pro-inflammatory pathway and validated the downregulation of NF-κB and the MAPK signaling pathway. Our findings highlighted the critical role of ECs in FD-associated vascular dysfunctions by establishing a reliable isogenic control and providing information on potential cellular targets to reduce the morbidity and mortality of FD patients with vascular complications.

scholarly journals Trinucleotide repeat expansion in the transcription factor 4 (TCF4) gene in Thai patients with Fuchs endothelial corneal dystrophy

Eye ◽  
2019 ◽  
Vol 34 (5) ◽  
pp. 880-885 ◽  
Author(s):  
Naoki Okumura ◽  
Vilavun Puangsricharern ◽  
Raina Jindasak ◽  
Noriko Koizumi ◽  
Yuya Komori ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Trinucleotide Repeat ◽  
Corneal Dystrophy ◽  
Repeat Expansion ◽  
Trinucleotide Repeat Expansion ◽  
Transcription Factor 4

scholarly journals Gene expression in the corneal endothelium of Fuchs endothelial corneal dystrophy patients with and without expansion of a trinucleotide repeat in TCF4

PLoS ONE ◽  
2018 ◽  
Vol 13 (7) ◽  
pp. e0200005 ◽  
Author(s):  
Eric D. Wieben ◽  
Ross A. Aleff ◽  
Xiaojia Tang ◽  
Krishna R. Kalari ◽  
Leo J. Maguire ◽  
...  
Keyword(s):  
Gene Expression ◽  
Corneal Endothelium ◽  
Trinucleotide Repeat ◽  
Corneal Dystrophy

scholarly journals The Fuchs corneal dystrophy-associated CTG repeat expansion in the TCF4 gene affects transcription from its alternative promoters

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Alex Sirp ◽  
Kristian Leite ◽  
Jürgen Tuvikene ◽  
Kaja Nurm ◽  
Mari Sepp ◽  
...  
Keyword(s):  
Transcription Initiation ◽  
Trinucleotide Repeat ◽  
Corneal Dystrophy ◽  
Protein Isoforms ◽  
Compensatory Mechanism ◽  
Alternative Promoters ◽  
Rna Seq ◽  
Increased Risk ◽  
Specific Manner ◽  
Transcription Factor 4

Abstract The CTG trinucleotide repeat (TNR) expansion in Transcription factor 4 (TCF4) intron 3 is the main cause of Fuchs’ endothelial corneal dystrophy (FECD) and may confer an increased risk of developing bipolar disorder (BD). Usage of alternative 5′ exons for transcribing the human TCF4 gene results in numerous TCF4 transcripts which encode for at least 18 N-terminally different protein isoforms that vary in their function and transactivation capability. Here we studied the TCF4 region containing the CTG TNR and characterized the transcription initiation sites of the nearby downstream 5′ exons 4a, 4b and 4c. We demonstrate that these exons are linked to alternative promoters and show that the CTG TNR expansion decreases the activity of the nearby downstream TCF4 promoters in primary cultured neurons. We confirm this finding using two RNA sequencing (RNA-seq) datasets of corneal endothelium from FECD patients with expanded CTG TNR in the TCF4 gene. Furthermore, we report an increase in the expression of various other TCF4 transcripts in FECD, possibly indicating a compensatory mechanism. We conclude that the CTG TNR affects TCF4 expression in a transcript-specific manner both in neurons and in the cornea.

scholarly journals The Effect of Phacoemulsification on Corneal Endothelial Cells Morphology and Thickness

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Abd Elaziz Mohamed Elmadina ◽  
Raghda Faisal Abdelfatah ◽  
Saif Hassan Alrasheed ◽  
Mustafa Abdu ◽  
Manzoor Ahmad Qureshi
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Density ◽  
Corneal Endothelium ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Endothelial Cell Density ◽  
P Value ◽  
Corneal Endothelial Cells ◽  
Before And After

Purpose:  To compare the corneal endothelial cells morphology and central corneal thickness (CCT) before and after phacoemulsification in Sudanese population. Place and Duration of Study:  Al-Neelain eye hospital, Khartoum, Sudan, from January 2018 to May 2018. Study Design:  Observational longitudinal study. Methods:  One hundred and forty eyes of 140 patients with immature senile cataract were selected by convenient sampling. The age ranged from 40 to 85 years. The patients underwent complete ocular examination including morphology of corneal endothelial cells and CCT using computerized non-contact specular microscope. Inclusion criteria for the study was eyes with normal corneal endothelial cells and cell density more than 1000 cells/mm2. We excluded patients with ocular or systemic diseases, previous history of intraocular surgery, refractive surgery or trauma as well as contact lenses wear. The patients underwent phacoemulsification by a single surgeon. The examination parameters were repeated one month after surgery. Descriptive and comparative statistical analyses were performed using SPSS for Windows Version 21.0. Results:  There was significant reduction in mean endothelial cells density after phacoemulsification compared to baseline with p < 0.001. There was also significant post-operative reduction in mean endothelial cells number as compared to baseline (P value < 0.001). Mean endothelial cells hexagonality was reduced after surgery with P value of 0.003. No significant difference was found between mean coefficient variation of endothelial cells size before and after phacoemulsification (P = 0.55). Central corneal thickness showed significant increase post-operatively, P = 0.003. Conclusion:  Phacoemulsification causes significant damage to corneal endothelium cells, including decrease in corneal endothelial cell density, hexagonality and cell number. Key Words:  Corneal endothelium, Endothelial cell density, Central corneal thickness, Phacoemulsification.

scholarly journals NAD+ precursors protect corneal endothelial cells from UVB-induced apoptosis

2020 ◽  
Vol 318 (4) ◽  
pp. C796-C805 ◽  
Author(s):  
Can Zhao ◽  
Wenjing Li ◽  
Haoyun Duan ◽  
Zongyi Li ◽  
Yanni Jia ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Apoptosis ◽  
Corneal Endothelium ◽  
Corneal Edema ◽  
Ultraviolet B ◽  
Subconjunctival Injection ◽  
Corneal Endothelial Cells ◽  
Nicotinamide Phosphoribosyltransferase ◽  
Mesenchymal Transition ◽  
Induced Apoptosis

Excessive exposure of the eye to ultraviolet B light (UVB) leads to corneal edema and opacification because of the apoptosis of the corneal endothelium. Our previous study found that nicotinamide (NIC), the precursor of nicotinamide adenine dinucleotide (NAD), could inhibit the endothelial-mesenchymal transition and accelerate healing the wound to the corneal endothelium in the rabbit. Here we hypothesize that NIC may possess the capacity to protect the cornea from UVB-induced endothelial apoptosis. Therefore, a mouse model and a cultured cell model were used to examine the effect of NAD+ precursors, including NIC, nicotinamide mononucleotide (NMN), and NAD, on the UVB-induced apoptosis of corneal endothelial cells (CECs). The results showed that UVB irradiation caused apparent corneal edema and cell apoptosis in mice, accompanied by reduced levels of NAD+ and its key biosynthesis enzyme, nicotinamide phosphoribosyltransferase (NAMPT), in the corneal endothelium. However, the subconjunctival injection of NIC, NMN, or NAD+ effectively prevented UVB-induced tissue damage and endothelial cell apoptosis in the mouse cornea. Moreover, pretreatment using NIC, NMN, and NAD+ increased the survival rate and inhibited the apoptosis of cultured human CECs irradiated by UVB. Mechanistically, pretreatment using nicotinamide (NIC) recovered the AKT activation level and decreased the BAX/BCL-2 ratio. In addition, the capacity of NIC to protect CECs was fully reversed in the presence of the AKT inhibitor LY294002. Therefore, we conclude that NAD+ precursors can effectively prevent the apoptosis of the corneal endothelium through reactivating AKT signaling; this represents a potential therapeutic approach for preventing UVB-induced corneal damage.

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