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

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.

Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 2006
Author(s):  
Ida Maria Westin ◽  
Andreas Viberg ◽  
Berit Byström ◽  
Irina Golovleva

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.


2000 ◽  
Vol 279 (5) ◽  
pp. C1648-C1655 ◽  
Author(s):  
Xing Cai Sun ◽  
Joseph A. Bonanno ◽  
Sergey Jelamskii ◽  
Qiang Xie

Functional studies support the presence of the Na+-HCO3 −cotransporter (NBC) in corneal endothelium and possibly corneal epithelium; however, molecular identification and membrane localization have not been reported. To test whether NBC is expressed in bovine cornea, Western blotting was performed, which showed a single band at ∼130 kDa for freshly isolated and cultured endothelial cells, but no band for epithelium. Two isoforms of NBC have recently been cloned in kidney (kNBC) and pancreas (pNBC). RT-PCR was run using cultured and fresh bovine corneal endothelial and fresh corneal epithelial total RNA and specific primers for kNBC and pNBC. RT-PCR analysis for pNBC was positive in endothelium and weak in epithelium. The RT-PCR product was subcloned and confirmed as pNBC by sequencing. No specific bands for kNBC were obtained from corneal cells. Indirect immunofluorescence and confocal microscopy indicated that NBC locates predominantly to the basolateral membrane in corneal endothelial cells. Furthermore, Na+-dependent HCO3 − fluxes and HCO3 −-dependent cotransport with Na+ were elicited only from the basolateral side of corneal endothelial cells. Therefore, we conclude that pNBC is present in the basolateral membrane of both fresh and cultured bovine corneal endothelium and weakly expressed in the corneal epithelium.


2019 ◽  
Author(s):  
Wenlin Zhang ◽  
Ricardo Frausto ◽  
Doug D. Chung ◽  
Christopher G. Griffis ◽  
Liyo Kao ◽  
...  

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.


Author(s):  
Anupama Chalimeswamy ◽  
Marasarakottige Yogananda Thanuja ◽  
Sudhir H. Ranganath ◽  
Kaveet Pandya ◽  
Uday B. Kompella ◽  
...  

Development ◽  
1971 ◽  
Vol 26 (3) ◽  
pp. 481-495
Author(s):  
Par Elisabeth Houssaint ◽  
Nicole Le Douarin

Cholinesterases in the chick liver. The role of the endoderm in the appearance of the activity of cholinesterases in the hepatic mesenchyme The histochemical method of Koelle & Friedenwald (1949), as modified by Gerebtzoff (1953), has been used to investigate the distribution of cholinesterases in the chick embryonic and adult liver. Non-specific cholinesterases and, in a lower proportion acetylcholinesterase, have been detected in the endothelial cells of blood sinusoids of both adult and embryonic hepatic tissue. The hepatocytes do not show any cholinesterase activity. Cholinesterases appear precociously in the liver mesenchyme, since they already occur in the septum transversum of the 3-day-old chick embryo. An experimental procedure preventing the invasion of the hepatic mesenchymal Anlage by the endodermic cords has been used. The experimentally isolated hepatic mesenchyme shows an important cholinesterase activity; therefore this activity does not depend on the presence of the hepatocytes. The grafting of the determined hepatic endodern in the somatopleura of the 3-day-old chick embryo results in the development of hepatic tissue in the body wall. In this experimentally produced liver, cholinesterase activities are present in the endothelial cells which have arisen from somatopleura mesenchymal cells, though normally somatopleural mesenchyme does not possess these enzymes. The role of the endoderm in the appearance of this enzymic activity in the somatopleural mesenchyme is discussed.


2007 ◽  
Vol 179 (4) ◽  
pp. 747-760 ◽  
Author(s):  
Angelika Kümin ◽  
Matthias Schäfer ◽  
Nikolas Epp ◽  
Philippe Bugnon ◽  
Christiane Born-Berclaz ◽  
...  

Peroxiredoxin 6 (Prdx6) is a cytoprotective enzyme with largely unknown in vivo functions. Here, we use Prdx6 knockout mice to determine its role in UV protection and wound healing. UV-mediated keratinocyte apoptosis is enhanced in Prdx6-deficient mice. Upon skin injury, we observe a severe hemorrhage in the granulation tissue of knockout animals, which correlates with the extent of oxidative stress. At the ultrastructural level endothelial cells appear highly damaged, and their rate of apoptosis is enhanced. Knock-down of Prdx6 in cultured endothelial cells also increases their susceptibility to oxidative stress, thus confirming the sensitivity of this cell type to loss of Prdx6. Wound healing studies in bone marrow chimeric mice demonstrate that Prdx6-deficient inflammatory and endothelial cells contribute to the hemorrhage phenotype. These results provide insight into the cross-talk between hematopoietic and resident cells at the wound site and the role of reactive oxygen species in this interplay.


2010 ◽  
Vol 24 (S1) ◽  
Author(s):  
Xinyu Wang ◽  
James Bynum ◽  
Salomon Stavchansky ◽  
Michael Dubick ◽  
Robert Hackman ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ovidiu-Dumitru Ilie ◽  
Emanuela Paduraru ◽  
Madalina-Andreea Robea ◽  
Ioana-Miruna Balmus ◽  
Roxana Jijie ◽  
...  

Background. As every organ within the body, the brain is also extremely susceptible to a plethora of noxious agents that change its chemistry. One component frequently found in current products against harmful species to crops is rotenone whose effect under prolonged exposure has been demonstrated to cause neurodegenerative disorders such as Parkinson’s disease. The latest reports have indeed revealed that rotenone promotes Parkinson’s in humans, but studies aiming to show congruent effects in zebrafish (Danio rerio) are lacking. Material and Methods. In this context, the aim of the present study was to demonstrate how chronic administration of rotenone for 3 weeks impairs the locomotor activity and sociability and induces oxidative stress in zebrafish. Results. There were no statistically significant differences following the analysis of their social interaction and locomotor tests ( p > 0.05 ). However, several exceptions have been noted in the control, rotenone, and probiotics groups when we compared their locomotor activity during the pretreatment and treatment interval ( p < 0.05 ). We further assessed the role of rotenone in disturbing the detoxifying system as represented by three enzymes known as superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA). Despite the fact that there were no statistically significant changes within SOD and GPx levels between the control group and rotenone, probiotics, and rotenone + probiotics ( p > 0.05 ), relevant changes have been observed between the analyzed groups ( p < 0.05 and p < 0.005 , respectively). On the other hand, significant differences ( p < 0.05 ) have been observed for MDA when we analyzed the data between the control group and the other three groups. Conclusions. Our results suggest that rotenone can be successfully used to trigger Parkinson’s disease-related symptomatology in zebrafish.


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