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Niksirat H, Siino V, Steinbach C, Levander F. The quantification of zebrafish ocular-associated proteins provides hints for sex-biased visual impairments and perception. Heliyon 2024; 10:e33057. [PMID: 38994070 PMCID: PMC11238053 DOI: 10.1016/j.heliyon.2024.e33057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 06/11/2024] [Accepted: 06/13/2024] [Indexed: 07/13/2024] Open
Abstract
Biochemical differences between sexes can also be seen in non-sexual organs and may affect organ functions and susceptibility to diseases. It has been shown that there are sex-biased visual perceptions and impairments. Abundance differences of eye proteins could provide explanations for some of these. Exploration of the ocular proteome was performed to find sex-based protein abundance differences in zebrafish Danio rerio. A label-free protein quantification workflow using high-resolution mass spectrometry was employed to find proteins with significant differences between the sexes. In total, 3740 unique master proteins were identified and quantified, and 49 proteins showed significant abundance differences between the eyes of male and female zebrafish. Those proteins belong to lipoproteins, immune system, blood coagulation, antioxidants, iron and heme-binding proteins, ion channels, pumps and exchangers, neuronal and photoreceptor proteins, and the cytoskeleton. An extensive literature review provided clues for the possible links between the sex-biased level of proteins and visual perception and impairments. In conclusion, sexual dimorphism at the protein level was discovered for the first time in the eye of zebrafish and should be accounted for in ophthalmological studies. Data are available via ProteomeXchange with identifier PXD033338.
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Affiliation(s)
- Hamid Niksirat
- Faculty of Fisheries and Protection of Waters, CENAKVA, University of South Bohemia in České Budějovice, Vodňany, Czech Republic
| | - Valentina Siino
- Department of Immunotechnology, Lund University, Lund, Sweden
| | - Christoph Steinbach
- Faculty of Fisheries and Protection of Waters, CENAKVA, University of South Bohemia in České Budějovice, Vodňany, Czech Republic
| | - Fredrik Levander
- Department of Immunotechnology, Lund University, Lund, Sweden
- National Bioinformatics Infrastructure Sweden (NBIS), Science for Life Laboratory, Lund University, Lund, Sweden
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2
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Yu HS, Hong EH, Kang JH, Lee YW, Lee WJ, Kang MH, Cho H, Shin YU, Seong M. Expression of microRNAs related to apoptosis in the aqueous humor and lens capsule of patients with glaucoma. Front Med (Lausanne) 2024; 11:1288854. [PMID: 38449883 PMCID: PMC10917207 DOI: 10.3389/fmed.2024.1288854] [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: 09/05/2023] [Accepted: 01/25/2024] [Indexed: 03/08/2024] Open
Abstract
Background The aim of this study is to investigate the expression profiles of microRNAs (miRNAs) related to apoptosis in the aqueous humor (AH) and lens capsule (LC) of patients with glaucoma. Methods AH and LC samples were collected from patients with open-angle glaucoma and control participants who were scheduled for cataract surgery. A miRNA PCR array comprising 84 miRNAs was used to analyze the AH (glaucoma, n = 3; control, n = 3) and LC samples (glaucoma, n = 3; control, n = 4). Additionally, the AH and LC samples (glaucoma, n = 3; control, n = 4) were subjected to quantitative real-time PCR to validate the differentially expressed miRNAs determined using the PCR array. Bioinformatics analysis was performed to identify the interactions between miRNAs and diseases. Additionally, the differential expression of these miRNAs and the target gene was validated through in vitro experiments using a retinal ganglion cell (RGC) model. Results Expression levels of 19 and 3 miRNAs were significantly upregulated in the AH and LC samples of the glaucoma group, respectively (p < 0.05). Of these, the expression levels of hsa-miR-193a-5p and hsa-miR-222-3p showed significant differences in both AH and LC samples. Bioinformatics analysis showed experimentally validated 8 miRNA:gene pairs. Among them, PTEN was selected to analyze the expression level in AH and LC from separate cohort (glaucoma, n = 5; control, n = 4). The result showed downregulation of PTEN concurrent with upregulation of the two miRNAs in LC samples of glaucoma group. In vitro experiments validated that the expression levels of hsa-miR-193a-5p and hsa-miR-222-3p were significantly upregulated, and that of PTEN was significantly downregulated in the H2O2-treated RGC, while the level of PTEN was recovered through co-treatment with miR-193a inhibitor or miR-222 inhibitor. Conclusion This is the first study to investigate the differential expression of apoptosis-related miRNAs in the AH and LC of patients with glaucoma. Hsa-miR-193a-5p and hsa-miR-222-3p, which were upregulated in both AH and LC, may be considered potential biomarkers for glaucoma.
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Affiliation(s)
- Hyo Seon Yu
- Department of Ophthalmology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Eun Hee Hong
- Department of Ophthalmology, Hanyang University College of Medicine, Seoul, Republic of Korea
- Department of Ophthalmology, Hanyang University Guri Hospital, Guri, Gyeonggi-do, Republic of Korea
- Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul, Republic of Korea
| | - Ji Hye Kang
- Department of Ophthalmology, Hanyang University College of Medicine, Seoul, Republic of Korea
- Graduate School of Biomedical Science & Engineering, Hanyang University, Seoul, Republic of Korea
| | - Yong Woo Lee
- Department of Ophthalmology, Kangwon National University Graduate School of Medicine, Kangwon National University Hospital, Chuncheon, Republic of Korea
| | - Won June Lee
- Department of Ophthalmology, Hanyang University College of Medicine, Seoul, Republic of Korea
- Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul, Republic of Korea
- Department of Ophthalmology, Hanyang University Hospital, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Min Ho Kang
- Department of Ophthalmology, Hanyang University College of Medicine, Seoul, Republic of Korea
- Department of Ophthalmology, Hanyang University Guri Hospital, Guri, Gyeonggi-do, Republic of Korea
| | - Heeyoon Cho
- Department of Ophthalmology, Hanyang University College of Medicine, Seoul, Republic of Korea
- Department of Ophthalmology, Hanyang University Guri Hospital, Guri, Gyeonggi-do, Republic of Korea
- NOON Eye Clinic, Guri, Gyeonggi-do, Republic of Korea
| | - Yong Un Shin
- Department of Ophthalmology, Hanyang University College of Medicine, Seoul, Republic of Korea
- Department of Ophthalmology, Hanyang University Guri Hospital, Guri, Gyeonggi-do, Republic of Korea
- Hanyang Institute of Bioscience and Biotechnology, Hanyang University, Seoul, Republic of Korea
| | - Mincheol Seong
- Department of Ophthalmology, Hanyang University College of Medicine, Seoul, Republic of Korea
- Department of Ophthalmology, Hanyang University Guri Hospital, Guri, Gyeonggi-do, Republic of Korea
- NOON Eye Clinic, Guri, Gyeonggi-do, Republic of Korea
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3
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Ng XY, Peh GSL, Yam GHF, Tay HG, Mehta JS. Corneal Endothelial-like Cells Derived from Induced Pluripotent Stem Cells for Cell Therapy. Int J Mol Sci 2023; 24:12433. [PMID: 37569804 PMCID: PMC10418878 DOI: 10.3390/ijms241512433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 08/13/2023] Open
Abstract
Corneal endothelial dysfunction is one of the leading causes of corneal blindness, and the current conventional treatment option is corneal transplantation using a cadaveric donor cornea. However, there is a global shortage of suitable donor graft material, necessitating the exploration of novel therapeutic approaches. A stem cell-based regenerative medicine approach using induced pluripotent stem cells (iPSCs) offers a promising solution, as they possess self-renewal capabilities, can be derived from adult somatic cells, and can be differentiated into all cell types including corneal endothelial cells (CECs). This review discusses the progress and challenges in developing protocols to induce iPSCs into CECs, focusing on the different media formulations used to differentiate iPSCs to neural crest cells (NCCs) and subsequently to CECs, as well as the characterization methods and markers that define iPSC-derived CECs. The hurdles and solutions for the clinical application of iPSC-derived cell therapy are also addressed, including the establishment of protocols that adhere to good manufacturing practice (GMP) guidelines. The potential risks of genetic mutations in iPSC-derived CECs associated with long-term in vitro culture and the danger of potential tumorigenicity following transplantation are evaluated. In all, this review provides insights into the advancement and obstacles of using iPSC in the treatment of corneal endothelial dysfunction.
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Affiliation(s)
- Xiao Yu Ng
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore; (X.Y.N.); (G.S.L.P.); (G.H.-F.Y.)
| | - Gary S. L. Peh
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore; (X.Y.N.); (G.S.L.P.); (G.H.-F.Y.)
- Ophthalmology and Visual Sciences Academic Clinical Program, SingHealth and Duke-NUS Medical School, Singapore 169857, Singapore;
| | - Gary Hin-Fai Yam
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore; (X.Y.N.); (G.S.L.P.); (G.H.-F.Y.)
- Corneal Regeneration Laboratory, Department of Ophthalmology, University of Pittsburgh, 6614, Pittsburgh, PA 15260, USA
| | - Hwee Goon Tay
- Ophthalmology and Visual Sciences Academic Clinical Program, SingHealth and Duke-NUS Medical School, Singapore 169857, Singapore;
- Centre for Vision Research, DUKE-NUS Medical School, Singapore 169857, Singapore
| | - Jodhbir S. Mehta
- Tissue Engineering and Cell Therapy Group, Singapore Eye Research Institute, Singapore 169856, Singapore; (X.Y.N.); (G.S.L.P.); (G.H.-F.Y.)
- Ophthalmology and Visual Sciences Academic Clinical Program, SingHealth and Duke-NUS Medical School, Singapore 169857, Singapore;
- Centre for Vision Research, DUKE-NUS Medical School, Singapore 169857, Singapore
- Department of Cornea and External Eye Disease, Singapore National Eye Centre, Singapore 168751, Singapore
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Ek-Vitorin JF, Shahidullah M, Lopez Rosales JE, Delamere NA. Patch clamp studies on TRPV4-dependent hemichannel activation in lens epithelium. Front Pharmacol 2023; 14:1101498. [PMID: 36909173 PMCID: PMC9998544 DOI: 10.3389/fphar.2023.1101498] [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: 11/17/2022] [Accepted: 02/06/2023] [Indexed: 02/26/2023] Open
Abstract
ATP release from the lens via hemichannels has been explained as a response to TRPV4 activation when the lens is subjected to osmotic swelling. To explore the apparent linkage between TRPV4 activation and connexin hemichannel opening we performed patch-clamp recordings on cultured mouse lens epithelial cells exposed to the TRPV4 agonist GSK1016790A (GSK) in the presence or absence of the TRPV4 antagonist HC067047 (HC). GSK was found to cause a fast, variable and generally large non-selective increase of whole cell membrane conductance evident as a larger membrane current (Im) over a wide voltage range. The response was prevented by HC. The GSK-induced Im increase was proportionally larger at negative voltages and coincided with fast depolarization and the simultaneous disappearance of an outward current, likely a K+ current. The presence of this outward current in control conditions appeared to be a reliable predictor of a cell's response to GSK treatment. In some studies, recordings were obtained from single cells by combining cell-attached and whole-cell patch clamp configurations. This approach revealed events with a channel conductance 180-270 pS following GSK application through the patch pipette on the cell-attached side. The findings are consistent with TRPV4-dependent opening of Cx43 hemichannels.
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Affiliation(s)
- Jose F Ek-Vitorin
- Department of Physiology, University of Arizona, Tucson, AZ, United States
| | - Mohammad Shahidullah
- Department of Physiology, University of Arizona, Tucson, AZ, United States.,Department of Ophthalmology and Vision Science, University of Arizona, Tucson, AZ, United States
| | | | - Nicholas A Delamere
- Department of Physiology, University of Arizona, Tucson, AZ, United States.,Department of Ophthalmology and Vision Science, University of Arizona, Tucson, AZ, United States
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5
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Role of Translationally Controlled Tumor Protein (TCTP) in the Development of Hypertension and Related Diseases in Mouse Models. Biomedicines 2022; 10:biomedicines10112722. [DOI: 10.3390/biomedicines10112722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 10/24/2022] [Accepted: 10/24/2022] [Indexed: 11/16/2022] Open
Abstract
Translationally controlled tumor protein (TCTP) is a multifunctional protein that plays a wide variety of physiological and pathological roles, including as a cytoplasmic repressor of Na,K-ATPase, an enzyme pivotal in maintaining Na+ and K+ ion gradients across the plasma membrane, by binding to and inhibiting Na,K-ATPase. Studies with transgenic mice overexpressing TCTP (TCTP-TG) revealed the pathophysiological significance of TCTP in the development of systemic arterial hypertension. Overexpression of TCTP and inhibition of Na,K-ATPase result in the elevation of cytoplasmic Ca2+ levels, which increases the vascular contractility in the mice, leading to hypertension. Furthermore, studies using an animal model constructed by multiple mating of TCTP-TG with apolipoprotein E knockout mice (ApoE KO) indicated that TCTP-induced hypertension facilitates the severity of atherosclerotic lesions in vivo. This review attempts to discuss the mechanisms underlying TCTP-induced hypertension and related diseases gleaned from studies using genetically altered animal models and the potential of TCTP as a target in the therapy of hypertension-related pathological conditions.
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Micun Z, Falkowska M, Młynarczyk M, Kochanowicz J, Socha K, Konopińska J. Levels of Trace Elements in the Lens, Aqueous Humour, and Plasma of Cataractous Patients-A Narrative Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:10376. [PMID: 36012010 PMCID: PMC9408557 DOI: 10.3390/ijerph191610376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 08/16/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
Cataracts are one of the most common causes of effective vision loss. Although most cases of cataracts are related to the ageing process, identifying modifiable risk factors can prevent their onset or progression. Many studies have suggested that micro and macroelement levels, not only in blood serum but also in the lens and aqueous humour, may affect the risk of the occurrence and severity of cataracts. This systematic review aims to summarise existing scientific reports concerning the importance of trace elements in cataractogenesis. Many authors have pointed out elevated or decreased levels of particular elements in distinct ocular compartments. However, it is not known if these alterations directly affect the increased risk of cataract occurrence. Further studies are needed to show whether changes in the levels of these elements are correlated with cataract severity and type. Such information would be useful for determining specific recommendations for micronutrient supplementation in preventing cataractogenesis.
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Affiliation(s)
- Zuzanna Micun
- Department of Ophthalmology, Medical University of Białystok, M. Skłodowskiej-Curie 24a, 15-276 Bialystok, Poland
| | - Martyna Falkowska
- Department of Bromatology, Faculty of Pharmacy with the Division of Laboratory Medicine, Medical University of Białystok, Mickiewicza 2D, 15-222 Bialystok, Poland
| | - Maryla Młynarczyk
- Department of Ophthalmology, Medical University of Białystok, M. Skłodowskiej-Curie 24a, 15-276 Bialystok, Poland
| | - Jan Kochanowicz
- Department of Neurology, Medical University of Bialystok, M. Skłodowskiej-Curie 24a, 15-276 Bialystok, Poland
| | - Katarzyna Socha
- Department of Bromatology, Faculty of Pharmacy with the Division of Laboratory Medicine, Medical University of Białystok, Mickiewicza 2D, 15-222 Bialystok, Poland
| | - Joanna Konopińska
- Department of Ophthalmology, Medical University of Białystok, M. Skłodowskiej-Curie 24a, 15-276 Bialystok, Poland
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Multi-Elemental Analysis of Human Optic Chiasm-A New Perspective to Reveal the Pathomechanism of Nerve Fibers' Degeneration. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19074420. [PMID: 35410100 PMCID: PMC8998695 DOI: 10.3390/ijerph19074420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 03/29/2022] [Accepted: 03/31/2022] [Indexed: 02/04/2023]
Abstract
The effect of metals on the functioning of the human eye is multifactorial and includes enzyme activity modulation, trace metal metabolic pathways changes, and cytotoxic activity. Functional dysfunctions appear mostly as a result of the accumulation of toxic xenobiotic metals or disturbances of micronutrients’ homeostasis. So far, the affinity of selected metals to eye tissues, i.e., the cornea, choroid, lens, and anterior chamber fluid, has been most studied. However, it is known that many eye symptoms are related to damage to the optic nerve. In order to fill this gap, the aim of the study is to perform a multi-element analysis of tissue collected postmortem from optic chiasm and optic nerves. A total of 178 samples from 107 subjects were tested. The concentrations of 51 elements were quantified by inductively coupled plasma mass spectrometry (ICP-MS) after the wet-mineralization step. In terms of elemental composition, the optic chiasm is dominated by two trace elements, i.e., iron (Fe) and zinc (Zn), besides macro-elements Ca, K, Na, P, and Mg. The subjects formed a homogeneous cluster (over 70% subjects) with the highest accumulation of aluminum (Al). The remaining two departing clusters were characterized by an increased content of most of the elements, including toxic elements such as bismuth (Bi), uranium (U), lead (Pb), chromium (Cr), and cadmium (Cd). Changes in elemental composition with age were analyzed statistically for the selected groups, i.e., females, males, and subjects with alcohol use disorder (AUD) and without AUD. A tendency of women to lose Se, Cu, Zn, Fe with age was observed, and a disturbed Ca/Mg, Na/K ratio in subjects with AUD. Although the observed trends were not statistically significant, they shed new light on the risks and possible pathologies associated with metal neurotoxicity in the visual tract.
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8
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Shi Y, Li X, Yang J. Mutations of CX46/CX50 and Cataract Development. Front Mol Biosci 2022; 9:842399. [PMID: 35223995 PMCID: PMC8874012 DOI: 10.3389/fmolb.2022.842399] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 01/12/2022] [Indexed: 12/24/2022] Open
Abstract
Cataract is a common disease in the aging population. Gap junction has been considered a central component in maintaining homeostasis for preventing cataract formation. Gap junction channels consist of connexin proteins with more than 20 members. Three genes including GJA1, GJA3, and GJA8, that encode protein Cx43 (connexin43), Cx46 (connexin46), and Cx50 (connexin50), respectively, have been identified in human and rodent lens. Cx46 together with Cx50 have been detected in lens fiber cells with high expression, whereas Cx43 is mainly expressed in lens epithelial cells. Disrupted expression of the two connexin proteins Cx46 and Cx50 is directly related to the development of severe cataract in human and mice. In this review article, we describe the main role of Cx46 and Cx50 connexin proteins in the lens and the relationship between mutations of Cx46 or Cx50 and hereditary cataracts. Furthermore, the latest progress in the fundamental research of lens connexin and the mechanism of cataract formation caused by lens connexin dysfunction are summarized. Overall, targeting connexin could be a novel approach for the treatment of cataract.
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Affiliation(s)
- Yumeng Shi
- Key Laboratory of Visual Impairment and Restoration of Shanghai, Department of Ophthalmology and Visual Science, Eye Ear Nose and Throat Hospital of Fudan University, Shanghai, China
| | - Xinbo Li
- Casey Eye Institute, Oregon Health and Science University, Portland, OR, United States
- *Correspondence: Jin Yang, ; Xinbo Li,
| | - Jin Yang
- Key Laboratory of Visual Impairment and Restoration of Shanghai, Department of Ophthalmology and Visual Science, Eye Ear Nose and Throat Hospital of Fudan University, Shanghai, China
- *Correspondence: Jin Yang, ; Xinbo Li,
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9
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Delamere NA, Shahidullah M. Ion Transport Regulation by TRPV4 and TRPV1 in Lens and Ciliary Epithelium. Front Physiol 2022; 12:834916. [PMID: 35173627 PMCID: PMC8841554 DOI: 10.3389/fphys.2021.834916] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 12/27/2021] [Indexed: 02/02/2023] Open
Abstract
Aside from a monolayer of epithelium at the anterior surface, the lens is formed by tightly compressed multilayers of fiber cells, most of which are highly differentiated and have a limited capacity for ion transport. Only the anterior monolayer of epithelial cells has high Na, K-ATPase activity. Because the cells are extensively coupled, the lens resembles a syncytium and sodium-potassium homeostasis of the entire structure is largely dependent on ion transport by the epithelium. Here we describe recent studies that suggest TRPV4 and TRPV1 ion channels activate signaling pathways that play an important role in matching epithelial ion transport activity with needs of the lens cell mass. A TRPV4 feedback loop senses swelling in the fiber mass and increases Na, K-ATPase activity to compensate. TRPV4 channel activation in the epithelium triggers opening of connexin hemichannels, allowing the release of ATP that stimulates purinergic receptors in the epithelium and results in the activation of Src family tyrosine kinases (SFKs) and SFK-dependent increase of Na, K-ATPase activity. A separate TRPV1 feedback loop senses shrinkage in the fiber mass and increases NKCC1 activity to compensate. TRPV1 activation causes calcium-dependent activation of a signaling cascade in the lens epithelium that involves PI3 kinase, ERK, Akt and WNK. TRPV4 and TRPV1 channels are also evident in the ciliary body where Na, K-ATPase is localized on one side of a bilayer in which two different cell types, non-pigmented and pigmented ciliary epithelium, function in a coordinated manner to secrete aqueous humor. TRPV4 and TRPV1 may have a role in maintenance of cell volume homeostasis as ions and water move through the bilayer.
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Hsueh YJ, Chen YN, Tsao YT, Cheng CM, Wu WC, Chen HC. The Pathomechanism, Antioxidant Biomarkers, and Treatment of Oxidative Stress-Related Eye Diseases. Int J Mol Sci 2022; 23:ijms23031255. [PMID: 35163178 PMCID: PMC8835903 DOI: 10.3390/ijms23031255] [Citation(s) in RCA: 53] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/20/2022] [Accepted: 01/21/2022] [Indexed: 12/13/2022] Open
Abstract
Oxidative stress is an important pathomechanism found in numerous ocular degenerative diseases. To provide a better understanding of the mechanism and treatment of oxidant/antioxidant imbalance-induced ocular diseases, this article summarizes and provides updates on the relevant research. We review the oxidative damage (e.g., lipid peroxidation, DNA lesions, autophagy, and apoptosis) that occurs in different areas of the eye (e.g., cornea, anterior chamber, lens, retina, and optic nerve). We then introduce the antioxidant mechanisms present in the eye, as well as the ocular diseases that occur as a result of antioxidant imbalances (e.g., keratoconus, cataracts, age-related macular degeneration, and glaucoma), the relevant antioxidant biomarkers, and the potential of predictive diagnostics. Finally, we discuss natural antioxidant therapies for oxidative stress-related ocular diseases.
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Affiliation(s)
- Yi-Jen Hsueh
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan 33305, Taiwan; (Y.-J.H.); (Y.-N.C.); (Y.-T.T.); (W.-C.W.)
- Center for Tissue Engineering, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan 33305, Taiwan
| | - Yen-Ning Chen
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan 33305, Taiwan; (Y.-J.H.); (Y.-N.C.); (Y.-T.T.); (W.-C.W.)
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan 33305, Taiwan
| | - Yu-Ting Tsao
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan 33305, Taiwan; (Y.-J.H.); (Y.-N.C.); (Y.-T.T.); (W.-C.W.)
| | - Chao-Min Cheng
- Institute of Biomedical Engineering, National Tsing Hua University, Hsinchu 30012, Taiwan;
| | - Wei-Chi Wu
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan 33305, Taiwan; (Y.-J.H.); (Y.-N.C.); (Y.-T.T.); (W.-C.W.)
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan 33305, Taiwan
| | - Hung-Chi Chen
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan 33305, Taiwan; (Y.-J.H.); (Y.-N.C.); (Y.-T.T.); (W.-C.W.)
- Center for Tissue Engineering, Chang Gung Memorial Hospital, Linkou Branch, Taoyuan 33305, Taiwan
- Department of Medicine, Chang Gung University College of Medicine, Taoyuan 33305, Taiwan
- Correspondence: ; Tel.: +886-3-328-1200 (ext. 7855); Fax: +886-3-328-7798
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11
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Andjelic S, Drašlar K, Hvala A, Hawlina M. Structural Characteristics of the Lens in Presenile Cataract. Front Med (Lausanne) 2021; 8:802275. [PMID: 35004779 PMCID: PMC8727346 DOI: 10.3389/fmed.2021.802275] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 11/23/2021] [Indexed: 11/13/2022] Open
Abstract
The purpose of this work is to examine the structure of the anterior lens epithelial cells (aLECs) of presenile idiopathic cortical cataract to investigate the possible structural reasons for its development. The anterior lens capsules (aLCs: basement membrane and associated lens epithelial cells) were obtained from routine uneventful cataract surgery of 5 presenile cataract patients (16 and 41 years old women and 29, 39, and 45 years old men). None of the patients had family history of cataract, medication, or trauma and they were otherwise healthy. In addition, the patients did not have any other abnormal features in the ocular status except cataract. The aLCs were prepared for scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The most prominent abnormal features observed by SEM for all 5 studied presenile cataract patients were the changes of the aLECs structure with the dents, the selective concavity of some LECs, at their apical side centrally toward the nucleus. In addition, TEM showed the thinning of the lens epithelium with the segmentally concave cells and the compressed and elongated nuclei. Abnormal and distinguishable structural features were observed in the anterior lens epithelium aLECs in all 5 patients with presenile cataract. Disturbed structure of aLECs, regularly present in presenile cataract type is shown that might be associated with water accumulation in the presenile idiopathic cortical cataract lens.
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Affiliation(s)
- Sofija Andjelic
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia
| | - Kazimir Drašlar
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Anastazija Hvala
- Department of Pathology, Medical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Marko Hawlina
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia
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12
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Flieger J, Dolar-Szczasny J, Rejdak R, Majerek D, Tatarczak-Michalewska M, Proch J, Blicharska E, Flieger W, Baj J, Niedzielski P. The Multi-Elemental Composition of the Aqueous Humor of Patients Undergoing Cataract Surgery, Suffering from Coexisting Diabetes, Hypertension, or Diabetic Retinopathy. Int J Mol Sci 2021; 22:ijms22179413. [PMID: 34502323 PMCID: PMC8430749 DOI: 10.3390/ijms22179413] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 08/23/2021] [Accepted: 08/26/2021] [Indexed: 11/25/2022] Open
Abstract
The aim of the study was the multi-elemental analysis of aqueous humor (AH) collected from patients undergoing cataract surgery. The study included: 16 patients with age-related macular degeneration AMD (99 controls), 10 patients with retinopathy (105 controls), 61 patients with hypertension (54 controls), and 33 patients with coexisting diabetes (82 controls). The control groups were recruited from patients with a lack of co-existing disease characterizing the specified studied group. The measurements were performed by the use of inductively coupled plasma optical emission spectrometry (ICP-OES). The statistical analysis was carried out using non-parametric testing (Mann–Whitney U). The level of significance was set at p = 0.05. The data obtained revealed substantial variations in elemental composition between the test groups in comparison to the controls. However, the significant variations concerned only a few elements. The phosphorous (P) level and the ratio of P/Ca were significant in retinopathy and diabetes, whereas cobalt (0.091 ± 0.107 mg/L vs. 0.031 ± 0.075 mg/L; p = 0.004) was significant in AMD. In co-existing hypertension, the levels of tin (0.293 ± 0.409 mg/L vs. 0.152 ± 0.3 mg/L; p = 0.031), titanium (0.096 ± 0.059 mg/L vs. 0.152 ± 0.192 mg/L; p = 0.045), and ruthenium (0.035 ± 0.109 mg/L vs. 0.002 ± 0.007 mg/L; p = 0.006) varied in comparison to the controls. The study revealed inter-elemental interactions. The correlation matrices demonstrated the domination of the positive correlations, whereas negative correlations mainly concerned sodium.
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Affiliation(s)
- Jolanta Flieger
- Department of Analytical Chemistry, Medical University of Lublin, Chodźki 4A, 20-093 Lublin, Poland; (M.T.-M.); (E.B.)
- Correspondence: ; Tel.: +48-81448-7182
| | - Joanna Dolar-Szczasny
- Department of General and Pediatric Ophthalmology, Medical University of Lublin, Chmielna 1, 20-079 Lublin, Poland; (J.D.-S.); (R.R.)
| | - Robert Rejdak
- Department of General and Pediatric Ophthalmology, Medical University of Lublin, Chmielna 1, 20-079 Lublin, Poland; (J.D.-S.); (R.R.)
| | - Dariusz Majerek
- Department of Applied Mathematics, University of Technology, Nadbystrzycka 38D, 20-618 Lublin, Poland;
| | | | - Jędrzej Proch
- Faculty of Chemistry, Department of Analytical Chemistry, Adam Mickiewicz University in Poznań, 89B Umultowska Street, 61-614 Poznań, Poland; (J.P.); (P.N.)
| | - Eliza Blicharska
- Department of Analytical Chemistry, Medical University of Lublin, Chodźki 4A, 20-093 Lublin, Poland; (M.T.-M.); (E.B.)
| | - Wojciech Flieger
- Department of Anatomy, Medical University of Lublin, 20-090 Lublin, Poland; (W.F.); (J.B.)
| | - Jacek Baj
- Department of Anatomy, Medical University of Lublin, 20-090 Lublin, Poland; (W.F.); (J.B.)
| | - Przemysław Niedzielski
- Faculty of Chemistry, Department of Analytical Chemistry, Adam Mickiewicz University in Poznań, 89B Umultowska Street, 61-614 Poznań, Poland; (J.P.); (P.N.)
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Cantrell LS, Schey KL. Proteomic characterization of the human lens and Cataractogenesis. Expert Rev Proteomics 2021; 18:119-135. [PMID: 33849365 DOI: 10.1080/14789450.2021.1913062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
INTRODUCTION The goal of this review is to highlight the triumphs and frontiers in measurement of the lens proteome as it relates to onset of age-related nuclear cataract. As global life expectancy increases, so too does the frequency of age-related nuclear cataracts. Molecular therapeutics do not exist for delay or relief of cataract onset in humans. Since lens fiber cells are incapable of protein synthesis after initial maturation, age-related changes in proteome composition and post-translational modification accumulation can be measured with various techniques. Several of these modifications have been associated with cataract onset. AREAS COVERED We discuss the impact of long-lived proteins on the lens proteome and lens homeostasis as well as proteomic techniques that may be used to measure proteomes at various levels of proteomic specificity and spatial resolution. EXPERT OPINION There is clear evidence that several proteome modifications are correlated with cataract formation. Past studies should be enhanced with cutting-edge, spatially resolved mass spectrometry techniques to enhance the specificity and sensitivity of modification detection as it relates to cataract formation.
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Affiliation(s)
- Lee S Cantrell
- Department of Biochemistry, Vanderbilt University, Nashville, TN, United States
| | - Kevin L Schey
- Department of Biochemistry, Vanderbilt University, Nashville, TN, United States
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14
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Delamere NA, Shahidullah M, Mathias RT, Gao J, Sun X, Sellitto C, White TW. Signaling Between TRPV1/TRPV4 and Intracellular Hydrostatic Pressure in the Mouse Lens. Invest Ophthalmol Vis Sci 2021; 61:58. [PMID: 32598448 PMCID: PMC7415899 DOI: 10.1167/iovs.61.6.58] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The lens uses feedback to maintain zero pressure in its surface cells. Positive pressures are detected by transient receptor potential vanilloid (TRPV4), which initiates a cascade that reduces surface cell osmolarity. The first step is opening of gap junction hemichannels. One purpose of the current study was to identify the connexin(s) in the hemichannels. Negative pressures are detected by TRPV1, which initiates a cascade that increases surface osmolarity. The increase in osmolarity was initially reported to be through inhibition of Na/K ATPase activity, but a recent study reported it was through stimulation of Na/K/2Cl (NKCC) cotransport. A second purpose of this study was to reconcile these two reports. Methods Intracellular hydrostatic pressures were measured using a microelectrode/manometer system. Lenses from TRPV1 or Cx50 null mice were studied. Specific inhibitors of Cx50 gap junction channels, NKCC, and Akt were used. Results Either knockout of Cx50 or blockade of Cx50 channels completely eliminated the response to positive surface pressures. Knockout of Cx50 also caused a positive drift in surface pressure. The short-term (∼20-minute) response to negative surface pressures was eliminated by blockade of NKCC, but a long-term (∼4-hour) response restored pressure to zero. Both short- and long-term responses were eliminated by knockout of TRPV1 or inhibition of Akt. Conclusions Hemichannels made from Cx50 are required for the response to positive surface pressures. Negative surface pressures first activate NKCC, but a backup system is inhibition of Na/K ATPase activity. Both responses are initiated by TRPV1 and go through PI3K/Akt before branching.
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15
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Kim JY, Park JH, Kang SS, Hwang SB, Tchah H. Topical nerve growth factor attenuates streptozotocin-induced diabetic cataracts via polyol pathway inhibition and Na +/K +-ATPase upregulation. Exp Eye Res 2020; 202:108319. [PMID: 33080303 DOI: 10.1016/j.exer.2020.108319] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 09/16/2020] [Accepted: 10/15/2020] [Indexed: 11/17/2022]
Abstract
The purpose of this study was to investigate whether and how topical nerve growth factor (NGF) attenuates streptozotocin (STZ)-induced diabetic cataracts in vivo. Rats were randomly divided into three groups, including the normal control rat group, STZ-induced diabetic cataract rat group (DM group), and STZ-induced diabetic cataract rat group treated with 200 μg/mL recombinant rat β-NGF (DM + NGF group). Cataract formation was evaluated by portable slit lamp biomicroscopy following pupil dilation at 8 weeks. The expression levels of NGF, aldose reductase (AR), and Na+/K+-ATPase in the lens epithelial cells (LECs) of the three groups were measured in the presence or absence of topical NGF. TUNEL-positive LECs were quantified to determine if hyperglycemia caused LEC apoptosis. At 8 weeks, the mean cataract score in the control group was significantly lower than that in DM and DM + NGF groups, and the score in the DM + NGF group was significantly lower than that in the DM group. At the equatorial zone and anterior central zone of lens, NGF and Na+/K+-ATPase expression levels were significantly decreased in the DM group; however, they were partially restored in the DM + NGF group. At the equatorial zone and anterior central zone of lens, AR expression and TUNEL-positive apoptotic LECs were significantly increased in the DM group compared with the control group, however, they were significantly decreased in the DM + NGF group. In conclusion, topical NGF could delay the progression of diabetic cataracts by attenuating polyol pathway activation and increasing Na+/K+-ATPase protein levels.
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Affiliation(s)
- Jae Yong Kim
- Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea; Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
| | - Jin Hyoung Park
- Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea; Miso Eye Clinic, Seoul, Republic of Korea
| | - Soon-Suk Kang
- Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea
| | - Sae-Byeok Hwang
- Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea; Miso Eye Clinic, Seoul, Republic of Korea
| | - Hungwon Tchah
- Research Institute for Biomacromolecules, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea; Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Republic of Korea.
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16
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Koç Ş, Baysal SS. Practical Method for Salt Intake Follow-Up in Hypertensive Patients. Metab Syndr Relat Disord 2020; 18:353-361. [PMID: 32580624 DOI: 10.1089/met.2020.0036] [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] [Indexed: 11/12/2022] Open
Abstract
Background: Obese and hypertensive (HT) patients should restrict salt intake. In excessive salt intake, ouabain-like compounds inhibit Na/K-ATPase (Na+ pump), which increases intracellular Na+ and Ca2+. Ca2+ has a vasotonic effect on arteries and an inotropic effect on the heart and may cause cortical opacities in the lens. To our knowledge, there is still no practical method for salt intake follow-up. This study tested whether salt intake follow-up can be performed with the help of opacity tracking. Methods: In total, 400 HT patients (age 30-69 years) with cortical lens opacities were included in the study. Changes in opacities based on biomicroscopic examination at baseline and after 3 months were recorded digitally with the help of imaging software. Salt intake at 1 and 3 months was evaluated with a 24-hr urine Na assay. Changes in opacities were compared among group 1 (∼50% salt reduction), group 2 (∼10% salt reduction), and group 3 (∼15% salt increase). Results: Age and changes in small opacity diameter (SOD) and large opacity diameter (LOD) were the most important determinants of the 50% salt reduction in the third month. For changes in LOD, the sensitivity was 88.5% [confidence interval (95% CI) 85.2-91.7] and specificity was 95.5% (95% CI 93.1-98.7) for predicting a 50% salt restriction during the 3-month period. For SOD, the values were 85% (95% CI 82.5-87) and 95% (95% CI 92.3-97.5), respectively. Conclusions: Opacity changes are a practical method for predicting a 50% reduction in salt intake over a 3-month period in 30- to 59-year-old HT patients.
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Affiliation(s)
- Şahbender Koç
- Department of Cardiology, University of Health Sciences. Keçiören Education and Training Hospital, Ankara, Turkey
| | - Sadettin Selçuk Baysal
- Department of Cardiology, University of Health Sciences, Şanlıurfa Mehmet Akif İnan Education and Training Hospital, Urfa, Turkey
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17
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Chen Y, Gao J, Li L, Sellitto C, Mathias RT, Donaldson PJ, White TW. The Ciliary Muscle and Zonules of Zinn Modulate Lens Intracellular Hydrostatic Pressure Through Transient Receptor Potential Vanilloid Channels. Invest Ophthalmol Vis Sci 2020; 60:4416-4424. [PMID: 31639828 PMCID: PMC6808041 DOI: 10.1167/iovs.19-27794] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose Lenses have an intracellular hydrostatic pressure gradient to drive fluid from central fiber cells to surface epithelial cells. Pressure is regulated by a feedback control system that relies on transient receptor potential vanilloid (TRPV)1 and TRPV4 channels. The ciliary muscle transmits tension to the lens through the zonules of Zinn. Here, we have examined if ciliary muscle tension influenced the lens intracellular hydrostatic pressure gradient. Methods We measured the ciliary body position and intracellular hydrostatic pressures in mouse lenses while pharmacologically causing relaxation or contraction of the ciliary muscle. We also used inhibitors of TRPV1 and TRPV4, in addition to phosphoinositide 3-kinase (PI3K) p110α knockout mice and immunostaining of phosphorylated protein kinase B (Akt), to determine how changes in ciliary muscle tension resulted in altered hydrostatic pressure. Results Ciliary muscle relaxation increased the distance between the ciliary body and the lens and caused a decrease in intracellular hydrostatic pressure that was dependent on intact zonules and could be blocked by inhibition of TRPV4. Ciliary contraction moved the ciliary body toward the lens and caused an increase in intracellular hydrostatic pressure and Akt phosphorylation that required intact zonules and was blocked by either inhibition of TRPV1 or genetic deletion of the p110α catalytic subunit of PI3K. Conclusions These results show that the hydrostatic pressure gradient within the lens was influenced by the tension exerted on the lens by the ciliary muscle through the zonules of Zinn. Modulation of the gradient of intracellular hydrostatic pressure in the lens could alter the water content, and the gradient of refractive index.
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Affiliation(s)
- Yadi Chen
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Junyuan Gao
- Renaissance Department of Physiology and Biophysics, Stony Brook University School of Medicine, Stony Brook, New York, United States
| | - Leping Li
- Renaissance Department of Physiology and Biophysics, Stony Brook University School of Medicine, Stony Brook, New York, United States
| | - Caterina Sellitto
- Renaissance Department of Physiology and Biophysics, Stony Brook University School of Medicine, Stony Brook, New York, United States
| | - Richard T Mathias
- Renaissance Department of Physiology and Biophysics, Stony Brook University School of Medicine, Stony Brook, New York, United States
| | - Paul J Donaldson
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | - Thomas W White
- Renaissance Department of Physiology and Biophysics, Stony Brook University School of Medicine, Stony Brook, New York, United States
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18
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Anbukkarasi M, Thomas PA, Teresa PA, Anand T, Geraldine P. Comparison of the efficacy of a Tabernaemontana divaricata extract and of biosynthesized silver nanoparticles in preventing cataract formation in an in-vivo system of selenite-induced cataractogenesis. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2019.101475] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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19
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Waugh DT. The Contribution of Fluoride to the Pathogenesis of Eye Diseases: Molecular Mechanisms and Implications for Public Health. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:E856. [PMID: 30857240 PMCID: PMC6427526 DOI: 10.3390/ijerph16050856] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 03/04/2019] [Accepted: 03/05/2019] [Indexed: 12/18/2022]
Abstract
This study provides diverse lines of evidence demonstrating that fluoride (F) exposure contributes to degenerative eye diseases by stimulating or inhibiting biological pathways associated with the pathogenesis of cataract, age-related macular degeneration and glaucoma. As elucidated in this study, F exerts this effect by inhibiting enolase, τ-crystallin, Hsp40, Na⁺, K⁺-ATPase, Nrf2, γ -GCS, HO-1 Bcl-2, FoxO1, SOD, PON-1 and glutathione activity, and upregulating NF-κB, IL-6, AGEs, HsP27 and Hsp70 expression. Moreover, F exposure leads to enhanced oxidative stress and impaired antioxidant activity. Based on the evidence presented in this study, it can be concluded that F exposure may be added to the list of identifiable risk factors associated with pathogenesis of degenerative eye diseases. The broader impact of these findings suggests that reducing F intake may lead to an overall reduction in the modifiable risk factors associated with degenerative eye diseases. Further studies are required to examine this association and determine differences in prevalence rates amongst fluoridated and non-fluoridated communities, taking into consideration other dietary sources of F such as tea. Finally, the findings of this study elucidate molecular pathways associated with F exposure that may suggest a possible association between F exposure and other inflammatory diseases. Further studies are also warranted to examine these associations.
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Affiliation(s)
- Declan Timothy Waugh
- EnviroManagement Services, 11 Riverview, Doherty's Rd, Bandon, P72 YF10 Co. Cork, Ireland.
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Some Biological Consequences of the Inhibition of Na,K-ATPase by Translationally Controlled Tumor Protein (TCTP). Int J Mol Sci 2018; 19:ijms19061657. [PMID: 29867020 PMCID: PMC6032315 DOI: 10.3390/ijms19061657] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 05/29/2018] [Accepted: 05/30/2018] [Indexed: 12/17/2022] Open
Abstract
Na,K-ATPase is an ionic pump that regulates the osmotic equilibrium and membrane potential of cells and also functions as a signal transducer. The interaction of Na,K-ATPase with translationally controlled tumor protein (TCTP) results, among others, in the inhibition of the former's pump activity and in the initiation of manifold biological and pathological phenomena. These phenomena include hypertension and cataract development in TCTP-overexpressing transgenic mice, as well as the induction of tumorigenesis signaling pathways and the activation of Src that ultimately leads to cell proliferation and migration. This review attempts to collate the biological effects of Na,K-ATPase and TCTP interaction and suggests that this interaction has the potential to serve as a possible therapeutic target for selected diseases.
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Inanc M, Tekin K, Erol YO, Sargon MF, Koc M, Budakoglu O, Yılmazbas P. The ultrastructural alterations in the lens capsule and epithelium in eyes with traumatic white cataract. Int Ophthalmol 2017; 39:47-53. [PMID: 29189944 DOI: 10.1007/s10792-017-0783-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 11/24/2017] [Indexed: 11/25/2022]
Abstract
PURPOSE To demonstrate the morphological and physiological characteristics of lens epithelial cells (LECs) in patients with traumatic cataract using transmission electron microscopy (TEM) to further understand penetrating ocular injury-induced cataract morphology and epithelial repair mechanisms involved at a cellular level. METHODS This is a prospective international study. Sixteen eyes of 16 consecutive patients who were diagnosed as traumatic white cataracts following the anterior lens capsule perforation and 13 eyes of 13 patients with idiopathic posterior subcapsular cataract were included to the study. The anterior lens capsules (aLCs: basement membrane and associated LECs) were obtained from cataract surgery and prepared for TEM. RESULTS Two prominent cell types were observed in all aLCs of the traumatic cases: degenerated type LECs having variable sized intraepithelial vacuoles close to injury site and normal appearing LECs having an euchromatic nucleus distant from the injury site. In control group, the LECs and all their elements were in normal ultrastructural pattern except some small intraepithelial vacuoles, which were fewer and smaller than the vacuoles in the degenerated LECs of the traumatic group. CONCLUSIONS The ultrastructural findings of our cases support that traumatically induced dysfunction of the lens epithelium may lead to an edema in superficial cortical lens fibers that subsequently undergo degeneration and produce a localized zone of vacuolization.
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Affiliation(s)
- Merve Inanc
- Ankara Ulucanlar Eye Training and Research Hospital, Ankara, 06240, Turkey.
| | | | | | | | - Mustafa Koc
- Ankara Ulucanlar Eye Training and Research Hospital, Ankara, 06240, Turkey
| | - Ozlem Budakoglu
- Ankara Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
| | - Pelin Yılmazbas
- Ankara Ulucanlar Eye Training and Research Hospital, Ankara, Turkey
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22
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Anterior lens capsule and epithelium thickness measurements using spectral-domain optical coherence tomography. BMC Ophthalmol 2017. [PMID: 28629391 PMCID: PMC5477114 DOI: 10.1186/s12886-017-0489-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Background To investigate the anterior lens capsule and epithelium thickness (defined as anterior lens capsular complex: ALCC) in normal Chinese subjects using spectral-domian optical coherence tomography (SD-OCT) and examine the factors that may influence the ALCC, such as age, gender, pupil diameter (PD) and signal strength index (SSI). Methods A prospective observational case series. One-hundred-thirty-four normal subjects (134 eyes) were included. The ALCCs were determined manually via SD-OCT. Using the pupil center as a reference position, the central ALCC (CALCC), nasal 1-mm ALCC (NALCC), temporal 1-mm ALCC (TALCC) and PD were measured manually. Results The mean CALCC, NALCC and TALCC were 33 ± 6 μm, 36 ± 7 μm and 34 ± 6 μm, respectively. The NALCC was significantly thicker than the CALCC (P < .001) and TALCC (P < .001). Moreover, CALCC was significantly thinner than TALCC (P = 0.013). Age was positively correlated with the CALCC (r = 0.292, P < .001), NALCC (r = 0.400, P < .001) and TALCC (r = 0.521, P < .001). PD, gender and SSI were not significantly correlated with the three ALCC parameters. Conclusions The SD-OCT can be used to demonstrate the ALCC thickness, and age is positively correlated with the ALCC in the central, nasal and temporal sides.
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Andjelic S, Drašlar K, Hvala A, Hawlina M. Anterior lens epithelium in cataract patients with retinitis pigmentosa - scanning and transmission electron microscopy study. Acta Ophthalmol 2017; 95:e212-e220. [PMID: 27679403 DOI: 10.1111/aos.13250] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 07/31/2016] [Indexed: 01/21/2023]
Abstract
PURPOSE In retinitis pigmentosa (RP) patients, relatively minor lens opacity in central part of posterior pole of the lens may cause disproportionate functional symptoms requiring cataract operation. To investigate the possible structural reasons for this opacity development, we studied the structure of the lens epithelium of patients with RP. METHODS The anterior lens capsule (aLC: basement membrane and associated lens epithelial cells, LECs) was obtained from cataract surgery and prepared for scanning and transmission electron microscopy (SEM and TEM). RESULTS Both SEM and TEM show a number of abnormal features in the anterior lens epithelium of cataract patients with RP. The abnormalities appear mainly as holes, thinning and degradation of the epithelium, with the dimensions from <1 μm to more than 50 μm. Other types of holes in size up to 20 μm were seen that may be formed by gradual stretching of the lens epithelium. Another type of abnormalities was cracks that were seen between adjacent LECs, with dimensions 0.1-2 μm × up to 10 μm. CONCLUSIONS Abnormal structural features were observed in the anterior lens epithelium that may cause water influx into the lens. This may lead to clouding along the water clefts leading towards the posterior pole in the RP cataractous lens. We suggest that the lens epithelium has a role in the development of the cataract in patients with RP.
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Affiliation(s)
| | - Kazimir Drašlar
- Department of Biology; Biotechnical Faculty; University of Ljubljana; Ljubljana Slovenia
| | - Anastazija Hvala
- Department of Pathology; Medical Faculty; University of Ljubljana; Ljubljana Slovenia
| | - Marko Hawlina
- Eye Hospital; University Medical Centre; Ljubljana Slovenia
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Kota S, Govada VR, Anantha RK, Verma MK. An Investigation into phytochemical constituents, antioxidant, antibacterial and anti-cataract activity of Alternanthera sessilis, a predominant wild leafy vegetable of South India. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2017. [DOI: 10.1016/j.bcab.2017.03.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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25
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Abdul Nasir NA, Agarwal R, Sheikh Abdul Kadir SH, Vasudevan S, Tripathy M, Iezhitsa I, Mohammad Daher A, Ibrahim MI, Mohd Ismail N. Reduction of oxidative-nitrosative stress underlies anticataract effect of topically applied tocotrienol in streptozotocin-induced diabetic rats. PLoS One 2017; 12:e0174542. [PMID: 28350848 PMCID: PMC5370128 DOI: 10.1371/journal.pone.0174542] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2016] [Accepted: 03/10/2017] [Indexed: 02/07/2023] Open
Abstract
Cataract, a leading cause of blindness, is of special concern in diabetics as it occurs at earlier onset. Polyol accumulation and increased oxidative-nitrosative stress in cataractogenesis are associated with NFκB activation, iNOS expression, ATP depletion, loss of ATPase functions, calpain activation and proteolysis of soluble to insoluble proteins. Tocotrienol was previously shown to reduce lens oxidative stress and inhibit cataractogenesis in galactose-fed rats. In current study, we investigated anticataract effects of topical tocotrienol and possible mechanisms involved in streptozotocin-induced diabetic rats. Diabetes was induced in Sprague Dawley rats by intraperitoneal injection of streptozotocin. Diabetic rats were treated with vehicle (DV) or tocotrienol (DT). A third group consists of normal, non-diabetic rats were treated with vehicle (NV). All treatments were given topically, bilaterally, twice daily for 8 weeks with weekly slit lamp monitoring. Subsequently, rats were euthanized and lenses were subjected to estimation of polyol accumulation, oxidative-nitrosative stress, NFκB activation, iNOS expression, ATP levels, ATPase activities, calpain activity and total protein levels. Cataract progression was delayed from the fifth week onwards in DT with lower mean of cataract stages compared to DV group (p<0.01) despite persistent hyperglycemia. Reduced cataractogenesis in DT group was accompanied with lower aldose reductase activity and sorbitol level compared to DV group (p<0.01). DT group also showed reduced NFκB activation, lower iNOS expression and reduced oxidative-nitrosative stress compared to DV group. Lenticular ATP and ATPase and calpain 2 activities in DT group were restored to normal. Consequently, soluble to insoluble protein ratio in DT group was higher compared to DV (p<0.05). In conclusion, preventive effect of topical tocotrienol on development of cataract in STZ-induced diabetic rats could be attributed to reduced lens aldose reductase activity, polyol levels and oxidative-nitrosative stress. These effects of tocotrienol invlove reduced NFκB activation, lower iNOS expression, restoration of ATP level, ATPase activities, calpain activity and lens protein levels.
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Affiliation(s)
- Nurul Alimah Abdul Nasir
- Center for Neuroscience Research, Faculty of Medicine, Universiti Teknologi MARA Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
- * E-mail:
| | - Renu Agarwal
- Center for Neuroscience Research, Faculty of Medicine, Universiti Teknologi MARA Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Siti Hamimah Sheikh Abdul Kadir
- Center for Neuroscience Research, Faculty of Medicine, Universiti Teknologi MARA Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Sushil Vasudevan
- Center for Neuroscience Research, Faculty of Medicine, Universiti Teknologi MARA Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Minaketan Tripathy
- Faculty of Pharmacy, Universiti Teknologi MARA Puncak Alam Campus, Puncak Alam, Selangor, Malaysia
| | - Igor Iezhitsa
- Center for Neuroscience Research, Faculty of Medicine, Universiti Teknologi MARA Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
- Research Institute of Pharmacology, Volgograd State Medical University, Volgograd, Russia
| | - Aqil Mohammad Daher
- Department of Community Medicine, Faculty of Medicine and Defence Health, National Defence University of Malaysia, Sungai Besi Camp, Kuala Lumpur, Malaysia
| | - Mohd Ikraam Ibrahim
- Center for Neuroscience Research, Faculty of Medicine, Universiti Teknologi MARA Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
| | - Nafeeza Mohd Ismail
- Center for Neuroscience Research, Faculty of Medicine, Universiti Teknologi MARA Sungai Buloh Campus, Sungai Buloh, Selangor, Malaysia
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Uldall M, Bhatt DK, Kruuse C, Juhler M, Jansen-Olesen I, Jensen RH. Choroid plexus aquaporin 1 and intracranial pressure are increased in obese rats: towards an idiopathic intracranial hypertension model? Int J Obes (Lond) 2017; 41:1141-1147. [PMID: 28344346 DOI: 10.1038/ijo.2017.83] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 02/03/2017] [Accepted: 03/06/2017] [Indexed: 01/03/2023]
Abstract
BACKGROUND/OBJECTIVES Idiopathic intracranial hypertension (IIH) is a condition of increased intracranial pressure (ICP) without identifiable cause. The majority of IIH patients are obese, which suggests a connection between ICP and obesity. The aim of the study was to compare ICP in lean and obese rats. We also aimed to clarify if any ICP difference could be attributed to changes in some well-known ICP modulators; retinol and arterial partial pressure of CO2 (pCO2). Another potential explanation could be differences in water transport across the choroid plexus (CP) epithelia, and thus we furthermore investigated expression profiles of aquaporin 1 (AQP1) and Na/K ATPase. METHODS ICP was measured in obese and lean Zucker rats over a period of 28 days. Arterial pCO2 and serum retinol were measured in serum samples. The CPs were isolated, and target messenger RNA (mRNA) and protein were analyzed by quantitative PCR and western blot, respectively. RESULTS Obese rats had elevated ICP compared to lean controls on all recording days except day 0 (P<0.001). Serum retinol (P=0.35) and arterial pCO2 (P=0.16) did not differ between the two groups. Both AQP1 mRNA and protein levels were increased in the CP of the obese rats compared to lean rats (P=0.0422 and P=0.0281). There was no difference in Na/K ATPase mRNA or protein levels (P=0.2688 and P=0.1304). CONCLUSION Obese Zucker rats display intracranial hypertension and increased AQP1 expression in CP compared to lean controls. The mechanisms behind these changes are still unknown, but appear to be unrelated to altered pCO2 levels or retinol metabolism. This indicates that the increase in ICP might be related to increased AQP1 levels in CP. Although further studies are warranted, obese Zucker rats could potentially model some aspects of the IIH pathophysiology.
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Affiliation(s)
- M Uldall
- Department of Neurology, Danish Headache Center, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark.,Glostrup Research Institute, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
| | - D K Bhatt
- Department of Neurology, Danish Headache Center, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark.,Glostrup Research Institute, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
| | - C Kruuse
- Department of Neurology, Neurovascular Research Unit, Herlev Hospital, University of Copenhagen, Herlev, Denmark
| | - M Juhler
- Department of Neurosurgery, Rigshospitalet Blegdamsvej, University of Copenhagen, Copenhagen, Denmark
| | - I Jansen-Olesen
- Department of Neurology, Danish Headache Center, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark.,Glostrup Research Institute, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
| | - R H Jensen
- Department of Neurology, Danish Headache Center, Rigshospitalet Glostrup, University of Copenhagen, Glostrup, Denmark
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Donaldson PJ, Grey AC, Maceo Heilman B, Lim JC, Vaghefi E. The physiological optics of the lens. Prog Retin Eye Res 2017; 56:e1-e24. [DOI: 10.1016/j.preteyeres.2016.09.002] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Revised: 09/09/2016] [Accepted: 09/13/2016] [Indexed: 11/17/2022]
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Gao J, Sun X, White TW, Delamere NA, Mathias RT. Feedback Regulation of Intracellular Hydrostatic Pressure in Surface Cells of the Lens. Biophys J 2016; 109:1830-9. [PMID: 26536260 DOI: 10.1016/j.bpj.2015.09.018] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 09/08/2015] [Accepted: 09/16/2015] [Indexed: 10/22/2022] Open
Abstract
In wild-type lenses from various species, an intracellular hydrostatic pressure gradient goes from ∼340 mmHg in central fiber cells to 0 mmHg in surface cells. This gradient drives a center-to-surface flow of intracellular fluid. In lenses in which gap-junction coupling is increased, the central pressure is lower, whereas if gap-junction coupling is reduced, the central pressure is higher but surface pressure is always zero. Recently, we found that surface cell pressure was elevated in PTEN null lenses. This suggested disruption of a feedback control system that normally maintained zero surface cell pressure. Our purpose in this study was to investigate and characterize this feedback control system. We measured intracellular hydrostatic pressures in mouse lenses using a microelectrode/manometer-based system. We found that all feedback went through transport by the Na/K ATPase, which adjusted surface cell osmolarity such that pressure was maintained at zero. We traced the regulation of Na/K ATPase activity back to either TRPV4, which sensed positive pressure and stimulated activity, or TRPV1, which sensed negative pressure and inhibited activity. The inhibitory effect of TRPV1 on Na/K pumps was shown to signal through activation of the PI3K/AKT axis. The stimulatory effect of TRPV4 was shown in previous studies to go through a different signal transduction path. Thus, there is a local two-legged feedback control system for pressure in lens surface cells. The surface pressure provides a pedestal on which the pressure gradient sits, so surface pressure determines the absolute value of pressure at each radial location. We speculate that the absolute value of intracellular pressure may set the radial gradient in the refractive index, which is essential for visual acuity.
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Affiliation(s)
- Junyuan Gao
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York
| | - Xiurong Sun
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York
| | - Thomas W White
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York
| | - Nicholas A Delamere
- Department of Physiology and Biophysics, University of Arizona, Tucson, Arizona
| | - Richard T Mathias
- Department of Physiology and Biophysics, Stony Brook University, Stony Brook, New York.
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29
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Andjelic S, Drašlar K, Hvala A, Lopic N, Strancar J, Hawlina M. Anterior lens epithelial cells attachment to the basal lamina. Acta Ophthalmol 2016; 94:e183-8. [PMID: 26581784 DOI: 10.1111/aos.12902] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 09/01/2015] [Indexed: 01/19/2023]
Abstract
PURPOSE To study the structure of the anterior lens epithelial cells (aLECs) and the contacts of the aLECs with the basal lamina (BL) in order to understand their role in the lens epithelium's function. METHODS The aLCs (BL and associated aLECs) were obtained from routine uneventful cataract surgery, prepared for and studied by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and confocal microscopy. RESULTS SEM shows that the basal surface of the aLECs (~10-15 μm) is with aLECs foldings (~1-3 μm) and extensions (~0.5-3 μm) attached to the BL. Confocal microscopy images of the basal sections of the aLECs after membrane staining also suggest that the basal part of aLECs has foldings (~1-3 μm). TEM shows in the aLECs basal parts, towards BL, the structures that look like entanglement (~1-4 μm). In cases where there is a swelling of the cytoplasm and offset of the aLECs from the BL, individual extensions (~0.5-2 μm) that extend to the BL are visible by TEM. CONCLUSIONS We provide detail evidence about the structural organization of the aLECs, in particular about their basal side which is in contact with the BL. This is supported by the complementary use of three techniques, SEM, TEM and confocal microscopy, each of them showing the same morphological features, the extensions and the entanglements of the aLECs cytoplasmic membrane at the border with the BL. The basal surface of the aLECs is increased. It suggests the functional importance of the contact between aLECs and BL.
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Affiliation(s)
| | - Kazimir Drašlar
- Department of Biology; Biotechnical Faculty; University of Ljubljana; Ljubljana Slovenia
| | - Anastazija Hvala
- Department of Pathology; Medical Faculty; University of Ljubljana; Ljubljana Slovenia
| | - Nina Lopic
- Laboratory of Biophysics; Condensed Matter Physics Department; “Jožef Stefan” Institute; Ljubljana Slovenia
| | - Janes Strancar
- Laboratory of Biophysics; Condensed Matter Physics Department; “Jožef Stefan” Institute; Ljubljana Slovenia
| | - Marko Hawlina
- Eye Hospital; University Medical Centre; Ljubljana Slovenia
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30
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Gosak M, Markovič R, Fajmut A, Marhl M, Hawlina M, Andjelić S. The Analysis of Intracellular and Intercellular Calcium Signaling in Human Anterior Lens Capsule Epithelial Cells with Regard to Different Types and Stages of the Cataract. PLoS One 2015; 10:e0143781. [PMID: 26636768 PMCID: PMC4670133 DOI: 10.1371/journal.pone.0143781] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 11/09/2015] [Indexed: 11/17/2022] Open
Abstract
In this work we investigated how modifications of the Ca2+ homeostasis in anterior lens epithelial cells (LECs) are associated with different types of cataract (cortical or nuclear) and how the progression of the cataract (mild or moderate) affects the Ca2+ signaling. We systematically analyzed different aspects of intra- and inter-cellular Ca2+ signaling in the human LECs, which are attached to surgically isolated lens capsule (LC), obtained during cataract surgery. We monitored the temporal and spatial changes in intracellular Ca2+ concentration after stimulation with acetylcholine by means of Fura-2 fluorescence captured with an inverted microscope. In our analysis we compared the features of Ca2+ signals in individual cells, synchronized activations, spatio-temporal grouping and the nature of intercellular communication between LECs. The latter was assessed by using the methodologies of the complex network theory. Our results point out that at the level of individual cells there are no significant differences when comparing the features of the signals with regard either to the type or the stage of the cataract. On the other hand, noticeable differences are observed at the multicellular level, despite inter-capsule variability. LCs associated with more developed cataracts were found to exhibit a slower collective response to stimulation, a less pronounced spatio-temporal clustering of LECs with similar signaling characteristics. The reconstructed intercellular networks were found to be sparser and more segregated than in LCs associated with mild cataracts. Moreover, we show that spontaneously active LECs often operate in localized groups with quite well aligned Ca2+ activity. The presence of spontaneous activity was also found to affect the stimulated Ca2+ responses of individual cells. Our findings indicate that the cataract progression entails the impairment of intercellular signaling thereby suggesting the functional importance of altered Ca2+ signaling of LECs in cataractogenesis.
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Affiliation(s)
- Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, Slovenia.,Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia
| | - Rene Markovič
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia.,Faculty of Education, University of Maribor, Maribor, Slovenia
| | - Aleš Fajmut
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia.,Faculty of Health Sciences, University of Maribor, Maribor, Slovenia
| | - Marko Marhl
- Faculty of Natural Sciences and Mathematics, University of Maribor, Maribor, Slovenia.,Faculty of Education, University of Maribor, Maribor, Slovenia
| | - Marko Hawlina
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia
| | - Sofija Andjelić
- Eye Hospital, University Medical Centre, Ljubljana, Slovenia
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31
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Anterior lens epithelium in intumescent white cataracts - scanning and transmission electron microscopy study. Graefes Arch Clin Exp Ophthalmol 2015; 254:269-76. [PMID: 26573390 DOI: 10.1007/s00417-015-3220-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Revised: 09/30/2015] [Accepted: 11/05/2015] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Our purpose was to study the structure of the lens epithelial cells (LECs) of intumescent white cataracts (IC) in comparison with nuclear cataracts (NC) in order to investigate possible structural reasons for development of IC. METHODS The anterior lens capsule (aLC: basement membrane and associated LECs) were obtained from cataract surgery and prepared for scanning electron microscopy (SEM) and transmission electron microscopy (TEM). RESULTS We observed by SEM that in IC, LEC swelling was pronounced with the clefts surrounding the groups of LECs. Another structural feature was spherical formations, that were observed on the apical side of LEC's, towards the fibre cell layer, both by SEM and TEM. Development of these structures, bulging out from the apical cell membrane of the LEC's and disrupting it, could be followed in steps towards the sphere formation. The degeneration of the lens epithelium and the structures of the aLC in IC similar to Morgagnian globules were also observed. None of these structural changes were observed in NC. CONCLUSIONS We show by SEM and TEM that, in IC, LECs have pronounced structural features not observed in NC. This supports the hypothesis that the disturbed structure of LECs plays a role in water accumulation in the IC lens. We also suggest that, in IC, LECs produce bulging spheres that represent unique structures of degenerated material, extruded from the LEC.
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32
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Gu Y, Xu B, Feng C, Ni Y, Hong N, Wang J, Jiang B. Topical Use of NaCl Solution with Different Concentration Affects Lens Transparency in Anesthetized Mice. Curr Eye Res 2015; 41:943-50. [PMID: 26470738 DOI: 10.3109/02713683.2015.1080280] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To study the influence of NaCl solution with different concentration on lens transparency in anesthetized mice. METHODS Four kinds of NaCl solution with different concentration were prepared as eye drops to imply graded osmolarity (100, 300, 500 and 1000 mOsmol/kg). Five groups of anesthetized mice were set-up to induce lens opacity, in which four groups were treated with NaCl solution and another group naturally exposed to air. The lens opacity was graded as no opacity, mild, medium and severe opacity at 0, 10, 20, 30, 45 and 60 min after the start of the experiment. A numerical value from 0 to 3 was assigned to each grade for the cataract index (CI) calculation and data analysis. The same procedure was repeated in all groups 48 h later. The reversion process of lens opacity was explored using a hypotonic NaCl solution (100 mOsmol/kg) in another pair of groups, a 500 mOsmol/kg NaCl solution group and natural exposure group. The gross appearance and time course of development and reversion of lens opacity were assessed. RESULTS Lens opacity primarily developed in a hypertonic NaCl solution-treated and naturally exposed eyes, and the gross anatomical appearance were similar. The speed of lens opacity development and CI changes were osmolarity-dependent, and the higher NaCl concentration solution used, the faster and more severe the formation of opacification. Both hypertonic NaCl-solution-induced lens opacity and natural exposure induced lens opacity could be resolved by hypotonic NaCl solution prior to anesthesia recovery. CONCLUSIONS This study indicates a crucial effect of NaCl concentration on the development and reversion of lens opacity in the anesthetized mice, and support the osmolarity theory in the reversible lens opacification phenomenon. It is also of practical significance to mouse eye studies that require lens transparency.
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Affiliation(s)
| | | | - Chunfei Feng
- b Department of Operation Room, First Affiliated Hospital, College of Medicine , Zhejiang University , Hangzhou , Zhejiang , China
| | - Yang Ni
- c State Key Lab of Modern Optical Instrumentation, Department of Optical Engineering , Zhejiang University , Hangzhou , Zhejiang , China
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Sellitto C, Li L, Gao J, Robinson ML, Lin RZ, Mathias RT, White TW. AKT activation promotes PTEN hamartoma tumor syndrome-associated cataract development. J Clin Invest 2013; 123:5401-9. [PMID: 24270425 DOI: 10.1172/jci70437] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Accepted: 09/12/2013] [Indexed: 01/03/2023] Open
Abstract
Mutations in the human phosphatase and tensin homolog (PTEN) gene cause PTEN hamartoma tumor syndrome (PHTS), which includes cataract development among its diverse clinical pathologies. Currently, it is not known whether cataract formation in PHTS patients is secondary to other systemic problems, or the result of the loss of a critical function of PTEN within the lens. We generated a mouse line with a lens-specific deletion of Pten (PTEN KO) and identified a regulatory function for PTEN in lens ion transport. Specific loss of PTEN in the lens resulted in cataract. PTEN KO lenses exhibited a progressive age-related increase in intracellular hydrostatic pressure, along with, increased intracellular sodium concentrations, and reduced Na+/K+-ATPase activity. Collectively, these defects lead to lens swelling, opacities and ultimately organ rupture. Activation of AKT was highly elevated in PTEN KO lenses compared to WT mice. Additionally, pharmacological inhibition of AKT restored normal Na+/K+-ATPase activity in primary cultured lens cells and reduced lens pressure in intact lenses from PTEN KO animals. These findings identify a direct role for PTEN in the regulation of lens ion transport through an AKT-dependent modulation of Na+/K+-ATPase activity, and provide a new animal model to investigate cataract development in PHTS patients.
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34
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Parker MD, Boron WF. The divergence, actions, roles, and relatives of sodium-coupled bicarbonate transporters. Physiol Rev 2013; 93:803-959. [PMID: 23589833 PMCID: PMC3768104 DOI: 10.1152/physrev.00023.2012] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The mammalian Slc4 (Solute carrier 4) family of transporters is a functionally diverse group of 10 multi-spanning membrane proteins that includes three Cl-HCO3 exchangers (AE1-3), five Na(+)-coupled HCO3(-) transporters (NCBTs), and two other unusual members (AE4, BTR1). In this review, we mainly focus on the five mammalian NCBTs-NBCe1, NBCe2, NBCn1, NDCBE, and NBCn2. Each plays a specialized role in maintaining intracellular pH and, by contributing to the movement of HCO3(-) across epithelia, in maintaining whole-body pH and otherwise contributing to epithelial transport. Disruptions involving NCBT genes are linked to blindness, deafness, proximal renal tubular acidosis, mental retardation, and epilepsy. We also review AE1-3, AE4, and BTR1, addressing their relevance to the study of NCBTs. This review draws together recent advances in our understanding of the phylogenetic origins and physiological relevance of NCBTs and their progenitors. Underlying these advances is progress in such diverse disciplines as physiology, molecular biology, genetics, immunocytochemistry, proteomics, and structural biology. This review highlights the key similarities and differences between individual NCBTs and the genes that encode them and also clarifies the sometimes confusing NCBT nomenclature.
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Affiliation(s)
- Mark D Parker
- Dept. of Physiology and Biophysics, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106-4970, USA.
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35
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Pandey KB, Jha R, Rizvi SI. Erythrocyte membrane transporters during human ageing: Modulatory role of tea catechins. Clin Exp Pharmacol Physiol 2013; 40:83-9. [DOI: 10.1111/1440-1681.12041] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 12/12/2012] [Indexed: 12/16/2022]
Affiliation(s)
| | - Rashmi Jha
- Department of Biochemistry; University of Allahabad; Allahabad; India
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36
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Gunning SJ, Chung KKH, Donaldson PJ, Webb KF. Identification of a nonselective cation channel in isolated lens fiber cells that is activated by cell shrinkage. Am J Physiol Cell Physiol 2012; 303:C1252-9. [PMID: 23054061 DOI: 10.1152/ajpcell.00237.2012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The initiation of lens cataract has long been associated with the development of a membrane "leak" in lens fiber cells that depolarizes the lens intracellular potential and elevates intracellular Na(+) and Ca(2+) concentrations. It has been proposed that the leak observed in cataractous lenses is due to the activation of a nonselective cation (NSC) conductance in the normal electrically tight fiber cells. Studies of the membrane properties of isolated fiber cells using the patch-clamp technique have demonstrated a differentiation-dependent shift in membrane permeability from K(+)-dominated in epithelial and short fiber cells toward larger contributions from anion and NSC conductances as fiber cells elongate. In this study, the NSC conductances in elongating lens fiber cells are demonstrated to be due to at least two distinct classes: a Gd(3+)-sensitive, mechanosensitive channel whose blockade is essential for obtaining viable isolated fiber cells, and a second Gd(3+)-insensitive, La(3+)-sensitive conductance that appears to be activated by cell shrinkage. This second conductance was eliminated by the replacement of extracellular Na(+) with the impermeant cation N-methyl-d-glucamine and was potentiated by both hypertonic stress and isosmotic cell shrinkage evoked by the replacement of extracellular Cl(-) with the impermeant anion gluconate. This additional cation conductance may play a role in normal lens physiology by mediating regulatory volume increase under osmotic or other physiological challenges. Since the inappropriate activation of NSC channels is implicated in the initiation of lens cataract, they represent potential targets for the development of novel anticataract therapies.
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Affiliation(s)
- S J Gunning
- Department of Optometry and Vision Science, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
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37
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Shahidullah M, Mandal A, Delamere NA. TRPV4 in porcine lens epithelium regulates hemichannel-mediated ATP release and Na-K-ATPase activity. Am J Physiol Cell Physiol 2012; 302:C1751-61. [PMID: 22492652 DOI: 10.1152/ajpcell.00010.2012] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In several tissues, transient receptor potential vanilloid 4 (TRPV4) channels are involved in the response to hyposmotic challenge. Here we report TRPV4 protein in porcine lens epithelium and show that TRPV4 activation is an important step in the response of the lens to hyposmotic stress. Hyposmotic solution (200 mosM) elicited ATP release from intact lenses and TRPV4 antagonists HC 067047 and RN 1734 prevented the release. In isosmotic solution, the TRPV4 agonist GSK1016790A (GSK) elicited ATP release. When propidium iodide (PI) (MW 668) was present in the bathing medium, GSK and hyposmotic solution both increased PI entry into the epithelium of intact lenses. Increased PI uptake and ATP release in response to GSK and hyposmotic solution were abolished by a mixture of agents that block connexin and pannexin hemichannels, 18α-glycyrrhetinic acid and probenecid. Increased Na-K-ATPase activity occurred in the epithelium of lenses exposed to GSK and 18α-glycyrrhetinic acid + probenecid prevented the response. Hyposmotic solution caused activation of Src family kinase and increased Na-K-ATPase activity in the lens epithelium and TRPV4 antagonists prevented the response. Ionomycin, which is known to increase cytoplasmic calcium, elicited ATP release, the magnitude of which was no greater when lenses were exposed simultaneously to ionomycin and hyposmotic solution. Ionomycin-induced ATP release was significantly reduced in calcium-free medium. TRPV4-mediated calcium entry was examined in Fura-2-loaded cultured lens epithelium. Hyposmotic solution and GSK both increased cytoplasmic calcium that was prevented by TRPV4 antagonists. The cytoplasmic calcium rise in response to hyposmotic solution or GSK was abolished when calcium was removed from the bathing solution. The findings are consistent with hyposmotic shock-induced TRPV4 channel activation which triggers hemichannel-mediated ATP release. The results point to TRPV4-mediated calcium entry that causes a cytoplasmic calcium increase which is an essential early step in the mechanism used by the lens to sense and respond to hyposmotic stress.
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38
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Shahidullah M, Mandal A, Beimgraben C, Delamere NA. Hyposmotic stress causes ATP release and stimulates Na,K-ATPase activity in porcine lens. J Cell Physiol 2012; 227:1428-37. [PMID: 21618533 DOI: 10.1002/jcp.22858] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Purinergic receptors in lens epithelium suggest lens function can be altered by chemical signals from aqueous humor or the lens itself. Here we show release of ATP by intact porcine lenses exposed to hyposmotic solution (200 mOsm). 18α-glycyrrhetinic acid (AGA) added together with probenecid eliminated the ATP increase. N-ethylmaleimide (200 µM), an exocytotic inhibitor, had no significant effect on ATP increase. Lenses exposed to hyposmotic solution displayed a ~400% increase of propidium iodide (PI) entry into the epithelium. The increased ability of PI (MW 668) to enter the epithelium suggests possible opening of connexin and/or pannexin hemichannels. This is consistent with detection of connexin 43, connexin 50, and pannexin 1 in the epithelium and the ability of AGA + probenecid to prevent ATP release. Na,K-ATPase activity doubled in the epithelium of lenses exposed to hyposmotic solution. The increase of Na,K-ATPase activity did not occur when apyrase was used to prevent extracellular ATP accumulation or when AGA + probenecid prevented ATP release. The increase of Na,K-ATPase activity was inhibited by the purinergic P2 antagonist reactive blue-2 and pertussis toxin, a G-protein inhibitor, but not by the P2X antagonist PPADS. Hyposmotic solution activated Src family kinase (SFK) in the epithelium, judged by Western blot. The SFK inhibitor PP2 abolished both SFK activation and the Na,K-ATPase activity increase. In summary, hyposmotic shock-induced ATP release is sufficient to activate a purinergic receptor- and SFK-dependent mechanism that stimulates Na,K-ATPase activity. The responses might signify an autoregulatory loop initiated by mechanical stress or osmotic swelling.
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Affiliation(s)
- M Shahidullah
- Department of Physiology, University of Arizona, Tucson, Arizona 85724, USA.
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39
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Zhao M, Chalmers L, Cao L, Vieira AC, Mannis M, Reid B. Electrical signaling in control of ocular cell behaviors. Prog Retin Eye Res 2012; 31:65-88. [PMID: 22020127 PMCID: PMC3242826 DOI: 10.1016/j.preteyeres.2011.10.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 10/01/2011] [Accepted: 10/04/2011] [Indexed: 12/13/2022]
Abstract
Epithelia of the cornea, lens and retina contain a vast array of ion channels and pumps. Together they produce a polarized flow of ions in and out of cells, as well as across the epithelia. These naturally occurring ion fluxes are essential to the hydration and metabolism of the ocular tissues, especially for the avascular cornea and lens. The directional transport of ions generates electric fields and currents in those tissues. Applied electric fields affect migration, division and proliferation of ocular cells which are important in homeostasis and healing of the ocular tissues. Abnormalities in any of those aspects may underlie many ocular diseases, for example chronic corneal ulcers, posterior capsule opacity after cataract surgery, and retinopathies. Electric field-inducing cellular responses, termed electrical signaling here, therefore may be an unexpected yet powerful mechanism in regulating ocular cell behavior. Both endogenous electric fields and applied electric fields could be exploited to regulate ocular cells. We aim to briefly describe the physiology of the naturally occurring electrical activities in the corneal, lens, and retinal epithelia, to provide experimental evidence of the effects of electric fields on ocular cell behaviors, and to suggest possible clinical implications.
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Affiliation(s)
- Min Zhao
- Department of Dermatology, UC Davis School of Medicine, 2921 Stockton Blvd., Sacramento, CA 95817, USA.
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Abstract
PURPOSE To analyse the anterior lens capsule thickness and ultrastructure changes of intumescent white cataracts in comparison with nuclear cataracts to prove possible structural reasons for surgical difficulties with the intumescent white cataract. METHODS Anterior lens capsules from 35 eyes with intumescent white and 35 eyes with nuclear cataracts were analysed for their thickness by semithin sections technique and for morphological characteristics by transmission electron microscopy. RESULTS Capsule thickness was not significantly different in intumescent white compared to nuclear cataracts (mean values 17.5 and 18.5 μm, respectively, p = 0.369). The main morphological features of capsules were extrusions of capsule at the basement membrane-epithelial border embedding cellular material which were significantly more frequent in intumescent cataracts. Filaments in the basement membrane as well as rarefication of its structure and lamellae were often concomitant with the extrusions. CONCLUSIONS Anterior capsules of white intumescent cataracts do not differ in thickness but have different ultrastructure morphology compared to nuclear cataracts. The extrusions of basement membrane at the basement membrane-epithelial border towards epithelium, the filamentary inclusions within basement membrane and its rarefication could be the structural causes of tensile weakness and hence additional reason to surgical problems.
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Affiliation(s)
- Marko Hawlina
- Eye Hospital, University Medical Center, Ljubljana, Slovenia.
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41
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Tröβe C, Rhodes JD, Sanderson J, Breck O, Waagbø R. Effect of plant-based feed ingredients on osmoregulation in the Atlantic salmon lens. Comp Biochem Physiol B Biochem Mol Biol 2010; 155:354-62. [DOI: 10.1016/j.cbpb.2009.12.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Revised: 12/16/2009] [Accepted: 12/20/2009] [Indexed: 11/24/2022]
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Suhail M. Na, K-ATPase: Ubiquitous Multifunctional Transmembrane Protein and its Relevance to Various Pathophysiological Conditions. J Clin Med Res 2010; 2:1-17. [PMID: 22457695 PMCID: PMC3299169 DOI: 10.4021/jocmr2010.02.263w] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2010] [Indexed: 12/30/2022] Open
Abstract
UNLABELLED The Na(+), K(+)-ATPase (NKA) is an ubiquitous enzyme consisting of α, β and γ subunits, and is responsible for the creation and maintenance of the Na(+) and K(+) gradients across the cell membrane by transporting 3 Na(+) out and 2 K(+) into the cell. Sodium pump regulation is tissue as well as isoform specific. Intracellular messengers differentially regulate the activity of the individual NKA isozymes. Regulation of specific NKA isozymes gives cells the ability to precisely coordinate NKA activity to their physiological requirements. It is the only known receptor for the cardiac glycosides used to treat congestive heart failure and cardiac arrhythmias. Endogenous ligands structurally similar to cardiac glycosides may act as natural regulators of the sodium pump in heart and other tissues. Identification of naturally occurring regulators of NKA could initiate the discovery of new hormone-like control systems involved in the etiology of selected disease processes, hence the importance of understanding the relation of the sodium pump and its ligands to disease. Diabetes has a marked effect on the metabolism of a variety of tissues and because the NKA is critical for the membrane potential and many transports, a change in its activity in diabetes would have profound consequence in these tissues. NKA is also involved in hypertension, salt balance, cardiovascular and renal disorders, sperm capacitation, cell volume regulation, apoptosis, rheumatoid arthritis, sepsis, neurological disorders, lung edema clearance and preeclampsia. NKA activity and expression in the collecting duct of kidney are modulated physiologically by hormones like aldosterone, vasopressin, and insulin. NKA enzyme activity and subunit levels are reduced in carcinoma, NKA-β levels were highly reduced in an invasive form of human renal clear cell carcinoma, androgen-dependent prostate cancer, in early stages of urothelial cancer, as well as in poorly differentiated, highly motile carcinoma cell lines obtained from various tissues suggesting a functional link between reduced NKA-β expression and cancer progression. It could be a target for the development of anticancer drugs as it serves as a signal transducer, it is a player in cell adhesion and its aberrant expression and activity are implicated in the development and progression of different cancers. KEYWORDS Na(+), K(+)-ATPase (NKA); Cardiotonic steroids (CTS); Diabetes; Hypertension; Cardiovascular and renal disorders; Signal transducer; Anticancer drugs.
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Affiliation(s)
- Mohd Suhail
- Department of Biochemistry, University of Allahabad, Allahabad-211002, India
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43
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Mathias RT, White TW, Gong X. Lens gap junctions in growth, differentiation, and homeostasis. Physiol Rev 2010; 90:179-206. [PMID: 20086076 DOI: 10.1152/physrev.00034.2009] [Citation(s) in RCA: 181] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The cells of most mammalian organs are connected by groups of cell-to-cell channels called gap junctions. Gap junction channels are made from the connexin (Cx) family of proteins. There are at least 20 isoforms of connexins, and most tissues express more than 1 isoform. The lens is no exception, as it expresses three isoforms: Cx43, Cx46, and Cx50. A common role for all gap junctions, regardless of their Cx composition, is to provide a conduit for ion flow between cells, thus creating a syncytial tissue with regard to intracellular voltage and ion concentrations. Given this rather simple role of gap junctions, a persistent question has been: Why are there so many Cx isoforms and why do tissues express more than one isoform? Recent studies of lens Cx knockout (KO) and knock in (KI) lenses have begun to answer these questions. To understand these roles, one must first understand the physiological requirements of the lens. We therefore first review the development and structure of the lens, its numerous transport systems, how these systems are integrated to generate the lens circulation, the roles of the circulation in lens homeostasis, and finally the roles of lens connexins in growth, development, and the lens circulation.
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Affiliation(s)
- Richard T Mathias
- Department of Physiology and Biophysics, SUNY at Stony Brook, Stony Brook, New York 11794-8661, USA.
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44
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Over-expression of translationally controlled tumor protein in lens epithelial cells seems to be associated with cataract development. Transgenic Res 2009; 18:953-60. [PMID: 19479337 DOI: 10.1007/s11248-009-9283-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Accepted: 05/14/2009] [Indexed: 10/20/2022]
Abstract
Inhibition of Na,K-ATPase causes opacification of the lens through abnormal increases in sodium and calcium levels, disturbed osmotic equilibrium, activation of proteolytic enzymes and cell damage. We previously identified Translationally Controlled Tumor Protein (TCTP) as a cytoplasmic repressor of Na,K-ATPase and confirmed that systemic hypertension is induced in transgenic mice over-expressing TCTP through inhibition of vascular Na,K-ATPase and increased intracellular calcium mobilization. In the current study, we confirmed the role of TCTP in causing intracellular calcium mobilization by inhibiting Na,K-ATPase in a human lens epithelial cell line and further showed that some of the TCTP-transgenic mice develop cataracts with an incidence rate of 7.38% compared to 1.47% in controls. We demonstrated that TCTP acts as a cataractogenic factor through the repression of Na,K-ATPase activity and calcium mobilization in lens epithelial cells.
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45
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Liu XC, Wang P, Yan H. A rabbit model to study biochemical damage to the lens after vitrectomy: effects of N-acetylcysteine. Exp Eye Res 2009; 88:1165-70. [PMID: 19450459 DOI: 10.1016/j.exer.2009.01.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2008] [Revised: 01/03/2009] [Accepted: 01/06/2009] [Indexed: 11/19/2022]
Abstract
The purpose of the present study was to determine whether the biochemical effects of vitrectomy can be studied in rabbits and to assess the possible protective effects of N-acetylcysteine on the lens following vitrectomy. Twenty-four New Zealand rabbits (2.3-2.4 kg) were divided into three groups of eight each. Left eyes underwent vitrectomy surgery. Unoperated right eyes served as controls. Equal numbers of treated eyes were not injected, injected with 20 mM N-acetylcysteine, or 100 mM N-acetylcysteine immediately after vitrectomy. Lens transparency was monitored by slit-lamp biomicroscopy pre- and post-vitrectomy. A series of biochemical measurements were performed on lenses five months after vitrectomy. No significant differences in lens transparency or structure were observed in the three groups of lenses. However, vitrectomy was associated with significantly decreased activity of Na(+)-K(+)-ATPase and catalase. Compared with the group not treated with N-acetylcysteine, catalase activity was increased significantly in the group treated with 20 mM N-acetylcysteine. The level of glutathione and the activities of Na(+)-K(+)-ATPase and glutathione reductase were also higher in the two N-acetylcysteine-treated groups than in the untreated group, although these differences did not reach statistical significance. For all measured parameters, the effect of 20 mM N-acetylcysteine appeared to be better than 100 mM N-acetylcysteine, although these differences were not statistically significant. From these results, we gather that vitrectomy is associated with long-term decreases in enzyme activity in the lens. Injection of N-acetylcysteine into the vitreous cavity protects against some of these changes. Antioxidants like N-acetylcysteine may slow or prevent post-vitrectomy cataracts.
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46
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The effects of GPX-1 knockout on membrane transport and intracellular homeostasis in the lens. J Membr Biol 2008; 227:25-37. [PMID: 19067024 DOI: 10.1007/s00232-008-9141-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2008] [Accepted: 11/05/2008] [Indexed: 10/21/2022]
Abstract
Glutathione peroxidase-1 (GPX-1) is an enzyme that protects the lens against H2O2-mediated oxidative damage. The purpose of the present study was to determine the effects of GPX-1 knockout (KO) on lens transport and intracellular homeostasis. To investigate these lenses we used (1) whole lens impedance studies to measure membrane conductance, resting voltage and fiber cell gap junction coupling conductance; (2) osmotic swelling of fiber cell membrane vesicles to determine water permeability; and (3) injection of Fura2 and Na+-binding benzofuran isophthalate (SBFI) into fiber cells to measure [Ca2+]i and [Na+]i, respectively, in intact lenses. These approaches were used to compare wild-type (WT) and GPX-1 KO lenses from mice around 2 months of age. There were no significant differences in clarity, size, resting voltage, membrane conductance or fiber cell membrane water permeability between WT and GPX-1 KO lenses. However, in GPX-1 KO lenses, coupling conductance was 72% of normal in the outer shell of differentiating fibers and 45% of normal in the inner core of mature fibers. Quantitative Western blots showed that GPX-1 KO lenses had about 50% as much labeled Cx46 and Cx50 protein as WT, whereas they had equivalent labeled AQP0 protein as WT. Both Ca2+ and Na+ accumulated significantly in the core of GPX-1 KO lenses. In summary, the major effect on lens transport of GPX-1 KO was a reduction in gap junction coupling conductance. This reduction affected the lens normal circulation by causing [Na+]i and [Ca2+]i to increase, which could increase cataract susceptibility in GPX-1 KO lenses.
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47
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Chan AW, Ho YS, Chung SK, Chung SS. Synergistic effect of osmotic and oxidative stress in slow-developing cataract formation. Exp Eye Res 2008; 87:454-61. [DOI: 10.1016/j.exer.2008.08.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2008] [Revised: 08/01/2008] [Accepted: 08/01/2008] [Indexed: 10/21/2022]
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48
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The alpha1 isoform of the Na+/K+ ATPase is up-regulated in dedifferentiated progenitor cells that mediate lens and retina regeneration in adult newts. Exp Eye Res 2008; 88:314-22. [PMID: 18755185 DOI: 10.1016/j.exer.2008.07.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 07/10/2008] [Accepted: 07/23/2008] [Indexed: 11/21/2022]
Abstract
Adult newts are able to regenerate their retina and lens after injury or complete removal through transdifferentiation of the pigmented epithelial tissues of the eye. This process needs to be tightly controlled, and several different mechanisms are likely to be recruited for this function. The Na(+)/K(+) ATPase is a transmembrane protein that establishes electrochemical gradients through the transport of Na(+) and K(+) and has been implicated in the modulation of key cellular processes such as cell division, migration and adhesion. Even though it is expressed in all cells, its isoform composition varies with cell type and is tightly controlled during development and regeneration. In the present study we characterize the expression pattern of Na(+)/K(+) ATPase alpha1 in the adult newt eye and during the process of lens and retina regeneration. We show that this isoform is up-regulated in undifferentiated cells during transdifferentiation. Such change in composition could be one of the mechanisms that newt cells utilize to modulate this process.
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49
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Webb KF, Donaldson PJ. Differentiation-dependent changes in the membrane properties of fiber cells isolated from the rat lens. Am J Physiol Cell Physiol 2008; 294:C1133-45. [PMID: 18367590 DOI: 10.1152/ajpcell.00315.2007] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Impedance measurements in whole lenses showed that lens fiber cells possess different permeability properties to the epithelial cells from which they differentiate. To confirm these observations at the cellular level, we analyzed the membrane properties of fiber cells isolated in the presence of the nonselective cation channel inhibitor Gd3+. Isolated fiber cells were viable in physiological [Ca2+] and exhibited a range of lengths that reflected their stage of differentiation. Analysis of a large population of fiber cells revealed a subgroup of cells whose conductivity matched values measured in the whole lens (1). In this group of cells, membrane resistance, conductivity, and reversal potential all varied with cell length, suggesting that the process of differentiation is associated with a change in the membrane properties of fiber cells. Using pharmacology and ion substitution experiments, we showed that newly differentiated fiber cells (<150 microm) contained variable combinations of Ba2+-and tetraethylammonium-sensitive K+ currents. Longer fiber cells (150-650 microm) were dominated by a lyotropic anion conductance, which also appears to plays a role in the intact lens. Longer cells also exhibited a low-level, nonselective conductance that was eliminated by the replacement of extracellular Na+ with N-methyl-d-glucamine, indicating that the lens contains both Gd3+-sensitive and -insensitive nonselective cation conductances. Fiber cell differentiation is therefore associated with a shift in membrane permeability from a dominant K+ conductance(s) toward larger contributions from anion and nonselective cation conductances as fiber cells elongate.
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Affiliation(s)
- Kevin F Webb
- Department of Physiology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
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50
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Burnett KG, Bain LJ, Baldwin WS, Callard GV, Cohen S, Di Giulio RT, Evans DH, Gómez-Chiarri M, Hahn ME, Hoover CA, Karchner SI, Katoh F, MacLatchy DL, Marshall WS, Meyer JN, Nacci DE, Oleksiak MF, Rees BB, Singer TD, Stegeman JJ, Towle DW, Van Veld PA, Vogelbein WK, Whitehead A, Winn RN, Crawford DL. Fundulus as the premier teleost model in environmental biology: opportunities for new insights using genomics. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. PART D, GENOMICS & PROTEOMICS 2007; 2:257-86. [PMID: 18071578 PMCID: PMC2128618 DOI: 10.1016/j.cbd.2007.09.001] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A strong foundation of basic and applied research documents that the estuarine fish Fundulus heteroclitus and related species are unique laboratory and field models for understanding how individuals and populations interact with their environment. In this paper we summarize an extensive body of work examining the adaptive responses of Fundulus species to environmental conditions, and describe how this research has contributed importantly to our understanding of physiology, gene regulation, toxicology, and ecological and evolutionary genetics of teleosts and other vertebrates. These explorations have reached a critical juncture at which advancement is hindered by the lack of genomic resources for these species. We suggest that a more complete genomics toolbox for F. heteroclitus and related species will permit researchers to exploit the power of this model organism to rapidly advance our understanding of fundamental biological and pathological mechanisms among vertebrates, as well as ecological strategies and evolutionary processes common to all living organisms.
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Affiliation(s)
- Karen G. Burnett
- Grice Marine Laboratory, College of Charleston, 205 Fort Johnson, Charleston, SC 29412, USA
| | - Lisa J. Bain
- Clemson Institute of Environmental Toxicology, Clemson University; Pendleton, SC 29670, USA
| | - William S. Baldwin
- Clemson Institute of Environmental Toxicology, Clemson University; Pendleton, SC 29670, USA
| | | | - Sarah Cohen
- Romberg Tiburon Center and Department of Biology, San Francisco State University, Tiburon, CA 94120, USA
| | - Richard T. Di Giulio
- Nicholas School of the Environment and Earth Sciences, Duke University, Durham, NC, USA
| | - David H. Evans
- Department of Zoology, University of Florida, Gainesville, FL 32611, USA
| | - Marta Gómez-Chiarri
- Department of Fisheries, Animal and Veterinary Science, University of Rhode Island, Kingston, RI 02881, USA
| | - Mark E. Hahn
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | | | - Sibel I. Karchner
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - Fumi Katoh
- Department of Biology, St. Francis Xavier University, Antigonish, N.S. B2G 2W5, Canada
| | - Deborah L. MacLatchy
- Faculty of Science, Wilfred Laurier University, Waterloo, Ontario, Canada N2L 3C5
| | - William S. Marshall
- Department of Biology, St. Francis Xavier University, Antigonish, N.S. B2G 2W5, Canada
| | - Joel N. Meyer
- Nicholas School of the Environment and Earth Sciences, Duke University, Durham, NC, USA
| | - Diane E. Nacci
- US Environmental Protection Agency Office of Research and Development, Narragansett, RI 02882, USA
| | - Marjorie F. Oleksiak
- Rosenstiel School of Marine & Atmospheric Science, University of Miami, Miami, FL 33149, USA
| | - Bernard B. Rees
- Department of Biological Sciences, University of New Orleans, New Orleans, LA 70148, USA
| | - Thomas D. Singer
- School of Optometry, University of Waterloo, Waterloo, ON, N2L 3G1, CANADA
| | - John J. Stegeman
- Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543, USA
| | - David W. Towle
- Center for Marine Functional Genomics, Mount Desert Island Biological Laboratory, Maine 04672, USA
| | - Peter A. Van Veld
- The College of William and Mary, Virginia Institute of Marine Science, Gloucester Point, VA 23062, USA
| | - Wolfgang K. Vogelbein
- The College of William and Mary, Virginia Institute of Marine Science, Gloucester Point, VA 23062, USA
| | - Andrew Whitehead
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Richard N. Winn
- Aquatic Biotechnology and Environmental Laboratory, University of Georgia, Athens, GA 30602, USA
| | - Douglas L. Crawford
- Rosenstiel School of Marine & Atmospheric Science, University of Miami, Miami, FL 33149, USA
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