1
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Guseman AJ, González JJ, Yang D, Gronenborn AM. Cumulative asparagine to aspartate deamidation fails to perturb γD-crystallin structure and stability. Protein Sci 2024; 33:e5120. [PMID: 39022918 PMCID: PMC11255865 DOI: 10.1002/pro.5120] [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: 01/30/2024] [Revised: 06/05/2024] [Accepted: 07/07/2024] [Indexed: 07/20/2024]
Abstract
Deamidation frequently is invoked as an important driver of crystallin aggregation and cataract formation. Here, we characterized the structural and biophysical consequences of cumulative Asn to Asp changes in γD-crystallin. Using NMR spectroscopy, we demonstrate that N- or C-terminal domain-confined or fully Asn to Asp changed γD-crystallin exhibits essentially the same 1H-15N HSQC spectrum as the wild-type protein, implying that the overall structure is retained. Only a very small thermodynamic destabilization for the overall Asn to Asp γD-crystallin variants was noted by chaotropic unfolding, and assessment of the colloidal stability, by measuring diffusion interaction parameters, yielded no substantive differences in association propensities. Furthermore, using molecular dynamics simulations, no significant changes in dynamics for proteins with Asn to Asp or iso-Asp changes were detected. Our combined results demonstrate that substitution of all Asn by Asp residues, reflecting an extreme case of deamidation, did not affect the structure and biophysical properties of γD-crystallin. This suggests that these changes alone cannot be the major determinant in driving cataract formation.
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Affiliation(s)
- Alex J. Guseman
- Department of Structural BiologyUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
| | - Jeremy J. González
- Department of Structural BiologyUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
| | - Darian Yang
- Department of Structural BiologyUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
| | - Angela M. Gronenborn
- Department of Structural BiologyUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
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2
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Shiels A. Through the Cat-Map Gateway: A Brief History of Cataract Genetics. Genes (Basel) 2024; 15:785. [PMID: 38927721 PMCID: PMC11202810 DOI: 10.3390/genes15060785] [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: 05/21/2024] [Revised: 06/06/2024] [Accepted: 06/13/2024] [Indexed: 06/28/2024] Open
Abstract
Clouding of the transparent eye lens, or cataract(s), is a leading cause of visual impairment that requires surgical replacement with a synthetic intraocular lens to effectively restore clear vision. Most frequently, cataract is acquired with aging as a multifactorial or complex trait. Cataract may also be inherited as a classic Mendelian trait-often with an early or pediatric onset-with or without other ocular and/or systemic features. Since the early 1990s, over 85 genes and loci have been genetically associated with inherited and/or age-related forms of cataract. While many of these underlying genes-including those for lens crystallins, connexins, and transcription factors-recapitulate signature features of lens development and differentiation, an increasing cohort of unpredicted genes, including those involved in cell-signaling, membrane remodeling, and autophagy, has emerged-providing new insights regarding lens homeostasis and aging. This review provides a brief history of gene discovery for inherited and age-related forms of cataract compiled in the Cat-Map database and highlights potential gene-based therapeutic approaches to delay, reverse, or even prevent cataract formation that may help to reduce the increasing demand for cataract surgery.
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Affiliation(s)
- Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
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3
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Serebryany E, Martin RW, Takahashi GR. The Functional Significance of High Cysteine Content in Eye Lens γ-Crystallins. Biomolecules 2024; 14:594. [PMID: 38786000 PMCID: PMC11118217 DOI: 10.3390/biom14050594] [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: 03/28/2024] [Revised: 05/07/2024] [Accepted: 05/14/2024] [Indexed: 05/25/2024] Open
Abstract
Cataract disease is strongly associated with progressively accumulating oxidative damage to the extremely long-lived crystallin proteins of the lens. Cysteine oxidation affects crystallin folding, interactions, and light-scattering aggregation especially strongly due to the formation of disulfide bridges. Minimizing crystallin aggregation is crucial for lifelong lens transparency, so one might expect the ubiquitous lens crystallin superfamilies (α and βγ) to contain little cysteine. Yet, the Cys content of γ-crystallins is well above the average for human proteins. We review literature relevant to this longstanding puzzle and take advantage of expanding genomic databases and improved machine learning tools for protein structure prediction to investigate it further. We observe remarkably low Cys conservation in the βγ-crystallin superfamily; however, in γ-crystallin, the spatial positioning of Cys residues is clearly fine-tuned by evolution. We propose that the requirements of long-term lens transparency and high lens optical power impose competing evolutionary pressures on lens βγ-crystallins, leading to distinct adaptations: high Cys content in γ-crystallins but low in βB-crystallins. Aquatic species need more powerful lenses than terrestrial ones, which explains the high methionine content of many fish γ- (and even β-) crystallins. Finally, we discuss synergies between sulfur-containing and aromatic residues in crystallins and suggest future experimental directions.
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Affiliation(s)
- Eugene Serebryany
- Department of Physiology & Biophysics, Stony Brook University, SUNY, Stony Brook, NY 11794, USA
- Laufer Center for Physical & Quantitative Biology, Stony Brook University, SUNY, Stony Brook, NY 11794, USA
| | - Rachel W. Martin
- Department of Chemistry, UCI Irvine, Irvine, CA 92697-2025, USA
- Department of Molecular Biology & Biochemistry, UCI Irvine, Irvine, CA 92697-3900, USA
| | - Gemma R. Takahashi
- Department of Molecular Biology & Biochemistry, UCI Irvine, Irvine, CA 92697-3900, USA
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4
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Miller AP, O'Neill SE, Lampi KJ, Reichow SL. The α-crystallin Chaperones Undergo a Quasi-ordered Co-aggregation Process in Response to Saturating Client Interaction. J Mol Biol 2024; 436:168499. [PMID: 38401625 PMCID: PMC11001518 DOI: 10.1016/j.jmb.2024.168499] [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: 08/15/2023] [Revised: 02/15/2024] [Accepted: 02/16/2024] [Indexed: 02/26/2024]
Abstract
Small heat shock proteins (sHSPs) are ATP-independent chaperones vital to cellular proteostasis, preventing protein aggregation events linked to various human diseases including cataract. The α-crystallins, αA-crystallin (αAc) and αB-crystallin (αBc), represent archetypal sHSPs that exhibit complex polydispersed oligomeric assemblies and rapid subunit exchange dynamics. Yet, our understanding of how this plasticity contributes to chaperone function remains poorly understood. Using biochemical and biophysical analyses combined with single-particle electron microscopy (EM), we examined structural changes in αAc, αBc and native heteromeric lens α-crystallins (αLc) in their apo-states and at varying degree of chaperone saturation leading to co-aggregation, using lysozyme and insulin as model clients. Quantitative single-particle analysis unveiled a continuous spectrum of oligomeric states formed during the co-aggregation process, marked by significant client-triggered expansion and quasi-ordered elongation of the sHSP oligomeric scaffold, whereby the native cage-like sHSP assembly displays a directional growth to accommodate saturating conditions of client sequestration. These structural modifications culminated in an apparent amorphous collapse of chaperone-client complexes, resulting in the creation of co-aggregates capable of scattering visible light. Intriguingly, these co-aggregates maintain internal morphological features of highly elongated sHSP oligomers with striking resemblance to polymeric α-crystallin species isolated from aged lens tissue. This mechanism appears consistent across αAc, αBc and αLc, albeit with varying degrees of susceptibility to client-induced co-aggregation. Importantly, our findings suggest that client-induced co-aggregation follows a distinctive mechanistic and quasi-ordered trajectory, distinct from a purely amorphous process. These insights reshape our understanding of the physiological and pathophysiological co-aggregation processes of α-crystallins, carrying potential implications for a pathway toward cataract formation.
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Affiliation(s)
- Adam P Miller
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA; Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA; Department of Chemistry, Portland State University, Portland, OR 97201, USA
| | - Susan E O'Neill
- Department of Chemistry, Portland State University, Portland, OR 97201, USA
| | - Kirsten J Lampi
- Biomaterial and Biomedical Sciences, Oregon Health & Science University, Portland, OR 97239, USA
| | - Steve L Reichow
- Department of Chemical Physiology and Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA; Vollum Institute, Oregon Health & Science University, Portland, OR 97239, USA; Department of Chemistry, Portland State University, Portland, OR 97201, USA.
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5
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Mabbitt PD. Structural biology in the Anthropocene epoch. Nat Struct Mol Biol 2024; 31:2. [PMID: 38253664 DOI: 10.1038/s41594-024-01222-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
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6
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Bergman MR, Hernandez SA, Deffler C, Yeo J, Deravi LF. Design and Characterization of Model Systems that Promote and Disrupt Transparency of Vertebrate Crystallins In Vitro. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2303279. [PMID: 37897315 PMCID: PMC10724405 DOI: 10.1002/advs.202303279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 08/31/2023] [Indexed: 10/30/2023]
Abstract
Positioned within the eye, the lens supports vision by transmitting and focusing light onto the retina. As an adaptive glassy material, the lens is constituted primarily by densely-packed, polydisperse crystallin proteins that organize to resist aggregation and crystallization at high volume fractions, yet the details of how crystallins coordinate with one another to template and maintain this transparent microstructure remain unclear. The role of individual crystallin subtypes (α, β, and γ) and paired subtype compositions, including how they experience and resist crowding-induced turbidity in solution, is explored using combinations of spectrophotometry, hard-sphere simulations, and surface pressure measurements. After assaying crystallin combinations, β-crystallins emerged as a principal component in all mixtures that enabled dense fluid-like packing and short-range order necessary for transparency. These findings helped inform the design of lens-like hydrogel systems, which are used to monitor and manipulate the loss of transparency under different crowding conditions. When taken together, the findings illustrate the design and characterization of adaptive materials made from lens proteins that can be used to better understand mechanisms regulating transparency.
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Affiliation(s)
- Michael R. Bergman
- Department of Chemistry and Chemical BiologyNortheastern University360 Huntington AveBostonMA02115USA
| | - Sophia A. Hernandez
- Department of Chemistry and Chemical BiologyNortheastern University360 Huntington AveBostonMA02115USA
| | - Caitlin Deffler
- Department of Chemistry and Chemical BiologyNortheastern University360 Huntington AveBostonMA02115USA
| | - Jingjie Yeo
- Sibley School of Mechanical and Aerospace EngineeringCornell University413 Upson Hall, 124 Hoy RdIthacaNY14850USA
| | - Leila F. Deravi
- Department of Chemistry and Chemical BiologyNortheastern University360 Huntington AveBostonMA02115USA
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7
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Xu J, Zhang Y, Liu J, Hu L, Luo C, Yao K, Chen X. Heteromeric formation with βA3 protects the low thermal stability of βB1-L116P. Br J Ophthalmol 2023; 107:1936-1942. [PMID: 36126102 DOI: 10.1136/bjo-2022-322247] [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] [Received: 07/16/2022] [Accepted: 08/22/2022] [Indexed: 11/04/2022]
Abstract
BACKGROUND/AIMS Congenital cataract is the leading cause of visual disability and blindness in childhood. βB1-crystallin (CRYBB1) comprises about 1/10th of crystallin structural proteins, forming heteromers to maintain lens transparency. We previously reported a CRYBB1 mutation (c.347T>C, p.L116P) affecting 16 patients in a congenital nuclear cataract family. In this study, we investigate the underlying pathogenic mechanism of βB1-L116P. METHODS Protein isolation, size-exclusion chromatography, spectroscopy, Uncle stability screens and molecular dynamics simulations were used to assess βA3- and βB1-crystallin thermal stability, structural properties and heteromer formation. RESULTS Cells that overexpressed βB1-L116P tended to form aggregates and precipitations under heat-shock stress. Thermal denaturation and time-dependent turbidity experiments showed that thermal stability was significantly impaired. Moreover, protein instability appeared to increase with elevated concentrations detected by the Uncle system. Additionally, βA3 had a relative protective effect on βB1-L116P after heteromers were formed, although βA3 was relatively unstable and was usually protected by basic β-crystallins. Molecular dynamic simulations revealed that L116P mutation altered the hydrophobic residues at the surface around the mutant site, providing solvents more access to the internal and hydrophobic parts of the protein. CONCLUSIONS Decreased βB1-crystallin thermal stability in the presence of the cataract-related L116P mutation contributes significantly to congenital cataract formation. Moreover, its formation of heteromers with βA3 protects against the low thermal stability of βB1-L116P.
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Affiliation(s)
- Jingjie Xu
- Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Ying Zhang
- Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Jian Liu
- Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- National Clinical Research Center for Child Health, Hangzhou, Zhejiang Province, China
| | - Lidan Hu
- Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- National Clinical Research Center for Child Health, Hangzhou, Zhejiang Province, China
| | - Chenqi Luo
- Eye Center, Second Hospital Affiliated to Medical College of Zhejiang University, Hangzhou, Zhejiang, China
| | - Ke Yao
- Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
| | - Xiangjun Chen
- Zhejiang University School of Medicine, Hangzhou, Zhejiang, China
- National Clinical Research Center for Child Health, Hangzhou, Zhejiang Province, China
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8
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Li J, Yan P, Li Y, Han M, Zeng Q, Li J, Yu Z, Zhang D, Chen X. Harnessing the power of Raman spectroscopic imaging for ophthalmology. Front Chem 2023; 11:1211121. [PMID: 37252371 PMCID: PMC10213270 DOI: 10.3389/fchem.2023.1211121] [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: 04/24/2023] [Accepted: 05/04/2023] [Indexed: 05/31/2023] Open
Abstract
Eye diseases can cause great inconvenience to people's daily life; therefore, it is necessary to study the causes of ocular diseases and related physiological processes. Raman spectroscopic imaging (RSI) is a non-destructive, non-contact detection technique with the advantages of label-free, non-invasive and highly specific. Compared with other mature imaging technologies, RSI can provide real-time molecular information and high-resolution imaging at relatively low cost, making it very suitable for quantitative detection of biological molecules. RSI can reflect the overall situation of the sample, revealing the content distribution of the same substance in different areas of the sample. This review focuses on the recent advances in ophthalmology, with particular emphasis on the powerful use of RSI techniques, as well as its combination with other imaging techniques. Finally, we prospect the wider application and future potential of RSI approaches in ophthalmology.
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Affiliation(s)
- Jing Li
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated People’s Hospital of Northwest University, Xi’an, Shaanxi, China
| | - Peirao Yan
- Center for Biomedical-photonics and Molecular Imaging, Xi’an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi’an, Shaanxi, China
| | - Yong Li
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated People’s Hospital of Northwest University, Xi’an, Shaanxi, China
| | - Ming Han
- Center for Biomedical-photonics and Molecular Imaging, Xi’an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi’an, Shaanxi, China
| | - Qi Zeng
- Center for Biomedical-photonics and Molecular Imaging, Xi’an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi’an, Shaanxi, China
| | - Juan Li
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated People’s Hospital of Northwest University, Xi’an, Shaanxi, China
| | - Zhe Yu
- Shaanxi Eye Hospital, Xi’an People’s Hospital (Xi’an Fourth Hospital), Affiliated People’s Hospital of Northwest University, Xi’an, Shaanxi, China
| | - Dongjie Zhang
- Center for Biomedical-photonics and Molecular Imaging, Xi’an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi’an, Shaanxi, China
| | - Xueli Chen
- Center for Biomedical-photonics and Molecular Imaging, Xi’an Key Laboratory of Intelligent Sensing and Regulation of Trans-Scale Life Information, School of Life Science and Technology, Xidian University, Xi’an, Shaanxi, China
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9
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Bennett TM, Zhou Y, Meyer KJ, Anderson MG, Shiels A. Whole-exome sequencing prioritizes candidate genes for hereditary cataract in the Emory mouse mutant. G3 (BETHESDA, MD.) 2023; 13:jkad055. [PMID: 36891866 PMCID: PMC10151407 DOI: 10.1093/g3journal/jkad055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/20/2023] [Accepted: 02/28/2023] [Indexed: 03/10/2023]
Abstract
The Emory cataract (Em) mouse mutant has long been proposed as an animal model for age-related or senile cataract in humans-a leading cause of visual impairment. However, the genetic defect(s) underlying the autosomal dominant Em phenotype remains elusive. Here, we confirmed development of the cataract phenotype in commercially available Em/J mice [but not ancestral Carworth Farms White (CFW) mice] at 6-8 months of age and undertook whole-exome sequencing of candidate genes for Em. Analysis of coding and splice-site variants did not identify any disease-causing/associated mutations in over 450 genes known to underlie inherited and age-related forms of cataract and other lens disorders in humans and mice, including genes for lens crystallins, membrane/cytoskeleton proteins, DNA/RNA-binding proteins, and those associated with syndromic/systemic forms of cataract. However, we identified three cataract/lens-associated genes each with one novel homozygous variant including predicted missense substitutions in Prx (p.R167C) and Adamts10 (p.P761L) and a disruptive in-frame deletion variant (predicted missense) in Abhd12 (p.L30_A32delinsS) that were absent in CFW and over 35 other mouse strains. In silico analysis predicted that the missense substitutions in Prx and Adamts10 were borderline neutral/damaging and neutral, respectively, at the protein function level, whereas, that in Abhd12 was functionally damaging. Both the human counterparts of Adamts10 and Abhd12 are clinically associated with syndromic forms of cataract known as Weil-Marchesani syndrome 1 and polyneuropathy, hearing loss, ataxia, retinitis pigmentosa, and cataract syndrome, respectively. Overall, while we cannot exclude Prx and Adamts10, our data suggest that Abhd12 is a promising candidate gene for cataract in the Em/J mouse.
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Affiliation(s)
- Thomas M Bennett
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Yuefang Zhou
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Kacie J Meyer
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Michael G Anderson
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Alan Shiels
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO 63110, USA
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10
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Zhang J, Li P, Sun L, Jiang N, Guo W, Wang J, Gao F, Li J, Li H, Zhang J, Mu H, Hu Y, Cui X. Knockout of miR-184 in zebrafish leads to ocular abnormalities by elevating p21 levels. FASEB J 2023; 37:e22927. [PMID: 37086087 DOI: 10.1096/fj.202300067r] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 03/20/2023] [Accepted: 04/04/2023] [Indexed: 04/23/2023]
Abstract
miR-184 is one of the most abundant miRNAs expressed in the lens and corneal tissue. Mutations in the seed region of miR-184 are responsible for inherited anterior segment dysgenesis. Animal models recapitulating miR-184-related anterior segment dysgenesis are still lacking, and the molecular basis of ocular abnormalities caused by miR-184 dysfunction has not been well elucidated in vivo. In the present study, we constructed a miR-184-/- zebrafish line by destroying both two dre-mir-184 paralogs with CRISPR-Cas9 technology. Although there were no gross developmental defects, the miR-184-/- zebrafish displayed microphthalmia and cataract phenotypes. Cytoskeletal abnormalities, aggregation of γ-crystallin, and lens fibrosis were induced in miR-184-/- lenses. However, no obvious corneal abnormalities were observed in miR-184-/- zebrafish. Instead of apoptosis, deficiency of miR-184 led to aberrant cell proliferation and a robust increase in p21 levels in zebrafish eyes. Inhibition of p21 by UC2288 compromised the elevation of lens fibrosis markers in miR-184-/- lenses. RNA-seq demonstrated that levels of four transcriptional factors HSF4, Sox9a, CTCF, and Smad6a, all of which could suppress p21 expression, were reduced in miR-184-/- eyes. The predicted zebrafish miR-184 direct target genes (e.g., atp1a3a and nck2a) were identified and verified in miR-184-/- eye tissues. The miR-184-/- zebrafish is the first animal model mimicking miR-184-related anterior segment dysgenesis and could broaden our understanding of the roles of miR-184 in eye development.
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Affiliation(s)
- Jing Zhang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Ping Li
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Luqian Sun
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Ning Jiang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Wenya Guo
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Jungai Wang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Fen Gao
- Kaifeng Key Lab of Myopia and Cataract, Kaifeng Central Hospital, Kaifeng, China
| | - Jing Li
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Hui Li
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Jun Zhang
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
| | - Hongmei Mu
- Kaifeng Key Lab of Myopia and Cataract, Kaifeng Central Hospital, Kaifeng, China
| | - Yanzhong Hu
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xiukun Cui
- Joint National Laboratory for Antibody Drug Engineering, The First Affiliated Hospital, School of Medicine, Henan University, Kaifeng, China
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Chhunchha B, Kubo E, Krueger RR, Singh DP. Hydralazine Revives Cellular and Ocular Lens Health-Span by Ameliorating the Aging and Oxidative-Dependent Loss of the Nrf2-Activated Cellular Stress Response. Antioxidants (Basel) 2023; 12:140. [PMID: 36671002 PMCID: PMC9854670 DOI: 10.3390/antiox12010140] [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: 11/18/2022] [Revised: 01/03/2023] [Accepted: 01/04/2023] [Indexed: 01/10/2023] Open
Abstract
A major hallmark of aging-associated diseases is the inability to evoke cellular defense responses. Transcriptional protein Nrf2 (nuclear factor erythroid-derived 2-related factor) plays a pivotal role in the oxidative stress response, cellular homeostasis, and health span. Nrf2's activation has been identified as a therapeutic target to restore antioxidant defense in aging. Here, we demonstrated that FDA-approved drug, hydralazine (Hyd), was a reactivator of the Nrf2/ARE (antioxidant response element) pathway in various ages and types of mouse (m) or human (h) lens epithelial cells (LECs) and mice lenses in-vitro/in-vivo. This led to Hyd-driven abatement of carbonyls, reduced reactive oxygen species (ROS), and reduced 4-HNE/MDA-adducts with cytoprotection, and extended lens healthspan by delaying/preventing lens opacity against aging/oxidative stress. We elucidated that Hyd activated the protective signaling by inducing Nrf2 to traverse from the cytoplasm to the nucleus and potentiated the ARE response by direct interaction of Nrf2 and ARE sequences of the promoter. Loss-of-function study and cotreatment of Hyd and antioxidant, N-acetyl cysteine (NAC) or Peroxiredoxin (Prdx)6, specified that Nrf2/ARE-driven increase in the promoter activity was Hyd-dependent. Our study provides proof-of concept evidence and, thereby, paves the way to repurposing Hyd as a therapeutic agent to delay/prevent aging and oxidative-related disorders.
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Affiliation(s)
- Bhavana Chhunchha
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Eri Kubo
- Department of Ophthalmology, Kanazawa Medical University, Kanazawa 9200293, Japan
| | - Ronald R. Krueger
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Dhirendra P. Singh
- Department of Ophthalmology and Visual Sciences, University of Nebraska Medical Center, Omaha, NE 68198, USA
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12
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Jha R, Priya B, Solu T, Patel I. Visual outcome and complications of small-incision cataract surgery. Oman J Ophthalmol 2023; 16:51-54. [PMID: 37007243 PMCID: PMC10062067 DOI: 10.4103/ojo.ojo_172_21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 06/24/2022] [Accepted: 08/26/2022] [Indexed: 02/23/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Small-incision cataract surgery (SICS) is a commonly performed procedure in developing countries. It does not require expensive machines and can be safely done in high-volume centers also yielding good visual outcomes in the majority of patients. The objective of our study was to assess visual outcomes after SICS conducted at a tertiary care center in South Gujarat and also assessment of various complications responsible for poor visual outcomes. MATERIALS AND METHODS Three hundred and fifteen cataract patients were included in the study. An assessment of intraoperative and postoperative complications was done. Postoperative visual acuity assessment was done and compared with preoperative visual acuity of the patient and factors responsible for poor visual outcomes were assessed. A follow-up examination was done on days 1, 3, 7, 14, and 30. RESULTS The mean age group of patients was 59.3 years. Females were slightly more (53.3%) in number as compared to males. The most common surgical complication encountered were striate keratopathy (6.35%), followed by iris damage (5.71%), posterior capsular rent (PCR) with vitreous loss (3.14%), hypotony (0.63%), intraocular lens decentration (0.63%), surgery-induced astigmatism (0.63%), choroidal detachment (0.32%), endophthalmitis (0.32%), and hyphema (0.32%). About 95.87% of patients had vision better than 6/18. Complications associated with poor visual outcome (<6/18) were PCR, endophthalmitis, choroidal detachment, and surgical-induced astigmatism. CONCLUSIONS Although SICS can have a significant chance of complications, good visual outcomes can be attained in the majority of patients.
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13
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Upadhyay AK, Mueller NH, Petrash JM, Kompella UB. Nano-assemblies enhance chaperone activity, stability, and delivery of alpha B-crystallin-D3 (αB-D3). J Control Release 2022; 352:411-421. [PMID: 36272662 DOI: 10.1016/j.jconrel.2022.10.026] [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: 06/10/2022] [Revised: 09/17/2022] [Accepted: 10/16/2022] [Indexed: 11/06/2022]
Abstract
Crystallins, small heat shock chaperone proteins that prevent protein aggregation, are of potential value in treating protein aggregation disorders. However, their therapeutic use is limited by their low potency and poor intracellular delivery. One approach to facilitate the development of crystallins is to improve their activity, stability, and delivery. In this study, zinc addition to αB-crystallin-D3 (αB-D3) formed supramolecular nano- and micro- assemblies, induced dose-dependent changes in structure (beta-sheet to alpha-helix) and increased surface hydrophobicity and chemical stability. Further, crystallin assemblies exhibited a size-dependent chaperone activity, with the nano-assemblies being superior to micro-assemblies and 4.3-fold more effective than the native protein in preventing β-mercaptoethanol induced aggregation of insulin. Insulin rescued by crystallin assemblies retained the activity as evidenced by glucose uptake in 3T3-L1 cells. The most active nano-assemblies enhanced protein stability, in the presence of urea, by 1.6-fold, whereas intracellular delivery was enhanced by 3.0-fold. The αB-D3 crystallin nano-assemblies exhibit uniquely enhanced stability, activity, and delivery compared to the native protein.
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Affiliation(s)
- Arun K Upadhyay
- Nanomedicine and Drug Delivery Laboratory, Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Niklaus H Mueller
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - J Mark Petrash
- Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Uday B Kompella
- Nanomedicine and Drug Delivery Laboratory, Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Ophthalmology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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14
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Quinlan RA, Clark JI. Insights into the biochemical and biophysical mechanisms mediating the longevity of the transparent optics of the eye lens. J Biol Chem 2022; 298:102537. [PMID: 36174677 PMCID: PMC9638808 DOI: 10.1016/j.jbc.2022.102537] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/20/2022] [Accepted: 09/22/2022] [Indexed: 11/18/2022] Open
Abstract
In the human eye, a transparent cornea and lens combine to form the "refracton" to focus images on the retina. This requires the refracton to have a high refractive index "n," mediated largely by extracellular collagen fibrils in the corneal stroma and the highly concentrated crystallin proteins in the cytoplasm of the lens fiber cells. Transparency is a result of short-range order in the spatial arrangement of corneal collagen fibrils and lens crystallins, generated in part by post-translational modifications (PTMs). However, while corneal collagen is remodeled continuously and replaced, lens crystallins are very long-lived and are not replaced and so accumulate PTMs over a lifetime. Eventually, a tipping point is reached when protein aggregation results in increased light scatter, inevitably leading to the iconic protein condensation-based disease, age-related cataract (ARC). Cataracts account for 50% of vision impairment worldwide, affecting far more people than other well-known protein aggregation-based diseases. However, because accumulation of crystallin PTMs begins before birth and long before ARC presents, we postulate that the lens protein PTMs contribute to a "cataractogenic load" that not only increases with age but also has protective effects on optical function by stabilizing lens crystallins until a tipping point is reached. In this review, we highlight decades of experimental findings that support the potential for PTMs to be protective during normal development. We hypothesize that ARC is preventable by protecting the biochemical and biophysical properties of lens proteins needed to maintain transparency, refraction, and optical function.
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Affiliation(s)
- Roy A Quinlan
- Department of Biosciences, Durham University, South Road Science Site, Durham, United Kingdom; Department of Biological Structure, University of Washington, Seattle, Washington, USA.
| | - John I Clark
- Department of Biological Structure, University of Washington, Seattle, Washington, USA.
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15
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Islam S, Do M, Frank BS, Hom GL, Wheeler S, Fujioka H, Wang B, Minocha G, Sell DR, Fan X, Lampi KJ, Monnier VM. α-Crystallin chaperone mimetic drugs inhibit lens γ-crystallin aggregation: potential role for cataract prevention. J Biol Chem 2022; 298:102417. [PMID: 36037967 PMCID: PMC9525908 DOI: 10.1016/j.jbc.2022.102417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 08/15/2022] [Accepted: 08/16/2022] [Indexed: 11/29/2022] Open
Abstract
Γ-Crystallins play a major role in age-related lens transparency. Their destabilization by mutations and physical chemical insults are associated with cataract formation. Therefore, drugs that increase their stability should have anticataract properties. To this end, we screened 2560 Federal Drug Agency–approved drugs and natural compounds for their ability to suppress or worsen H2O2 and/or heat-mediated aggregation of bovine γ-crystallins. The top two drugs, closantel (C), an antihelminthic drug, and gambogic acid (G), a xanthonoid, attenuated thermal-induced protein unfolding and aggregation as shown by turbidimetry fluorescence spectroscopy dynamic light scattering and electron microscopy of human or mouse recombinant crystallins. Furthermore, binding studies using fluorescence inhibition and hydrophobic pocket–binding molecule bis-8-anilino-1-naphthalene sulfonic acid revealed static binding of C and G to hydrophobic sites with medium-to-low affinity. Molecular docking to HγD and other γ-crystallins revealed two binding sites, one in the “NC pocket” (residues 50–150) of HγD and one spanning the “NC tail” (residues 56–61 to 168–174 in the C-terminal domain). Multiple binding sites overlap with those of the protective mini αA-crystallin chaperone MAC peptide. Mechanistic studies using bis-8-anilino-1-naphthalene sulfonic acid as a proxy drug showed that it bound to MAC sites, improved Tm of both H2O2 oxidized and native human gamma D, and suppressed turbidity of oxidized HγD, most likely by trapping exposed hydrophobic sites. The extent to which these drugs act as α-crystallin mimetics and reduce cataract progression remains to be demonstrated. This study provides initial insights into binding properties of C and G to γ-crystallins.
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Affiliation(s)
- Sidra Islam
- Dept of Pathology and Biochemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Michael Do
- Dept of Pathology and Biochemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Brett S Frank
- Dept of Pathology and Biochemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Grant L Hom
- Dept of Pathology and Biochemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Samuel Wheeler
- Dept of Integrative Biosciences, Oregon Health & Sciences University, Portland, OR 97239
| | - Hisashi Fujioka
- Cryo-EM Core Facility, School of Medicine, Case Western Reserve University, Case Western Reserve University, Cleveland, OH 44016
| | - Benlian Wang
- Center for Proteomics and Bioinformatics, Dept of Nutrition, Case Western Reserve University, Cleveland, OH 44106
| | - Geeta Minocha
- Dept of Pathology and Biochemistry, Case Western Reserve University, Cleveland, OH 44106
| | - David R Sell
- Dept of Pathology and Biochemistry, Case Western Reserve University, Cleveland, OH 44106
| | - Xingjun Fan
- Dept of Cell Biology and Anatomy, Augusta University, Georgia, GA 30912
| | - Kirsten J Lampi
- Dept of Integrative Biosciences, Oregon Health & Sciences University, Portland, OR 97239
| | - Vincent M Monnier
- Dept of Pathology and Biochemistry, Case Western Reserve University, Cleveland, OH 44106; Dept of Biochemistry, Case Western Reserve University, Cleveland OH 44106.
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16
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Yang C, Miao A, Yang C, Huang C, Chen H, Jiang Y, Deng C, Sun N. Precise Detection of Cataracts with Specific High-Risk Factors by Layered Binary Co-Ionizers Assisted Aqueous Humor Metabolic Analysis. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2105905. [PMID: 35621284 PMCID: PMC9313487 DOI: 10.1002/advs.202105905] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 04/26/2022] [Indexed: 06/14/2023]
Abstract
Diabetes and high myopia as well-known high-risk factors can aggravate cataracts, yet clinical coping strategy remains a bottleneck. Metabolic analysis tends to be powerful for precisely detection and mechanism exploration since most of diseases including cataracts are accompanied by metabolic disorder. Herein, a layered binary co-ionizers assisted aqueous humor metabolic analysis tool is proposed for potentially etiological typing and detection of cataracts, including age-related cataracts (ARC), cataracts with diabetes mellitus (CDM), and cataracts with high myopia (CHM). Startlingly, taking advantage of the optimal machine learning algorithm and all metabolic fingerprints, 100% of accuracy, precision, and recall rates are achieved for arbitrary comparison between groups. Moreover, 11, 9, and 7 key metabolites with explicit identities are confirmed as markers of discriminating CDM from ARC, CHM from ARC, and CDM from CHM, and the corresponding area under the curve values of validation cohorts are 0.985, 1.000, and 1.000. Finally, the critical impact of diabetes/high myopia on cataracts is revealed by excavating the change levels and metabolic pathways of key metabolites. This work updates the insights of prevention and treatment about cataracts at metabolic level and throws out huge surprises and progresses metabolic diagnosis toward a reality.
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Affiliation(s)
- Chenjie Yang
- Department of ChemistryInstitue of Metabolism and Integrate Biology (IMIB)Zhongshan HospitalFudan UniversityShanghai200433China
| | - Aizhu Miao
- Eye Institute and Department of Ophthalmology, Eye & ENT HospitalFudan UniversityShanghai200031China
| | - Chaochao Yang
- Department of ChemistryInstitue of Metabolism and Integrate Biology (IMIB)Zhongshan HospitalFudan UniversityShanghai200433China
| | - Chuwen Huang
- Department of Gastroenterology and HepatologyZhongshan HospitalFudan UniversityShanghai200032China
| | - Haolin Chen
- Department of ChemistryInstitue of Metabolism and Integrate Biology (IMIB)Zhongshan HospitalFudan UniversityShanghai200433China
| | - Yongxiang Jiang
- Eye Institute and Department of Ophthalmology, Eye & ENT HospitalFudan UniversityShanghai200031China
| | - Chunhui Deng
- Department of ChemistryInstitue of Metabolism and Integrate Biology (IMIB)Zhongshan HospitalFudan UniversityShanghai200433China
| | - Nianrong Sun
- Department of Gastroenterology and HepatologyZhongshan HospitalFudan UniversityShanghai200032China
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17
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Muranov KO, Ostrovsky MA. Biochemistry of Eye Lens in the Norm and in Cataractogenesis. BIOCHEMISTRY. BIOKHIMIIA 2022; 87:106-120. [PMID: 35508906 DOI: 10.1134/s0006297922020031] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 09/30/2021] [Accepted: 09/30/2021] [Indexed: 06/14/2023]
Abstract
The absence of cellular organelles in fiber cells and very high cytoplasmic protein concentration (up to 900 mg/ml) minimize light scattering in the lens and ensure its transparency. Low oxygen concentration, powerful defense systems (antioxidants, antioxidant enzymes, chaperone-like protein alpha-crystallin, etc.) maintain lens transparency. On the other hand, the ability of crystallins to accumulate age-associated post-translational modifications, which reduce the resistance of lens proteins to oxidative stress, is an important factor contributing to the cataract formation. Here, we suggest a mechanism of cataractogenesis common for the action of different cataractogenic factors, such as age, radiation, ultraviolet light, diabetes, etc. Exposure to these factors leads to the damage and death of lens epithelium, which allows oxygen to penetrate into the lens through the gaps in the epithelial layer and cause oxidative damage to crystallins, resulting in protein denaturation, aggregation, and formation of multilamellar bodies (the main cause of lens opacification). The review discusses various approaches to the inhibition of lens opacification (cataract development), in particular, a combined use of antioxidants and compounds enhancing the chaperone-like properties of alpha-crystallin. We also discuss the paradox of high efficiency of anti-cataract drugs in laboratory settings with the lack of their clinical effect, which might be due to the late use of the drugs at the stage, when the opacification has already formed. A probable solution to this situation will be development of new diagnostic methods that will allow to predict the emergence of cataract long before the manifestation of its clinical signs and to start early preventive treatment.
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Affiliation(s)
- Konstantin O Muranov
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, 119334, Russia.
| | - Mikhail A Ostrovsky
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, 119334, Russia
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18
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Zhang F, Richter G, Bourgeois B, Spreitzer E, Moser A, Keilbach A, Kotnik P, Madl T. A General Small-Angle X-ray Scattering-Based Screening Protocol for Studying Physical Stability of Protein Formulations. Pharmaceutics 2021; 14:69. [PMID: 35056965 PMCID: PMC8778066 DOI: 10.3390/pharmaceutics14010069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 12/22/2021] [Accepted: 12/23/2021] [Indexed: 11/16/2022] Open
Abstract
A fundamental step in developing a protein drug is the selection of a stable storage formulation that ensures efficacy of the drug and inhibits physiochemical degradation or aggregation. Here, we designed and evaluated a general workflow for screening of protein formulations based on small-angle X-ray scattering (SAXS). Our SAXS pipeline combines automated sample handling, temperature control, and fast data analysis and provides protein particle interaction information. SAXS, together with different methods including turbidity analysis, dynamic light scattering (DLS), and SDS-PAGE measurements, were used to obtain different parameters to provide high throughput screenings. Using a set of model proteins and biopharmaceuticals, we show that SAXS is complementary to dynamic light scattering (DLS), which is widely used in biopharmaceutical research and industry. We found that, compared to DLS, SAXS can provide a more sensitive measure for protein particle interactions, such as protein aggregation and repulsion. Moreover, we show that SAXS is compatible with a broader range of buffers, excipients, and protein concentrations and that in situ SAXS provides a sensitive measure for long-term protein stability. This workflow can enable future high-throughput analysis of proteins and biopharmaceuticals and can be integrated with well-established complementary physicochemical analysis pipelines in (biopharmaceutical) research and industry.
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Affiliation(s)
- Fangrong Zhang
- Key Laboratory of Gastrointestinal Cancer, Ministry of Education, School of Basic Medical Sciences, Fujian Medical University, Fuzhou 350122, China;
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (G.R.); (B.B.); (E.S.)
| | - Gesa Richter
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (G.R.); (B.B.); (E.S.)
| | - Benjamin Bourgeois
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (G.R.); (B.B.); (E.S.)
| | - Emil Spreitzer
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (G.R.); (B.B.); (E.S.)
| | - Armin Moser
- Anton Paar GmbH, 8054 Graz, Austria; (A.M.); (A.K.); (P.K.)
| | | | - Petra Kotnik
- Anton Paar GmbH, 8054 Graz, Austria; (A.M.); (A.K.); (P.K.)
| | - Tobias Madl
- Gottfried Schatz Research Center for Cell Signaling, Metabolism and Aging, Molecular Biology and Biochemistry, Medical University of Graz, 8010 Graz, Austria; (G.R.); (B.B.); (E.S.)
- BioTechMed-Graz, 8010 Graz, Austria
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19
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Cantrell LS, Schey KL. Data-Independent Acquisition Mass Spectrometry of the Human Lens Enhances Spatiotemporal Measurement of Fiber Cell Aging. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2021; 32:2755-2765. [PMID: 34705440 PMCID: PMC9685647 DOI: 10.1021/jasms.1c00193] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The ocular lens proteome undergoes post-translational and progressive degradation as fiber cells age. The oldest fiber cells and the proteins therein are present at birth and are retained through death. Transparency of the lens is maintained in part by the high abundance Crystallin family proteins (up to 300 mg/mL), which establishes a high dynamic range of protein abundance. As a result, previous data-dependent analysis (DDA) measurements of the lens proteome are less equipped to identify the lowest abundance proteins. To probe more deeply into the lens proteome, we measured the insoluble lens proteome of an 18-year-old human with DDA and data-independent analysis (DIA) methods. By applying more recent library-free DIA search methods, 5,161 protein groups, 50,386 peptides, and 4,960 deamidation sites were detected: significantly outperforming the quantity of identifications in using DDA and pan-human DIA library searches. Finally, by segmenting the lens into multiple fiber cell-age-related regions, we uncovered cell-age-related changes in proteome composition and putative function.
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Affiliation(s)
- Lee S Cantrell
- Chemical and Physical Biology Program, Vanderbilt University, Nashville, Tennessee 37212, United States
| | - Kevin L Schey
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee 37212, United States
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20
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Li Y, Parkinson DY, Feng J, Xia CH, Gong X. Quantitative X-ray tomographic analysis reveals calcium precipitation in cataractogenesis. Sci Rep 2021; 11:17401. [PMID: 34465795 PMCID: PMC8408149 DOI: 10.1038/s41598-021-96867-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/12/2021] [Indexed: 02/07/2023] Open
Abstract
Cataracts, named for pathological light scattering in the lens, are known to be associated with increased large protein aggregates, disrupted protein phase separation, and/or osmotic imbalances in lens cells. We have applied synchrotron phase contrast X-ray micro-computed tomography to directly examine an age-related nuclear cataract model in Cx46 knockout (Cx46KO) mice. High-resolution 3D X-ray tomographic images reveal amorphous spots and strip-like dense matter precipitates in lens cores of all examined Cx46KO mice at different ages. The precipitates are predominantly accumulated in the anterior suture regions of lens cores, and they become longer and dense as mice age. Alizarin red staining data confirms the presence of calcium precipitates in lens cores of all Cx46KO mice. This study indicates that the spatial and temporal calcium precipitation is an age-related event associated with age-related nuclear cataract formation in Cx46KO mice, and further suggests that the loss of Cx46 promotes calcium precipitates in the lens core, which is a new mechanism that likely contributes to the pathological light scattering in this age-related cataract model.
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Affiliation(s)
- Yuxing Li
- Vision Science Program and School of Optometry, University of California, Berkeley, 693 Minor Hall, Berkeley, CA, 94720-2020, USA
- Tsinghua-Berkeley Shenzhen Institute (TBSI), UC Berkeley, Berkeley, CA, USA
| | - Dilworth Y Parkinson
- Advanced Light Source Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jun Feng
- Advanced Light Source Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Chun-Hong Xia
- Vision Science Program and School of Optometry, University of California, Berkeley, 693 Minor Hall, Berkeley, CA, 94720-2020, USA
| | - Xiaohua Gong
- Vision Science Program and School of Optometry, University of California, Berkeley, 693 Minor Hall, Berkeley, CA, 94720-2020, USA.
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21
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Shiels A, Hejtmancik JF. Inherited cataracts: Genetic mechanisms and pathways new and old. Exp Eye Res 2021; 209:108662. [PMID: 34126080 PMCID: PMC8595562 DOI: 10.1016/j.exer.2021.108662] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/13/2021] [Accepted: 06/01/2021] [Indexed: 12/15/2022]
Abstract
Cataract(s) is the clinical equivalent of lens opacity and is caused by light scattering either by high molecular weight protein aggregates in lens cells or disruption of the lens microarchitecture itself. Genetic mutations underlying inherited cataract can provide insight into the biological processes and pathways critical for lens homeostasis and transparency, classically including the lens crystallins, connexins, membrane proteins or components, and intermediate filament proteins. More recently, cataract genes have been expanded to include newly identified biological processes such as chaperone or protein degradation components, transcription or growth factors, channels active in the lens circulation, and collagen and extracellular matrix components. Cataracts can be classified by age, and in general congenital cataracts are caused by severe mutations resulting in major damage to lens proteins, while age related cataracts are associated with variants that merely destabilize proteins thereby increasing susceptibility to environmental insults over time. Thus there might be separate pathways to opacity for congenital and age-related cataracts whereby congenital cataracts induce the unfolded protein response (UPR) and apoptosis to destroy the lens microarchitecture, while in age related cataract high molecular weight (HMW) aggregates formed by denatured crystallins bound by α-crystallin result in light scattering without severe damage to the lens microarchitecture.
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Affiliation(s)
- Alan Shiels
- Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, 63110, USA.
| | - J Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, 20892-1860, USA.
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22
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Timsina R, Mainali L. Association of Alpha-Crystallin with Fiber Cell Plasma Membrane of the Eye Lens Accompanied by Light Scattering and Cataract Formation. MEMBRANES 2021; 11:447. [PMID: 34203836 PMCID: PMC8232717 DOI: 10.3390/membranes11060447] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Revised: 06/11/2021] [Accepted: 06/12/2021] [Indexed: 02/04/2023]
Abstract
α-crystallin is a major protein found in the mammalian eye lens that works as a molecular chaperone by preventing the aggregation of proteins and providing tolerance to stress in the eye lens. These functions of α-crystallin are significant for maintaining lens transparency. However, with age and cataract formation, the concentration of α-crystallin in the eye lens cytoplasm decreases with a corresponding increase in the membrane-bound α-crystallin, accompanied by increased light scattering. The purpose of this review is to summarize previous and recent findings of the role of the: (1) lens membrane components, i.e., the major phospholipids (PLs) and sphingolipids, cholesterol (Chol), cholesterol bilayer domains (CBDs), and the integral membrane proteins aquaporin-0 (AQP0; formally MIP26) and connexins, and (2) α-crystallin mutations and post-translational modifications (PTMs) in the association of α-crystallin to the eye lens's fiber cell plasma membrane, providing thorough insights into a molecular basis of such an association. Furthermore, this review highlights the current knowledge and need for further studies to understand the fundamental molecular processes involved in the association of α-crystallin to the lens membrane, potentially leading to new avenues for preventing cataract formation and progression.
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Affiliation(s)
- Raju Timsina
- Department of Physics, Boise State University, Boise, ID 83725, USA;
| | - Laxman Mainali
- Department of Physics, Boise State University, Boise, ID 83725, USA;
- Biomolecular Sciences Graduate Program, Boise State University, Boise, ID 83725, USA
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23
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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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24
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Affiliation(s)
- Andrew W Truman
- Department of Biological Sciences, University of North Carolina at Charlotte, Charlotte, North Carolina, USA.
| | - Dimitra Bourboulia
- Department of Urology, SUNY Upstate Medical University, Syracuse, New York, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, New York, USA.
| | - Mehdi Mollapour
- Department of Urology, SUNY Upstate Medical University, Syracuse, New York, USA; Department of Biochemistry and Molecular Biology, SUNY Upstate Medical University, Syracuse, New York, USA; Upstate Cancer Center, SUNY Upstate Medical University, Syracuse, New York, USA.
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