1
|
Li D, Ju F, Wang H, Fan C, Jacob JC, Gul S, Zaliani A, Wartmann T, Polidori MC, Bruns CJ, Zhao Y. Combination of the biomarkers for aging and cancer? - Challenges and current status. Transl Oncol 2023; 38:101783. [PMID: 37716258 PMCID: PMC10514562 DOI: 10.1016/j.tranon.2023.101783] [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: 01/30/2023] [Revised: 09/04/2023] [Accepted: 09/07/2023] [Indexed: 09/18/2023] Open
Abstract
The proportion of patients diagnosed with cancer has been shown to rise with the increasing aging global population. Advanced age is a major risk factor for morbidity and mortality in older adults. As individuals experience varying health statuses, particularly with age, it poses a challenge for medical professionals in the cancer field to obtain standardized treatment outcomes. Hence, relying solely on chronological age and disease-related parameters is inadequate for clinical decision-making for elderly patients. With functional, multimorbidity-related, and psychosocial changes that occur with aging, oncologic diseases may develop and be treated differently from younger patients, leading to unique challenges in treatment efficacy and tolerance. To overcome this challenge, personalized therapy using biomarkers has emerged as a promising solution. Various categories of biomarkers, including inflammatory, hematological, metabolic, endocrine, and DNA modification-related indicators, may display features related to both cancer and aging, aiding in the development of innovative therapeutic approaches for patients with cancer in old age. Furthermore, physical functional measurements as non-molecular phenotypic biomarkers are being investigated for their potential complementary role in structured multidomain strategies to combat age-related diseases such as cancer. This review provides insight into the current developments, recent discoveries, and significant challenges in cancer and aging biomarkers, with a specific focus on their application in advanced age.
Collapse
Affiliation(s)
- Dai Li
- Department of General, Visceral, Tumor and Transplantation Surgery, University Hospital of Cologne, Kerpener Straße 62, 50937 Cologne, Germany; Department of Anesthesiology, Changhai Hospital, Naval Medical University, Shanghai, China
| | - Feng Ju
- Department of General, Visceral, Tumor and Transplantation Surgery, University Hospital of Cologne, Kerpener Straße 62, 50937 Cologne, Germany
| | - Han Wang
- Department of Anesthesiology, Changhai Hospital, Naval Medical University, Shanghai, China
| | - Chunfu Fan
- Medical faculty, University of Cologne, Germany
| | | | - Sheraz Gul
- Fraunhofer Institute for Translational Medicine and Pharmacology, Schnackenburgallee 114, d-22525 Hamburg, Germany; Fraunhofer Cluster of Excellence Immune-Mediated Diseases CIMD, Hamburg Site, Schnackenburgallee 114, d-22525 Hamburg, Germany
| | - Andrea Zaliani
- Fraunhofer Institute for Translational Medicine and Pharmacology, Schnackenburgallee 114, d-22525 Hamburg, Germany; Fraunhofer Cluster of Excellence Immune-Mediated Diseases CIMD, Hamburg Site, Schnackenburgallee 114, d-22525 Hamburg, Germany
| | - Thomas Wartmann
- Department of General, Visceral und Vascular Surgery, Otto von Guericke University, Magdeburg, Leipziger Str. 44, Magdeburg, 39120, Germany
| | - Maria Cristina Polidori
- Ageing Clinical Research, Department II of Internal Medicine and Center for Molecular Medicine Cologne, University of Cologne, Faculty of Medicine and University Hospital Cologne, Cologne, Germany; Cologne Excellence Cluster on Cellular Stress-Responses in Aging-Associated Diseases (CECAD), University of Cologne, Cologne Germany
| | - Christiane J Bruns
- Department of General, Visceral, Tumor and Transplantation Surgery, University Hospital of Cologne, Kerpener Straße 62, 50937 Cologne, Germany; Center for Integrated Oncology (CIO) Aachen, Bonn, Cologne and Düsseldorf, Cologne, Germany
| | - Yue Zhao
- Department of General, Visceral, Tumor and Transplantation Surgery, University Hospital of Cologne, Kerpener Straße 62, 50937 Cologne, Germany.
| |
Collapse
|
2
|
Lim JC, Caballero Arredondo M, Braakhuis AJ, Donaldson PJ. Vitamin C and the Lens: New Insights into Delaying the Onset of Cataract. Nutrients 2020; 12:E3142. [PMID: 33066702 PMCID: PMC7602486 DOI: 10.3390/nu12103142] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/06/2020] [Accepted: 10/09/2020] [Indexed: 12/18/2022] Open
Abstract
Cataracts or clouding of the lens is the leading cause of blindness in the world. Age and diabetes are major risk factors, and with an increasing aging and diabetic population, the burden of cataracts will grow. Cataract surgery is an effective way to restore vision; however, alternatives to cataract surgery are required to reduce the looming cataract epidemic. Since it is well established that oxidative damage plays a major role in the etiology of cataracts, antioxidants have been promoted as therapies to delay and/or prevent cataracts. However, many antioxidant interventions including vitamin C have produced mixed results as anti-cataract therapies. Progress has been made towards our understanding of lens physiology and the mechanisms involved in the delivery and uptake of antioxidants to the lens which may guide future studies aimed at addressing some of the inconsistencies seen in previous animal and human studies. Of interest is the potential for vitamin C based supplements in delaying the onset of cataracts post vitrectomy which occurs in up to 80% of patients within two years. These targeted approaches are required to reduce the burden of cataract on hospitals and improve the quality of life of our aging and diabetic population.
Collapse
Affiliation(s)
- Julie C Lim
- Department of Physiology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1142, New Zealand;
| | - Mariana Caballero Arredondo
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1142, New Zealand; (M.C.A.); (A.J.B.)
| | - Andrea J. Braakhuis
- Discipline of Nutrition, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1142, New Zealand; (M.C.A.); (A.J.B.)
| | - Paul J. Donaldson
- Department of Physiology, New Zealand National Eye Centre, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1142, New Zealand;
| |
Collapse
|
3
|
Berry V, Georgiou M, Fujinami K, Quinlan R, Moore A, Michaelides M. Inherited cataracts: molecular genetics, clinical features, disease mechanisms and novel therapeutic approaches. Br J Ophthalmol 2020; 104:1331-1337. [PMID: 32217542 DOI: 10.1136/bjophthalmol-2019-315282] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 11/20/2019] [Accepted: 01/28/2020] [Indexed: 02/01/2023]
Abstract
Cataract is the most common cause of blindness in the world; during infancy and early childhood, it frequently results in visual impairment. Congenital cataracts are phenotypically and genotypically heterogeneous and can occur in isolation or in association with other systemic disorders. Significant progress has been made in identifying the molecular genetic basis of cataract; 115 genes to date have been found to be associated with syndromic and non-syndromic cataract and 38 disease-causing genes have been identified to date to be associated with isolated cataract. In this review, we briefly discuss lens development and cataractogenesis, detail the variable cataract phenotypes and molecular mechanisms, including genotype-phenotype correlations, and explore future novel therapeutic avenues including cellular therapies and pharmacological treatments.
Collapse
Affiliation(s)
- Vanita Berry
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK
| | - Michalis Georgiou
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Kaoru Fujinami
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK.,National Institute of Sensory Organs, National Hospital Organization, Tokyo Medical Centre, Tokyo, Japan
| | - Roy Quinlan
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK.,Department of Biosciences, School of Biological and Medical Sciences, University of Durham, Durham, UK
| | - Anthony Moore
- Moorfields Eye Hospital NHS Foundation Trust, London, UK.,Ophthalmology Department, University of California School of Medicine, San Francisco, California, USA
| | - Michel Michaelides
- Department of Genetics, UCL Institute of Ophthalmology, University College London, London, UK .,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| |
Collapse
|
4
|
Cataractogenic load – A concept to study the contribution of ionizing radiation to accelerated aging in the eye lens. MUTATION RESEARCH-REVIEWS IN MUTATION RESEARCH 2019; 779:68-81. [DOI: 10.1016/j.mrrev.2019.02.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Revised: 02/12/2019] [Accepted: 02/14/2019] [Indexed: 12/11/2022]
|
5
|
Chemerovski-Glikman M, Mimouni M, Dagan Y, Haj E, Vainer I, Allon R, Blumenthal EZ, Adler-Abramovich L, Segal D, Gazit E, Zayit-Soudry S. Rosmarinic Acid Restores Complete Transparency of Sonicated Human Cataract Ex Vivo and Delays Cataract Formation In Vivo. Sci Rep 2018; 8:9341. [PMID: 29921877 PMCID: PMC6008418 DOI: 10.1038/s41598-018-27516-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 05/22/2018] [Indexed: 12/31/2022] Open
Abstract
Cataract, the leading cause of vision impairment worldwide, arises from abnormal aggregation of crystallin lens proteins. Presently, surgical removal is the only therapeutic approach. Recent findings have triggered renewed interest in development of non-surgical treatment alternatives. However, emerging treatments are yet to achieve full and consistent lens clearance. Here, the first ex vivo assay to screen for drug candidates that reduce human lenticular protein aggregation was developed. This assay allowed the identification of two leading compounds as facilitating the restoration of nearly-complete transparency of phacoemulsified cataractous preparation ex vivo. Mechanistic studies demonstrated that both compounds reduce cataract microparticle size and modify their amyloid-like features. In vivo studies confirmed that the lead compound, rosmarinic acid, delays cataract formation and reduces the severity of lens opacification in model rats. Thus, the ex vivo assay may provide an initial platform for broad screening of potential novel therapeutic agents towards pharmacological treatment of cataract.
Collapse
Affiliation(s)
- Marina Chemerovski-Glikman
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, 69978, Israel
| | - Michael Mimouni
- Department of Ophthalmology, Rambam Health Care Campus, Technion Israel Institute of Technology, Haifa, Israel
| | - Yarden Dagan
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, 69978, Israel
| | - Esraa Haj
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, 69978, Israel
| | - Igor Vainer
- Department of Ophthalmology, Rambam Health Care Campus, Technion Israel Institute of Technology, Haifa, Israel
| | - Raviv Allon
- Department of Ophthalmology, Rambam Health Care Campus, Technion Israel Institute of Technology, Haifa, Israel
| | - Eytan Z Blumenthal
- Department of Ophthalmology, Rambam Health Care Campus, Technion Israel Institute of Technology, Haifa, Israel
| | - Lihi Adler-Abramovich
- Department of Oral Biology, The Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, 69978, Israel
| | - Daniel Segal
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, 69978, Israel
- Sagol Interdisciplinary School of Neurosciences, Tel-Aviv University, Tel Aviv, 69978, Israel
| | - Ehud Gazit
- Department of Molecular Microbiology and Biotechnology, George S. Wise Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, 69978, Israel.
- Department of Materials Science and Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, Tel Aviv, 6997801, Israel.
| | - Shiri Zayit-Soudry
- Department of Ophthalmology, Rambam Health Care Campus, Technion Israel Institute of Technology, Haifa, Israel.
| |
Collapse
|
6
|
Hotspots of age-related protein degradation: the importance of neighboring residues for the formation of non-disulfide crosslinks derived from cysteine. Biochem J 2017; 474:2475-2487. [PMID: 28592682 DOI: 10.1042/bcj20170268] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 05/30/2017] [Accepted: 06/07/2017] [Indexed: 12/27/2022]
Abstract
Over time, the long-lived proteins that are present throughout the human body deteriorate. Typically, they become racemized, truncated, and covalently cross-linked. One reaction responsible for age-related protein cross-linking in the lens was elucidated recently and shown to involve spontaneous formation of dehydroalanine (DHA) intermediates from phosphoserine. Cys residues are another potential source of DHA, and evidence for this was found in many lens crystallins. In the human lens, some sites were more prone to forming non-disulfide covalent cross-links than others. Foremost among them was Cys5 in βA4 crystallin. The reason for this enhanced reactivity was investigated using peptides. Oxidation of Cys to cystine was a prerequisite for DHA formation, and DHA production was accelerated markedly by the presence of a Lys, one residue separated from Cys5. Modeling and direct investigation of the N-terminal sequence of βA4 crystallin, as well as a variety of homologous peptides, showed that the epsilon amino group of Lys can promote DHA production by nucleophilic attack on the alpha proton of cystine. Once a DHA residue was generated, it could form intermolecular cross-links with Lys and Cys. In the lens, the most abundant cross-link involved Cys5 of βA4 crystallin attached via a thioether bond to glutathione. These findings illustrate the potential of Cys and disulfide bonds to act as precursors for irreversible covalent cross-links and the role of nearby amino acids in creating 'hotpsots' for the spontaneous processes responsible for protein degradation in aged tissues.
Collapse
|
7
|
Rakete S, Nagaraj RH. UVA Light-mediated Ascorbate Oxidation in Human Lenses. Photochem Photobiol 2017; 93:1091-1095. [PMID: 28084012 DOI: 10.1111/php.12717] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/05/2016] [Indexed: 12/11/2022]
Abstract
Whether ascorbate oxidation is promoted by UVA light in human lenses and whether this process is influenced by age and GSH levels are not known. In this study, we used paired lenses from human donors. One lens of each pair was exposed to UVA light, whereas the other lens was kept in the dark for the same period of time as the control. Using LC-MS/MS analyses, we found that older lenses (41-73 years) were more susceptible to UVA-induced ascorbate oxidation than younger lenses (18-40 years). Approximately 36% of the ascorbate (relative to control) was oxidized in older lenses compared to ~16% in younger lenses. Furthermore, lenses with higher levels of GSH were less susceptible to UVA-induced ascorbate oxidation compared to those with lower levels, and this effect was not dependent on age. The oxidation of ascorbate led to elevated levels of reactive α-dicarbonyl compounds. In summary, our study showed that UVA light exposure leads to ascorbate oxidation in human lenses and that such oxidation is more pronounced in aged lenses and is inversely related to GSH levels. Our findings suggest that UVA light exposure could lead to protein aggregation through ascorbate oxidation in human lenses.
Collapse
Affiliation(s)
- Stefan Rakete
- Department of Ophthalmology, School of Medicine, University of Colorado, Aurora, CO
| | - Ram H Nagaraj
- Department of Ophthalmology, School of Medicine, University of Colorado, Aurora, CO.,Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO
| |
Collapse
|
8
|
Avila F, Friguet B, Silva E. Photosensitizing Activity of Endogenous Eye Lens Chromophores: An Attempt to Unravel Their Contributions to Photo-Aging and Cataract Disease. Photochem Photobiol 2015; 91:767-79. [DOI: 10.1111/php.12443] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 02/20/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Felipe Avila
- Escuela de Nutrición y Dietética; Facultad de Ciencias de la Salud; Universidad de Talca; Talca Chile
- Programa de Investigación de Excelencia Interdisciplinario en Envejecimiento Saludable (PIEI-ES); Universidad de Talca; Talca Chile
| | - Bertrand Friguet
- UPMC Univ. Paris 06; CNRS UMR 8256; INSERM U1164; Adaptation Biologique et Vieillissement; Institute of Biology Paris-Seine; Paris France
| | - Eduardo Silva
- Departamento de Química Física; Facultad de Química; Pontifícia Universidad Católica de Chile; Santiago Chile
| |
Collapse
|
9
|
Klüver E, Meyer M. Thermoplastic processing, rheology, and extrudate properties of wheat, soy, and pea proteins. POLYM ENG SCI 2014. [DOI: 10.1002/pen.24032] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Enno Klüver
- FILK Research Institute of Leather and Plastic Sheeting; Meissner Ring 1-5 D-09599 Freiberg Germany
| | - Michael Meyer
- FILK Research Institute of Leather and Plastic Sheeting; Meissner Ring 1-5 D-09599 Freiberg Germany
| |
Collapse
|
10
|
Linetsky M, Raghavan CT, Johar K, Fan X, Monnier VM, Vasavada AR, Nagaraj RH. UVA light-excited kynurenines oxidize ascorbate and modify lens proteins through the formation of advanced glycation end products: implications for human lens aging and cataract formation. J Biol Chem 2014; 289:17111-23. [PMID: 24798334 DOI: 10.1074/jbc.m114.554410] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Advanced glycation end products (AGEs) contribute to lens protein pigmentation and cross-linking during aging and cataract formation. In vitro experiments have shown that ascorbate (ASC) oxidation products can form AGEs in proteins. However, the mechanisms of ASC oxidation and AGE formation in the human lens are poorly understood. Kynurenines are tryptophan oxidation products produced from the indoleamine 2,3-dioxygenase (IDO)-mediated kynurenine pathway and are present in the human lens. This study investigated the ability of UVA light-excited kynurenines to photooxidize ASC and to form AGEs in lens proteins. UVA light-excited kynurenines in both free and protein-bound forms rapidly oxidized ASC, and such oxidation occurred even in the absence of oxygen. High levels of GSH inhibited but did not completely block ASC oxidation. Upon UVA irradiation, pigmented proteins from human cataractous lenses also oxidized ASC. When exposed to UVA light (320-400 nm, 100 milliwatts/cm(2), 45 min to 2 h), young human lenses (20-36 years), which contain high levels of free kynurenines, lost a significant portion of their ASC content and accumulated AGEs. A similar formation of AGEs was observed in UVA-irradiated lenses from human IDO/human sodium-dependent vitamin C transporter-2 mice, which contain high levels of kynurenines and ASC. Our data suggest that kynurenine-mediated ASC oxidation followed by AGE formation may be an important mechanism for lens aging and the development of senile cataracts in humans.
Collapse
Affiliation(s)
- Mikhail Linetsky
- From the Departments of Chemistry, Ophthalmology and Visual Sciences,
| | | | - Kaid Johar
- the Iladevi Cataract and IOL Research Center, Gurukul Road, Memnagar, Ahmedabad, Gujarat-380052, India
| | | | - Vincent M Monnier
- Pathology, and Biochemistry, Case Western Reserve University, Cleveland, Ohio 44106 and
| | - Abhay R Vasavada
- the Iladevi Cataract and IOL Research Center, Gurukul Road, Memnagar, Ahmedabad, Gujarat-380052, India
| | | |
Collapse
|
11
|
Shang F, Taylor A. Roles for the ubiquitin-proteasome pathway in protein quality control and signaling in the retina: implications in the pathogenesis of age-related macular degeneration. Mol Aspects Med 2012; 33:446-66. [PMID: 22521794 PMCID: PMC3417153 DOI: 10.1016/j.mam.2012.04.001] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 04/05/2012] [Indexed: 10/28/2022]
Abstract
The accumulation of damaged or postsynthetically modified proteins and dysregulation of inflammatory responses and angiogenesis in the retina/RPE are thought be etiologically related to formation of drusen and choroidal neovascularization (CNV), hallmarks of age-related macular degeneration (AMD). The ubiquitin-proteasome pathway (UPP) plays crucial roles in protein quality control, cell cycle control and signal transduction. Selective degradation of aberrant proteins by the UPP is essential for timely removal of potentially cytotoxic damaged or otherwise abnormal proteins. Proper function of the UPP is thought to be required for cellular function. In contrast, age--or stress induced--impairment the UPP or insufficient UPP capacity may contribute to the accumulation of abnormal proteins, cytotoxicity in the retina, and AMD. Crucial roles for the UPP in eye development, regulation of signal transduction, and antioxidant responses are also established. Insufficient UPP capacity in retina and RPE can result in dysregulation of signal transduction, abnormal inflammatory responses and CNV. There are also interactions between the UPP and lysosomal proteolytic pathways (LPPs). Means that modulate the proteolytic capacity are making their way into new generation of pharmacotherapies for delaying age-related diseases and may augment the benefits of adequate nutrition, with regard to diminishing the burden of AMD.
Collapse
Affiliation(s)
- Fu Shang
- Laboratory for Nutrition and Vision Research, USDA Human Nutrition Research Center on Aging, Boston, MA 02111, USA.
| | | |
Collapse
|
12
|
Shang F, Taylor A. Role of the ubiquitin-proteasome in protein quality control and signaling: implication in the pathogenesis of eye diseases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2012; 109:347-96. [PMID: 22727427 DOI: 10.1016/b978-0-12-397863-9.00010-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The ubiquitin-proteasome pathway (UPP) plays important roles in many cellular functions, such as protein quality control, cell cycle control, and signal transduction. The selective degradation of aberrant proteins by the UPP is essential for the timely removal of potential cytotoxic damaged or otherwise abnormal proteins. Conversely, accumulation of the cytotoxic abnormal proteins in eye tissues is etiologically associated with many age-related eye diseases such as retina degeneration, cataract, and certain types of glaucoma. Age- or stress-induced impairment or overburdening of the UPP appears to contribute to the accumulation of abnormal proteins in eye tissues. Cell cycle and signal transduction are regulated by the conditional UPP-dependent degradation of the regulators of these processes. Impairment or overburdening of the UPP could also result in dysregulation of cell cycle control and signal transduction. The consequences of the improper cell cycle and signal transduction include defects in ocular development, wound healing, angiogenesis, or inflammatory responses. Methods that enhance or preserve UPP function or reduce its burden may be useful strategies for preventing age-related eye diseases.
Collapse
Affiliation(s)
- Fu Shang
- Laboratory for Nutrition and Vision Research, USDA Human Nutrition Research Center on Aging, Boston, Massachusetts, USA
| | | |
Collapse
|
13
|
Avila F, Friguet B, Silva E. Simultaneous chemical and photochemical protein crosslinking induced by irradiation of eye lens proteins in the presence of ascorbate: the photosensitizing role of an UVA-visible-absorbing decomposition product of vitamin C. Photochem Photobiol Sci 2010; 9:1351-8. [PMID: 20734005 DOI: 10.1039/c0pp00048e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Exposure to light has been implicated as a risk factor during aging of the eye lens and in cataract generation. In order to visualize the actual effect of UVA-visible light on this tissue, we incubated water-soluble eye lens proteins with ascorbate in the presence and absence of UVA-visible light for 3, 6 and 9 days at low oxygen concentration. The samples incubated in the presence of light were characterized by an initially small but continuous increase over time of the protein crosslinking. This was not the result of more extensive glycation because the decrease in amino group content of the proteins and the decomposition of ascorbate was the same in both irradiated and unirradiated samples. The augmented crosslinking capacity observed in the presence of UVA-visible light is due to the generation of a chromophore from the decomposition of ascorbate. This chromophore, obtained after 3, 6 and 9 days of incubation of solutions containing only ascorbate, induces both protein-crosslinking and oxidation after exposure to UVA-visible light in the presence of lens proteins. The extent of the crosslinking was proportional to the amount of the chromophore present in the solution. The presence of this chromophore was also determined when ascorbate was incubated with four-fold higher concentrations of N-α-acetyl lysine and N-α-acetyl arginine. When these samples were used as photosensitizers, the crosslinking degree was conditioned by the presence of this chromophore; nonetheless, the ascorbate-mediated advanced glycation end product (AGE) generation also made a contribution. The results of this work indicate that ascorbate oxidation, which generates the AGEs responsible for the chemical crosslinking of the lens proteins, also simultaneously produces a chromophore that can act as a photosensitizer, further increasing the protein crosslinking.
Collapse
Affiliation(s)
- Felipe Avila
- Departamento de Química Física, Facultad de Química, Pontificia Universidad Católica de Chile, Casilla 306, Correo 22, Santiago de Chile
| | | | | |
Collapse
|
14
|
Abstract
Not only are human lenses different in many ways from those of non-primates, they also undergo dramatic changes with age. These age-dependent alterations lead to perturbations in the properties of older lenses, and ultimately to disturbances in visual function, which typically become apparent at middle age. Recent data suggest that many, if not all, of these age-dependent features can be traced to the lack of macromolecular turnover in the lens and to the inexorable modifications to proteins and membrane components over a period of decades. Exposure of lenses to heat can reproduce many of these alterations, suggesting that long-term incubation at body temperature may be an important factor in aging the human lens. Two conclusions flow from this. Firstly, the human lens may be an ideal tissue for studying macromolecular aging in man. Secondly, it will be extremely challenging to examine the origin of human age-related conditions, such as presbyopia and nuclear cataract, using traditional laboratory animals. Characterising the unfolding and decomposition of long-lived macromolecules appears to provide the key to understanding the two most common human lens disorders: presbyopia and age-related nuclear cataract.
Collapse
|
15
|
Nakadate Y, Mizuguchi C, Azuma M, Tachibana T. Generation of a rat monoclonal antibody specific for glyoxalase I. Hybridoma (Larchmt) 2010; 28:447-50. [PMID: 20025505 DOI: 10.1089/hyb.2009.0048] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Glyoxalase I (GLO1) is a key enzyme that plays a role in the detoxification of methylglyoxal (MG), a toxic cellular metabolite produced during glycolysis. The present study reports on the preparation and properties of a monoclonal antibody (MAb) directed against mouse GLO1. The antibody was produced by hybridization of mouse myeloma cells with lymph node cells from an immunized rat. The MAb 6F10 specifically recognized GLO1, as evidenced by immunoblotting using a variety of extracts from cultured cells. In immunostaining using MAb 6F10, a diffuse cytoplasmic and nuclear staining pattern was observed. The MAb 6F10 promises to be useful in immunoblotting and immunostaining experiments in various cells and tissues to determine the expression levels of GLO1, as well as to further analyze the biological function of this protein.
Collapse
Affiliation(s)
- Yusuke Nakadate
- Department of Bioengineering, Graduate School of Engineering, Osaka City University, Osaka, Japan
| | | | | | | |
Collapse
|
16
|
Sharma KK, Santhoshkumar P. Lens aging: effects of crystallins. Biochim Biophys Acta Gen Subj 2009; 1790:1095-108. [PMID: 19463898 DOI: 10.1016/j.bbagen.2009.05.008] [Citation(s) in RCA: 234] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2009] [Revised: 05/01/2009] [Accepted: 05/13/2009] [Indexed: 02/01/2023]
Abstract
The primary function of the eye lens is to focus light on the retina. The major proteins in the lens--alpha, beta, and gamma-crystallins--are constantly subjected to age-related changes such as oxidation, deamidation, truncation, glycation, and methylation. Such age-related modifications are cumulative and affect crystallin structure and function. With time, the modified crystallins aggregate, causing the lens to increasingly scatter light on the retina instead of focusing light on it and causing the lens to lose its transparency gradually and become opaque. Age-related lens opacity, or cataract, is the major cause of blindness worldwide. We review deamidation, and glycation that occur in the lenses during aging keeping in mind the structural and functional changes that these modifications bring about in the proteins. In addition, we review proteolysis and discuss recent observations on how crystallin fragments generated in vivo, through their anti-chaperone activity may cause crystallin aggregation in aging lenses. We also review hyperbaric oxygen treatment induced guinea pig and 'humanized' ascorbate transporting mouse models as suitable options for studies on age-related changes in lens proteins.
Collapse
Affiliation(s)
- K Krishna Sharma
- Department of Ophthalmology, University of Missouri-Columbia, 1 Hospital Drive, Columbia, MO 65212, USA.
| | | |
Collapse
|
17
|
Glenn JV, Stitt AW. The role of advanced glycation end products in retinal ageing and disease. Biochim Biophys Acta Gen Subj 2009; 1790:1109-16. [PMID: 19409449 DOI: 10.1016/j.bbagen.2009.04.016] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 04/16/2009] [Accepted: 04/23/2009] [Indexed: 01/05/2023]
Abstract
The retina is exposed to a lifetime of potentially damaging environmental and physiological factors that make the component cells exquisitely sensitive to age-related processes. Retinal ageing is complex and a raft of abnormalities can accumulate in all layers of the retina. Some of this pathology serves as a sinister preamble to serious conditions such as age-related macular degeneration (AMD) which remains the leading cause of irreversible blindness in the Western world. The formation of advanced glycation end products (AGEs) is a natural function of ageing but accumulation of these adducts also represents a key pathophysiological event in a range of important human diseases. AGEs act as mediators of neurodegeneration, induce irreversible changes in the extracellular matrix, vascular dysfunction and pro-inflammatory signalling. Since many cells and tissues of the eye are profoundly influenced by such processes, it is fitting that advanced glycation is now receiving considerable attention as a possible pathogenic factor in visual disorders. This review presents the current evidence for a pathogenic role for AGEs and activation of the receptor for AGEs (RAGE) in initiation and progression of retinal disease. It draws upon the clinical and experimental literature and highlights the opportunities for further research that would definitively establish these adducts as important instigators of retinal disease. The therapeutic potential for novel agents that can ameliorate AGE formation of attenuate RAGE signalling in the retina is also discussed.
Collapse
Affiliation(s)
- Josephine V Glenn
- Centre for Vision & Vascular Science, School of Medicine, Dentistry & Biomedical Sciences, Queen's University Belfast, Belfast, BT12 6BA, Northern Ireland, UK
| | | |
Collapse
|
18
|
Nakadate Y, Uchida K, Shikata K, Yoshimura S, Azuma M, Hirata T, Konishi H, Kiyama H, Tachibana T. The formation of argpyrimidine, a methylglyoxal–arginine adduct, in the nucleus of neural cells. Biochem Biophys Res Commun 2009; 378:209-12. [DOI: 10.1016/j.bbrc.2008.11.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2008] [Accepted: 11/06/2008] [Indexed: 10/21/2022]
|
19
|
Fan X, Monnier VM. Inhibition of crystallin ascorbylation by nucleophilic compounds in the hSVCT2 mouse model of lenticular aging. Invest Ophthalmol Vis Sci 2008; 49:4945-52. [PMID: 18421088 DOI: 10.1167/iovs.08-1813] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Senile cataracts are associated with oxidation, fragmentation, cross-linking, insolubilization, and yellow pigmentation of lens crystallins. This process is partially explained by advanced glycation end products (AGEs) from ascorbic acid (ASA), as the authors unequivocally demonstrated in an hSVCT2 transgenic mouse. The authors present the first pharmacologic intervention study against ascorbylation in these mice. METHODS Five groups of mice from 2 to 9 months of age (10 mice/group) were fed a diet containing 0.1% (wt/wt) aminoguanidine, pyridoxamine, penicillamine, and nucleophilic compounds NC-I and NC-II. AGEs were determined in crystallin digests using high-performance liquid chromatography, liquid chromatography-mass spectrometry, or gas chromatography-mass spectrometry. Lens protein extract was incubated in vitro with ASA or dehydroascorbic acid. RESULTS The ASA level increased approximately 10-fold in all groups and was unaffected by treatment. AGEs were increased several-fold in transgenic compared with control lenses. Body weight, food intake, lenticular glutathione, and glycated lysine level were unaltered. In vitro, all compounds inhibited AGE formation. In vivo, NC-I and NC-II significantly decreased protein fluorescence at lambda(ex)335/(em)385 (P = 0.045, P = 0.017, respectively) and lambda(ex)370/(em)440 (P = 0.029, P = 0.007, respectively). Other inhibitors had no effect. After 7 months, only NC-I and NC-II induced a 50% reduction in pentosidine (P = NS for NC-I; P = 0.035 for NC-II). NC-I also decreased carboxymethyllysine (P = 0.032) and carboxyethyllysine (P = NS). Fluorescent cross-link K2P was decreased by NC-I, NC-II, aminoguanidine, and pyridoxamine (P = NS). CONCLUSIONS Pharmacologically blocking protein ascorbylation with absorbable guanidino compounds is feasible and may represent a new strategy for the delay of age-related nuclear sclerosis of the lens.
Collapse
Affiliation(s)
- Xingjun Fan
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
| | | |
Collapse
|
20
|
Ávila F, Matus A, Fuentealba D, Lissi E, Friguet B, Silva E. Autosensitized oxidation of glycated bovine lens proteins irradiated with UVA-visible light at low oxygen concentration. Photochem Photobiol Sci 2008; 7:718-24. [DOI: 10.1039/b719167g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
21
|
Linetsky M, Shipova E, Cheng R, Ortwerth BJ. Glycation by ascorbic acid oxidation products leads to the aggregation of lens proteins. Biochim Biophys Acta Mol Basis Dis 2007; 1782:22-34. [PMID: 18023423 DOI: 10.1016/j.bbadis.2007.10.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2007] [Revised: 10/03/2007] [Accepted: 10/10/2007] [Indexed: 11/30/2022]
Abstract
Previous studies from this laboratory have shown that there are striking similarities between the yellow chromophores, fluorophores and modified amino acids released by proteolytic digestion from calf lens proteins ascorbylated in vitro and their counterparts isolated from aged and cataractous lens proteins. The studies reported in this communication were conducted to further investigate whether ascorbic acid-mediated modification of lens proteins could lead to the formation of lens protein aggregates capable of scattering visible light, similar to the high molecular aggregates found in aged human lenses. Ascorbic acid, but not glucose, fructose, ribose or erythrulose, caused the aggregation of calf lens proteins to proteins ranging from 2.2 x 10(6) up to 3.0 x 10(8 )Da. This compared to proteins ranging from 1.8 x 10(6) up to 3.6 x 10(8 )Da for the water-soluble (WS) proteins isolated from aged human lenses. This aggregation was likely due to the glycation of lens crystallins because [U-(14)C] ascorbate was incorporated into the aggregate fraction and because NaCNBH(3), which reduces the initial Schiff base, prevented any protein aggregation. Reactions of ascorbate with purified crystallin fractions showed little or no aggregation of alpha-crystallin, significant aggregation of beta(H)-crystallin, but rapid precipitation of purified beta(L)- and gamma-crystallin. The aggregation of lens proteins can be prevented by the binding of damaged crystallins to alpha-crystallin due to its chaperone activity. Depending upon the ratios between the components of the incubation mixtures, alpha-crystallin prevented the precipitation of the purified beta(L)- and gamma-crystallin fractions during ascorbylation. The addition of at least 20% of alpha-crystallin by weight into glycation mixtures with beta(L)-, or gamma-crystallins completely inhibited protein precipitation, and increased the amount of the high molecular weight aggregates in solution. Static and dynamic light scattering measurements of the supernatants from the ascorbic acid-modified mixtures of alpha- and beta(L)-, or gamma-crystallins showed similar molar masses (up to 10(8 )Da) and hydrodynamic diameter (up to 80( )nm). These data support the hypothesis, that if the lens reducing environment is compromised, the ascorbylation of lens crystallins can significantly change the short range interactions between different classes of crystallins leading to protein aggregation, light scattering and eventually to senile cataract formation.
Collapse
|
22
|
Dai Z, Nemet I, Shen W, Monnier VM. Isolation, purification and characterization of histidino-threosidine, a novel Maillard reaction protein crosslink from threose, lysine and histidine. Arch Biochem Biophys 2007; 463:78-88. [PMID: 17466255 PMCID: PMC1978223 DOI: 10.1016/j.abb.2007.03.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2007] [Revised: 03/05/2007] [Accepted: 03/12/2007] [Indexed: 11/18/2022]
Abstract
We isolated a novel acid-labile yellow chromophore from the incubation of lysine, histidine and d-threose and identified its chemical structure by one and two-dimensional NMR spectroscopy combined with LC-tandem mass spectrometry. This new cross-link exhibits a UV absorbance maximum at 305 nm and a molecular mass of 451 Da. The proposed structure is 2-amino-5-(3-((4-(2-amino-2-carboxyethyl)-1H-imidazol-1-yl)methyl)-4-(1,2-dihydroxyethyl)-2-formyl-1H-pyrrol-1-yl)pentatonic acid, a cross-link between lysine and histidine with addition of two threose molecules. It was in part deduced and confirmed through synthesis of the analogous compound from n-butylamine, imidazole and d-threose. We assigned the compound the trivial name histidino-threosidine. Systemic incubation revealed that histidino-threosidine can be formed in low amounts from fructose, glyceraldehyde, methylglyoxal, glycolaldehyde, ascorbic acid, and dehydroascorbic acid, but at a much higher yield with degradation products of ascorbic acid, i.e. threose, erythrose, and erythrulose. Bovine lens protein incubated with 10 and 50 mM threose for two weeks yielded 560 and 2840 pmol/mg histidino-threosidine. Histidino-threosidine is to our knowledge the first Maillard reaction product known to involve histidine in a crosslink.
Collapse
Affiliation(s)
- Zhenyu Dai
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | | | | | | |
Collapse
|
23
|
Wang Z, Handa JT, Green WR, Stark WJ, Weinberg RS, Jun AS. Advanced glycation end products and receptors in Fuchs' dystrophy corneas undergoing Descemet's stripping with endothelial keratoplasty. Ophthalmology 2007; 114:1453-60. [PMID: 17320180 DOI: 10.1016/j.ophtha.2006.10.049] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2006] [Revised: 10/06/2006] [Accepted: 10/17/2006] [Indexed: 10/23/2022] Open
Abstract
PURPOSE To describe the histopathologic features of Descemet's membrane (DM) obtained from Fuchs' endothelial corneal dystrophy (FECD) corneas undergoing Descemet's stripping with endothelial keratoplasty (DSEK) and to assess the presence of advanced glycation end products (AGEs) and their receptors in FECD endothelium and DM. DESIGN Prospective observational case series. PARTICIPANTS Five eyes of 5 patients undergoing DSEK for FECD and 4 normal control eyebank corneas. METHODS Descemet's membrane and corneal endothelium from FECD patients undergoing DSEK were assessed with hematoxylin-eosin staining and immunohistochemistry for AGEs, receptor of AGEs (RAGE), and galectin 3 (AGE-R3). MAIN OUTCOME MEASURES Histopathologic abnormalities and presence of AGEs, RAGE, and AGE-R3 in DSEK specimens. RESULTS Histopathologic assessment of DSEK specimens from FECD patients disclosed thickening and nodularity of DM and loss of endothelial cells. Immunohistochemical staining of FECD DM for AGE, RAGE, and AGE-R3 showed an abundance of AGEs in the anterior portion of DM, mild positivity for RAGE, and moderate positivity for AGE-R3. CONCLUSIONS Tissue quality after DSEK is sufficient to allow detailed histopathologic analysis. The presence of AGEs, RAGE, and AGE-R3 in DM and corneal endothelium of FECD patients supports a link between accumulation of AGEs, oxidative stress, and corneal endothelial cell apoptosis in the pathogenesis of FECD.
Collapse
Affiliation(s)
- Zhiyou Wang
- Wilmer Eye Institute, The Johns Hopkins Medical Institutions, Baltimore, Maryland 21287, USA
| | | | | | | | | | | |
Collapse
|
24
|
Cheng R, Feng Q, Ortwerth BJ. LC-MS display of the total modified amino acids in cataract lens proteins and in lens proteins glycated by ascorbic acid in vitro. Biochim Biophys Acta Mol Basis Dis 2006; 1762:533-43. [PMID: 16540295 DOI: 10.1016/j.bbadis.2006.01.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2005] [Revised: 01/22/2006] [Accepted: 01/23/2006] [Indexed: 10/25/2022]
Abstract
We previously reported chromatographic evidence supporting the similarity of yellow chromophores isolated from aged human lens proteins, early brunescent cataract lens proteins and calf lens proteins ascorbylated in vitro [Cheng, R. et al. Biochimica et Biophysica Acta 1537, 14-26, 2001]. In this paper, new evidence supporting the chemical identity of the modified amino acids in these protein populations were collected by using a newly developed two-dimensional LC-MS mapping technique supported by tandem mass analysis of the major species. The pooled water-insoluble proteins from aged normal human lenses, early stage brunescent cataract lenses and calf lens proteins reacted with or without 20 mM ascorbic acid in air for 4 weeks were digested with a battery of proteolytic enzymes under argon to release the modified amino acids. Aliquots equivalent to 2.0 g of digested protein were subjected to size-exclusion chromatography on a Bio-Gel P-2 column and four major A330nm-absorbing peaks were collected. Peaks 1, 2 and 3, which contained most of the modified amino acids were concentrated and subjected to RP-HPLC/ESI-MS, and the mass elution maps were determined. The samples were again analyzed and those peaks with a 10(4) - 10(6) response factor were subjected to MS/MS analysis to identify the daughter ions of each modification. Mass spectrometric maps of peaks 1, 2 and 3 from cataract lenses showed 58, 40 and 55 mass values, respectively, ranging from 150 to 600 Da. Similar analyses of the peaks from digests of the ascorbylated calf lens proteins gave 81, 70 and 67 mass values, respectively, of which 100 were identical to the peaks in the cataract lens proteins. A total of 40 of the major species from each digest were analyzed by LC-MS/MS and 36 were shown to be identical. Calf lens proteins incubated without ascorbic acid showed several similar mass values, but the response factors were 100 to 1000-fold less for every modification. Based upon these data, we conclude that the majority of the major modified amino acids present in early stage brunescent Indian cataract lens proteins appear to arise as a result of ascorbic acid modification, and are presumably advanced glycation end-products.
Collapse
Affiliation(s)
- Rongzhu Cheng
- Mason Eye Institute, University of Missouri-Columbia, 404 Portland St. Columbia, MO 65201, USA.
| | | | | |
Collapse
|
25
|
Abstract
We report here the isolation of a novel acid-labile yellow chromophore from the enzymatic digest of human lens proteins and the identification of its chemical structure by LC-MS and NMR. This new chromophore exhibited a UV absorbance maximum at 343 nm and a molecular mass of 370 Da. One- and two-dimensional NMR analyses elucidated the structure as being 1-(5-amino-5-carboxypentyl)-4-(5-amino-5-carboxypentyl-amino)-3-hydroxy-2, 3-dihydropyridinium, a cross-link between the epsilon-amino groups of two lysine residues and a five-carbon atom ring. We assigned it the trivial name of K2P. Quantitative determinations of K2P in individual normal human lens or cataract lens water-soluble and water-insoluble protein digests revealed a significant enhancement of K2P in the early stage of brunescent cataract lens proteins (type I/II, 613 +/- 362 pmol/mg of water-insoluble sonicate supernatant (WISS) protein or 85 +/- 51 pmol/mg of water-soluble [WS] protein) when compared with aged normal human lens proteins (261 +/- 93 pmol/mg of WISS protein or 23 +/- 15 pmol/mg of WS protein). Furthermore, a gradual decrease of K2P in the late stages of brunescent cataract lenses with the development of the browning color in the lens argues different coloration mechanisms during the processes of normal aging and cataract development. This new cross-link may serve as a quantitatively significant biomarker for assessing the role of lens protein modifications during aging and in the pathogenesis of cataract.
Collapse
Affiliation(s)
- Rongzhu Cheng
- Mason Eye Institute--East University of Missouri-Columbia, MO 65203, USA.
| | | | | | | |
Collapse
|
26
|
Linetsky MD, Shipova EV, Legrand RD, Argirov OO. Glucose-derived Amadori compounds of glutathione. Biochim Biophys Acta Gen Subj 2005; 1724:181-93. [PMID: 15893878 DOI: 10.1016/j.bbagen.2005.04.003] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2004] [Revised: 04/04/2005] [Accepted: 04/05/2005] [Indexed: 10/25/2022]
Abstract
Under the chromatographic conditions used in these studies we observed time- and concentration-dependent formation of N-1-Deoxy-fructos-1-yl glutathione as the major glycation product formed in the mixtures of GSH with glucose. N-1-Deoxy-fructos-1-yl glutathione had a characteristic positively charged ion with m/z=470 Th in its LC-MS spectra. Mixtures of glutathione disulfide and glucose generated two compounds: N-1-Deoxy-fructos-1-yl GSSG (m/z=775 Th) as major adduct and bis di-N, N'-1-Deoxy-fructos-1-yl GSSG (m/z=937 Th) as the minor one. All three compounds showed a resonance signal at 55.2 ppm in the 13C-NMR spectra as C1 methylene group of deoxyfructosyl, which represents direct evidence that they are Amadori compounds. All three compounds purified from GSSG/Glc or GSH/Glc mixtures also showed LC-MS/MS fragmentation patterns identical to those of the synthetically synthesized N-1-Deoxy-fructos-1-yl glutathione, N-1-Deoxy-fructos-1-yl GSSG and bis di-N, N'-1-Deoxy-fructos-1-yl GSSG. N-1-Deoxy-fructos-1-yl glutathione was shown to be a poor substrate for glutathione peroxidase (6.7% of the enzyme's original specific activity) and glutathione-S-transferase (25.7% of the original enzyme's specific activity). Glutathione reductase failed to recycle the disulfide bond within the structure of di-substituted bis di-N, N'-1-Deoxy-fructos-1-yl GSSG. It showed only 1% of the original enzyme's specific activity, but retained its ability to reduce the disulfide bond within the structure of N-1-Deoxy-fructos-1-yl GSSG by 57% of its original specific activity. Since the GSH concentration in diabetic lens is significantly decreased and the glucose concentration can increase 10-fold and higher, the formation of Amadori products of the different forms of glutathione with this monosaccharide may be favored under these conditions and could contribute to a lowering of glutathione levels and an increase of oxidative stress observed in diabetic lens.
Collapse
Affiliation(s)
- Mikhail D Linetsky
- Department of Ophthalmology, University of Missouri, Columbia, MO 65212, USA.
| | | | | | | |
Collapse
|
27
|
Mody VC, Kakar M, Elfving A, Söderberg PG, Löfgren S. Ascorbate in the guinea pig lens: dependence on drinking water supplementation. ACTA ACUST UNITED AC 2005; 83:228-33. [PMID: 15799738 DOI: 10.1111/j.1600-0420.2005.00416.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
PURPOSE To investigate whether lens ascorbate concentration can be elevated with drinking water supplementation. METHODS Pigmented guinea pigs received drinking water supplemented with L-ascorbate, concentration 0.00, 2.84, 5.68 or 8.52 mm for a duration of 4 weeks. In addition, the chow fed to all animals contained 125 mmol L-ascorbate per kg of chow. At the end of the supplementation period, the guinea pigs were killed. Each lens was extracted. The lens was processed and ascorbate concentration was measured using high performance liquid chromatography (HPLC) with 254 nm ultraviolet radiation detection. The data were analysed with regression. RESULTS At the end of the test period, all lenses were devoid of cataract as observed by slit-lamp examination. All lenses contained a detectable concentration of ascorbate. Estimated 95% confidence intervals for mean animal-averaged lens ascorbate concentrations (micromol/g wet weight of whole lens) per group were 0.51 +/- 0.04 (0.00 mm; n = 6), 0.70 +/- 0.18 (2.84 mm; n = 6), 0.71 +/- 0.11 (5.68 mm; n = 5), and 0.71 +/- 0.06 (8.52 mm; n = 6). Animal-averaged lens ascorbate concentration [Asc(lens)] (micromol/g wet weight lens) increased with ascorbate supplementation in drinking water [Asc(water)] (M), in agreement with the model: [Asc(lens)] = A - Be(-kAsc(water)]. CONCLUSION Lens ascorbate concentration increases with drinking water supplementation in the guinea pig without cataract development. The currently presented method for measurement of whole lens ascorbate content is suitable.
Collapse
Affiliation(s)
- Vino C Mody
- St. Erik's Eye Hospital, Karolinska Institute, Stockholm, Sweden.
| | | | | | | | | |
Collapse
|
28
|
Cheng R, Feng Q, Argirov OK, Ortwerth BJ. Structure elucidation of a novel yellow chromophore from human lens protein. J Biol Chem 2004; 279:45441-9. [PMID: 15316021 DOI: 10.1074/jbc.m405664200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We report here the isolation of a novel acid-labile yellow chromophore from the enzymatic digest of human lens proteins and the identification of its chemical structure by liquid chromatography-mass spectrometry, liquid chromatography-tandem mass spectrometry, and (1)H, (13)C, and two-dimensional NMR. This new chromophore exhibited a UV absorbance maximum at 343 nm and fluorescence at 410 nm when excited at 343 nm. Analysis of the purified compound by reversed-phase HPLC with in-line electrospray ionization mass spectrometry revealed a molecular mass of 370 Da. One- and two-dimensional NMR analyses elucidated the structure to be 1-(5-amino-5-carboxypentyl)-4-(5-amino-5-carboxypentylamino)-3-hydroxy-2,3-dihydropyridinium, a cross-link between the epsilon-amino groups of two lysine residues, and a five-carbon ring. Because this cross-link contains two lysine residues and a dihydropyridinium ring, we assigned it the trivial name of K2P. Quantitative determinations of K2P in individual normal human lens or cataract lens water-soluble and water-insoluble protein digests were made using a high-performance liquid chromatograph equipped with a diode array detector. These measurements revealed a significant enhancement of K2P in cataract lens proteins (613 +/- 362 pmol/mg of water-insoluble sonicate supernatant (WISS) protein or 85 +/- 51 pmol/mg of WS protein) when compared with aged normal human lens proteins (261 +/- 93 pmol/mg of WISS protein or 23 +/- 15 pmol/mg of water-soluble (WS) protein). These data provide chemical evidence for increased protein cross-linking during aging and cataract development in vivo. This new cross-link may serve as a quantitatively more significant biomarker for assessing the role of lens protein modifications during aging and in the pathogenesis of cataract.
Collapse
Affiliation(s)
- Rongzhu Cheng
- Mason Eye Institute, The University of Missouri, Columbia, Missouri 65201, USA.
| | | | | | | |
Collapse
|
29
|
Krone CA, Ely JTA. Ascorbic acid, glycation, glycohemoglobin and aging. Med Hypotheses 2004; 62:275-9. [PMID: 14962639 DOI: 10.1016/s0306-9877(03)00313-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2003] [Accepted: 10/19/2003] [Indexed: 11/28/2022]
Abstract
The glycation of proteins alters both their structure and function. These changes have been linked to diabetic disorders and aging. The glycation of hemoglobin is also used as a diagnostic tool; the extent of glycation being a reflection of blood glucose averaged over a two to three month period. Accurate measures of average blood sugar (e.g., glycohemoglobin (GHb)) are important in clinical management of diabetes, pregnancy, cancer, etc. Ascorbic acid (AA) can react with proteins, including hemoglobin, and possibly interfere with GHb measurements. Past reports on the impact of AA on in vivo glycation have been equivocal. We studied GHb in subjects supplementing up to 20 g AA daily and found that for each 30 micromol/L increase in plasma AA, GHb was reduced by approximately 0.1. These results suggest that high AA intake can depress glycation, reduce GHb and lead to a clinically relevant underestimation of average blood sugar. Because AA is the most commonly consumed dietary supplement, awareness of an AA-associated bias in GHb is imperative. Of even broader significance is the possibility of AA-mediated inhibition of glycation in all proteins and the implications for aging. Moreover, AA could contribute through several other mechanisms to slowing of human aging (e.g., antioxidant properties, acceleration of pentose phosphate pathway, replacement of structural proteins).
Collapse
Affiliation(s)
- Cheryl A Krone
- Applied Research Institute, PO Box 1969, Palmerston North, New Zealand.
| | | |
Collapse
|
30
|
Abstract
Quantitative changes in the 330 nm absorbing chromophores and 350/450 nm fluorophores of water-soluble (WS) and water-insoluble (WI) proteins of individual human cataract lenses were characterized and compared with aged normal human lens. Twenty-five brunescent cataract lenses from India were selected from five different stages (types I-V) based upon the color of the lens. The WS and WI proteins from each lens were collected and subjected to an extensive enzymatic digestion procedure under argon. The lens protein digests were separated by Bio-Gel P-2 size-exclusion chromatography and individual peaks were analyzed further by reversed-phase HPLC. The total WI proteins increased and the total WS protein decreased with the development of cataract, especially in the late stages of cataract (III-V). The total 330 nm absorbance and 350/450 nm fluorescence of the WI fraction also increased, however, the A(330) and fluorescence per mg lens protein were constant except for type V (black) lenses. Bio-Gel P-2 chromatography separated the chromophores and fluorophores into four fractions. The main fraction (designated as peak 2+3) from the cataract WI proteins was several times higher than that present in aged normal human lens WI proteins. A significant increase of this fraction was observed in WI proteins, but not in WS proteins with cataract development. Similarly, fractions 1 and 4 in the WI proteins also increased gradually but fraction 5 did not. Reversed-phase HPLC resolved fraction (2+3) of the water-insoluble sonicate supernatant proteins into four 330 nm absorbing peaks and eight fluorescent peaks. Among these peaks, a late-eluting peak (peak 8) increased 10 to 15-fold with the progress of cataract, and accounted for 80% of the total chromophores in type V lenses. This peak may represent limit digests of advanced glycation end-products (AGEs) derived protein cross-links. HPLC profiles of fraction 5 from both WS and WI proteins showed numerous new peaks which were not observed in either WS protein from cataract or WI proteins from aged normal human. The severe coloration and the higher levels of numerous novel chromophores and fluorophores in brunescent cataractous lenses reveal the possibility that a different chemistry occurs during cataract development.
Collapse
Affiliation(s)
- Rongzhu Cheng
- Mason Eye Institute-East, School of Medicine, The University of Missouri, 404 Portland St., Columbia, MO 65201, USA.
| | | | | |
Collapse
|