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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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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3
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Patil H, Yi H, Cho KI, Ferreira PA. Proteostatic Remodeling of Small Heat Shock Chaperones─Crystallins by Ran-Binding Protein 2─and the Peptidyl-Prolyl cis-trans Isomerase and Chaperone Activities of Its Cyclophilin Domain. ACS Chem Neurosci 2024; 15:1967-1989. [PMID: 38657106 DOI: 10.1021/acschemneuro.3c00792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Abstract
Disturbances in protein phase transitions promote protein aggregation─a neurodegeneration hallmark. The modular Ran-binding protein 2 (Ranbp2) is a cytosolic molecular hub for rate-limiting steps of phase transitions of Ran-GTP-bound protein ensembles exiting nuclear pores. Chaperones also regulate phase transitions and proteostasis by suppressing protein aggregation. Ranbp2 haploinsufficiency promotes the age-dependent neuroprotection of the chorioretina against phototoxicity by proteostatic regulations of neuroprotective substrates of Ranbp2 and by suppressing the buildup of polyubiquitylated substrates. Losses of peptidyl-prolyl cis-trans isomerase (PPIase) and chaperone activities of the cyclophilin domain (CY) of Ranbp2 recapitulate molecular effects of Ranbp2 haploinsufficiency. These CY impairments also stimulate deubiquitylation activities and phase transitions of 19S cap subunits of the 26S proteasome that associates with Ranbp2. However, links between CY moonlighting activity, substrate ubiquitylation, and proteostasis remain incomplete. Here, we reveal the Ranbp2 regulation of small heat shock chaperones─crystallins in the chorioretina by proteomics of mice with total or selective modular deficits of Ranbp2. Specifically, loss of CY PPIase of Ranbp2 upregulates αA-Crystallin, which is repressed in adult nonlenticular tissues. Conversely, impairment of CY's chaperone activity opposite to the PPIase pocket downregulates a subset of αA-Crystallin's substrates, γ-crystallins. These CY-dependent effects cause age-dependent and chorioretinal-selective declines of ubiquitylated substrates without affecting the chorioretinal morphology. A model emerges whereby inhibition of Ranbp2's CY PPIase remodels crystallins' expressions, subdues molecular aging, and preordains the chorioretina to neuroprotection by augmenting the chaperone capacity and the degradation of polyubiquitylated substrates against proteostatic impairments. Further, the druggable Ranbp2 CY holds pan-therapeutic potential against proteotoxicity and neurodegeneration.
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Affiliation(s)
- Hemangi Patil
- Department of Ophthalmology Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Haiqing Yi
- Department of Ophthalmology Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Kyoung-In Cho
- Department of Ophthalmology Duke University Medical Center, Durham, North Carolina 27710, United States
| | - Paulo A Ferreira
- Department of Ophthalmology Duke University Medical Center, Durham, North Carolina 27710, United States
- Department of Pathology Duke University Medical Center, Durham, North Carolina 27710, United States
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4
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Quinn RL. Bomb pulse 14 C evidence for consistent remodeling rates of cortical femur collagen in middle-late adulthood. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 183:e24887. [PMID: 38229464 DOI: 10.1002/ajpa.24887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 11/21/2023] [Accepted: 11/28/2023] [Indexed: 01/18/2024]
Abstract
OBJECTIVES Bomb pulse (BP) radiocarbon (14 C) dating methods are used by forensic anthropologists to estimate the year-of-death (YOD) of unidentified individuals. Method resolution and accuracy depend on establishing lag times, or the difference between a tissue's BP 14 C-derived year and the YOD, of various tissue types from known deceased persons. Bone lag times span many years and are thought to increase with age as a function of slowing remodeling rates. However, remodeling rates for various skeletal elements, bone structures and phases are not well known. MATERIALS AND METHODS Here a simple method is used to estimate bone remodeling rates from a compilation of published cortical femur bone collagen BP 14 C measurements (n = 102). Linear regression models and nonparametric tests are used to detect changes in lag times and remodeling rates with increasing age-at-death. RESULTS Remodeling rates and lag times of 3.5%/year and 29 years, respectively, are estimated from individuals aged 40-97 years. In contrast to previous work, the analysis yielded modest and negligible changes in remodeling rates and lag times with advancing age. Moreover, statistically significant differences in remodeling rates and lag times were not found between reported females and males. DISCUSSION Implications for the temporal contexts within an individual's lifetime of biogeochemical data in archaeology and forensic anthropology are discussed, warranting additional BP 14 C studies of known individuals and integration with histomorphometric analysis.
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Affiliation(s)
- Rhonda L Quinn
- School of Earth, Environment and Society, Bowling Green State University, Bowling Green, Ohio, USA
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5
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Heath SL, Guseman AJ, Gronenborn AM, Horne WS. Probing effects of site-specific aspartic acid isomerization on structure and stability of GB1 through chemical protein synthesis. Protein Sci 2024; 33:e4883. [PMID: 38143426 PMCID: PMC10868458 DOI: 10.1002/pro.4883] [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: 11/15/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 12/26/2023]
Abstract
Chemical modifications of long-lived proteins, such as isomerization and epimerization, have been evoked as prime triggers for protein-damage related diseases. Deamidation of Asn residues, which results in formation of a mixture of l- and d-Asp and isoAsp via an intermediate aspartyl succinimide, can result in the disruption of cellular proteostasis and toxic protein depositions. In contrast to extensive data on the biological prevalence and functional implications of aspartyl succinimide formation, much less is known about the impact of the resulting altered backbone composition on properties of individual proteins at a molecular level. Here, we report the total chemical synthesis, biophysical characterization, and NMR structural analysis of a series of variants of the B1 domain of protein G from Streptococcal bacteria (GB1) in which all possible Asp isomers as well as an aspartyl succinimide were individually incorporated at a defined position in a solvent-exposed loop. Subtle local structural effects were observed; however, these were accompanied by notable differences in thermodynamic folded stability. Surprisingly, the noncanonical backbone connectivity of d-isoAsp led to a variant that exhibited enhanced stability relative to the natural protein.
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Affiliation(s)
- Shelby L. Heath
- Department of ChemistryUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Alex J. Guseman
- Department of Structural BiologyUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
| | - Angela M. Gronenborn
- Department of ChemistryUniversity of PittsburghPittsburghPennsylvaniaUSA
- Department of Structural BiologyUniversity of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
| | - W. Seth Horne
- Department of ChemistryUniversity of PittsburghPittsburghPennsylvaniaUSA
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6
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Patil H, Cho KI, Ferreira PA. Proteostatic remodeling of small heat shock chaperones - crystallins by Ran-binding protein 2 and the peptidyl-prolyl cis-trans isomerase and chaperone activities of its cyclophilin domain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.26.577462. [PMID: 38352504 PMCID: PMC10862737 DOI: 10.1101/2024.01.26.577462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
Disturbances in phase transitions and intracellular partitions of nucleocytoplasmic shuttling substrates promote protein aggregation - a hallmark of neurodegenerative diseases. The modular Ran-binding protein 2 (Ranbp2) is a cytosolic molecular hub for rate-limiting steps of disassembly and phase transitions of Ran-GTP-bound protein ensembles exiting nuclear pores. Chaperones also play central roles in phase transitions and proteostasis by suppressing protein aggregation. Ranbp2 haploinsufficiency promotes the age-dependent neuroprotection of the chorioretina against photo-oxidative stress by proteostatic regulations of Ranbp2 substrates and by countering the build-up of poly-ubiquitylated substrates. Further, the peptidyl-prolyl cis-trans isomerase (PPIase) and chaperone activities of the cyclophilin domain (CY) of Ranbp2 modulate the proteostasis of selective neuroprotective substrates, such as hnRNPA2B1, STAT3, HDAC4 or L/M-opsin, while promoting a decline of ubiquitylated substrates. However, links between CY PPIase activity on client substrates and its effect(s) on ubiquitylated substrates are unclear. Here, proteomics of genetically modified mice with deficits of Ranbp2 uncovered the regulation of the small heat shock chaperones - crystallins by Ranbp2 in the chorioretina. Loss of CY PPIase of Ranbp2 up-regulates αA-crystallin proteostasis, which is repressed in non-lenticular tissues. Conversely, the αA-crystallin's substrates, γ-crystallins, are down-regulated by impairment of CY's C-terminal chaperone activity. These CY-dependent effects cause the age-dependent decline of ubiquitylated substrates without overt chorioretinal morphological changes. A model emerges whereby the Ranbp2 CY-dependent remodeling of crystallins' proteostasis subdues molecular aging and preordains chorioretinal neuroprotection by augmenting the chaperone buffering capacity and the decline of ubiquitylated substrates against proteostatic impairments. Further, CY's moonlighting activity holds pan -therapeutic potential against neurodegeneration.
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7
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Zhang Y, Bi J, Ning Y, Feng J. Methodology Advances in Vertebrate Age Estimation. Animals (Basel) 2024; 14:343. [PMID: 38275802 PMCID: PMC10812784 DOI: 10.3390/ani14020343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 01/09/2024] [Accepted: 01/18/2024] [Indexed: 01/27/2024] Open
Abstract
Age is a core metric in vertebrate management, and the correct estimation of the age of an individual plays a principal role in comprehending animal behavior, identifying genealogical information, and assessing the potential reproductive capacity of populations. Vertebrates have a vertebral column and a distinct head containing a developed brain; they have played an important role in the study of biological evolution. However, biological age estimations constantly exhibit large deviations due to the diversity of vertebrate taxon species, sample types, and determination methods. To systematically and comprehensively understand age estimation methods in different situations, we classify the degree of damage to vertebrates during sample collection, present the sample types and their applications, list commonly applied methods, present methodological recommendations based on the combination of accuracy and implementability, and, finally, predict future methods for vertebrate age assessments, taking into account the current level of research and requirements. Through comprehensive data gathering and compilation, this work serves as an introduction and summary for those who are eager to catch up on related fields and facilitates the rapid and accurate selection of an evaluation method for researchers engaged in related research. This is essential to promote animal conservation and guide the smooth implementation of conservation management plans.
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Affiliation(s)
- Yifei Zhang
- College of Life Science, Jilin Agricultural University, Changchun 130118, China; (Y.Z.); (J.B.)
- Jilin Provincial International Cooperation Key Laboratory for Biological Control of Agricultural Pests, Changchun 130118, China
| | - Jinping Bi
- College of Life Science, Jilin Agricultural University, Changchun 130118, China; (Y.Z.); (J.B.)
- Jilin Provincial International Cooperation Key Laboratory for Biological Control of Agricultural Pests, Changchun 130118, China
| | - Yao Ning
- College of Life Science, Jilin Agricultural University, Changchun 130118, China; (Y.Z.); (J.B.)
- Jilin Provincial International Cooperation Key Laboratory for Biological Control of Agricultural Pests, Changchun 130118, China
| | - Jiang Feng
- College of Life Science, Jilin Agricultural University, Changchun 130118, China; (Y.Z.); (J.B.)
- Jilin Provincial International Cooperation Key Laboratory for Biological Control of Agricultural Pests, Changchun 130118, China
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun 130117, China
- Key Laboratory of Vegetation Ecology of Education Ministry, Institute of Grassland Science, Northeast Normal University, Changchun 130024, China
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8
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Overly KE, Shervette VR. Caribbean deepwater snappers: Application of the bomb radiocarbon age estimation validation in understanding aspects of ecology and life history. PLoS One 2023; 18:e0295650. [PMID: 38150486 PMCID: PMC10752517 DOI: 10.1371/journal.pone.0295650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 11/21/2023] [Indexed: 12/29/2023] Open
Abstract
Reef fishes have been utilized as food fish throughout the U.S. Caribbean and Gulf of Mexico waters for centuries, with increasing fishing effort in recent decades. As a result, many species have experienced declines in landings, including deepwater snappers such as queen snapper Etelis oculatus and blackfin snapper Lutjanus buccanella. However, little to no peer-reviewed published research exists on basic life history parameters for either species. Confirming the accuracy of an age estimation method for a fish species is essential for ensuring sustainable fisheries management. This is because in the assessment of fisheries species population age-based parameters, including longevity, age at sexual maturity, growth rate, mortality, age-specific reproductive output, and lifetime reproductive output, are important in understanding overall life history strategies of managed stocks. The past stock assessment on U.S. Caribbean queen snapper utilized an estimated longevity of 8 y, derived from length frequencies for fish from St. Lucia. Blackfin snapper has an estimated longevity of 27 y based on a relatively small study from offshore waters of the southeastern U.S. The focus of our investigation was to estimate maximum longevity of two data-poor species in the U.S. Caribbean. The accuracy of ageing methods was tested via bomb radiocarbon age estimation validation and effects of depth on Δ14C in otolith cores and eye lens core values were examined. Results from our work indicate a maximum validated age of 45 y for queen snapper, and 43 y for blackfin snapper. Our findings indicate queen snapper and blackfin snapper are long-lived (> 40 y). The resulting Δ14C comparison between eye lens cores and otolith cores has important implications for the study of age validation, specifically when deepwater species are involved.
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Affiliation(s)
- Katherine E. Overly
- Technical and Engineering Support Alliance, National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Southeast Fisheries Science Center, Panama City, Florida, United States of America
- School of Forest, Fisheries, and Geomatics Sciences, University of Florida, Gainesville, Florida, United States of America
| | - Virginia R. Shervette
- Fish/Fisheries Conservation Lab, University of South Carolina Aiken, Aiken, South Carolina, United States of America
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Adav SS, Ng KW. Recent omics advances in hair aging biology and hair biomarkers analysis. Ageing Res Rev 2023; 91:102041. [PMID: 37634889 DOI: 10.1016/j.arr.2023.102041] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/27/2023] [Accepted: 08/23/2023] [Indexed: 08/29/2023]
Abstract
Aging is a complex natural process that leads to a decline in physiological functions, which is visible in signs such as hair graying, thinning, and loss. Although hair graying is characterized by a loss of pigment in the hair shaft, the underlying mechanism of age-associated hair graying is not fully understood. Hair graying and loss can have a significant impact on an individual's self-esteem and self-confidence, potentially leading to mental health problems such as depression and anxiety. Omics technologies, which have applications beyond clinical medicine, have led to the discovery of candidate hair biomarkers and may provide insight into the complex biology of hair aging and identify targets for effective therapies. This review provides an up-to-date overview of recent omics discoveries, including age-associated alterations of proteins and metabolites in the hair shaft and follicle, and highlights the significance of hair aging and graying biomarker discoveries. The decline in hair follicle stem cell activity with aging decreased the regeneration capacity of hair follicles. Cellular senescence, oxidative damage and altered extracellular matrix of hair follicle constituents characterized hair follicle and hair shaft aging and graying. The review attempts to correlate the impact of endogenous and exogenous factors on hair aging. We close by discussing the main challenges and limitations of the field, defining major open questions and offering an outlook for future research.
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Affiliation(s)
- Sunil S Adav
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
| | - Kee Woei Ng
- School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore; Nanyang Environment and Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, CleanTech One, 637141, Singapore.
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10
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Zhang X, Liu B, Lal K, Liu H, Tran M, Zhou M, Ezugwu C, Gao X, Dang T, Au ML, Brown E, Wu H, Liao Y. Antioxidant System and Endoplasmic Reticulum Stress in Cataracts. Cell Mol Neurobiol 2023; 43:4041-4058. [PMID: 37874455 PMCID: PMC10842247 DOI: 10.1007/s10571-023-01427-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 10/14/2023] [Indexed: 10/25/2023]
Abstract
The primary underlying contributor for cataract, a leading cause of vision impairment and blindness worldwide, is oxidative stress. Oxidative stress triggers protein damage, cell apoptosis, and subsequent cataract formation. The nuclear factor-erythroid 2-related factor 2 (Nrf2) serves as a principal redox transcriptional factor in the lens, offering a line of defense against oxidative stress. In response to oxidative challenges, Nrf2 dissociates from its inhibitor, Kelch-like ECH-associated protein 1 (Keap1), moves to the nucleus, and binds to the antioxidant response element (ARE) to activate the Nrf2-dependent antioxidant system. In parallel, oxidative stress also induces endoplasmic reticulum stress (ERS). Reactive oxygen species (ROS), generated during oxidative stress, can directly damage proteins, causing them to misfold. Initially, the unfolded protein response (UPR) activates to mitigate excessive misfolded proteins. Yet, under persistent or severe stress, the failure to rectify protein misfolding leads to an accumulation of these aberrant proteins, pushing the UPR towards an apoptotic pathway, further contributing to cataractogenesis. Importantly, there is a dynamic interaction between the Nrf2 antioxidant system and the ERS/UPR mechanism in the lens. This interplay, where ERS/UPR can modulate Nrf2 expression and vice versa, holds potential therapeutic implications for cataract prevention and treatment. This review explores the intricate crosstalk between these systems, aiming to illuminate strategies for future advancements in cataract prevention and intervention. The Nrf2-dependent antioxidant system communicates and cross-talks with the ERS/UPR pathway. Both mechanisms are proposed to play pivotal roles in the onset of cataract formation.
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Affiliation(s)
- Xi Zhang
- College of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Bingqing Liu
- College of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Kevin Lal
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Haihua Liu
- Peking University First Hospital, Beijing, China
| | - Myhoa Tran
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Manyu Zhou
- College of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Chimdindu Ezugwu
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Xin Gao
- College of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Terry Dang
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - My-Lien Au
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Erica Brown
- School of Medicine, Texas Christian University and University of North Texas Health Science Center, Fort Worth, TX, USA
| | - Hongli Wu
- Pharmaceutical Sciences, College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX, USA.
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, TX, USA.
| | - Yan Liao
- College of Traditional Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China.
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11
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Paredes J, Wang Z, Patel P, Rose KL, Schey KL. Dehydroalanine and dehydrobutyrine in aging and cataractous lenses reveal site-specific consequences of spontaneous protein degradation. FRONTIERS IN OPHTHALMOLOGY 2023; 3:1241001. [PMID: 38983090 PMCID: PMC11182102 DOI: 10.3389/fopht.2023.1241001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/02/2023] [Indexed: 07/11/2024]
Abstract
Introduction Protein post-translational modifications (PTMs) have been associated with aging and age-related diseases. PTMs are particularly impactful in long-lived proteins, such as those found in the ocular lens, because they accumulate with age. Two PTMs that lead to protein-protein crosslinks in aged and cataractous lenses are dehydroalanine (DHA) and dehydrobutyrine (DHB); formed from cysteine/serine and threonine residues, respectively. The purpose of this study was to quantitate DHA and DHB in human lens proteins as a function of age and cataract status. Methods Human lenses of various ages were divided into five donor groups: transparent lenses (18-22-year-old, 48-64-year-old, and 70-93-year-old) and cataractous human lenses of two age groups (48-64-year-old lenses, and 70-93-year-old lenses) and were subjected to proteomic analysis. Relative DHA and DHB peptide levels were quantified and compared to their non-modified peptide counterparts. Results For most lens proteins containing DHA or DHB, higher amounts of DHA- and DHB-modified peptides were detected in aged and cataractous lenses. DHA-containing peptides were classified into three groups based on abundance changes with age and cataract: those that (1) increased only in age-related nuclear cataract (ARNC), (2) increased in aged and cataractous lenses, and (3) decreased in aged lenses and ARNC. There was no indication that DHA or DHB levels were dependent on lens region. In most donor groups, proteins with DHA and DHB were more likely to be found among urea-insoluble proteins rather than among water- or urea-soluble proteins. Discussion DHA and DHB formation may induce structural effects that make proteins less soluble in water that leads to age-related protein insolubility and possibly aggregation and light scattering.
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Affiliation(s)
- Jessica Paredes
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
| | - Zhen Wang
- Department of Biochemistry, Vanderbilt University, Nashville, TN, United States
| | - Purvi Patel
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN, United States
| | - Kristie L. Rose
- Department of Biochemistry, Vanderbilt University, Nashville, TN, United States
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN, United States
| | - Kevin L. Schey
- Department of Chemistry, Vanderbilt University, Nashville, TN, United States
- Department of Biochemistry, Vanderbilt University, Nashville, TN, United States
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN, United States
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12
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Subczynski WK, Pasenkiewicz-Gierula M, Widomska J. Protecting the Eye Lens from Oxidative Stress through Oxygen Regulation. Antioxidants (Basel) 2023; 12:1783. [PMID: 37760086 PMCID: PMC10525422 DOI: 10.3390/antiox12091783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/08/2023] [Accepted: 09/18/2023] [Indexed: 09/29/2023] Open
Abstract
Molecular oxygen is a primary oxidant that is involved in the formation of active oxygen species and in the oxidation of lipids and proteins. Thus, controlling oxygen partial pressure (concentration) in the human organism, tissues, and organs can be the first step in protecting them against oxidative stress. However, it is not an easy task because oxygen is necessary for ATP synthesis by mitochondria and in many biochemical reactions taking place in all cells in the human body. Moreover, the blood circulatory system delivers oxygen to all parts of the body. The eye lens seems to be the only organ that is protected from the oxidative stress through the regulation of oxygen partial pressure. The basic mechanism that developed during evolution to protect the eye lens against oxidative damage is based on the maintenance of a very low concentration of oxygen within the lens. This antioxidant mechanism is supported by the resistance of both the lipid components of the lens membrane and cytosolic proteins to oxidation. Any disturbance, continuous or acute, in the working of this mechanism increases the oxygen concentration, in effect causing cataract development. Here, we describe the biophysical basis of the mechanism and its correlation with lens transparency.
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Affiliation(s)
| | - Marta Pasenkiewicz-Gierula
- Department of Computational Biophysics and Bioinformatics, Jagiellonian University, 30-387 Krakow, Poland;
| | - Justyna Widomska
- Department of Biophysics, Medical University of Lublin, 20-090 Lublin, Poland
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13
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Johnstone-Belford EC, Jacobsen G, Fallon SJ, Dipnall JF, Blau S. The effects of diet and beauty products on the uptake and storage of 14C in hair and nails: ramifications for the application of bomb pulse dating to forensic anthropological casework. Forensic Sci Int 2023; 349:111771. [PMID: 37385158 DOI: 10.1016/j.forsciint.2023.111771] [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: 04/23/2023] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 07/01/2023]
Abstract
Radiocarbon dating is a useful tool in the examination of unknown human remains. Recent studies have shown that the analysis of hair and nail samples can provide a highly accurate estimation of the year of death (YOD). However, little research has examined factors that may influence the uptake and storage of 14C in these tissues, such as diet, or the use of beauty products. This study measured the level of 14C in human hair and nail samples collected from living individuals to determine whether diet, and the use of hair dye or nail polish, has a significant impact on the estimation of YOD. The results of this study showed that diet did not appear to impact the radiocarbon content in human hair and nail, and thus should not be considered a limitation when analysing samples obtained from unidentified human remains. The use of nail polish, and in the majority of cases, hair dye, did not significantly impact the 14C concentration in nails and hair. While the results of this study are preliminary, they suggest that in most cases, both hair and nail can be successfully analysed using radiocarbon dating to estimate an individual's YOD. However, best practice should involve the analysis of multiple tissue types, to minimise any error that may be introduced as a result of the decedent's use of beauty products.
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Affiliation(s)
| | - G Jacobsen
- Australian Nuclear Science and Technology Organisation, Australia
| | - S J Fallon
- Radiocarbon Dating Laboratory, The Australian National University, Australia
| | - J F Dipnall
- School of Public Health and Preventative Medicine, Monash University, Australia
| | - S Blau
- Victorian Institute of Forensic Medicine/ Department of Forensic Medicine, Monash University, Australia
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14
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Cramer A, Højfeldt G, Schjerling P, Agergaard J, van Hall G, Olsen J, Hölmich P, Kjaer M, Barfod KW. Achilles Tendon Tissue Turnover Before and Immediately After an Acute Rupture. Am J Sports Med 2023; 51:2396-2403. [PMID: 37313851 DOI: 10.1177/03635465231177890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
BACKGROUND An Achilles tendon rupture (ATR) is a frequent injury and results in the activation of tendon cells and collagen expression, but it is unknown to what extent turnover of the tendon matrix is altered before or after a rupture. PURPOSE/HYPOTHESIS The purpose of this study was to characterize tendon tissue turnover before and immediately after an acute rupture in patients. It was hypothesized that a rupture would result in pronounced collagen synthesis in the early phase (first 2 weeks) after the injury. STUDY DESIGN Cross-sectional study; Level of evidence, 3. METHODS The study included patients (N = 18) eligible for surgery after an ATR. At the time of inclusion, the patients ingested deuterium oxide (2H2O) orally, and on the day of surgery (within 14 days of the injury), they received a 3-hour flood-primed infusion of an 15N-proline tracer. During surgery, the patients had 1 biopsy specimen taken from the ruptured part of the Achilles tendon and 1 that was 3 to 5 cm proximal to the rupture as a control. The biopsy specimens were analyzed for carbon-14 (14C) levels in the tissue to calculate long-term turnover (years), incorporation of 2H-alanine (from 2H2O) into the tissue to calculate the fractional synthesis rate (FSR) of proteins in the short term (days), and incorporation of 15N-proline into the tissue to calculate the acute FSR (hours). RESULTS Both the rupture and the control samples showed consistently lower levels of 14C compared with the predicted level of 14C in a healthy tendon, which indicated increased tendon turnover in a fraction (48% newly synthesized) of the Achilles tendon already for a prolonged period before the rupture. Over the first days after the rupture, the synthesis rate for collagen was relatively constant, and the average synthesis rate on the day of surgery (2-14 days after the rupture) was 0.025% per hour, irrespective of the length of time after a rupture and the site of sampling (rupture vs control). No differences were found in the FSR between the rupture and control samples in the days after the rupture. CONCLUSION Higher than normal tissue turnover in the Achilles tendon before a rupture indicated that changes in the tendon tissue preceded the injury. In addition, we observed no increase in tendon collagen tissue turnover in the first 2 weeks after an ATR. This favors the view that an increase in the formation of new tendon collagen is not an immediate phenomenon during the regeneration of ruptured tendons in patients. REGISTRATION NCT03931486 (ClinicalTrials.gov identifier).
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Affiliation(s)
- Allan Cramer
- Sports Orthopedic Research Center-Copenhagen, Department of Orthopedic Surgery, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark
| | - Grith Højfeldt
- Institute of Sports Medicine Copenhagen, Department of Orthopedic Surgery, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Peter Schjerling
- Institute of Sports Medicine Copenhagen, Department of Orthopedic Surgery, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jakob Agergaard
- Institute of Sports Medicine Copenhagen, Department of Orthopedic Surgery, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gerrit van Hall
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Clinical Metabolomics Core Facility, Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Olsen
- Aarhus AMS Centre, Department of Physics and Astronomy, Aarhus University, Aarhus, Denmark
| | - Per Hölmich
- Sports Orthopedic Research Center-Copenhagen, Department of Orthopedic Surgery, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark
| | - Michael Kjaer
- Institute of Sports Medicine Copenhagen, Department of Orthopedic Surgery, Bispebjerg Hospital, University of Copenhagen, Copenhagen, Denmark
- Center for Healthy Aging, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kristoffer Weisskirchner Barfod
- Sports Orthopedic Research Center-Copenhagen, Department of Orthopedic Surgery, Hvidovre Hospital, University of Copenhagen, Hvidovre, Denmark
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15
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Leifsdóttir RR, Campana SE. Species independence of eye lens dimensions in teleosts and elasmobranchs. PLoS One 2023; 18:e0286388. [PMID: 37262043 DOI: 10.1371/journal.pone.0286388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2022] [Accepted: 05/16/2023] [Indexed: 06/03/2023] Open
Abstract
The vertebrate eye lens grows incrementally, adding layers of elongated, tightly packed lens fiber cells at the outer margin of the lens. With subsequent growth, previously-deposited fiber cells degrade, leaving a region of fully denucleated and organelle-free cells which are responsible for the high transparency and low light scattering characteristics of the lens. The objective of this study was to determine if the horizon separating the gelatinous outer cortex of the lens from its hardened interior occurred at a consistent location within the lens of several teleost and elasmobranch fish species, and could be linked to fiber cell morphology or function. A fixed ratio of 0.69±0.01 of hardened eye lens diameter (HD) to overall eye lens diameter (LD) was observed in a broad size range of Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), thorny skate (Amblyraja radiata) and round ray (Rajella fyllae). The location of the hardened lens horizon was similar to that reported for optical plasticity and spherical aberration, but not that of fiber cell denucleation, suggesting that fiber cell dehydration continues after the loss of internal organelles. Our findings support a previous suggestion that the maintenance of optical quality during fish eye lens growth requires a precisely-fixed HD:LD ratio, while the ubiquity of a fixed ratio across fish taxa may suggest that many fish species possess a common refractive index profile. The linear relationship between HD and fish length should allow fish length to be backcalculated from the diameter of the isolated lens core, thus aiding research using isotope ratios of lens laminae or inner cores to reconstruct early life history events.
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Affiliation(s)
| | - Steven E Campana
- Life and Environmental Science, University of Iceland, Reykjavik, Iceland
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16
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Bisciotti GN, Bisciotti A, Auci A, Bisciotti A, Eirale C, Corsini A, Volpi P. Achilles Tendon Repair after Tenorraphy Imaging and the Doughnut Metaphor. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:5985. [PMID: 37297589 PMCID: PMC10253009 DOI: 10.3390/ijerph20115985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 05/15/2023] [Accepted: 05/26/2023] [Indexed: 06/12/2023]
Abstract
After Achilles tendon tenorraphy, tendon tissue undergoes a long period of biological healing. During this period, tissue turnover shows heterogeneity between its peripheral and central regions. This case report concerns the description of the tendon healing process of an athlete who underwent an Achilles tendon tenorraphy. As the reparative processes progressed, magnetic resonance imaging (MRI) showed centralization of the hyperintensity area and the tendon assumed a doughnut-like appearance. At the same time, ultrasound (US) assessment showed a progressive reorganization of the tendon fibrillar structure. Therefore, for the athlete, MRI and US assessment together represent a useful tool for the decision-making process after Achilles tendon tenorraphy.
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Affiliation(s)
- Gian Nicola Bisciotti
- Paris Saint Germain Football Club (France), Kinemove Rehabilitation Centers, 54027 Pontremoli, Italy;
| | | | - Alessio Auci
- Azienda USL Toscana Nord-Ovest, 54100 Massa, Italy;
| | | | - Cristiano Eirale
- Paris Saint Germain Football Club, 78100 Saint Germain en Laye, France;
| | | | - Piero Volpi
- IRCCS Humanitas Research Hospital, 20089 Rozzano, Italy (P.V.)
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17
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Mong MA. Vitamin K and the Visual System-A Narrative Review. Nutrients 2023; 15:nu15081948. [PMID: 37111170 PMCID: PMC10143727 DOI: 10.3390/nu15081948] [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: 02/01/2023] [Revised: 03/30/2023] [Accepted: 03/31/2023] [Indexed: 04/29/2023] Open
Abstract
Vitamin K occupies a unique and often obscured place among its fellow fat-soluble vitamins. Evidence is mounting, however, that vitamin K (VK) may play an important role in the visual system apart from the hepatic carboxylation of hemostatic-related proteins. However, to our knowledge, no review covering the topic has appeared in the medical literature. Recent studies have confirmed that matrix Gla protein (MGP), a vitamin K-dependent protein (VKDP), is essential for the regulation of intraocular pressure in mice. The PREDIMED (Prevención con Dieta Mediterránea) study, a randomized trial involving 5860 adults at risk for cardiovascular disease, demonstrated a 29% reduction in the risk of cataract surgery in participants with the highest tertile of dietary vitamin K1 (PK) intake compared with those with the lowest tertile. However, the specific requirements of the eye and visual system (EVS) for VK, and what might constitute an optimized VK status, is currently unknown and largely unexplored. It is, therefore, the intention of this narrative review to provide an introduction concerning VK and the visual system, review ocular VK biology, and provide some historical context for recent discoveries. Potential opportunities and gaps in current research efforts will be touched upon in the hope of raising awareness and encouraging continued VK-related investigations in this important and highly specialized sensory system.
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Affiliation(s)
- Michael A Mong
- Department of Ophthalmology, Veteran Affairs North Texas Health Care Medical Center, Dallas, TX 75216, USA
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18
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Gialeli C, Gonçalves I. Evaluation of Glycosaminoglycans Biological Age in Cells and Tissues. Methods Mol Biol 2023; 2619:91-98. [PMID: 36662464 DOI: 10.1007/978-1-0716-2946-8_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Bomb pulse refers to the sharp increase of the atmospheric levels of the carbon isotope 14C due to nuclear testing during the late 1950s and early 1960s. After the nuclear test ban, atmospheric 14C levels decreased exponentially because of the diffusion and equilibration with the ocean and biosphere, as well as the incorporation indirectly into all living cells. Thus, assessing the anthropogenic 14C serves as an isotopic chronometer providing the opportunity to estimate the age of a tissue and its components with a relatively high precision comparing it with the atmospheric levels at a certain time stamp.This protocol describes the use of the bomb pulse dating as a retrospective tracer of tissue components such as the glycosaminoglycans (GAGs) and subsequent proteoglycans turnover using accelerator mass spectrometry.
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Affiliation(s)
- Chrysostomi Gialeli
- Department of Clinical Sciences Malmö, Lund University, Clinical Research Center, Malmö, Sweden.
| | - Isabel Gonçalves
- Department of Clinical Sciences Malmö, Lund University, Clinical Research Center, Malmö, Sweden
- Department of Cardiology, Malmö, Skåne University Hospital, Lund University, Malmö, Sweden
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19
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Johnstone-Belford E, Fallon S, Dipnall J, Blau S. The importance of bone sample selection when using radiocarbon analysis in cases of unidentified human remains. Forensic Sci Int 2022; 341:111480. [DOI: 10.1016/j.forsciint.2022.111480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 09/28/2022] [Accepted: 10/01/2022] [Indexed: 11/04/2022]
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20
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Khanijou JK, Yee Z, Raida M, Lee JM, Tay EZE, Gruber J, Walczyk T. Efficiency of Protein Renewal Is Limited by Feed Intake and Not by Protein Lifetime in Aging Caenorhabditis elegans. J Proteome Res 2022; 21:2664-2686. [PMID: 36181456 DOI: 10.1021/acs.jproteome.2c00383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Protein turnover maintains the proteome's functional integrity. Here, protein turnover efficiency over time in wild-type Caenorhabditis elegans was assessed using inverse [15N]-pulse labeling up to 7 days after the egg-laying phase at 20 °C. Isotopic analysis of some abundant proteins was executed favoring data quality over quantity for mathematical modeling. Surprisingly, isotopic enrichment over time reached an upper limit showing an apparent cessation of protein renewal well before death, with protein fractions inaccessible to turnover ranging from 14 to 83%. For life span modulation, worms were raised at different temperatures after egg laying. Mathematical modeling of isotopic enrichment points either to a slowdown of protein turnover or to an increasing protein fraction resistant to turnover with time. Most notably, the estimated time points of protein turnover cessation from our mathematical model were highly correlated with the observed median life span. Thrashing and pumping rates over time were linearly correlated with isotopic enrichment, therefore linking protein/tracer intake to protein turnover rate and protein life span. If confirmed, life span extension is possible by optimizing protein turnover rate through modulating protein intake in C. elegans and possibly other organisms. While proteome maintenance benefits from a high protein turnover rate, protein turnover is fundamentally energy-intensive, where oxidative stress contributes to damage that it is supposed to repair.
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Affiliation(s)
- Jasmeet Kaur Khanijou
- Department of Chemistry, National University of Singapore (NUS), Singapore 117543, Singapore.,Shared Analytics, Singapore Institute of Food and Biotechnology Innovation (SIFBI), Agency for Science, Technology and Research (A*STAR), Singapore 138673, Singapore
| | - Zhuangli Yee
- Yale-NUS College, Singapore 138527, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore 117597, Singapore
| | - Manfred Raida
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore 117597, Singapore.,Singapore Lipidomics Incubator (SLING), Life Sciences Institute, National University of Singapore, Singapore 117456, Singapore
| | - Jin Meng Lee
- Department of Chemistry, National University of Singapore (NUS), Singapore 117543, Singapore
| | - Evan Zhi En Tay
- Department of Chemistry, National University of Singapore (NUS), Singapore 117543, Singapore
| | - Jan Gruber
- Yale-NUS College, Singapore 138527, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), Singapore 117597, Singapore
| | - Thomas Walczyk
- Department of Chemistry, National University of Singapore (NUS), Singapore 117543, Singapore
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21
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Timsina R, Wellisch S, Haemmerle D, Mainali L. Binding of Alpha-Crystallin to Cortical and Nuclear Lens Lipid Membranes Derived from a Single Lens. Int J Mol Sci 2022; 23:ijms231911295. [PMID: 36232595 PMCID: PMC9570235 DOI: 10.3390/ijms231911295] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2022] [Revised: 09/17/2022] [Accepted: 09/22/2022] [Indexed: 11/16/2022] Open
Abstract
Several studies reported that α-crystallin concentrations in the eye lens cytoplasm decrease with a corresponding increase in membrane-bound α-crystallin with age and cataracts. The influence of the lipid and cholesterol composition difference between cortical membrane (CM) and nuclear membrane (NM) on α-crystallin binding to membranes is still unclear. This study uses the electron paramagnetic resonance (EPR) spin-labeling method to investigate the α-crystallin binding to bovine CM and NM derived from the total lipids extracted from a single lens. Compared to CMs, NMs have a higher percentage of membrane surface occupied by α-crystallin and binding affinity, correlating with less mobility and more order below and on the surface of NMs. α-Crystallin binding to CM and NM decreases mobility with no significant change in order and hydrophobicity below and on the surface of membranes. Our results suggest that α-crystallin mainly binds on the surface of bovine CM and NM and such surface binding of α-crystallin to membranes in clear and young lenses may play a beneficial role in membrane stability. However, with decreased cholesterol content within the CM, which mimics the decreased cholesterol content in the cataractous lens membrane, α-crystallin binding increases the hydrophobicity below the membrane surface, indicating that α-crystallin binding forms a hydrophobic barrier for the passage of polar molecules, supporting the barrier hypothesis in developing cataracts.
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Affiliation(s)
- Raju Timsina
- Department of Physics, Boise State University, Boise, ID 83725, USA
| | | | - Dieter Haemmerle
- 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 Programs, Boise State University, Boise, ID 83725, USA
- Correspondence: ; Tel.: +1-(208)-426-4003
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22
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Hale OJ, Cooper HJ. Native Ambient Mass Spectrometry of an Intact Membrane Protein Assembly and Soluble Protein Assemblies Directly from Lens Tissue. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 134:e202201458. [PMID: 38505128 PMCID: PMC10946450 DOI: 10.1002/ange.202201458] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Indexed: 12/16/2022]
Abstract
Membrane proteins constitute around two-thirds of therapeutic targets but present a significant challenge for structural analysis due to their low abundance and solubility. Existing methods for structural analysis rely on over-expression and/or purification of the membrane protein, thus removing any links back to actual physiological environment. Here, we demonstrate mass spectrometry analysis of an intact oligomeric membrane protein directly from tissue. Aquaporin-0 exists as a 113 kDa tetramer, with each subunit featuring six transmembrane helices. We report the characterisation of the intact assembly directly from a section of sheep eye lens without sample pre-treatment. Protein identity was confirmed by mass measurement of the tetramer and subunits, together with top-down mass spectrometry, and the spatial distribution was determined by mass spectrometry imaging. Our approach allows simultaneous analysis of soluble protein assemblies in the tissue.
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Affiliation(s)
- Oliver J. Hale
- School of BiosciencesUniversity of BirminghamEdgbastonB15 2TTUK
| | - Helen J. Cooper
- School of BiosciencesUniversity of BirminghamEdgbastonB15 2TTUK
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23
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Hale OJ, Cooper HJ. Native Ambient Mass Spectrometry of an Intact Membrane Protein Assembly and Soluble Protein Assemblies Directly from Lens Tissue. Angew Chem Int Ed Engl 2022; 61:e202201458. [PMID: 35665580 PMCID: PMC9401010 DOI: 10.1002/anie.202201458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Indexed: 11/16/2022]
Abstract
Membrane proteins constitute around two-thirds of therapeutic targets but present a significant challenge for structural analysis due to their low abundance and solubility. Existing methods for structural analysis rely on over-expression and/or purification of the membrane protein, thus removing any links back to actual physiological environment. Here, we demonstrate mass spectrometry analysis of an intact oligomeric membrane protein directly from tissue. Aquaporin-0 exists as a 113 kDa tetramer, with each subunit featuring six transmembrane helices. We report the characterisation of the intact assembly directly from a section of sheep eye lens without sample pre-treatment. Protein identity was confirmed by mass measurement of the tetramer and subunits, together with top-down mass spectrometry, and the spatial distribution was determined by mass spectrometry imaging. Our approach allows simultaneous analysis of soluble protein assemblies in the tissue.
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Affiliation(s)
- Oliver J. Hale
- School of BiosciencesUniversity of BirminghamEdgbastonB15 2TTUK
| | - Helen J. Cooper
- School of BiosciencesUniversity of BirminghamEdgbastonB15 2TTUK
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24
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Bjerager J, Dabbah S, Belmouhand M, Kessel L, Hougaard JL, Rothenbuehler SP, Sander B, Larsen M. Long-term development of lens fluorescence in a twin cohort: Heritability and effects of age and lifestyle. PLoS One 2022; 17:e0268458. [PMID: 35617652 PMCID: PMC9135443 DOI: 10.1371/journal.pone.0268458] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 04/30/2022] [Indexed: 11/20/2022] Open
Abstract
The blue-green autofluorescence of the ocular lens increases with age, glycemia and smoking, as the irreplaceable structural proteins of the lens slowly accumulate damage from the encounter with reactive molecular species. We have conducted a prospective study of lens autofluorescence over two decades in a twin cohort. The study included 131 phakic, non-diabetic adult twins (median age at follow-up 58 years, range 41-66 years) who were examined twice at an interval of 21 years. Change in anterior lens peak autofluorescence was analyzed in relation to age, current and baseline glycemia, cumulative smoking and heritability. The level of lens autofluorescence in the study population increased as a function of age and smoking (p ≤.002), but not as a function of glycemia (p ≥.069). Lens autofluorescence remained a highly heritable trait (90.6% at baseline and 93.3% at follow-up), but whereas the combined effect of age and cumulative smoking explained 57.2% of the variance in lens autofluorescence at baseline in mid-life, it only accounted for 31.6% at follow-up 21 years later. From mid to late adulthood, the level of blue-green fluorescence remained overwhelmingly heritable, but became less predictable from age, smoking habits and glycemic status. Presumably, as the lens ages, its intrinsic characteristics come to dominate over environmental and systemic factors, perhaps in a prelude to the development of cataract.
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Affiliation(s)
- Jakob Bjerager
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark
| | - Sami Dabbah
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark
- Department of Ophthalmology, Odense University Hospital, Odense, Denmark
| | | | - Line Kessel
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark
- Faculty of Health and Medical Sciences, Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Leth Hougaard
- Department of Clinical Sciences, Ophthalmology in Malmö, Lund University, Malmö, Sweden
| | - Simon P. Rothenbuehler
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark
- University Hospital Basel, Basel, Switzerland
| | - Birgit Sander
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark
| | - Michael Larsen
- Department of Ophthalmology, Rigshospitalet, Glostrup, Denmark
- Faculty of Health and Medical Sciences, Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
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25
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Norton-Baker B, Mehrabi P, Kwok AO, Roskamp KW, Rocha MA, Sprague-Piercy MA, von Stetten D, Miller RJD, Martin RW. Deamidation of the human eye lens protein γS-crystallin accelerates oxidative aging. Structure 2022; 30:763-776.e4. [PMID: 35338852 PMCID: PMC9081212 DOI: 10.1016/j.str.2022.03.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2021] [Revised: 12/14/2021] [Accepted: 03/01/2022] [Indexed: 11/23/2022]
Abstract
Cataract, a clouding of the eye lens from protein precipitation, affects millions of people every year. The lens proteins, the crystallins, show extensive post-translational modifications (PTMs) in cataractous lenses. The most common PTMs, deamidation and oxidation, promote crystallin aggregation; however, it is not clear precisely how these PTMs contribute to crystallin insolubilization. Here, we report six crystal structures of the lens protein γS-crystallin (γS): one of the wild-type and five of deamidated γS variants, from three to nine deamidation sites, after sample aging. The deamidation mutations do not change the overall fold of γS; however, increasing deamidation leads to accelerated disulfide-bond formation. Addition of deamidated sites progressively destabilized protein structure, and the deamidated variants display an increased propensity for aggregation. These results suggest that the deamidated variants are useful as models for accelerated aging; the structural changes observed provide support for redox activity of γS-crystallin in the lens.
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Affiliation(s)
- Brenna Norton-Baker
- Department of Chemistry, University of California, Irvine, CA 92697-2025, USA; Department for Atomically Resolved Dynamics, Max-Planck-Institute for Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Pedram Mehrabi
- Department for Atomically Resolved Dynamics, Max-Planck-Institute for Structure and Dynamics of Matter, Luruper Chaussee 149, 22761 Hamburg, Germany; Institute for Nanostructure and Solid-State Physics, Universität Hamburg, HARBOR, Luruper Chaussee 149, 22761 Hamburg, Germany
| | - Ashley O Kwok
- Department of Chemistry, University of California, Irvine, CA 92697-2025, USA
| | - Kyle W Roskamp
- Department of Chemistry, University of California, Irvine, CA 92697-2025, USA
| | - Megan A Rocha
- Department of Chemistry, University of California, Irvine, CA 92697-2025, USA
| | - Marc A Sprague-Piercy
- Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, USA
| | - David von Stetten
- European Molecular Biology Laboratory, Hamburg Unit C/O Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - R J Dwayne Miller
- Departments of Chemistry and Physics, University of Toronto, 80 St. George Street, Toronto, ON M5S 3H6, Canada
| | - Rachel W Martin
- Department of Chemistry, University of California, Irvine, CA 92697-2025, USA; Department of Molecular Biology and Biochemistry, University of California, Irvine, CA 92697-3900, USA.
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26
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Savina ED, Tsentalovich YP, Sherin PS. Influence of viscosity on mechanism and products of radical reactions of kynurenic acid and tryptophan. Russ Chem Bull 2022. [DOI: 10.1007/s11172-021-3350-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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27
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Harvey SR, O’Neale C, Schey KL, Wysocki VH. Native Mass Spectrometry and Surface Induced Dissociation Provide Insight into the Post-Translational Modifications of Tetrameric AQP0 Isolated from Bovine Eye Lens. Anal Chem 2022; 94:1515-1519. [PMID: 35015511 PMCID: PMC9161558 DOI: 10.1021/acs.analchem.1c04322] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Aquaporin-0 (AQP0) is a tetrameric membrane protein and the most abundant membrane protein in the eye lens. Interestingly, there is little to no cellular turnover once mature lens fiber cells are formed, and hence, age-related modifications accumulate with time. While bottom-up mass spectrometry-based approaches can provide identification of post-translational modifications, they cannot provide information on how these modifications coexist in a single chain or complex. Native mass spectrometry, however, enables the transfer of the intact complex into the gas-phase allowing modifications to be identified at the tetramer level. Here, we present the use of native mass spectrometry and surface-induced dissociation to study the post-translational modifications of AQP0 isolated and purified from bovine eye lens, existing as multiple forms due to the different modification states naturally present.
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Affiliation(s)
- Sophie R Harvey
- Department of Chemistry and Biochemistry and Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, OH 43210
| | - Carla O’Neale
- Vanderbilt University Department of Biochemistry and Mass Spectrometry Research Center, Nashville, TN 37240
| | - Kevin L Schey
- Vanderbilt University Department of Biochemistry and Mass Spectrometry Research Center, Nashville, TN 37240
| | - Vicki H Wysocki
- Department of Chemistry and Biochemistry and Resource for Native Mass Spectrometry Guided Structural Biology, The Ohio State University, Columbus, OH 43210,
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28
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Jørgensen AE, Schjerling P, Krogsgaard MR, Petersen MM, Olsen J, Kjær M, Heinemeier KM. Collagen Growth Pattern in Human Articular Cartilage of the Knee. Cartilage 2021; 13:408S-418S. [PMID: 33147986 PMCID: PMC8804751 DOI: 10.1177/1947603520971016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE During skeletal growth, the articular cartilage expands to maintain its cover of bones in joints, however, it is unclear when and how cartilage grows. We aim to determine the expanding growth pattern and timing across the tibia plateau in human knees. DESIGN Six human tibia plateaus (2 healthy, 2 with osteoarthritis, and 2 with posttraumatic osteoarthritis) were used for full-depth cartilage sampling systematically across the joint surface at 12 medial and 4 lateral sites. Methodologically, we took advantage of the performed nuclear bomb tests in the years 1955 to 1963, which increased the atmospheric 14C that was incorporated into human tissues. Cartilage was treated enzymatically to extract collagen, analyzed for 14C content, and year at formation was determined from historical atmospheric 14C concentrations. RESULTS By age-determination, each tibia condyle had central points of formation surrounded by later-formed cartilage toward the periphery. Furthermore, the tibia plateaus contained collagen with 14C levels corresponding to mean donor age of 11.7 years (±3.8 SD). Finally, the medial condyle had lower 14C levels corresponding to formation 1 year later than the lateral condyle (P = 0.009). CONCLUSIONS Human cartilage on the tibia plateau contains collagen that has experienced little if any turnover since school-age. The cartilage formation develops from 2 condyle centers and radially outward with the medial condyle finishing slightly later than the lateral condyle. This suggests a childhood programmed cartilage formation with a very limited adulthood collagen turnover.
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Affiliation(s)
- Adam E.M. Jørgensen
- Institute of Sports Medicine Copenhagen,
Department of Orthopedic Surgery M81, Bispebjerg and Frederiksberg Hospital,
Copenhagen, Denmark,Center for Healthy Aging, Faculty of
Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark,Adam E.M. Jørgensen, Institute of Sports
Medicine Copenhagen, Department of Orthopedic Surgery M81, Bispebjerg and
Frederiksberg Hospital, Nielsine Nielsensvej 11, Copenhagen, Denmark, DK-2400,
Denmark.
| | - Peter Schjerling
- Institute of Sports Medicine Copenhagen,
Department of Orthopedic Surgery M81, Bispebjerg and Frederiksberg Hospital,
Copenhagen, Denmark,Center for Healthy Aging, Faculty of
Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Michael R. Krogsgaard
- Section for Sports Traumatology M51,
Department of Orthopedic Surgery, Bispebjerg and Frederiksberg Hospital, Copenhagen,
Denmark
| | - Michael M. Petersen
- Musculoskeletal Tumor Section,
Department of Orthopedic Surgery, Rigshospitalet, Faculty of Health and Medical
Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jesper Olsen
- Aarhus AMS Centre (AARAMS), Department
of Physics and Astronomy, Aarhus University, Aarhus C, Denmark
| | - Michael Kjær
- Institute of Sports Medicine Copenhagen,
Department of Orthopedic Surgery M81, Bispebjerg and Frederiksberg Hospital,
Copenhagen, Denmark,Center for Healthy Aging, Faculty of
Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Katja M. Heinemeier
- Institute of Sports Medicine Copenhagen,
Department of Orthopedic Surgery M81, Bispebjerg and Frederiksberg Hospital,
Copenhagen, Denmark,Center for Healthy Aging, Faculty of
Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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29
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Friedrich MG, Wang Z, Schey KL, Truscott RJW. Spontaneous Cleavage at Glu and Gln Residues in Long-Lived Proteins. ACS Chem Biol 2021; 16:2244-2254. [PMID: 34677941 DOI: 10.1021/acschembio.1c00379] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Long-lived proteins (LLPs) are prone to deterioration with time, and one prominent breakdown process is the scission of peptide bonds. These cleavages can either be enzymatic or spontaneous. In this study, human lens proteins were examined and many were found to have been cleaved on the C-terminal side of Glu and Gln residues. Such cleavages could be reproduced experimentally by in vitro incubation of Glu- or Gln-containing peptides at physiological pHs. Spontaneous cleavage was dependent on pH and amino acid sequence. These model peptide studies suggested that the mechanism involves a cyclic intermediate and is therefore analogous to that characterized for cleavage of peptide bonds adjacent to Asp and Asn residues. An increased amount of some Glu/Gln cleaved peptides in the insoluble fraction of human lenses suggests that cleavage may act to destabilize proteins. Spontaneous cleavage at Glu and Gln, as well as recently described cross-linking at these residues, can therefore be added to the similar processes affecting long-lived proteins that have already been documented for Asn and Asp residues.
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Affiliation(s)
- Michael G. Friedrich
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
| | - Zhen Wang
- Department of Biochemistry and Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Kevin L. Schey
- Department of Biochemistry and Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, United States
| | - Roger J. W. Truscott
- Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW 2522, Australia
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30
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Examining the use of different sample types following decomposition to estimate year of death using bomb pulse dating. J Forensic Leg Med 2021; 85:102275. [PMID: 34794085 DOI: 10.1016/j.jflm.2021.102275] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 10/26/2021] [Accepted: 10/31/2021] [Indexed: 11/20/2022]
Abstract
When human remains are discovered, confirming the identification of the decedent is the first part of the forensic medical investigation. In cases where the remains are skeletonised or badly decomposed, differential preservation often increases the difficulty of this task. Bomb pulse dating, which directly compares levels of 14 C within human tissues to atmospheric levels, can provide an estimate of the year of death, which may assist in the identification process. This study measured the 14 C content in samples of hair, nail and puparia collected from donors at the Australian Facility for Taphonomic Experimental Research (AFTER). The radiocarbon results demonstrated that the nail samples provided the most accurate year of death estimation, with 91% correctly predicting YOD, closely followed by hair, with a 79% correct prediction rate, with both hair and nails having a lag time of 0-1 years. This is consistent with the time taken for atmospheric CO 2 to enter the food chain, and be taken in by humans. Puparia was found to have the highest levels of 14 C, and was the least consistent with the actual YOD (46% correct). However, predicted YOD ranges were still within 4 years of the actual YOD. Based on the results of this study, hair, nail and puparia should be considered as useful samples to obtain accurate estimates for YOD using bomb pulse dating.
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31
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Teglind R, Dawidson I, Balkefors J, Alkass K. Analysis of 14C, 13C and Aspartic Acid Racemization in Teeth and Bones to Facilitate Identification of Unknown Human Remains: Outcomes of Practical Casework. Biomolecules 2021; 11:1655. [PMID: 34827653 PMCID: PMC8615977 DOI: 10.3390/biom11111655] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 10/22/2021] [Accepted: 11/02/2021] [Indexed: 11/16/2022] Open
Abstract
The identification of unknown human remains represents an important task in forensic casework. If there are no clues as to the identity of the remains, then the age, sex, and origin are the most important factors to limit the search for a matching person. Here, we present the outcome of application of so-called bomb pulse radiocarbon (14C derived from above-ground nuclear bomb tests during 1955-1963) analysis to birthdate human remains. In nine identified cases, 14C analysis of tooth crowns provided an estimate of the true date of birth with an average absolute error of 1.2 ± 0.8 years. Analysis of 14C in tooth roots also showed a good precision with an average absolute error of 2.3 ± 2.5 years. Levels of 14C in bones can determine whether a subject has lived after 1955 or not, but more precise carbon turnover data for bones would be needed to calculate date of birth and date of death. Aspartic acid racemization analysis was performed on samples from four cases; in one of these, the year of birth could be predicted with good precision, whereas the other three cases are still unidentified. The stable isotope 13C was analyzed in tooth crowns to estimate provenance. Levels of 13C indicative of Scandinavian provenance were found in known Scandinavian subjects. Teeth from four Polish subjects all showed higher 13C levels than the average for Scandinavian subjects.
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Affiliation(s)
- Rebecka Teglind
- Department of Oncology-Pathology, Karolinska Institute, 171 77 Stockholm, Sweden;
- Department of Forensic Medicine, The National Board of Forensic Medicine, 171 77 Stockholm, Sweden;
| | - Irena Dawidson
- Department of Forensic Medicine, The National Board of Forensic Medicine, 171 77 Stockholm, Sweden;
| | - Jonas Balkefors
- Tandem Laboratory, Ångström Laboratory, Uppsala University, 751 20 Uppsala, Sweden;
| | - Kanar Alkass
- Department of Oncology-Pathology, Karolinska Institute, 171 77 Stockholm, Sweden;
- Department of Forensic Medicine, The National Board of Forensic Medicine, 171 77 Stockholm, Sweden;
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32
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Sherin PS, Vyšniauskas A, López-Duarte I, Ogilby PR, Kuimova MK. Visualising UV-A light-induced damage to plasma membranes of eye lens. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2021; 225:112346. [PMID: 34736070 DOI: 10.1016/j.jphotobiol.2021.112346] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 10/01/2021] [Accepted: 10/19/2021] [Indexed: 01/16/2023]
Abstract
An eye lens is constantly exposed to the solar UV radiation, which is considered the most important external source of age-related changes to eye lens constituents. The accumulation of modifications of proteins and lipids with age can eventually lead to the development of progressive lens opacifications, such as cataracts. Though the impact of solar UV radiation on the structure and function of proteins is actively studied, little is known about the effect of photodamage on plasma membranes of lens cells. In this work we exploit Fluorescence Lifetime Imaging Microscopy (FLIM), together with viscosity-sensitive fluorophores termed molecular rotors, to study the changes in viscosity of plasma membranes of porcine eye lens resulting from two different types of photodamage: Type I (electron transfer) and Type II (singlet oxygen) reactions. We demonstrate that these two types of photodamage result in clearly distinct changes in viscosity - a decrease in the case of Type I damage and an increase in the case of Type II processes. Finally, to simulate age-related changes that occur in vivo, we expose an intact eye lens to UV-A light under anaerobic conditions. The observed decrease in viscosity within plasma membranes is consistent with the ability of eye lens constituents to sensitize Type I photodamage under natural irradiation conditions. These changes are likely to alter the transport of metabolites and predispose the whole tissue to the development of pathological processes such as cataracts.
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Affiliation(s)
- Peter S Sherin
- Chemistry Department, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, London W12 0BZ, UK; International Tomography Center SB RAS, Institutskaya street 3A, Novosibirsk 630090, Russia.
| | - Aurimas Vyšniauskas
- Center for Physical Sciences and Technology, Saulėtekio av. 3, Vilnius LT-10257, Lithuania; Chemistry Department, Vilnius University, Naugarduko st. 24, Vilnius LT-03225, Lithuania
| | - Ismael López-Duarte
- Chemistry Department, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, London W12 0BZ, UK
| | - Peter R Ogilby
- Department of Chemistry, Aarhus University, Langelandsgade 140, Aarhus DK-8000, Denmark
| | - Marina K Kuimova
- Chemistry Department, Molecular Sciences Research Hub, Imperial College London, 82 Wood Lane, London W12 0BZ, UK.
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33
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Ariosa-Morejon Y, Santos A, Fischer R, Davis S, Charles P, Thakker R, Wann AK, Vincent TL. Age-dependent changes in protein incorporation into collagen-rich tissues of mice by in vivo pulsed SILAC labelling. eLife 2021; 10:66635. [PMID: 34581667 PMCID: PMC8478409 DOI: 10.7554/elife.66635] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 09/03/2021] [Indexed: 12/11/2022] Open
Abstract
Collagen-rich tissues have poor reparative capacity that predisposes to common age-related disorders such as osteoporosis and osteoarthritis. We used in vivo pulsed SILAC labelling to quantify new protein incorporation into cartilage, bone, and skin of mice across the healthy life course. We report dynamic turnover of the matrisome, the proteins of the extracellular matrix, in bone and cartilage during skeletal maturation, which was markedly reduced after skeletal maturity. Comparing young adult with older adult mice, new protein incorporation was reduced in all tissues. STRING clustering revealed changes in epigenetic modulators across all tissues, a decline in chondroprotective growth factors such as FGF2 and TGFβ in cartilage, and clusters indicating mitochondrial dysregulation and reduced collagen synthesis in bone. Several pathways were implicated in age-related disease. Fewer changes were observed for skin. This methodology provides dynamic protein data at a tissue level, uncovering age-related molecular changes that may predispose to disease.
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Affiliation(s)
- Yoanna Ariosa-Morejon
- Kennedy Institute of Rheumatology, Arthritis Research UK Centre for OA Pathogenesis, University of Oxford, Oxford, United Kingdom
| | - Alberto Santos
- Big Data Institute, Li-Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom.,Center for Health Data Science, Faculty of Health Sciences, University of Copenhagen, Copenhagen, United Kingdom
| | - Roman Fischer
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, United Kingdom
| | - Simon Davis
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, United Kingdom
| | - Philip Charles
- Nuffield Department of Medicine, Target Discovery Institute, University of Oxford, Oxford, United Kingdom
| | - Rajesh Thakker
- Academic Endocrine Unit, OCDEM, Churchill Hospital, University of Oxford, Oxford, United Kingdom
| | - Angus Kt Wann
- Kennedy Institute of Rheumatology, Arthritis Research UK Centre for OA Pathogenesis, University of Oxford, Oxford, United Kingdom
| | - Tonia L Vincent
- Kennedy Institute of Rheumatology, Arthritis Research UK Centre for OA Pathogenesis, University of Oxford, Oxford, United Kingdom
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34
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New insights into the mechanisms of age-related protein-protein crosslinking in the human lens. Exp Eye Res 2021; 209:108679. [PMID: 34147508 DOI: 10.1016/j.exer.2021.108679] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 06/11/2021] [Accepted: 06/14/2021] [Indexed: 12/31/2022]
Abstract
Although protein crosslinking is often linked with aging as well as some age-related diseases, very few molecular details are available on the nature of the amino acids involved, or mechanisms that are responsible for crosslinking. Recent research has shown that several amino acids are able to generate reactive intermediates that ultimately lead to covalent crosslinking through multiple non-enzymatic mechanisms. This information has been derived from proteomic investigations on aged human lenses and the mechanisms of crosslinking, in each case, have been elucidated using model peptides. Residues involved in spontaneous protein-protein crosslinking include aspartic acid, asparagine, cysteine, lysine, phosphoserine, phosphothreonine, glutamic acid and glutamine. It has become clear, therefore, that several amino acids can act as potential sites for crosslinking in the long-lived proteins that are present in aged individuals. Moreover, the lens has been an invaluable model tissue and source of crosslinked proteins from which to determine crosslinking mechanisms that may lead to crosslinking in other human tissues.
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35
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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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36
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Shervette VR, Overly KE, Rivera Hernández JM. Radiocarbon in otoliths of tropical marine fishes: Reference Δ14C chronology for north Caribbean waters. PLoS One 2021; 16:e0251442. [PMID: 33979387 PMCID: PMC8115809 DOI: 10.1371/journal.pone.0251442] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/26/2021] [Indexed: 11/30/2022] Open
Abstract
Reef fishes support important fisheries throughout the Caribbean, but a combination of factors in the tropics makes otolith microstructure difficult to interpret for age estimation. Therefore, validation of ageing methods, via application of Δ14C is a major research priority. Utilizing known-age otolith material from north Caribbean fishes, we determined that a distinct regional Δ14C chronology exists, differing from coral-based chronologies compiled for ageing validation from a wide-ranging area of the Atlantic and from an otolith-based chronology from the Gulf of Mexico. Our north Caribbean Δ14C chronology established a decline series with narrow prediction intervals that proved successful in ageing validation of three economically important reef fish species. In examining why our north Caribbean Δ14C chronology differed from some of the coral-based Δ14C data reported from the region, we determined differences among study objectives and research design impact Δ14C temporal relationships. This resulted in establishing the first of three important considerations relevant to applying Δ14C chronologies for ageing validation: 1) evaluation of the applicability of original goal/objectives and study design of potential Δ14C reference studies. Next, we determined differences between our Δ14C chronology and those from Florida and the Gulf of Mexico were explained by differences in regional patterns of oceanic upwelling, resulting in the second consideration for future validation work: 2) evaluation of the applicability of Δ14C reference data to the region/location where fish samples were obtained. Lastly, we emphasize the application of our north Caribbean Δ14C chronology should be limited to ageing validation studies of fishes from this region known to inhabit shallow water coral habitat as juveniles. Thus, we note the final consideration to strengthen findings of future age validation studies: 3) use of Δ14C analysis for age validation should be limited to species whose juvenile habitat is known to reflect the regional Δ14C reference chronology.
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Affiliation(s)
- Virginia R. Shervette
- Fish/Fisheries Conservation Lab, University of South Carolina Aiken, Aiken, SC, United States of America
- University of South Carolina, Marine Sciences, Columbia, SC, United States of America
- * E-mail:
| | - Katherine E. Overly
- Riverside Technology for the NOAA National Marine Fisheries Service, Panama City Laboratory, Panama City, Florida, United States of America
| | - Jesús M. Rivera Hernández
- Fish/Fisheries Conservation Lab, University of South Carolina Aiken, Aiken, SC, United States of America
- University of South Carolina, Marine Sciences, Columbia, SC, United States of America
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37
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Age of black dogfish (Centroscyllium fabricii) estimated from fin spines growth bands and eye lens bomb radiocarbon dating. Polar Biol 2021. [DOI: 10.1007/s00300-021-02832-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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38
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Minaeva O, Sarangi S, Ledoux DM, Moncaster JA, Parsons DS, Washicosky KJ, Black CA, Weng FJ, Ericsson M, Moir RD, Tripodis Y, Clark JI, Tanzi RE, Hunter DG, Goldstein LE. In Vivo Quasi-Elastic Light Scattering Eye Scanner Detects Molecular Aging in Humans. J Gerontol A Biol Sci Med Sci 2021; 75:e53-e62. [PMID: 32515825 DOI: 10.1093/gerona/glaa121] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Indexed: 12/30/2022] Open
Abstract
The absence of clinical tools to evaluate individual variation in the pace of aging represents a major impediment to understanding aging and maximizing health throughout life. The human lens is an ideal tissue for quantitative assessment of molecular aging in vivo. Long-lived proteins in lens fiber cells are expressed during fetal life, do not undergo turnover, accumulate molecular alterations throughout life, and are optically accessible in vivo. We used quasi-elastic light scattering (QLS) to measure age-dependent signals in lenses of healthy human subjects. Age-dependent QLS signal changes detected in vivo recapitulated time-dependent changes in hydrodynamic radius, protein polydispersity, and supramolecular order of human lens proteins during long-term incubation (~1 year) and in response to sustained oxidation (~2.5 months) in vitro. Our findings demonstrate that QLS analysis of human lens proteins provides a practical technique for noninvasive assessment of molecular aging in vivo.
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Affiliation(s)
- Olga Minaeva
- Molecular Aging & Development Laboratory, Boston University School of Medicine, Massachusetts.,Department of Ophthalmology, Boston Children's Hospital, Massachusetts
| | - Srikant Sarangi
- Molecular Aging & Development Laboratory, Boston University School of Medicine, Massachusetts.,Department of Biomedical Engineering, Boston University, Massachusetts
| | - Danielle M Ledoux
- Department of Ophthalmology, Boston Children's Hospital, Massachusetts.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
| | - Juliet A Moncaster
- Molecular Aging & Development Laboratory, Boston University School of Medicine, Massachusetts.,Boston University Photonics Center, Boston University, Massachusetts
| | - Douglas S Parsons
- Molecular Aging & Development Laboratory, Boston University School of Medicine, Massachusetts.,Boston University Photonics Center, Boston University, Massachusetts
| | - Kevin J Washicosky
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Charlestown
| | - Caitlin A Black
- Department of Ophthalmology, Boston Children's Hospital, Massachusetts
| | - Frank J Weng
- Department of Ophthalmology, Boston Children's Hospital, Massachusetts
| | - Maria Ericsson
- Electron Microscopy Facility, Harvard Medical School, Boston, Massachusetts
| | - Robert D Moir
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Neurology, Harvard Medical School, Boston, Massachusetts
| | - Yorghos Tripodis
- Department of Biostatistics, Boston University School of Public Health, Massachusetts
| | - John I Clark
- Department of Biological Structure, University of Washington, Seattle
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, Department of Neurology, Massachusetts General Hospital, Charlestown.,Department of Neurology, Harvard Medical School, Boston, Massachusetts
| | - David G Hunter
- Department of Ophthalmology, Boston Children's Hospital, Massachusetts.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
| | - Lee E Goldstein
- Molecular Aging & Development Laboratory, Boston University School of Medicine, Massachusetts.,Boston University Alzheimer's Disease Center, Massachusetts
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39
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Spontaneous protein–protein crosslinking at glutamine and glutamic acid residues in long-lived proteins. Biochem J 2021; 478:327-339. [DOI: 10.1042/bcj20200798] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 12/15/2020] [Accepted: 12/18/2020] [Indexed: 11/17/2022]
Abstract
Long-lived proteins (LLPs) are susceptible to the accumulation of both enzymatic and spontaneous post-translational modifications (PTMs). A prominent PTM observed in LLPs is covalent protein–protein crosslinking. In this study, we examined aged human lenses and found several proteins to be crosslinked at Glu and Gln residues. This new covalent bond involves the amino group of Lys or an α-amino group. A number of these crosslinks were found in intermediate filament proteins. Such crosslinks could be reproduced experimentally by incubation of Glu- or Gln-containing peptides and their formation was consistent with an amino group attacking a glutarimide intermediate. These findings show that both Gln and Glu residues can act as sites for spontaneous covalent crosslinking in LLPs and they provide a mechanistic explanation for an otherwise puzzling observation, that a major fraction of Aβ in the human brain is crosslinked via Glu 22 and the N-terminal amino group.
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40
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Bonnin EA, Fornasiero EF, Lange F, Turck CW, Rizzoli SO. NanoSIMS observations of mouse retinal cells reveal strict metabolic controls on nitrogen turnover. BMC Mol Cell Biol 2021; 22:5. [PMID: 33430763 PMCID: PMC7798281 DOI: 10.1186/s12860-020-00339-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 12/17/2020] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Most of the cells of the mammalian retina are terminally differentiated, and do not regenerate once fully developed. This implies that these cells have strict controls over their metabolic processes, including protein turnover. We report the use of metabolic labelling procedures and secondary ion mass spectrometry imaging to examine nitrogen turnover in retinal cells, with a focus on the outer nuclear layer, inner nuclear layer, and outer plexiform layer. RESULTS We find that turnover can be observed in all cells imaged using NanoSIMS. However, the rate of turnover is not constant, but varies between different cellular types and cell regions. In the inner and outer nuclear layers, turnover rate is higher in the cytosol than in the nucleus of each cell. Turnover rates are also higher in the outer plexiform layer. An examination of retinal cells from mice that were isotopically labeled very early in embryonic development shows that proteins produced during this period can be found in all cells and cell regions up to 2 months after birth, even in regions of high turnover. CONCLUSIONS Our results indicate that turnover in retinal cells is a highly regulated process, with strict metabolic controls. We also observe that turnover is several-fold higher in the synaptic layer than in cell layers. Nevertheless, embryonic proteins can still be found in this layer 2 months after birth, suggesting that stable structures persist within the synapses, which remain to be determined.
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Affiliation(s)
- Elisa A Bonnin
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Excellence Cluster Multiscale Bioimaging, 37073, Göttingen, Germany.
- Center for Biostructural Imaging of Neurodegeneration (BIN), 37075, Göttingen, Germany.
| | - Eugenio F Fornasiero
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Excellence Cluster Multiscale Bioimaging, 37073, Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration (BIN), 37075, Göttingen, Germany
| | - Felix Lange
- Department of Nanobiophotonics, Max Planck Institute for Biophysical Chemistry, 37077, Göttingen, Germany
- Clinic for Neurology, University Medical Center Göttingen, 37075, Göttingen, Germany
| | - Christoph W Turck
- Proteomics and Biomarkers, Max Planck Institute of Psychiatry, Munich, Germany
| | - Silvio O Rizzoli
- Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Excellence Cluster Multiscale Bioimaging, 37073, Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration (BIN), 37075, Göttingen, Germany
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The distribution of cellular turnover in the human body. Nat Med 2021; 27:45-48. [PMID: 33432173 DOI: 10.1038/s41591-020-01182-9] [Citation(s) in RCA: 165] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2020] [Accepted: 11/16/2020] [Indexed: 01/28/2023]
Abstract
We integrated ubiquity, mass and lifespan of all major cell types to achieve a comprehensive quantitative description of cellular turnover. We found a total cellular mass turnover of 80 ± 20 grams per day, dominated by blood cells and gut epithelial cells. In terms of cell numbers, close to 90% of the (0.33 ± 0.02) × 1012 cells per day turnover was blood cells.
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Guseman AJ, Whitley MJ, González JJ, Rathi N, Ambarian M, Gronenborn AM. Assessing the Structures and Interactions of γD-Crystallin Deamidation Variants. Structure 2020; 29:284-291.e3. [PMID: 33264606 DOI: 10.1016/j.str.2020.11.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Revised: 10/12/2020] [Accepted: 11/06/2020] [Indexed: 11/25/2022]
Abstract
Cataracts involve the deposition of the crystallin proteins in the vertebrate eye lens, causing opacification and blindness. They are associated with either genetic mutation or protein damage that accumulates over the lifetime of the organism. Deamidation of Asn residues in several different crystallins has been observed and is frequently invoked as a cause of cataract. Here, we investigated the properties of Asp variants, deamidation products of γD-crystallin, by solution NMR, X-ray crystallography, and other biophysical techniques. No substantive structural or stability changes were noted for all seven Asn to Asp γD-crystallins. Importantly, no changes in diffusion interaction behavior could be detected. Our combined experimental results demonstrate that introduction of single Asp residues on the surface of γD-crystallin by deamidation is unlikely to be the driver of cataract formation in the eye lens.
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Affiliation(s)
- Alex J Guseman
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Matthew J Whitley
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Jeremy J González
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Nityam Rathi
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Mikayla Ambarian
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA
| | - Angela M Gronenborn
- Department of Structural Biology, University of Pittsburgh School of Medicine, 3501 Fifth Avenue, Pittsburgh, PA 15261, USA.
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Wang Y, Liu Z, Huang C, Zhao L, Jiang X, Liu Y, Liu Y, Wan Y, Chou Y, Li X. Analysis of lens epithelium telomere length in age-related cataract. Exp Eye Res 2020; 201:108279. [PMID: 32991882 DOI: 10.1016/j.exer.2020.108279] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Revised: 09/23/2020] [Accepted: 09/25/2020] [Indexed: 11/28/2022]
Abstract
We aimed to investigate the associations among lens epithelium telomere length (LETL), cataract types, and systemic pro-senescence factors in patients with age-related cataract. In this prospective study, the general demographic factors, body mass index, smoking history, depression, hypertension, diabetes, various psychological measures, and uncorrected distant visual acuity of patients with age-related cataract were recorded. Lens Opacities Classification System III (LOCS III) scores and lens density measured by Scheimpflug imaging were used to evaluate the cataracts. LETL was measured by real-time polymerase chain reaction. Correlations among these parameters were analyzed. The LOCS III nuclear opalescence (NO) score was associated with age (β = 0.053, P < 0.001) and Patient Health Questionnaire-9 score (β = -0.042, P = 0.004). Smoking was identified as a risk factor affecting LOCS III NO score (odds ratio = 1.546, 95% confidence interval, 1.128-2.119), but not the LOCS III cortical or posterior subcapsular scores. LETLs showed a weak association with systemic factors and LOCS III scores, and a significantly moderate correlation with the average objective lens densities of different regions measured by Scheimpflug imaging (r values ranged from -0.278 to -0.523, P < 0.05). However, there was no correlation between the LETLs and the maximum lens densities. The groups with a relatively low lens density had longer LETLs. In Conclusion, being an age-related disease, cortical cataract was also associated with "aging of the lens epithelium." Notably, lens epithelium activity rarely showed systemic effects. Thus, future studies should emphasize the importance of the telomeric system in cataractous process and aging.
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Affiliation(s)
- Yinhao Wang
- Peking University Third Hospital, Beijing, China
| | - Ziyuan Liu
- Peking University Third Hospital, Beijing, China
| | - Chen Huang
- Peking University Third Hospital, Beijing, China
| | | | | | - Yan Liu
- Peking University Third Hospital, Beijing, China
| | - Yushi Liu
- Peking University Third Hospital, Beijing, China
| | - Yu Wan
- Peking University Third Hospital, Beijing, China
| | - Yilin Chou
- Peking University Third Hospital, Beijing, China
| | - Xuemin Li
- Peking University Third Hospital, Beijing, China.
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Grosas AB, Rekas A, Mata JP, Thorn DC, Carver JA. The Aggregation of αB-Crystallin under Crowding Conditions Is Prevented by αA-Crystallin: Implications for α-Crystallin Stability and Lens Transparency. J Mol Biol 2020; 432:5593-5613. [PMID: 32827531 DOI: 10.1016/j.jmb.2020.08.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 08/13/2020] [Accepted: 08/13/2020] [Indexed: 02/08/2023]
Abstract
One of the most crowded biological environments is the eye lens which contains a high concentration of crystallin proteins. The molecular chaperones αB-crystallin (αBc) with its lens partner αA-crystallin (αAc) prevent deleterious crystallin aggregation and cataract formation. However, some forms of cataract are associated with structural alteration and dysfunction of αBc. While many studies have investigated the structure and function of αBc under dilute in vitro conditions, the effect of crowding on these aspects is not well understood despite its in vivo relevance. The structure and chaperone ability of αBc under conditions that mimic the crowded lens environment were investigated using the polysaccharide Ficoll 400 and bovine γ-crystallin as crowding agents and a variety of biophysical methods, principally contrast variation small-angle neutron scattering. Under crowding conditions, αBc unfolds, increases its size/oligomeric state, decreases its thermal stability and chaperone ability, and forms kinetically distinct amorphous and fibrillar aggregates. However, the presence of αAc stabilizes αBc against aggregation. These observations provide a rationale, at the molecular level, for the aggregation of αBc in the crowded lens, a process that exhibits structural and functional similarities to the aggregation of cataract-associated αBc mutants R120G and D109A under dilute conditions. Strategies that maintain or restore αBc stability, as αAc does, may provide therapeutic avenues for the treatment of cataract.
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Affiliation(s)
- Aidan B Grosas
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
| | - Agata Rekas
- National Deuteration Facility, Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234, Australia
| | - Jitendra P Mata
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights, NSW 2234, Australia
| | - David C Thorn
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia
| | - John A Carver
- Research School of Chemistry, The Australian National University, Canberra, ACT, 2601, Australia.
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45
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Zhang C, Svensson RB, Couppé C, Schjerling P, Skovgaard D, Kjaer M, Magnusson SP. Regional differences in turnover, composition, and mechanics of the porcine flexor tendon. Connect Tissue Res 2020; 61:475-484. [PMID: 31134816 DOI: 10.1080/03008207.2019.1620222] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
PURPOSE Recent data suggest that there is a lack of turnover in the core of human tendon, but it remains unknown whether there are regional differences between core and periphery of the cross section. The purpose of this project was to investigate regional differences in turnover as estimated by the accumulation of fluorescent Advanced Glycation End-products (AGEs) and regional differences in mechanical properties. MATERIALS AND METHODS Tendons were obtained from lean control (n = 4) and diabetic Göttingen minipigs (streptozotocin-induced, n = 6). The deep digital flexor tendon of one hind limb was separated into a proximal, central and distal part. Autofluorescence was measured in the core and periphery of the proximal and distal parts of the tendon, and mechanical properties were tested on fascicles taken from the core and periphery of the central tendon (only diabetic animals). RESULTS Autofluorescence was greater in the proximal than the distal part. In the distal part of the lean control animals, autofluorescent AGE accumulation was also greater in the core than the periphery. Peak modulus in the core region (704 ± 79 MPa) was higher than the periphery (466 ± 53 MPa, p < 0.05) in diabetic tendons. CONCLUSION Taken together, autofluorescence varied both along the length and across the tendon cross section, indicating higher turnover in the distal and peripheral regions. In addition, mechanical properties differed across the tendon cross-section.
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Affiliation(s)
- Cheng Zhang
- Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, and Center for Healthy Aging, University of Copenhagen , Copenhagen, Denmark
| | - Rene B Svensson
- Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, and Center for Healthy Aging, University of Copenhagen , Copenhagen, Denmark
| | - Christian Couppé
- Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, and Center for Healthy Aging, University of Copenhagen , Copenhagen, Denmark.,Department of Physical and Occupational Therapy, Bispebjerg Hospital , Copenhagen, Denmark
| | - Peter Schjerling
- Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, and Center for Healthy Aging, University of Copenhagen , Copenhagen, Denmark
| | - Dorthe Skovgaard
- Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet , Copenhagen, Denmark
| | - Michael Kjaer
- Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, and Center for Healthy Aging, University of Copenhagen , Copenhagen, Denmark
| | - S Peter Magnusson
- Institute of Sports Medicine Copenhagen, Bispebjerg Hospital, and Center for Healthy Aging, University of Copenhagen , Copenhagen, Denmark.,Department of Physical and Occupational Therapy, Bispebjerg Hospital , Copenhagen, Denmark
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Zhuravleva YS, Morozova OB, Tsentalovich YP, Sherin PS. Proton-coupled electron transfer as the mechanism of reaction between triplet state of kynurenic acid and tryptophan. J Photochem Photobiol A Chem 2020. [DOI: 10.1016/j.jphotochem.2020.112522] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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47
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Savina ED, Tsentalovich YP, Sherin PS. UV-A induced damage to lysozyme via Type I photochemical reactions sensitized by kynurenic acid. Free Radic Biol Med 2020; 152:482-493. [PMID: 31751763 DOI: 10.1016/j.freeradbiomed.2019.11.017] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Revised: 11/12/2019] [Accepted: 11/13/2019] [Indexed: 02/06/2023]
Abstract
In this work we studied the mechanisms of Type I photodamage to a model protein, hen egg white lysozyme (HEWL), sensitized by kynurenic acid (KNA) - one of the most efficient photosensitizers of the human eye lens present in trace amounts within tissue. The kynurenic acid radical, KNA•-, formed in the quenching of triplet KNA by HEWL, can be readily oxidized by molecular oxygen with the formation of superoxide anion radical O2•-. This leads to two ways of damage to proteins: either via the direct reactions between KNA•- and HEWL• radicals (Type Ia) or via the reactions between superoxide anion O2•- and HEWL• radicals (Type Ib). Our results demonstrate significant degradation of the protein during Type Ia photolysis with the formation of various oligomeric and oxygenated forms of HEWL and several deoxygenated products of KNA. Liquid chromatography-mass spectrometry analysis revealed the cross-linking of HEWL via tryptophan (Trp62) and tyrosine (Tyr23) residues and, for the first time, the covalent binding of KNA to protein via tryptophan (Trp62 and Trp123) residues. It was found that Type Ib reactions lead to substantially smaller damage to HEWL; the degradation quantum yields (Φdeg) of HEWL are 1.3 ± 0.3% and 0.12 ± 0.03% for Type Ia and Ib photolyses, respectively. Low Φdeg values for both types of photolysis indicate the Back Electron Transfer (BET) with the restoration of initial reagents as the main radical decay path with significantly higher BET efficiency in the case of Type Ib reactions. Therefore, in essentially oxygen-free tissues like the eye lens, the direct radical reactions via Type Ia mechanism could induce significantly larger damage to proteins, leading to their cross-linking and oxidation. The accumulation of these modifications can cause the development of various diseases, in particular, cataracts in the eye lens.
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Affiliation(s)
- Ekaterina D Savina
- International Tomography Center SB RAS, Institutskaya str. 3A, 630090, Novosibirsk, Russia; Novosibirsk State University, Pirogova str. 2, 630090, Novosibirsk, Russia
| | - Yuri P Tsentalovich
- International Tomography Center SB RAS, Institutskaya str. 3A, 630090, Novosibirsk, Russia; Novosibirsk State University, Pirogova str. 2, 630090, Novosibirsk, Russia
| | - Peter S Sherin
- International Tomography Center SB RAS, Institutskaya str. 3A, 630090, Novosibirsk, Russia; Novosibirsk State University, Pirogova str. 2, 630090, Novosibirsk, Russia.
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48
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Våben C, Heinemeier KM, Schjerling P, Olsen J, Petersen MM, Kjaer M, Krogsgaard MR. No detectable remodelling in adult human menisci: an analysis based on the C 14 bomb pulse. Br J Sports Med 2020; 54:1433-1437. [PMID: 32409517 PMCID: PMC7677461 DOI: 10.1136/bjsports-2019-101360] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/21/2020] [Indexed: 11/30/2022]
Abstract
Objectives Bone and other human tissues remodel through life, for example, as a response to increasing load, and this prevents permanent destruction of the tissue. Non-traumatic meniscal rupture is a common musculoskeletal disease, but it is unknown if it is caused by inability of the menisci to remodel. The aim of this study was to determine whether meniscal collagen is remodelling throughout life. Methods The life-long turnover of the human meniscal collagens was explored by the 14C bomb pulse method. 14C levels were determined in menisci from 18 patients with osteoarthritis and 7 patients with healthy knees. Results There was a negligible turnover of the meniscal collagen in adults. This low turnover was observed in menisci from patients with knee osteoarthritis and in healthy menisci. Conclusion This study provides evidence that essentially no remodelling occurs in the adult human meniscal collagen structure and explains the clinical degeneration that is often seen in menisci of middle-aged and elderly persons. It suggests that strengthening of the collagen structure of menisci, as response to physical activity, may occur during childhood, while it is not possible in the adult population.
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Affiliation(s)
- Christoffer Våben
- Section for Sportstraumatology M51, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Katja M Heinemeier
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark.,Center for Healthy Aging, University of Copenhagen Faculty of Health Sciences, Copenhagen, Denmark
| | - Peter Schjerling
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Jesper Olsen
- Department of Physics and Astronomy, Aarhus Accelerator Mass Spectrometry (AMS) Centre, Aarhus Universitet, Aarhus, Denmark
| | - Michael Mørk Petersen
- Musculoskeletal Tumor Section, Department of Orthopaedic Surgery, Rigshospitalet, Copenhagen, Denmark
| | - Michael Kjaer
- Institute of Sports Medicine, Department of Orthopaedic Surgery M, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
| | - Michael R Krogsgaard
- Section for Sportstraumatology M51, Bispebjerg and Frederiksberg Hospital, Copenhagen, Denmark
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Yang X, Xu J, Fu C, Jia Z, Yao K, Chen X. The cataract-related S39C variant increases γS-crystallin sensitivity to environmental stress by destroying the intermolecular disulfide cross-links. Biochem Biophys Res Commun 2020; 526:459-465. [DOI: 10.1016/j.bbrc.2020.03.072] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 03/11/2020] [Indexed: 02/06/2023]
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50
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Basisty N, Holtz A, Schilling B. Accumulation of "Old Proteins" and the Critical Need for MS-based Protein Turnover Measurements in Aging and Longevity. Proteomics 2020; 20:e1800403. [PMID: 31408259 PMCID: PMC7015777 DOI: 10.1002/pmic.201800403] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 07/31/2019] [Indexed: 12/31/2022]
Abstract
Aging and age-related diseases are accompanied by proteome remodeling and progressive declines in cellular machinery required to maintain protein homeostasis (proteostasis), such as autophagy, ubiquitin-mediated degradation, and protein synthesis. While many studies have focused on capturing changes in proteostasis, the identification of proteins that evade these cellular processes has recently emerged as an approach to studying the aging proteome. With advances in proteomic technology, it is possible to monitor protein half-lives and protein turnover at the level of individual proteins in vivo. For large-scale studies, these technologies typically include the use of stable isotope labeling coupled with MS and comprehensive assessment of protein turnover rates. Protein turnover studies have revealed groups of highly relevant long-lived proteins (LLPs), such as the nuclear pore complexes, extracellular matrix proteins, and protein aggregates. Here, the role of LLPs during aging and age-related diseases and the methods used to identify and quantify their changes are reviewed. The methods available to conduct studies of protein turnover, used in combination with traditional proteomic methods, will enable the field to perform studies in a systems biology context, as changes in proteostasis may not be revealed in studies that solely measure differential protein abundances.
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Affiliation(s)
| | - Anja Holtz
- The Buck Institute for Research on AgingNovatoCAUSA
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