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Gross C, Guérin LP, Socol BG, Germain L, Guérin SL. The Ins and Outs of Clusterin: Its Role in Cancer, Eye Diseases and Wound Healing. Int J Mol Sci 2023; 24:13182. [PMID: 37685987 PMCID: PMC10488069 DOI: 10.3390/ijms241713182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 08/17/2023] [Accepted: 08/21/2023] [Indexed: 09/10/2023] Open
Abstract
Clusterin (CLU) is a glycoprotein originally discovered in 1983 in ram testis fluid. Rapidly observed in other tissues, it was initially given various names based on its function in different tissues. In 1992, it was finally named CLU by consensus. Nearly omnipresent in human tissues, CLU is strongly expressed at fluid-tissue interfaces, including in the eye and in particular the cornea. Recent research has identified different forms of CLU, with the most prominent being a 75-80 kDa heterodimeric protein that is secreted. Another truncated version of CLU (55 kDa) is localized to the nucleus and exerts pro-apoptotic activities. CLU has been reported to be involved in various physiological processes such as sperm maturation, lipid transportation, complement inhibition and chaperone activity. CLU was also reported to exert important functions in tissue remodeling, cell-cell adhesion, cell-substratum interaction, cytoprotection, apoptotic cell death, cell proliferation and migration. Hence, this protein is sparking interest in tissue wound healing. Moreover, CLU gene expression is finely regulated by cytokines, growth factors and stress-inducing agents, leading to abnormally elevated levels of CLU in many states of cellular disturbance, including cancer and neurodegenerative conditions. In the eye, CLU expression has been reported as being severely increased in several pathologies, such as age-related macular degeneration and Fuch's corneal dystrophy, while it is depleted in others, such as pathologic keratinization. Nevertheless, the precise role of CLU in the development of ocular pathologies has yet to be deciphered. The question of whether CLU expression is influenced by these disorders or contributes to them remains open. In this article, we review the actual knowledge about CLU at both the protein and gene expression level in wound healing, and explore the possibility that CLU is a key factor in cancer and eye diseases. Understanding the expression and regulation of CLU could lead to the development of novel therapeutics for promoting wound healing.
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Affiliation(s)
- Christelle Gross
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec City, QC G1V 0A6, Canada; (C.G.); (B.G.S.); (L.G.)
- Centre de Recherche du CHU de Québec, Axe Médecine Régénératrice, Québec City, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada
| | | | - Bianca G. Socol
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec City, QC G1V 0A6, Canada; (C.G.); (B.G.S.); (L.G.)
| | - Lucie Germain
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec City, QC G1V 0A6, Canada; (C.G.); (B.G.S.); (L.G.)
- Centre de Recherche du CHU de Québec, Axe Médecine Régénératrice, Québec City, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada
- Département de Chirurgie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada
| | - Sylvain L. Guérin
- Centre de Recherche en Organogénèse Expérimentale de l’Université Laval/LOEX, Québec City, QC G1V 0A6, Canada; (C.G.); (B.G.S.); (L.G.)
- Centre de Recherche du CHU de Québec, Axe Médecine Régénératrice, Québec City, QC G1J 1Z4, Canada
- Département d’Ophtalmologie, Faculté de Médecine, Université Laval, Québec City, QC G1V 0A6, Canada
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Yavrum F, Elgin U, Kocer ZA, Fidanci V, Sen E. Evaluation of aqueous humor and serum clusterin levels in patients with glaucoma. BMC Ophthalmol 2021; 21:25. [PMID: 33422048 PMCID: PMC7796574 DOI: 10.1186/s12886-020-01781-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 12/21/2020] [Indexed: 12/03/2022] Open
Abstract
Background To compare the aqueous humor (AH) and the serum clusterin levels of patients with pseudoexfoliation syndrome (PEX), pseudoexfoliation glaucoma (PEXG), and primary open-angle glaucoma (POAG) with each other and with an age- and sex-matched control group. Methods This prospective, cross-sectionalstudy evaluated 92 eyes from 92 adult cases of uncomplicated phacoemulsification and posterior chamber intraocular lens (IOL) implantation. The cases were divided into PEX, PEXG, POAG, and control groups. Serum samples were taken from the antecubital vein just before the surgery, and the AH samples were aspirated at the beginning of the surgery. Kruskal-Wallis H, One-way ANOVA, Mann-Whitney U with Bonferroni correction and Chi-Square tests were used for statistical analysis. Results The serum clusterin levels were the highest in the PEXG group, but no statistically significant differences were observed between the groups (p=0.633). The mean AH clusterin levels were 286.79±29.64 μg/mL in the PEXG group, 263.92±31.70 μg/mL in the PEX group, 272.59±49.71 μg/mL in the POAG group, and 193.50±62.38 μg/mL in the control group (p< 0.001). This came out to be 1.48 times increase for the PEXG group, 1.36 for the PEX group, and 1.41 for the POAG group when compared with the control subjects. Conclusions A higher level of clusterin in the anterior chamber was found to be associated with PEX and PEXG. In addition, a high level of anterior chamber clusterin in POAG, which is a new finding, showed that this molecule might be important not only in pseudoexfoliation, but also other types of glaucoma like POAG.
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Affiliation(s)
| | - Ufuk Elgin
- University of Health Sciences, Ulucanlar Eye Research Hospital, Ankara, Turkey
| | - Zeynep Adiyaman Kocer
- University of Health Sciences, Ankara Research and Training Hospital, Ankara, Turkey
| | - Vildan Fidanci
- University of Health Sciences, Ankara Research and Training Hospital, Ankara, Turkey
| | - Emine Sen
- University of Health Sciences, Ulucanlar Eye Research Hospital, Ankara, Turkey
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Can Demirdöğen B, Demirkaya-Budak S, Özge G, Mumcuoğlu T. Evaluation of Tear Fluid and Aqueous Humor Concentration of Clusterin as Biomarkers for Early Diagnosis of Pseudoexfoliation Syndrome and Pseudoexfoliative Glaucoma. Curr Eye Res 2019; 45:805-813. [PMID: 31765245 DOI: 10.1080/02713683.2019.1698055] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE Pseudoexfoliation syndrome (PEX) is an age-related disorder of the extracellular matrix characterized by the accumulation of fibrillary deposits in the anterior chamber of the eye, which leads to the development of pseudoexfoliative glaucoma (PEG). Early identification of subjects with higher susceptibility to PEX and PEG development is very important so that these conditions are managed at earlier stages, which requires that an objective biomarker is defined. Therefore, in the present study, we aimed to determine if aqueous humor and tear fluid concentrations of clusterin, an extracellular chaperone, are objective biomarkers for PEX and PEG risk. METHODS Tear fluid was obtained from 80 patients with PEG, 80 patients with PEX, and 80 controls, using Schirmer strips. Aqueous humor was also collected during cataract surgery from 12 patients with PEG, 17 patients with PEX, and 22 controls, who also gave tear samples. Clusterin concentration was determined by ELISA. RESULTS Clusterin concentration in aqueous humor was significantly higher in patients with PEG than in PEX cases (P = .002) and controls (P = .004). Receiver operating characteristics analysis revealed that this parameter is a robust classifier to distinguish PEG and PEX cases. Tear fluid clusterin concentrations did not differ significantly between groups. Aqueous humor and tear fluid levels of clusterin were not significantly correlated. CONCLUSIONS In conclusion, tear fluid clusterin level in patients with PEG and PEX was determined for the first time, which showed no difference between study groups. Aqueous humor clusterin level was markedly higher in patients with PEG.
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Affiliation(s)
- Birsen Can Demirdöğen
- Department of Biomedical Engineering, TOBB University of Economics and Technology , Ankara, Turkey
| | - Sinem Demirkaya-Budak
- Department of Biomedical Engineering, TOBB University of Economics and Technology , Ankara, Turkey
| | - Gökhan Özge
- Department of Ophthalmology, Gülhane Training and Research Hospital, University of Health Sciences , Ankara, Turkey
| | - Tarkan Mumcuoğlu
- Department of Ophthalmology, Gülhane Training and Research Hospital, University of Health Sciences , Ankara, Turkey
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Yu V, Bhattacharya D, Webster A, Bauskar A, Flowers C, Heur M, Chintala SK, Itakura T, Wilson MR, Barr JT, Jeong S, Wang M, Fini ME. Clusterin from human clinical tear samples: Positive correlation between tear concentration and Schirmer strip test results. Ocul Surf 2018; 16:478-486. [PMID: 30077709 PMCID: PMC6175631 DOI: 10.1016/j.jtos.2018.08.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Revised: 07/24/2018] [Accepted: 08/01/2018] [Indexed: 01/02/2023]
Abstract
PURPOSE To investigate the relationship between tear concentration of the homeostatic protein clusterin (CLU) and dry eye signs and symptoms, and to characterize tear CLU protein. METHODS Two independent studies were conducted, one in Tucson (44 subjects), the other in Los Angeles (52 subjects). A cohort study design was employed to enroll patients without regard to dry eye diagnosis. Dry eye signs and symptoms were assessed using clinical tests. Tear samples were collected by Schirmer strip, and also by micropipette at slit lamp when possible. CLU from both sample types was quantified by immunoassay. The relationship between CLU concentration and clinical test scores was determined by Pearson's correlation coefficient (for individual eyes) and multiple linear regression analysis (including both eyes). CLU was also evaluated biochemically by western blotting. RESULTS In the Tucson cohort, a positive correlation was observed between tear CLU concentration and results of the Schirmer strip test, a measure of tear flow (p = 0.021 includes both eyes). This result was corroborated in the Los Angeles cohort (p = 0.013). The mean tear CLU concentration was 31 ± 14 μg/mL (n = 18 subjects, 33 eyes; range = 7-48 μg/mL). CLU from clinical tear samples appeared biochemically similar to CLU from a non-clinical tear sample and from blood plasma. CONCLUSIONS Results support the hypothesis that an optimal concentration of tear CLU is important for ocular surface health, and that this drops below the effective threshold in dry eye. Tear CLU measurement might identify patients that could benefit from supplementation. Information about concentration will aid development of therapeutic dosage parameters.
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Affiliation(s)
- Valerie Yu
- MD Program, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA
| | - Dhruva Bhattacharya
- Department of Ophthalmology & Vision Science, University of Arizona College of Medicine, Tucson, AZ, USA
| | - Andrew Webster
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA
| | - Aditi Bauskar
- PhD Program in Medical Biology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA
| | - Charles Flowers
- USC Roski Eye Institute and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA
| | - Martin Heur
- USC Roski Eye Institute and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA
| | - Shravan K Chintala
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA
| | - Tatsuo Itakura
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA
| | - Mark R Wilson
- Illawarra Health and Medical Research Institute, School of Biological Sciences, University of Wollongong, Wollongong, New South Wales, Australia
| | - Joseph T Barr
- The Ohio State University College of Optometry, Columbus, OH, USA
| | - Shinwu Jeong
- USC Institute for Genetic Medicine, USC Roski Eye Institute and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA
| | - Mingwu Wang
- Department of Ophthalmology & Vision Science, University of Arizona College of Medicine, Tucson, AZ, USA
| | - M Elizabeth Fini
- USC Institute for Genetic Medicine, Keck School of Medicine of USC, University of Southern California, Los Angeles, CA, USA.
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Fini ME, Bauskar A, Jeong S, Wilson MR. Clusterin in the eye: An old dog with new tricks at the ocular surface. Exp Eye Res 2016; 147:57-71. [PMID: 27131907 DOI: 10.1016/j.exer.2016.04.019] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 04/22/2016] [Accepted: 04/23/2016] [Indexed: 12/30/2022]
Abstract
The multifunctional protein clusterin (CLU) was first described in 1983 as a secreted glycoprotein present in ram rete testis fluid that enhanced aggregation ('clustering') of a variety of cells in vitro. It was also independently discovered in a number of other systems. By the early 1990s, CLU was known under many names and its expression had been demonstrated throughout the body, including in the eye. Its homeostatic activities in proteostasis, cytoprotection, and anti-inflammation have been well documented, however its roles in health and disease are still not well understood. CLU is prominent at fluid-tissue interfaces, and in 1996 it was demonstrated to be the most highly expressed transcript in the human cornea, the protein product being localized to the apical layers of the mucosal epithelia of the cornea and conjunctiva. CLU protein is also present in human tears. Using a preclinical mouse model for desiccating stress that mimics human dry eye disease, the authors recently demonstrated that CLU prevents and ameliorates ocular surface barrier disruption by a remarkable sealing mechanism dependent on attainment of a critical all-or-none concentration in the tears. When the CLU level drops below the critical all-or-none threshold, the barrier becomes vulnerable to desiccating stress. CLU binds selectively to the ocular surface subjected to desiccating stress in vivo, and in vitro to LGALS3 (galectin-3), a key barrier component. Positioned in this way, CLU not only physically seals the ocular surface barrier, but it also protects the barrier cells and prevents further damage to barrier structure. CLU depletion from the ocular surface epithelia is seen in a variety of inflammatory conditions in humans and mice that lead to squamous metaplasia and a keratinized epithelium. This suggests that CLU might have a specific role in maintaining mucosal epithelial differentiation, an idea that can now be tested using the mouse model for desiccating stress. Most excitingly, the new findings suggest that CLU could serve as a novel biotherapeutic for dry eye disease.
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Affiliation(s)
- M Elizabeth Fini
- USC Institute for Genetic Medicine and Departments of Cell & Neurobiology and Ophthalmology, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA 90089-9037, USA.
| | - Aditi Bauskar
- USC Institute for Genetic Medicine and Graduate Program in Medical Biology, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA 90089-9037, USA.
| | - Shinwu Jeong
- USC Institute for Genetic Medicine and Department of Ophthalmology, Keck School of Medicine of USC, University of Southern California, 2250 Alcatraz St., Suite 240, Los Angeles, CA 90089-9037, USA.
| | - Mark R Wilson
- Illawarra Health and Medical Research Institute, School of Biological Sciences, University of Wollongong, Northfields Avenue, Wollongong, New South Wales, 2522 Australia.
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Doudevski I, Rostagno A, Cowman M, Liebmann J, Ritch R, Ghiso J. Clusterin and complement activation in exfoliation glaucoma. Invest Ophthalmol Vis Sci 2014; 55:2491-9. [PMID: 24550356 DOI: 10.1167/iovs.13-12941] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
PURPOSE The study was done to better understand the biological significance of clusterin co-localization with the exfoliation deposits (XF deposits), and provide insight into a pathogenic mechanism involving activation of the complement system and its pro-inflammatory consequences in patients with exfoliation glaucoma. METHODS Exfoliation lens deposits were analyzed by high resolution atomic force microscopy imaging and confocal immunofluorescence. Levels of clusterin and vitronectin, as well as of the complement activation products C3a and soluble C5b-9, were assessed via ELISA. RESULTS Atomic-force microscopy examination of lenses with exfoliation syndrome (XFS) revealed a dense fibrillar network on the anterior, aqueous-bathed surface of the lens, while the epithelial side displayed no discernible structural features at the same resolution. Clusterin colocalized with XF deposits, demonstrating integral association with the fibrils. Levels of activation-derived complement components C3a and soluble C5b-9, as well as the complement inhibitors clusterin and vitronectin, were found significantly elevated (1.7-fold, P < 0.05; 4.1-fold, P < 0.05; 1.8-fold, P < 0.01; and 3.0-fold, P < 0.01, respectively) in aqueous humor from glaucoma patients with XFS compared to non-XFS glaucoma controls. CONCLUSIONS The data provide compelling evidence for the activation of the complement system in XFS, highlighting the generation of subproducts with potent proinflammatory activity, which are capable of triggering and chronically maintaining levels of subclinical inflammation, suggesting novel targets for therapeutic intervention. The colocalization of clusterin in exfoliation fibrils suggests a failed attempt to prevent tissue accumulation of protein aggregates, as seen in other protein folding disorders, likely due to the abnormal high levels of misfolded proteins overwhelming its chaperone capacity.
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Affiliation(s)
- Ivo Doudevski
- Department of Pathology, New York University School of Medicine, New York, New York, United States
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Charnay Y, Imhof A, Vallet PG, Kovari E, Bouras C, Giannakopoulos P. Clusterin in neurological disorders: Molecular perspectives and clinical relevance. Brain Res Bull 2012; 88:434-43. [DOI: 10.1016/j.brainresbull.2012.05.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 05/07/2012] [Indexed: 10/28/2022]
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Jurkunas UV, Bitar MS, Rawe I, Harris DL, Colby K, Joyce NC. Increased clusterin expression in Fuchs' endothelial dystrophy. Invest Ophthalmol Vis Sci 2008; 49:2946-55. [PMID: 18378577 DOI: 10.1167/iovs.07-1405] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To investigate the differential expression of the glycoprotein clusterin/apoJ (CLU) in normal and Fuchs' endothelial dystrophy (FED) corneal endothelium and to compare the expression of various forms of CLU in normal and FED tissue. METHODS FED and pseudophakic bullous keratopathy (PBK) corneal buttons were removed during transplantation, and normal corneas were obtained from tissue banks. Human corneal endothelial cells and Descemet's membrane (HCEC-DM) complex was dissected from the stroma. Proteins were separated on 2-D gels and subjected to comparative proteomic analysis. Relative expression of presecretory CLU (pre-sCLU), secretory (s)CLU, and nuclear (n)CLU were compared between normal and FED HCEC-DM by Western blot analysis. Expression of CLU mRNA was compared by using RT-PCR. Subcellular localization of CLU was compared in corneal wholemounts from normal eyes and eyes with FED by immunocytochemistry followed by confocal microscopy. RESULTS Proteomic analysis revealed an apparent increase in CLU expression in FED HCEC-DM compared with the normal control. Western blot analysis demonstrated that pre-sCLU protein expression was 5.2 times higher in FED than in normal samples (P = 3.52E-05), whereas the mature form modified for secretion (sCLU) was not significantly elevated (P = 0.092). Expression of nCLU protein was significantly elevated in FED (P = 0.013). RT-PCR analysis revealed that CLU mRNA was significantly increased (P = 0.002) in FED samples, but not in PBK samples. CLU also had a distinctive localization in FED samples with enhanced intracellular staining around the guttae and in the nuclei of endothelial cells. CONCLUSIONS CLU expression is markedly elevated in FED-affected tissue, pointing to a yet undiscovered form of dysregulation of endothelial cell function involved in FED pathogenesis.
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Affiliation(s)
- Ula V Jurkunas
- Schepens Eye Research Institute, Boston, Massachusetts, USA.
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Bertazolli-Filho R, Laicine EM, Haddad A, Rodrigues MLP. Molecular and biochemical analysis of ceruloplasmin expression in rabbit and rat ciliary body. Curr Eye Res 2006; 31:155-61. [PMID: 16500766 DOI: 10.1080/02713680500507234] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE To verify the capability of rabbit and rat ciliary body to synthesize and secrete ceruloplasmin. METHODS Isolated ciliary body (CB) was cultured in the presence of [35S]-methionine, and the incubation medium was processed for immunoprecipitation. Total RNA from CB was processed for RT-PCR, and the amplification products were sequenced. Also, sections of CB were immunostained for the localization of ceruloplasmin. RESULTS A labeled peptide, having a molecular weight of about 135 kDa, the expected size of ceruloplasmin, was immunopurified in the incubation media from both animal species. The RT-PCR and sequencing experiments detected the presence of ceruloplasmin mRNA in rat samples. Both layers of rabbit and rat ciliary epithelium (CE) exhibited ceruloplasmin reactivity after immunohistochemical processing. CONCLUSIONS Taken altogether, these results indicate the CB, particularly its epithelium, as one of the possible sources of the ocular intrinsic ceruloplasmin.
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Affiliation(s)
- Rubens Bertazolli-Filho
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, USP, Ribeirão Preto, Brazil
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Funding M, Vorum H, Honoré B, Nexø E, Ehlers N. Proteomic analysis of aqueous humour from patients with acute corneal rejection. ACTA ACUST UNITED AC 2005; 83:31-9. [PMID: 15715554 DOI: 10.1111/j.1600-0420.2005.00381.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
PURPOSE To compare the basic proteomic composition of aqueous humour (AH) from patients with corneal rejection (patients) with AH from patients with cataract (controls). METHODS Aqueous humour was analysed for total protein concentration using Bradford's method and for protein composition using two-dimensional (2D) gel electrophoresis. Image analysis was used to detect protein spots in 2D gels that were increased by more than factor 2 in patients as compared with controls. Increased spots were identified by immunoblotting and mass spectrometry. RESULTS Aqueous humour from patients contained significantly higher total protein concentration than did AH from controls. A total of 31 spots were significantly increased in 2D gels from patients. The spots were derived from albumin, alpha1-antitrypsin, apolipoprotein J, cytokeratin type II, serin proteinase inhibitor and transthyretin. After correction of spot volumes by total protein concentrations, 10 spots derived from albumin, cytokeratin type II and alpha1-antitrypsin remained significantly increased. CONCLUSION The proteomic composition of AH differed significantly between patients and controls. The identified proteins suggest that the changes in AH are due to at least three different mechanisms: breakdown of the aqueous-blood barrier, enzymatic degradation, and liberation of locally synthesized proteins.
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Affiliation(s)
- Mikkel Funding
- Department of Ophthalmology, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C, Denmark.
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Dota A, Nishida K, Quantock AJ, Kinoshita S. Clusterin in human corneal endothelium and aqueous humor. Exp Eye Res 1999; 69:705-8. [PMID: 10620400 DOI: 10.1006/exer.1999.0757] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Nishida K, Quantock AJ, Dota A, Choi-Miura NH, Kinoshita S. Apolipoproteins J and E co-localise with amyloid in gelatinous drop-like and lattice type I corneal dystrophies. Br J Ophthalmol 1999; 83:1178-82. [PMID: 10502582 PMCID: PMC1722813 DOI: 10.1136/bjo.83.10.1178] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS Apolipoprotein J (apoJ) and apolipoprotein E (apoE) are thought to contribute to amyloid formation in patients with Alzheimer's disease. The aim of this investigation was to discover whether or not these apolipoproteins associate with corneal amyloid in gelatinous drop-like corneal dystrophy (GDCD) and lattice corneal dystrophy type I (LCD-I). METHODS Corneas from three eyes of three patients with GDCD and one eye of one patient with LCD-I were examined immunohistochemically using antibodies against apoJ and apoE. Two normal corneas were similarly examined. Tissue sections of brain from a patient with Alzheimer's disease were used as positive controls for the antibodies. For all negative controls, mouse IgG was used instead of the primary antibody. RESULTS Intense apoJ and apoE immunoreactivities were found in congophilic amyloid deposits in GDCD and LCD-I. These deposits were located subepithelially in GDCD, and subepithelially and intrastromally in LCD-I. In GDCD, immunostaining of subepithelial amyloid with anti-apoJ was noticeably stronger than with anti-apoE. CONCLUSIONS As in senile plaques in brain from a patient with Alzheimer's disease, apoJ and apoE co-localise with amyloid in corneas with GDCD and LCD-I.
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Affiliation(s)
- K Nishida
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
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Abstract
The male rat striatum was examined for age-related changes in mRNAs expressed in astrocytes and microglia in two rat genotypes that differ by 35% in mean and maximum life spans: F344 and the longer-lived F1 (BN x F344) hybrid. The findings extend the established age-related increases in GFAP (glial fibrillary acidic protein) to other glial mRNAs: two lipoprotein mRNAs that are predominantly expressed in striatal astrocytes, apoE (apolipoprotein E) and apoJ (apolipoprotein J, clusterin, CLI, or SGP-2), and two mRNAs expressed in striatal microglia, TGF-beta1 and complement C1qB. By Northern blot hybridization, both genotypes showed progressive increases of GFAP mRNA to > 2.5-fold by the lifespan. Although the rat strains differed 35% in life span, the slope of the GFAP mRNA regression on age did not differ. Relative to GFAP, the increases of apoE, apoJ, C1q, and TGF-beta1 mRNAs were smaller, < or = 1.5-fold. Because prior studies showed that acute damage to striatal afferents induced astrocyte gene expression increases resembling those that also occur during aging, we examined long-term effects of damage to substantia nigra neurons on striatal astrocyte changes during aging. Young F344 rats were given 6-OHDA lesions that cause striatal dopamine deficits and induce GFAP. When examined 15 months later at age 18 months, there was no effect during prior lesions on the age-related elevation of GFAP mRNA. We conclude that aging changes in striatal GFAP mRNAs do not interact with loss of dopaminergic output to the striatum from 6-OHDA lesions and may be independent of the relatively modest dopaminergic losses during normal aging.
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Affiliation(s)
- G M Pasinetti
- Department of Psychiatry, Mt. Sinai School of Medicine, New York, New York 10029-6574, USA.
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Nishida K, Kawasaki S, Kinoshita S. Clusterin may be essential for maintaining ocular surface epithelium as a non-keratinizing epithelium. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 438:629-35. [PMID: 9634947 DOI: 10.1007/978-1-4615-5359-5_89] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- K Nishida
- Department of Ophthalmology, Kyoto Prefectural University of Medicine, Japan
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Shanmugaratnam J, Berg E, Kimerer L, Johnson RJ, Amaratunga A, Schreiber BM, Fine RE. Retinal Muller glia secrete apolipoproteins E and J which are efficiently assembled into lipoprotein particles. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1997; 50:113-20. [PMID: 9406925 DOI: 10.1016/s0169-328x(97)00176-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
We have shown that apolipoprotein E (ApoE) is synthesized by Muller cells, the major glial cell of the rabbit retina, and secreted into the vitreous after which it is taken up by retinal ganglion cells and rapidly transported into the optic nerve [Amaratunga et al., J. Biol. Chem. 271 (1996) 5628-5632]. In this report we demonstrate that the ApoE secreted by Muller cells in vivo and in culture is efficiently assembled into lipoprotein particles. Apolipoprotein J (ApoJ) is also synthesized by these cells and assembled into lipoprotein particles. The lipoproteins are triglyceride-rich and contain cholesterol esters and free cholesterol. They are heterogeneous, with densities between 1.006 and 1.18 and diameters between 14 and 45 nm. We discuss the possible role of these lipoproteins in supplying the needs of neurons for lipids, especially long axonal projection neurons such as retinal ganglion cells, which are vulnerable to age-related neurodegenerative diseases including Alzheimer's disease.
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Affiliation(s)
- J Shanmugaratnam
- Department of Biochemistry, Boston University School of Medicine, MA 02118, USA
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