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Martín-García D, García-Aranda M, Redondo M. Therapeutic Potential of Clusterin Inhibition in Human Cancer. Cells 2024; 13:665. [PMID: 38667280 PMCID: PMC11049052 DOI: 10.3390/cells13080665] [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: 02/05/2024] [Revised: 03/11/2024] [Accepted: 04/09/2024] [Indexed: 04/28/2024] Open
Abstract
Clusterin (CLU) protein is involved in various pathophysiological processes including carcinogenesis and tumor progression. In recent years, the role of the secretory isoform has been demonstrated in tumor cells, where it inhibits apoptosis and favors the acquisition of resistance to conventional treatments used to treat cancer. To determine the possible therapeutic potential of inhibiting this protein, numerous studies have been carried out in this field. In this article, we present the existing knowledge to date on the inhibition of this protein in different types of cancer and analyze the importance it could have in the development of new therapies targeted against this disease.
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Affiliation(s)
- Desirée Martín-García
- Surgical Specialties, Biochemistry and Immunology Department, Faculty of Medicine, University of Málaga, 29010 Málaga, Spain;
- Red de Investigación en Servicios de Salud en Enfermedades Crónicas (REDISSEC), Red de Investigación en Cronicidad, Atención Primaria y Promoción de la Salud (RICAPPS), Instituto de Investigación Biomédica de Málaga (IBIMA), 29590 Málaga, Spain;
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina—IBIMA Plataforma BIONAND, 29590 Málaga, Spain
- Research and Innovation Unit, Hospital Costa del Sol, 29602 Marbella, Spain
| | - Marilina García-Aranda
- Red de Investigación en Servicios de Salud en Enfermedades Crónicas (REDISSEC), Red de Investigación en Cronicidad, Atención Primaria y Promoción de la Salud (RICAPPS), Instituto de Investigación Biomédica de Málaga (IBIMA), 29590 Málaga, Spain;
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina—IBIMA Plataforma BIONAND, 29590 Málaga, Spain
- Research and Innovation Unit, Hospital Costa del Sol, 29602 Marbella, Spain
| | - Maximino Redondo
- Surgical Specialties, Biochemistry and Immunology Department, Faculty of Medicine, University of Málaga, 29010 Málaga, Spain;
- Red de Investigación en Servicios de Salud en Enfermedades Crónicas (REDISSEC), Red de Investigación en Cronicidad, Atención Primaria y Promoción de la Salud (RICAPPS), Instituto de Investigación Biomédica de Málaga (IBIMA), 29590 Málaga, Spain;
- Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina—IBIMA Plataforma BIONAND, 29590 Málaga, Spain
- Research and Innovation Unit, Hospital Costa del Sol, 29602 Marbella, Spain
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2
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Rajanala K, Upadhyay A. Epigenetic Switches in Retinal Homeostasis and Target for Drug Development. Int J Mol Sci 2024; 25:2840. [PMID: 38474086 DOI: 10.3390/ijms25052840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024] Open
Abstract
Retinal homeostasis, a tightly regulated process maintaining the functional integrity of the retina, is vital for visual function. Emerging research has unveiled the critical role of epigenetic regulation in controlling gene expression patterns during retinal development, maintenance, and response to mutational loads and injuries. Epigenetic switches, including DNA methylation, histone modifications, and non-coding RNAs, play pivotal roles in orchestrating retinal gene expression and cellular responses through various intracellular, extracellular, and environmental modulators. This review compiles the current knowledge on epigenetic switches in retinal homeostasis, providing a deeper understanding of their impact on retinal structural integrity and function and using them as potential targets for therapeutic interventions.
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Affiliation(s)
| | - Arun Upadhyay
- Ocugen Inc., 11 Great Valley Parkway, Malvern, PA 19355, USA
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3
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Jun JH, Kim JS, Palomera LF, Jo DG. Dysregulation of histone deacetylases in ocular diseases. Arch Pharm Res 2024; 47:20-39. [PMID: 38151648 DOI: 10.1007/s12272-023-01482-x] [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: 06/15/2023] [Accepted: 12/20/2023] [Indexed: 12/29/2023]
Abstract
Ocular diseases are a growing global concern and have a significant impact on the quality of life. Cataracts, glaucoma, age-related macular degeneration, and diabetic retinopathy are the most prevalent ocular diseases. Their prevalence and the global market size are also increasing. However, the available pharmacotherapy is currently limited. These diseases share common pathophysiological features, including neovascularization, inflammation, and/or neurodegeneration. Histone deacetylases (HDACs) are a class of enzymes that catalyze the removal of acetyl groups from lysine residues of histone and nonhistone proteins. HDACs are crucial for regulating various cellular processes, such as gene expression, protein stability, localization, and function. They have also been studied in various research fields, including cancer, inflammatory diseases, neurological disorders, and vascular diseases. Our study aimed to investigate the relationship between HDACs and ocular diseases, to identify a new strategy for pharmacotherapy. This review article explores the role of HDACs in ocular diseases, specifically focusing on diabetic retinopathy, age-related macular degeneration, and retinopathy of prematurity, as well as optic nerve disorders, such as glaucoma and optic neuropathy. Additionally, we explore the interplay between HDACs and key regulators of fibrosis and angiogenesis, such as TGF-β and VEGF, highlighting the potential of targeting HDAC as novel therapeutic strategies for ocular diseases.
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Affiliation(s)
- Jae Hyun Jun
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Korea
- Department of Pharmacology, CKD Research Institute, Chong Kun Dang Pharmaceutical Co., Yongin, 16995, Korea
| | - Jun-Sik Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Korea
| | - Leon F Palomera
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Korea
| | - Dong-Gyu Jo
- School of Pharmacy, Sungkyunkwan University, Suwon, 16419, Korea.
- Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul, 06351, Korea.
- Biomedical Institute for Convergence, Sungkyunkwan University, Suwon, 16419, Korea.
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Kapuganti RS, Sahoo L, Mohanty PP, Hayat B, Parija S, Alone DP. Role of clusterin gene 3'-UTR polymorphisms and promoter hypomethylation in the pathogenesis of pseudoexfoliation syndrome and pseudoexfoliation glaucoma. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194980. [PMID: 37652361 DOI: 10.1016/j.bbagrm.2023.194980] [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: 03/06/2023] [Revised: 08/16/2023] [Accepted: 08/21/2023] [Indexed: 09/02/2023]
Abstract
Pseudoexfoliation (PEX) is a multifactorial age-related disease characterized by the deposition of extracellular fibrillar aggregates in the anterior ocular tissues. This study aims to identify the genetic and epigenetic contribution of clusterin (CLU) in PEX pathology. CLU is a molecular chaperone upregulated in PEX and genetically associated with the disease. Sequencing of a 2.9 kb region encompassing the previously associated rs2279590 in 250 control and 313 PEX [(207 pseudoexfoliation syndrome (PEXS) and 106 pseudoexfoliation glaucoma (PEXG)] individuals identified three single nucleotide polymorphisms (SNPs), rs9331942, rs9331949 and rs9331950, in the 3'-UTR of CLU of which rs9331942 and rs9331949 were found to be significantly associated with PEXS and PEXG as risk factors. Following in silico analysis, in vitro luciferase reporter assays in human embryonic kidney cells revealed that risk alleles at rs9331942 and rs9331949 bind to miR-223 and miR-1283, respectively, suggesting differential regulation of clusterin in the presence of risk alleles at the SNPs. Further, through bisulfite sequencing, we also identified that CLU promoter is hypomethylated in DNA from blood and lens capsules of PEX patients compared to controls that correlated with decreased expression of DNA methyltransferase 1 (DNMT1). Promoter demethylation of CLU using DNMT inhibitor, 5'-aza-dC, in human lens epithelial cells increased CLU expression. Chromatin immunoprecipitation assays showed that the demethylated CLU promoter provides increased access to the transcription factor, Sp1, which might lead to enhanced expression of CLU. In conclusion, this study highlights the different molecular mechanisms of clusterin regulation in pseudoexfoliation pathology.
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Affiliation(s)
- Ramani Shyam Kapuganti
- School of Biological Sciences, National Institute of Science Education and Research (NISER) Bhubaneswar, P.O. Bhimpur-Padanpur, Jatni, Khurda, Odisha, 752050, India; Homi Bhabha National Institute (HBNI), Training School Complex, Anushaktinagar, Mumbai, 400094, India
| | - Lipsa Sahoo
- School of Biological Sciences, National Institute of Science Education and Research (NISER) Bhubaneswar, P.O. Bhimpur-Padanpur, Jatni, Khurda, Odisha, 752050, India; Homi Bhabha National Institute (HBNI), Training School Complex, Anushaktinagar, Mumbai, 400094, India
| | | | - Bushra Hayat
- School of Biological Sciences, National Institute of Science Education and Research (NISER) Bhubaneswar, P.O. Bhimpur-Padanpur, Jatni, Khurda, Odisha, 752050, India; Homi Bhabha National Institute (HBNI), Training School Complex, Anushaktinagar, Mumbai, 400094, India
| | - Sucheta Parija
- All India Institute of Medical Sciences, Bhubaneswar, Sijua, Patrapada, Bhubaneswar, Odisha, 751019, India
| | - Debasmita Pankaj Alone
- School of Biological Sciences, National Institute of Science Education and Research (NISER) Bhubaneswar, P.O. Bhimpur-Padanpur, Jatni, Khurda, Odisha, 752050, India; Homi Bhabha National Institute (HBNI), Training School Complex, Anushaktinagar, Mumbai, 400094, India.
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5
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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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Garcia-Garcia J, Usategui-Martin R, Sanabria MR, Fernandez-Perez E, Telleria JJ, Coco-Martin RM. Pathophysiology of Age-Related Macular Degeneration: Implications for Treatment. Ophthalmic Res 2022; 65:615-636. [PMID: 35613547 DOI: 10.1159/000524942] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/29/2022] [Indexed: 12/16/2022]
Abstract
Age-related macular degeneration (AMD) is a complex, multifactorial, progressive retinal disease that affects millions of people worldwide and has become the leading cause of visual impairment in developed countries. The disease etiopathogenesis is not understood fully, although many triggers and processes that lead to dysfunction and degeneration of the retinal pigment epithelium (RPE) have already been identified. Thus, the lack of cellular control of oxidative stress, altered proteostasis, dysfunction of lipid homeostasis, and mitochondrial dysfunction form an internal feedback loop that causes the RPE to fail and allows accumulation of abnormal misfolded proteins and abnormal lipids that will form drusen. An inadequate antioxidant response, deficits in autophagy mechanisms, and dysregulation of the extracellular matrix (ECM) help to increase the deposition of abnormal drusen material over time. The drusen then act as inflammatory centers that trigger chronic inflammation of the subretinal space in which microglia and recruited macrophages are also involved, and where the complement system is a key component. Choriocapillaris degeneration and nutritional influences are also classic elements recognized in the AMD pathophysiology. The genetic component of the disease is embodied in the recognition of the described risk or protective polymorphisms of some complement and ECM related genes (mainly CFH and ARMS2/HTRA1). Thus, carriers of the risk haplotype at ARMS2/HTRA1 have a higher risk of developing late AMD at a younger age. Finally, gut microbiota and epigenetics may play a role in modulating the progression to advanced AMD with the presence of local inflammatory conditions. Because of multiple implicated processes, different complex combinations of treatments will probably be the best option to obtain the best visual results; they in turn will differ depending on the type and spectrum of disease affecting individual patients or the disease stage in each patient at a specific moment. This will undoubtedly lead to personalized medicine for control and hopefully find a future cure. This necessitates the continued unraveling of all the processes involved in the pathogenesis of AMD that must be understood to devise the combinations of treatments for different concurrent or subsequent problems.
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Affiliation(s)
- Julián Garcia-Garcia
- Instituto de Oftalmobiologia Aplicada (IOBA), University of Valladolid, Valladolid, Spain
| | - Ricardo Usategui-Martin
- Instituto de Oftalmobiologia Aplicada (IOBA), University of Valladolid, Valladolid, Spain
- RICORS of Inflammation and Immunopathology of Organs and Systems Network, ISCIII, Madrid, Spain
- Dpto. de Biología Celular, Histología y Farmacología, University of Valladolid, Valladolid, Spain
| | - Maria Rosa Sanabria
- Instituto de Oftalmobiologia Aplicada (IOBA), University of Valladolid, Valladolid, Spain
- RICORS of Inflammation and Immunopathology of Organs and Systems Network, ISCIII, Madrid, Spain
- Ophthalmology Department, Palencia University Hospital Complex, Palencia, Spain
| | - Esther Fernandez-Perez
- Instituto de Oftalmobiologia Aplicada (IOBA), University of Valladolid, Valladolid, Spain
| | - Juan Jose Telleria
- Institute of Biology and Molecular Genetics (IBGM) University of Valladolid, Valladolid, Spain
- Dpto. de Biología Celular, Histología y Farmacología, University of Valladolid, Valladolid, Spain
| | - Rosa M Coco-Martin
- Instituto de Oftalmobiologia Aplicada (IOBA), University of Valladolid, Valladolid, Spain
- RICORS of Inflammation and Immunopathology of Organs and Systems Network, ISCIII, Madrid, Spain
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7
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The essential role of N6-methyladenosine RNA methylation in complex eye diseases. Genes Dis 2022; 10:505-520. [DOI: 10.1016/j.gendis.2022.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 04/29/2022] [Accepted: 05/08/2022] [Indexed: 11/20/2022] Open
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Caputo V, Strafella C, Termine A, Fabrizio C, Ruffo P, Cusumano A, Giardina E, Ricci F, Cascella R. Epigenomic signatures in age-related macular degeneration: Focus on their role as disease modifiers and therapeutic targets. Eur J Ophthalmol 2021; 31:2856-2867. [PMID: 34798695 DOI: 10.1177/11206721211028054] [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] [Indexed: 12/29/2022]
Abstract
Epigenetics is characterized by molecular modifications able to shape gene expression profiles in response to inner and external stimuli. Therefore, epigenetic elements are able to provide intriguing and useful information for the comprehension and management of different human conditions, including aging process, and diseases. On this subject, Age-related Macular Degeneration (AMD) represents one of the most frequent age-related disorders, dramatically affecting the quality of life of older adults worldwide. The etiopathogenesis is characterized by an interplay among multiple genetic and non-genetic factors, which have been extensively studied. Nevertheless, a deeper dissection of molecular machinery associated with risk, onset, progression and effectiveness of therapies is still missing. In this regard, epigenetic signals may be further explored to disentangle disease etiopathogenesis, the possible therapeutic avenues and the differential response to AMD treatment. This review will discuss the epigenomic signatures mostly investigated in AMD, which could be applied to improve the knowledge of disease mechanisms and to set-up novel or modified treatment options.
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Affiliation(s)
- Valerio Caputo
- Genomic Medicine Laboratory UILDM, IRCCS Santa Lucia Foundation, Rome, Italy.,Medical Genetics Laboratory, Department of Biomedicine and Prevention, Tor Vergata University, Rome, Italy
| | - Claudia Strafella
- Genomic Medicine Laboratory UILDM, IRCCS Santa Lucia Foundation, Rome, Italy.,Medical Genetics Laboratory, Department of Biomedicine and Prevention, Tor Vergata University, Rome, Italy
| | - Andrea Termine
- Genomic Medicine Laboratory UILDM, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Carlo Fabrizio
- Genomic Medicine Laboratory UILDM, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Paola Ruffo
- Genomic Medicine Laboratory UILDM, IRCCS Santa Lucia Foundation, Rome, Italy
| | - Andrea Cusumano
- UOSD of Ophthalmology PTV Foundation "Policlinico Tor Vergata", Rome, Italy
| | - Emiliano Giardina
- Genomic Medicine Laboratory UILDM, IRCCS Santa Lucia Foundation, Rome, Italy.,UILDM Lazio ONLUS Foundation, Department of Biomedicine and Prevention, Tor Vergata University, Rome, Italy
| | - Federico Ricci
- UNIT Retinal Diseases PTV Foundation "Policlinico Tor Vergata", Rome, Italy
| | - Raffaella Cascella
- Medical Genetics Laboratory, Department of Biomedicine and Prevention, Tor Vergata University, Rome, Italy.,Department of Biomedical Sciences, Catholic University Our Lady of Good Counsel, Tirana, Albania
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Potential of Long Non-Coding RNAs in Age-Related Macular Degeneration. Int J Mol Sci 2021; 22:ijms22179178. [PMID: 34502084 PMCID: PMC8431062 DOI: 10.3390/ijms22179178] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/16/2021] [Accepted: 08/24/2021] [Indexed: 12/12/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of visual impairment in the aging population with poorly known pathogenesis and lack of effective treatment. Age and family history are the strongest AMD risk factors, and several loci were identified to contribute to AMD. Recently, also the epigenetic profile was associated with AMD, and some long non-coding RNAs (lncRNAs) were shown to involve in AMD pathogenesis. The Vax2os1/2 (ventral anterior homeobox 2 opposite strand isoform 1) lncRNAs may modulate the balance between pro- and anti-angiogenic factors in the eye contributing to wet AMD. The stress-induced dedifferentiation of retinal pigment epithelium cells can be inhibited by the ZNF503-AS1 (zinc finger protein 503 antisense RNA 2) and LINC00167 lncRNAs. Overexpression of the PWRN2 (Prader-Willi region non-protein-coding RNA 2) lncRNA aggravated RPE cells apoptosis and mitochondrial impairment induced by oxidative stress. Several other lncRNAs were reported to exert protective or detrimental effects in AMD. However, many studies are limited to an association between lncRNA and AMD in patients or model systems with bioinformatics. Therefore, further works on lncRNAs in AMD are rational, and they should be enriched with mechanistic and clinical studies to validate conclusions obtained in high-throughput in vitro research.
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Wu J, Liu LL, Cao M, Hu A, Hu D, Luo Y, Wang H, Zhong JN. DNA methylation plays important roles in retinal development and diseases. Exp Eye Res 2021; 211:108733. [PMID: 34418429 DOI: 10.1016/j.exer.2021.108733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Revised: 08/16/2021] [Accepted: 08/17/2021] [Indexed: 12/16/2022]
Abstract
DNA methylation is important in developing and post-mitotic cells in various tissues. Recent studies have shown that DNA methylation is highly dynamic, and plays important roles during retinal development and aging. In addition, the dynamic regulation of DNA methylation is involved in the occurrence and development of age-related macular degeneration and diabetic retinopathy and shows potential in disease diagnoses and prognoses. This review introduces the epigenetic concepts of DNA methylation and demethylation with an emphasis on their regulatory roles in retinal development and related diseases. Moreover, we propose exciting ideas such as its crosstalk with other epigenetic modifications and retinal regeneration, to provide a potential direction for understanding retinal diseases from the epigenetic perspective.
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Affiliation(s)
- Jing Wu
- Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases of Ministry of Education, Gannan Medical University, Ganzhou, 341000, Jiangxi Province, China; Department of Ophthalmology, Lishui Municipal Central Hospital, Lishui, 323000, Zhejiang Province, China
| | - Lin-Lin Liu
- Department of Ophthalmology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, 341000, Jiangxi Province, China
| | - Miao Cao
- Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases of Ministry of Education, Gannan Medical University, Ganzhou, 341000, Jiangxi Province, China; Department of Ophthalmology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, 341000, Jiangxi Province, China
| | - Ang Hu
- Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases of Ministry of Education, Gannan Medical University, Ganzhou, 341000, Jiangxi Province, China
| | - Die Hu
- Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases of Ministry of Education, Gannan Medical University, Ganzhou, 341000, Jiangxi Province, China; Department of Ophthalmology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, 341000, Jiangxi Province, China
| | - Yan Luo
- Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases of Ministry of Education, Gannan Medical University, Ganzhou, 341000, Jiangxi Province, China
| | - Hui Wang
- Department of Ophthalmology, The First Affiliated Hospital of Gannan Medical University, Ganzhou, 341000, Jiangxi Province, China.
| | - Jia-Ning Zhong
- Key Laboratory of Prevention and Treatment of Cardiovascular and Cerebrovascular Diseases of Ministry of Education, Gannan Medical University, Ganzhou, 341000, Jiangxi Province, China.
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11
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Micera A, Balzamino BO, Di Zazzo A, Dinice L, Bonini S, Coassin M. Biomarkers of Neurodegeneration and Precision Therapy in Retinal Disease. Front Pharmacol 2021; 11:601647. [PMID: 33584278 PMCID: PMC7873955 DOI: 10.3389/fphar.2020.601647] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/09/2020] [Indexed: 12/11/2022] Open
Abstract
Vision-threatening retinal diseases affect millions of people worldwide, representing an important public health issue (high social cost) for both technologically advanced and new-industrialized countries. Overall RD group comprises the retinitis pigmentosa, the age-related macular degeneration (AMD), the diabetic retinopathy (DR), and idiopathic epiretinal membrane formation. Endocrine, metabolic, and even lifestyles risk factors have been reported for these age-linked conditions that represent a “public priority” also in this COVID-19 emergency. Chronic inflammation and neurodegeneration characterize the disease evolution, with a consistent vitreoretinal interface impairment. As the vitreous chamber is significantly involved, the latest diagnostic technologies of imaging (retina) and biomarker detection (vitreous) have provided a huge input at both medical and surgical levels. Complement activation and immune cell recruitment/infiltration as well as detrimental intra/extracellular deposits occur in association with a reactive gliosis. The cell/tissue aging route shows a specific signal path and biomolecular profile characterized by the increased expression of several glial-derived mediators, including angiogenic/angiostatic, neurogenic, and stress-related factors (oxidative stress metabolites, inflammation, and even amyloid formation). The possibility to access vitreous chamber by collecting vitreous reflux during intravitreal injection or obtaining vitreous biopsy during a vitrectomy represents a step forward for an individualized therapy. As drug response and protein signature appear unique in each single patient, therapies should be individualized. This review addresses the current knowledge about biomarkers and pharmacological targets in these vitreoretinal diseases. As vitreous fluids might reflect the early stages of retinal sufferance and/or late stages of neurodegeneration, the possibility to modulate intravitreal levels of growth factors, in combination to anti-VEGF therapy, would open to a personalized therapy of retinal diseases.
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Affiliation(s)
- Alessandra Micera
- Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Sciences, IRCCS - Fondazione Bietti, Rome, Italy
| | - Bijorn Omar Balzamino
- Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Sciences, IRCCS - Fondazione Bietti, Rome, Italy
| | - Antonio Di Zazzo
- Ophthalmology Operative Complex Unit, University Campus Bio-Medico, Rome, Italy
| | - Lucia Dinice
- Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Sciences, IRCCS - Fondazione Bietti, Rome, Italy
| | - Stefano Bonini
- Ophthalmology Operative Complex Unit, University Campus Bio-Medico, Rome, Italy
| | - Marco Coassin
- Ophthalmology Operative Complex Unit, University Campus Bio-Medico, Rome, Italy
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12
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Li X, He S, Zhao M. An Updated Review of the Epigenetic Mechanism Underlying the Pathogenesis of Age-related Macular Degeneration. Aging Dis 2020; 11:1219-1234. [PMID: 33014534 PMCID: PMC7505275 DOI: 10.14336/ad.2019.1126] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2019] [Accepted: 11/26/2019] [Indexed: 12/27/2022] Open
Abstract
Epigenetics has been recognized to play an important role in physiological and pathological processes of the human body. Accumulating evidence has indicated that epigenetic mechanisms contribute to the pathogenesis of age-related macular degeneration (AMD). Although the susceptibility related to genetic variants has been revealed by genome-wide association studies, those genetic variants may predict AMD risk only in certain human populations. Other mechanisms, particularly those involving epigenetic factors, may play an important role in the pathogenesis of AMD. Therefore, we briefly summarize the most recent reports related to such epigenetic mechanisms, including DNA methylation, histone modification, and non-coding RNA, and the interplay of genetic and epigenetic factors in the pathogenesis of AMD.
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Affiliation(s)
- Xiaohua Li
- 1Henan Provincial People's Hospital, Zhengzhou, China.,2Henan Eye Hospital, Henan Eye Institute, Henan Key Laboratory of Ophthalmology and Visual Science, Zhengzhou, China.,3People's Hospital of Zhengzhou University, Zhengzhou, China.,4People's Hospital of Henan University, Zhengzhou, China
| | - Shikun He
- 1Henan Provincial People's Hospital, Zhengzhou, China.,2Henan Eye Hospital, Henan Eye Institute, Henan Key Laboratory of Ophthalmology and Visual Science, Zhengzhou, China.,3People's Hospital of Zhengzhou University, Zhengzhou, China.,4People's Hospital of Henan University, Zhengzhou, China.,5Departments of Pathology and Ophthalmology, Keck School of Medicine of the University of Southern California, Los Angeles, CA, USA.,6Ophthalmology Optometry Centre, Peking University People's Hospital, Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China
| | - Mingwei Zhao
- 6Ophthalmology Optometry Centre, Peking University People's Hospital, Beijing Key Laboratory of Diagnosis and Therapy of Retinal and Choroid Diseases, Beijing, China
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13
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Gemenetzi M, Lotery AJ. Epigenetics in age-related macular degeneration: new discoveries and future perspectives. Cell Mol Life Sci 2020; 77:807-818. [PMID: 31897542 PMCID: PMC7058675 DOI: 10.1007/s00018-019-03421-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Revised: 12/04/2019] [Accepted: 12/10/2019] [Indexed: 12/13/2022]
Abstract
The study of epigenetics has explained some of the 'missing heritability' of age-related macular degeneration (AMD). The epigenome also provides a substantial contribution to the organisation of the functional retina. There is emerging evidence of specific epigenetic mechanisms associated with AMD. This 'AMD epigenome' may offer the chance to develop novel AMD treatments.
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Affiliation(s)
- M Gemenetzi
- NIHR Biomedical Research Centre At Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, 162 City Road, London, EC1V 2PD, UK
| | - A J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University Hospital Southampton, University of Southampton, South Lab and Path Block, Mailpoint 806, Level D, Southampton, SO16 6YD, UK.
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Mohana Devi S, Mahalaxmi I, Kaavya J, Chinnkulandhai V, Balachandar V. Does epigenetics have a role in age related macular degeneration and diabetic retinopathy? Genes Dis 2020; 8:279-286. [PMID: 33997175 PMCID: PMC8093576 DOI: 10.1016/j.gendis.2020.01.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 01/06/2020] [Indexed: 02/08/2023] Open
Abstract
Epigenetic mechanisms play an important part in the regulation of gene expression and these alterations may induce long-term changes in gene function and metabolism. They have received extensive attention in bridging the gap between environmental exposures and disease development via their influence on gene expression. DNA methylation is the earliest discovered epigenetic alteration. In this review, we try to examine the role of DNA methylation and histone modification in Age related macular degeneration (AMD) and Diabetic Retinopathy (DR), its vascular complications and recent progress. Given the complex nature of AMD and DR, it is crucial to improve therapeutics which will greatly enhance the quality of life and reduce the burden for millions of patients living with these potentially blinding conditions.
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Affiliation(s)
- S Mohana Devi
- SN ONGC Department of Genetics and Molecular Biology, Vision Research Foundation, Sankara Nethralaya, 41/18, College Road, Chennai, 600006, India
| | - I Mahalaxmi
- Department of Zoology, Avinashilingam Institute for Home Science and Higher Education for Women, Avinashilingam University for Women, Coimbatore, Tamil Nadu, 641046, India
| | - J Kaavya
- Department of Zoology, Avinashilingam Institute for Home Science and Higher Education for Women, Avinashilingam University for Women, Coimbatore, Tamil Nadu, 641046, India
| | - V Chinnkulandhai
- Department of Biochemistry, Dr.N.G.P Arts and Science College, Coimbatore, Tamil Nadu, 641046, India
| | - V Balachandar
- Human Molecular Genetics and Stem Cells Laboratory, Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
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15
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Xu Z, Ruan Z, Huang X, Liu Q, Li Z, Zhou X, Zhang X, Shang L. Identification of aberrantly methylated differentially expressed genes in age-related macular degeneration. Medicine (Baltimore) 2019; 98:e15083. [PMID: 30946360 PMCID: PMC6455998 DOI: 10.1097/md.0000000000015083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
DNA methylation plays a significant role in many diseases. Age-related macular degeneration (AMD) is a leading cause of vision loss for people aged 50 years and above, but the etiology and pathogenesis are largely unknown. This study aimed to identify the aberrantly methylated differentially expressed genes (DEGs) in AMD and predict the related pathways on the basis of public data.Aberrant methylation can influence the functions of key genes by altering their expression. Here, we found out DEGs by overlapping public microarray data (GSE29801 and GSE102952). Functional and enrichment analyses of selected genes were performed using the DAVID database. Subsequently, protein-protein interaction (PPI) networks were constructed by using STRING and visualized in cytoscape to determine hub genes. Finally, we collected AMD patients' blood samples to identify the methylation statuses of these hub genes by using methylated DNA immunoprecipitation.In total, 156 hypermethylation-low expression genes and 127 hypomethylation-high expression genes were predicted. The hypermethylation-low expression genes were enriched in biological processes of response to cardiac conduction, ATP binding, and cell-cell junction assembly. The top 5 hub genes of the PPI network were HSP90AA1, HSPA1L, HSPE1, HSP90B1, and NOP56. Meanwhile, the hypomethylation-high expression genes were enriched in the biological processes of response to positive regulation of the MAPK cascade, actin cytoskeleton reorganization, dentate gyrus development, and cell migration. The top 5 hub genes of this PPI network were PIK3R1, EZR, IGF2, SLC2A1, and CDKN1C. Moreover, the methylation statuses of NOP56, EZR, IGF2, SLC2A1, CDKN1C were confirmed to be altered in the blood of AMD patients.This study indicated possible aberrantly methylated DEGs and differentially expressed pathways in AMD by bioinformatics analysis, providing novel insights for unraveling the pathogenesis of AMD. Hub genes, including NOP56, EZR, IGF2, SLC2A1, CDKN1C, might serve as aberrant methylation-based candidate biomarkers for AMD in future applications.
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Affiliation(s)
- Zixuan Xu
- Jiangxi Research Institute of Ophthalmology and Visual Sciences, Affiliated Eye Hospital of Nanchang University, Nanchang
| | - Zhaohui Ruan
- Jiangxi Research Institute of Ophthalmology and Visual Sciences, Affiliated Eye Hospital of Nanchang University, Nanchang
| | - Xuetao Huang
- Department of Ophthalmology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou
| | - Qiang Liu
- Jiangxi Research Institute of Ophthalmology and Visual Sciences, Affiliated Eye Hospital of Nanchang University, Nanchang
| | - Zhaozhi Li
- Key Laboratory of Bio-resources and Eco-environment, College of Life Sciences, Sichuang University, Chengdu, China
| | - Xueyun Zhou
- Jiangxi Research Institute of Ophthalmology and Visual Sciences, Affiliated Eye Hospital of Nanchang University, Nanchang
| | - Xian Zhang
- Jiangxi Research Institute of Ophthalmology and Visual Sciences, Affiliated Eye Hospital of Nanchang University, Nanchang
| | - Lei Shang
- Jiangxi Research Institute of Ophthalmology and Visual Sciences, Affiliated Eye Hospital of Nanchang University, Nanchang
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Foster EM, Dangla-Valls A, Lovestone S, Ribe EM, Buckley NJ. Clusterin in Alzheimer's Disease: Mechanisms, Genetics, and Lessons From Other Pathologies. Front Neurosci 2019; 13:164. [PMID: 30872998 PMCID: PMC6403191 DOI: 10.3389/fnins.2019.00164] [Citation(s) in RCA: 203] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 02/12/2019] [Indexed: 01/10/2023] Open
Abstract
Clusterin (CLU) or APOJ is a multifunctional glycoprotein that has been implicated in several physiological and pathological states, including Alzheimer's disease (AD). With a prominent extracellular chaperone function, additional roles have been discussed for clusterin, including lipid transport and immune modulation, and it is involved in pathways common to several diseases such as cell death and survival, oxidative stress, and proteotoxic stress. Although clusterin is normally a secreted protein, it has also been found intracellularly under certain stress conditions. Multiple hypotheses have been proposed regarding the origin of intracellular clusterin, including specific biogenic processes leading to alternative transcripts and protein isoforms, but these lines of research are incomplete and contradictory. Current consensus is that intracellular clusterin is most likely to have exited the secretory pathway at some point or to have re-entered the cell after secretion. Clusterin's relationship with amyloid beta (Aβ) has been of great interest to the AD field, including clusterin's apparent role in altering Aβ aggregation and/or clearance. Additionally, clusterin has been more recently identified as a mediator of Aβ toxicity, as evidenced by the neuroprotective effect of CLU knockdown and knockout in rodent and human iPSC-derived neurons. CLU is also the third most significant genetic risk factor for late onset AD and several variants have been identified in CLU. Although the exact contribution of these variants to altered AD risk is unclear, some have been linked to altered CLU expression at both mRNA and protein levels, altered cognitive and memory function, and altered brain structure. The apparent complexity of clusterin's biogenesis, the lack of clarity over the origin of the intracellular clusterin species, and the number of pathophysiological functions attributed to clusterin have all contributed to the challenge of understanding the role of clusterin in AD pathophysiology. Here, we highlight clusterin's relevance to AD by discussing the evidence linking clusterin to AD, as well as drawing parallels on how the role of clusterin in other diseases and pathways may help us understand its biological function(s) in association with AD.
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Affiliation(s)
| | | | | | | | - Noel J. Buckley
- Department of Psychiatry, University of Oxford, Oxford, United Kingdom
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Characterization of SIRT1/DNMTs Functions and LINE-1 Methylation in Patients with Age-Related Macular Degeneration. J Clin Med 2019; 8:jcm8020159. [PMID: 30717113 PMCID: PMC6406755 DOI: 10.3390/jcm8020159] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2019] [Revised: 01/27/2019] [Accepted: 01/29/2019] [Indexed: 11/17/2022] Open
Abstract
Previous studies proposed the application of DNA methylation signatures as clinical biomarkers of age-related macular degeneration (AMD). However, the characterization of Long Interspersed Nuclear Element-1 (LINE-1) methylation levels—a surrogate marker of global DNA methylation—in AMD patients has not been investigated so far. In the present study, we first characterized DNA methyltransferases (DNMTs) and Sirtuin 1 (SIRT1) functions in blood samples of 40 AMD patients and 10 age- and sex-matched controls. Then, we evaluated whether changes in DNMTs functions were associated with different LINE-1 methylation levels in leukocyte DNA. We demonstrated that total DNMTs activity was 48% higher in AMD patients than in controls (p = 0.005). AMD patients also exhibited up-regulation of DNMT1 and DNMT3B expression (FC = 2.6; p = 0.003 and FC = 2.4; p = 0.018, respectively). In line with increased DNMTs functions, the LINE-1 methylation level was higher in AMD patients than in controls (mean = 69.10%; SE = 0.68 vs. mean = 65.73%; SE = 0.59; p = 0.020). All p-values were adjusted by Bonferroni correction. In AMD patients, LINE-1 methylation level was positively associated with total DNMTs activity (r = 0.694; p < 0.001), DNMT1 (r = 0.579; p < 0.001), and DNMT3B (r = 0.521; p = 0.001) expression. Our results encourage further large-size prospective research to understand the relationship between LINE-1 methylation and AMD aetiology, and its usefulness in the clinical setting.
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Desmettre T. [Epigenetics in age-related macular degeneration (AMD) - French translation of the article]. J Fr Ophtalmol 2018; 41:981-990. [PMID: 30454959 DOI: 10.1016/j.jfo.2018.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/02/2018] [Accepted: 06/07/2018] [Indexed: 02/02/2023]
Abstract
Age-related macular degeneration (AMD) is a complex multifactorial condition involving multiple genetic, environmental and constitutional factors. Inflammation, oxidative stress and lipid metabolism seem to be the most important factors in the pathogenesis of the disease. The importance of genetic factors has mainly been revealed with the influence of histocompatibility complement factor H (CFH) variations and the ARSM2 susceptibility gene. Another component, epigenetics, could help to explain some of the relationships between environmental and genetic factors. Epigenetics is defined as the study of modulations of gene activity that can be transmitted over cell divisions without involving mutation of the DNA sequence. The molecules that are involved in these mechanisms are referred to as the epigenome. The mechanisms involve DNA methylation, histone modification, chromatin remodeling, and gene inhibition by non-coding RNA. Epigenetics could explain how the environment may induce relatively stable changes in traits or even diseases, possibly inheritable over several generations. Epigenetic traits established during development, and/or acquired under the influence of nutritional factors or other environmental factors, could influence the interactions between genes and the environment. Several authors have recently shown the influence of epigenetic factors in the pathogenesis of ocular diseases such as cataract, dry eye, glaucoma, diabetic retinopathy and more recently AMD. A better understanding of the involvement of genetic variants at risk, their relationship with epigenetics and environmental factors would certainly help to better assess the risk of developing AMD or better understand recent changes in the incidence of the disease.
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Affiliation(s)
- T Desmettre
- Centre de rétine médicale, 187, rue de Menin, 59520 Marquette-Lez-Lille, France; London International Medical Centre, 18-22 Queen Anne Street, London, W1G 8HU, Royaume-Uni.
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19
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Desmettre TJ. Epigenetics in Age-related Macular Degeneration (AMD). J Fr Ophtalmol 2018; 41:e407-e415. [PMID: 30458925 DOI: 10.1016/j.jfo.2018.09.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Accepted: 09/04/2018] [Indexed: 01/03/2023]
Abstract
Age-related Macular Degeneration (AMD) is a complex multifactorial condition involving multiple genetic, environmental and constitutional factors. Inflammation, oxidative stress and lipid metabolism seem to be the most important factors in the pathogenesis of the disease. The importance of genetic factors has mainly been revealed with the influence of histocompatibility complement factor H (CFH) variations and the ARSM2 susceptibility gene. Another component, epigenetics, could help to explain some of the relationships between environmental and genetic factors. Epigenetics is defined as the study of modulations of gene activity that can be transmitted over cell divisions without involving mutation of the DNA sequence. The molecules that are involved in these mechanisms are referred to as the epigenome. The mechanisms involve DNA methylation, histone modification, chromatin remodeling, and gene inhibition by non-coding RNA. Epigenetics could explain how the environment may induce relatively stable changes in traits or even diseases, possibly inheritable over several generations. Epigenetic traits established during development, and/or acquired under the influence of nutritional factors or other environmental factors, could influence the interactions between genes and the environment. Several authors have recently shown the influence of epigenetic factors in the pathogenesis of ocular diseases such as cataract, dry eye, glaucoma, diabetic retinopathy and more recently AMD. A better understanding of the involvement of genetic variants at risk, their relationship with epigenetics and environmental factors would certainly help to better assess the risk of developing AMD or better understand recent changes in the incidence of the disease.
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Affiliation(s)
- T J Desmettre
- Centre de rétine médicale, 187, rue de Menin, 59520 Marquette-Lez-Lille, France; London International Medical Centre, 18-22 Queen Anne Street, London, W1G 8HU, United Kingdom.
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20
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Hamid MA, Moustafa MT, Càceres-Del-Carpio J, Kuppermann BD, Kenney MC. Effects of Antiangiogenic Drugs on Expression Patterns of Epigenetic Pathway Genes. Ophthalmic Surg Lasers Imaging Retina 2018; 49:S29-S33. [PMID: 30339265 DOI: 10.3928/23258160-20180814-05] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Accepted: 08/05/2018] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVE To investigate the effects of antiangiogenic drugs on the transcription profile of acetylation genes in immortalized human retinal pigment epithelium cells (ARPE-19) in vitro. MATERIALS AND METHODS This in vitro study evaluated the effect of antiangiogenic drugs on the expression of histone acetylation genes on immortalized ARPE-19 cell cultures. ARPE-19 cells were cultured, plated, and treated for 24 hours with aflibercept (Eylea; Regeneron, Tarrytown, NY), ranibizumab (Lucentis; Genentech, South San Francisco, CA), or bevacizumab (Avastin; Genentech, South San Francisco, CA) at one (1×) or two times (2×) the concentrations of the clinical intravitreal dose. Untreated cells were used as controls. RNA was isolated, and real-time quantitative reverse transcription polymerase chain reaction analysis was performed on individual samples to quantify expression levels of genes associated with epigenetic acetylation pathways: histone acetyltransferase 1 (HAT1) and histone deacetylases 1, 6, and 11 (HDAC1, HDAC6, and HDAC11). Differences in cycle thresholds (ΔΔCts) were obtained, and folds were calculated using the formula 2^ΔΔCt. Main outcome measures were expression levels of candidate genes in treated versus untreated samples. RESULTS Compared with untreated cells, 1× ranibizumab-treated cells expressed higher levels of HDAC6, and 2× ranibizumab-treated cells expressed higher HDAC11 levels. Bevacizumab-treated (1×) cells had significant change in HDAC1, HDAC6, and HDAC11. In cultures treated with 2× bevacizumab, only HDAC11 expression levels were significantly affected compared with controls. Aflibercept-treated (1×) cells had changes in expression of HDAC1, HDAC6, and HDAC11. At 2× concentration, only HDAC11 was significantly changed. CONCLUSION Our results show that antiangiogenic drugs can affect the transcription profile of genes regulating the histone acetylation status in ARPE-19 cells in vitro. This finding may have an implication in differential patient response to anti-vascular endothelial growth factor therapy by means of possible interactions between treatment and patient's epigenomic profile. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:S29-S33.].
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Totan Y, Güler E, Yüce A, Dervişogulları MS. The adverse effects of valproic acid on visual functions in the treatment of retinitis pigmentosa. Indian J Ophthalmol 2017; 65:984-988. [PMID: 29044065 PMCID: PMC5678336 DOI: 10.4103/ijo.ijo_978_16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Purpose: To evaluate the efficacy and safety of valproic acid (VPA) treatment in patients with retinitis pigmentosa (RP). Methods: A total of 48 eyes of 24 patients (13 males, 11 females) with RP prescribed VPA were included. The length of VPA treatment was 6–12 months (mean 9.4 months). Parameters evaluated were best-corrected visual acuity (BCVA) (logarithm of the minimum angle of resolution [logMAR]), visual field analyses (VFAs) with Humprey automated perimetry, multifocal electroretinography (ERG) with Roland-RETI scan, and VPA side effects. Results: Mean age was 34.3 ± 10.3 years (range 18–56 years). Fifteen of the patients (30 eyes) had two ERG and VFA tracings, allowing comparison between baseline and follow-up (range 6–12 months). Mean BCVA before and after VPA therapy was 0.36 ± 0.38 and 0.36 ± 0.37 logMAR, respectively (P = 0.32). Quantitative perimetric indices including mean deviation and pattern standard deviation were not significantly changed after VPA therapy (P > 0.05). P1 amplitudes (in terms of nV/deg2 and mV) of ERG waves were significantly decreased in the rings 1, 3, and 4 after VPA therapy (P < 0.05). Regarding the N1 amplitudes, the only significant decrease was observed in area 1 (P = 0.03). In addition, N1 latency was significantly increased in area 3 after VPA therapy (P = 0.04). Conclusions: VPA therapy did not have any significant benefit on BCVA and VFA. In addition, it may be associated with decline in some ERG parameters. Therefore, physicians should avoid prescribing VPA for RP until its safety and efficacy are appropriately evaluated.
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Affiliation(s)
| | - Emre Güler
- Department of Ophthalmology, Medipol University Medical School, İstanbul, Turkey
| | - Aslıhan Yüce
- Department of Ophthalmology, Başkent University Medical School, Ankara, Turkey
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Ye Z, Li Z, He S. Long non‑coding RNA associated‑competing endogenous RNAs are induced by clusterin in retinal pigment epithelial cells. Mol Med Rep 2017; 16:8399-8405. [PMID: 28944909 DOI: 10.3892/mmr.2017.7606] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 06/30/2017] [Indexed: 11/05/2022] Open
Abstract
Age related macular degeneration is one of the most common causes of vision loss in the elderly. Long noncoding RNAs (lncRNAs) serve important roles in regulating gene expression by acting as competing endogenous RNAs (ceRNAs). However, the roles of specific lncRNAs and their associated ceRNA function induced by clusterin in cultured retinal pigment epithelial (RPE) cells remain to be fully elucidated. Based on high throughput sequencing data from RPE cells treated with or without clusterin, the present study identified differentially expressed mRNAs, lncRNAs and microRNAs (miRNAs). A lncRNA‑mRNA‑microRNA (miRNA) network (ceRNA network) was subsequently constructed based on the bioinformatic database miRanda and miRNA targets database miRTarBase. These results demonstrated the expression pattern of several lncRNAs, and a clear clusterin‑associated ceRNA network in RPE cells, which included 75 lncRNAs and 32 miRNAs in RPE cells induced by clusterin. Collectively, the present study uncovered and characterized via bioinformatics the global properties of the ceRNA network in human RPE cells in response to clusterin. These results may aid in the elucidation of the molecular mechanisms of clusterin in age‑related macular degeneration.
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Affiliation(s)
- Zi Ye
- Department of Ophthalmology, People's Liberation Army General Hospital, Beijing 100853, P.R. China
| | - Zhaohui Li
- Department of Ophthalmology, People's Liberation Army General Hospital, Beijing 100853, P.R. China
| | - Shouzhi He
- Department of Ophthalmology, People's Liberation Army General Hospital, Beijing 100853, P.R. China
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23
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Epigenetics in Alzheimer's Disease: Perspective of DNA Methylation. Mol Neurobiol 2017; 55:1026-1044. [PMID: 28092081 DOI: 10.1007/s12035-016-0357-6] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 12/28/2016] [Indexed: 12/12/2022]
Abstract
Research over the years has shown that causes of Alzheimer's disease are not well understood, but over the past years, the involvement of epigenetic mechanisms in the developing memory formation either under pathological or physiological conditions has become clear. The term epigenetics represents the heredity of changes in phenotype that are independent of altered DNA sequences. Different studies validated that cytosine methylation of genomic DNA decreases with age in different tissues of mammals, and therefore, the role of epigenetic factors in developing neurological disorders in aging has been under focus. In this review, we summarized and reviewed the involvement of different epigenetic mechanisms especially the DNA methylation in Alzheimer's disease (AD), late-onset Alzheimer's disease (LOAD), familial Alzheimer's disease (FAD), and autosomal dominant Alzheimer's disease (ADAD). Down to the minutest of details, we tried to discuss the methylation patterns like mitochondrial DNA methylation and ribosomal DNA (rDNA) methylation. Additionally, we mentioned some therapeutic approaches related to epigenetics, which could provide a potential cure for AD. Moreover, we reviewed some recent studies that validate DNA methylation as a potential biomarker and its role in AD. We hope that this review will provide new insights into the understanding of AD pathogenesis from the epigenetic perspective especially from the perspective of DNA methylation.
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24
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Pennington KL, DeAngelis MM. Epigenetic Mechanisms of the Aging Human Retina. J Exp Neurosci 2016; 9:51-79. [PMID: 26966390 PMCID: PMC4777243 DOI: 10.4137/jen.s25513] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 01/07/2016] [Accepted: 01/13/2016] [Indexed: 12/20/2022] Open
Abstract
Degenerative retinal diseases, such as glaucoma, age-related macular degeneration, and diabetic retinopathy, have complex etiologies with environmental, genetic, and epigenetic contributions to disease pathology. Much effort has gone into elucidating both the genetic and the environmental risk factors for these retinal diseases. However, little is known about how these genetic and environmental risk factors bring about molecular changes that lead to pathology. Epigenetic mechanisms have received extensive attention of late for their promise of bridging the gap between environmental exposures and disease development via their influence on gene expression. Recent studies have identified epigenetic changes that associate with the incidence and/or progression of each of these retinal diseases. Therefore, these epigenetic modifications may be involved in the underlying pathological mechanisms leading to blindness. Further genome-wide epigenetic studies that incorporate well-characterized tissue samples, consider challenges similar to those relevant to gene expression studies, and combine the genome-wide epigenetic data with genome-wide genetic and expression data to identify additional potentially causative agents of disease are needed. Such studies will allow researchers to create much-needed therapeutics to prevent and/or intervene in disease progression. Improved therapeutics will greatly enhance the quality of life and reduce the burden of disease management for millions of patients living with these potentially blinding conditions.
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Affiliation(s)
- Katie L Pennington
- Postdoctoral Fellow, Department of Ophthalmology & Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Margaret M DeAngelis
- Associate Professor, Department of Ophthalmology & Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
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25
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Alivand MR, Sabouni F, Soheili ZS. Probable Chemical Hypoxia Effects on Progress of CNV Through Induction of Promoter CpG Demethylation and Overexpression of IL17RC in Human RPE Cells. Curr Eye Res 2016; 41:1245-54. [DOI: 10.3109/02713683.2015.1095933] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Mohammad Reza Alivand
- Molecular Medicine Department, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
- Department of Medical Genetic, Medical Faculty, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Farzaneh Sabouni
- Molecular Medicine Department, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Zahra-Soheila Soheili
- Molecular Medicine Department, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
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26
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Berner AK, Kleinman ME. Therapeutic Approaches to Histone Reprogramming in Retinal Degeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:39-44. [PMID: 26427391 PMCID: PMC4988123 DOI: 10.1007/978-3-319-17121-0_6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recent data have revealed epigenetic derangements and subsequent chromatin remodeling as a potent biologic switch for chronic inflammation and cell survival which are important therapeutic targets in the pathogenesis of several retinal degenerations. Histone deacetylases (HDACs) are a major component of this system and serve as a unique control of the chromatin remodeling process. With a multitude of targeted HDAC inhibitors now available, their use in both basic science and clinical studies has widened substantially. In the field of ocular biology, there are data to suggest that HDAC inhibition may suppress neovascularization and may be a possible treatment for retinitis pigmentosa and dry age-related macular degeneration (AMD). However, the effects of these inhibitors on cell survival and chemokine expression in the chorioretinal tissues remain very unclear. Here, we review the multifaceted biology of HDAC activity and pharmacologic inhibition while offering further insight into the importance of this epigenetic pathway in retinal degenerations. Our laboratory investigations aim to open translational avenues to advance dry AMD therapeutics while exploring the role of acetylation on inflammatory gene expression in the aging and degenerating retina.
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Affiliation(s)
- Andre K Berner
- , 740 S. Limestone St., Suite E-300, 40536, Lexington, KY, USA.
| | - Mark E Kleinman
- Department of Ophthalmology and Visual Sciences, University of Kentucky, 40536, Lexington, KY, USA.
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Lardenoije R, Iatrou A, Kenis G, Kompotis K, Steinbusch HWM, Mastroeni D, Coleman P, Lemere CA, Hof PR, van den Hove DLA, Rutten BPF. The epigenetics of aging and neurodegeneration. Prog Neurobiol 2015; 131:21-64. [PMID: 26072273 PMCID: PMC6477921 DOI: 10.1016/j.pneurobio.2015.05.002] [Citation(s) in RCA: 243] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 05/13/2015] [Accepted: 05/13/2015] [Indexed: 12/14/2022]
Abstract
Epigenetics is a quickly growing field encompassing mechanisms regulating gene expression that do not involve changes in the genotype. Epigenetics is of increasing relevance to neuroscience, with epigenetic mechanisms being implicated in brain development and neuronal differentiation, as well as in more dynamic processes related to cognition. Epigenetic regulation covers multiple levels of gene expression; from direct modifications of the DNA and histone tails, regulating the level of transcription, to interactions with messenger RNAs, regulating the level of translation. Importantly, epigenetic dysregulation currently garners much attention as a pivotal player in aging and age-related neurodegenerative disorders, such as Alzheimer's disease, Parkinson's disease, and Huntington's disease, where it may mediate interactions between genetic and environmental risk factors, or directly interact with disease-specific pathological factors. We review current knowledge about the major epigenetic mechanisms, including DNA methylation and DNA demethylation, chromatin remodeling and non-coding RNAs, as well as the involvement of these mechanisms in normal aging and in the pathophysiology of the most common neurodegenerative diseases. Additionally, we examine the current state of epigenetics-based therapeutic strategies for these diseases, which either aim to restore the epigenetic homeostasis or skew it to a favorable direction to counter disease pathology. Finally, methodological challenges of epigenetic investigations and future perspectives are discussed.
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Affiliation(s)
- Roy Lardenoije
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands
| | - Artemis Iatrou
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands
| | - Gunter Kenis
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands
| | - Konstantinos Kompotis
- Center for Integrative Genomics, University of Lausanne, Genopode Building, 1015 Lausanne-Dorigny, Switzerland
| | - Harry W M Steinbusch
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands
| | - Diego Mastroeni
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands; L.J. Roberts Alzheimer's Disease Center, Banner Sun Health Research Institute, 10515 W. Santa Fe Drive, Sun City, AZ 85351, USA
| | - Paul Coleman
- L.J. Roberts Alzheimer's Disease Center, Banner Sun Health Research Institute, 10515 W. Santa Fe Drive, Sun City, AZ 85351, USA
| | - Cynthia A Lemere
- Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
| | - Patrick R Hof
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, New York, NY 10029, USA
| | - Daniel L A van den Hove
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands; Laboratory of Translational Neuroscience, Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Fuechsleinstrasse 15, 97080 Wuerzburg, Germany
| | - Bart P F Rutten
- School for Mental Health and Neuroscience (MHeNS), Department of Psychiatry and Neuropsychology, Maastricht University, Universiteitssingel 50, 6200 MD Maastricht, The Netherlands.
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Yang HJ, Ratnapriya R, Cogliati T, Kim JW, Swaroop A. Vision from next generation sequencing: multi-dimensional genome-wide analysis for producing gene regulatory networks underlying retinal development, aging and disease. Prog Retin Eye Res 2015; 46:1-30. [PMID: 25668385 PMCID: PMC4402139 DOI: 10.1016/j.preteyeres.2015.01.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2014] [Revised: 01/18/2015] [Accepted: 01/21/2015] [Indexed: 01/10/2023]
Abstract
Genomics and genetics have invaded all aspects of biology and medicine, opening uncharted territory for scientific exploration. The definition of "gene" itself has become ambiguous, and the central dogma is continuously being revised and expanded. Computational biology and computational medicine are no longer intellectual domains of the chosen few. Next generation sequencing (NGS) technology, together with novel methods of pattern recognition and network analyses, has revolutionized the way we think about fundamental biological mechanisms and cellular pathways. In this review, we discuss NGS-based genome-wide approaches that can provide deeper insights into retinal development, aging and disease pathogenesis. We first focus on gene regulatory networks (GRNs) that govern the differentiation of retinal photoreceptors and modulate adaptive response during aging. Then, we discuss NGS technology in the context of retinal disease and develop a vision for therapies based on network biology. We should emphasize that basic strategies for network construction and analyses can be transported to any tissue or cell type. We believe that specific and uniform guidelines are required for generation of genome, transcriptome and epigenome data to facilitate comparative analysis and integration of multi-dimensional data sets, and for constructing networks underlying complex biological processes. As cellular homeostasis and organismal survival are dependent on gene-gene and gene-environment interactions, we believe that network-based biology will provide the foundation for deciphering disease mechanisms and discovering novel drug targets for retinal neurodegenerative diseases.
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Affiliation(s)
- Hyun-Jin Yang
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, 6 Center Drive, Bethesda, MD 20892-0610, USA
| | - Rinki Ratnapriya
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, 6 Center Drive, Bethesda, MD 20892-0610, USA
| | - Tiziana Cogliati
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, 6 Center Drive, Bethesda, MD 20892-0610, USA
| | - Jung-Woong Kim
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, 6 Center Drive, Bethesda, MD 20892-0610, USA
| | - Anand Swaroop
- Neurobiology-Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, 6 Center Drive, Bethesda, MD 20892-0610, USA.
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Bonacini M, Coletta M, Ramazzina I, Naponelli V, Modernelli A, Davalli P, Bettuzzi S, Rizzi F. Distinct promoters, subjected to epigenetic regulation, drive the expression of two clusterin mRNAs in prostate cancer cells. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2014; 1849:44-54. [PMID: 25464035 DOI: 10.1016/j.bbagrm.2014.11.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Revised: 10/24/2014] [Accepted: 11/03/2014] [Indexed: 01/13/2023]
Abstract
The human clusterin (CLU) gene codes for several mRNAs characterized by different sequences at their 5' end. We investigated the expression of two CLU mRNAs, called CLU 1 and CLU 2, in immortalized (PNT1a) and tumorigenic (PC3 and DU145) prostate epithelial cells, as well as in normal fetal fibroblasts (WI38) following the administration of the epigenetic drugs 5-aza-2'-deoxycytidine (AZDC) and trichostatin A (TSA) given either as single or combined treatment (AZDC-TSA). Our experimental evidences show that: a) CLU 1 is the most abundant transcript variant. b) CLU 2 is expressed at a low level in normal fibroblasts and virtually absent in prostate cancer cells. c) CLU 1, and to a greater extent CLU 2 expression, increased by AZDC-TSA treatment in prostate cancer cells. d) Both CLU 1 and CLU 2 encode for secreted CLU. e) P2, a novel promoter that overlaps the CLU 2 Transcription Start Site (TSS), drives CLU 2 expression. f) A CpG island, methylated in prostate cancer cells and not in normal fibroblasts, is responsible for long-term heritable regulation of CLU 1 expression. g) ChIP assay of histone tail modifications at CLU promoters (P1 and P2) shows that treatment of prostate cancer cells with AZDC-TSA causes enrichment of Histone3(Lys9)acetylated (H3K9ac) and reduction of Histone3(Lys27)trimethylated (H3K27me3), inducing active transcription of both CLU variants. In conclusion, we show for the first time that the expression of CLU 2 mRNA is driven by a novel promoter, P2, whose activity responds to epigenetic drugs treatment through changes in histone modifications.
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Affiliation(s)
- Martina Bonacini
- Department of Biomedicine, Biotechnology and Translational Research, University of Parma, Via Volturno 39/a, 43126 Parma, Italy
| | - Mariangela Coletta
- Department of Biomedicine, Biotechnology and Translational Research, University of Parma, Via Volturno 39/a, 43126 Parma, Italy
| | - Ileana Ramazzina
- Department of Biomedicine, Biotechnology and Translational Research, University of Parma, Via Volturno 39/a, 43126 Parma, Italy; Centre for Molecular and Translational Oncology (COMT), University of Parma, Parco Area delle Scienze 11/a, 43124 Parma, Italy; National Institute of Biostructure and Biosystems (INBB), Viale Medaglie d'Oro 305, 00136 Rome, Italy
| | - Valeria Naponelli
- Department of Biomedicine, Biotechnology and Translational Research, University of Parma, Via Volturno 39/a, 43126 Parma, Italy; Centre for Molecular and Translational Oncology (COMT), University of Parma, Parco Area delle Scienze 11/a, 43124 Parma, Italy; National Institute of Biostructure and Biosystems (INBB), Viale Medaglie d'Oro 305, 00136 Rome, Italy
| | - Alice Modernelli
- Department of Biomedicine, Biotechnology and Translational Research, University of Parma, Via Volturno 39/a, 43126 Parma, Italy
| | - Pierpaola Davalli
- Department of Biomedical Sciences, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy
| | - Saverio Bettuzzi
- Department of Biomedicine, Biotechnology and Translational Research, University of Parma, Via Volturno 39/a, 43126 Parma, Italy; Centre for Molecular and Translational Oncology (COMT), University of Parma, Parco Area delle Scienze 11/a, 43124 Parma, Italy; National Institute of Biostructure and Biosystems (INBB), Viale Medaglie d'Oro 305, 00136 Rome, Italy.
| | - Federica Rizzi
- Department of Biomedicine, Biotechnology and Translational Research, University of Parma, Via Volturno 39/a, 43126 Parma, Italy; Centre for Molecular and Translational Oncology (COMT), University of Parma, Parco Area delle Scienze 11/a, 43124 Parma, Italy; National Institute of Biostructure and Biosystems (INBB), Viale Medaglie d'Oro 305, 00136 Rome, Italy
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Meaney S. Epigenetic regulation of cholesterol homeostasis. Front Genet 2014; 5:311. [PMID: 25309573 PMCID: PMC4174035 DOI: 10.3389/fgene.2014.00311] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 08/20/2014] [Indexed: 01/15/2023] Open
Abstract
Although best known as a risk factor for cardiovascular disease, cholesterol is a vital component of all mammalian cells. In addition to key structural roles, cholesterol is a vital biochemical precursor for numerous biologically important compounds including oxysterols and bile acids, as well as acting as an activator of critical morphogenic systems (e.g., the Hedgehog system). A variety of sophisticated regulatory mechanisms interact to coordinate the overall level of cholesterol in cells, tissues and the entire organism. Accumulating evidence indicates that in additional to the more “traditional” regulatory schemes, cholesterol homeostasis is also under the control of epigenetic mechanisms such as histone acetylation and DNA methylation. The available evidence supporting a role for these mechanisms in the control of cholesterol synthesis, elimination, transport and storage are the focus of this review.
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Affiliation(s)
- Steve Meaney
- School of Biological Sciences, College of Sciences and Health, Dublin Institute of Technology Dublin, Ireland ; Environmental Sustainability and Health Institute, Dublin Institute of Technology Dublin, Ireland
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Gemenetzi M, Lotery AJ. The role of epigenetics in age-related macular degeneration. Eye (Lond) 2014; 28:1407-17. [PMID: 25233816 DOI: 10.1038/eye.2014.225] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 07/31/2014] [Indexed: 12/27/2022] Open
Abstract
It is becoming increasingly evident that epigenetic mechanisms influence gene expression and can explain how interactions between genetics and the environment result in particular phenotypes during development. The extent to which this epigenetic effect contributes to phenotype heritability in age-related macular degeneration (AMD) is currently ill defined. However, emerging evidence suggests that epigenetic changes are relevant to AMD and as such provide an exciting new avenue of research for AMD. This review addresses information on the impact of posttranslational modification of the genome on the pathogenesis of AMD, such as DNA methylation changes affecting antioxidant gene expression, hypoxia-regulated alterations in chromatin structure, and histone acetylation status in relation to angiogenesis and inflammation. It also contains information on the role of non-coding RNA-mediated gene regulation in AMD at a posttranscriptional (before translation) level. Our aim was to review the epigenetic mechanisms that cause heritable changes in gene activity without changing the DNA sequence. We also describe some long-term alterations in the transcriptional potential of a cell, which are not necessarily heritable but remains to be defined in the future. Increasing understanding of the significance of common and rare genetic variants and their relationship to epigenetics and environmental influences may help in establishing methods to assess the risk of AMD. This in turn may allow new therapeutic interventions for the leading cause of central vision impairment in patients over the age of 50 years in developed countries. Search strategy We searched the MEDLINE/PubMed database following MeSH suggestions for articles including the terms: 'ocular epigenetic mechanisms', 'human disease epigenetics', and 'age-related macular degeneration genetics'. The headline used to locate related articles in PubMed was 'epigenetics in ocular disease', and to restrict search, we used the headlines 'DNA methylation in age related macular degeneration', 'altered gene expression in AMD pathogenesis'. A manual search was also based on references from these articles as well as review articles.
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Affiliation(s)
- M Gemenetzi
- Southampton Eye Unit, Southampton University Hospital, Southampton, UK
| | - A J Lotery
- 1] Southampton Eye Unit, Southampton University Hospital, Southampton, UK [2] Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, University Hospital Southampton, Southampton, UK
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Epigenetic modifications as potential therapeutic targets in age-related macular degeneration and diabetic retinopathy. Drug Discov Today 2014; 19:1387-93. [DOI: 10.1016/j.drudis.2014.03.026] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 03/12/2014] [Accepted: 03/31/2014] [Indexed: 12/14/2022]
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Kumar A, Midha N, Gogia V, Gupta S, Sehra S, Chohan A. Efficacy of oral valproic acid in patients with retinitis pigmentosa. J Ocul Pharmacol Ther 2014; 30:580-6. [PMID: 24955739 DOI: 10.1089/jop.2013.0166] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
PURPOSE To evaluate the efficacy of valproic acid (VPA) on visual function in patients with retinitis pigmentosa (RP). METHODS Thirty patients (60 eyes) with typical RP were recruited for the study. Of these, 15 patients received oral VPA (500 mg once daily) for a period of 1 year (group 1) and the remaining 15 received no treatment (group 2) and served as controls. The effect of VPA on visual function was determined in terms of visual acuity, amplitude and implicit time in multifocal electroretinography (mfERG), and visual evoked response (VER) performed at presentation and at the third month, sixth month, and 1 year in both groups. Side effects of oral VPA were also monitored. RESULTS At 1-year follow-up, 14 of 15 patients in group 1 had improvement in median best corrected visual acuity (BCVA) from 1.8 [Range (R) 1-3] at baseline to 1.3 (R, 0.6-1.3) (P<0.001). In contrast, there was a slight decrease in median BCVA from 1.8 (0.8- 3) logarithm of the minimum angle of resolution (logMAR) at baseline to 1.83 (P=0.3) in the control arm. There was also a statistically significant increase in improvement in amplitude and latency/implicit time in mfERG and VER in this group (P<0.001). However, no such improvement was observed in the control arm. CONCLUSIONS Thus, VPA seems to have a positive effect on the visual functions in RP patients. Long-term studies evaluating the dose modifications, genetic analysis, and change in visual fields will add to our current knowledge.
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Affiliation(s)
- Atul Kumar
- Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical Sciences , New Delhi, India
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Pan JR, Wang C, Yu QL, Zhang S, Li B, Hu J. Effect of Methyl-CpG binding domain protein 2 (MBD2) on AMD-like lesions in ApoE-deficient mice. ACTA ACUST UNITED AC 2014; 34:408-414. [DOI: 10.1007/s11596-014-1292-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 04/17/2014] [Indexed: 01/07/2023]
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Yan B, Yao J, Tao ZF, Jiang Q. Epigenetics and ocular diseases: from basic biology to clinical study. J Cell Physiol 2014; 229:825-33. [PMID: 24318407 DOI: 10.1002/jcp.24522] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 12/02/2013] [Indexed: 12/23/2022]
Abstract
Epigenetics is an emerging field in ophthalmology and has opened a new avenue for understanding ocular development and ocular diseases related to aging and environment. Epigenetic mechanisms, including DNA methylation, histone modifications, chromatin remodeling, and deployment of non-coding RNAs, result in the heritable silencing of gene expression without any change in DNA sequence. Accumulating evidence suggests a potential link between gene expression, chromatin structure, non-coding RNAs, and cellular differentiation during ocular development. Disruption of the balance of epigenetic networks could become the etiology of several ocular diseases. Here, we summarized the current knowledge about epigenetic regulatory mechanisms in ocular development and diseases.
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Affiliation(s)
- Biao Yan
- Eye Hospital, Nanjing Medical University, Nanjing, China
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Oxidative stress, hypoxia, and autophagy in the neovascular processes of age-related macular degeneration. BIOMED RESEARCH INTERNATIONAL 2014; 2014:768026. [PMID: 24707498 PMCID: PMC3950832 DOI: 10.1155/2014/768026] [Citation(s) in RCA: 163] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Revised: 10/13/2013] [Accepted: 10/13/2013] [Indexed: 11/25/2022]
Abstract
Age-related macular degeneration (AMD) is the leading cause of severe and irreversible loss of vision in the elderly in developed countries. AMD is a complex chronic neurodegenerative disease associated with many environmental, lifestyle, and genetic factors. Oxidative stress and the production of reactive oxygen species (ROS) seem to play a pivotal role in AMD pathogenesis. It is known that the macula receives the highest blood flow of any tissue in the body when related to size, and anything that can reduce the rich blood supply can cause hypoxia, malfunction, or disease. Oxidative stress can affect both the lipid rich retinal outer segment structure and the light processing in the macula. The response to oxidative stress involves several cellular defense reactions, for example, increases in antioxidant production and proteolysis of damaged proteins. The imbalance between production of damaged cellular components and degradation leads to the accumulation of detrimental products, for example, intracellular lipofuscin and extracellular drusen. Autophagy is a central lysosomal clearance system that may play an important role in AMD development. There are many anatomical changes in retinal pigment epithelium (RPE), Bruch's membrane, and choriocapillaris in response to chronic oxidative stress, hypoxia, and disturbed autophagy and these are estimated to be crucial components in the pathology of neovascular processes in AMD.
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Wang J, Yu JT, Tan MS, Jiang T, Tan L. Epigenetic mechanisms in Alzheimer's disease: implications for pathogenesis and therapy. Ageing Res Rev 2013; 12:1024-41. [PMID: 23688931 DOI: 10.1016/j.arr.2013.05.003] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Accepted: 05/08/2013] [Indexed: 12/14/2022]
Abstract
The vast majority of Alzheimer's disease (AD) are late-onset forms (LOAD) likely due to the interplay of environmental influences and individual genetic susceptibility. Epigenetic mechanisms, including DNA methylation, histone modifications and non-coding RNAs, constitute dynamic intracellular processes for translating environmental stimuli into modifications in gene expression. Over the past decade it has become increasingly clear that epigenetic mechanisms play a pivotal role in aging the pathogenesis of AD. Here, we provide a review of the major mechanisms for epigenetic modification and how they are reportedly altered in aging and AD. Moreover, we also consider how aberrant epigenetic modifications may lead to AD pathogenesis, and we review the therapeutic potential of epigenetic treatments for AD.
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Affiliation(s)
- Jun Wang
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, China
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38
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Trougakos IP. The molecular chaperone apolipoprotein J/clusterin as a sensor of oxidative stress: implications in therapeutic approaches - a mini-review. Gerontology 2013; 59:514-23. [PMID: 23689375 DOI: 10.1159/000351207] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Accepted: 04/03/2013] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Organisms are constantly exposed to physiological and environmental stresses and therefore require an efficient surveillance of genome and proteome quality in order to prevent disruption of homeostasis. Central to the intra- and extracellular proteome surveillance system are the molecular chaperones that contribute to both proteome maintenance and clearance. The conventional protein product of the apolipoprotein J/clusterin (CLU) gene is a heterodimeric secreted glycoprotein (also termed as sCLU) with a ubiquitous expression in human tissues. CLU exerts a small heat shock protein-like stress-induced chaperone activity and has been functionally implicated in numerous physiological processes as well as in ageing and most age-related diseases including tumorigenesis, neurodegeneration, and cardiovascular and metabolic syndromes. OBJECTIVE The CLU gene is differentially regulated by a wide variety of stimuli due to the combined presence of many distinct regulatory elements in its promoter that make it an extremely sensitive cellular biosensor of environmental and/or oxidative stress. Downstream to CLU gene induction, the CLU protein seems to actively intervene in pathological states of increased oxidative injury due to its chaperone-related property to inhibit protein aggregation and precipitation (a main feature of oxidant injury), as well as due to its reported distribution in both extra- and, most likely, intracellular compartments. CONCLUSION On the basis of these findings, CLU has emerged as a unique regulator of cellular proteostasis. Nevertheless, it seemingly exerts a dual function in pathology. For instance, in normal cells and during early phases of carcinogenesis, CLU may inhibit tumor progression as it contributes to suppression of proteotoxic stress. In advanced neoplasia, however, it may offer a significant survival advantage in the tumor by suppressing many therapeutic stressors and enhancing metastasis. This review will critically present a synopsis of recent novel findings that relate to the function of this amazing molecule and support the notion that CLU is a biosensor of oxidative injury; a common link between ageing and all pathologies where CLU has been implicated. Potential future perspectives, implications and opportunities for translational research and the development of new therapies will be discussed.
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Affiliation(s)
- Ioannis P Trougakos
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Athens, Greece
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Melville H, Carpiniello M, Hollis K, Staffaroni A, Golestaneh N. Stem cells: a new paradigm for disease modeling and developing therapies for age-related macular degeneration. J Transl Med 2013; 11:53. [PMID: 23452406 PMCID: PMC3599723 DOI: 10.1186/1479-5876-11-53] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 02/19/2013] [Indexed: 02/06/2023] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness in people over age 55 in the U.S. and the developed world. This condition leads to the progressive impairment of central visual acuity. There are significant limitations in the understanding of disease progression in AMD as well as a lack of effective methods of treatment. Lately, there has been considerable enthusiasm for application of stem cell biology for both disease modeling and therapeutic application. Human embryonic stem cells and induced pluripotent stem cells (iPSCs) have been used in cell culture assays and in vivo animal models. Recently a clinical trial was approved by FDA to investigate the safety and efficacy of the human embryonic stem cell-derived retinal pigment epithelium (RPE) transplantation in sub-retinal space of patients with dry AMD These studies suggest that stem cell research may provide both insight regarding disease development and progression, as well as direction for therapeutic innovation for the millions of patients afflicted with AMD.
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Affiliation(s)
- Heather Melville
- Georgetown University School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
| | - Matthew Carpiniello
- Georgetown University School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
| | - Kia Hollis
- Georgetown University School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
| | - Andrew Staffaroni
- Georgetown University School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
| | - Nady Golestaneh
- Georgetown University School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
- Department of Ophthalmology, Georgetown University, School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
- Department of Neurology, Georgetown University, School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, School of Medicine, 3900 Reservoir Rd, Washington, DC 20057, USA
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Epigenetic Mechanisms of Retinal Disease. Retina 2013. [DOI: 10.1016/b978-1-4557-0737-9.00033-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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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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Gorin MB. Genetic insights into age-related macular degeneration: controversies addressing risk, causality, and therapeutics. Mol Aspects Med 2012; 33:467-86. [PMID: 22561651 DOI: 10.1016/j.mam.2012.04.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2012] [Accepted: 04/10/2012] [Indexed: 01/19/2023]
Abstract
Age-related macular degeneration (AMD) is a common condition among the elderly population that leads to the progressive central vision loss and serious compromise of quality of life for its sufferers. It is also one of the few disorders for whom the investigation of its genetics has yielded rich insights into its diversity and causality and holds the promise of enabling clinicians to provide better risk assessments for individuals as well as to develop and selectively deploy new therapeutics to either prevent or slow the development of disease and lessen the threat of vision loss. The genetics of AMD began initially with the appreciation of familial aggregation and increase risk and expanded with the initial association of APOE variants with the disease. The first major breakthroughs came with family-based linkage studies of affected (and discordant) sibs, which identified a number of genetic loci and led to the targeted search of the 1q31 and 10q26 loci for associated variants. Three of the initial four reports for the CFH variant, Y402H, were based on regional candidate searches, as were the two initial reports of the ARMS2/HTRA1 locus variants. Case-control association studies initially also played a role in discovering the major genetic variants for AMD, and the success of those early studies have been used to fuel enthusiasm for the methodology for a number of diseases. Until 2010, all of the subsequent genetic variants associated with AMD came from candidate gene testing based on the complement factor pathway. In 2010, several large-scale genome-wide association studies (GWAS) identified genes that had not been previously identified. Much of this historical information is available in a number of recent reviews (Chen et al., 2010b; Deangelis et al., 2011; Fafowora and Gorin, 2012b; Francis and Klein, 2011; Kokotas et al., 2011). Large meta analysis of AMD GWAS has added new loci and variants to this collection (Chen et al., 2010a; Kopplin et al., 2010; Yu et al., 2011). This paper will focus on the ongoing controversies that are confronting AMD genetics at this time, rather than attempting to summarize this field, which has exploded in the past 5 years.
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Affiliation(s)
- Michael B Gorin
- Department of Ophthalmology, David Geffen School of Medicine, UC, Los Angeles, CA, USA.
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Abstract
Clusterin, also known as apolipoprotein J, is a ubiquitous multifunctional glycoprotein. Following its identification in 1983, clusterin was found to be clearly increased in Alzheimer's disease (AD). Later research demonstrated that clusterin could bind amyloid-beta (Abeta) peptides and prevent fibril formation, a hallmark of AD pathology. In addition to preventing excessive inflammation, intracellular clusterin was found to reduce apoptosis and oxidative stress. Although early studies were inconclusive, two recent large-scale genome-wide association studies (GWAS) independently identified variants within the clusterin gene as risk factors for developing AD. This review focuses on the characteristics of clusterin and possible mechanisms of its relationship to AD.
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Affiliation(s)
- Zhong-Chen Wu
- Department of Neurology, Qingdao Municipal Hospital, School of Medicine, Qingdao University, Qingdao, Shandong Province, China
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Pelzel HR, Nickells RW. A role for epigenetic changes in the development of retinal neurodegenerative conditions. J Ocul Biol Dis Infor 2012; 4:104-10. [PMID: 23515137 DOI: 10.1007/s12177-012-9079-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 03/05/2012] [Indexed: 11/25/2022] Open
Affiliation(s)
- Heather R Pelzel
- Department of Biology, University of Wisconsin-Whitewater, 800 W Main St, Whitewater, WI 53190 USA
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The role of clusterin in Alzheimer's disease: pathways, pathogenesis, and therapy. Mol Neurobiol 2012; 45:314-26. [PMID: 22274961 DOI: 10.1007/s12035-012-8237-1] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2011] [Accepted: 01/12/2012] [Indexed: 10/14/2022]
Abstract
Genetic variation in clusterin gene, also known as apolipoprotein J, has been associated with Alzheimer's disease (AD) through replicated genome-wide studies, and plasma clusterin levels are associated with brain atrophy, baseline prevalence and severity, and rapid clinical progression in patients with AD, highlighting the importance of clusterin in AD pathogenesis. Emerging data suggest that clusterin contributes to AD through various pathways, including amyloid-β aggregation and clearance, lipid metabolism, neuroinflammation, and neuronal cell cycle control and apoptosis. Moreover, epigenetic regulation of the clusterin expression also seems to play an important role in the pathogenesis of AD. Emerging knowledge of the contribution of clusterin to the pathogenesis of AD presents new opportunities for AD therapy.
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Cell culture model that mimics drusen formation and triggers complement activation associated with age-related macular degeneration. Proc Natl Acad Sci U S A 2011; 108:18277-82. [PMID: 21969589 DOI: 10.1073/pnas.1109703108] [Citation(s) in RCA: 152] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We introduce a human retinal pigmented epithelial (RPE) cell-culture model that mimics several key aspects of early stage age-related macular degeneration (AMD). These include accumulation of sub-RPE deposits that contain molecular constituents of human drusen, and activation of complement leading to formation of deposit-associated terminal complement complexes. Abundant sub-RPE deposits that are rich in apolipoprotein E (APOE), a prominent drusen constituent, are formed by RPE cells grown on porous supports. Exposure to human serum results in selective, deposit-associated accumulation of additional known drusen components, including vitronectin, clusterin, and serum amyloid P, thus suggesting that specific protein-protein interactions contribute to the accretion of plasma proteins during drusen formation. Serum exposure also leads to complement activation, as evidenced by the generation of C5b-9 immunoreactive terminal complement complexes in association with APOE-containing deposits. Ultrastructural analyses reveal two morphologically distinct forms of deposits: One consisting of membrane-bounded multivesicular material, and the other of nonmembrane-bounded particle conglomerates. Collectively, these results suggest that drusen formation involves the accumulation of sub-RPE material rich in APOE, a prominent biosynthetic product of the RPE, which interacts with a select group of drusen-associated plasma proteins. Activation of the complement cascade appears to be mediated via the classical pathway by the binding of C1q to ligands in APOE-rich deposits, triggering direct activation of complement by C1q, deposition of terminal complement complexes and inflammatory sequelae. This model system will facilitate the analysis of molecular and cellular aspects of AMD pathogenesis, and the testing of new therapeutic agents for its treatment.
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Epigenetic mechanisms in Alzheimer's disease. Neurobiol Aging 2011; 32:1161-80. [PMID: 21482442 DOI: 10.1016/j.neurobiolaging.2010.08.017] [Citation(s) in RCA: 168] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2010] [Revised: 07/20/2010] [Accepted: 08/07/2010] [Indexed: 12/20/2022]
Abstract
Epigenetic modifications help orchestrate sweeping developmental, aging, and disease-causing changes in phenotype by altering transcriptional activity in multiple genes spanning multiple biologic pathways. Although previous epigenetic research has focused primarily on dividing cells, particularly in cancer, recent studies have shown rapid, dynamic, and persistent epigenetic modifications in neurons that have significant neuroendocrine, neurophysiologic, and neurodegenerative consequences. Here, we provide a review of the major mechanisms for epigenetic modification and how they are reportedly altered in aging and Alzheimer's disease (AD). Because of their reach across the genome, epigenetic mechanisms may provide a unique integrative framework for the pathologic diversity and complexity of AD.
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Ellis L, Pili R. Histone Deacetylase Inhibitors: Advancing Therapeutic Strategies in Hematological and Solid Malignancies. Pharmaceuticals (Basel) 2010; 3:2411-2469. [PMID: 21151768 PMCID: PMC3000686 DOI: 10.3390/ph3082441] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Advancement in the understanding of cancer development in recent years has identified epigenetic abnormalities as a common factor in both tumorigenesis and refractory disease. One such event is the dysregulation of histone deacetylases (HDACs) in both hematological and solid tumors, and has consequently resulted in the development of HDAC inhibitors (HDACI) to overcome this. HDACI exhibit pleiotropic biological effects including inhibition of angiogenesis and the induction of autophagy and apoptosis. Although HDACI exhibit modest results as single agents in preclinical and clinical data, they often fall short, and therefore HDACI are most promising in combinational strategies with either standard treatments or with other experimental chemotherapies and targeted therapies. This review will discuss the induction of autophagy and apoptosis and the inhibition of angiogenesis by HDACI, and also pre-clinical and clinical combination strategies using these agents.
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Affiliation(s)
- Leigh Ellis
- Roswell Park Cancer Institute, Genitourinary Program, Grace Cancer Drug Center, Buffalo, NY 14263, USA;
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Epigenetic regulatory mechanisms in vertebrate eye development and disease. Heredity (Edinb) 2010; 105:135-51. [PMID: 20179734 DOI: 10.1038/hdy.2010.16] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Eukaryotic DNA is organized as a nucleoprotein polymer termed chromatin with nucleosomes serving as its repetitive architectural units. Cellular differentiation is a dynamic process driven by activation and repression of specific sets of genes, partitioning the genome into transcriptionally active and inactive chromatin domains. Chromatin architecture at individual genes/loci may remain stable through cell divisions, from a single mother cell to its progeny during mitosis, and represents an example of epigenetic phenomena. Epigenetics refers to heritable changes caused by mechanisms distinct from the primary DNA sequence. Recent studies have shown a number of links between chromatin structure, gene expression, extracellular signaling, and cellular differentiation during eye development. This review summarizes recent advances in this field, and the relationship between sequence-specific DNA-binding transcription factors and their roles in recruitment of chromatin remodeling enzymes. In addition, lens and retinal differentiation is accompanied by specific changes in the nucleolar organization, expression of non-coding RNAs, and DNA methylation. Epigenetic regulatory mechanisms in ocular tissues represent exciting areas of research that have opened new avenues for understanding normal eye development, inherited eye diseases and eye diseases related to aging and the environment.
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Nuutinen T, Suuronen T, Kauppinen A, Salminen A. Clusterin: a forgotten player in Alzheimer's disease. ACTA ACUST UNITED AC 2009; 61:89-104. [PMID: 19651157 DOI: 10.1016/j.brainresrev.2009.05.007] [Citation(s) in RCA: 202] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 05/13/2009] [Accepted: 05/14/2009] [Indexed: 11/16/2022]
Abstract
Clusterin, also known as apolipoprotein J, is a versatile chaperone molecule which contains several amphipathic and coiled-coil alpha-helices, typical characteristics of small heat shock proteins. In addition, clusterin has three large intrinsic disordered regions, so-called molten globule domains, which can stabilize stressed protein structures. Twenty years ago, it was demonstrated that the expression of clusterin was clearly increased in Alzheimer's disease (AD). Later it was observed that clusterin can bind amyloid-beta peptides and prevent their fibrillization. Clusterin is also involved in the clearance of amyloid-beta peptides and fibrils by binding to megalin receptors and enhancing their endocytosis within glial cells. Clusterin is a complement inhibitor and can suppress complement activation observed in AD. Clusterin is also present in lipoprotein particles and regulates cholesterol and lipid metabolism of brain which is disturbed in AD. Clusterin is a stress-induced chaperone which is normally secreted but in conditions of cellular stress, it can be transported to cytoplasm where it can bind to Bax protein and inhibit neuronal apoptosis. Clusterin can also bind to Smad2/3 proteins and potentiate the neuroprotective TGFbeta signaling. An alternative splicing can produce a variant isoform of clusterin which can be translocated to nuclei where it induces apoptosis. The role of nuclear clusterin in AD needs to be elucidated. We will review here the extensive literature linking clusterin to AD and examine the recent progress in clusterin research with the respect to AD pathology. Though clusterin can be viewed as a multipotent guardian of brain, it is unable to prevent the progressive neuropathology in chronic AD.
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Affiliation(s)
- Tapio Nuutinen
- Department of Neuroscience and Neurology, University of Kuopio, P.O. Box 1627, FIN-70211 Kuopio, Finland
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