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Tan LX, Oertel FC, Cheng A, Cobigo Y, Keihani A, Bennett DJ, Abdelhak A, Montes SC, Chapman M, Chen RY, Cordano C, Ward ME, Casaletto K, Kramer JH, Rosen HJ, Boxer A, Miller BL, Green AJ, Elahi FM, Lakkaraju A. Targeting complement C3a receptor resolves mitochondrial hyperfusion and subretinal microglial activation in progranulin-deficient frontotemporal dementia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.29.595206. [PMID: 38854134 PMCID: PMC11160746 DOI: 10.1101/2024.05.29.595206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Mutations in progranulin ( GRN ) cause frontotemporal dementia ( GRN -FTD) due to deficiency of the pleiotropic protein progranulin. GRN -FTD exhibits diverse pathologies including lysosome dysfunction, lipofuscinosis, microgliosis, and neuroinflammation. Yet, how progranulin loss causes disease remains unresolved. Here, we report that non-invasive retinal imaging of GRN -FTD patients revealed deficits in photoreceptors and the retinal pigment epithelium (RPE) that correlate with cognitive decline. Likewise, Grn -/- mice exhibit early RPE dysfunction, microglial activation, and subsequent photoreceptor loss. Super-resolution live imaging and transcriptomic analyses identified RPE mitochondria as an early driver of retinal dysfunction. Loss of mitochondrial fission protein 1 (MTFP1) in Grn -/- RPE causes mitochondrial hyperfusion and bioenergetic defects, leading to NF-kB-mediated activation of complement C3a-C3a receptor signaling, which drives further mitochondrial hyperfusion and retinal inflammation. C3aR antagonism restores RPE mitochondrial integrity and limits subretinal microglial activation. Our study identifies a previously unrecognized mechanism by which progranulin modulates mitochondrial integrity and complement-mediated neuroinflammation.
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2
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Hwang HM, Yamashita S, Matsumoto Y, Ito M, Edwards A, Sasaki J, Dutta DJ, Mohammad S, Yamashita C, Wetherill L, Schwantes-An TH, Abreu M, Mahnke AH, Mattson SN, Foroud T, Miranda RC, Chambers C, Torii M, Hashimoto-Torii K. Reduction of APOE accounts for neurobehavioral deficits in fetal alcohol spectrum disorders. Mol Psychiatry 2024:10.1038/s41380-024-02586-6. [PMID: 38734844 DOI: 10.1038/s41380-024-02586-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 04/20/2024] [Accepted: 04/25/2024] [Indexed: 05/13/2024]
Abstract
A hallmark of fetal alcohol spectrum disorders (FASD) is neurobehavioral deficits that still do not have effective treatment. Here, we present that reduction of Apolipoprotein E (APOE) is critically involved in neurobehavioral deficits in FASD. We show that prenatal alcohol exposure (PAE) changes chromatin accessibility of Apoe locus, and causes reduction of APOE levels in both the brain and peripheral blood in postnatal mice. Of note, postnatal administration of an APOE receptor agonist (APOE-RA) mitigates motor learning deficits and anxiety in those mice. Several molecular and electrophysiological properties essential for learning, which are altered by PAE, are restored by APOE-RA. Our human genome-wide association study further reveals that the interaction of PAE and a single nucleotide polymorphism in the APOE enhancer which chromatin is closed by PAE in mice is associated with lower scores in the delayed matching-to-sample task in children. APOE in the plasma is also reduced in PAE children, and the reduced level is associated with their lower cognitive performance. These findings suggest that controlling the APOE level can serve as an effective treatment for neurobehavioral deficits in FASD.
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Affiliation(s)
- Hye M Hwang
- Center for Neuroscience Research, The Children's Research Institute, Children's National Hospital, Washington, DC, USA
| | - Satoshi Yamashita
- Center for Neuroscience Research, The Children's Research Institute, Children's National Hospital, Washington, DC, USA
| | - Yu Matsumoto
- Center for Neuroscience Research, The Children's Research Institute, Children's National Hospital, Washington, DC, USA
| | - Mariko Ito
- Center for Neuroscience Research, The Children's Research Institute, Children's National Hospital, Washington, DC, USA
- Department of Diabetes, Endocrinology and Metabolism, Tokyo Medical University, Tokyo, Japan
| | - Alex Edwards
- Center for Neuroscience Research, The Children's Research Institute, Children's National Hospital, Washington, DC, USA
| | - Junko Sasaki
- Center for Neuroscience Research, The Children's Research Institute, Children's National Hospital, Washington, DC, USA
- Department of Diabetes, Endocrinology and Metabolism, Tokyo Medical University, Tokyo, Japan
| | - Dipankar J Dutta
- Center for Neuroscience Research, The Children's Research Institute, Children's National Hospital, Washington, DC, USA
| | - Shahid Mohammad
- Center for Neuroscience Research, The Children's Research Institute, Children's National Hospital, Washington, DC, USA
| | - Chiho Yamashita
- Center for Neuroscience Research, The Children's Research Institute, Children's National Hospital, Washington, DC, USA
| | - Leah Wetherill
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Tae-Hwi Schwantes-An
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Marco Abreu
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Amanda H Mahnke
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University School of Medicine, Bryan, TX, USA
| | - Sarah N Mattson
- Center for Behavioral Teratology, San Diego State University, San Diego, CA, USA
| | - Tatiana Foroud
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Rajesh C Miranda
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University School of Medicine, Bryan, TX, USA
| | - Christina Chambers
- Department of Pediatrics, University of California San Diego, San Diego, CA, USA
| | - Masaaki Torii
- Center for Neuroscience Research, The Children's Research Institute, Children's National Hospital, Washington, DC, USA.
- Departments of Pediatrics, and Pharmacology & Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC, USA.
| | - Kazue Hashimoto-Torii
- Center for Neuroscience Research, The Children's Research Institute, Children's National Hospital, Washington, DC, USA.
- Departments of Pediatrics, and Pharmacology & Physiology, School of Medicine and Health Sciences, The George Washington University, Washington, DC, USA.
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3
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Jiang WI, Cao Y, Xue Y, Ji Y, Winer BY, Zhang M, Singhal NS, Pierce JT, Chen S, Ma DK. Suppressing APOE4-induced mortality and cellular damage by targeting VHL. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.28.582664. [PMID: 38464138 PMCID: PMC10925324 DOI: 10.1101/2024.02.28.582664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Mortality rate increases with age and can accelerate upon extrinsic or intrinsic damage to individuals. Identifying factors and mechanisms that curb population mortality rate has wide-ranging implications. Here, we show that targeting the VHL-1 (Von Hippel-Lindau) protein suppresses C. elegans mortality caused by distinct factors, including elevated reactive oxygen species, temperature, and APOE4, the genetic variant that confers high risks of neurodegeneration in Alzheimer's diseases and all-cause mortality in humans. These mortality factors are of different physical-chemical nature, yet result in similar cellular dysfunction and damage that are suppressed by deleting VHL-1. Stabilized HIF-1 (hypoxia inducible factor), a transcription factor normally targeted for degradation by VHL-1, recapitulates the protective effects of deleting VHL-1. HIF-1 orchestrates a genetic program that defends against mitochondrial abnormalities, excess oxidative stress, cellular proteostasis dysregulation, and endo-lysosomal rupture, key events that lead to mortality. Genetic Vhl inhibition also alleviates cerebral vascular injury and synaptic lesions in APOE4 mice, supporting an evolutionarily conserved mechanism. Collectively, we identify the VHL-HIF axis as a potent modifier of APOE4 and mortality and propose that targeting VHL-HIF in non-proliferative animal tissues may suppress tissue injuries and mortality by broadly curbing cellular damage.
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Affiliation(s)
- Wei I. Jiang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
| | - Yiming Cao
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
| | - Yue Xue
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
| | - Yichun Ji
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
| | - Benjamin Y. Winer
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
- Immunology Program, Memorial Sloan Kettering Cancer Center; New York, NY, USA
- Howard Hughes Medical Institute; Chevy Chase, MD, USA
| | - Mengqi Zhang
- Department of Neurology, University of California, San Francisco, San Francisco, USA
| | - Neel S. Singhal
- Department of Neurology, University of California, San Francisco, San Francisco, USA
| | - Jonathan T. Pierce
- Department of Neuroscience, The Center for Learning and Memory, Waggoner Center for Alcohol and Addiction Research, Institute of Neuroscience, University of Texas at Austin, Austin, Texas, USA
| | - Song Chen
- Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
| | - Dengke K. Ma
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, USA
- Department of Physiology, University of California, San Francisco, San Francisco, CA, USA
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA
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4
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Hultgren NW, Zhou T, Williams DS. Machine learning-based 3D segmentation of mitochondria in polarized epithelial cells. Mitochondrion 2024; 76:101882. [PMID: 38599302 DOI: 10.1016/j.mito.2024.101882] [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: 04/25/2023] [Revised: 03/18/2024] [Accepted: 04/07/2024] [Indexed: 04/12/2024]
Abstract
Mitochondria are dynamic organelles that alter their morphological characteristics in response to functional needs. Therefore, mitochondrial morphology is an important indicator of mitochondrial function and cellular health. Reliable segmentation of mitochondrial networks in microscopy images is a crucial initial step for further quantitative evaluation of their morphology. However, 3D mitochondrial segmentation, especially in cells with complex network morphology, such as in highly polarized cells, remains challenging. To improve the quality of 3D segmentation of mitochondria in super-resolution microscopy images, we took a machine learning approach, using 3D Trainable Weka, an ImageJ plugin. We demonstrated that, compared with other commonly used methods, our approach segmented mitochondrial networks effectively, with improved accuracy in different polarized epithelial cell models, including differentiated human retinal pigment epithelial (RPE) cells. Furthermore, using several tools for quantitative analysis following segmentation, we revealed mitochondrial fragmentation in bafilomycin-treated RPE cells.
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Affiliation(s)
- Nan W Hultgren
- Department of Ophthalmology and Stein Eye Institute, University of California, Los Angeles, CA 90095, USA.
| | - Tianli Zhou
- Department of Ophthalmology and Stein Eye Institute, University of California, Los Angeles, CA 90095, USA
| | - David S Williams
- Department of Ophthalmology and Stein Eye Institute, University of California, Los Angeles, CA 90095, USA; Department of Neurobiology, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA; Brain Research Institute, University of California, Los Angeles, CA 90095, USA.
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5
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Sun X, Zhou Y, Wang Z, Peng M, Wei X, Xie Y, Wen C, Liu J, Ye M. Biomolecular Condensates Decipher Molecular Codes of Cell Fate: From Biophysical Fundamentals to Therapeutic Practices. Int J Mol Sci 2024; 25:4127. [PMID: 38612940 PMCID: PMC11012904 DOI: 10.3390/ijms25074127] [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: 02/29/2024] [Revised: 04/03/2024] [Accepted: 04/05/2024] [Indexed: 04/14/2024] Open
Abstract
Cell fate is precisely modulated by complex but well-tuned molecular signaling networks, whose spatial and temporal dysregulation commonly leads to hazardous diseases. Biomolecular condensates (BCs), as a newly emerging type of biophysical assemblies, decipher the molecular codes bridging molecular behaviors, signaling axes, and clinical prognosis. Particularly, physical traits of BCs play an important role; however, a panoramic view from this perspective toward clinical practices remains lacking. In this review, we describe the most typical five physical traits of BCs, and comprehensively summarize their roles in molecular signaling axes and corresponding major determinants. Moreover, establishing the recent observed contribution of condensate physics on clinical therapeutics, we illustrate next-generation medical strategies by targeting condensate physics. Finally, the challenges and opportunities for future medical development along with the rapid scientific and technological advances are highlighted.
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Affiliation(s)
- Xing Sun
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China; (X.S.); (Y.Z.); (Z.W.); (M.P.); (X.W.)
- Molecular Biology Research Center and Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410000, China; (Y.X.); (C.W.)
| | - Yangyang Zhou
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China; (X.S.); (Y.Z.); (Z.W.); (M.P.); (X.W.)
| | - Zhiyan Wang
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China; (X.S.); (Y.Z.); (Z.W.); (M.P.); (X.W.)
| | - Menglan Peng
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China; (X.S.); (Y.Z.); (Z.W.); (M.P.); (X.W.)
| | - Xianhua Wei
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China; (X.S.); (Y.Z.); (Z.W.); (M.P.); (X.W.)
| | - Yifang Xie
- Molecular Biology Research Center and Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410000, China; (Y.X.); (C.W.)
| | - Chengcai Wen
- Molecular Biology Research Center and Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410000, China; (Y.X.); (C.W.)
| | - Jing Liu
- Molecular Biology Research Center and Center for Medical Genetics, School of Life Sciences, Central South University, Changsha 410000, China; (Y.X.); (C.W.)
| | - Mao Ye
- Molecular Science and Biomedicine Laboratory, State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Aptamer Engineering Center of Hunan Province, Hunan University, Changsha 410082, China; (X.S.); (Y.Z.); (Z.W.); (M.P.); (X.W.)
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6
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Guo J, Chen S, Zhang Y, Liu J, Jiang L, Hu L, Yao K, Yu Y, Chen X. Cholesterol metabolism: physiological regulation and diseases. MedComm (Beijing) 2024; 5:e476. [PMID: 38405060 PMCID: PMC10893558 DOI: 10.1002/mco2.476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 01/09/2024] [Accepted: 01/12/2024] [Indexed: 02/27/2024] Open
Abstract
Cholesterol homeostasis is crucial for cellular and systemic function. The disorder of cholesterol metabolism not only accelerates the onset of cardiovascular disease (CVD) but is also the fundamental cause of other ailments. The regulation of cholesterol metabolism in the human is an extremely complex process. Due to the dynamic balance between cholesterol synthesis, intake, efflux and storage, cholesterol metabolism generally remains secure. Disruption of any of these links is likely to have adverse effects on the body. At present, increasing evidence suggests that abnormal cholesterol metabolism is closely related to various systemic diseases. However, the exact mechanism by which cholesterol metabolism contributes to disease pathogenesis remains unclear, and there are still unknown factors. In this review, we outline the metabolic process of cholesterol in the human body, especially reverse cholesterol transport (RCT). Then, we discuss separately the impact of abnormal cholesterol metabolism on common diseases and potential therapeutic targets for each disease, including CVD, tumors, neurological diseases, and immune system diseases. At the end of this review, we focus on the effect of cholesterol metabolism on eye diseases. In short, we hope to provide more new ideas for the pathogenesis and treatment of diseases from the perspective of cholesterol.
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Affiliation(s)
- Jiarui Guo
- Eye Center of the Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang ProvinceChina
| | - Silong Chen
- Eye Center of the Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang ProvinceChina
| | - Ying Zhang
- Eye Center of the Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang ProvinceChina
- Institute of Translational MedicineZhejiang University School of MedicineHangzhouZhejiang ProvinceChina
| | - Jinxia Liu
- Eye Center of the Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang ProvinceChina
| | - Luyang Jiang
- Eye Center of the Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang ProvinceChina
| | - Lidan Hu
- National Clinical Research Center for Child HealthThe Children's HospitalZhejiang University School of MedicineHangzhouZhejiang ProvinceChina
| | - Ke Yao
- Eye Center of the Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang ProvinceChina
| | - Yibo Yu
- Eye Center of the Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang ProvinceChina
| | - Xiangjun Chen
- Eye Center of the Second Affiliated HospitalZhejiang University School of MedicineHangzhouZhejiang ProvinceChina
- Institute of Translational MedicineZhejiang University School of MedicineHangzhouZhejiang ProvinceChina
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7
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Qu S, Lin H, Pfeiffer N, Grus FH. Age-Related Macular Degeneration and Mitochondria-Associated Autoantibodies: A Review of the Specific Pathogenesis and Therapeutic Strategies. Int J Mol Sci 2024; 25:1624. [PMID: 38338904 PMCID: PMC10855900 DOI: 10.3390/ijms25031624] [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: 12/21/2023] [Revised: 01/22/2024] [Accepted: 01/25/2024] [Indexed: 02/12/2024] Open
Abstract
Age-related macular degeneration (AMD) is a severe retinal disease that causes irreversible visual loss and blindness in elderly populations worldwide. The pathological mechanism of AMD is complex, involving the interactions of multiple environmental and genetic factors. A poor understanding of the disease leads to limited treatment options and few effective prevention methods. The discovery of autoantibodies in AMD patients provides an opportunity to explore the pathogenesis and treatment direction of the disease. This review focuses on the mitochondria-associated autoantibodies and summarizes the functional roles of mitochondria under physiological conditions and their alterations during the pathological states. Additionally, it discusses the crosstalk between mitochondria and other organelles, as well as the mitochondria-related therapeutic strategies in AMD.
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Affiliation(s)
| | | | | | - Franz H. Grus
- Department of Experimental and Translational Ophthalmology, University Medical Center, Johannes Gutenberg University, 55131 Mainz, Germany; (S.Q.); (H.L.)
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8
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Hernandez BJ, Skiba NP, Plössl K, Strain M, Liu Y, Grigsby D, Kelly U, Cady MA, Manocha V, Maminishkis A, Watkins T, Miller SS, Ashley‐Koch A, Stamer WD, Weber BHF, Bowes Rickman C, Klingeborn M. Polarized Desmosome and Hemidesmosome Shedding via Small Extracellular Vesicles is an Early Indicator of Outer Blood-Retina Barrier Dysfunction. JOURNAL OF EXTRACELLULAR BIOLOGY 2023; 2:e116. [PMID: 38108061 PMCID: PMC10720597 DOI: 10.1002/jex2.116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 08/30/2023] [Accepted: 09/11/2023] [Indexed: 12/19/2023]
Abstract
The retinal pigmented epithelium (RPE) constitutes the outer blood-retinal barrier, enables photoreceptor function of the eye, and is constantly exposed to oxidative stress. As such, dysfunction of the RPE underlies pathology leading to development of age-related macular degeneration (AMD), the leading cause of vision loss among the elderly in industrialized nations. A major responsibility of the RPE is to process photoreceptor outer segments, which relies on the proper functioning of its endocytic pathways and endosomal trafficking. Exosomes and other extracellular vesicles (EVs) from RPE are an essential part of these pathways and may be early indicators of cellular stress. To test the role of small EVs (sEVs) including exosomes, that may underlie the early stages of AMD, we used a polarized primary RPE cell culture model under chronic subtoxic oxidative stress. Unbiased proteomic analyses of highly purified basolateral sEVs from oxidatively stressed RPE cultures revealed changes in proteins involved in epithelial barrier integrity. There were also significant changes in proteins accumulating in the basal-side sub-RPE extracellular matrix during oxidative stress, that could be prevented with an inhibitor of sEV release. Thus, chronic subtoxic oxidative stress in primary RPE cultures induces changes in sEV content, including basal-side specific desmosome and hemidesmosome shedding via sEVs. These findings provide novel biomarkers of early cellular dysfunction and opportunity for therapeutic intervention in age-related retinal diseases (e.g., AMD).
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Affiliation(s)
- Belinda J. Hernandez
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
| | - Nikolai P. Skiba
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
| | - Karolina Plössl
- Institute of Human GeneticsUniversity of RegensburgRegensburgGermany
| | - Madison Strain
- Duke Molecular Physiology Institute, Department of MedicineDuke UniversityDurhamNorth CarolinaUSA
| | - Yutao Liu
- Department of Cellular Biology and AnatomyAugusta UniversityAugustaGeorgiaUSA
| | - Daniel Grigsby
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
| | - Una Kelly
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
| | - Martha A. Cady
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
| | - Vikram Manocha
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
| | - Arvydas Maminishkis
- Ophthalmic Genetics and Visual Function Branch, Section on Epithelial and Retinal Physiology and DiseaseNational Eye Institute, National Institutes of HealthBethesdaMarylandUSA
| | - TeddiJo Watkins
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
- Office of Animal Welfare Assurance, Duke Animal Care and Use ProgramDuke UniversityDurhamNorth CarolinaUSA
| | - Sheldon S. Miller
- Ophthalmic Genetics and Visual Function Branch, Section on Epithelial and Retinal Physiology and DiseaseNational Eye Institute, National Institutes of HealthBethesdaMarylandUSA
| | - Allison Ashley‐Koch
- Duke Molecular Physiology Institute, Department of MedicineDuke UniversityDurhamNorth CarolinaUSA
| | - W. Daniel Stamer
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
- Department of Biomedical EngineeringDuke UniversityDurhamNorth CarolinaUSA
| | - Bernhard H. F. Weber
- Institute of Human GeneticsUniversity of RegensburgRegensburgGermany
- Institute of Clinical Human GeneticsUniversity Hospital RegensburgRegensburgGermany
| | - Catherine Bowes Rickman
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
- Department of Cell BiologyDuke UniversityDurhamNorth CarolinaUSA
| | - Mikael Klingeborn
- Department of Ophthalmology, Duke Eye CenterDuke UniversityDurhamNorth CarolinaUSA
- McLaughlin Research InstituteGreat FallsMontanaUSA
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9
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Ferreira PA. Nucleocytoplasmic transport at the crossroads of proteostasis, neurodegeneration and neuroprotection. FEBS Lett 2023; 597:2567-2589. [PMID: 37597509 DOI: 10.1002/1873-3468.14722] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 08/04/2023] [Accepted: 08/05/2023] [Indexed: 08/21/2023]
Abstract
Nucleocytoplasmic transport comprises the multistep assembly, transport, and disassembly of protein and RNA cargoes entering and exiting nuclear pores. Accruing evidence supports that impairments to nucleocytoplasmic transport are a hallmark of neurodegenerative diseases. These impairments cause dysregulations in nucleocytoplasmic partitioning and proteostasis of nuclear transport receptors and client substrates that promote intracellular deposits - another hallmark of neurodegeneration. Disturbances in liquid-liquid phase separation (LLPS) between dense and dilute phases of biomolecules implicated in nucleocytoplasmic transport promote micrometer-scale coacervates, leading to proteinaceous aggregates. This Review provides historical and emerging principles of LLPS at the interface of nucleocytoplasmic transport, proteostasis, aging and noxious insults, whose dysregulations promote intracellular aggregates. E3 SUMO-protein ligase Ranbp2 constitutes the cytoplasmic filaments of nuclear pores, where it acts as a molecular hub for rate-limiting steps of nucleocytoplasmic transport. A vignette is provided on the roles of Ranbp2 in nucleocytoplasmic transport and at the intersection of proteostasis in the survival of photoreceptor and motor neurons under homeostatic and pathophysiological environments. Current unmet clinical needs are highlighted, including therapeutics aiming to manipulate aggregation-dissolution models of purported neurotoxicity in neurodegeneration.
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Affiliation(s)
- Paulo A Ferreira
- Department of Ophthalmology, Department of Pathology, Duke University Medical Center, NC, Durham, USA
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10
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Tan LX, Germer CJ, Thamban T, La Cunza N, Lakkaraju A. Optineurin tunes outside-in signaling to regulate lysosome biogenesis and phagocytic clearance in the retina. Curr Biol 2023; 33:3805-3820.e7. [PMID: 37586372 PMCID: PMC10529777 DOI: 10.1016/j.cub.2023.07.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 06/16/2023] [Accepted: 07/19/2023] [Indexed: 08/18/2023]
Abstract
Balancing the competing demands of phagolysosomal degradation and autophagy is a significant challenge for phagocytic tissues. Yet how this plasticity is accomplished in health and disease is poorly understood. In the retina, circadian phagocytosis and degradation of photoreceptor outer segments by the postmitotic retinal pigment epithelium (RPE) are essential for healthy vision. Disrupted autophagy due to mechanistic target of rapamycin (mTOR) overactivation in the RPE is associated with blinding macular degenerations; however, outer segment degradation is unaffected in these diseases, indicating that distinct mechanisms regulate these clearance mechanisms. Here, using advanced imaging and mouse models, we identify optineurin as a key regulator that tunes phagocytosis and lysosomal capacity to meet circadian demands and helps prioritize outer segment clearance by the RPE in macular degenerations. High-resolution live-cell imaging implicates optineurin in scissioning outer segment tips prior to engulfment, analogous to microglial trogocytosis of neuronal processes. Optineurin is essential for recruiting light chain 3 (LC3), which anchors outer segment phagosomes to microtubules and facilitates phagosome maturation and fusion with lysosomes. This dynamically activates transcription factor EB (TFEB) to induce lysosome biogenesis in an mTOR-independent, transient receptor potential-mucolipin 1 (TRPML1)-dependent manner. RNA-seq analyses show that expression of TFEB target genes temporally tracks with optineurin recruitment and that lysosomal and autophagy genes are controlled by distinct transcriptional programs in the RPE. The unconventional plasma membrane-to-nucleus signaling mediated by optineurin ensures outer segment degradation under conditions of impaired autophagy in macular degeneration models. Independent regulation of these critical clearance mechanisms would help safeguard the metabolic fitness of the RPE throughout the organismal lifespan.
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Affiliation(s)
- Li Xuan Tan
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Colin J Germer
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Thushara Thamban
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Nilsa La Cunza
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA; Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Anatomy, School of Medicine, University of California, San Francisco, San Francisco, CA 94143, USA.
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11
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Abyadeh M, Gupta V, Paulo JA, Sheriff S, Shadfar S, Fitzhenry M, Amirkhani A, Gupta V, Salekdeh GH, Haynes PA, Graham SL, Mirzaei M. Apolipoprotein ε in Brain and Retinal Neurodegenerative Diseases. Aging Dis 2023; 14:1311-1330. [PMID: 37199411 PMCID: PMC10389820 DOI: 10.14336/ad.2023.0312-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Accepted: 03/12/2023] [Indexed: 05/19/2023] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia that remains incurable and has become a major medical, social, and economic challenge worldwide. AD is characterized by pathological hallmarks of senile plaques (SP) and neurofibrillary tangles (NFTs) that damage the brain up to twenty years before a clinical diagnosis is made. Interestingly these pathological features have also been observed in retinal neurodegenerative diseases including age related macular degeneration (ARMD), glaucoma and diabetic retinopathy (DR). An association of AD with these diseases has been suggested in epidemiological studies and several common pathological events and risk factors have been identified between these diseases. The E4 allele of Apolipoprotein E (APOE) is a well-established genetic risk factor for late onset AD. The ApoE ε4 allele is also associated with retinal neurodegenerative diseases however in contrast to AD, it is considered protective in AMD, likewise ApoE E2 allele, which is a protective factor for AD, has been implicated as a risk factor for AMD and glaucoma. This review summarizes the evidence on the effects of ApoE in retinal neurodegenerative diseases and discusses the overlapping molecular pathways in AD. The involvement of ApoE in regulating amyloid beta (Aβ) and tau pathology, inflammation, vascular integrity, glucose metabolism and vascular endothelial growth factor (VEGF) signaling is also discussed.
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Affiliation(s)
| | - Vivek Gupta
- Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Macquarie Park, North Ryde, Sydney, NSW 2109, Australia.
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
| | - Samran Sheriff
- Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Macquarie Park, North Ryde, Sydney, NSW 2109, Australia.
| | - Sina Shadfar
- Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Macquarie Park, North Ryde, Sydney, NSW 2109, Australia.
| | - Matthew Fitzhenry
- Australian Proteome Analysis Facility, Macquarie University, Macquarie Park, NSW 2113, Australia.
| | - Ardeshir Amirkhani
- Australian Proteome Analysis Facility, Macquarie University, Macquarie Park, NSW 2113, Australia.
| | - Veer Gupta
- School of Medicine, Deakin University, VIC, Australia.
| | - Ghasem H Salekdeh
- School of Natural Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia.
| | - Paul A Haynes
- School of Natural Sciences, Macquarie University, Macquarie Park, NSW 2109, Australia.
| | - Stuart L Graham
- Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Macquarie Park, North Ryde, Sydney, NSW 2109, Australia.
| | - Mehdi Mirzaei
- Department of Clinical Medicine, Faculty of Medicine, Health and Human Sciences, Macquarie Medical School, Macquarie University, Macquarie Park, North Ryde, Sydney, NSW 2109, Australia.
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12
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Hernandez BJ, Skiba NP, Plößl K, Strain M, Grigsby D, Kelly U, Cady MA, Manocha V, Maminishkis A, Watkins T, Miller SS, Ashley-Koch A, Stamer WD, Weber BHF, Rickman CB, Klingeborn M. Polarized Desmosome and Hemidesmosome Shedding via Exosomes is an Early Indicator of Outer Blood-Retina Barrier Dysfunction. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.12.544677. [PMID: 37398366 PMCID: PMC10312606 DOI: 10.1101/2023.06.12.544677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
The retinal pigmented epithelium (RPE) constitutes the outer blood-retinal barrier, enables photoreceptor function of the eye, and is constantly exposed to oxidative stress. As such, dysfunction of the RPE underlies pathology leading to development of age-related macular degeneration (AMD), the leading cause of vision loss among the elderly in industrialized nations. A major responsibility of the RPE is to process photoreceptor outer segments, which relies on the proper functioning of its endocytic pathways and endosomal trafficking. Exosomes and other extracellular vesicles from RPE are an essential part of these pathways and may be early indicators of cellular stress. To test the role of exosomes that may underlie the early stages of AMD, we used a polarized primary RPE cell culture model under chronic subtoxic oxidative stress. Unbiased proteomic analyses of highly purified basolateral exosomes from oxidatively stressed RPE cultures revealed changes in proteins involved in epithelial barrier integrity. There were also significant changes in proteins accumulating in the basal-side sub-RPE extracellular matrix during oxidative stress, that could be prevented with an inhibitor of exosome release. Thus, chronic subtoxic oxidative stress in primary RPE cultures induces changes in exosome content, including basal-side specific desmosome and hemidesmosome shedding via exosomes. These findings provide novel biomarkers of early cellular dysfunction and opportunity for therapeutic intervention in age-related retinal diseases, (e.g., AMD) and broadly from blood-CNS barriers in other neurodegenerative diseases.
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13
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Che X, Wu J, Liu H, Su J, Chen X. Cellular liquid-liquid phase separation: Concept, functions, regulations, and detections. J Cell Physiol 2023; 238:847-865. [PMID: 36870067 DOI: 10.1002/jcp.30980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Revised: 10/05/2022] [Accepted: 02/08/2023] [Indexed: 03/06/2023]
Abstract
Liquid-liquid phase separation is a multicomponent system separated into phases with different compositions and structures. It has been identified and explored in organisms after being introduced from the thermodynamic field. Condensate, the product of phase separation, exists in different scales of cellular structures, such as nucleolus, stress granules, and other organelles in nuclei or cytoplasm. And also play critical roles in different cellular behaviors. Here, we review the concept, thermodynamical and biochemical principles of phase separation. We summarized the main functions including the adjustment of biochemical reaction rates, the regulation of macromolecule folding state, subcellular structural support, the mediation of subcellular location, and intimately linked to different kinds of diseases, such as cancer and neurodegeneration. Advanced detection methods to investigate phase separation are collected and analyzed. We conclude with the discussion of anxiety of phase separation, and thought about how progress can be made to develop precise detection methods and disclose the potential application of condensates.
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Affiliation(s)
- Xuanlin Che
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, Xiangya Hospital, Changsha, Hunan, China.,Hunan Engineering Research Center of Skin Health and Disease, Xiangya Hospital, Changsha, Hunan, China.,Xiangya Clinical Research Center for Cancer Immunotherapy, Central South University, Changsha, Hunan, China
| | - Jiajun Wu
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
| | - Hua Liu
- Department of Orthopaedics, Xiangya Hospital, Central South University, Changsha, China
| | - Juan Su
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, Xiangya Hospital, Changsha, Hunan, China.,Hunan Engineering Research Center of Skin Health and Disease, Xiangya Hospital, Changsha, Hunan, China.,Xiangya Clinical Research Center for Cancer Immunotherapy, Central South University, Changsha, Hunan, China
| | - Xiang Chen
- Department of Dermatology, Xiangya Hospital, Central South University, Changsha, Hunan, China.,Hunan Key Laboratory of Skin Cancer and Psoriasis, Xiangya Hospital, Changsha, Hunan, China.,Hunan Engineering Research Center of Skin Health and Disease, Xiangya Hospital, Changsha, Hunan, China.,Xiangya Clinical Research Center for Cancer Immunotherapy, Central South University, Changsha, Hunan, China
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14
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Fisher CR, Shaaeli AA, Ebeling MC, Montezuma SR, Ferrington DA. Investigating mitochondrial fission, fusion, and autophagy in retinal pigment epithelium from donors with age-related macular degeneration. Sci Rep 2022; 12:21725. [PMID: 36526679 PMCID: PMC9758189 DOI: 10.1038/s41598-022-26012-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of irreversible blindness in developed countries, characterized by the death of retinal pigment epithelial (RPE) cells and photoreceptors. Previous studies report an accumulation of damaged and dysfunctional mitochondria in RPE of human donors with AMD. Understanding how damaged mitochondria accumulate in AMD is an important step in discovering disease mechanisms and identifying therapeutic targets. In this report, we assessed mitochondrial fission and fusion by quantifying proteins and measured mitochondrial autophagy (mitophagy) via protein analysis and advanced imaging techniques using mitochondrial targeted mKeima in primary human RPE from donors with or without AMD. We report disease-specific differences in mitochondrial proteins that regulate fission, fusion, and mitophagy that were present at baseline and with treatments to stimulate these pathways. Data suggest AMD RPE utilize receptor-mediated mitophagy as a compensatory mechanism for deficits in the ubiquitin-mediated mitophagy pathway. These changes in mitochondrial homeostasis could lead to the buildup of damaged and dysfunctional mitochondria observed in the RPE of AMD donors.
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Affiliation(s)
- Cody R. Fisher
- grid.17635.360000000419368657Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455 USA ,grid.17635.360000000419368657Graduate Program in Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455 USA
| | - Adam A. Shaaeli
- grid.17635.360000000419368657Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455 USA ,grid.17635.360000000419368657Undergraduate program in Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455 USA
| | - Mara C. Ebeling
- grid.17635.360000000419368657Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455 USA
| | - Sandra R. Montezuma
- grid.17635.360000000419368657Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455 USA
| | - Deborah A. Ferrington
- grid.17635.360000000419368657Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, MN 55455 USA ,grid.17635.360000000419368657Graduate Program in Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455 USA ,grid.17635.360000000419368657Stem Cell Institute, University of Minnesota, Minneapolis, MN 55455 USA ,grid.280881.b0000 0001 0097 5623Doheny Eye Institute, Pasadena, CA 91103 USA
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15
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Dall'Agnese A, Platt JM, Zheng MM, Friesen M, Dall'Agnese G, Blaise AM, Spinelli JB, Henninger JE, Tevonian EN, Hannett NM, Lazaris C, Drescher HK, Bartsch LM, Kilgore HR, Jaenisch R, Griffith LG, Cisse II, Jeppesen JF, Lee TI, Young RA. The dynamic clustering of insulin receptor underlies its signaling and is disrupted in insulin resistance. Nat Commun 2022; 13:7522. [PMID: 36473871 PMCID: PMC9727033 DOI: 10.1038/s41467-022-35176-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 11/17/2022] [Indexed: 12/12/2022] Open
Abstract
Insulin receptor (IR) signaling is central to normal metabolic control and is dysregulated in metabolic diseases such as type 2 diabetes. We report here that IR is incorporated into dynamic clusters at the plasma membrane, in the cytoplasm and in the nucleus of human hepatocytes and adipocytes. Insulin stimulation promotes further incorporation of IR into these dynamic clusters in insulin-sensitive cells but not in insulin-resistant cells, where both IR accumulation and dynamic behavior are reduced. Treatment of insulin-resistant cells with metformin, a first-line drug used to treat type 2 diabetes, can rescue IR accumulation and the dynamic behavior of these clusters. This rescue is associated with metformin's role in reducing reactive oxygen species that interfere with normal dynamics. These results indicate that changes in the physico-mechanical features of IR clusters contribute to insulin resistance and have implications for improved therapeutic approaches.
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Affiliation(s)
| | - Jesse M Platt
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
- Division of Gastroenterology, Department of Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Ming M Zheng
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Max Friesen
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
| | - Giuseppe Dall'Agnese
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
- Department of Medicine, University of Udine, Udine, 33100, Italy
| | - Alyssa M Blaise
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
| | | | | | - Erin N Tevonian
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Nancy M Hannett
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
| | | | - Hannah K Drescher
- Division of Gastroenterology, Department of Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Lea M Bartsch
- Division of Gastroenterology, Department of Medicine, Massachusetts General Hospital, Boston, MA, 02114, USA
| | - Henry R Kilgore
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
| | - Rudolf Jaenisch
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Linda G Griffith
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Center for Gynepathology Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Ibrahim I Cisse
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Jacob F Jeppesen
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA
- Global Drug Discovery, Novo Nordisk, Copenhagen, Denmark
| | - Tong I Lee
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA.
| | - Richard A Young
- Whitehead Institute for Biomedical Research, Cambridge, MA, 02142, USA.
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
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16
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Malek G, Campisi J, Kitazawa K, Webster C, Lakkaraju A, Skowronska-Krawczyk D. Does senescence play a role in age-related macular degeneration? Exp Eye Res 2022; 225:109254. [PMID: 36150544 PMCID: PMC10032649 DOI: 10.1016/j.exer.2022.109254] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 09/07/2022] [Accepted: 09/14/2022] [Indexed: 12/29/2022]
Abstract
Advanced age is the most established risk factor for developing age-related macular degeneration (AMD), one of the leading causes of visual impairment in the elderly, in Western and developed countries. Similarly, after middle age, there is an exponential increase in pathologic molecular and cellular events that can induce senescence, traditionally defined as an irreversible loss of the cells' ability to divide and most recently reported to also occur in select post-mitotic and terminally differentiated cells, such as neurons. Together these facts raise the question as to whether or not cellular senescence, may play a role in the development of AMD. A number of studies have reported the effect of ocular-relevant inducers of senescence using primarily in vitro models of poorly polarized, actively dividing retinal pigment epithelial (RPE) cell lines. However, in interpretating the data, the fidelity of these culture models to the RPE in vivo, must be considered. Fewer studies have explored the presence and/or impact of senescent cells in in vivo models that present with phenotypic features of AMD, leaving this an open field for further investigation. The goal of this review is to discuss current thoughts on the potential role of senescence in AMD development and progression, with consideration of the model systems used and their relevance to human disease.
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Affiliation(s)
- Goldis Malek
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, USA.
| | - Judith Campisi
- Buck Institute for Research on Aging, Novato, CA, USA; Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Koji Kitazawa
- Buck Institute for Research on Aging, Novato, CA, USA; Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Corey Webster
- Buck Institute for Research on Aging, Novato, CA, USA
| | - Aparna Lakkaraju
- Departments of Ophthalmology and Anatomy, School of Medicine, University of California, San Francisco, CA, USA
| | - Dorota Skowronska-Krawczyk
- Department of Physiology and Biophysics, Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, University of California, Irvine, CA, USA
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17
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Tan LX, Li J, Germer CJ, Lakkaraju A. Analysis of mitochondrial dynamics and function in the retinal pigment epithelium by high-speed high-resolution live imaging. Front Cell Dev Biol 2022; 10:1044672. [PMID: 36393836 PMCID: PMC9651161 DOI: 10.3389/fcell.2022.1044672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Accepted: 10/19/2022] [Indexed: 11/13/2022] Open
Abstract
Mitochondrial dysfunction is strongly implicated in neurodegenerative diseases including age-related macular degeneration (AMD), which causes irreversible blindness in over 50 million older adults worldwide. A key site of insult in AMD is the retinal pigment epithelium (RPE), a monolayer of postmitotic polarized cells that performs essential functions for photoreceptor health and vision. Recent studies from our group and others have identified several features of mitochondrial dysfunction in AMD including mitochondrial fragmentation and bioenergetic defects. While these studies provide valuable insight at fixed points in time, high-resolution, high-speed live imaging is essential for following mitochondrial injury in real time and identifying disease mechanisms. Here, we demonstrate the advantages of live imaging to investigate RPE mitochondrial dynamics in cell-based and mouse models. We show that mitochondria in the RPE form extensive networks that are destroyed by fixation and discuss important live imaging considerations that can interfere with accurate evaluation of mitochondrial integrity such as RPE differentiation status and acquisition parameters. Our data demonstrate that RPE mitochondria show localized heterogeneities in membrane potential and ATP production that could reflect focal changes in metabolism and oxidative stress. Contacts between the mitochondria and organelles such as the ER and lysosomes mediate calcium flux and mitochondrial fission. Live imaging of mouse RPE flatmounts revealed a striking loss of mitochondrial integrity in albino mouse RPE compared to pigmented mice that could have significant functional consequences for cellular metabolism. Our studies lay a framework to guide experimental design and selection of model systems for evaluating mitochondrial health and function in the RPE.
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Affiliation(s)
- Li Xuan Tan
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, United States
| | - Jianlong Li
- Department of Cell and Tissue Biology, School of Dentistry, University of California, San Francisco, CA, United States
| | - Colin J. Germer
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, United States
- Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, CA, United States
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, CA, United States
- Pharmaceutical Sciences and Pharmacogenomics Graduate Program, University of California, San Francisco, CA, United States
- Department of Anatomy, School of Medicine, University of California, San Francisco, CA, United States
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18
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Bharti K, den Hollander AI, Lakkaraju A, Sinha D, Williams DS, Finnemann SC, Bowes-Rickman C, Malek G, D'Amore PA. Cell culture models to study retinal pigment epithelium-related pathogenesis in age-related macular degeneration. Exp Eye Res 2022; 222:109170. [PMID: 35835183 PMCID: PMC9444976 DOI: 10.1016/j.exer.2022.109170] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/23/2022] [Accepted: 06/29/2022] [Indexed: 11/04/2022]
Abstract
Age-related macular degeneration (AMD) is a disease that affects the macula - the central part of the retina. It is a leading cause of irreversible vision loss in the elderly. AMD onset is marked by the presence of lipid- and protein-rich extracellular deposits beneath the retinal pigment epithelium (RPE), a monolayer of polarized, pigmented epithelial cells located between the photoreceptors and the choroidal blood supply. Progression of AMD to the late nonexudative "dry" stage of AMD, also called geographic atrophy, is linked to progressive loss of areas of the RPE, photoreceptors, and underlying choriocapillaris leading to a severe decline in patients' vision. Differential susceptibility of macular RPE in AMD and the lack of an anatomical macula in most lab animal models has promoted the use of in vitro models of the RPE. In addition, the need for high throughput platforms to test potential therapies has driven the creation and characterization of in vitro model systems that recapitulate morphologic and functional abnormalities associated with human AMD. These models range from spontaneously formed cell line ARPE19, immortalized cell lines such as hTERT-RPE1, RPE-J, and D407, to primary human (fetal or adult) or animal (mouse and pig) RPE cells, and embryonic and induced pluripotent stem cell (iPSC) derived RPE. Hallmark RPE phenotypes, such as cobblestone morphology, pigmentation, and polarization, vary significantly betweendifferent models and culture conditions used in different labs, which would directly impact their usability for investigating different aspects of AMD biology. Here the AMD Disease Models task group of the Ryan Initiative for Macular Research (RIMR) provides a summary of several currently used in vitro RPE models, historical aspects of their development, RPE phenotypes that are attainable in these models, their ability to model different aspects of AMD pathophysiology, and pros/cons for their use in the RPE and AMD fields. In addition, due to the burgeoning use of iPSC derived RPE cells, the critical need for developing standards for differentiating and rigorously characterizing RPE cell appearance, morphology, and function are discussed.
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Affiliation(s)
- Kapil Bharti
- Ocular and Stem Cell Translational Research Section, National Eye Institute, NIH, Bethesda, MD, USA.
| | - Anneke I den Hollander
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands; AbbVie, Genomics Research Center, Cambridge, MA, USA.
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, USA.
| | - Debasish Sinha
- Department of Ophthalmology, Cell Biology and Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - David S Williams
- Stein Eye Institute, Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
| | - Silvia C Finnemann
- Center of Cancer, Genetic Diseases, and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY, USA.
| | - Catherine Bowes-Rickman
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA.
| | - Goldis Malek
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, USA.
| | - Patricia A D'Amore
- Mass Eye and Ear, Departments of Ophthalmology and Pathology, Harvard Medical School, Boston, MA, USA.
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19
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Hazim RA, Paniagua AE, Tang L, Yang K, Kim KKO, Stiles L, Divakaruni AS, Williams DS. Vitamin B3, nicotinamide, enhances mitochondrial metabolism to promote differentiation of the retinal pigment epithelium. J Biol Chem 2022; 298:102286. [PMID: 35868562 PMCID: PMC9396405 DOI: 10.1016/j.jbc.2022.102286] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 07/14/2022] [Accepted: 07/15/2022] [Indexed: 01/04/2023] Open
Abstract
In the mammalian retina, a metabolic ecosystem exists in which photoreceptors acquire glucose from the choriocapillaris with the help of the retinal pigment epithelium (RPE). While the photoreceptor cells are primarily glycolytic, exhibiting Warburg-like metabolism, the RPE is reliant on mitochondrial respiration. However, the ways in which mitochondrial metabolism affect RPE cellular functions are not clear. We first used the human RPE cell line, ARPE-19, to examine mitochondrial metabolism in the context of cellular differentiation. We show that nicotinamide induced rapid differentiation of ARPE-19 cells, which was reversed by removal of supplemental nicotinamide. During the nicotinamide-induced differentiation, we observed using quantitative PCR, Western blotting, electron microscopy, and metabolic respiration and tracing assays that (1) mitochondrial gene and protein expression increased, (2) mitochondria became larger with more tightly folded cristae, and (3) mitochondrial metabolism was enhanced. In addition, we show that primary cultures of human fetal RPE cells responded similarly in the presence of nicotinamide. Furthermore, disruption of mitochondrial oxidation of pyruvate attenuated the nicotinamide-induced differentiation of the RPE cells. Together, our results demonstrate a remarkable effect of nicotinamide on RPE metabolism. We also identify mitochondrial respiration as a key contributor to the differentiated state of the RPE and thus to many of the RPE functions that are essential for retinal health and photoreception.
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Affiliation(s)
- Roni A Hazim
- Department of Ophthalmology and Stein Eye Institute
| | | | - Lisa Tang
- Department of Ophthalmology and Stein Eye Institute
| | - Krista Yang
- Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095
| | - Kristen K O Kim
- Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095
| | - Linsey Stiles
- Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095; Department of Medicine, Endocrinology. UCLA David Geffen School of Medicine. Los Angeles, CA, 90095, USA
| | - Ajit S Divakaruni
- Department of Molecular and Medical Pharmacology, UCLA David Geffen School of Medicine, Los Angeles, CA 90095
| | - David S Williams
- Department of Ophthalmology and Stein Eye Institute; Department of Neurobiology, David Geffen School of Medicine at UCLA; Molecular Biology Institute; Brain Research Institute, University of California, Los Angeles, CA.
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20
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Potential participation of CTRP6, a complement regulator, in the pathology of age related macular degeneration. Jpn J Ophthalmol 2022; 66:326-334. [PMID: 35397057 DOI: 10.1007/s10384-022-00913-4] [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: 10/27/2021] [Accepted: 02/24/2022] [Indexed: 10/18/2022]
Abstract
PURPOSE To investigate the localized expression of C1q/tumor necrosis factor related protein (CTRP) 6 in human age-related macular degeneration (AMD) retinal tissues. EXPERIMENTAL STUDY DESIGN 4 AMD and 3 non-AMD whole eyes of Caucasian donors were used. Eyecups were excised at Eye Bank CorneaGen, Inc. METHODS To elucidate the effects of CTRP6, C3b was measured by an enzyme-linked immunosorbent-like assay. CFB versus CTRP6 competitive binding assay was applied to clarify the inhibition by CTRP6 of C3bBb complex formation. The cornea, iris, lens, and vitreous were removed and the eyes were cut into a posterior eye-cup including the retina, choroid, and sclera. Six-µm-thick serial sections of frozen samples underwent hematoxylin-eosin (HE) staining and indirect immunohistochemical staining using primary antibodies, anti-CTRP6, -CTRP5, -CTRP10, -Complement factor H (CFH) and -Clusterin (CLU). Results The two in vitro studies confirmed that CTRP6 has an inhibitory effect on alternative pathways of complement (APC) function and that the molecular target of CTRP6 is the inhibition of the formation of C3bBb. Localized expression for CTRP6 and CFH was found in the drusen of the AMD eyes, both associated with APC inhibition, CLU associated with membrane-attack complex (MAC) inhibition, and CTRP5 associated with retinal degeneration. CONCLUSION The localized expression of CTRP6 in the drusen of AMD eyes may open a new insight into the possible involvement of APC regulatory factors in the pathogenesis of AMD, together with the known CFH so far analyzed solely as an APC inhibitor.
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Lewandowski D, Sander CL, Tworak A, Gao F, Xu Q, Skowronska-Krawczyk D. Dynamic lipid turnover in photoreceptors and retinal pigment epithelium throughout life. Prog Retin Eye Res 2021; 89:101037. [PMID: 34971765 PMCID: PMC10361839 DOI: 10.1016/j.preteyeres.2021.101037] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 12/13/2022]
Abstract
The retinal pigment epithelium-photoreceptor interphase is renewed each day in a stunning display of cellular interdependence. While photoreceptors use photosensitive pigments to convert light into electrical signals, the RPE supports photoreceptors in their function by phagocytizing shed photoreceptor tips, regulating the blood retina barrier, and modulating inflammatory responses, as well as regenerating the 11-cis-retinal chromophore via the classical visual cycle. These processes involve multiple protein complexes, tightly regulated ligand-receptors interactions, and a plethora of lipids and protein-lipids interactions. The role of lipids in maintaining a healthy interplay between the RPE and photoreceptors has not been fully delineated. In recent years, novel technologies have resulted in major advancements in understanding several facets of this interplay, including the involvement of lipids in phagocytosis and phagolysosome function, nutrient recycling, and the metabolic dependence between the two cell types. In this review, we aim to integrate the complex role of lipids in photoreceptor and RPE function, emphasizing the dynamic exchange between the cells as well as discuss how these processes are affected in aging and retinal diseases.
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Affiliation(s)
- Dominik Lewandowski
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Christopher L Sander
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Aleksander Tworak
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Fangyuan Gao
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Qianlan Xu
- Department of Physiology and Biophysics, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Dorota Skowronska-Krawczyk
- Department of Physiology and Biophysics, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA.
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