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Hashimoto Y, Campbell M. Eyes on glutamate in angiogenesis and barrier formation. Neuron 2024; 112:1895-1897. [PMID: 38901398 DOI: 10.1016/j.neuron.2024.05.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2024] [Revised: 05/15/2024] [Accepted: 05/17/2024] [Indexed: 06/22/2024]
Abstract
In this issue of Neuron, Biswas et al.1 demonstrate the roles of glutamatergic neuronal activity in the regulation of angiogenesis and retinal vascular endothelial barrier maturation using three different knockout mouse models. Their findings shed light on how aberrant glutamatergic activity can impact neural vascular function and barrier integrity.
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Affiliation(s)
- Yosuke Hashimoto
- Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland
| | - Matthew Campbell
- Smurfit Institute of Genetics, Trinity College Dublin, D02 VF25 Dublin, Ireland; FutureNeuro, Science Foundation Ireland Research Centre for Chronic and Rare Neurological Diseases, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, D02 YN77 Dublin, Ireland.
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2
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Zhang Z, Li W, Han X, Tian D, Yan W, Liu M, Cao L. Circadian rhythm disruption-mediated downregulation of Bmal1 exacerbates DSS-induced colitis by impairing intestinal barrier. Front Immunol 2024; 15:1402395. [PMID: 38895112 PMCID: PMC11183104 DOI: 10.3389/fimmu.2024.1402395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Accepted: 05/15/2024] [Indexed: 06/21/2024] Open
Abstract
Background Circadian rhythm disruption (CRD) is thought to increase the risk of inflammatory bowel disease. The deletion of Bmal1, a core transcription factor, leads to a complete loss of the circadian rhythm and exacerbates the severity of dextran sodium sulfate (DSS)-induced colitis in mice. However, the underlying mechanisms by which CRD and Bmal1 mediate IBD are still unclear. Methods We used a CRD mouse model, a mouse colitis model, and an in vitro model of colonic epithelial cell monolayers. We also knocked down and overexpressed Bmal1 in Caco-2 cells by transfecting lentivirus in vitro. The collected colon tissue and treated cells were assessed and analyzed using immunohistochemistry, immunofluorescence staining, quantitative reverse transcription-polymerase chain reaction, western blot, flow cytometry, transmission electron microscopy, and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labelling staining. Results We found that CRD mice with downregulated Bmal1 expression were more sensitive to DSS-induced colitis and had more severely impaired intestinal barrier function than wild-type mice. Bmal1-/- mice exhibited more severe colitis, accompanied by decreased tight junction protein levels and increased apoptosis of intestinal epithelial cells compared with wild-type mice, which were alleviated by using the autophagy agonist rapamycin. Bmal1 overexpression attenuated Lipopolysaccharide-induced apoptosis of intestinal epithelial cells and impaired intestinal epithelial cells barrier function in vitro, while inhibition of autophagy reversed this protective effect. Conclusion This study suggests that CRD leads to the downregulation of Bmal1 expression in the colon, which may exacerbate DSS-induced colitis in mice, and that Bmal1 may serve as a novel target for treating inflammatory bowel disease.
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Affiliation(s)
| | | | | | | | | | - Mei Liu
- Department of Gastroenterology and Hepatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Li Cao
- Department of Gastroenterology and Hepatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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3
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Qi J, Li H, Du Y, Liu Y, He W, Meng J, Wei L, Zhang K, Lu Y, Zhu X. Circulating Autoantibody Profiling Identifies LIMS1 as a Potential Target for Pathogenic Autoimmunity in pathologic Myopia. Mol Cell Proteomics 2024; 23:100783. [PMID: 38729610 PMCID: PMC11215957 DOI: 10.1016/j.mcpro.2024.100783] [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: 10/16/2023] [Revised: 04/22/2024] [Accepted: 05/06/2024] [Indexed: 05/12/2024] Open
Abstract
High myopia is a leading cause of blindness worldwide, among which pathologic myopia, characterized by typical myopic macular degeneration, is the most detrimental. However, its pathogenesis remains largely unknown. Here, using a HuProt array, we first initiated a serological autoantibody profiling of high myopia and identified 18 potential autoantibodies, of which anti-LIMS1 autoantibody was validated by a customized focused microarray. Further subgroup analysis revealed its actual relevance to pathologic myopia, rather than simple high myopia without myopic macular degeneration. Mechanistically, anti-LIMS1 autoantibody predominantly belonged to IgG1/IgG2/IgG3 subclasses. Serum IgG obtained from patients with pathologic myopia could disrupt the barrier function of retinal pigment epithelial cells via cytoskeleton disorganization and tight junction component reduction, and also trigger a pro-inflammatory mediator cascade in retinal pigment epithelial cells, which were all attenuated by depletion of anti-LIMS1 autoantibody. Together, these data uncover a previously unrecognized autoimmune etiology of myopic macular degeneration in pathologic myopia.
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Affiliation(s)
- Jiao Qi
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, People's Republic of China; NHC Key Laboratory of Myopia and Related Eye Diseases, Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, People's Republic of China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, People's Republic of China; State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Hao Li
- Department of Ophthalmology, Zhongshan Hospital, Fudan University, Shanghai, People's Republic of China
| | - Yu Du
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, People's Republic of China; NHC Key Laboratory of Myopia and Related Eye Diseases, Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, People's Republic of China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, People's Republic of China; State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Yun Liu
- MOE Key Laboratory of Metabolism and Molecular Medicine, Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Fudan University, Shanghai, People's Republic of China
| | - Wenwen He
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, People's Republic of China; NHC Key Laboratory of Myopia and Related Eye Diseases, Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, People's Republic of China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, People's Republic of China; State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Jiaqi Meng
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, People's Republic of China; NHC Key Laboratory of Myopia and Related Eye Diseases, Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, People's Republic of China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, People's Republic of China; State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Ling Wei
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, People's Republic of China; NHC Key Laboratory of Myopia and Related Eye Diseases, Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, People's Republic of China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, People's Republic of China; State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Keke Zhang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, People's Republic of China; NHC Key Laboratory of Myopia and Related Eye Diseases, Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, People's Republic of China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, People's Republic of China; State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China
| | - Yi Lu
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, People's Republic of China; NHC Key Laboratory of Myopia and Related Eye Diseases, Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, People's Republic of China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, People's Republic of China; State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China.
| | - Xiangjia Zhu
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, People's Republic of China; NHC Key Laboratory of Myopia and Related Eye Diseases, Key Laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, People's Republic of China; Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, People's Republic of China; State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, People's Republic of China.
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4
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Lawrence JH, Patel A, King MW, Nadarajah CJ, Daneman R, Musiek ES. Microglia drive diurnal variation in susceptibility to inflammatory blood-brain barrier breakdown. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.10.588924. [PMID: 38645230 PMCID: PMC11030435 DOI: 10.1101/2024.04.10.588924] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
The blood-brain barrier (BBB) is critical for maintaining brain homeostasis but is susceptible to inflammatory dysfunction. Permeability of the BBB to lipophilic molecules shows circadian variation due to rhythmic transporter expression, while basal permeability to polar molecules is non-rhythmic. Whether daily timing influences BBB permeability in response to inflammation is unknown. Here, we induced systemic inflammation through repeated lipopolysaccharide (LPS) injections either in the morning (ZT1) or evening (ZT13) under standard lighting conditions, then examined BBB permeability to a polar molecule, sodium fluorescein. We observed clear diurnal variation in inflammatory BBB permeability, with a striking increase in paracellular leak across the BBB specifically following evening LPS injection. Evening LPS led to persisting glia activation and inflammation in the brain that was not observed in the periphery. The exaggerated evening neuroinflammation and BBB disruption were suppressed by microglial depletion or through keeping mice in constant darkness. Our data show that diurnal rhythms in microglial inflammatory responses to LPS drive daily variability in BBB breakdown and reveals time-of-day as a key regulator of inflammatory BBB disruption.
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Rajeswaren V, Wagner BD, Patnaik JL, Mandava N, Mathias MT, Manoharan N, de Carlo Forest TE, Gnanaraj R, Lynch AM, Palestine AG. Elevated tumor necrosis factor alpha and vascular endothelial growth factor in intermediate age-related macular degeneration and geographic atrophy. FRONTIERS IN OPHTHALMOLOGY 2024; 4:1356957. [PMID: 38984140 PMCID: PMC11182128 DOI: 10.3389/fopht.2024.1356957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2023] [Accepted: 03/06/2024] [Indexed: 07/11/2024]
Abstract
Introduction Tumor necrosis factor alpha (TNF-α) is an inflammatory cytokine implicated in pathological changes to the retinal pigment epithelium that are similar to changes in geographic atrophy (GA), an advanced form of age related macular degeneration (AMD). TNF-α also modulates expression of other cytokines including vascular endothelial growth factor (VEGF), leading to choroidal atrophy in models of AMD. The purpose of this study was to investigate systemic TNF-α and VEGF in patients with GA and intermediate AMD (iAMD) compared to controls without AMD. Methods We examined plasma levels of TNF-α and VEGF in patients with GA, iAMD, and controls without AMD from the University of Colorado AMD registry (2014 to 2021). Cases and controls were characterized by multimodal imaging. TNF-α and VEGF were measured via multiplex immunoassay and data were analyzed using a non-parametric rank based linear regression model fit to plasma biomarkers. Results There were 97 GA, 199 iAMD patients and 139 controls. TNF-α was significantly increased in GA (Median:9.9pg/ml, IQR:7.3-11.8) compared to iAMD (Median:7.4, IQR:5.3-9.1) and in both GA and iAMD compared to controls (Median:6.4, IQR:5.3-7.8), p<0.01 for all comparisons. VEGF was significantly increased in iAMD (Median:8.9, IQR:4.8-14.3) compared to controls (Median:7.7, IQR:4.6-11.1), p<0.01. There was a significant positive correlation between TNF-α and VEGF in GA (0.46, p<0.01), and iAMD (0.20, p=0.01) with no significant interaction between TNF-α and VEGF in any group. Discussion These findings suggest TNF-α and VEGF may contribute to systemic inflammatory processes associated with iAMD and GA. TNF-α and VEGF may function as systemic biomarkers for disease development.
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Affiliation(s)
- Vivian Rajeswaren
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Brandie D. Wagner
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, United States
- Colorado School of Public Health, University of Colorado School of Medicine, Aurora, CO, United States
| | - Jennifer L. Patnaik
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Naresh Mandava
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Marc T. Mathias
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Niranjan Manoharan
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, United States
| | | | - Ramya Gnanaraj
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Anne M. Lynch
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Alan G. Palestine
- Department of Ophthalmology, University of Colorado School of Medicine, Aurora, CO, United States
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6
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Li W, Tiedt S, Lawrence JH, Harrington ME, Musiek ES, Lo EH. Circadian Biology and the Neurovascular Unit. Circ Res 2024; 134:748-769. [PMID: 38484026 DOI: 10.1161/circresaha.124.323514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Accepted: 02/14/2024] [Indexed: 03/19/2024]
Abstract
Mammalian physiology and cellular function are subject to significant oscillations over the course of every 24-hour day. It is likely that these daily rhythms will affect function as well as mechanisms of disease in the central nervous system. In this review, we attempt to survey and synthesize emerging studies that investigate how circadian biology may influence the neurovascular unit. We examine how circadian clocks may operate in neural, glial, and vascular compartments, review how circadian mechanisms regulate cell-cell signaling, assess interactions with aging and vascular comorbidities, and finally ask whether and how circadian effects and disruptions in rhythms may influence the risk and progression of pathophysiology in cerebrovascular disease. Overcoming identified challenges and leveraging opportunities for future research might support the development of novel circadian-based treatments for stroke.
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Affiliation(s)
- Wenlu Li
- Neuroprotection Research Laboratories, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Boston (W.L., E.H.L.)
- Consortium International pour la Recherche Circadienne sur l'AVC, Munich, Germany (W.L., S.T., J.H.L., M.E.H., E.S.M., E.H.L.)
| | - Steffen Tiedt
- Consortium International pour la Recherche Circadienne sur l'AVC, Munich, Germany (W.L., S.T., J.H.L., M.E.H., E.S.M., E.H.L.)
- Institute for Stroke and Dementia Research, University Hospital, Ludwig-Maximilians-Universität München, Munich, Germany (S.T.)
| | - Jennifer H Lawrence
- Consortium International pour la Recherche Circadienne sur l'AVC, Munich, Germany (W.L., S.T., J.H.L., M.E.H., E.S.M., E.H.L.)
- Department of Neurology, Washington University School of Medicine, St. Louis, MO (J.H.L., E.S.M.)
| | - Mary E Harrington
- Consortium International pour la Recherche Circadienne sur l'AVC, Munich, Germany (W.L., S.T., J.H.L., M.E.H., E.S.M., E.H.L.)
- Neuroscience Program, Smith College, Northampton, MA (M.E.H.)
| | - Erik S Musiek
- Consortium International pour la Recherche Circadienne sur l'AVC, Munich, Germany (W.L., S.T., J.H.L., M.E.H., E.S.M., E.H.L.)
- Department of Neurology, Washington University School of Medicine, St. Louis, MO (J.H.L., E.S.M.)
| | - Eng H Lo
- Neuroprotection Research Laboratories, Departments of Radiology and Neurology, Massachusetts General Hospital, Harvard Medical School, Boston (W.L., E.H.L.)
- Consortium International pour la Recherche Circadienne sur l'AVC, Munich, Germany (W.L., S.T., J.H.L., M.E.H., E.S.M., E.H.L.)
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7
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Abstract
The brain is a complex organ, fundamentally changing across the day to perform basic functions like sleep, thought, and regulating whole-body physiology. This requires a complex symphony of nutrients, hormones, ions, neurotransmitters and more to be properly distributed across the brain to maintain homeostasis throughout 24 hours. These solutes are distributed both by the blood and by cerebrospinal fluid. Cerebrospinal fluid contents are distinct from the general circulation because of regulation at brain barriers including the choroid plexus, glymphatic system, and blood-brain barrier. In this review, we discuss the overlapping circadian (≈24-hour) rhythms in brain fluid biology and at the brain barriers. Our goal is for the reader to gain both a fundamental understanding of brain barriers alongside an understanding of the interactions between these fluids and the circadian timing system. Ultimately, this review will provide new insight into how alterations in these finely tuned clocks may lead to pathology.
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Affiliation(s)
- Velia S Vizcarra
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | - Ryann M Fame
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Lauren M Hablitz
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY, 14642, USA
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8
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Bora K, Kushwah N, Maurya M, Pavlovich MC, Wang Z, Chen J. Assessment of Inner Blood-Retinal Barrier: Animal Models and Methods. Cells 2023; 12:2443. [PMID: 37887287 PMCID: PMC10605292 DOI: 10.3390/cells12202443] [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: 09/03/2023] [Revised: 10/07/2023] [Accepted: 10/08/2023] [Indexed: 10/28/2023] Open
Abstract
Proper functioning of the neural retina relies on the unique retinal environment regulated by the blood-retinal barrier (BRB), which restricts the passage of solutes, fluids, and toxic substances. BRB impairment occurs in many retinal vascular diseases and the breakdown of BRB significantly contributes to disease pathology. Understanding the different molecular constituents and signaling pathways involved in BRB development and maintenance is therefore crucial in developing treatment modalities. This review summarizes the major molecular signaling pathways involved in inner BRB (iBRB) formation and maintenance, and representative animal models of eye diseases with retinal vascular leakage. Studies on Wnt/β-catenin signaling are highlighted, which is critical for retinal and brain vascular angiogenesis and barriergenesis. Moreover, multiple in vivo and in vitro methods for the detection and analysis of vascular leakage are described, along with their advantages and limitations. These pre-clinical animal models and methods for assessing iBRB provide valuable experimental tools in delineating the molecular mechanisms of retinal vascular diseases and evaluating therapeutic drugs.
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Affiliation(s)
| | | | | | | | | | - Jing Chen
- Department of Ophthalmology, Boston Children’s Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA
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9
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Mitchell JW, Gillette MU. Development of circadian neurovascular function and its implications. Front Neurosci 2023; 17:1196606. [PMID: 37732312 PMCID: PMC10507717 DOI: 10.3389/fnins.2023.1196606] [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: 03/30/2023] [Accepted: 08/14/2023] [Indexed: 09/22/2023] Open
Abstract
The neurovascular system forms the interface between the tissue of the central nervous system (CNS) and circulating blood. It plays a critical role in regulating movement of ions, small molecules, and cellular regulators into and out of brain tissue and in sustaining brain health. The neurovascular unit (NVU), the cells that form the structural and functional link between cells of the brain and the vasculature, maintains the blood-brain interface (BBI), controls cerebral blood flow, and surveils for injury. The neurovascular system is dynamic; it undergoes tight regulation of biochemical and cellular interactions to balance and support brain function. Development of an intrinsic circadian clock enables the NVU to anticipate rhythmic changes in brain activity and body physiology that occur over the day-night cycle. The development of circadian neurovascular function involves multiple cell types. We address the functional aspects of the circadian clock in the components of the NVU and their effects in regulating neurovascular physiology, including BBI permeability, cerebral blood flow, and inflammation. Disrupting the circadian clock impairs a number of physiological processes associated with the NVU, many of which are correlated with an increased risk of dysfunction and disease. Consequently, understanding the cell biology and physiology of the NVU is critical to diminishing consequences of impaired neurovascular function, including cerebral bleeding and neurodegeneration.
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Affiliation(s)
- Jennifer W. Mitchell
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, IL, United States
- Neuroscience Program, University of Illinois Urbana-Champaign, Urbana, IL, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, IL, United States
| | - Martha U. Gillette
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, IL, United States
- Neuroscience Program, University of Illinois Urbana-Champaign, Urbana, IL, United States
- Beckman Institute for Advanced Science and Technology, University of Illinois Urbana-Champaign, Urbana, IL, United States
- Department of Molecular and Integrative Physiology, University of Illinois Urbana-Champaign, Urbana, IL, United States
- Carle-Illinois College of Medicine, University of Illinois Urbana-Champaign, Urbana, IL, United States
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10
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Malhan D, Schoenrock B, Yalçin M, Blottner D, Relόgio A. Circadian regulation in aging: Implications for spaceflight and life on earth. Aging Cell 2023; 22:e13935. [PMID: 37493006 PMCID: PMC10497835 DOI: 10.1111/acel.13935] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 06/30/2023] [Accepted: 07/07/2023] [Indexed: 07/27/2023] Open
Abstract
Alterations in the circadian system are characteristic of aging on Earth. With the decline in physiological processes due to aging, several health concerns including vision loss, cardiovascular disorders, cognitive impairments, and muscle mass loss arise in elderly populations. Similar health risks are reported as "red flag" risks among astronauts during and after a long-term Space exploration journey. However, little is known about the common molecular alterations underlying terrestrial aging and space-related aging in astronauts, and controversial conclusions have been recently reported. In light of the regulatory role of the circadian clock in the maintenance of human health, we review here the overlapping role of the circadian clock both on aging on Earth and spaceflight with a focus on the four most affected systems: visual, cardiovascular, central nervous, and musculoskeletal systems. In this review, we briefly introduce the regulatory role of the circadian clock in specific cellular processes followed by alterations in those processes due to aging. We next summarize the known molecular alterations associated with spaceflight, highlighting involved clock-regulated genes in space flown Drosophila, nematodes, small mammals, and astronauts. Finally, we discuss common genes that are altered in terms of their expression due to aging on Earth and spaceflight. Altogether, the data elaborated in this review strengthen our hypothesis regarding the timely need to include circadian dysregulation as an emerging hallmark of aging on Earth and beyond.
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Affiliation(s)
- Deeksha Malhan
- Institute for Systems Medicine and Faculty of Human MedicineMSH Medical School HamburgHamburgGermany
| | - Britt Schoenrock
- Institute of Integrative NeuroanatomyCharité‐Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Müge Yalçin
- Institute for Systems Medicine and Faculty of Human MedicineMSH Medical School HamburgHamburgGermany
- Institute for Theoretical Biology (ITB)Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
- Molecular Cancer Research Center (MKFZ), Medical Department of Hematology, Oncology, and Tumour Immunology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
| | - Dieter Blottner
- Institute of Integrative NeuroanatomyCharité‐Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
- Neuromuscular System and Neuromuscular SignalingBerlin Center of Space Medicine & Extreme EnvironmentsBerlinGermany
| | - Angela Relόgio
- Institute for Systems Medicine and Faculty of Human MedicineMSH Medical School HamburgHamburgGermany
- Institute for Theoretical Biology (ITB)Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
- Molecular Cancer Research Center (MKFZ), Medical Department of Hematology, Oncology, and Tumour Immunology, Charité—Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt‐Universität zu Berlin, and Berlin Institute of HealthBerlinGermany
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11
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Bell B, Anzi S, Sasson E, Ben-Zvi A. Unique features of the arterial blood-brain barrier. Fluids Barriers CNS 2023; 20:51. [PMID: 37370096 DOI: 10.1186/s12987-023-00450-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 06/05/2023] [Indexed: 06/29/2023] Open
Abstract
CNS vasculature differs from vascular networks of peripheral organs by its ability to tightly control selective material exchange across capillary barriers. Capillary permeability is mostly defined by unique cellular components of the endothelium. While capillaries are extensively investigated, the barrier properties of larger vessels are understudied. Here, we investigate barrier properties of CNS arterial walls. Using tracer challenges and various imaging modalities, we discovered that at the mouse cortex, the arterial barrier does not reside at the classical level of the endothelium. The arterial wall's unique permeability acts bi-directionally; CSF substances travel along the glymphatic path and can penetrate from the peri-vascular space through arteriolar walls towards the lumen. We found that caveolae vesicles in arteriole endothelial are functional transcytosis machinery components, and that a similar mechanism is evident in the human brain. Our discoveries highlight vascular heterogeneity investigations as a potent approach to uncover new barrier mechanisms.
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Affiliation(s)
- Batia Bell
- Department of Developmental Biology and Cancer Research, Faculty of Medicine, Hubert H. Humphrey Center for Experimental Medicine and Cancer Research, The Institute for Medical Research Israel-Canada, Hebrew University of Jerusalem, 91120, Jerusalem, Israel
| | - Shira Anzi
- Department of Developmental Biology and Cancer Research, Faculty of Medicine, Hubert H. Humphrey Center for Experimental Medicine and Cancer Research, The Institute for Medical Research Israel-Canada, Hebrew University of Jerusalem, 91120, Jerusalem, Israel
| | - Esther Sasson
- Department of Developmental Biology and Cancer Research, Faculty of Medicine, Hubert H. Humphrey Center for Experimental Medicine and Cancer Research, The Institute for Medical Research Israel-Canada, Hebrew University of Jerusalem, 91120, Jerusalem, Israel
| | - Ayal Ben-Zvi
- Department of Developmental Biology and Cancer Research, Faculty of Medicine, Hubert H. Humphrey Center for Experimental Medicine and Cancer Research, The Institute for Medical Research Israel-Canada, Hebrew University of Jerusalem, 91120, Jerusalem, Israel.
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12
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Chan YJ, Hsiao G, Wan WN, Yang TM, Tsai CH, Kang JJ, Lee YC, Fang TC, Cheng YW, Li CH. Blue light exposure collapses the inner blood-retinal barrier by accelerating endothelial CLDN5 degradation through the disturbance of GNAZ and the activation of ADAM17. Fluids Barriers CNS 2023; 20:31. [PMID: 37095509 PMCID: PMC10124034 DOI: 10.1186/s12987-023-00430-7] [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: 12/08/2022] [Accepted: 04/07/2023] [Indexed: 04/26/2023] Open
Abstract
Blue light is part of the natural light spectrum that emits high energy. Currently, people are frequently exposed to blue light from 3C devices, resulting in a growing incidence of retinopathy. The retinal vasculature is complex, and retinal vessels not only serve the metabolic needs of the retinal sublayers, but also maintain electrolyte homeostasis by forming the inner blood-retinal barrier (iBRB). The iBRB, which is primarily composed of endothelial cells, has well-developed tight junctions. However, with exposure to blue light, the risks of targeting retinal endothelial cells are currently unknown. We found that endothelial claudin-5 (CLDN5) was rapidly degraded under blue light, coinciding with the activation of a disintegrin and metalloprotease 17 (ADAM17), even at non-cytotoxic lighting. An apparently broken tight junction and a permeable paracellular cleft were observed. Mice exposed to blue light displayed iBRB leakage, conferring attenuation of the electroretinogram b-wave and oscillatory potentials. Both pharmacological and genetic inhibition of ADAM17 remarkably alleviated CLDN5 degradation induced by blue light. Under untreated condition, ADAM17 is sequestered by GNAZ (a circadian-responsive, retina-enriched inhibitory G protein), whereas ADAM17 escapes from GNAZ by blue light illuminance. GNAZ knockdown led to ADAM17 hyperactivation, CLDN5 downregulation, and paracellular permeability in vitro, and retinal damage mimicked blue light exposure in vivo. These data demonstrate that blue light exposure might impair the iBRB by accelerating CLDN5 degradation through the disturbance of the GNAZ-ADAM17 axis.
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Affiliation(s)
- Yen-Ju Chan
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan
- School of Pharmacy, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan
| | - George Hsiao
- Department of Pharmacology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
- TMU Neuroscience Research Center, Taipei Medical University, Taipei, Taiwan
| | - Wang-Nok Wan
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan
| | - Tsung-Min Yang
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan
- School of Pharmacy, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan
| | - Chi-Hao Tsai
- Department of Ophthalmology, School of Medicine, The University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Jaw-Jou Kang
- Institute of Food Safety and Health Risk Assessment, School of Pharmaceutical Sciences, National Yang Ming Chiao Tung University, Taipei, 112, Taiwan
| | - Yu-Cheng Lee
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Te-Chao Fang
- TMU Research Center of Urology and Kidney, Taipei Medical University, Taipei, Taiwan
- Division of Nephrology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Division of Nephrology, Department of Internal Medicine, Taipei Medical University Hospital, Taipei Medical University, Taipei, Taiwan
| | - Yu-Wen Cheng
- School of Pharmacy, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan.
- TMU Neuroscience Research Center, Taipei Medical University, Taipei, Taiwan.
| | - Ching-Hao Li
- Department of Physiology, School of Medicine, College of Medicine, Taipei Medical University, 250 Wuxing Street, Taipei, 110, Taiwan.
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.
- TMU Neuroscience Research Center, Taipei Medical University, Taipei, Taiwan.
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13
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Hashimoto Y, Greene C, Munnich A, Campbell M. The CLDN5 gene at the blood-brain barrier in health and disease. Fluids Barriers CNS 2023; 20:22. [PMID: 36978081 PMCID: PMC10044825 DOI: 10.1186/s12987-023-00424-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Accepted: 03/14/2023] [Indexed: 03/30/2023] Open
Abstract
The CLDN5 gene encodes claudin-5 (CLDN-5) that is expressed in endothelial cells and forms tight junctions which limit the passive diffusions of ions and solutes. The blood-brain barrier (BBB), composed of brain microvascular endothelial cells and associated pericytes and end-feet of astrocytes, is a physical and biological barrier to maintain the brain microenvironment. The expression of CLDN-5 is tightly regulated in the BBB by other junctional proteins in endothelial cells and by supports from pericytes and astrocytes. The most recent literature clearly shows a compromised BBB with a decline in CLDN-5 expression increasing the risks of developing neuropsychiatric disorders, epilepsy, brain calcification and dementia. The purpose of this review is to summarize the known diseases associated with CLDN-5 expression and function. In the first part of this review, we highlight the recent understanding of how other junctional proteins as well as pericytes and astrocytes maintain CLDN-5 expression in brain endothelial cells. We detail some drugs that can enhance these supports and are being developed or currently in use to treat diseases associated with CLDN-5 decline. We then summarise mutagenesis-based studies which have facilitated a better understanding of the physiological role of the CLDN-5 protein at the BBB and have demonstrated the functional consequences of a recently identified pathogenic CLDN-5 missense mutation from patients with alternating hemiplegia of childhood. This mutation is the first gain-of-function mutation identified in the CLDN gene family with all others representing loss-of-function mutations resulting in mis-localization of CLDN protein and/or attenuated barrier function. Finally, we summarize recent reports about the dosage-dependent effect of CLDN-5 expression on the development of neurological diseases in mice and discuss what cellular supports for CLDN-5 regulation are compromised in the BBB in human diseases.
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Affiliation(s)
- Yosuke Hashimoto
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin, D02 VF25, Ireland.
| | - Chris Greene
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin, D02 VF25, Ireland
| | - Arnold Munnich
- Institut Imagine, INSERM UMR1163, Université Paris Cité, Paris, F-75015, France
- Departments of Pediatric Neurology and Medical Genetics, Hospital Necker Enfants Malades, Université Paris Cité, Paris, F-75015, France
| | - Matthew Campbell
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin, D02 VF25, Ireland.
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14
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Eum SY, Schurhoff N, Teglas T, Wolff G, Toborek M. Circadian disruption alters gut barrier integrity via a ß-catenin-MMP-related pathway. Mol Cell Biochem 2023; 478:581-595. [PMID: 35976519 PMCID: PMC9938043 DOI: 10.1007/s11010-022-04536-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 08/04/2022] [Indexed: 10/15/2022]
Abstract
We evaluated the mechanistic link between circadian rhythms and gut barrier permeability. Mice were subjected to either constant 24-h light (LL) or 12-h light/dark cycles (LD). Mice housed in LL experienced a significant increase in gut barrier permeability that was associated with dysregulated ß-catenin expression and altered expression of tight junction (TJ) proteins. Silencing of ß-catenin resulted in disruption of barrier function in SW480 cells, with ß-catenin appearing to be an upstream regulator of the core circadian components, such as Bmal1, Clock, and Per1/2. In addition, ß-catenin silencing downregulated ZO-1 and occludin TJ proteins with only limited or no changes at their mRNA levels, suggesting post transcriptional regulation. Indeed, silencing of ß-catenin significantly upregulated expression of matrix metallopeptidase (MMP)-2 and MMP-9, and blocking MMP-2/9 activity attenuated epithelial disruption induced by ß-catenin silencing. These results indicate the regulatory role of circadian disruption on gut barrier integrity and the associations between TJ proteins and circadian rhythms, while demonstrating the regulatory role of ß-catenin in this process.
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Affiliation(s)
- Sung Yong Eum
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33155, USA
| | - Nicolette Schurhoff
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33155, USA
| | - Timea Teglas
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33155, USA
| | - Gretchen Wolff
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33155, USA
- Institute for Diabetes and Cancer (IDC), Helmholtz Diabetes Center, Helmholtz Centre Munich, Neuherberg, Germany
- Joint Heidelberg-IDC Translational Diabetes Program, Inner Medicine 1, Heidelberg University Hospital, Heidelberg, Germany
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33155, USA.
- Institute of Physiotherapy and Health Sciences, The Jerzy Kukuczka Academy of Physical Education, 40-065, Katowice, Poland.
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Suite 528, 1011 NW 15th Street, Miami, FL, 33136, USA.
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15
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O'Leary F, Campbell M. The blood-retina barrier in health and disease. FEBS J 2023; 290:878-891. [PMID: 34923749 DOI: 10.1111/febs.16330] [Citation(s) in RCA: 63] [Impact Index Per Article: 63.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/05/2021] [Accepted: 12/17/2021] [Indexed: 12/20/2022]
Abstract
The blood-retina barrier (BRB) is the term used to define the properties of the retinal capillaries and the retinal pigment epithelium (RPE), which separate the systemic circulation from the retina. More specifically, the inner blood-retina barrier (iBRB) is used to describe the properties of the endothelial cells that line the microvasculature of the inner retina, while the outer blood-retina barrier (oBRB) refers to the properties of the RPE cells that separate the fenestrated choriocapillaris from the retina. The BRB is not a fixed structure; rather, it is dynamic, with its components making unique contributions to its function and structural integrity, and therefore the retina. For example, while tight junction (TJ) proteins between retinal endothelial cells are the key molecular structures in the maintenance of the iBRB, other cell types surrounding endothelial cells are also important. In fact, this overall structure is termed the neurovascular unit (NVU). The integrity of the BRB is crucial in the maintenance of a 'dry', tightly regulated retinal microenvironment through the regulation of transcellular and paracellular transport. Specifically, breakdown of TJs can result in oedema formation, a hallmark feature of many retinal diseases. Here, we will describe the oBRB briefly, with a more in-depth focus on the structure and function of the iBRB in health and diseased states. Finally, the contribution of the BRB to the pathophysiology of age-related macular degeneration (AMD), diabetic retinopathy (DR) and other rarer retinal diseases will be discussed.
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Affiliation(s)
- Fionn O'Leary
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
| | - Matthew Campbell
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin 2, Ireland
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16
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Schurhoff N, Toborek M. Circadian rhythms in the blood-brain barrier: impact on neurological disorders and stress responses. Mol Brain 2023; 16:5. [PMID: 36635730 PMCID: PMC9835375 DOI: 10.1186/s13041-023-00997-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 01/03/2023] [Indexed: 01/14/2023] Open
Abstract
Circadian disruption has become more prevalent in society due to the increase in shift work, sleep disruption, blue light exposure, and travel via different time zones. The circadian rhythm is a timed transcription-translation feedback loop with positive regulators, BMAL1 and CLOCK, that interact with negative regulators, CRY and PER, to regulate both the central and peripheral clocks. This review highlights the functions of the circadian rhythm, specifically in the blood-brain barrier (BBB), during both healthy and pathological states. The BBB is a highly selective dynamic interface composed of CNS endothelial cells, astrocytes, pericytes, neurons, and microglia that form the neurovascular unit (NVU). Circadian rhythms modulate BBB integrity through regulating oscillations of tight junction proteins, assisting in functions of the NVU, and modulating transporter functions. Circadian disruptions within the BBB have been observed in stress responses and several neurological disorders, including brain metastasis, epilepsy, Alzheimer's disease, and Parkinson's disease. Further understanding of these interactions may facilitate the development of improved treatment options and preventative measures.
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Affiliation(s)
- Nicolette Schurhoff
- grid.26790.3a0000 0004 1936 8606Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Suite 528, 1011 NW 15th Street, Miami, FL 33155 USA
| | - Michal Toborek
- grid.26790.3a0000 0004 1936 8606Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Suite 528, 1011 NW 15th Street, Miami, FL 33155 USA ,grid.445174.7Institute of Physiotherapy and Health Sciences, The Jerzy Kukuczka Academy of Physical Education, 40-065 Katowice, Poland
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17
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Xu H, Chen M. Immune response in retinal degenerative diseases - Time to rethink? Prog Neurobiol 2022; 219:102350. [PMID: 36075351 DOI: 10.1016/j.pneurobio.2022.102350] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 08/24/2022] [Accepted: 09/02/2022] [Indexed: 11/30/2022]
Abstract
Retinal degeneration comprises a group of diseases whereby either the retinal neurons or the neurovascular unit degenerates leading to the loss of visual function. Although the initial cause varies in different conditions, inflammation is known to play an important role in disease pathogenesis. Recent advances in molecular and cell biology and systems biology have yielded unexpected findings, including the heterogeneity of immune cells in the degenerative retina, bidirectional neuron-microglia cross talk, and links to the gut microbiome. Here we discuss the immune response in retinal degenerative conditions, taking into account both regional (retinal) and systemic factors. We propose to classify retinal degeneration into dry and wet forms based on whether the blood-retinal barrier (BRB) is breached and fluid is accumulated in retinal parenchyma. The dry form has a relatively intact BRB and is characterised by progressive retinal thinning. Immune response to degenerative insults is dominated by the retinal defence system, which remains to be regulated by neurons. In contrast, the wet form has retinal oedema due to BRB damaged. Inflammation is executed by infiltrating immune cells as well as the retinal defence system. The gut microbiome will have easy access to the retina in wet retinal degeneration and may affect significantly retinal immune response.
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Affiliation(s)
- Heping Xu
- Aier Institute of Optometry and Vision Science, Changsha 410000, China; The Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Sciences, Queen's University Belfast, BT9 7BL, UK.
| | - Mei Chen
- The Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry & Biomedical Sciences, Queen's University Belfast, BT9 7BL, UK.
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18
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Obert E, Grek C, Ghatnekar G, Rohrer B. Evaluation of a connexin-based peptide for the treatment of age-related macular degeneration. Heliyon 2022; 8:e11359. [PMID: 36387470 PMCID: PMC9660603 DOI: 10.1016/j.heliyon.2022.e11359] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 09/30/2022] [Accepted: 10/25/2022] [Indexed: 11/11/2022] Open
Abstract
A critical target in age-related macular degeneration (AMD) is the retinal pigment epithelium (RPE), which forms the outer blood-retina barrier (BRB). RPE-barrier dysfunction might result from the disruption of intercellular tight junctions (TJs). A Connexin43 (Cx43)-based peptide, aCT1, has been shown to prevent VEGF-induced loss of transepithelial resistance, choroidal neovascularization (CNV) and RPE-cell damage via the stabilization of TJs. Here, we probe the relative efficacies of aCT1 alone, anti-VEGF alone, and aCT1 with anti-VEGF in treating AMD pathologies. aCT1 monotherapy administered as topical eye drops with and without a VEGF blocking antibody administered systemically was tested in a mouse model of laser-induced CNV. The CNV mouse is the standard neovascular AMD model, reproducing hallmarks of its pathology. CNV lesion size and fluid accumulation were assessed using optical coherence tomography. During the angiogenesis phase of CNV lesion development, single applications of anti-VEGF or aCT1 reduced lesion and fluid dome size equally. The combinatorial aCT1/anti-VEGF strategy demonstrated lack of additive effects in this model. These data suggest that TJ stabilization by aCT1 is effective in ameliorating RPE dysfunction in a model of AMD-like angiogenesis, and that this strategy is as effective as the current clinical standard of care, anti-VEGF therapy. Critically, aCT1 holds potential as a new neovascular AMD treatment that can be administered using eye drops, which is preferable to the intravitreal injections required for standard anti-VEGF therapy.
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19
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Fan R, Peng X, Xie L, Dong K, Ma D, Xu W, Shi X, Zhang S, Chen J, Yu X, Yang Y. Importance of Bmal1 in Alzheimer's disease and associated aging-related diseases: Mechanisms and interventions. Aging Cell 2022; 21:e13704. [PMID: 36056774 PMCID: PMC9577946 DOI: 10.1111/acel.13704] [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: 02/22/2022] [Revised: 06/16/2022] [Accepted: 08/11/2022] [Indexed: 01/25/2023] Open
Abstract
With the aging world population, the prevalence of aging-related disorders is on the rise. Diseases such as Alzheimer's, type 2 diabetes mellitus (T2DM), Parkinson's, atherosclerosis, hypertension, and osteoarthritis are age-related, and most of these diseases are comorbidities or risk factors for AD; however, our understandings of molecular events that regulate the occurrence of these diseases are still not fully understood. Brain and muscle Arnt-like protein-1 (Bmal1) is an irreplaceable clock gene that governs multiple important physiological processes. Continuous research of Bmal1 in AD and associated aging-related diseases is ongoing, and this review picks relevant studies on a detailed account of its role and mechanisms in these diseases. Oxidative stress and inflammation turned out to be common mechanisms by which Bmal1 deficiency promotes AD and associated aging-related diseases, and other Bmal1-dependent mechanisms remain to be identified. Promising therapeutic strategies involved in the regulation of Bmal1 are provided, including melatonin, natural compounds, metformin, d-Ser2-oxyntomodulin, and other interventions, such as exercise, time-restricted feeding, and adiponectin. The establishment of the signaling pathway network for Bmal1 in aging-related diseases will lead to advances in the comprehension of the molecular and cellular mechanisms, shedding light on novel treatments for aging-related diseases and promoting aging-associated brain health.
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Affiliation(s)
- Rongping Fan
- Department of Endocrinology, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina,Branch of National Clinical Research Center for Metabolic DiseasesWuhanChina
| | - Xuemin Peng
- Department of Endocrinology, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina,Branch of National Clinical Research Center for Metabolic DiseasesWuhanChina
| | - Lei Xie
- Department of Endocrinology, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina,Branch of National Clinical Research Center for Metabolic DiseasesWuhanChina
| | - Kun Dong
- Department of Endocrinology, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina,Branch of National Clinical Research Center for Metabolic DiseasesWuhanChina
| | - Delin Ma
- Department of Endocrinology, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina,Branch of National Clinical Research Center for Metabolic DiseasesWuhanChina
| | - Weijie Xu
- Department of Endocrinology, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina,Branch of National Clinical Research Center for Metabolic DiseasesWuhanChina
| | - Xiaoli Shi
- Department of Endocrinology, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina,Branch of National Clinical Research Center for Metabolic DiseasesWuhanChina
| | - Shujun Zhang
- Department of Endocrinology, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina,Branch of National Clinical Research Center for Metabolic DiseasesWuhanChina
| | - Juan Chen
- Department of Neurosurgery, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina
| | - Xuefeng Yu
- Department of Endocrinology, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina,Branch of National Clinical Research Center for Metabolic DiseasesWuhanChina
| | - Yan Yang
- Department of Endocrinology, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanChina,Branch of National Clinical Research Center for Metabolic DiseasesWuhanChina
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20
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Corey TM, Woodley VV, O'Connor M, Connolly E, Doyle S, Shrader S, Phipps C, Isaac K, Lawrence M. Evaluation of the Dose-Dependent Inflammatory Response and No-Observable Adverse Effect Level of Intravitreal Endotoxin in the African Green Monkey. Transl Vis Sci Technol 2022; 11:17. [PMID: 35980670 PMCID: PMC9404367 DOI: 10.1167/tvst.11.8.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate the inflammatory effects and no-observed adverse effect level (NOAEL) of intravitreal endotoxin in an African green monkey model of uveitis. Methods Fifteen green monkeys were administered intravitreal endotoxin ranging from 0.005 to 0.08 endotoxin unit (EU)/eye. Inflammation was evaluated by slit-lamp biomicroscopy, indirect fundoscopy, tonometry, color fundus photography, ocular coherence tomography, laser flare photometry, and histopathology, with analysis of cytokine levels in aqueous and vitreous humor. The inter-rater reliability of a refined nonhuman primate ophthalmic scoring system was evaluated. Results A dose-dependent inflammatory response was observed beginning at 0.02 EU/eye; no inflammatory response exceeding the vehicle was observed at 0.005 EU/eye. Retinal pathology was minimal, and posterior visualization degraded with increasing inflammation. Inflammation was observed by histopathology at 0.04 EU/eye. Inter-rater reliability of the scoring system was high, with 99.2% of individual scores differing by 1 scale unit or less and 87.2% of summary scores differing by 2 scale units or less. Conclusions The NOAEL for intravitreal endotoxin in the green monkey is 0.005 EU/eye, with inflammation increasing with increasing dose beginning at 0.02 EU/eye. This updated nonhuman primate ophthalmic scoring system allows for high inter-rater reliability for the quantification of mild to severe inflammation in the green monkey eye. Translational Relevance Validation of the ophthalmic inflammation scoring system enables application of the green monkey as a valuable translational model. Candidate therapeutics should be confirmed to have endotoxin levels below this threshold before safety testing in this species to enable interpretation of inflammation and minimize impact on animal welfare.
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Affiliation(s)
| | | | | | - Emma Connolly
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.,Department of Clinical Medicine, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Sarah Doyle
- Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.,Department of Clinical Medicine, School of Medicine, Trinity College Dublin, Dublin, Ireland
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21
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Godbole NM, Chowdhury AA, Chataut N, Awasthi S. Tight Junctions, the Epithelial Barrier, and Toll-like Receptor-4 During Lung Injury. Inflammation 2022; 45:2142-2162. [PMID: 35779195 DOI: 10.1007/s10753-022-01708-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 05/31/2022] [Accepted: 06/13/2022] [Indexed: 11/25/2022]
Abstract
Lung epithelium is constantly exposed to the environment and is critically important for the orchestration of initial responses to infectious organisms, toxins, and allergic stimuli, and maintenance of normal gaseous exchange and pulmonary function. The integrity of lung epithelium, fluid balance, and transport of molecules is dictated by the tight junctions (TJs). The TJs are formed between adjacent cells. We have focused on the topic of the TJ structure and function in lung epithelial cells. This review includes a summary of the last twenty years of literature reports published on the disrupted TJs and epithelial barrier in various lung conditions and expression and regulation of specific TJ proteins against pathogenic stimuli. We discuss the molecular signaling and crosstalk among signaling pathways that control the TJ structure and function. The Toll-like receptor-4 (TLR4) recognizes the pathogen- and damage-associated molecular patterns released during lung injury and inflammation and coordinates cellular responses. The molecular aspects of TLR4 signaling in the context of TJs or the epithelial barrier are not fully known. We describe the current knowledge and possible networking of the TLR4-signaling with cellular and molecular mechanisms of TJs, lung epithelial barrier function, and resistance to treatment strategies.
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Affiliation(s)
- Nachiket M Godbole
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, 1110 N. Stonewall Avenue, Oklahoma City, OK, 73117, USA
| | - Asif Alam Chowdhury
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, 1110 N. Stonewall Avenue, Oklahoma City, OK, 73117, USA
| | - Neha Chataut
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, 1110 N. Stonewall Avenue, Oklahoma City, OK, 73117, USA
| | - Shanjana Awasthi
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Oklahoma Health Sciences Center, 1110 N. Stonewall Avenue, Oklahoma City, OK, 73117, USA.
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22
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Ben-Zvi A, Liebner S. Developmental regulation of barrier- and non-barrier blood vessels in the CNS. J Intern Med 2022; 292:31-46. [PMID: 33665890 DOI: 10.1111/joim.13263] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 02/01/2021] [Indexed: 12/22/2022]
Abstract
The blood-brain barrier (BBB) is essential for creating and maintaining tissue homeostasis in the central nervous system (CNS), which is key for proper neuronal function. In most vertebrates, the BBB is localized to microvascular endothelial cells that acquire barrier properties during angiogenesis of the neuroectoderm. Complex and continuous tight junctions, and the lack of fenestrae combined with low pinocytotic activity render the BBB endothelium a tight barrier for water-soluble molecules that may only enter the CNS via specific transporters. The differentiation of these unique endothelial properties during embryonic development is initiated by endothelial-specific flavours of the Wnt/β-catenin pathway in a precise spatiotemporal manner. In this review, we summarize the currently known cellular (neural precursor and endothelial cells) and molecular (VEGF and Wnt/β-catenin) mechanisms mediating brain angiogenesis and barrier formation. Moreover, we introduce more recently discovered crosstalk with cellular and acellular elements within the developing CNS such as the extracellular matrix. We discuss recent insights into the downstream molecular mechanisms of Wnt/β-catenin in particular, the recently identified target genes like Foxf2, Foxl2, Foxq1, Lef1, Ppard, Zfp551, Zic3, Sox17, Apcdd1 and Fgfbp1 that are involved in refining and maintaining barrier characteristics in the mature BBB endothelium. Additionally, we elute to recent insight into barrier heterogeneity and differential endothelial barrier properties within the CNS, focussing on the circumventricular organs as well as on the neurogenic niches in the subventricular zone and the hippocampus. Finally, open questions and future BBB research directions are highlighted in the context of taking benefit from understanding BBB development for strategies to modulate BBB function under pathological conditions.
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Affiliation(s)
- A Ben-Zvi
- From the, The Department of Developmental Biology and Cancer Research, Institute for Medical Research IMRIC, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - S Liebner
- Institute of Neurology (Edinger Institute), University Hospital, Goethe University Frankfurt, Frankfurt am Main, Germany.,Excellence Cluster Cardio-Pulmonary Systems (ECCPS), Partner Site Frankfurt, Frankfurt am Main, Germany.,German Center for Cardiovascular Research (DZHK), Partner Site Rhine-Main, Frankfurt am Main, Germany
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Ribas-Latre A, Eckel-Mahan K. Nutrients and the Circadian Clock: A Partnership Controlling Adipose Tissue Function and Health. Nutrients 2022; 14:2084. [PMID: 35631227 PMCID: PMC9147080 DOI: 10.3390/nu14102084] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 04/13/2022] [Accepted: 05/09/2022] [Indexed: 01/14/2023] Open
Abstract
White adipose tissue (WAT) is a metabolic organ with flexibility to retract and expand based on energy storage and utilization needs, processes that are driven via the coordination of different cells within adipose tissue. WAT is comprised of mature adipocytes (MA) and cells of the stromal vascular cell fraction (SVF), which include adipose progenitor cells (APCs), adipose endothelial cells (AEC) and infiltrating immune cells. APCs have the ability to proliferate and undergo adipogenesis to form MA, the main constituents of WAT being predominantly composed of white, triglyceride-storing adipocytes with unilocular lipid droplets. While adiposity and adipose tissue health are controlled by diet and aging, the endogenous circadian (24-h) biological clock of the body is highly active in adipose tissue, from adipocyte progenitor cells to mature adipocytes, and may play a unique role in adipose tissue health and function. To some extent, 24-h rhythms in adipose tissue rely on rhythmic energy intake, but individual circadian clock proteins are also thought to be important for healthy fat. Here we discuss how and why the clock might be so important in this metabolic depot, and how temporal and qualitative aspects of energy intake play important roles in maintaining healthy fat throughout aging.
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Affiliation(s)
- Aleix Ribas-Latre
- Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA;
- Helmholtz Institute for Metabolic, Obesity and Vascular Research (HI-MAG) of the Helmholtz Zentrum München at the University of Leipzig, University Hospital Leipzig, D-04103 Leipzig, Germany
| | - Kristin Eckel-Mahan
- Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA;
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA
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24
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Abstract
The accumulation of neurotoxic amyloid-beta (Aβ) in the brain is one of the characteristic hallmarks of Alzheimer's disease (AD). Aβ-peptide brain homeostasis is governed by its production and various clearance mechanisms. The blood-brain barrier provides a large surface area for influx and efflux mechanisms into and out of the brain. Different transporters and receptors have been implicated to play crucial roles in Aβ clearance from brain. Besides Aβ transport, the blood-brain barrier tightly regulates the brain's microenvironment; however, vascular alterations have been shown in patients with AD. Here, we summarize how the blood-brain barrier changes during aging and in disease and focus on recent findings of how the ABC transporter P-glycoprotein (ABCB1/P-gp) and the receptor low-density lipoprotein receptor-related protein 1 (LRP1) play a role in Aβ clearance from brain.
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25
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Harford DA, Delaney C, O'Callaghan J, Hudson N, Connolly R, Doyle S, Farrell M, Doherty CP, Cahill M, Campbell M. Decreased CSF1R Signaling and the Accumulation of Reticular Pseudo-Drusen? Ophthalmic Surg Lasers Imaging Retina 2021; 52:666-671. [PMID: 34908483 DOI: 10.3928/23258160-20211101-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) is caused by dominant-acting mutations in the gene colony-stimulating factor 1 receptor (CSF1R). It is an ultra-rare leukoencephalopathy that involves demyelination of white matter and early-onset dementia. It has been well validated that mutations in the kinase region of the gene cause decreased signaling of the receptor via its two cognate ligands interleukin-34 (IL-34) and colony-stimulating factor-1 (CSF-1). In this article, we report a thorough analysis of retinal integrity in a 48-year-old genetically diagnosed ALSP patient. We show that although the optic nerve, optic chiasm, and optic tracts are relatively preserved, the patient has visual field deficits likely due to optic radiation and/or cortical atrophy. Intriguingly, we report the appearance of inner retinal vascular leakage and the appearance of reticular pseudo-drusen (RPD)-like deposits. We propose that the early stages of RPD accumulation may be associated with an attenuated CSF-1 receptor signaling axis. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:666-671.].
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26
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Hudson N, Campbell M. Tight Junctions of the Neurovascular Unit. Front Mol Neurosci 2021; 14:752781. [PMID: 34867185 PMCID: PMC8640090 DOI: 10.3389/fnmol.2021.752781] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 10/07/2021] [Indexed: 11/13/2022] Open
Abstract
The homeostatic balance of the brain and retina is maintained by the presence of the blood-brain and inner blood-retinal barrier (BBB/iBRB, respectively) which are highly specialized barriers. Endothelial cells forming the lining of these blood vessels are interconnected by the presence of tight junctions which form the BBB and iBRB. These tight junctions, formed of numerous interacting proteins, enable the entry of molecules into neural tissues while restricting the entry of harmful material such as anaphylatoxins, bacteria and viruses. If the tight junction complex becomes dysregulated due to changes in expression levels of one or more of the components, this can have detrimental effects leading to brain and retinal pathology.
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Affiliation(s)
- Natalie Hudson
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin, Ireland
| | - Matthew Campbell
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin, Ireland
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27
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Goncalves A, Dreffs A, Lin CM, Sheskey S, Hudson N, Keil J, Campbell M, Antonetti DA. Vascular Expression of Permeability-Resistant Occludin Mutant Preserves Visual Function in Diabetes. Diabetes 2021; 70:1549-1560. [PMID: 33883214 PMCID: PMC8336002 DOI: 10.2337/db20-1220] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 04/01/2021] [Indexed: 12/20/2022]
Abstract
Diabetic retinopathy is one of the leading causes of vision loss and blindness. Extensive preclinical and clinical evidence exists for both vascular and neuronal pathology. However, the relationship of these changes in the neurovascular unit and impact on vision remains to be determined. Here, we investigate the role of tight junction protein occludin phosphorylation at S490 in modulating barrier properties and its impact on visual function. Conditional vascular expression of the phosphorylation-resistant Ser490 to Ala (S490A) form of occludin preserved tight junction organization and reduced vascular endothelial growth factor (VEGF)-induced permeability and edema formation after intraocular injection. In the retinas of streptozotocin-induced diabetic mice, endothelial-specific expression of the S490A form of occludin completely prevented diabetes-induced permeability to labeled dextran and inhibited leukostasis. Importantly, vascular-specific expression of the occludin mutant completely blocked the diabetes-induced decrease in visual acuity and contrast sensitivity. Together, these results reveal that occludin acts to regulate barrier properties downstream of VEGF in a phosphorylation-dependent manner and that loss of inner blood-retinal barrier integrity induced by diabetes contributes to vision loss.
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Affiliation(s)
- Andreia Goncalves
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI
| | - Alyssa Dreffs
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI
| | - Cheng-Mao Lin
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI
| | - Sarah Sheskey
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI
| | - Natalie Hudson
- Neurovascular Genetics Unit, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Jason Keil
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI
| | - Matthew Campbell
- Neurovascular Genetics Unit, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - David A Antonetti
- Department of Ophthalmology and Visual Sciences, University of Michigan Kellogg Eye Center, Ann Arbor, MI
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28
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Li F, Egea PF, Vecchio AJ, Asial I, Gupta M, Paulino J, Bajaj R, Dickinson MS, Ferguson-Miller S, Monk BC, Stroud RM. Highlighting membrane protein structure and function: A celebration of the Protein Data Bank. J Biol Chem 2021; 296:100557. [PMID: 33744283 PMCID: PMC8102919 DOI: 10.1016/j.jbc.2021.100557] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 02/10/2021] [Accepted: 03/16/2021] [Indexed: 12/13/2022] Open
Abstract
Biological membranes define the boundaries of cells and compartmentalize the chemical and physical processes required for life. Many biological processes are carried out by proteins embedded in or associated with such membranes. Determination of membrane protein (MP) structures at atomic or near-atomic resolution plays a vital role in elucidating their structural and functional impact in biology. This endeavor has determined 1198 unique MP structures as of early 2021. The value of these structures is expanded greatly by deposition of their three-dimensional (3D) coordinates into the Protein Data Bank (PDB) after the first atomic MP structure was elucidated in 1985. Since then, free access to MP structures facilitates broader and deeper understanding of MPs, which provides crucial new insights into their biological functions. Here we highlight the structural and functional biology of representative MPs and landmarks in the evolution of new technologies, with insights into key developments influenced by the PDB in magnifying their impact.
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Affiliation(s)
- Fei Li
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA; Department of Neurology, University of California San Francisco, San Francisco, California, USA
| | - Pascal F Egea
- Department of Biological Chemistry, School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | - Alex J Vecchio
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, USA
| | | | - Meghna Gupta
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA
| | - Joana Paulino
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA
| | - Ruchika Bajaj
- Department of Bioengineering and Therapeutic Sciences, University of California San Francisco, San Francisco, California, USA
| | - Miles Sasha Dickinson
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA
| | - Shelagh Ferguson-Miller
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - Brian C Monk
- Sir John Walsh Research Institute and Department of Oral Sciences, University of Otago, North Dunedin, Dunedin, New Zealand
| | - Robert M Stroud
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, California, USA.
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Self-Assembling Tacrolimus Nanomicelles for Retinal Drug Delivery. Pharmaceutics 2020; 12:pharmaceutics12111072. [PMID: 33182620 PMCID: PMC7698121 DOI: 10.3390/pharmaceutics12111072] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/03/2020] [Accepted: 11/05/2020] [Indexed: 12/16/2022] Open
Abstract
Neovascular age-related macular degeneration (AMD) is characterized by an increase in reactive oxygen species (ROS) and pro-inflammatory cytokines in the retinal pigment epithelium cells. The primary purpose of this study was the development of a clear, tacrolimus nanomicellar formulation (TAC-NMF) for AMD. The optimized formulation had a mean diameter of 15.41 nm, a zeta potential of 0.5 mV, and an entrapment efficiency of 97.13%. In-vitro cytotoxicity studies revealed the dose-dependent cytotoxicity of TAC-NMF on various ocular cell lines, such as human retinal pigment epithelium (D407), monkey retinal choroidal endothelial (RF/6A) cells, and human corneal epithelium (CCL 20.2) cells. Cellular uptake and in-vitro distribution studies using flow cytometry and confocal microscopy, respectively, indicated an elevated uptake of TAC-NMF in a time-dependent manner. Biocompatibility assay using macrophage RAW 264.7 cell line resulted in low production of inflammatory cytokines such as IL-6, IL-1β and TNF-α after treatment with TAC-NMF. There was a decrease in ROS in D407 cells pre-treated with sodium iodate (ROS inducing agent) after treating with TAC-NMF and tacrolimus drug. Similarly, there was a reduction in the pro-inflammatory cytokines and VEGF-A in D407 cells pretreated with sodium iodate. This indicates that TAC-NMF could lower pro-inflammatory cytokines and ROS commonly seen in AMD.
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30
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Neuronal Activity Regulates Blood-Brain Barrier Efflux Transport through Endothelial Circadian Genes. Neuron 2020; 108:937-952.e7. [PMID: 32979312 DOI: 10.1016/j.neuron.2020.09.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 07/22/2020] [Accepted: 08/31/2020] [Indexed: 01/11/2023]
Abstract
The blood vessels in the central nervous system (CNS) have a series of unique properties, termed the blood-brain barrier (BBB), which stringently regulate the entry of molecules into the brain, thus maintaining proper brain homeostasis. We sought to understand whether neuronal activity could regulate BBB properties. Using both chemogenetics and a volitional behavior paradigm, we identified a core set of brain endothelial genes whose expression is regulated by neuronal activity. In particular, neuronal activity regulates BBB efflux transporter expression and function, which is critical for excluding many small lipophilic molecules from the brain parenchyma. Furthermore, we found that neuronal activity regulates the expression of circadian clock genes within brain endothelial cells, which in turn mediate the activity-dependent control of BBB efflux transport. These results have important clinical implications for CNS drug delivery and clearance of CNS waste products, including Aβ, and for understanding how neuronal activity can modulate diurnal processes.
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31
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Shivshankar P, Fekry B, Eckel-Mahan K, Wetsel RA. Circadian Clock and Complement Immune System-Complementary Control of Physiology and Pathology? Front Cell Infect Microbiol 2020; 10:418. [PMID: 32923410 PMCID: PMC7456827 DOI: 10.3389/fcimb.2020.00418] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 07/08/2020] [Indexed: 12/11/2022] Open
Abstract
Mammalian species contain an internal circadian (i.e., 24-h) clock that is synchronized to the day and night cycles. Large epidemiological studies, which are supported by carefully controlled studies in numerous species, support the idea that chronic disruption of our circadian cycles results in a number of health issues, including obesity and diabetes, defective immune response, and cancer. Here we focus specifically on the role of the complement immune system and its relationship to the internal circadian clock system. While still an incompletely understood area, there is evidence that dysregulated proinflammatory cytokines, complement factors, and oxidative stress can be induced by circadian disruption and that these may feed back into the oscillator at the level of circadian gene regulation. Such a feedback cycle may contribute to impaired host immune response against pathogenic insults. The complement immune system including its activated anaphylatoxins, C3a and C5a, not only facilitate innate and adaptive immune response in chemotaxis and phagocytosis, but they can also amplify chronic inflammation in the host organism. Consequent development of autoimmune disorders, and metabolic diseases associated with additional environmental insults that activate complement can in severe cases, lead to accelerated tissue dysfunction, fibrosis, and ultimately organ failure. Because several promising complement-targeted therapeutics to block uncontrolled complement activation and treat autoimmune diseases are in various phases of clinical trials, understanding fully the circadian properties of the complement system, and the reciprocal regulation by these two systems could greatly improve patient treatment in the long term.
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Affiliation(s)
- Pooja Shivshankar
- Research Center for Immunology and Autoimmune Diseases, Brown Foundation Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Baharan Fekry
- Center for Metabolic and Degenerative Diseases, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Kristin Eckel-Mahan
- Center for Metabolic and Degenerative Diseases, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
| | - Rick A Wetsel
- Research Center for Immunology and Autoimmune Diseases, Brown Foundation Institute of Molecular Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX, United States
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32
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Hashimoto Y, Tachibana K, Kondoh M. Tight junction modulators for drug delivery to the central nervous system. Drug Discov Today 2020; 25:1477-1486. [DOI: 10.1016/j.drudis.2020.05.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/30/2020] [Accepted: 05/10/2020] [Indexed: 12/21/2022]
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33
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Hashimoto Y, Campbell M. Tight junction modulation at the blood-brain barrier: Current and future perspectives. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183298. [PMID: 32353377 DOI: 10.1016/j.bbamem.2020.183298] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/09/2020] [Accepted: 03/28/2020] [Indexed: 12/14/2022]
Abstract
The blood-brain barrier (BBB) is the one of the most robust physical barriers in the body, comprised of tight junction (TJ) proteins in brain microvascular endothelial cells. The need for drugs to treat central nervous systems diseases is ever increasing, however the presence of the BBB significantly hampers the uptake of drugs into the brain. To overcome or circumvent the barrier, many kinds of techniques are being developed. Modulating the paracellular route by disruption of the TJ complex has been proposed as a potential drug delivery system to treat brain diseases, however, it has several limitations and is still in a developmental stage. However, recent significant advance in medical equipment /tools such as targeted ultra-sound technologies may resolve these limitations. In this review, we introduce recent advances in site- or molecular size-selective BBB disruption/modulation technologies and we include details on pharmacological inhibitory molecules against intercellular TJ proteins to modulate the BBB.
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Affiliation(s)
- Yosuke Hashimoto
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland.
| | - Matthew Campbell
- Trinity College Dublin, Smurfit Institute of Genetics, Dublin 2, Ireland.
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34
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Keep RF, Jones HC, Drewes LR. This was the year that was: brain barriers and brain fluid research in 2019. Fluids Barriers CNS 2020; 17:20. [PMID: 32138786 PMCID: PMC7059280 DOI: 10.1186/s12987-020-00181-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
This editorial highlights advances in brain barrier and brain fluid research published in 2019, as well as addressing current controversies and pressing needs. Topics include recent advances related to: the cerebral endothelium and the neurovascular unit; the choroid plexus, arachnoid membrane; cerebrospinal fluid and the glymphatic hypothesis; the impact of disease states on brain barriers and brain fluids; drug delivery to the brain; and translation of preclinical data to the clinic. This editorial also mourns the loss of two important figures in the field, Malcolm B. Segal and Edward G. Stopa.
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Affiliation(s)
- Richard F. Keep
- Department of Neurosurgery, University of Michigan, R5018 BSRB, 109 Zina Pitcher Place, Ann Arbor, MI 48109-2200 USA
| | | | - Lester R. Drewes
- Department of Biomedical Sciences, University of Minnesota Medical School Duluth, Duluth, MN 55812 USA
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35
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Hudson N, Cahill M, Campbell M. Inner blood-retina barrier involvement in dry age-related macular degeneration (AMD) pathology. Neural Regen Res 2020; 15:1656-1657. [PMID: 32209767 PMCID: PMC7437601 DOI: 10.4103/1673-5374.276332] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Affiliation(s)
- Natalie Hudson
- Neurovascular Genetics Unit, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Mark Cahill
- Royal Victoria Eye and Ear Hospital, Adelaide Road, Dublin 2, Ireland
| | - Matthew Campbell
- Neurovascular Genetics Unit, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
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36
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Shakhmantsir I, Dooley SJ, Kishore S, Chen D, Pierce E, Bennett J, Sehgal A. RNA Splicing Factor Mutations That Cause Retinitis Pigmentosa Result in Circadian Dysregulation. J Biol Rhythms 2019; 35:72-83. [PMID: 31726916 DOI: 10.1177/0748730419887876] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Circadian clocks regulate multiple physiological processes in the eye, but their requirement for retinal health remains unclear. We previously showed that Drosophila homologs of spliceosome proteins implicated in human retinitis pigmentosa (RP), the most common genetically inherited cause of blindness, have a role in the brain circadian clock. In this study, we report circadian phenotypes in murine models of RP. We found that mice carrying a homozygous H2309P mutation in Pre-mRNA splicing factor 8 (Prpf8) display a lengthened period of the circadian wheel-running activity rhythm. We show also that the daily cycling of circadian gene expression is dampened in the retina of Prpf8-H2309P mice. Surprisingly, molecular rhythms are intact in the eye cup, which includes the retinal pigment epithelium (RPE), even though the RPE is thought to be the primary tissue affected in this form of RP. Downregulation of Prp31, another RNA splicing factor implicated in RP, leads to period lengthening in a human cell culture model. The period of circadian bioluminescence in primary fibroblasts of human RP patients is not significantly altered. Together, these studies link a prominent retinal disorder to circadian deficits, which could contribute to disease pathology.
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Affiliation(s)
- Iryna Shakhmantsir
- Chronobiology and Sleep institute (CSI) and Howard Hughes Medical Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Graduate Program in Cell and Molecular Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Scott J Dooley
- Graduate Program in Cell and Molecular Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.,Center for Advanced Retinal and Ocular Therapeutics, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Siddharth Kishore
- Graduate Program in Cell and Molecular Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Dechun Chen
- Chronobiology and Sleep institute (CSI) and Howard Hughes Medical Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Eric Pierce
- Ocular Genomics Institute, Mass Eye and Ear, Harvard Medical School, Boston, Massachusetts
| | - Jean Bennett
- Center for Advanced Retinal and Ocular Therapeutics, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Amita Sehgal
- Chronobiology and Sleep institute (CSI) and Howard Hughes Medical Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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