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Sharif NA. Degeneration of retina-brain components and connections in glaucoma: Disease causation and treatment options for eyesight preservation. CURRENT RESEARCH IN NEUROBIOLOGY 2022; 3:100037. [PMID: 36685768 PMCID: PMC9846481 DOI: 10.1016/j.crneur.2022.100037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 03/30/2022] [Accepted: 04/01/2022] [Indexed: 01/25/2023] Open
Abstract
Eyesight is the most important of our sensory systems for optimal daily activities and overall survival. Patients who experience visual impairment due to elevated intraocular pressure (IOP) are often those afflicted with primary open-angle glaucoma (POAG) which slowly robs them of their vision unless treatment is administered soon after diagnosis. The hallmark features of POAG and other forms of glaucoma are damaged optic nerve, retinal ganglion cell (RGC) loss and atrophied RGC axons connecting to various brain regions associated with receipt of visual input from the eyes and eventual decoding and perception of images in the visual cortex. Even though increased IOP is the major risk factor for POAG, the disease is caused by many injurious chemicals and events that progress slowly within all components of the eye-brain visual axis. Lowering of IOP mitigates the damage to some extent with existing drugs, surgical and device implantation therapeutic interventions. However, since multifactorial degenerative processes occur during aging and with glaucomatous optic neuropathy, different forms of neuroprotective, nutraceutical and electroceutical regenerative and revitalizing agents and processes are being considered to combat these eye-brain disorders. These aspects form the basis of this short review article.
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Affiliation(s)
- Najam A. Sharif
- Duke-National University of Singapore Medical School, Singapore,Singapore Eye Research Institute (SERI), Singapore,Department of Pharmacology and Neuroscience, University of North Texas Health Sciences Center, Fort Worth, Texas, USA,Department of Pharmaceutical Sciences, Texas Southern University, Houston, TX, USA,Department of Surgery & Cancer, Imperial College of Science and Technology, St. Mary's Campus, London, UK,Department of Pharmacy Sciences, School of School of Pharmacy and Health Professions, Creighton University, Omaha, NE, USA,Ophthalmology Innovation Center, Santen Incorporated, 6401 Hollis Street (Suite #125), Emeryville, CA, 94608, USA,Ophthalmology Innovation Center, Santen Incorporated, 6401 Hollis Street (Suite #125), Emeryville, CA, 94608, USA.
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Vernazza S, Oddone F, Tirendi S, Bassi AM. Risk Factors for Retinal Ganglion Cell Distress in Glaucoma and Neuroprotective Potential Intervention. Int J Mol Sci 2021; 22:7994. [PMID: 34360760 PMCID: PMC8346985 DOI: 10.3390/ijms22157994] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/21/2021] [Accepted: 07/23/2021] [Indexed: 12/14/2022] Open
Abstract
Retinal ganglion cells (RGCs) are a population of neurons of the central nervous system (CNS) extending with their soma to the inner retina and with their axons to the optic nerve. Glaucoma represents a group of neurodegenerative diseases where the slow progressive death of RGCs results in a permanent loss of vision. To date, although Intra Ocular Pressure (IOP) is considered the main therapeutic target, the precise mechanisms by which RGCs die in glaucoma have not yet been clarified. In fact, Primary Open Angle Glaucoma (POAG), which is the most common glaucoma form, also occurs without elevated IOP. This present review provides a summary of some pathological conditions, i.e., axonal transport blockade, glutamate excitotoxicity and changes in pro-inflammatory cytokines along the RGC projection, all involved in the glaucoma cascade. Moreover, neuro-protective therapeutic approaches, which aim to improve RGC degeneration, have also been taken into consideration.
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Affiliation(s)
- Stefania Vernazza
- Department of Experimental Medicine (DIMES), University of Genoa, 16126 Genoa, Italy; (S.T.); (A.M.B.)
| | | | - Sara Tirendi
- Department of Experimental Medicine (DIMES), University of Genoa, 16126 Genoa, Italy; (S.T.); (A.M.B.)
- Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), 56122 Pisa, Italy
| | - Anna Maria Bassi
- Department of Experimental Medicine (DIMES), University of Genoa, 16126 Genoa, Italy; (S.T.); (A.M.B.)
- Inter-University Center for the Promotion of the 3Rs Principles in Teaching & Research (Centro 3R), 56122 Pisa, Italy
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3
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Micera A, Balzamino BO, Di Zazzo A, Dinice L, Bonini S, Coassin M. Biomarkers of Neurodegeneration and Precision Therapy in Retinal Disease. Front Pharmacol 2021; 11:601647. [PMID: 33584278 PMCID: PMC7873955 DOI: 10.3389/fphar.2020.601647] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/09/2020] [Indexed: 12/11/2022] Open
Abstract
Vision-threatening retinal diseases affect millions of people worldwide, representing an important public health issue (high social cost) for both technologically advanced and new-industrialized countries. Overall RD group comprises the retinitis pigmentosa, the age-related macular degeneration (AMD), the diabetic retinopathy (DR), and idiopathic epiretinal membrane formation. Endocrine, metabolic, and even lifestyles risk factors have been reported for these age-linked conditions that represent a "public priority" also in this COVID-19 emergency. Chronic inflammation and neurodegeneration characterize the disease evolution, with a consistent vitreoretinal interface impairment. As the vitreous chamber is significantly involved, the latest diagnostic technologies of imaging (retina) and biomarker detection (vitreous) have provided a huge input at both medical and surgical levels. Complement activation and immune cell recruitment/infiltration as well as detrimental intra/extracellular deposits occur in association with a reactive gliosis. The cell/tissue aging route shows a specific signal path and biomolecular profile characterized by the increased expression of several glial-derived mediators, including angiogenic/angiostatic, neurogenic, and stress-related factors (oxidative stress metabolites, inflammation, and even amyloid formation). The possibility to access vitreous chamber by collecting vitreous reflux during intravitreal injection or obtaining vitreous biopsy during a vitrectomy represents a step forward for an individualized therapy. As drug response and protein signature appear unique in each single patient, therapies should be individualized. This review addresses the current knowledge about biomarkers and pharmacological targets in these vitreoretinal diseases. As vitreous fluids might reflect the early stages of retinal sufferance and/or late stages of neurodegeneration, the possibility to modulate intravitreal levels of growth factors, in combination to anti-VEGF therapy, would open to a personalized therapy of retinal diseases.
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Affiliation(s)
- Alessandra Micera
- Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Sciences, IRCCS - Fondazione Bietti, Rome, Italy
| | - Bijorn Omar Balzamino
- Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Sciences, IRCCS - Fondazione Bietti, Rome, Italy
| | - Antonio Di Zazzo
- Ophthalmology Operative Complex Unit, University Campus Bio-Medico, Rome, Italy
| | - Lucia Dinice
- Research and Development Laboratory for Biochemical, Molecular and Cellular Applications in Ophthalmological Sciences, IRCCS - Fondazione Bietti, Rome, Italy
| | - Stefano Bonini
- Ophthalmology Operative Complex Unit, University Campus Bio-Medico, Rome, Italy
| | - Marco Coassin
- Ophthalmology Operative Complex Unit, University Campus Bio-Medico, Rome, Italy
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Guo L, Davis BM, Ravindran N, Galvao J, Kapoor N, Haamedi N, Shamsher E, Luong V, Fico E, Cordeiro MF. Topical recombinant human Nerve growth factor (rh-NGF) is neuroprotective to retinal ganglion cells by targeting secondary degeneration. Sci Rep 2020; 10:3375. [PMID: 32099056 PMCID: PMC7042238 DOI: 10.1038/s41598-020-60427-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 01/16/2020] [Indexed: 12/13/2022] Open
Abstract
Optic neuropathy is a major cause of irreversible blindness worldwide, and no effective treatment is currently available. Secondary degeneration is believed to be the major contributor to retinal ganglion cell (RGC) death, the endpoint of optic neuropathy. Partial optic nerve transection (pONT) is an established model of optic neuropathy. Although the mechanisms of primary and secondary degeneration have been delineated in this model, until now how this is influenced by therapy is not well-understood. In this article, we describe a clinically translatable topical, neuroprotective treatment (recombinant human nerve growth factor, rh-NGF) predominantly targeting secondary degeneration in a pONT rat model. Topical application of rh-NGF twice daily for 3 weeks significantly improves RGC survival as shown by reduced RGC apoptosis in vivo and increased RGC population in the inferior retina, which is predominantly affected in this model by secondary degeneration. Topical rh-NGF also promotes greater axonal survival and inhibits astrocyte activity in the optic nerve. Collectively, these results suggest that topical rh-NGF exhibits neuroprotective effects on retinal neurons via influencing secondary degeneration process. As topical rh-NGF is already involved in early clinical trials, this highlights its potential in multiple indications in patients, including those affected by glaucomatous optic neuropathy.
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Affiliation(s)
- Li Guo
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom.
| | - Benjamin M Davis
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Nivedita Ravindran
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Joana Galvao
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Neel Kapoor
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Nasrin Haamedi
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Ehtesham Shamsher
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Vy Luong
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom
| | - Elena Fico
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom.,Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy
| | - M Francesca Cordeiro
- Glaucoma & Retinal Neurodegeneration Research Group, Institute of Ophthalmology, University College London, London, United Kingdom. .,Western Eye Hospital, Imperial College Healthcare NHS Trust, London, United Kingdom.
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Mesentier-Louro LA, Rosso P, Carito V, Mendez-Otero R, Santiago MF, Rama P, Lambiase A, Tirassa P. Nerve Growth Factor Role on Retinal Ganglion Cell Survival and Axon Regrowth: Effects of Ocular Administration in Experimental Model of Optic Nerve Injury. Mol Neurobiol 2019; 56:1056-1069. [PMID: 29869196 DOI: 10.1007/s12035-018-1154-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 05/24/2018] [Indexed: 01/04/2023]
Abstract
Retinal ganglion cell (RGC) degeneration occurs within 2 weeks following optic nerve crush (ONC) as a consequence of reduced retro-transport of growth factors including nerve growth factor (NGF). The hypothesis that intravitreal (ivt) and eye drop (ed) administration of recombinant human NGF (rhNGF) might counteract ONC in adult rats is explored in this study. We found that both ivt- and ed-rhNGF reduced RGC loss and stimulated axonal regrowth. Chiefly, survival and regenerative effects of rhNGF were associated with a reduction of cells co-expressing Nogo-A/p75NTR at crush site borders, which contribute to glia scar formation following nerve injury, and induce further degeneration. We also found that ocular application of rhNGF reduced p75NTR and proNGF and enhanced phosphorylation of TrkA and its intracellular signals at retina level. Nogo-R and Rock2 expression was also normalized by ed-rhNGF treatment in both ONC and contralateral retina. Our findings that ocular applied NGF reaches and exerts biological actions on posterior segment of the eye give a further insight into the neurotrophin diffusion/transport through eye structures and/or their trafficking in optic nerve. In addition, the use of a highly purified NGF form in injury condition in which proNGF/p75NTR binding is favored indicates that increased availability of mature NGF restores the balance between TrkA and p75NGF, thus resulting in RGC survival and axonal growth. In conclusion, ocular applied NGF is confirmed as a good experimental paradigm to study mechanisms of neurodegeneration and regeneration, disclose biomarkers, and time windows for efficacy treatment following cell or nerve injury.
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Affiliation(s)
- Louise A Mesentier-Louro
- Eye Repair Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Pamela Rosso
- Institute of Cell Biology and Neurobiology (IBCN), National Research Council (CNR), Via di Fosso di Fiorano, 64 (00143), Rome, Italy
| | - Valentina Carito
- Institute of Cell Biology and Neurobiology (IBCN), National Research Council (CNR), Via di Fosso di Fiorano, 64 (00143), Rome, Italy
| | - Rosalia Mendez-Otero
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marcelo F Santiago
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Paolo Rama
- Eye Repair Unit, Division of Neuroscience, San Raffaele Scientific Institute, Milan, Italy
| | - Alessandro Lambiase
- Section of Ophthalmology, Department of Sense Organs, University Sapienza, Rome, Italy
| | - Paola Tirassa
- Institute of Cell Biology and Neurobiology (IBCN), National Research Council (CNR), Via di Fosso di Fiorano, 64 (00143), Rome, Italy.
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6
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Rocco ML, Balzamino BO, Esposito G, Petrella C, Aloe L, Micera A. NGF/anti-VEGF combined exposure protects RCS retinal cells and photoreceptors that underwent a local worsening of inflammation. Graefes Arch Clin Exp Ophthalmol 2016; 255:567-574. [PMID: 28013393 DOI: 10.1007/s00417-016-3567-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Revised: 11/26/2016] [Accepted: 12/06/2016] [Indexed: 11/26/2022] Open
Abstract
PURPOSE Our previous study highlighted the potential nerve growth factor (NGF) effect on damaged photoreceptors from a rat model of spontaneous Retinitis Pigmentosa (RP). Herein, we tested the combined NGF/anti-vascular endothelial growth factor (αVEGF) effect on cultured retinal cells isolated from Royal College of Surgeons (RCS) rats receiving an intravitreal VEGF injection (iv-VEGF) to exacerbate retinal inflammation/neovascularization. METHODS RCS (n = 75) rats were equally grouped as untreated (n = 25), iv-saline (single saline intravitreal injection; n = 25) and iv-VEGF (single VEGF intravitreal injection; n = 25). Morphological and biochemical analysis or in vitro stimulations with the biomolecular investigation were carried out on explanted retinas. Isolated retinal cells were treated with NGF and αVEGF, either alone or in combination, for 6 days and cells were harvested for morphological and biomolecular analyses. RESULTS Infiltrating inflammatory cells were detected in iv-VEGF exposed RCS retinas, indicative of exacerbated inflammation and neovascularization. In cell cultures, NGF/αVEGF significantly increased retinal cell survival as well as rhodopsin expression and neurite outgrowth in photoreceptors. Particularly, NGF/αVEGF upregulated Bcl-2 mRNA, downregulated Bax mRNA, upregulated trkANGFR mRNA and finally upregulated both NGF mRNA and protein. CONCLUSIONS These data confirm and extend our previous findings on NGF-photoreceptor crosstalk, highlighting that the NGF/αVEGF combination might be an interesting approach for improving neuroprotection of RCS retinal cells and likewise photoreceptors in the presence of neovascularization. Further studies are required to translate this in vitro approach into clinical practice.
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Affiliation(s)
| | - Bijorn Omar Balzamino
- Research Laboratories in Ophthalmology, IRCCS-G.B. Bietti Foundation, Via Santo Stefano Rotondo, 6 I-00184, Rome, Italy
| | - Graziana Esposito
- Research Laboratories in Ophthalmology, IRCCS-G.B. Bietti Foundation, Via Santo Stefano Rotondo, 6 I-00184, Rome, Italy
| | - Carla Petrella
- Institute of Cell Biology and Neurobiology, CNR, Rome, Italy
| | - Luigi Aloe
- Institute of Cell Biology and Neurobiology, CNR, Rome, Italy
| | - Alessandra Micera
- Research Laboratories in Ophthalmology, IRCCS-G.B. Bietti Foundation, Via Santo Stefano Rotondo, 6 I-00184, Rome, Italy.
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Aloe L, Rocco ML, Balzamino BO, Micera A. Nerve Growth Factor: A Focus on Neuroscience and Therapy. Curr Neuropharmacol 2016; 13:294-303. [PMID: 26411962 PMCID: PMC4812798 DOI: 10.2174/1570159x13666150403231920] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Nerve growth factor (NGF) is the firstly discovered and best characterized neurotrophic factor, known to play a critical protective role in the development and survival of sympathetic, sensory and forebrain cholinergic neurons. NGF promotes neuritis outgrowth both in vivo and in vitro and nerve cell recovery after ischemic, surgical or chemical injuries. Recently, the therapeutic property of NGF has been demonstrated on human cutaneous and corneal ulcers, pressure ulcer, glaucoma, maculopathy and retinitis pigmentosa. NGF eye drops administration is well tolerated, with no detectable clinical evidence of systemic or local adverse effects. The aim of this review is to summarize these biological properties and the potential clinical development of NGF.
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Affiliation(s)
- Luigi Aloe
- Institute of Cell Biology and Neurobiology, National Research Council (CNR); NGF Section, Via Fosso di Fiorano, 64/65 - 00143 Rome, Italy.
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Song W, Huang P, Zhang C. Neuroprotective therapies for glaucoma. DRUG DESIGN DEVELOPMENT AND THERAPY 2015; 9:1469-79. [PMID: 25792807 PMCID: PMC4362661 DOI: 10.2147/dddt.s80594] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Glaucoma is the second leading cause for blindness worldwide. It is mainly caused by glaucomatous optic neuropathy (GON) characterized by retinal ganglion cell loss, which leads to visual field defect and blindness. Up to now, the main purpose of antiglaucomatous therapies has been to lower intraocular pressure (IOP) through surgeries and medications. However, it has been found that progressive GON is still present in some patients with effective IOP decrease. Therefore, risk factors other than IOP elevation, like neurotrophin deprivation and excitotoxicity, contribute to progressive GON. Novel approaches of neuroprotection may be more effective for preserving the function of the optic nerve.
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Affiliation(s)
- Wei Song
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China
| | - Ping Huang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China
| | - Chun Zhang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, People's Republic of China
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Neurotrophic molecules in the treatment of neurodegenerative disease with focus on the retina: status and perspectives. Cell Tissue Res 2013; 353:205-18. [PMID: 23463189 DOI: 10.1007/s00441-013-1585-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Accepted: 02/07/2013] [Indexed: 01/19/2023]
Abstract
Neurotrophic factors are operationally defined as molecules that promote the survival and differentiation of neurons. Chemically, they belong to divergent classes of molecules but most of the classic neurotrophic factors are proteins. Together with stem cells, viral vectors and genetically engineered cells, they constitute important tools in neuroprotective and regenerative neurobiology. Protein neurotrophic molecules signal through receptors located on the cell membrane. Their downstream signaling exploits pathways that are often common to chemically different factors and frequently target a relatively restricted set of transcription factors, RNA interference and diverse molecular machinery involved in the life vs. death decisions of neurons. Application of neurotrophic factors with the aim of curing or, at least, improving the outcome of neurodegenerative diseases requires (1) profound knowledge of the complex molecular pathology of the disease, (2) the development of animal models as closely as possible resembling the human disease, (3) the identification of target cells to be addressed, (4) intense efforts in chemical engineering to ensure the stability of molecules or to design carriers and small analogs with the ability to cross the blood-brain barrier and (5) scrutinity with regard to possible side effects. Last, but not least, engineering efforts to optimize administration, e.g., by designing the right canulae and infusion devices, are important for the successful translation of preclinical advances into clinical benefit. This article presents selected examples of neurotrophic factors that are currently being tested in animal models or developed for transfer to the clinic, with a major focus on factors with the potential of becoming applicable in various forms of retinal degeneration.
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10
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Targeting reactive astrogliosis by novel biotechnological strategies. Biotechnol Adv 2012; 30:261-71. [DOI: 10.1016/j.biotechadv.2011.06.016] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 06/16/2011] [Indexed: 12/21/2022]
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11
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Calza A, Florenzano F, Pellegrini D, Tirassa P. Time-dependent activation of c-fos in limbic brain areas by ocular administration of nerve growth factor in adult rats. J Ocul Pharmacol Ther 2011; 27:209-18. [PMID: 21510807 DOI: 10.1089/jop.2010.0139] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
PURPOSE The ocular administration of the neurotrophin nerve growth factor (NGF) has been successfully used in humans to recover damaged ocular tissues. Studies on animal models have demonstrated the ability of ocular applied NGF to reach the retina and the optic nerve and affect brain visual areas. The aim of this study was to examine whether the ocular application of NGF as eye drops might affect brain areas other than the primary visual centers. METHODS Two drops (10 μL) of NGF solution (200 μg/mL) or saline were applied as collyrium to both eyes of adult male Sprague-Dawley rats. The animals were sacrificed at 4, 8, or 24 h after treatment and the brains were fixed through intracardiac perfusion. Coronal brain sections were cut with a cryostat and used for immunohistochemical time series and double immunofluorescence studies using c-fos and NeuN as markers for neuronal activation. RESULTS The immunohistochemical studies show a time-dependent effect of NGF eye drop treatment. At 4 h after NGF ocular administration, the increase in c-fos immunoreactivity is mainly observed in areas belonging to the central visual system, such as the lateral geniculate nucleus and visual cortex. At 8 h posttreatment, c-fos expression is enhanced in several limbic structures, including the frontal cortex, hippocampus, amygdala, and hypothalamus. The effects of NGF on c-fos distribution persist at 24 h postadministration. Specificity of NGF-induced c-fos in brain was confirmed using inactivated NGF. The neuronal nature of the NGF-activated cells was demonstrated by confocal microscopy observation of c-fos and NeuN colocalization. CONCLUSION This study demonstrates that NGF, when applied on ocular surface, is able to activate c-fos in several areas of the limbic system in a time-dependent manner. These findings suggest that the effects of NGF eye drops are not restricted to the primary visual areas, but are extended to all the retinal central targets, including the forebrain structure. Based on these data, the use of NGF eye drops as a strategy to produce NGF-mediated protective and reparative actions in brain is hypothesizable.
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Affiliation(s)
- Arianna Calza
- National Council of Research, Institute of Cellular Biology and Neurobiology, Rome, Italy
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12
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Johnson TV, Bull ND, Martin KR. Neurotrophic factor delivery as a protective treatment for glaucoma. Exp Eye Res 2010; 93:196-203. [PMID: 20685205 DOI: 10.1016/j.exer.2010.05.016] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 04/21/2010] [Accepted: 05/23/2010] [Indexed: 12/13/2022]
Abstract
Glaucoma is a progressive optic neuropathy and a major cause of visual impairment worldwide. Neuroprotective therapies for glaucoma aim to ameliorate retinal ganglion cell degeneration through direct or indirect action on these neurons. Neurotrophic factor (NTF) delivery is a key target for the development of potential neuroprotective glaucoma treatments. This article will critically summarize the evidence that NTF deprivation and/or dysfunction plays a role in the pathogenesis of glaucoma. Experimental support for the neuroprotective potential of NTF supplementation in animal models of glaucoma will be reviewed, in particular for brain-derived neurotrophic factor, ciliary neurotrophic factor, and glial cell line-derived neurotrophic factor. Finally, the challenges of clinical translation will be considered with an emphasis on the most promising NTF delivery strategies including slow-release drug delivery, gene therapy, and cell transplantation.
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Affiliation(s)
- Thomas V Johnson
- Centre for Brain Repair, University of Cambridge, Forvie Site, Robinson Way, Cambridge CB2 0PY, UK
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Blood pressure treatment in acute ischemic stroke: a review of studies and recommendations. Curr Opin Neurol 2010; 23:46-52. [PMID: 20038827 DOI: 10.1097/wco.0b013e3283355694] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE OF REVIEW Elevated blood pressure (BP) is frequent in patients with acute ischemic stroke. Pathophysiological data support its usefulness to maintain adequate perfusion of the ischemic penumba. This review article aims to summarize the available evidence from clinical studies that examined the prognostic role of BP during the acute phase of ischemic stroke and intervention studies that assessed the efficacy of active BP alteration. RECENT FINDINGS We found 34 observational studies (33,470 patients), with results being inconsistent among the studies; most studies reported a negative association between increased levels of BP and clinical outcome, whereas a few studies showed clinical improvement with higher BP levels, clinical deterioration with decreased BP, or no association at all. Similarly, the conclusions drawn by the 18 intervention studies included in this review (1637 patients) were also heterogeneous. Very recent clinical data suggest a possible beneficial effect of early treatment with some antihypertensives on late clinical outcome. SUMMARY Observational and interventional studies of management of acute poststroke hypertension yield conflicting results. We discuss different explanations that may account for this and discuss the current guidelines and pathophysiological considerations for the management of acute poststroke hypertension.
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