1
|
Smith AW, Rohrer B, Wheless L, Samantaray S, Ray SK, Inoue J, Azuma M, Banik NL. Calpain inhibition reduces structural and functional impairment of retinal ganglion cells in experimental optic neuritis. J Neurochem 2016; 139:270-284. [PMID: 27513991 DOI: 10.1111/jnc.13770] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 07/29/2016] [Accepted: 08/01/2016] [Indexed: 12/27/2022]
Abstract
Optic neuritis (ON), inflammation of the optic nerve, is strongly associated with multiple sclerosis. ON pathology is characterized by attack of autoreactive T cells against optic nerve antigens, resulting in demyelination, death of retinal ganglion cells, and cumulative visual impairment. A model of experimental autoimmune encephalomyelitis (EAE) was utilized to study the onset and progression of ON and the neuroprotective efficacy of oral treatment with the calpain inhibitor SNJ 1945. EAE was actively induced in B10.PL mice with myelin basic protein on Days 0 and 2, and mice received twice daily oral dosing of SNJ 1945 from Day 9 until sacrificing (Day 26). Visual function was determined by electroretinogram recordings and daily measurement of optokinetic responses (OKR) to a changing pattern stimulus. Optic nerve and retinal histopathology was investigated by immunohistochemical and luxol fast blue staining. EAE mice manifested losses in OKR thresholds, a measurement of visual acuity, which began early in the disease course. There was a significant bias toward unilateral OKR impairment among EAE-ON eyes. Treatment with SNJ 1945, initiated after the onset of OKR threshold decline, improved visual acuity, pattern electroretinogram amplitudes, and paralysis, with attenuation of retinal ganglion cell death. Furthermore, calpain inhibition spared oligodendrocytes, prevented degradation of axonal neurofilament protein, and attenuated reactive astrocytosis. The trend of early, unilateral visual impairment in EAE-ON parallels the clinical presentation of ON exacerbations associated with multiple sclerosis. Calpain inhibition may represent an ideal candidate therapy for the preservation of vision in clinical ON. As in multiple sclerosis (MS) patients, optic neuritis (ON) and early, primarily monocular loss in spatial acuity is observed in a rodent model (EAE, experimental autoimmune encephalomyelitis). Daily oral treatment with the calpain inhibitor SNJ 1945 preserves visual acuity and preserves retinal ganglion cells (Brn3a, brain-specific homeobox/POU domain protein 3A) and their axons (MOSP, myelin oligodendrocyte-specific protein). Calpain inhibition may represent a candidate therapy for the preservation of vision in ON.
Collapse
Affiliation(s)
- Amena W Smith
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Baerbel Rohrer
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, USA. .,Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA. .,Alexion Pharmaceuticals, Cheshire, Connecticut, USA. .,Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, USA.
| | - Lee Wheless
- Medicine-Division of Biostatistics and Epidemiology, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Supriti Samantaray
- Department of Neurology and Neurosurgery, Medical University of South Carolina, Charleston, South Carolina, USA
| | - Swapan K Ray
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, South Carolina, USA
| | - Jun Inoue
- Senju Pharmaceutical Co Ltd, Kobe, Japan
| | | | - Naren L Banik
- Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina, USA. .,Alexion Pharmaceuticals, Cheshire, Connecticut, USA. .,Department of Neurology and Neurosurgery, Medical University of South Carolina, Charleston, South Carolina, USA. .,Research Service, Ralph H. Johnson VA Medical Center, Charleston, South Carolina, USA.
| |
Collapse
|
2
|
Herrera SL, Palmer VL, Whittaker H, Smith BC, Kim A, Schellenberg AE, Thiessen JD, Buist R, Del Bigio MR, Martin M. Damage to the optic chiasm in myelin oligodendrocyte glycoprotein-experimental autoimmune encephalomyelitis mice. MAGNETIC RESONANCE INSIGHTS 2014; 7:23-31. [PMID: 25520558 PMCID: PMC4226389 DOI: 10.4137/mri.s19750] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Revised: 09/30/2014] [Accepted: 10/02/2014] [Indexed: 12/19/2022]
Abstract
Optic chiasm lesions in myelin oligodendrocyte glycoprotein (MOG)–experimental autoimmune encephalomyelitis (EAE) mice were characterized using magnetic resonance imaging (MRI) and validated using electron microscopy (EM). MR images were collected from 3 days after induction to remission, approximately 20 days after induction. Hematoxylin and eosin, solochrome cyanin–stained sections, and EM images were obtained from the optic chiasms of some mice approximately 4 days after disease onset when their scores were thought to be the highest. T2-weighted imaging and apparent diffusion coefficient map hyperintensities corresponded to abnormalities in the optic chiasms of EAE mice. Mixed inflammation was concentrated at the lateral surface. Degeneration of oligodendrocytes, myelin, and early axonal damage were also apparent. A marked increase in chiasm thickness was observed. T2-weighted and diffusion-weighted MRI can detect abnormalities in the optic chiasms of MOG-EAE mice. MRI is an important method in the study of this model toward understanding optic neuritis.
Collapse
Affiliation(s)
- Sheryl L Herrera
- Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Vanessa L Palmer
- Biomedical Engineering Program, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Heather Whittaker
- Biopsychology Program, University of Winnipeg, Winnipeg, Manitoba, Canada
| | | | - Annie Kim
- Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Angela E Schellenberg
- Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Manitoba, Canada. ; General Surgery, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Jonathan D Thiessen
- Imaging Program, Lawson Health Research Institute, London, Ontario, Canada. ; Medical Biophysics, Western University, London, Ontario, Canada
| | - Richard Buist
- Radiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | | | - Melanie Martin
- Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba, Canada. ; Biomedical Engineering Program, University of Manitoba, Winnipeg, Manitoba, Canada. ; Physics, University of Winnipeg, Winnipeg, Manitoba, Canada. ; Pharmacology and Therapeutics, University of Manitoba, Winnipeg, Manitoba, Canada. ; Radiology, University of Manitoba, Winnipeg, Manitoba, Canada
| |
Collapse
|
3
|
Lin TH, Kim JH, Perez-Torres C, Chiang CW, Trinkaus K, Cross AH, Song SK. Axonal transport rate decreased at the onset of optic neuritis in EAE mice. Neuroimage 2014; 100:244-53. [PMID: 24936685 DOI: 10.1016/j.neuroimage.2014.06.009] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Revised: 05/30/2014] [Accepted: 06/03/2014] [Indexed: 12/21/2022] Open
Abstract
Optic neuritis is frequently the first symptom of multiple sclerosis (MS), an inflammatory demyelinating neurodegenerative disease. Impaired axonal transport has been considered as an early event of neurodegenerative diseases. However, few studies have assessed the integrity of axonal transport in MS or its animal models. We hypothesize that axonal transport impairment occurs at the onset of optic neuritis in experimental autoimmune encephalomyelitis (EAE) mice. In this study, we employed manganese-enhanced MRI (MEMRI) to assess axonal transport in optic nerves in EAE mice at the onset of optic neuritis. Axonal transport was assessed as (a) optic nerve Mn(2+) accumulation rate (in % signal change/h) by measuring the rate of increased total optic nerve signal enhancement, and (b) Mn(2+) transport rate (in mm/h) by measuring the rate of change in optic nerve length enhanced by Mn(2+). Compared to sham-treated healthy mice, Mn(2+) accumulation rate was significantly decreased by 19% and 38% for EAE mice with moderate and severe optic neuritis, respectively. The axonal transport rate of Mn(2+) was significantly decreased by 43% and 65% for EAE mice with moderate and severe optic neuritis, respectively. The degree of axonal transport deficit correlated with the extent of impaired visual function and diminished microtubule-associated tubulins, as well as the severity of inflammation, demyelination, and axonal injury at the onset of optic neuritis.
Collapse
Affiliation(s)
- Tsen-Hsuan Lin
- Department of Physics, Washington University, St. Louis, MO 63130, USA
| | - Joong Hee Kim
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Carlos Perez-Torres
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Chia-Wen Chiang
- Department of Chemistry, Washington University, St. Louis, MO 63130, USA
| | - Kathryn Trinkaus
- Divison of Biostatistics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Anne H Cross
- Department of Neurology, Washington University School of Medicine, St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Sheng-Kwei Song
- Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO 63110, USA.
| |
Collapse
|
4
|
Ramos de Carvalho JE, Verbraak FD, Aalders MC, van Noorden CJ, Schlingemann RO. Recent advances in ophthalmic molecular imaging. Surv Ophthalmol 2013; 59:393-413. [PMID: 24529711 DOI: 10.1016/j.survophthal.2013.09.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 09/23/2013] [Accepted: 09/24/2013] [Indexed: 12/30/2022]
Abstract
The aim of molecular imaging techniques is the visualization of molecular processes and functional changes in living animals and human patients before morphological changes occur at the cellular and tissue level. Ophthalmic molecular imaging is still in its infancy and has mainly been used in small animals for pre-clinical research. The goal of most of these pre-clinical studies is their translation into ophthalmic molecular imaging techniques in clinical care. We discuss various molecular imaging techniques and their applications in ophthalmology.
Collapse
Affiliation(s)
- J Emanuel Ramos de Carvalho
- Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Ophthalmology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
| | - Frank D Verbraak
- Department of Ophthalmology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Maurice C Aalders
- Department of Biomedical Engineering and Physics, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Cornelis J van Noorden
- Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Reinier O Schlingemann
- Ocular Angiogenesis Group, Departments of Ophthalmology and Cell Biology and Histology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Department of Ophthalmology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands; Netherlands Institute for Neuroscience, Royal Academy of Sciences, Amsterdam, The Netherlands.
| |
Collapse
|
5
|
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.
Collapse
|