1
|
Lyso-Lipid-Induced Oligodendrocyte Maturation Underlies Restoration of Optic Nerve Function. eNeuro 2022; 9:ENEURO.0429-21.2022. [PMID: 35027445 PMCID: PMC8805197 DOI: 10.1523/eneuro.0429-21.2022] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Revised: 12/17/2021] [Accepted: 01/04/2022] [Indexed: 11/25/2022] Open
Abstract
Protein hyperdeimination and deficiency of lyso-phospholipids (LPC 18:1) has been associated with the pathology of demyelinating disease in both humans and mice. We uncovered interesting biology of LPC 18:1, in which LPC 18:1 induced optic nerve function restoration through oligodendrocyte maturation and remyelination in mouse model systems. Our in vitro studies show LPC 18:1 protection against neuron-ectopic hyperdeimination and stimulation of oligodendrocyte maturation, while in vivo investigations recorded optic nerve function improvement following optic nerve injections of LPC 18:1, in contrast with LPC 18:0. Thus, just a change in a single bond renders a dramatic alternation in biological function. The incorporation of isobaric C13-histidine in newly synthesized myelin proteins and quantitative proteome shifts are consistent with remyelination underlying restoration in optic nerve function. These results suggest that exogenous LPC 18:1 may provide a therapeutic avenue for stemming vision loss in demyelinating diseases.
Collapse
|
2
|
Ding D, Enriquez-Algeciras M, Valdivia AO, Torres J, Pole C, Thompson JW, Chou TH, Perez-Pinzon M, Porciatti V, Udin S, Nestler E, Bhattacharya SK. The Role of Deimination in Regenerative Reprogramming of Neurons. Mol Neurobiol 2019; 56:2618-2639. [PMID: 30051351 PMCID: PMC6348056 DOI: 10.1007/s12035-018-1262-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 07/17/2018] [Indexed: 10/28/2022]
Abstract
Neurons from the adult central nervous system (CNS) demonstrate limited mRNA transport and localized protein synthesis versus developing neurons, correlating with lower regenerative capacity. We found that deimination (posttranslational conversion of protein-bound arginine into citrulline) undergoes upregulation during early neuronal development while declining to a low basal level in adults. This modification is associated with neuronal arborization from amphibians to mammals. The mRNA-binding proteins (ANP32a, REF), deiminated in neurons, have been implicated in local protein synthesis. Overexpression of the deiminating cytosolic enzyme peptidyl arginine deiminase 2 in nervous systems results in increased neuronal transport and neurite outgrowth. We further demonstrate that enriching deiminated proteins rescues transport deficiencies both in primary neurons and mouse optic nerve even in the presence of pharmacological transport blockers. We conclude that deimination promotes neuronal outgrowth via enhanced transport and local protein synthesis and represents a new avenue for neuronal regeneration in the adult CNS.
Collapse
Affiliation(s)
- Di Ding
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - Mabel Enriquez-Algeciras
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - Anddre Osmar Valdivia
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - Juan Torres
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - Cameron Pole
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - John W Thompson
- Neurological Surgery, University of Miami, Miami, FL, 33136, USA
| | - Tsung-Han Chou
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - Miguel Perez-Pinzon
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
- Department of Neurology, University of Miami, Miami, FL, 33136, USA
| | - Vittorio Porciatti
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA
| | - Susan Udin
- Department of Physiology and Biophysics, State University of New York, Buffalo, 553 Biomedical Res. Building, Buffalo, NY, 14214, USA
| | - Eric Nestler
- Fishberg Department of Neuroscience and Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, One Gustave L. Levy Place, Box 1065, New York, NY, 10029, USA
| | - Sanjoy K Bhattacharya
- Bascom Palmer Eye Institute, University of Miami, 1638 N.W. 10th Avenue, #706, Miami, FL, 33136, USA.
- Department of Ophthalmology/Neuroscience Program, University of Miami, Miami, FL, 33136, USA.
| |
Collapse
|
3
|
Integrative properties of retinal ganglion cell electrical responsiveness depend on neurotrophic support and genotype in the mouse. Exp Eye Res 2015; 145:68-74. [PMID: 26614910 DOI: 10.1016/j.exer.2015.11.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 10/30/2015] [Accepted: 11/09/2015] [Indexed: 12/18/2022]
Abstract
Early stages of glaucoma and optic neuropathies are thought to show inner retina remodeling and functional changes of retinal ganglion cells (RGCs) before they die. To assess RGC functional plasticity, we investigated the contrast-gain control properties of the pattern electroretinogram (PERG), a sensitive measure of RGC function, as an index of spatio-temporal integration occurring in the inner retina circuitry subserving PERG generators. We studied the integrative properties of the PERG in mice exposed to different conditions of neurotrophic support. We also investigated the effect of genotypic differences among mouse strains with different susceptibility to glaucoma (C57BL/6J, DBA/2J, DBA/2.Gpnmb(+)). Results show that the integrative properties of the PERG recorded in the standard C57BL/6J inbred mouse strain are impaired after deficit of neurotrophic support and partially restored after exogenous neurotrophic administration. Changes in PERG amplitude, latency, and contrast-dependent responses differ between mouse strains with different susceptibility to glaucoma. Results represent a proof of concept that the PERG could be used as a tool for in-vivo monitoring of RGC functional plasticity before RGC death, the effect of neuroactive treatments, as well as for high-throughput tool for phenotypic screening of different mouse genotypes.
Collapse
|
4
|
Chou TH, Tomarev S, Porciatti V. Transgenic mice expressing mutated Tyr437His human myocilin develop progressive loss of retinal ganglion cell electrical responsiveness and axonopathy with normal iop. Invest Ophthalmol Vis Sci 2014; 55:5602-9. [PMID: 25125600 DOI: 10.1167/iovs.14-14793] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
PURPOSE To characterize age-related changes of retinal ganglion cell (RGC) function, IOP, and anatomical markers of axon/glia integrity in a transgenic mouse expressing Tyr437His mutant of human myocilin protein. METHODS Retinal ganglion cell electrical responsiveness was tested with pattern electroretinogram (PERG) in 11 transgenic mice expressing mutated myocilin at different ages over 18 months under ketamine/xylazine anesthesia. Twelve age-matched C57BL/6J mice also were tested as controls. Intraocular pressure was measured with a Tonolab tonometer. Immunohistochemistry for GFAP and neurofilament was performed on dissected optic nerve heads. RESULTS In transgenic mice expressing mutated myocilin, the PERG amplitude progressively decreased with increasing age by approximately 50%, whereas the PERG peak latency increased by approximately 40 ms (ANOVA, P < 0.05). In contrast, PERGs of young and old control mice had similar amplitudes and peak latencies. In transgenic mice, GFAP staining was more intense and extended than in control mice, and increased with increasing age; neurofilament staining showed swollen and partially degenerated axons in old transgenic mice. The IOP of young transgenic mice was similar to that of control mice and did not significantly change with increasing age. CONCLUSIONS Transgenic mice expressing mutated human myocilin display progressive age-related changes in RGC electrical responsiveness that are not associated with IOP elevation but are associated with marked astrogliosis and axonopathy. Our results support the view that MYOC expression in the optic nerve may impact structural, metabolic, or neurotrophic support to RGC axons, thereby influencing their susceptibility to glaucomatous damage independently of IOP.
Collapse
Affiliation(s)
- Tsung-Han Chou
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States
| | - Stanislav Tomarev
- Retinal Ganglion Cell Biology Section, Laboratory of Retinal Cell and Molecular Biology, National Eye Institute, National Institutes of Health, Bethesda, Maryland, United States
| | - Vittorio Porciatti
- Bascom Palmer Eye Institute, University of Miami, Miller School of Medicine, Miami, Florida, United States
| |
Collapse
|
5
|
Chou TH, Bohorquez J, Toft-Nielsen J, Ozdamar O, Porciatti V. Robust mouse pattern electroretinograms derived simultaneously from each eye using a common snout electrode. Invest Ophthalmol Vis Sci 2014; 55:2469-75. [PMID: 24667861 DOI: 10.1167/iovs.14-13943] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
PURPOSE We recorded pattern electroretinograms (PERGs) simultaneously from each eye in mice using binocular stimulation and a common noncorneal electrode. METHODS The PERG was derived simultaneously from each eye in 71 ketamine/xylazine anesthetized mice (C57BL/6J, 4 months old) from subcutaneous needles (active, snout; reference, back of the head; ground, root of the tail) in response to contrast-reversal of gratings (0.05 cycles/deg, >95% contrast) generated on two custom-made light-emitting diode (LED) tablets alternating at slight different frequencies (OD, 0.984 Hz; OS, 0.992 Hz). Independent PERG signals from each eye were retrieved using one channel continuous acquisition and phase-locking average (OD, 369 epochs of 492 ms; OS, 372 epochs of 496 ms). The PERG was the average of three consecutive repetitions. RESULTS Binocular snout PERGs had high amplitude (mean, 25.3 μV, SD 6.6) and no measurable interocular cross-talk. Responses were reliable (test-retest variability within-session, 14%, SD 7; between sessions, 25%, SD 9; interocular asymmetry within-session, 9%, SD 7; between sessions, 13%, SD 5). Retinal ganglion cells (RGCs) were the main source of the binocular snout PERG, as optic nerve crush in three mice abolished the signal. CONCLUSIONS The PERG, a sensitive measure of RGC function, is used increasingly in mouse models of glaucoma and optic nerve disease. Compared to current methods, the binocular snout PERG represents a substantial improvement in terms of simplicity and speed. It also overcomes limitations of corneal electrodes that interfere with invasive procedures of the eye and facilitates experiments based on comparison between the responses of the two eyes.
Collapse
Affiliation(s)
- Tsung-Han Chou
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States
| | | | | | | | | |
Collapse
|
6
|
Bonilha VL, Shadrach KG, Rayborn ME, Li Y, Pauer GJT, Hagstrom SA, Bhattacharya SK, Hollyfield JG. Retinal deimination and PAD2 levels in retinas from donors with age-related macular degeneration (AMD). Exp Eye Res 2013; 111:71-8. [PMID: 23562679 DOI: 10.1016/j.exer.2013.03.017] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Revised: 03/21/2013] [Accepted: 03/22/2013] [Indexed: 12/17/2022]
Abstract
Deimination is a form of protein posttranslational modification carried out by the peptidyl arginine deiminases (PADs) enzymes. PAD2 is the principal deiminase expressed in the retina. Elevated levels of PAD2 and protein deimination are present in a number of human neurological diseases, with or without ocular manifestation. To define the association of deimination with the pathogenesis of age-related macular degeneration (AMD), we studied protein deimination and PAD2 levels in retinas of AMD donor eyes compared to age-matched non-AMD retinas. Eyes from non-AMD and AMD donors were fixed in 4% paraformaldehyde and 0.5% glutaraldehyde in phosphate buffer. Retina and retinal pigment epithelium (RPE) from donor eyes were processed for immunohistochemical detection and western blotting using antibodies to PAD2 and citrulline residues. The ganglion cell, inner plexiform, inner nuclear and outer nuclear layers were labeled by both PAD2 and citrulline antibodies. Changes in the localization of deiminated residues and PAD2 were evident as the retinal layers were remodeled coincident with photoreceptor degeneration in AMD retinas. Immunodetection of either PAD2 or citrulline residues could not be evaluated in the RPE layer due to the high autofluorescence levels in this layer. Interestingly, higher deimination immunoreactivity was detected in AMD retinal lysates. However, no significant changes in PAD2 were detected in the AMD and non-AMD retinas and RPE lysates. Our observations show increased levels of protein deimination but not PAD2 in AMD retinas and RPE, suggesting a reduced rate of turnover of deiminated proteins in these AMD retinas.
Collapse
Affiliation(s)
- Vera L Bonilha
- Department of Ophthalmology, The Cole Eye Institute(i31), Cleveland Clinic Lerner College of Medicine, 9500 Euclid Avenue, Cleveland, OH 44195, USA.
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Yang X, Chou TH, Ruggeri M, Porciatti V. A new mouse model of inducible, chronic retinal ganglion cell dysfunction not associated with cell death. Invest Ophthalmol Vis Sci 2013; 54:1898-904. [PMID: 23422821 DOI: 10.1167/iovs.12-11375] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
PURPOSE To develop a mouse model of inducible, chronic retinal ganglion cell (RGC) dysfunction not associated with cell death. METHODS Eighteen C57BL/6J mice were longitudinally tested with pattern electroretinogram (PERG) and spectral-domain optical coherence tomography (OCT) before and after aspiration of the contralateral superior colliculus (SC), which removed terminals of optic tract axons and the superficial layers of the SC. At the 4-month end points, retinas were harvested for Brn3b immunostaining and BDNF immunoblotting. RESULTS The PERG lost approximately 60% of its baseline amplitude (P < 0.01) within the first day after lesion, and remained at a reduced level over 4 months. At the end point, the density of Brn3b-positive RGCs was normal, but their nucleus size was reduced by approximately 24% (P < 001). OCT measurements showed thinning of the inner, but not outer, retina by approximately 9% (P < 0.01) starting 10 to 20 days after lesion. Retinal nerve fiber layer thickness was unchanged. At the end point, retinal homogenates showed a substantial overexpression of BDNF protein level. CONCLUSIONS Mechanical SC lesion in adult mice results in a rapid, chronic loss of RGC electrical responsiveness that is followed by cell shrinkage but not cell death. The SC-lesion mouse represents a new, inducible model that allows investigating stages and mechanisms of RGC dysfunction without the confounding effects of cell death that are common in the existing models of optic neuropathies and optic nerve lesions.
Collapse
Affiliation(s)
- Xu Yang
- Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida 33136, USA
| | | | | | | |
Collapse
|