Arginase 2 deletion reduces neuro-glial injury and improves retinal function in a model of retinopathy of prematurity.
Retinopathy of prematurity (ROP) is a major cause of vision impairment in low birth weight infants. While previous work has focused on defining the mechanisms of vascular injury leading to retinal neovascularization, recent studies show that neurons are also affected. This study was undertaken to de...
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2011-01-01
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| Series: | PLoS ONE |
| Online Access: | http://europepmc.org/articles/PMC3141070?pdf=render |
| _version_ | 1818129373827432448 |
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| author | Subhadra P Narayanan Jutamas Suwanpradid Alan Saul Zhimin Xu Amber Still Robert W Caldwell Ruth B Caldwell |
| author_facet | Subhadra P Narayanan Jutamas Suwanpradid Alan Saul Zhimin Xu Amber Still Robert W Caldwell Ruth B Caldwell |
| author_sort | Subhadra P Narayanan |
| collection | DOAJ |
| description | Retinopathy of prematurity (ROP) is a major cause of vision impairment in low birth weight infants. While previous work has focused on defining the mechanisms of vascular injury leading to retinal neovascularization, recent studies show that neurons are also affected. This study was undertaken to determine the role of the mitochondrial arginine/ornithine regulating enzyme arginase 2 (A2) in retinal neuro-glial cell injury in the mouse model of ROP.Studies were performed using wild type (WT) and A2 knockout (A2-/-) mice exposed to Oxygen Induced Retinopathy (OIR). Neuronal injury and apoptosis were assessed using immunohistochemistry, TUNEL (terminal deoxynucleotidyl transferase dUTP nick end) labeling and Western blotting. Electroretinography (ERG) was used to assess retinal function. Neuro-glial injury in WT ROP mice was evident by TUNEL labeling, retinal thinning, decreases in number of rod bipolar cells and glial cell activation as compared with room air controls. Significant reduction in numbers of TUNEL positive cells, inhibition of retinal thinning, preservation of the rod bipolar cells and prevention of glial activation were observed in the A2-/- retinas. Retinal function was markedly impaired in the WT OIR mice as shown by decreases in amplitude of the b-wave of the ERG. This defect was significantly reduced in A2-/- mice. Levels of the pro-apoptotic proteins p53, cleaved caspase 9, cytochrome C and the mitochondrial protein Bim were markedly increased in WT OIR retinas compared to controls, whereas the pro-survival Mitochondrial protein BCL-xl was reduced. These alterations were largely blocked in the A2-/- OIR retina.Our data implicate A2 in neurodegeneration during ROP. Deletion of A2 significantly improves neuronal survival and function, possibly through the regulation of mitochondrial membrane permeability mediated apoptosis during retinal ischemia. These molecular events are associated with decreased activation of glial cells, suggesting a rescue effect on macroglia as well. |
| first_indexed | 2024-12-11T07:48:07Z |
| format | Article |
| id | doaj.art-46029143221c4ae6971dbf17ca85d418 |
| institution | Directory Open Access Journal |
| issn | 1932-6203 |
| language | English |
| last_indexed | 2024-12-11T07:48:07Z |
| publishDate | 2011-01-01 |
| publisher | Public Library of Science (PLoS) |
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| series | PLoS ONE |
| spelling | doaj.art-46029143221c4ae6971dbf17ca85d4182022-12-22T01:15:25ZengPublic Library of Science (PLoS)PLoS ONE1932-62032011-01-0167e2246010.1371/journal.pone.0022460Arginase 2 deletion reduces neuro-glial injury and improves retinal function in a model of retinopathy of prematurity.Subhadra P NarayananJutamas SuwanpradidAlan SaulZhimin XuAmber StillRobert W CaldwellRuth B CaldwellRetinopathy of prematurity (ROP) is a major cause of vision impairment in low birth weight infants. While previous work has focused on defining the mechanisms of vascular injury leading to retinal neovascularization, recent studies show that neurons are also affected. This study was undertaken to determine the role of the mitochondrial arginine/ornithine regulating enzyme arginase 2 (A2) in retinal neuro-glial cell injury in the mouse model of ROP.Studies were performed using wild type (WT) and A2 knockout (A2-/-) mice exposed to Oxygen Induced Retinopathy (OIR). Neuronal injury and apoptosis were assessed using immunohistochemistry, TUNEL (terminal deoxynucleotidyl transferase dUTP nick end) labeling and Western blotting. Electroretinography (ERG) was used to assess retinal function. Neuro-glial injury in WT ROP mice was evident by TUNEL labeling, retinal thinning, decreases in number of rod bipolar cells and glial cell activation as compared with room air controls. Significant reduction in numbers of TUNEL positive cells, inhibition of retinal thinning, preservation of the rod bipolar cells and prevention of glial activation were observed in the A2-/- retinas. Retinal function was markedly impaired in the WT OIR mice as shown by decreases in amplitude of the b-wave of the ERG. This defect was significantly reduced in A2-/- mice. Levels of the pro-apoptotic proteins p53, cleaved caspase 9, cytochrome C and the mitochondrial protein Bim were markedly increased in WT OIR retinas compared to controls, whereas the pro-survival Mitochondrial protein BCL-xl was reduced. These alterations were largely blocked in the A2-/- OIR retina.Our data implicate A2 in neurodegeneration during ROP. Deletion of A2 significantly improves neuronal survival and function, possibly through the regulation of mitochondrial membrane permeability mediated apoptosis during retinal ischemia. These molecular events are associated with decreased activation of glial cells, suggesting a rescue effect on macroglia as well.http://europepmc.org/articles/PMC3141070?pdf=render |
| spellingShingle | Subhadra P Narayanan Jutamas Suwanpradid Alan Saul Zhimin Xu Amber Still Robert W Caldwell Ruth B Caldwell Arginase 2 deletion reduces neuro-glial injury and improves retinal function in a model of retinopathy of prematurity. PLoS ONE |
| title | Arginase 2 deletion reduces neuro-glial injury and improves retinal function in a model of retinopathy of prematurity. |
| title_full | Arginase 2 deletion reduces neuro-glial injury and improves retinal function in a model of retinopathy of prematurity. |
| title_fullStr | Arginase 2 deletion reduces neuro-glial injury and improves retinal function in a model of retinopathy of prematurity. |
| title_full_unstemmed | Arginase 2 deletion reduces neuro-glial injury and improves retinal function in a model of retinopathy of prematurity. |
| title_short | Arginase 2 deletion reduces neuro-glial injury and improves retinal function in a model of retinopathy of prematurity. |
| title_sort | arginase 2 deletion reduces neuro glial injury and improves retinal function in a model of retinopathy of prematurity |
| url | http://europepmc.org/articles/PMC3141070?pdf=render |
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