Retinal genes are differentially expressed in areas of primary versus secondary degeneration following partial optic nerve injury
Background: Partial transection (PT) of the optic nerve is an established experimental model of secondary degeneration in the central nervous system. After a dorsal transection, retinal ganglion cells (RGCs) with axons in ventral optic nerve are intact but vulnerable to secondary degeneration, where...
| Main Authors: | , , , , , , |
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| Format: | Journal Article |
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Public Library of Science
2018
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| Online Access: | http://hdl.handle.net/20.500.11937/66744 |
| _version_ | 1848761382515769344 |
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| author | Chiha, W. LeVaillant, C. Bartlett, C. Hewitt, A. Melton, Phillip Fitzgerald, Melinda Harvey, A. |
| author_facet | Chiha, W. LeVaillant, C. Bartlett, C. Hewitt, A. Melton, Phillip Fitzgerald, Melinda Harvey, A. |
| author_sort | Chiha, W. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Background: Partial transection (PT) of the optic nerve is an established experimental model of secondary degeneration in the central nervous system. After a dorsal transection, retinal ganglion cells (RGCs) with axons in ventral optic nerve are intact but vulnerable to secondary degeneration, whereas RGCs in dorsal retina with dorsal axons are affected by primary and secondary injuries. Using microarray, we quantified gene expression changes in dorsal and ventral retina at 1 and 7 days post PT, to characterize pathogenic pathways linked to primary and secondary degeneration. Results: In comparison to uninjured retina Cryba1, Cryba2 and Crygs, were significantly downregulated in injured dorsal retina at days 1 and 7. While Ecel1, Timp1, Mt2A and CD74, which are associated with reducing excitotoxicity, oxidative stress and inflammation, were significantly upregulated. Genes associated with oxygen binding pathways, immune responses, cytokine receptor activity and apoptosis were enriched in dorsal retina at day 1 after PT. Oxygen binding and apoptosis remained enriched at day 7, as were pathways involved in extracellular matrix modification. Fewer changes were observed in ventral retina at day 1 after PT, most associated with the regulation of protein homodimerization activity. By day 7, apoptosis, matrix organization and signal transduction pathways were enriched. Discriminant analysis was also performed for specific functional gene groups to compare expression intensities at each time point. Altered expression of selected genes (ATF3, GFAP, Ecel1, TIMP1, Tp53) and proteins (GFAP, ECEL1 and ATF3) were semi-quantitatively assessed by qRT-PCR and immunohistochemistry respectively. Conclusion: There was an acute and complex primary injury response in dorsal retina indicative of a dynamic interaction between neuroprotective and neurodegenerative events; ventral retina vulnerable to secondary degeneration showed a delayed injury response. Both primary and secondary injury resulted in the upregulation of numerous genes linked to RGC death, but differences in the nature of these changes strongly suggest that death occurred via different molecular mechanisms. |
| first_indexed | 2025-11-14T10:30:47Z |
| format | Journal Article |
| id | curtin-20.500.11937-66744 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:30:47Z |
| publishDate | 2018 |
| publisher | Public Library of Science |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-667442018-07-17T00:14:49Z Retinal genes are differentially expressed in areas of primary versus secondary degeneration following partial optic nerve injury Chiha, W. LeVaillant, C. Bartlett, C. Hewitt, A. Melton, Phillip Fitzgerald, Melinda Harvey, A. Background: Partial transection (PT) of the optic nerve is an established experimental model of secondary degeneration in the central nervous system. After a dorsal transection, retinal ganglion cells (RGCs) with axons in ventral optic nerve are intact but vulnerable to secondary degeneration, whereas RGCs in dorsal retina with dorsal axons are affected by primary and secondary injuries. Using microarray, we quantified gene expression changes in dorsal and ventral retina at 1 and 7 days post PT, to characterize pathogenic pathways linked to primary and secondary degeneration. Results: In comparison to uninjured retina Cryba1, Cryba2 and Crygs, were significantly downregulated in injured dorsal retina at days 1 and 7. While Ecel1, Timp1, Mt2A and CD74, which are associated with reducing excitotoxicity, oxidative stress and inflammation, were significantly upregulated. Genes associated with oxygen binding pathways, immune responses, cytokine receptor activity and apoptosis were enriched in dorsal retina at day 1 after PT. Oxygen binding and apoptosis remained enriched at day 7, as were pathways involved in extracellular matrix modification. Fewer changes were observed in ventral retina at day 1 after PT, most associated with the regulation of protein homodimerization activity. By day 7, apoptosis, matrix organization and signal transduction pathways were enriched. Discriminant analysis was also performed for specific functional gene groups to compare expression intensities at each time point. Altered expression of selected genes (ATF3, GFAP, Ecel1, TIMP1, Tp53) and proteins (GFAP, ECEL1 and ATF3) were semi-quantitatively assessed by qRT-PCR and immunohistochemistry respectively. Conclusion: There was an acute and complex primary injury response in dorsal retina indicative of a dynamic interaction between neuroprotective and neurodegenerative events; ventral retina vulnerable to secondary degeneration showed a delayed injury response. Both primary and secondary injury resulted in the upregulation of numerous genes linked to RGC death, but differences in the nature of these changes strongly suggest that death occurred via different molecular mechanisms. 2018 Journal Article http://hdl.handle.net/20.500.11937/66744 10.1371/journal.pone.0192348 http://creativecommons.org/licenses/by/4.0/ Public Library of Science fulltext |
| spellingShingle | Chiha, W. LeVaillant, C. Bartlett, C. Hewitt, A. Melton, Phillip Fitzgerald, Melinda Harvey, A. Retinal genes are differentially expressed in areas of primary versus secondary degeneration following partial optic nerve injury |
| title | Retinal genes are differentially expressed in areas of primary versus secondary degeneration following partial optic nerve injury |
| title_full | Retinal genes are differentially expressed in areas of primary versus secondary degeneration following partial optic nerve injury |
| title_fullStr | Retinal genes are differentially expressed in areas of primary versus secondary degeneration following partial optic nerve injury |
| title_full_unstemmed | Retinal genes are differentially expressed in areas of primary versus secondary degeneration following partial optic nerve injury |
| title_short | Retinal genes are differentially expressed in areas of primary versus secondary degeneration following partial optic nerve injury |
| title_sort | retinal genes are differentially expressed in areas of primary versus secondary degeneration following partial optic nerve injury |
| url | http://hdl.handle.net/20.500.11937/66744 |