Dysmyelination, demyelination and reactive astrogliosis in the optic nerve of the taiep rat
Taiep is an autosomal recessive mutant rat that shows a highly hypomyelinated central nervous system (CNS). Oligodendrocytes accumulate microtubules (MTs) in association with endoplasmic reticulum (ER) membranes forming MT-ER complexes. The microtubular defect in oligodendrocytes, the abnormal forma...
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BMC
1999-01-01
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| Series: | Biological Research |
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| Online Access: | http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97601999000400005 |
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| author | JUAN KRSULOVIC EDUARDO COUVE MANUEL RONCAGLIOLO |
| author_facet | JUAN KRSULOVIC EDUARDO COUVE MANUEL RONCAGLIOLO |
| author_sort | JUAN KRSULOVIC |
| collection | DOAJ |
| description | Taiep is an autosomal recessive mutant rat that shows a highly hypomyelinated central nervous system (CNS). Oligodendrocytes accumulate microtubules (MTs) in association with endoplasmic reticulum (ER) membranes forming MT-ER complexes. The microtubular defect in oligodendrocytes, the abnormal formation of CNS myelin and the astrocytic reaction were characterized by immunocytochemical and ultrastructural methods during the first year of life. Optic nerves of both control and taiep rats were processed by the immunoperoxidase method using antibodies against tubulin, myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP). Taiep oligodendrocytes are strongly immunoreactive against tubulin, indicative of a significant accumulation of microtubules. Early differentiated oligodendrocytes observed with electron microscopy show that MT-ER complexes are mainly present in the cell body. This defect increases during the first year of life; oligodendrocytes show large MT-ER complexes projected within oligodendrocyte processes. Using anti-MBP, there was a progressive reduction of immunolabeling in the myelin sheaths as taiep rats grew older. Ultrastructural analysis revealed severely dysmyelinated axons with a frequently collapsed periaxonal collar. However, through age the myelin sheath became gradually infiltrated by MTs, suggesting their contribution to premature loss of myelin in the taiep rat. Axons of one-year-old taiep rats were severely demyelinated. Modifications in astrocytes revealed by the GFAP antibody showed a strong hypertrophy with increased immunostaining in their processes. As demyelination of axons progressed, taiep rats developed a strong astrogliosis. The present findings suggest that in taiep rats the early abnormal myelination of axons affects the adequate maintenance of myelin, leading to a progressive loss of myelin components and severe astrogliosis, features that should be considered in the pathogenesis of dysmyelinating diseases |
| first_indexed | 2024-12-23T20:55:37Z |
| format | Article |
| id | doaj.art-1241df98da9f4bd281732de895216050 |
| institution | Directory Open Access Journal |
| issn | 0716-9760 0717-6287 |
| language | English |
| last_indexed | 2024-12-23T20:55:37Z |
| publishDate | 1999-01-01 |
| publisher | BMC |
| record_format | Article |
| series | Biological Research |
| spelling | doaj.art-1241df98da9f4bd281732de8952160502022-12-21T17:31:31ZengBMCBiological Research0716-97600717-62871999-01-01324253262Dysmyelination, demyelination and reactive astrogliosis in the optic nerve of the taiep ratJUAN KRSULOVICEDUARDO COUVEMANUEL RONCAGLIOLOTaiep is an autosomal recessive mutant rat that shows a highly hypomyelinated central nervous system (CNS). Oligodendrocytes accumulate microtubules (MTs) in association with endoplasmic reticulum (ER) membranes forming MT-ER complexes. The microtubular defect in oligodendrocytes, the abnormal formation of CNS myelin and the astrocytic reaction were characterized by immunocytochemical and ultrastructural methods during the first year of life. Optic nerves of both control and taiep rats were processed by the immunoperoxidase method using antibodies against tubulin, myelin basic protein (MBP) and glial fibrillary acidic protein (GFAP). Taiep oligodendrocytes are strongly immunoreactive against tubulin, indicative of a significant accumulation of microtubules. Early differentiated oligodendrocytes observed with electron microscopy show that MT-ER complexes are mainly present in the cell body. This defect increases during the first year of life; oligodendrocytes show large MT-ER complexes projected within oligodendrocyte processes. Using anti-MBP, there was a progressive reduction of immunolabeling in the myelin sheaths as taiep rats grew older. Ultrastructural analysis revealed severely dysmyelinated axons with a frequently collapsed periaxonal collar. However, through age the myelin sheath became gradually infiltrated by MTs, suggesting their contribution to premature loss of myelin in the taiep rat. Axons of one-year-old taiep rats were severely demyelinated. Modifications in astrocytes revealed by the GFAP antibody showed a strong hypertrophy with increased immunostaining in their processes. As demyelination of axons progressed, taiep rats developed a strong astrogliosis. The present findings suggest that in taiep rats the early abnormal myelination of axons affects the adequate maintenance of myelin, leading to a progressive loss of myelin components and severe astrogliosis, features that should be considered in the pathogenesis of dysmyelinating diseaseshttp://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97601999000400005myelin mutanttaiep ratoptic nervedysmyelinationdemyelinationastrogliosis |
| spellingShingle | JUAN KRSULOVIC EDUARDO COUVE MANUEL RONCAGLIOLO Dysmyelination, demyelination and reactive astrogliosis in the optic nerve of the taiep rat Biological Research myelin mutant taiep rat optic nerve dysmyelination demyelination astrogliosis |
| title | Dysmyelination, demyelination and reactive astrogliosis in the optic nerve of the taiep rat |
| title_full | Dysmyelination, demyelination and reactive astrogliosis in the optic nerve of the taiep rat |
| title_fullStr | Dysmyelination, demyelination and reactive astrogliosis in the optic nerve of the taiep rat |
| title_full_unstemmed | Dysmyelination, demyelination and reactive astrogliosis in the optic nerve of the taiep rat |
| title_short | Dysmyelination, demyelination and reactive astrogliosis in the optic nerve of the taiep rat |
| title_sort | dysmyelination demyelination and reactive astrogliosis in the optic nerve of the taiep rat |
| topic | myelin mutant taiep rat optic nerve dysmyelination demyelination astrogliosis |
| url | http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0716-97601999000400005 |
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