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Neurodegeneration in Autoimmune Optic Neuritis Is Associated with Altered APP Cleavage in Neurons and Up-Regulation of p53.

Herold S, Kumar P, Wichert SP, Kretzschmar B, Bähr M, Rossner MJ, Hein K - PLoS ONE (2015)

Bottom Line: Furthermore, genes that are highly specific for autoimmune-driven neurodegeneration were compared to those regulated in RGCs after optic nerve axotomy at corresponding time points.Furthermore, using ingenuity pathway analysis (IPA), we identified amyloid precursor protein (APP) as a potential upstream regulator of changes in gene expression in the preclinical EAE but neither in clinical EAE, nor at any time point after optic nerve transection.Therefore, the gene pathway analysis lead to the hypothesis that altered cleavage of APP in neurons in the preclinical phase of EAE leads to the enhanced production of APP intracellular domain (AICD), which in turn acts as a transcriptional regulator and thereby initiates an apoptotic signaling cascade via up-regulation of the target gene p53.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, University Medicine Göttingen, Göttingen, Germany.

ABSTRACT
Multiple Sclerosis (MS) is a chronic autoimmune inflammatory disease of the central nervous system (CNS). Histopathological and radiological analysis revealed that neurodegeneration occurs early in the disease course. However, the pathological mechanisms involved in neurodegeneration are poorly understood. Myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) in Brown Norway rats (BN-rats) is a well-established animal model, especially of the neurodegenerative aspects of MS. Previous studies in this animal model indicated that loss of retinal ganglion cells (RGCs), the neurons that form the axons of the optic nerve, occurs in the preclinical phase of the disease and is in part independent of overt histopathological changes of the optic nerve. Therefore, the aim of this study was to identify genes which are involved in neuronal cell loss at different disease stages of EAE. Furthermore, genes that are highly specific for autoimmune-driven neurodegeneration were compared to those regulated in RGCs after optic nerve axotomy at corresponding time points. Using laser capture micro dissection we isolated RNA from unfixed RGCs and performed global transcriptome analysis of retinal neurons. In total, we detected 582 genes sequentially expressed in the preclinical phase and 1150 genes in the clinical manifest EAE (P < 0.05, fold-induction >1.5). Furthermore, using ingenuity pathway analysis (IPA), we identified amyloid precursor protein (APP) as a potential upstream regulator of changes in gene expression in the preclinical EAE but neither in clinical EAE, nor at any time point after optic nerve transection. Therefore, the gene pathway analysis lead to the hypothesis that altered cleavage of APP in neurons in the preclinical phase of EAE leads to the enhanced production of APP intracellular domain (AICD), which in turn acts as a transcriptional regulator and thereby initiates an apoptotic signaling cascade via up-regulation of the target gene p53.

No MeSH data available.


Related in: MedlinePlus

p53-immunoreactivity of RGCs in the preclinical phase of the disease.A strong increase in p53-immunoreactivity was detected in RGC-layer in preclinical EAE (MOG_7dpi). Line indicates borders of the RGC-layer. Arrowheads indicate p53-positive RGCs.
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pone.0138852.g005: p53-immunoreactivity of RGCs in the preclinical phase of the disease.A strong increase in p53-immunoreactivity was detected in RGC-layer in preclinical EAE (MOG_7dpi). Line indicates borders of the RGC-layer. Arrowheads indicate p53-positive RGCs.

Mentions: Based on densitometric measurement of band-intensities we detected an increase of 21.5% in p53 in preclinical EAE (MOG_7dpi) compared to sham-immunized control animals. Western blot analysis for full-length APP in retinal lysates suggests that cleavage products of APP seem to be shifted. Furthermore, we performed immunohistochemistry to validate the hypothetical pathway for neurodegeneration in EAE. In healthy control animals we did not detect any p53 positive RGC (Fig 5) whereas in the retina of preclinical EAE an extensive amount of RGCs displayed immune-positive reaction for p53.


Neurodegeneration in Autoimmune Optic Neuritis Is Associated with Altered APP Cleavage in Neurons and Up-Regulation of p53.

Herold S, Kumar P, Wichert SP, Kretzschmar B, Bähr M, Rossner MJ, Hein K - PLoS ONE (2015)

p53-immunoreactivity of RGCs in the preclinical phase of the disease.A strong increase in p53-immunoreactivity was detected in RGC-layer in preclinical EAE (MOG_7dpi). Line indicates borders of the RGC-layer. Arrowheads indicate p53-positive RGCs.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4591258&req=5

pone.0138852.g005: p53-immunoreactivity of RGCs in the preclinical phase of the disease.A strong increase in p53-immunoreactivity was detected in RGC-layer in preclinical EAE (MOG_7dpi). Line indicates borders of the RGC-layer. Arrowheads indicate p53-positive RGCs.
Mentions: Based on densitometric measurement of band-intensities we detected an increase of 21.5% in p53 in preclinical EAE (MOG_7dpi) compared to sham-immunized control animals. Western blot analysis for full-length APP in retinal lysates suggests that cleavage products of APP seem to be shifted. Furthermore, we performed immunohistochemistry to validate the hypothetical pathway for neurodegeneration in EAE. In healthy control animals we did not detect any p53 positive RGC (Fig 5) whereas in the retina of preclinical EAE an extensive amount of RGCs displayed immune-positive reaction for p53.

Bottom Line: Furthermore, genes that are highly specific for autoimmune-driven neurodegeneration were compared to those regulated in RGCs after optic nerve axotomy at corresponding time points.Furthermore, using ingenuity pathway analysis (IPA), we identified amyloid precursor protein (APP) as a potential upstream regulator of changes in gene expression in the preclinical EAE but neither in clinical EAE, nor at any time point after optic nerve transection.Therefore, the gene pathway analysis lead to the hypothesis that altered cleavage of APP in neurons in the preclinical phase of EAE leads to the enhanced production of APP intracellular domain (AICD), which in turn acts as a transcriptional regulator and thereby initiates an apoptotic signaling cascade via up-regulation of the target gene p53.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, University Medicine Göttingen, Göttingen, Germany.

ABSTRACT
Multiple Sclerosis (MS) is a chronic autoimmune inflammatory disease of the central nervous system (CNS). Histopathological and radiological analysis revealed that neurodegeneration occurs early in the disease course. However, the pathological mechanisms involved in neurodegeneration are poorly understood. Myelin oligodendrocyte glycoprotein (MOG)-induced experimental autoimmune encephalomyelitis (EAE) in Brown Norway rats (BN-rats) is a well-established animal model, especially of the neurodegenerative aspects of MS. Previous studies in this animal model indicated that loss of retinal ganglion cells (RGCs), the neurons that form the axons of the optic nerve, occurs in the preclinical phase of the disease and is in part independent of overt histopathological changes of the optic nerve. Therefore, the aim of this study was to identify genes which are involved in neuronal cell loss at different disease stages of EAE. Furthermore, genes that are highly specific for autoimmune-driven neurodegeneration were compared to those regulated in RGCs after optic nerve axotomy at corresponding time points. Using laser capture micro dissection we isolated RNA from unfixed RGCs and performed global transcriptome analysis of retinal neurons. In total, we detected 582 genes sequentially expressed in the preclinical phase and 1150 genes in the clinical manifest EAE (P < 0.05, fold-induction >1.5). Furthermore, using ingenuity pathway analysis (IPA), we identified amyloid precursor protein (APP) as a potential upstream regulator of changes in gene expression in the preclinical EAE but neither in clinical EAE, nor at any time point after optic nerve transection. Therefore, the gene pathway analysis lead to the hypothesis that altered cleavage of APP in neurons in the preclinical phase of EAE leads to the enhanced production of APP intracellular domain (AICD), which in turn acts as a transcriptional regulator and thereby initiates an apoptotic signaling cascade via up-regulation of the target gene p53.

No MeSH data available.


Related in: MedlinePlus