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- Baldo, B., et al.
(författare)
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SIRT1 is increased in affected brain regions and hypothalamic metabolic pathways are altered in Huntington disease
- 2019
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Ingår i: Neuropathology and Applied Neurobiology. - : Wiley. - 0305-1846 .- 1365-2990. ; 45:4, s. 361-379
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Metabolic dysfunction is involved in modulating the disease process in Huntington disease (HD) but the underlying mechanisms are not known. The aim of this study was to investigate if the metabolic regulators sirtuins are affected in HD. Methods: Quantitative real-time polymerase chain reactions were used to assess levels of SIRT1-3 and downstream targets in post mortem brain tissue from HD patients and control cases as well as after selective hypothalamic expression of mutant huntingtin (HTT) using recombinant adeno-associated viral vectors in mice. Results: We show that mRNA levels of the metabolic regulator SIRT1 are increased in the striatum and the cerebral cortex but not in the less affected cerebellum in post mortem HD brains. Levels of SIRT2 are only increased in the striatum and SIRT3 is not affected in HD. Interestingly, mRNA levels of SIRT1 are selectively increased in the lateral hypothalamic area (LHA) and ventromedial hypothalamus (VMH) in HD. Further analyses of the LHA and VMH confirmed pathological changes in these regions including effects on SIRT1 downstream targets and reduced mRNA levels of orexin (hypocretin), prodynorphin and melanin-concentrating hormone (MCH) in the LHA and of brain-derived neurotrophic factor (BDNF) in the VMH. Analyses after selective hypothalamic expression of mutant HTT suggest that effects on BDNF, orexin, dynorphin and MCH are early and direct, whereas changes in SIRT1 require more widespread expression of mutant HTT. Conclusions: We show that SIRT1 expression is increased in HD-affected brain regions and that metabolic pathways are altered in the HD hypothalamus.
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- Craggs, L. J. L., et al.
(författare)
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Clusterin/Apolipoprotein J immunoreactivity is associated with white matter damage in cerebral small vessel diseases
- 2016
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Ingår i: Neuropathology and Applied Neurobiology. - : Wiley. - 0305-1846 .- 1365-2990. ; 42:2, s. 194-209
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Tidskriftsartikel (refereegranskat)abstract
- AimBrain clusterin is known to be associated with the amyloid- deposits in Alzheimer's disease (AD). We assessed the distribution of clusterin immunoreactivity in cerebrovascular disorders, particularly focusing on white matter changes in small vessel diseases. MethodsPost-mortem brain tissues from the frontal or temporal lobes of a total of 70 subjects with various disorders including cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), cerebral amyloid angiopathy (CAA) and AD were examined using immunohistochemistry and immunofluorescence. We further used immunogold electron microscopy to study clusterin immunoreactivity in extracellular deposits in CADASIL. ResultsImmunostaining with clusterin antibodies revealed strong localization in arterioles and capillaries, besides cortical neurones. We found that clusterin immunostaining was significantly increased in the frontal white matter of CADASIL and pontine autosomal dominant microangiopathy and leukoencephalopathy subjects. In addition, clusterin immunostaining correlated with white matter pathology severity scores. Immunostaining in axons ranged from fine punctate deposits in single axons to larger confluent areas with numerous swollen axon bulbs, similar to that observed with known axon damage markers such as non-phosphorylated neurofilament H and the amyloid precursor protein. Immunofluorescence and immunogold electron microscopy experiments showed that whereas clusterin immunoreactivity was closely associated with vascular amyloid- in CAA, it was lacking within the granular osmiophilic material immunolabelled by NOTCH3 extracelluar domain aggregates found in CADASIL. ConclusionsOur results suggest a wider role for clusterin associated with white matter damage in addition to its ability to chaperone proteins for clearance via the perivascular drainage pathways in several disease states.
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- Dahlrot, R. H., et al.
(författare)
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Prognostic value of O-6-methylguanine-DNA methyltransferase (MGMT) protein expression in glioblastoma excluding nontumour cells from the analysis
- 2018
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Ingår i: Neuropathology and Applied Neurobiology. - : Wiley. - 0305-1846 .- 1365-2990. ; 44:2, s. 172-184
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Tidskriftsartikel (refereegranskat)abstract
- Aims: It is important to predict response to treatment with temozolomide (TMZ) in glioblastoma (GBM) patients. Both MGMT protein expression and MGMT promoter methylation status have been reported to predict the response to TMZ. We investigated the prognostic value of quantified MGMT protein levels in tumour cells and the prognostic importance of combining information of MGMT protein level and MGMT promoter methylation status.Methods: MGMT protein expression was quantified in tumour cells in 171 GBMs from the population‐based Region of Southern Denmark (RSD)‐cohort using a double immunofluorescence approach. Pyrosequencing was performed in 157 patients. For validation we used GBM‐patients from a Nordic Study (NS) investigating the effect of radiotherapy and different TMZ schedules.Results: When divided at the median, patients with low expression of MGMT protein (AF‐low) had the best prognosis (HR = 1.5, P = 0.01). Similar results were observed in the subgroup of patients receiving the Stupp regimen (HR = 2.0, P = 0.001). In the NS‐cohort a trend towards superior survival (HR = 1.6, P = 0.08) was seen in patients with AF‐low. Including MGMT promoter methylation status, we found for both cohorts that patients with methylated MGMT promoter and AF‐low had the best outcome; median OS 23.1 and 20.0 months, respectively.Conclusion: Our data indicate that MGMT protein expression in tumour cells has an independent prognostic significance. Exclusion of nontumour cells contributed to a more exact analysis of tumour‐specific MGMT protein expression. This should be incorporated in future studies evaluating MGMT status before potential integration into clinical practice.
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- Eide, P. K., et al.
(författare)
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Astrogliosis and impaired aquaporin-4 and dystrophin systems in idiopathic normal pressure hydrocephalus
- 2018
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Ingår i: Neuropathology and Applied Neurobiology. - : Wiley. - 0305-1846. ; 44:5, s. 474-490
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Idiopathic normal pressure hydrocephalus (iNPH) is one subtype of dementia that may improve following drainage of cerebrospinal fluid (CSF). This prospective observational study explored whether expression of the water channel aquaporin-4 (AQP4) and the anchoring molecule dystrophin 71 (Dp71) are altered at astrocytic perivascular endfeet and in adjacent neuropil of iNPH patient. Observations were related to measurements of pulsatile and static intracranial pressure (ICP). Methods: The study included iNPH patients undergoing overnight monitoring of the pulsatile/static ICP in whom a biopsy was taken from the frontal cerebral cortex during placement of the ICP sensor. Reference (Ref) biopsies were sampled from 13 patients who underwent brain surgery for epilepsy, tumours or cerebral aneurysms. The brain tissue specimens were examined by light microscopy, immunohistochemistry, densitometry and morphometry. Results: iNPH patients responding to surgery (n = 44) had elevated pulsatile ICP, indicative of impaired intracranial compliance. As compared to the Ref patients, the cortical biopsies of iNPH patients revealed prominent astrogliosis and reduced expression of AQP4 and Dp71 immunoreactivities in the astrocytic perivascular endfeet and in parts of the adjacent neuropil. There was a significant correlation between degree of astrogliosis and reduction of AQP4 and Dp71 at astrocytic perivascular endfeet. Conclusions: Idiopathic normal pressure hydrocephalus patients responding to CSF diversion present with abnormal pulsatile ICP, indicative of impaired intracranial compliance. A main histopathological finding was astrogliosis and reduction of AQP4 and of Dp71 in astrocytic perivascular endfeet. We propose that the altered AQP4 and Dp71 complex contributes to the subischaemia prevalent in the brain tissue of iNPH.
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- Ek Olofsson, H., et al.
(författare)
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A cortical microvascular structure in vascular dementia, Alzheimer's disease, frontotemporal lobar degeneration and nondemented controls : a sign of angiogenesis due to brain ischaemia?
- 2019
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Ingår i: Neuropathology and Applied Neurobiology. - : Wiley. - 0305-1846 .- 1365-2990. ; 45:6, s. 557-569
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Tidskriftsartikel (refereegranskat)abstract
- Aims: We observed a microvascular structure in the cerebral cortex that has not, to our knowledge, been previously described. We have termed the structure a ‘raspberry’, referring to its appearance under a bright-field microscope. We hypothesized that raspberries form through angiogenesis due to some form of brain ischaemia or hypoperfusion. The aims of this study were to quantify raspberry frequency within the cerebral cortex according to diagnosis (vascular dementia, Alzheimer's disease, frontotemporal lobar degeneration and nondemented controls) and brain regions (frontal, temporal, parietal and occipital cortices, regardless of diagnosis). Materials and methods: In each of 10 age-matched subjects per group, a 20-mm section of the cerebral cortex was examined in haematoxylin-and-eosin-stained sections of the frontal, temporal and parietal, and/or occipital lobes. Tests were performed to validate the haematoxylin-and-eosin-based identification of relative differences between the groups, and to investigate inter-rater variability. Results: Raspberry frequency was highest in subjects with vascular dementia, followed by those with frontotemporal lobar degeneration, Alzheimer's disease and last, nondemented controls. The frequency of raspberries in subjects with vascular dementia differed from that of all other groups at a statistically significant level. In the cerebral lobes, there was a statistically significant difference between the frontal and occipital cortices. Conclusions: We believe the results support the hypothesis that raspberries are a sign of angiogenesis in the adult brain. It is pertinent to discuss possible proangiogenic stimuli, including brain ischaemia (such as mild hypoperfusion due to a combination of small vessel disease and transient hypotension), neuroinflammation and protein pathology.
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- Schuelke, Markus, et al.
(författare)
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Myopathology in the times of modern genetics.
- 2017
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Ingår i: Neuropathology and applied neurobiology. - : Wiley. - 1365-2990 .- 0305-1846. ; 43:1, s. 44-61
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Forskningsöversikt (refereegranskat)abstract
- The advent of Next Generation Sequencing (NGS) technologies has accelerated the rate of novel disease gene discovery. Analysis of the large datasets generated by whole exome sequencing, whole genome sequencing, and other NGS approaches poses a challenge to physicians and pathologists searching for disease causing variants amongst the 50,000-3 million polymorphisms typically seen in these datasets. This review describes strategies that successfully combine classical neuropathological investigation (e.g. histology, immunostaining, and electron microscopy) with modern NGS technologies to pinpoint the underlying genetic cause of a disease. We describe filtering techniques and free online bioinformatic tools that can help physicians and researchers establish a molecular diagnosis from NGS data. The ethical issues raised by NGS data are outlined. We provide specific examples that illustrate how traditional and contemporary approaches integrate to solve a difficult diagnosis or to correct initially wrong assumptions based on data generated from one method alone. This article is protected by copyright. All rights reserved.
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