Alzheimer's disease (AD) is characterized by amyloid-beta (A beta) deposits, which come in myriad morphologies with varying clinical relevance. Previously, we observed an atypical A beta deposit,... Show moreAlzheimer's disease (AD) is characterized by amyloid-beta (A beta) deposits, which come in myriad morphologies with varying clinical relevance. Previously, we observed an atypical A beta deposit, referred to as the coarse-grained plaque. In this study, we evaluate the plaque's association with clinical disease and perform in-depth immunohistochemical and morphological characterization. The coarse-grained plaque, a relatively large (o approximate to 80 mu m) deposit, characterized as having multiple cores and A beta-devoid pores, was prominent in the neocortex. The plaque was semi-quantitatively scored in the middle frontal gyrus of A beta-positive cases (n = 74), including non-demented cases (n = 15), early-onset (EO)AD (n = 38), and late-onset (LO)AD cases (n = 21). The coarse-grained plaque was only observed in cases with clinical dementia and more frequently present in EOAD compared to LOAD. This plaque was associated with a homozygousAPOE epsilon 4 status and cerebral amyloid angiopathy (CAA). In-depth characterization was done by studying the coarse-grained plaque's neuritic component (pTau, APP, PrP (c)), A beta isoform composition (A beta(40), A beta(42), A beta(N3pE), pSer8A beta), its neuroinflammatory component (C4b, CD68, MHC-II, GFAP), and its vascular attribution (laminin, collagen IV, norrin). The plaque was compared to the classic cored plaque, cotton wool plaque, and CAA. Similar to CAA but different from classic cored plaques, the coarse-grained plaque was predominantly composed of A beta(40). Furthermore, the coarse-grained plaque was distinctly associated with both intense neuroinflammation and vascular (capillary) pathology. Confocal laser scanning microscopy (CLSM) and 3D analysis revealed for most coarse-grained plaques a particular A beta(40)shell structure and a direct relation with vessels. Based on its morphological and biochemical characteristics, we conclude that the coarse-grained plaque is a divergent A beta plaque-type associated with EOAD. Differences in A beta processing and aggregation, neuroinflammatory response, and vascular clearance may presumably underlie the difference between coarse-grained plaques and other A beta deposits. Disentangling specific A beta deposits between AD subgroups may be important in the search for disease-mechanistic-based therapies. Show less
Bulk, M.; Kenkhuis, B.; Graaf, L.M. van der; Goeman, J.J.; Natte, R.; Weerd, L. van der 2018
Hereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D) is an early onset hereditary form of cerebral amyloid angiopathy (CAA) pathology, caused by the E22Q mutation in the amyloid... Show moreHereditary cerebral hemorrhage with amyloidosis-Dutch type (HCHWA-D) is an early onset hereditary form of cerebral amyloid angiopathy (CAA) pathology, caused by the E22Q mutation in the amyloid beta (A beta) peptide. Transforming growth factor beta 1 (TGF beta 1) is a key player in vascular fibrosis and in the formation of angiopathic vessels in transgenic mice. Therefore, we investigated whether the TGF beta pathway is involved in HCHWA-D pathogenesis in human postmortem brain tissue from frontal and occipital lobes. Components of the TGF pathway were analyzed with quantitative RT-PCR. TGF beta 1 and TGF beta Receptor 2 (TGFBR2) gene expression levels were significantly increased in HCHWA-D in comparison to the controls, in both frontal and occipital lobes. TGF beta-induced pro-fibrotic target genes were also upregulated. We further assessed pathway activation by detecting phospho-SMAD2/3 (pSMAD2/3), a direct TGF beta down-stream signaling mediator, using immunohistochemistry. We found abnormal pSMAD2/3 granular deposits specifically on HCHWA-D angiopathic frontal and occipital vessels. We graded pSMAD2/3 accumulation in angiopathic vessels and found a positive correlation with the CAA load independent of the brain area. We also observed pSMAD2/3 granules in a halo surrounding occipital vessels, which was specific for HCHWA-D. The result of this study indicates an upregulation of TGF beta 1 in HCHWA-D, as was found previously in AD with CAA pathology. We discuss the possible origins and implications of the TGF beta pathway deregulation in the microvasculature in HCHWA-D. These findings identify the TGF beta pathway as a potential biomarker of disease progression and a possible target of therapeutic intervention in HCHWA-D. Show less
Bulk, M.; Abdelmoula, W.M.; Nabuurs, R.J.A.; Graaf, L.M. van der; Mulders, C.W.H.; Mulder, A.A.; ... ; Weerd, L. van der 2018
The value of iron-based MRI changes for the diagnosis and staging of Alzheimer's disease (AD) depends on an association between cortical iron accumulation and AD pathology. Therefore, this study... Show moreThe value of iron-based MRI changes for the diagnosis and staging of Alzheimer's disease (AD) depends on an association between cortical iron accumulation and AD pathology. Therefore, this study determined the cortical distribution pattern of MRI contrast changes in cortical regions selected based on the known distribution pattern of tau pathology and investigated whether MRI contrast changes reflect the underlying AD pathology in the different lobes. T-2*-weighted MRI was performed on postmortem cortical tissue of controls, late-onset AD (LOAD), and early-onset AD (EOAD) followed by histology and correlation analyses. Combining ex vivo high-resolution MRI and histopathology revealed that: 1) LOAD and EOAD have a different distribution pattern of AD pathological hallmarks and MRI contrast changes over the cortex, with EOAD showing more severe MRI changes; 2) per lobe, severity of AD pathological hallmarks correlates with iron accumulation, and hence with MRI. Therefore, iron-sensitive MRI sequences allow detection of the cortical distribution pattern of AD pathology ex vivo. Show less
Duijn, S. van; Bulk, M.; Duinen, S.G. van; Nabuurs, R.J.A.; Buchem, M.A. van; Weerd, L. van der; Natte, R. 2017
Cerebral deposits of amyloid-β peptides (Aβ) form the neuropathological hallmarks of Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA). In the brain, Aβ can aggregate as insoluble... Show moreCerebral deposits of amyloid-β peptides (Aβ) form the neuropathological hallmarks of Alzheimer's disease (AD) and cerebral amyloid angiopathy (CAA). In the brain, Aβ can aggregate as insoluble fibrils present in amyloid plaques and vascular amyloid, or as diffuse plaques consisting of mainly non-fibrillar Aβ. Previously, magnetic resonance imaging (MRI) has been shown to be capable of detecting individual amyloid plaques, not only via the associated iron, but also Aβ itself has been suggested to be responsible for a decrease in the image intensity. In this current study we aim to investigate the MRI properties of the different cerebral Aβ deposits including diffuse plaques and vascular amyloid. Postmortem 60-μm-thick brain sections of AD, CAA, and Down's syndrome patients, known to contain Aβ, were studied. High resolution T2*- and T2-weighted MRI scans and quantitative relaxation maps were acquired using a microcoil on a Bruker 9.4T MRI system. Specific MRI characteristics of each type of Aβ deposit were examined by co-registration of the MRI with Congo Red and Aβ-immunostainings of the same sections. Our results show that only fibrillar Aβ, present in both vascular and parenchymal amyloid, induced a significant change in T2* and T2 values. However, signal changes were not as consistent for all of the vessels affected by CAA, irrespective of possible dyshoric changes. In contrast, the non-fibrillar diffuse plaques did not create any detectable MRI signal changes. These findings are relevant for the interpretation and further development of (quantitative) MRI methods for the detection and follow-up of AD and CAA. Show less
Duijn, S. van; Nabuurs, R.J.A.; Duinen, S.G. van; Natte, R.; Buchem, M.A. van; Alia, A. 2013
Epidemiological studies indicate that the incidence of Alzheimer's disease (AD) is higher in women than in men. There is evidence that changes in metabolites in the brain associated with the... Show moreEpidemiological studies indicate that the incidence of Alzheimer's disease (AD) is higher in women than in men. There is evidence that changes in metabolites in the brain associated with the development of AD are present earlier than structural brain changes. The effect of sex on the metabolic profile during the development of AD has not yet been studied. In this study we longitudinally monitored and compared in vivo metabolic changes in male and female AβPPswe, PSEN1dE9 transgenic mice brains using magnetic resonance spectroscopy. Our results show a lower level of glutamate as well as of N-acetylaspartate (NAA) in transgenic mice. The decline in NAA with age was more apparent in female mice. The level of taurine was higher in female mice and showed a faster decline over time. In conclusion, our study is the first to suggest that changes in the metabolic profile during AD development are influenced by sex. Show less
Duijn, S. van; Nabuurs, R.J.A.; Duinen, S.G. van; Natte, R.; Buchem, M.A. van; Alia, A. 2013
Abstract. Epidemiological studies indicate that the incidence of Alzheimer’s disease (AD) is higher inwomen than in men. There is evidence that changes in metabolites in the brain associated with... Show moreAbstract. Epidemiological studies indicate that the incidence of Alzheimer’s disease (AD) is higher inwomen than in men. There is evidence that changes in metabolites in the brain associated with the development of AD are present earlier than structural brain changes. The effect of sex on the metabolic profile during the development of AD has not yet been studied. In this study we longitudinally monitored and compared in vivo metabolic changes in male and female APPswe, PSEN1dE9 transgenic mice brains using magnetic resonance spectroscopy. Our results show a lower level of glutamate as well as of N-acetylaspartate (NAA) in transgenic mice. The decline in NAA with age was more apparent in female mice. The level of taurine was higher in female mice and showed a faster decline over time. In conclusion, our study is the first to suggest that changes in the metabolic profile during AD development are influenced by sex. Abstract. Epidemiological studies indicate that the incidence of Alzheimer’s disease (AD) is higher inwomen than in men. There is evidence that changes in metabolites in the brain associated with the development of AD are present earlier than structural brain changes. The effect of sex on the metabolic profile during the development of AD has not yet been studied. In this study we longitudinally monitored and compared in vivo metabolic changes in male and female APPswe, PSEN1dE9 transgenic mice brains using magnetic resonance spectroscopy. Our results show a lower level of glutamate as well as of N-acetylaspartate (NAA) in transgenic mice. The decline in NAA with age was more apparent in female mice. The level of taurine was higher in female mice and showed a faster decline over time. In conclusion, our study is the first to suggest that changes in the metabolic profile during AD development are influenced by sex. Show less
Duijn, S. van; Nabuurs, R.J.A.; Duinen, S.G. van; Natte, R. 2013
Better knowledge of the distribution of iron in the brains of Alzheimer’s disease (AD) patients may facilitate the development of an in vivo magnetic resonance (MR) marker for AD and may cast light... Show moreBetter knowledge of the distribution of iron in the brains of Alzheimer’s disease (AD) patients may facilitate the development of an in vivo magnetic resonance (MR) marker for AD and may cast light on the role of this potentially toxic molecule in the pathogenesis of AD. Several histological iron staining techniques have been used in the past but they have not been systematically tested for sensitivity and specificity. This article compares three histochemical techniques and ferritin immunohistochemistry to visualize iron in paraffin-embedded human AD brain tissue. The specificity of the histochemical techniques was tested by staining sections after iron extraction. Iron was demonstrated in the white matter, in layers IV/V of the frontal neocortex, in iron containing plaques, and in microglia. In our hands, these structures were best visualized using the Meguro iron stain, a method that has not been described for iron staining in human brain or AD in particular. Ferritin immunohistochemistry stained microglia and iron containing plaques similar to the Meguro method but was less intense in myelin-associated iron. The Meguro method is most suitable for identifying iron-positive structures in paraffinembedded human AD brain tissue. Better knowledge of the distribution of iron in the brains of Alzheimer’s disease (AD) patients may facilitate the development of an in vivo magnetic resonance (MR) marker for AD and may cast light on the role of this potentially toxic molecule in the pathogenesis of AD. Several histological iron staining techniques have been used in the past but they have not been systematically tested for sensitivity and specificity. This article compares three histochemical techniques and ferritin immunohistochemistry to visualize iron in paraffin-embedded human AD brain tissue. The specificity of the histochemical techniques was tested by staining sections after iron extraction. Iron was demonstrated in the white matter, in layers IV/V of the frontal neocortex, in iron containing plaques, and in microglia. In our hands, these structures were best visualized using the Meguro iron stain, a method that has not been described for iron staining in human brain or AD in particular. Ferritin immunohistochemistry stained microglia and iron containing plaques similar to the Meguro method but was less intense in myelin-associated iron. The Meguro method is most suitable for identifying iron-positive structures in paraffinembedded human AD brain tissue. Show less
Duijn, S. van; Nabuurs, R.J.A.; Rooden, S. van; Maat-Schieman, M.L.C.; Duinen, S.G. van; Buchem, M.A. van; ... ; Natte, R. 2011
For the interpretation of magnetic resonance imaging (MRI) abnormalities in brain pathology, often ex vivo tissue is used. The purpose of this study was to determine the pathological substrate of... Show moreFor the interpretation of magnetic resonance imaging (MRI) abnormalities in brain pathology, often ex vivo tissue is used. The purpose of this study was to determine the pathological substrate of several distinct forms of MR hypointensities that were found in formalin-fixed brain tissue with amyloid-beta deposits. Samples of brain cortex were scanned using effective transverse relaxation time-weighted protocols at several resolutions on a 9.4 T MRI scanner. High resolution MRI showed large coarse hypointensities throughout the cortical gray and white matter, corresponding to macroscopic discolorations and microscopic circumscribed areas of granular basophilic neuropil changes, without any further specific tissue reactions or amyloid-beta related pathology. These coarse MRI hypointensities were identified as localized areas of absent neuropil replaced by membrane/myelin sheath remnants using electron microscopy. Interestingly, the presence/absence of these tissue alterations was not related to amyloid deposits, but strongly correlated to the fixation time of the samples in unrefreshed formalin. These findings show that prolonged storaged of formalin fixed brain tissue results in subtle histology artifacts, which show on MRI as hypointensities that on first appearance are indistinguishable from genuine brain pathology. This indicates that postmortem MRI should be interpreted with caution, especially if the history of tissue preservation is not fully known. Magn Reson Med 65:1750-1758, 2011. (C)2011 Wiley-Liss, Inc. Show less
Coremans, I.; Wiggenraad, R.; Jong, M. de; Santvoort, J. van; Ages, D.; Putter, H.; ... ; Creutzberg, C. 2011
A simple inductively coupled microcoil has been designed to image tissue samples placed on a microscope slide, samples which can subsequently be stained histologically. As the exact same tissue is... Show moreA simple inductively coupled microcoil has been designed to image tissue samples placed on a microscope slide, samples which can subsequently be stained histologically. As the exact same tissue is used for MRI and histology, the two data sets can be compared without the need for complicated image registration techniques. The design can be integrated into any MRI system using existing commercial hardware. Compared with a commercial 25-mm-diameter birdcage, the signal-to-noise ratio was increased by a factor of 3.8, corresponding to an approximate 15-fold reduction in the data acquisition time. An example is shown of ex vivo samples from patients with Alzheimer's disease, in which the coregistration of highly sensitive iron staining and amyloid-beta deposits is confirmed. Copyright (C) 2010 John Wiley & Sons, Ltd. Show less
Duijn, S. van; Nabuurs, R.J.A.; Rooden, S. van; Maat-Schieman, M.L.C.; Duinen, S.G. van; Buchem, M.A. van; ... ; Natte, R. 2011
For the interpretation of magnetic resonance imaging (MRI) abnormalities in brain pathology, often ex vivo tissue is used. The purpose of this study was to determine the pathological substrate of... Show moreFor the interpretation of magnetic resonance imaging (MRI) abnormalities in brain pathology, often ex vivo tissue is used. The purpose of this study was to determine the pathological substrate of several distinct forms of MR hypointensities that were found in formalin-fixed brain tissue with amyloid-beta deposits. Samples of brain cortex were scanned using effective transverse relaxation time-weighted protocols at several resolutions on a 9.4 T MRI scanner. High resolution MRI showed large coarse hypointensities throughout the cortical gray and white matter, corresponding to macroscopic discolorations and microscopic circumscribed areas of granular basophilic neuropil changes, without any further specific tissue reactions or amyloid-beta related pathology. These coarse MRI hypointensities were identified as localized areas of absent neuropil replaced by membrane/myelin sheath remnants using electron microscopy. Interestingly, the presence/ absence of these tissue alterations was not related to amyloid deposits, but strongly correlated to the fixation time of the samples in unrefreshed formalin. These findings show that prolonged storaged of formalin fixed brain tissue results in subtle histology artifacts, which show on MRI as hypointensities that on first appearance are indistinguishable from genuine brain pathology. This indicates that postmortem MRI should be interpreted with caution, especially if the history of tissue preservation is not fully known. For the interpretation of magnetic resonance imaging (MRI) abnormalities in brain pathology, often ex vivo tissue is used. The purpose of this study was to determine the pathological substrate of several distinct forms of MR hypointensities that were found in formalin-fixed brain tissue with amyloid-beta deposits. Samples of brain cortex were scanned using effective transverse relaxation time-weighted protocols at several resolutions on a 9.4 T MRI scanner. High resolution MRI showed large coarse hypointensities throughout the cortical gray and white matter, corresponding to macroscopic discolorations and microscopic circumscribed areas of granular basophilic neuropil changes, without any further specific tissue reactions or amyloid-beta related pathology. These coarse MRI hypointensities were identified as localized areas of absent neuropil replaced by membrane/myelin sheath remnants using electron microscopy. Interestingly, the presence/ absence of these tissue alterations was not related to amyloid deposits, but strongly correlated to the fixation time of the samples in unrefreshed formalin. These findings show that prolonged storaged of formalin fixed brain tissue results in subtle histology artifacts, which show on MRI as hypointensities that on first appearance are indistinguishable from genuine brain pathology. This indicates that postmortem MRI should be interpreted with caution, especially if the history of tissue preservation is not fully known. Show less
