Luc Buée
university of lille
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Featured researches published by Luc Buée.
Neurology | 1999
André Delacourte; J. P. David; Nicolas Sergeant; Luc Buée; Annick Wattez; Patrick Vermersch; F. Ghozali; Catherine Fallet-Bianco; Florence Pasquier; Florence Lebert; H. Petit; C. Di Menza
Objective: To determine the spatiotemporal mapping of neurofibrillary degeneration (NFD) in normal aging and the different stages of AD. Background: The pathophysiologic significance of AD lesions, namely amyloid plaques and neurofibrillary tangles, is still unclear, especially their interrelationship and their link with cognitive impairment. Methods: The study included 130 patients of various ages and different cognitive statuses, from nondemented control subjects (n = 60, prospective study) to patients with severe definite AD. Paired helical filaments (PHF)-tau and Aβ were used as biochemical and histologic markers of NFD and amyloid plaques, respectively. Results: NFD with PHF-tau was systematically present in variable amounts in the hippocampal region of nondemented patients age >75 years. When NFD was found in other brain areas, it was always along a stereotyped, sequential, hierarchical pathway. The progression was categorized into 10 stages according to the brain regions affected: transentorhinal cortex (S1), entorhinal (S2), hippocampus (S3), anterior temporal cortex (S4), inferior temporal cortex (S5), medium temporal cortex (S6), polymodal association areas (prefrontal, parietal inferior, temporal superior) (S7), unimodal areas (S8), primary motor (S9a) or sensory (S9b, S9c) areas, and all neocortical areas (S10). Up to stage 6, the disease could be asymptomatic. In all cases studied here, stage 7 individuals with two polymodal association areas affected by tau pathologic states were cognitively impaired. Conclusions: The relationship between NFD and Alzheimer-type dementia, and the criteria for a biochemical diagnosis of AD, are documented, and an association between AD and the extent of NFD in defined brain areas is shown.
Neuroscience Letters | 1991
Howard Fillit; Wanhong Ding; Luc Buée; Jill Kalman; Larry D. Altstiel; Brian A. Lawlor; Giselle Wolf-Klein
Recent investigations have demonstrated a local inflammatory response in Alzheimers disease (AD), including microglia and cytokines. Levels of the cytokine tumor necrosis factor alpha (TNF-alpha) in sera from patients with AD and age-matched controls were measured by an enzyme-linked immunoassay and a cytotoxicity bioassay. Significantly elevated levels of TNF were found in AD sera compared to controls. Elevated circulating TNF may be derived from the local CNS inflammatory reaction in AD, and may account for some systemic manifestations of AD such as weight loss. Future studies may determine if, in the absence of complicating disorders which may elevate TNF, circulating TNF could be a marker of AD inflammatory activity.
Brain Pathology | 1999
Luc Buée; André Delacourte
Neurodegenerative disorders referred to as tauopathies have cellular hyperphosphorylated tau protein aggregates in the absence of amyloid deposits. Comparative biochemistry of tau aggregates shows that they differ in both phosphorylation and content of tau isoforms. The six tau isoforms found in human brain contain either three (3R) or four microtubule‐binding domains (4R). In Alzheimers disease, all six tau isoforms are abnormally phosphorylated and aggregate into paired helical filaments. They are detected by immunoblotting as a major tau triplet (tau55, 64 and 69). In corticobasal degeneration and progressive supranuclear palsy, only 4R‐t.au isoforms aggregate into twisted and straight filaments respectively. They appear as a major tau doublet (tau64 and 69). Finally, in Picks disease, only 3R‐tau isoforms aggregate into random coiled filaments. They are characterized by another major tau doublet (tau55 and 64). These differences in tau isoforms may be related to either the degeneration of particular cell populations in a given disorder or aberrant cell trafficking of particular tau isoforms. Finally, recent findings provide a direct link between a genetic defect in tau and its abnormal aggregation into filaments in fronto‐temporal dementia with Parkinsonism linked to chromosome 17, demonstrating that tau aggregation is sufficient for nerve cell degeneration. Thus, tau mutations and polymorphisms may also be instrumental in many neurodegenerative disorders.
Acta Neuropathologica | 1994
Luc Buée; Patrick R. Hof; Constantin Bouras; A. Delacourte; Daniel P. Perl; John H. Morrison; Howard Fillit
Alterations of the cerebral microvasculature have been reported in aging and in neurodegenerative disorders such as Alzheimers disease. However, the exact role of microvascular alterations in the pathogenesis of neurodegeneration remains unknown. In the present report, the cerebral cortex microvasculature was studied by immunohistochemistry using a monoclonal antibody against vascular heparan sulfate proteoglycan protein core in normal aging controls, Alzheimers disease, Down syndrome, Guam amyotrophic lateral sclerosis/parkinsonian dementia complex, Picks disease and dementia pugilistica. In all dementing illnesses, increased microvascular pathology was evident compared to normal controls. Decreased microvascular density and numerous atrophic vessels were the primary abnormalities observed in all dementing disorders. These microvascular abnormalities demonstrated regional and laminar selectivity, and were primarly found in layers III and V of frontal and temporal cortex. Quantitative analysis employing computer-assisted microscopy demonstrated that the decrease in microvascular density in Alzheimers disease was statistically significant compared to age-matched controls. In addition, extracellular heparan sulfate proteoglycan deposits were observed which colocalized with thioflavine S-positive senile plaques in Alzheimers disease, Down syndrome and selected Guam dementia cases. In some cases, heparan sulfate proteoglycan was seen in senile plaques that appeared to be diffuse or primitive plaques that stained weakly with thioflavine. Heparan sulfate proteoglycan-containing neurons were also observed in Alzheimers disease, as well as in Down syndrome and Guam cases. Glial staining for heparan sulfate proteoglycan was never observed. Our data support previous observations that microvascular pathology is found in aging and in Alzheimers disease. The changes in Alzheimers disease exceed those found in normal aging controls. We also found microvascular pathology in all other dementing disorders studied. Our studies further demonstrated that the microvascular pathology displays regional and laminar patterns which parallel patterns of neuronal loss. Finally, we also found that heparan sulfate proteoglycan is present in senile plaques and neurons not only as previously reported in Alzheimers disease, but also in Down syndrome and Guam cases. Heparan sulfate proteoglycan in senile plaques may be derived from either the degenerating microvasculature or from degenerating neurons. Further studies are necessary to determine the role of microvascular disease in the progression of Alzheimers disease and other dementing disorders.
Genes, Brain and Behavior | 2008
Katharina Schindowski; Karim Belarbi; Luc Buée
Neurotrophic factors (NTF) are small, versatile proteins that maintain survival and function to specific neuronal populations. In general, the axonal transport of NTF is important as not all of them are synthesized at the site of its action. Nerve growth factor (NGF), for instance, is produced in the neocortex and the hippocampus and then retrogradely transported to the cholinergic neurons of the basal forebrain. Neurodegenerative dementias like Alzheimer’s disease (AD) are linked to deficits in axonal transport. Furthermore, they are also associated with imbalanced distribution and dysregulation of NTF. In particular, brain‐derived neurotrophic factor (BDNF) plays a crucial role in cognition, learning and memory formation by modulating synaptic plasticity and is, therefore, a critical molecule in dementia and neurodegenerative diseases. Here, we review the changes of NTF expression and distribution (NGF, BDNF, neurotrophin‐3, neurotrophin‐4/5 and fibroblast growth factor‐2) and their receptors [tropomyosin‐related kinase (Trk)A, TrkB, TrkC and p75NTR] in AD and AD models. In addition, we focus on the interaction with neuropathological hallmarks Tau/neurofibrillary tangle and amyloid‐β (Abeta)/amyloid plaque pathology and their influence on axonal transport processes in order to unify AD‐specific cholinergic degeneration and Tau and Abeta misfolding through NTF pathophysiology.
Human Molecular Genetics | 2010
Sébastien S. Hébert; Aikaterini S. Papadopoulou; Pascal Y. Smith; Marie-Christine Galas; Emmanuel Planel; Asli Silahtaroglu; Nicolas Sergeant; Luc Buée; Bart De Strooper
Type III RNase Dicer is responsible for the maturation and function of microRNA (miRNA) molecules in the cell. It is now well-documented that Dicer and the fine-tuning of the miRNA gene network are important for neuronal integrity. However, the underlying mechanisms involved in neuronal death, particularly in the adult brain, remain poorly defined. Here we show that the absence of Dicer in the adult forebrain is accompanied by a mixed neurodegenerative phenotype. Although neuronal loss is observed in the hippocampus, cellular shrinkage is predominant in the cortex. Interestingly, neuronal degeneration coincides with the hyperphosphorylation of endogenous tau at several epitopes previously associated with neurofibrillary pathology. Transcriptome analysis of enzymes involved in tau phosphorylation identified ERK1 as one of the candidate kinases responsible for this event in vivo. We further demonstrate that miRNAs belonging to the miR-15 family are potent regulators of ERK1 expression in mouse neuronal cells and co-expressed with ERK1/2 in vivo. Finally, we show that miR-15a is specifically downregulated in Alzheimers disease brain. In summary, these results support the hypothesis that changes in the miRNA network may contribute to a neurodegenerative phenotype by affecting tau phosphorylation.
Journal of Neuropathology and Experimental Neurology | 1996
André Delacourte; Yves Robitaille; Nicolas Sergeant; Luc Buée; Patrick R. Hof; Annick Wattez; Andrée Laroche-Cholette; Jean Mathieu; Pierre Chagnon; Denis Gauvreau
Picks disease (PiD) is characterized by a pan-laminar frontotemporal cortical atrophy, widespread degeneration of the white matter, chromatolytic neurons, and Pick bodies (PB). Microtubule-associated Tau proteins are the main cytoskeletal components modified during these neurodegenerative changes. In the present study, pathological alterations of Tau proteins were investigated in the brains of five PiD cases at both neuropathological and biochemical levels, using the monoclonal antibody AD2 which recognizes a phosphorylation-dependent Tau epitope and strongly labeled PB. A large number of cortical and subcortical regions were studied on frozen materials. Tau proteins were analyzed on mono- and two-dimensional gel electrophoreses using a quantitative western blot approach. In all specimens, a 55 and 64 kDa Tau doublet was observed in limbic, frontal, and temporal cortices as well as in striatum and substantia nigra. In contrast, Alzheimers disease (AD) brains are characterized by the presence of the 55, 64, and 69 kDa Tau triplet whereas the 64 and 69 kDa doublet is more typical of progressive supranuclear palsy and corticobasal degeneration. Thus, the 55 and 64 kDa doublet appears to be specific to PiD, less acidic than AD Tau proteins, and well correlated with the presence of PB.
Journal of Biological Chemistry | 2011
Audrey Sultan; Fabrice Nesslany; Marie Violet; Séverine Bégard; Anne Loyens; Smail Talahari; Zeyni Mansuroglu; Daniel Marzin; Nicolas Sergeant; Sandrine Humez; Morvane Colin; Eliette Bonnefoy; Luc Buée; Marie-Christine Galas
Tau, a neuronal protein involved in neurodegenerative disorders such as Alzheimer disease, which is primarily described as a microtubule-associated protein, has also been observed in the nuclei of neuronal and non-neuronal cells. However, the function of the nuclear form of Tau in neurons has not yet been elucidated. In this work, we demonstrate that acute oxidative stress and mild heat stress (HS) induce the accumulation of dephosphorylated Tau in neuronal nuclei. Using chromatin immunoprecipitation assays, we demonstrate that the capacity of endogenous Tau to interact with neuronal DNA increased following HS. Comet assays performed on both wild-type and Tau-deficient neuronal cultures showed that Tau fully protected neuronal genomic DNA against HS-induced damage. Interestingly, HS-induced DNA damage observed in Tau-deficient cells was completely rescued after the overexpression of human Tau targeted to the nucleus. These results highlight a novel role for nuclear Tau as a key player in early stress response.
Expert Review of Proteomics | 2008
Nicolas Sergeant; Alexis Bretteville; Malika Hamdane; Marie-Laure Caillet-Boudin; Pierre Grognet; Stéphanie Bombois; David Blum; André Delacourte; Florence Pasquier; Eugeen Vanmechelen; Susanna Schraen-Maschke; Luc Buée
Microtubule-associated Tau proteins belong to a family of factors that polymerize tubulin dimers and stabilize microtubules. Tau is strongly expressed in neurons, localized in the axon and is essential for neuronal plasticity and network. From the very beginning of Tau discovery, proteomics methods have been essential to the knowledge of Tau biochemistry and biology. In this review, we have summarized the main contributions of several proteomic methods in the understanding of Tau, including expression, post-translational modifications and structure, in both physiological and pathophysiological aspects. Finally, recent advances in proteomics technology are essential to develop further therapeutic targets and early predictive and discriminative diagnostic assays for Alzheimer’s disease and related disorders.
Acta Neuropathologica | 1992
Patrick R. Hof; Constantin Bouras; Luc Buée; André Delacourte; Daniel P. Perl; John H. Morrison
SummaryHead trauma has been associated with the occurrence of Alzhiemers disease and plays a clear role in the etiopathogenesis of the boxers encephalopathy referred to as dementia pugilistica. Neurofibrillary tangles (NFT), one of the pathological hallmarks of Alzheimers disease are observed in very high densities in the brains of former professional boxers suffering from dementia pugilistica. In Alzheimers disease, NFT display striking regional and laminar distribution patterns that have been correlated with the localization of neurons forming specific corticocortical connections. In dementia pugilistica cases, NFT were concentrated in the superficial layers in the neocortex, whereas in Alzheimers disease they predominated in the deep layers. Thus, the association cortex of brains from dementia pugilistica patients demonstrated an inverse NFT distribution as compared to Alzheimers disease. This finding suggests that a more circumscribed population of cortical pyramidal neurons might be affected in dementia pugilistica than in Alzheimers disease.