Matrix metalloproteinases in peripheral blood and cerebrospinal fluid in patients with Alzheimer's disease

ABSTRACTBackground: Deposition of amyloid β in senile plaques and in cerebral blood vessels is one hallmark of the pathogenesis of Alzheimer's disease (AD). The ability of several matrix metalloproteinases (MMPs) to degrade amyloid precursor protein leading to aggregation of amyloid β, as well as the increased expression of MMPs in post mortem brain tissue of Alzheimer's patients, indicate that MMPs play an important role in the pathogenesis of AD.Methods: We investigated levels of MMP-2,-3,-9 and -10 in plasma and cerebrospinal fluid (CSF) of AD patients (n = 14) by gelatin and casein zymography. Comparisons between AD patients and controls relative to levels of MMP-2, MMP-3, MMP-9, and MMP-10 were made with Wilcoxon rank statistics. Pearson correlations were computed as measures of association.Results: MMP-3 in AD was significantly elevated in plasma (p = 0.006) and there was a trend towards increase in CSF (p = 0.05). MMP-2 in CSF of AD patients was significantly decreased (p = 0.02) while levels in plasma remained unchanged. MMP-9 and MMP-10 could not be detected in CSF; MMP-10 was unchanged in plasma, but MMP-9 was significantly decreased (p = 0.02).Conclusions: These findings constitute further evidence for the important role of MMPs in the pathogenesis of AD.

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Cerebrospinal fluid levels of the neurotrophic factor neuroleukin are increased in early Alzheimer’s disease, but not in cerebral amyloid angiopathy

Alzheimer s Research & Therapy ◽

10.1186/s13195-021-00899-0 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Anna M. De Kort ◽

H. Bea Kuiperij ◽

Daniel Alcolea ◽

Iris Kersten ◽

Alexandra A. M. Versleijen ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cerebrospinal Fluid ◽

Cerebral Amyloid Angiopathy ◽

Medical Center ◽

Senile Plaques ◽

Amyloid Β ◽

Amyloid Angiopathy ◽

Cerebral Amyloid ◽

Neuro Inflammation

Abstract Background Neuroleukin (NLK) is a protein with neurotrophic properties and is present in a proportion of senile plaques and amyloid laden vessels. It has been suggested that NLK is part of a neuroprotective response to amyloid β-induced cell death. The aim of our study was to investigate the value of cerebrospinal fluid (CSF) NLK levels as a biomarker of vascular amyloid deposition in patients with cerebral amyloid angiopathy (CAA) and in patients with amnestic mild cognitive impairment (aMCI) and Alzheimer’s disease (AD). Methods CSF NLK levels were quantified by ELISA in CAA patients (n = 25) and controls (n = 27) and in two independent samples of aMCI patients, AD patients, and controls: (1) From the Radboud University Medical Center (Nijmegen), we included n = 19 aMCI patients, n = 40 AD patients, and n = 32 controls. (2) From the Hospital of Sant Pau (Barcelona), we included n = 33 aMCI patients, n = 17 AD patients, and n = 50 controls. Results CSF NLK levels were similar in CAA patients and controls (p = 0.95). However, we found an elevated CSF concentration of NLK in aMCI (p < 0.0001) and AD patients (p < 0.0001) compared to controls in both samples sets. In addition, we found a correlation of CSF NLK with CSF YKL-40 (age-adjusted-spearman-rank-coefficient = 0.82, p < 0.0001) in aMCI/AD patients, a well-known glial marker of neuro-inflammation. Conclusions We found that CSF NLK levels are elevated in aMCI and AD patients compared to controls, but are not increased in CAA patients. CSF NLK levels may be related to an increased neuroinflammatory state in early stages of AD, given its association with YKL-40.

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Does Intraneuronal Accumulation of Carboxyl-terminal Fragments of the Amyloid Precursor Protein Trigger Early Neurotoxicity in Alzheimer’s Disease?

Current Alzheimer Research ◽

10.2174/1567205016666190325092841 ◽

2019 ◽

Vol 16 (5) ◽

pp. 453-457 ◽

Cited By ~ 16

Author(s):

I. Lauritzen ◽

R. Pardossi-Piquard ◽

A. Bourgeois ◽

A. Bécot ◽

F. Checler

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Senile Plaques ◽

Amyloid Β ◽

Brain Network ◽

Current Evidence ◽

Behavioral Alterations ◽

Disease Etiology ◽

Intracellular Organelles

Background: Alzheimer’s disease (AD) is associated with extracellular accumulation and aggregation of amyloid β (Aβ) peptides ultimately seeding in senile plaques. Recent data show that their direct precursor C99 (βCTF) also accumulates in AD-affected brain as well as in AD-like mouse models. C99 is consistently detected much earlier than Aβ, suggesting that this metabolite could be an early contributor to AD pathology. C99 accumulates principally within endolysosomal and autophagic structures and its accumulation was described as both a consequence and one of the causes of endolysosomalautophagic pathology, the occurrence of which has been documented as an early defect in AD. C99 was also accompanied by C99-derived C83 (αCTF) accumulation occurring within the same intracellular organelles. Both these CTFs were found to dimerize leading to the generation of higher molecular weight CTFs, which were immunohistochemically characterized in situ by means of aggregate-specific antibodies. Discussion: Here, we discuss studies demonstrating a direct link between the accumulation of C99 and C99-derived APP-CTFs and early neurotoxicity. We discuss the role of C99 in endosomal-lysosomalautophagic dysfunction, neuroinflammation, early brain network alterations and synaptic dysfunction as well as in memory-related behavioral alterations, in triple transgenic mice as well as in newly developed AD animal models. Conclusion: This review summarizes current evidence suggesting a potential role of the β -secretasederived APP C-terminal fragment C99 in Alzheimer’s disease etiology

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Amyloid β-peptide and Alzheimer's disease

Essays in Biochemistry ◽

10.1042/bse0560099 ◽

2014 ◽

Vol 56 ◽

pp. 99-110 ◽

Cited By ~ 15

Author(s):

David Allsop ◽

Jennifer Mayes

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Senile Plaques ◽

Strong Support ◽

Amyloid Β ◽

Amyloid Β Peptide ◽

Amyloid Cascade Hypothesis ◽

Sequence Of Events ◽

Aβ Amyloid ◽

Amyloid Cascade

One of the hallmarks of AD (Alzheimer's disease) is the formation of senile plaques in the brain, which contain fibrils composed of Aβ (amyloid β-peptide). According to the ‘amyloid cascade’ hypothesis, the aggregation of Aβ initiates a sequence of events leading to the formation of neurofibrillary tangles, neurodegeneration, and on to the main symptom of dementia. However, emphasis has now shifted away from fibrillar forms of Aβ and towards smaller and more soluble ‘oligomers’ as the main culprit in AD. The present chapter commences with a brief introduction to the disease and its current treatment, and then focuses on the formation of Aβ from the APP (amyloid precursor protein), the genetics of early-onset AD, which has provided strong support for the amyloid cascade hypothesis, and then on the development of new drugs aimed at reducing the load of cerebral Aβ, which is still the main hope for providing a more effective treatment for AD in the future.

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Microglia in Alzheimer’s Disease

Current Alzheimer Research ◽

10.2174/1567205017666200212155234 ◽

2020 ◽

Vol 17 (1) ◽

pp. 29-43 ◽

Cited By ~ 3

Author(s):

Patrick Süß ◽

Johannes C.M. Schlachetzki

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Neurodegenerative Disorder ◽

Current Knowledge ◽

Imaging Techniques ◽

Amyloid Β ◽

Disease Stage ◽

Disease Modifying Therapy ◽

Transcriptomic Signature

: Alzheimer’s Disease (AD) is the most frequent neurodegenerative disorder. Although proteinaceous aggregates of extracellular Amyloid-β (Aβ) and intracellular hyperphosphorylated microtubule- associated tau have long been identified as characteristic neuropathological hallmarks of AD, a disease- modifying therapy against these targets has not been successful. An emerging concept is that microglia, the innate immune cells of the brain, are major players in AD pathogenesis. Microglia are longlived tissue-resident professional phagocytes that survey and rapidly respond to changes in their microenvironment. Subpopulations of microglia cluster around Aβ plaques and adopt a transcriptomic signature specifically linked to neurodegeneration. A plethora of molecules and pathways associated with microglia function and dysfunction has been identified as important players in mediating neurodegeneration. However, whether microglia exert either beneficial or detrimental effects in AD pathology may depend on the disease stage. : In this review, we summarize the current knowledge about the stage-dependent role of microglia in AD, including recent insights from genetic and gene expression profiling studies as well as novel imaging techniques focusing on microglia in human AD pathology and AD mouse models.

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NLRP3 Inflammasome: A Starring Role in Amyloid-β- and Tau-Driven Pathological Events in Alzheimer’s Disease

Journal of Alzheimer s Disease ◽

10.3233/jad-210268 ◽

2021 ◽

pp. 1-22

Author(s):

Mariana Van Zeller ◽

Diogo M. Dias ◽

Ana M. Sebastião ◽

Cláudia A. Valente

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Glial Cells ◽

Neurofibrillary Tangles ◽

Nlrp3 Inflammasome ◽

Neuronal Death ◽

Inflammatory Responses ◽

Senile Plaques ◽

Amyloid Β ◽

Wide Range

Alzheimer’s disease (AD) is the most prevalent neurodegenerative disease commonly diagnosed among the elderly population. AD is characterized by the loss of synaptic connections, neuronal death, and progressive cognitive impairment, attributed to the extracellular accumulation of senile plaques, composed by insoluble aggregates of amyloid-β (Aβ) peptides, and to the intraneuronal formation of neurofibrillary tangles shaped by hyperphosphorylated filaments of the microtubule-associated protein tau. However, evidence showed that chronic inflammatory responses, with long-lasting exacerbated release of proinflammatory cytokines by reactive glial cells, contribute to the pathophysiology of the disease. NLRP3 inflammasome (NLRP3), a cytosolic multiprotein complex sensor of a wide range of stimuli, was implicated in multiple neurological diseases, including AD. Herein, we review the most recent findings regarding the involvement of NLRP3 in the pathogenesis of AD. We address the mechanisms of NLRP3 priming and activation in glial cells by Aβ species and the potential role of neurofibrillary tangles and extracellular vesicles in disease progression. Neuronal death by NLRP3-mediated pyroptosis, driven by the interneuronal tau propagation, is also discussed. We present considerable evidence to claim that NLRP3 inhibition, is undoubtfully a potential therapeutic strategy for AD.

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Astrocytes and neuroinflammation in Alzheimer's disease

Biochemical Society Transactions ◽

10.1042/bst20140155 ◽

2014 ◽

Vol 42 (5) ◽

pp. 1321-1325 ◽

Cited By ~ 47

Author(s):

Emma C. Phillips ◽

Cara L. Croft ◽

Ksenia Kurbatskaya ◽

Michael J. O’Neill ◽

Michael L. Hutton ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Inflammatory Responses ◽

Amyloid Β ◽

Synaptic Dysfunction ◽

Amyloid Β Peptide ◽

Substantial Evidence ◽

Models Of Disease ◽

Opposing Effects

Increased production of amyloid β-peptide (Aβ) and altered processing of tau in Alzheimer's disease (AD) are associated with synaptic dysfunction, neuronal death and cognitive and behavioural deficits. Neuroinflammation is also a prominent feature of AD brain and considerable evidence indicates that inflammatory events play a significant role in modulating the progression of AD. The role of microglia in AD inflammation has long been acknowledged. Substantial evidence now demonstrates that astrocyte-mediated inflammatory responses also influence pathology development, synapse health and neurodegeneration in AD. Several anti-inflammatory therapies targeting astrocytes show significant benefit in models of disease, particularly with respect to tau-associated neurodegeneration. However, the effectiveness of these approaches is complex, since modulating inflammatory pathways often has opposing effects on the development of tau and amyloid pathology, and is dependent on the precise phenotype and activities of astrocytes in different cellular environments. An increased understanding of interactions between astrocytes and neurons under different conditions is required for the development of safe and effective astrocyte-based therapies for AD and related neurodegenerative diseases.

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Cerebrospinal Fluid Biomarkers of Alzheimer’s Disease: Current Evidence and Future Perspectives

Brain Sciences ◽

10.3390/brainsci11020215 ◽

2021 ◽

Vol 11 (2) ◽

pp. 215

Author(s):

Donovan A. McGrowder ◽

Fabian Miller ◽

Kurt Vaz ◽

Chukwuemeka Nwokocha ◽

Cameil Wilson-Clarke ◽

...

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cerebrospinal Fluid ◽

Late Onset ◽

Amyloid Β ◽

Current Evidence ◽

Csf Biomarkers ◽

Diagnostic Efficacy ◽

Neurofilament Light ◽

New Biomarkers

Alzheimer’s disease is a progressive, clinically heterogeneous, and particularly complex neurodegenerative disease characterized by a decline in cognition. Over the last two decades, there has been significant growth in the investigation of cerebrospinal fluid (CSF) biomarkers for Alzheimer’s disease. This review presents current evidence from many clinical neurochemical studies, with findings that attest to the efficacy of existing core CSF biomarkers such as total tau, phosphorylated tau, and amyloid-β (Aβ42), which diagnose Alzheimer’s disease in the early and dementia stages of the disorder. The heterogeneity of the pathophysiology of the late-onset disease warrants the growth of the Alzheimer’s disease CSF biomarker toolbox; more biomarkers showing other aspects of the disease mechanism are needed. This review focuses on new biomarkers that track Alzheimer’s disease pathology, such as those that assess neuronal injury (VILIP-1 and neurofilament light), neuroinflammation (sTREM2, YKL-40, osteopontin, GFAP, progranulin, and MCP-1), synaptic dysfunction (SNAP-25 and GAP-43), vascular dysregulation (hFABP), as well as CSF α-synuclein levels and TDP-43 pathology. Some of these biomarkers are promising candidates as they are specific and predict future rates of cognitive decline. Findings from the combinations of subclasses of new Alzheimer’s disease biomarkers that improve their diagnostic efficacy in detecting associated pathological changes are also presented.

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Increased Cerebrospinal Fluid Production as a Possible Mechanism Underlying Caffeine's Protective Effect against Alzheimer's Disease

International Journal of Alzheimer s Disease ◽

10.4061/2011/617420 ◽

2011 ◽

Vol 2011 ◽

pp. 1-6 ◽

Cited By ~ 11

Author(s):

Peter Wostyn ◽

Debby Van Dam ◽

Kurt Audenaert ◽

Peter Paul De Deyn

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Cerebrospinal Fluid ◽

Late Onset ◽

Senile Plaques ◽

Protective Effects ◽

Caffeine Consumption ◽

Neuroprotective Effects ◽

Csf Production

Alzheimer's disease (AD), the most common type of dementia among older people, is characterized by the accumulation of β-amyloid (Aβ) senile plaques and neurofibrillary tangles composed of hyperphosphorylated tau in the brain. Despite major advances in understanding the molecular etiology of the disease, progress in the clinical treatment of AD patients has been extremely limited. Therefore, new and more effective therapeutic approaches are needed. Accumulating evidence from human and animal studies suggests that the long-term consumption of caffeine, the most commonly used psychoactive drug in the world, may be protective against AD. The mechanisms underlying the suggested beneficial effect of caffeine against AD remain to be elucidated. In recent studies, several potential neuroprotective effects of caffeine have been proposed. Interestingly, a recent study in rats showed that the long-term consumption of caffeine increased cerebrospinal fluid (CSF) production, associated with the increased expression of Na+-K+ATPase and increased cerebral blood flow. Compromised function of the choroid plexus and defective CSF production and turnover, with diminished clearance of Aβ, may be one mechanism implicated in the pathogenesis of late-onset AD. If reduced CSF turnover is a risk factor for AD, then therapeutic strategies to improve CSF flow are reasonable. In this paper, we hypothesize that long-term caffeine consumption could exert protective effects against AD at least in part by facilitating CSF production, turnover, and clearance. Further, we propose a preclinical experimental design allowing evaluation of this hypothesis.

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