Amyloid β protein negatively regulates human platelet activation induced by thrombin receptor-activating protein

Abstract Amyloid β protein deposition in cerebral vessels, a characteristic of Alzheimer's disease, is a risk factor for intracerebral hemorrhage. Amyloid β protein directly modulates human platelet function; however, the exact mechanism of action is unclear. Therefore, we investigated the effects of amyloid β protein on human platelet activation using an aggregometer with laser scattering. Amyloid β protein decreased platelet aggregation induced by thrombin receptor-activating protein, but not by collagen and ADP. Amyloid β protein also suppressed platelet aggregation induced by SCP0237 and A3227. Platelet-derived growth factor-AB secretion and phosphorylated-heat shock protein 27 release by thrombin receptor-activating protein were inhibited by amyloid β protein. Additionally, thrombin receptor-activating protein-induced phosphorylation of JNK and p38 MAP kinase was reduced by amyloid β protein. Collectively, our results strongly suggest that amyloid β protein negatively regulates protease-activated receptor-elicited human platelet activation. These findings may indicate a cause of intracerebral hemorrhage due to amyloid β protein.

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Amyloid β protein negatively regulates the human platelet activation induced by thrombin receptor-activating protein

10.21203/rs.3.rs-391777/v1 ◽

2021 ◽

Author(s):

Daisuke Mizutani ◽

Haruhiko Tokuda ◽

Takashi Onuma ◽

Kodai Uematsu ◽

Daiki Nakashima ◽

...

Keyword(s):

Platelet Aggregation ◽

Intracerebral Hemorrhage ◽

Platelet Activation ◽

Human Platelet ◽

Amyloid Β ◽

Human Platelets ◽

The Other ◽

Thrombin Receptor ◽

Amyloid Β Protein ◽

Β Protein

Abstract Background: Amyloid β protein (Aβ) is the main product derived from amyloid precursor protein (APP) by sequential enzymatic actions. Deposition of Aβ in the brain parenchyma or cerebral vessels is a primary morphological feature of Alzheimer’s disease (AD). In addition, abnormal accumulation of Aβ in the cerebral vessels is known as cerebral amyloid angiopathy (CAA), which is considered a risk factor for intracerebral hemorrhage, particularly in the elderly. CAA reportedly contributes to the development of vascular cognitive decline in addition to AD. On the other hand, human platelets are recognized as the principal components affecting the onset and progression of AD. Although there are several studies showing that Aβ directly modulates human platelet functions, the exact mechanism underlying the Aβ effects on human platelets remains to be elucidated.Methods: The present study investigated the effects of Aβ on human platelet activation using a platelet aggregometer with laser scattering, followed by western blot analysis and ELISA.Results: Aβ at doses up to 7 µM alone failed to affect platelet aggregation or platelet-derived growth factor (PDGF)-AB secretion. On the other hand, Aβ decreased the platelet aggregation induced by thrombin receptor-activating protein (TRAP), but not collagen or ADP. Aβ also suppressed platelet aggregation induced by SCP0237, a selective protease-activated receptor (PAR)-1 agonist, and A3227, a selective PAR-4 agonist. The PDGF-AB secretion and the phosphorylated-heat shock protein (HSP)27 release by TRAP were inhibited by Aβ. In addition, the TRAP-induced phosphorylation of JNK and the phosphorylation of p38 MAP kinase followed by phosphorylation of HSP27 were reduced by Aβ.Conclusion: The results of the present study strongly suggest that Aβ negatively regulates PAR-elicited human platelet activation. These findings may indicate one of the causes of intracerebral hemorrhage due to CAA.

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The Inhalation Anesthetic Isoflurane Induces a Vicious Cycle of Apoptosis and Amyloid β-Protein Accumulation

Yearbook of Anesthesiology and Pain Management ◽

10.1016/s1073-5437(08)70801-5 ◽

2008 ◽

Vol 2008 ◽

pp. 35-36

Author(s):

H.T. Lee

Keyword(s):

Amyloid Β ◽

Protein Accumulation ◽

Amyloid Β Protein ◽

Vicious Cycle ◽

Inhalation Anesthetic ◽

Β Protein

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LOW-DOSE PHOSPHODIESTERASE III INHIBITOR (CILOSTAZOL) REDUCES THE VASCULAR AMYLOID BURDEN IN AMYLOID-Β PROTEIN PRECURSOR TRANSGENIC MICE

10.26226/morressier.58e389aed462b802923858c2 ◽

2017 ◽

Author(s):

Yusuke Yakushiji

Keyword(s):

Transgenic Mice ◽

Low Dose ◽

Amyloid Β ◽

Amyloid Β Protein ◽

Amyloid Burden ◽

Protein Precursor ◽

Β Protein ◽

Phosphodiesterase Iii Inhibitor ◽

Phosphodiesterase Iii

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Extracellular Protein Aggregates Colocalization and Neuronal Dystrophy in Comorbid Alzheimer’s and Creutzfeldt–Jakob Disease: A Micromorphological Pilot Study on 20 Brains

International Journal of Molecular Sciences ◽

10.3390/ijms22042099 ◽

2021 ◽

Vol 22 (4) ◽

pp. 2099

Author(s):

Nikol Jankovska ◽

Tomas Olejar ◽

Radoslav Matej

Keyword(s):

Prion Protein ◽

Fluorescent Microscopy ◽

Amyloid Β ◽

Amyloid Β Protein ◽

Β Protein ◽

Key Characteristics ◽

Jakob Disease ◽

Immunohistochemical Methods ◽

Confocal Fluorescent Microscopy ◽

Codon 129

Alzheimer’s disease (AD) and sporadic Creutzfeldt–Jakob disease (sCJD) are both characterized by extracellular pathologically conformed aggregates of amyloid proteins—amyloid β-protein (Aβ) and prion protein (PrPSc), respectively. To investigate the potential morphological colocalization of Aβ and PrPSc aggregates, we examined the hippocampal regions (archicortex and neocortex) of 20 subjects with confirmed comorbid AD and sCJD using neurohistopathological analyses, immunohistochemical methods, and confocal fluorescent microscopy. Our data showed that extracellular Aβ and PrPSc aggregates tended to be, in most cases, located separately, and “compound” plaques were relatively rare. We observed PrPSc plaque-like structures in the periphery of the non-compact parts of Aβ plaques, as well as in tau protein-positive dystrophic structures. The AD ABC score according to the NIA-Alzheimer’s association guidelines, and prion protein subtype with codon 129 methionine–valine (M/V) polymorphisms in sCJD, while representing key characteristics of these diseases, did not correlate with the morphology of the Aβ/PrPSc co-aggregates. However, our data showed that PrPSc aggregation could dominate during co-aggregation with non-compact Aβ in the periphery of Aβ plaques.

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Molecular Insight into Cu2+-Induced Conformational Transitions of Amyloid β-Protein from Fast Kinetic Analysis and Molecular Dynamics Simulations

ACS Chemical Neuroscience ◽

10.1021/acschemneuro.0c00502 ◽

2021 ◽

Author(s):

Shaoying Xu ◽

Wenjuan Wang ◽

Xiaoyan Dong ◽

Yan Sun

Keyword(s):

Molecular Dynamics ◽

Kinetic Analysis ◽

Molecular Dynamics Simulations ◽

Amyloid Β ◽

Conformational Transitions ◽

Amyloid Β Protein ◽

Β Protein ◽

Fast Kinetic ◽

Dynamics Simulations ◽

Insight Into

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Correction to: Amyloid β-protein oligomers promote the uptake of tau fibril seeds potentiating intracellular tau aggregation

Alzheimer s Research & Therapy ◽

10.1186/s13195-021-00824-5 ◽

2021 ◽

Vol 13 (1) ◽

Author(s):

Woo Shik Shin ◽

Jing Di ◽

Qin Cao ◽

Binsen Li ◽

Paul M. Seidler ◽

...

Keyword(s):

Amyloid Β ◽

Amyloid Β Protein ◽

Β Protein ◽

Tau Aggregation

An amendment to this paper has been published and can be accessed via the original article.

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Amyloid β-protein deposition in skin of patients with dementia

The Lancet ◽

10.1016/0140-6736(92)90046-6 ◽

1992 ◽

Vol 339 (8787) ◽

pp. 245 ◽

Cited By ~ 38

Author(s):

Hilkka Soininen ◽

Stina Syrjänen ◽

Outi Heinonen ◽

Heikki Neittaanmäki ◽

Riitta Miettinen ◽

...

Keyword(s):

Amyloid Β ◽

Amyloid Β Protein ◽

Protein Deposition ◽

Β Protein

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Amyloid-β Oligomers Induce Only Mild Changes to Inhibitory Bouton Dynamics

Journal of Alzheimer s Disease Reports ◽

10.3233/adr-200291 ◽

2021 ◽

Vol 5 (1) ◽

pp. 153-160 ◽

Cited By ~ 1

Author(s):

Marvin Ruiter ◽

Christine Lützkendorf ◽

Jian Liang ◽

Corette J. Wierenga

Keyword(s):

Hippocampal Slices ◽

Inhibitory Neuron ◽

Amyloid Β ◽

Inhibitory Neurons ◽

Inhibitory Synapses ◽

Amyloid Β Protein ◽

Protein Precursor ◽

Β Protein ◽

Plaque Load ◽

Early Alzheimer’S Disease

The amyloid-β protein precursor is highly expressed in a subset of inhibitory neuron in the hippocampus, and inhibitory neurons have been suggested to play an important role in early Alzheimer’s disease plaque load. Here we investigated bouton dynamics in axons of hippocampal interneurons in two independent amyloidosis models. Short-term (24 h) amyloid-β (Aβ)-oligomer application to organotypic hippocampal slices slightly increased inhibitory bouton dynamics, but bouton density and dynamics were unchanged in hippocampus slices of young-adult AppNL - F - G-mice, in which Aβ levels are chronically elevated. These results indicate that loss or defective adaptation of inhibitory synapses are not a major contribution to Aβ-induced hyperexcitability.

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