Publications by authors named "Miguel Angel Ontiveros-Torres"

Alzheimer's disease (AD) is clinically characterized by a progressive loss of cognitive functions and short-term memory. AD patients present two distinctive neuropathological lesions: neuritic plaques and neurofibrillary tangles (NFTs), constituted of beta-amyloid peptide (Aβ) and phosphorylated and truncated tau proteins. Aβ deposits around cerebral blood vessels (cerebral amyloid angiopathy, CAA) is a major contributor to vascular dysfunction in AD.

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Alzheimer's disease (AD) is a neurodegenerative disease, characterized histopathologically by intra-neuronal tau-related lesions and by the accumulation of amyloid β-peptide (Aβ) in the brain parenchyma and around cerebral blood vessels. According to the vascular hypothesis of AD, an alteration in the neurovascular unit (NVU) could lead to Aβ vascular accumulation and promote neuronal dysfunction, accelerating neurodegeneration and dementia. To date, the effects of insoluble vascular Aβ deposits on the NVU and the blood-brain barrier (BBB) are unknown.

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Background: Transmissible spongiform encephalopathies (TSEs) are rare neurodegenerative disorders that affect animals and humans. Bovine spongiform encephalopathy (BSE) in cattle, and Creutzfeld-Jakob Disease (CJD) in humans belong to this group. The causative agent of TSEs is called "prion", which corresponds to a pathological form (PrPSc) of a normal cellular protein (PrPC) expressed in nerve cells.

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Article Synopsis
  • Alzheimer's disease (AD) and progressive supranuclear palsy (PSP) are both tauopathies, characterized by abnormal tau protein aggregates; AD features a 1:1 ratio of 4-repeat to 3-repeat tau isoforms, while PSP shows a predominance of the 4-repeat isoform.
  • The study aimed to compare how pathological tau is processed in PSP compared to AD, utilizing double and triple immunofluorescent labeling techniques analyzed through confocal microscopy.
  • Results indicated that phosphorylated tau was similarly abundant in both conditions, but PSP had unique tau truncation patterns and extracellular NFTs that could lead to the identification of distinct biomarkers for differentiating AD from PSP.
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Article Synopsis
  • About 50 million people suffer from dementia globally, with Alzheimer's disease being the most prevalent type, leading to significant disability among the elderly.
  • Alzheimer's is marked by memory loss and cognitive decline, with key brain lesions included neuritic plaques and neurofibrillary tangles caused by tau protein abnormalities.
  • The review discusses how tau undergoes pathological changes—like hyperphosphorylation and truncation—contributing to the progression from pre-NFTs to NFTs, highlighting the role of the PHF core in forming these tangles and tau phosphorylation's potential protective effects.
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We recently developed the National Dementia Biobank in México (BioBanco Nacional de Demencias, BND) as a unit for diagnosis, research, and tissue transfer for research purposes. BND is associated with the Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de Mexico (UNAM), Mexico. The donation of fluids, brain, and other organs of deceased donors is crucial for understanding the underlying mechanisms of neurodegenerative diseases and for the development of successful treatment.

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Background: Neurofibrillary tangles (NFTs) and amyloid plaques are the neuropathological hallmarks in brains with Alzheimer's disease (AD). Post-translational modifications of tau, such as phosphorylation and truncation, have been proposed as initiators in the assembly of the abnormal paired helical filaments that constitute the NFTs. Neurons and NFTs are sites of matrix metalloproteinases (MMPs).

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It has been reported that the main function of tau protein is to stabilize microtubules and promote the movement of organelles through the axon in neurons. In Alzheimer's disease, tau protein is the major constituent of the paired helical filament, and it undergoes post-translational modifications including hyperphosphorylation and truncation. Whether other functions of tau protein are involved in Alzheimer's disease is less clear.

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Alzheimer's disease (AD) is a degenerative and irreversible disorder whose progressiveness is dependent on age. It is histopathologically characterized by the massive accumulation of insoluble forms of tau and amyloid-β (Aβ) asneurofibrillary tangles and neuritic plaques, respectively. Many studies have documented that these two polypeptides suffer several posttranslational modifications employing postmortem tissue sections from brains of patients with AD.

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