Publications by authors named "Figueiredo-Pereira M"

Neuroinflammation is a key pathological hallmark of Alzheimer's disease (AD). Investigational and FDA approved drugs targeting inflammation already exist, thus drug repurposing for AD is a suitable approach. BT-11 is an investigational drug that reduces inflammation in the gut and improves cognitive function.

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Alzheimer's disease (AD) is the major form of dementia prevalent in older adults and with a high incidence in females. Identification of early biomarkers is essential for preventive intervention to delay its progression. Furthermore, due to its multifactorial nature, a multi-target approach could be therapeutically beneficial.

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Nearly two-thirds of patients with Alzheimer's are women. Identifying therapeutics specific for women is critical to lowering their elevated risk for developing this major cause of adult dementia. Moreover, targeting epigenetic processes that regulate multiple cellular pathways is advantageous given Alzheimer's multifactorial nature.

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Alzheimer's disease (AD) is a progressive neurodegenerative disease that is most prevalent in females. While estrogen provides neuroprotection in females, sex mediated differences in the development of AD pathology are not fully elucidated. Therefore, comparing events between sexes in early-stage AD pathology may reveal more effective therapeutic targets of intervention.

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We investigated the relevance of the prostaglandin D2 pathway in Alzheimer's disease, because prostaglandin D2 is a major prostaglandin in the brain. Thus, its contribution to Alzheimer's disease merits attention, given the known impact of the prostaglandin E2 pathway in Alzheimer's disease. We used the TgF344-AD transgenic rat model because it exhibits age-dependent and progressive Alzheimer's disease pathology.

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Alzheimer's disease is a multifactorial disease that exhibits cognitive deficits, neuronal loss, amyloid plaques, neurofibrillary tangles and neuroinflammation in the brain. Hence, a multi-target drug would improve treatment efficacy. We applied a new multi-scale predictive modelling framework that integrates machine learning with biophysics and systems pharmacology to screen drugs for Alzheimer's disease using patients' tissue samples.

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Background: Inflammation in the brain is mediated by the cyclooxygenase pathway, which leads to the production of prostaglandins. Prostaglandin (PG) D2, the most abundant PG in the brain, increases under pathological conditions and is spontaneously metabolized to PGJ2. PGJ2 is highly neurotoxic, with the potential to transition neuroinflammation into a chronic state and contribute to neurodegeneration as seen in many neurological diseases.

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Article Synopsis
  • Mitochondrial impairment and abnormal calcium levels are linked to Parkinson's disease, leading to reduced ATP and increased calpain activation, which affects the integrity of Parkin, a protein involved in maintaining cellular health.
  • Experiments with mitochondrial inhibitors (such as oligomycin) showed that they cause calpain to cleave Parkin into smaller fragments, while other agents induced different types of cleavage that suggest involvement in apoptosis.
  • Pre-treatment with certain inhibitors can stabilize Parkin and reduce its cleavage, highlighting the potential connection between Parkin phosphorylation and its cleavage due to mitochondrial dysfunction and calcium imbalance, which may play a role in the progression of Parkinson's disease.
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Background: Prostaglandins are products of the cyclooxygenase pathway, which is implicated in Parkinson's disease (PD). Limited knowledge is available on mechanisms by which prostaglandins contribute to PD neurodegeneration. To address this gap, we focused on the prostaglandin PGD2/J2 signaling pathway, because PGD2 is the most abundant prostaglandin in the brain, and the one that increases the most under pathological conditions.

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Methamphetamine (MA) is an addictive drug with neurotoxic effects on the brain producing cognitive impairment and increasing the risk for neurodegenerative disease. Research has focused largely on examining the neurochemical and behavioral deficits induced by injecting relatively high doses of MA [30 mg/kg of body weight (bw)] identifying the upper limits of MA-induced neurotoxicity. Accordingly, we have developed an appetitive mouse model of voluntary oral MA administration (VOMA) based on the consumption of a palatable sweetened oatmeal mash containing a known amount of MA.

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Regulation of the amyloid precursor protein (APP) processing by α- and β-secretases is of special interest to Alzheimer's disease (AD), as these proteases prevent or mediate amyloid beta formation, respectively. Neuroinflammation is also implicated in AD. Our data demonstrate that the endogenous mediator of inflammation prostaglandin J2 (PGJ2) promotes full-length APP (FL-APP) processing by α- and β-secretases.

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In Alzheimer's disease proteasome activity is reportedly downregulated, thus increasing it could be therapeutically beneficial. The proteasome-associated deubiquitinase USP14 disassembles polyubiquitin-chains, potentially delaying proteasome-dependent protein degradation. We assessed the protective efficacy of inhibiting or downregulating USP14 in rat and mouse (Usp14) neuronal cultures treated with prostaglandin J2 (PGJ2).

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The ubiquitin-proteasome system (UPS) is a crucial protein degradation system in eukaryotes. Herein, we will review advances in the understanding of the role of several proteins of the UPS in Alzheimer's disease (AD) and functional recovery after spinal cord injury (SCI). The UPS consists of many factors that include E3 ubiquitin ligases, ubiquitin hydrolases, ubiquitin and ubiquitin-like molecules, and the proteasome itself.

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Prostaglandins (PGs) are produced via cyclooxygenases, which are enzymes that play a major role in neuroinflammation. Epidemiological studies show that chronic treatment with low levels of cyclooxygenase inhibitors (nonsteroidal anti-inflammatory drugs (NSAIDs)) lowers the risk for Alzheimer's disease (AD) and Parkinson's disease (PD) by as much as 50%. Unfortunately, inhibiting cyclooxygenases with NSAIDs blocks the synthesis of downstream neuroprotective and neurotoxic PGs, thus producing adverse side effects.

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The immune response of the CNS is a defense mechanism activated upon injury to initiate repair mechanisms while chronic over-activation of the CNS immune system (termed neuroinflammation) may exacerbate injury. The latter is implicated in a variety of neurological and neurodegenerative disorders such as Alzheimer and Parkinson diseases, amyotrophic lateral sclerosis, multiple sclerosis, traumatic brain injury, HIV dementia, and prion diseases. Cyclooxygenases (COX-1 and COX-2), which are key enzymes in the conversion of arachidonic acid into bioactive prostanoids, play a central role in the inflammatory cascade.

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Neuroinflammation is a major risk factor in Parkinson's disease (PD). Alternative approaches are needed to treat inflammation, as anti-inflammatory drugs such as NSAIDs that inhibit cyclooxygenase-2 (COX-2) can produce devastating side effects, including heart attack and stroke. New therapeutic strategies that target factors downstream of COX-2, such as prostaglandin J2 (PGJ2), hold tremendous promise because they will not alter the homeostatic balance offered by COX-2 derived prostanoids.

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Purpose: To develop an experimental model of acute inflammation, like aphthous ulcers, in oral cavity of rabbits, and also, to evaluate the results of the application of a polysaccharide spongy film of molasses from sugar cane as assist treatment in the healing process.

Methods: Twenty adult rabbits weighting between 2.5 kg and 3.

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Article Synopsis
  • The cAMP-signaling pathway is a crucial cellular mechanism that influences various biological processes, despite being regulated by a small molecule, cAMP.
  • The pathway involves key components like G-protein-coupled receptors, adenylate cyclases, and protein kinase A, which hold potential for new drug targets.
  • Recent findings highlight cAMP’s role in regulating protein degradation through the ubiquitin/proteasome pathway, suggesting new therapeutic strategies for treating neurodegenerative disorders and other diseases linked to protein accumulation.
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Proteasomal and mitochondrial dysfunctions are implicated in chronic neurodegenerative diseases. To investigate the impact of mitochondrial impairment on the proteasome, we treated rat cerebral cortical neurons with oligomycin, antimycin, or rotenone, which inhibit different elements of the electron transport chain. Firstly, we observed a reduction in ubiquitinated proteins and E1 activity.

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Proteasome impairment and accumulation of ubiquitinated proteins are implicated in neurodegeneration associated with different forms of spinal cord injury. We show herein that elevating cAMP in rat spinal cord neurons increases 26S proteasome activity in a protein kinase A-dependent manner. Treating spinal cord neurons with dibutyryl-cAMP (db-cAMP) also raised the levels of various components of the UPP including proteasome subunits Rpt6 and β5, polyubiquitin shuttling factor p62/sequestosome1, E3 ligase CHIP, AAA-ATPase p97 and the ubiquitin gene ubB.

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In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding.

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Neurofibrillary tangles (NFTs) are hallmarks of Alzheimer's disease (AD). The main component of NFTs is TAU, a highly soluble microtubule-associated protein. However, when TAU is cleaved at Asp421 by caspases it becomes prone to aggregation leading to NFTs.

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The ubiquitin/proteasome pathway (UPP) is the major proteolytic quality control system in cells and involves tightly regulated removal of unwanted proteins and retention of those that are essential. In addition to its function in normal protein degradation, the UPP plays a critical role in the quality control process by degrading mutated or abnormally folded proteins. The proteolytic component of the UPP is a multiprotein complex known as the proteasome.

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Proteotoxicity resulting from accumulation of damaged/unwanted proteins contributes prominently to cellular aging and neurodegeneration. Proteasomal removal of these proteins upon covalent polyubiquitination is highly regulated. Recent reports proposed a role for autophagy in clearance of diffuse ubiquitinated proteins delivered by p62/SQSTM1.

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The mitomycin derivative 10-decarbamoyl mitomycin C (DMC) more rapidly activates a p53-independent cell death pathway than mitomycin C (MC). We recently documented that an increased proportion of mitosene1-beta-adduct formation occurs in human cells treated with DMC in comparison to those treated with MC. Here, we compare the cellular and molecular response of human cancer cells treated with MC and DMC.

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