260 research outputs found

    Bacteriophages a bio sustainable solution to tackle Alzheimer´s disease

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    Introduction: Amyloid-beta (AB) is a prime suspect to cause Alzheimers disease (AD), an irreversible, progressive and age-dependent neurodegenerative disorder affecting millions of people worldwide. An accumulation of AB in the brain leads to its aggregation into soluble oligomeric and fibrillar clusters, which are the culprits to impair synaptic function and memory formation in mice models. Currently, we lack diagnostic tools to detect AB oligomers (ABOs) in the brain, all the methods used provide a late diagnosis when there are already symptoms. Moreover, the existence of the blood-brain-barrier (BBB) is the major bottleneck for reaching the brain. To overcome this, bacteriophages (phages: bacterial viruses) are a solution, once they posses the capacity to cross the BBB. Aims: Hence, our main goals were the development of a solution to 1) detect ABOs in the brain and monitor AD progression and 2) delay or prevent the onset of the symptoms. Methods: We resorted to phage engineering with AB-targeting peptides described to recognize ABOs and fibrils with high affinity. These were tested for their capacity to detect ABOs in tissues samples and their effect on AB aggregation. Results: The engineered phages are able to detect the early and toxic forms of AB in brain tissue of APP/PS1 transgenic mice and human donors. Moreover, these phages also possess a high therapeutic potential by inhibiting the aggregation process of AB. Conclusion: We provide a highly versatile bio-inspired solution based on phages displaying AB peptides to detect early soluble AB oligomers in the brain, and possibly prevent, or delay, the onset of the symptoms, consequently inhibiting AD progression.The authors thank the Project EARLY - Phage towards initial amyloid-beta funded by TecMinho through the iProof initiative, in the scope of the project UI-Transfer, co-financed by COMPETE 2020, through Fundo Europeu de Desenvolvimento Regional (FEDER). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020, center grant UID/MULTI/04046/2020 (to BioISI), PhD fellowship SFRH/BD/101171/2014 (to J.S.C.), and by Alzheimer Nederland (H.W.K.).info:eu-repo/semantics/publishedVersio

    M13 phage grafted with peptide motifs as a tool to detect amyloid- oligomers in brain tissue

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    Oligomeric clusters of amyloid- (A) are one of the major biomarkers for Alzheimers disease (AD). However, proficient methods to detect A-oligomers in brain tissue are lacking. Here we show that synthetic M13 bacteriophages displaying A-derived peptides on their surface preferentially interact with A-oligomers. When exposed to brain tissue isolated from APP/PS1-transgenic mice, these bacteriophages detect small-sized A-aggregates in hippocampus at an early age, prior to the occurrence of A-plaques. Similarly, the bacteriophages reveal the presence of such small A-aggregates in post-mortem hippocampus tissue of ADpatients. These results advocate bacteriophages displaying A-peptides as a convenient and low-cost tool to identify A-oligomers in post-mortem brain tissue of AD-model mice and AD patients.FCT -Fundação para a Ciência e a Tecnologia(SFRH/BD/101171/2014)info:eu-repo/semantics/publishedVersio

    Natural killer cells modulate motor neuron-immune cell cross talk in models of Amyotrophic Lateral Sclerosis.

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    In amyotrophic lateral sclerosis (ALS), immune cells and glia contribute to motor neuron (MN) degeneration. We report the presence of NK cells in post-mortem ALS motor cortex and spinal cord tissues, and the expression of NKG2D ligands on MNs. Using a mouse model of familial-ALS, hSOD1G93A, we demonstrate NK cell accumulation in the motor cortex and spinal cord, with an early CCL2-dependent peak. NK cell depletion reduces the pace of MN degeneration, delays motor impairment and increases survival. This is confirmed in another ALS mouse model, TDP43A315T. NK cells are neurotoxic to hSOD1G93A MNs which express NKG2D ligands, while IFNγ produced by NK cells instructs microglia toward an inflammatory phenotype, and impairs FOXP3+/Treg cell infiltration in the spinal cord of hSOD1G93A mice. Together, these data suggest a role of NK cells in determining the onset and progression of MN degeneration in ALS, and in modulating Treg recruitment and microglia phenotype

    Comparative interactomics analysis of different ALS-associated proteins identifies converging molecular pathways

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    Amyotrophic lateral sclerosis (ALS) is a devastating neurological disease with no effective treatment available. An increasing number of genetic causes of ALS are being identified, but how these genetic defects lead to motor neuron degeneration and to which extent they affect common cellular pathways remains incompletely understood. To address these questions, we performed an interactomic analysis to identify binding partners of wild-type (WT) and ALS-associated mutant versions of ATXN2, C9orf72, FUS, OPTN, TDP-43 and UBQLN2 in neuronal cells. This analysis identified several known but also many novel binding partners of these proteins

    Amyotrophic Lateral Sclerosis, a Multisystem Pathology: Insights into the Role of TNF\u3b1

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    Amyotrophic lateral sclerosis (ALS) is considered a multifactorial, multisystem disease in which inflammation and the immune system play important roles in development and progression. The pleiotropic cytokine TNF\u3b1 is one of the major players governing the inflammation in the central nervous system and peripheral districts such as the neuromuscular and immune system. Changes in TNF\u3b1 levels are reported in blood, cerebrospinal fluid, and nerve tissues of ALS patients and animal models. However, whether they play a detrimental or protective role on the disease progression is still not clear. Our group and others have recently reported opposite involvements of TNFR1 and TNFR2 in motor neuron death. TNFR2 mediates TNF\u3b1 toxic effects on these neurons presumably through the activation of MAP kinase-related pathways. On the other hand, TNFR2 regulates the function and proliferation of regulatory T cells (Treg) whose expression is inversely correlated with the disease progression rate in ALS patients. In addition, TNF\u3b1 is considered a procachectic factor with a direct catabolic effect on skeletal muscles, causing wasting. We review and discuss the role of TNF\u3b1 in ALS in the light of its multisystem nature

    Regulation of Kir4.1 expression in astrocytes and astrocytic tumors: a role for interleukin-1 beta

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    <p>Abstract</p> <p>Objective</p> <p>Decreased expression of inwardly rectifying potassium (Kir) channels in astrocytes and glioma cells may contribute to impaired K<sup>+</sup> buffering and increased propensity for seizures. Here, we evaluated the potential effect of inflammatory molecules, such as interleukin-1β (IL-1β) on Kir4.1 mRNA and protein expression.</p> <p>Methods</p> <p>We investigated Kir4.1 (Kcnj10) and IL-1β mRNA expression in the temporal cortex in a rat model of temporal lobe epilepsy 24 h and 1 week after induction of status epilepticus (SE), using real-time PCR and western blot analysis. The U373 glioblastoma cell line and human fetal astrocytes were used to study the regulation of Kir4.1 expression in response to pro-inflammatory cytokines. Expression of Kir4.1 protein was also evaluated by means of immunohistochemistry in surgical specimens of patients with astrocytic tumors (<it>n</it> = 64), comparing the expression in tumor patients with (<it>n</it> = 38) and without epilepsy (<it>n</it> = 26).</p> <p>Results</p> <p>Twenty-four hours after onset of SE, Kir4.1 mRNA and protein were significantly down-regulated in temporal cortex of epileptic rats. This decrease in expression was followed by a return to control level at 1 week after SE. The transient downregulation of Kir4.1 corresponded to the time of prominent upregulation of IL-1β mRNA. Expression of Kir4.1 mRNA and protein in glial cells in culture was downregulated after exposure to IL-1β. Evaluation of Kir4.1 in tumor specimens showed a significantly lower Kir4.1 expression in the specimens of patients with epilepsy compared to patients without epilepsy. This paralleled the increased presence of activated microglial cells, as well as the increased expression of IL-1β and the cytoplasmic translocation of high mobility group box 1 (HMGB1).</p> <p>Conclusions</p> <p>Taken together, these findings indicate that alterations in expression of Kir4.1 occurring in epilepsy-associated lesions are possibly influenced by the local inflammatory environment and in particular by the inflammatory cytokine IL-1β.</p

    Dementia in Rare Genetic Neurodevelopmental Disorders:A Systematic Literature Review

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    BACKGROUND AND OBJECTIVES: Knowledge of young-onset Alzheimer disease in adults with Down syndrome has greatly improved clinical care. However, little is known about dementia in rare genetic neurodevelopmental disorders (RGNDs). In this review, a comprehensive overview is provided of reports on dementia and cognitive/adaptive trajectories in adults with RGNDs. METHODS: A systematic literature review was conducted in Embase, Medline ALL, and PsycINFO on December 6, 2022. The protocol was registered in PROSPERO (CRD42021223041). Search terms for dementia, cognitive and adaptive functioning, and RGNDs were combined using generic terms and the Orphanet database. Study characteristics and descriptive data on genetic diagnosis, clinical and neuropathologic features, comorbidities, and diagnostic methods were extracted using a modified version of the Cochrane Data Extraction Template. RESULTS: The literature search yielded 40 publications (17 cohorts, 23 case studies) describing dementia and/or cognitive or adaptive trajectories in adults with 14 different RGNDs. Dementia was reported in 49 individuals (5 cohorts, 20 cases) with a mean age at onset of 44.4 years. Diagnostics were not disclosed for half of the reported individuals (n = 25/49, 51.0%). A total of 44 different psychodiagnostic instruments were used. MRI was the most reported additional investigation (n = 12/49, 24.5%). Comorbid disorders most frequently associated with cognitive/adaptive decline were epilepsy, psychotic disorders, and movement disorders. DISCUSSION: Currently available literature shows limited information on aging in RGNDs, with relatively many reports of young-onset dementia. Longitudinal data may provide insights into converging neurodevelopmental degenerative pathways. We provide recommendations to optimize dementia screening, diagnosis, and research.</p

    Dementia in Rare Genetic Neurodevelopmental Disorders:A Systematic Literature Review

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    BACKGROUND AND OBJECTIVES: Knowledge of young-onset Alzheimer disease in adults with Down syndrome has greatly improved clinical care. However, little is known about dementia in rare genetic neurodevelopmental disorders (RGNDs). In this review, a comprehensive overview is provided of reports on dementia and cognitive/adaptive trajectories in adults with RGNDs. METHODS: A systematic literature review was conducted in Embase, Medline ALL, and PsycINFO on December 6, 2022. The protocol was registered in PROSPERO (CRD42021223041). Search terms for dementia, cognitive and adaptive functioning, and RGNDs were combined using generic terms and the Orphanet database. Study characteristics and descriptive data on genetic diagnosis, clinical and neuropathologic features, comorbidities, and diagnostic methods were extracted using a modified version of the Cochrane Data Extraction Template. RESULTS: The literature search yielded 40 publications (17 cohorts, 23 case studies) describing dementia and/or cognitive or adaptive trajectories in adults with 14 different RGNDs. Dementia was reported in 49 individuals (5 cohorts, 20 cases) with a mean age at onset of 44.4 years. Diagnostics were not disclosed for half of the reported individuals (n = 25/49, 51.0%). A total of 44 different psychodiagnostic instruments were used. MRI was the most reported additional investigation (n = 12/49, 24.5%). Comorbid disorders most frequently associated with cognitive/adaptive decline were epilepsy, psychotic disorders, and movement disorders. DISCUSSION: Currently available literature shows limited information on aging in RGNDs, with relatively many reports of young-onset dementia. Longitudinal data may provide insights into converging neurodevelopmental degenerative pathways. We provide recommendations to optimize dementia screening, diagnosis, and research.</p

    Reduced expression of the glucocorticoid receptor in the hippocampus of patients with drug-resistant temporal lobe epilepsy and comorbid depression

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    Objective: Depressive disorders are common among about 50% of the patients with drug-resistant temporal lobe epilepsy (TLE). The underlying etiology remains elusive, but hypothalamus-pituitary-adrenal (HPA) axis activation due to changes in glucocorticoid receptor (GR) protein expression could play an important role. Therefore, we set out to investigate expression of the GR in the hippocampus, an important brain region for HPA axis feedback, of patients with drug-resistant TLE, with and without comorbid depression. Methods: GR expression was studied using immunohistochemistry on hippocampal sections from well-characterized TLE patients with depression (TLE + D, n = 14) and without depression (TLE − D, n = 12) who underwent surgery for drug-resistant epilepsy, as well as on hippocampal sections from autopsy control cases (n = 9). Video–electroencephalography (EEG), magnetic resonance imaging (MRI), and psychiatric and memory assessments were performed prior to surgery. Results: Abundant GR immunoreactivity was present in dentate gyrus granule cells and CA1 pyramidal cells of controls. In contrast, neuronal GR expression was lower in patients with TLE, particularly in the TLE + D group. Quantitative analysis showed a smaller GR+ area in TLE + D as compared to TLE − D patients and controls. Furthermore, the ratio between the number of GR+/NeuN+ cells was lower in patients with TLE + D as compared to TLE − D and correlated negatively with the depression severity based on psychiatric history. The expression of the GR was also lower in glial cells of TLE + D compared to TLE − D patients and correlated negatively to the severity of depression. Significance: Reduced hippocampal GR expression may be involved in the etiology of depression in patients with TLE and could constitute a biological marker of depression in these patients.Fil: D`alessio, Luciana. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Centro Universitario de Neurología "Dr. José María Ramos Mejía".; ArgentinaFil: Mesarosova, Lucia. University of Amsterdam; Países BajosFil: Anink, Jasper J.. University of Amsterdam; Países BajosFil: Kochen, Sara Silvia. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Centro Universitario de Neurología "Dr. José María Ramos Mejía".; ArgentinaFil: Solis, Patricia Cristina Lourdes. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Centro Universitario de Neurología "Dr. José María Ramos Mejía".; ArgentinaFil: Oddo, Silvia Andrea. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Centro Universitario de Neurología "Dr. José María Ramos Mejía".; ArgentinaFil: Konopka, Hector Felix. Universidad Nacional Arturo Jauretche. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Provincia de Buenos Aires. Ministerio de Salud. Hospital Alta Complejidad en Red El Cruce Dr. Néstor Carlos Kirchner Samic. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Unidad Ejecutora de Estudios en Neurociencias y Sistemas Complejos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Centro Universitario de Neurología "Dr. José María Ramos Mejía".; ArgentinaFil: Iyer, Anand M.. University of Amsterdam; Países BajosFil: Mühlebner, Angelika. University of Amsterdam; Países BajosFil: Lucassen, Paul J.. University of Amsterdam; Países BajosFil: Aronica, Eleonora. University of Amsterdam; Países Bajos. Stichting Epilepsie Instellingen Nederland; Países BajosFil: van Vliet, Erwin A.. University of Amsterdam; Países Bajo

    Complement C5 contributes to brain injury after subarachnoid hemorrhage

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    Previous studies showed that complement activation is associated with poor functional outcome after aneurysmal subarachnoid hemorrhage (SAH). We investigated whether complement activation is underlying brain injury after aneurysmal SAH (n = 7) and if it is an appropriate treatment target. We investigated complement expression in brain tissue of aneurysmal SAH patients (n = 930) and studied the role of common genetic variants in C3 and C5 genes in outcome. We analyzed plasma levels (n = 229) to identify the functionality of a single nucleotide polymorphism (SNP) associated with outcome. The time course of C5a levels was measured in plasma (n = 31) and CSF (n = 10). In an SAH mouse model, we studied the extent of microglia activation and cell death in wild-type mice, mice lacking the C5a receptor, and in mice treated with C5-specific antibodies (n = 15 per group). Brain sections from aneurysmal SAH patients showed increased presence of complement components C1q and C3/C3b/iC3B compared to controls. The complement component 5 (C5) SNP correlated with C5a plasma levels and poor disease outcome. Serial measurements in CSF revealed that C5a was > 1400-fold increased 1 day after aneurysmal SAH and then gradually decreased. C5a in plasma was 2-fold increased at days 3–10 after aneurysmal SAH. In the SAH mouse model, we observed a ≈ 40% reduction in both microglia activation and cell death in mice lacking the C5a receptor, and in mice treated with C5-specific antibodies. These data show that C5 contributes to brain injury after experimental SAH, and support further study of C5-specific antibodies as novel treatment option to reduce brain injury and improve prognosis after aneurysmal SAH
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