Search results for "APT"
showing 10 items of 5479 documents
Structure and Synaptic Function of Metal Binding to the Amyloid Precursor Protein and its Proteolytic Fragments
2017
Alzheimer’s disease (AD) is ultimately linked to the Amyloid Precursor Protein (APP). However, current research reveals an important synaptic function of APP and APP-like proteins (APLP1 and 2). In this context various neurotrophic and neuroprotective functions have been reported for the APP proteolytic fragments sAPPα, sAPPβ, and the monomeric amyloid-beta peptide (Aβ). APP is a metalloprotein and binds copper and zinc ions. Synaptic activity correlates with a release of these ions into the synaptic cleft and dysregulation of their homeostasis is linked to different neurodegenerative diseases. Metal binding to APP or its fragments affects its structure and its proteolytic cleavage and ther…
Under pressure: phenotypic divergence and convergence associated with microhabitat adaptations in Triatominae
2021
AbstractBackgroundTriatomine bugs, the vectors of Chagas disease, associate with vertebrate hosts in highly diverse ecotopes. When these blood-sucking bugs adapt to new microhabitats, their phenotypes may change. Although understanding phenotypic variation is key to the study of adaptive evolution and central to phenotype-based taxonomy, the drivers of phenotypic change and diversity in triatomines remain poorly understood.Methods/FindingsWe combined a detailed phenotypic appraisal (including morphology and morphometrics) with mitochondrialcytband nuclear ITS2 DNA-sequence analyses to studyRhodnius ecuadoriensispopulations from across the species’ range. We found three major, naked-eye phen…
Lymph node - an organ for T-cell activation and pathogen defense.
2016
The immune system is a multicentered organ that is characterized by intimate interactions between its cellular components to efficiently ward off invading pathogens. A key constituent of this organ system is the distinct migratory activity of its cellular elements. The lymph node represents a pivotal meeting point of immune cells where adaptive immunity is induced and regulated. Additionally, besides barrier tissues, the lymph node is a critical organ where invading pathogens need to be eliminated in order to prevent systemic distribution of virulent microbes. Here, we explain how the lymph node is structurally and functionally organized to fulfill these two critical functions - pathogen de…
Parallels and differences between innate and adaptive lymphocytes.
2016
Lymphocytes are essential in innate and adaptive immunity. Recent insights suggest that some innate lymphocytes execute functions with adaptive characteristics, while adaptive lymphocytes can operate in ways reminiscent of innate cells. Rather than partitioning lymphocytes according to the type of effector function they execute, we propose that a relevant discrimination relates to the existence of conventional T cells in a naive state. The naive state can be seen as an actively repressed condition that supports T cell diversity and enables the flexible differentiation of effector cells in a manner that best addresses the antigenic challenge. We discuss these considerations in the context of…
Meningeal γδ T cell-derived IL-17 controls synaptic plasticity and short-term memory
2019
The notion of "immune privilege" of the brain has been revised to accommodate its infiltration, at steady state, by immune cells that participate in normal neurophysiology. However, the immune mechanisms that regulate learning and memory remain poorly understood. Here, we show that noninflammatory interleukin-17 (IL-17) derived from a previously unknown fetal-derived meningeal-resident γδ T cell subset promotes cognition. When tested in classical spatial learning paradigms, mice lacking γδ T cells or IL-17 displayed deficient short-term memory while retaining long-term memory. The plasticity of glutamatergic synapses was reduced in the absence of IL-17, resulting in impaired long-term poten…
Combined B, T and NK Cell Deficiency Accelerates Atherosclerosis in BALB/c Mice.
2016
This study focused on the unique properties of both the Ldlr knockout defect (closely mimicking the human situation) and the BALB/c (C) inbred mouse strain (Th-2 slanted immune response). We generated two immunodeficient strains with severe combined B- and T-cell immunodeficiency with or without a complete lack of natural killer cells to revisit the role of adaptive immune responses on atherogenesis. C-Ldlr-/- Rag1-/- mice, which show severe combined B- and T-cell immunodeficiency and C-Ldlr-/- Rag1-/- Il2rg-/- mice, which combine the T- and B-cell defect with a complete lack of natural killer cells and inactivation of multiple cytokine signalling pathways were fed an atherogenic Western ty…
Bronchial inflammation and bacterial load in stable COPD is associated with TLR4 overexpression.
2017
Toll-like receptors (TLRs) and nucleotide-binding oligomerisation domain (NOD)-like receptors (NLRs) are two major forms of innate immune sensors but their role in the immunopathology of stable chronic obstructive pulmonary disease (COPD) is incompletely studied. Our objective here was to investigate TLR and NLR signalling pathways in the bronchial mucosa in stable COPD.Using immunohistochemistry, the expression levels of TLR2, TLR4, TLR9, NOD1, NOD2, CD14, myeloid differentiation primary response gene 88 (MyD88), Toll-interleukin-1 receptor domain-containing adaptor protein (TIRAP), and the interleukin-1 receptor-associated kinases phospho-IRAK1 and IRAK4 were measured in the bronchial muc…
Putative Role of Taurine as Neurotransmitter During Perinatal Cortical Development
2017
Neurotransmitters and neuronal activity affect neurodevelopmental events like neurogenesis, neuronal migration, apoptosis and differentiation. Beside glutamate and gamma-amino butyric acid, the aminosulfonic acid taurine has been considered as possible neurotransmitter that influences early neuronal development. In this article I review recent studies of our group which demonstrate that taurine can affect a variety of identified neuronal populations in the immature neocortex and directly modulates neuronal activity. These experiments revealed that taurine evoke dose-dependent membrane responses in a variety of neocortical neuron populations, including Cajal-Retzius cells, subplate neurons a…
Neurons in the pigeon caudolateral nidopallium differentiate Pavlovian conditioned stimuli but not their associated reward value in a sign-tracking p…
2016
AbstractAnimals exploit visual information to identify objects, form stimulus-reward associations, and prepare appropriate behavioral responses. The nidopallium caudolaterale (NCL), an associative region of the avian endbrain, contains neurons exhibiting prominent response modulation during presentation of reward-predicting visual stimuli, but it is unclear whether neural activity represents valuation signals, stimulus properties, or sensorimotor contingencies. To test the hypothesis that NCL neurons represent stimulus value, we subjected pigeons to a Pavlovian sign-tracking paradigm in which visual cues predicted rewards differing in magnitude (large vs. small) and delay to presentation (s…
Neural oscillations in the infralimbic cortex after electrical stimulation of the amygdala. Relevance to acute stress processing
2017
The stress system coordinates the adaptive reactions of the organism to stressors. Therefore, dysfunctions in this circuit may correlate to anxiety-related disorders, including depression. Comprehending the dynamics of this network may lead to a better understanding of the mechanisms that underlie these diseases. The central nucleus of the amygdala (CeA) activates the hypothalamic–pituitary–adrenal axis and brainstem nodes by triggering endocrine, autonomic and behavioral stress responses. The medial prefrontal cortex plays a significant role in regulating reactions to stressors, and is specifically important for limiting fear responses. Brain oscillations reflect neural systems activity. S…