Publications by authors named "Margarita Concha"

Herpes simplex virus type 1 (HSV-1) is a neurotropic virus able to reach the central nervous system (CNS) after primary infection in oronasal mucosa. HSV-1 establishes latency inside neurons due the repression of its gene expression process, which is related to periodic reactivations in response to cellular stress conditions, constituting a risk factor for neurodegenerative diseases such as Alzheimer's disease (AD). The immediate-early gene Arc plays an essential role in neuronal morphology, synaptic plasticity and memory formation.

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Herpes simplex virus type 1 (HSV-1) is a ubiquitous pathogen that establishes a latent persistent neuronal infection in humans. The pathogenic effects of repeated viral reactivation in infected neurons are still unknown. Several studies have reported that during HSV-1 epithelial infection, the virus could modulate diverse cell signaling pathways remodeling the Golgi apparatus (GA) membranes, but the molecular mechanisms implicated, and the functional consequences to neurons is currently unknown.

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Herpes simplex virus type-1 (HSV-1) is ubiquitous and is able to establish a lifelong persistent latent infection in neurons of infected individuals. It has been estimated that in approximately 70% of the population over 50 years old, the virus enters the brain and infects neurons, and possibly undergoes recurrent reactivation episodes during lifetime, especially in immunodepressed individuals. We previously showed that the sensors AMP-dependent kinase (AMPK) and Sirtuin 1 (Sirt1), involved in survival pathways and neuroprotection, were affected during the course of HSV-1 infection.

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Currently, it is unclear whether a neuron that undergoes viral reactivation and produces infectious particles survives and resumes latency or is killed, which is intriguing even if still unanswered. Previous reports have shown that herpes simplex virus type 1 (HSV-1) inhibits apoptosis during early infection, but is pro-apoptotic during productive infection. Taking in consideration that the stress sensors AMPK and Sirt1 are involved in neuronal survival and neuroprotection, we hypothesized that HSV-1 could activate the AMPK/Sirt1 axis as a strategy to establish latency through inhibition of apoptosis and restoration of the energy status.

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Background: Currently, it is unclear whether asymptomatic recurrent reactivations of herpes simplex virus type 1 (HSV-1) occur in the central nervous systems of infected people, and if these events could lead to a progressive deterioration of neuronal function. In this context, HSV-1 constitutes an important candidate to be included among the risk factors for the development of neuropathies associated with chronic neuroinflammation.

Objective: The aim of this study was to assess in vivo inflammatory and neurodegenerative markers in the brain during productive and latent HSV-1 infection using a mouse model of herpes simplex encephalitis.

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Background: Serum amyloid A (SAA) is an acute phase protein that is elevated in blood during inflammation. The role of this protein in allergic diseases of airways remains unclear.

Aims: The objective of this study was to evaluate the SAA in blood, lung and bronchial cells in a murine model of bronchial hypersensitivity to Aspergillus fumigatus.

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Teleosts are the first group of vertebrates possessing an acquired immune system; however, it is less developed than in mammals and is highly influenced by environmental changes. Therefore, innate immunity effectors play a more critical role in survival of pathogen-challenged fish. In a previous study we showed that trout high density lipoprotein (HDL), and its major apolipoprotein (ApoA-I) are widely expressed in primary defense barriers and other immune-relevant tissues, displaying important antibacterial activity in vitro.

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Herpes simplex virus type 1 (HSV-1) is the most common pathogenic cause of sporadic acute encephalitis and it produces latent persistent infection lifelong in infected individuals. Brain inflammation is associated with activation of glial cells, which can detect pathogen-associated molecular patterns (PAMPs) through a variety of pattern-recognition receptors (PRR), including Toll-like receptors (TLRs). In this study, we evaluated the expression and activation of TLR2, TLR3, and TLR4 in HSV-1-infected astrocyte and neuronal primary cultures.

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Herpes simplex virus type 1 (HSV-1) is ubiquitous, neurotropic, and the most common pathogenic cause of sporadic acute encephalitis in humans. Herpes simplex encephalitis is associated with a high mortality rate and significant neurological, neuropsychological, and neurobehavioral sequels. HSV-1 infects limbic system structures in the central nervous system (CNS), and has been suggested as an environmental risk factor for Alzheimer's disease.

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Herpes Simplex Virus Type 1 (HSV-1) is ubiquitous, neurotropic, and the most common pathogenic causes of sporadic acute encephalitis in humans. Herpes simplex encephalitis is associated with a high mortality rate and significant neurological, neuropsychological, and neurobehavioral sequelae, which afflict patients for life. HSV-1 infects limbic system structures in the central nervous system and has been suggested as an environmental risk factor for Alzheimer's disease.

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Serum amyloid A (SAA) is a family of acute-phase proteins, recognized as important effectors of innate immunity in higher vertebrates. Under pro-inflammatory conditions, up-regulation of saa transcripts occurs not only in the liver, but also in several extrahepatic tissues of a wide variety of vertebrates. SAA is also known as the precursor to amyloid A (AA), a major component of amyloid fibrils deposited in liver, kidney and spleen of humans suffering chronic inflammatory diseases.

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Acute serum amyloid A (A-SAA) has been considered a major acute-phase reactant and an effector of innate immunity in all vertebrates. The work presented here shows that the expression of A-SAA is strongly induced in a wide variety of immune-relevant tissues in rainbow trout, either naturally infected with Flavobacterium psychrophilum or challenged with lipopolysaccharide (LPS) or CpG oligonucleotides (CpG ODN). Nevertheless, A-SAA was undetectable by Western blot either in the plasma or in high-density lipoprotein (HDL) of infected or challenged fish, using either an anti-mouse SAA1 IgG or an anti-trout A-SAA peptide serum, which recognise both the intact recombinant trout A-SAA and fragments derived from it.

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Antimicrobial proteins and peptides play an important role in the primary defence barriers in vertebrates and invertebrates. In a previous study it was shown that high-density lipoprotein (HDL) and its major apolipoproteins, ApoA-I and ApoA-II display antimicrobial activity in the carp (Cyprinus carpio L.).

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High density lipoprotein (HDL) has been shown to play an important role in the dietary lipid mobilisation in the carp. In spite of this, previous studies have failed to demonstrate the synthesis of the major protein component of HDL, apolipoprotein A-I (apoA-I), in the proximal intestine of the carp. Therefore, the aim of the present study was to evaluate the expression of apoA-I throughout the entire intestine.

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We have previously shown that high density lipoprotein is the most abundant protein in the carp plasma and displays bactericidal activity in vitro. Therefore the aim of this study was to analyze the contribution of its principal apolipoproteins, apoA-I and apoA-II, in defense. Both apolipoproteins were isolated by a two step procedure involving affinity and gel filtration chromatography and were shown to display bactericidal and/or bacteriostatic activity in the micromolar range against Gram-positive and Gram-negative bacteria, including some fish pathogens.

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Antimicrobial proteins and peptides play an important role in the primary defence of epithelial barriers in vertebrates and invertebrates. Here we report the detection of the apolipoproteins A-I and A-II in the epidermis and epidermal mucus of the carp (Cyprinus carpio L.) by immunohistochemistry and Western blot analysis.

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In a previous study we had demonstrated that a 15-kDa protein present in carp intestinal brush-border membrane vesicles (BBMV) was able to bind the endocytosis tracer horseradish peroxidase (HRP) with high specificity. Here we show that this protein corresponds to a peripheral membrane protein, identified by partial amino acid sequence analysis as the intestinal fatty acid-binding protein (I-FABP), a member of the small cytosolic fatty acid binding protein family (FABPs). The presence of I-FABP and its HRP-binding activity was demonstrated both in the cytosolic and membrane-associated fractions of intestinal mucosa by Western and ligand blot analyses, respectively.

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