scholarly journals Non-Typeable Haemophilus influenzae Invade Choroid Plexus Epithelial Cells in a Polar Fashion

2020 ◽  
Vol 21 (16) ◽  
pp. 5739
Author(s):  
Christian Wegele ◽  
Carolin Stump-Guthier ◽  
Selina Moroniak ◽  
Christel Weiss ◽  
Manfred Rohde ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Haemophilus Influenzae ◽  
Choroid Plexus ◽  
Human Respiratory Tract ◽  
Meningeal Inflammation ◽  
Invasive Infections ◽  
The Brain ◽  
Adhesion And Invasion

Non-typeable Haemophilus influenzae (NTHI) is a pathogen of the human respiratory tract causing the majority of invasive H. influenzae infections. Severe invasive infections such as septicemia and meningitis occur rarely, but the lack of a protecting vaccine and the increasing antibiotic resistance of NTHI impede treatment and emphasize its relevance as a potential meningitis causing pathogen. Meningitis results from pathogens crossing blood–brain barriers and invading the immune privileged central nervous system (CNS). In this study, we addressed the potential of NTHI to enter the brain by invading cells of the choroid plexus (CP) prior to meningeal inflammation to enlighten NTHI pathophysiological mechanisms. A cell culture model of human CP epithelial cells, which form the blood–cerebrospinal fluid barrier (BCSFB) in vivo, was used to analyze adhesion and invasion by immunofluorescence and electron microscopy. NTHI invade CP cells in vitro in a polar fashion from the blood-facing side. Furthermore, NTHI invasion rates are increased compared to encapsulated HiB and HiF strains. Fimbriae occurrence attenuated adhesion and invasion. Thus, our findings underline the role of the BCSFB as a potential entry port for NTHI into the brain and provide strong evidence for a function of the CP during NTHI invasion into the CNS during the course of meningitis.

Thiamine transport in the central nervous system

1976 ◽  
Vol 230 (4) ◽  
pp. 1101-1107 ◽  
Author(s):  
R Spector
Keyword(s):  
Choroid Plexus ◽  
Intraventricular Injection ◽  
Simple Diffusion ◽  
Thiamine Transport ◽  
Choroid Plexuses ◽  
The Central Nervous System ◽  
The Brain ◽  
Thiamine Phosphates

Total thiamine (free thiamine and thiamine phosphates) transport into the cerebrospinal fluid (CSF), brain, and choroid plexus and out of the CSF was measured in rabbits. In vivo, total thiamine transport into CSF, choroid plexus, and brain was saturable. At the normal plasma total thiamine concentration, less than 5% of total thiamine entry into CSF, choroid plexus, and brain was by simple diffusion. The relative turnovers of total thiamine in choroid plexus, whole brain, and CSF were 5, 2, and 14% per h, respectively, when measured by the penetration of 35S-labeled thiamine injected into blood. From the CSF, clearance of [35S]thiamine relative to mannitol was not saturable after the intraventricular injection of various concentrations of thiamine. However, a portion of the [35S]thiamine cleared from the CSF entered brain by a saturable mechanism. In vitro, choroid plexuses, isolated from rabbits and incubated in artificial CSF, accumulated [35S]thiamine against a concentration gradient by an active saturable process that did not depend on pyrophosphorylation of the [35S]thiamine. The [35S]thiamine accumulated within the choroid plexus in vitro was readily released. These results were interpreted as showing that the entry of total thiamine into the brain and CSF from blood is regulated by a saturable transport system, and that the locus of this system may be, in part, in the choroid plexus.

scholarly journals A Comparative Transcriptome Analysis of Human and Porcine Choroid Plexus Cells in Response to Streptococcus suis Serotype 2 Infection Points to a Role of Hypoxia

2021 ◽  
Vol 11 ◽  
Author(s):  
Alexa N. Lauer ◽  
Rene Scholtysik ◽  
Andreas Beineke ◽  
Christoph Georg Baums ◽  
Kristin Klose ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Inflammatory Response ◽  
Choroid Plexus ◽  
Cellular Proliferation ◽  
Inflammatory Responses ◽  
Streptococcus Suis ◽  
Gene Set Enrichment Analysis ◽  
Rna Seq

Streptococcus suis (S. suis) is an important opportunistic pathogen, which can cause septicemia and meningitis in pigs and humans. Previous in vivo observations in S. suis-infected pigs revealed lesions at the choroid plexus (CP). In vitro experiments with primary porcine CP epithelial cells (PCPEC) and human CP epithelial papilloma (HIBCPP) cells demonstrated that S. suis can invade and traverse the CP epithelium, and that the CP contributes to the inflammatory response via cytokine expression. Here, next generation sequencing (RNA-seq) was used to compare global transcriptome profiles of PCPEC and HIBCPP cells challenged with S. suis serotype (ST) 2 infected in vitro, and of pigs infected in vivo. Identified differentially expressed genes (DEGs) were, amongst others, involved in inflammatory responses and hypoxia. The RNA-seq data were validated via quantitative PCR of selected DEGs. Employing Gene Set Enrichment Analysis (GSEA), 18, 28, and 21 enriched hallmark gene sets (GSs) were identified for infected HIBCPP cells, PCPEC, and in the CP of pigs suffering from S. suis ST2 meningitis, respectively, of which eight GSs overlapped between the three different sample sets. The majority of these GSs are involved in cellular signaling and pathways, immune response, and development, including inflammatory response and hypoxia. In contrast, suppressed GSs observed during in vitro and in vivo S. suis ST2 infections included those, which were involved in cellular proliferation and metabolic processes. This study suggests that similar cellular processes occur in infected human and porcine CP epithelial cells, especially in terms of inflammatory response.

scholarly journals Effects of Psa and F1 on the Adhesive and Invasive Interactions of Yersinia pestis with Human Respiratory Tract Epithelial Cells

2006 ◽  
Vol 74 (10) ◽  
pp. 5636-5644 ◽  
Author(s):  
Fengzhi Liu ◽  
Huaiqing Chen ◽  
Estela M. Galván ◽  
Melissa A. Lasaro ◽  
Dieter M. Schifferli
Keyword(s):  
Epithelial Cells ◽  
Respiratory Tract ◽  
Yersinia Pestis ◽  
Bacterial Adhesion ◽  
Wild Type Strain ◽  
Cell Types ◽  
Human Respiratory Tract ◽  
Bacterial Uptake

ABSTRACT Yersinia pestis, the causative agent of plague, expresses the Psa fimbriae (pH 6 antigen) in vitro and in vivo. To evaluate the potential virulence properties of Psa for pneumonic plague, an Escherichia coli strain expressing Psa was engineered and shown to adhere to three types of human respiratory tract epithelial cells. Psa binding specificity was confirmed with Psa-coated polystyrene beads and by inhibition assays. Individual Y. pestis cells were found to be able to express the capsular antigen fraction 1 (F1) concomitantly with Psa on their surface when analyzed by flow cytometry. To better evaluate the separate effects of F1 and Psa on the adhesive and invasive properties of Y. pestis, isogenic Δcaf (F1 genes), Δpsa, and Δcaf Δpsa mutants were constructed and studied with the three respiratory tract epithelial cells. The Δpsa mutant bound significantly less to all three epithelial cells compared to the parental wild-type strain and the Δcaf and Δcaf Δpsa mutants, indicating that Psa acts as an adhesin for respiratory tract epithelial cells. An antiadhesive effect of F1 was clearly detectable only in the absence of Psa, underlining the dominance of the Psa+ phenotype. Both F1 and Psa inhibited the intracellular uptake of Y. pestis. Thus, F1 inhibits bacterial uptake by inhibiting bacterial adhesion to epithelial cells, whereas Psa seems to block bacterial uptake by interacting with a host receptor that doesn't direct internalization. The Δcaf Δpsa double mutant bound and invaded all three epithelial cell types well, revealing the presence of an undefined adhesin(s) and invasin(s).

scholarly journals Potential Roles and Functions of Listerial Virulence Factors during Brain Entry

Toxins ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 297
Author(s):  
Franjo Banović ◽  
Horst Schroten ◽  
Christian Schwerk
Keyword(s):  
Virulence Factors ◽  
Current Knowledge ◽  
Cellular Adhesion ◽  
The Body ◽  
Listeriolysin O ◽  
The Brain ◽  
Adhesion And Invasion

Although it rarely induces disease in humans, Listeria monocytogenes (Lm) is important due to the frequency of serious pathological conditions—such as sepsis and meningitis—it causes in those few people that do get infected. Virulence factors (VF) of Lm—especially those involved in the passage through multiple cellular barriers of the body, including internalin (Inl) family members and listeriolysin O (LLO)—have been investigated both in vitro and in vivo, but the majority of work was focused on the mechanisms utilized during penetration of the gut and fetoplacental barriers. The role of listerial VF during entry into other organs remain as only partially solved puzzles. Here, we review the current knowledge on the entry of Lm into one of its more significant destinations, the brain, with a specific focus on the role of various VF in cellular adhesion and invasion.

scholarly journals Filament Tip-Associated Antigens Involved in Adherence to and Invasion of Murine Pulmonary Epithelial Cells In Vivo and HeLa Cells In Vitro by Nocardia asteroides

1998 ◽  
Vol 66 (10) ◽  
pp. 4676-4689 ◽  
Author(s):  
Blaine L. Beaman ◽  
LoVelle Beaman
Keyword(s):  
Epithelial Cells ◽  
Hela Cells ◽  
Nocardia Asteroides ◽  
Pulmonary Epithelial Cells ◽  
Pulmonary Epithelial Cell ◽  
Vitro Model ◽  
The Brain ◽  
Invasion Assays

ABSTRACT The interactions of Nocardia asteroides GUH-2 with pulmonary epithelial cells of C57BL/6 mice and with HeLa cells were studied. Electron microscopy demonstrated that only the tips of log-phase cells penetrated pulmonary epithelial cells following intranasal administration, and nocardiae were recovered from the brain. Coccobacillary cells neither invaded nor disseminated. Serum from immunized mice (IMS) decreased attachment to and penetration of pulmonary epithelial cell surfaces by log-phase GUH-2 and inhibited spread to the brain. IMS was adsorbed against stationary-phase cells. Western immunoblots suggested that this adsorbed IMS was reactive primarily with 43- and 62-kDa proteins. Immunofluorescence showed that adsorbed IMS preferentially labeled the tips of log-phase GUH-2 cells. Since this IMS was reactive to culture filtrate antigens, several of these proteins were cut from gels, and mice were immunized. Sera against 62-, 55-, 43-, 36-, 31-, and 25-kDa antigens were obtained. The antisera against the 43- and 36-kDa proteins labeled the filament tips of GUH-2 cells. Only the antiserum against the 43-kDa antigen increased pulmonary clearance, inhibited apical attachment to and penetration of pulmonary epithelial cells, and prevented spread to the brain. An in vitro model with HeLa cells demonstrated that the tips of log-phase cells of GUH-2 adhered to and penetrated the surface of HeLa cells. Invasion assays with amikacin treatment demonstrated that nocardiae were internalized. Adsorbed IMS blocked attachment to and invasion of these cells. These data suggested that a filament tip-associated 43-kDa protein was involved in attachment to and invasion of pulmonary epithelial cells and HeLa cells by N. asteroides GUH-2.

scholarly journals Glucocorticoids reset circadian clock in choroid plexus via period genes

2020 ◽  
Author(s):  
Karolína Liška ◽  
Martin Sládek ◽  
Vendula Čečmanová ◽  
Alena Sumová
Keyword(s):  
Cerebrospinal Fluid ◽  
Choroid Plexus ◽  
Glucocorticoid Receptors ◽  
Clock Gene ◽  
Time Of Day ◽  
The Body ◽  
Surgical Removal ◽  
The Brain

The epithelial cells of choroid plexus (CP) in brain ventricles produce cerebrospinal fluid and act as the blood-cerebrospinal fluid barrier. In this study, we confirmed that CP in the 4th ventricle is composed of cellular oscillators that all harbor glucocorticoid receptors and are mutually synchronized to produce a robust clock gene expression rhythm detectable at the tissue level in vivo and in vitro. Animals lacking glucocorticoids (GCs) due to surgical removal of adrenal glands had Per1, Per2, Nr1d1 and Bmal1 clock gene rhythmicity in their CP significantly dampened, whereas subjecting them to daily bouts of synthetic GC analog, dexamethasone (DEX), reinforced those rhythms. We verified these in vivo effects using an in vitro model of organotypic CP explants; depending on time of its application, DEX significantly increased the amplitude and efficiently reset the phase of the CP clock. The results are the first description of a PRC for a non-neuronal clock in the brain, demonstrating that CP clock shares some properties with the non-neuronal clocks elsewhere in the body. Finally, we found that DEX exhibited multiple synergic effects on the CP clock, including acute activation of Per1 expression and change of PER2 protein turnover rate. The DEX-induced shifts of the CP clock were partially mediated via PKA-ERK1/2 pathway. The results provide first evidence that the GC rhythm strengthens and entrains the clock in the CP helping thus fine-tune the brain environment according to time of day.

scholarly journals Basal Sodium-Dependent Vitamin C Transporter 2 polarization in choroid plexus explant cells in normal or scorbutic conditions

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Viviana Ulloa ◽  
Natalia Saldivia ◽  
Luciano Ferrada ◽  
Katterine Salazar ◽  
Fernando Martínez ◽  
...  
Keyword(s):  
Vitamin C ◽  
Choroid Plexus ◽  
Basolateral Membrane ◽  
Adult Brain ◽  
Epithelial Structure ◽  
The Brain ◽  
Guinea Pig Brain ◽  
Embryonic Brain Development

Abstract Vitamin C is incorporated into the cerebrospinal fluid (CSF) through choroid plexus cells. While the transfer of vitamin C from the blood to the brain has been studied functionally, the vitamin C transporter, SVCT2, has not been detected in the basolateral membrane of choroid plexus cells. Furthermore, it is unknown how its expression is induced in the developing brain and modulated in scurvy conditions. We concluded that SVCT2 is intensely expressed in the second half of embryonic brain development and postnatal stages. In postnatal and adult brain, SVCT2 is highly expressed in all choroidal plexus epithelial cells, shown by colocalization with GLUT1 in the basolateral membranes and without MCT1 colocalization, which is expressed in the apical membrane. We confirmed that choroid plexus explant cells (in vitro) form a sealed epithelial structure, which polarized basolaterally, endogenous or overexpressed SVCT2. These results are reproduced in vivo by injecting hSVCT2wt-EYFP lentivirus into the CSF. Overexpressed SVCT2 incorporates AA (intraperitoneally injected) from the blood to the CSF. Finally, we observed in Guinea pig brain under scorbutic condition, that normal distribution of SVCT2 in choroid plexus may be regulated by peripheral concentrations of vitamin C. Additionally, we observed that SVCT2 polarization also depends on the metabolic stage of the choroid plexus cells.

scholarly journals Immune response and pathogen invasion at the choroid plexus in the onset of cerebral toxoplasmosis

2022 ◽  
Vol 19 (1) ◽  
Author(s):  
Caio Andreeta Figueiredo ◽  
Johannes Steffen ◽  
Lorena Morton ◽  
Sushmitha Arumugam ◽  
Oliver Liesenfeld ◽  
...  
Keyword(s):  
Immune Response ◽  
Endothelial Cells ◽  
Epithelial Cells ◽  
Choroid Plexus ◽  
The Body ◽  
Potential Contribution ◽  
Pathogen Invasion ◽  
The Impact

Abstract Background Toxoplasma gondii (T. gondii) is a highly successful parasite being able to cross all biological barriers of the body, finally reaching the central nervous system (CNS). Previous studies have highlighted the critical involvement of the blood–brain barrier (BBB) during T. gondii invasion and development of subsequent neuroinflammation. Still, the potential contribution of the choroid plexus (CP), the main structure forming the blood–cerebrospinal fluid (CSF) barrier (BCSFB) have not been addressed. Methods To investigate T. gondii invasion at the onset of neuroinflammation, the CP and brain microvessels (BMV) were isolated and analyzed for parasite burden. Additionally, immuno-stained brain sections and three-dimensional whole mount preparations were evaluated for parasite localization and morphological alterations. Activation of choroidal and brain endothelial cells were characterized by flow cytometry. To evaluate the impact of early immune responses on CP and BMV, expression levels of inflammatory mediators, tight junctions (TJ) and matrix metalloproteinases (MMPs) were quantified. Additionally, FITC-dextran was applied to determine infection-related changes in BCSFB permeability. Finally, the response of primary CP epithelial cells to T. gondii parasites was tested in vitro. Results Here we revealed that endothelial cells in the CP are initially infected by T. gondii, and become activated prior to BBB endothelial cells indicated by MHCII upregulation. Additionally, CP elicited early local immune response with upregulation of IFN-γ, TNF, IL-6, host-defence factors as well as swift expression of CXCL9 chemokine, when compared to the BMV. Consequently, we uncovered distinct TJ disturbances of claudins, associated with upregulation of MMP-8 and MMP-13 expression in infected CP in vivo, which was confirmed by in vitro infection of primary CP epithelial cells. Notably, we detected early barrier damage and functional loss by increased BCSFB permeability to FITC-dextran in vivo, which was extended over the infection course. Conclusions Altogether, our data reveal a close interaction between T. gondii infection at the CP and the impairment of the BCSFB function indicating that infection-related neuroinflammation is initiated in the CP.

scholarly journals Immune Response and Pathogen Invasion at the Choroid Plexus in the Onset of Cerebral Toxoplasmosis

2021 ◽  
Author(s):  
Caio Andreeta Figueiredo ◽  
JOhannes Steffen ◽  
Lorena Morton ◽  
Sushmita Arumugam ◽  
OLiver Liesenfeld ◽  
...  
Keyword(s):  
Immune Response ◽  
Endothelial Cells ◽  
Epithelial Cells ◽  
Choroid Plexus ◽  
The Body ◽  
Potential Contribution ◽  
Pathogen Invasion ◽  
The Impact

Abstract Background: Toxoplasma gondii ( T. gondii ) is a highly successful parasite being able to cross all biological barriers of the body, finally reaching the central nervous system (CNS). Previous studies have highlighted the critical involvement of the blood-brain barrier (BBB) during T. gondii invasion and development of subsequent neuroinflammation. Still, the potential contribution of the choroid plexus (CP), a main structure forming the blood-cerebrospinal fluid (CSF)-barrier (BCSFB) have not been addressed. Methods: To investigate T. gondii invasion and the onset of neuroinflammation, the CP and brain microvessels (BMV) were isolated and analysed for parasite burden. Additionally, immuno-stained brain sections and three dimensional whole mount preparations were evaluated for parasite localization and morphological alterations. Activation of choroidal and brain endothelial cells were characterized by flow cytometry. To evaluate the impact of early immune responses on CP and BMV, expression levels of inflammatory mediators, tight junctions (TJ) and matrix metalloproteinases (MMPs) were quantified. Additionally, FITC-dextran was applied to determine infection-related changes in BCSFB permeability. Finally, the response of primary CP epithelial cells to T. gondii parasites was tested in vitro . Results: Here we revealed that endothelial cells in the CP are initially infected by T. gondii, and become activated prior to BBB endothelial cells indicated by MHCII upregulation. Additionally, CP elicited early local immune response with upregulation of IFN-γ, TNF, IL-6, host-defence factors as well as swift expression of CXCL9 chemokine, when compared to the BMV. Consequently, we uncovered distinct TJ disturbances of claudins, associated with upregulation of MMP-8 and MMP-13 expression in infected CP in vivo , which was confirmed by in vitro infection of primary CP epithelial cells. Notably, we detected early barrier damage and functional loss by increased BCSFB permeability to FITC-dextran in vivo , which was extended over the infection course. Conclusions: Altogether, our data reveal a close interaction between T. gondii infection at the CP and the impairment of the BCSFB function indicating that infection-related neuroinflammation is initiated in the CP.

Effect of pH and inhibitors on beta-amyloid fibril assembly

1996 ◽  
Vol 54 ◽  
pp. 752-753
Author(s):  
Beverly E. Maleeff ◽  
Timothy K. Hart ◽  
Stephen J. Wood ◽  
Ronald Wetzel
Keyword(s):  
Amyloid Fibril ◽  
Peptide Fragment ◽  
Hydrophobic Peptides ◽  
Amyloid Fibril Formation ◽  
Effects Of Ph ◽  
Severity Of The Disease ◽  
Kinetics Of ◽  
The Brain

Alzheimer's disease is characterized post-mortem in part by abnormal extracellular neuritic plaques found in brain tissue. There appears to be a correlation between the severity of Alzheimer's dementia in vivo and the number of plaques found in particular areas of the brain. These plaques are known to be the deposition sites of fibrils of the protein β-amyloid. It is thought that if the assembly of these plaques could be inhibited, the severity of the disease would be decreased. The peptide fragment Aβ, a precursor of the p-amyloid protein, has a 40 amino acid sequence, and has been shown to be toxic to neuronal cells in culture after an aging process of several days. This toxicity corresponds to the kinetics of in vitro amyloid fibril formation. In this study, we report the biochemical and ultrastructural effects of pH and the inhibitory agent hexadecyl-N-methylpiperidinium (HMP) bromide, one of a class of ionic micellar detergents known to be capable of solubilizing hydrophobic peptides, on the in vitro assembly of the peptide fragment Aβ.

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