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1.
Dev Cell ; 58(21): 2217-2234.e8, 2023 11 06.
Article in English | MEDLINE | ID: mdl-37852253

ABSTRACT

Despite their burden, most congenital defects remain poorly understood, due to lack of knowledge of embryological mechanisms. Here, we identify Greb1l mutants as a mouse model of crisscross heart. Based on 3D quantifications of shape changes, we demonstrate that torsion of the atrioventricular canal occurs together with supero-inferior ventricles at E10.5, after heart looping. Mutants phenocopy partial deficiency in retinoic acid signaling, which reflect overlapping pathways in cardiac precursors. Spatiotemporal gene mapping and cross-correlated transcriptomic analyses further reveal the role of Greb1l in maintaining a pool of dorsal pericardial wall precursor cells during heart tube elongation, likely by controlling ribosome biogenesis and cell differentiation. Consequently, we observe growth arrest and malposition of the outflow tract, which are predictive of abnormal tube remodeling in mutants. Our work on a rare cardiac malformation opens novel perspectives on the origin of a broader spectrum of congenital defects associated with GREB1L in humans.


Subject(s)
Crisscross Heart , Humans , Animals , Mice , Morphogenesis/genetics , Heart , Heart Ventricles , Stem Cells
2.
Cytotherapy ; 22(12): 780-791, 2020 12.
Article in English | MEDLINE | ID: mdl-33069566

ABSTRACT

BACKGROUND AIMS: Several studies report on Good Manufacturing Process (GMP)-compliant manufacturing protocols for the ex vivo expansion of tumor-infiltrating lymphocytes (TILs) for the treatment of patients with refractory melanoma and other solid malignancies. Further opportunities for improvements in terms of ergonomy and operating time have been identified. METHODS: To enable GMP-compliant TILs production for adoptive cell therapy needs, a simple automated and reproducible protocol for TILs manufacturing with the use of a closed system was developed and implemented at the authors' institution. RESULTS: This protocol enabled significant operating time reduction during TILs expansion while allowing the generation of high-quality TILs products. CONCLUSIONS: A simplified and efficient method of TILs expansion will enable the broadening of individualized tumor therapy and will increase patients' access to state-of-the-art TILs adoptive cell therapy treatment.


Subject(s)
Cell Culture Techniques/methods , Hospitals , Lymphocytes, Tumor-Infiltrating/cytology , Automation , Cell Count , Cell Proliferation , Cryopreservation , Female , Humans , Kinetics , Phenotype , Quality Control
3.
Microvasc Res ; 132: 104067, 2020 11.
Article in English | MEDLINE | ID: mdl-32877697

ABSTRACT

Edema formation due to the collapse of physiological barriers and the associated delayed healing process is still a central problem in the treatment of burn injuries. In healthy individuals, tight junctions form a barrier to fluid and small molecules. Cingulin is a cytoplasmic component of tight junctions and is involved in the regulation of the paracellular barrier. Endothelial specific cingulin knock-out mice provide new insight into the influence of tight junction proteins on edema formation and angiogenesis during wound healing. Knock-out mice lacking the head domain of cingulin in endothelial cells (CgnΔEC) were created by breeding Cgnfl/fl mice with Tie1-cre mice. Using a no-touch hot air jet a burn trauma was induced on the ear of the mouse. Over a period of 12 days microcirculatory parameters such as edema formation, angiogenesis and leukocyte-endothelial interactions were visualized using intravital fluorescence microscopy. At baseline, CgnΔEC mice surprisingly showed significantly less tracer extravasation compared to Cgnfl/fl littermates, whereas, after burn injury, edema was consistently higher in CgnΔEC mice. Non-perfused area after wounding was increased, but there was no difference in vessel diameters, contraction or dilation of arteries in CgnΔEC mice. Moreover, cingulin knock-out did not cause a difference in leukocyte adhesion after burn injury. In summary, cingulin limits non-perfused area after burn injury and maintains the paracellular barrier of blood vessels. Since edema formation with serious systemic effects is a central problem of burn wounds, understanding the importance of tight junction proteins might help to find new treatment strategies for burn wounds.


Subject(s)
Burns/metabolism , Edema/metabolism , Endothelial Cells/metabolism , Membrane Proteins/metabolism , Microvessels/metabolism , Skin/blood supply , Tight Junctions/metabolism , Wound Healing , Animals , Burns/genetics , Burns/pathology , Capillary Permeability , Disease Models, Animal , Edema/genetics , Edema/pathology , Endothelial Cells/pathology , Leukocyte Rolling , Male , Membrane Proteins/deficiency , Membrane Proteins/genetics , Mice, Inbred C57BL , Mice, Knockout , Microvessels/pathology , Neovascularization, Physiologic , Signal Transduction , Tight Junctions/genetics , Tight Junctions/pathology
4.
Cell Rep ; 32(3): 107932, 2020 07 21.
Article in English | MEDLINE | ID: mdl-32698004

ABSTRACT

Cilia and the intraflagellar transport (IFT) proteins involved in ciliogenesis are associated with congenital heart diseases (CHDs). However, the molecular links between cilia, IFT proteins, and cardiogenesis are yet to be established. Using a combination of biochemistry, genetics, and live-imaging methods, we show that IFT complex B proteins (Ift88, Ift54, and Ift20) modulate the Hippo pathway effector YAP1 in zebrafish and mouse. We demonstrate that this interaction is key to restrict the formation of the proepicardium and the myocardium. In cellulo experiments suggest that IFT88 and IFT20 interact with YAP1 in the cytoplasm and functionally modulate its activity, identifying a molecular link between cilia-related proteins and the Hippo pathway. Taken together, our results highlight a noncanonical role for IFT complex B proteins during cardiogenesis and shed light on a mechanism of action for ciliary proteins in YAP1 regulation.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Carrier Proteins/metabolism , Cell Cycle Proteins/metabolism , Flagella/metabolism , Heart/embryology , Organogenesis , Protein Serine-Threonine Kinases/metabolism , Trans-Activators/metabolism , Zebrafish Proteins/metabolism , Zebrafish/embryology , Animals , Biological Transport , Bone Morphogenetic Proteins/metabolism , Cilia/metabolism , HEK293 Cells , HeLa Cells , Humans , Mice, Inbred C57BL , Pericardium/metabolism , Protein Binding , Signal Transduction , YAP-Signaling Proteins
5.
J Chem Phys ; 148(21): 214702, 2018 Jun 07.
Article in English | MEDLINE | ID: mdl-29884037

ABSTRACT

We present a room temperature STM study of perylene self-assembly on Ag(110) beyond the monolayer coverage regime. Coupling of the perylene aromatic boards yields π-π bonded stacks. The perylene stacks self-assemble into a continuous three-dimensional epitaxial overlayer of (3 × 5) symmetry. The self-assembly is driven by thermodynamic balance established under coupling of the intra- and intermolecular interactions and the molecule-substrate interaction all accommodating the short-range thermal motion of the constituent molecules. The balance bestows to the overlayer the unique ability to accommodate the underlying substrate morphology and to spread over the surface steps as a single structure preserving its lateral order and keeping epitaxial relationship with every surface terrace. The complete epitaxy is driven by (i) anchoring of half of the perylene stacks into specific adsorption sites on each terrace, (ii) interlacing of the perylene stacks across the steps within the entire H-bonded network, and (iii) relaxation of the overlayer strain via enhancement of the overlayer-specific vibrational modes and short-range thermal motion of the constituent molecules. This complete epitaxy phenomenon is described via (i) structural and statistical analysis of the molecularly resolved STM topographies, (ii) monitoring of the short-range molecular displacements under the strain relaxation, (iii) highlighting of specific intra-molecular and inter-molecular vibration modes through detailed analysis of HREELS spectra, and (iv) parametrization of the intermolecular interaction via pair potential calculation.

6.
Nat Commun ; 8: 14582, 2017 02 27.
Article in English | MEDLINE | ID: mdl-28239148

ABSTRACT

Although in flies the atypical cadherin Fat is an upstream regulator of Hippo signalling, the closest mammalian homologue, Fat4, has been shown to regulate tissue polarity rather than growth. Here we show in the mouse heart that Fat4 modulates Hippo signalling to restrict growth. Fat4 mutant myocardium is thicker, with increased cardiomyocyte size and proliferation, and this is mediated by an upregulation of the transcriptional activity of Yap1, an effector of the Hippo pathway. Fat4 is not required for the canonical activation of Hippo kinases but it sequesters a partner of Yap1, Amotl1, out of the nucleus. The nuclear translocation of Amotl1 is accompanied by Yap1 to promote cardiomyocyte proliferation. We, therefore, identify Amotl1, which is not present in flies, as a mammalian intermediate for non-canonical Hippo signalling, downstream of Fat4. This work uncovers a mechanism for the restriction of heart growth at birth, a process which impedes the regenerative potential of the mammalian heart.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Cadherins/metabolism , Heart/growth & development , Membrane Proteins/metabolism , Phosphoproteins/metabolism , Angiopoietin-Like Protein 1 , Animals , Animals, Newborn , Cardiomegaly/genetics , Cardiomegaly/pathology , Cell Cycle Proteins , Cell Proliferation , Desmosomes/metabolism , Desmosomes/ultrastructure , Gene Expression Regulation, Developmental , Mice , Models, Biological , Protein Binding , Rats , Signal Transduction , YAP-Signaling Proteins
7.
J Chem Phys ; 145(15): 154705, 2016 Oct 21.
Article in English | MEDLINE | ID: mdl-27782454

ABSTRACT

We present a room temperature STM study of perylene adsorption on Ag(110) at the monolayer coverage regime. We found that structure and symmetry of the perylene monolayer are settled by thermodynamic balance of the three factors: (i) the ability of perylene molecules to recognize specific adsorption sites on the (110) lattice, (ii) the intermolecular interaction, and (iii) the accommodation of thermal motion of the molecules. The moderate strength of the site recognition and the intermolecular interaction, of the same order of magnitude as kT ∼ 25 meV, represents a key feature of the thermodynamic balance. It bestows to this system the unique quality to form the quasi-liquid monolayer of epitaxial as well as self-assembling character. The perylene monolayer accommodates the short-range motion of the molecules instead of quenching it. It precludes the formation of possible solid nuclei and maintains common registry of the included molecules. The surface registry of the quasi-liquid phase is provided by locking of a structure-related fraction of the perylene molecules into specific adsorption sites of the (110) lattice favorable in terms of intermolecular interaction.

8.
J Immunol ; 194(11): 5312-9, 2015 Jun 01.
Article in English | MEDLINE | ID: mdl-25904549

ABSTRACT

Staphylococcus aureus is a common cause of bacterial infections in respiratory diseases. It secretes molecules to dampen host immunity, and the recently identified adenosine is one of these molecules. The type IIA secretory phospholipase A2 (sPLA2-IIA) is a host protein endowed with antibacterial properties, especially against Gram-positive bacteria such as S. aureus. However, the role of adenosine in sPLA2-IIA-mediated S. aureus killing by host is still unknown. The present studies showed that the S. aureus mutant lacking adenosine production (∆adsA strain) increased sPLA2-IIA expression in guinea pig airways and was cleared more efficiently, compared with the wild-type strain. S. aureus ∆adsA strain induced sPLA2-IIA expression by alveolar macrophages after phagocytic process via NOD2-NF-κB-dependent mechanism. However, S. aureus adenosine (wild-type and adsA-complemented strains) and exogenous adenosine downregulated S. aureus phagocytosis by alveolar macrophages, leading to inhibition of sPLA2-IIA expression. This occurred through inhibition of p38 phosphorylation via adenosine receptors A2a-, A2b-, and protein kinase A-dependent pathways. Taken together, our studies suggest that, in the airway, S. aureus escapes sPLA2-IIA-mediated killing through adenosine-mediated inhibition of phagocytosis and sPLA2-IIA expression.


Subject(s)
Adenosine/immunology , Group II Phospholipases A2/biosynthesis , Host-Pathogen Interactions , Macrophages, Alveolar/immunology , Phagocytosis/immunology , Staphylococcal Infections/immunology , Staphylococcus aureus/immunology , Adenosine/genetics , Animals , Bronchoalveolar Lavage Fluid , CHO Cells , Cell Line , Cricetinae , Cricetulus , Cyclic AMP-Dependent Protein Kinases/metabolism , Group II Phospholipases A2/antagonists & inhibitors , Guinea Pigs , Imidazoles/pharmacology , Male , NF-kappa B/metabolism , Nod2 Signaling Adaptor Protein/immunology , Phosphorylation , Pyridines/pharmacology , Receptor, Adenosine A2A/metabolism , Receptor, Adenosine A2B/metabolism , Staphylococcal Infections/microbiology , Staphylococcus aureus/genetics , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/metabolism
9.
Nat Commun ; 5: 5105, 2014 Oct 07.
Article in English | MEDLINE | ID: mdl-25290234

ABSTRACT

Young cystic fibrosis (CF) patients' airways are mainly colonized by Staphylococcus aureus, while Pseudomonas aeruginosa predominates in adults. However, the mechanisms behind this infection switch are unclear. Here, we show that levels of type-IIA-secreted phospholipase A2 (sPLA2-IIA, a host enzyme with bactericidal activity) increase in expectorations of CF patients in an age-dependent manner. These levels are sufficient to kill S. aureus, with marginal effects on P. aeruginosa strains. P. aeruginosa laboratory strains and isolates from CF patients induce sPLA2-IIA expression in bronchial epithelial cells from CF patients (these cells are a major source of the enzyme). In an animal model of lung infection, P. aeruginosa induces sPLA2-IIA production that favours S. aureus killing. We suggest that sPLA2-IIA induction by P. aeruginosa contributes to S. aureus eradication in CF airways. Our results indicate that a bacterium can eradicate another bacterium by manipulating the host immunity.


Subject(s)
Cystic Fibrosis/microbiology , Epithelial Cells/enzymology , Group II Phospholipases A2/metabolism , Pseudomonas aeruginosa/physiology , Sputum/enzymology , Staphylococcus aureus/physiology , ADP Ribose Transferases , Adolescent , Adult , Animals , Bacterial Toxins , Bronchi , Child , Child, Preschool , Cystic Fibrosis/enzymology , Disease Progression , Guinea Pigs , Humans , Mice , Respiratory Mucosa , Young Adult
10.
Biochimie ; 107 Pt A: 95-104, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25201511

ABSTRACT

Pseudomonas aeruginosa pulmonary infection is a leading cause of death in numerous diseases such as cystic fibrosis (CF). The host cytosolic phospholipase A2α (cPLA2α) releases lipid mediators that play an important role in the pathogenesis of diseases, but its role in lung injury induced by P. aeruginosa infection is still obscure. Using an animal model of P. aeruginosa lung infection, we showed that the CHA strain of P. aeruginosa was more potent than the PAK strain in inducing mouse mortality and lung injury, and that both mouse mortality and lung injury were reduced in cPLA2α(-/-) mice as compared to cPLA2α(+/+) mice. This was accompanied by decreased levels of IL6 but not other inflammatory cytokines (IL1ß, KC and TNFα) in the bronchoalveolar lavage fluids (BALFs) of cPLA2α(-/-) mice. Given that CFTR(-/-) mice exhibit increased cPLA2α activation in the lung, the role of cPLA2α was further examined in this lung infection model. Compared to littermates, P. aeruginosa infection caused increased mortality in CFTR(-/-) mice with high IL6 levels in BALFs, which was attenuated by pharmacological inhibition of cPLA2α. In addition, compared to IL6(-/-) mice, an enhanced mortality was also observed in P. aeruginosa infected IL6(+/+) mice. Since alveolar macrophages (AMs) are the primary inflammatory cytokine source in the lung, murine AMs cell line (MH-S) were used to investigate the signalling pathways involved in this process. Incubation of MH-S cells with P. aeruginosa induced IL6 production, which was mediated by MAPKs ERK/p38 and was abolished by cPLA2α inhibitors. Furthermore, among cPLA2 downstream signalling pathways, only 15-lipoxygenase (15-LOX) and cyclooxygenase-2 (COX-2) were proven to participate in this P. aeruginosa-induced IL6 expression. Based on all these observations, we conclude that cPLA2α enhances P. aeruginosa-induced animal lethality in part via IL6 induction and that MAPKs ERK/p38, 15-LOX and COX-2 signalling pathways were involved in this process.


Subject(s)
Group IV Phospholipases A2/metabolism , Interleukin-6/metabolism , Lung Diseases/metabolism , Pseudomonas Infections/metabolism , Animals , Arachidonate 15-Lipoxygenase/metabolism , Arachidonic Acids/pharmacology , Bronchoalveolar Lavage Fluid/chemistry , Cell Line , Cyclooxygenase 2/metabolism , Enzyme Inhibitors/pharmacology , Extracellular Signal-Regulated MAP Kinases/antagonists & inhibitors , Extracellular Signal-Regulated MAP Kinases/metabolism , Female , Group IV Phospholipases A2/antagonists & inhibitors , Group IV Phospholipases A2/genetics , Host-Pathogen Interactions , Immunoblotting , Lung Diseases/genetics , Lung Diseases/microbiology , Macrophages, Alveolar/drug effects , Macrophages, Alveolar/metabolism , Macrophages, Alveolar/microbiology , Male , Mice, Inbred C57BL , Mice, Inbred CFTR , Mice, Knockout , Pseudomonas Infections/genetics , Pseudomonas Infections/mortality , Pseudomonas aeruginosa/classification , Pseudomonas aeruginosa/physiology , Species Specificity , Survival Rate , p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors , p38 Mitogen-Activated Protein Kinases/metabolism
11.
Mol Biol Cell ; 25(13): 1995-2005, 2014 Jul 01.
Article in English | MEDLINE | ID: mdl-24807907

ABSTRACT

The regulation of Rho-family GTPases is crucial to direct the formation of cell-cell junctions and tissue barriers. Cingulin (CGN) and paracingulin (CGNL1) control RhoA activation in epithelial cells by interacting with RhoA guanidine exchange factors. CGNL1 depletion also inhibits Rac1 activation during junction assembly. Here we show that, unexpectedly, Madin-Darby canine kidney epithelial cells depleted of both CGN and CGNL1 (double-KD cells) display normal Rac1 activation and tight junction (TJ) formation, despite decreased junctional recruitment of the Rac1 activator Tiam1. The expression of the Rac1 inhibitor MgcRacGAP is decreased in double-KD cells, and the barrier development and Rac1 activation phenotypes are rescued by exogenous expression of MgcRacGAP. MgcRacGAP colocalizes with CGN and CGNL1 at TJs and forms a complex and interacts directly in vitro with CGN and CGNL1. Depletion of either CGN or CGNL1 in epithelial cells results in decreased junctional localization of MgcRacGAP but not of ECT2, a centralspindlin-interacting Rho GEF. These results provide new insight into coordination of Rho-family GTPase activities at junctions, since apical accumulation of CGN and CGNL1 at TJs during junction maturation provides a mechanism to spatially restrict down-regulation of Rac1 activation through the recruitment of MgcRacGAP.


Subject(s)
Cytoskeletal Proteins/metabolism , GTPase-Activating Proteins/metabolism , Membrane Proteins/metabolism , Microfilament Proteins/metabolism , Tight Junctions/metabolism , rac1 GTP-Binding Protein/metabolism , Animals , Coculture Techniques , Dogs , Enzyme Activation , Epithelium , Humans , Keratinocytes/metabolism , MCF-7 Cells , Madin Darby Canine Kidney Cells , Mice, Knockout , Protein Multimerization
12.
PLoS One ; 9(3): e90466, 2014.
Article in English | MEDLINE | ID: mdl-24595157

ABSTRACT

Pseudomonas aeruginosa is an opportunistic pathogen involved in nosocomial infections. While a number of studies have demonstrated the roles of TLR2, TLR4 and TLR5 in host defense againt P. aeruginosa infection, the implication of TLR9 in this process has been overlooked. Here, we show that P. aeruginosa DNA stimulates the inflammatory response through TLR9 pathway in both a cell line and primary alveolar macrophages (AMs). This activation requires asparagine endopeptidase- and endosomal acidification. Interestingly, TLR9-/- mice resisted to lethal lung infection by P. aeruginosa, compared to WT C57BL/6 mice. The resistance of TLR9-/- mice to P. aeruginosa infection was associated with: (i) a higher ability of TLR9-/- AMs to kill P. aeruginosa; (ii) a rapid increase in the pro-inflammatory cytokines such as TNFα, IL-1ß and IL-6 production; and (iii) an increase in nitric oxide (NO) production and inductible NO synthase expression in AMs. In addition, inhibition of both IL-1ß and NO production resulted in a significant decrease of P. aeruginosa clearance by AMs. Altogether these results indicate that TLR9 plays a detrimental role in pulmonary host defense toward P. aeruginosa by reducing the AMs clearance activity and production of IL-1ß and NO necessary for bacteria killing.


Subject(s)
Lung/microbiology , Lung/pathology , Pseudomonas Infections/microbiology , Pseudomonas Infections/prevention & control , Pseudomonas aeruginosa/physiology , Toll-Like Receptor 9/deficiency , Animals , Cell Separation , Cytokines/biosynthesis , DNA, Bacterial/metabolism , Endosomes/drug effects , Endosomes/metabolism , Female , Hydrogen-Ion Concentration , Immunity, Innate/drug effects , Lung/drug effects , Lung/immunology , Macrophages, Alveolar/drug effects , Macrophages, Alveolar/metabolism , Male , Mice, Inbred C57BL , Microbial Viability/drug effects , Nitric Oxide/metabolism , Nitric Oxide Synthase Type II/metabolism , Oligodeoxyribonucleotides/pharmacology , Pneumonia/immunology , Pneumonia/microbiology , Pneumonia/pathology , Pseudomonas Infections/immunology , Pseudomonas Infections/pathology , Pseudomonas aeruginosa/drug effects , Signal Transduction/drug effects , Survival Analysis , Toll-Like Receptor 4/metabolism , Toll-Like Receptor 9/metabolism
13.
Emerg Microbes Infect ; 3(10): e71, 2014 Oct.
Article in English | MEDLINE | ID: mdl-26038497

ABSTRACT

Rift Valley fever virus (RVFV) is an enzootic virus circulating in Africa that is transmitted to its vertebrate host by a mosquito vector and causes severe clinical manifestations in humans and ruminants. RVFV has a tripartite genome of negative or ambisense polarity. The M segment contains five in-frame AUG codons that are alternatively used for the synthesis of two major structural glycoproteins, GN and GC, and at least two accessory proteins, NSm, a 14-kDa cytosolic protein, and P78/NSm-GN, a 78-kDa glycoprotein. To determine the relative contribution of P78 and NSm to RVFV infectivity, AUG codons were knocked out to generate mutant viruses expressing various sets of the M-encoded proteins. We found that, in the absence of the second AUG codon used to express NSm, a 13-kDa protein corresponding to an N-terminally truncated form of NSm, named NSm', was synthesized from AUG 3. None of the individual accessory proteins had any significant impact on RVFV virulence in mice. However, a mutant virus lacking both NSm and NSm' was strongly attenuated in mice and grew to reduced titers in murine macrophages, a major target cell type of RVFV. In contrast, P78 was not associated with reduced viral virulence in mice, yet it appeared as a major determinant of virus dissemination in mosquitoes. This study demonstrates how related accessory proteins differentially contribute to RVFV propagation in mammalian and arthropod hosts.

14.
PLoS One ; 8(2): e55873, 2013.
Article in English | MEDLINE | ID: mdl-23409073

ABSTRACT

The cytoplamic junctional proteins cingulin and paracingulin have been implicated in the regulation of gene expression in different cultured cell models. In renal epithelial MDCK cells, depletion of either protein results in a Rho-dependent increase in the expression of claudin-2. Here we examined MDCK cell clones depleted of both cingulin and paracingulin (double-KD cells), and we found that unexpectedly the expression of claudin-2, and also the expression of ZO-3 and claudin-3, were decreased, while RhoA activity was still higher than in control cells. The decreased expression of claudin-2 and other TJ proteins in double-KD cells correlated with reduced levels of the transcription factor GATA-4, and was rescued by overexpression of GATA-4, but not by inhibiting RhoA activity. These results indicate that in MDCK cells GATA-4 is required for the expression of claudin-2 and other TJ proteins, and that maintenance of GATA-4 expression requires either cingulin or paracingulin. These results and previous studies suggest a model whereby cingulin and paracingulin redundantly control the expression of specific TJ proteins through distinct GATA-4- and RhoA-dependent mechanisms, and that in the absence of sufficient levels of GATA-4 the RhoA-mediated upregulation of claudin-2 is inhibited.


Subject(s)
Cytoskeletal Proteins/metabolism , GATA4 Transcription Factor/metabolism , Gene Expression Regulation , Membrane Proteins/metabolism , Tight Junction Proteins/genetics , Animals , Cell Line , Claudin-2/genetics , Claudin-2/metabolism , Claudin-3/genetics , Claudin-3/metabolism , Cytoskeletal Proteins/genetics , Gene Knockdown Techniques , Membrane Proteins/genetics , Phenotype , Zonula Occludens Proteins/genetics , Zonula Occludens Proteins/metabolism , rhoA GTP-Binding Protein/metabolism
15.
J Cell Sci ; 125(Pt 21): 5005-14, 2012 Nov 01.
Article in English | MEDLINE | ID: mdl-22946046

ABSTRACT

Cingulin (CGN) is a 140 kDa protein, which is localized to the cytoplasmic region of vertebrate tight junctions (TJ), and regulates gene expression and RhoA signaling in cultured cells. To investigate the function of CGN at the organism level, we generated CGN knockout (CGN(-/-)) mice by homologous recombination. CGN(-/-) mice are viable and fertile, and are born at the expected mendelian ratios. Immunohistochemistry, immunofluorescence, electron microscopy and permeability assays of epithelial tissues of CGN(-/-) mice show no cingulin labeling at junctions, a normal localization of TJ proteins, and normal TJ structure and barrier function. Microarray analysis of intestinal cells does not show significant changes in gene expression between CGN(-/-) and CGN(+/+) mice, whereas immunoblotting analysis shows a twofold increase in the levels of claudin-2 protein in the duodenum and the kidney of CGN(-/-) mice, compared to CGN(+/+) littermates. Furthermore, CGN(-/-) mice show an exacerbated response to the ulcerogenic action of cysteamine, whereas acute injury of the colon by dextran sodium sulfate elicits undistinguishable responses in CGN(-/-) and CGN(+/+) mice. We conclude that at the organism level cingulin is dispensable for the structure and barrier function of TJ, and is embedded in signaling networks that control the expression of claudin-2, and the mucosal response to acute injury in the duodenum.


Subject(s)
Claudins/metabolism , Duodenum/pathology , Intestinal Mucosa/metabolism , Membrane Proteins/genetics , Tight Junctions/metabolism , Animals , Claudins/genetics , Cysteamine , Cytokines/blood , Dextran Sulfate/pharmacology , Duodenal Ulcer/chemically induced , Duodenal Ulcer/metabolism , Duodenal Ulcer/pathology , Duodenum/metabolism , Gene Expression , Gene Knockout Techniques , Inflammation Mediators/blood , Intestinal Mucosa/pathology , Kidney/metabolism , Kidney/pathology , Liver/metabolism , Membrane Proteins/metabolism , Membrane Proteins/physiology , Mice , Mice, 129 Strain , Mice, Inbred C57BL , Mice, Knockout , Organ Specificity , Permeability , Tight Junction Proteins/genetics , Tight Junction Proteins/metabolism , Tight Junctions/pathology
16.
J Gen Virol ; 93(Pt 7): 1456-1464, 2012 Jul.
Article in English | MEDLINE | ID: mdl-22513390

ABSTRACT

Currently, there are no worldwide licensed vaccines for Rift Valley fever (RVF) that are both safe and effective. Development and evaluation of vaccines, diagnostics and treatments depend on the availability of appropriate animal models. Animal models are also necessary to understand the basic pathobiology of infection. Here, we report the use of an inbred MBT/Pas mouse model that consistently reproduces RVF disease and serves our purpose for testing the efficacy of vaccine candidates; an attenuated Rift Valley fever virus (RVFV) and a recombinant RVFV-capripoxvirus. We show that this model is relevant for vaccine testing.


Subject(s)
Disease Models, Animal , Drug Evaluation, Preclinical/methods , Rift Valley Fever/immunology , Rift Valley Fever/prevention & control , Rift Valley fever virus/immunology , Vaccination/methods , Viral Vaccines/immunology , Animals , Female , Humans , Mice , Vaccines, Attenuated/administration & dosage , Vaccines, Attenuated/immunology , Viral Vaccines/administration & dosage
17.
J Biol Chem ; 287(16): 13159-69, 2012 Apr 13.
Article in English | MEDLINE | ID: mdl-22315225

ABSTRACT

Paracingulin is an M(r) 150-160 kDa cytoplasmic protein of vertebrate epithelial tight and adherens junctions and comprises globular head, coiled-coil rod, and globular tail domains. Unlike its homologous tight junction protein cingulin, paracingulin has been implicated in the control of junction assembly and has been localized at extrajunctional sites in association with actin filaments. Here we analyze the role of paracingulin domains, and specific regions within the head and rod domains, in the function and localization of paracingulin by inducible overexpression of exogenous proteins in epithelial Madin Darby canine kidney (MDCK) cells and by expression of mutated and chimeric constructs in Rat1 fibroblasts and MDCK cells. The overexpression of the rod + tail domains of paracingulin perturbs the development of the tight junction barrier and Rac1 activation during junction assembly by the calcium switch, indicating that regulation of junction assembly by paracingulin is mediated by these domains. Conversely, only constructs containing the head domain target to junctions in MDCK cells and Rat1 fibroblasts. Furthermore, expression of chimeric cingulin and paracingulin constructs in Rat1 fibroblasts and MDCK cells identifies specific sequences within the head and rod domains of paracingulin as critical for targeting to actin filaments and regulation of junction assembly, respectively. In summary, we characterize the functionally important domains of paracingulin that distinguish it from cingulin.


Subject(s)
Actin Cytoskeleton/metabolism , Adherens Junctions/physiology , Cytoskeletal Proteins/chemistry , Cytoskeletal Proteins/metabolism , Tight Junctions/physiology , Animals , Calcium/metabolism , Cell Polarity/physiology , Cells, Cultured , Cytoplasm/metabolism , Cytoskeletal Proteins/genetics , Dogs , Epithelial Cells/cytology , Fibroblasts/cytology , Gene Expression/physiology , Humans , Kidney/cytology , Protein Structure, Tertiary/physiology , Rats , rac1 GTP-Binding Protein/metabolism
18.
PLoS Negl Trop Dis ; 5(12): e1421, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22163058

ABSTRACT

BACKGROUND: Rift Valley fever virus (RVFV) causes disease in livestock and humans. It can be transmitted by mosquitoes, inhalation or physical contact with the body fluids of infected animals. Severe clinical cases are characterized by acute hepatitis with hemorrhage, meningoencephalitis and/or retinitis. The dynamics of RVFV infection and the cell types infected in vivo are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: RVFV strains expressing humanized Renilla luciferase (hRLuc) or green fluorescent protein (GFP) were generated and inoculated to susceptible Ifnar1-deficient mice. We investigated the tissue tropism in these mice and the nature of the target cells in vivo using whole-organ imaging and flow cytometry. After intraperitoneal inoculation, hRLuc signal was observed primarily in the thymus, spleen and liver. Macrophages infiltrating various tissues, in particular the adipose tissue surrounding the pancreas also expressed the virus. The liver rapidly turned into the major luminescent organ and the mice succumbed to severe hepatitis. The brain remained weakly luminescent throughout infection. FACS analysis in RVFV-GFP-infected mice showed that the macrophages, dendritic cells and granulocytes were main target cells for RVFV. The crucial role of cells of the monocyte/macrophage/dendritic lineage during RVFV infection was confirmed by the slower viral dissemination, decrease in RVFV titers in blood, and prolonged survival of macrophage- and dendritic cell-depleted mice following treatment with clodronate liposomes. Upon dermal and nasal inoculations, the viral dissemination was primarily observed in the lymph node draining the injected ear and in the lungs respectively, with a significant increase in survival time. CONCLUSIONS/SIGNIFICANCE: These findings reveal the high levels of phagocytic cells harboring RVFV during viral infection in Ifnar1-deficient mice. They demonstrate that bioluminescent and fluorescent viruses can shed new light into the pathogenesis of RVFV infection.


Subject(s)
Liver/virology , Phagocytes/virology , Rift Valley Fever/virology , Rift Valley fever virus/physiology , Animals , Clodronic Acid , Flow Cytometry , Gene Knockout Techniques , Green Fluorescent Proteins/genetics , Immunohistochemistry , Liposomes , Mice , Mice, Knockout , Microscopy, Fluorescence , Pancreas/virology , Rift Valley Fever/physiopathology , Rift Valley fever virus/genetics , Rift Valley fever virus/pathogenicity , Survival Analysis , Thymus Gland/virology , Vero Cells , Viral Nonstructural Proteins/genetics
19.
J Immunol ; 185(10): 6146-56, 2010 Nov 15.
Article in English | MEDLINE | ID: mdl-20937849

ABSTRACT

Rift Valley fever (RVF) is an arthropod-borne viral disease repeatedly reported in many African countries and, more recently, in Saudi Arabia and Yemen. RVF virus (RVFV) primarily infects domesticated ruminants, resulting in miscarriage in pregnant females and death for newborns and young animals. It also has the ability to infect humans, causing a feverish syndrome, meningoencephalitis, or hemorrhagic fever. The various outcomes of RVFV infection in animals and humans argue for the existence of host genetic determinants controlling the disease. We investigated the susceptibility of inbred mouse strains to infection with the virulent RVFV ZH548 strain. Compared with classical BALB/cByJ mice, wild-derived Mus m. musculus MBT/Pas mice exhibited earlier and greater viremia and died sooner, a result in sharp contrast with their resistance to infection with West Nile virus and influenza A. Infection of mouse embryonic fibroblasts (MEFs) from MBT/Pas mice with RVFV also resulted in higher viral production. Microarray and quantitative RT-PCR experiments showed that BALB/cByJ MEFs displayed a significant activation of the type I IFN pathway. In contrast, MBT/Pas MEFs elicited a delayed and partial type I IFN response to RVFV infection. RNA interference-mediated inhibition of genes that were not induced by RVFV in MBT/Pas MEFs increased viral production in BALB/cByJ MEFs, thus demonstrating their functional importance in limiting viral replication. We conclude that the failure of MBT/Pas murine strain to induce, in due course, a complete innate immune response is instrumental in the selective susceptibility to RVF.


Subject(s)
Immunity, Innate/genetics , Rift Valley Fever/genetics , Rift Valley Fever/immunology , Animals , Disease Models, Animal , Fibroblasts/immunology , Fibroblasts/virology , Gene Expression Profiling , Genetic Predisposition to Disease , Immunohistochemistry , Male , Mice , Mice, Inbred C57BL , Oligonucleotide Array Sequence Analysis , Reverse Transcriptase Polymerase Chain Reaction
20.
Ann N Y Acad Sci ; 1165: 88-98, 2009 May.
Article in English | MEDLINE | ID: mdl-19538293

ABSTRACT

Tight junctions (TJ) regulate the passage of solutes across epithelial sheets, contribute to the establishment and maintenance of epithelial apico-basal polarity and are involved in the regulation of gene expression and cell proliferation. Cingulin, a Mr 140 kDa protein localized in the cytoplasmic region of TJ, is not directly required for TJ formation and epithelial polarity but regulates RhoA signaling, through its interaction with the RhoA activator GEF-H1, and gene expression. Here we describe in more detail the effect of cingulin mutation in embryoid bodies (EB) on gene expression, by identifying the genes that show the highest degree of up- or downregulation, and the putative canonical pathways that might be affected by cingulin. Furthermore, we show that full-length canine GEF-H1, produced in baculovirus-infected insect cells, interacts with regions both in the cingulin globular head, and in the coiled-coil rod domain. These results extend our previous studies and provide new perspectives for the mechanistic analysis of cingulin function.


Subject(s)
Gene Expression Regulation , Membrane Proteins/physiology , Signal Transduction/genetics , Tight Junctions/metabolism , rhoA GTP-Binding Protein/metabolism , Animals , Cell Communication , Cells, Cultured , Embryonic Stem Cells/metabolism , Guanine Nucleotide Exchange Factors/metabolism , Humans , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice , Microfilament Proteins/genetics , Microfilament Proteins/metabolism , Models, Biological , Mutation , rhoA GTP-Binding Protein/genetics
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