bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activation of Notch in lgd mutant cells requires the fusion of late endosomes with the lysosome
Authors: Schneider Markus , Troost Tobias , Grawe Ferdi , Martinez-Arias Alfonso , Klein Thomas 
Published: November 2012

Summary
The tumour suppressor Lethal (2) giant discs (Lgd) is a regulator of endosomal trafficking of the Notch signalling receptor as well as other transmembrane proteins in Drosophila. The loss of its function results in an uncontrolled ligand-independent activation of the Notch signalling receptor. Here, we investigated the consequences of loss of lgd function and the requirements for the activation of Notch. We show that the activation of Notch in lgd cells is independent of Kuz and dependent on γ-secretase. We found that the lgd cells have a defect that delays degradation of transmembrane proteins, which are residents of the plasma membrane. Furthermore, our results show that the activation of Notch in lgd cells occurs in the lysosome. By contrast, the pathway is activated at an earlier phase in mutants of the gene that encodes the ESCRT-III component Shrub, which is an interaction partner of Lgd. We further show that activation of Notch appears to be a general consequence of loss of lgd function. In addition, electron microscopy of lgd cells revealed that they contain enlarged multi-vesicular bodies. The presented results further elucidate the mechanism of uncontrolled Notch activation upon derailed endocytosis.
Protein tyrosine phosphatase SHP2 suppresses podosome rosette formation in Src-transformed fibroblasts
Authors: Pan Yi-Ru , Cho Ke-Huan , Lee Hsiao-Hui , Chang Zee-Fen , Chen Hong-Chen 
Published: November 2012

Summary
Podosomes are actin-enriched membrane protrusions that play important roles in extracellular matrix degradation and invasive cell motility. Podosomes undergo self-assembly into large rosette-like structures in Src-transformed fibroblasts, osteoclasts and certain highly invasive cancer cells. Several protein tyrosine kinases have been shown to be important for the formation of podosome rosettes, but little is known regarding the role of protein tyrosine phosphatases in this process. We found that knockdown of the Src homolog domain-containing phosphatase 2 (SHP2) significantly increased podosome rosette formation in Src-transformed fibroblasts. By contrast, SHP2 overexpression suppressed podosome rosette formation in these cells. The phosphatase activity of SHP2 was essential for the suppression of podosome rosette formation. SHP2 selectively suppressed the tyrosine phosphorylation of Tks5, a scaffolding protein required for podosome formation. The inhibitory effect of SHP2 on podosome rosette formation was associated with the increased activation of Rho-associated kinase (ROCK) and the enhanced polymerization of vimentin filaments. A higher content of polymerized vimentin filaments was correlated with a lower content of podosome rosettes. Taken together, our findings indicate that SHP2 serves as a negative regulator of podosome rosette formation through the dephosphorylation of Tks5 and the activation of ROCK-mediated polymerization of vimentin in Src-transformed fibroblasts.
Determination of the two dimensional distribution of the attempt relaxation times and activation energies from temperature dependence of dielectric dispersion
Authors: Mikonis Andrejus , Banys Jūras , Grigalaitis Robertas , Matulis Algirdas , Lapinskas Saulius , Völkel Georg 
Published: November 2012

Abstract
We present a method for numerical calculation of two dimensional distributions of the attempt relaxation times and activation energies from the temperature dependence of the experimental dielectric permittivity dispersion. We introduce empirical attempts to account for broad and/or asymmetric dispersions with the idea of using a weighted collection of Debye relaxation times. Then we present a modification of the aforementioned idea including attempt relaxation time and activation energy using the Arrhenius law, which significantly complicates the computation of the aforementioned distribution. Incorporating the activation energy and the attempt relaxation time into the equation transforms the discretized matrix equations into tensor equations. We rework the tensor equations into simpler matrix equations, thus permitting us to solve the presented discretized integral equation by using existing Least Distance Problem solving methods. Also, we present a regularization method and a way to choose the regularization parameter based on a best fit criterion. In the end we discuss the method showing some simulated results and experimental results. We then point out some problems involved in the calculations and propose methods to reduce their significance.
The Tim3–Galectin 9 Pathway Induces Antibacterial Activity in Human Macrophages Infected with Mycobacterium tuberculosis
Authors: Sada-Ovalle Isabel , Chávez-Galán Leslie , Torre-Bouscoulet Luis , Nava-Gamiño Lourdes , Barrera Lourdes , Jayaraman Pushpa , Torres-Rojas Martha , Salazar-Lezama Miguel Angel , Behar Samuel M. 
Published: November 2012

Abstract
T cell Ig and mucin domain 3 (Tim3) is an inhibitory molecule involved in immune tolerance, autoimmune responses, and antiviral immune evasion. However, we recently demonstrated that Tim3 and Galectin-9 (Gal9) interaction induces a program of macrophage activation that results in killing of Mycobacterium tuberculosis in the mouse model of infection. In this study, we sought to determine whether the Tim3–Gal9 pathway plays a similar role in human pulmonary TB. We identified that pulmonary TB patients have reduced expression of Tim3 on CD14+ monocytes in vivo. By blocking Tim3 and Gal9 interaction in vitro, we show that these molecules contribute to the control of intracellular bacterial replication in human macrophages. The antimicrobial effect was partially dependent on the production of IL-1β. Our results establish that Tim3–Gal9 interaction activates human M. tuberculosis –infected macrophages and leads to the control of bacterial growth through the production of the proinflammatory cytokine IL-1β. Data presented in this study suggest that one of the potential pathways activated by Tim3/Gal9 is the secretion of IL-1β, which plays a crucial role in antimicrobial immunity by modulating innate inflammatory networks.
Enzymatic Discovery of a HER-2/neu Epitope That Generates Cross-Reactive T Cells
Authors: Henle Andrea M. , Erskine Courtney L. , Benson Linda M. , Clynes Raphael , Knutson Keith L. 
Published: November 2012

Abstract
Patients with HER-2/neu–expressing breast cancer remain at risk for relapse following standard therapy. Vaccines targeting HER-2/neu to prevent relapse are in various phases of clinical testing. Many vaccines incorporate the HER-2/neu HLA-A2–binding peptide p369–377 (KIFGSLAFL), because it has been shown that CTLs specific for this epitope can directly kill HER-2/neu–overexpressing breast cancer cells. Thus, understanding how tumors process this epitope may be important for identifying those patients who would benefit from immunization. Proteasome preparations were used to determine if p369–377 was processed from larger HER-2/neu–derived fragments. HPLC, mass spectrometry, cytotoxicity assays, IFN-γ ELISPOT, and human breast cancer cell lines were used to assess the proteolytic fragments. Processing of p369–377 was not detected by purified 20S proteasome and immunoproteasome, indicating that tumor cells may not be capable of processing this Ag from the HER-2/neu protein and presenting it in the context of HLA class I. Instead, we show that other extracellular domain HER-2/neu peptide sequences are consistently processed by the proteasomes. One of these sequences, p373–382 (SLAFLPESFD), bound HLA-A2 stronger than did p369–377. CTLs specific for p373–382 recognized both p373–382 and p369–377 complexed with HLA-A2. CTLs specific for p373–382 also killed human breast cancer cell lines at higher levels than did CTLs specific for p369–377. Conversely, CTLs specific for p369–377 recognized p373–382. Peptide p373–382 is a candidate epitope for breast cancer vaccines, as it is processed by proteasomes and binds HLA-A2.
Phosphoinositide 3-OH Kinase Regulates Integrin-Dependent Processes in Neutrophils by Signaling through Its Effector ARAP3
Authors: Gambardella Laure , Anderson Karen E. , Jakus Zoltán , Kovács Miklós , Voigt Susann , Hawkins Phillip T. , Stephens Len , Mócsai Attila , Vermeren Sonja 
Published: November 2012

Abstract
ARAP3, a GTPase activating protein for Rho and Arf family GTPases, is one of many phosphoinositide 3-OH kinase (PI3K) effectors. In this study, we investigate the regulatory input of PI3K upstream of ARAP3 by analyzing neutrophils from an ARAP3 pleckstrin homology (PH) domain point mutation knock-in mouse (R302, 303A), in which ARAP3 is uncoupled from activation by PI3K. ARAP3 PH domain point mutant neutrophils are characterized by disturbed responses linked to stimulation by either integrin ligands or immobilized immune complexes. These cells exhibit increased β2 integrin inside-out signaling (binding affinity and avidity), and our work suggests the disturbed responses to immobilized immune complexes are secondary to this. In vitro, neutrophil chemotaxis is affected in the mutant. In vivo, ARAP3 PH domain point mutant bone marrow chimeras exhibit reduced neutrophil recruitment to the peritoneum on induction of sterile peritonitis and also reduced inflammation in a model for rheumatoid arthritis. The current work suggests a dramatic regulatory input of PI3K into the regulation of β2 integrin activity, and processes dependent on this, by signaling through its effector ARAP3.
Phosphatidylinositol 3-Kinase-γ Signaling Promotes Campylobacter jejuni–Induced Colitis through Neutrophil Recruitment in Mice
Authors: Sun Xiaolun , Liu Bo , Sartor Ryan Balfour , Jobin Christian 
Published: November 2012

Abstract
Crypt abscesses caused by excessive neutrophil accumulation are prominent features of human campylobacteriosis and its associated pathology. The molecular and cellular events responsible for this pathological situation are currently unknown. We investigated the contribution of PI3K-γ signaling in Campylobacter jejuni–induced neutrophil accumulation and intestinal inflammation. Germ-free and specific pathogen-free Il10−/− and germ-free Il10−/−;Rag2−/− mice were infected with C. jejuni (109 CFU/mouse). PI3K-γ signaling was manipulated using either the pharmacological PI3K-γ inhibitor AS252424 (i.p. 10 mg/kg daily) or genetically using Pi3k-γ−/− mice. After up to 14 d, inflammation was assessed histologically and by measuring levels of colonic Il1β, Cxcl2, and Il17a mRNA. Neutrophils were depleted using anti-Gr1 Ab (i.p. 0.5 mg/mouse/every 3 d). Using germ-free Il10−/−;Rag2−/− mice, we observed that innate immune cells are the main cellular compartment responsible for campylobacteriosis. Pharmacological blockade of PI3K-γ signaling diminished C. jejuni–induced intestinal inflammation, neutrophil accumulation, and NF-κB activity, which correlated with reduced Il1β (77%), Cxcl2 (73%), and Il17a (72%) mRNA accumulation. Moreover, Pi3k-γ−/− mice pretreated with anti–IL-10R were resistant to C. jejuni–induced intestinal inflammation compared with Wt mice. This improvement was accompanied by a reduction of C. jejuni translocation into the colon and extraintestinal tissues and by attenuation of neutrophil migratory capacity. Furthermore, neutrophil depletion attenuated C. jejuni–induced crypt abscesses and intestinal inflammation. Our findings indicate that C. jejuni–induced PI3K-γ signaling mediates neutrophil recruitment and intestinal inflammation in Il10−/− mice. Selective pharmacological inhibition of PI3K-γ may represent a novel means to alleviate severe cases of campylobacteriosis, especially in antibiotic-resistant strains.
AnHLA-DRB1–Coded Signal Transduction Ligand Facilitates Inflammatory Arthritis: A New Mechanism of Autoimmunity
Authors: Holoshitz Joseph , Liu Ying , Fu Jiaqi , Joseph Jeena , Ling Song , Colletta Alessandro , Sharma Prannda , Begun Dana , Goldstein Steven , Taichman Russell 
Published: November 2012

AbstractParticular alleles of HLA contribute to disease susceptibility and severity in many autoimmune conditions, but the mechanisms underlying these associations are often unknown. In this study, we demonstrate that the shared epitope (SE), an HLA-DRB1–coded sequence motif that is the single most significant genetic risk factor for erosive rheumatoid arthritis, acts as a signal transduction ligand that potently activates osteoclastogenesis, both in vitro and in vivo. The SE enhanced the production of several pro-osteoclastogenic factors and facilitated osteoclast (OC) differentiation in mouse and human cells in vitro. Transgenic mice expressing a human HLA-DRB1 allele that code the SE motif demonstrated markedly higher propensity for osteoclastogenesis and enhanced bone degradation capacity ex vivo. In addition, the SE enhanced the differentiation of Th17 cells expressing the receptor activator for NF-κB ligand. When the two agents were combined, IL-17 and the SE enhanced OC differentiation synergistically. When administered in vivo to mice with collagen-induced arthritis, the SE ligand significantly increased arthritis severity, synovial tissue OC abundance, and bone erosion. Thus, the SE contributes to arthritis severity by activating an OC-mediated bone-destructive pathway. These findings suggest that besides determining the target specificity of autoimmune responses, HLA molecules may influence disease outcomes by shaping the pathogenic consequences of such responses.
TIM-3 Regulates Innate Immune Cells To Induce Fetomaternal Tolerance
Authors: Chabtini Lola , Mfarrej Bechara , Mounayar Marwan , Zhu Bing , Batal Ibrahim , Dakle Pranal J. , Smith Brian D. , Boenisch Olaf , Najafian Nader , Akiba Hisaya , Yagita Hideo , Guleria Indira 
Published: November 2012

Abstract
TIM-3 is constitutively expressed on subsets of macrophages and dendritic cells. Its expression on other cells of the innate immune system and its role in fetomaternal tolerance has not yet been explored. In this study, we investigate the role of TIM-3–expressing innate immune cells in the regulation of tolerance at the fetomaternal interface (FMI) using an allogeneic mouse model of pregnancy. Blockade of TIM-3 results in accumulation of inflammatory granulocytes and macrophages at the uteroplacental interface and upregulation of proinflammatory cytokines. Furthermore, TIM-3 blockade inhibits the phagocytic potential of uterine macrophages resulting in a build up of apoptotic bodies at the uteroplacental interface that elicits a local immune response. In response to inflammatory cytokines, Ly-6ChiGneg monocytic myeloid–derived suppressor cells expressing inducible NO synthase and arginase 1 are induced. However, these suppressive cells fail to downregulate the inflammatory cascade induced by inflammatory granulocytes (Ly-6CintGhi) and apoptotic cells; the increased production of IFN-γ and TNF-α by inflammatory granulocytes leads to abrogation of tolerance at the FMI and fetal rejection. These data highlight the interplay between cells of the innate immune system at the FMI and their influence on successful pregnancy in mice.
TLR9-Dependent IL-23/IL-17 Is Required for the Generation of Stachybotrys chartarum–Induced Hypersensitivity Pneumonitis
Authors: Bhan Urvashi , Newstead Michael J. , Zeng Xianying , Podsaid Amy , Goswami Moloy , Ballinger Megan N. , Kunkel Steven L. , Standiford Theodore J. 
Published: November 2012

Abstract
Hypersensitivity pneumonitis (HP) is an inflammatory lung disease that develops after repeated exposure to inhaled particulate Ag. Stachybotrys chartarum is a dimorphic fungus that has been implicated in a number of respiratory illnesses, including HP. In this study, we have developed a murine model of S. chartarum–induced HP that reproduces pathology observed in human HP, and we have hypothesized that TLR9-mediated IL-23 and IL-17 responses are required for the generation of granulomatous inflammation induced by inhaled S. chartarum. Mice that undergo i.p. sensitization and intratracheal challenge with 106 S. chartarum spores developed granulomatous inflammation with multinucleate giant cells, accompanied by increased accumulation of T cells. S. chartarum sensitization and challenge resulted in robust pulmonary expression of IL-17 and IL-23. S. chartarum–mediated granulomatous inflammation required intact IL-23 or IL-17 responses and required TLR9, because TLR9−/− mice displayed reduced IL-17 and IL-23 expression in whole lung associated with decreased accumulation of IL-17 expressing CD4+ and γδ T cells. Compared with S. chartarum–sensitized dendritic cells (DC) isolated from WT mice, DCs isolated from TLR9−/− mice had a reduced ability to produce IL-23 in responses to S. chartarum. Moreover, shRNA knockdown of IL-23 in DCs abolished IL-17 production from splenocytes in response to Ag challenge. Finally, the intratracheal reconstitution of IL-23 in TLR9−/− mice recapitulated the immunopathology observed in WT mice. In conclusion, our studies suggest that TLR9 is critical for the development of Th17-mediated granulomatous inflammation in the lung in response to S. chartarum.
AMP-Activated Protein Kinase Restricts IFN-γ Signaling
Authors: Meares Gordon P. , Qin Hongwei , Liu Yudong , Holdbrooks Andrew T. , Benveniste Etty N. 
Published: November 2012

AbstractInflammation in the CNS contributes to neurologic disorders. Neuroinflammation involves the release of inflammatory molecules from glial cells, such as astrocytes and microglia, and can lead to neuronal damage if unabated. In multiple sclerosis, peripheral immune cells, including IFN-γ–producing Th1 cells, infiltrate the CNS and are important in shaping the inflammatory microenvironment, in part through cytokine-mediated interactions with glial cells. Recent evidence suggests that AMP-activated protein kinase (AMPK), a central regulator of energetic metabolism, can regulate inflammatory gene expression. In this study, we identified that IFN-γ induces biphasic AMPK signaling, suggestive of negative-feedback mechanisms. Activation of AMPK suppresses several IFN-γ–induced cytokines and chemokines in primary astrocytes and microglia. IFN-γ regulates gene expression through activation of STAT1, and deletion of AMPK results in a marked increase in basal expression of STAT1. Conversely, activation of AMPK blocks IFN-γ–induced STAT1 expression. Deletion of AMPK leads to increased basal and IFN-γ–induced expression of inflammatory molecules, including TNF-α, CXCL10, and CCL2. AMPK does not affect the phosphorylation of STAT1, but instead attenuates nuclear translocation of STAT1, DNA binding, and subsequent gene expression. In vivo, AMPK signaling during experimental autoimmune encephalomyelitis, an animal model of multiple sclerosis, is downregulated in the brain at onset and peak of disease. Diminution of AMPK signaling in vivo correlates with increased expression of IFN-γ and CCL2 in the CNS. Overall, these findings provide the first link between AMPK and STAT1 and may provide important clues about how bioenergetics and inflammation are linked.
Non‐stoichiometry in Oxide Thin Films: A Chemical Capacitance Study of the Praseodymium‐Cerium Oxide System
Authors: Chen Di , Bishop Sean R. , Tuller Harry L. 
Published: November 2012

AbstractWhile the properties of functional oxide thin films often depend strongly on their oxygen stoichiometry, there have been few ways to extract this information reliably and in situ. In this work, the derivation of the oxygen non‐stoichiometry of dense Pr0.1Ce0.9O2−δ thin films from an analysis of chemical capacitance obtained by impedance spectroscopy is described. Measurements are performed on electrochemical cells of the form Pr0.1Ce0.9O2−δ/Y0.16Zr0.84O1.92/Pr0.1Ce0.9O2−δ over the temperature range of 450 to 800 °C and oxygen partial pressure range of 10−5 to 1 atm O2. With the aid of a defect equilibria model, approximations relate chemical capacitance directly to non‐stoichiometry, without need for fitting parameters. The calculated non‐stoichiometry allows extraction of the thermodynamic constants defining defect generation. General agreement of these constants with bulk values derived by thermogravimetric analysis is found, thereby confirming the suitability of this technique for measuring oxygen non‐stoichiometry of thin oxide films. Potential sources of error observed in earlier chemical capacitance studies on perovskite structured oxide films are also discussed.
Hierarchical Multi‐Step Folding of Polymer Bilayers
Authors: Stoychev Georgi , Turcaud Sébastien , Dunlop John W. C. , Ionov Leonid 
Published: November 2012

AbstractA highly complex multi‐step folding of isotropic stimuli‐responsive polymer bilayers resulting in a variety of 2D and 3D structures is reported. Experimental observations allow determination of empirical rules, which can be used to direct the folding of polymer films in a predictable manner. In particular, it is demonstrated that these rules can be used for the design of a 3D pyramid. The understanding and know‐how attained in this study allow the very simple design of highly complex, self‐folding 3D objects and open new horizons for 3D patterning, important for the design of microfluidic devices, biomaterials, and soft electronics.
Epilepsy with cognitive deficit and autism spectrum disorders: Prospective diagnosis by array CGH
Authors: Nicholl Jillian , Waters Wendy , Suwalski Shanna , Brown Sue , Hull Yvonne , Harbord Michael G. , Entwistle John , Thompson Suzanna , Clark Damian , Pridmore Claire , Haan Eric , Barnett Christopher , McGregor Lesley , Liebelt Jan , Thompson Elizabeth M. , Friend Kathryn , Bain Sharon M. , Yu Sui , Mulley John C. 
Published: November 2012

AbstractThe clinical significance of chromosomal microdeletions and microduplications was predicted based on their gene content, de novo or familial inheritance and accumulated knowledge recorded on public databases. A patient group comprised of 247 cases with epilepsy and its common co‐morbidities of developmental delay, intellectual disability, autism spectrum disorders, and congenital abnormalities was reviewed prospectively in a diagnostic setting using a standardized oligo‐array CGH platform. Seventy‐three (29.6%) had copy number variations (CNVs) and of these 73 cases, 27 (37.0%) had CNVs that were likely causative. These 27 cases comprised 10.9% of the 247 cases reviewed. The range of pathogenic CNVs associated with seizures was consistent with the existence of many genetic determinants for epilepsy. © 2012 Wiley Periodicals, Inc.