A Role for CD148 in the control of cell growth and Cell-cell interactions

A variety of signal transduction events are controlled by the opposing, balanced activities of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs). Until recently scientists have focused on PTKs, but recent findings have recognized that PTPs play specific and active roles in the regulation of many physiological processes. CD148 is a receptor tyrosine phosphatase with a large extracellular domain and a single catalytic domain. It is expressed on a wide variety of cell types including fibroblasts, endothelial cells, and hematopoietic cells. A number of studies have addressed the role of CD148 in the regulation of cell growth and differentiation using fibroblasts or tumor cell lines. In cultured cells with epithelioid morphology CD148 transcript levels are dramatically upregulated as culture density increases. Although CD148 is expressed on the surface of hemopoietic cells, only a few studies have been published examining the expression of CD148 in human lymphocytes, especially T cells. These reports showed that CD148 plays a role in T cell activation where it participates in the regulation of the T-cell receptor. We have analyzed the possible involvement of CD148 in epithelial growth and cell-cell interactions. Using polarized epithelial cells as a model, we have applied a transcriptional silencing approach based on lentiviral-mediated RNA interference. We show that CD148 expression is required for epithelial cell growth control and proper assembly of epithelial sheets

Variants within the immunoregulatory CBLB gene are associated with multiple sclerosis

A genome wide association scan of ~6.6 million genotyped or imputed variants in 882 Sardinian Multiple Sclerosis (MS) cases and 872 controls suggested association of CBLB gene variants with disease, which was confirmed in 1,775 cases and 2,005 controls (overall P =1.60 × 10-10). CBLB encodes a negative regulator of adaptive immune responses and mice lacking the orthologue are prone to experimental autoimmune encephalomyelitis, the animal model of MS

A Molecular Dynamics study of a miRNA:mRNA interaction

none5noIn this paper we present a methodology to evaluate the binding free energy of a miRNA:mRNA complex through molecular dynamics (MD)-thermodynamic integration (TI) simulations. We applied our method to the Caenorhabditis elegans let-7 miRNA:lin-41 mRNA complex-a validated miRNA:mRNA interaction-in order to estimate the energetic stability of the structure. To make the miRNA:mRNA simulation possible and realistic, the methodology introduces specific solutions to overcome some of the general challenges of nucleic acid simulations and binding free energy computations that have been discussed widely in many previous research reports. The main features of the proposed methodology are: (1) positioning of the restraints imposed on the simulations in order to guarantee complex stability; (2) optimal sampling of the phase space to achieve satisfactory accuracy in the binding energy value; (3) determination of a suitable trade-off between computational costs and accuracy of binding free energy computation by the assessment of the scalability characteristics of the parallel simulations required for the TI. The experiments carried out demonstrate that MD simulations are a viable strategy for the study of miRNA binding characteristics, opening the way to the development of new computational target prediction methods based on three-dimensional structure information.nonePACIELLO, GIULIA; ACQUAVIVA, ANDREA; FICARRA, ELISA; DERIU, MARCO AGOSTINO; MACII, EnricoPACIELLO, GIULIA; ACQUAVIVA, ANDREA; FICARRA, ELISA; DERIU, MARCO AGOSTINO; MACII, Enric

When Stiffness Matters: Mechanosensing in Heart Development and Disease

During embryonic morphogenesis, the heart undergoes a complex series of cellular phenotypic maturations (e.g. transition of myocytes from proliferative to quiescent or maturation of the contractile apparatus), and this involves stiffening of the extracellular matrix acting in concert with morphogenetic signals. The maladaptive remodelling of the myocardium, one of the processes involved in determination of heart failure, also involve mechanical cues, with a progressive stiffening of the tissue that produces cellular mechanical damage, inflammation and ultimately myocardial fibrosis. The assessment of the biomechanical dependence of the molecular machinery (in myocardial and non-myocardial cells) is therefore essential to contextualize the maturation of the cardiac tissue at early stages and understand its pathologic evolution in ageing. Since systems to perform multiscale modelling of cellular and tissue mechanics have been developed, it appears particularly novel to design integrated mechano-molecular models of heart development and disease to be tested in ex vivo reconstituted cells/tissue-mimicking conditions. In the present contribution, we will discuss the latest implication of mechanosensing in heart development and pathology, describe the most recent models of cell/tissue mechanics and delineate novel strategies to target the consequences of heart failure with personalized approaches based on tissue engineering and induced pluripotent stem cells (iPSCs) technologies

Influenza Virus Affects Intestinal Microbiota and Secondary <i>Salmonella</i> Infection in the Gut through Type I Interferons

<div><p>Human influenza viruses replicate almost exclusively in the respiratory tract, yet infected individuals may also develop gastrointestinal symptoms, such as vomiting and diarrhea. However, the molecular mechanisms remain incompletely defined. Using an influenza mouse model, we found that influenza pulmonary infection can significantly alter the intestinal microbiota profile through a mechanism dependent on type I interferons (IFN-Is). Notably, influenza-induced IFN-Is produced in the lungs promote the depletion of obligate anaerobic bacteria and the enrichment of Proteobacteria in the gut, leading to a “dysbiotic” microenvironment. Additionally, we provide evidence that IFN-Is induced in the lungs during influenza pulmonary infection inhibit the antimicrobial and inflammatory responses in the gut during <i>Salmonella</i>-induced colitis, further enhancing <i>Salmonella</i> intestinal colonization and systemic dissemination. Thus, our studies demonstrate a systemic role for IFN-Is in regulating the host immune response in the gut during <i>Salmonella</i>-induced colitis and in altering the intestinal microbial balance after influenza infection.</p></div

Influenza Virus Affects Intestinal Microbiota and Secondary Salmonella Infection in the Gut through Type I Interferons

<p>Page 1 shows the peak in the weight loss observed at 9 days post PR8 infection in WT and <i>Ifnar1</i>^−/− mice (related to Fig. 1).</p> <p>Page 2: WT and <i>Ifnar1</i>^−/− mice were monitored daily until euthanasia at 8 dpi; weight loss is shown (related to Fig. 2B).</p> <p>Page 3 shows the 16S copy number of <i>Enterobacteriaceae</i> other than <i>Salmonella</i>: for each sample, the <i>Salmonella</i> 16S gene copy number was subtracted from the total <i>Enterobacteriaceae</i> 16S gene copy number (related to Fig. 2I). </p> <p>Page 4 shows <i>Ifnβ </i>and<i> Ifnα4</i> transcription<i> </i>in both the lungs and cecum of WT and <i>Ifnar1</i>^−/− mice after pIC non-surgical intratracheal instillation (top panels) or PR8 infection (bottom panels) (related to Fig.4).</p

PR8-induced IFN-Is alter the fecal microbiota composition, Analysis of fecal microbiota in WT and <i>Ifnar1</i>^<i>-/-</i> mice performed by MiSeq and 16S qPCR during influenza infection.

<p>A) Experimental model. Fecal samples were collected from mice on day 0 before infection and on day 9 after mock and PR8 infection. Mice were euthanized at 17 dpi. B, C) The fecal microbiota from WT and <i>Ifnar1</i>^<i>-/-</i> mice on day 0 before infection (n = 6 WT, n = 6 <i>Ifnar1</i>^<i>-/-</i>), and on day 9 after mock (n = 3 WT, n = 3 <i>Ifnar1</i>^<i>-/-</i>) and PR8 infection (n = 3 WT, n = 3 <i>Ifnar1</i>^<i>-/-</i>) was analyzed by sequencing using the Illumina MiSeq system. Graphed is the average relative abundance of each bacterial phylum (B) and genus (C); the cut-off abundance level was set at 0.5%. D) Analysis of the fecal <i>Enterobacteriaceae</i> using 16S qPCR. Fecal samples were collected from mice on day 0 before infection (n = 10 WT, n = 8 <i>Ifnar1</i>^<i>-/-</i>) and on day 9 after mock (n = 5 WT, n = 4 <i>Ifnar1</i>^<i>-/-</i>) and PR8 infection (n = 5 WT, n = 4 <i>Ifnar1</i>^<i>-/-</i>). Copy numbers of <i>Enterobacteriaceae</i> per μl of fecal microbial DNA is shown. Each dot represents one mouse, the geometric mean is indicated. P values were calculated by One-Way ANOVA (Bonferroni multiple comparison test). ***p < 0.001; ns, not significant. One representative experiment is shown. Abbreviations are as follows: Uncl., unclassified; uninf, uninfected.</p