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• Notch-1 intervenes in the reparative processes of the airway mucosa. • cigarette smoke exposure limits Notch-1 signaling activation in bronchial epithelial cells. • cigarette smoke exposure hinders repair processes in bronchial epithelial cells. Notch-1 intervenes in the reparative processes of mucosa by controlling cell proliferation, differentiation and stem cell maintenance. Cigarette smoke alters airway epithelial homeostasis. The present study explored whether: Smokers showed altered Notch-1 expression; and whether in bronchial epithelial cells (16HBE): a) cigarette smoke extracts (CSE) altered the expression of Notch-1, of its ligand Jagged-1 (Jag-1) and the nuclear translocation of Notch-1; b) Notch-1 signaling activation as well as CSE modified Ki67, PCNA, p21, IL-33 expression, cell proliferation and repair processes. Notch-1 expression was assessed in the epithelium from large airway surgical samples from non-smoker and smoker subjects by immunohistochemistry.16HBE were cultured with/without CSE and Jag-1. A Notch-1 inhibitor (DAPT) was used as control. The expression of Notch-1, Jag-1, Ki67, PCNA, p21, IL-33 and cell proliferation (by CFSE) were all assessed by flow cytometry. Notch-1 nuclear expression was evaluated by immunofluorescence and western blot analysis. Repair processes were assessed by wound assay. Smokers had cytoplasmic but not nuclear Notch-1 expression. Although CSE increased Notch-1 expression, it counteracted Notch-1 signaling activation since it reduced Jag-1 expression and Notch-1 nuclear translocation. Notch-1 signaling activation by Jag-1 increased Ki67, PCNA and repair processes but reduced intracellular IL-33 and p21 expression without affecting cell proliferation. DAPT counteracted the effects of Notch-1 activation on PCNA and IL-33. CSE increased Ki67, PCNA, p21 and IL-33 expression but reduced cell proliferation and repair processes. In conclusion, cigarette smoke exposure, limiting Notch-1 signaling activation and hindering repair processes, amplifies injury processes in bronchial epithelial cells. [ABSTRACT FROM AUTHOR]

Background: Alterations in the nasal epithelial barrier homeostasis and increased interleukin 33 (IL‐33) expression contribute to the pathogenesis of chronic rhinosinusitis with nasal polyps (CRSwNP). Aims: As Notch‐1 signaling is crucial in repair processes of mucosa, the current study assessed Notch‐1/Jagged‐1 signaling and IL‐33 in the epithelium of nasal polyps biopsies from allergic (A‐CRSwNP; n = 9) and not allergic (NA‐CRSwNP; n = 9) subjects by immunohistochemistry. We also assessed, in a model of nasal epithelial cells, the effects of stimulation of Notch‐1 with Jagged‐1 on the expression of IL‐33 (by flow cytometry, immunofluorescence, and immunocytochemistry), Jagged‐1 (by flow cytometry), and p‐CREB transcription factor (by western blot analysis). Results: Ex vivo (a) in normal epithelium, the expression of Notch‐1 and IL‐33 were higher in NA‐CRSwNP than in A‐CRSwNP; (b) in metaplastic epithelium, the expression of Notch‐1, Jagged‐1, and IL‐33 were higher in NA‐CRSwNP than in A‐CRSwNP; (c) in hyperplastic epithelium, the expression of Notch‐1, Jagged‐1, and IL‐33 were higher in A‐CRSwNP than in NA‐CRSwNP; and (d) in basal epithelial cells, no differences were observed in the expression of Jagged‐1, IL‐33, and Notch‐1. The expression of Notch‐1 significantly correlated with the expression of IL‐33. In vitro, stimulation of Notch‐1 with Jagged‐1 induced the expression of (a) Jagged‐1; (b) IL‐33; and (c) p‐CREB transcription factor. The inhibitor of Notch‐1, DAPT, reduced all the effects of Jagged‐1 on nasal epithelial cells. Conclusions: The data herein provided support, for the first time, a putative role of Notch‐1/Jagged‐1 signaling in the overexpression of IL‐33 in the epithelium of nasal polyps from patients with CRSwNP. The current study assessed for the first time Notch‐1, Jagged‐1, and interleukin 33 expression in the epithelium of CRSwNP from allergic and not allergic exsmoker subjects. The data demonstrated a role of Notch‐1/Jagged‐1 signaling in a positive feedback upregulating Jagged‐1 expression and in promoting proinflammatory responses inducing p‐CREB and IL‐33 expression in nasal epithelial cells. [ABSTRACT FROM AUTHOR]

SUMMARY The identification of immunodominant and universal mycobacterial peptides could be applied to vaccine design and have an employment as diagnostic reagents. In this paper we have investigated the fine specificity, clonal composition and HLA class II restriction of CD4+ T cell clones specific for an immunodominant epitope spanning amino acids 91–110 of the 16-kDa protein of Mycobacterium tuberculosis . Twenty-one of the tested 28 clones had a Th1 profile, while seven clones had a Th0 profile. None of the clones had a Th2 profile. While the TCR AV gene usage of the clones was heterogeneous, a dominant TCR BV2 gene family was used by 18 of the 28 clones. The CDR3 regions of BV2+ T cell clones showed variation in lengths, but a putative common motif R-L/V-G/S-Y/W-E/D was detected in 13 of the 18 clones. Moreover, the last two to three residues of the putative CDR3 loops, encoded by conserved BJ sequences, could also play a role in peptide recognition. Antibody blockade and fine restriction analysis using HLA-DR homozygous antigen-presenting cells established that 16 of 18 BV2+ peptide-specific clones were DR restricted and two clones were DR-DQ and DR-DP restricted. Additionally, five of the 18 TCRBV2+ clones recognized peptide 91–110 in association with both parental and diverse HLA-DR molecules, indicating their promiscuous recognition pattern. The ability of peptide 91–110 to bind a wide range of HLA-DR molecules, and to stimulate a Th1-type interferon (IFN)-γ response more readily, encourage the use of this peptide as a subunit vaccine component. [ABSTRACT FROM AUTHOR]

• Cigarette smoke is considered a risk factor for lung and colorectal cancer. • Cigarette smoke induces epithelial mesenchymal transition features in Caco2. • Cigarette smoke increases the invasive potential of Caco2. Cigarette smoke is considered a risk factor for lung and colorectal cancer. A convincing link between epithelial-to-mesenchymal transition (EMT) with colorectal cancer progression and therapeutic resistance has emerged. Deregulated expression of E-Cadherin and Claudin-1 and increased miR-21 expression and invasiveness represent hallmarks of EMT. The effects of cigarette smoke exposure on EMT in colorectal adenocarcinoma cells are largely unknown. The aim of the study is to evaluate the effect of cigarette smoke extract (CSE) on miR-21, Claudin-1 and E-Cadherin, molecules associated to EMT in colorectal cancer cells. A human colorectal adenocarcinoma cell line (Caco-2) was treated with CSE at different concentration (5% and 10%) and for different time points (3 h and 24 h). Metabolic activity (by MTS assay), cell necrosis/cell apoptosis (evaluating Propidium Iodide/Annexin V expression by flow cytometry), miR-21, Claudin-1 and E-Cadherin gene expression were evaluated by Real time PCR. Cell permeability, actin polymerization and cancer cell migration was assessed by Trans-Epitelial Electrical Resistance (TEER), Phalloidin expression and matrigel system, respectively. CSE at all the tested concentrations and at all time points reduced cell necrosis. CSE at 10% increased miR-21 and reduced the metabolic activity, cell necrosis, Claudin-1 and E-cadherin mRNA at 3 h. Cell permeability, actin polymerization and cancer cell migration were all increased upon CSE exposure. These results showed that CSE increasing miR-21, Claudin-1 and E-Cadherin and enhancing the aggressiveness of cancer cells, may concur to colorectal cancer progression. [ABSTRACT FROM AUTHOR]