23 research outputs found

    Excavation Shoring Failure Threatens a Historic Church: Exploration of Causes and Remedial Measures

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    The city of Beirut is home to a very large number of historic monuments. Given the recent development boom following the years of civil strife, modern projects have begun to encroach on the spaces afforded older monuments. Recently, excavation works adjacent to the Lady of Annunciation Church resulted in severe cracking and deformations within the walls and floors of the stone and brick structure. The shoring provisions which were executed within the excavated lot consisted of contiguous bored piles with pre-stressed anchors. The failure occurred when the excavation works had progressed to a level of about 12m below original grade. Faced with the imminent catastrophic collapse of the church, the Municipality of Beirut ordered the immediate backfilling of the site in order to limit further movements. The case study presented in this paper includes the details and results of the geotechnical forensic investigation which included an array of measures and efforts, all implemented in an environment of urgency, given the need to find the cause of the failure, and propose and implement remedial measures which would spare the church. The analyses, monitoring measures and actual remedial works adopted and successfully completed at the site are presented and discussed

    Differentiation associated regulation of microRNA expression in vivo in human CD8+ T cell subsets

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    BACKGROUND: The differentiation of CD8+ T lymphocytes following priming of naïve cells is central in the establishment of the adaptive immune response. Yet, the molecular events underlying this process are not fully understood. MicroRNAs have been recently shown to play a key role in the regulation of haematopoiesis in mouse, but their implication in peripheral lymphocyte differentiation in humans remains largely unknown. METHODS: In order to explore the potential implication of microRNAs in CD8+ T cell differentiation in humans, microRNA expression profiles were analysed using microarrays and quantitative PCR in several human CD8+ T cell subsets defining the major steps of the T cell differentiation pathway. RESULTS: We found expression of a limited set of microRNAs, including the miR-17~92 cluster. Moreover, we reveal the existence of differentiation-associated regulation of specific microRNAs. When compared to naive cells, miR-21 and miR-155 were indeed found upregulated upon differentiation to effector cells, while expression of the miR-17~92 cluster tended to concomitantly decrease. CONCLUSIONS: This study establishes for the first time in a large panel of individuals the existence of differentiation associated regulation of microRNA expression in human CD8+ T lymphocytes in vivo, which is likely to impact on specific cellular functions

    A microRNA profile of human CD8(+) regulatory T cells and characterization of the effects of microRNAs on Treg cell-associated genes.

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    Recently, regulatory T (Treg) cells have gained interest in the fields of immunopathology, transplantation and oncoimmunology. Here, we investigated the microRNA expression profile of human natural CD8(+)CD25(+) Treg cells and the impact of microRNAs on molecules associated with immune regulation. We purified human natural CD8(+) Treg cells and assessed the expression of FOXP3 and CTLA-4 by flow cytometry. We have also tested the ex vivo suppressive capacity of these cells in mixed leukocyte reactions. Using TaqMan low-density arrays and microRNA qPCR for validation, we could identify a microRNA 'signature' for CD8(+)CD25(+)FOXP3(+)CTLA-4(+) natural Treg cells. We used the 'TargetScan' and 'miRBase' bioinformatics programs to identify potential target sites for these microRNAs in the 3'-UTR of important Treg cell-associated genes. The human CD8(+)CD25(+) natural Treg cell microRNA signature includes 10 differentially expressed microRNAs. We demonstrated an impact of this signature on Treg cell biology by showing specific regulation of FOXP3, CTLA-4 and GARP gene expression by microRNA using site-directed mutagenesis and a dual-luciferase reporter assay. Furthermore, we used microRNA transduction experiments to demonstrate that these microRNAs impacted their target genes in human primary Treg cells ex vivo. We are examining the biological relevance of this 'signature' by studying its impact on other important Treg cell-associated genes. These efforts could result in a better understanding of the regulation of Treg cell function and might reveal new targets for immunotherapy in immune disorders and cancer

    NFAT-1, Sp-1, Sp-3, and miR-21: New regulators of chemokine C receptor 7 expression in mature human dendritic cells

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    The chemokine C receptor 7 (CCR7) is a G-protein-coupled heptahelical receptor (GPCR) that is expressed on a wide variety of cells including memory T cells, B cells, mature dendritic cells, and cancer cells. Activated by its ligands CCL19 or CCL21, CCR7 plays a major role in metastasis of cancer cells. Recent studies demonstrated the role of NF-κB and AP-1 transcription factors in addition to let-7 microRNA in CCR7 expression. Our ChIP assays further show the binding of Sp-1, Sp-3 and NFAT-1 transcription factors to their potential binding sites in the 1Kb promoter region with the later found to inhibit whilst Sp-1, and Sp-3 were found to stimulate CCR7 expression as demonstrated by transfection assays. On the other hand, in addition to the known let-7 regulation of CCR7, we found miR-21 to have a highly conserved target region in CCR7 3'UTR and to be significantly down-regulated during the course of dendritic cell maturation, allowing for high expression of CCR7.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Circulating miR-150 and miR-342 in plasma are novel potential biomarkers for acute myeloid leukemia.

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    MicroRNAs (miRNAs) are small (19-22-nt) single-stranded noncoding RNA molecules whose deregulation of expression can contribute to human disease including the multistep processes of carcinogenesis in human. Circulating miRNAs are emerging biomarkers in many diseases and cancers such as type 2 diabetes, pulmonary disease, colorectal cancer, and gastric cancer among others; however, defining a plasma miRNA signature in acute myeloblastic leukemia (AML) that could serve as a biomarker for diagnosis or in the follow-up has not been done yet.Journal ArticleResearch Support, Non-U.S. Gov'tSCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Downregulation of microRNA-24 and -181 parallels the upregulation of IFN-γ secreted by activated human CD4 lymphocytes

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    IFN-γ is a cytokine with important roles in the innate and adaptive immune responses. This cytokine is secreted by activated T cells, NK cells and macrophages. Studies on the regulation of human IFN-γ expression had been previously focused on the promoter region. Consequently, the role of microRNAs (miRs) in this regulation has not been investigated yet. As miR-24 and miR-181 were found to have potential target sites in IFN-γ mRNA 3'UTR, we assessed their impact on IFN-γ expression by co-stimulating PB CD4+ T cells with anti-CD3, anti-CD28, IL-12, and IL-18. This co-stimulation cocktail induced an abundant secretion of IFN-γ together with a down-regulation of miR-24, and miR-181. Existence of a link between these two phenomena was further substantiated by transfection and transduction assays that showed that these two miRs negatively regulate IFN-γ expression by directly binding to their target sites in the mRNA. Thus, identifying target sites for miR-24 and miR-181 in IFN-γ-3'UTR points to a novel regulatory mechanism of this crucial gene. © 2014 American Society for Histocompatibility and Immunogenetics.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Human CD8+ CD25 + CD127 low regulatory T cells: microRNA signature and impact on TGF-β and IL-10 expression.

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    Regulatory T cells (Tregs) are central for maintaining immune balance and their dysfunction drives the expansion of critical immunologic disorders. During the past decade, microRNAs (miRNAs) have emerged as potent regulators of gene expression among which immune-related genes and their immunomodulatory properties have been associated with different immune-based diseases. The miRNA signature of human peripheral blood (PB) CD8+ CD25 + CD127 low Tregs has not been described yet. We thus identified, using TaqMan low-density array (TLDA) technique followed by individual quantitative real-time polymerase chain reaction (qRT-PCR) confirmation, 14 miRNAs, among which 12 were downregulated whereas two were upregulated in CD8 + CD25 + CD127 low Tregs in comparison to CD8 + CD25 - T cells. In the next step, microRNA Data Integration Portal (mirDIP) was used to identify potential miRNA target sites in the 3'-untranslated region (3'-UTR) of key Treg cell-immunomodulatory genes with a special focus on interleukin 10 (IL-10) and transforming growth factor β (TGF-β). Having identified potential miR target sites in the 3'-UTR of IL-10 (miR-27b-3p and miR-340-5p) and TGF-β (miR-330-3p), we showed through transfection and transduction assays that the overexpression of two underexpressed miRNAs, miR-27b-3p and miR-340-5p, downregulated IL-10 expression upon targeting its 3'-UTR. Similarly, overexpression of miR-330-3p negatively regulated TGF-β expression. These results highlighted an important impact of the CD8 + Treg mirnome on the expression of genes with significant implication on immunosuppression. These observations could help in better understanding the mechanism(s) orchestrating Treg immunosuppressive function toward unraveling new targets for treating autoimmune pathologies and cancer.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    ApolipoproteinL1 is expressed in papillary thyroid carcinomas

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    The apolipoprotein L (apoL) family has not yet been ascribed any definite patho-physiological function although the conserved BH3 protein domain suggests a role in programmed cell death. As repression of the regular apoptotic program is considered a hallmark of tumor progression, we investigated apoL expression in cancer. We show that the levels of one member of the family, apolipoprotein L1 (apoL1) is higher in papillary thyroid carcinoma compared to normal tissue. A combination of qRTPCR, immunohistochemistry and in situ hybridization allowed us to ascribe this increase to endogenous overexpression in carcinoma cells. Whether apoL1 plays an instrumental role in refraining cell death is the subject of ongoing molecular biology experiments.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

    Human natural Treg microRNA signature: role of microRNA-31 and microRNA-21 in FOXP3 expression.

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    Treg are the main mediators of dominant tolerance. Their mechanisms of action and applications are subjects of considerable debate currently. However, a human microRNA (miR) Treg signature has not been described yet. We investigated human natural Treg and identified a signature composed of five miR (21, 31, 125a, 181c and 374). Among those, two were considerably under-expressed (miR-31 and miR-125a). We identified a functional target sequence for miR-31 in the 3' untranslated region (3' UTR) of FOXP3 mRNA. Using lentiviral transduction of fresh cord blood T cells, we demonstrated that miR-31 and miR-21 had an effect on FOXP3 expression levels. We showed that miR-31 negatively regulates FOXP3 expression by binding directly to its potential target site in the 3' UTR of FOXP3 mRNA. We next demonstrated that miR-21 acted as a positive, though indirect, regulator of FOXP3 expression. Transduction of the remaining three miR had no direct effect on FOXP3 expression or on the phenotype and will remain the subject of future investigations. In conclusion, not only have we identified and validated a miR signature for human natural Treg, but also unveiled some of the mechanisms by which this signature was related to the control of FOXP3 expression in these cells.Journal ArticleResearch Support, Non-U.S. Gov'tFLWINinfo:eu-repo/semantics/publishe

    Apoptotic and non-apoptotic modalities of thymoquinone-induced lymphoma cell death: Highlight of the role of cytosolic calcium and necroptosis

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    Targeting non-apoptotic modalities might be therapeutically promising in diffuse large B cell lymphoma (DLBCL) patients with compromised apoptotic pathways. Thymoquinone (TQ) has been reported to promote apoptosis in cancer cells, but little is known about its effect on non-apop-totic pathways. This work investigates TQ selectivity against DLBCL cell lines and the cell death mechanisms. TQ reduces cell viability and kills cell lines with minimal toxicity on normal hematological cells. Mechanistically, TQ promotes the mitochondrial caspase pathway and increases genotoxicity. However, insensitivity of most cell lines to caspase inhibition by z-VAD-fmk (ben-zyloxycarbonyl-Val-Ala-Asp-fluoromethyl ketone) pointed to a critical role of non-apoptotic signaling. In cells dying through non-apoptotic death, TQ increases endoplasmic reticulum (ER) stress markers and substantially increases cytosolic calcium ([Ca2+]c) through ER calcium depletion and activation of store-operated calcium entry (SOCE). Chelation of [Ca2+]c, but not SOCE inhibitors, reduces TQ-induced non-apoptotic cell death, highlighting the critical role of calcium in a non-apoptotic effect of TQ. Investigations showed that TQ-induced [Ca2+]c signaling is primarily initiated by necroptosis upstream to SOCE, and inhibition necroptosis by necrostatin-1 alone or with z-VAD-fmk blocks the cell death. Finally, TQ exhibits an improved selectivity profile over standard chemotherapy agents, suggesting a therapeutic relevance of the pro-necroptotic effect of TQ as a fail-safe mechanism for DLBCL therapies targeting apoptosis.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
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