miR-126-3p promotes matrix-dependent perivascular cell attachment, migration and intercellular interaction

microRNAs (miRNAs) can regulate the interplay between perivascular cells (PVC) and endothelial cells (EC) during angiogenesis, but the relevant PVC-specific miRNAs are not yet defined. Here, we identified miR-126-3p and miR-146a to be exclusively upregulated in PVC upon interaction with EC, determined their influence on the PVC phenotype and elucidate their molecular mechanisms of action. Specifically the increase of miR-126-3p strongly promoted the motility of PVC on the basement membrane-like composite and stabilized networks of endothelial cells. Subsequent miRNA target analysis showed that miR-126-3p inhibits SPRED1 and PLK2 expression, induces ERK1/2 phosphorylation and stimulates TLR3 expression to modulate cell-cell and cell-matrix contacts of PVC. Gain of expression experiments in vivo demonstrated that miR-126-3p stimulates PVC coverage of newly formed vessels and transform immature into mature, less permeable vessels. In conclusion we showed that miR-126-3p regulates matrix-dependent PVC migration and intercellular interaction to modulate vascular integrity

A Computational Profiling of Changes in Gene Expression and Transcription Factors Induced by vFLIP K13 in Primary Effusion Lymphoma

Infection with Kaposi's sarcoma associated herpesvirus (KSHV) has been linked to the development of primary effusion lymphoma (PEL), a rare lymphoproliferative disorder that is characterized by loss of expression of most B cell markers and effusions in the body cavities. This unique clinical presentation of PEL has been attributed to their distinctive plasmablastic gene expression profile that shows overexpression of genes involved in inflammation, adhesion and invasion. KSHV-encoded latent protein vFLIP K13 has been previously shown to promote the survival and proliferation of PEL cells. In this study, we employed gene array analysis to characterize the effect of K13 on global gene expression in PEL-derived BCBL1 cells, which express negligible K13 endogenously. We demonstrate that K13 upregulates the expression of a number of NF-κB responsive genes involved in cytokine signaling, cell death, adhesion, inflammation and immune response, including two NF-κB subunits involved in the alternate NF-κB pathway, RELB and NFKB2. In contrast, CD19, a B cell marker, was one of the genes downregulated by K13. A comparison with K13-induced genes in human vascular endothelial cells revealed that although there was a considerable overlap among the genes induced by K13 in the two cell types, chemokines genes were preferentially induced in HUVEC with few exceptions, such as RANTES/CCL5, which was induced in both cell types. Functional studies confirmed that K13 activated the RANTES/CCL5 promoter through the NF-κB pathway. Taken collectively, our results suggest that K13 may contribute to the unique gene expression profile, immunophenotype and clinical presentation that are characteristics of KSHV-associated PEL

Rôle de la chimiokine RANTES/CCL5 et de ses ligands membranaires dans l angiogenèse (Application en biothérapie)

L angiogenese est un processus physiopathologique consistant en la formation de nouveaux vaisseaux. Parmi ies facteurs responsables de cette angiogenese les chimiokines sont des médiateurs de la formation des néo-vaisseaux. Le role angiogénique de la chimiokine RANTES/CCL5 est encore source de controverses. Nos travaux démontrent que RANTES/CCLS délivrée localement a l aide de biomatériau de nitrocellulose induit la formation de capillaires sanguins dans un modele de délivrance sous-cutané chez le rat. L effet angiogénique de RANTES/CCL5 a été caractérisé in vitro dans les cellules endothéliales HUV-EC-Cs. Nous demontrons que RANTES/CCL5 induit l étalement et la migration de cellules HUV-EC~Cs et participe a la formation de réseaux vasculaires par le biais d une sécrétion de VEGF. La liaison de RANTES/CCL5 a ses récepteurs protéiques, CCR1 et CCR5 ainsi qu aux protéoglycannes membranaires, CD44, syndécanne-1 et syndécanne-4 est indispensable a l induction de son effet pro-angiogénique. De plus, la liaison de RANTES/CCL5 aux chahes glycosaminoglycannes de type héparane sulfate est essentielle a ses effets biologiques in vitro. Ayant pour objectif de développer une stratégie thérapeutique permettant de lutter contre Vangiogenése, nous avons utilisé deux mutants de RANTESXCCLS caractérisés par une incapacité de lier les chaines lycosaminoglvcanniques. Ces mutants [44ANAA4I]-RANTES/CCL5 et [E66A]-RANTES/CCL5 sont moins efficaces que RANTES/CCL5 pour induire des effets cellulaires impliques dans l'angiogenese in vivo et in vitro. A Finverse, nous avons envisagé l utiIisation d un biomatériau permettant la déiivrance locale de RANTES/CCL5 dans un modele d ischémie de patte de souris, pathologie pour laquelle un traitement induisant Fangiogenese aurait un effet bénéfique pour la survie tissulaire.Angiogenesis is a physiopathological process defined by new blood vessel formation. Chemokines are described as possible mediators of angiogenesis. The angiogenic role of the chemokine RANTES/CCL5 is controversial. Our study demonstrated that the local delivery of RANTES/CCL5 by a nitrocellulose biomaterial in a rat subcutaneous model leads to the formation of vessels around the biomaterial. We described that the treatment with RANTES/CCL5 of the endothelial cells line (HUV-EC-Cs) induced the cell spreading, migration and the vascular network formation through VEGF secretion, in vitro. We performed the analysis of the role of the RANTES/CCL5 receptors, CCR1 or CCR5 and membrane proteogiycans, CD44, syndecan-1 or syndecan-4 in angiogenesis process induced by RANTES/CCL5. Moreover the binding of RANTES/CCL5 on glycosaminoglycan heparan sulfate chains was essential for these effects. The aim of this study was to develop therapeutics strategies in pathologies characterized by a deleterious angiogenesis such as cancers. The glycosaminoglycan-binding deficient mutants [MANAAQ]-RANTES/CCL5 and [E66A]- RANTES/CCL5 were less effective than RANTES/CCL5 to induce angiogenesis. In contrary, the association of RANTES/CCL5 with a polysaccharide biomaterial could constitute a strategy to local diffusion of this chemokine in order to induce a neovascularization in hypoxic tissue such as in the ischemic mice leg model.PARIS13-BU Sciences (930792102) / SudocSudocFranceF