Karkeni E, Astier J, Tourniaire F, El Abed M, Romier B, Gouranton E, et al. Obesity- associated inflammation induces microRNA-155 expression in adipocytes and adipose tissue: outcome on adipocyte function. J Clin Endocrinol Metab. 2016:jc20153410.
 Karkeni E, Marcotorchino J, Tourniaire F, Astier J, Peiretti F, Darmon P, et al. Vitamin D limits chemokineexpression in adipocytes and macrophage migration in vitro and in male mice. Endocrinology. 2015;156:1782-93.
TNF-a was used to mimic mild inflammatory conditions, as described previously . To find out how TNF-a regulates chemokineexpression we ran GSEA analysis of the microarray data, which indicated NF-kB as the main response element present in the overrepresented genes (Table S6). Then, to confirm experimentally the involvement of NF-kB in the regulation of chemokines, we used 2 transgenic models: adipose tissue from aP2- p65 overexpressing mice (Figure 3), and MEFs invalidated for p65 gene (Figure 4), the latter being treated or not with TNF-a. All chemokine genes were overexpressed in aP2- p65 adipose tissue and lost their TNF-a dependent expression in p65-null cells. However, the existence of a residual albeit non significant gene induction following TNF-a treatment was observed for Cxcl1, Cxcl10 and Cx3cl1 in p65 null MEFs. This effect could be explained by the fact that TNF-a is also able to mediate its pro- inflammatory effects, besides NF-kB, via another signaling pathways such as p38 or JNK. Indeed, pretreatment of adipocytes with a JNK inhibitor before TNF-a treatment reduced CCL5 and CXCL10 expression in human adipocytes whereas inhibition of NF-kB completely suppressed TNF-a chemokine upregulation (Figure 5). Our results are in agreement with studies from Jiao and colleagues, who identified six CCLs (i.e. CCL2, CCL3, CCL6, CCL7, CCL8 and CCL9) upregulated in the adipose tissue of HFD induced and genetically obese mice . They observed that FFAs could induce the expression of these chemokines in 3T3-L1 adipocytes and that JNK inhibition could only limit the expression of MCP-1/CCL2 and MCP-3/CCL7 whereas NF-kB inhibition was able to repress the expression of all the chemokines tested. These data are similar to what we observed in TNF-a treated adipocytes and support the fact that NF-kB is the major regulator of chemokineexpression in response to pro-inflammatory mole- cules even if redundant signalling pathways could also participate. In conclusion, our results show that adipocytes are intrinsically able to initiate adipose tissue infiltration by all subtypes of leukocytes through the secretion of multiple chemokines under the effect of TNF-a, via a NF-kB dependent pathway. Also, the high number of chemokines induced (most of which have redundant properties) supports the fact that leukocyte adipose tissue infiltration observed during obesity is not related to one or two proteins such as CCL2 or CCL5. We propose that less ‘classical’ chemokines should be investigated for their role in the develop- ment of insulin resistance through recruitment of leukocytes in the adipose tissue and their use as alternative or more sensitive markers of infiltration. In particular, it would be of interest to investigate in more details the role of CCL19, as the expression level of this chemokine in adipocytes was found to be highly sensitive to TNF-a as well as adiposity.
1 Cytokines and Viral Infections, Immunology Infection and Inflammation Department, Institut Cochin, INSERM, U1016, Paris, France, 2 CNRS, UMR8104, Paris, France, 3 Université Paris Descartes, Sorbonne Paris Cité, Paris, France, 4 McGill University Health Centre, Montréal, QC, Canada, 5 Université Paris Diderot, Paris, France
The intestinal barrier, one of the first targets of HIV/simian immunodeficiency virus (SIV) is subjected to major physiological changes during acute infection. Having previously shown that pharmaceutical injection of interleukin-7 (IL-7) triggers chemokineexpression in many organs leading to massive T-cell homing, in particular to the intestine, we here explored mucosal IL-7 expression as part of the cytokine storm occurring during the acute phase of SIV infection in rhesus macaques. Quantifying both mRNA and protein in tissues, we demonstrated a transient increase of IL-7 expression in the small intestine of SIV-infected rhesus macaques, starting with local detection of the virus by day 3 of infection. We also observed increased transcription levels of several chemokines in the small intestine. In infected macaques, ileal IL-7 expression correlated with the transcrip- tion of four of these chemokines. Among these chemokines, the macrophage and/or T-cell attractant chemokines CCL4, CCL25, and CCL28 also demonstrated increased transcription in uninfected IL-7-treated monkeys. Through immunohistofluorescence staining and image analysis, we observed increased CD8 + T-cell numbers and stable
interact to regulate chemokineexpression upon muscle
Reports in rodents have shown muscle damage, elevated in- ﬂammatory markers, and leukocyte inﬁltration, 24e48 h after downhill running [18,24,25] . We therefore performed our analyses 28 h post-exercise. In soleus, eccentric exercise increased the per- centage of ﬁbers with central nuclei, indicating regeneration post- damage. No such effect was detected in quadriceps. However, markers of in ﬂammation and macrophage inﬁltration increased in exercised quadriceps and soleus. These ﬁndings suggest our pro- tocol was an adequate stimulus for both muscles, but soleus was more affected. Previous reports have also shown that slow-twitch muscles, like soleus, are more affected by eccentric exercise
• CD127 expression is increased in EC upon stimulation by TNFa with higher expression when IL-7 is added in human EC derived from blood progenitors.
• In combination with TNFa, IL-7 triggers increase in mRNA expression of CCL4, CCL5 in macaque intestinal EC and CCL2, CCL4 and CCL5 in human EC, while only increasing CXCL8 proteins in intestinal macaque or CXCL10 proteins in human endothelial cells compared to TNFa stimulation alone after overnight culture. Among the chemokines overexpressed in the gut mucosa of both SIV infected and IL-7 macaques, only CCL4 and CXCL8 were expressed upon IL-7 stimulation of TNF-stimulated endothelial cells, suggesting that other cell types participate to the IL-7-dependent chemokineexpression in vivo. Moreover, CXCL8 levels in the culture supernatants were lower in TNF-stimulated human endothelial cells derived from blood progenitors than in simian primary intestinal endothelial cells, suggesting a specific capacity of the latter to respond to IL-7 through IL-8 expression.
Enzyme-linked immunoassay for cytokines, chemokines, and cysteinyl leukotrienes
Cells were washed with media and suspended at 1 · 10 6 cells per well,
then stimulated with codeine for 3, 8, and 16 h. Cell-free superna- tants were isolated and analyzed for human cytokine and chemokineexpression using the following commercial enzyme-linked immuno- assay (ELISA) kits; granulocyte-macrophage colony-stimulating factor (GM-CSF), macrophage inﬂammatory protein–1a (MIP-1a), tumor necrosis factor (TNF)-a, IL-8, IL-6 (according to the manu- facturer’s instructions; R&D Systems, Minneapolis, MN, USA), and CysLT (Cayman Chemcial, Ann Arbor, MI, USA). The lower limits of detection, respectively, are 7.8, 31.2, 15.6, 31.2, 3.12, and 13 pg/ml. In some cases, cells were preincubated with signaling inhibitors UO126 [ERK mitogen-activated protein (MAP) kinase inhibitor, 1 lM], SB203580 (p38 inhibitor; 50 lM), or SP600125 (JNK inhib- itor; 30 lM) for 30 min prior to activation (all inhibitors were pur- chased from Calbiochem, La Jolla, CA, USA).
microscopy of sections of dystrophic RCS rat retina (but not of control rat retina) showed the presence of cells in the lumen of choriocapillaries with the characteristic appearance of intralysosomal ROS remnants (Fig. 5A). Ultrastructural analysis confirmed the presence of both the early (Fig. 5B) and late (Fig. 5C) stages of ROS degradation, which are usually observed only in RPE cells. Taken together, our data show that cells positive for MC markers and containing ROS/rhodopsin can be found outside the photoreceptor cell layer, the exclusive site of physiological rhodopsin expression. The presence of rhodopsin-positive SrMCs in the inner retina suggests an exit via the retinal vessels, and their presence in the choroids points to an exit route through the choroid or ciliary body.
interactions, but to constitutive clustering (30- 33,53). BRET of CX3CL1 in the HEK cell line met all of them: (i) Replacing one of the monomers with an irrelevant protein produced no transfer (Figure 2A); (ii) expression of an excess of a non-tagged unit along with the Luc- and YFP-chimeras reduced BRET (Figure 2F); (iii) BRET signals for a given acceptor/donor ratio (at constant amount of donor) reached saturation: at a sufficient acceptor concentration, each donor molecule was engaged in a cluster and the BRET signal reached a maximum (Figure 2C). If BRET were due to random collision, BRET amplitude would increase continuously with the acceptor/donor ratio; (iv) BRET versus the total amount of tagged protein (donor plus acceptor) at a given acceptor/donor ratio should be constant or vary only slightly: this curve should not go to zero at low protein density, as recently pointed out (32,33), and it clearly did not for CX3CL1 (Figure 2D). The same criterion can be checked by directly plotting the BRET against the acceptor concentrations (30) (Figure 2E). These data, obtained with transfected HEK cells were supplemented with data from HTRF of primary cells (Figure 3B). All the data sets provided convergent evidence that CX3CL1 behaves as an aggregating protein, both as a transfected protein in cell lines and as a native protein expressed in HUVEC cells.
Nadine Dragin 1,2,3 , Patrice Nancy 4 , José Villegas 2,3,5 , Régine Roussin 6 , Rozen Le Panse 2,3,5 &
Sonia Berrih-Aknin 2,3,5
The early-onset form of Myasthenia Gravis (MG) is prevalent in women and associates with ectopic germinal centers (GCs) development and inflammation in the thymus. we aimed to investigate the contribution of estrogens in the molecular processes involved in thymic GCs formation. We examined expression of genes involved in anti-acetylcholine receptor (AChR) response in MG, MHC class II and α-AChR subunit as well as chemokines involved in GC development (CXCL13, CCL21and CXCL12). In resting conditions, estrogens have strong regulatory effects on thymic epithelial cells (TECs), inducing a decreased protein expression of the above molecules. In knockout mouse models for estrogen receptor or aromatase, we observed that perturbation in estrogen transduction pathway altered MHC Class II, α-AChR, and CXCL13 expression. However, in inflammatory conditions, estrogen effects were partially overwhelmed by pro-inflammatory cytokines. Interestingly, estrogens were able to control production of type I interferon and therefore play dual roles during inflammatory events. In conclusion, we showed that estrogens inhibited expression of α-AChR and HLA-DR in TECs, suggesting that estrogens may alter the tolerization process and favor environment for an autoimmune response. By contrast, under inflammatory conditions, estrogen effects depend upon strength of the partner molecules with which it is confronted to.
We show that treatment of adipocytes with FFAs down- regulates PPARG protein and mRNA levels. Knockdown of adipocyte PPARG resulted in upregulation of MCP1 gene expression and secretion, leading to enhanced macrophage chemotaxis. Rosi inhibited these effects. In a
involved in glial cell function by directly screening for defects in MB axon pruning. We found that orion 1 , a viable X-chromosome mutation, is necessary for both the pruning of some γ axons and removal of the resulting debris. We show that Orion is secreted from the neurons, remains near the axon membranes where it associates with inﬁltrating astrocytes, and is necessary for astro- cyte inﬁltration into the γ bundle. This implies a role for an as- yet-undeﬁned Orion receptor on the surface of the astrocytes. Orion bears some chemokine features, for example, a CX3C motif, three glycosaminoglycan (GAG) binding consensus sequences that are required for its function. Altogether, our results identify a neuron-secreted extracellular messenger, which is likely to be the long-searched-for signal responsible for astro- cyte inﬁltration and engulfment of the degenerated larval axons and demonstrate its involvement for neuronal remodeling.
(*) Allerton F., Bomassi E., Damoiseaux C., De Lorenzi D., Fisher A., Muller N., Hendrickx T., Vrancken A.
Canine idiopathic pulmonary fibrosis (CIPF) is a progressive interstitial lung disease mainly affecting West Highland white terriers (WHWTs). The CIPF course varies greatly among dogs from rapid deterioration to slowly progressive forms and the survival time from onset of clinical signs ranges from a few months to several years. In human IPF, increased chemokine (CC-motif) ligand 2 (CCL2) concentrations in bronchoalveolar lavage fluid (BALF) are indicative of a poor outcome and serum concentrations are correlated with clinical parameters of lung function. In dogs, serum and BALF CCL2 concentrations were shown to be elevated in WHWTs with CIPF compared with healthy WHWTs. The aim of the present study was to investigate whether serum CCL2 concentrations measured in WHWTs with CIPF at diagnosis (1) can be used as an indicator of prognosis and (2) correlate with lung function parameters. CCL2 concentrations were determined by ELISA (Canine CCL2 Quantikine ELISA kit, R&D Systems) in the serum of 60 WHWTs suspected of CIPF (median age 11.7 years, range 5.7 - 14.5), for which a follow-up was available (median follow-up time 8.6 months, range 0 - 71.8). Serum sampling extended from May 2007 to January 2015. CIPF diagnosis was confirmed by thoracic high resolution computed tomography, lung histopathology, or both examinations in 17, 6 and 27 WHWTs respectively. Kaplan-Meier analysis was conducted to investigate differences in survival times according to serum CCL2 concentrations at diagnosis. Spearman analysis was used to assess correlations between serum CCL2 concentrations and lung function parameters, namely the distance walked in the 6–minute
Conclusion: Convergence of TGF- ␤ and IL-1 ␤ signaling pathways on the CCL20 promoter are required for efficient fibroblast expression of CCL20.
Significance: These findings identify potential targets to reduce chronic inflammation in airway disease.
CCL20 is the only chemokine ligand for the chemokine recep- tor CCR6, which is expressed by the critical antigen presenting cells, dendritic cells. Increased expression of CCL20 is likely involved in the increased recruitment of dendritic cells observed in fibroinflammatory diseases such as chronic obstructive pul- monary disease (COPD). CCL20 expression is increased by the proinflammatory cytokine IL-1 ␤ . We have determined that IL- 1 ␤ -dependent CCL20 expression is also dependent on the mul- tifunctional cytokine TGF- ␤ . TGF- ␤ is expressed in a latent form that must be activated to function, and activation is achieved through binding to the integrin ␣ v ␤ 8 (itgb8). Here we confirm correlative increases in ␣ v ␤ 8 and IL-1 ␤ with CCL20 protein in lung parenchymal lysates of a large cohort of COPD patients. How IL-1 ␤ - and ␣ v ␤ 8-mediated TGF- ␤ activation conspire to increase fibroblast CCL20 expression remains unknown, because these pathways have not been shown to directly interact. We evaluate the 5 ⴕ-flanking region of CCL20 to determine that IL-1 ␤ -driven CCL20 expression is dependent on
Arnaud Pousset – REP+ André Malraux – Montereau-Fault-Yonne Correction des exercices de jeudi 26/03 :
Les expressions B, D, E, H, J et G peuvent être développées, pour souvenirs, vous pouvez regarder le chapitre NC2 développer une expression.
2.3. syntaxe des expressions régulières Perl (PCRE)
Les expression régulières Perl sont disponibles quand l’extension PCRE est disponible. C’est en pratique toujours le cas (elle est en standard avec PHP).
Les expressions régulières Perl sont plus performantes (plus rapides) et plus puissantes que les expressions régulières POSIX. Leur syntaxe est plus étendue que pour POSIX, évidemment. Je vous encourage vivement (comme d’habitude) à lire la documentation (chapitre « IV. LXXXIX. Expressions régulières compatibles Perl ») qui donne des détails importants que je ne développerai sûrement pas aussi profondément dans ce chapitre. En particulier, je
Janeway, C. A., Jr. (2001). How the immune system works to protect the host from infection: a personal view. Proceedings of the National Academy of Sciences of the United States of America
Kanazawa, S., Okamoto, T., and Peterlin, B. M. (2000). Tat competes with CIITA for the binding to P-TEFb and blocks the expression of MHC class II genes in HIV infection. Immunity 12, 61-70. Kelly, J. M., Takeda, K., Darcy, P. K., Yagita, H., and Smyth, M. J. (2002). A role for IFN-gamma in primary and secondary immunity generated by NK cell-sensitive tumor-expressing CD80 in vivo. Journal of Immunology 168, 4472-4479.
Netrins are axon guidance molecules that play critical roles during the development of the nervous system. The expression of netrins has also been described in several tissues of the adult but their expression and role in the adult nervous system is poorly defined. In this study, we investigated the expression of netrins and their receptors in the adult mouse retina. We found no expression of netrin-1 transcript or protein in wild-type adult retinal tissue, a result which was corroborated using a netrin-1 reporter mouse which labels netrin-1 expressing cells. We found that netrin-3 however was present in retinal ganglion cells (RGC) and subsets of amacrine cells. Netrin receptors expression was also investigated. Deleted in colorectal cancer (DCC) was found in RGC axons while neogenin was distributed in RGCs dendrites and horizontal cells soma and dendrites. UNC-5 homolog receptors were found to be present in cell body of RGCs and in Müller cells radial processes. Together, these results present a distribution of netrin signaling members in different cell population of the adult rodent retina, suggesting a role for them in the function of the mature visual system.
Glu268 does not interact with any of the chemokine residues, providing further support for the existence of the 2:1 stoichiometry.
These results do not accord with the conclusions made by Kufareva et al., who proposed that CXCR4 interacts with CXCL12 in a 1:1 stoichiometry, despite its dimeric nature and subsequently to the exclusion of the 2:1 hypothesis on the basis of functional complementation and dilution assays (Kufareva et al., 2014). Nevertheless, the functional rescue that can be observed upon co-expression of complementary mutants of CXCR4 (between 60 and 100 % as seen in Fig. 4 of Ref. (Kufareva et al., 2014)), while supporting the existence of receptor dimers, does not exclude the 2:1 stoichiometry hypothesis. We herein propose a dynamic model which could fit with the coexistence of both 1:1 and 2:1 complexes. We hypothesize that during the second step of the two-site two-step mechanism of the CXCR4-CXCL12 recognition (Crump et al., 1997; Kofuku et al., 2009), the chemokine N- terminal tail 1 KPVSLSYR 8 enters the CXCR4 transmembrane cavity, while the receptor N- terminus partially detaches from the chemokine core domain recognition site 12 RFFESH 17 . Indeed, intrinsically disordered regions such as the CXCR4 N-terminus are known to bind their protein partners with high specificity but low affinity (Huang and Liu, 2009; Uversky and Dunker, 2010). For the CXCR4-CXCL12 complex, it was reported that the receptor N- terminal peptide 1-38 binds to the chemokine core domain with a dissociation constant of 4.5 µM (Veldkamp et al., 2006).