Chronic obstructive pulmonary disease (COPD) is characterized by an inflammatory process and airway remodeling involving matrix metalloproteinases (MMPs). Thus, we analyzed the expression and release ...of MMP-12 (macrophage metalloelastase) in bronchoalveolar lavage (BAL) and lung tissue from COPD patients and control subjects.
Immunocytochemistry and immunochemistry were performed to analyze the expression of MMP-12 in BAL cells and bronchial biopsies. Western blotting was used for the evaluation of MMP-12 in BAL fluids.
The number of MMP-12 expressing macrophages together with the staining intensity was higher in BAL samples from COPD patients than in controls subjects. Similar results were noted in bronchial biopsies with higher MMP-12 expression in COPD subjects than in controls. Enhanced MMP-12 level was also observed in BAL fluids from patient with COPD in comparison to control subjects.
This study demonstrated that COPD patients produce greater quantities of MMP-12 than controls, which may be a critical step in the pathogenesis of COPD and emphysema.
Introduction Les myalgies représentent un motif fréquent de consultation dont les étiologies sont complexes et souvent mal étiquetées. Patients et méthodes Patiente âgée aujourd’hui de 53 ans, IMC ...23,1 kg/m2 , présentant en 2008 des épisodes récurrents de douleurs musculaires, sans rhabdomyolyse, de plus en plus invalidantes au quotidien, étiquetées « fibromyalgie ». Réévaluée en 2010 après mise sous L-carnitine. Explorations : test d’effort maximal évaluant la tolérance à l’effort ; calorimétrie indirecte d’effort évaluant la part respective des substrats oxydés ; biopsie musculaire (vastus lateralis) à l’aiguille de Bergström ; polarographie évaluant le métabolisme mitochondrial musculaire ; activité carnitine palmitoyl transférase II (CPT II). Cas clinique La patiente présentait en 2008 une intolérance à l’effort sévère : VO2 max à 57% de la valeur prédite, seuil ventilatoire à 31% de la VO2 max théorique, élévation des potentiels d’oxydoréduction cytosolique (rapport lactate/pyruvate) et mitochondrial (rapport ↕-hydroxybutyrate/acétoacétate). La calorimétrie indirecte d’effort montrait une glucodépendance précoce. Après biopsie musculaire, la polarographie a révélé une altération fonctionnelle de la translocation des acides gras : Vmax, vitesse maximale de respiration mitochondriale, à 1,2 μmol/min/g (2,2–13) pour le substrat palmitoyl-CoA + carnitine ; à 8,1 (2–15) pour le substrat palmitoylcarnitine. L’activité CPT II était très abaissée : 1,69 nmoles/min/mg (1,65–3,95). La patiente a été placée sous L-carnitine (Levocarnyl® , 4 g/jour). Elle a constaté une amélioration significative de sa qualité de vie, dans son travail et ses loisirs. Une biopsie musculaire a été refaite en octobre 2010. La translocation intramitochondriale des acides gras est totalement normalisée en polarographie : Vmax à 5,6 μmol/min/g pour le substrat palmitoyl-CoA + carnitine ; à 6,0 pour le substrat palmitoylcarnitine. Conclusion Ce cas illustre bien l’importance de la prise en compte de la notion de déficit fonctionnel, objectivé par la polarographie, après biopsie musculaire, dans le contexte des myopathies métaboliques.
Background: Important features of airway remodeling in asthma include the formation of subepithelial fibrosis and increased deposition of types I and III collagen. TGF-β, IL-11, and IL-17 are ...profibrotic cytokines involved in the formation of subepithelial fibrosis and are increased in patients with asthma, particularly in those with severe disease. Objective: The purpose of this study was to investigate the effect of corticosteroids on the expression of these profibrotic cytokines and on extracellular matrix deposition. Methods: We used immunocytochemistry to measure the expression of TGF-β, IL-11, IL-17, and collagen types I and III in the airways of patients with mild asthma (n = 9), patients with moderate-to-severe asthma (n = 10), and control subjects without asthma (n = 6). Baseline bronchial biopsy specimens were obtained in all groups. In addition, repeat biopsies were obtained in the patients with moderate-to-severe asthma after a 2-week course of oral corticosteroids. Results: TGF-β expression was significantly higher in all groups with asthma, and it did not decrease after treatment with oral corticosteroids. Levels of IL-11 and IL-17 were increased in patients with moderate-to-severe asthma compared with patients with mild asthma and normal controls (P < .05). The expression of these cytokines decreased with oral corticosteroids in the moderate-to-severe group to levels that were comparable to those seen in the patients with mild asthma and in the normal controls (P < .005). Expression of types I and III collagens was higher in the patients with moderate-to-severe asthma than in the patients with mild asthma and the controls (P < .05; P < .001). Treatment with corticosteroids did not decrease the expression of types I and III collagens. Conclusions: These results confirm the association of increased levels of TGF-β, IL-11, IL-17, and types I and III collagens with severe disease and suggest that the failure of cortico-steroids to decrease collagen deposition might be due to per-sistently elevated TGF-β expression. (J Allergy Clin Immunol 2003;111:1293-8.)
Background: IL-17 is a cytokine that has been reported to be produced by T lymphocytes. In vitro, IL-17 activates fibro-blasts and macrophages for the secretion of GM-CSF, TNF-α, IL-1β, and IL-6. A ...number of these cytokines are involved in the airway remodeling that is observed within the lungs of asthmatic individuals. Objective: In this study, we investigated the expression of IL-17 in sputum and bronchoalveolar lavage specimens obtained from asthmatic subjects and from nonasthmatic control subjects. Methods: IL-17 was detected through use of immunocytochemistry, in situ hybridization, and Western blot. Bronchial fibroblasts were stimulated with IL-17, and cytokine production and chemokine production were detected through use of ELISA and RT-PCR. Results: Using immunocytochemistry, we demonstrated that the numbers of cells positive for IL-17 are significantly increased in sputum and bronchoalveolar lavage fluids of subjects with asthma in comparison with control subjects (P < .001 and P < .005, respectively). We demonstrated that in addition to T cells, eosinophils in sputum and bronchoalveolar lavage fluids expressed IL-17. Peripheral blood eosinophils were also positive for IL-17, and the level of IL-17 in eosinophils purified from peripheral blood was significantly higher in subjects with asthma than in controls (P < .01). To further investigate the mechanism of action of IL-17 in vivo, we examined the effect of this cytokine on fibroblasts isolated from bronchial biopsies of asthmatic and nonasthmatic subjects. IL-17 did enhance the production of pro-fibrotic cytokines (IL-6 and IL-11) by fibroblasts, and this was inhibited by dexamethasone. Similarly, IL-17 increased the level of other fibroblast-derived inflammatory mediators, such as the α-chemokines, IL-8, and growth-related oncogene-α. Conclusion: Our results, which demonstrate for the first time that eosinophils are a potential source of IL-17 within asthmatic airways, suggest that IL-17 might have the potential to amplify inflammatory responses through the release of proinflammatory mediators such as α-chemokines. (J Allergy Clin Immunol 2001;108:430-8.)
It has been shown that histamine induces early changes on endothelial cells (EC), such as a transient expression of P-selectin and secretion and/or surface expression of early mediators (eg, ...prostacyclin PG1(2), platelet-activating factor PAF, and leukotriene B4 LTB4). However, delayed effects of histamine on EC and particularly on cytokine production are undefined. In this study, the effect of histamine on interleukin (IL)-8 production by EC was evaluated using an enzyme-linked immunosorbent assay (ELISA) method and mRNA expression. The results showed that histamine increased the secretion and the mRNA expression of IL-8 by EC. Histamine-induced IL-8 production was (1) dose-dependent (at a dose > or = 10(-6) mol/L), (2) potentialized by costimulation with tumor necrosis factor (TNF)-alpha, (3) inhibited by H1 or H2 histamine receptor antagonists, and (4) significantly increased 4 hours after the initial stimulation. These data suggest that histamine may be involved in the control of the late inflammatory reaction associated to allergic disorders through IL-8 secretion by EC.
The allergic inflammatory reaction is characterized by leucocyte adherence and infiltration processes which are controlled by the expression of adhesion molecules on the surface of vascular ...endothelium. One of the main mediators implicated in allergic reactions is represented by histamine. Histamine is a potent activator of endothelial cells (EC): it induces the expression of P-selectin on the surface of endothelium and the secretion of IL-6 and IL-8.
Loratadine (L), a histamine H1-antagonist, and one of its active metabolites, descarboxyethoxyloratadine (DCL), were studied at different concentrations for their ability to reduce the histamine-induced activation of human umbilical vein EC (HUVEC).
HUVEC were stimulated in the presence of histamine at 10(-6) M, 10(-5) M and 10(-4) M. We assessed by ELISA the expression of P-selectin on EC surface, as well as cytokine production in EC supernatants of 24 h culture.
Our results showed that for a 10(-4) M-histamine stimulation, L and DCL have a similar inhibitory effect on P-selectin expression (IC50 = 13 x 10-9 M and 23 x 10-9 M, respectively). L and DCL inhibited significantly IL-6 and IL-8 secretion induced by histamine with a more powerful efficiency of the active metabolite. For the dose of 10(-4) M histamine, a 50% inhibition of IL-6 secretion was obtained for a dose of DCL equal to 2.6 x 10(-12) M whereas the same magnitude of effects were only reached for a higher concentration of L (0.3 x 10-6 M). Similar results were obtained for IL-8 (IC50 = 0.2 x 10-6 M for L and 10-9 M for DCL). Analysis of IL-8 mRNA expression by RT-PCR was in accordance with these data.
These results demonstrate that both L and DCL are active to reduce the histamine-induced activation of EC. Interestingly, DCL seems to be effective at lesser concentrations especially to inhibit cytokine secretion.
Background: In atopic dermatitis (AD) there is evidence of tissue fibrosis involving a number of structural changes, including papillary dermal fibrosis and epidermal hyperplasia. These changes are ...suggested to be the result of chronic inflammation of the skin. Several remodeling-associated cytokines, including transforming growth factor (TGF) β1, IL-11, and IL-17, have been shown to be increased in allergic diseases, including asthma. Objective: We investigated TGF-β1, IL-11, and IL-17 expression in skin biopsy specimens recovered from acute and chronic skin lesions from patients with AD, as well as from uninvolved skin of patients with AD and skin from healthy volunteers. We also examined the correlation between the expression of these cytokines and the extent of total, type I, and type III collagen deposition. Methods: We evaluated the expression of TGF-β1, IL-11, and IL-17 by means of immunohistochemistry. Collagen deposition was assessed by means of immunohistochemistry and van Gieson staining. Results: TGF-β1 expression was markedly enhanced in both acute and particularly chronic lesions (
P < .001). Although IL-11 expression was significantly increased only in chronic lesions (
P < .0001), IL-17 was preferentially associated with acute lesions (
P < .005). Although collagen type III deposition was not significantly different among the groups, type I collagen deposition was significantly increased in chronic AD lesions (
P < .0005). There was a significant correlation between IL-11 and type I collagen deposition, as well as the number of eosinophils in skin specimens from patients with AD (
r
2 = 0.527, and
r
2 = 0.622, respectively;
P < .0001). Conclusion: These results suggest that TGF-β1, IL-11, and IL-17 are involved in the remodeling of skin lesions in patients with AD. However, IL-11 and IL-17 are preferentially expressed at different stages of the disease. Type I collagen appeared to be the major subtype involved in this repair process.
Mechanisms that allow a selective eosinophil emigration in different eosinophilic lung diseases remain poorly understood. In this study, we tested the hypothesis that eosinophils might participate in ...their own recruitment, particularly through adhesion molecule expression on human endothelial cells (EC). Blood eosinophils from donors with blood eosinophilia were purified and maintained in culture medium for 1 and 18 h. The expression of ICAM‐1, E‐selectin, and VCAM‐1 on human umbilical vein endothelial cells (HUVEC) was evaluated by ELISA and flow cytometry analysis after addition of eosinophil supernatants. Eosinophil supernatants collected after 1 h induced a weak increase of CAM expression on HUVEC. In contrast, supernatants from eosinophils cultured for 18 h considerably amplified ICAM‐1, E‐selectin, and VCAM‐1 expression on the surface of EC. These levels of CAM expression (in optical density determined by ELISA) were about two‐ or threefold more important than those obtained with eosinophil supernatants collected after a 1‐h culture. The characterization of the implicated molecules showed that anti‐IL‐1β antibodies significantly inhibited ICAM‐1, E‐selectin, and VCAM‐1 expression, whereas anti‐TNF‐α antibodies only induced a moderate inhibition. Our data support the hypothesis that eosinophils, through the release of at least IL‐1β and TNF‐α, might participate in the amplification of the inflammatory reaction by activating the vascular endothelium. J. Leukoc. Biol. 63: 351–358; 1998.
The local inflammatory response that occurs after repeated exposure to allergens or during the late-phase reaction results from a complex network of interactions between inflammatory cells (mast ...cells, eosinophils, macrophages) and resident cells belonging to the lung structure itself like EC, fibroblasts, or bronchial epithelial cells. Among structural cells, EC represent critical elements: they control leukocyte traffic through the expression of adhesion molecules; they are also able to amplify leukocyte activation through the production of proinflammatory cytokines like IL-1, IL-6, or of chemokines like IL-8. Three cell models have been successively considered. When supernatants of alveolar macrophages, recovered from patients exhibiting a late asthmatic response after allergen exposure, were tested on HUVEC cultures, a TNF alpha-dependent ICAM-1 and E-selectin overexpression was observed. Among mast-cell mediators, histamine was already known to induce a rapid and transient expression of P-selectin; we demonstrated that histamine also induced an IL-6 and IL-8 secretion by HUVEC, which was concentration-dependent and inhibited by H1 or H2 receptor antagonists. Finally purified eosinophils obtained from donors with hypereosinophilia similarly increased adhesion molecule expression and chemokine production. The precise nature of the eosinophil product(s) involved in this process is currently under investigation.
We here report the identification of a novel human endothelial cell-specific molecule (called ESM-1) cloned from a human umbilical vein endothelial cell (HUVEC) cDNA library. Constitutive ESM-1 gene ...expression (as demonstrated by Northern blot and reverse transcription-polymerase chain reaction analysis) was found in HUVECs but not in the other human cell lines tested. The cDNA sequence contains an open reading frame of 552 nucleotides and a 1398-nucleotide 3′-untranslated region including several domains involved in mRNA instability and five putative polyadenylation consensus sequences. The deduced 184-amino acid sequence defines a cysteine-rich protein with a functional NH2-terminal hydrophobic signal sequence. Searches in several data bases confirmed the unique identity of this sequence. A rabbit immune serum raised against the 14-kDa COOH-terminal peptide of ESM-1 immunoprecipitated a 20-kDa protein only in ESM-1-transfected COS cells. Immunoblotting and immunoprecipitation of HUVEC lysates revealed a specific 20-kDa band corresponding to ESM-1. In addition, constitutive ESM-1 gene expression was shown to be tissue-restricted to the human lung. Southern blot analysis suggests that a single gene encodes ESM-1. A time-dependent up-regulation of ESM-1 mRNA was seen after addition of tumor necrosis factor α (TNFα) or interleukin (IL)-1β but not with IL-4 or interferon γ (IFNγ) alone. In addition, when IFNγ was combined with TNFα, IFNγ inhibited the TNFα-induced increase of ESM-1 mRNA level. These data suggest that ESM-1 may have potent implications in the areas of vascular cell biology and human lung physiology.
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