GW501516-activated PPARβ/δ promotes liver fibrosis via p38-JNK MAPK-induced hepatic stellate cell proliferation.

ABSTRACT: BACKGROUND: After liver injury, the repair process comprises activation and proliferation of hepatic stellate cells (HSCs), which produce extracellular matrix (ECM) proteins. Peroxisome proliferator-activated receptor beta/delta (PPARβ/δ) is highly expressed in these cells, but its function in liver repair remains incompletely understood. This study investigated whether activation of PPARβ/δ with the ligand GW501516 influenced the fibrotic response to injury from chronic carbon tetrachloride (CCl4) treatment in mice. Wild type and PPARβ/δ-null mice were treated with CCl4 alone or CCl4 co-administered with GW501516. To unveil mechanisms underlying the PPARβ/δ-dependent effects, we analyzed the proliferative response of human LX-2 HSCs to GW501516 in the presence or absence of PPARβ/δ. RESULTS: We found that GW501516 treatment enhanced the fibrotic response. Compared to the other experimental groups, CCl4/GW501516-treated wild type mice exhibited increased expression of various profibrotic and pro-inflammatory genes, such as those involved in extracellular matrix deposition and macrophage recruitment. Importantly, compared to healthy liver, hepatic fibrotic tissues from alcoholic patients showed increased expression of several PPAR target genes, including phosphoinositide-dependent kinase-1, transforming growth factor beta-1, and monocyte chemoattractant protein-1. GW501516 stimulated HSC proliferation that caused enhanced fibrotic and inflammatory responses, by increasing the phosphorylation of p38 and c-Jun N-terminal kinases through the phosphoinositide-3 kinase/protein kinase-C alpha/beta mixed lineage kinase-3 pathway. CONCLUSIONS: This study clarified the mechanism underlying GW501516-dependent promotion of hepatic repair by stimulating proliferation of HSCs via the p38 and JNK MAPK pathways.

Inflammatory diseases: is ubiquitinated NEMO at the hub?

Many patients with Crohn's disease carry mutations in NOD2, a molecule that can both activate and attenuate the pro-inflammatory effects of NF-kappa B. Recent studies implicate NOD2-induced ubiquitination of the NF-kappa B regulator NEMO as a potential means of manipulating the NF-kappa B signal.

Body composition using bio-impedance analysis in pediatric patients with inflammatory bowel disease. Corcordance with dual energy X-ray absorptiometry and comparison with healthy controls

Introduction: Growth is a central process in paediatrics. Weight and height evaluation are therefore routine exams for every child but in some situation, particularly inflammatory bowel disease (IBD), a wider evaluation of nutritional status needs to be performed. Objectives: To assess the accuracy of bio-impedance analysis (BIA) compared to the gold standard dual energy X-ray absorptiometry (DEXA) in estimating percentage body fat (fat mass; FM) and lean body mass (fat free mass; FFM) in children with inflammatory bowel disease (IBD). To compare FM and FFM levels between patients with IBD and healthy controls. Methods: Twenty-nine healthy controls (12 females; mean age: 12.7 ± 1.9 years) and 21 patients (11 females; 14.3 ± 1.3 years) were recruited from August 2011 to October 2012 at our institution. BIA was performed in all children and DEXA in patients only. Concordance between BIA and DEXA was assessed using Lin's concordance correlation and the Bland-Altman method. Between-group comparisons were made using analysis of variance adjusting for age. Results: BIA-derived FM% showed a good concordance with DEXA-derived values, while BIA-derived FFM% tended to be slightly higher than DEXA-derived values (table). No differences were found between patients and controls regarding body mass index (mean ± SD: 19.3 ± 3.3 vs. 20.1 ± 2.8 kg/m2, respectively; age-adjusted P = 0.08) and FM% (boys: 25.3 ± 10.2 vs. 22.6 ± 7.1%, for patients and controls, respectively; P = 0.20; girls: 28.2 ± 5.7 vs. 26.4 ± 7.7%; P = 0.91). Also, no differences were found regarding FFM% in boys (74.9 ± 10.2 vs. 77.4 ± 7.1%; P = 0.22) and girls (71.8 ± 5.6 vs. 73.5 ± 7.7%; P = 0.85). Conclusion: BIA adequately assesses body composition (FM%) in children with IBD and could advantageously replace DEXA, which is more expensive and less available. No differences in body composition were found between children with IBD and healthy controls.

Type I IFN-mediated regulation of IL-1 production in inflammatory disorders.

Although contributing to inflammatory responses and to the development of certain autoimmune pathologies, type I interferons (IFNs) are used for the treatment of viral, malignant, and even inflammatory diseases. Interleukin-1 (IL-1) is a strongly pyrogenic cytokine and its importance in the development of several inflammatory diseases is clearly established. While the therapeutic use of IL-1 blocking agents is particularly successful in the treatment of innate-driven inflammatory disorders, IFN treatment has mostly been appreciated in the management of multiple sclerosis. Interestingly, type I IFNs exert multifaceted immunomodulatory effects, including the reduction of IL-1 production, an outcome that could contribute to its efficacy in the treatment of inflammatory diseases. In this review, we summarize the current knowledge on IL-1 and IFN effects in different inflammatory disorders, the influence of IFNs on IL-1 production, and discuss possible therapeutic avenues based on these observations.

Stratégies thérapeutiques dans les myopathies inflammatoires [Therapeutic strategies in idiopatic inflammatory myopathies]

Idiopathic inflammatory myopathies, such as polymyositis and dermatomyositis, share common clinical features such as progressive, symmetrical muscle weakness prevailing in the lower limbs, associated sometimes with muscle pains. High CK and typical biopsy insure the diagnosis. Possible causes for secondary myopathies and associated diseases should be actively investigated. The search for autoantibodies helps to better classify inflammatory myopathies and to better define the prognosis of the myopathy. Glucocorticoids are the cornerstone of the early phase therapy. Glucocorticoid-sparing agents, such as azathioprine and methotrexate, are second line agents but can be readily prescribed. In case of therapeutic resistance, a rescue treatment (ciclosporine, immunoglobulins, rituximab, cyclophosphamide) could be considered.

Is there histomorphological evidence of plantar metatarsal fat pad atrophy in patients with diabetes?

The etiology of diabetic foot ulceration remains incompletely understood. Among other factors such as foot deformity in the presence of neuropathy, plantar fat pad atrophy has been identified as a contributory factor in diabetic foot ulceration. An association between fat pad atrophy and diabetic foot ulceration has been documented by imaging and histomorphological analysis of the calcaneal fat pad. However, histomorphological analysis of the metatarsal fat pad has not been performed to date. The present study entailed 14 patients with diabetes and 14 nondiabetic controls and was aimed at documenting histomorphological evidence for presumed plantar metatarsal fat pad atrophy in patients with diabetes. Histological stains and computer-assisted planimetry were performed on samples of metatarsal fat obtained during forefoot surgery. The histomorphological and planimetric analyses of adipocyte cross-sectional area and nuclear density demonstrated no differences between patients with diabetes and control patients. Our findings demonstrate that systemic atrophy of the metatarsal fat pad is not present in the diabetic foot and may not explain the structural changes previously proposed by noninvasive imaging. Level of Clinical Evidence: 3.

Calprotectine fécale: outil diagnostique dans les maladies inflammatoires chroniques de l'intestin [Fecal calprotectin: a diagnostic tool for inflammatory bowel disease].

Fecal calprotectin (FC) is a valid biomarker to discriminate with a good sensitivity and specificity the presence of mucosal lesions of the gastrointestinal tube (e.g. ulcers in the context of inflammatory bowel disease (IBD)) from functional disorders (e.g. irritable bowel syndrome). FC is not specific for IBD and can be elevated also in gastrointestinal infections, ischemic colitis or neoplasia. An elevated FC should stimulate further investigations, notably an endoscopic workup. The level of FC correlates with the endoscopic score in Crohn's disease and ulcerative colitis. The correlation of FC and the endoscopic severity is better than the one of CRP or blood leukocytes. Thus, FC can also be used in the follow-up of IBD patients.

Role of biological agents in auto-inflammatory disease in children

BACKGROUND: Biological agents (BA) have recently completed the treatment options in auto-inflammatory diseases (AID) in children with the aim to improve the outcome. TNF-α blocking agents have been the first BA successfully used in children. However, other biological agents targeting cytokines including IL-1 and IL-6 have been shown to be effective (anti-IL-1/6), especially in AID like systemiconset juvenile arthritis (SoJIA) or cryopyrine-associated periodic syndrome (CAPS). In Switzerland, Etanercept has been approved for the treatment of JIA since 2000 and Canakinumab for the treatment of paediatric CAPS since 2009.OBJECTIVES: Evaluation of the use of biological agents in AID in Western Switzerland.METHODS: We selected all patients with AID seen in the Réseau Romand de Rhumatologie Pédiatrique (Lausanne, Geneva, Aigle, Sion, and Neuchâtel) who were treated with the following BA: anti-TNF-α (Etanercept, Infliximab, Adalimumab) and Abatacept, and anti-IL-1/6 (Anakinra, Canakinumab, Tocilizumab). We looked at minor and major adverse events and the activity of the disease before and after treatment with BA and with special regards on anti-IL-1/6.RESULTS: Among 921 children and adolescents followed between 2004 and 2010, we selected 85 patients with AID (PFAPA: 40, FMF: 6, HyperIgD: 1, CAPS: 3, SoJIA: 34). Only patients with CAPS and SoJIA were treated with BA. They had a mean age of 9 years (3-22) and F: M ratio of 1.6:1. 7 patients were treated with one BA, 6 patients with 2 different BAs and 3 with 3 BAs. 3 patients with CAPS were treated with anti-IL-1 and responded very well. 13 SoJIA patients were treated with BA (anti-TNF-α: 8, Abatacept: 1, anti-IL-1/6: 8). 4 patients treated by anti-TNF-α were switched to anti-IL-1/6 because of lack of response to treatment (cf Table 1). We did not have any serious adverse events and no serious infections.CONCLUSIONS: Patients with SoJIA and CAPS clearly benefit from treatment with BA. General tolerance was good. In the CAPS group the response to IL-1 was excellent. In SoJIA, 3/4 patients, switched from anti-TNF-α to anti-IL-1/6 for lack of therapeutic response, did not respond well to the second medication. These patientsseem to represent a population relatively resistant to treatment with BA. Due to the low number of patients in our cohort, the response to BA in SoJIA patients non-responder to anti- TNF-α agents should be further studied.

The role of oxidative stress during inflammatory processes.

Abstract The production of various reactive oxidant species in excess of endogenous antioxidant defense mechanisms promotes the development of a state of oxidative stress, with significant biological consequences. In recent years, evidence has emerged that oxidative stress plays a crucial role in the development and perpetuation of inflammation, and thus contributes to the pathophysiology of a number of debilitating illnesses, such as cardiovascular diseases, diabetes, cancer, or neurodegenerative processes. Oxidants affect all stages of the inflammatory response, including the release by damaged tissues of molecules acting as endogenous danger signals, their sensing by innate immune receptors from the Toll-like (TLRs) and the NOD-like (NLRs) families, and the activation of signaling pathways initiating the adaptive cellular response to such signals. In this article, after summarizing the basic aspects of redox biology and inflammation, we review in detail the current knowledge on the fundamental connections between oxidative stress and inflammatory processes, with a special emphasis on the danger molecule high-mobility group box-1, the TLRs, the NLRP-3 receptor, and the inflammasome, as well as the transcription factor nuclear factor-κB.

Inflammatory myofibroblastic tumor of the trachea with concomitant granulomatous lymph node lesions.

We report herein the case of a 57-year-old lady who had two concomittant lesions, an inflammatory myofibroblastic tumor in the trachea, and severe granulomatous lesions in the adjacent hilar lymph nodes. While these two lesions shared histological and some immunohistochemical features lesions. They differed in terms of ALK-1 expression, which was positive in the tracheal tumor and negative in the lymph nodes. The discussion of the case circles around putative pathophysiological links between the lesions. The authors favor the idea that the lymph nodes present a sarcoid-like granulomatous reaction to the inflammatory myofibroblastic tumor in the trachea over a coexistence of two independent entities. However, no conclusive evidence for this interpretation can be presented based on the existing literature.

Inflammatory role of ASC in antigen-induced arthritis is independent of caspase-1, NALP-3, and IPAF.

Because IL-1beta plays an important role in inflammation in human and murine arthritis, we investigated the contribution of the inflammasome components ASC, NALP-3, IPAF, and caspase-1 to inflammatory arthritis. We first studied the phenotype of ASC-deficient and wild-type mice during Ag-induced arthritis (AIA). ASC(-/-) mice showed reduced severity of AIA, decreased levels of synovial IL-1beta, and diminished serum amyloid A levels. In contrast, mice deficient in NALP-3, IPAF, or caspase-1 did not show any alteration of joint inflammation, thus indicating that ASC associated effects on AIA are independent of the classical NALP-3 or IPAF inflammasomes. Because ASC is a ubiquitous cytoplasmic protein that has been implicated in multiple cellular processes, we explored other pathways through which ASC may modulate inflammation. Ag-specific proliferation of lymph node and spleen cells from ASC-deficient mice was significantly decreased in vitro, as was the production of IFN-gamma, whereas IL-10 production was enhanced. TCR ligation by anti-CD3 Abs in the presence or absence of anti-CD28 Abs induced a reduction in T cell proliferation in ASC(-/-) T cells compared with wild-type ones. In vivo lymph node cell proliferation was also significantly decreased in ASC(-/-) mice, but no effects on apoptosis were observed either in vitro or in vivo in these mice. In conclusion, these results strongly suggest that ASC modulates joint inflammation in AIA through its effects on cell-mediated immune responses but not via its implication in inflammasome formation.

Online teaching of inflammatory skin pathology by a French-speaking international university network

Introduction: Developments in technology, webbased teaching and whole slide imaging have broadened the teaching horizon in anatomic pathology. Creating online learning material including many types of media like radiologic images, videos, clinical and macroscopic photographs and whole slides imaging is now accessible to almost every university. Unfortunately, a major limiting factor to maintain and update the learning material is the amount of work, time and resources needed. In this perspective, a French national university network was initiated in 2011 to build mutualised online teaching pathology modules with clinical cases and tests. This network has been extended to an international level in 2012-2014 (Quebec, Switzerland and Ivory Coast). Method: One of the first steps of the international project was to build a learning module on inflammatory skin pathology intended for interns and residents of pathology and dermatology. A pathology resident from Quebec spent 6 weeks in France and Switzerland to develop the contents and build the module on an e-learning Moodle platform (http: //moodle.sorbonne-paris-cite.fr) under the supervision of two dermatopathologists (BV, MB). The learning module contains text, interactive clinical cases, tests with feedback, whole slides images (WSI), images and clinical photographs. For that module, the virtual slides are decentralized in 2 universities (Bordeaux and Paris 7). Each university is responsible of its own slide scanning, image storage and online display with virtual slide viewers. Results: The module on inflammatory skin pathology includes more than 50 web pages with French original content, tests and clinical cases, links to over 45 WSI and more than 50 micro and clinical photographs. The whole learning module is currently being revised by four dermatopathologists and two senior pathologists. It will be accessible to interns and residents in spring 2014. The experience and knowledge gained from that work will be transferred to the next international fellowship intern whose work will be aimed at creating lung and breast pathology learning modules. Conclusion: The challenges of sustaining a project of this scope are numerous. The technical aspect of whole-slide imaging and storage needs to be developed by each university or group. The content needs to be regularly updated, completed and its use and existence needs to be promoted by the different actors in pathology. Of the great benefits of that kind of project are the international partnerships and connections that have been established between numerous Frenchspeaking universities and pathologists with the common goals of promoting education in pathology and the use of technology including whole slide imaging. * The Moodle website is hosted by PRES Sorbonne Paris Cité, and financial supports for hardware have been obtained from UNF3S (http://www.unf3s.org/) and PRES Sorbonne Paris Cité. Financial support for international fellowships has been obtained from CFQCU (http://www.cfqcu.org/).

Pulmonary inflammatory myofibroblastic tumour after Hodgkin's lymphoma.

Positron emission tomography (PET)/CT plays a major role in staging, assessing response to treatment and during follow-up of paediatric Hodgkin's lymphoma (HL). Owing to high sensitivity to detect viable tumoural tissue, negative PET/CT is highly predictive of survival. However, (18)F-FDG is not specific for malignant disease and may concentrate in numerous benign/inflammatory lesions that may cause 'false-positive' results and follow-up PET/CT studies should be interpreted with caution. We report a case of pulmonary inflammatory myofibroblastic tumour, which developed during follow-up in a young patient with complete remission of a stage IIB HL and was fully treated with surgical resection.

Role of major histocompatibility complex class II expression by non-hematopoietic cells in autoimmune and inflammatory disorders: facts and fiction.

It is well established that interactions between CD4(+) T cells and major histocompatibility complex class II (MHCII) positive antigen-presenting cells (APCs) of hematopoietic origin play key roles in both the maintenance of tolerance and the initiation and development of autoimmune and inflammatory disorders. In sharp contrast, despite nearly three decades of intensive research, the functional relevance of MHCII expression by non-hematopoietic tissue-resident cells has remained obscure. The widespread assumption that MHCII expression by non-hematopoietic APCs has an impact on autoimmune and inflammatory diseases has in most instances neither been confirmed nor excluded by indisputable in vivo data. Here we review and put into perspective conflicting in vitro and in vivo results on the putative impact of MHCII expression by non-hematopoietic APCs-in both target organs and secondary lymphoid tissues-on the initiation and development of representative autoimmune and inflammatory disorders. Emphasis will be placed on the lacunar status of our knowledge in this field. We also discuss new mouse models-developed on the basis of our understanding of the molecular mechanisms that regulate MHCII expression-that constitute valuable tools for filling the severe gaps in our knowledge on the functions of non-hematopoietic APCs in inflammatory conditions.