Anti-CD74 IgA antibodies show diagnostic potential for axial spondyloarthritis but are not associated with microscopic gut inflammation.

OBJECTIVES: Gut inflammation commonly occurs in axial SpA (axSpA), and is linked to disease activity and outcome. Given the role of IgA in mucosal immunity, we explored the association between anti-CD74 IgA antibodies, gut inflammation and axSpA. METHODS: Anti-CD74 IgA was measured by ELISA in serum samples of axSpA patients, fulfilling the 2009 Assessment of SpondyloArthritis international Society classification criteria. A group of fibromyalgia (FM) and RA patients served as non-inflammatory and inflammatory controls. Newly diagnosed axSpA patients underwent ileocolonoscopy; mucosal biopsies were histopathologically assessed as normal, acute or chronically inflamed. Optimal anti-CD74 IgA cut-off values were determined with a receiver operating characteristics curve. RESULTS: axSpA patients (n = 281) showed higher anti-CD74 IgA levels [mean (s.d.) 18.8 (12.4) U/ml] compared with 100 FM patients [10.9 (5.0) U/ml, P < 0.001] and 34 RA patients [13.7 (9.6) U/ml, P = 0.02]. The area under the receiver operating characteristics curve for diagnosis (axSpA vs FM) was 0.70, providing a sensitivity of 60% and specificity of 87% (cut-off 15 U/ml). Antibody concentrations were not significantly different between axSpA patients with (n = 40) and without (n = 69) gut inflammation (P = 0.83), yielding an area under the receiver operating characteristics curve of 0.51. Anti-CD74 IgA levels were not associated with degree of bone marrow oedema on MRI of the sacroiliac joints, CRP or any other disease-specific feature such as the use of NSAIDs or biological treatment. CONCLUSION: Serum anti-CD74 IgA is a potentially useful diagnostic biomarker for axSpA. However, antibody levels do not correlate with any phenotypical feature, including microscopic gut inflammation, suggesting this to be a disease-specific rather than an inflammatory marker.

Commensal microbiota influence systemic autoimmune responses.

Antinuclear antibodies are a hallmark feature of generalized autoimmune diseases, including systemic lupus erythematosus and systemic sclerosis. However, the processes underlying the loss of tolerance against nuclear self-constituents remain largely unresolved. Using mice deficient in lymphotoxin and Hox11, we report that approximately 25% of mice lacking secondary lymphoid organs spontaneously develop specific antinuclear antibodies. Interestingly, we find this phenotype is not caused by a defect in central tolerance. Rather, cell-specific deletion and in vivo lymphotoxin blockade link these systemic autoimmune responses to the formation of gut-associated lymphoid tissue in the neonatal period of life. We further demonstrate antinuclear antibody production is influenced by the presence of commensal gut flora, in particular increased colonization with segmented filamentous bacteria, and IL-17 receptor signaling. Together, these data indicate that neonatal colonization of gut microbiota influences generalized autoimmunity in adult life.

High intensity interval training is associated with greater impact on physical fitness, insulin sensitivity and muscle mitochondrial content in males with overweight/obesity, as opposed to continuous endurance training: a randomized controlled trial.

OBJECTIVES: To evaluate the effect of high intensity training (HIT) on physical fitness, basal respiratory exchange ratio (bRER), insulin sensitivity and muscle histology in overweight/obese men compared to continuous aerobic training (CAT). MATERIAL AND METHODS: 16 male participants with overweight/obesity (age: 42-57 years, body mass index: 28-36 kg/m2) were randomized to HIT (n=8) or CAT (n=8) for 10 weeks, twice a week. HIT was composed of 10 minutes high intensity, 10 minutes continuous aerobic, 10 minutes high intensity exercises. CAT was composed of three times 10 minutes continuous exercising. Changes in anthropometry, physical and metabolic fitness were evaluated. Muscle histology (mitochondria and lipid content) was evaluated by transmission electron microscopy (TEM). RESULTS: HIT showed a significant increase for peak VO2 (P=0.01), for insulin sensitivity (AUC glucose (P<0,001), AUC insulin (P<0,001), OGTT composite score (P=0.007)) and a significant decrease of bRER (P<0.001) compared to CAT. Muscle mitochondrial content was significantly increased after HIT at the subsarcolemmal (P=0.004 number and P=0.001 surface) as well as the intermyofibrillar site (P<0.001 number and P=0.001 surface). CONCLUSION: High intensity training elicits stronger beneficial effects on physical fitness, basal RER, insulin sensitivity, and muscle mitochondrial content, as compared to continuous aerobic training.

An ER-directed gelsolin nanobody targets the first step in amyloid formation in a gelsolin amyloidosis mouse model.

Hereditary gelsolin amyloidosis is an autosomal dominantly inherited amyloid disorder. A point mutation in the GSN gene (G654A being the most common one) results in disturbed calcium binding by the second gelsolin domain (G2). As a result, the folding of G2 is hampered, rendering the mutant plasma gelsolin susceptible to a proteolytic cascade. Consecutive cleavage by furin and MT1-MMP-like proteases generates 8 and 5 kDa amyloidogenic peptides that cause neurological, ophthalmological and dermatological findings. To this day, no specific treatment is available to counter the pathogenesis. Using GSN nanobody 11 as a molecular chaperone, we aimed to protect mutant plasma gelsolin from furin proteolysis in the trans-Golgi network. We report a transgenic, GSN nanobody 11 secreting mouse that was used for crossbreeding with gelsolin amyloidosis mice. Insertion of the therapeutic nanobody gene into the gelsolin amyloidosis mouse genome resulted in improved muscle contractility. X-ray crystal structure determination of the gelsolin G2:Nb11 complex revealed that Nb11 does not directly block the furin cleavage site. We conclude that nanobodies can be used to shield substrates from aberrant proteolysis and this approach might establish a novel therapeutic strategy in amyloid diseases.

Transient Receptor Potential Channels in Intestinal Inflammation: What Is the Impact of Cigarette Smoking?

Inflammatory bowel disease (IBD) is characterized by severe gastrointestinal inflammation and results from a complex interplay between genetic and environmental factors. IBD includes two prominent subtypes: Crohn's disease (CD) and ulcerative colitis (UC). One of the main risk factors for the development of CD is cigarette smoking, while UC is rather a disease of ex-smokers. To date, many of the mechanisms underlying the immune imbalance in IBD and the involvement of cigarette smoke (CS) are incompletely understood. Transient receptor potential (TRP) proteins are non-selective cation channels that, upon activation, lead to plasma membrane depolarization and, in general, to Ca2+ influx. TRP channels of the ankyrin and vanilloid family, expressed by sensory neurons in the central and enteric nervous systems, have been extensively studied in the context of intestinal inflammation. Moreover, recent advances made on the role of non-neuronal expressed TRP channels shed light on the involvement of epithelial cells in inflammatory processes. This review focuses on how CS may impact TRP channel function in intestinal inflammation. Firstly, we discuss the current knowledge on neuronal TRP channels, known to be linked to IBD, in health, immune homeostasis and intestinal inflammation. Subsequently, we address how TRP channels are activated by CS and its components in other organ systems and also hypothesize on the potential implications for CS-mediated TRP channel activation in gut inflammation.

Chronic cigarette smoke exposure induces microbial and inflammatory shifts and mucin changes in the murine gut.

Inflammatory bowel diseases (IBD) are complex multifactorial diseases characterized by an inappropriate host response to an altered commensal microbiome and dysfunctional mucus barrier. Cigarette smoking is the best known environmental risk factor in IBD. Here, we studied the influence of chronic smoke exposure on the gut microbiome, mucus layer composition and immune factors in conventional mice. We compared smoke-exposed with air-exposed mice (n = 12) after a smoke exposure of 24 weeks. Both Illumina sequencing (n = 6) and denaturing gradient gel electrophoresis (n = 12) showed that bacterial activity and community structure were significantly altered in the colon due to smoke exposure. Interestingly, an increase of Lachnospiraceae sp. activity in the colon was observed. Also, the mRNA expression of Muc2 and Muc3 increased in the ileum, whereas Muc4 increased in the distal colon of smoke-exposed mice (n = 6). Furthermore, we observed increased Cxcl2 and decreased Ifn-γ in the ileum, and increased Il-6 and decreased Tgf-ß in the proximal colon. Tight junction gene expression remained unchanged. We infer that the modulating role of chronic smoke exposure as a latently present risk factor in the gut may be driven by the altered epithelial mucus profiles and changes in microbiome composition and immune factors.

Follicles of various maturation stages react differently to enzymatic isolation: a comparison of different isolation protocols.

Isolation of human follicles is based on digestion of the tissue by combinations of enzymes. Follicle vitality and morphology are often based on the analysis of pooled follicles of different maturation stages. Information is therefore lacking on the effect of the isolation protocol to individual follicles of different maturation stages. A study was conducted using five protocols combining different enzymes and varying concentrations. Isolated follicles were classified according to their maturation stages, counted and characterized for vitality, morphology, early apoptosis and organization of transzonal projections. No statistical differences were found between the protocols when outcome parameters were analysed on a pool of follicles regardless of their maturation status. Differences were observed in quality when the follicles were analysed separately according to their maturation status. Combining morphologic characteristics and vitality, both Liberase DH and Liberase TM combined with collagenase IV were better at isolating high-quality primordial follicles, compared with collagenase IV. No statistical difference between the isolation protocols was found for primary follicles. If only high-quality isolated secondary follicles are needed, collagenase IV is found to be most advantageous. Follicles of different maturation stages react differently when enzymatic isolation protocols are compared.

Role of metallothioneins as danger signals in the pathogenesis of colitis.

Inflammatory bowel diseases (IBDs) are recurrent intestinal pathologies characterized by a compromised epithelial barrier and an exaggerated immune activation. Mediators of immune cell infiltration may represent new therapeutic opportunities. Metallothioneins (MTs) are stress-responsive proteins with immune-modulating functions. Metallothioneins have been linked to IBDs, but their role in intestinal inflammation is inconclusive. We investigated MT expression in colonic biopsies from IBDs and acute infectious colitis patients and healthy controls and evaluated MT's role in experimental colitis using MT knockout mice and anti-MT antibodies. Antibody potential to target extracellular MT and its mechanism was tested in vitro. Biopsies of patients with active colitis showed infiltration of MT-positive cells in a pattern that correlated with the grade of inflammation. MT knockout mice displayed less severe acute dextran sulphate sodium (DSS)-induced colitis compared to congenic wild-type mice based on survival, weight loss, colon length, histological inflammation and leukocyte infiltration. Chronic DSS-colitis confirmed that Mt1 and Mt2 gene disruption enhances clinical outcome. Blockade of extracellular MT with antibodies reduced F4/80-positive macrophage infiltration in DSS- and trinitrobenzene sulphonic acid-colitis, with a tendency towards a better outcome. Whole-body single-photon emission computer tomography of mice injected with radioactive anti-MT antibodies showed antibody accumulation in the colon during colitis and clearance during recovery. Necrotic and not apoptotic cell death resulted in western blot MT detection in HT29 cell supernatant. In a Boyden chamber migration assay, leukocyte attraction towards the necrotic cell supernatant could be abolished with anti-MT antibody, indicating the chemotactic potential of endogenous released MT. Our results show that human colitis is associated with infiltration of MT-positive inflammatory cells. Since antibody blockade of extracellular MT can reduce colitis in mice, MT may act as a danger signal and may represent a novel target for reducing leukocyte infiltration and inflammation in IBD patients.

Chaperone nanobodies protect gelsolin against MT1-MMP degradation and alleviate amyloid burden in the gelsolin amyloidosis mouse model.

Gelsolin amyloidosis is an autosomal dominant incurable disease caused by a point mutation in the GSN gene (G654A/T), specifically affecting secreted plasma gelsolin. Incorrect folding of the mutant (D187N/Y) second gelsolin domain leads to a pathological proteolytic cascade. D187N/Y gelsolin is first cleaved by furin in the trans-Golgi network, generating a 68 kDa fragment (C68). Upon secretion, C68 is cleaved by MT1-MMP-like proteases in the extracellular matrix, releasing 8 kDa and 5 kDa amyloidogenic peptides which aggregate in multiple tissues and cause disease-associated symptoms. We developed nanobodies that recognize the C68 fragment, but not native wild type gelsolin, and used these as molecular chaperones to mitigate gelsolin amyloid buildup in a mouse model that recapitulates the proteolytic cascade. We identified gelsolin nanobodies that potently reduce C68 proteolysis by MT1-MMP in vitro. Converting these nanobodies into an albumin-binding format drastically increased their serum half-life in mice, rendering them suitable for intraperitoneal injection. A 12-week treatment schedule of heterozygote D187N gelsolin transgenic mice with recombinant bispecific gelsolin-albumin nanobody significantly decreased gelsolin buildup in the endomysium and concomitantly improved muscle contractile properties. These findings demonstrate that nanobodies may be of considerable value in the treatment of gelsolin amyloidosis and related diseases.

Tauroursodeoxycholic acid inhibits experimental colitis by preventing early intestinal epithelial cell death.

Ulcerative colitis (UC) is characterized by increased epithelial cell death and subsequent breakdown of the intestinal epithelial barrier, which perpetuates chronic intestinal inflammation. Since fecal bile acid dysmetabolism is associated with UC and tauroursodeoxycholic acid (TUDCA) has been shown to improve murine colitis, we evaluated the effect of TUDCA on intestinal epithelial cell death in a mouse model of UC-like barrier dysfunction elicited by dextran sulfate sodium (DSS). We identified the prevention of colonic caspase-3 induction, a key proapoptotic marker which was also over-activated in UC, as the earliest event resulting in a clear clinical benefit. Whereas vehicle-treated mice showed a cumulative mortality of 40%, all TUDCA-treated mice survived the DSS experiment during a 14-day follow-up period. In line with a barrier protective effect, TUDCA decreased bacterial translocation to the spleen and stimulated mucin production. Similarly, TUDCA inhibited lipopolysaccharide-induced intestinal permeability and associated enterocyte apoptosis. The anti-apoptotic effect was confirmed in vitro by a dose-dependent inhibition of both receptor-dependent (using tumor necrosis factor and Fas ligand) and receptor-independent (staurosporine) caspase-3 induction in HT29 colonic epithelial cells. These data imply that caspase-3 activation is an early marker of colitis that is prevented by TUDCA treatment. These data, together with the previously reported beneficial effect in colitis, suggest that TUDCA could be an add-on strategy to current immunosuppressive treatment of UC patients.

Degree of bone marrow oedema in sacroiliac joints of patients with axial spondyloarthritis is linked to gut inflammation and male sex: results from the GIANT cohort.

INTRODUCTION: Bone marrow oedema (BMO) of the sacroiliac joints (SIJs) is a hallmark of axial spondyloarthritis (SpA). However, the relationship between the extent of BMO and disease phenotype is poorly understood. OBJECTIVE: To assess the link between BMO of the SIJs and gut inflammation. We have also evaluated the correlation between BMO and established disease activity parameters. METHODS: Sixty-eight patients with axial SpA from the Gent Inflammatory Arthritis and spoNdylitis cohorT underwent ileocolonoscopy and MRI of the SIJs. Histopathological analysis and SPondyloArthritis Research Consortium of Canada (SPARCC) scores were performed. RESULTS: A significant higher SPARCC score (median (range)) was observed in axial SpA patients showing chronic gut inflammation (16.9 (3.8-68.3)) compared with axial SpA patients showing normal gut histology (9.8 (0.0-45.0); p<0.05). In a multiple linear regression model, we identified, besides chronic gut inflammation (effect size of 11.3, 95% CI (2.1 to 20.4)), male sex (effect size of 10.5, 95% CI (3.3 to 17.8)) to be independently associated to the extent of BMO. There was a low to moderate correlation between the degree of BMO and C-reactive protein(r=0.39, p=0.002) and Ankylosing Spondylitis Disease Activity Score (r=0.35, p=0.007). CONCLUSIONS: Higher degrees of BMO were observed in patients showing chronic gut inflammation. These data solidify a link between mucosal inflammation and progressive disease in axial SpA.

Sphingosine-1-phosphate prevents chemotherapy-induced human primordial follicle death.

STUDY QUESTION: Can Sphingosine-1-phosphate (S1P), a ceramide-induced death pathway inhibitor, prevent cyclophosphamide (Cy) or doxorubicin (Doxo) induced apoptotic follicle death in human ovarian xenografts? SUMMARY ANSWER: S1P can block human apoptotic follicle death induced by both drugs, which have differing mechanisms of cytotoxicity. WHAT IS KNOWN ALREADY: S1P has been shown to decrease the impact of chemotherapy and radiation on germinal vesicle oocytes in animal studies but no human translational data exist. STUDY DESIGN, SIZE, DURATION: Experimental human ovarian xenografting to test the in vivo protective effect of S1P on primordial follicle survival in the chemotherapy setting. The data were validated by assessing the same protective effect in the ovaries of xenografted mice in parallel. PARTICIPANTS/MATERIALS, SETTING, METHODS: Xenografted mice were treated with Cy (75 mg/kg), Cy+S1P (200 µM), Doxo (10 mg/kg), Doxo+S1P or vehicle only (Control). S1P was administered via continuous infusion using a mini-osmotic pump beginning 24 h prior to and ending 72 h post-chemotherapy. Grafts were then recovered and stained with anti-caspase 3 antibody for the detection of apoptosis in primordial follicles. The percentage of apoptotic to total primordial follicles was calculated in each group. MAIN RESULTS AND THE ROLE OF CHANCE: Both Cy and Doxo resulted in a significant increase in apoptotic follicle death in human ovarian xenografts compared with controls (62.0 ± 3.9% versus 25.7 ± 7.4%, P < 0.01 and 76.7 ± 7.4% versus 25.7 ± 7.4%, P < 0.01, respectively). This chemotherapy-induced apoptotic death was reduced both in the Cy+S1P (32.7 ± 4.4%, P < 0.01) and the Doxo+S1P group (27.1 ± 7.6%, P < 0.01) compared with Cy and Doxo groups, respectively. In the Doxo+S1P and Cy+S1P groups, the percentages of apoptotic follicles were similar to those of vehicle-treated controls (P > 0.05). The findings from the ovaries of the severe combined immunodeficient mice mirrored the findings with human tissue. LIMITATIONS, REASONS FOR CAUTION: The functionality of the rescued human ovarian follicles needs to be evaluated in future studies though the studies in rodents showed that rescued oocytes can result in healthy offspring. In addition, the impact of S1P on cancer cells should be further studied. WIDER IMPLICATIONS OF THE FINDINGS: S1P and its future analogs hold promise for preserving fertility by pharmacological means for patients undergoing chemotherapy. STUDY FUNDING/COMPETING INTEREST(S): This research is supported by NIH's NICHD and NCI (5R01HD053112-06 and 5R21HD061259-02) and the Flemish Foundation for Scientific Research (FWO-Vlaanderen, grant number FWO G0.065.11N10). The authors have no conflicts of interest to disclose.

Spray-dried polyelectrolyte microparticles in oral antigen delivery: stability, biocompatibility, and cellular uptake.

During the past decade, extensive research has undeniably improved the formulation and delivery of oral vaccines. Nevertheless, several factors, such as the harsh gastrointestinal environment together with tolerance induction to exogenous antigens, have thus far impeded the optimal effectiveness and clinical application of oral delivery systems. The current study encompasses an initial evaluation of the stability, biocompatibility, and cellular uptake of two promising candidate systems for oral antigen delivery, that is, calcium carbonate- (CP) and mannitol-templated (MP) porous microspheres. Both spray-dried formulations were efficiently internalized by human intestinal epithelial cells (Caco-2 and HT-29) and degraded into phagolysosomal intracellular compartments. In addition, cellular particle uptake and processing significantly up-regulated the expression of (HLA) class-II and costimulatory molecules on intestinal epithelial cells. Even though the high surface-area-to-volume ratio of the microspheres was expected to favor protease access, antigen release was remarkably limited in simulated intestinal fluid and was even absent under gastric conditions. Finally, neither CP nor MP exerted cytotoxicity upon prolonged in vitro incubation with high antigen concentration. Altogether, these data support the potential of CP and MP for oral antigen delivery and motivate the further development of these promising carrier systems in in vivo studies.

Identification and validation of novel adipokines released from primary human adipocytes.

Adipose tissue is a major endocrine organ, releasing signaling and mediator proteins, termed adipokines, via which adipose tissue communicates with other organs. Expansion of adipose tissue in obesity alters adipokine secretion, which may contribute to the development of metabolic diseases. Although recent profiling studies have identified numerous adipokines, the amount of overlap from these studies indicates that the adipokinome is still incompletely characterized. Therefore, we conducted a complementary protein profiling on concentrated conditioned medium derived from primary human adipocytes. SDS-PAGE/liquid chromatography-electrospray ionization tandem MS and two-dimensional SDS-PAGE/matrix-assisted laser desorption ionization/time of flight MS identified 347 proteins, 263 of which were predicted to be secreted. Fourty-four proteins were identified as novel adipokines. Furthermore, we validated the regulation and release of selected adipokines in primary human adipocytes and in serum and adipose tissue biopsies from morbidly obese patients and normal-weight controls. Validation experiments conducted for complement factor H, αB-crystallin, cartilage intermediate-layer protein, and heme oxygenase-1 show that the release and expression of these factors in adipocytes is regulated by differentiation and stimuli, which affect insulin sensitivity, as well as by obesity. Heme oxygenase-1 especially reveals to be a novel adipokine of interest. In vivo, circulating levels and adipose tissue expression of heme oxygenase-1 are significantly increased in obese subjects compared with lean controls. Collectively, our profiling study of the human adipokinome expands the list of adipokines and further highlights the pivotal role of adipokines in the regulation of multiple biological processes within adipose tissue and their potential dysregulation in obesity.

Secretory products from epicardial adipose tissue of patients with type 2 diabetes mellitus induce cardiomyocyte dysfunction.

BACKGROUND: Secreted factors from epicardial adipose tissue (EAT) have been implicated in the development of cardiomyocyte dysfunction. This study aimed to assess whether alterations in the secretory profile of EAT in patients with type 2 diabetes mellitus (DM2) affect contractile function and insulin action in cardiomyocytes. METHODS AND RESULTS: Contractile function and insulin action were analyzed in primary adult rat cardiomyocytes incubated with conditioned media (CM) generated from explants of EAT biopsies obtained from patients without and with DM2. CM from subcutaneous and pericardial adipose tissue biopsies from the same patients served as the control. Cardiomyocytes treated with CM (EAT) from DM2 patients showed reductions in sarcomere shortening, cytosolic Ca(2+) fluxes, expression of sarcoplasmic endoplasmic reticulum ATPase 2a, and decreased insulin-mediated Akt-Ser473-phosphorylation as compared with CM from the other groups. Profiling of the CM showed that activin A, angiopoietin-2, and CD14 selectively accumulated in CM-EAT-DM2 versus CM-EAT in patients without DM2 and CM from the other fat depots. Accordingly, EAT biopsies from DM2 patients were characterized by clusters of CD14-positive monocytes. Furthermore, SMAD2-phosphorylation, a downstream target of activin A signaling, was elevated in cardiomyocytes treated with CM (EAT) from DM2 patients, and the detrimental effects of CM (EAT) from DM2 patients were partially abolished in cardiomyocytes pretreated with a neutralizing antibody against activin A. Finally, both recombinant activin A and angiopoietin-2 reduced cardiomyocyte contractile function, but only activin A reduced the expression of sarcoplasmic endoplasmic reticulum ATPase 2a. CONCLUSIONS: Collectively, our data implicate DM2-related alterations in the secretory profile of EAT in the pathogenesis of diabetes mellitus-related heart disease.

Microscopic gut inflammation in axial spondyloarthritis: a multiparametric predictive model.

OBJECTIVE: To assess the rates and explore predictors of microscopic gut inflammation in a cohort of patients with axial and peripheral spondyloarthritis (SpA). METHODS: Ileocolonoscopy was performed in 65 patients with axial and peripheral SpA from the Gent Inflammatory Arthritis and spoNdylitis cohorT. Histopathological analysis and scoring were performed by an experienced pathologist. RESULTS: Overall, 46.2% of the patients with SpA showed microscopic gut inflammation. In axial SpA, the following parameters were independently associated with gut involvement: male sex (OR=8.9, p=0.035); high disease activity measured by the Bath Ankylosing Spondylitis Disease Activity Index (OR=2.05, p=0.032); restricted spinal mobility measured by the Bath Ankylosing Spondylitis Metrology Index (OR=1.94, p=0.009); and younger age (OR=0.85, p=0.013). No clear association was found for human leucocyte antigen-B27 status, presence of peripheral arthritis, enthesitis, uveitis, psoriasis, intake of non-steroidal anti-inflammatory drugs and family history of SpA. The prevalence of gut inflammation in non-radiographic axial SpA and ankylosing spondylitis was comparable. CONCLUSIONS: The prevalence of microscopic gut inflammation in SpA remains unaltered over time. Younger age (shorter symptom duration), progressive disease, male sex and higher disease activity are independently associated with microscopic gut inflammation in axial SpA.

Cigarette smoke and the terminal ileum: increased autophagy in murine follicle-associated epithelium and Peyer's patches.

Cigarette smoke (CS) exposure is associated with increased autophagy in several cell types, such as bronchial epithelial cells. Smoking is also an environmental risk factor in Crohn's disease, in which impairment of the autophagy-mediated anti-bacterial pathway has been implicated. So far, it is unknown whether CS induces autophagy in the gut. Here, we examined the effect of chronic CS exposure on autophagy in the follicle-associated epithelium (FAE) of murine Peyer's patches. Transmission electron microscopy revealed that the proportion of cell area occupied by autophagic vesicles significantly increased in the FAE after CS exposure. An increased number of autophagic vesicles was observed in the FAE, whereas the vesicle size remained unaltered. Besides enterocytes, also M-cells contain more autophagic vesicles upon CS exposure. In addition, the mRNA level of the autophagy-related protein Atg7 in the underlying Peyer's patches is increased after CS exposure, which indicates that the autophagy-inducing effect of CS is not limited to the FAE. In conclusion, our results demonstrate that CS exposure induces autophagy in murine FAE and in the underlying immune cells of Peyer's patches, suggesting that CS exposure increases the risk for Crohn's disease by causing epithelial oxidative damage, which needs to be repaired by autophagy.

Fulminant cryptosporidiosis after near-drowning: a human Cryptosporidium parvum strain implicated in invasive gastrointestinal adenocarcinoma and cholangiocarcinoma in an experimental model.

In the present work, we report the characterization of a Cryptosporidium parvum strain isolated from a patient who nearly drowned in the Deule River (Lille, France) after being discharged from the hospital where he had undergone allogeneic stem cell transplantation. After being rescued and readmitted to the hospital, he developed fulminant cryptosporidiosis. The strain isolated from the patient's stools was identified as C. parvum II2A15G2R1 (subtype linked to zoonotic exposure) and inoculated into SCID mice. In this host, this virulent C. parvum isolate induced not only severe infection but also invasive gastrointestinal and biliary adenocarcinoma. The observation of adenocarcinomas that progressed through all layers of the digestive tract to the subserosa and spread via blood vessels confirmed the invasive nature of the neoplastic process. These results indicate for the first time that a human-derived C. parvum isolate is able to induce digestive cancer. This study is of special interest considering the exposure of a large number of humans and animals to this waterborne protozoan, which is highly tumorigenic when inoculated in a rodent model.

Different types of tissue composition in inflammatory or reparative upper airway disorders.

BACKGROUND: Composition changes of extracellular matrix (ECM) can lead to functional disorders of the upper airways (UA). The aim of this study was to systematically measure both the association patterns and the correlation degree between tissue composition parameters in UA inflammatory diseases. METHODOLOGY: Nasal samples were obtained from patients with chronic rhinosinusitis with (CRS+NP), without nasal polyps (CRS), with post-operative adhesions (S) and normal nasal mucosa (NM). A reproducible semi-quantitative method, which takes epithelial and lamina propria damages into account was applied for haematoxylin and eosin, alpha-smooth muscle actin, reticulin, elastin, laminin and collagen type IV stainings. RESULTS: The most severe cases of epithelial shedding have been found in a significant higher amount in CRS+NP when compared with NM. The most severe cases of inflammatory reaction were mainly found in CRS+NP. CRS+NP had significantly more severe cases of oedema than NM. Excluding elastin, networks in other ECM proteins were found modified in fibrotic fields but to a lesser extend in oedematous regions in all conditions. CONCLUSION: Although non specific, oedema in the lamina propria is a key-feature of CRS+NP, while fibrosis, massively present in CRS and S, affects profoundly the distribution of ECM proteins in these areas.

Cigarette smoking alters epithelial apoptosis and immune composition in murine GALT.

Smokers have a twofold increased risk to develop Crohn's disease (CD). However, little is known about the mechanisms through which smoking affects CD pathogenesis. Especially Crohn's ileitis is negatively influenced by smoking. Interestingly, the ileum and, more in particular, the Peyer's patches in the terminal ileum are also the sites where the first CD lesions are found. Several chemokines are implicated in the pathogenesis, among which is the CCL20-CCR6 pathway. Here, we studied the gut-associated lymphoid tissue in C57BL/6 wild-type mice and in CCR6-deficient mice after exposure to air or cigarette smoke for 24 weeks. Apoptotic index of the follicle-associated epithelium overlying the Peyer's patches was evaluated. We found that chronic smoke exposure induced apoptosis in the follicle-associated epithelium. Furthermore, immune cell numbers and differentiation along with chemokine expression were determined in Peyer's patches. Important changes in immune cell composition were observed: total dendritic cells, CD4+ T cells (including regulatory T cells) and CD8+ T cells increased significantly after smoke exposure. The CD11b+ dendritic cell subset almost doubled. Interestingly, these changes were accompanied by an upregulated mRNA expression of the chemokines CCL9 and CCL20. However, no differences in the increase of dendritic cells were observed between wild-type and CCR6-deficient mice. Our results show that cigarette smoke exposure increases apoptosis in the follicle-associated epithelium and is associated with immune cell accumulation in Peyer's patches.