Nicotinamide phosphoribosyltransferase as a target in inflammation- related disorders.

NAD(+) biosynthesis through nicotinamide phosphoribosyltransferase (NAMPT) holds potential as a target for the treatment of inflammatory disorders due to NAD(+)'s role in immune cell signaling and metabolism. In addition to its activity as an enzyme, NAMPT is also secreted in the extracellular space where it acts as a pro-inflammatory and proangiogenic cytokine. NAMPT inhibition with FK866 has anti-inflammatory activity in different models of immune disorders and it prevents ischemia-reperfusion-induced heart damage by dampening the production of neutrophil chemoattractants. NAMPT blockade with a neutralizing antibody has beneficial effects in an acute lung injury model. Last, but not least, the anticancer activity of NAMPT inhibitors may also reflect, at least in part, their ability to modify the cancer microenvironment through their anti-inflammatory properties. Overall, NAMPT inhibition holds potential for the treatment of inflammation-related disorders and the development of effective and safe NAMPT inhibitors remains an area of strong interest in pharmaceutical research.

Identification and characterization of novel classes of macrophage migration inhibitory factor (MIF) inhibitors with distinct mechanisms of action.

Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, is considered an attractive therapeutic target in multiple inflammatory and autoimmune disorders. In addition to its known biologic activities, MIF can also function as a tautomerase. Several small molecules have been reported to be effective inhibitors of MIF tautomerase activity in vitro. Herein we employed a robust activity-based assay to identify different classes of novel inhibitors of the catalytic and biological activities of MIF. Several novel chemical classes of inhibitors of the catalytic activity of MIF with IC(50) values in the range of 0.2-15.5 microm were identified and validated. The interaction site and mechanism of action of these inhibitors were defined using structure-activity studies and a battery of biochemical and biophysical methods. MIF inhibitors emerging from these studies could be divided into three categories based on their mechanism of action: 1) molecules that covalently modify the catalytic site at the N-terminal proline residue, Pro(1); 2) a novel class of catalytic site inhibitors; and finally 3) molecules that disrupt the trimeric structure of MIF. Importantly, all inhibitors demonstrated total inhibition of MIF-mediated glucocorticoid overriding and AKT phosphorylation, whereas ebselen, a trimer-disrupting inhibitor, additionally acted as a potent hyperagonist in MIF-mediated chemotactic migration. The identification of biologically active compounds with known toxicity, pharmacokinetic properties, and biological activities in vivo should accelerate the development of clinically relevant MIF inhibitors. Furthermore, the diversity of chemical structures and mechanisms of action of our inhibitors makes them ideal mechanistic probes for elucidating the structure-function relationships of MIF and to further determine the role of the oligomerization state and catalytic activity of MIF in regulating the function(s) of MIF in health and disease.

A pipeline approach with spatial information for segmenting multiple sclerosis lesions on brain magnetic resonance imaging

Background: Conventional magnetic resonance imaging (MRI) techniques are highly sensitive to detect multiple sclerosis (MS) plaques, enabling a quantitative assessment of inflammatory activity and lesion load. In quantitative analyses of focal lesions, manual or semi-automated segmentations have been widely used to compute the total number of lesions and the total lesion volume. These techniques, however, are both challenging and time-consuming, being also prone to intra-observer and inter-observer variability.Aim: To develop an automated approach to segment brain tissues and MS lesions from brain MRI images. The goal is to reduce the user interaction and to provide an objective tool that eliminates the inter- and intra-observer variability.Methods: Based on the recent methods developed by Souplet et al. and de Boer et al., we propose a novel pipeline which includes the following steps: bias correction, skull stripping, atlas registration, tissue classification, and lesion segmentation. After the initial pre-processing steps, a MRI scan is automatically segmented into 4 classes: white matter (WM), grey matter (GM), cerebrospinal fluid (CSF) and partial volume. An expectation maximisation method which fits a multivariate Gaussian mixture model to T1-w, T2-w and PD-w images is used for this purpose. Based on the obtained tissue masks and using the estimated GM mean and variance, we apply an intensity threshold to the FLAIR image, which provides the lesion segmentation. With the aim of improving this initial result, spatial information coming from the neighbouring tissue labels is used to refine the final lesion segmentation.Results:The experimental evaluation was performed using real data sets of 1.5T and the corresponding ground truth annotations provided by expert radiologists. The following values were obtained: 64% of true positive (TP) fraction, 80% of false positive (FP) fraction, and an average surface distance of 7.89 mm. The results of our approach were quantitatively compared to our implementations of the works of Souplet et al. and de Boer et al., obtaining higher TP and lower FP values.Conclusion: Promising MS lesion segmentation results have been obtained in terms of TP. However, the high number of FP which is still a well-known problem of all the automated MS lesion segmentation approaches has to be improved in order to use them for the standard clinical practice. Our future work will focus on tackling this issue.

Emerging therapies for gout.

Over the past decade much has been learned about the mechanisms of crystal-induced inflammation and renal excretion of uric acid, which has led to more specific targeting of gout therapies and a more potent approach to future management of gout. This article outlines agents being developed for more aggressive lowering of urate and more specific anti-inflammatory activity. The emerging urate-lowering therapies include lesinurad, arhalofenate, ulodesine, and levotofisopam. Novel gout-specific anti-inflammatories include the interleukin-1β inhibitors anakinra, canakinumab, and rilonacept, the melanocortins, and caspase inhibitors. The historic shortcomings of current gout treatment may, in part, be overcome by these novel approaches.

Postsurgical Prophylaxis in Crohn's Disease: Which Patients, Which Agents?

NlmCategory="UNASSIGNED">Crohn's disease (CD) evolution is characterized by increasing proportions of patients developing complications such as strictures, abscesses and fistulas that require surgical management. After resection of a diseased intestinal segment, CD recurrence concerns up to 60% of patients within a year post surgery. The mucosa just above the site of the intestinal anastomosis is at particularly high risk of relapse. Prophylactic medical therapy to prevent recurrence has been shown to be effective with a variety of medications, but the recurrence rate remains high, demanding that a better risk stratification of patients be achieved. Recognized risk factors for postsurgical CD recurrence include young age at diagnosis and at surgery, smoking, need for repeated surgeries and penetrating disease. These patients require full dose immunosuppressive or anti-tumor necrosis factor (anti-TNF) therapy, which should be initiated in the immediate postoperative period, to prevent the onset of an inflammatory activity in the bowel. Systematic follow-up by endoscopy to monitor treatment benefit should also be part of the management, as endoscopic recurrence heralds clinical relapse in these patients. The role of noninvasive markers of mucosal inflammation, such as stool calprotectin levels, show promise to complete this monitoring. Although the efficacy of mesalazine and imidazole antibiotics has been long recognized, more aggressive approaches, such as thiopurines and anti-TNF antibodies, have shown higher efficacies in direct comparison trials. The potential place of anti-homing agents is not yet defined, but these agents should in principle be of interest for this prophylactic indication due to their mode of action and interesting side-effect profile. The current recommendations are based on a step-up approach that includes immunosuppressors and/or imidazole antibiotics, followed by an anti-TNF agent, such as infliximab and adalimumab, both already tested in randomized trials in this indication. When endoscopic recurrence is identified during follow-up, upscaling to anti-TNF or dose escalation is advocated.

Life-course socioeconomic status and DNA methylation of genes regulating inflammation

BACKGROUND: In humans, low socioeconomic status (SES) across the life course is associated with greater diurnal cortisol production, increased inflammatory activity and higher circulating antibodies for several pathogens, all suggesting a dampened immune response. Recent evidence suggests that DNA methylation of pro-inflammatory genes may be implicated in the biological embedding of the social environment. METHODS: The present study examines the association between life-course SES and DNA methylation of candidate genes, selected on the basis of their involvement in SES-related inflammation, in the context of a genome-wide methylation study. Participants were 857 healthy individuals sampled from the EPIC Italy prospective cohort study. RESULTS: Indicators of SES were associated with DNA methylation of genes involved in inflammation. NFATC1, in particular, was consistently found to be less methylated in individuals with low vs high SES, in a dose-dependent manner. IL1A, GPR132 and genes belonging to the MAPK family were also less methylated among individuals with low SES. In addition, associations were found between SES and CXCL2 and PTGS2, but these genes were consistently more methylated among low SES individuals. CONCLUSIONS: Our findings support the hypothesis that the social environment leaves an epigenetic signature in cells. Although the functional significance of SES-related DNA methylation is still unclear, we hypothesize that it may link SES to chronic disease risk.

The Intestinal Microbiota Contributes to the Ability of Helminths to Modulate Allergic Inflammation.

Intestinal helminths are potent regulators of their host's immune system and can ameliorate inflammatory diseases such as allergic asthma. In the present study we have assessed whether this anti-inflammatory activity was purely intrinsic to helminths, or whether it also involved crosstalk with the local microbiota. We report that chronic infection with the murine helminth Heligmosomoides polygyrus bakeri (Hpb) altered the intestinal habitat, allowing increased short chain fatty acid (SCFA) production. Transfer of the Hpb-modified microbiota alone was sufficient to mediate protection against allergic asthma. The helminth-induced anti-inflammatory cytokine secretion and regulatory T cell suppressor activity that mediated the protection required the G protein-coupled receptor (GPR)-41. A similar alteration in the metabolic potential of intestinal bacterial communities was observed with diverse parasitic and host species, suggesting that this represents an evolutionary conserved mechanism of host-microbe-helminth interactions.

Information seeking activity and adherence to therapy: Findings from the Swiss Inflammatory Bowel Disease Cohort Study

Background: In spite of the relapsing nature of inflammatory bowel diseases (IBD), on average, 40% of IBD patients are nonadherent to treatments. On the other hand, they are often actively seeking information on their disease. The relationship between information seeking behaviour and adherence to treatment is poorly documented. The main aim of this study was to examine this association among IBD patients. Methods: We used data from the Swiss IBD cohort study. Baseline data included questions on adherence to ongoing treatments. A survey was conducted in October 2009 to assess information sources and themes searched by patients. Crude odds ratio (OR) and 95% CI were calculated for the association between adherence and information seeking. Adjustment for potential confounders and main known risk factors was performed using multivariate logistic regression. Differences in the proportions of information sources and themes were compared between adherent and non-adherent patients. Results: The number of patients eligible was 488. Nineteen percent (N = 99) were non-adherent to treatment and one third (N = 159) were active information seekers. Crude OR for being non-adherent was 69% higher among information seekers compared to non-seekers (OR = 1.69; 95%CI 0.99 2.87). Adjusted OR for non-adherence was OR = 2.39 (95%CI 1.32 4.34) for information seekers compared to non-seekers. Family doctors were 15.2% more often consulted (p = 0.019) among patients who were adherent to treatment compared to those who were not, as were books and TV (+13.1%; p = 0.048). No difference was observed for internet or gastroenterologists as sources of information. Themes of information linked to tips for disease management were 14.2% more often searched among non-adherent patients (p = 0.028) compared to adherent. No difference was observed for the other themes (research and development on IBD, therapies, basic information on the disease, patients' experiences sharing, miscellaneous). Conclusions: Active information seeking was shown to be strongly associated with non-adherence to treatment in a population of IBD patients in Switzerland. Surprisingly themes related to therapies were not especially those on which nonadherent patients focused. Indeed, management of symptoms and everyday life with the disease seemed to be the most pressing information concerns of patients. Results suggest that the family doctor plays an important role in the multidisciplinary care approach needed for IBD patients.

Monitoring inflammatory bowel disease activity: clinical activity is judged to be more relevant than endoscopic severity or biomarkers.

BACKGROUND: There is increasing evidence for the clinical relevance of mucosal healing (MH) as therapeutic treatment goal in inflammatory bowel disease (IBD). We aimed to investigate by which method gastroenterologists monitor IBD activity in daily practice. METHODS: A questionnaire was sent to all board-certified gastroenterologists in Switzerland to specifically address their strategy to monitor IBD between May 2009 and April 2010. RESULTS: The response rate was 57% (153/270). Fifty-two percent of gastroenterologists worked in private practice and 48% worked in hospitals. Seventy-eight percent judged clinical activity to be the most relevant criterion for monitoring IBD activity, 15% chose endoscopic severity, and 7% chose biomarkers. Seventy percent of gastroenterologists based their therapeutic decisions on clinical activity, 24% on endoscopic severity, and 6% on biomarkers. The following biomarkers were used for IBD activity monitoring: CRP, 94%; differential blood count, 78%; fecal calprotectin (FC), 74%; iron status, 63%; blood sedimentation rate, 3%; protein electrophoresis, 0.7%; fecal neutrophils, 0.7%; and vitamin B12, 0.7%. Gastroenterologists in hospitals and those with ≤ 10 years of professional experience used FC more frequently compared with colleagues in private practice (P=0.035) and those with > 10 years of experience (P<0.001). CONCLUSIONS: Clinical activity is judged to be more relevant for monitoring IBD activity and guiding therapeutic decisions than endoscopic severity and biomarkers. As such, the accumulating scientific evidence on the clinical impact of mucosal healing does not yet seem to influence the management of IBD in daily gastroenterologic practice.

Pharmacological inhibition of nicotinamide phosphoribosyltransferase/visfatin enzymatic activity identifies a new inflammatory pathway linked to NAD.

Nicotinamide phosphoribosyltransferase (NAMPT), also known as visfatin, is the rate-limiting enzyme in the salvage pathway of NAD biosynthesis from nicotinamide. Since its expression is upregulated during inflammation, NAMPT represents a novel clinical biomarker in acute lung injury, rheumatoid arthritis, and Crohn's disease. However, its role in disease progression remains unknown. We report here that NAMPT is a key player in inflammatory arthritis. Increased expression of NAMPT was confirmed in mice with collagen-induced arthritis, both in serum and in the arthritic paw. Importantly, a specific competitive inhibitor of NAMPT effectively reduced arthritis severity with comparable activity to etanercept, and decreased pro-inflammatory cytokine secretion in affected joints. Moreover, NAMPT inhibition reduced intracellular NAD concentration in inflammatory cells and circulating TNFalpha levels during endotoxemia in mice. In vitro pharmacological inhibition of NAMPT reduced the intracellular concentration of NAD and pro-inflammatory cytokine secretion by inflammatory cells. Thus, NAMPT links NAD metabolism to inflammatory cytokine secretion by leukocytes, and its inhibition might therefore have therapeutic efficacy in immune-mediated inflammatory disorders.

Patients' information-seeking activity is associated with treatment compliance in inflammatory bowel disease patients.

Background. Despite the chronic and relapsing nature of inflammatory bowel diseases (IBD), at least 30% to 45% of the patients are noncompliant to treatment. IBD patients often seek information about their disease. Aim. To examine the association between information-seeking activity and treatment compliance among IBD patients. To compare information sources and concerns between compliant and noncompliant patients. Methods. We used data from the Swiss IBD cohort study, and from a qualitative survey conducted to assess information sources and concerns. Crude and adjusted odds ratios (OR) for noncompliance were calculated. Differences in the proportions of information sources and concerns were compared between compliant and noncompliant patients. Results. A total of 512 patients were included. About 18% (n = 99) of patients were reported to be noncompliant to drug treatment and two-thirds (n = 353) were information seekers. The OR for noncompliance among information seekers was 2.44 (95%CI: 1.34-4.41) after adjustment for confounders and major risk factors. General practitioners were 15.2% more often consulted (p = 0.019) among compliant patients, as were books and television (+13.1%; p = 0.048), whereas no difference in proportions was observed for sources such as internet or gastroenterologists. Information on tips for disease management were 14.2% more often sought among noncompliant patients (p = 0.028). No difference was observed for concerns on research and development on IBD or therapies. Conclusion. In Switzerland, IBD patients noncompliant to treatment were more often seeking disease-related information than compliant patients. Daily management of symptoms and disease seemed to be an important concern of those patients.

How do Swiss Gastroenterologists assess Activity of Inflammatory Bowel Disease in Daily Practice: by Clinical Indices, Endoscopic Activity, or Biomarkers?

Background a nd A ims: There is a n ongoing d ebate which i sthe most appropriate w ay t o measure inflammatory boweldisease (IBD) activity (be it b y clinical i ndices, e ndoscopy, orbiomarkers). Accumulating evidence associates m ucosalhealing with a reduction in I BD-related s urgery andhospitalizations. We a imed to i nvestigate which outcomeparameters are used in daily practice for IBD monitoring.Methods: A q uestionnaire was sent in J uly 2010 t o all boardcertified gastroenterologists in S witzerland to evaluate t heassessment strategy of IBD activity, t he items on whichtherapeutic decisions w ere based upon, and the kind ofbiomarkers used for monitoring IBD activity.Results: Response rate was 57% (153/270). Mean physician'sage was 5 0±9years, mean duration o f gastroenterologicpractice 1 4±8years, 52% of them were working in p rivatepractice a nd 48% in h ospitals. S eventy-eight percent usedclinical activity i ndices as g old standard for IBD activityassessment, followed by 15% choosing endoscopic activity, and7% favouring biomarkers. Gastroenterologists based theirtherapeutic decisions in 70% on clinical activity indices, 24% onendoscopic activity, a nd 6% o n biomarkers. Most frequentlyused biomarkers were C-reactive protein (94%), complete bloodcount (78%) and fecal calprotectin (74%).Conclusions: I n daily p ractice, most IBD patients a remonitored based u pon t heir clinical a ctivity. B iomarkers a reperceived as l ess important compared to clinical andendoscopic activity. S imilar to activity a ssessment, alsotherapeutic decisions a re mostly made on the basis of clinicalactivity indices. The upcoming scientific evidence on the impactof mucosal h ealing does n ot yet seem to influence the dailypractice of gastroenterologists.

Neuroendocrine, metabolic, and immune functions during the acute phase response of inflammatory stress in monosodium L-glutamate-damaged, hyperadipose male rat.

In rats, neonatal treatment with monosodium L-glutamate (MSG) induces several metabolic and neuroendocrine abnormalities, which result in hyperadiposity. No data exist, however, regarding neuroendocrine, immune and metabolic responses to acute endotoxemia in the MSG-damaged rat. We studied the consequences of MSG treatment during the acute phase response of inflammatory stress. Neonatal male rats were treated with MSG or vehicle (controls, CTR) and studied at age 90 days. Pituitary, adrenal, adipo-insular axis, immune, metabolic and gonadal functions were explored before and up to 5 h after single sub-lethal i.p. injection of bacterial lipopolysaccharide (LPS; 150 microg/kg). Our results showed that, during the acute phase response of inflammatory stress in MSG rats: (1) the corticotrope-adrenal, leptin, insulin and triglyceride responses were higher than in CTR rats, (2) pro-inflammatory (TNFalpha) cytokine response was impaired and anti-inflammatory (IL-10) cytokine response was normal, and (3) changes in peripheral estradiol and testosterone levels after LPS varied as in CTR rats. These data indicate that metabolic and neroendocrine-immune functions are altered in MSG-damaged rats. Our study also suggests that the enhanced corticotrope-corticoadrenal activity in MSG animals could be responsible, at least in part, for the immune and metabolic derangements characterizing hypothalamic obesity.