Myeloid cell influx into the colonic epithelium is associated with disease severity and non-response to anti-Tumor Necrosis Factor Therapy in patients with Ulcerative Colitis.

Ulcerative colitis (UC) is an idiopathic chronic inflammatory disease of the colon with sharply rising global prevalence. Dysfunctional epithelial compartment (EC) dynamics are implicated in UC pathogenesis although EC-specific studies are sparse. Applying orthogonal high-dimensional EC profiling to a Primary Cohort (PC; n=222), we detail major epithelial and immune cell perturbations in active UC. Prominently, reduced frequencies of mature BEST4+OTOP2+ absorptive and BEST2+WFDC2+ secretory epithelial enterocytes were associated with the replacement of homeostatic, resident TRDC+KLRD1+HOPX+ γδ+ T cells with RORA+CCL20+S100A4+ TH17 cells and the influx of inflammatory myeloid cells. The EC transcriptome (exemplified by S100A8, HIF1A, TREM1, CXCR1) correlated with clinical, endoscopic, and histological severity of UC in an independent validation cohort (n=649). Furthermore, therapeutic relevance of the observed cellular and transcriptomic changes was investigated in 3 additional published UC cohorts (n=23, 48 and 204 respectively) to reveal that non-response to anti-Tumor Necrosis Factor (anti-TNF) therapy was associated with EC related myeloid cell perturbations. Altogether, these data provide high resolution mapping of the EC to facilitate therapeutic decision-making and personalization of therapy in patients with UC.

Endoscopic submucosal dissection for colorectal dysplasia in inflammatory bowel disease: a US multicenter study.

Background and study aims In patients with inflammatory bowel disease (IBD), endoscopically visible lesions with distinct borders can be considered for endoscopic resection. The role of endoscopic submucosal dissection (ESD) for these lesions is not well defined because of a paucity of data. We aimed to evaluate the outcomes of colorectal ESD of dysplastic lesions in patients with IBD across centers in the United States. Patients and methods This was a retrospective analysis of consecutive patients with IBD who were referred for ESD of dysplastic colorectal lesions at nine centers. The primary endpoints were the rates of en bloc resection and complete (R0) resection. The secondary endpoints were the rates of adverse events and lesion recurrence. Results A total of 45 dysplastic lesions (median size 30mm, interquartile range [IQR] 23 to 42 mm) in 41 patients were included. Submucosal fibrosis was observed in 73 %. En bloc resection was achieved in 43 of 45 lesions (96 %) and R0 resection in 34 of 45 lesions (76 %). Intraprocedural perforation occurred in one patient (2.4 %) and was treated successfully with clip placement. Delayed bleeding occurred in four patients (9.8 %). No severe intraprocedural bleeding or delayed perforation occurred. During a median follow-up of 18 months (IQR 13 to 37 months), local recurrence occurred in one case (2.6 %). Metachronous lesions were identified in 11 patients (31 %). Conclusions ESD, when performed by experts, is safe and effective for large, dysplastic colorectal lesions in patients with IBD. Despite the high prevalence of submucosal fibrosis, en bloc resection was achieved in nearly all patients with IBD undergoing ESD. Careful endoscopic surveillance is necessary to monitor for local recurrence and metachronous lesions after ESD.

Improved Smoking Cessation Rates in a Pharmacist-Led Program Embedded in an Inflammatory Bowel Disease Specialty Medical Home.

BACKGROUND: Cigarette smoking is associated with disease progression, poor outcomes, and increased biologic use in Crohn's Disease (CD). In this prospective study, we describe the structure and results of a pharmacist-driven smoking cessation program in an Inflammatory Bowel Disease (IBD) Specialty Medical Home. METHODS: One pharmacist designed and implemented a collaborative drug therapy management (CDTM) program, which allowed the pharmacist to initiate and modify smoking cessation aids, monitor medication safety and efficacy, and provide behavioral counseling. Crohn's Disease patients who were current smokers and referred to the program were analyzed. Clinical and demographic data, disease activity, and smoking history were collected. The primary outcome was the proportion of patients in the enrolled group and the declined group who quit smoking at least once during the follow-up period. Secondary outcomes include demographic and clinical differences between enrolled and declined patients, and enrolled quitters and non-quitters. RESULTS: Thirty-two patients were referred to the program and 19 participated. Over a median follow-up period of 305 [264-499] days, 42% (8/19) of enrolled patients quit smoking at least once. Fifteen percent (2/13) of declined patients quit smoking. Patients who continued to smoke had more instances of loss of response to a biologic, need to start a new biologic, or escalation of biologic therapy. The CDTM pharmacist was able to provide all necessary clinical services for smokers enrolled in the program. CONCLUSIONS: A pharmacist-led smoking cessation program in a specialty medical home is feasible. It may result in successful quit attempts and may optimize IBD medication use.

Exclusivity and Compensation in NFκB Dimer Distributions and IκB Inhibition.

The NFκB transcription factor family members RelA, p50, and cRel form homo- and heterodimers that are inhibited by IκBα, IκBß, and IκBε. These NFκB family members have diverse biological functions, and their expression profiles differ, leading to different concentrations in different tissue types. Here we present definitive biophysical measurements of the NFκB dimer affinities and inhibitor affinities to better understand dimer exchange and how the presence of inhibitors may alter the equilibrium concentrations of NFκB dimers in the cellular context. Fluorescence anisotropy binding experiments were performed at low concentrations to mimic intracellular concentrations. We report binding affinities much stronger than those that had been previously reported by non-equilibrium gel shift and analytical ultracentrifugation assays. The results reveal a wide range of NFκB dimer affinities and a strong preference of each IκB for a small subset of NFκB dimers. Once the preferred IκB is bound, dimer exchange no longer occurs over a period of days. A mathematical model of the cellular distribution of these canonical NFκB transcription factors based on the revised binding affinities recapitulates intracellular observations and provides simple, precise explanations for observed cellular phenomena.

Assessment of confined space entry and rescue training for aircraft rescue and fire fighting (ARFF) members in the United States.

INTRODUCTION: Fire and emergency service workers, including Aircraft Rescue and Fire Fighting members, may be called on to perform confined space entry and rescue operations. The purpose of the present study was to develop a comprehensive and valid understanding of the present state of confined space entry and rescue training effectiveness and resultant compliance or use of best practices among trained Aircraft Rescue and Fire Fighting personnel. METHOD: The study used a convergent, parallel mixed-methods approach. Qualitative data (n = 20) were collected via semi-structured interviews at four locations. Data were coded, analyzed and super-ordinate and sub-ordinate themes were derived. Quantitative data (n = 158) from Aircraft Rescue and Fire Fighting members were analyzed. RESULTS: Interviewees believed there is a lack of standardization in training, but believed training should not be completed in the same format every time. Several participants (50%) desired more realistic training. Other concerns were associated with staffing, personal readiness, and resource adequacy. With regard to survey outcomes, most respondents reported that their organizations completed confined space training (69.8%), but only 55.3% indicated this training was conducted as a full-scale exercise and nearly 40% indicated that rescue practice was not performed despite standards mandating annual rescue practice. Following training, 55.4% indicated training evaluation information was not presented. CONCLUSIONS: Participants mostly agreed their training effectively addressed OSHA requirements, such as how to test the atmosphere, the need for and use of personal protective equipment, how to identify pertinent permit information and methods to retrieve victims in limited space. Some gaps exist between current training practices and established training requirements and standards. PRACTICAL APPLICATIONS: Aircraft Rescue and Fire Fighting organizations need to bolster aspects of their training, particularly with regard to standardizing training efforts, practicing rescues, providing evaluation feedback and written materials and providing adequate resources.

Suppressor of IKKepsilon forms direct interactions with cytoskeletal proteins, tubulin and α-actinin, linking innate immunity to the cytoskeleton.

Suppressor of IKKepsilon (SIKE) is associated with the type I interferon response of the innate immune system through TANK-binding kinase 1 (TBK1). Originally characterized as an endogenous inhibitor of TBK1 when overexpressed in viral infection and pathological cardiac hypertrophic models, a mechanistic study revealed that SIKE acts as a high-affinity substrate of TBK1, but its function remains unknown. In this work, we report that scratch assay analysis of parental and SIKE CRISPR/Cas9 knockout HAP1 cells showed an ~ 20% decrease in cell migration. Investigation of the SIKE interaction network through affinity purification/mass spectrometry showed that SIKE formed interactions with cytoskeletal proteins. In immunofluorescence assays, endogenous SIKE localized to cytosolic puncta in both epithelial and myeloid cells and to nuclear puncta in myeloid cells, while in epithelial cells additional staining occurred in stress fiber-like structures and adjacent to the plasma membrane. Using cellular markers, co-occurrence of SIKE fluorescence with actin, α-actinin, and ezrin was detected. Reciprocal immunoprecipitation revealed a SIKE:tubulin interaction sensitive to the phosphorylation state of SIKE, but a SIKE:α-actinin interaction was unchanged by SIKE phosphorylation. In vitro precipitation assays confirmed a direct SIKE interaction with tubulin and α-actinin. These results indicate that SIKE may promote cell migration by directly associating with the cytoskeleton. In this role, SIKE may mediate cytoskeletal rearrangement necessary in innate immunity, but also link a key catalytic hub, TBK1, to the cytoskeleton. DATABASE: The mass spectrometry proteomics data have been deposited to the ProteomeXchange Consortium via the PRIDE [1] partner repository with the dataset identifier PXD007262.

Cyclic-di-GMP binding induces structural rearrangements in the PlzA and PlzC proteins of the Lyme disease and relapsing fever spirochetes: a possible switch mechanism for c-di-GMP-mediated effector functions.

The c-di-GMP network of Borrelia burgdorferi, a causative agent of Lyme disease, consists of Rrp1, a diguanylate cyclase/response regulator; Hpk1, a histidine kinase; PdeA and PdeB, c-di-GMP phosphodiesterases; and PlzA, a PilZ domain c-di-GMP receptor. Borrelia hermsii, a causative agent of tick-borne relapsing fever, possesses a putative c-di-GMP regulatory network that is uncharacterized. While B. burgdorferi requires c-di-GMP to survive within ticks, the associated effector mechanisms are poorly defined. Using site-directed mutagenesis, size exclusion chromatography, isothermal titration calorimetry and fluorescence resonance energy transfer, we investigate the interaction of c-di-GMP with the Borrelia PilZ domain-containing Plz proteins: B. burgdorferi PlzA and B. hermsii PlzC. The Plz proteins were determined to be monomeric in their apo and holo forms and to bind c-di-GMP with high affinity with a 1:1 stoichiometry. C-di-GMP binding induced structural rearrangements in PlzA and PlzC. C-di-GMP binding proved to be dependent on positive charge at R145 of the PilZ domain motif, R145xxxR. Comparative sequence analyses led to the identification of Borrelia consensus sequences for the PilZ domain signature motifs. This study provides insight into c-di-GMP:Plz receptor interaction and identifies a possible switch mechanism that may regulate Plz protein effector functions.

Chromoendoscopy Is More Effective Than Standard Colonoscopy in Detecting Dysplasia During Long-term Surveillance of Patients With Colitis.

BACKGROUND & AIMS: Patients with colitis have an increased risk of colorectal cancer, compared with persons without colitis. Many studies have shown chromoendoscopy (CE) to be superior to standard methods of detecting dysplasia in patients with colitis at index examination. We performed a prospective, longitudinal study to compare standard colonoscopy vs CE in detecting dysplasia in patients with inflammatory bowel diseases in a surveillance program. METHODS: We analyzed data from 68 patients (44 men, 24 women) diagnosed with ulcerative colitis (n = 55) or Crohn's disease (n = 13) at Mount Sinai Medical Center from September 2005 through October 2011. The patients were followed from June 2006 through October 2011 (median, 27.8 months); each patient was analyzed by random biopsy, targeted white light examination (WLE), and CE. Specimens were reviewed by a single blinded pathologist. The 3 methods were compared by using the generalized estimating equations method, and the odds ratios (ORs) for detection of dysplasia were calculated (primary outcome). Time to colectomy was analyzed by using the Cox model. RESULTS: In the 208 examinations conducted, 44 dysplastic lesions were identified in 24 patients; 6 were detected by random biopsy, 11 by WLE, and 27 by CE. Ten patients were referred for colectomy, and no carcinomas were found. At any time during the study period, CE (OR, 5.4; 95% confidence interval [CI], 2.9-9.9) and targeted WLE (OR, 2.3; 95% CI, 1.0-5.3) were more likely than random biopsy analysis to detect dysplasia. CE was superior to WLE (OR, 2.4; 95% CI, 1.4-4.0). Patients identified as positive for dysplasia were more likely to need colectomy (hazard ratio, 12.1; 95% CI, 3.2-46.2). CONCLUSIONS: In a prospective study of 68 patients with inflammatory bowel diseases, CE was superior to random biopsy or WLE analyses in detecting dysplasia in patients with colitis during an almost 28-month period. A negative result from CE examination was the best indicator of a dysplasia-free outcome, whereas a positive result was associated with earlier referral for colectomy.

Colorectal cancer in colitis: a relic of the past?

The incidence of dysplasia and colorectal cancer in patients with long-standing colitis seems to be decreasing and controversy surrounds our detection and management strategies. Dysplasia is rarer, flatter, and smaller than in previous decades. Current surveillance guidelines, onerous in terms of colonoscopic workload and an emphasis on random biopsies, have yet to be shown to prevent colon cancers and colon cancer death in these patients. The evidence base for adjunct techniques such as chromoendoscopy is strong but adoption has been slow. We need to better risk-stratify patients with colitis and direct diminishing medical resources accordingly. Modulating dysplasia and cancer risk will involve optimizing medical therapies and focusing our colonoscopic efforts on those who will most likely benefit.

Surveillance in inflammatory bowel disease: chromoendoscopy and digital mucosal enhancement.

Patients with long-standing inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer. Performing periodic dysplasia screening and surveillance may diminish this risk. To date, chromoendoscopy is the only technique that has consistently yielded positive results in large, well-designed dysplasia-detection trials. Most major society guidelines endorse chromoendoscopy as an adjunct, accepted, or preferred dysplasia-detection tool. This review outlines the available endoscopic technologies for the detection of dysplasia in IBD, considers the evidence supporting their use, and assesses which modalities are ready for use in clinical practice.

Mechanism of endogenous regulation of the type I interferon response by suppressor of IκB kinase epsilon (SIKE), a novel substrate of TANK-binding kinase 1 (TBK1).

TANK-binding kinase 1 (TBK1) serves as a key convergence point in multiple innate immune signaling pathways. In response to receptor-mediated pathogen detection, TBK1 phosphorylation promotes production of pro-inflammatory cytokines and type I interferons. Increasingly, TBK1 dysregulation has been linked to autoimmune disorders and cancers, heightening the need to understand the regulatory controls of TBK1 activity. Here, we describe the mechanism by which suppressor of IKKε (SIKE) inhibits TBK1-mediated phosphorylation of interferon regulatory factor 3 (IRF3), which is essential to type I interferon production. Kinetic analyses showed that SIKE not only inhibits IRF3 phosphorylation but is also a high affinity TBK1 substrate. With respect to IRF3 phosphorylation, SIKE functioned as a mixed-type inhibitor (K(i, app) = 350 nM) rather than, given its status as a TBK1 substrate, as a competitive inhibitor. TBK1 phosphorylation of IRF3 and SIKE displayed negative cooperativity. Both substrates shared a similar Km value at low substrate concentrations (∼50 nM) but deviated >8-fold at higher substrate concentrations (IRF3 = 3.5 µM; SIKE = 0.4 µM). TBK1-SIKE interactions were modulated by SIKE phosphorylation, clustered in the C-terminal portion of SIKE (Ser-133, -185, -187, -188, -190, and -198). These sites exhibited striking homology to the phosphorylation motif of IRF3. Mutagenic probing revealed that phosphorylation of Ser-185 controlled TBK1-SIKE interactions. Taken together, our studies demonstrate for the first time that SIKE functions as a TBK1 substrate and inhibits TBK1-mediated IRF3 phosphorylation by forming a high affinity TBK1-SIKE complex. These findings provide key insights into the endogenous control of a critical catalytic hub that is achieved not by direct repression of activity but by redirection of catalysis through substrate affinity.

The effect of intravenous cyclosporine on rates of colonic surgery in hospitalized patients with severe Crohn's colitis.

BACKGROUND: The role of intravenous (IV) cyclosporine in severe Crohn's colitis (CC) is poorly studied. AIM: Our primary aim was to determine the in-hospital colonic resection rate in patients with severe CC who received IV cyclosporine, and the potential predictors of resection among these patients. METHODS: An inpatient pharmacy query of all patients who received IV cyclosporine at Mount Sinai Medical Center for 12.5 years after January 1, 1996 was reviewed. Patients with CC or indeterminate colitis favoring Crohn's were included and their medical records were reviewed. Subsequent need for colonic surgery was assessed. A Kaplan-Meier plot with log-rank testing was performed to determine the rate of colonic surgery avoidance. Forward stepwise logistic regression was performed to determine independent predictors of surgery. RESULTS: Forty-eight patients met our inclusion criteria. Prior thiopurine and anti-tumor necrosis factor (anti-TNF) use was 85% and 69%, respectively. The median follow-up time was 12 months (range, 1 to 60 mo). 12.5% of patients required colonic resection during their admission for IV cyclosporine. Anti-TNF use in the 4 weeks preceding IV cyclosporine was the only predictor of surgery in this setting (P=0.05). The cumulative colonic surgery avoidance rate was 72±13% at 6 months and 59±15% at 12 months. CONCLUSIONS: The use of IV cyclosporine resulted in a low rate of in-hospitalization colonic surgery among CC patients with severe disease, the majority of whom previously failed anti-TNFs and thiopurines.

Lateral clustering of TLR3:dsRNA signaling units revealed by TLR3ecd:3Fabs quaternary structure.

Toll-like receptor 3 (TLR3) recognizes dsRNA and initiates an innate immune response through the formation of a signaling unit (SU) composed of one double-stranded RNA (dsRNA) and two TLR3 molecules. We report the crystal structure of human TLR3 ectodomain (TLR3ecd) in a quaternary complex with three neutralizing Fab fragments. Fab15 binds an epitope that overlaps the C-terminal dsRNA binding site and, in biochemical assays, blocks the interaction of TLR3ecd with dsRNA, thus directly antagonizing TLR3 signaling through inhibition of SU formation. In contrast, Fab12 and Fab1068 bind TLR3ecd at sites distinct from the N- and C-terminal regions that interact with dsRNA and do not inhibit minimal SU formation with short dsRNA. Molecular modeling based on the co-structure rationalizes these observations by showing that both Fab12 and Fab1068 prevent lateral clustering of SUs along the length of the dsRNA ligand. This model is further supported by cell-based assay results using dsRNA ligands of lengths that support single and multiple SUs. Thus, their antagonism of TLR3 signaling indicates that lateral clustering of SUs is required for TLR3 signal transduction.

Innate immune agonist, dsRNA, induces apoptosis in ovarian cancer cells and enhances the potency of cytotoxic chemotherapeutics.

Ovarian cancer is the most lethal gynecological cancer. Here we show that innate immune agonist, dsRNA, directly induces ovarian cancer cell death and identify biomarkers associated with responsiveness to this targeted treatment. Nuclear staining and MTT assays following dsRNA stimulation revealed two subpopulations, sensitive (OVCAR-3, CAOV-3; patient samples malignant 1 and 2) and resistant (DOV-13, SKOV-3). Microarray analysis identified 75 genes with differential expression that further delineated these two subpopulations. qPCR and immunoblot analyses showed increased dsRNA receptor expression after stimulation as compared to resistant and immortalized ovarian surface epithelial cells (e.g., 70-fold with malignant 2, 43-fold with OVCAR-3). Using agonists, antagonists, and shRNA-mediated knockdown of dsRNA receptors, we show that TLR3, RIG-I, and mda5 coordinated a caspase 8/9- and interferon-dependent cell death. In resistant cells, dsRNA receptor overexpression restored dsRNA sensitivity. When dsRNA was combined with carboplatin or paclitaxel, cell viability significantly decreased over individual treatments (1.5- to 7.5-fold). Isobologram analyses showed synergism in dsRNA combinations (CI=0.4-0.82) vs. an additive effect in carboplatin/paclitaxel treatment (CI=1.5-2). Our data identify a predictive marker, dsRNA receptor expression, to target dsRNA responsive populations and show that, in dsRNA-sensitive cells, dsRNA induces apoptosis and enhances the potency of cytotoxic chemotherapeutics.

Measuring the effect of ligand binding on the interface stability of multimeric proteins using dynamic light scattering.

We have demonstrated that an approach using guanidine hydrochloride at low concentrations to progressively disrupt protein-protein interactions can be quantitated using dynamic light scattering. This approach is sensitive enough to detect ligand-induced changes of subunit-subunit interactions for homo-hexameric glutamate dehydrogenase, allowing ΔΔG of reversible subunit dissociation to be calculated. The use of dynamic light scattering makes this approach generally applicable to soluble proteins to monitor the relative strength of protein-protein interactions with a particular emphasis on assessing the impact of ligand binding on such interfaces.

Once-daily dosing of delayed-release oral mesalamine (400-mg tablet) is as effective as twice-daily dosing for maintenance of remission of ulcerative colitis.

BACKGROUND & AIMS: The practice of dosing mesalamines in divided doses for the treatment of ulcerative colitis (UC) began with sulfasalazine and was driven by sulfapyridine toxicity. This convention and the assumption that dosing multiple times a day is necessary to treat UC had not been challenged until recently. This study was conducted to determine the efficacy and safety of once-daily dosing of delayed-release mesalamine (Asacol 400-mg tablets) compared with twice-daily dosing for maintaining remission in UC patients. METHODS: A multicenter, randomized, investigator-blinded, 12-month, active-control trial was conducted to assess the noninferiority of delayed-release mesalamine 1.6-2.4 g/day administered once daily compared with twice daily in patients with mild-to-moderate UC currently in clinical remission. The primary end point was maintenance of clinical remission at month 6. RESULTS: A total of 1023 patients were randomized and dosed. The primary objective of noninferiority was met. At month 6, 90.5% of patients receiving once-daily dosing had maintained clinical remission, compared with 91.8% of patients receiving twice-daily dosing (95% confidence interval for twice daily - once daily, -2.3 to 4.9). At month 12, 85.4% of patients receiving once-daily dosing had maintained clinical remission, compared with 85.4% of patients receiving twice-daily dosing (95% confidence interval for twice daily - once daily, -4.6 to 4.7). Both regimens had low rates of withdrawals as a result of adverse events and serious adverse events. CONCLUSIONS: Once-daily dosing of delayed-release mesalamine at doses of 1.6-2.4 g/day was shown to be as effective as twice-daily dosing for maintenance of clinical remission in patients with UC.