TNF promoter hypomethylation is associated with mucosal inflammation in IBD and anti-TNF response.

Background and aims: Inflammatory Bowel Diseases (IBD) are chronic inflammatory conditions influenced heavily by environmental factors. DNA methylation is a form of epigenetic regulation linking environmental stimuli to gene expression changes and inflammation. Here, we investigated how DNA methylation of the TNF promoter differs between inflamed and uninflamed mucosa of IBD patients, including anti-TNF responders and non-responders. Methods: We obtained mucosal biopsies from 200 participants (133 IBD and 67 controls) and analyzed TNF promoter methylation using bisulfite sequencing, comparing inflamed with uninflamed segments, in addition to paired inflamed/uninflamed samples from individual patients. We conducted similar analyses on purified intestinal epithelial cells from bowel resections. We also compared TNF methylation levels of inflamed and uninflamed mucosa from a separate cohort of 15 anti-TNF responders and 17 non-responders. Finally, we sequenced DNA methyltransferase genes to identify rare variants in IBD patients and functionally tested them using rescue experiments in a zebrafish genetic model of DNA methylation deficiency. Results: TNF promoter methylation levels were decreased in inflamed mucosa of IBD patients and correlated with disease severity. Isolated IECs from inflamed tissue showed proportional decreases in TNF methylation. Anti-TNF non-responders showed lower levels of TNF methylation than responders in uninflamed mucosa. Our sequencing analysis revealed two missense variants in DNMT1, one of which had reduced function in vivo. Conclusions: Our study reveals an association of TNF promoter hypomethylation with mucosal inflammation, suggesting that IBD patients may be particularly sensitive to inflammatory environmental insults affecting DNA methylation. Together, our analyses indicate that TNF promoter methylation analysis may aid in the characterization of IBD status and evaluation of anti-TNF therapy response.

A mechanistic biomarker investigation of fialuridine hepatotoxicity using the chimeric TK-NOG Hu-liver mouse model and in vitro micropatterned hepatocyte cocultures.

Fialuridine (FIAU) is a nucleoside-based drug that caused liver failure and deaths in a human clinical trial that were not predicted by nonclinical safety studies. A recent report concluded that a TK-NOG humanized liver (hu-liver) mouse model detected human-specific FIAU liver toxicity, and broader use of that model could improve drug safety testing. We further evaluated this model at similar dose levels to assess FIAU sensitivity and potential mechanistic biomarkers. Although we were unable to reproduce the marked acute liver toxicity with two separate studies (including one with a "sensitized" donor), we identified molecular biomarkers reflecting the early stages of FIAU mitochondrial toxicity, which were not seen with its stereoisomer (FIRU). Dose dependent FIAU-induced changes in hu-liver mice included more pronounced reductions in mitochondrial to nuclear DNA (mtDNA/nucDNA) ratios in human hepatocytes compared to mouse hepatocytes and kidneys of the same animals. FIAU treatment also triggered a p53 transcriptional response and opposing changes in transcripts of nuclear- and mitochondrial-encoded mitochondrial proteins. The time dependent accumulation of FIAU into mtDNA is consistent with the ≥9-week latency of liver toxicity observed for FIAU in the clinic. Similar changes were observed in an in vitro micro-patterned hepatocyte coculture system. In addition, FIAU-dependent mtDNA/nucDNA ratio and transcriptional alterations, especially reductions in mitochondrially encoded transcripts, were seen in livers of non-engrafted TK-NOG and CD-1 mice dosed for a shorter period. Conclusion: These mechanistic biomarker findings can be leveraged in an in vitro model and in a more routine preclinical model (CD-1 mice) to identify nucleosides with such a FIAU-like mitochondrial toxicity mechanistic liability potential. Further optimization of the TK-NOG hu-liver mouse model is necessary before broader adoption for drug safety testing.

Increased activity of MAPKAPK2 within mesenchymal cells as a target for inflammation associated fibrosis in Crohn's Disease.

BACKGROUND: Mesenchymal stromal cells are suggested to play a critical role in the Crohn's Disease (CD) associated fibrosis. MAPKAPK2 (MK2) has emerged as a potential therapeutic target to reduce inflammation in CD. However, cell-specific pattern of pMK2 activation and its role in the CD associated fibrosis are unknown. The objectives of this study were to evaluate cell-specific changes in MK2 activity between predominantly inflammatory CD versus CD with fibrotic complication and define the role of stromal cell-specific MK2 activation in CD-associated fibrosis. METHODS: CD tissue, CD tissue derived mesenchymal stromal cells known as myo-/fibroblasts (CD-MFs), fibroblast specific MK2 conditional KO mice were used. RESULTS: We observed that in the inflamed area of predominantly inflammatory CD, high MK2 activity was equally distributed between mesenchymal and hematopoietic cells. By contrast, in CD with fibrotic complications, high MK2 activity was mostly associated with mesenchymal stromal cells. Using ex vivo CD tissue explants and IL-10KO murine colitis model, we demonstrated that pro-fibrotic responses are significantly reduced by treatment with the MK2 inhibitor PF-3644022. Inhibition of MK2 activity in primary cultures of CD-MFs significantly reduced basal and TGF-ß1-induced profibrotic responses. Using fibroblast-specific MK2 knockout mice in chronic DSS colitis, we demonstrated that fibroblast intrinsic MK2 signaling is among the key processes involved in the chronic inflammation induced profibrotic responses. CONCLUSIONS: Our data suggest that activation of MK2 within fibroblasts contributes to the chronic inflammation induced fibrosis in CD and that targeting MK2 has potential for the development of novel therapeutic approaches for fibrosis in CD.

Vedolizumab, Adalimumab, and Methotrexate Combination Therapy in Crohn's Disease (EXPLORER).

BACKGROUND & AIMS: Although biologics have revolutionized the treatment of Crohn's disease (CD), an efficacy ceiling has been reached. Combining biologic therapies may improve remission rates. METHODS: EXPLORER, a phase 4, single-arm, open-label study, evaluated triple combination therapy with vedolizumab (300 mg on day 1, weeks 2 and 6, and then every 8 weeks), adalimumab (160 mg on day 2, 80 mg at week 2, then 40 mg every 2 weeks), and methotrexate (15 mg weekly) in biologic-naïve patients with newly diagnosed, moderate- to high-risk CD. Endoscopic remission at week 26 (primary end point; Simple Endoscopic Score for CD ≤2), clinical remission at weeks 10 and 26 (secondary end point; Crohn's Disease Activity Index <150), and incidences of adverse events and serious adverse events were evaluated. RESULTS: Among 55 enrolled patients, the mean CD duration was 0.4 years, the mean baseline Simple Endoscopic Score for CD was 12.6, and the mean baseline Crohn's Disease Activity Index was 265.5. At week 26, 19 patients (34.5%) were in endoscopic remission. At weeks 10 and 26, 34 (61.8%) and 30 patients (54.5%), respectively, were in clinical remission. Post hoc Bayesian analysis showed that the probabilities that triple combination therapy produced a higher endoscopic remission rate (33.5%; 95% credible interval, 22.4-45.7) than placebo (14%), vedolizumab monotherapy (27%), or adalimumab monotherapy (30%) were 99.9% or higher, 86.3%, and 71.4%, respectively. Six patients had serious adverse events. CONCLUSIONS: Combination therapy resulted in endoscopic and clinical remission at week 26 in 34.5% and 54.5% of patients, respectively, with no safety signal related to the treatment regimen. This supports further evaluation of combination therapy in CD. CLINICALTRIALS: gov number: NCT02764762.

Incidence of retained biopsy specimens after esophagogastroduodenoscopy and colonoscopy.

Background and study aims In gastrointestinal endoscopy, biopsies must transit through the accessory channel and cap, presenting an opportunity for loss of tissue. We sought to determine the incidence of specimen retention in the accessory channel or cap and identify procedure characteristics associated with specimen retention. Patients and methods After completion of standard endoscopic procedures in which biopsies were obtained, the biopsy cap and accessory channel were inspected, brushed, and irrigated for any retained biopsy specimens according to a standard protocol. For controls, the same protocol was applied to procedures in which biopsies were not obtained. Specimen bottles from the recovery protocol were sent for pathological examination regardless of whether any visible tissue was present. Results A total of 216 outpatient procedures were included: 55 esophagogastroduodenoscopies (EGDs) and 50 colonoscopies in which biopsies were obtained and 56 EGDs and 55 colonoscopies in the control group. Retained specimens were found in either the cap or channel in 50 of 105 (48%). In 20 of 105 (19%), retained specimens were found just in the cap, in six of 105 (5.7%), retained specimens were found just in the channel, while in 24 of 105 (23%), retained specimens were found in both the cap and channel. Retained specimens were more likely to be found in EGDs compared to colonoscopies (58% vs. 36%, P = 0.031). No retained specimens were found in the control group. Conclusions Retained specimens are startingly common in standard gastrointestinal endoscopic procedures and could potentially change diagnoses and management. Quality improvement measures should be instituted to monitor prevalence of retained biopsies and methods to prevent them should be developed.

Etrolizumab as induction and maintenance therapy in patients with moderately to severely active Crohn's disease (BERGAMOT): a randomised, placebo-controlled, double-blind, phase 3 trial.

BACKGROUND: Etrolizumab is a gut-targeted anti-ß7 monoclonal antibody targeting α4ß7 and αEß7 integrins. We aimed to compare the safety and efficacy of two doses of etrolizumab with placebo in patients with Crohn's disease. METHODS: BERGAMOT was a randomised, placebo-controlled, double-blind, phase 3 study done at 326 treatment centres worldwide. We included patients aged 18-80 years with moderately to severely active Crohn's disease (Crohn's Disease Activity Index [CDAI] score of 220-480, and a mean daily stool frequency score of ≥6 or a mean daily stool frequency score of >3, and a mean daily abdominal pain score of >1, as well as the presence of active inflammation on screening ileocolonoscopy) who had intolerance, inadequate response, or no response to one or more of corticosteroids, immunosuppressants, or anti-TNF therapy within the past 5 years. BERGAMOT consisted of three induction cohorts (a placebo-controlled, double-blind exploratory cohort [cohort 1]; an active treatment cohort not containing a placebo control [cohort 2]; and a placebo-controlled, double-blind pivotal cohort [cohort 3]) and one maintenance cohort. In induction cohort 3, during the 14-week induction, patients were randomly assigned (2:3:3) to receive matched placebo, 105 mg etrolizumab subcutaneously every 4 weeks (at weeks 0, 4, 8, and 12) or 210 mg etrolizumab subcutaneously (at weeks 0, 2, 4, 8, and 12), stratified by concomitant treatment with oral corticosteroids, concomitant treatment with immunosuppressants, baseline disease activity, and previous exposure to anti-TNF therapy. To preserve masking, all patients received two injections at weeks 0, 4, 8, and 12 and one injection at week 2. Week 14 etrolizumab responders from all cohorts were re-randomly assigned (1:1) to receive 105 mg etrolizumab (etrolizumab maintenance group) or placebo (placebo maintenance group) every 4 weeks for 52 weeks; patients in the induction placebo group underwent a sham re-randomisation to preserve masking. During maintenance, randomisation was stratified by CDAI remission status, concomitant treatment with oral corticosteroids, induction dose regimen, and previous exposure to anti-TNF therapy. All participants and study site personnel were masked to treatment assignment for both induction and maintenance. Co-primary induction endpoints at week 14 (placebo vs 210 mg etrolizumab) were clinical remission (mean stool frequency ≤3 and mean abdominal pain ≤1, with no worsening) and endoscopic improvement (≥50% reduction in Simple Endoscopic Score for Crohn's Disease [SES-CD]). Co-primary maintenance endpoints at week 66 (placebo vs etrolizumab) were clinical remission and endoscopic improvement. Efficacy was analysed using a modified intention-to-treat (mITT) population, defined as all randomised patients who received at least one dose of study drug (induction) and as all patients re-randomised into maintenance who received at least one dose of study drug in the maintenance phase (maintenance). Safety analyses included all patients who received at least one dose of study drug. Maintenance safety analyses include all adverse events occurring in both induction and maintenance. This trial is registered with ClinicalTrials.gov, NCT02394028, and is closed to recruitment. FINDINGS: Between March 20, 2015, and Sept 7, 2021, 385 patients (209 [54%] male and 326 [85%] white) were randomly assigned in induction cohort 3 to receive placebo (n=97), 105 mg etrolizumab (n=143), or 210 mg etrolizumab (n=145). 487 patients had a CDAI-70 response in any of the induction cohorts and were enrolled into the maintenance cohort, of whom 434 had a response to etrolizumab and were randomly assigned to placebo (n=217) or 105 mg etrolizumab (n=217). At week 14, 48 (33%) of 145 patients in the 210 mg induction etrolizumab group versus 28 (29%) of 96 patients in the placebo induction group were in clinical remission (adjusted treatment difference 3·8% [95% CI -8·3 to 15·3]; p=0·52), and 40 (27%) versus 21 (22%) showed endoscopic improvement (5·8% [-5·4 to 17·1]; p=0·32). At week 66, a significantly higher proportion of patients receiving etrolizumab than those receiving placebo had clinical remission (76 [35%] of 217 vs 52 [24%] of 217; adjusted treatment difference 11·3% [95% CI 2·7-19·7]; p=0·0088) and endoscopic improvement (51 [24%] vs 26 [12%]; 11·5% [4·1-18·8]; p=0·0026). Similar proportions of patients reported one or more adverse events during induction (95 [66%] of 143 in the 105 mg etrolizumab group, 85 [59%] of 145 in the 210 mg etrolizumab group, and 51 [53%] of 96 in the placebo group) and maintenance (189 [87%] of 217 in the etrolizumab group and 190 [88%] of 217 in the placebo group). During induction, the most common treatment-related adverse events were injection site erythema (six [4%] of 143 in the 105 mg etrolizumab group, four [3%] of 145 in the 210 mg etrolizumab group, and none of 96 in the placebo group), and arthralgia (two [1%], one [1%], and four [4%]). In the maintenance cohort, the most common treatment-related adverse events were injection site erythema (six [3%] of 217 in the etrolizumab group vs 14 [6%] of 217 in the placebo: group), arthralgia (five [2%] vs eight [4%]), and headache (five [2%] vs seven [3%]). The most common serious adverse event was exacerbation of Crohn's disease (14 [6%] of 217 patients taking placebo and four [2%] of 217 patients taking 105 mg etrolizumab in the maintenance cohort). INTERPRETATION: A significantly higher proportion of patients with moderately to severely active Crohn's disease achieved clinical remission and endoscopic improvement with etrolizumab than placebo during maintenance, but not during induction. FUNDING: F Hoffmann-La Roche.

MK2 Inhibitors as a Potential Crohn's Disease Treatment Approach for Regulating MMP Expression, Cleavage of Checkpoint Molecules and T Cell Activity.

Crohn's Disease (CD) and Ulcerative Colitis (UC) are the two major forms of inflammatory bowel disease (IBD), which are incurable chronic immune-mediated diseases of the gastrointestinal tract. Both diseases present with chronic inflammation that leads to epithelial barrier dysfunction accompanied by loss of immune tolerance and inflammatory damage to the mucosa of the GI tract. Despite extensive research in the field, some of the mechanisms associated with the pathology in IBD remain elusive. Here, we identified a mechanism by which the MAPK-activated protein kinase 2 (MK2) pathway contributes to disease pathology in CD by regulating the expression of matrix metalloproteinases (MMPs), which cleave checkpoint molecules on immune cells and enhance T cell activity. By utilizing pharmaceuticals targeting MMPs and MK2, we show that the cleavage of checkpoint molecules and enhanced T cell responses may be reduced. The data presented here suggest the potential for MK2 inhibitors as a therapeutic approach for the treatment of CD.

Metabolic targeting of NRF2 potentiates the efficacy of the TRAP1 inhibitor G-TPP through reduction of ROS detoxification in colorectal cancer.

Tumor necrosis factor receptor-associated protein 1 (TRAP1) is a mitochondrial homolog of HSP90 chaperones. It plays an important role in protection against oxidative stress and apoptosis by regulating reactive oxidative species (ROS). To further elucidate the mechanistic role of TRAP1 in regulating tumor cell survival, we used gamitrinib-triphenylphosphonium (G-TPP) to inhibit TRAP1 signaling pathways in colon cancer. Inhibition of TRAP1 by G-TPP disrupted redox homeostasis and induced cell death. However, colon cancers show a wide range of responses to G-TPP treatment through the induction of variable ER stress responses and ROS accumulation. Interestingly, a strong inverse correlation was observed between the expression of TRAP1 and antioxidant genes in colon tumor tissues using the GSE106582 database. Using a luciferase reporter assay, we detected increased transcriptional activation of antioxidant response elements (AREs) in G-TPP-treated DLD1 and RKO cells but not in SW48 cells. We found that G-TPP induced upregulation of GRP78, CHOP and PARP cleavage in G-TPP-sensitive cells (SW48). In contrast, G-TPP treatment of G-TPP-resistant cells (DLD1 and RKO) resulted in excessive activation of the antioxidant gene NRF2, leading to ROS detoxification and improved cell survival. The NRF2 target genes HO1 and NQO1 were upregulated in G-TPP-treated DLD1 cells, making the cells more resistant to G-TPP treatment. Furthermore, treatment with both a NRF2 inhibitor and a TRAP1 inhibitor led to excessive ROS production and exacerbated G-TPP-induced cell death in G-TPP-resistant cells. Taken together, dual targeting of TRAP1 and NRF2 may potentially overcome colon cancer resistance by raising cellular ROS levels above the cytotoxic threshold.

Proactive infliximab optimisation using a pharmacokinetic dashboard versus standard of care in patients with Crohn's disease: study protocol for a randomised, controlled, multicentre, open-label study (the OPTIMIZE trial).

INTRODUCTION: Preliminary data indicates that proactive therapeutic drug monitoring (TDM) is associated with better outcomes compared with empiric dose escalation and/or reactive TDM, and that pharmacokinetic (PK) modelling can improve the precision of individual dosing schedules in Crohn's disease (CD). However, there are no data regarding the utility of a proactive TDM combined PK-dashboard starting early during the induction phase, when disease activity and drug clearance are greatest. The aim of this randomised, controlled, multicentre, open-label trial is to evaluate the efficacy and safety of a proactive TDM combined PK dashboard-driven infliximab dosing compared with standard of care (SOC) dosing in patients with moderately to severely active CD. METHODS AND ANALYSIS: Eligible adolescent and adult (aged ≥16-80 years) patients with moderately to severely active CD will be randomised 1:1 to receive either infliximab monotherapy with proactive TDM using a PK dashboard (iDose, Projections Research) or SOC infliximab therapy, with or without a concomitant immunomodulator (IMM) (thiopurine or methotrexate) at the discretion of the investigator. The primary outcome of the study is the proportion of subjects with sustained corticosteroid-free clinical remission and no need for rescue therapy from week 14 throughout week 52. Rescue therapy is defined as any IFX dose escalation other than what is forecasted by iDose either done empirically or based on reactive TDM; addition of an IMM after week 2; reintroduction of corticosteroids after initial tapering; switch to another biologic or need for CD-related surgery. The secondary outcomes will include both efficacy and safety end points, such as endoscopic and biological remission, durability of response and CD-related surgery and hospitalisation. ETHICS AND DISSEMINATION: The protocol has been approved by the Institutional Review Board Committee of the Beth Israel Deaconess Medical Center (IRB#:2021P000391). Results will be disseminated in peer-reviewed journals and presented at scientific meetings. TRIAL REGISTRATION NUMBER: NCT04835506.

Biodiversity influences the effects of oil disturbance on coastal ecosystems.

Biodiversity can enhance the response of ecosystems to disturbance. However, whether diversity can reduce the ecological effect of human-induced novel and extreme disturbances is unclear. In April 2010, the Deepwater Horizon (DwH) platform exploded, allowing an uncontrolled release of crude oil into the northern Gulf of Mexico. Initial surveys following the spill found that ecological impacts on coastal ecosystems varied greatly across habitat-type and trophic group; however, to date, few studies have tested the influence of local biodiversity on these responses. We used a meta-analytic approach to synthesize the results of 5 mesocosm studies that included 10 independent oil experiments and 5 independent oil + dispersant experiments. We tested whether biodiversity increased the resistance and/or resilience of coastal ecosystems to oil disturbance and whether a biodiversity effect depended on the type of diversity present (taxonomic or genetic) and/or the response type measured (population, community, or ecosystem level). We found that diversity can influence the effects of oiling, but the direction and magnitude of this diversity effect varied. Diversity reduced the negative impact of oiling for within-trophic-level responses and tended to be stronger for taxonomic than genetic diversity. Further, diversity effects were largely driven by the presence of highly resistant or quick to recover taxa and genotypes, consistent with the insurance hypothesis. However, we found no effect of diversity on the response to the combination of oil and dispersant exposure. We conclude that areas of low biodiversity may be particularly vulnerable to future oil disturbances and provide insight into the benefit of incorporating multiple measures of diversity in restoration projects and management decisions.

Adaptive immunity induces mutualism between commensal eukaryotes.

Pathogenic fungi reside in the intestinal microbiota but rarely cause disease. Little is known about the interactions between fungi and the immune system that promote commensalism. Here we investigate the role of adaptive immunity in promoting mutual interactions between fungi and host. We find that potentially pathogenic Candida species induce and are targeted by intestinal immunoglobulin A (IgA) responses. Focused studies on Candida albicans reveal that the pathogenic hyphal morphotype, which is specialized for adhesion and invasion, is preferentially targeted and suppressed by intestinal IgA responses. IgA from mice and humans directly targets hyphal-enriched cell-surface adhesins. Although typically required for pathogenesis, C. albicans hyphae are less fit for gut colonization1,2 and we show that immune selection against hyphae improves the competitive fitness of C. albicans. C. albicans exacerbates intestinal colitis3 and we demonstrate that hyphae and an IgA-targeted adhesin exacerbate intestinal damage. Finally, using a clinically relevant vaccine to induce an adhesin-specific immune response protects mice from C. albicans-associated damage during colitis. Together, our findings show that adaptive immunity suppresses harmful fungal effectors, with benefits to both C. albicans and its host. Thus, IgA uniquely uncouples colonization from pathogenesis in commensal fungi to promote homeostasis.

A Randomized Trial Comparing the Specific Carbohydrate Diet to a Mediterranean Diet in Adults With Crohn's Disease.

BACKGROUND & AIMS: This study compared the effectiveness of the Specific Carbohydrate Diet (SCD) to the Mediterranean diet (MD) as treatment for Crohn's disease (CD) with mild to moderate symptoms. METHODS: Adult patients with CD and with mild-to-moderate symptoms were randomly assigned 1:1 to consume the MD or SCD for 12 weeks. For the first 6 weeks, participants received prepared meals and snacks according to their assigned diet. After 6 weeks, participants were instructed to follow the diet independently. The primary outcome was symptomatic remission at week 6. Key secondary outcomes at week 6 included fecal calprotectin (FC) response (FC <250 µg/g and reduction by >50% among those with baseline FC >250 µg/g) and C-reactive protein (CRP) response (high-sensitivity CRP <5 mg/L and >50% reduction from baseline among those with high-sensitivity CRP >5 mg/L). RESULTS: The study randomized 194 patients, and 191 were included in the efficacy analyses. The percentage of participants who achieved symptomatic remission at week 6 was not superior with the SCD (SCD, 46.5%; MD, 43.5%; P = .77). FC response was achieved in 8 of 23 participants (34.8%) with the SCD and in 4 of 13 participants (30.8%) with the MD (P = .83). CRP response was achieved in 2 of 37 participants (5.4%) with the SCD and in 1 of 28 participants (3.6%) with the MD (P = .68). CONCLUSIONS: The SCD was not superior to the MD to achieve symptomatic remission, FC response, and CRP response. CRP response was uncommon. Given these results, the greater ease of following the MD and other health benefits associated with the MD, the MD may be preferred to the SCD for most patients with CD with mild to moderate symptoms. ClinicalTrials.gov Identifier: NCT03058679.

Whole-genome sequencing of African Americans implicates differential genetic architecture in inflammatory bowel disease.

Whether or not populations diverge with respect to the genetic contribution to risk of specific complex diseases is relevant to understanding the evolution of susceptibility and origins of health disparities. Here, we describe a large-scale whole-genome sequencing study of inflammatory bowel disease encompassing 1,774 affected individuals and 1,644 healthy control Americans with African ancestry (African Americans). Although no new loci for inflammatory bowel disease are discovered at genome-wide significance levels, we identify numerous instances of differential effect sizes in combination with divergent allele frequencies. For example, the major effect at PTGER4 fine maps to a single credible interval of 22 SNPs corresponding to one of four independent associations at the locus in European ancestry individuals but with an elevated odds ratio for Crohn disease in African Americans. A rare variant aggregate analysis implicates Ca2+-binding neuro-immunomodulator CALB2 in ulcerative colitis. Highly significant overall overlap of common variant risk for inflammatory bowel disease susceptibility between individuals with African and European ancestries was observed, with 41 of 241 previously known lead variants replicated and overall correlations in effect sizes of 0.68 for combined inflammatory bowel disease. Nevertheless, subtle differences influence the performance of polygenic risk scores, and we show that ancestry-appropriate weights significantly improve polygenic prediction in the highest percentiles of risk. The median amount of variance explained per locus remains the same in African and European cohorts, providing evidence for compensation of effect sizes as allele frequencies diverge, as expected under a highly polygenic model of disease.

Disturbance-driven changes to northern Gulf of Mexico nekton communities following the Deepwater Horizon oil spill.

The 2010 Deepwater Horizon (DwH) oil spill in the Gulf of Mexico discharged ~3.19 million barrels of oil into Gulf waters, making it one of the largest marine disasters in history in terms of volume. We report on the results of a study to assess oil impacts to coastal fishes and invertebrates. Using two-decades of fisheries-independent data in coastal Alabama and Mississippi, we document variability following both natural and anthropogenic disturbances from two periods pre-DwH (1997-2001 and 2007-2009), one intra-spill period for acute DwH effects (2010-2012) and one period post-spill for chronic, longer-term impacts (2014-2017). Results indicated significant changes to community structure, relative abundance, and diversity in the intra-spill period. Causation for changes is confounded by variables such as behavioral emigration, altered freshwater inflow, death of consumers, and the mandated fishery closure. Results highlight the need for long-term, comprehensive monitoring/observing systems to provide adequate background for assessing future disturbances.

Preclinical Safety Evaluation and Human Dosimetry of [18F]MK-6240, a Novel PET Tracer for Imaging Neurofibrillary Tangles.

PURPOSE: [18F]MK-6240 is a selective, high-affinity positron emission tomography tracer for imaging neurofibrillary tangles, a key pathological signature that correlates with cognitive decline in Alzheimer disease. This report provides safety information from preclinical toxicology studies and first-in-human whole-body biodistribution and dosimetry studies of [18F]MK-6240 for its potential application in human brain imaging studies. PROCEDURES: MK-6240 was administered intravenously (IV) in a 7-day rat toxicity study at × 50, × 100, and × 1000 dose margins relative to projected highest clinical dose of 0.333 µg/kg. The IV formulation of MK-6240 for clinical use and the formulation used in the 7-day rat toxicity study was tested for hemolysis potential in human and Wistar rat whole blood. Sequential whole-body positron emission tomography scans were performed in three healthy young subjects after IV bolus injection of 180 ± 0.3 MBq [18F]MK-6240 to characterize organ biodistribution and estimate whole-body radiation exposure (effective dose). RESULTS: MK-6240 administered IV in a 7-day rat toxicity study did not show any test article-related changes. The no-observed-adverse-effect level in rats was ≥ 333 µg/kg/day which provides a margin 1000-fold over an anticipated maximum clinical dose of 0.333 µg/kg. Additionally, the MK-6240 formulation was not hemolytic in human or Wistar rat blood. [18F]MK-6240 activity was widely distributed to the brain and the rest of the body, with organ absorbed doses largest for the gall bladder (202 µGy/MBq). The average (±SD) effective dose was 29.4 ± 0.6 µSv/MBq, which is in the typical range for F-18 radiolabeled ligands. CONCLUSIONS: Microdoses of [18F]MK-6240 are safe for clinical positron emission tomography imaging studies. Single IV administration of 185 MBq (5 mCi) [18F]MK-6240 is anticipated to result in a total human effective dose of 5.4 mSv and thus allows multiple positron emission tomography scans of the same subject per year.

Expansion of Bacteriophages Is Linked to Aggravated Intestinal Inflammation and Colitis.

Bacteriophages are the most abundant members of the microbiota and have the potential to shape gut bacterial communities. Changes to bacteriophage composition are associated with disease, but how phages impact mammalian health remains unclear. We noted an induction of host immunity when experimentally treating bacterially driven cancer, leading us to test whether bacteriophages alter immune responses. Treating germ-free mice with bacteriophages leads to immune cell expansion in the gut. Lactobacillus, Escherichia, and Bacteroides bacteriophages and phage DNA stimulated IFN-γ via the nucleotide-sensing receptor TLR9. The resultant immune responses were both phage and bacteria specific. Additionally, increasing bacteriophage levels exacerbated colitis via TLR9 and IFN-γ. Similarly, ulcerative colitis (UC) patients responsive to fecal microbiota transplantation (FMT) have reduced phages compared to non-responders, and mucosal IFN-γ positively correlates with bacteriophage levels. Bacteriophages from active UC patients induced more IFN-γ compared to healthy individuals. Collectively, these results indicate that bacteriophages can alter mucosal immunity to impact mammalian health.

Family History Associates With Increased Risk of Colorectal Cancer in Patients With Inflammatory Bowel Diseases.

BACKGROUND & AIMS: Individuals with inflammatory bowel diseases (IBDs) have an increased risk of developing colorectal cancer (CRC). Although family history of CRC is a well-established risk factor in healthy individuals, its role in patients with IBD is less clear. We aimed to estimate the risk of CRC in a cohort of patients with IBD from Utah and the significance of family history of CRC in a first-degree relative (FDR). METHODS: We identified Utah residents with IBD, using the Intermountain Healthcare and University of Utah Health Sciences databases, from January 1, 1996, through December 31, 2011. CRCs were identified using the Utah Cancer Registry and linked to pedigrees from the Utah Population Database. CRC incidence was compared with that of the state population by standardized incidence ratios (SIRs). RESULTS: A cohort of 9505 individuals with IBD was identified and 101 developed CRC during the study period. The SIR for CRC in patients with Crohn's disease was 3.4 (95% CI, 2.3-4.4), and in patients with ulcerative colitis was 5.2 (95% CI, 3.9-6.6). Patients with IBD and a concurrent diagnosis of primary sclerosing cholangitis had the greatest risk of CRC (SIR, 14.8; 95% CI, 8.3-21.2). A history of CRC in a FDR was associated with a nearly 8-fold increase in risk of CRC in patients with IBD (SIR, 7.9; 95% CI, 1.6-14.3), compared with the state population. CONCLUSIONS: Patients with IBD have a 3- to 5-fold increase in risk of CRC, and those with CRC in a FDR have an almost 8-fold increase in risk. Family history may act as a simple measure to identify individuals with IBD at highest risk for CRC and indicates the need for enhanced surveillance in this population.

A Novel Finger Illusion Reveals Reduced Weighting of Bimanual Hand Cortical Representations in People With Complex Regional Pain Syndrome.

Complex regional pain syndrome (CRPS) is associated with deficits in sensorimotor control. Herein we have used a novel finger illusion to investigate whether CRPS is associated with reduced weighting of bimanual hand representations. The illusion normally induces a compelling feeling that the hands are close together when in fact they are 12 cm apart. People with CRPS and age, gender, and dominant hand-matched controls tested the illusion in the midline then on either side of the midline. The illusion had 2 variants; the passive pincer-grip position, without contact (no grasp condition) and with contact (grasp condition) of the artificial finger. The primary outcome was the perceived vertical distance between the index fingers. Twenty people with CRPS and 20 controls participated (mean age 44.4 ± 11.7 years). During the no grasp condition, participants with CRPS perceived the vertical distance significantly closer to the actual 12 cm (mean 8.0 cm, 95% confidence interval 6.5-9.5 cm), than controls did (mean 6.4 cm, 95% confidence interval 5.5-7.2 cm]). That is, the illusion was weaker in people with CRPS than in controls during no grasp. There was no such difference during grasp; that is, both groups showed the predicted illusion response. There was no effect of hand placement relative to midline or relative to the opposite hand. We conclude that people with unilateral CRPS have lower weighting of bimanual hand representation than controls have, independent of hand location. However, adding additional cutaneous input returns those with CRPS to the expected performance. We suggest the results have clear clinical and research implications. PERSPECTIVE: An abnormal weighting of bilateral hand representation may reflect a vulnerability for chronic CRPS, an adaptation to the disease, and/or a potential therapeutic target. That addition of cutaneous input immediately normalizes the problem points to the possible role of bimanual tasks in prevention or rehabilitation.