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.

Outer Membrane Vesicles Released from Garlic Exosome-like Nanoparticles (GaELNs) Train Gut Bacteria that Reverses Type 2 Diabetes via the Gut-Brain Axis.

Gut microbiota function has numerous effects on humans and the diet humans consume has emerged as a pivotal determinant of gut microbiota function. Here, a new concept that gut microbiota can be trained by diet-derived exosome-like nanoparticles (ELNs) to release healthy outer membrane vesicles (OMVs) is introduced. Specifically, OMVs released from garlic ELN (GaELNs) trained human gut Akkermansia muciniphila (A. muciniphila) can reverse high-fat diet-induced type 2 diabetes (T2DM) in mice. Oral administration of OMVs released from GaELNs trained A. muciniphila can traffick to the brain where they are taken up by microglial cells, resulting in inhibition of high-fat diet-induced brain inflammation. GaELNs treatment increases the levels of OMV Amuc-1100, P9, and phosphatidylcholines. Increasing the levels of Amuc-1100 and P9 leads to increasing the GLP-1 plasma level. Increasing the levels of phosphatidylcholines is required for inhibition of cGas and STING-mediated inflammation and GLP-1R crosstalk with the insulin pathway that leads to increasing expression of Insulin Receptor Substrate (IRS1 and IRS2) on OMV targeted cells. These findings reveal a molecular mechanism whereby OMVs from plant nanoparticle-trained gut bacteria regulate genes expressed in the brain, and have implications for the treatment of brain dysfunction caused by a metabolic syndrome.

Exosome-like nanoparticles from Mulberry bark prevent DSS-induced colitis via the AhR/COPS8 pathway.

Bark protects the tree against environmental insults. Here, we analyzed whether this defensive strategy could be utilized to broadly enhance protection against colitis. As a proof of concept, we show that exosome-like nanoparticles (MBELNs) derived from edible mulberry bark confer protection against colitis in a mouse model by promoting heat shock protein family A (Hsp70) member 8 (HSPA8)-mediated activation of the AhR signaling pathway. Activation of this pathway in intestinal epithelial cells leads to the induction of COP9 Constitutive Photomorphogenic Homolog Subunit 8 (COPS8). Utilizing a gut epithelium-specific knockout of COPS8, we demonstrate that COPS8 acts downstream of the AhR pathway and is required for the protective effect of MBELNs by inducing an array of anti-microbial peptides. Our results indicate that MBELNs represent an undescribed mode of inter-kingdom communication in the mammalian intestine through an AhR-COPS8-mediated anti-inflammatory pathway. These data suggest that inflammatory pathways in a microbiota-enriched intestinal environment are regulated by COPS8 and that edible plant-derived ELNs may hold the potential as new agents for the prevention and treatment of gut-related inflammatory disease.

P027 Brain Fog in Patients With Inflammatory Bowel Disease, and Association With Use of Probiotics.

BACKGROUND: Brain fog has been minimally studied in patients with inflammatory bowel disease (IBD). IBD patients frequently consume probiotics, whether sanctioned by a physician or not. However, probiotic consumption in itself has been shown to increase the incidence of brain fog. We aimed to study the association between brain fog in IBD patients with or without probiotic use. METHODS: We conducted a cross-sectional study among patients visiting a busy IBD clinic. Patients aged >18 with a biopsy-proven diagnosis of inflammatory bowel disease, without pre-existing psychiatric illness or current use of opioid medications were included. They were divided into 2 groups: those using probiotics and those who did not. Patients were given a questionnaire that included details about symptoms of brain fog. Groups were analyzed by chi-square test for differences in baseline demographics, and Mann Whitney U test to compare outcomes between groups. A p-value < 0.05 was considered statistically significant. RESULTS: Of the 66 patients included (mean age 44±2 years), 35 (53%) were female and 59 (89.4%) were Caucasian. Among these patients, 31.8% (n = 21) took probiotics as dietary supplements with the majority (67%, n = 14) taking probiotics for over a year. Overall, there was a trend for an association between probiotic use and brain fog in all patients (p = 0.080) but no statistical significance was attained. However, brain fog was significantly associated with probiotic use among Caucasian patients (p = 0.044). Furthermore, there was a statistically significant association between brain fog and male patients using probiotics (p = 0.004). Duration of probiotic use was also associated with brain fog (p = 0.038). CONCLUSION: Consumption of probiotics was independently associated with brain fog in men, as well as Caucasian patients with IBD respectively. Given the high prevalence of probiotic use in IBD patients, prospective studies are warranted to examine the causal relationship between probiotics and IBD-associated brain fog to guide prescription of probiotic supplements for IBD.

Effects of Gastric Neuromodulation on Crohn's Disease in Patients With Coexisting Symptoms of Gastroparesis.

INTRODUCTION: Crohn's Disease (CD) results from chronic inflammation of the gastrointestinal (GI) tract involving TNF-α release. Gastrointestinal electrical stimulation (GES), a form of neuromodulation used to treat upper GI motility symptoms (UGI Sx), exerts an anti-inflammatory effect via TNF-α suppression. We hypothesized patients with CD symptoms in patients with gastroparesis (GP) may respond to GES. METHODS: We retrospectively examined 284 patients with symptomatic gastroparesis (Gp Sx), who underwent GES placement. Patients with Gp Sx were evaluated by validated GI Sx patient reported outcome. Scores were obtained at baseline, after temporary GES placement and after permanent GES placement. Eleven patients from this cohort with coexisting CD were analyzed for improvements in their CD symptomatology using the Harvey Bradshaw Index (HBI). HBI scores were compared from before GES to after two sequential applications of electrical stimulation (temporary then permanent). A 3-point decrease in HBI indicated a clinical response and an HBI <5 indicated clinical remission after GES. An unadjusted repeated measures model was used in the analysis with statistical significance set at p ≤ 0.05. RESULTS: Our cohort prevalence of CD was 3.9% (2 M & 9 F, mean age 49.8 yrs.). Within both the Gp + CD & Gp subgroups, UGI Sx substantially improved after temporary and permanent GES. Furthermore, 55% of the GP + CD subgroup demonstrated a clinical response by HBI, while one patient achieved clinical remission (p < 0.01). CD medications were reviewed before and after GES placement, and any interval changes are unlikely to explain the improved HBI scores. DISCUSSION: We conclude that both UGI and CD symptoms in GP + CD patients responded well to GES. The interaction of Gp and CD and the effects of neuromodulation on CD symptoms warrant additional investigation.

Methotrexate Is Not Superior to Placebo in Maintaining Steroid-Free Response or Remission in Ulcerative Colitis.

BACKGROUND & AIMS: Parenteral methotrexate induces clinical remission but not endoscopic improvement of mucosal inflammation in patients with ulcerative colitis (UC). We performed a randomized, placebo-controlled trial to assess the efficacy of parenteral methotrexate in maintaining steroid-free response or remission in patients with UC after induction therapy with methotrexate and steroids. METHODS: We performed a 48-week trial, from February 2012 through May 2016, of 179 patients with active UC (Mayo score of 6-12 with endoscopy subscore ≥ 2) despite previous conventional or biological therapy. The study comprised a 16-week open label methotrexate induction period followed by a 32-week double-blind, placebo-controlled maintenance period. Patients were given subcutaneous methotrexate (25 mg/wk) and a 12-week steroid taper. At week 16, steroid-free responders were randomly assigned to groups that either continued methotrexate (25 mg/wk, n = 44) or were given placebo (n = 40) until week 48. We compared the efficacy of treatment by analyzing the proportion of patients who remained relapse free and were in remission at week 48 without use of steroids or other medications to control disease activity. RESULTS: Ninety-one patients (51%) achieved response at week 16, and 84 patients were included in the maintenance period study. During this period, 60% of patients in the placebo group (24/40) and 66% in the methotrexate group (29/44) had a relapse of UC (P = .75). At week 48, 30% of patients in the placebo group (12/40) and 27% of patients in the methotrexate group (12/44) were in steroid-free clinical remission without need for additional therapies (P = .86). No new safety signals for methotrexate were detected. CONCLUSIONS: Parenteral methotrexate (25 mg/wk) was not superior to placebo in preventing relapses of UC in patients who achieved steroid-free response during induction therapy. ClinicalTrials.gov, Number: NCT01393405.

Genome-Wide Association Study Identifies African-Specific Susceptibility Loci in African Americans With Inflammatory Bowel Disease.

BACKGROUND & AIMS: The inflammatory bowel diseases (IBD) ulcerative colitis (UC) and Crohn's disease (CD) cause significant morbidity and are increasing in prevalence among all populations, including African Americans. More than 200 susceptibility loci have been identified in populations of predominantly European ancestry, but few loci have been associated with IBD in other ethnicities. METHODS: We performed 2 high-density, genome-wide scans comprising 2345 cases of African Americans with IBD (1646 with CD, 583 with UC, and 116 inflammatory bowel disease unclassified) and 5002 individuals without IBD (controls, identified from the Health Retirement Study and Kaiser Permanente database). Single-nucleotide polymorphisms (SNPs) associated at P < 5.0 × 10-8 in meta-analysis with a nominal evidence (P < .05) in each scan were considered to have genome-wide significance. RESULTS: We detected SNPs at HLA-DRB1, and African-specific SNPs at ZNF649 and LSAMP, with associations of genome-wide significance for UC. We detected SNPs at USP25 with associations of genome-wide significance for IBD. No associations of genome-wide significance were detected for CD. In addition, 9 genes previously associated with IBD contained SNPs with significant evidence for replication (P < 1.6 × 10-6): ADCY3, CXCR6, HLA-DRB1 to HLA-DQA1 (genome-wide significance on conditioning), IL12B,PTGER4, and TNC for IBD; IL23R, PTGER4, and SNX20 (in strong linkage disequilibrium with NOD2) for CD; and KCNQ2 (near TNFRSF6B) for UC. Several of these genes, such as TNC (near TNFSF15), CXCR6, and genes associated with IBD at the HLA locus, contained SNPs with unique association patterns with African-specific alleles. CONCLUSIONS: We performed a genome-wide association study of African Americans with IBD and identified loci associated with UC in only this population; we also replicated IBD, CD, and UC loci identified in European populations. The detection of variants associated with IBD risk in only people of African descent demonstrates the importance of studying the genetics of IBD and other complex diseases in populations beyond those of European ancestry.

Refractory pouchitis improves after administration of the green tea polyphenol EGCG: a retrospective review.

INTRODUCTION: Ulcerative colitis (UC) is a common, chronic, inflammatory process limited to the colon. UC affects up to 1 million individuals in the USA alone and requires resection in up to 30% of patients. Resection is often followed by creation of a pouch. Pouchitis is the most common complication of ileal pouch-anal anastomosis (IPAA) following total proctocolectomy, affecting up to 50% of patients. Symptoms include increased stool frequency, urgency, cramping, and bleeding. Management of pouchitis is complex in antibiotic refractory cases. Plant-based polyphenolic compounds have shown protective effects against UC. We conducted a retrospective review of pouchitis patients treated with EGCG 200-400 mg twice daily. RESULTS: Seven of nine (78%) patients experienced significant improvement based on reduced frequency of bowel movements and bleeding, while five of nine (56%) experienced complete relief. One patient experienced no improvement with EGCG, and one had progression of pouchitis symptoms while taking EGCG. No significant adverse events were noted by patients while taking EGCG. DISCUSSION: The green tea-derived molecule EGCG exhibits an efficacy signal in the IBD-related condition of pouchitis. Impressively, 78% of patients experienced noticeable improvement in pouchitis symptoms after initiation of EGCG, while 56% of treated patients entered complete remission. These positive responses to EGCG in patients with pouchitis suggests the need to confirm these findings in a formal, controlled trial. Based on recent findings documenting its effects on epithelial permeability and mucosal inflammation, combined with its favorable safety profile, a possible preventative role could also be explored.

Targeted drug delivery to intestinal macrophages by bioactive nanovesicles released from grapefruit.

The gut mucosal immune system is considered to play an important role in counteracting potential adverse effects of food-derived antigens including nanovesicles. Whether nanovesicles naturally released from edible fruit work in a coordinated manner with gut immune cells to maintain the gut in a noninflammatory status is not known. Here, as proof of concept, we demonstrate that grapefruit-derived nanovesicles (GDNs) are selectively taken up by intestinal macrophages and ameliorate dextran sulfate sodium (DSS)-induced mouse colitis. These effects were mediated by upregulating the expression of heme oxygenase-1 (HO-1) and inhibiting the production of IL-1ß and TNF-α in intestinal macrophages. The inherent biocompatibility and biodegradability, stability at wide ranges of pH values, and targeting of intestinal macrophages led us to further develop a novel GDN-based oral delivery system. Incorporating methotrexate (MTX), an anti-inflammatory drug, into GDNs and delivering the MTX-GDNs to mice significantly lowered the MTX toxicity when compared with free MTX, and remarkably increased its therapeutic effects in DSS-induced mouse colitis. These findings demonstrate that GDNs can serve as immune modulators in the intestine, maintain intestinal macrophage homeostasis, and can be developed for oral delivery of small molecule drugs to attenuate inflammatory responses in human disease.

Tryptophan As a New Member of RNA-Induced Silencing Complexes Prevents Colon Cancer Liver Metastasis.

Essential amino acids (EAA) and microRNAs (miRs) control biological activity of a cell. Whether EAA regulates the activity of miR has never been demonstrated. Here, as proof-of-concept, a tryptophan (Trp, an EAA) complex containing Argonaute 2 (Ago2) and miRs including miR-193a (Trp/Ago2/miR-193a) is identified. Trp binds miR-193a-3p and interacts with Ago2. Trp/Ago2/miR-193a increases miR-193a-3p activity via enhancing Argonaute 2 (Ago2) RNase activity. Other miRs including miR-103 and miR-107 in the Trp complex enhance miR-193a activity by targeting the same genes. Mechanistically, the Trp/Ago2/miR-193a complex interacts with Trp-binding pockets of the PIWI domain of Ago2 to enhance Ago2 mediated miR activity. This newly formed Ago2/Trp/miR-193a-3p complex is more efficient than miR-193a-3p alone in inhibiting the expression of targeted genes and inhibiting colon cancer liver metastasis. The findings show that Trp regulates miR activity through communication with the RNA-induced silencing complexes (RISC), which provides the basis for tryptophan based miR therapy.

FGF21 Depletion Attenuates Colitis through Intestinal Epithelial IL-22-STAT3 Activation in Mice.

Fibroblast growth factor 21 (FGF21) is a glucose and lipid metabolic regulator. Recent research revealed that FGF21 was also induced by inflammatory stimuli. Its role in inflammatory bowel disease (IBD) has not been investigated. In this study, an experimental IBD model was established in FGF21 knockout (KO) and wild-type (WT) mice by adding 2.5% (wt/vol) dextran sodium sulfate (DSS) to their drinking water for 7 days. The severity of the colitis and the inflammation of the mouse colon tissues were analyzed. In WT mice, acute DSS treatment induced an elevation in plasma FGF21 and a significant loss of body weight in a time-dependent manner. Surprisingly, the loss of body weight and the severity of the colitis induced by DSS treatment in WT mice were significantly attenuated in FGF21 KO mice. Colon and circulating pro-inflammatory factors were significantly lower in the FGF21 KO mice compared to the WT mice. As shown by BrdU staining, the FGF21 KO mice demonstrated increased colonic epithelial cell proliferation. DSS treatment reduced intestinal Paneth cell and goblet cell numbers in the WT mice, and this effect was attenuated in the FGF21 KO mice. Mechanistically, FGF21 deficiency significantly increased the signal transducer and activator of transcription (STAT)-3 activation in intestinal epithelial cells and increased the expression of IL-22. Further study showed that the expression of suppressor of cytokine signaling-2/3 (SOCS 2/3), a known feedback inhibitor of STAT3, was significantly inhibited in the DSS-treated FGF2 KO mice compared to the WT mice. We conclude that FGF21 deficiency attenuated the severity of DSS-induced acute colitis, which is likely mediated by enhancing the activation of the IL-22-STAT3 signaling pathway in intestinal epithelial cells.

Development and validation of a product acceptability questionnaire for intranasal Q-Griffithsin COVID-19 prophylaxis (SPRAY PAL).

OBJECTIVES: Patient experiences are critical when determining the acceptability of novel interventional pharmaceuticals. Here, we report the development and validation of a product acceptability questionnaire (SPRAY PAL) assessing feasibility, acceptability and tolerability of an intranasal Q-Griffithsin (Q-GRFT) drug product designed for COVID-19 prophylaxis. DESIGN: SPRAY PAL validation was undertaken as part of an ongoing phase 1 clinical trial designed to test the safety, pharmacokinetics and tolerability of intranasally administered Q-GRFT for the prevention of SARS-CoV-2 infection. SETTING: The phase 1 clinical trial took place at a University Outpatient Clinical Trials Unit from November 2021 to September 2023. PARTICIPANTS: The initial SPRAY PAL questionnaire was piloted among healthy volunteers ages 25 to 55 in phase 1a of the clinical trial (N=18) and revised for administration in phase 1b for participants ages 24-59 (N=22). RESULTS: Spearman correlations tested convergent and discriminant validity. Internal consistency was assessed using Cronbach's alpha, and test-retest reliability was assessed using intraclass correlation coefficients of responses collected from three repeated questionnaire administrations. The initial version demonstrated excellent internal consistency. The revised version demonstrated very good internal consistency after removal of one item (alpha=0.739). Excellent test-retest reliability (intraclass coefficient=0.927) and adequate convergent (r's=0.208-0.774) and discriminant (r's=0.123-0.392) validity were achieved. Subscales adequately distinguished between the constructs of acceptability, feasibility and tolerability. CONCLUSIONS: The SPRAY PAL product acceptability questionnaire is a valid and reliable patient-reported outcomes measure that can be considered a credible tool for assessing patient-reported information about product acceptability, feasibility of use, tolerability of product and side effects and cost of product for novel intranasal drug formulations. The SPRAY PAL is generalisable, and items may be readily adapted to assess other intranasal formulations. TRIAL REGISTRATION NUMBERS: NCT05122260 and NCT05437029.

An extracellular vesicular mutant KRAS-associated protein complex promotes lung inflammation and tumor growth.

Extracellular vesicles (EVs) contain more than 100 proteins. Whether there are EVs proteins that act as an 'organiser' of protein networks to generate a new or different biological effect from that identified in EV-producing cells has never been demonstrated. Here, as a proof-of-concept, we demonstrate that EV-G12D-mutant KRAS serves as a leader that forms a protein complex and promotes lung inflammation and tumour growth via the Fn1/IL-17A/FGF21 axis. Mechanistically, in contrast to cytosol derived G12D-mutant KRAS complex from EVs-producing cells, EV-G12D-mutant KRAS interacts with a group of extracellular vesicular factors via fibronectin-1 (Fn1), which drives the activation of the IL-17A/FGF21 inflammation pathway in EV recipient cells. We show that: (i), depletion of EV-Fn1 leads to a reduction of a number of inflammatory cytokines including IL-17A; (ii) induction of IL-17A promotes lung inflammation, which in turn leads to IL-17A mediated induction of FGF21 in the lung; and (iii) EV-G12D-mutant KRAS complex mediated lung inflammation is abrogated in IL-17 receptor KO mice. These findings establish a new concept in EV function with potential implications for novel therapeutic interventions in EV-mediated disease processes.

Garlic exosome-like nanoparticles reverse high-fat diet induced obesity via the gut/brain axis.

Background: Obesity is becoming a global epidemic and reversing the pathological processes underlying obesity and metabolic co-morbidities is challenging. Obesity induced chronic inflammation including brain inflammation is a hallmark of obesity via the gut-brain axis. The objective of this study was to develop garlic exosome-like nanoparticles (GaELNs) that inhibit systemic as well as brain inflammatory activity and reverse a HFD induced obesity in mice. Methods: GELNs were isolated and administrated orally into HFD fed mice. GaELNs were fluorescent labeled for monitoring their in vivo trafficking route after oral administration and quantified the number particles in several tissues. The brain inflammation was determined by measuring inflammatory cytokines by ELISA and real-time PCR. Mitochondrial membrane permeability of microglial cells was determined using JC-10 fluorescence dye. The in vivo apoptotic cell death was quantified by TUNEL assay. The brain metabolites were identified and quantified by LC-MS analysis. Memory function of the mice was determined by several memory functional analysis. The effect of GaELNs on glucose and insulin response of the mice was determined by glucose and insulin tolerance tests. c-Myc localization and interaction with BASP1 and calmodulin was determined by confocal microscopy. Results: Our results show that GaELNs is preferentially taken up microglial cells and inhibits the brain inflammation in HFD mice. GaELN phosphatidic acid (PA) (36:4) is required for the uptake of GaELNs via interaction with microglial BASP1. Formation of the GaELNs/BASP1 complex is required for inhibition of c-Myc mediated expression of STING. GaELN PA binds to BASP1, leading to inhibition of c-Myc expression and activity through competitively binding to CaM with c-Myc transcription factor. Inhibition of STING activity leads to reducing the expression of an array of inflammatory cytokines including IFN-γ and TNF-α. IFN-γ induces the expression of IDO1, which in turn the metabolites generated as IDO1 dependent manner activate the AHR pathway that contributes to developing obesity. The metabolites derived from the GaELNs treated microglial cells promote neuronal differentiation and inhibit mitochondrial mediated neuronal cell death. GaELNs treated HFD mice showed improved memory function and increased glucose tolerance and insulin sensitivity in these mice. Conclusion: Collectively, these results demonstrate how nanoparticles from a healthy diet can inhibit unhealthy high-fat diet induced brain inflammation and reveal a link between brain microglia/diet to brain inflammatory disease outcomes via diet-derived exosome-like nanoparticles.

miR-375 prevents high-fat diet-induced insulin resistance and obesity by targeting the aryl hydrocarbon receptor and bacterial tryptophanase (tnaA) gene.

Background: Diet manipulation is the basis for prevention of obesity and diabetes. The molecular mechanisms that mediate the diet-based prevention of insulin resistance are not well understood. Here, as proof-of-concept, ginger-derived nanoparticles (GDNP) were used for studying molecular mechanisms underlying GDNP mediated prevention of high-fat diet induced insulin resistance. Methods: Ginger-derived nanoparticles (GDNP) were isolated from ginger roots and administered orally to C57BL/6 high-fat diet mice. Fecal exosomes released from intestinal epithelial cells (IECs) of PBS or GDNP treated high-fat diet (HFD) fed mice were isolated by differential centrifugation. A micro-RNA (miRNA) polymerase chain reaction (PCR) array was used to profile the exosomal miRs and miRs of interest were further analyzed by quantitative real time (RT) PCR. miR-375 or antisense-miR375 was packed into nanoparticles made from the lipids extracted from GDNP. Nanoparticles was fluorescent labeled for monitoring their in vivo trafficking route after oral administration. The effect of these nanoparticles on glucose and insulin response of mice was determined by glucose and insulin tolerance tests. Results: We report that HFD feeding increased the expression of AhR and inhibited the expression of miR-375 and VAMP7. Treatment with orally administered ginger-derived nanoparticles (GDNP) resulted in reversing HFD mediated inhibition of the expression of miR-375 and VAMP7. miR-375 knockout mice exhibited impaired glucose homeostasis and insulin resistance. Induction of intracellular miR-375 led to inhibition of the expression of AhR and VAMP7 mediated exporting of miR-375 into intestinal epithelial exosomes where they were taken up by gut bacteria and inhibited the production of the AhR ligand indole. Intestinal exosomes can also traffic to the liver and be taken up by hepatocytes, leading to miR-375 mediated inhibition of hepatic AhR over-expression and inducing the expression of genes associated with the hepatic insulin response. Altogether, GDNP prevents high-fat diet-induced insulin resistance by miR-375 mediated inhibition of the aryl hydrocarbon receptor mediated pathways over activated by HFD feeding. Conclusion: Collectively our findings reveal that oral administration of GDNP to HFD mice improves host glucose tolerance and insulin response via regulating AhR expression by GDNP induced miR-375 and VAMP7.

High-fat diet-induced upregulation of exosomal phosphatidylcholine contributes to insulin resistance.

High-fat diet (HFD) decreases insulin sensitivity. How high-fat diet causes insulin resistance is largely unknown. Here, we show that lean mice become insulin resistant after being administered exosomes isolated from the feces of obese mice fed a HFD or from patients with type II diabetes. HFD altered the lipid composition of exosomes from predominantly phosphatidylethanolamine (PE) in exosomes from lean animals (L-Exo) to phosphatidylcholine (PC) in exosomes from obese animals (H-Exo). Mechanistically, we show that intestinal H-Exo is taken up by macrophages and hepatocytes, leading to inhibition of the insulin signaling pathway. Moreover, exosome-derived PC binds to and activates AhR, leading to inhibition of the expression of genes essential for activation of the insulin signaling pathway, including IRS-2, and its downstream genes PI3K and Akt. Together, our results reveal HFD-induced exosomes as potential contributors to the development of insulin resistance. Intestinal exosomes thus have potential as broad therapeutic targets.

Positive correlation of image analysis by mini-endoscopy with micro-PET scan and histology in rats after esophagoduodenal anastomosis.

BACKGROUND: Visual inspection of induced carcinogenic transformation is of crucial interest when evaluating growth patterns and therapeutic effects. In previous studies we have used micro-PET scan to analyze the esophageal adenocarcinoma (EAC) transformation in an intact rat model of esophagoduodenal anastomosis (EDA), in which intestinal metaplasia and EAC were reproduced successfully. Our current study aimed to test the feasibility of evaluating the outcomes of our EDA model with a recently developed mini-endoscope. METHODS: EDA was performed as described previously. Postoperative rats underwent evaluation with upper endoscopy with the mini-endoscope (±endoscopic biopsy) and a micro-PET scan with (18)F-FDG 3 months after the EDA procedure. Rats were euthanized and the esophagi were collected for histological observation, immunohistochemical staining, and TdT labeling assay. We compared the endoscopic images with the radiographic images of (18)F-FDG uptake by micro-PET scan and correlated the endoscopic images with the histological changes in the EDA rats. RESULTS: The endoscope provided visualization of the entire esophageal tract and upper stomach, with the smallest detectable lesion being 0.5 mm in diameter. Mini-endoscopy was performed regularly and was tolerated without any significant procedure-related alterations in the esophageal tract. The visualized esophageal lesion correlated well with the micro-PET image and the histological changes in the EDA rats. CONCLUSIONS: The new mini-endoscope constitutes a practical and reliable tool for diagnosis and regular follow-up of the esophagus in rats. Lesions identified by endoscopic observation were consistent with the changes found in the micro-PET scan, histopathology, and alteration of cellular and molecular events in esophageal mucosa. This instrument will allow for serial endoscopic evaluations, similar to endoscopic screening in humans, which will significantly enhance the preclinical development and evaluation of experimental intravesical antitumor therapies.

Practical guidelines on endoscopic treatment for Crohn's disease strictures: a consensus statement from the Global Interventional Inflammatory Bowel Disease Group.

Stricture formation is a common complication of Crohn's disease, resulting from the disease process, surgery, or drugs. Endoscopic balloon dilation has an important role in the management of strictures, with emerging techniques, such as endoscopic electroincision and stenting, showing promising results. The underlying disease process, altered bowel anatomy from disease or surgery, and concurrent use of immunosuppressive drugs can make endoscopic procedures more challenging. There is an urgent need for the standardisation of endoscopic procedures and peri-procedural management strategies. On the basis of an extensive literature review and the clinical experience of the consensus group, which consisted of representatives from the Interventional Inflammatory Bowel Disease Group, we propose detailed guidance on all aspects of the principles and techniques for endoscopic procedures in the treatment of inflammatory bowel disease-associated strictures.

Enhancement of the gut barrier integrity by a microbial metabolite through the Nrf2 pathway.

The importance of gut microbiota in human health and pathophysiology is undisputable. Despite the abundance of metagenomics data, the functional dynamics of gut microbiota in human health and disease remain elusive. Urolithin A (UroA), a major microbial metabolite derived from polyphenolics of berries and pomegranate fruits displays anti-inflammatory, anti-oxidative, and anti-ageing activities. Here, we show that UroA and its potent synthetic analogue (UAS03) significantly enhance gut barrier function and inhibit unwarranted inflammation. We demonstrate that UroA and UAS03 exert their barrier functions through activation of aryl hydrocarbon receptor (AhR)- nuclear factor erythroid 2-related factor 2 (Nrf2)-dependent pathways to upregulate epithelial tight junction proteins. Importantly, treatment with these compounds attenuated colitis in pre-clinical models by remedying barrier dysfunction in addition to anti-inflammatory activities. Cumulatively, the results highlight how microbial metabolites provide two-pronged beneficial activities at gut epithelium by enhancing barrier functions and reducing inflammation to protect from colonic diseases.

Clinical Efficacy of Serum-Derived Bovine Immunoglobulin in Patients With Refractory Inflammatory Bowel Disease.

BACKGROUND: Inflammatory bowel disease (IBD) can have autoimmunity and/or intestinal barrier dysfunction as part of pathophysiology and may be refractory to all available treatment options. Serum-derived bovine immunoglobulin (SBI) binds microbial components with postulated downstream effects of normalized gut immune and barrier function, which may be useful for managing IBD. The purpose of our study was to evaluate the effectiveness of SBI in the management of refractory IBD, particularly symptoms of chronic diarrhea and loose stools. METHODS: We retrospectively analyzed charts for patients diagnosed with IBD (n = 40) who were refractory to standard treatment. Patients received oral SBI 5 g daily for a period of at least 6 weeks. Twelve patients with IBD fulfilled study inclusion criteria. Each patient graded the severity and frequency of gastrointestinal symptoms before starting SBI and at 6 weeks of treatment using a standardized patient assessment form. Means and standard deviations for all symptom scores at baseline and week 6 of treatment were analyzed. RESULTS: Mean symptom scores decreased significantly for nausea (P = 0.02 for severity and P = 0.03 for mean symptom score) and diarrhea (P = 0.0006, P = 0.0001 and P = 0.0001 for severity, frequency and mean symptom score, respectively). CONCLUSIONS: Therapy with SBI alleviated some refractory gastrointestinal symptoms in patients with IBD, including nausea and diarrhea. Increased duration, dosage and/or frequency of SBI might provide additional symptom improvement and could be tested through controlled clinical trials with larger sample sizes and longer follow-up.