Aberrant hepatic trafficking of gut-derived T cells is not specific to primary sclerosing cholangitis

Background and Aims The “gut homing” hypothesis suggests the pathogenesis of primary sclerosing cholangitis (PSC) is driven by aberrant hepatic expression of gut adhesion molecules and subsequent recruitment of gut‐derived T cells to the liver. However, inconsistencies lie within this theory including an absence of investigations and comparisons with other chronic liver diseases (CLD). Here, we examine “the gut homing theory” in patients with PSC with associated inflammatory bowel disease (PSC‐IBD) and across multiple inflammatory liver diseases. Approach and Results Expression of MAdCAM‐1, CCL25, and E‐Cadherin were assessed histologically and using RT‐PCR on explanted liver tissue from patients with CLD undergoing OLT and in normal liver. Liver mononuclear cells were isolated from explanted tissue samples and the expression of gut homing integrins and cytokines on hepatic infiltrating gut‐derived T cells was assessed using flow cytometry. Hepatic expression of MAdCAM‐1, CCL25 and E‐Cadherin was up‐regulated in all CLDs compared with normal liver. There were no differences between disease groups. Frequencies of α4β7, αEβ7, CCR9, and GPR15 expressing hepatic T cells was increased in PSC‐IBD, but also in CLD controls, compared with normal liver. β7 expressing hepatic T cells displayed an increased inflammatory phenotype compared with β7 negative cells, although this inflammatory cytokine profile was present in both the inflamed and normal liver. Conclusions These findings refute the widely accepted “gut homing” hypothesis as the primary driver of PSC and indicate that aberrant hepatic recruitment of gut‐derived T cells is not unique to PSC, but is a panetiological feature of CLD

Interplay of constipation, intestinal barrier dysfunction and fungal exposome in aetiopathogenesis of Parkinson’s disease:hypothesis with supportive data

Constipation is a forerunner to Parkinson’s disease (PD) diagnosis, worsening thereafter. We explore the relationship of intestinal barrier dysfunction to constipation and whether intestinal fungal load is an aggravating factor. Fungal load was quantified by real-time PCR, using ITS1F-ITS2 primer set, on microbial DNA extract from stool in 68 participants with PD, 102 without. Fungal load was 60% higher per decade after age 60 years, with no PD status interaction with age. After age adjustment, it was associated inversely with dietary renal acid load. It was unrelated to the presence of constipation or barrier dysfunction. Neither consumption of antimicrobials nor of other targeted exogenous substances was associated. Enzyme-linked immunosorbent assays measured barrier dysfunction markers, faecal alpha-1 antitrypsin (AAT), zonulin and serum intestinal fatty acid-binding protein (I-FABP). Barrier dysfunction was associated with constipation and slower radiographic colonic transit. Functional constipation was 28% more frequent with a doubling of AAT concentration. More colonic-transit test markers were retained in the transverse colon, the higher the AAT and zonulin concentrations, anatomically spotlighting abnormality for the entire colon. In contrast, the concentration of the small intestinal barrier marker I-FABP was associated with looser stool consistency, which is consistent with secondary microbial overgrowth. By showing a relationship of intestinal barrier dysfunction to constipation, this study supports the hypothesis that dysfunction may be consequential. Dysfunction may be a necessary, but not sufficient, precursor to PD, in allowing inflammaging. Since ageing is the clearest risk for PD, a gut pathogen escalating in abundance from the sixth decade, integral to fungal load, and whose reproduction and virulence is favoured by alkalinity, tallies.</p

Faecal metabolite deficit, gut inflammation and diet in Parkinson’s disease: integrative analysis indicates inflammatory response syndrome

Background: Gut-brain axis is widely implicated in the pathophysiology of Parkinson's disease (PD). We take an integrated approach to considering the gut as a target for disease-modifying intervention, using continuous measurements of disease facets irrespective of diagnostic divide. Methods: We characterised 77 participants with diagnosed-PD, 113 without, by dietary/exogenous substance intake, faecal metabolome, intestinal inflammation, serum cytokines/chemokines, clinical phenotype including colonic transit time. Complete-linkage hierarchical cluster analysis of metabolites discriminant for PD-status was performed. Results: Longer colonic transit was linked to deficits in faecal short-chain-fatty acids outside PD, to a ‘tryptophan-containing metabolite cluster’ overall. Phenotypic cluster analysis aggregated colonic transit with brady/hypokinesia, tremor, sleep disorder and dysosmia, each individually associated with tryptophan-cluster deficit. Overall, a faster pulse was associated with deficits in a metabolite cluster including benzoic acid and an imidazole-ring compound (anti-fungals) and vitamin B3 (anti-inflammatory) and with higher serum CCL20 (chemotactic for lymphocytes/dendritic cells towards mucosal epithelium). The faster pulse in PD was irrespective of postural hypotension. The benzoic acid-cluster deficit was linked to (well-recognised) lower caffeine and alcohol intakes, tryptophan-cluster deficit to higher maltose intake. Free-sugar intake was increased in PD, maltose intake being 63% higher (p = .001). Faecal calprotectin was 44% (95% CI 5%, 98%) greater in PD [p = .001, adjusted for proton-pump inhibitors (p = .001)], with 16% of PD-probands exceeding a cut-point for clinically significant inflammation compatible with inflammatory bowel disease. Higher maltose intake was associated with exceeding this calprotectin cut-point. Conclusions: Emerging picture is of (i) clinical phenotype being described by deficits in microbial metabolites essential to gut health; (ii) intestinal inflammation; (iii) a systemic inflammatory response syndrome

Exome sequencing and genotyping identify a rare variant in NLRP7 gene associated with ulcerative colitis.

Background and Aims Although genome-wide association studies [GWAS] in inflammatory bowel disease [IBD] have identified a large number of common disease susceptibility alleles for both Crohn’s disease [CD] and ulcerative colitis [UC], a substantial fraction of IBD heritability remains unexplained, suggesting that rare coding genetic variants may also have a role in pathogenesis. We used high-throughput sequencing in families with multiple cases of IBD, followed by genotyping of cases and controls, to investigate whether rare protein-altering genetic variants are associated with susceptibility to IBD. Methods Whole-exome sequencing was carried out in 10 families in whom three or more individuals were affected with IBD. A stepwise filtering approach was applied to exome variants, to identify potential causal variants. Follow-up genotyping was performed in 6025 IBD cases [2948 CD; 3077 UC] and 7238 controls. Results Our exome variant analysis revealed coding variants in the NLRP7 gene that were present in affected individuals in two distinct families. Genotyping of the two variants, p.S361L and p.R801H, in IBD cases and controls showed that the p.S361L variant was significantly associated with an increased risk of ulcerative colitis [odds ratio 4.79, p = 0.0039] and IBD [odds ratio 3.17, p = 0.037]. A combined analysis of both variants showed suggestive association with an increased risk of IBD [odds ratio 2.77, p = 0.018]. Conclusions The results suggest that NLRP7 signalling and inflammasome formation may be a significant component in the pathogenesis of IBD

A comprehensive review on the applicability of hydrogen and natural gas as gaseous fuel for dual fuel engine operation

Hydrogen and natural gas are promising alternatives to fossil fuels in combustion engines for sustainable environment. Consumption of fossil fuels is a matter of growing concern that needs to be dealt with seriously for a sustainable, better tomorrow as fossil fuels have dreadful implications on the environment. Therefore, there is an urgent need across the globe to quest for environment-friendly alternative fuels, which can power internal combustion engines. Moreover, regulated and unregulated emissions from engines have been affecting human health and the environment. In this review article, hydrogen in combination with natural gas along with diesel as a pilot fuel is investigated. The impactsof exhaust gas recirculation with hydrogen and natural gas are also discussed. It is observed from the review that an H2 proportion of up to 5 30 is beneficial in combination with natural gas as well with other alternative fuels. The further increase in the hydrogen proportion create the problem of backfiring, knocking as well as increasing the NOx emissions. The transportation and storage are the biggest problems with the hydrogen fuel. Among the alternatives, gaseous fuels have great importance, and they need proper attention for inclusion in the CI engine as a fuel used in dual-fuel mode