Ethanol exposure diminishes intestinal abundance in both mice and humans and can be recovered in experimental ALD by oral supplementation. promotes intestinal barrier integrity and ameliorates experimental ALD. Our data suggest that patients with ALD might benefit from supplementation.
Obesity and obesity-related disorders have dramatically increased globally in the last decades. These entities are commonly associated with a state of insulin resistance and the relationship between extensive lipid deposition and insulin resistance is widely accepted. The underlying mechanisms for insulin resistance, however, are still incompletely understood. Evidence from experimental research and human studies in the last years has suggested that innate immune pathways and inflammatory mechanisms also might play a role. Insulin resistance in case of obesity is commonly accompanied by low-grade systemic inflammation and adipose tissue inflammation. The expression of various pro-inflammatory cytokines such as tumor necrosis factor (TNF)-α, interleukin (IL)-1 and IL-6 is increased in adipose tissue and its expression linked to systemic inflammation and accompanying insulin resistance. Weight loss reduces this enhanced cytokine expression in the adipose tissue and thereby improves systemic inflammation. Whereas there is also substantial evidence that pro-inflammatory cytokines, certain members of the inflammasome and various transcription factors such as nuclear factor-κB play a major role in animal models of insulin resistance and type 2 diabetes, human studies neutralizing certain pro-inflammatory cytokines suggest so far that not all pro-inflammatory cytokines are of equal clinical importance. First clinical studies favor an important role for IL-1 family members and probably IL-6 but not for TNF-α in insulin-resistant states. Although we still have missing links in the understanding of insulin resistance, certain inflammatory pathways have also evolved in humans as central players.
ObjectiveNicotinamide phosphoribosyltransferase (NAMPT, also referred to as pre-B cell colony-enhancing factor or visfatin) is critically required for the maintenance of cellular nicotinamide adenine dinucleotide (NAD) supply catalysing the rate-limiting step of the NAD salvage pathway. NAMPT is strongly upregulated in inflammation including IBD and counteracts an increased cellular NAD turnover mediated by NAD-depleting enzymes. These constitute an important mechanistic link between inflammatory, metabolic and transcriptional pathways and NAD metabolism.DesignWe investigated the impact of NAMPT inhibition by the small-molecule inhibitor FK866 in the dextran sulfate sodium (DSS) model of colitis and the azoxymethane/DSS model of colitis-associated cancer. The impact of NAD depletion on differentiation of mouse and human primary monocytes/macrophages was studied in vitro. Finally, we tested the efficacy of FK866 compared with dexamethasone and infliximab in lamina propria mononuclear cells (LPMNC) isolated from patients with IBD.ResultsFK866 ameliorated DSS-induced colitis and suppressed inflammation-associated tumorigenesis in mice. FK866 potently inhibited NAMPT activity as demonstrated by reduced mucosal NAD, resulting in reduced abundances and activities of NAD-dependent enzymes including PARP1, Sirt6 and CD38, reduced nuclear factor kappa B activation, and decreased cellular infiltration by inflammatory monocytes, macrophages and activated T cells. Remarkably, FK866 effectively supressed cytokine release from LPMNCs of patients with IBD. As FK866 was also effective in Rag1−⁄− mice, we mechanistically linked FK866 treatment with altered monocyte/macrophage biology and skewed macrophage polarisation by reducing CD86, CD38, MHC-II and interleukin (IL)-6 and promoting CD206, Egr2 and IL-10.ConclusionOur data emphasise the importance of NAD immunometabolism for mucosal immunity and highlight FK866-mediated NAMPT blockade as a promising therapeutic approach in acute intestinal inflammation.
Dietary factors and the associated lifestyle play a major role in the pathophysiology of many diseases. Several diets, especially a Western lifestyle with a high consumption of meat and carbohydrates and a low consumption of vegetables, have been linked to common diseases, such as metabolic syndrome, atherosclerosis, inflammatory bowel diseases, and colon cancer. The gastrointestinal tract harbors a complex and yet mainly molecularly defined microbiota, which contains an enormous number of different species. Recent advances in sequencing technologies have allowed the characterization of the human microbiome and opened the possibility to study the effect of "environmental" factors on this microbiome. The most important environmental factor is probably "what we eat," and the initial studies have revealed fascinating results on the interaction of nutrients with our microbiota. Whereas short-term changes in dietary patterns may not have major influences, long-term diets can affect the microbiota in a substantial manner. This issue may potentially have major relevance for human gastrointestinal health and disease because our microbiota has features to regulate many immune and metabolic functions. Increasing our knowledge on the interaction between nutrients and microbiota may have tremendous consequences and result in a better understanding of diseases, even beyond the gastrointestinal tract, and finally lead to better preventive and therapeutic strategies.
Checkpoint molecules such as programmed cell death protein-1 (PD-1) and its ligand PD-L1 are critically required for tumor immune escape. The objective of this study was to investigate tumoral PD-1 and PD-L1 mRNA-expression in a cohort of ovarian cancer (OC) patients in relation to tumor mutations. We analyzed mRNA expression of PD-1, PD-L1 and IFNG by quantitative real-time PCR in tissue of 170 patients with low grade-serous (LGSOC), high-grade serous (HGSOC), endometrioid and clear cell OC compared to 28 non-diseased tissues (ovaries and fallopian tubes) in relation to tumor protein 53 (TP53) and breast cancer gene 1/2 (BRCA1/2) mutation status. TP53-mutated OC strongly expressed PD-L1 compared to TP53 wild-type OC (p = 0.028) and BRCA1/2-mutated OC increasingly expressed PD-1 (p = 0.024) and PD-L1 (p = 0.012) compared to BRCA1/2 wild-type OC. For the first time in human, we noted a strong correlation between tumoral IFNG and PD-1 or PD-L1 mRNA-expression, respectively (p < 0.001). OC tissue increasingly expressed PD-1 compared to healthy controls (vs. ovaries: p < 0.001; vs. tubes: p = 0.018). PD-1 and PD-L1 mRNA-expression increased with higher tumor grade (p = 0.008 and p = 0.027, respectively) and younger age (< median age, p = 0.001). Finally, in the major subgroup of our cohort, FIGO stage III/IV HGSOC, high PD-1 and PD-L1 mRNA-expression was associated with reduced progression-free (p = 0.024) and overall survival (p = 0.049) but only in the univariate analysis. Our study suggests that in OC PD-1/PD-L1 mRNA-expression is controlled by IFNγ and affected by TP53 and BRCA1/2 mutations. We suggest that these mutations might serve as potential predictive factors that guide anti-PD1/PD-L1 immunotherapy.
LCN2 drives ethanol-induced neutrophilic inflammation and propagates the development of ALD. Despite a critical role for LCN2 in immunity and infection, pharmacological neutralisation of LCN2 might be of promise in ALD.
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