Genetically predicted circulating concentrations of micronutrients and risk of colorectal cancer among individuals of European descent: a Mendelian randomization study.

BACKGROUND: The literature on associations of circulating concentrations of minerals and vitamins with risk of colorectal cancer is limited and inconsistent. Evidence from randomized controlled trials (RCTs) to support the efficacy of dietary modification or nutrient supplementation for colorectal cancer prevention is also limited. OBJECTIVES: To complement observational and RCT findings, we investigated associations of genetically predicted concentrations of 11 micronutrients (ß-carotene, calcium, copper, folate, iron, magnesium, phosphorus, selenium, vitamin B-6, vitamin B-12, and zinc) with colorectal cancer risk using Mendelian randomization (MR). METHODS: Two-sample MR was conducted using 58,221 individuals with colorectal cancer and 67,694 controls from the Genetics and Epidemiology of Colorectal Cancer Consortium, Colorectal Cancer Transdisciplinary Study, and Colon Cancer Family Registry. Inverse variance-weighted MR analyses were performed with sensitivity analyses to assess the impact of potential violations of MR assumptions. RESULTS: Nominally significant associations were noted for genetically predicted iron concentration and higher risk of colon cancer [ORs per SD (ORSD): 1.08; 95% CI: 1.00, 1.17; P value = 0.05] and similarly for proximal colon cancer, and for vitamin B-12 concentration and higher risk of colorectal cancer (ORSD: 1.12; 95% CI: 1.03, 1.21; P value = 0.01) and similarly for colon cancer. A nominally significant association was also noted for genetically predicted selenium concentration and lower risk of colon cancer (ORSD: 0.98; 95% CI: 0.96, 1.00; P value = 0.05) and similarly for distal colon cancer. These associations were robust to sensitivity analyses. Nominally significant inverse associations were observed for zinc and risk of colorectal and distal colon cancers, but sensitivity analyses could not be performed. None of these findings survived correction for multiple testing. Genetically predicted concentrations of ß-carotene, calcium, copper, folate, magnesium, phosphorus, and vitamin B-6 were not associated with disease risk. CONCLUSIONS: These results suggest possible causal associations of circulating iron and vitamin B-12 (positively) and selenium (inversely) with risk of colon cancer.

Zebrafish In-Vivo Screening for Compounds Amplifying Hematopoietic Stem and Progenitor Cells: - Preclinical Validation in Human CD34+ Stem and Progenitor Cells.

The identification of small molecules that either increase the number and/or enhance the activity of human hematopoietic stem and progenitor cells (hHSPCs) during ex vivo expansion remains challenging. We used an unbiased in vivo chemical screen in a transgenic (c-myb:EGFP) zebrafish embryo model and identified histone deacetylase inhibitors (HDACIs), particularly valproic acid (VPA), as significant enhancers of the number of phenotypic HSPCs, both in vivo and during ex vivo expansion. The long-term functionality of these expanded hHSPCs was verified in a xenotransplantation model with NSG mice. Interestingly, VPA increased CD34+ cell adhesion to primary mesenchymal stromal cells and reduced their in vitro chemokine-mediated migration capacity. In line with this, VPA-treated human CD34+ cells showed reduced homing and early engraftment in a xenograft transplant model, but retained their long-term engraftment potential in vivo, and maintained their differentiation ability both in vitro and in vivo. In summary, our data demonstrate that certain HDACIs lead to a net expansion of hHSPCs with retained long-term engraftment potential and could be further explored as candidate compounds to amplify ex-vivo engineered peripheral blood stem cells.

4-O'-methylhonokiol protects from alcohol/carbon tetrachloride-induced liver injury in mice.

Alcoholic liver disease (ALD) is a leading cause of liver cirrhosis, liver cancer, and related mortality. The endocannabinoid system contributes to the development of chronic liver diseases, where cannabinoid receptor 2 (CB2) has been shown to have a protecting role. Thus, here, we investigated how CB2 agonism by 4'-O-methylhonokiol (MHK), a biphenyl from Magnolia grandiflora, affects chronic alcohol-induced liver fibrosis and damage in mice. A combination of alcohol (10% vol/vol) and CCl4 (1 ml/kg) was applied to C57BL/6 mice for 5 weeks. MHK (5 mg/kg) was administered daily, and liver damage assessed by serum AST and ALT levels, histology, gene, and protein expression. Endocannabinoids (ECs) and related lipid derivatives were measured by liquid chromatography and mass spectrometry (LC-MS) in liver tissues. In vitro, MHK was studied in TGFß1-activated hepatic stellate cells (HSC). MHK treatment alleviated hepatic fibrosis, paralleled by induced expression of matrix metalloproteinases (MMP)-2, -3, -9, and -13, and downregulation of CB1 mRNA. Necrotic lesions and hepatic inflammation were moderately improved, while IL-10 mRNA increased and IFNγ, Mcl-1, JNK1, and RIPK1 normalized by MHK. Hepatic anandamide (AEA) and related N-acetylethanolamines (NAEs) were elevated in MHK group, whereas fatty acid synthase and diacylglycerol O-acyltransferase 2 expression reduced. In vitro, MHK prevented HSC activation and induced apoptosis via induction of bak1 and bcl-2. To conclude, MHK revealed hepatoprotective effects during alcohol-induced liver damage through the induction of MMPs, AEA, and NAEs and prevention of HSC activation, indicating MHK as a potent therapeutic for liver fibrosis and ALD. KEY MESSAGES: Methylhonokiol improves liver damage and survival. Methylhonokiol reduces hepatic fibrosis and necroinflammation. Methylhonokiol prevents myofibroblast activation and induces apoptosis. Methylhonokiol upregulates endocannabinoids and related N-acylethanolamines. Methylhonokiol contributes to lipid hydrolysis via PPARα/γ.

Metabolomic tissue signature in human non-alcoholic fatty liver disease identifies protective candidate metabolites.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common chronic liver disorder in industrialized countries, yet its pathophysiology is incompletely understood. Small-molecule metabolite screens may offer new insights into disease mechanisms and reveal new treatment targets. METHODS: Discovery (N = 33) and replication (N = 66) of liver biopsies spanning the range from normal liver histology to non-alcoholic steatohepatitis (NASH) were ascertained ensuring rapid freezing under 30 s in patients. 252 metabolites were assessed using GC/MS. Replicated metabolites were evaluated in a murine high-fat diet model of NAFLD. RESULTS: In a two-stage metabolic screening, hydroquinone (HQ, p(combined) = 3.0 × 10(-4)) and nicotinic acid (NA, p(combined) = 3.9 × 10(-9)) were inversely correlated with histological NAFLD severity. A murine high-fat diet model of NAFLD demonstrated a protective effect of these two substances against NAFLD: Supplementation with 1% HQ reduced only liver steatosis, whereas 0.6% NA reduced both liver fat content and serum transaminase levels and induced a complex regulatory network of genes linked to NALFD pathogenesis in a global expression pathway analysis. Human nutritional intake of NA equivalent was also consistent with a protective effect of NA against NASH progression. CONCLUSION: This first small-molecular screen of human liver tissue identified two replicated protective metabolites. Either the use of NA or targeting its regulatory pathways might be explored to treat or prevent human NAFLD.

Oral glutamine supplementation improves intestinal permeability dysfunction in a murine acute graft-vs.-host disease model.

Although a profound barrier dysfunction has been reported, little is known about the pathophysiological mechanism evoking gastrointestinal graft-vs.-host disease (GI-GvHD) and apparent therapeutic options. The aim of this study was to evaluate the influence of oral glutamine on the course of GI-GvHD in an acute semiallogenic graft-vs.-host disease (GvHD) in irradiated B6D2F1 mice. An acute semiallogenic GvHD was induced by intraperitoneal injection of lymphocytes from C57BL/6 mice to irradiated B6D2F1 mice. Half of the GvHD animals received oral glutamine supplementation for 6 days started at the time of lymphocyte transfer. Six days after induction of the semiallogenic GvHD, jejunum specimens were prepared. The expression of the proinflammatory cytokine TNF-α and the tight junction protein occludin was investigated by PCR. Histological changes along with the apoptotic response were evaluated and intestinal permeability was assessed. Animals with GvHD showed a strong increase in paracellular permeability as a sign of the disturbed barrier function. TNF-α expression was significantly increased and the expression of the tight junction protein occludin decreased. GvHD led to mucosal atrophy, crypt hyperplasia, crypt apoptosis, and a disintegration of the tight junctions. Glutamine-treated mice showed reduced expression of TNF-α, increased occludin expression, fewer histological changes in the jejunum, smaller number of apoptotic cells in the crypt, and reduced gastrointestinal permeability. In conclusion, oral glutamine seems to have beneficial effects on the severity of inflammatory changes in the course of GvHD and might be a therapeutic option.

Probiotic bacteria reduced duration and severity but not the incidence of common cold episodes in a double blind, randomized, controlled trial.

To investigate the effect of long-term consumption of probiotic bacteria on viral respiratory tract infections (common cold, influenza), a randomized, double blind, controlled intervention study was performed during two winter/spring periods (3 and 5 month). Four hundred and seventy-nine healthy adults were supplemented daily with vitamins plus minerals with or without probiotic lactobacilli and bifidobacteria. The intake of the probiotic had no effect on the incidence of common cold infections (verum=158, control=153 episodes, influenza was not observed), but significantly shortened duration of episodes by almost 2 days (7.0+/-0.5 versus 8.9+/-1.0 days, p=0.045), reduced the severity of symptoms and led to larger increases in cytotoxic T plus T suppressor cell counts and in T helper cell counts.

Effect of Lactobacillus gasseri PA 16/8, Bifidobacterium longum SP 07/3, B. bifidum MF 20/5 on common cold episodes: a double blind, randomized, controlled trial.

BACKGROUND & AIMS: The aim of this study was to investigate whether the consumption of Lactobacillus gasseri PA 16/8, Bifidobacterium longum SP 07/3, B. bifidum MF 20/5 (5 x 10(7) cfu/tablet) during at least 3 months influences the severity of symptoms and the incidence and duration of the common cold. METHODS: A randomized, double-blind, placebo-controlled intervention study was performed over at least 3 months during two winter/spring periods. Four hundred and seventy nine healthy adults (aged 18-67) were supplemented daily with vitamins and minerals with or without the probiotic bacteria. Cellular immune parameters were evaluated in a randomly drawn subgroup of 122 volunteers before and after 14 days of supplementation. During common cold episodes, the participants recorded symptoms daily. Stool samples were collected before and after 14 days of probiotic supplementation to quantify fecal Lactobacilli and Bifidobacteria using qRT-PCR. RESULTS: The total symptom score, the duration of common cold episodes, and days with fever during an episode were lower in the probiotic-treated group than in the control group: 79.3+/-7.4 vs. 102.5+/-12.2 points (P = 0.056), 7.0+/-0.5 vs. 8.9+/-1.0 days (P = 0.045), 0.24+/-0.1 vs. 1.0+/-0.3 days (P = 0.017). A significantly higher enhancement of cytotoxic plus T suppressor cells (CD8+) and a higher enhancement of T helper cells (CD4+) was observed in the probiotic-treated group. Fecal lactobacilli and bifidobacteria increased significantly after probiotic supplementation. CONCLUSIONS: The intake of probiotic bacteria during at least 3 months significantly shortened common cold episodes by almost 2 days and reduced the severity of symptoms.