Thrombospondin-1 (TSP1) is a matricellular protein with many important roles in mediating carcinogenesis, fibrosis, leukocyte recruitment, and metabolism. We have previously shown a role of diet in the absence of TSP1 in liver metabolism in the context of a colorectal cancer model. However, the metabolic implications of TSP1 regulation by diet in the liver metabolism are currently understudied. Therefore Discrete correlation summation (DCS) was used to re-interrogate data and determine the metabolic alterations of TSP1 deficiency in the liver, providing new insights into the role of TSP1 in liver injury and the progression of liver pathologies such as nonalcoholic fatty liver disease (NAFLD). DCS analysis provides a straightforward approach to rank covariance and data clustering when analyzing complex data sets. Using this approach, our previous liver metabolite data was re-analyzed by comparing wild-type (WT) and Thrombospondin-1 null (Thbs1−/−) mice, identifying changes driven by genotype and diet. Principal component analysis showed clustering of animals by genotype regardless of diet, indicating that TSP1 deficiency alters metabolite handling in the liver. High-fat diet consumption significantly altered over 150 metabolites in the Thbs1−/− livers versus approximately 90 in the wild-type livers, most involved in amino acid metabolism. The absence of Thbs1 differentially regulated tryptophan and tricarboxylic acid cycle metabolites implicated in the progression of NAFLD. Overall, the lack of Thbs1 caused a significant shift in liver metabolism with potential implications for liver injury and the progression of NAFLD.
1 October 2014 in Journal of the Academy of Nutrition and Dietetics
A discussion of the gut microbiome’s development, determinants, and dysbiosis in cancers of the esophagus and stomach Karan Grover, Stephanie Gregory, John F. Gibbs, Nancy J. Emenaker
The concept of green chemoprevention was introduced in 2012 by Drs. Jed Fahey and Thomas Kensler as whole-plant foods and/or extract-based interventions demonstrating cancer prevention activity. Refining concepts and research demonstrating proof-of-principle approaches are highlighted within this review. Early approaches included extensively investigated whole foods, including broccoli sprouts and black raspberries showing dose–responsive effects across a range of activities in both animals and humans with minimal or no apparent toxicity. A recent randomized crossover trial evaluating the detoxification of tobacco carcinogens by a broccoli seed and sprout extract in the high-risk cohort of current smokers highlights the use of a dietary supplement as a potential next-generation green chemoprevention or green cancer prevention approach. Challenges are addressed, including the selection of dose, duration and mode of delivery, choice of control group, and standardization of the plant food or extract. Identification and characterization of molecular targets and careful selection of high-risk cohorts for study are additional important considerations when designing studies. Goals for precision green cancer prevention include acquiring robust evidence from carefully controlled human studies linking plant foods, extracts, and compounds to modulation of targets for cancer risk reduction in individual cancer types.
Sucralfate, which binds to the matrix of the ulcer bed, is theoretically advantageous for duodenal ulcer therapy, but has not fulfilled its promise clinically. We examined the effects of sucralfate and related compounds in a human intestinal epithelial (Caco-2) cell culture model of restitution on sheet migration across and adhesion to collagen I. Migration was quantitated across a collagen I matrix treated with sucralfate or related compounds and correlated with cell adhesion. Caco-2 motility was significantly and dose-responsively inhibited by sucralfate at therapeutic luminal concentrations. Sucrose octaacetate, the sucralfate backbone, and lactose octaacetate exhibited similar effects while the β-bonded disaccharide maltose octaacetate had little effect. Sucrose itself slightly stimulated motility. Adhesion effects paralleled motility. Thus, sucralfate may inhibit intestinal epithelial motility by sterically interfering with adhesion to collagen I. A sucralfate analog with a lactose octaacetate backbone might retain growth factor binding without inhibiting enterocyte motility, perhaps improving its clinical efficacy.