Wanping Aw

Beneficial effects of soluble dietary Jerusalem artichoke ( Helianthus tuberosus ) in the prevention of the onset of type 2 diabetes and non-alcoholic fatty liver disease in high-fructose diet-fed rats

Jerusalem artichoke (JA) has the potential to attenuate lipid disturbances and insulin resistance (IR), but the underlying mechanisms are not well understood. In the present study, we elucidated the physiological responses and mechanisms of JA intervention with a comprehensive transcriptome analysis. Wistar rats were fed a control diet, a 60 % fructose-enriched diet (FRU), or a FRU with 10 % JA (n 6-7) for 4 weeks. An oral glucose tolerance test was carried out on day 21. Liver samples were collected for biochemical and global gene expression analyses (GeneChip® Rat Genome 230 2.0 Array, Affymetrix). Fructose feeding resulted in IR and hepatic TAG accumulation; dietary JA supplementation significantly improved these changes. Transcriptomic profiling revealed that the expression of malic enzyme 1 (Me1), associated with fatty acid synthesis; decorin (Dcn), related to fibrosis; and cytochrome P450, family 1, subfamily a, polypeptide 2 (Cyp1a2) and nicotinamide phosphoribosyltransferase (Nampt), associated with inflammation, was differentially altered by the FRU, whereas dietary JA supplementation significantly improved the expression of these genes. We established for the first time the molecular mechanisms driving the beneficial effects of JA in the prevention of type 2 diabetes and non-alcoholic fatty liver disease. We propose that 10 % JA supplementation may be beneficial for the prevention of the onset of these diseases.

Metabolic Interactions of Purine Derivatives with Human ABC Transporter ABCG2: Genetic Testing to Assess Gout Risk

In mammals, excess purine nucleosides are removed from the body by breakdown in the liver and excretion from the kidneys. Uric acid is the end product of purine metabolism in humans. Two-thirds of uric acid in the human body is normally excreted through the kidney, whereas one-third undergoes uricolysis (decomposition of uric acid) in the gut. Elevated serum uric acid levels result in gout and could be a risk factor for cardiovascular disease and diabetes. Recent studies have shown that human ATP-binding cassette transporter ABCG2 plays a role of renal excretion of uric acid. Two non-synonymous single nucleotide polymorphisms (SNPs), i.e., 421C>A (major) and 376C>T (minor), in the ABCG2 gene result in impaired transport activity, owing to ubiquitination-mediated proteosomal degradation and truncation of ABCG2, respectively. These genetic polymorphisms are associated with hyperuricemia and gout. Allele frequencies of those SNPs are significantly higher in Asian populations than they are in African and Caucasian populations. A rapid and isothermal genotyping method has been developed to detect the SNP 421C>A, where one drop of peripheral blood is sufficient for the detection. Development of simple genotyping methods would serve to improve prevention and early therapeutic intervention for high-risk individuals in personalized healthcare.

A new trend in personalized medicine: rapid detection of SNPs in drug transporter genes by the SmartAmp method.

Clinical validation of genetic polymorphisms and the development of new technologies for the rapid detection of clinically important variants are critical issues in the advancement of personalized medicine. The Smart Amplification (SmartAmp) process was recently developed as a rapid and cost‐effective method that enables rapid detection of genetic polymorphisms within ~40 min, under isothermal conditions, and without the need for DNA isolation or polymerase chain reaction (PCR) amplification. 1 This article addresses the molecular mechanisms involved in the SmartAmp method and its clinical applications.

The application of omics technologies in the functional evaluation of inulin and inulin-containing prebiotics dietary supplementation

Inulin, a natural renewable polysaccharide resource produced by various plants in nature, has been reported to possess a significant number of diverse pharmaceutical and food applications. Recently, there has been rapid progress in high-throughput technologies and platforms to assay global mRNA, proteins, metabolites and gut microbiota. In this review, we will describe the current status of utilizing omics technologies of elucidating the impact of inulin and inulin-containing prebiotics at the transcriptome, proteome, metabolome and gut microbiome levels. Although many studies in this review have addressed the impact of inulin comprehensively, these omics technologies only enable us to understand physiological information at each different stage of mRNA, protein, metabolite and gut microbe. We believe that a synergistic approach is vital in order to fully illustrate the intricate beauty behind the relatively modest influence of food factors like inulin on host health.

Eggshell membrane powder ameliorates intestinal inflammation by facilitating the restitution of epithelial injury and alleviating microbial dysbiosis

Gut microbiota is an essential factor in the shaping of intestinal immune system development and driving inflammation in inflammatory bowel disease (IBD). We report the effects and microbe-host interactions underlying an intervention using fine powder of eggshell membrane (ESM) against IBD. ESM attenuated lipopolysaccharide-induced inflammatory cytokine production and promoted the Caco-2 cell proliferation by up-regulating growth factors in vitro. In a murine model of dextran sodium sulphate-induced colitis, ESM significantly suppressed the disease activity index and colon shortening. These effects were associated with significant ameliorations of gene expressions of inflammatory mediators, intestinal epithelial cell proliferation, restitution-related factors and antimicrobial peptides. Multifaceted integrated omics analyses revealed improved levels of energy metabolism-related genes, proteins and metabolites. Concomitantly, cecal metagenomic information established an essential role of ESM in improving dysbiosis characterized by increasing the diversity of bacteria and decreasing absolute numbers of pathogenic bacteria such as Enterobacteriaceae and E. coli, as well as in the regulation of the expansion of Th17 cells by suppressing the overgrowth of segmented filamentous bacteria. Such modulations have functional effects on the host; i.e., repairing the epithelium, regulating energy requirements and eventually alleviating mucosal inflammation. These findings are first insights into ESM’s modulation of microbiota and IBD suppression, providing new perspectives on the prevention/treatment of IBD.

Identification of Branched Chain Amino Acids; Underlying Molecular Pathways Using Transcriptomic Analysis: Application to Cirrhosis

Oral administration of branched-chain amino acids (BCAA) is important in improving the prognosis of patients with chronic liver disease. BCAA can improve albumin synthesis, hepatic encephalopathy, insulin resistance, and suppress hepatocarcinoma, leading to higher event-free survival rate and better quality of life. We addressed the effects of BCAA dietary supplementation on global gene expression in liver and skeletal muscle and the molecular mechanisms underlying the improvement in liver cirrhosis using DNA microarray analysis combined with RNase protection assay. We established, for the first time, the regulatory gene pathways of processes involved in hepatic fibrosis and energy metabolism (hypoalbuminemia, hyperammonemia, and carbohydrate catabolism, and their relationships) under BCAA supplementation.

Abstract CN4-2: Genetic polymorphisms of ABC transporters in cancer chemotherapy: Development of SmartAmp2 method for clinical genetic testing

Pharmacogenomics data can facilitate our understanding of the sources of variability in drug response, which can potentially lead to improved safety and efficacy of chemotherapy for individual patients. Genetic polymorphisms of human ABC transporter genes are reportedly related to the risk of diseases or patients9 responses to medication. However, a key requirement for the development of individualized medicine or personalized therapy is the ability to rapidly and conveniently test patients for genetic polymorphisms and/or mutations. For rapid genetic diagnosis, we have recently developed a rapid and cost-effective method named “SmartAmp2” that enables us to clinically test genotypes. Since ABCB1, ABCG2, ABCC4, and ABCC11 genes are known to be critically involved in cancer chemotherapy, we have examined whether the SmartAmp2 method could detect SNPs in those ABC transporter genes. In our study using clinical samples, the SmartAmp2 method has been proven to accurately detect and discriminate all possible homozygotes and heterozygotes of the SNPs we tested. Furthermore, we developed SmartAmp2 primers to detect mutations of K-RAS and EGFR genes in colon and lung cancers. Since the SmartAmp2 method enables us to detect genetic polymorphisms or mutations within 30 to 45 min under isothermal conditions without DNA isolation and PCR amplification, this method would provide a practical tool of genetic testing in cancer chemotherapy. Citation Information: Clin Cancer Res 2010;16(7 Suppl):CN4-2