Browsing by Author "Wang, Xiaoliang"

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    1-Alpha, 25-dihydroxyvitamin D3 alters the pharmacokinetics of mycophenolic acid in renal transplant recipients by regulating two extrahepatic UDP-glucuronosyltransferases 1A8 and 1A10
    (Elsevier, 2016-12) Wang, Xiaoliang; Wang, Hongwei; Shen, Bing; Overholser, Brian R.; Cooper, Bruce R.; Lu, Yinghao; Tang, Huamei; Zhou, Chongzhi; Sun, Xing; Zhong, Lin; Favus, Murray J.; Decker, Brian S.; Liu, Wanqing; Peng, Zhihai; Department of Medicine, IU School of Medicine
    Mycophenolic acid (MPA) is an important immunosuppressant broadly used in renal transplantation. However, the large inter-patient variability in mycophenolic acid (MPA) pharmacokinetics (PK) limits its use. We hypothesize that extrahepatic metabolism of MPA may have significant impact on MPA PK variability. Two intestinal UDP-glucuronosyltransferases 1A8 and 1A10 plays critical role in MPA metabolism. Both in silico and previous genome-wide analyses suggested that vitamin D (VD) may regulate intestinal UGT1A expression. We validated the VD response elements (VDREs) across the UGT1A locus with chromatin immunoprecipitation (ChIP) and luciferase reporter assays. The impact of 1-alpha,25-dihydroxyvitamin D3 (D3) on UGT1A8 and UGT1A10 transcription and on MPA glucuronidation was tested in human intestinal cell lines LS180, Caco-2 and HCT-116. The correlation between transcription levels of VD receptor (VDR) and the two UGT genes were examined in human normal colorectal tissue samples (n = 73). PK alterations of MPA following the parent drug, mycophenolate mofetil (MMF), and D3 treatment was assessed among renal transplant recipients (n = 10). Our ChIP assay validate three VDREs which were further demonstrated as transcriptional enhancers with the luciferase assays. D3 treatment significantly increased transcription of both UGT genes as well as MPA glucuronidation in cells. The VDR mRNA level was highly correlated with that of both UGT1A8 and UGT1A10 in human colorectal tissue. D3 treatment in patients led to about 40% reduction in both AUC0-12 and Cmax while over 70% elevation of total clearance of MPA. Our study suggested a significant regulatory role of VD on MPA metabolism and PK via modulating extrahepatic UGT activity.
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    Exploratory genome-wide interaction analysis of non-steroidal anti-inflammatory drugs and predicted gene expression on colorectal cancer risk
    (American Association for Cancer Research, 2020-09) Wang, Xiaoliang; Su, Yu-Ru; Petersen, Paneen S.; Bien, Stephanie; Schmit, Stephanie L.; Drew, David A.; Albanes, Demetrius; Berndt, Sonja I.; Brenner, Hermann; Campbell, Peter T.; Casey, Graham; Chang-Claude, Jenny; Gallinger, Steven J.; Gruber, Stephen B.; Haile, Robert W.; Harrison, Tabitha A.; Hoffmeister, Michael; Jacobs, Eric J.; Jenkins, Mark A.; Joshi, Amit D.; Li, Li; Lin, Yi; Lindor, Noralane M.; Le Marchand, Loïc; Martin, Vicente; Milne, Roger; Maclnnis, Robert; Moreno, Victor; Nan, Hongmei; Newcomb, Polly A.; Potter, John D.; Rennert, Gad; Rennert, Hedy; Slattery, Martha L.; Thibodeau, Steve N.; Weinstein, Stephanie J.; Woods, Michael O.; Chan, Andrew T.; White, Emily; Hsu, Li; Peters, Ulrike; Global Health, School of Public Health
    Background: Regular use of nonsteroidal anti-inflammatory drugs (NSAID) is associated with lower risk of colorectal cancer. Genome-wide interaction analysis on single variants (G × E) has identified several SNPs that may interact with NSAIDs to confer colorectal cancer risk, but variations in gene expression levels may also modify the effect of NSAID use. Therefore, we tested interactions between NSAID use and predicted gene expression levels in relation to colorectal cancer risk. Methods: Genetically predicted gene expressions were tested for interaction with NSAID use on colorectal cancer risk among 19,258 colorectal cancer cases and 18,597 controls from 21 observational studies. A Mixed Score Test for Interactions (MiSTi) approach was used to jointly assess G × E effects which are modeled via fixed interaction effects of the weighted burden within each gene set (burden) and residual G × E effects (variance). A false discovery rate (FDR) at 0.2 was applied to correct for multiple testing. Results: Among the 4,840 genes tested, genetically predicted expression levels of four genes modified the effect of any NSAID use on colorectal cancer risk, including DPP10 (PG×E = 1.96 × 10-4), KRT16 (PG×E = 2.3 × 10-4), CD14 (PG×E = 9.38 × 10-4), and CYP27A1 (PG×E = 1.44 × 10-3). There was a significant interaction between expression level of RP11-89N17 and regular use of aspirin only on colorectal cancer risk (PG×E = 3.23 × 10-5). No interactions were observed between predicted gene expression and nonaspirin NSAID use at FDR < 0.2. Conclusions: By incorporating functional information, we discovered several novel genes that interacted with NSAID use.
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    Integrated miR-mRNA Network Underlying Hepatic Fat Accumulation in Humans
    Srivastava, Rajneesh; Wang, Xiaoliang; Lin, Jingmei; Wei, Rongrong; Chaturvedi, Praneet; Chalasani, Naga P.; Janga, Sarath Chandra; Liu, Wanqing
    Background: An integrate miRs and mRNAs analysis in the development of Non-Alcoholic Fatty Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH) is lacking. We aimed to identify miRs as well as the miR-mRNA regulatory network involved in hepatic fat accumulation and human NAFLD. Materials and Methods: Hepatic fat content (HFC) was measured, and liver histology was characterized for 73 liver tissue samples. MicroRNAs and mRNAs significantly associated with HFC were identified based on genome-wide mRNA and miR expression profiling data. These miRs and mRNAs were further used to build miR-mRNA association networks in NAFLD and normal samples based on the potential miR-mRNA targeting, as well as to conduct a pathway enrichment analysis. Results: We identified 62 miRs significantly correlated with HFC (p<0.05), with miR-518b and miR-19b demonstrated to be the most significant positive and negative correlation with HFC, respectively (p<0.008 for both). Many miRs that were previously associated with NAFLD/NASH were also observed. Integrated network analysis indicated that a few miRs-30b*, 616, 17*, 129-5p, 204, and 20a controlled >80% of HFC-associated mRNAs in this network, and the regulation network was significantly rewired from normal to NAFLD. Pathway analyses revealed that inflammation pathways mediated by chemokine and cytokine signaling, Wnt signaling, lntegrin signaling and Natural killer cell mediated cytotoxicity were enriched (p<0.05) in hepatic fat accumulation.
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    Transcriptional regulation of PNPLA3 and its impact on susceptibility to nonalcoholic fatty liver Disease (NAFLD) in humans
    (Impact Journals, 2016-10-13) Liu, Wanqing; Anstee, Quentin M.; Wang, Xiaoliang; Gawrieh, Samer; Gamazon, Eric R.; Athinarayanan, Shaminie; Liu, Yang-Lin; Darlay, Rebecca; Cordell, Heather J.; Daly, Ann K.; Day, Chris P.; Chalasani, Naga; Department of Medicine, IU School of Medicine
    The increased expression of PNPLA3148M leads to hepatosteatosis in mice. This study aims to investigate the genetic control of hepatic PNPLA3 transcription and to explore its impact on NAFLD risk in humans. Through a locus-wide expression quantitative trait loci (eQTL) mapping in two human liver sample sets, a PNPLA3 intronic SNP, rs139051 A>G was identified as a significant eQTL (p = 6.6×10-8) influencing PNPLA3 transcription, with the A allele significantly associated with increased PNPLA3 mRNA. An electrophoresis mobility shift assay further demonstrated that the A allele has enhanced affinity to nuclear proteins than the G allele. The impact of this eQTL on NAFLD risk was further tested in three independent populations. We found that rs139051 did not independently affect the NAFLD risk, whilst rs738409 did not significantly modulate PNPLA3 transcription but was associated with NAFLD risk. The A-G haplotype associated with higher transcription of the disease-risk rs738409 G allele conferred similar risk for NAFLD compared to the G-G haplotype that possesses a lower transcription level. Our study suggests that the pathogenic role of PNPLA3148M in NAFLD is independent of the gene transcription in humans, which may be attributed to the high endogenous transcription level of PNPLA3 gene in human livers.