Browsing by Author "Liu, Wanqing"

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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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    ADH1B*2 is Associated With Reduced Severity of Nonalcoholic Fatty Liver Disease in Adults, Independent of Alcohol Consumption
    (Elsevier, 2020) Vilar-Gomez, Eduardo; Sookoian, Silvia; Pirola, Carlos Jose; Liang, Tiebing; Gawrieh, Samer; Cummings, Oscar; Liu, Wanqing; Chalasani, Naga; Medicine, School of Medicine
    Background & Aims Alcohol dehydrogenase 1B (ADH1B) is involved in alcohol metabolism. The allele A ( ADH1B*2) of rs1229984: A>G variant in ADH1B is associated a higher alcohol metabolizing activity, compared to the ancestral allele G ( ADH1B*1). Moderate alcohol consumption is associated with reduced severity of nonalcoholic fatty liver disease (NAFLD), based on histologic analysis, compared with no alcohol consumption. However, it is unclear whether ADH1B*2 modifies the relationship between moderate alcohol consumption and severity of NAFLD. We examined the association between ADH1B*2 and moderate alcohol consumption and histologic severity of NAFLD. Methods We collected data from 1557 multi-ethnic adult patients with biopsy-proven NAFLD enrolled into 4 different studies conducted by the NASH Clinical Research Network. Histories of alcohol consumption were obtained from answers to standardized questionnaires. Liver biopsies were analyzed by histology and scored centrally according to the NASH CRN criteria. We performed covariate adjusted logistic regressions to identify associations between histologic features of NAFLD severity and moderate alcohol consumption and/or ADH1B*2. Results A higher proportion of Asians/Pacific Islanders/Hawaiians carried the ADH1B*2 allele (86%) than other racial groups (4%–13%). However, the study population comprised mostly non-Hispanic whites (1153 patients, 74%), so the primary analysis focused on this group. Among them, 433 were moderate drinkers and 90 were ADH1B*2 carriers. After we adjusted for confounders, including alcohol consumption status, ADH1B*2 was associated with lower frequency of steatohepatitis (odds ratio [OR], 0.52; P<.01) or fibrosis (odds ratio, 0.69; P=.050) compared with ADH1B*1. Moderate alcohol consumption (g/day) reduced the severity of NAFLD in patients with ADH1B*1 or ADH1B*2. However, ADH1B*2, compared to ADH1B*1, was associated with a reduced risk of definite NASH ( ADH1B*2 OR, 0.80; P<.01 vs ADH1B*1 OR, 0.96; P=.036) and a reduced risk of an NAFLD activity score of 4 or higher ( ADH1B*2 OR, 0.83; P=.012 vs ADH1B*1 OR, 0.96; P=.048) ( P<.01 for the difference in the effect of moderate alcohol consumption between alleles). The relationship between body mass index and NAFLD severity was significantly modified by ADH1B*2, even after we controlled for alcohol consumption. Conclusions ADH1B*2 reduces the risk of NASH and fibrosis in adults with NAFLD regardless of alcohol consumption status. ADH1B*2 might modify the association between high body mass index and NAFLD severity.
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    Causal relationships between NAFLD, T2D and obesity have implications for disease subphenotyping
    (Elsevier, 2020-08) Liu, Zhipeng; Zhang, Yang; Graham, Sarah; Wang, Xiaokun; Cai, Defeng; Huang, Menghao; Pique-Regi, Roger; Dong, Xiaocheng Charlie; Chen, Y. Eugene; Willer, Cristen; Liu, Wanqing; Biochemistry and Molecular Biology, School of Medicine
    Background & aims: Non-alcoholic fatty liver disease (NAFLD), type 2 diabetes (T2D) and obesity are epidemiologically correlated with each other but the causal inter-relationships between them remain incompletely understood. We aimed to explore the causal relationships between the 3 diseases. Methods: Using both UK Biobank and publicly available genome-wide association study data, we performed a 2-sample bidirectional Mendelian randomization analysis to test the causal inter-relationships between NAFLD, T2D, and obesity. Transgenic mice expressing the human PNPLA3-I148M isoforms (TghPNPLA3-I148M) were used as an example to validate causal effects and explore underlying mechanisms. Results: Genetically driven NAFLD significantly increased the risk of T2D and central obesity but not insulin resistance or generalized obesity, while genetically driven T2D, body mass index and WHRadjBMI causally increased NAFLD risk. The animal study focusing on PNPLA3 corroborated these causal effects: compared to the TghPNPLA3-I148I controls, the TghPNPLA3-I148M mice developed glucose intolerance and increased visceral fat, but maintained normal insulin sensitivity, reduced body weight, and decreased circulating total cholesterol. Mechanistically, the TghPNPLA3-I148M mice demonstrated decreased pancreatic insulin but increased glucagon secretion, which was associated with increased pancreatic inflammation. In addition, transcription of hepatic cholesterol biosynthesis pathway genes was significantly suppressed, while transcription of thermogenic pathway genes was activated in subcutaneous and brown adipose tissues but not in visceral fat in TghPNPLA3-I148M mice. Conclusions: Our study suggests that lifelong, genetically driven NAFLD causally promotes T2D with a late-onset type 1-like diabetic subphenotype and central obesity; while genetically driven T2D, obesity, and central obesity all causally increase the risk of NAFLD. This causal relationship revealed new insights into how nature and nurture drive these diseases, providing novel hypotheses for disease subphenotyping. Lay summary: Non-alcoholic fatty liver disease, type 2 diabetes and obesity are epidemiologically correlated with each other, but their causal relationships were incompletely understood. Herein, we identified causal relationships between these conditions, which suggest that each of these closely related diseases should be further stratified into subtypes. This is important for accurate diagnosis, prevention and treatment of these diseases.
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    The CYP3A5 genotypes of both liver transplant recipients and donors influence the time-dependent recovery of tacrolimus clearance during the early stage following transplantation
    (Wiley, 2021-10) Huang, Li; Assiri, Abdullah A.; Wen, Peihao; Zhang, Kun; Fan, Junwei; Xing, Tonghai; Liu, Yuan; Zhang, Jinyan; Wang, Zhaowen; Su, Zhaojie; Chen, Jiajia; Xiao, Yi; Wang, Rui; Na, Risi; Yuan, Liyun; Liu, Dehua; Xia, Junjie; Zhong, Lin; Liu, Wanqing; Guo, Wenzhi; Overholser, Brian R.; Peng, Zhihai; Medicine, School of Medicine
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    Epidermal Growth Factor Receptor (EGFR) Pathway Genes and Interstitial Lung Disease: An Association Study
    (Springer Nature, 2014-05-13) Li, Chong; Wei, Rongrong; Jones-Hall, Yava L.; Vittal, Ragini; Zhang, Min; Liu, Wanqing; Medicine, School of Medicine
    The etiology and pathogenesis of idiopathic interstitial lung disease (ILD) remain incompletely understood. Genetic susceptibility to ILD has been demonstrated in previous studies. It is well known that EGFR inhibitors can induce ILD in human lung cancer patient with ethnic differences, which prompted us to hypothesize that genetic variation in EGFR pathway genes confer susceptibility to ILD. We aimed in this study to investigate whether functional polymorphisms of EGFR and its ligands genes (EGF and TGFA) were associated with ILD. Three EGFR [-216G/T (rs712830), -191A/C (rs712829), 497R > K(A/G) (rs2227983)], one EGF [61A/G, (rs4444903)] and one TGFA (rs3821262C/T) polymorphisms previously demonstrated to alter gene functions were genotyped in 229 sporadic idiopathic ILD patients and 693 normal healthy individuals. Allelic and genotypic association tests between these polymorphisms and ILD were performed. The EGF 61A/G polymorphism was significantly associated with elevated risk of ILD, with the frequency of G allele significantly increased in the ILD patient population (OR = 1.33, 95%CI = 1.07-1.66, P = 0.0099). None of the other polymorphisms were associated with risk of ILD. Our study suggested that the EGF 61A/G polymorphism may be associated with sporadic ILD. While a false positive finding cannot be excluded, independent studies are warranted to further validate this result.
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    Fatty acid desaturase 1 gene polymorphisms control human hepatic lipid composition
    (Wiley, 2015-01) Wang, Libo; Athinarayanan, Shaminie; Jiang, Guanglong; Chalasani, Naga; Zhang, Min; Liu, Wanqing; Department of Medical and Molecular Genetics, IU School of Medicine
    Fatty acid desaturase (FADS) genes and their variants have been associated with multiple metabolic phenotypes, including liver enzymes and hepatic fat accumulation, but the detailed mechanism remains unclear. We aimed to delineate the role of FADSs in modulating lipid composition in human liver. We performed a targeted lipidomic analysis of a variety of phospholipids, sphingolipids, and ceramides among 154 human liver tissue samples. The associations between previously genome-wide association studies (GWASs)-identified six FADS single-nucleotide polymorphisms (SNPs), and these lipid levels as well as total hepatic fat content (HFC) were tested. The potential function of these SNPs in regulating transcription of three FADS genes (FADS1, FADS2, and FADS3) in the locus was also investigated. We found that though these SNPs were in high linkage disequilibrium (r(2) > 0.8), the rare alleles of these SNPs were consistently and significantly associated with the accumulation of multiple long-chain fatty acids (LCFAs), with C47H85O13P (C36:4), a phosphatidylinositol (PI), and C43H80O8PN (C38:3), a phosphatidylethanolamine (PE), reached the Bonferroni corrected significance (P < 3 × 10(-4)). Meanwhile, these SNPs were significantly associated with increased ratios between the more saturated and relatively less saturated forms of LCFAs, especially between PEs, PIs, and phosphatidylcholines (PCs; P ≤ 3.5 × 10(-6)). These alleles were also associated with increased total HFC (P < 0.05). Further analyses revealed that these alleles were associated with decreased hepatic expression of FADS1 (P = 0.0018 for rs174556), but not FADS2 or FADS3 (P > 0.05). CONCLUSION: Our findings revealed critical insight into the mechanism underlying FADS1 and its polymorphisms in modulating hepatic lipid deposition by altering gene transcription and controlling lipid composition in human livers.
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    Fatty Acid Desaturase 1 Influences Hepatic Lipid Homeostasis by Modulating the PPARα‐FGF21 Axis
    (Wiley, 2020-12-25) Athinarayanan, Shaminie; Fan, Yang-Yi; Wang, Xiaokun; Callaway, Evelyn; Cai, Defeng; Chalasani, Naga; Chapkin, Robert S.; Liu, Wanqing; Medicine, School of Medicine
    The fatty acid desaturase 1 (FADS1), also known as delta-5 desaturase (D5D), is one of the rate-limiting enzymes involved in the desaturation and elongation cascade of polyunsaturated fatty acids (PUFAs) to generate long-chain PUFAs (LC-PUFAs). Reduced function of D5D and decreased hepatic FADS1 expression, as well as low levels of LC-PUFAs, were associated with nonalcoholic fatty liver disease. However, the causal role of D5D in hepatic lipid homeostasis remains unclear. In this study, we hypothesized that down-regulation of FADS1 increases susceptibility to hepatic lipid accumulation. We used in vitro and in vivo models to test this hypothesis and to delineate the molecular mechanisms mediating the effect of reduced FADS1 function. Our study demonstrated that FADS1 knockdown significantly reduced cellular levels of LC-PUFAs and increased lipid accumulation and lipid droplet formation in HepG2 cells. The lipid accumulation was associated with significant alterations in multiple pathways involved in lipid homeostasis, especially fatty acid oxidation. These effects were demonstrated to be mediated by the reduced function of the peroxisome proliferator-activated receptor alpha (PPARα)-fibroblast growth factor 21 (FGF21) axis, which can be reversed by treatment with docosahexaenoic acid, PPARα agonist, or FGF21. In vivo, FADS1-knockout mice fed with high-fat diet developed increased hepatic steatosis as compared with their wild-type littermates. Molecular analyses of the mouse liver tissue largely corroborated the observations in vitro, especially along with reduced protein expression of PPARα and FGF21. Conclusion: Collectively, these results suggest that dysregulation in FADS1 alters liver lipid homeostasis in the liver by down-regulating the PPARα-FGF21 signaling axis.
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    Genetic Polymorphism of Cytochrome P450 4F2, Vitamin E Level and Histological Response in Adults and Children with Nonalcoholic Fatty Liver Disease Who Participated in PIVENS and TONIC Clinical Trials
    (Public Library of Science, 2014-04-23) Athinarayanan, Shaminie; Wei, Rongrong; Zhang, Min; Bai, Shaochun; Traber, Maret G.; Yates, Katherine; Cummings, Oscar W.; Molleston, Jean; Liu, Wanqing; Chalasani, Naga; Medical and Molecular Genetics, School of Medicine
    Vitamin E improved liver histology in children and adults with NAFLD who participated in TONIC and PIVENS clinical trials, but with significant inter-individual variability in its efficacy. Cytochrome P450 4F2 (CYP4F2) is the major enzyme metabolizing Vit E, with two common genetic variants (V433M, rs2108622 and W12G, rs3093105) found to alter its activity. We investigated the relationship between CYP4F2 genotypes, α-tocopherol levels and histological improvement in these two trials. V433M and W12G variants were genotyped in TONIC (n = 155) and PIVENS (n = 213) DNA samples. The relationships between CYP4F2 genotypes, plasma α-tocopherol levels at baseline and weeks 48 (w48) and 96 (w96) and histological end points (overall improvement in liver histology and resolution of NASH) were investigated. As a result, the V433M genotype was significantly associated with baseline plasma α-tocopherol in the TONIC trial (p = 0.004), but not in PIVENS. Among those receiving Vit E treatment, CYP4F2 V433M genotype was associated with significantly decreased plasma α-tocopherol levels at w48 (p = 0.003 for PIVENS and p = 0.026 for TONIC) but not at w96. The w96 α-tocopherol level was significantly associated with resolution of NASH (p = 0.006) and overall histology improvement (p = 0.021)in the PIVENS, but not in the TONIC trial. There was no significant association between CYP4F2 genotypes and histological end points in either trial. Our study suggested the a moderate role of CYP4F2 polymorphisms in affecting the pharmacokinetics of Vit E as a therapeutic agent. In addition, there may be age-dependent relationship between CYP4F2 genetic variability and Vit E pharmacokinetics in NAFLD.
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    Impact of the Association Between PNPLA3 Genetic Variation and Dietary Intake on the Risk of Significant Fibrosis in Patients With NAFLD
    (Wolters Kluwer, 2021) Vilar-Gomez, Eduardo; Pirola, Carlos Jose; Sookoian, Silvia; Wilson, Laura A.; Belt, Patricia; Liang, Tiebing; Liu, Wanqing; Chalasani, Naga; Medicine, School of Medicine
    Introduction: This study explored the relationship between patatin-like phospholipase domain-containing 3 gene (PNPLA3 rs738409), nutrient intake, and liver histology severity in patients with nonalcoholic fatty liver disease (NAFLD). Methods: PNPLA3-rs738409 variant was genotyped in 452 non-Hispanic whites with histologically confirmed NAFLD who completed Food Frequency Questionnaire within 6 months of their liver biopsy. The fibrosis severity on liver histology was the outcome of interest. Results: The distribution of PNPLA3 genotypes was CC: 28%, CG: 46%, and GG: 25%. High-carbohydrate (% of energy/d) intake was positively associated (adjusted [Adj] odds ratio [OR]: 1.03, P < 0.01), whereas higher n-3 polyunsaturated fatty acids (n-3 PUFAs) (g/d) (Adj. OR: 0.17, P < 0.01), isoflavones (mg/d) (Adj. OR: 0.74, P = 0.049), methionine (mg/d) (Adj. OR: 0.32, P < 0.01), and choline (mg/d) (Adj. OR: 0.32, P < 0.01) intakes were inversely associated with increased risk of significant fibrosis (stage of fibrosis ≥2). By using an additive model of inheritance, our moderation analysis showed that PNPLA3 rs738409 significantly modulates the relationship between carbohydrate (%), n-3 PUFAs, total isoflavones, methionine, and choline intakes and fibrosis severity in a dose-dependent, genotype manner. These dietary factors tended to have a larger and significant effect on fibrosis severity among rs738409 G-allele carriers. Associations between significant fibrosis and carbohydrates (Adj. OR: 1.04, P = 0.019), n-3 PUFAs (Adj. OR: 0.16, P < 0.01), isoflavones (Adj. OR: 0.65, P = 0.025), methionine (Adj. OR: 0.30, P < 0.01), and total choline (Adj. OR: 0.29, P < 0.01) intakes remained significant only among rs738409 G-allele carriers. Discussion: This gene-diet interaction study suggests that PNPLA3 rs738409 G-allele might modulate the effect of specific dietary nutrients on risk of fibrosis in patients with NAFLD.
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    In a pilot study, reduced fatty acid desaturase 1 function was associated with nonalcoholic fatty liver disease and response to treatment in children
    (Springer Nature, 2018-11) Nobili, Valerio; Alisi, Anna; Liu, Zhipeng; Liang, Tiebing; Crudele, Annalisa; Raponi, Massimiliano; Lin, Jingmei; Chalasani, Naga P.; Liu, Wanqing; Pathology and Laboratory Medicine, School of Medicine
    BACKGROUND: FADS1 gene encodes delta 5 desaturase, a rate-limiting enzyme in the metabolism of n-3 and n-6 polyunsaturated fatty acids (PUFAs). Minor alleles of FADS1 locus polymorphisms are associated with reduced FADS1 expression and intra-hepatic fat accumulation. However, the relationship between FADS1 expression and pediatric nonalcoholic fatty liver disease (NAFLD) risk remains to be explored. METHODS: We analyzed FADS1 transcription levels and their association with intra-hepatic fat and histology in children, and we performed pathway enrichment analysis on transcriptomic profiles associated with FADS1 polymorphisms. We also evaluated the weight of FADS1 alleles on the response to combined docosahexaenoic acid, choline, and vitamin E (DHA-CHO-VE) treatment. RESULTS: FADS1 mRNA level was significantly and inversely associated with intra-hepatic fat (p = 0.004), degree of steatosis (p = 0.03), fibrosis (p = 0.05), and NASH (p = 0.008) among pediatric livers. Transcriptomics demonstrated a significant enrichment of a number of pathways strongly related to NAFLD (e.g., liver damage, fibrosis, and hepatic stellate cell activation). Compared to children who are common allele homozygotes, children with FADS1 minor alleles had a greater reduction in steatosis, fibrosis, and NAFLD activity score after DHA-CHO-VE. CONCLUSION: This study suggests that decreased FADS1 expression may be associated with NAFLD in children but an increased response to DHA-CHO-VE.