Waddah Alrefai

Summary

Affiliation: University of Illinois at Chicago
Country: USA

Publications

  1. doi request reprint Overactivation of intestinal SREBP2 in mice increases serum cholesterol
    Ke Ma
    Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
    PLoS ONE 9:e84221. 2014
  2. pmc D-Glucose modulates intestinal Niemann-Pick C1-like 1 (NPC1L1) gene expression via transcriptional regulation
    Pooja Malhotra
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, and Jesse Brown VA Medical Center, Chicago, Illinois 60612, USA
    Am J Physiol Gastrointest Liver Physiol 304:G203-10. 2013
  3. pmc Enteropathogenic Escherichia coli inhibits ileal sodium-dependent bile acid transporter ASBT
    Fadi Annaba
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
    Am J Physiol Gastrointest Liver Physiol 302:G1216-22. 2012
  4. ncbi request reprint Bile acid transporters: structure, function, regulation and pathophysiological implications
    Waddah A Alrefai
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, USA
    Pharm Res 24:1803-23. 2007
  5. ncbi request reprint Modulation of human Niemann-Pick C1-like 1 gene expression by sterol: Role of sterol regulatory element binding protein 2
    Waddah A Alrefai
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois, and Jesse Brown Veterans Affairs Medical Center, Chicago, IL 60612, USA
    Am J Physiol Gastrointest Liver Physiol 292:G369-76. 2007
  6. ncbi request reprint Molecular cloning and promoter analysis of downregulated in adenoma (DRA)
    Waddah A Alrefai
    University of Illinois at Chicago, Jesse Brown VA Medical Center, Medical Research Service, Chicago, IL 60612, USA
    Am J Physiol Gastrointest Liver Physiol 293:G923-34. 2007
  7. ncbi request reprint Cholesterol modulates human intestinal sodium-dependent bile acid transporter
    Waddah A Alrefai
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown Veteran Affairs Medical Center, Medical Research Service 600 151 820 South Damen Ave, Chicago, Illinois 60612, USA
    Am J Physiol Gastrointest Liver Physiol 288:G978-85. 2005
  8. pmc Modulation of ileal apical Na+-dependent bile acid transporter ASBT by protein kinase C
    Zaheer Sarwar
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown Veterans Affairs Medical Center, Chicago, Illinios 60612, USA
    Am J Physiol Gastrointest Liver Physiol 297:G532-8. 2009
  9. ncbi request reprint Modulation of ileal bile acid transporter (ASBT) activity by depletion of plasma membrane cholesterol: association with lipid rafts
    Fadi Annaba
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, IL, USA
    Am J Physiol Gastrointest Liver Physiol 294:G489-97. 2008
  10. ncbi request reprint Taurodeoxycholate modulates apical Cl-/OH- exchange activity in Caco2 cells
    Waddah A Alrefai
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, and Jesse Brown VA Medical Center, Chicago, Ilinois 60612, USA
    Dig Dis Sci 52:1270-8. 2007

Research Grants

  1. Regulation of Intestinal Bile Acid Transport
    Waddah Alrefai; Fiscal Year: 2009
  2. Regulation of Intestinal Bile Acid Transport
    Waddah Alrefai; Fiscal Year: 2007

Collaborators

Detail Information

Publications35

  1. doi request reprint Overactivation of intestinal SREBP2 in mice increases serum cholesterol
    Ke Ma
    Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois, United States of America
    PLoS ONE 9:e84221. 2014
    ..In conclusion, activation of intestinal SREBP2 alone seems to be sufficient to increase plasma cholesterol, highlighting the essential role of intestine in maintaining cholesterol homeostasis in the body. ..
  2. pmc D-Glucose modulates intestinal Niemann-Pick C1-like 1 (NPC1L1) gene expression via transcriptional regulation
    Pooja Malhotra
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, and Jesse Brown VA Medical Center, Chicago, Illinois 60612, USA
    Am J Physiol Gastrointest Liver Physiol 304:G203-10. 2013
    ..In conclusion, glucose appears to directly modulate NPC1L1 expression via transcriptional mechanisms and the involvement of phosphatase-dependent pathways...
  3. pmc Enteropathogenic Escherichia coli inhibits ileal sodium-dependent bile acid transporter ASBT
    Fadi Annaba
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
    Am J Physiol Gastrointest Liver Physiol 302:G1216-22. 2012
    ..Our studies provide novel evidence for the alterations in the activity of ASBT by EPEC infection and suggest a possible effect for EPEC in influencing intestinal bile acid homeostasis...
  4. ncbi request reprint Bile acid transporters: structure, function, regulation and pathophysiological implications
    Waddah A Alrefai
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, Chicago, Illinois 60612, USA
    Pharm Res 24:1803-23. 2007
    ..This review will highlight current knowledge about structure, function and molecular characterization of bile acid transporters and discuss the implications of their defects in various hepatic and intestinal disorders...
  5. ncbi request reprint Modulation of human Niemann-Pick C1-like 1 gene expression by sterol: Role of sterol regulatory element binding protein 2
    Waddah A Alrefai
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois, and Jesse Brown Veterans Affairs Medical Center, Chicago, IL 60612, USA
    Am J Physiol Gastrointest Liver Physiol 292:G369-76. 2007
    ..Our study demonstrated the modulation of human NPC1L1 expression and promoter activity by cholesterol in a SREBP-2-dependent mechanism...
  6. ncbi request reprint Molecular cloning and promoter analysis of downregulated in adenoma (DRA)
    Waddah A Alrefai
    University of Illinois at Chicago, Jesse Brown VA Medical Center, Medical Research Service, Chicago, IL 60612, USA
    Am J Physiol Gastrointest Liver Physiol 293:G923-34. 2007
    ..Our studies provide evidence for the involvement of HNF-4, YY1, and GATA transcription factors in DRA expression in intestinal differentiated epithelial cells...
  7. ncbi request reprint Cholesterol modulates human intestinal sodium-dependent bile acid transporter
    Waddah A Alrefai
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown Veteran Affairs Medical Center, Medical Research Service 600 151 820 South Damen Ave, Chicago, Illinois 60612, USA
    Am J Physiol Gastrointest Liver Physiol 288:G978-85. 2005
    ..These data provide novel evidence for the direct regulation of human ASBT function by cholesterol and suggest that this phenomenon may play a central role in cholesterol homeostasis...
  8. pmc Modulation of ileal apical Na+-dependent bile acid transporter ASBT by protein kinase C
    Zaheer Sarwar
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown Veterans Affairs Medical Center, Chicago, Illinios 60612, USA
    Am J Physiol Gastrointest Liver Physiol 297:G532-8. 2009
    ..Our novel findings demonstrate a posttranscriptional modulation of ileal ASBT function and membrane expression by phorbol ester via a PKCzeta-dependent pathway...
  9. ncbi request reprint Modulation of ileal bile acid transporter (ASBT) activity by depletion of plasma membrane cholesterol: association with lipid rafts
    Fadi Annaba
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, IL, USA
    Am J Physiol Gastrointest Liver Physiol 294:G489-97. 2008
    ....
  10. ncbi request reprint Taurodeoxycholate modulates apical Cl-/OH- exchange activity in Caco2 cells
    Waddah A Alrefai
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, and Jesse Brown VA Medical Center, Chicago, Ilinois 60612, USA
    Dig Dis Sci 52:1270-8. 2007
    ..In conclusion, our studies provide direct evidence for inhibition of human intestinal apical Cl(-)/OH(-) exchange activity by bile acids via Ca(2+)-, PI3 kinase-, and PKC beta I-dependent pathways in Caco2 cells...
  11. pmc Green tea catechin EGCG inhibits ileal apical sodium bile acid transporter ASBT
    Fadi Annaba
    Department of Medicine, University of Illinois at Chicago, and Jesse Brown Veterans Affairs Medical Center, USA
    Am J Physiol Gastrointest Liver Physiol 298:G467-73. 2010
    ..In conclusion, our data demonstrate a novel role of lipid rafts in the modulation of ASBT function by the dietary component EGCG, which may underlie the hypocholesterolemic effects of green tea...
  12. pmc Regulation of monocarboxylate transporter 1 (MCT1) promoter by butyrate in human intestinal epithelial cells: involvement of NF-kappaB pathway
    Alip Borthakur
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, Chicago, Illinois 60612, USA
    J Cell Biochem 103:1452-63. 2008
    ..Our results demonstrate the involvement of NF-kappaB pathway in the regulation of MCT1 promoter activity by butyrate...
  13. pmc Mechanisms of lysophosphatidic acid (LPA) mediated stimulation of intestinal apical Cl-/OH- exchange
    Amika Singla
    Section of Digestive Diseases and Nutrition, Department of Physiology, University of Illinois at Chicago, Chicago, IL 60612, USA
    Am J Physiol Gastrointest Liver Physiol 298:G182-9. 2010
    ..Our results demonstrate that LPA stimulates apical Cl(-)/OH(-) exchange activity and surface levels of DRA in intestinal epithelial cells. This increase in Cl(-)/OH(-) exchange may contribute to the antidiarrheal effects of LPA...
  14. pmc Enteropathogenic Escherichia coli infection inhibits intestinal serotonin transporter function and expression
    Ali Esmaili
    Section of Digestive Diseases and Nutrition, University of Illinois at Chicago, Chicago, Illinois 60612, USA
    Gastroenterology 137:2074-83. 2009
    ..The present studies examined the effects of EPEC infection on SERT activity and expression in intestinal epithelial cells and elucidated the underlying mechanisms...
  15. ncbi request reprint Involvement of c-Src and protein kinase C delta in the inhibition of Cl(-)/OH- exchange activity in Caco-2 cells by serotonin
    Seema Saksena
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois and Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois 60612, USA
    J Biol Chem 280:11859-68. 2005
    ..viii) 5-HT stimulated tyrosine phosphorylation of c-Src kinase and PKC delta...
  16. pmc Lactobacillus acidophilus stimulates the expression of SLC26A3 via a transcriptional mechanism
    Geetu Raheja
    Department of Medicine, University of Illinois at Chicago and Jesse Brown Veterans Affairs Medical Center, 60612, USA
    Am J Physiol Gastrointest Liver Physiol 298:G395-401. 2010
    ..In conclusion, increase in DRA promoter activity and expression may contribute to the upregulation of intestinal electrolyte absorption and might underlie the potential antidiarrheal effects of LA...
  17. ncbi request reprint Serotonin inhibits Na+/H+ exchange activity via 5-HT4 receptors and activation of PKC alpha in human intestinal epithelial cells
    Ravinder K Gill
    Section of Digestive Diseases and Nutrition, University of Illinois at Chicago, Jesse Brown VA Medical Center, IL 60612, USA
    Gastroenterology 128:962-74. 2005
    ..The present studies examined the acute effects of 5-hydroxytryptamine (5-HT) on NHE activity using Caco-2 cells as an in vitro model...
  18. pmc The probiotic Lactobacillus acidophilus stimulates chloride/hydroxyl exchange activity in human intestinal epithelial cells
    Alip Borthakur
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, and Jesse Brown Veterans Affairs Medical Center, Chicago, IL 60612, USA
    J Nutr 138:1355-9. 2008
    ..Our results suggest that LA secretes soluble effector molecule(s) into the culture medium that stimulate apical Cl(-)/OH(-) exchange activity via phosphatidylinositol-3 kinase mediated mechanism...
  19. pmc Ileal apical Na+-dependent bile acid transporter ASBT is upregulated in rats with diabetes mellitus induced by low doses of streptozotocin
    Fadi Annaba
    Department of Medicine, University of Illinois at Chicago, USA
    Am J Physiol Gastrointest Liver Physiol 299:G898-906. 2010
    ..The increase in ASBT expression may contribute to disturbances in cholesterol homeostasis associated with diabetes mellitus...
  20. pmc Mechanisms underlying modulation of monocarboxylate transporter 1 (MCT1) by somatostatin in human intestinal epithelial cells
    Seema Saksena
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois 60612, USA
    Am J Physiol Gastrointest Liver Physiol 297:G878-85. 2009
    ..Our findings demonstrate that increased MCT1 association with CD147 at the apical membrane in response to SST is p38 MAP kinase dependent and underlies the stimulatory effects of SST on butyrate uptake...
  21. pmc Mechanisms of transcriptional modulation of the human anion exchanger SLC26A3 gene expression by IFN-{gamma}
    Seema Saksena
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
    Am J Physiol Gastrointest Liver Physiol 298:G159-66. 2010
    ..Mutations in the potential GAS element abrogated the inhibitory effects of IFN-gamma. These studies provide evidence for the involvement of STAT1 in the inhibition of SLC26A3 gene expression by IFN-gamma in the human intestine...
  22. pmc Epidermal growth factor upregulates serotonin transporter in human intestinal epithelial cells via transcriptional mechanisms
    Ravinder K Gill
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, 60612, USA
    Am J Physiol Gastrointest Liver Physiol 300:G627-36. 2011
    ..Our findings define novel mechanisms of transcriptional regulation of SERT by EGF via EGFR at the promoter level that may contribute to the beneficial effects of EGF in gut disorders...
  23. pmc Stimulation of apical Cl⁻/HCO₃⁻(OH⁻) exchanger, SLC26A3 by neuropeptide Y is lipid raft dependent
    Seema Saksena
    Dept of Medicine, University of Illinois at Chicago and Jesse Brown Veterans Affairs Medical Center, Illinois 60612, USA
    Am J Physiol Gastrointest Liver Physiol 299:G1334-43. 2010
    ..Our findings suggest that the alteration in the association of DRA with lipid rafts may contribute to the proabsorptive effects of NPY in the human intestine...
  24. pmc Platelet-activating factor-induced NF-kappaB activation and IL-8 production in intestinal epithelial cells are Bcl10-dependent
    Alip Borthakur
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, Chicago, Illinois 60612, USA
    Inflamm Bowel Dis 16:593-603. 2010
    ..However, its mechanisms of inducing inflammatory responses are not fully understood. Therefore, studies were designed to explore the mechanisms of PAF-induced inflammatory cascade in intestinal epithelial cells...
  25. ncbi request reprint Regulation of NHE3 by nitric oxide in Caco-2 cells
    Ravinder K Gill
    Section of Digestive and Liver Diseases, Department of Medicine, University of Illinois at Chicago and West Side Veterans Affairs Medical Center, Chicago, Illinois 60612, USA
    Am J Physiol Gastrointest Liver Physiol 283:G747-56. 2002
    ..These data provide novel evidence that NO inhibits NHE3 activity via activation of soluble guanylate cyclase, resulting in an increase in intracellular cGMP levels and activation of protein kinase G...
  26. ncbi request reprint Expression and membrane localization of MCT isoforms along the length of the human intestine
    Ravinder K Gill
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, Medical Research Service 600 151, Jesse Brown Veterans Affairs Medical Center, 820 South Damen Ave, Chicago, Illinois 60612, USA
    Am J Physiol Cell Physiol 289:C846-52. 2005
    ..We speculate that distinct MCT isoforms may be involved in SCFA transport across the apical or basolateral membranes in polarized colonic epithelial cells...
  27. ncbi request reprint Function, expression, and characterization of the serotonin transporter in the native human intestine
    Ravinder K Gill
    Research Assistant Professor, Univ of Illinois at Chicago, Jesse Brown V A Medical Center, Medical Research Service 600 151 820 South Damen Ave, Chicago, IL 60612
    Am J Physiol Gastrointest Liver Physiol 294:G254-62. 2008
    ....
  28. pmc Characterization of the 5'-flanking region and regulation of expression of human anion exchanger SLC26A6
    Seema Saksena
    Department of Medicine, University of Illinois at Chicago, Jesse Brown VA Medical Center, Chicago, Illinois 60612, USA
    J Cell Biochem 105:454-66. 2008
    ..Mutations in the potential ISRE site abrogated the inhibitory effects of IFNgamma. These studies provided novel evidence for the involvement of IRF-1 in the regulation of SLC26A6 gene expression by IFNgamma in the human intestine...
  29. pmc Serotonin modifies cytoskeleton and brush-border membrane architecture in human intestinal epithelial cells
    Ravinder K Gill
    Dept of Medicine, Univ of Illinois at Chicago, Medical Research Service, Jesse Brown VA Medical Center, 820 S Damen Ave, Chicago, IL 60612, USA
    Am J Physiol Gastrointest Liver Physiol 295:G700-8. 2008
    ....
  30. pmc PKC-dependent stimulation of the human MCT1 promoter involves transcription factor AP2
    Seema Saksena
    Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
    Am J Physiol Gastrointest Liver Physiol 296:G275-83. 2009
    ..These findings showing the regulation of MCT1 promoter by PKC and AP2 are of significant importance for an understanding of the molecular regulation of SCFA absorption in the human intestine...
  31. pmc Regulation of intestinal serotonin transporter expression via epigenetic mechanisms: role of HDAC2
    Ravinder K Gill
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, Chicago, IL 60612, USA
    Am J Physiol Cell Physiol 304:C334-41. 2013
    ..Our results identify a novel role of HDAC2 as a regulator of SERT gene expression in intestinal epithelial cells...
  32. pmc Role of Fyn and PI3K in H2O2-induced inhibition of apical Cl-/OH- exchange activity in human intestinal epithelial cells
    Seema Saksena
    Department of Medicine, University of Illinois at Chicago, Jesse Brown VA Medical Center, Chicago, IL 60612, USA
    Biochem J 416:99-108. 2008
    ....
  33. ncbi request reprint Inhibition of apical Cl-/OH- exchange activity in Caco-2 cells by phorbol esters is mediated by PKCepsilon
    Seema Saksena
    Section of Digestive and Liver Diseases, Department of Medicine, University of Illinois at Chicago and West Side Department of Veterans Affairs Medical Center, Chicago, Illinois 60612, USA
    Am J Physiol Cell Physiol 283:C1492-500. 2002
    ....
  34. ncbi request reprint Modulation of Cl-/OH- exchange activity in Caco-2 cells by nitric oxide
    Seema Saksena
    Section of Digestive and Liver Diseases, Department of Medicine, University of Illinois at Chicago and Chicago Veteran s Affairs System West Side Division, Chicago, Illinois 60612, USA
    Am J Physiol Gastrointest Liver Physiol 283:G626-33. 2002
    ..Our results suggest that NO-induced inhibition of Cl-/OH- exchange may play an important role in the pathophysiology of diarrhea associated with inflammatory bowel diseases...
  35. pmc SREBP2 mediates the modulation of intestinal NPC1L1 expression by curcumin
    Pradeep Kumar
    Section of Digestive Diseases and Nutrition, Department of Medicine, University of Illinois at Chicago, USA
    Am J Physiol Gastrointest Liver Physiol 301:G148-55. 2011
    ..Our studies demonstrate that curcumin directly modulates intestinal NPC1L1 expression via transcriptional regulation and the involvement of SREBP2 transcription factor...

Research Grants5

  1. Regulation of Intestinal Bile Acid Transport
    Waddah Alrefai; Fiscal Year: 2009
    ..A better understanding of the role of bile acid absorption in cholesterol related disorders may help advance new therapeutic modalities to counter diseases such as hypercholesterolemia and atherosclerosis. ..
  2. Regulation of Intestinal Bile Acid Transport
    Waddah Alrefai; Fiscal Year: 2007
    ..A better understanding of the role of bile acid absorption in cholesterol related disorders may help advance new therapeutic modalities to counter diseases such as hypercholesterolemia and atherosclerosis. ..