Faculty

D. Brent Polk, MD
D. Brent Polk, MD
Professor of Pediatrics
Pediatrics
CHL Mail Stop 71 Off Campus Los Angeles

Challenges in IBD Research: Novel Technologies Inflamm Bowel Dis. 2019 May 16; 25(Supplement_2):S24-S30. . View in PubMed

Epidermal growth factor suppresses intestinal epithelial cell shedding through a MAPK-dependent pathway J Cell Sci. 2017 01 01; 130(1):90-96. . View in PubMed

Optical reconstruction of murine colorectal mucosa at cellular resolution Am J Physiol Gastrointest Liver Physiol. 2015 May 01; 308(9):G721-35. . View in PubMed

Redeeming an old foe: protective as well as pathophysiological roles for tumor necrosis factor in inflammatory bowel disease Am J Physiol Gastrointest Liver Physiol. 2015 Feb 01; 308(3):G161-70. . View in PubMed

Necrotising enterocolitis is characterised by disrupted immune regulation and diminished mucosal regulatory (FOXP3)/effector (CD4, CD8) T cell ratios Gut. 2013 Jan; 62(1):73-82. . View in PubMed

Epidermal growth factor receptor inhibits colitis-associated cancer in mice J Clin Invest. 2012 Aug; 122(8):2780-92. . View in PubMed

Berberine promotes recovery of colitis and inhibits inflammatory responses in colonic macrophages and epithelial cells in DSS-treated mice Am J Physiol Gastrointest Liver Physiol. 2012 Mar 01; 302(5):G504-14. . View in PubMed

ErbB2 and ErbB3 regulate recovery from dextran sulfate sodium-induced colitis by promoting mouse colon epithelial cell survival Lab Invest. 2012 Mar; 92(3):437-50. . View in PubMed

Berberine induces caspase-independent cell death in colon tumor cells through activation of apoptosis-inducing factor PLoS One. 2012; 7(5):e36418. . View in PubMed

Characterization of a probiotic-derived soluble protein which reveals a mechanism of preventive and treatment effects of probiotics on intestinal inflammatory diseases Gut Microbes. 2012 Jan-Feb; 3(1):25-8. . View in PubMed

Transactivation of EGFR by LPS induces COX-2 expression in enterocytes PLoS One. 2012; 7(5):e38373. . View in PubMed

Spermine oxidase mediates the gastric cancer risk associated with Helicobacter pylori CagAGastroenterology. 2011 Nov; 141(5):1696-708. e1-2. . View in PubMed

STAT6 activation in ulcerative colitis: a new target for prevention of IL-13-induced colon epithelial cell dysfunction Inflamm Bowel Dis. 2011 Nov; 17(11):2224-34. . View in PubMed

Alanyl-glutamine promotes intestinal epithelial cell homeostasis in vitro and in a murine model of weanling undernutrition Am J Physiol Gastrointest Liver Physiol. 2011 Oct; 301(4):G612-22. . View in PubMed

Tumor necrosis factor receptor 1-dependent depletion of mucus in immature small intestine: a potential role in neonatal necrotizing enterocolitis Am J Physiol Gastrointest Liver Physiol. 2011 Oct; 301(4):G656-66. . View in PubMed

Probiotics and immune health Curr Opin Gastroenterol. 2011 Oct; 27(6):496-501. . View in PubMed

TNF transactivation of EGFR stimulates cytoprotective COX-2 expression in gastrointestinal epithelial cells Am J Physiol Gastrointest Liver Physiol. 2011 Aug; 301(2):G220-9. . View in PubMed

TNF-a converting enzyme-mediated ErbB4 transactivation by TNF promotes colonic epithelial cell survival Am J Physiol Gastrointest Liver Physiol. 2011 Aug; 301(2):G338-46. . View in PubMed

Specific epidermal growth factor receptor autophosphorylation sites promote mouse colon epithelial cell chemotaxis and restitution Am J Physiol Gastrointest Liver Physiol. 2011 Aug; 301(2):G368-76. . View in PubMed

Colon-specific delivery of a probiotic-derived soluble protein ameliorates intestinal inflammation in mice through an EGFR-dependent mechanism J Clin Invest. 2011 Jun; 121(6):2242-53. . View in PubMed

KSR1 is a functional protein kinase capable of serine autophosphorylation and direct phosphorylation of MEK1 Exp Cell Res. 2011 Feb 15; 317(4):452-63. . View in PubMed

Sprouty keeps bowel kinases regular in colon cancer, while miR-21 targets Sprouty Cancer Biol Ther. 2011 Jan 01; 11(1):122-4. . View in PubMed

KSR1 protects from interleukin-10 deficiency-induced colitis in mice by suppressing T-lymphocyte interferon-? production. Gastroenterology. 2011 Jan; 140(1):265-74.. View in PubMed

ErbB4 promotes cyclooxygenase-2 expression and cell survival in colon epithelial cells Lab Invest. 2010 Oct; 90(10):1415-24. . View in PubMed

Helicobacter pylori: gastric cancer and beyond Nat Rev Cancer. 2010 Jun; 10(6):403-14. . View in PubMed

Disruption of NF-kappaB signalling by ancient microbial molecules: novel therapies of the future? Gut. 2010 Apr; 59(4):421-6.. View in PubMed

Probiotics: progress toward novel therapies for intestinal diseases Curr Opin Gastroenterol. 2010 Mar; 26(2):95-101. . View in PubMed

Endoscopic ultrasound to guide the combined medical and surgical management of pediatric perianal Crohn's disease Inflamm Bowel Dis. 2010 Mar; 16(3):461-8. . View in PubMed

Functional analysis of the p40 and p75 proteins from Lactobacillus casei BL23 J Mol Microbiol Biotechnol. 2010; 19(4):231-41. . View in PubMed

Ontogeny of FOXP3(+) regulatory T cells in the postnatal human small intestinal and large intestinal lamina propria Pediatr Dev Pathol. 2009 Nov-Dec; 12(6):443-9. . View in PubMed

Epidermal growth factor receptor activation protects gastric epithelial cells from Helicobacter pylori-induced apoptosis Gastroenterology. 2009 Apr; 136(4):1297-1307, e1-3. . View in PubMed

Helicobacter pylori regulates cellular migration and apoptosis by activation of phosphatidylinositol 3-kinase signaling J Infect Dis. 2009 Mar 01; 199(5):641-51. . View in PubMed

The ErbB4 growth factor receptor is required for colon epithelial cell survival in the presence of TNF Gastroenterology. 2009 Jan; 136(1):217-26. . View in PubMed

Low levels of tumor necrosis factor alpha increase tumor growth by inducing an endothelial phenotype of monocytes recruited to the tumor site Cancer Res. 2009 Jan 01; 69(1):338-48. . View in PubMed

Mechanisms of probiotic action: Implications for therapeutic applications in inflammatory bowel diseases Inflamm Bowel Dis. 2008 Nov; 14(11):1585-96. . View in PubMed

TNFR1 promotes tumor necrosis factor-mediated mouse colon epithelial cell survival through RAF activation of NF-kappaB J Biol Chem. 2008 Oct 24; 283(43):29485-94. . View in PubMed

Transactivation of EGF receptor and ErbB2 protects intestinal epithelial cells from TNF-induced apoptosis Proc Natl Acad Sci U S A. 2008 Aug 19; 105(33):11772-7. . View in PubMed

Tumor necrosis factor inhibits ligand-stimulated EGF receptor activation through a TNF receptor 1-dependent mechanism Am J Physiol Gastrointest Liver Physiol. 2008 Aug; 295(2):G285-93. . View in PubMed

Raf protects against colitis by promoting mouse colon epithelial cell survival through NF-kappaB Gastroenterology. 2008 Aug; 135(2):539-51. . View in PubMed

Probiotics ameliorate the hydrogen peroxide-induced epithelial barrier disruption by a PKC- and MAP kinase-dependent mechanism Am J Physiol Gastrointest Liver Physiol. 2008 Apr; 294(4):G1060-9. . View in PubMed

Epidermal growth factor stimulates Rac activation through Src and phosphatidylinositol 3-kinase to promote colonic epithelial cell migration Am J Physiol Gastrointest Liver Physiol. 2008 Jan; 294(1):G276-85. . View in PubMed

Integrin alpha1beta1 controls reactive oxygen species synthesis by negatively regulating epidermal growth factor receptor-mediated Rac activation Mol Cell Biol. 2007 May; 27(9):3313-26. . View in PubMed

Soluble proteins produced by probiotic bacteria regulate intestinal epithelial cell survival and growth Gastroenterology. 2007 Feb; 132(2):562-75. . View in PubMed

p38 kinase regulates epidermal growth factor receptor downregulation and cellular migration EMBO J. 2006 Dec 13; 25(24):5683-92. . View in PubMed

Cysteine-rich domains of muc3 intestinal mucin promote cell migration, inhibit apoptosis, and accelerate wound healing Gastroenterology. 2006 Nov; 131(5):1501-17. . View in PubMed

Probiotics as functional food in the treatment of diarrhea Curr Opin Clin Nutr Metab Care. 2006 Nov; 9(6):717-21. . View in PubMed

Bmp signaling is required for intestinal growth and morphogenesis Dev Dyn. 2006 Jun; 235(6):1563-70. . View in PubMed

The role of decay-accelerating factor as a receptor for Helicobacter pylori and a mediator of gastric inflammation J Biol Chem. 2006 May 12; 281(19):13317-23. . View in PubMed

Regulation of apoptosis during homeostasis and disease in the intestinal epithelium Inflamm Bowel Dis. 2006 May; 12(5):413-24. . View in PubMed

NODing off and Ramping up Inflamm Bowel Dis. 2005 Sep; 11(9):860-1. . View in PubMed

Kinase suppressor of Ras-1 protects intestinal epithelium from cytokine-mediated apoptosis during inflammation J Clin Invest. 2004 Nov; 114(9):1272-80. . View in PubMed

Commensal bacteria in the gut: learning who our friends are Curr Opin Gastroenterol. 2004 Nov; 20(6):565-71. . View in PubMed

Epidermal growth factor-stimulated intestinal epithelial cell migration requires Src family kinase-dependent p38 MAPK signaling J Biol Chem. 2004 Oct 22; 279(43):44513-21. . View in PubMed

Recurrent abdominal pain: symptom subtypes based on the Rome II Criteria for pediatric functional gastrointestinal disorders J Pediatr Gastroenterol Nutr. 2004 Feb; 38(2):187-91. . View in PubMed

Tumor necrosis factor regulates intestinal epithelial cell migration by receptor-dependent mechanisms Am J Physiol Cell Physiol. 2003 Apr; 284(4):C953-61. . View in PubMed

Probiotic bacterium prevents cytokine-induced apoptosis in intestinal epithelial cells J Biol Chem. 2002 Dec 27; 277(52):50959-65. . View in PubMed

Histopathology of ulcerative colitis in initial rectal biopsy in children Am J Surg Pathol. 2002 Nov; 26(11):1441-9. . View in PubMed

Research agenda for pediatric gastroenterology, hepatology and nutrition: developmental physiology and pathophysiologyReport of the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition for the Children's Digestive Health and Nutrition Foundation. J Pediatr Gastroenterol Nutr. 2002; 35 Suppl 3:S242-5. . View in PubMed

Kinase suppressor of Ras determines survival of intestinal epithelial cells exposed to tumor necrosis factor Cancer Res. 2001 Dec 15; 61(24):8668-75. . View in PubMed

In vivo visualization of pyloric mucosal hypertrophy in infants with hypertrophic pyloric stenosis: is there an etiologic role? AJR Am J Roentgenol. 2001 Oct; 177(4):843-8.. View in PubMed

Activation of peroxisome proliferator-activated receptor gamma suppresses nuclear factor kappa B-mediated apoptosis induced by Helicobacter pylori in gastric epithelial cells J Biol Chem. 2001 Aug 17; 276(33):31059-66. . View in PubMed

Kinase suppressor of ras is necessary for tumor necrosis factor alpha activation of extracellular signal-regulated kinase/mitogen-activated protein kinase in intestinal epithelial cells Cancer Res. 2001 Feb 01; 61(3):963-9. . View in PubMed

Aminosalicylic acid inhibits IkappaB kinase alpha phosphorylation of IkappaBalpha in mouse intestinal epithelial cells J Biol Chem. 1999 Dec 17; 274(51):36631-6. . View in PubMed

Epidermal and hepatocyte growth factors stimulate chemotaxis in an intestinal epithelial cell line Am J Physiol. 1999 Dec; 277(6 Pt 1):C1149-59. . View in PubMed

Conversion of TNF alpha from antiproliferative to proliferative ligand in mouse intestinal epithelial cells by regulating mitogen-activated protein kinase Exp Cell Res. 1999 Jun 15; 249(2):349-58. . View in PubMed

Mesalamine blocks tumor necrosis factor growth inhibition and nuclear factor kappaB activation in mouse colonocytes Gastroenterology. 1999 Mar; 116(3):602-9. . View in PubMed

Epidermal and hepatocyte growth factors stimulate chemotaxis in an intestinal epithelial cell line Am J Physiol. 1999 12; 277(6):C1149-59. . View in PubMed

Hypertrophied pyloric mucosa in patients with hypertrophic pyloric stenosis Pediatr Radiol. 1998 Nov; 28(11):901. . View in PubMed

Epidermal growth factor receptor-stimulated intestinal epithelial cell migration requires phospholipase C activity Gastroenterology. 1998 Mar; 114(3):493-502. . View in PubMed

Tumor necrosis factor alpha regulates proliferation in a mouse intestinal cell line Gastroenterology. 1997 Apr; 112(4):1231-40. . View in PubMed

Recurrent necrotizing jejunitis in a child J Pediatr. 1996 Feb; 128(2):246-9. . View in PubMed

Shc is a substrate of the rat intestinal epidermal growth factor receptor tyrosine kinase Gastroenterology. 1995 Dec; 109(6):1845-51. . View in PubMed

Impaired human responses to tetanus toxoid in vitamin A-deficient SCID mice reconstituted with human peripheral blood lymphocytes Infect Immun. 1995 Aug; 63(8):2867-72. . View in PubMed

The antral nipple sign of pyloric mucosal prolapse: endoscopic correlation of a new sonographic observation in patients with pyloric stenosis J Ultrasound Med. 1995 Apr; 14(4):283-7. . View in PubMed

Cell density-dependent regulation of PLC gamma 1 tyrosine phosphorylation and catalytic activity in an intestinal cell line (IEC-6) J Cell Physiol. 1995 Mar; 162(3):427-33. . View in PubMed

Ontogenic regulation of phospholipase C-gamma 1 activity and expression in the rat small intestine Gastroenterology. 1994 Jul; 107(1):109-16. . View in PubMed

Intestinal Na+/H+ exchanger activity is up-regulated by bowel resection in the weanling rat Pediatr Res. 1993 Mar; 33(3):215-20. . View in PubMed

Improved growth and disease activity after intermittent administration of a defined formula diet in children with Crohn's disease JPEN J Parenter Enteral Nutr. 1992 Nov-Dec; 16(6):499-504. . View in PubMed

Bacterial meningitis presenting with normal cerebrospinal fluid Pediatr Infect Dis J. 1987 Nov; 6(11):1040-2. . View in PubMed

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