The aims of this proposal are to investigate the mechanisms of gastric survival of Hilicobacter pylori with specific reference to the urease generated at high quantities by this orgasms. Our analysis mechanisms of generation of an electro-chemical gradient of hydrogen ions is to be extended to an analysis of the properties and regulation of the urease with respect to (a) investigation of internal urease of H. pylori as a regulator of bacterial periplasmic pH in an acid milieu; (b) investigation of the mechanisms of internal urease by medium pH including assessment of the role of possible transporters and inner and outer membrane processes; (c) determination of the function of the gene products of the urease operon and especially the membrane inserted gene products in control of urease function; (d) Determination of the mechanism of externalization of the urease of H. pylori and urease effects at neutral pH; (e) analysis of the likely gastric environment of H. pylori as a function of urease activity; (f) assessment of NH3 generation inside H. pylori as a modulator of gastric cellular pH and [Ca]. Various techniques to be applied include fluorimetric measurements of transmembrane potentials and periplasmic pH, urease operon functional analysis by mutagenesis and yeast 2 hybrid analysis, video imaging and confocal microscopy of organisms and cells to which they adhere. Understanding the means of survival and cytotoxicity of this pathogen will enable more rational treatment of peptic ulcer disease.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK053642-03
Application #
2906164
Study Section
Special Emphasis Panel (ZDK1-GRB-8 (O2))
Program Officer
Hamilton, Frank A
Project Start
1997-09-30
Project End
2002-09-29
Budget Start
1999-09-30
Budget End
2000-09-29
Support Year
3
Fiscal Year
1999
Total Cost
Indirect Cost
Name
University of California Los Angeles
Department
Physiology
Type
Schools of Medicine
DUNS #
119132785
City
Los Angeles
State
CA
Country
United States
Zip Code
90095
Sachs, G; Marcus, E A; Wen, Y et al. (2018) Editorial: control of acid secretion. Aliment Pharmacol Ther 48:682-683
van Leeuwen, Marina T; Gurney, Howard; Turner, Jennifer J et al. (2016) Patterns and trends in the incidence of paediatric and adult germ cell tumours in Australia, 1982-2011. Cancer Epidemiol 43:15-21
Marcus, Elizabeth A; Vagin, Olga; Tokhtaeva, Elmira et al. (2013) Helicobacter pylori impedes acid-induced tightening of gastric epithelial junctions. Am J Physiol Gastrointest Liver Physiol 305:G731-9
Marcus, Elizabeth A; Sachs, George; Scott, David R (2013) The role of ExbD in periplasmic pH homeostasis in Helicobacter pylori. Helicobacter 18:363-72
Marcus, E A; Inatomi, N; Nagami, G T et al. (2012) The effects of varying acidity on Helicobacter pylori growth and the bactericidal efficacy of ampicillin. Aliment Pharmacol Ther 36:972-9
Goebel, M; Stengel, A; Lambrecht, N W G et al. (2011) Selective gene expression by rat gastric corpus epithelium. Physiol Genomics 43:237-54
Shin, Jai Moo; Munson, Keith; Sachs, George (2011) Gastric H+,K+-ATPase. Compr Physiol 1:2141-53
Shin, J M; Vagin, O; Munson, K et al. (2011) Erratum to: Molecular mechanisms in therapy of acid-related diseases. Cell Mol Life Sci 68:921
Sachs, George; Scott, David R; Wen, Yi (2011) Gastric infection by Helicobacter pylori. Curr Gastroenterol Rep 13:540-6
Sachs, George; Marcus, Elizabeth A; Scott, David R (2011) The role of the NMDA receptor in Helicobacter pylori-induced gastric damage. Gastroenterology 141:1967-9

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