Characterization of Hela cell vacuoles induced by Helicobacter pylori broth culture supernatant

Cover, Timothy L.; Halter, Susan A.; Blaser, Martin J.

doi:10.1016/0046-8177(92)90261-z

Cited by 69 publications

(58 citation statements)

References 25 publications

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“…Because the cells were extensively vacuolated (Fig. 1, panel F), which is a well documented characteristic of VacA-intoxicated cells (11,43), the diffuse green fluorescence was most readily evident in the nucleus. These results indicate that VacA induces cytochrome c release from mitochondria within living intact cells.…”

Section: Vaca Induces Cytochrome C Release Into the Cytosol Of Intactmentioning

confidence: 99%

Cellular Vacuolation and Mitochondrial Cytochrome c Release Are Independent Outcomes of Helicobacter pylori Vacuolating Cytotoxin Activity That Are Each Dependent on Membrane Channel Formation

Willhite

Cover²,

Blanke³

2003

Journal of Biological Chemistry

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Section: Vaca Induces Cytochrome C Release Into the Cytosol Of Intactmentioning

confidence: 99%

Cellular Vacuolation and Mitochondrial Cytochrome c Release Are Independent Outcomes of Helicobacter pylori Vacuolating Cytotoxin Activity That Are Each Dependent on Membrane Channel Formation

Willhite

Cover²,

Blanke³

2003

Journal of Biological Chemistry

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“…There is evidence that the autophagocytic pathway converges with the endosomal pathway at a prelysosomal level (37,38). On the basis ofmorphological exmination, vacuoles have been suggested to originate from endosomes (7) or autophagosomes (39,40). If this latter proposal were correct, increased autophagocytosis would enhance the effect of vacA.…”

mentioning

confidence: 99%

Cellular vacuoles induced by Helicobacter pylori originate from late endosomal compartments.

Papini

Bernard

Milia

et al. 1994

Proc. Natl. Acad. Sci. U.S.A.

221

179

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Pathogenic strains of Helicobacter pylon cause progressive vacuolatlon and death of epithelial cells. To identify the nature of vacuoles, the distribution of markers of various membrane traffic compartments was studied. Vacuoles derive from the endocytic pathway since they include the fluid-phase marker Lucifer yellow. Early endosome markers such as rab5, trerrin, and trnsferrin receptor, as well as the lysosomal hydrolase cathepsin D, are excluded from these structures. In contrast, the vacuolar membrane is specifically stained by ity-purified antibodies against rab7, a small GTPase, localized to late endosomal compartments. The labeling of rab7 on vacuolar membranes increases as vacuolation progresses, without a concomitant increase of cellular rab7. Cell vacuolation is inhibited by the microtubule-depolymerizing agents nocodazole and colchicine. Taken together, these findins indicate that the vacuoles specifically originate from late endosomal compartments.Strong evidence indicates that toxigenic strains of Helicobacter pylori play a major role in the development of type B gastritis, peptic ulcers, and gastric adenocarcinoma (1-3). Biopsies of H. pylori-colonized stomach epithelium show cellular swelling, expansion of endosomal compartments, and extensive vacuolation (4). A vacuolar degeneration of epithelial cells, followed by cell death, is induced in vitro by H. pylori bacterial extracts (5-7). The luminal pH of these vacuoles is acidic, as deduced from the uptake of neutral red, a membrane-permeant amine that becomes protonated in the vacuolar lumen, and from the potentiating effect of ammonia (8). Two virulence factors, produced by pathogenic strains of H. pylori are thought to be mainly responsible for this cell degeneration and death: a urease and a cytotoxin (3,4,7,8). The urease hydrolyzes urea and the ammonia produced permeates membranes, as neutral red does, and accumulates as ammonium ions inside intracellular acidic compartments, thus causing their osmotic swelling (9-11). However important, this process alone cannot account for the manyfold increase in vacuole volume, because, without membrane addition, it would lead to vacuole rupture.Recently a cytotoxin has been isolated from culture supernatants of a virulent strain of H. pylori (12) and shown to cause vacuolation in vitro (12) and in vivo (13). The genes encoding this protein (vacA; H. pylori vacuolating toxin A), and a bacterial antigen (cagA) characteristic of H. pylori pathogenic strains, have been recently cloned and sequenced, and they share no similarity with any other known protein (13,14). Thus, the molecular mechanism of action of vacA and the sequence of events leading to vacuolar cell degeneration and death remain largely obscure.The inhibition of vacuole formation by bafilomycins, specific inhibitors of the vacuolar-type ATPase proton pump (V-ATPase) (15), indicates that vacuoles originate from intracellular compartments endowed with a V-ATPase, such as endosomes, lysosomes, or the trans-Golgi network (TGN) (16)(17)(18)....

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“…Vacuolation was quantified by neutral red accumulation as described by Cover et al (25). The cells were incubated with freshly prepared 0.05% neutral red in phosphate-buffered saline (PBS) containing 0.3% bovine serum albumin and then washed three times with PBS containing 0.3% bovine serum albumin.…”

Section: Assay For Vacuolating Activitymentioning

confidence: 99%

Helicobacter pylori Vacuolating Cytotoxin Induces Activation of the Proapoptotic Proteins Bax and Bak, Leading to Cytochrome c Release and Cell Death, Independent of Vacuolation

Yamasaki

Wada

Kumatori

et al. 2006

Journal of Biological Chemistry

146

156

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Characterization of Hela cell vacuoles induced by Helicobacter pylori broth culture supernatant

Cited by 69 publications

References 25 publications

Cellular Vacuolation and Mitochondrial Cytochrome c Release Are Independent Outcomes of Helicobacter pylori Vacuolating Cytotoxin Activity That Are Each Dependent on Membrane Channel Formation

Cellular Vacuolation and Mitochondrial Cytochrome c Release Are Independent Outcomes of Helicobacter pylori Vacuolating Cytotoxin Activity That Are Each Dependent on Membrane Channel Formation

Cellular vacuoles induced by Helicobacter pylori originate from late endosomal compartments.

Helicobacter pylori Vacuolating Cytotoxin Induces Activation of the Proapoptotic Proteins Bax and Bak, Leading to Cytochrome c Release and Cell Death, Independent of Vacuolation

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