Effects of P. aeruginosa-derived bacterial products on tracheal ciliary function: role of O2 radicals

Jackowski, J. T.; Szépfalusi, Zsolt; Wanner, D.; Seybold, Zsuzsanna V.; Sielczak, M. W.; Lauredo, Isabel T.; Adams, Terry; Abraham, William M.; Wanner, Adam

doi:10.1152/ajplung.1991.260.2.l61

Cited by 35 publications

(35 citation statements)

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“…It has been shown previously that H 2 O 2 disrupts the respiratory epithelium, causing ciliary stasis (4,14,17). H 2 O 2 also depletes epithelial ATP levels, and because ciliary beating is heavily ATP dependent (5), this was suggested to be the mechanism for H 2 O 2 -induced epithelial ciliary stasis (30).…”

Section: Discussionmentioning

confidence: 96%

Relative Roles of Pneumolysin and Hydrogen Peroxide from Streptococcus pneumoniae in Inhibition of Ependymal Ciliary Beat Frequency

et al. 2000

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Ciliated ependymal cells line the ventricular system of the brain and the cerebral aqueducts. This study characterizes the relative roles of pneumolysin and hydrogen peroxide (H 2 O 2 ) in pneumococcal meningitis, using the in vitro ependymal ciliary beat frequency (CBF) as an indicator of toxicity. We have developed an ex vivo model to examine the ependymal surface of the brain slices cut from the fourth ventricle. The ependymal cells had cilia beating at a frequency of between 38 and 44Hz. D39 (wild-type) and PLN-A (pneumolysinnegative) pneumococci at 10 8 CFU/ml both caused ciliary slowing. Catalase protected against PLN-A-induced ciliary slowing but afforded little protection from D39. Lysed PLN-A did not reduce CBF, whereas lysed D39 caused rapid ciliary stasis. There was no effect of catalase, penicillin, or catalase plus penicillin on the CBF. H 2 O 2 at a concentration as low as 100 M caused ciliary stasis, and this effect was abolished by coincubation with catalase. An additive inhibition of CBF was demonstrated using a combination of both toxins. A significant inhibition of CBF at between 30 and 120 min was demonstrated with both toxins compared with either H 2 O 2 (10 M) or pneumolysin (1 HU/ml) alone. D39 released equivalent levels of H 2 O 2 to those released by PLN-A, and these concentrations were sufficient to cause ciliary stasis. The brain slices did not produce H 2 O 2 , and in the presence of 10 8 CFU of D39 or PLN-A per ml there was no detectable bacterially induced increase of H 2 O 2 release from the brain slice. Coincubation with catalase converted the H 2 O 2 produced by the pneumococci to H 2 O. Penicillin-induced lysis of bacteria dramatically reduced H 2 O 2 production. The hemolytic activity released from D39 was sufficient to cause rapid ciliary stasis, and there was no detectable release of hemolytic activity from the pneumolysin-negative PLN-A. These data demonstrate that D39 bacteria released pneumolysin, which caused rapid ciliary stasis. D39 also released H 2 O 2 , which contributed to the toxicity, but this was masked by the more severe effects of pneumolysin. H 2 O 2 released from intact PLN-A was sufficient to cause rapid ciliary stasis, and catalase protected against H 2 O 2 -induced cell toxicity, indicating a role for H 2 O 2 in the response. There is also a slight additive effect of pneumolysin and H 2 O 2 on ependymal toxicity; however, the precise mechanism of action and the role of these toxins in pathogenesis remain unclear.

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Section: Discussionmentioning

confidence: 96%

Relative Roles of Pneumolysin and Hydrogen Peroxide from Streptococcus pneumoniae in Inhibition of Ependymal Ciliary Beat Frequency

et al. 2000

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“…Finally, whereas both pyocyanin and 1-HP have been studied for their effects in mammalian model systems (17,21), PCA has not previously been recognized as having potential relevance to human disease. Moreover, because the physical structure and hence chemical properties of pyocyanin, 1-HP, and PCA are different, understanding the contribution of phenazine derivatives to the pathophysiology of P. aeruginosaassociated disease will require not only an understanding of their individual effects, but also an understanding of their combined effects, as well as their effects in the presence of other virulence factors.…”

Section: Discussionmentioning

confidence: 99%

Phenazine-1-carboxylic acid, a secondary metabolite ofPseudomonas aeruginosa, alters expression of immunomodulatory proteins by human airway epithelial cells

Denning¹,

Reszka²,

O’Malley³

et al. 2003

American Journal of Physiology-Lung Cellular and Molecular Phys

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“…Bacterial Culture and Preparation of Cell-free Supernatants-P. aeruginosa strain PAO1 was grown in M9 buffer (20) for 72 h at 37°C (to late log phase). Cell-free supernatant was obtained by centrifugation at 10,000 rpm for 60 min at 4°C and by filtration through a 0.22-m filter (Corning).…”

Section: Methodsmentioning

confidence: 99%

Cloning of the Amino-terminal and 5′-Flanking Region of the Human MUC5AC Mucin Gene and Transcriptional Up-regulation by Bacterial Exoproducts

Li¹,

Gallup²,

Fan³

et al. 1998

Journal of Biological Chemistry

163

124

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To obtain gene regulatory sequence for the mucin gene MUC5AC, we have isolated the MUC5AC amino terminus cDNA and 5-flanking region. This was possible through the use of rapid amplification of cDNA endspolymerase chain reaction (RACE-PCR) in which the 5 sequence of the human gastric mucin cDNA HGM-1 (1) was used to design the first MUC5AC-specific primer. Primers for subsequent rounds of RACE were designed from the 5-ends of amplified RACE products. After five rounds of RACE-PCR, we could no longer generate upstream extensions of the cDNA and hypothesized that we had reached the 5-end. Primer extension and RNase protection analysis confirmed this. Combined nucleotide sequence for the RACE-PCR products was 3.3 kb with an open reading frame encoding 1100 amino acids. A putative translation start site was found at nucleotide ؉48. This was followed by a 45 nucleotide putative signal sequence. This amino-terminal sequence contains no tandem repeats but is >60% similar to the amino-terminal nucleotide sequence of MUC2. The positions of cysteine residues in this MUC2-similar region are almost 100% conserved between the two genes. Northern analysis showed expression of cognate RNA in the stomach and airway but not muscle and esophagus. This pattern was the same as that obtained using previously reported 3-MUC5AC sequences. We have cloned approximately 4 kb of genomic DNA upstream of the transcription start site and have sequenced 1366 nucleotides containing a TATA box, a CACCC box, and putative binding sites for NFB and Sp 1. Within 4 kb of the transcription start site are elements mediating transcriptional up-regulation in response to bacterial exoproducts.Mucin is a glycoprotein secreted from epithelial cells at many body surfaces. In the airways, mucin interacts with cilia to trap and clear pathogens and irritants. This mucociliary mechanism is impaired when mucin is produced excessively as in cystic fibrosis, chronic bronchitis, and asthma. Mucociliary impairment leads to airway mucus plugging, which promotes chronic infection, airflow obstruction, and sometimes death.Nine mucin genes are known to be expressed in man: MUC5AC, MUC5B,. The mRNAs encoding two of them, MUC2 and MUC5AC, have been shown to be up-regulated in cystic fibrosis airways (13,14) 1 and likely contribute to the airway mucus plugging characteristic of this disease. Insofar as DNA-RNA transcription is controlled by mechanisms amenable to pharmaceutical intervention, an understanding of mucin transcription may suggest ways of inhibiting mucin overproduction.Both MUC2 and MUC5AC map to chromosome 11p15.5 and may have arisen from a common ancestral gene. The structure of MUC2 is known. Its central region, comprising Ͼ50% of the polypeptide, contains two tandem repeat sequences rich in threonine, serine, and proline (4, 17); this is flanked up-and downstream by cysteine-rich regions (17, 18). The threonine and serine residues represent O-glycosylation sites, whereas the cysteine residues are thought to mediate intermolecular interactions underlying mu...

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Effects of P. aeruginosa-derived bacterial products on tracheal ciliary function: role of O2 radicals

Cited by 35 publications

References 0 publications

Relative Roles of Pneumolysin and Hydrogen Peroxide from Streptococcus pneumoniae in Inhibition of Ependymal Ciliary Beat Frequency

Relative Roles of Pneumolysin and Hydrogen Peroxide from Streptococcus pneumoniae in Inhibition of Ependymal Ciliary Beat Frequency

Phenazine-1-carboxylic acid, a secondary metabolite ofPseudomonas aeruginosa, alters expression of immunomodulatory proteins by human airway epithelial cells

Cloning of the Amino-terminal and 5′-Flanking Region of the Human MUC5AC Mucin Gene and Transcriptional Up-regulation by Bacterial Exoproducts

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