Proteomic analysis of the function of spot in Helicobacter pylori anti-oxidative stress in vitro and colonization in vivo.
As a microaerobe, Helicobacter pylori employs the global regulator SpoT for defending against oxidative stress in vitro. However, the mechanisms how SpoT affects bacterial gene expression is still unknown. Moreover, the function of SpoT in H. pylori colonization in the host is remaining undetermined. To explore the functions of the SpoT in H. pylori pathogenesis, we constructed H. pylori 26695 spoT-deficient mutant (ΔspoT). While grown in ambient atmosphere, protein expression profile of the ΔspoT was analyzed with 2D gel electrophoresis and real-time PCR. Compared to the wild type, the spoT-deficient strain downregulated its transcription of the oxidative-induced genes, as well as the genes responsible for protein degradation and that related to energy metabolism. Meanwhile, the colonization ability of ΔspoT strains in Mongolian gerbil was tested, the results demonstrated a decayed colonization in the mouse stomach with ΔspoT than the wild type. As a matter of facts, the AGS cells infected with the ΔspoT strains excreted increased level of the gastric inflammation cytokines IL-8, and the ΔspoT strains showed poor survival ability when treated with reactive oxygen stress (sodium nitroprusside). The elevated capacity of stimulating cytokines and fragility to reactive oxygen stress may be contribute to decreased colonization of the spoT-deficient mutant in the mouse stomach. Conclusively, we speculate that spoT is a key regulator of the genes for H. pylori spreading in the air and colonization in host stomach.
Department of Microbiology, Key Laboratory for Experimental Teratology of Chinese Ministry of Education, School of Medicine, Shandong University, Jinan, Shandong, China.
Yundong
Y
Sun
Xinpeng
X
Li
Wen
W
Li
Min
M
Zhao
Lixiang
L
Wang
Shili
S
Liu
Jiping
J
Zeng
Zhifang
Z
Liu
Jihui
J
Jia
D000332:Aerobiosis / Q000502:physiology; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015169:Colony Count, Microbial; D003470:Culture Media; D005849:Gerbillinae; D016481:Helicobacter Infections / Q000276:immunology / Q000378:metabolism / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects / Q000472:pathogenicity / Q000502:physiology*; D016209:Interleukin-8 / Q000276:immunology / Q000378:metabolism; D050296:Microbial Viability / Q000187:drug effects; D009154:Mutation; D009599:Nitroprusside / Q000494:pharmacology; D016877:Oxidants / Q000494:pharmacology; D018384:Oxidative Stress; D040901:Proteomics; D011755:Pyrophosphatases / Q000172:deficiency / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D013270:Stomach / Q000382:microbiology*
D001426:Bacterial Proteins; D003470:Culture Media; D016209:Interleukin-8; D016877:Oxidants; D009599:Nitroprusside; C027627:guanosine-3',5'-bis(diphosphate) 3'-pyrophosphatase; D011755:Pyrophosphatases