scholarly journals NADH-Dependent Flavin Oxidoreductase of Mycoplasma Hyopneumoniae Functions as a Potential Novel Virulence Factor and not Only as a Metabolic Enzyme

Author(s):  
Xing Xie ◽  
Fei Hao ◽  
Rong Chen ◽  
Jingjing Wang ◽  
Yanna Wei ◽  
...  

Abstract Background: Mycoplasma hyopneumoniae (Mhp) is the main pathogen of enzootic pneumonia, pigs infected with Mhp demonstrate mainly poor growth and a reduced feed conversion rate, a disease that has a significant impact on the pig industry and pock production worldwide. The pathogenesis, especially possible virulence factors of Mhp, has still not been fully clarified.Results: The transcriptome and proteomic analysis of Mhp strains differed in virulence based on reported literature, and RNA transcription expression levels between high- and low-virulence strains initially indicated that nicotinamide adenine dinucleotide (NADH)-dependent flavin oxidoreductase (NFOR) was related to Mhp pathogenicity. Prokaryotic expression and purification of the NFOR protein of Mhp were performed, a rabbit-origin polyclonal antibody of NFOR was prepared, and multiple sequence alignment and evolutionary analysis of Mhp NFOR were performed. For the first time, it was found that the NFOR protein was conserved among all Mhp strains, and NFOR was localized on the cell surface and could adhere to immortalized porcine bronchial epithelial cells (hTERT-PBECs). Adhesion to hTERT-PBECs could be specifically inhibited by an NFOR polyclonal antibody, and the adhesion rates of both high- and low-virulence strains, 168 and 168L, significantly decreased by more than 40%. Moreover, Mhp NFOR could not only recognize and interact with host fibronectin and plasminogen but could also induce cellular oxidative stress and apoptosis in hTERT-PBECs. Lactate dehydrogenase release of Mhp NFOR in hTERT-PBECs was significantly positively correlated with the virulence of Mhp.Conclusions: Overall, in addition to being a metabolic enzyme related to oxidative stress, NFOR may also function as a potential novel virulence factor of Mhp, thus contributing to the pathogenesis process of Mhp, providing new ideas and theoretical support for studying the pathogenic mechanisms of other mycoplasmas.

2021 ◽  
Vol 12 ◽  
Author(s):  
Xing Xie ◽  
Fei Hao ◽  
Rong Chen ◽  
Jingjing Wang ◽  
Yanna Wei ◽  
...  

Mycoplasma hyopneumoniae (Mhp) is the main pathogen that causes enzootic pneumonia, a disease that has a significant impact on the pig industry worldwide. The pathogenesis of enzootic pneumonia, especially possible virulence factors of Mhp, has still not been fully elucidated. The transcriptomic and proteomic analyses of different Mhp strains reported in the literature have revealed differences in virulence, and differences in RNA transcription levels between high- and low-virulence strains initially indicated that nicotinamide adenine dinucleotide (NADH)-dependent flavin oxidoreductase (NFOR) was related to Mhp pathogenicity. Prokaryotic expression and purification of the NFOR protein from Mhp were performed, a rabbit-derived polyclonal antibody against NFOR was prepared, and multiple sequence alignment and evolutionary analyses of Mhp NFOR were performed. For the first time, it was found that the NFOR protein was conserved among all Mhp strains, and NFOR was localized to the cell surface and could adhere to immortalized porcine bronchial epithelial cells (hTERT-PBECs). Adhesion to hTERT-PBECs could be specifically inhibited by an anti-NFOR polyclonal antibody, and the rates of adhesion to both high- and low-virulence strains, 168 and 168L, significantly decreased by more than 40%. Moreover, Mhp NFOR not only recognized and interacted with host fibronectin and plasminogen but also induced cellular oxidative stress and apoptosis in hTERT-PBECs. The release of lactate dehydrogenase by hTERT-PBECs incubated with Mhp NFOR was significantly positively correlated with the virulence of Mhp. Overall, in addition to being a metabolic enzyme related to oxidative stress, NFOR may also function as a potential novel virulence factor of Mhp, thus contributing to the pathogenesis of Mhp; these findings provide new ideas and theoretical support for studying the pathogenic mechanisms of other mycoplasmas.


2019 ◽  
Vol 201 (6) ◽  
Author(s):  
Qingqing Gao ◽  
Le Xia ◽  
Xiaobo Wang ◽  
Zhengqin Ye ◽  
Jinbiao Liu ◽  
...  

ABSTRACTStrains of avian pathogenicEscherichia coli(APEC), the common pathogen of avian colibacillosis, encounter reactive oxygen species (ROS) during the infection process. Superoxide dismutases (SODs), acting as antioxidant factors, can protect against ROS-mediated host defenses. Our previous reports showed that thesodAgene (encoding a Mn-cofactor-containing SOD [MnSOD]) is highly expressed during the septicemic infection process of APEC.sodAhas been proven to be a virulence factor of certain pathogens, but its role in the pathogenicity of APEC has not been fully identified. In this study, we deleted thesodAgene from the virulent APEC O2 strain E058 and examined thein vitroandin vivophenotypes of the mutant. ThesodAmutant was more sensitive to hydrogen peroxide in terms of both its growth and viability than was the wild type. The ability to form a biofilm was weakened in thesodAmutant. ThesodAmutant was significantly more easily phagocytosed by chicken macrophages than was the wild-type strain. Chicken infection assays revealed significantly attenuated virulence of thesodAmutant compared with the wild type at 24 h postinfection. The virulence phenotype was restored by complementation of thesodAgene. Quantitative real-time reverse transcription-PCR revealed that the inactivation ofsodAreduced the expression of oxidative stress response geneskatE,perR, andosmCbut did not affect the expression ofsodBandsodC. Taken together, our studies indicate that SodA is important for oxidative resistance and virulence of APEC E058.IMPORTANCEAvian colibacillosis, caused by strains of avian pathogenicEscherichia coli, is a major bacterial disease of severe economic significance to the poultry industry worldwide. The virulence mechanisms of APEC are not completely understood. This study investigated the influence of an antioxidant protein, SodA, on the phenotype and pathogenicity of APEC O2 strain E058. This is the first report demonstrating that SodA plays an important role in protecting a specific APEC strain against hydrogen peroxide-induced oxidative stress and contributes to the virulence of this pathotype strain. Identification of this virulence factor will enhance our knowledge of APEC pathogenic mechanisms, which is crucial for designing successful strategies against associated infections and transmission.


1999 ◽  
Vol 893 (1 OXIDATIVE/ENE) ◽  
pp. 79-94 ◽  
Author(s):  
GARY E. GIBSON ◽  
LARRY C. H. PARK ◽  
HUI ZHANG ◽  
SANDRO SORBI ◽  
NOEL Y. CALINGASAN

1970 ◽  
Vol 10 (46) ◽  
pp. 534 ◽  
Author(s):  
ES Batterham

Maize-meat meal and maize-meat and bone meal diets were supplemented with dl-tryptophan, l-lysine or a mineral-vitamin-antibiotic (MVA) premix and fed to pigs during the 1s to 45 kg growth phase. Diets were offered at an estimated 145 kcal of digestible energy and 7g crude protein per kg liveweight per day. The basal maize-meat meal diet produced poor growth and feed conversion and the combined addition of all three supplements increased growth by 46 per cent, feed conversion by 21 per cent, and lean in the ham by 4.7 per cent. This effect resulted from responses to dl-tryptophan, the MVA and an interaction between dl-tryptophan and l-lysine, with l-lysine depressing gain and feed conversion in the absence of dl- tryptophan and increasing gain, feed conversion, and lean in the ham in its presence. The basal maize-meat and bone meal diet also produced poor growth and feed conversion, and the combined addition of all three supplements resulted in an 82 per cent increase in growth, a 35 per cent increase in feed conversion, and a 3.3 per cent increase in lean in the ham. Both dl-tryptophan and MYA separately increased growth and feed conversion and combined they had an even greater effect. The l-lysine increased feed conversion and lean in the ham. The l-lysine also increased growth rates on the dl-tryptophan supplemented diets, but this effect was not significant (P>0.05).


2005 ◽  
Vol 68 (7) ◽  
pp. 1525-1534 ◽  
Author(s):  
JAMES L. SMITH

Colonic spirochetosis is a disease caused by the gram-negative bacteria Brachyspira aalborgi and Brachyspira pilosicoli. B. pilosicoli induces disease in both humans and animals, whereas B. aalborgi affects only humans and higher primates. Symptoms in humans include diarrhea, rectal bleeding, and abdominal cramps. Colonic spirochetosis is common in third world countries; however, in developed countries, the disease is observed mainly in homosexual males. Terminally ill patients infected with Brachyspira are particularly at risk for developing spirochetemia. Diarrhea, poor growth performance, and decreased feed-to-gain efficiency is seen in pigs with colonic spirochetosis. The disease in chickens is characterized by delayed and/or reduced egg production, diarrhea, poor feed conversion, and retarded growth. Thus, colonic spirochetosis can represent a serious economic loss in the swine and poultry industries. The organisms are transmitted by the fecal-oral route, and several studies have demonstrated that human, primate, pig, dog, or bird strains of B. pilosicoli can be transmitted to pigs, chickens, and mice. B. pilosicoli may be a zoonotic pathogen, and although it has not been demonstrated, there is a possibility that both B. pilosicoli and B. aalborgi can be transferred to humans via contact with the feces of infected animals, meat from infected animals, or food contaminated by food handlers. Neither B. pilosicoli nor B. aalborgi has been well characterized in terms of basic cellular functions, pathogenicity, or genetics. Studies are needed to more thoroughly understand these Brachyspira species and their disease mechanisms.


2020 ◽  
Vol 11 ◽  
Author(s):  
Masaya Yamaguchi ◽  
Moe Takemura ◽  
Kotaro Higashi ◽  
Kana Goto ◽  
Yujiro Hirose ◽  
...  

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Yunli Zhao ◽  
Ling Jin ◽  
Yuxin Chi ◽  
Jing Yang ◽  
Quan Zhen ◽  
...  

Oxidative stress has been proven as one of the most critical regulatory mechanisms involved in fine Particulate Matter- (PM2.5-) mediated toxicity. For a better understanding of the underlying mechanisms that enable oxidative stress to participate in PM2.5-induced toxic effects, the current study explored the effects of oxidative stress induced by PM2.5 on UPR and lifespan in C. elegans. The results implicated that PM2.5 exposure induced oxidative stress response, enhanced metabolic enzyme activity, activated UPR, and shortened the lifespan of C. elegans. Antioxidant N-acetylcysteine (NAC) could suppress the UPR through reducing the oxidative stress; both the antioxidant NAC and UPR inhibitor 4-phenylbutyric acid (4-PBA) could rescue the lifespan attenuation caused by PM2.5, indicating that the antioxidant and moderate proteostasis contribute to the homeostasis and adaptation to oxidative stress induced by PM2.5.


2020 ◽  
Vol 168 (4) ◽  
pp. 337-348
Author(s):  
Guangdong Zhao ◽  
Chen Wang ◽  
Ying Wang ◽  
Lijun Wang ◽  
Baohua Xu ◽  
...  

Abstract N-Terminal asparagine amidohydrolase is a component of the ubiquitin-dependent N-end rule pathway of protein degradation that has been implicated in a variety of physiological functions, including the sensing of heme, oxygen, nitric oxide, selective elimination of misfolded proteins and the repair of DNA. We identified the Apis cerana cerana N-terminal asparagine amidohydrolase (AccNtan1) gene from A. cerana cerana and investigated its role in oxidation resistance. Multiple sequence alignments and phylogenetic analysis revealed that N-terminal asparagine amidohydrolase is highly conserved in insect species. Quantitative real-time polymerase chain reaction analysis indicated that the expression levels of AccNtan1 were significantly lower in the wing, honey sac and abdomen than in other tissues and were significantly higher in early stages of development, including the larva, prepupa and pink-eyed pupa stages, than in later stages. We further observed that AccNtan1 expression was induced by several environmental stressors, including aberrant temperature, H2O2, UV, heavy metals and pesticides. Moreover, a bacteriostatic assay suggested that overexpression of AccNtan1 enhances the resistance of bacteria to oxidative stress. In addition, knockdown of AccNtan1 using RNA interference significantly affected the expression levels of most antioxidant genes and the activity levels of several antioxidant enzymes. Thus, we hypothesize that AccNtan1 plays important roles in environmental stress responses and antioxidative processes.


2004 ◽  
Vol 287 (5) ◽  
pp. H2122-H2131 ◽  
Author(s):  
Mohamed Benderdour ◽  
Guy Charron ◽  
Blandine Comte ◽  
Riwa Ayoub ◽  
Diane Beaudry ◽  
...  

Mitochondrial dysfunction subsequent to increased oxidative stress and alterations in energy metabolism is considered to play a role in the development of cardiac hypertrophy and its progression to failure, although the sequence of events remains to be elucidated. This study aimed at characterizing the impact of hypertrophy development on the activity and expression of mitochondrial NADP+-isocitrate dehydrogenase (mNADP+-ICDH), a metabolic enzyme that controls redox and energy status. We expanded on our previous finding of its inactivation through posttranslational modification by the lipid peroxidation product 4-hydroxynonenal (HNE) in 7-wk-old spontaneously hypertensive rat (SHR) hearts before hypertrophy development (Benderdour et al. J Biol Chem 278: 45154–45159, 2003). In this study, we used 7-, 15-, and 30-wk-old SHR and Sprague-Dawley (SD) rats with abdominal aortic coarctation. Compared with age-matched control Wistar-Kyoto (WKY) rats, SHR hearts showed a significant 25% decrease of mNADP+-ICDH activity, which preceded in time 1) the decline in its protein and mRNA expression levels (between 10% and 35%) and 2) the increase in hypertrophy markers. The chronic and persistent loss of mNADP+-ICDH activity in SHR was associated with enhanced tissue accumulation of HNE-mNADP+-ICDH and total HNE-protein adducts at all ages and contrasted with the profile of changes in the activity of other mitochondrial enzymes involved in antioxidant or energy metabolism. Two-way ANOVA of the data also revealed a significant effect of age on most parameters measured in SHR and WKY hearts. The mNADP+-ICDH activity, protein, and mRNA expression were reduced between 25% and 35% in coarctated SD rats and were normalized by treatment of SHR or coarctated SD rats with renin-angiotensin system inhibitors, which prevented or attenuated hypertrophy. Altogether, our data show that cardiac mNADP+-ICDH activity and expression are differentially and sequentially affected in hypertrophy development and, to a lesser extent, with aging. Decreased cardiac mNADP+-ICDH activity, which is attributed at least in part to HNE adduct formation, appears to be a relevant early and persistent marker of mitochondrial oxidative stress-related alterations in hypertrophy development. Potentially, this could also contribute to the aetiology of cardiomyopathy.


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