scholarly journals Host Specificity of Flagellins from Segmented Filamentous Bacteria Affects Their Patterns of Interaction with Mouse Ileal Mucosal Proteins

2017 ◽  
Vol 83 (18) ◽  
Author(s):  
Huahai Chen ◽  
Yeshi Yin ◽  
Yanling Wang ◽  
Xin Wang ◽  
Charlie Xiang

ABSTRACT Segmented filamentous bacteria (SFB) are known modulators of the mammalian immune system. Currently, the technology for investigating SFB culture in vitro is immature, and as a result, the mechanisms of SFB colonization and immune regulation are not yet fully elucidated. In this study, we investigated the gene diversity and host specificity of SFB flagellin genes. The fliC1 and fliC2 genes are relatively conserved, while the fliC3 and fliC4 genes are more variable, especially at the central and C-terminal regions. Host specificity analysis demonstrated that the fliC1 genes do not cluster together based on the host organism, whereas the fliC3 and fliC4 genes were host specific at the nucleotide and deduced amino acid levels. SFB flagellin protein expression in the ileum mucosa and cecal contents was detected by using fluorescence in situ hybridization (FISH) combined with immunohistochemical (IHC) analysis, immunoblotting, and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Although the purified SFB FliC3 protein originating from both mouse and rat was able to activate Toll-like receptor 5 (TLR5)-linked NF-κB signaling, no host specificity was observed. Interestingly, the patterns of interaction with mouse ileum mucosal proteins were different for mouse FliC3 (mFliC3) and rat FliC3 (rFliC3). Gene Ontology (GO) and KEGG analyses indicated that more adherence-related proteins interacted with mFliC3, while more lysosome- and proteolysis-related proteins interacted with rFliC3. In vitro degradation experiments indicated that the stability of rFliC3 was lower than that of mFliC3 when they were incubated with mouse ileum mucosal proteins. In summary, the gene diversity and host specificity of SFB flagellin genes were investigated, and SFB flagellin expression was detected in gut samples. IMPORTANCE Since SFB genomes contain only one copy of each FliC gene, the diversity of FliC is representative of SFB strain diversity. Currently, little is known regarding the diversity and specificity of members of the group of SFB. The work presented herein demonstrates that select SFB strains, exhibiting unique FliC patterns, are present in a variety of mammalian hosts. SFB fliC genes were found to interact with a number of unique targets, providing further evidence for SFB host selection. Together, this work represents a major advancement in identifying SFB and delineating how members of the group of SFB interact with the host. Future examination of FliC genes will likely enhance our knowledge of intestinal colonization by the gut microbiota.

1993 ◽  
Vol 27 (2) ◽  
pp. 141-150 ◽  
Author(s):  
H. L. B. M. Klaasen ◽  
J. P. Koopman ◽  
M. E. Van Den Brink ◽  
M. H. Bakker ◽  
F. G. J. Poelma ◽  
...  

Segmented, filamentous bacteria (SFBs) form a group of bacteria with similar morphology and are identified on the basis of their morphology only. The relationships of these organisms are unclear as the application of formal taxonomic criteria is impossible currently due to the lack of an in vitro technique to culture SFBs. The intestine of laboratory animals such as mice, rats, chickens, dogs, cats and pigs is known to harbour SFBs. To see whether this extends to other animal species, intestines from 18 vertebrate species, including man, were examined. SFBs were detected with light microscopy in the cat, dog, rhesus monkey, crab-eating macaque, domestic fowl, South African claw-footed toad, carp, man, laboratory mouse and rat, wood mouse, jackdaw and magpie. These results suggest that non-pathogenic SFBs are ubiquitous in the animal kingdom. Among apparently identical animals, there was considerable variation in the degree of SFB colonization. It is suggested that SFB colonization could serve as a criterion of standardization of laboratory animals.


Nature ◽  
2015 ◽  
Vol 520 (7545) ◽  
pp. 99-103 ◽  
Author(s):  
Pamela Schnupf ◽  
Valérie Gaboriau-Routhiau ◽  
Marine Gros ◽  
Robin Friedman ◽  
Maryse Moya-Nilges ◽  
...  

1992 ◽  
Vol 5 (6) ◽  
Author(s):  
H. L. B. M. Klaasen ◽  
J. P. Koopman ◽  
F. G. J. Poelma ◽  
M. E. Van Den Brink ◽  
M. H. Bakker ◽  
...  

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Zhiya Deng ◽  
Maomao Sun ◽  
Jie Wu ◽  
Haihong Fang ◽  
Shumin Cai ◽  
...  

AbstractOur previous studies showed that silent mating-type information regulation 2 homologue-1 (SIRT1, a deacetylase) upregulation could attenuate sepsis-induced acute kidney injury (SAKI). Upregulated SIRT1 can deacetylate certain autophagy-related proteins (Beclin1, Atg5, Atg7 and LC3) in vitro. However, it remains unclear whether the beneficial effect of SIRT1 is related to autophagy induction and the underlying mechanism of this effect is also unknown. In the present study, caecal ligation and puncture (CLP)-induced mice, and an LPS-challenged HK-2 cell line were established to mimic a SAKI animal model and a SAKI cell model, respectively. Our results demonstrated that SIRT1 activation promoted autophagy and attenuated SAKI. SIRT1 deacetylated only Beclin1 but not the other autophagy-related proteins in SAKI. SIRT1-induced autophagy and its protective effect against SAKI were mediated by the deacetylation of Beclin1 at K430 and K437. Moreover, two SIRT1 activators, resveratrol and polydatin, attenuated SAKI in CLP-induced septic mice. Our study was the first to demonstrate the important role of SIRT1-induced Beclin1 deacetylation in autophagy and its protective effect against SAKI. These findings suggest that pharmacologic induction of autophagy via SIRT1-mediated Beclin1 deacetylation may be a promising therapeutic approach for future SAKI treatment.


Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1754
Author(s):  
Giuseppe Garroni ◽  
Francesca Balzano ◽  
Sara Cruciani ◽  
Renzo Pala ◽  
Donatella Coradduzza ◽  
...  

Human adipose tissue-derived stem cells (hADSCs) are highly suitable for regeneration therapies being easily collected and propagated in vitro. The effects of different external factors and culturing conditions are able to affect hADSC proliferation, senescence, differentiation, and migration, even at the molecular level. In the present paper, we exposed hADSCs to an exhausted medium from the breast cancer cell line (MCF-7) to evaluate whether the soluble factors released by these cells may be able to induce changes in stem cell behavior. In particular, we investigated the expression of stemness-related genes (OCT4; Sox 2; Nanog), the cell-cycle regulators p21 (WAF1/CIP1) p53, epigenetic markers (DNMT1 and Sirt1), and autophagy-related proteins. From our results, we can infer that the exhausted medium from MCF-7 is able to influence the hADSCs behavior increasing the expression of stemness-related genes, cell proliferation, and autophagy. Polyamines detectable in MCF-7 exhausted medium could be related to the higher proliferation capability observed in hADSCs, suggesting direct crosstalk between these molecules and the observed changes in stem cell potency.


2020 ◽  
Vol 22 (1) ◽  
pp. 38
Author(s):  
Martina Gatti ◽  
Francesca Beretti ◽  
Manuela Zavatti ◽  
Emma Bertucci ◽  
Soraia Ribeiro Luz ◽  
...  

Background—Osteoporosis is characterized by defects in both quality and quantity of bone tissue, which imply high susceptibility to fractures with limitations of autonomy. Current therapies for osteoporosis are mostly concentrated on how to inhibit bone resorption but give serious adverse effects. Therefore, more effective and safer therapies are needed that even encourage bone formation. Here we examined the effect of extracellular vesicles secreted by human amniotic fluid stem cells (AFSC) (AFSC-EV) on a model of osteoporosis in vitro. Methods—human AFSC-EV were added to the culture medium of a human pre-osteoblast cell line (HOB) induced to differentiate, and then treated with dexamethasone as osteoporosis inducer. Aspects of differentiation and viability were assessed by immunofluorescence, Western blot, mass spectrometry, and histological assays. Since steroids induce oxidative stress, the levels of reactive oxygen species and of redox related proteins were evaluated. Results—AFSC-EV were able to ameliorate the differentiation ability of HOB both in the case of pre-osteoblasts and when the differentiation process was affected by dexamethasone. Moreover, the viability was increased and parallelly apoptotic markers were reduced. The presence of EV positively modulated the redox unbalance due to dexamethasone. Conclusion—these findings demonstrated that EV from hAFSC have the ability to recover precursor cell potential and delay local bone loss in steroid-related osteoporosis.


Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2529
Author(s):  
Haeyeop Kim ◽  
Woo Seok Yang ◽  
Khin Myo Htwe ◽  
Mi-Nam Lee ◽  
Young-Dong Kim ◽  
...  

Dipterocarpus tuberculatus Roxb. has been used traditionally as a remedy for many diseases, especially inflammation. Therefore, we analyzed and explored the mechanism of the anti-inflammatory effect of a Dipterocarpus tuberculatus Roxb. ethanol extract (Dt-EE). Dt-EE clearly and dose-dependently inhibited the expression of pro-inflammatory cytokines such as IL-6, TNF-α, and IL-1β in lipopolysaccharide (LPS)-treated RAW264.7 cells. Also, Dt-EE suppressed the activation of the MyD88/TRIF-mediated AP-1 pathway and the AP-1 pathway related proteins JNK2, MKK4/7, and TAK1, which occurred as a result of inhibiting the kinase activity of IRAK1 and IRAK4, the most upstream factors of the AP-1 pathway. Finally, Dt-EE displayed hepatoprotective activity in a mouse model of hepatitis induced with LPS/D-galactosamine (D-GalN) through decreasing the serum levels of alanine aminotransferase and suppressing the activation of JNK and IRAK1. Therefore, our results strongly suggest that Dt-EE could be a candidate anti-inflammatory herbal medicine with IRAK1/AP-1 inhibitory and hepatoprotective properties.


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