The introduction of bacteroides spp. derived outer membrane vesicles as new obesity treating candidates: focus on the improvement of fasting-induced adipose factor and tight junctions expression in c
Sara Ahmadi badi,
1 Seyed davar siadat,
2,* Arfa moshiri,
3 Fatemeh ettehad marvastti,
4 Abolfazl fateh,
5 Farzam vaziri,
6
2. Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
3. Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
5. Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
6. Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran
Abstract
Introduction
The gut microbiota is considered as an environmental factor in obesity etiology. it exerts related effects through various mechanisms including the influence on fat storage and gut barrier permeability. increased gut barrier permeability and fat deposition through decreased tight junctions (zo-1 and occludin) and decreased fasting-induced adipose factor, fiaf, respectively occur during obesity. on the other hand, fiaf gene expression is controlled by peroxisome proliferator-activated receptors (ppars). bacteroides spp. are important members of gut microbiota that produce omvs as a strategy to interact with the host. we evaluated the effect of b. fragilis and b. thetaiotaomicron derived omvs and related bacteria on zo-1, occludin, fiaf and ppars genes expression in caco-2 cell line.
Methods
B. fragilis and b. thetaiotaomicron were grown on bhi broth. omvs extracted using tris-edta -sodium deoxycholate buffers and sequential centrifugation.caco-2 cell line was treated with both omvs and related. to evaluate cell viability mtt assay was applied. quantitative pcr was performed using sybr green qpcr.
Results
B. fragilis and b. thetaiotamicron produced spherical shape omvs with a diameter ranging 30-110 nm and specific protein profile. mtt assays showed more than 95% viability of caco-2 cells treated with b. fragilis and b. thetaiotaomicron derived omvs. although b. fragilis decreases zo-1 and no significant change of occludin mrna levels, its omvs significantly elevate the level of these transcripts in caco-2 cells. in the cells treated with b. thetaiotamicron and its omvs, only zo-1 mrna levels were elevated. also, the levels of fiaf, pparα, and pparδ transcripts were significantly increased in b. fragilis treated caco-2 cells. b. fragilis derived omvs elevated only ppars mrna in this cell line. while b. thetaiotamicron reduced the expression of fiaf and ppars mrna in caco-2 cells, its omvs increased pparδ and pparᵧ transcripts with no significant change on fiaf and pparα mrna levels.
Conclusion
B. fragilis and b. thetaiotamicron derived omvs could be possible probiotic candidates for obesity treatment based on the beneficial effect on fiaf, ppars, zo-1 and occludin transcripts.
Keywords
Bacteroides fragilis , b. thetaiotamicron, gut microbiota, fiaf, ppars, zo-1 and occludin
