Effects Of Brucella Outer Membrane Protein OMP25 On MAPK Signaling Pathways

Brucellosis mainly cause livestock symptom such as abortion, stillbirth, orchitis, bring virulence were expressed in aggressivity to the host cell and its fertility.Brucella outer membrane protein are the main virulence factors, it’s related closely to the adhesion and colonization of the Brucella.Protein OMP25 is an important outer membrane proteins of Brucella, it shows an important role to maintain the stability of the Brucella and its own structureon, after deleted protein OMP25 the poisonous force of Brucella decreased obviously.MAPK signaling pathway widely exists in eukaryotic cell signal transduction pathway, could be activated by cytokines and bacteria, such as signal, to produced reaction.Relationship between OMP25 outer membrane protein and the signal path are studied in this experiment, studing the outer membrane protein of the activation of signaling pathways, and the secretion of cytokines to infect cells, the effect of for further research to explore the pathogenic mechanism of Brucella.The following research around the above views:Screened and identificated of significantly expression of cytokines in Brucella OMP25 strains and 2308 strains infect human trophoblast cells.cell model of absence of OMP25 Brucella strains and 2308 infect human trophoblast, using the method of ELISA detecting infection after 0 h, 8 h, 24 h, 48 h cells that cytokines in the supernatant fluid, determine the significant difference in production of cytokines.Results show that in, OMP25 group、2308 group and the PBS had no significant difference on IL- 10, IL- 1β in each period;When post-infected for 4 h, 2308 groups higher than PBS control group, and significant difference on IL-1;OMP25 strains infect group had a significantly lower than the 2308 infection group in IL- 1 release(P < 0.05);Compared with the 2308 group, TNF-α release a quantity to OMP25 sets in 4 h, 8 h, 24 h, 48 h have significant difference.Studies have shown that Brucella infection process of the host cell membrane protein OMP25 and cytokine TNF-α release quantity of closely related.Analysis Brucella OMP25 effect on MAPK signaling pathways.Building OMP25 and 2308 Brucella strains’ infect human trophoblast(HPT-8) cell model, collecting total protein infect cells, after being quantitatived detected of phosphorylation.Incubated cells with concentration of 10 μM signaling pathway inhibitor for 1 h, Brucella OMP25 strains and Brucella 2308 with the proportion of 100:1 infect cells.ELISA method detected infect TNF- α in the cells supernatant fluid at 4h, 8h, 24 h, 48 h, blocking the signal pathway to get a further validated.The result shows that: the group of 2308 activate phosphorylated the GSK-3a/b, JNK, P38, P70S6 Kinase, RSK2, HSP27 phosphorylation site during 26 proteins.OMP25 group activated P38γ pathway.Inhibitors experiment results show that,after MAPK P38 inhibition incubated cells,both OMP25 strains group and 2308 infected group had a TNF-α secretion decreased, JNK and ERK inhibition incubated cells have no obviously change.Research shows that Brucella 2308 strains and Brucella OMP25 strains activated P38 branch of MAPK signal pathway.And the secretion of TNF-α had a relationship with p38 lightningDetect Brucella OMP25 strain and Brucella 2308 strains infected mice activated which MAPK signal pathway, make a further elaborated what role OMP25 played in activating MAPK signaling pathway mechanism.Intraperitoneal injected 35 days pregnant mice with Brucella 2308 infection and OMP25 strains, collected infected mice peripheral blood serum detected Ig G and TNF-α burst size, Observated pathological slice of mice from Brucella OMP25 group and parental strains group, immunohistochemical analysed of Brucella impact of MAPK signaling pathways after infected in the body level.Results showed that group OMP25 strains and 2308 strains’ TNF-α released quantity were lower than control group.Pathological results showed that compared with the group of OMP25 strains, 2308 infected group appear more obvious pathological changes.Immunohistochemical results show that OMP25 group endometrial and 2308 strains infected mice endometrium activated MAPK signaling pathways phosphorylated p38 branch and ERK.The results showed that 2308 strains of Brucella and OMP25 strains have increased the expression of TNF-α, and activate the MAPK signaling pathways p38 branch and ERK branch at the same time.