DNA Vaccines On Ubiquitin Proteasome Of Chronic MPTP Parkinson’s Disease Mouse

Objective:To explore immunological therapeutic effects mechanisms of optimized nucleic acid vaccine(p VAX1-IL-4/SYN-B)on ubiquitin proteasome of Parkinson’s disease mouse.Methods:male C57BL/6 mice were randomly divided into four Groups: PBS model group,empty plasmid model group,optimized DNA vaccine model group and plasmid plus lactacystin.The groups were intraperitoneally injected with MPTP solution.Then the anterior tibial muscles of mouse hind leg were respectively injected with 100 ul of PBS、 empty plasmid、p VAX1-IL-4/SYN-B and p VAX1-IL-4/SYN-B unilaterally,total for three times at two weeks interval.In the last injectin,proteasome inhibitor,lactacystin were directly into the medial forebrain bundle(i MFB)of mice.Three weeks after the final injection,the behavior changes of mice were observed,tyrosine hydroxylase(TH)expression in substantia nigra of mice was observed by immunohistochemistry;TH 、 ubiquitin 、 20 S proteasome 、α-syn expression in substantia nigra of mice were detected by Western blot;α-syn and each of the ubiquitin and 20 S proteasome in substantia nigra of mice were surveyed by dual staining.Results:1.animals with the optimized DNA vaccine model group improv emented significantly in motor symptoms compared with PBS group、 empty plasmid group and plasmid plus lactacystin group(P<0.05).2.Western blot and immunohistochemistry showed the expression level of TH in substantia nigra of mice of optimized DNA vaccine groups were added mostly contrasted with PBS group 、empty plasmid group or plasmid plus lactacystin group(P<0.05).3.Western blot showed the expression level of 20 S proteasome of mice of optimized DNA vaccine groups were rised remarkablely,compared with PBS group 、empty plasmid group or plasmid plus lactacystin group(P<0.05);the expression level of α-syn of mice of optimized DNA vaccine groups were decreased remarkablely compared with PBS group、 empty plasmid group or plasmid plus lactacystin group.(P<0.05);the expression level of ubiquitin of mice of optimized DNA vaccine groups were decreased remarkablely compared with PBS group 、empty plasmid group or plasmid plus lactacystin group.4.Double label immunofluorescence showed that the α-syn and each of the ubiquitin and 20 S proteasom were co-localization in substantia nigra of mice;Robust decreases immunoreactivity for α-syn with ubiquitin and strong increases for α-syn with 20 S proteasome in optimized DNA vaccine groups were easily distinguishable from PD groups.Conclusions:One possible is that optimized DNA vaccine has protected effects in chronic MPTP Parkinson’s mice,which generated hα-syn antibodies to promote the clearance the abnormal a-syn via lysosome,thus reduce the ubiquition proteasome toxicity to maintain its function.The other possible is that optimized DNA vaccine generating antibodies in the vaccinated mice recognize and promote the clearance the a-syn aggregates via ubiquition proteasome,therefore reduing the toxicity of dopamine neurons.