Transcriptomic analysis:the protection of over-expression thioredoxin reductase 1 in Parkinson’s disease

Background Parkinson’s disease(PD)is the second most common neurodegenerative disease.The pathologic characteristic feature is the loss of dopaminergic neurons in the substantia nigra(SN).However,the biochemical mechanisms are unclear.A large number of studies have shown that oxidative damage is the primary cause of PD.Hence,antioxidants could become a suitable option to treat PD.The thioredoxin(Trx)system represents a useful,potentially disease-relevant oxidation-reduction system.Thioredoxin reductase 1(TR1)is a significant component of the Trx system.Methods The overexpression lentivirus(LV)or LV-TR1 in the TR1-A53T model of PD by the stereotactic brain,and successful overexpression of LV or LV-TR1 in the MPP^(+)-induced cellular model by LV or LV-TR1 transfection.Results We confirmed that interleukin-7 mRNA levels increased in MPP^(+)compared to that in the control and MPP^(+)-TR1 groups using quantitative polymerase chain reaction.Theγ-H_(2)AX level was increased in the Tg-A53T group compared to that in the TR1-A53T group by western blotting.The expression of Na^(+)-K^(+)-ATP was decreased in the MPP^(+)group compared to that in the control and MPP^(+)-TR1 groups by high content screening.Tg-A53T(the C57BL/6 mice transferred with mutant human a-syn);TR1-A53T(A53T mice which were injected TR1-LV 2µl in SNc on two sides with minipump).The mice were fed for 10 months.control(the N2a cells cultivated with DMEM);MPP^(+)(the N2a cells dealt with MPP^(+)(1 mM)48 h),MPP^(+)-LV(the N2a cells over-expressed LV for 24 h then dealt with MPP^(+)(1 mM)48 h).MPP^(+)-TR1(the N2a cell over-expressed TR1-LV for 24 h then dealt with MPP^(+)(1 mM)48 h).From the Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis,we confirmed that the overexpression of TR1 in SN pars compacta cells decreased oxidative stress,apoptosis,DNA damage,and inflammatory response and increased NADPH,Na^(+)-K^(+)-ATP,and immune response in this PD model.Conclusions Our study shows that overexpressed TR1 can be developed as a neuroprotective agent for PD.Therefore,our findings demonstrate a new targeted protein for the treatment of PD.

Broken electron transfer pathway in enzyme:Gold clusters inhibiting TrxR1/Trx via cell studies and theory simulations

Thioredoxin reductase 1(TrxR1)is over activity in tumor cell to maintain their redox balance.Although gold clusters have great potential in antitumor drug as they could well inhibit TrxR1,the molecular mechanism has not been disclosed yet.In this work,we revealed gold clusters can well inhibit the activity of TrxR1 in lung tumor cells and further disclosed the inhibition mechanism by using computational simulation methods.We firstly inferred the binding sites of gold in the hydrophobic cavities on TrxR1.The simulation results show that the gold ion(released from Au cluster)interact with–SH of Cys189 in TrxR1,this greatly increase the distance between the C-terminal redox center of TrxR1 and the Trx redox center,thereby destroy the electron transfer pathway between them.Our electron transfer destroying mechanism is different from the previous hypothesis that gold binds to the Sec498 of TrxR1 which has never been proved by experimental and theory studies.This work provides a new understanding of the gold clusters to inhibit TrxR1 activity.