Effect Of Pyrroloquinoline Quinine (PQQ) On Proliferation And Apoptosis Of NSCs

Neurodegenerative disease is a kind of disease which is caused by the abnormally degeneration of the central nervous system organization. The symptoms of the neurodegenerative disease are the degeneration and loss of neurons. Recent research found that idative stress which caused by he production of excessive free radicals in the organism has plays an important role in the process of neurodegenerative disease attacking. In recent years, Neural stem cells (NSCs) have raised a lot of concern in regeneration and reconstruction of the CNS due to its ability of renew and multi-lineage differentiation potential. But the low cell viability and weakness of vulnerable to oxidative stress injury, have limited the application of NSCs in the clinical treatment of neurodegenerative disease. Pyrroloquinline quinine (PQQ) exists widely in the nature. As the coenzyme of oxidoreductase, it takes part in many kinds of redox reactions, and has a variety of ability of biological functions. Especially its powerful free-radicals scavengine capacity and neuro-protection has been attracting attention.Firstly, NSCs in vitro suspension culture, use H2O2and Glu which induce oxidative stress to establish the injury model. The results show that both can make toxic action on NSCs, and its toxic effects are time-dependency and concentration-dependent. Accordingly, we use H2O20.35mM24h and Glu15mM48h, respectively dispose NSCs, built the direct and the indirect oxidative stress injury model.Secondly, we use CCK-8kit, immunofluorescence staining method to examine the effect of PQQ on the proliferation, apoptosis and differentiation of NSCs. The results show that certain concentrations (0.003-3μM) of PQQ can promot the growth of NSCs, and there is a concentration-dependent. But high concentrations (30μM or above) may have the inhibition on the proliferation of NSCs. PQQ has no significant impact on the spontaneous apoptosis and differation of NSCs.Finally, we investigate the neuroprotective effect of pretreatment and aftertreatment of PQQ on NSCs through the use of Hoechst33258-PI staining, AV-PI and the detection of intracellular enzyme activity. The results show that the treatment of PQQ before the drug-induced can significantly improve the cell viability and has the concentration-effect relationship. While the PQQ of aftertreatment had no effect. The morphology of cells in pretreatment of PQQ group has chromatin condensation of fragments, and the number of the living cells increased, the refractive index enhanced. The early/late apoptotic cells ratio also reduced. The activities of antioxidant enzymes in the intracellular level of detection of PQQ pretreatment can significantly increase the activity of SOD and CAT, but not significant changes in GSH-Px. PQQ has a protective effect of NSCs oxidative stress injury, and may be achieved by increasing the intracellular antioxidant enzyme activity.In summary, the results of this study shows that PQQ can promote the proliferation of NSCs, and the pretreatment of PQQ has a significant protective effect on NSCs damage caused by oxidative stress, provides a new means for the treatment of neurodegenerative diseases.