[Dual effects of different concentrations of alpha-synuclein on the XXXX of @entity2955 in SH-SY5Y cells].

@entity16628 @entity137 @entity2734 @entity191 @entity16629 @entity4286 @entity2955 @entity528 @entity2359
a-synuclein ( @entity2734 ) has been postulated to play a pivotal role in the pathogenesis of @entity191 ( @entity191 ). However, the physiological functions of @entity2734 and the molecular and cellular mechanisms underlying @entity528 remain unclear. Recent studies suggest that @entity2734 plays dual roles of neuroprotection and @entity2359 depending on its concentration or level of expression. In the present study, we explored the potential mechanisms for @entity2734 to regulate neuronal survival. @entity2734 at different concentrations (0.1 to 40 mumol/L) with or without 50 mumol/L @entity2955 ( @entity2955 ) were added into the culture medium of the SH-SY5Y dopaminergic neural cells. The cell viability was measured on post-treatment day 1, 2 and 3. The activity of proteasome inhibited by @entity2734 was tested by a proteasome activity assay system after 2 h of @entity2734 treatment. According to the activity of proteasome inhibited by @entity2734 , the correlative dose of proteasome inhibitor-- @entity16628 (10 nmol/L to 5 mumol/L) with or without 50 mumol/L @entity2955 were used and the cell viability was assayed on post-treatment day 1, 2 and 3. The results showed that @entity2734 played dual roles of neuroprotection and @entity2359 depending on its concentration. At low concentration (0.1 to 5 mumol/L), @entity2734 promoted the proliferation and protected neurons against the @entity2359 of @entity2955 ; in contrast, at high concentration (10 to 40 mumol/L), @entity2734 possessed @entity137 . The results of @entity16628 treatment implied that the dual roles of @entity2734 were related to the moderate and strong inhibition of proteasome activity. The @entity16629 specific inhibitor @entity4286 completely blocked the protection of both @entity2734 and @entity16628 , suggesting that MAPK pathway might be involved in the neuroprotection of @entity2734 .
