Objective To study whether and how rotenone reduces the activity of protein phophatase 2A (PP2A).Methods MN9D cells (mouse midbrain dopaminergic cell line) were divided into normal group (normal cultured), control group (dimethyl sulfoxide of same volume with rotenone group was added in medium), rotenone group (50 nmol/L rotenone was added to the culture medium for 24 hours) and rotenone+C2 group (pretreatment of 5 mol/L C2-ceramide for eight hours, and then exposed to 50 nmol/L rotenone for 24 hours). MTT was used to detect cell viability. Total PP2A levels and tyrosine phosphorylation levels were measured with Western blotting. PP2A activity was detected with colorimetric assay.Results Compared with the control group, the cell viability reduced (P<0.01), phosphorylation of tyrosine 307 of PP2A inceased (P<0.01), and activity of PP2A decreased in the rotenone group (P<0.05). And compared with the rotenone group, the cell viability improved (P<0.01), phosphorylation of tyrosine 307 of PP2A deceased (P<0.01), and activity of PP2A increased (P<0.05) in the rotenone+C2 group.Conclusion Rotenone can inhibit activity of PP2A through increasing phosphorylation of tyrosine 307 at the catalytic subunit of PP2A, which might be involved in reducing cell viability, and implicate a new treatment strategy for Parkinson's disease.
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