Curcumin up-regulates ABCA1 expression through inhibiting the activity of CaN in N2a/APP695swe cells

Abstract:

Objective：To investigate the effect of Curcumin on the activity of Calcineurin（CaN） and the expression of ATP-binding cas－sette transporter A1（ABCA1） in N2a/APP695swe cells，and to explore the mechanism of the regulation of Curcumin on the expression of ABCA1 in N2a/APP695swe cells. Methods：MTT assay was used to detect N2a/APP695swe cell viabilities in different concentrations of Curcumin or the CaN activity inhabitor cyclosporinA（CsA） treatment. According to the results determined by MTT，N2a/APP695swe cells were co-cultured with 5 μmol/L Curcumin for 24 h，or 0.5 μmol/L CsA for 48 h，then，the CaN activities were measured by enzyme substrate color metric methods. Western blot and real-time PCR were performed to evaluate the expression of ABCA1. Results：Cell survival rate was （110.495±4.005）%，the highest in 5 μmol/L Curcumin group（P=0.023），followed by （105.532±4.292）%，（115.211±4.826）%，（76.317±4.475）%，（69.177±5.267）%，（54.687±3.912）%，respectively in 0.1，0.5，1，2，4 μmol/L CsA groups. There were significant differences in cell survival rate between untreated group and 0.5，1，2，4 μmol/L CsA groups（P=0.001，0.000，0.000，0.000）. Compared with that（18.519±1.664） nmol/mg of normal group，the CaN activity was increased in N2a/APP695swe cells（24.488±3.041） nmol/mg（P=0.007），CaN activities were distinctly decreased in Curcumin group（16.717±2.055） nmol/mg（P=0.002） and CsA group（4.928±1.232）nmol/mg（P=0.000）. Furthermore，Western blot and real-time PCR showed that the expression of ABCA1 was higher in Curcumin group（real-time PCR：1.988±0.355；Western blot：0.294±0.015） than in the model group（real-time PCR：1.000；Western blot：0.175±0.008）（P=0.009 in real-time PCR and P=0.000 in Western blot）. Compared with that of model group，the expression of ABCA1 in CsA group（real-time PCR：4.000±0.464；Western blot：0.470±0.016） was increased（both P=0.000 in real-time PCR and Western blot）. Conclusion：Curcumin may up-regulate the expression of ABCA1 in N2a/APP695swe cells via inhibiting the CaN activity.