Effects of lysophosphatidylcholine on beta-amyloid-induced neuronal apoptosis.
OBJECTIVE
We have investigated the effects of lysophosphatidylcholine (LPC), a product of lipid peroxidation, on Abeta(1-42)-induced SH-SY5Y cell apoptosis.


METHODS
The viability of cultured SH-SY5Y cells was measured using a CCK-8 kit. Apoptosis was determined by Chip-based flow cytometric assay. The mRNA transcription of Bcl-2, Bax, and caspase-3 were detected by using reverse transcription and real-time quantitative PCR and the protein levels of Bax and caspase-3 were analyzed by Western blotting. The cytosolic calcium concentration of SH-SY5Y cells was tested by calcium influx assay. G2A expression in SH-SY5Y cells was silenced by small interfering RNA.


RESULTS
Long-term exposure of SH-SY5Y cells to LPC augmented the neurotoxicity of Abeta(1-42). Furthermore, after LPC treatment, the Bax/Bcl-x(L) ratio and the expression levels, as well as the activity of caspase-3 were, elevated, whereas the expression level of TRAF1 was reduced. Because LPC was reported to be a specific ligand for the orphan G-protein coupled receptor, G2A, we investigated LPC-mediated changes in calcium levels in SH-SY5Y cells. Our results demonstrated that LPC can enhance the Abeta(1-42)-induced elevation of intracellular calcium. Interestingly, Abeta(1-42) significantly increased the expression of G2A in SH-SY5Y cells, whereas knockdown of G2A using siRNA reduced the effects of LPC on Abeta(1-42)-induced neurotoxicity.


CONCLUSIONS
The effects of LPC on Abeta(1-42)-induced apoptosis may occur through the signal pathways of the orphan G-protein coupled receptor.
Qin
Zhen-xia
ZX
Key Lab of Brain Functional Genomics, MOE&STCSM, Shanghai Institute of Brain Functional Genomics, East China Normal University, Shanghai, China.
Zhu
Hui-yan
HY
Hu
Ying-he
YH