Effects of presenilins and beta-amyloid precursor protein on delayed rectifier potassium channels in cultured rat hippocampal neurons.
OBJECTIVE
To study the effects of presenilin-1 (PS-1), presenilin-2 (PS-2), and amyloid beta-protein precursor (APP695) on delayed rectifier potassium channels (IK) in the cultured rat hippocampal neurons.


METHODS
PS-1, PS-2, and APP695 were transfected into the cultured rat hippocampal neurons by transient transfection techniques. The IK current was observed by the whole cell patch-clamp techniques.


RESULTS
IK was increased in cultured rat hippocampal neurons, after transient transfection of PS-1, PS-2, and APP695. IK amplitudes and densities were significantly increased from (1689 +/- 412) pA, (48 +/- 18) pA/pF (mock cells, GFP alone, n=17) to (5565 +/- 1403) pA, (252 +/- 107) pA/pF (PS-1/GFP, n=22, P<0.01), (3804 +/- 1651) pA, (120 +/- 58) pA/pF (PS-2/GFP, n=16, P<0.01), and (4978 +/- 904) pA, (218 +/- 70) pA/pF (APP695, n=22, P<0.01). But PS-1, PS-2, and APP695 did not alter the activation curve of IK (P>0.05).


CONCLUSIONS
Overexpression of PS-1, PS-2, and APP695 increased IK in the cultured rat hippocampal neurons. The upregulation of IK may be related to neuronal apoptosis after PS-1, PS-2, and APP695 were transfected.
Zhang
Wei
W
Department of Pharmacology, Institute of Materia Medica, Peking Union Medical College and Chinese Academy of Medical Science, Beijing 100050, China.
Jin
Hong-wei
HW
Wang
Xiao-liang
XL
D016564:Amyloid beta-Protein Precursor / Q000235:genetics / Q000502:physiology*; D000818:Animals; D002478:Cells, Cultured; D051668:Delayed Rectifier Potassium Channels; D005333:Fetus; D006624:Hippocampus / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000502:physiology*; D009474:Neurons / Q000378:metabolism; D010957:Plasmids; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D053764:Presenilin-1; D053766:Presenilin-2; D051381:Rats; D017208:Rats, Wistar; D014162:Transfection; D015854:Up-Regulation
D016564:Amyloid beta-Protein Precursor; D051668:Delayed Rectifier Potassium Channels; D008565:Membrane Proteins; D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D053764:Presenilin-1; D053766:Presenilin-2