Effects of amyloid-β peptides on voltage-gated L-type Ca(V)1.2 and Ca(V)1.3 Ca(2+) channels

Mol Cells. 2011 Sep;32(3):289-94. doi: 10.1007/s10059-011-0075-x. Epub 2011 Aug 4.

Abstract

Overload of intracellular Ca(2+) has been implicated in the pathogenesis of neuronal disorders, such as Alzheimer's disease. Various mechanisms produce abnormalities in intracellular Ca(2+) homeostasis systems. L-type Ca(2+) channels have been known to be closely involved in the mechanisms underlying the neurodegenerative properties of amyloid-β (Aβ) peptides. However, most studies of L-type Ca(2+) channels in Aβ-related mechanisms have been limited to Ca(V)1.2, and surprisingly little is known about the involvement of Ca(V)1.3 in Aβ-induced neuronal toxicity. In the present study, we examined the expression patterns of Ca(V)1.3 after Aβ(25-35) exposure for 24 h and compared them with the expression patterns of Ca(V)1.2. The expression levels of Ca(V)1.3 were not significantly changed by Aβ(25-35) at both the mRNA levels and the total protein level in cultured hippocampal neurons. However, surface protein levels of Ca(V)1.3 were significantly increased by Aβ(25-35), but not by Aβ(35-25). We next found that acute treatment with Aβ(25-35) increased Ca(V)1.3 channel activities in HEK293 cells using whole-cell patch-clamp recordings. Furthermore, using GTP pulldown and co-immunoprecipitation assays in HEK293 cell lysates, we found that amyloid precursor protein interacts with β(3) subunits of Ca(2+) channels instead of Ca(V)1.2 or Ca(V)1.3 α(1) subunits. These results show that Aβ(25-35) chronically or acutely upregulates Ca(V)1.3 in the rat hippocampal and human kidney cells (HEK293). This suggests that Ca(V)1.3 has a potential role along with Ca(V)1.2 in the pathogenesis of Alzheimer's disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alzheimer Disease / metabolism*
  • Alzheimer Disease / pathology
  • Alzheimer Disease / physiopathology
  • Amyloid beta-Peptides / metabolism
  • Amyloid beta-Peptides / pharmacology*
  • Animals
  • Calcium / metabolism*
  • Calcium Channel Blockers / pharmacology
  • Calcium Channels / genetics
  • Calcium Channels / metabolism*
  • Calcium Channels, L-Type / genetics
  • Calcium Channels, L-Type / metabolism*
  • Cells, Cultured
  • Gene Expression
  • HEK293 Cells
  • Hippocampus / metabolism*
  • Hippocampus / pathology
  • Hippocampus / physiopathology
  • Homeostasis / drug effects
  • Humans
  • Immunoprecipitation
  • Ion Channel Gating / drug effects
  • Neurons / cytology
  • Neurons / drug effects
  • Neurons / metabolism*
  • Patch-Clamp Techniques
  • Peptide Fragments / metabolism
  • Peptide Fragments / pharmacology*
  • Rats
  • Up-Regulation

Substances

  • Amyloid beta-Peptides
  • CACNA1D protein, human
  • Calcium Channel Blockers
  • Calcium Channels
  • Calcium Channels, L-Type
  • L-type calcium channel alpha(1C)
  • Peptide Fragments
  • Cacna1d protein, rat
  • Calcium