Amyloid Plaques in PSAPP Mice Bind Less Metal than Plaques in Human Alzheimer's Disease
Amyloid beta (A{Beta}) is the primary component of Alzheimer's disease (AD) plaques, a key pathological feature of the disease. Metal ions of zinc (Zn), copper (Cu), iron (Fe), and calcium (Ca) are elevated in human amyloid plaques and are thought to be involved in neurodegeneration. Transgenic mouse models of AD also exhibit amyloid plaques, but fail to exhibit the high degree of neurodegeneration observed in humans. In this study, we imaged the Zn, Cu, Fe, and Ca ion distribution in the PSAPP transgenic mouse model representing end-stage AD (N = 6) using synchrotron X-ray fluorescence (XRF) microprobe. In order to account for differences in density in the plaques, the relative protein content was imaged with synchrotron Fourier transform infrared microspectroscopy (FTIRM) on the same samples. FTIRM results revealed a 61% increase in protein content in the plaques compared to the surrounding tissue. After normalizing to protein density, we found that the PSAPP plaques contained only a 29% increase in Zn and there was actually less Cu, Fe, and Ca in the plaque compared to the surrounding tissue. Since metal binding to A{beta} is thought to induce redox chemistry that is toxic to neurons, the reduced metal binding in PSAPP mice is consistent with the lack of neurodegeneration in these animals. These findings were in stark contrast to the high metal ion content observed in human AD plaques, further implicating the role of metal ions in human AD pathology.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States). National Synchrotron Light Source
- Sponsoring Organization:
- Doe - Office Of Science
- DOE Contract Number:
- DE-AC02-98CH10886
- OSTI ID:
- 980004
- Report Number(s):
- BNL-92922-2010-JA; TRN: US1005392
- Journal Information:
- NeuroImage, Vol. 47, Issue 4
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
ANIMALS
CALCIUM
CHEMISTRY
COPPER
DENSITY
DISEASES
DISTRIBUTION
FLUORESCENCE
HUMAN POPULATIONS
IONS
IRON
METALS
MICE
NERVE CELLS
PATHOLOGY
PROTEINS
SYNCHROTRONS
ZINC
national synchrotron light source