Distinct Dendritic Spine and Nuclear Phases of Calcineurin Activation after Exposure to Amyloid-β Revealed by a Novel Fluorescence Resonance Energy Transfer Assay
- Hai-Yan Wu1,
- Eloise Hudry1,
- Tadafumi Hashimoto1,
- Kengo Uemura1,
- Zhan-Yun Fan1,
- Oksana Berezovska1,
- Cynthia L. Grosskreutz2,
- Brian J. Bacskai1, and
- Bradley T. Hyman1
- 1Department of Neurology/Alzheimer's Disease Research Laboratory, Massachusetts General Hospital, Charlestown, Massachusetts 02129, and
- 2Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts 02114
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Author contributions: H.-Y.W., K.U., O.B., B.J.B., and B.T.H. designed research; H.-Y.W., E.H., and T.H. performed research; K.U., Z.-Y.F., O.B., C.L.G., and B.J.B. contributed unpublished reagents/analytic tools; H.-Y.W., E.H., and T.H. analyzed data; H.-Y.W., E.H., and B.T.H. wrote the paper.
Abstract
Calcineurin (CaN) activation is critically involved in the regulation of spine morphology in response to oligomeric amyloid-β (Aβ) as well as in synaptic plasticity in normal memory, but no existing techniques can monitor the spatiotemporal pattern of CaN activity. Here, we use a spectral fluorescence resonance energy transfer approach to monitor CaN activation dynamics in real time with subcellular resolution. When oligomeric Aβ derived from Tg2576 murine transgenic neurons or human AD brains were applied to wild-type murine primary cortical neurons, we observe a dynamic progression of CaN activation within minutes, first in dendritic spines, and then in the cytoplasm and, in hours, in the nucleus. CaN activation in spines leads to rapid but reversible morphological changes in spines and in postsynaptic proteins; longer exposure leads to NFAT (nuclear factor of activated T-cells) translocation to the nucleus and frank spine loss. These results provide a framework for understanding the role of calcineurin in synaptic alterations associated with AD pathogenesis.
- Received January 16, 2012.
- Revision received February 25, 2012.
- Accepted February 28, 2012.
- Copyright © 2012 the authors 0270-6474/12/325298-12$15.00/0
