Format

Send to:

Choose Destination
See comment in PubMed Commons below
J Neurosci. 2013 Dec 4;33(49):19086-98. doi: 10.1523/JNEUROSCI.2508-13.2013.

Pharmacologic inhibition of ROCK2 suppresses amyloid-β production in an Alzheimer's disease mouse model.

Author information

  • 1Center for Neurodegenerative Disease, and Departments of Neurology, Cell Biology, and Biochemistry, Emory University School of Medicine, Atlanta, Georgia 30322, Medicinal Chemistry, Translational Research Institute, The Scripps Research Institute, Jupiter, Florida 33458, Department of Pathology, University of Washington, Seattle, Washington 98104, Departments of Pathology and Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland 21205, and Unit of Clinical and Translational Neuroscience and Laboratory of Behavioral Neuroscience, National Institute on Aging, Baltimore, Maryland 21224.

Abstract

Alzheimer's disease (AD) is the leading cause of dementia and has no cure. Genetic, cell biological, and biochemical studies suggest that reducing amyloid-β (Aβ) production may serve as a rational therapeutic avenue to delay or prevent AD progression. Inhibition of RhoA, a Rho GTPase family member, is proposed to curb Aβ production. However, a barrier to this hypothesis has been the limited understanding of how the principal downstream effectors of RhoA, Rho-associated, coiled-coil containing protein kinase (ROCK) 1 and ROCK2, modulate Aβ generation. Here, we report that ROCK1 knockdown increased endogenous human Aβ production, whereas ROCK2 knockdown decreased Aβ levels. Inhibition of ROCK2 kinase activity, using an isoform-selective small molecule (SR3677), suppressed β-site APP cleaving enzyme 1 (BACE1) enzymatic action and diminished production of Aβ in AD mouse brain. Immunofluorescence and confocal microscopy analyses revealed that SR3677 alters BACE1 endocytic distribution and promotes amyloid precursor protein (APP) traffic to lysosomes. Moreover, SR3677 blocked ROCK2 phosphorylation of APP at threonine 654 (T654); in neurons, T654 was critical for APP processing to Aβ. These observations suggest that ROCK2 inhibition reduces Aβ levels through independent mechanisms. Finally, ROCK2 protein levels were increased in asymptomatic AD, mild cognitive impairment, and AD brains, demonstrating that ROCK2 levels change in the earliest stages of AD and remain elevated throughout disease progression. Collectively, these findings highlight ROCK2 as a mechanism-based therapeutic target to combat Aβ production in AD.

PMID:
24305806
[PubMed - indexed for MEDLINE]
PMCID:
PMC3850036
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk