Rho-associated protein kinase 1 (ROCK1) is increased in Alzheimer's disease and ROCK1 depletion reduces amyloid-β levels in brain

Benjamin W. Henderson, Erik G. Gentry, Travis Rush, Juan C Troncoso, Madhav Thambisetty, Thomas J. Montine, Jeremy H. Herskowitz

Research output: Contribution to journalArticle

Abstract

Alzheimer's disease (AD) is the leading cause of dementia and mitigating amyloid-β (Aβ) levels may serve as a rational therapeutic avenue to slow AD progression. Pharmacologic inhibition of the Rho-associated protein kinases (ROCK1 and ROCK2) is proposed to curb Aβ levels, and mechanisms that underlie ROCK2′s effects on Aβ production are defined. How ROCK1 affects Aβ generation remains a critical barrier. Here, we report that ROCK1 protein levels were elevated in mild cognitive impairment due to AD (MCI) and AD brains compared to controls. Aβ42 oligomers marginally increased ROCK1 and ROCK2 protein levels in neurons but strongly induced phosphorylation of Lim kinase 1 (LIMK1), suggesting that Aβ42 activates ROCKs. RNAi depletion of ROCK1 or ROCK2 suppressed endogenous Aβ40 production in neurons, and Aβ40 levels were reduced in brains of ROCK1 heterozygous knock-out mice compared to wild-type littermate controls. ROCK1 knockdown decreased amyloid precursor protein (APP), and treatment with bafilomycin accumulated APP levels in neurons depleted of ROCK1. These observations suggest that reduction of ROCK1 diminishes Aβ levels by enhancing APP protein degradation. Collectively, these findings support the hypothesis that both ROCK1 and ROCK2 are therapeutic targets to combat Aβ production in AD. (Figure presented.) Mitigating amyloid-β (Aβ) levels is a rational strategy for Alzheimer's disease (AD) treatment, however, therapeutic targets with clinically available drugs are lacking. We hypothesize that Aβ accumulation in mild cognitive impairment because of AD (MCI) and AD activates the RhoA/ROCK pathway which in turn fuels production of Aβ. Escalation of this cycle over the course of many years may contribute to the buildup of amyloid pathology in MCI and/or AD.

Original languageEnglish (US)
Pages (from-to)525-531
Number of pages7
JournalJournal of Neurochemistry
DOIs
StatePublished - Aug 1 2016

Keywords

  • Alzheimer's disease
  • amyloid-β
  • mild cognitive impairment
  • Rho kinase
  • ROCK1
  • ROCK2

ASJC Scopus subject areas

  • Biochemistry
  • Medicine(all)
  • Cellular and Molecular Neuroscience

Fingerprint Dive into the research topics of 'Rho-associated protein kinase 1 (ROCK1) is increased in Alzheimer's disease and ROCK1 depletion reduces amyloid-β levels in brain'. Together they form a unique fingerprint.

  • Cite this