Serum response factor and myocardin mediate arterial hypercontractility and cerebral blood flow dysregulation in Alzheimer's phenotype

Nienwen Chow, Robert D. Bell, Rashid Deane, Jeffrey W. Streb, Jiyuan Chen, Andrew Brooks, William Van Nostrand, Joseph M. Miano, Berislav V. Zlokovic

Research output: Contribution to journalArticle

149 Scopus citations

Abstract

Cerebral angiopathy contributes to cognitive decline and dementia in Alzheimer's disease (AD) through cerebral blood flow (CBF) reductions and dysregulation. We report vascular smooth muscle cells (VSMC) in small pial and intracerebral arteries, which are critical for CBF regulation, express in AD high levels of serum response factor (SRF) and myocardin (MYOCD), two interacting transcription factors that orchestrate a VSMC-differentiated phenotype. Consistent with this finding, AD VSMC overexpressed several SRF-MYOCD-regulated contractile proteins and exhibited a hypercontractile phenotype. MVOCD overexpression in control human cerebral VSMC induced an AD-like hypercontractile phenotype and diminished both endothelial-dependent and -independent relaxation in the mouse aorta ex vivo. In contrast, silencing SRF normalized contractile protein content and reversed a hypercontractile phenotype in AD VSMC. MYOCD in vivo gene transfer to mouse pial arteries increased contractile protein content and diminished CBF responses produced by brain activation in wildtype mice and in two AD models, the Dutch/Iowa/Swedish triple mutant human amyloid β-peptide (Aβ)-precursor protein (APP)-expressing mice and APPsw+/- mice. Silencing Srf had the opposite effect. Expression of SRF did not change in VSMC subjected to Alzheimer's neurotoxin, Aβ. Thus, SRF-MYOCD overexpression in small cerebral arteries appears to initiate independently of Aβ a pathogenic pathway mediating arterial hypercontractility and CBF dysregulation, which are associated with Alzheimer's dementia.

Original languageEnglish (US)
Pages (from-to)823-828
Number of pages6
JournalProceedings of the National Academy of Sciences of the United States of America
Volume104
Issue number3
DOIs
StatePublished - Jan 16 2007
Externally publishedYes

Keywords

  • Cerebral vasculature
  • Dementia
  • Differentiation
  • Smooth muscle

ASJC Scopus subject areas

  • General

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