1. Journal of Huntington’s Disease 3 (2014) 159–174
DOI 10.3233/JHD-130081
IOS Press
159
Research Report
Assessment of Chloroquine Treatment for
Modulating Autophagy Flux in Brain of WT
and HD Mice
Petr Vodickaa,∗
, Junghyun Limb
, Dana T. Williamsa
, Kimberly B. Kegela
, Kathryn Chasec
,
Hyunsun Parkd
, Deanna Marchioninid
, Stephen Wilkinsone
, Tania Meade
, Helen Birche
, Dawn Yatese
,
Kathy Lyonsf
, Celia Dominguezd
, Maria Beconid,1
, Zhenyu Yueb
, Neil Aroninc
and Marian DiFigliaa
aDepartment of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
bDepartment of Neurology, Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at
Mount Sinai, Leon and Norma Hess Center for Science and Medicine, New York, NY, USA
cDepartments of Medicine and Cell Biology, University of Massachusetts, Worcester, MA, USA
dCHDI Management/CHDI Foundation, Los Angeles, CA, USA
eBioFocus DPI Limited, Chesterford Research Park, UK
fIndependent consultant
Abstract.
Background:Increasingmutanthuntingtin(mHTT)clearancethroughtheautophagypathwaymaybeawaytotreatHuntington’s
disease (HD). Tools to manipulate and measure autophagy flux in brain in vivo are not well established.
Objective: To examine the in vivo pharmacokinetics and pharmacodynamics of the lysosomal inhibitor chloroquine (CQ) and
the levels of selected autophagy markers to determine usefulness of CQ as a tool to study autophagy flux in brain.
Methods: Intraperitoneal injections of CQ were administered to WT and HDQ175/Q175
mice. CQ levels were measured by LC-
MS/MS in WT brain, muscle and blood at 4 to 24 hours after the last dose. Two methods of tissue preparation were used to detect
by Western blot levels of the macroautophagy markers LC3II and p62, the chaperone mediated autophagy receptor LAMP-2A
and the late endosome/lysosomal marker RAB7.
Results: Following peripheral administration, CQ levels were highest in muscle and declined rapidly between 4 and 24 hours.
In the brain, CQ levels were greater in the cortex than striatum, and levels persisted up to24 hours post-injection. CQ treatment
induced changes in LC3II and p62 that were variable across regions and tissue preparations. HDQ175/Q175
mice exposed to CQ
had variable but diminished levels of LC3II, p62 and LAMP-2A, and increased levels of RAB7. Higher levels of mHTT were
found in the membrane compartment of CQ treated HD mice.
Conclusion: Our findings suggest that the response of brain to CQ treatment, a blocker of autophagy flux, is variable and not as
robust as it has been demonstrated in vitro, suggesting that CQ treatment has limitations for modulating autophagy flux in vivo.
Alternative methods, compounds, and technologies need to be developed to further investigate autophagy flux in vivo, especially
in the brain.
1Present address: Retrophin Inc., Cambridge, MA, USA.
∗Correspondence to: Petr Vodicka, Department of Neurology,
Massachusetts General Hospital, 114 16th Street, Charlestown, MA
02129, USA. Tel.: +1 6177265762; Fax: +1 6177261264; E-mail:
pvodicka@partners.org.
ISSN 1879-6397/14/$27.50 © 2014 – IOS Press and the authors. All rights reserved