Evaluation of Rett Syndrome Symptom Improvement by Metabolic Modulators in Mecp2‐Mutant Mice

Christie M. Buchovecky1, Misty G. Hill1, Jennifer M. Borkey1, Stephanie M. Kyle1, Monica J. Justice1

1 Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
Publication Name:  Current Protocols in Mouse Biology
Unit Number:   
DOI:  10.1002/9780470942390.mo130157
Online Posting Date:  December, 2013
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Abstract

Mouse models recapitulate many symptoms of Rett Syndrome, an X‐linked disorder caused by mutations in methyl‐CpG‐binding protein 2 (MECP2). The study of Mecp2‐null male mice has provided insight into pathogenesis of the disorder—most recently, dysregulation of cholesterol and lipid metabolism. Perisymptomatic treatment with statin drugs successfully mitigates the effects of this metabolic syndrome, increases longevity, and improves motor function. Described here is a metabolic drug screening protocol and timeline for symptom evaluation in Mecp2‐mutant mice. Specifically, mice are treated twice weekly with a compound of interest alongside subjective health assessments, bi‐weekly body composition measurements, and blood chemistries. Throughout treatment, behavioral phenotyping tests are carried out at specific time points. This protocol is highly adaptable to other neurological diseases; however, the time for completion depends on the specific mutant model under study. The protocol highlights the use of techniques described in several different Current Protocols in Mouse Biology articles to carry out testing in a preclinical model. Curr. Protoc. Mouse Biol. 3:187‐204 © 2013 by John Wiley & Sons, Inc.

Keywords: drug treatment; cholesterol; lipid; behavioral assessment; Rett Syndrome; neurodevelopmental disorders; metabolism

     
 
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Table of Contents

  • Introduction
  • Basic Protocol 1: Treatment of Mecp2‐Mutant Mouse Models with Metabolic Modulators
  • Support Protocol 1: Accelerating Rotarod‐Repeated Measures Assessment
  • Support Protocol 2: Open‐Field Activity Assessment
  • Support Protocol 3: Prepulse Inhibition of Acoustic Startle Reflex
  • Support Protocol 4: Unrestrained Whole‐Body Plethysmography
  • Commentary
  • Literature Cited
  • Figures
  • Tables
     
 
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Materials

Basic Protocol 1: Treatment of Mecp2‐Mutant Mouse Models with Metabolic Modulators

  Materials
  • Age‐ and sex‐matched Mecp2‐mutant mice and wild‐type littermates (e.g., B6.Mecp2tm1.1Bird; The Jackson Laboratory, JaxMice cat. no. 003890; or other mutants or strain backgrounds; Katz et al., )
  • Compound of interest
  • Appropriate vehicle for compound (e.g., sterile saline, ethanol, and/or DMSO)
  • Liquid N 2
  • Scale for weighing compounds
  • Glass vials for storing organic compounds
  • Appropriate protective equipment for handling compounds (follow manufacturer's guidelines)
  • Appropriate equipment for compound administration (e.g., 10‐ml syringes with ∼26‐G needles for subcutaneous injection)
  • Waste container for sharp items
  • Mouse whole‐body composition analyzer (e.g., Bruker MiniSpec NMR; optional)
  • Serum separator tubes (e.g., BD Vacutainer Blood Collection tubes)
  • ∼25‐G needles and syringes for cardiac punctures
  • Cryo‐safe tubes for tissue collection
  • Additional reagents and equipment for mouse blood collection (Donovan and Brown, ; Rathkolb et al., ), subjective health assessments according to guidelines proposed for preclinical evaluation in mice (Katz et al., ), euthanasia (method to be determined by experimenter and institution, performed in accordance with relevant animal care and use guidelines and regulations; Donovan and Brown, ), post‐mortem dissection and examination (Antal et al., ), clinical chemistry procedures (Rathkolb et al., ), measurement of lipids and lipoproteins in mice (Tailleux and Staels, ), and characterization of whole‐body cholesterol fluxes in mice (Brufau and Groen, )

Support Protocol 1: Accelerating Rotarod‐Repeated Measures Assessment

  Materials
  • Treated and control, age‐ and sex‐matched Mecp2‐mutant mice and wild‐type littermates (e.g., B6.Mecp2tm1.1Bird; The Jackson Laboratory, JaxMice cat. no. 003890; or other mutants or strain backgrounds; Katz et al., )
  • Ethanol
  • Rotarod apparatus for mice and rats (Stoelting, cat. no. 52790) or equivalent (also see Brooks et al., )
  • Isolated room without noise or traffic
  • Adjustable light source
  • Light monitor
  • White noise source
  • Noise meter
  • Additional reagents and equipment for rotarod testing (Brooks et al., )

Support Protocol 2: Open‐Field Activity Assessment

  Materials
  • Treated and control, age‐ and sex‐matched Mecp2‐mutant mice and wild‐type littermates (e.g., B6.Mecp2tm1.1Bird; The Jackson Laboratory, JaxMice cat. no. 003890; or other mutants or strain backgrounds; Katz et al., )
  • Ethanol
  • Animal activity monitors: open‐field mouse configuration (AccuScan Fusion monitor, http://www.accuscan‐usa.com, or equivalent; also see Thomas et al., )
  • Isolated room without noise or traffic
  • Adjustable light source
  • Light monitor
  • White noise source
  • Noise meter
  • Additional reagents and equipment for open‐field testing (Thomas et al., )

Support Protocol 3: Prepulse Inhibition of Acoustic Startle Reflex

  Materials
  • Treated and control, age‐ and sex‐matched Mecp2‐mutant mice and wild‐type littermates (e.g., B6.Mecp2tm1.1Bird; The Jackson Laboratory, JaxMice cat. no. 003890; or other mutants or strain backgrounds; Katz et al., )
  • Ethanol
  • Startle Response Lab system (San Diego Instruments, or equivalent) and associated software
  • Isolated room without noise or traffic
  • Additional reagents and equipment for prepulse inhibition testing (Ouagazzal and Meziane, )

Support Protocol 4: Unrestrained Whole‐Body Plethysmography

  Materials
  • Treated and control, age‐ and sex‐matched Mecp2‐mutant mice and wild‐type littermates (e.g., B6.Mecp2tm1.1Bird; The Jackson Laboratory, JaxMice cat. no. 003890; or other mutants or strain backgrounds; Katz et al., )
  • Unrestrained whole‐body plethysmography system for mouse (Buxco, EMMS PLY 310, http://www.electromedsys.com/, or equivalent), with associated software
  • Isolated room without noise or traffic
  • Chart for recording activity
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Figures

Videos

Literature Cited

Literature Cited
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