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MARCH
17 -
(J.Clin.Invest., March,2010) Chronic administration
of membrane sealant prevents severe cardiac injury and ventricular dilatation in
dystrophic dogs
DeWayne Townsend,
Immanuel Turner, Soichiro Yasuda, Joshua Martindale,
Jennifer Davis, Michael Shillingford, Joe N.
Kornegay and Joseph M. Metzger - USA
Duchenne muscular dystrophy (DMD) is a fatal disease of
striated muscle deterioration caused by lack of the cytoskeletal protein
dystrophin. Dystrophin deficiency causes muscle membrane instability, skeletal
muscle wasting, cardiomyopathy, and heart failure. Advances in palliative
respiratory care have increased the incidence of heart disease in DMD patients,
for which there is no cure or effective therapy. Here we have shown that chronic
infusion of membrane-sealing poloxamer to severely affected dystrophic dogs
reduced myocardial fibrosis, blocked increased serum cardiac troponin I (cTnI)
and brain type natriuretic peptide (BNP), and fully prevented left-ventricular
remodeling. Mechanistically, we observed a markedly greater primary defect of
reduced cell compliance in dystrophic canine myocytes than in the mildly
affected mdx mouse myocytes, and this was associated with a lack of
utrophin upregulation in the dystrophic canine cardiac myocytes. Interestingly,
after chronic poloxamer treatment, the poor compliance of isolated canine
myocytes remained evident, but this could be restored to normal upon direct
application of poloxamer. Collectively, these findings indicate that dystrophin
and utrophin are critical to membrane stability–dependent cardiac myocyte
mechanical compliance and that poloxamer confers a highly effective
membrane-stabilizing chemical surrogate in dystrophin/utrophin deficiency. We
propose that membrane sealant therapy is a potential treatment modality for DMD
heart disease and possibly other disorders with membrane defect etiologies.
13 -
(Cardiovasc Res,
Mar 2010) The histone deacetylase inhibitor suberoylanilide
hydroxamic acid reduces cardiac arrhythmias in dystrophic mice
Claudia Colussi, Roberta Berni, Jessica Rosati, Stefania
Straino, Serena Vitale, Francesco Spallotta, Silvana Baruffi, Leonardo Bocchi,
Francesca Delucchi, Stefano Rossi, Monia Savi, Dante Rotili, Federico Quaini,
Emilio Macchi, Donatella Stilli, Ezio Musso, Antonello Mai, Carlo Gaetano, and
Maurizio C. Capogrossi - Italy
Aims The effect of histone
deacetylase inhibitors on dystrophic heart function is not established. To
investigate this aspect, dystrophic mdx mice and wild-type (WT) animals were
treated 90 days either with suberoylanilide hydroxamic acid (SAHA, 5 mg/kg/day)
or with an equivalent amount of vehicle.
Methods and results The
following parameters were evaluated: (i) number of ventricular arrhythmias in
resting and stress conditions (restraint test) or after aconitine administration;
(ii) cardiac excitability, conduction velocity, and refractoriness; (iii)
expression and distribution of connexins (Cxs) and Nav1.5 sodium
channel. Ventricular arrhythmias were negligible in all resting animals. During
restraint, however, an increase in the number of arrhythmias was detected in
vehicle-treated mdx mice (mdx-V) when compared with SAHA-treated mdx (mdx-SAHA)
mice or normal control (WT-V). Interestingly, aconitine, a sodium channel
pharmacologic opener, induced ventricular arrhythmias in 83% of WT-V mice, 11%
of mdx-V, and in 57% of mdx-SAHA. Epicardial multiple lead recording revealed a
prolongation of the QRS complex in mdx-V mice in comparison to WT-V and WT-SAHA
mice, paralleled by a significant reduction in impulse propagation velocity.
These alterations were efficiently counteracted by SAHA. Molecular analyses
revealed that in mdx mice, SAHA determined Cx remodelling of Cx40, Cx37 and Cx32,
whereas expression levels of Cx43 and Cx45 were unaltered. Remarkably, Cx43
lateralization observed in mdx control animals was reversed by SAHA treatment
which also re-induced Nav1.5 expression.
Conclusion SAHA attenuates
arrhythmias in mdx mice by a mechanism in which Cx remodelling and sodium
channel re-expression could play an important role.
10 -
(Journal of Pineal Research 2010, 48(3): 282-289)
Melatonin treatment normalizes plasma pro-inflammatory cytokines and
nitrosative/oxidative stress in patients suffering from Duchenne muscular
dystrophy
Mariam Chahbouni, Germaine Escames, Carmen Venegas, Belén
Sevilla, José Antonio García, Luis C. López, Antonio Muñoz-Hoyos, Antonio
Molina-Carballo, Darío Acuña-Castroviejo - Spain
Duchenne muscular dystrophy (DMD), a lethal disorder
characterized by dystrophin absence, courses with chronic inflammation,
sarcolemmal damage, and skeletal muscle degeneration. Among the multiple
pathogenic mechanisms proposed for DMD, oxidative stress and inflammation are
directly involved in the dystrophic process. Unfortunately, there is no current
treatment for DMD, and the inflammatory process is an important target for
therapies. Based on the antioxidant and anti-inflammatory properties of
melatonin, we investigated whether melatonin treatment may reduce the dystrophic
process. Ten DMD patients aged 12.8 ± 0.98 yr, were treated with melatonin
(60 mg at 21:00 hr plus 10 mg at 09:00 hr), and plasma levels of lipid
peroxidation (LPO), nitrites (NOx),
interleukin (IL)-1β, IL-2, IL-6, tumor necrosis factor-α, interferon-γ, and
plasma markers of muscle injury, were determined at 3, 6 and 9 months of
treatment. Healthy age- and sex-matched subjects were used as controls. The
results show a significant increase in LPO, NOx,
and cytokine levels in plasma of DMD patients compared with controls. Melatonin
administration reduced these values to control levels at 3 months of treatment,
decreasing further 9 months later. In parallel, melatonin also reduced plasma
levels of creatine kinase (CK; 50%), lactate dehydrogenase (28%), aspartate
aminotransferase (28%), alanine aminotransferase (20%), and myoglobin (13%).
These findings strongly support the conclusion that melatonin administration
significantly reduced the hyperoxidative and inflammatory process in DMD
patients, reducing the muscle degenerative process.
6 - (Journal of Child Neurology,
2010) Use of Corticosteroids in a
Population-Based Cohort of Boys With Duchenne and Becker Muscular Dystrophy
Dennis J. Matthews,
Katherine A. James, Lisa A. Miller, Shree
Pandya, Kimberly A. Campbell, Emma Ciafaloni,
Katherine D. Mathews, Timothy M. Miller,
Christopher Cunniff, MD, F. John Meaney, Charlotte M.
Druschel, Paul A. Romitti, P, and Deborah J. Fox -
USA.
The use of corticosteroids for treatment of Duchenne and
Becker muscular dystrophy in clinical practice from 1991
through 2005 was reviewed in a large population-based cohort (MD
STARnet) of boys in 4 regional sites and 6 clinics of the United
States. Corticosteroid use increased from 20% (11 of 56 individuals)
in 1991 to 44% (93 of 218 individuals) in 2005. Average use
varied by site and ranged from 15% to 49%. The median age of
corticosteroid initiation was 6.9 years (range, 3.7-17.4 years).
Dosage and growth information was available for 102 participants and
showed a median dose as 0.729 mg/kg for prednisone and 0.831 mg/kg
for deflazacort. T. The most common reasons that corticosteroids were
discontinued included weight gain, behavioral side effects, and loss
of ambulation, resulting in full-time wheelchair use. Substantial
variations in clinical practice were identified among study sites.
3 -
PTC Therapeutics and Genzyme Corporation Announce Preliminary Results from the
Phase 2b Clinical Trial of Ataluren for Nonsense Mutation Duchenne/Becker
Muscular Dystrophy
FEBRUARY
20 - (American Academy of Neurology
Meeting, April 2010)
Preliminary Results with AVI-4658
of Dystrophin Expression, Safety and Pharmacokinetics from the First Systemic
Administration Study in Boys with Duchene Muscular Dystrophy (DMD), with a
Phosphorodiamidate Morpholino Oligomer (PMO) to Skip Exon 51
Francesco Muntoni, London, United Kingdom, Kate
Bushby, Newcastle upon Tyne, United Kingdom, Cirak Sebahattin, London, United
Kingdom, Michela Guglieri, Newcastle upon Tyne, United Kingdom, Shirley Leow,
Stephen B. Shrewsbury, Bothell, WA
OBJECTIVE: We have previously identified a PMO to skip exon 51 in DMD
patients, restore the reading frame and enable dystrophin expression. The
current study, on repeated IV treatment to select an effective, tolerated dose,
should complete in February 2010. BACKGROUND: DMD is the commonest
inherited muscular dystrophy, affecting 1 in every 3,500 boys. DMD boys present
with leg weakness by age 5, wheelchair confinement by age 10-12; respiratory
insufficiency requiring mechanical ventilation by late teens, and cardiomyopathy,
placing a huge burden on patient and parents/caregivers. Out of frame deletions
abolishing the production of the muscle protein dystrophin are the commonest
mutations. DESIGN/METHODS: Open label, dose escalation study in ambulant
DMD boys aged 5-15 years with relevant deletions, of 12 weekly administrations
of AVI-4658; muscle biopsy to assess dystrophin expression at baseline and 14
weeks. Clinical parameters are followed for 26 weeks, consisting of safety
(adverse events, physical examinations, laboratory tests), skeletal muscle,
pulmonary and cardiac function, and pharmacokinetics at 1st, 6th
and 12th doses. A DSMB guides dose escalation decisions (across the
doses 0.5, 1.0, 2.0, 4.0, 10.0 and 20.0 mg/kg). RESULTS: Cohorts 1, 2, 3
and 4 completed 12 weeks of dosing (October 2009). Cohort 1 has completed follow
up to 26 weeks. Cohorts 5 and 6 are proceeding with dosing. No drug related SAEs
or severe drug related AEs have been reported so far. To date, maximum
cumulative PMO dose approaches 3,000mg. Preliminary analysis of the exon
skipping, RNA and dystrophin protein expression will be presented and safety
data updated. CONCLUSIONS/RELEVANCE: The first PMO for DMD has been well
tolerated at all doses to date. Preliminary data is expected to show dystrophin
expression at one or more doses and will allow dose selection for confirmatory
clinical studies and extended (compassionate) use Supported by: Medical Research
Council, UK and AVI Biopharma.
20 -
(American Academy of Neurology
Meeting, April 2010)
Preclinical Safety of AVI-4658, a
Phosphorodiamidate Morpholino Oligomer (PMO) Being Developed To Skip Exon 51 in
Duchenne Muscular Dystrophy
Peter Sazani, Stephen Shrewsbury, Bothell, WA
OBJECTIVE: The current studies were designed to assess the safety of
AVI-4658 (and PMO in general). BACKGROUND: AVI-4658 is a PMO that skips
dystrophin exon 51, restores the reading frame and enable dystrophin expression
in selected DMD boys, proven by our recent single IM dose study in the UK. To
enable clinical trials in the US, three 12-week GLP studies in animals were
performed. Published data suggests the older phosphorothioate antisense
oligonucleotides have dose limiting toxicities. DESIGN/METHODS: (1)
mdx mice were dosed IV with 0, 12, 120 or 960mg/kg (the maximum feasible
dose (MFD)), or subcutaneously at 960mg/kg; wild type C57 mice at 0 and 960
mg/kg (i.e., 7 groups) with AVI-4658. (2) A second identical study with
AVI-4225, the PMO to skip exon 23 of in the dystrophic mouse and restore
dystrophin, was also performed. (3) Cynomolgus monkeys were dosed IV with 0, 5,
40 or 320mg/kg (MFD) and 320mg/kg subcutaneously. A 28 day recovery period was
included in all studies. RESULTS: In mice, both AVI-4658 and AVI-4225
were well tolerated at doses including 960 mg/kg/injection, with no adverse
effects. Findings were generally limited to the kidney, and were generally
reversible, as shown in the 28 day recovery groups. No evidence of kidney
function change was detected. In cynomolgus monkeys, AVI-4658 was also well
tolerated at all doses including 320 mg/kg/injection, with no adverse effects.
Findings were similar to those seen in the mouse studies.
CONCLUSIONS/RELEVANCE: AVI-4658, the first PMO for DMD, was extremely well
tolerated at all doses in dystrophic mice, normal mice and primates. In
addition, AVI-4225, which restores dystrophin in mdx mice, also led to no
adverse effects. Based on this preclinical package, and encouraging safety and
dystrophin expression results from a concurrent UK clinical study, US clinical
studies are anticipated.
20 -
(American
Academy of Neurology Meeting, April 2010)
A Phase I/IIa Systemic Study on
Antisense Oligonucleotide Compound PRO051 in Patients with Duchenne Muscular
Dystrophy
Nathalie M. Goemans, Leuven, Belgium, Mar
Tulinius, Gothenburg, Sweden, Gunnar Buyse, Leuven, Belgium, Sjef J. de Kimpe,
Judith C. van Deutekom, Leiden, The Netherlands
OBJECTIVE: In this phase I/IIa open label study we evaluated the systemic
delivery of the antisense oligonucleotide compound PRO051 in Duchenne Muscular
Dystrophy (DMD) patients. BACKGROUND: DMD patients suffer from
progressive muscle degeneration due to mutations in the DMD gene and the
resulting absence of dystrophin at the muscle fiber membrane. PRO051, an
antisense oligonucleotide compound, induces specific exon 51 skipping during
pre-mRNA splicing, and can induce novel dystrophin expression in a subpopulation
of DMD patients (Van Deutekom N Eng J Med 2007;357(26):2719-2722).
DESIGN/METHODS: Twelve DMD patients received 5 weekly subcutaneous
injections. Four dosing cohorts were applied (0.5 mg/kg, 2 mg/kg, 4 mg/kg, 6
mg/kg), three patients each. Muscle biopsies were taken at baseline for patients
in cohort 1, and at two and seven weeks after the last administration for all
patients. Adverse events were recorded and safety assessments (laboratory
analysis and ECG) were performed at regular intervals. RESULTS: PRO051
induced specific exon 51 skipping in cohorts 2, 3 and 4, and novel dystrophin
expression in a dose related manner in all cohorts. The treatment was well
tolerated, none of the patients discontinued. A review of the safety data
revealed no clinically significant changes in laboratory values and ECG.
Antibodies against dystrophin were not detected. CONCLUSIONS/RELEVANCE:
This is the first study showing successful systemic administration of an
antisense oligonucleotide compound in DMD patients. An extension study is
ongoing to collect at least 6 months safety data in all 12 patients at 6 mg/kg.
A phase 3 study is in preparation. Supported by: Prosensa Therapeutics BV, the
Netherlands.
20 - (American
Academy of Neurology Meeting, April 2010)
Gentamicin Treatment of Duchenne
Muscular Dystrophy Reinforces the Potential for Mutation Suppression Therapy
Vinod Malik, Louise R. Rodino-Klapac,
Laurence Viollet, OH, Cheryl Wall, Wendy King, Roula Al-Dahhak, Sarah Lewis,
Christopher J. Shilling, Janaiah Kota, Columbus, OH, John Hayes, Forest Grove,
OR, John D. Mahan, Katherine J. Campbell, Columbus, OH, Brenda Banwell, Toronto,
ON, Canada, Majed Dasouki, Victoria Watts, Kansas City, KS , Kumaraswamy
Sivakumar, Ricardo Bien-Willner, Scottsdale, AZ, Kevin M. Flanigan, Zarife
Sahenk, Columbus, OH, Richard J. Barohn, Kansas City, KS, Christopher M. Walker,
Jerry R. Mendell, Columbus, OH
OBJECTIVE: Establish if the biopotency of gentamicin demonstrated in the
mdx mouse can be confirmed in a clinical setting and if so, how could it
be administered considering that readthrough would be an ongoing requirement.
Address the percent increase in dystrophin expression required to provide
clinically meaningful outcomes, and the potential immunogenicity of newly
expressed dystrophin epitopes following treatment. BACKGROUND: Mutation
suppression, also referred to as readthrough of stop codons, to restore the
dystrophin gene is undergoing clinical trials in Duchenne muscular dystrophy (DMD).
DESIGN/METHODS: Duchenne muscular dystrophy (DMD) subjects included: 1)
Cohort 1 (n = 10) stop codon patients and Cohort 2 (n=8) frameshift controls
receiving 14-days of gentamicin (7.5 mg/day). 2) Cohort 3 (n =12) and Cohort 4
(n=4) received an unprecedented six month delivery of weekly or twice-weekly
gentamicin permitting an accumulating dystrophin pool to reach potential
therapeutic levels. Readthrough was assessed in pre-and post-treatment biopsies
and by clinical outcomes. RESULTS: In the 14-day biopotency study serum
CK dropped by 50%, not seen in frameshift DMD controls. After 6-months of
gentamicin, dystrophin levels significantly increased (p = 0.027) reaching
levels 13% to 15% of normal accompanied by a drop in serum CK, stabilization of
strength by manual muscle testing and a slight increase in forced vital capacity
without adverse events. Stable transcripts that escaped nonsense mediated decay
predicted the greatest increase of dystrophin following gentamicin. The
efficiency of readthrough was not affected by either the stop codon or the
fourth nucleotide surrounding the stop. Novel immunogenic epitopes were found in
post-treatment biopsies by antigen specific IFN-g ELISpots.
CONCLUSIONS/RELEVANCE: The results support on-going efforts to achieve
drug-induced mutation suppression of stop codons. Immunogenic epitopes resulting
from readthrough emphasize the importance of monitoring T cell immunity during
clinical gene manipulation trials including mutation suppression, exon skipping
and gene therapy. Supported by: NIH, NINDS, MDA, Jesse's Journey, The University
of Kansas Medical Center GCRC
Grant
20 - (American Academy of Neurology
Meeting, April 2010)
Transient Expression of a
Therapeutic Dystrophin Transgene in Duchenne Muscular Dystrophy Revealed by T
Cell Mediated Immunity
Jerry Mendell, Katherine Campbell, Louise
Rodino-Klapac, Zarife Sahenk, Christopher Shilling, Sarah Lewis, Columbus, OH,
Dawn Bowles, Steven Gray, Chengwen Li, Chapel Hill, NC, Gloria Galloway, New
Albany, OH, Vinod Malik, Brian Coley, Reed Clark, Columbus, OH, Juan Li, Xiao
Xiao , Jade Samulski, Scott McPhee, R. Samulski, Chapel Hill, NC, Christopher
Walker, Columbus, OH
OBJECTIVE: Describe the immune response following gene therapy for
Duchenne muscular dystrophy (DMD) using adeno-associated virus (AAV) to transfer
the mini-dystrophin gene. BACKGROUND: Gene therapy for DMD is a
potentially promising means of gene replacement to restore dystrophin
expression. This study reports the first clinical trial of viral mediated gene
transfer in DMD. DESIGN/METHODS: Six DMD subjects were enrolled in a
double-blind gene transfer study to the biceps muscle. Four were receiving
glucocorticoid therapy at the time of gene transfer. The mini-dystrophin
transgene used in this study encoded the actin binding domain, 5 rod spectrin
repeats (R1, R2, R22, R23, and R24), 3 hinge domains (H1, H3 and H4), and the
cysteine-rich domain. Expression was under control of the human cytomegalovirus
immediate early promoter. Vector genomes were packaged in a hybrid AAV 2 capsid
with 6 amino acid substitutions designed to minimize recognition by serum
neutralizing antibodies. RESULTS: Four of six subjects with
frame-shifting deletions in the DMD gene had detectable T cell responses to
mini-dystrophin. Most of the targeted epitopes were non-self, located in
sequences unique to the therapeutic dystrophin protein. However in at least one
instance the dystrophin-specific T cells were present at low frequency before
vector treatment and expanded rapidly after mini-dystrophin expression. The
target of this unexpected memory T cell response was a self-epitope expressed
from the defective dystrophin gene in revertant muscle fibers.
CONCLUSIONS/RELEVANCE: This study illustrates the potential for a host
response to foreign transgene products that are caused by large deletions or
frame-shifting mutations. Recall of auto-reactive T cells has important clinical
significance beyond gene therapy for DMD. Similar cell-mediated immune responses
could be elicited by any strategy that increases expression of functional
dystrophin in subjects with DMD and should be considered in the design and
monitoring of experimental therapies for this disease.
Supported by: The MDA and Jesse's Journey.
20 -
(American
Academy of Neurology Meeting, April 2010)
Initial Efficacy and Safety
Evaluation in Cynomolgus Monkeys of AVI-5038, a Peptide Conjugated
Phosphorodiamidate Morpholino Oligomer (PPMO) Being Developed To Skip Exon 50 in
Duchenne Muscular Dystrophy
Peter Sazani, Stephen Shrewsbury, Bothell, WA
OBJECTIVE: To evaluate the efficacy of AVI-5038 at inducing skipping of
dystrophin exon 50, as determined by RT-PCR, and also perform an initial
toxicology assessment. BACKGROUND: AVI-5038 is a PPMO that induces
dystrophin exon 50, and is designed to restore the reading frame and enable
dystrophin expression in DMD patients. DESIGN/METHODS: Cynomolgus monkeys
were dosed IV with 0, 3, or 9 mg/kg with AVI-5038, once weekly for 4 weeks.
Following a 21 day recovery period, animals were sacrificed and a toxicological
evaluation was performed. Selected muscle tissues were also evaluated by RT-PCR
for evidence of skipping of dystrophin exon 50. RESULTS: AVI-5038 was
well tolerated, with no adverse effects detected at doses up to 9 mg/kg.
Toxicological findings were generally limited to the kidney, and included
basophilic granules and instances of tubular degeneration / regeneration that
was dose dependant. No clear evidence of kidney function change was detected, as
shown by clinical chemistry and urinalysis evaluations. Significant levels of
exon skipping were detected by RT-PCR in all major muscle groups evaluated,
including diaphragm, heart, and quadriceps, at 9 mg/kg.
CONCLUSIONS/RELEVANCE: AVI-5038, the first PPMO for DMD, was extremely well
tolerated at all tested doses in primates. In addition, the safety data indicate
that higher doses could be used to produce greater efficacy. Exon skipping was
induced by the PPMO in healthy primate's muscles following systemic
administration.
20 -
(American
Academy of Neurology Meeting, April 2010)
Outcome Measures Validation Study
for Mesoangioblasts Transplantation in Children Affected by Duchenne Muscular
Dystrophy
Serena Bonfiglio, Alberto Lerario, Andrea
Tettamanti, Sarah Marktel, Sara Napolitano, Stefano Previtali, Marina Scarlato,
Maria Grazia Natali Sora, Nereo Bresolin, Giancarlo Comi, Roberto Gatti, Fabio
Ciceri, Giulio Cossu, Yvan Torrente, Milano, Italy
OBJECTIVE: The aim of this study is to establish a reliable tool of
reproducible assessment of muscle strength in children affected by Duchenne
muscular dystrophy (DMD) which will be selected for mesoangioblasts
transplantation. BACKGROUND: We have developed a potential treatment for
DMD based on infusion of cells (mesoangioblasts) from a healthy donor capable.
The results of the current functional study will hopefully establish reliable
qualitative and quantitative tool to assess results of a future cell therapy
clinical trial with mesoangioblasts. DESIGN/METHODS: This is a single
centre, prospective, non-randomised, study of validation of outcome measures on
30 ambulant patients aged 5 to 12 years old affected by DMD including a cohort
of 15 healthy aged matched males. We perform two days evaluation each three
month for one year. During each assessment the following outcome measures are
applied to DMD subjects: North Star Scale and 6 minute walking test during the
first day; quantitative assessment using the Kin Com 125 machine during the
second day. The controls subjects will perform quantitative assessment twice in
a year. Twice during this evaluation year patients perform spyrometry, cardiac
assessment and lower limb MRI. RESULTS: We divided the patients into 3
subgroups of age (5-7 years, 8-9 years, 10-12 years). The results of this
preliminary part of the study show specific correlation between functional and
quantitative tests in stronger children. Kin Com measurements correlate
appropriately with functional tests for 10-12 years old DMD boys, while show a
major variability in muscle strength for 8-9 years old DMD boys. The comparison
with healthy subjects showed a difference of muscle strength that increases with
age. CONCLUSIONS/RELEVANCE: This preliminary study demonstrates that our
assessment may represent a useful tool to monitor the progress of DMD in
ambulant children to determine the pre-transplantation story of the children who
will be later treated with mesoangioblasts.
20 -
(American
Academy of Neurology Meeting, April 2010)
The 6-Minute Walk Test in Duchenne
Muscular Dystrophy: Longitudinal Observations
Craig McDonald, Erik Henricson, Sacramento, CA,
Richard Abresch, Davis, CA, Jay Han, Alina Nicorici, Erica Goude, Sacramento,
CA, Gary Elfring, Allen Reha, Samit Hirawat, Langdon Miller, S. Plainfield, NJ
OBJECTIVE: To develop the six-minute walk test (6MWT) as a
clinically-valid outcome measure for ambulatory boys with Duchenne muscular
dystrophy (DMD). BACKGROUND: We evaluated longitudinal changes in the
ambulation of boys with (DMD) and age-matched controls, ages 4-13 years, using a
6MWT modified for use in DMD therapeutic trials. DESIGN/METHODS: We
tested 18 boys with confirmed DMD and 22 healthy boys, ages 4-13 years using a
our previously reported 6MWT methodology. Boys were tested at baseline and after
1
year. RESULTS: The median [range] test-retest interval was 58 [35-84]
weeks in boys with DMD and 66 [51-114] weeks in healthy boys. At baseline, 13/18
(72%) boys with DMD were using corticosteroids. The groups were similar in age,
height, and weight. Mean six-minute walk distance (6MWD) declined (p=0.054) in
boys with DMD (mean [SD] change = -54 [100] m) but increased in healthy boys
(mean [SD] change = 16 [54] m). Mean stride length decreased in boys with DMD
(mean [SD] change = -0.03 [0.18] m) but increased in healthy boys (mean [SD]
change = 0.03 [0.18] m). Cadence decreased in boys with DMD (mean [SD] change =
-9 [15] strides/min) but was stable in healthy boys (mean [SD] change = 0.02 [9]
strides/min). In boys with DMD, change in 6MWD correlated strongly with change
in stride length (r=0.94, p<0.0001) and change in cadence (0.71, p=0.0045). In
healthy boys, change in 6MWD correlated strongly with change in stride length
(r=0.73, p=0.0001) but not at all with change in cadence (r=0.002).
CONCLUSIONS/RELEVANCE: This modified 6MWT shows clinically important changes
over an 1-year
period. These changes are age-dependent, consistent with the known natural
history of DMD. Improvement or stabilization of 6MWD during the course of a
long-term therapeutic trial would represent a clinically meaningful benefit for
boys with DMD. Supported by: PTC
Therapeutics, Inc.
20 -
(American
Academy of Neurology Meeting, April 2010)
Risk Factors for Fractures in the
Muscular Dystrophy Surveillance, Tracking and Research Network Cohort
Lisa A. Miller, Kathy James, Denver, CO,
Katherine Mathews, Iowa City, IA, Shree Pandya, Rochester, NY, Susan Apkon,
Seattle, WA, Chris Cunniff, Tucson, AZ
OBJECTIVE: To determine the occurrence of fractures and assess risk
factors for fractures among the Muscular Dystrophy Surveillance, Tracking and
Research Network (MD STARnet) cohort, a large population-based cohort of
individuals with well-characterized dystrophinopathy. BACKGROUND:
Fracture occurrence is a significant problem in Duchenne muscular dystrophy,
with reported rates between 21% and 44%. DESIGN/METHODS: All males with
definite or probable dystrophinopathy identified through MD STARnet who were
greater than 3 years of age and had a birth year from 1982 to 2006 were
included. Data were abstracted annually from medical records for all individuals
with a potential dystrophinopathy in the surveillance regions of Arizona,
Colorado, Iowa, Georgia and Western New York. Cox proportional hazard modeling,
a complex multivariate survival analysis, was used to assess risk factors for
fractures. For each patient, wheelchair use (part-time or full-time);
bisphosphonate, steroid, and calcium/vitamin D use prior to fracture; and the
duration of each were determined at each month of fracture occurrence.
RESULTS: There were 187 first fractures among 578 individuals (32.4
percent). The most common site was the femur (31.4 percent), followed by the
tibia/fibula (16.0 percent). The fracture risk for individuals who were in a
wheel chair full-time was 3.2 times higher than for individuals who were
ambulating, but for every month of full-time wheel chair use, risk decreased by
2.0 percent. For each additional month of steroid use beyond 6 months, fracture
risk increased by 1.2 percent. Calcium/vitamin D and bisphosphonate use prior to
fracture did not significantly affect risk. CONCLUSIONS/RELEVANCE: Our
results confirm the high rate of fractures in individuals with dystrophinopathy
and their relation to steroid use. In this population, the risk of fracture is
higher during early wheel chair use and decreases over time. Fracture risk in
these individuals is likely complex and the result of multiple factors.
Supported by: Centers for Disease Control and Prevention Cooperative Agreement
(5U01DD000191).
20 -
(American
Academy of Neurology Meeting, April 2010)
Disparities in the Diagnosis of
Duchenne and Becker Muscular Dystrophy: Data from the MDSTARnet, 1999-2007
Christopher Cunniff, Jennifer Andrews, Tucson,
AZ, Emma Ciafaloni, Rochester, NY, Deborah Fox, Troy, NY, Caleb Holtzer,
Zhenqiang Lu, Tucson, AZ, Lisa Miller, Denver, CO, John Meaney, Tucson, AZ
OBJECTIVE: To characterize the association of sociodemographic factors
with delays at specific steps in the diagnosis of Duchenne and Becker Muscular
Dystrophy (DBMD). BACKGROUND: Prior studies of DBMD observed diagnostic
delays ranging from 1.9 to 4.3 years, with diagnosis occurring around age 5
years. No studies report on sociodemographic disparities in the diagnostic
process. DESIGN/METHODS: We analyzed medical records for 593 boys in the
MDSTARnet database and assessed mean age differences by sociodemographic group
at first sign or symptom, initial medical evaluation, and first creatine kinase
(CK) test using generalized linear regression models and T tests. We assessed
the uptake of diagnostic testing and mutation analysis using the Cox
Proportional Hazard Model. RESULTS: Family history information was
available for 549 boys. Of these, 174 (29.3%) had a known family history of DBMD
prior to diagnosis. Boys with a family history were diagnosed at 33 months and
experienced each step to diagnosis at a younger age than boys without a family
history (p<.001). Boys without a family history were diagnosed on average at 66
months. Within this group, age at evaluation was younger for boys with more
educated mothers (p<.001). Whites underwent CK and DNA testing earlier than
Blacks and Hispanics (p<.005). Mean ages for boys grouped by socioeconomic
status or place of residence were not different at any time point. The rate of
point mutation analysis following a negative deletion/duplication test was
greater among boys with more educated mothers (p<.001).
CONCLUSIONS/RELEVANCE: In the MDSTARnet population, children without a
family history are diagnosed at age 5 years, 6 months, despite longstanding
symptoms. Differences in race/ethnicity and mother education are associated with
longer delays at multiple steps in the diagnostic process. The reasons for such
delay are not known but may result from lack of awareness of symptoms or
decreased access to diagnostic services. Supported by: A cooperative agreement
from the Centers for Disease Control and Prevention through the Association of
American Medical Colleges, grant number U36/CCU319276, AAMC ID number
MM-1064-09/09. Publication and report contents are solely the responsibility of
the authors and do not necessarily represent the official views of the AAMC or
the CDC. This study was also funded by the Centers for Disease Control and
Prevention under the Cooperative Agreement for Surveillance and Epidemiologic
Research of Duchenne and Becker Muscular Dystrophy DD000187, DD000189, DD000190,
DD000191.
20 -
(American
Academy of Neurology Meeting, April 2010)
Respiratory Care Trends for
Duchenne and Becker Muscular Dystrophies (DBMD): Data from the MD STARnet,
2001-2007
Daniel A. Mandel, Atlanta, GA, Daniel W.
Sheehan, Buffalo, NY, Shree Pandya, Rochester, NY, Christina P. Westfield,
Deborah J. Fox, Troy, NY, Sarah K. Nabukera, Katherine Mathews, Iowa City, IA,
Christopher Cunniff, Tucson, AZ, Carolyn M. Constantin, Atlanta, GA, David J.
Birnkrant, Cleveland, OH
OBJECTIVE: To profile forced vital capacity (FVC) monitoring for males
who have DBMD and to evaluate non-invasive positive pressure ventilation (NPPV)
and mechanical insufflator/exsufflator (MI/E) use among males with very low FVC
measurements. BACKGROUND: Semiannual FVC measurements are recommended for
patients age > 12 who have Duchenne muscular dystrophy. FVC measurements
of < 1 L are associated with complications of hypoventilation and early
mortality. NPPV and MI/E are used to support patients with poor pulmonary
function. DESIGN/METHODS: MD STARnet is a population-based surveillance
system that identifies all patients who have DBMD in defined geographic areas.
MD STARnet records were analyzed for 132, 177, and 199 males age > 12 in
2001, 2004, and 2007, respectively. Inclusion criteria for FVC < 1L were:
> 5 recorded FVC measurements; > 2 consecutive FVC measurements
< 1 L; and no subsequent FVC measurements > 1L. Sample sizes for FVC <
1 were 11, 22, and 33 in 2001, 2004, and 2007, respectively. Logistic regression
models were used to investigate NPPV and MI/E use over time, clustering on
patient. RESULTS: The percentage of males who have DBMD age > 12
years with a recorded FVC measurement ranged from 60-65% in the three study
years. The rates of NPPV use significantly increased among males with FVC <
1L (Wald X2 = 11.5, p = .003) over the study period. NPPV
rates ranged from a low of 27% in 2001 to a high of 85% in 2007. Rates of MI/E
use followed a less clear pattern: 18% in 2001; 9% in 2004, 58% in 2007.
CONCLUSIONS/RELEVANCE: Data show consistent FVC monitoring for males who
have DBMD and increasing use of NPPV for males who have very low FVC
measurements between 2001 and 2007. MI/E was relatively underused compared with
NPPV. Supported by: CDC cooperative agreements DD000187, DD000189, DD000190, and
DD000191.
20 -
(American
Academy of Neurology Meeting, April 2010)
Neuropsychological Profile of
Adult Patients with Duchenne Muscular Dystrophy
Natalia Sierra, Lilia Mesa, Alberto Dubrovsky,
Pablo Sojo, Teresa Torralva, María Roca, Fernando Chloaca, Laura Pirra, Facundo
Manes, Buenos Aires, Argentina
OBJECTIVE: To analyze the cognitive profile of adult patients with normal
IQ diagnosed with Duchenne Muscular Dystrophy (DMD). BACKGROUND: Research
on muscular dystrophies has focused extensively on the impact of peripheral
neural structures affected by the degenerative nature of the disease. However,
investigating the cognitive impairment in these patients may contribute to the
understanding of the pathophysiological changes occurring on the central nervous
system (CNS) and its relationship with peripheral structures. DESIGN/METHODS:
Ten patients with diagnosis of DMD aged between 17 and 28 years were assessed
with a general comprehensive cognitive battery as well as a specific executive
battery. All patients had within normal IQ scores. RESULTS: Tasks
associated with a motor component such as the Complex Rey Figure (z= -2,02) and
TMT-A (z= -2,31) and TMT-B (z=-2,47) were impaired. Performance deficits were
also found on tasks of verbal inhibitory control (z=-3,02) with normal scores on
reading speed (z=-0,69) and color naming (z=-0,81) on the Stroop task. Decreased
scores were observed for tasks of theory of mind (z=-1,19) and decision-making
(Iowa Gambling Task), although performance on the latter did not correlate
significantly with theory of mind or verbal inhibitory control scores (both p >
.05). CONCLUSIONS/RELEVANCE: These results are in accordance with
previous studied (e.g. Hinton et al, 2007) and suggest that normal IQ patients
with DMD present theory of mind and verbal inhibitory control deficits. Our
results also revealed decision-making impairments, although apparently not
associated with theory of mind and executive deficits.
20 -
(American
Academy of Neurology Meeting, April 2010)
Pulmonary Function Characteristics
of Boys with Duchenne and Becker Muscular Dystrophy by Age Groups and Steroid
Use: One-Year Data from the CINRG Longitudinal Study Project
R. Ted Abresch, Craig M. McDonald, Davis, CA,
Jay J. Han, Sacramento, CA, Robert Leshner, Washington, DC, Diana Escolar,
McLean, VA, Avital Cnaan, Eric Hoffman, Adrienne Arrieta, Tina Duong, Fenming Hu,
Washington, DC, Julaine Florence, Saint Louis, MO, CINRG Investigators,
Washington, DC
OBJECTIVE: To describe the pulmonary function characteristics of Duchenne
Muscular Dystrophy (DMD) over a one-year time period. BACKGROUND: Lack of
well-characterized pulmonary function data inhibits the development of
therapeutic clinical trials in DMD. DESIGN/METHODS: Pulmonary function
tests (PFTs) were performed in subjects with confirmed DMD at ages <7, 7-12,
13-18 and > 18 in 20 centers from the Cooperative International Neuromuscular
Research Group at baseline and 12 months. Fifteen percent of subjects were
steroid na
ve.
Pulmonary function measures included absolute and % predicted forced vital
capacity (FVC and %FVC), forced expiratory volume in 1 second a (FEV1,
%FEV1), peak expiratory flow rate (PEFR, %PEFR), maximum inspiratory
pressure (MIP, %MIP), and maximum expiratory pressure (MEP, %MEP). Significance
was accepted at p < 0.05. RESULTS: There was a significant one-year
increase in FVC (0.15l 
0.1
[sd]), FEV1 (0.15l 0.2)
and PEFR (0.49 l/s 0.5)
in the <7 year age groups (n=10). There was a significant one-year increase in
FVC and FEV1 (0.11l 0.2
and 0.13l 0.2,
respectively; n=85), as well as MIP and MEP (3.7 cmH20
12.5
and 5.7 cmH20 10.9,
respectively; n = 102) in the 7-12 year age groups. There was a significant
one-year decline in %FVC and %PEFR (-5.8%
5.7
and 5.0% 10.3,
respectively) in the 13-18 year age groups (n=57). At age
19
(n=23) there was a significant one-year decline in FVC (-0.14l
0.2),
%FVC (-3.0% 3.4),
FEV1 (-0.14l 0.2),
%FEV1 (-3.6% 
3.9),
%PEFR (-3.5% 6.5)
and %MIP (-2.7% 2.8).
No other PFT measures exhibited significant differences over a one-year period.
CONCLUSIONS/RELEVANCE: Pulmonary function testing reflects changes
associated with growth at age groups <7 and 7-12. DMD subjects exhibit
significant one-year PFT declines in the 13-18 and >18 year age groups.
Supported by: National Institute of Disability and Rehabilitation Research Grant
H133B980008-03; National Institutes of Health Grant 1U54HD053177-01A1;
Department of Defense Grant 0616USAMRAA.
20 -
(American
Academy of Neurology Meeting, April 2010)
Functional Motor Performance
Characteristics of Boys with Duchenne Muscular Dystrophy by Age Groups and
Steroid Use: One-Year Data from the CINRG Longitudinal Study Project
Craig McDonald, Erik Henricson, Sacramento, CA,
Richard T. Abresch, Davis, CA, Jay J. Han, Sacramento, CA, Robert Leshner,
Washington, DC, Diana Escolar, McLean, VA, Eric Hoffman, Avital Cnaan, Addrienne
Arrietta, Fenming Hu, Angela Zimmerman, Tina Duong, Washington, DC, Julaine
Florence, Saint Louis, MO, CINRG Investigators, Washington, DC
OBJECTIVE: To describe the changes in timed function testing (TFT) in
Duchenne muscular dystrophy (DMD) over one-year and the predictive value of TFTs
for determining loss of ambulation. BACKGROUND: In DMD, TFT measures are
used as clinical endpoints for therapeutic clinical trials and may predict loss
of ambulation over one-year. DESIGN/METHODS: TFTs were performed in 255
subjects with confirmed DMD at ages <7, 7-12, and >13 in 20 centers from
the Cooperative International Neuromuscular Research Group at baseline and 12
months. Fifteen percent of subjects were steroid nave.
TFTs (in seconds) included run/walk 10 meters, climb 4 steps, and standing from
lying. Significance was accepted at p < 0.05. RESULTS: There was a mean
decrease in all TFTs over one-year for the <7 year group (n=56): run/walk 10
meters (-0.46 1.7[sd]),
climb 4 steps (-1.83 4.4)
and standing from lying (-0.65 2.9).
There was a significant one-year increase in all TFTs in 7-12 year olds (n=65):
run/walk 10 meters (+1.38 1.8),
climb 4 steps (+2.47 4.9)
and standing from lying (+3.42 6.1).
Those >13 also increased time to run/walk 10 meters (+3.21
5.2,
n=10) and climb 4 steps (+1.58 1.3,
n=7). Only one subject >13 was able to perform standing from lying. Loss
of ambulation over 12 months was compared for three groups: baseline run/walk 10
meters < 6 seconds, 6-12 seconds, and >12 seconds. Survival analysis for the
milestone of loss of ambulation showed all three groups to be significantly
different using a Log-rank test (p<0.0001). CONCLUSIONS/RELEVANCE: In DMD,
TFTs show relative improvement with time in younger subjects <7 years. For those
7 and older TFTs show disease-related progression in both steroid-users and
steroid-na
ve
subjects. Timed to run/walk 10 meters is predictive of loss of ambulation over
the following 12 months. Supported by: National Institute of Disability and
Rehabilitation Research Grant H133B980008-03; National Institutes of Health
Grant 1U54HD053177-01A1; Department of Defense Grant 0616USAMRAA
20 -
(American
Academy of Neurology Meeting, April 2010)
A Cooperative International
Neuromuscular Research Group (CINRG) Study of the Relationship between
Impairment, Activity Limitation, Participation and Quality of Life in Persons
with Confirmed Dystrophinopathies: One Year Follow-Up of Skeletal Muscle
Strength and Timed Motor Performance
Erik Henricson, Craig McDonald,
Sacramento, CA, Richard Abresch, Davis, CA, Jay Han, Sacramento, CA, Robert
Leshner, Eric Hoffman, Washington, DC, Diana Escolar, McLean, VA, Avital Cnaan,
Fengming Hu, Angela Zimmerman, Tina Duong, Washington, DC, Julaine Florence,
Saint Louis, MO, Adrienne Arrieta, CINRG Investigators, Washington, DC
OBJECTIVE: To evaluate 12-month change in skeletal muscle strength and
timed motor function tests in individuals with Duchenne muscular dystrophy (DMD)
aged 2-28 years. BACKGROUND: Lack of adequate natural history data in
steroid-treated DMD and lack of well-characterized outcome measures across age
ranges limits the ability to assess therapeutic effectiveness in clinical trials
in DMD. DESIGN/METHODS: We enrolled males with confirmed DMD from 20
participating centers from 10 countries of the Cooperative International
Neuromuscular Research Group (CINRG). Ambulatory and transitioning participants
underwent strength assessment (modified MRC manual muscle test (MMT),
quantitative muscle tests (QMT) of grip, elbow flexion/extension, knee
flexion/extension) and timed function tests ((TFT) stand from supine, run/walk
10m, climb 4 stairs) at baseline, and months 3, 6, 9, 12. RESULTS:
255/347 males with DMD aged 2 to 28 years of age underwent strength and
functional testing, and 15% were glucocorticoid-nave.
Significant changes over 12 months included: Children <7 years decreased time to
climb 4 steps by 1.83(SD=4.4)s (p<0.0001 N=56) and increased quantitative grip
strength by 2.96(SD=2.5)lbs (p<0.0001 N=37) and knee flexors by 1.18(SD=2.6)lbs
(p<0.04 N=37). Children aged 7-12 years increased time to run/walk 10m by
1.38(SD=1.8)s (p<0.0001 N=65), time to climb 4 stairs by 2.47(SD=4.9)s (p<0.0001
N=65) and time to stand from supine by 3.42(SD=6.1)s (p<0.0001 N=65). Children
aged 13-18 years decreased quantitative elbow extensor strength by
1.23(SD=1.1)lbs (p<0.001 N=61) and elbow flexor strength by 0.98(SD=1.3)lbs
(p<0.01 N=61) and decreased manual muscle test score by 0.32(SD=0.4) points
(p<0.01 N=61). Adults aged >18 years who were testable decreased quantitative
grip strength by 0.6(SD=0.9)lbs (p<0.02 N=31). CONCLUSIONS/RELEVANCE: Few
measures of strength and function in steroid-treated boys with DMD show
significant disease-related changes over one-year. Relative stability over this
time suggests that clinical trials must demonstrate improvement rather than
stabilization using these measures. Supported by: National Institute of
Disability and Rehabilitation Research Grant H133B980008-03 National Institutes
of Health Grant 1U54HD053177-01A1 Department of Defense Grant 0616USAMRAA.
20 -
(American
Academy of Neurology Meeting, April 2010)
Multiple Sclerosis in a Patient
with Duchenne Muscular Dystrophy
Adrienne A. Salomon, Negar Sodeifi, Babak
Movassaghi, David Libell, Morgantown, WV
OBJECTIVE: To describe a rare association of multiple sclerosis (MS) in a
patient with Duchenne Muscular Dystrophy (DMD). BACKGROUND: MS is an
autoimmune disorder that most commonly begins between ages 20 and 40, but can be
seen at any age. The average age at diagnosis is 31 years in males. DMD is an
X-linked disorder which affects the DYS gene. It is the most common muscular
dystrophy and carries an average life expectancy ranging from early teens to
mid30s. No reported association between these two conditions was found.
DESIGN/METHODS: Case report involving a 23-year-old man with known DMD who
presented with unilateral left eye blurry vision. The patient admitted to having
suffered a similar episode of visual changes approximately one year prior.
Examination revealed left eye visual acuity of 20/100 with abnormal enhancement
of the left optic nerve on MRI consistent with optic neuritis. MRI of the brain
demonstrated multiple periventricular and juxtacortical lesions with
post-contrast enhancement. Lumbar puncture was significant for increased
oligoclonal bands with elevated IgG index (1.63) and myelin basic protein (3.5
g/L).
While the patient's diagnosis of DMD had previously been established by
neurological examination, family history, elevated creatine kinase levels, and
DNA analysis, the patient's new findings were consistent with a diagnosis of MS
based on McDonald criteria. RESULTS: The patient received high-dose
intravenous solumedrol for three days. The patient improved minimally during his
hospital course and was discharged on a steroid taper. Follow-up examination
confirmed resolution of his blurry vision with no further symptoms at six
months. CONCLUSIONS/RELEVANCE: We report the rare association between DMD
and MS. The patient's clinical course suggests that DMD did not impact the
clinical course or treatment of his MS. The fact that many DMD patients do not
survive long enough to manifest symptoms of MS may partly explain the rare
association of these two disorders.
20 -
(American
Academy of Neurology Meeting, April 2010)
Expression of Heat Shock Proteins in Skeletal Muscle from Idiopathic
Inflammatory Myopathy and Duchenne Muscular Dystrophy Patients
Jan L. De Bleecker, Kim K. Creus, Ghent,
Belgium, Jean-Jacques Martin, Antwerp, Belgium, Joachim Weis, Aachen, Germany,
Boel De Paepe, Ghent, Belgium
OBJECTIVE: To investigate heat shock protein families 70 (HSP70) and
HSP90 in idiopathic inflammatory myopathies (IIM) and Duchenne Muscular
dystrophy (DMD). BACKGROUND: HSP70 and HSP90 chaperones assure proper
protein folding and activity. Furthermore, HSP90 enhances the cytotoxic activity
of inflammatory cells. In view of current approaches exploring anti-HSP90
therapy in inflammatory diseases, more in-depth knowledge of the individual pros
and cons of chaperones could be relevant. DESIGN/METHODS: The expression
of HSP70 and HSP90 was investigated in muscle biopsies from controls, and from
IIM and DMD patients using immunofluorescence, in situ hybridization and Western
blotting. RESULTS: Inflammatory cells in IIM and DMD expressed low levels
of HSP70, HSP90 expression was increased in macrophages and cytotoxic T-cells in
proximity of invaded nonnecrotic myofibers of PM/IBM. HSP90alpha mRNA was
localized in endomysial infiltrates of PM/IBM along with faint HSP90beta
expression. Part of the invaded nonnecrotic myofibers showed sarcolemmal
staining for HSP70 and HSP90 proteins. The sarcoplasm of most small fibers, and
some normal appearing myofibers were strongly HSP70 positive. Double staining
showed important overlap between HSP70 and HSP90alpha in small NCAM+ fibers, and
rare co-localization with HSP90beta. Western blotting detected HSP70 and HSP90
proteins in all muscle tissues, but protein levels were increased in all (HSP70)
or part of (HSP90) IIM/DMD patients. In normal controls that had received
glucocorticoids prior to biopsy, nuclear over cytoplasmic protein ratios were
increased for HSP70, and decreased for HSP90. CONCLUSIONS/RELEVANCE: Our
data appoint pathological and physiological roles for HSP70 and HSP90, ascribing
these factors both adverse and beneficiary potential. On the one hand, HSP90 was
associated with the active invasion targeting the nonnecrotic myofibers in
PM/IBM. On the other hand, a strong expression of HSP70 occured in myofibers at
different regeneration-stages, with important but no absolute overlap with HSP90
in the small regenerating muscle fibers, indicating both general and
member-specific involvement. Supported by: L'Association Fran
aise
contre les Myopathies (AFM, France) L'Association Belge contre les Maladies
neuro-Musculaires (ABMM, Belgium) The Muscular Dystrophy Association (MDA, USA).
20 -
(American
Academy of Neurology Meeting, April 2010)
Adult Murine Derived
Mesoangioblasts Successfully Recovered Dysferlin Expression in a Murine Model of
Dysferlinopathy
Jordi Díaz-Manera, Barcelona, Spain, Thierry
Touvier, Rossana Tonlorenzi, Laura Perani, Arianna Dellavalle, Graziella
Messina, Patrizia Pessina, Milano, Italy, Eduard Gallardo, Isabel Illa,
Barcelona, Spain, Yvan Torrente, Giulio Cossu, Milano, Italy
OBJECTIVE: Our aim was to treat a mouse model of dysferlinopathy with
transplantation of adult derived murine mesoangioblasts (mMABs). BACKGROUND:
Mutations in dysferlin gene produce a muscular dystrophy characterized by adult
onset and progressive weakness leading to a severe phenotype. The A/J mouse is a
good model to study cell therapy as it completely lacks dysferlin and develops a
slowly progressive muscular dystrophy. Mesangioblasts (MABs) are vessel
associated progenitors that has been successfully used in preclinical models for
cell therapy for muscular dystrophy including the a-sarcoglycan null mice and
the Golden Retriever dogs affected by Duchenne's disease. DESIGN/METHODS:
Murine mesoangioblasts were obtained from skeletal muscle of 8 days old wild
type mice (C57 strain), and labeled with a lentiviral vector expressing nuclear
LacZ. To avoid an immunological response, A/J-SCID mice were generated by
crossing A/J and SCID strains. Firstly, we performed a single intramuscular
injection of 5x105 mMABs both in cardiotoxin treated and untreated
muscles from 5 months old mice. Then we proceed with a single injection of 5x105
mMABs in the right femoral artery. We analyzed the expression of dysferlin
3 weeks after the injection using immunofluorescence, quantitative RT-PCR and
Western-Blot. RESULTS: The first dystrophic features in AJ-SCID mice
appeared at 4-5 months of age, without significant differences in the
progression and distribution of them compared with control A/J mice. Three weeks
after transplantation, multiple areas of injected muscles expressed dysferlin
which was absent in non-injected contralateral muscles. Presence of the protein
in the membrane of Lac-Z + fibers was also demonstrated in intra-arterially
injected animals. The expression of dysferlin was significantly higher in
muscles treated with cardiotoxin. CONCLUSIONS/RELEVANCE: Treatment with
wild type mMABs successfully recovered the expression of dysferlin in A/J-SCID
mice. This fact suggests that adult derived mesoangioblasts may be a promising
candidate for future cell-therapy protocols in dysferlinopathy patients.
Supported by: European Federation of Neurology grant for young neurologist.
20
- (American
Academy of Neurology Meeting, April 2010)
rAAV5 Mediated Delivery of
Dysferlin as a Therapeutic Strategy for LGMD2B and Miyoshi Myopathy
Louise R. Rodino-Klapac, Kimberly M. Shontz,
Chrystal Montgomery, Vinod Malik, Nancy Davis, Paul M. L. Janssen, K. Reed
Clark, Columbus, OH, Robert H. Brown, Worcester, MA, Jerry R. Mendell, Columbus,
OH
OBJECTIVE: To develop an adeno-associated virus (AAV) mediated
therapeutic transgene to treat dysferlinopathies including limb-girdle muscular
dystrophy (LGMD) type 2B and Miyoshi myopathy (MM). No therapeutic treatments
are currently available for these disorders. BACKGROUND: The size of the
DYSF cDNA (6.5 kb) negates packaging into traditional AAV serotypes (capacity <
4.7 kb) known to express well in muscle (i.e. rAAV1, 2, 6, 8). Potential
advantages of a full cDNA versus a truncated transgene include: maintaining
structural-functional protein domains, evading protein misfolding, and avoiding
novel epitopes that could be immunogenic. This work describes in vivo
delivery of AAV5.DYSF to limb muscle and diaphragm of dysferlin deficient (Dysf-/-)
mice by both intramuscular and vascular (femoral artery) approaches.
DESIGN/METHODS: A cassette containing the DYSF cDNA driven by the muscle
specific MHCK7 promoter was packaged into an AAV2/5 vector. Physiological
characterization of three dysferlin deficient mouse strains (AJ, SJL, and
129-Dysftm1Kcam/J ) revealed functional deficits in the diaphragm but
not skeletal muscle. Efficacy of rAAV5.MHCK7.DYSF gene replacement was tested
following intramuscular and intravascular delivery to skeletal muscle and
diaphragm of 4-6 week old Dysf -/- mice. Functional improvement was
measured by tetanic force and resistance to fatigue in the diaphragm at 2
months. RESULTS: Robust dysferlin gene expression was achieved in a
dose-dependent manner by both intramuscular and vascular approaches. Western
blot analysis confirmed the immunostaining results demonstrating a 237kDa band
in treated samples that was absent in controls. Band intensity correlated with
dose. Gene transfer improved both force generation and resistance to fatigue in
the functionally impaired diaphragm in Dysf-/- mice.
CONCLUSIONS/RELEVANCE: These results provide proof of principle that a
full-length dysferlin cDNA can be delivered efficiently to muscle using AAV5
leading to physiological improvement. Future studies in a larger animal model
using a vascular approach targeting multiple muscles will guide clinical trial
design for LGMD2B and MM patients.
Supported by: Day Foundation.
19 - (Biochimica et
Biophysica Acta (BBA) - Biomembranes, February 2010) Morpholinos and
Their Peptide Conjugates: Therapeutic Promise and Challenge for Duchenne
Muscular Dystrophy
Hong M. Moulton
and Jon D. Moulton - USA
Exon-skipping efficacy of
phosphodiamidate morpholino oligomers (PMOs) or the conjugates of PMOs with
cell-penetrating peptides (PPMOs) have been tested in various animal models of
Duchenne muscular
dystrophy
(DMD), including mdx mice, utrophin-dystrophin double-knockout mice and
CXMD dogs as well as in DMD patients in clinical trials. The studies have shown
that PMOs can diffuse into leaky muscle cells, modify splicing of DMD
transcripts, induce expression of partially-functional dystrophin and improve
function of some skeletal muscles. PMOs are non-toxic, with a report of mdx
mice tolerating a 3 g/Kg dose and no drug-related safety issue in human has been
reported. However, because of their poor cell uptake and rapid renal clearance,
large and frequently repeated doses of PMOs are likely required for functional
benefit in some skeletal muscles of DMD patients. In addition, PMOs do not enter
cardiomyocytes sufficiently to relieve heart pathology, the efficacy of delivery
to various muscles varies greatly and delivery across the tissue of each
skeletal muscle tissue is patchy. PPMOs enter cells at far lower doses, enter
cardiomyocytes in useful quantities, and deliver more evenly to myocytes both
when different muscles are compared and when assessed at the level of single
muscle tissue sections. Compared to PMOs, far lower doses of PPMOs can restore
dystrophin sufficiently to reduce disease pathology, increase skeletal and
cardiac muscle functions and prolong survival of animals. The biggest challenge
for PPMO is determining safe and effective doses. The toxicity of PPMOs will
require caution when moving into the clinic. The first PPMO-based DMD drug is
currently in pre-clinical development for DMD patients who can benefit from
skipping exon 50.
19 -
Perioral skin biopsy to study skeletal muscle protein expression
19 -
Surgical management of severe scoliosis with high risk pulmonary dysfunction in
Duchenne muscular dystrophy: patient function, quality of life and satisfaction.
19 -
Cells of extraembryonic mesodermal origin confer human dystrophin in the Mdx
model of duchenne muscular dystrophy
19 -
Systemic Myostatin Inhibition via Liver-Targeted Gene Transfer in Normal and
Dystrophic Mice
13 -
Functional improvement of patients with progressive muscular dystrophy by bone
marrow and umbilical cord blood mesenchymal stem cell transplantations
4 -
(Molecular Therapy 2010;18(2):386–393)
Complete Genetic Correction of iPS Cells From
Duchenne Muscular Dystrophy
Yasuhiro Kazuki, Masaharu Hiratsuka, Masato Takiguchi,
Mitsuhiko Osaki, Naoyo Kajitani, Hidetoshi Hoshiya, Kei Hiramatsu, Toko Yoshino,
Kanako Kazuki, Chie Ishihara, Shoko Takehara, Katsumi Higaki, Masato Nakagawa,
Kazutoshi Takahashi, Shinya Yamanaka and Mitsuo Oshimura - Japan
Human artificial chromosome (HAC) has several advantages as a
gene therapy vector, including stable episomal maintenance that avoids
insertional mutations and the ability to carry large gene inserts including the
regulatory elements. Induced pluripotent stem (iPS) cells have great potential
for gene therapy, as such cells can be generated from the individual's own
tissues, and when reintroduced can contribute to the specialized function of any
tissue. As a proof of concept, we show herein the complete correction of a
genetic deficiency in iPS cells derived from Duchenne muscular dystrophy (DMD)
model (mdx) mice and a human DMD patient using a HAC with a complete genomic
dystrophin sequence (DYS-HAC). Deletion or mutation of dystrophin in iPS cells
was corrected by transferring the DYS-HAC via microcell-mediated chromosome
transfer (MMCT). DMD patient- and mdx-specific iPS cells with the DYS-HAC gave
rise to differentiation of three germ layers in the teratoma, and human
dystrophin expression was detected in muscle-like tissues. Furthermore, chimeric
mice from mdx-iPS (DYS-HAC) cells were produced and DYS-HAC was detected in all
tissues examined, with tissue-specific expression of dystrophin. Therefore, the
combination of patient-specific iPS cells and HAC-containing defective genes
represents a powerful tool for gene and cell therapies.
4 -
Bringing down the barriers in translational medicine for inherited neuromuscular
diseases.
4 -
Evaluation of Skeletal and Cardiac Muscle Function after Chronic Administration
of Thymosin beta-4 in the Dystrophin Deficient Mouse
JANUARY
12 -
Cytokinetics Announces Positive Data From Phase I Clinical Trial of CK-2017357:
Statistically Significant Increases in Muscle Force Production Demonstrated
During Treatment With Novel Skeletal Muscle Activator
12 - (International
Journal of Cardiology, 2009)
Relationship of natriuretic peptide and transthoracic echocardiographic findings
in 135 subjects with muscular dystrophy
Miyuki Kawakubo, Nobusada Funabashi, Maiko Takahashi, Makoto
Sueishi, Yasufumi Motoyoshi, Takashi Mikata, Idai Uchida, Takehiro Asakawa, Riyo
Takahashi, Midori Takamatsu, Yukie Matsuoka, Masaaki Minegishi, Hideki Naga, Rei
Yajima, Akihisa Kataoka, Kwangho Lee, Issei Komuro - Japan
Purpose: To
examine the usefulness of plasma atrial (ANP) and brain natriuretic peptide (BNP)
levels and transthoracic echocardiogram (TTE) findings in predicting left
ventricular (LV) dysfunction in muscular dystrophies (MD).
Materials and methods:
135 MD subjects (83 Duchenne MD (DMD), all males,
mean age 22 ± 7 years, 20 Becker MD (BMD), all males, 45 ± 16 years, 21
limb-girdle MD (LGMD), 14 males, 52 ± 13 years, and 11 facioscapulohumeral MD (FSHD),
all males, 58 ± 13 years) underwent TTE and measurement of BNP and ANP.
Results: In DMD,
TTE revealed asynergy of the LV posterior-wall (72%), interventricular septum (IVS)
(29%) and LV apex-wall (24%); in BMD subjects: TTE revealed asynergy of LV
posterior-wall (50%) and IVS (25%); in LGMD and FSHD subjects: TTE revealed
asynergy of LV posterior-wall (33 and 27%, respectively). LV end-diastolic (LVDdI)
and end-systolic diameter index (LVDsI) were significantly larger in DMD than
FSHD, and LV ejection fraction (LVEF) was significantly lower in DMD than LGMD
and FSHD. In DMD, when LVEF was > = 35%, BNP and ANP levels remained low, but
when LVEF < 35%, BNP and ANP levels showed steep increase. Relationship between
LVEF and BNP or ANP levels was curvilinear (R2 = 0.69 and
0.55, respectively, p < 0.001) using following equation: BNP = 673491×EF− 2.897,
ANP = 5716.6 × EF− 1.422, respectively. When LVDdI > = 40 mm/m2
or LVDsI > = 35 mm/m2, LVEF < = 35%, plasma BNP and ANP levels
increased steeply and the relationship between LVDdI, LVDsI, or LVEF and plasma
BNP or ANP levels was curvilinear.
Conclusion: In
DMD, LVEF was significantly lower, asynergy of LV posterior-wall was more
frequent and BNP and ANP levels were dramatically higher when LVDdI > = 40 mm/m2,
LVDsI > = 35 mm/m2 or LVEF < 35%.
9 - (PNAS, 2010)
Leaky RyR2 trigger ventricular arrhythmias in
Duchenne muscular dystrophy
Jérémy Fauconnier; Jérôme Thireau; Steven Reiken; Cécile
Cassana; Sylvain Richarda; Stefan Matecki; Andrew R. Marks; Alain Lacampagne -
France
Patients with Duchenne muscular dystrophy (DMD) have a
progressive dilated cardiomyopathy associated with fatal cardiac arrhythmias.
Electrical and functional abnormalities have been attributed to cardiac fibrosis;
however, electrical abnormalities may occur in the absence of overt cardiac
histopathology. Here we show that structural and functional remodeling of the
cardiac sarcoplasmic reticulum (SR) Ca2+ release channel/ryanodine
receptor (RyR2) occurs in the mdx mouse model of DMD. RyR2 from mdx
hearts were S-nitrosylated and depleted of calstabin2 (FKBP12.6), resulting in
“leaky” RyR2 channels and a diastolic SR Ca2+ leak. Inhibiting the
depletion of calstabin2 from the RyR2 complex with the Ca2+ channel
stabilizer S107 (“rycal”) inhibited the SR Ca2+ leak, inhibited
aberrant depolarization in isolated cardiomyocytes, and prevented arrhythmias in
vivo. This suggests that diastolic SR Ca2+ leak via RyR2 due to
S-nitrosylation of the channel and calstabin2 depletion from the channel complex
likely triggers cardiac arrhythmias. Normalization of the RyR2-mediated
diastolic SR Ca2+ leak prevents fatal sudden cardiac arrhythmias in
DMD.