Thank you for your interest in our research. This section
contains information about our Institution Review Board (IRB)
approved research projects that are part of the Neuromuscular
Disease Project. We also provide information on enrolling
patients/submitting samples and access to our consent forms
in a password-protectedarea. These forms as well as
nonpassword-protected brochures can be downloaded from this
web site.
This section provides technical information for researchers
who would like to learn about our neuromuscular disease research
and information on how to refer a family to our research studies.
To Enroll a Patient:
Click the link above to obtain informed consent, locate muscle
specimens and gather medical records. Contact
Jessica Blasko to obtain a password to access the password-protected
section, or to speak with her directly about our research
studies.
Neuromuscular diseases are a group
of disorders that can be relatively mild, moderate, or severe,
and can present early or later in life. Severe cases may lead
to death in early infancy while milder cases may cause significant,
chronic muscle weakness . These disorders can be X-linked or
autosomally inherited.
Over recent years, investigators have gained more knowledge
about transmission of nerve impulses, the function of the
neuromuscular junction, the physical and biochemical processes
of muscular development, contraction, and wasting. As summarized
by (1)
O'Brien and Kunkel (2001), neuromuscular disease research
has significantly progressed since dystrophin was cloned.
Some interesting discoveries pertaining to the genes that
code for several proteins that control the structure and function
of normal and diseased muscle have been made.
Perhaps the most significant information that is being elucidated
relates to the functions of dystrophin and its associated
protein complex (DAPC). Despite the progress that has been
made, a delay in developing treatment has taken longer than
expected. New advances have created the potential for several
therapies which will be explored further, in hope that we
will be better able to manage muscular dystrophies. Our research
is dedicated to this goal.
Figure 1.
The Dystrophin Associate Complex and various muscle proteins.
The disease names in the boxes located next to specific proteins
are the disorders that may manifest when the given protein is
altered. Many of the diseases that we are researching can be
found in this diagram.
The neuromuscular diseases which we are studying include:
Please click on the name of the neuromuscular disorder
for a brief overview of the disease. Use the links to the
Online Mendelian Inheritance in Man (OMIM) for a more technical
explanation of the disorder. Use the link to Diagnostic
Criteria for Neuromuscular Disorders to view online text
chapters for a detailed explanation of diagnosing specific
neuromuscular disorders.
Our Projects
There are four subprojects that comprise the Neuromuscular Disease
Project, each with separate but overlapping aims. Please click
on the laboratory below to link to detailed information on each
investigator. Click on the Project title to learn about his
or her research contribution to this project and the lab members
involved in the neuromuscular disease project.
Project 1: The
Kunkel Laboratory
Gene expression and biochemical studies of filamin/sarcoglycan-related
dystrophies. Directed by the Program Director, Dr. Lou
Kunkel, this project will continue his laboratory’s
interest in understanding the underlying basis of the muscular
dystrophies and using that information to develop targeted
treatments. Project 1 will focus on a subset of the Kunkel
laboratory’s effort, with emphasis on the role of the
sarcoglycans and newly identified filamin-2 in the pathogenesis
of the limb girdle muscular dystrophies (LGMD). We will
explore this function via conventional biochemical and genetic
analysis, and by the new expression array (Core C). We will
have the unique opportunity to study the mRNA expression
profiles of the different muscle biopsies we have collected
over the years and plan to collect as part of this program
in collaboration with Core B. These expression patterns
will be confirmed by our ongoing biochemical work on muscle
proteins in the muscular dystrophies. We also are very excited
about the possibilities of our recently described muscle
stem cells and their potential role in developing a therapy
for muscle disorders. These will be studied in collaboration
with project 4 to determine their existence in dystrophies
and whether normal cells will be equally effective as they
were in dystrophin-deficient mice.
AIMS:
To continue the analysis of Filamin 2 as a new component
of the dystrophin associated protein complex and its role
in LGMD.
To identify additional novel FLNC/sarcoglycan-associated
interacting proteins by yeast two-hybrid and biochemical
cross-linking of proteins made in muscle.
To use chip-based mRNA expression arrays to analyze/compare
dystrophin, sarcoglycan, calpain-3 and filamin-deficient
muscle to normal muscle in order to identify changes that
are common among the dystrophies or specific to a particular
form of dystrophy.
To validate results of expression arrays and characterize
genes that are unique to each of the dystrophies as potential
modifiers of the phenotype and begin to test new hypotheses
about the molecular pathogenesis of muscle degeneration.
To analyze SP stem cell populations within sarcoglycan-deficient
mouse models of human dystrophy, studying the influence
these mutations have on the stem cells and whether normal
stem cells can be corrective in these respective dystrophies.
Project 2: The
Brown Laboratory (Day Neuromuscular Research Laboratory)
Gene expression and biochemical studies of dysferlin-related
dystrophies. Dr. Brown is trying to characterize the
biological properties of dysferlin and its role in the pathogenesis
of limb-girdle muscular dystrophy type 2B (LGMD2B) and Miyoshi
myopathy (MM), and to initiate studies of cell therapy in
these two diseases. These biological studies will entail
an investigation of dysferlin-interacting proteins, using
both conventional and newer (microarray) methods. The cell
therapy studies will characterize muscle stem cells in dysferlin-deficient
mice and assess the feasibility of using normal muscle stem
cells to replace dysferlin in these animals.
AIMS:
To characterize dysferlin gene mutations and abnormalities
of dysferlin protein expression in patients with MM and
LGMD 2B and use this information to extend our studies
of dysferlin as a novel muscle membrane protein.
To identify proteins that interact with normal and mutant
dysferlin via conventional analysis.
To use chip-based mRNA expression to analyze/compare
dysferlin-deficient human muscle to identify changes of
muscle gene expression that are either common to all dystrophies
or specific to the dysferlinopathies.
To validate results of expression arrays and characterize
genes that are unique to each of the dystrophies as potential
modifiers of the phenotype and begin to test new hypotheses
about the molecular pathogenesis of muscle degeneration
in the dysferlinopathies.
To analyze SP cell populations in MM and LGMD 2B in
a mouse model of dysferlin deficiency.
Project 3: The
Beggs Laboratory
Gene Expression and Biochemical Analysis of Muscle Development
in Myotubular Myopathy. The goal of this Project is
to understand the molecular basis for X-linked myotubular
myopathy (XLMTM) by determining the effects of myotubularin
mutations on gene expression. Pathologically, XLMTM is characterized
by incomplete muscle maturation caused by defects in myotubularin,
a dual specificity protein phosphatase. This study entails
the developmental characterization of global gene expression
of known genes and novel expressed sequence tags (ESTs)
in XLMTM and related disorders from the SP stem cell stage
through to mature muscle. Understanding perturbations in
gene expression will shed light on the function of myotubularin
and its role in normal muscle development and may allow
identification of therapeutic targets to stimulate normal
muscle development in patients with XLMTM and related disorders
of muscle development.
AIMS:
To ascertain and characterize fresh muscle, muscle cell
cultures and frozen muscle biopsies from patients with
XLMTM and CTNM.
To isolate and characterize muscle stem cells (SP cells)
from myotubularin-deficient patients. To use chip-based
mRNA expression arrays to analyze perturbations of gene
expression associated with abnormalities of myotubularin
in cultured muscle cells.
To use chip-based mRNA expression arrays to analyze/compare
XLMTM and CTNM human muscle to identify disease-specific
and nonspecific changes in muscle gene expression.
To validate results of expression arrays and characterize
genes whose expression is specifically perturbed by myotubularin
dysfunction.
Project 4: The
Gussoni Laboratory
Gene expression in, and therapeutic application of, muscle
stem cells. The long-term goals of this project are
to isolate and characterize stem cells from human skeletal
muscle, and test their ability to correct muscular deficiencies
in-vivo. These studies will require the use of the fluorescence-activated
cell sorter and microarray techniques to purify human muscle
cells and identify the genes they specifically express.
Human muscle stem cells will be introduced into the circulation
of different animal models of muscle disorders and their
ability to target and repair damaged muscle will be assessed.
AIMS:
To optimize the isolation of muscle stem cells (SP cells)
in humans.
To use chip-based mRNA expression arrays to identify
genes expressed by human muscle SP cells.
To analyze candidate genes from gene chip technology
using other conventional techniques.
To optimize conditions to propagate and culture human
SP cells in vitro.
To evaluate the differentiation potential of human muscle
SP cells in vivo.
Cores
The responsibilities of each core are listed below.
Core A: Administrative
Core. (Louis
Kunkel, Ph.D., P.I.) Each Project interacts with
the Administrative Core, both regarding the maintenance
and oversight of the program, and also as part of the executive
committee. The web portal for the project is maintained
by this Core and is used by all the projects.
Core B: Clinical Specimen
and Data Core (CSDC) (Elizabeth.
Engle, M.D., P.I.) Each project interacts with the
CSDC and the services of Core B are essential to the Program
Project. Core B centralizes data and tissue collections
and developed a database within the Program Project. This
core increases efficiency to provide standardization to
the analysis of data for each project within the Program
Project.
Core C: Gene Expression
and Bioinformatics Core (GEBC) (I.
Kohane, M.D., Ph.D., P.I.) Core C consists of the
hardware for arraying and analysis of data, as well as the
informatics to work with the data. This Core provides expertise
on arraying and hybridization to each of the projects. There
is also a major informatics segment to the Core, which provides
the analysis of the raw data. The benchmark array sets from
normal muscle will be performed in this Core and they will
also be analyzed. The Core provides the informatic analysis
of the data specific to each project and sets expression
level thresholds to assist investigators to choose the specific
clones on which to concentrate.
Goals
The common fundamental goals of the projects is characterizing
and understanding normal and abnormal patterns of gene expression
in developing muscle from the stem cell state through to maturity.
Further, we aim to understand the molecular consequences of
specific genetic defects and to identify appropriate targets
for therapeutic intervention.
Based on these fundamental goals, there are three complementary
approaches to our research:
To enroll patients with specific neuromuscular disorders
in our research
To identify new muscle-specific genes and proteins through
biochemical and molecular analysis
To research gene expression using microarray technology
To enroll a patient
in our research
Visit our Inclusion
Criteria Section to see if the patient is suitable for
our research studies. Alternatively, you may contactthe research study coordinator to inquire as to whether
a patient is or is not appropriate for our research.
Obtain written informed consent. All participants must
read, understand, and sign our IRB-approved informed consent
forms in order to participate in our research. If there
is muscle tissue available from the affected patient (see
below), the patient or parent/guardian if patient is under
age 18 must sign a consent form for DNA studies and a consent
form for muscle tissue studies. Clinicians obtaining consent
from their patients sign as our “collaborating physician/genetic
counselor” on section VII of the consent forms. To
access the consent forms on this web site, contactJessica Blasko to obtain your password.
Locate Specimens. Please refer to our Disease
Flow Chart to see which specimens are needed for each
neuromuscular disease we are researching. In the ideal situation,
the patient you wish to enroll will have a defined genetic
mutation and an available muscle tissue specimen.
Blood: In some cases, we will need blood samples from the
affected patient and all available and consenting first-degree
relatives.
Muscle tissue: For most of our research, we require unfixed,
frozen muscle. Often, we can use tissue remaining from a
surgical biopsy or autopsy. Alternatively, if a surgical
procedure is planned for the near future, this may provide
an opportunity to obtain a muscle specimen without additional
risk or discomfort to the patient.
If you are a physician or a genetic counselor and would
like access to the instructions for submitting specimens,
click here. To
obtain your password, contact
Jessica Blasko.
Gather copies of relevant medical records. Medical records
will help us correlate our research findings with existing
clinical data. If available, please send a pedigree including
all affected family members and first and second degree
relatives of each. Also, muscle pathology reports, EMG,
serum muscle enzymes, and results of any other neuromuscular-related
tests are important. Please also include notes from neurologists
and/or geneticists describing the initial presentation.
Please ask your patient to sign an authorization for release
of medical information.
Reporting Results
Our work consists of research studies of indefinite duration.
Due to the lengthy and unpredictable nature of these studies,
it is unlikely that we would make any clinically-relevant findings
in the near future. In addition, because this is a research
laboratory, we cannot report results from this study. In the
United States, the Clinical Laboratory Improvement Act/Amendment
(CLIA) requires that laboratories performing clinical tests
meet certain quality and expertise standards. However, if we
obtain information that we think might be of significance to
the family, we may be able to have these results confirmed by
a CLIA-certified clinical laboratory.
Although there is no financial cost for participation in our
research study, there will most likely be a charge associated
with the repeat clinical testing. The charge may vary depending
on the laboratory. If the patient’s results were confirmed
they would be reported to the patient’s referring physician/genetic
counselor. Although we do not always have definitive tests that
might help to make a genetic diagnosis, participation of affected
families will greatly aid our research on neuromuscular disease.
Patient Support
Last, as you know, it is important to recognize the emotional
needs of your patients. Having a neuromuscular disease can be
emotionally trying on the patient as well as on the entire family.
Please visit our Links to learn
about the different support groups that are available to individuals
with neuromuscular diseases and their families. It may be useful
to pass on this information to your patients. Support groups
can offer valuable educational information and emotional support
to individuals who share the common diagnosis of a neuromuscular
disease. Contact your local Muscular Dystrophy Association Clinic
for more information, or visit the web site at www.mdausa.org.
Reference:
Obrien, K. F., and Kunkel, L. M. Dystrophin and muscular dystrophy:
past, present, and future. Molecular Genetics and Metabolism
34, pp75-88 (2001).
