The MGH Center for Genomic Medicine Batten Disease Research Program

1. CLN2,
CLN3,
CLN5,
CLN6,
Unknown
NCL
The
MGH
Center
for
Genomic
Medicine
Ba>en
Disease
Research
Program
InvesFgaFng
the
molecular
basis
of
NCL:
a
geneFc
research
path
towards
drug
development
Susan
L.
Cotman,
Ph.D.
(Principal
InvesFgator),
Uma
Chandrachud,
Ph.D.,
Elisabeth
Butz,
Ph.D.,
Abigail
Nowell,
Madeline
C.
Klein
Center
for
Genomic
Medicine,
Department
of
Neurology,
Massachuse>s
General
Hospital,
Harvard
Medical
School
Introduc)on
and
Laboratory
Objec)ves
!
DNA
mutaFons
in
one
of
at
least
13
different
genes
lead
to
the
clinical
symptoms
of
Ba>en
disease,
or
NCL
(for
neuronal
ceroid
lipofuscinosis).
In
some
cases,
idenFfying
the
geneFc
cause
of
disease
remains
a
significant
challenge.
! In
many
forms
of
NCL,
how
the
DNA
mutaFons
lead
to
the
disrupted
cellular
processes
is
not
yet
completely
understood.
It
is
also
sFll
not
well
understood
which
disrupted
processes
lead
to
the
disease
symptoms.
!
Understanding
the
steps
in
the
disease
process,
from
geneFc
trigger
(DNA
mutaFon)
to
clinical
onset
and
progression,
is
important
for
designing
therapies.
!
Our
laboratory
uses
geneFc
model
organisms
as
well
as
human
cell
culture
systems
to
formulate
and
test
hypotheses
regarding
NCL
protein
funcFon
and
the
NCL
disease
process.
! We
also
parFcipate
in
collaboraFve
efforts
to
improve
the
methods
for
idenFfying
the
DNA
mutaFons
and
to
further
improve
the
availability
of
paFent
samples.
Conclusions
! The
increasingly
well
characterized
disease
models
that
now
exist,
which
recapitulate
NCL
DNA
mutaFons,
are
contribuFng
to
important
advances
in
our
understanding
of
the
molecular
basis
of
the
NCLs
! Research
with
these
model
systems
is
leading
to
new
candidate
drug
targets
that
are
currently
being
studied
for
drug
development
! Screening
of
drug
libraries
is
idenFfying
new
informaFon
and
new
candidate
drugs/drug
targets
! Our
understanding
of
the
funcFons
of
the
NCL
proteins
is
increasing,
which
will
lead
to
be>er
targeted
therapies
and
biomarker
tools
for
monitoring
treatment
! New
methods
for
determining
the
underlying
NCL
DNA
mutaFons
are
leading
to
an
increasing
awareness
of
shared
disease
biology
with
other
forms
of
human
disease
and
in
a
greater
appreciaFon
of
how
mutaFons
in
NCL
genes
affect
human
health
more
broadly.
This
knowledge
will
increase
awareness
and
correctly
idenFfy
more
paFents
and
the
underlying
genes
causing
their
disease
! There
is
an
increasing
uFlizaFon
of
paFent
samples
linked
to
geneFc
and
clinical
informaFon
and
a
greater
effort
to
deepen
this
important
resource
Acknowledgements: We thank our numerous scientific and clinical collaborators and supporters, as well as the organizations who’ve provided funding to support our research. We would
also like to expressly thank the families and patients who’ve donated samples and participated in our research studies. Recent funding sources include the Batten Disease Support and
Research Association, the National Institutes of Health: National Institute for Neurological Diseases and Stroke, the MGH Executive Committee on Research, Catherine’s Hope for a Cure,
Beyond Batten Disease Foundation, Beat Batten, and Our Promise to Nicholas.
A
research
tool-­‐kit
for
protein
detec)on
and
func)on
analysis,
and
for
drug
discovery
Drug screening
to identify
disease
modifiers/drugs
-unbiased drug libraries
-candidate drug testing
Protein detection assay development
for isoform-specific quantification of NCL
proteins in biological samples
Facilita)ng
the
gene)c
research
cycle
for
all
forms
of
NCL
Conceptualiza)on
of
the
NCL
disease
process
Model
systems
we
have
developed
and/or
use
for
NCL
research
GeneFc
Studies
to
IdenFfy
‘Unknowns’
and
GeneFc
Modifiers
• Next
GeneraFon
Sequencing
of
Whole
Exomes/Genomes
• Candidate
Gene
Screening
• Adult
NCL
Gene
Discovery
ConsorFum
• AnalyFc
and
TranslaFonal
GeneFcs
Unit
of
MGH
(Dr.
Mark
Daly,
Dr.
Daniel
MacArthur)
Mouse
models
and
cell
culture
models
• Useful
in
idenFfying
possible
early,
pre-­‐
clinical
symptoms
• Biomarkers
development
• Improved
descripFon
of
the
disease
process
• Preclinical
tesFng
of
candidate
disease
modifying
treatments
Screening
for
drugs
using
mouse
and
human
neuronal
cells
• Unbiased
screen
of
a
large
drug
library
• CollaboraFng
partners
with
other
academic
labs
and
pharmaceuFcal/biotech
companies
to
test
candidate
treatments,
either
small
molecule
or
other
geneFc
approaches
Systems
for
translaFon
of
findings
to
human
paFents
Fibroblasts
Lymphoblasts
**Human
induced
pluripotent
stem
cells
(hiPS
cells)—can
be
differenFated
into
affected
cell
types,
like
neurons
and
glia
MGH-­‐Ba>en
Disease
Center
• Clinic:
paFent
care
and
opFonal
research
study
enrollment
(Dr.
Kathryn
Swoboda,
Dr.
Florian
Eichler)
• NCL
Registry
and
Biorepository
• CollaboraFonwith
Dr.
Jon
Mink
(U
of
Rochester)
and
Dr.
Forbes
Porter
(NIH),
and
others,
to
deepen
biological
samples
linked
to
clinical
and
geneFc
informaFon
Cln3∆ex7/8 knock-in mice
• Genetic replica of the ~1-kb
deletion mutation most frequently
observed in CLN3 patients
• Cln6nclf mice
• Tpp1knock-out mice
(provided by Drs. Lobel and Sleat)
CbCln3∆ex7/8 and
CbCln6nclf mouse
neuronal precursor cells
Patient fibroblasts and
reprogrammed human induced
pluripotent stem (hiPS) cells (all
forms of NCL)
Can be turned into brain cells and
other relevant cell types
• Phenotyping
(characterizing abnormalities at
the cellular and whole
organism level)
• Disease modifier studies
(cell-based screening and mouse
modifier studies)
• Molecular analysis
(single gene and genomic level)
Potential modifiers:
Mitochondrial pathways
Intracellular Ca2+
Autophagy pathway modifiers
êAutophagy clearance
êendocytosis
êlysosomal protein trafficking
Mitochondrial changes
Subunit c
storage
Sensorimotor
processing affected
Gliosis
Motor function decline
Working
chronology of the
disease process in
NCL genetic
models
cln3 knockout Dictyostelium
discoideum (collaboration
with Dr. Rob Huber)
• Social amoeba, single cell
stage to multicellular stage
developmental life cycle
• Expression of human
CLN3 in the cln3- Dicty
cells rescues
abnormalities
demonstrating conserved
function across evolution
Conception
NCL gene status
= two abnormal copies of an NCL gene
Lifeline of a person with two NCL mutations
Clinical Diagnosis
End-stage
disease
Conception
NCL gene status
= at least one normal copy of NCL gene
End-of-life
Lifeline of an unaffected individual
• Different genetic or environmental modifiers could act at
different stages and affect the progression towards end-stage
disease, which primarily affects the brain and eyes. However,
new research indicates other organ systems may also ultimately
become affected.
• Identifying these modifying factors and then targeting them
through interventions/drugs (blue arrows) could slow or halt
further advancement of disease progression. We also have to
develop better ways of monitoring the effects of treatments,
which are a key component of successful clinical trials and
reaching new drug approval.
CLN3
Drug libraries (e.g. >2000
FDA-approved drugs)
1. Assays are developed that measure a difference between
unaffected and affected cells. In this example, there are
more green dots (a lysosome-related structure called an
autophagosome, labeled by a fluorescent marker) in
affected cells than in unaffected cells.
2. Automated screen performed
3. Hits identified that make the
affected cells look more like the
unaffected cells (e.g. potential drugs,
also tool compounds for research)
4. Follow-up studies and
optimization are performed, which
often leads to new rounds of
modified drug library testing
Unaffected Affected