Identifying modifiers of CLN3 disease

1. CLN3
Iden*fying
modifiers
of
CLN3
disease
Susan
L.
Cotman,
Ph.D.
(Principal
Inves*gator),
Uma
Chandrachud,
Ph.D.,
Elisabeth
Butz,
Ph.D.,
Abigail
Nowell,
Madeline
C.
Klein
Center
for
Genomic
Medicine,
Department
of
Neurology,
MassachuseMs
General
Hospital,
Harvard
Medical
School
Introduc)on
! A
‘disease
modifier’
is
something
that
either
worsens
or
improves
the
disease.
! A
disease
modifier
that
improves
the
disease
could
be
developed
into
a
drug.
! A
disease
modifier
that
worsens
the
disease
can
lead
to
the
iden*fica*on
of
a
new
‘drug
target’
that
could
be
modulated
in
the
opposite
direc*on,
for
posi*ve
disease-­‐modifying
effects
! Few
drug
targets
for
CLN3
disease
have
been
sufficiently
tested
! We
are
taking
several
different
approaches
to
iden*fying
candidate
modifiers
for
CLN3
disease,
including:
1) cell-­‐based
drug
screening
2) mouse
gene*cs
3) cell-­‐based
gene*c
screening
! By
iden*fying
and
valida*ng
a
disease
modifier
in
mouse
and
human
cell
model
systems,
we
can
establish
the
needed
‘proof-­‐of-­‐concept’
data
to
facilitate
further
drug
development
around
these
disease
modifier
targets
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. Our disease modifier studies have been supported by 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, Batten Disease Research, Beyond Batten Disease Foundation, Beat Batten, and the Jacobson Family Fund.
Our
model
systems
for
CLN3
disease
modifier
research
Cln3∆ex7/8
mice
have
been
engineered
to
carry
the
same
muta*on
found
in
many
affected
children,
known
as
the
‘common
1-­‐kb
dele*on’.
CLN3
disease
characteris*cs
have
been
well
established
in
these
mice.
DNA
changes
elsewhere
in
the
genome
can
cause
the
CLN3
disease
process
to
move
more
quickly
or
slowly
(=‘gene*c
modifiers’).
Iden*fying
these
DNA
changes
that
alter
disease
course
can
lead
to
new
candidate
drug
targets
and
treatments.
Pre-­‐clinical
‘efficacy’
studies
can
be
carried
out
in
this
system
for
any
candidate
drug
treatment.
Brain-­‐derived
cell
lines
were
established
from
Cln3∆ex7/8
mice
(‘CbCln3∆ex7/8
neuronal
cells’)
and
shown
to
model
early-­‐stage
pathological
features
of
CLN3
disease.
In
addi*on
to
helping
us
beMer
understand
the
chronology
of
events
in
the
CLN3
disease
process,
these
cell
lines
can
be
used
to
screen
drug
libraries
and
‘gene
knockout’
libraries
to
iden*fy
new
candidate
drugs
or
drug
targets,
respec*vely.
The
benefit
of
using
these
cell
lines
is
that
they
model
both
the
known
disease
gene*cs
and
cell
type
most
affected.
They
are
also
rela*vely
easy
to
work
with
in
a
laboratory
sebng,
making
them
useful
for
larger-­‐
scale
library
screening
approaches.
Skin
biopsy
samples
can
be
turned
into
‘induced
pluripotent
stem
cells’
(iPSC)
by
a
process
known
as
cellular
reprogramming.
We
and
others
have
generated
mul*ple
iPSC
lines
from
CLN3
pa*ents
and
unaffected
rela*ves.
These
cells
can
be
turned
into
almost
any
type
of
cell
we
want
to
study,
including
brain
or
heart
cells.
This
allows
us
to
study
the
human
cell
biology
of
CLN3
disease
in
the
laboratory.
This
is
considered
by
some
to
be
the
best
model
system
for
preclinical
tes*ng
of
candidate
drugs
or
disease
treatments,
because
the
disease-­‐causing
muta*on
and
the
rest
of
the
genomic
background
are
that
of
human
CLN3
pa*ents.
These
cell
lines
can
be
used
in
both
screening
and
candidate
drug/treatment
tes*ng
approaches,
complemen*ng
the
use
of
the
mouse
model
systems.
Examples
of
candidate
modifier
tes)ng
using
Cln3∆ex7/8
mice
and
classical
mouse
gene)cs
Do
muta*ons
in
other
NCL
genes
modify
disease?
Does
loss
of
a
gene
involved
in
lysosomal
Ca2+
regula*on
modify
CLN3
disease?
Conclusions
! Iden*fying
disease
modifiers
will
provide
new
avenues
to
disease
therapies.
! We
are
currently
working
in
several
areas
to
iden*fy
candidate
disease
modifiers
for
CLN3
disease
! Recent
progress
strongly
supports
further
efforts
in
targe*ng
lysosomal
Ca2+
channels,
which
could
ul*mately
lead
to
new
drugs
for
tes*ng
in
CLN3
disease
human
clinical
trials
! Lysosomal
Ca2+
channels
are
of
interest
as
candidate
disease
targets
in
other
forms
of
NCL
as
well,
and
in
more
common
late-­‐onset
neurodegenera*ve
diseases;
therefore,
this
work
is
likely
to
have
impact
for
CLN3
and
other
forms
of
NCL
and
neurodegenera*ve
disease
Collaborators on CLN3 disease modifier research projects:
Dr. Emyr Lloyd-Evans (Cardiff University, Wales), Dr. Christian Grimm (Munich), Dr. Yulia Grishchuk (Mass General/Harvard Medical School), Dr. Marco Sardiello (Baylor College of Medicine),
Dr. Luk Vandenberghe (Mass Eye and Ear/Harvard Medical School)
Cln3∆ex7/8 mice
Cln6nclf mice
Cln3∆ex7/8 mice
Mcoln1ko mice
Wildtype
Cln3 mutant
Mcoln1 mutant
Double mutant
YES-The double mutant is more severely affected than the Cln3 single
mutant animal (and the Mcoln1 single mutant); this indicates a
modifying effect of the other lysosomal gene’s loss of function and
suggests these genes function in converging pathways
NO-The double mutant is only as affected as the Cln6 single mutant; this
supports the notion that these genes function in a common pathway, with
Cln6 functioning upstream of Cln3
Cln3 mutant
Cln6 mutant
Double mutant