Annual Report 2011 - Center for Advanced Biotechnology and ...

In the prior year, we have made considerable progress investigating late infantile
neuronal ceroid lipofuscinosis (LINCL), a recessive neurodenerative disease of
childhood that is due to deficiencies in the lysosomal protease tripeptidyl-peptidase 1
(TPP1). In one study, we performed mass spectrometric analyses on storage material
and lysosomal fractions from an LINCL mouse model. This revealed several
candidates for proteins stored in brain. In depth analysis of the most prominent of
these, glial fibrillary acidic protein, revealed that this protein represented a
contaminant that adventitiously associated with storage material and lysosomes during
the isolation procedure. We also used the mouse model to explore potential
therapeutic approaches and found that intrathecal administration of recombinant
human TPP1 resulted in significant delivery of enzyme to the brain. Importantly, this
treatment prolonged lifespan and improved decreased disease symptoms. Finally, in
collaboration with scientists at the University of Missouri and BioMarin Therapeutics,
as a step towards the clinic we conducted pilot enzyme replacement studies using an
LINCL dog model.
We are also continuing our investigation of the lysosomal proteome. Following the
principles of de Duve and colleagues that lead to the discovery of the lysosome, we
analyzed rat liver subcellular fractions using mass spectrometry to identify and
determine the distribution of different proteins. This led to the identification of
numerous candidate lysosomal proteins and provided further evidence that ABCB6 is
lysosomal and that superoxide dismutase 1 has a mixed cytoplasmic-lysosomal
localization.
Percent survival
100
50
0
1.2 mg/animal
0.38 mg/animal
0.12 mg/animal
0.038 mg/animal
vehicle
0 30 60 90 120 150 180
Time (days)
Acute intrathecal administration of recombinant human TPP1 extends lifespan of a
LINCL mouse model. Animals were administered the indicated dose of TPP1 at the
age of 28-30 days and then followed for survival.
Jennifer Wiseman
Research Teaching Spec.
Caifeng Zhao
Research Teaching Spec.
23