1) Researchers generated a mouse model of Adult Polyglucosan Body Disease (APBD) with a Y329S mutation to further study the disease and test potential treatments. 2) Initial results found that mice with the Y329S mutation developed polyglucosan bodies in the liver, brain, and muscle and lived longer than a related knockout mouse model. 3) A high-throughput drug screen identified 15 FDA-approved compounds that decreased polyglucosan content in cell cultures, and further testing is being done to validate these potential drug candidates. 4) Improved diagnostic techniques for APBD are also being developed, including GBE enzyme assays and RNA sequencing to identify genetic changes underlying the condition.

1. 2013 Research Update
APBDRF
H. Orhan AKMAN, PhD
Dr. DiMauro’s Laboratory
Columbia University Medical Center
Department of Neurology
New York

2. Adult Polyglucosan Body Disease
Diagnosis, and Development of tools for Research and Treatment
Mouse model of APBD
Possible Pharmacological
Treatments of APBD
Diagnosis of Manifesting
Heterozygote Patients

3. Mouse model of APBD with Y329S
mutation
Generation of mouse model of APBD:
Y329S TAT to TCT
Tyr
Ser
FRT
LoxP
5’ ARM 2.1 kb
5’ ARM
Exon 7
Exon 7
PGK- Neomycin
3’ARM 6.5 kb
3’ARM

4. Breeding scheme and expected
genotypes
Y329S TAT to TCT
Tyr
Ser
FRT
LoxP
5’ ARM 2.1 kb
5’ ARM
1
Exon 7
PGK-Neomycin
3’ARM 6.5 kb
3’ARM
Exon 7
2
1

5. Expected & other genotypes
Y329S-Neo
5’
Exon 7
PGK-Neomycin
3’
Exon 7
PGK-Neomycin
3’
WT-Neo
5’
Y329S
5’
Exon 7
3’
Exon 7
3’
WT-lox
5’
Exon-7 del or D
5’
3’

6. Polyglucosan can be used in the liver
during fasting

7. Polyglucosan can be used in the liver
during fasting

8. Difference between Gbe1Y329S and
Gbe1neo/neo mice
Gbe1+/+
Gbe1neo/neo
Percent
change
Percent
change
Gbe1ys/ys
Brain
230 ± 17
25 ± 8
11%
41± 9
n=4
17.8%
Heart
457 ± 56
72 ± 34
16%
92± 21
n=4
20.1%
Liver
855 ± 43
115 ± 42
13%
210± 35
n=4
24.6%
38 ± 18
15%
ND
Muscle 251 ± 23
n=4
ND

9. Gbe1Y329S mice live longer than
Gbe1neo/neo mice

10. Gbe1Y329S mice has polyglucosan in the
liver
PAS
Diastase-PAS

11. Muscle
PAS
Diastase-PAS

12. Brain
30 days old mice
PAS
Diastase-PAS

13. Cerebellum
30 days old mice
PAS
Diastase-PAS

14. Brain 4 month old mice
PAS
Diastase-PAS

15. Brain 4 month old mice Gbe1ys-neo
PAS
Diastase-PAS

16. High throughput screening
We have tested 1700 FDA approved
compounds.
Analysis has yield 15 compounds decreasing
PGB content in tissue culture

17. Control
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
Relative Glycogen Content
(microgram/mg protein)
Validation of 15 HTS hits
5.0
4.0
3.0
2.0
1.0
0.0

18. Treatment with Guaiacol
YS untreated
YS treated
PAS
Diastase-PAS

19. Quantification of glycogen in tissues

20. Diagnosis of APBD
GBE enzyme assay
Histologic examination of
sural nerve biopsy
Sequencing genomic DNA
and messenger RNA.

21. Sequencing mRNA Proof of second
genetic change

22. Search for the genetic change that
eliminates the normal allele
12 to 15
14 to 16
C P1 P2 P3 C
1 to 6
C P1 P2 P3 C
5 to 10
9 to 14

23. THANK YOU
Salvatore DiMauro, MD
Sindu Krishna, PhD
Pablo Abreu
Michio Hirano, MD
Valentina Emmanuelle, MD
Carmen Paradas, MD
Sergey Pompou, MD