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Antisense Oligonucleotide-mediated Suppression of Muscle Glycogen Synthase 1 Synthesis as an Approach for Substrate Reduction Therapy of Pompe Disease.

Clayton NP, Nelson CA, Weeden T, Taylor KM, Moreland RJ, Scheule RK, Phillips L, Leger AJ, Cheng SH, Wentworth BM - Mol Ther Nucleic Acids (2014)

Bottom Line: GS-PPMO systemic administration to Pompe mice led to a dose-dependent decrease in glycogen synthase transcripts in the quadriceps, and the diaphragm but not the liver.Associated with these decreases in transcript levels were correspondingly lower tissue levels of muscle specific glycogen synthase and activity.Importantly, these reductions resulted in significant decreases in the aberrant accumulation of lysosomal glycogen in the quadriceps, diaphragm, and heart of Pompe mice.

View Article: PubMed Central - PubMed

Affiliation: Genzyme, A Sanofi Company, Framingham, Massachusetts, USA.

ABSTRACT
Pompe disease is an autosomal recessive disorder caused by a deficiency of acid α-glucosidase (GAA; EC 3.2.1.20) and the resultant progressive lysosomal accumulation of glycogen in skeletal and cardiac muscles. Enzyme replacement therapy using recombinant human GAA (rhGAA) has proven beneficial in addressing several aspects of the disease such as cardiomyopathy and aberrant motor function. However, residual muscle weakness, hearing loss, and the risks of arrhythmias and osteopenia persist despite enzyme therapy. Here, we evaluated the relative merits of substrate reduction therapy (by inhibiting glycogen synthesis) as a potential adjuvant strategy. A phosphorodiamidate morpholino oligonucleotide (PMO) designed to invoke exon skipping and premature stop codon usage in the transcript for muscle specific glycogen synthase (Gys1) was identified and conjugated to a cell penetrating peptide (GS-PPMO) to facilitate PMO delivery to muscle. GS-PPMO systemic administration to Pompe mice led to a dose-dependent decrease in glycogen synthase transcripts in the quadriceps, and the diaphragm but not the liver. An mRNA response in the heart was seen only at the higher dose tested. Associated with these decreases in transcript levels were correspondingly lower tissue levels of muscle specific glycogen synthase and activity. Importantly, these reductions resulted in significant decreases in the aberrant accumulation of lysosomal glycogen in the quadriceps, diaphragm, and heart of Pompe mice. Treatment was without any overt toxicity, supporting the notion that substrate reduction by GS-PPMO-mediated inhibition of muscle specific glycogen synthase represents a viable therapeutic strategy for Pompe disease after further development.

No MeSH data available.


Related in: MedlinePlus

Serum chemistries of Pompe mice treated with GS-PPMO compared to control animals. (a–f) Levels of ALT, AST, LDH, CK, BUN, or CK in serum collected 24 hours after the final dose. Data represent mean ± SEM, n = 9–10 mice per group as indicated in the Materials and Methods. P < 0.05, (*) compared to WT, (^) compared to vehicle.
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fig6: Serum chemistries of Pompe mice treated with GS-PPMO compared to control animals. (a–f) Levels of ALT, AST, LDH, CK, BUN, or CK in serum collected 24 hours after the final dose. Data represent mean ± SEM, n = 9–10 mice per group as indicated in the Materials and Methods. P < 0.05, (*) compared to WT, (^) compared to vehicle.

Mentions: We also investigated the potential toxicologic impact of GS-PPMO treatment and knockdown of GYS1 mRNA to assess the therapeutic index associated with administering this particular type of antisense oligonucleotide for Pompe disease. Pompe mice treated with either dose of GS-PPMO did not demonstrate significant differences in weight gain from mice in the control cohort (Figure 5). Examination of blood biomarkers of liver, muscle, and kidney damage also did not reveal any deviations from those noted in control mice (Figure 6a–f). Finally, histological analysis of the kidney and liver of GS-PPMO-treated Pompe mice revealed normal architecture and the absence of discernible lesions (Figure 7). These data suggest that systemic administration of GS-PPMO is well tolerated, at the doses tested.


Antisense Oligonucleotide-mediated Suppression of Muscle Glycogen Synthase 1 Synthesis as an Approach for Substrate Reduction Therapy of Pompe Disease.

Clayton NP, Nelson CA, Weeden T, Taylor KM, Moreland RJ, Scheule RK, Phillips L, Leger AJ, Cheng SH, Wentworth BM - Mol Ther Nucleic Acids (2014)

Serum chemistries of Pompe mice treated with GS-PPMO compared to control animals. (a–f) Levels of ALT, AST, LDH, CK, BUN, or CK in serum collected 24 hours after the final dose. Data represent mean ± SEM, n = 9–10 mice per group as indicated in the Materials and Methods. P < 0.05, (*) compared to WT, (^) compared to vehicle.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4217081&req=5

fig6: Serum chemistries of Pompe mice treated with GS-PPMO compared to control animals. (a–f) Levels of ALT, AST, LDH, CK, BUN, or CK in serum collected 24 hours after the final dose. Data represent mean ± SEM, n = 9–10 mice per group as indicated in the Materials and Methods. P < 0.05, (*) compared to WT, (^) compared to vehicle.
Mentions: We also investigated the potential toxicologic impact of GS-PPMO treatment and knockdown of GYS1 mRNA to assess the therapeutic index associated with administering this particular type of antisense oligonucleotide for Pompe disease. Pompe mice treated with either dose of GS-PPMO did not demonstrate significant differences in weight gain from mice in the control cohort (Figure 5). Examination of blood biomarkers of liver, muscle, and kidney damage also did not reveal any deviations from those noted in control mice (Figure 6a–f). Finally, histological analysis of the kidney and liver of GS-PPMO-treated Pompe mice revealed normal architecture and the absence of discernible lesions (Figure 7). These data suggest that systemic administration of GS-PPMO is well tolerated, at the doses tested.

Bottom Line: GS-PPMO systemic administration to Pompe mice led to a dose-dependent decrease in glycogen synthase transcripts in the quadriceps, and the diaphragm but not the liver.Associated with these decreases in transcript levels were correspondingly lower tissue levels of muscle specific glycogen synthase and activity.Importantly, these reductions resulted in significant decreases in the aberrant accumulation of lysosomal glycogen in the quadriceps, diaphragm, and heart of Pompe mice.

View Article: PubMed Central - PubMed

Affiliation: Genzyme, A Sanofi Company, Framingham, Massachusetts, USA.

ABSTRACT
Pompe disease is an autosomal recessive disorder caused by a deficiency of acid α-glucosidase (GAA; EC 3.2.1.20) and the resultant progressive lysosomal accumulation of glycogen in skeletal and cardiac muscles. Enzyme replacement therapy using recombinant human GAA (rhGAA) has proven beneficial in addressing several aspects of the disease such as cardiomyopathy and aberrant motor function. However, residual muscle weakness, hearing loss, and the risks of arrhythmias and osteopenia persist despite enzyme therapy. Here, we evaluated the relative merits of substrate reduction therapy (by inhibiting glycogen synthesis) as a potential adjuvant strategy. A phosphorodiamidate morpholino oligonucleotide (PMO) designed to invoke exon skipping and premature stop codon usage in the transcript for muscle specific glycogen synthase (Gys1) was identified and conjugated to a cell penetrating peptide (GS-PPMO) to facilitate PMO delivery to muscle. GS-PPMO systemic administration to Pompe mice led to a dose-dependent decrease in glycogen synthase transcripts in the quadriceps, and the diaphragm but not the liver. An mRNA response in the heart was seen only at the higher dose tested. Associated with these decreases in transcript levels were correspondingly lower tissue levels of muscle specific glycogen synthase and activity. Importantly, these reductions resulted in significant decreases in the aberrant accumulation of lysosomal glycogen in the quadriceps, diaphragm, and heart of Pompe mice. Treatment was without any overt toxicity, supporting the notion that substrate reduction by GS-PPMO-mediated inhibition of muscle specific glycogen synthase represents a viable therapeutic strategy for Pompe disease after further development.

No MeSH data available.


Related in: MedlinePlus