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Second-generation compound for the modulation of utrophin in the therapy of DMD.

Guiraud S, Squire SE, Edwards B, Chen H, Burns DT, Shah N, Babbs A, Davies SG, Wynne GM, Russell AJ, Elsey D, Wilson FX, Tinsley JM, Davies KE - Hum. Mol. Genet. (2015)

Bottom Line: These studies in the mdx mouse demonstrate that oral administration of SMT022357 leads to increased utrophin expression in skeletal, respiratory and cardiac muscles.This results in improved sarcolemmal stability and prevents dystrophic pathology through a significant reduction of regeneration, necrosis and fibrosis.This detailed evaluation of the SMT C1100 drug series strongly endorses the therapeutic potential of utrophin modulation as a disease modifying therapeutic strategy for all DMD patients irrespective of their dystrophin mutation.

View Article: PubMed Central - PubMed

Affiliation: Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK, simon.guiraud@dpag.ox.ac.uk kay.davies@dpag.ox.ac.uk.

No MeSH data available.


Related in: MedlinePlus

SMT022357 treatment results in a decrease in regeneration with no change in fibre type composition in the skeletal muscle. (A) Semi-quantitative RT-PCR demonstrates a decrease of skeletal muscle regeneration/myogenic differentiation markers Bex1, myogenin and cell cycle dependent-kinase inhibitors (CDKI) p21 and p27 from EDL of mdx mice dosed with SMT022357 (357, n = 8) compared to vehicle (Ve, n = 8). S13 ribosomal protein was used as an internal control for the RT-PCR. A 12% decrease in Bex1 (P = 0.034), 21% decrease in p21 (P = 0.002), 67% decrease in p27 (P < 0.001) and 64% decrease in Myogenin (P < 0.001) transcript levels were quantified by ImageJ software in SMT022357 group compared to vehicle. (B) Immunofluoresence staining for type 1a, 2a and 2b fibre types in the EDL of 7 weeks old mdx mice treated for 5 weeks with 30 mg/kg/day SMT022357 or vehicle (n = 6 per group). Sections were stained with anti-MYHC1, anti-MYHC2A anti-MYHC2B and anti-mouse secondary antibody. Percentage of type 1a, 2a and 2b fibre types was quantified by ImageJ software in the whole EDL muscle (n = 6 per group). No change was observed in fibre type composition of whole EDL muscle treated with SMT022357 compared to treatment with vehicle only. Scale bar: 100 µm.
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DDV154F3: SMT022357 treatment results in a decrease in regeneration with no change in fibre type composition in the skeletal muscle. (A) Semi-quantitative RT-PCR demonstrates a decrease of skeletal muscle regeneration/myogenic differentiation markers Bex1, myogenin and cell cycle dependent-kinase inhibitors (CDKI) p21 and p27 from EDL of mdx mice dosed with SMT022357 (357, n = 8) compared to vehicle (Ve, n = 8). S13 ribosomal protein was used as an internal control for the RT-PCR. A 12% decrease in Bex1 (P = 0.034), 21% decrease in p21 (P = 0.002), 67% decrease in p27 (P < 0.001) and 64% decrease in Myogenin (P < 0.001) transcript levels were quantified by ImageJ software in SMT022357 group compared to vehicle. (B) Immunofluoresence staining for type 1a, 2a and 2b fibre types in the EDL of 7 weeks old mdx mice treated for 5 weeks with 30 mg/kg/day SMT022357 or vehicle (n = 6 per group). Sections were stained with anti-MYHC1, anti-MYHC2A anti-MYHC2B and anti-mouse secondary antibody. Percentage of type 1a, 2a and 2b fibre types was quantified by ImageJ software in the whole EDL muscle (n = 6 per group). No change was observed in fibre type composition of whole EDL muscle treated with SMT022357 compared to treatment with vehicle only. Scale bar: 100 µm.

Mentions: Utrophin is up-regulated during regeneration in skeletal muscle (21). In order to study regeneration after treatment with SMT022357, the expression of different regeneration/myogenic differentiation markers (45) was analysed by semi-quantitative RT–PCR. A decrease in all these markers was noted in EDL muscles treated with SMT022357 (Fig. 3A), demonstrating that daily drug treatment for 5 weeks results in a reduction in regeneration and, importantly, that the increase of utrophin is independent of this process. This suggests that the higher levels of utrophin must be derived from drug treatment rather than regeneration. It is also well established that dystrophic muscle type I fibres present greater utrophin expression than type II fibres (36,46,47). Thus, we investigated the expression of type I, IIa and IIb myosin heavy chains in EDL muscle. No change in fibre-type composition was noted after treatment with SMT022357 (Fig. 3B), supporting the fact that SMT022357 increases the utrophin expression in both fast-twitch (type II) and slow-twitch (type I) fibres.Figure 3.


Second-generation compound for the modulation of utrophin in the therapy of DMD.

Guiraud S, Squire SE, Edwards B, Chen H, Burns DT, Shah N, Babbs A, Davies SG, Wynne GM, Russell AJ, Elsey D, Wilson FX, Tinsley JM, Davies KE - Hum. Mol. Genet. (2015)

SMT022357 treatment results in a decrease in regeneration with no change in fibre type composition in the skeletal muscle. (A) Semi-quantitative RT-PCR demonstrates a decrease of skeletal muscle regeneration/myogenic differentiation markers Bex1, myogenin and cell cycle dependent-kinase inhibitors (CDKI) p21 and p27 from EDL of mdx mice dosed with SMT022357 (357, n = 8) compared to vehicle (Ve, n = 8). S13 ribosomal protein was used as an internal control for the RT-PCR. A 12% decrease in Bex1 (P = 0.034), 21% decrease in p21 (P = 0.002), 67% decrease in p27 (P < 0.001) and 64% decrease in Myogenin (P < 0.001) transcript levels were quantified by ImageJ software in SMT022357 group compared to vehicle. (B) Immunofluoresence staining for type 1a, 2a and 2b fibre types in the EDL of 7 weeks old mdx mice treated for 5 weeks with 30 mg/kg/day SMT022357 or vehicle (n = 6 per group). Sections were stained with anti-MYHC1, anti-MYHC2A anti-MYHC2B and anti-mouse secondary antibody. Percentage of type 1a, 2a and 2b fibre types was quantified by ImageJ software in the whole EDL muscle (n = 6 per group). No change was observed in fibre type composition of whole EDL muscle treated with SMT022357 compared to treatment with vehicle only. Scale bar: 100 µm.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4492389&req=5

DDV154F3: SMT022357 treatment results in a decrease in regeneration with no change in fibre type composition in the skeletal muscle. (A) Semi-quantitative RT-PCR demonstrates a decrease of skeletal muscle regeneration/myogenic differentiation markers Bex1, myogenin and cell cycle dependent-kinase inhibitors (CDKI) p21 and p27 from EDL of mdx mice dosed with SMT022357 (357, n = 8) compared to vehicle (Ve, n = 8). S13 ribosomal protein was used as an internal control for the RT-PCR. A 12% decrease in Bex1 (P = 0.034), 21% decrease in p21 (P = 0.002), 67% decrease in p27 (P < 0.001) and 64% decrease in Myogenin (P < 0.001) transcript levels were quantified by ImageJ software in SMT022357 group compared to vehicle. (B) Immunofluoresence staining for type 1a, 2a and 2b fibre types in the EDL of 7 weeks old mdx mice treated for 5 weeks with 30 mg/kg/day SMT022357 or vehicle (n = 6 per group). Sections were stained with anti-MYHC1, anti-MYHC2A anti-MYHC2B and anti-mouse secondary antibody. Percentage of type 1a, 2a and 2b fibre types was quantified by ImageJ software in the whole EDL muscle (n = 6 per group). No change was observed in fibre type composition of whole EDL muscle treated with SMT022357 compared to treatment with vehicle only. Scale bar: 100 µm.
Mentions: Utrophin is up-regulated during regeneration in skeletal muscle (21). In order to study regeneration after treatment with SMT022357, the expression of different regeneration/myogenic differentiation markers (45) was analysed by semi-quantitative RT–PCR. A decrease in all these markers was noted in EDL muscles treated with SMT022357 (Fig. 3A), demonstrating that daily drug treatment for 5 weeks results in a reduction in regeneration and, importantly, that the increase of utrophin is independent of this process. This suggests that the higher levels of utrophin must be derived from drug treatment rather than regeneration. It is also well established that dystrophic muscle type I fibres present greater utrophin expression than type II fibres (36,46,47). Thus, we investigated the expression of type I, IIa and IIb myosin heavy chains in EDL muscle. No change in fibre-type composition was noted after treatment with SMT022357 (Fig. 3B), supporting the fact that SMT022357 increases the utrophin expression in both fast-twitch (type II) and slow-twitch (type I) fibres.Figure 3.

Bottom Line: These studies in the mdx mouse demonstrate that oral administration of SMT022357 leads to increased utrophin expression in skeletal, respiratory and cardiac muscles.This results in improved sarcolemmal stability and prevents dystrophic pathology through a significant reduction of regeneration, necrosis and fibrosis.This detailed evaluation of the SMT C1100 drug series strongly endorses the therapeutic potential of utrophin modulation as a disease modifying therapeutic strategy for all DMD patients irrespective of their dystrophin mutation.

View Article: PubMed Central - PubMed

Affiliation: Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford OX1 3PT, UK, simon.guiraud@dpag.ox.ac.uk kay.davies@dpag.ox.ac.uk.

No MeSH data available.


Related in: MedlinePlus