Urinary titin is not an early biomarker of skeletal muscle atrophy induced by muscle denervation in mice

Figures

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  Fig 1. The effects of muscle atrophy induced by denervation on muscle weight and titin expression levels. (A) The weight in the TA and SOL muscles of the CON and DEN groups on post-operative day 10. (B) Quantification of real-time PCR products for titin expression in the TA and SOL muscles of the CON and DEN groups on post-operative day 10. (C) Typical SDS-PAGE image showing titin level in the TA and SOL muscles of the CON and DEN groups. (D) Quantification of titin in the TA and SOL muscles of the CON and DEN groups on post-operative day 10. Data are presented as the means ± standard error of the mean (SEM). **p < 0.01 and ***p < 0.001 by an unpaired t-test.

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  Fig 2. The effects of muscle atrophy induced by denervation on the mRNA expression levels of muscle atrophy–related gene. Quantification of real-time polymerase chain reaction (PCR) products for MuRF1 (A), and atrogin-1 (B) expression in the TA and SOL muscles of the CON and DEN groups on post-operative day 10. Data are presented as means ± standard error of the mean (SEM). **p < 0.01 and ***p < 0.001 by an unpaired t-test.

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  Fig 3. The effects of muscle atrophy induced by denervation on urinary N-titin/Cr values. (A) Time course changes in urinary N-titin/Cr levels used #27602 Mouse Titin N-fragment Assay Kit. Open circles: CON group. Closed circles: DEN group. Data are presented as means ± standard error of the mean (SEM). **p < 0.01 (0 days vs. 1 day after the operation in the CON group) and ### < 0.001 (0 days vs. 1 day after the operation in the DEN group) by one-way repeated measures analysis of variance (ANOVA). (B) Urinary N-titin/Cr values in severe muscular dystrophy models. Values of urinary N-titin/Cr in wild-type and dKO mice. Data are presented as means ± standard error of the mean (SEM). n = 3/group. ***p < 0.001 by an unpaired t-test. (C) Time course changes in urinary N-titin/Cr levels used #SEB667 ELISA Kit. Open circles: CON group. Closed circles: DEN group. Data are presented as means ± standard error of the mean (SEM). (D) Urinary N-titin/Cr values in severe muscular dystrophy models. Values of urinary N-titin/Cr in wild-type and dKO mice. Data are presented as means ± standard error of the mean (SEM). n = 3/group. ***p < 0.001 by an unpaired t-test.

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  Fig 4. The effects of muscle atrophy induced by denervation on the stabilization of muscle membrane and expression levels of connexin 43. (A) Evans blue staining in the TA and SOL muscles of the CON and DEN groups on post-operative day 6. The TA muscle of mdx mice is shown as a positive control. Scale bar: 100 μm. (B) Immunohistochemical staining of connexin 43 in the TA and SOL muscles. Scale bar: 50 μm. (C) Western blot of connexin 43 in the TA muscle. The bar graph shows relative connexin levels compared to those of GAPDH. Data are presented as means ± standard error of the mean (SEM). n = 6/group. *p < 0.05 by an unpaired t-test.