Figure 7. Skeletal muscle-targeted LRRC8A deletion impairs muscle endurance, force generation and insulin-stimulated oxygen consumption.

(A) Exercise treadmill tolerance test for KO mice (n = 14) compared to WT littermates (n = 15). (B) Hang times on inversion testing of KO (n = 8) and WT (n = 9) mice. (C–E) Ex vivo isometric peak tetanic tension (C), time to fatigue (D) and half relaxation time (E) of isolated soleus muscle from KO (n = 7) compared to WT (n = 7) mice. (F) Oxygen consumption rate (OCR) in WT and Lrrc8a KO primary myotubes +/- insulin stimulation (10 nM) (n = 6 independent experiments) and quantification of basal OCR, OCR post-Oligomycin, OCR post-FCCP and OCR post-Antimycin A. (G) ATP‐linked respiration obtained by subtracting the OCR after oligomycin from baseline cellular OCR. (H) Extracellular acidification rate (ECAR) in WT and Lrrc8a KO primary myotubes +/- insulin stimulation (10 nM) (n = 6 independent experiments) and quantification of basal OCR, OCR-post Oligomycin, OCR-post FCCP and OCR post-Antimycin A. Statistical significance between the indicated values were calculated using a two-tailed Student’s t-test. Error bars represent mean ± s.e.m. *, p<0.05, **, p<0.01, ***, p<0.001, ****, p<0.0001.

Figure 7—figure supplement 1. Quantification of skeletal muscle fiber type in WT and Skm KO TA muscle.

TA muscles of WT and Skm KO were sectioned and immunostained with myosin heavy chains (MHC) isoforms Type I (red), Type IIa (blue), Type IIx (black), Type IIb (green) and Laminin (Gray). Scale bar: 100 µm. Mean percentage of fibers expressing MHC Type I, Type IIa, Type IIx, Type IIb and Laminin relative to total number of fibers in a TA muscle sections of WT (n = 4) and Skm KO (n = 4) mice (right).

Figure 7—figure supplement 2. Lrrc8a ablation in C2C12 myotubes downregulates glucose and glycogen-associated genes.

Differentially expressed glucose and glycogen metabolism-associated gene after RNA-seq analysis of C2C12 WT and Lrrc8a KO myotube (n = 3, each). Statistical significance between the indicated values were calculated using a two-tailed Student’s t-test. Error bars represent mean ± s.e.m. *, p<0.05, **, p<0.01, ***, p<0.001, ****, p<0.0001.

Figure 7—video 1. Exercise Treadmill Testing of WT and Myf5-Cre/ SWELL1flflmice.

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