Journal: Skeletal Muscle

Article Title: Complement-independent pathogenic influences of anti-HMGCR + and anti-SRP + immune-mediated necrotizing myopathy autoantibodies on engineered muscle function

doi: 10.1186/s13395-025-00400-7

Figure Lengend Snippet: IMNM autoantibodies induce hMMT myotube atrophy. A Representative 40x confocal images of myotubes formed in hMMTs within each condition immunostained for sarcomeric α-actinin (SAA, magenta) and counterstained with Hoechst 33,342 (cyan). Scale bar = 50 μm. B Dot plot of hMMT nuclear fusion index for individual hMMTs. C Dot plot of mean SAA positive coverage within flattened confocal stack images for individual hMMTs. D Dot plot of myotube width variation as quantified by the coefficient of variance for single myotubes. n = 146 for (+) and (-) healthy IgG, n = 138 for Ceri, n = 524 for anti-HMGCR, and n = 550 for anti-SRP. E Histogram illustrating myotube diameter frequency across treatment conditions. F Dot plot showing average myotube diameter for individual hMMTs. N = 7 patients for anti-HMGCR + and N = 7 for anti-SRP + IgG treatments. Cerivastatin (Ceri, 75 nM) treatment served as a positive control and no added IgG (-) or Healthy IgG treatment served as negative controls. n = 3 hMMTs per treatment condition. Samples were tested across N = 2 independent experiments which are distinguished in graphs by circle and triangle datapoints. Data for hMMTs treated with total IgGs are binned according to whether they induced a direct contractile effect (DCE; HP2-4 and SP5) or no contractile effect (NCE; HP1, 5–7 and SP1-4, 6, 7) on hMMT force production as indicated by the data in Fig. . All values are reported as means \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\:\pm\:$$\end{document} SEM; * p < 0.05,** p < 0.01, *** p < 0.001, and **** p < 0.0001

Article Snippet: Immortalized 2D myotube after seeding growth media , Skeletal Muscle Cell Basal Medium (Cat. #C-23260, Promo-Cell), 20% FBS, 1% P/S.

Techniques: Positive Control

Journal: Skeletal Muscle

Article Title: Complement-independent pathogenic influences of anti-HMGCR + and anti-SRP + immune-mediated necrotizing myopathy autoantibodies on engineered muscle function

doi: 10.1186/s13395-025-00400-7

Figure Lengend Snippet: Sarcomere structures are disrupted after mechanical load. A Left panel shows a representative 40x confocal image of hMMT myotubes post electrical field stimulation immunostained for sarcomeric α-actinin (SAA, magenta) and f-actin (actin, yellow) which corresponds to the input for the ZlineDetection program. Scale bar = 50 μm. Middle panel shows a corresponding output from the ZLineDetection program with a further zoom in (right panel) to illustrate the retention of striations following a mechanical load under control conditions. B - E Dot plots of mean ( B ) Z-lines per image, ( C ) continuous Z-line length, ( D ) sarcomere length, and ( E ) orientation order parameter (OOP). N = 7 patients for anti-HMGCR + and N = 7 patients for anti-SRP + IgG treatments. Cerivastatin (Ceri, 75 nM) treatment served as a positive control and no added IgG (-) or Healthy IgG treatment served as negative controls. n = 3 hMMTs per treatment condition. Samples were tested across N = 2 independent experiments which are distinguished in graphs by circle and triangle datapoints. Data for hMMTs treated with total IgGs are binned according to whether they induced a direct contractile effect (DCE; HP2-4 and SP5) or no contractile effect (NCE; HP1, 5–7 and SP1-4, 6, 7) on hMMT force production as indicated by the data in Fig. . All values are reported as means \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\:\pm\:$$\end{document} SEM; * p ≤ 0.05

Article Snippet: Immortalized 2D myotube after seeding growth media , Skeletal Muscle Cell Basal Medium (Cat. #C-23260, Promo-Cell), 20% FBS, 1% P/S.

Techniques: Control, Positive Control

Journal: Skeletal Muscle

Article Title: Complement-independent pathogenic influences of anti-HMGCR + and anti-SRP + immune-mediated necrotizing myopathy autoantibodies on engineered muscle function

doi: 10.1186/s13395-025-00400-7

Figure Lengend Snippet: IMNM patient autoantibodies enter immortalized myoblast-derived myotubes in 2-D culture. A Representative z-projection (far right image) and single confocal slices (far left and middle images) of an immortalized myoblast-derived myotube in 2-D culture that was treated with total IgG from a healthy donor or an IMNM patient with HMGCR+ (HP4) or SRP+ (SP5) autoantibodies and then immunostained for anti-human IgG (magenta), sarcomeric α-actinin (SAA, cyan) and a Hoechst nuclear counterstain (gray). Scale bar = 20 μm. B Dot plot displaying mean human IgG immunostaining intensity quantified for individual regions of interest in immortalized myoblast-derived myotubes treated with total IgGs. N = 7 patients for anti-HMGCR + IgG treatments (anti-HMGCR Patient 1 [HP1], anti-HMGCR Patient 2 [HP2], and anti-HMGCR Patient 3 [HP3] and so on) and N = 7 patients for anti-SRP + IgG treatments (anti-SRP Patient 1 [SP1], anti-SRP Patient 2 [SP2], and anti-SRP Patient 3 [SP3] and so on). All values are reported as means \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\:\pm\:$$\end{document} SEM; ** p < 0.01 and **** p < 0.0001

Article Snippet: Immortalized 2D myotube after seeding growth media , Skeletal Muscle Cell Basal Medium (Cat. #C-23260, Promo-Cell), 20% FBS, 1% P/S.

Techniques: Derivative Assay, Immunostaining