Fig. 2.

Deletion of NLRP3 attenuates muscle loss, reduces myopathy, and improves muscle function in mice. WT and NLRP3^−/− mice were aged to 10 (adult) and 24 mo (old). A: %change in mass of tibialis anterior (TA), extensor digitorum longus (EDL), and soleus muscles between adult and old WT and NLRP3^−/− mice were calculated relative to body mass and heart mass. B: representative micrographs of hematoxylin and eosin-stained transverse sections from TA muscle in adult and old WT and NLRP3^−/− mice. Scale bar, 250 μm. Inset images of micrographs from 24-mo-old mice shown on the right. C: quantification of changes in mean cross-sectional area (CSA) of TA muscles between 10- and 24-mo-old WT and NLRP3^−/− mice. D: representative immunofluorescence micrographs of TA muscles labeled for type IIB (red), type IIX (unstained), and type IIA (green) myofibers. Scale bar, 200 μm. Inset images of micrographs from 24-mo-old mice shown on the right. E: quantification of the mean CSA changes between 10- and 24-mo-old WT and NLRP3^−/− mice within each fiber type. F: quantification of myopathic fibers in adult and old WT mice. G: quantification of myopathic fibers in adult and old NLRP3^−/−mice. H: quantification of relative muscle strength and endurance using latency to fall during a wire hang test. All data are means ± SE, and individual data points represent separate mice; n = 10–11 WT mice; n = 9–12 NLRP3^−/− mice. Statistical analyses were performed using Student’s t-test. *P < 0.05.