FIGURE 6.

BM cells from WT mice could rescue the impaired muscle regeneration of IL-6^−/− mice. IL-6^−/− mice were injected WT BM cells (2 × 10⁷ cells/mice), and TA muscles were injected with cardiotoxin (CTX). A and B, the inflammatory response in injured muscle (at day 1 and day 3 after injury) was examined by immunostaining with anti-Mac-2 (A, brown) or inducible NO synthase (B, brown) antibody, nuclei were stained by hematoxylin (blue). Scale bars, 50 μm (n = 3 in each group). C, At 5 days after injury, the mRNA expression levels of MyoD and myogenin were assessed by qRT-PCR (n = 3 in each group). D, At 15 days after injury, H&E (left) and laminin (right)-stained muscle from IL-6^−/− and IL-6^−/− with WT BM cells mice (n = 3 in each group) were examined. Scale bars, 50 μm. The right graph indicated the mean cross-sectional area (CSA) of muscle myofiber in each group. *, p < 0.05, compared with IL-6^−/− values. BM, bone marrow.