Fig. 4. NFAT5 regulates myofiber formation during muscle regeneration in vivo. (A) Cells were isolated from the TA muscles of wild-type (+/+) and NFAT5^+/- mice 3 days following injury and analyzed for Mac-1 expression by flow cytometry. Similar percentages of Mac-1⁺ macrophages were observed in regenerating muscle from wild-type (+/+) and NFAT5^+/- mice. (B) TA sections obtained from wild-type(+/+) and NFAT5^+/- mice were stained with hematoxylin and eosin 5 and 14 days following injury. Bar, 50 µm. (C) The number of regenerating TA myofibers per field was reduced in NFAT5^+/- mice 5 days (^*P<0.05) but not 14 days following injury. (D) The XSA of regenerating TA myofibers was similar in both wild-type (+/+) and NFAT5^+/- mice 5 days following injury but decreased in NFAT5^+/- mice 14 days following injury. (E) Myofiber number was similar in uninjured soleus muscles of both wild-type (+/+) and NFAT5^+/- mice. All data are mean ± s.e.m., n=4-8 for each genotype.