Fig. 6

The in vivo effect of MMP7 on myelin sheath structure. a and b Representative transmission electron microscopy images of myelinated nerve fibers in the normal sciatic nerve. c and d Representative transmission electron microscopy images of myelinated nerve fibers in the sciatic nerve segments of rats treated with saline at 14 days after crush injury. e and f Representative transmission electron microscopy images of myelinated nerve fibers in the sciatic nerve segments of rats treated with MMP7 recombinant protein at 14 days after crush injury. Scale bars in (a, c, and e) represented 10 μm while scale bars in (b, d, and f) represented 200 nm. g Histogram of g-ratio (axon diameter to nerve fiber diameter) in rats injected with saline or MMP7 recombinant protein. Asterisk indicated significant different from saline control, ** p-value < 0.01, *** p-value < 0.001, n = 3