Combination Treatment of C16 Peptide and Angiopoietin-1 Alleviates Neuromyelitis Optica in an Experimental Model

Figure 6

Electron micrograph demonstrating the prevention of perivascular edema, demyelination/axon loss, and neuronal apoptosis in the C + A-treated groups. (a, f, k) In control rats, the normal myelinated axons exhibited dark, ring-shaped myelin sheaths surrounding axons in both the optic nerve (a) and the white matter of the spinal cord (f); normal neuronal nuclei showed uncondensed chromatin (k). (b, g, l) Vehicle-treated NMO rats at 1 week pi. (b, g) Myelin sheath displaying splitting, vacuoles, and loose and fused changes, with atrophied axons (white arrow in b). (l) Apoptotic neuron with a shrunken nucleus and condensed and fragmented and margination of nuclear chromatin. (c, h, m) Meanwhile, in the C + A-treated rats, myelin sheath splitting and axonal loss were reduced. (d, i, n) At 8 weeks pi, more myelin sheaths were undergoing vesicular disintegration and demyelination, both in the optic nerve (d) and in the white matter of the spinal cord (i). Very severe tissue edema and apoptotic neurons with shrunken nuclei were found (n). In contrast, in the C + A-treated rats, more myelin sheaths surrounding intact axons were observed (e, j), while the morphology of the nucleus was relatively normal (o). (a–e) Scale bar = 0.5 μm. (f–j) Scale bar = 1 μm. (k–o) Scale bar = 2 μm. (a–e) Transverse sections through the optic nerve. (f–o) Transverse sections through the anterior horn of the lumbar spinal cord.

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