c-Jun expression in human neuropathies: a pilot study.

Schwann cell dedifferentiation following nerve injury is important to permit neural survival and axonal regrowth. Animal studies have shown that the transcription factor c-Jun is upregulated in Schwann cells of injured and pathological nerves where it acts as an important regulator of Schwann cell plasticity, promoting dedifferentiation and demyelination. This pilot immunohistochemical study investigates whether c-Jun is also upregulated in human neuropathies. We examined c-Jun expression in normal and diseased human nerves, as well as in dermal myelinated nerve fibres. Our findings show that although as predicted c-Jun is rarely expressed in normal nerves, it is expressed in Schwann cell nuclei of pathological nerves as predicted by animal studies. Pathological dermal myelinated nerve fibres also show clear nuclear c-Jun expression. Further studies of c-Jun expression will help clarify its role in human neuropathies.