Figure 5.

Sural nerve biopsies of NF2 patients show reduced NRG1 type III levels. (A) Percentage of NRG1-positive myelinated fibres in nerve samples of healthy control individuals versus chronic inflammatory demyelinating polyneuropathy (CIDP), axonopathy and patients with NF2 (data represent mean ± SEM; for significance levels see ‘Results’ section). (B) Expression of NRG1/myelin protein zero (P0) versus neurofilament (NF)/myelin protein zero in sural nerve biopsies of healthy control individuals as well as chronic inflammatory demyelinating polyneuropathy, axonopathy and patients with NF2. Typical examples of immunohistochemical double-labelling. Visualization of bound neurofilament (NF) and NRG1 antibodies with diaminobenzidine (brown) and of myelin protein zero antibodies with fast red (red), counterstained with Mayer’s haemalum. Scale bar = 20 µm. (C) Sural nerve fibre densities per mm² of indicated disease conditions (data represent mean ± SEM). (D) Sural nerve biopsies of patients with NF2 and healthy control subjects were lysed and immunoblotted for NRG1 type III. Actin and the axonal marker tau served as loading control (n = 3). Blot quantifications (density values) are depicted below respective lanes and are normalized to actin and healthy control samples.