Fig. 4

Measurement of cytokine expression in sera. Significantly lower expression of GM-CSF in CIDP sera compared to control sera was observed by cytokine ELISA array (a) which was confirmed by specific GM-CSF ELISA array (b). The effect of lower GM-CSF expression on gene expression was verified by adding recombinant rat GM-CSF to the Schwann cells treated with CIDP sera. c Addition of GM-CSF to the Schwann cells reversed the effect of CIDP sera on gene expression of p57kip2 and c-Jun. d CIDP-conditioned Schwann cells show significantly lower expression of BDNF and GDNF and higher expression of NGF. Down-regulation of BDNF and GDNF was reversed by addition of GM-CSF whereas expression of NGF was further increased by GM-CSF. GAPDH was used as a housekeeping gene for qPCR. *p < 0.05, **p < 0.01, ****p < 0.0001 (ANOVA and unpaired Student’s t test)