The investigators conducting the behavior and electrophysiological experiments were blinded throughout the entire process including statistical analysis. Treatment protocols, drug application and placement of osmotic pump Fingolimod (S5002; Selleckchem, Munich, Germany) was dissolved in 0.9% saline solution (NaCl) to a final concentration of 9.5?mg/ml. action potential amplitude (SNAP) as well as the sensory nerve conduction velocity (SCV) compared to baseline in both groups without any differences between fingolimod or vehicle treatment (both 2-way ANOVA, SNAP: F(1,30)?=?28.48, p?=?0.0092 (vehicle) and p?=?0.002 (fingolimod); SCV: F(1,30)?=?20.30, p?=?0.0135 (vehicle) and p?=?0.0285 (fingolimod); Fig.?3D,E). In summary, CD86?/? NOD mice developed a sensory-motor axonal-demyelinating neuropathy as described previously. However, we observed additional negative effects of fingolimod therapy on myelination as indicated by the differences in MCV and F-wave latency between fingolimod and vehicle treated mice. Open in a separate window Physique 3 Electrophysiological characteristics of fingolimod treatment in CD86?/? NOD mice. (A) The compound motor action potential amplitude (CMAP) of the sciatic nerve declined similarly in both fingolimod and vehicle treated CD86?/? NOD mice. (B) Motor fibers showed electrophysiological indicators of demyelination indicated by the decrease of motor nerve conduction velocity (MCV), which was more pronounced in the fingolimod treated mice compared to vehicle treatment. (C) F-wave latency increased in both groups with disease progression. Again, fingolimod treated mice were more affected than mice in the vehicle group. Similar to motor fibers, the (D) sensory nerve action potential amplitude (SNAP) and (E) sensory nerve conduction velocity (SCV) declined in both treatment groups. Statistical analysis: Dorsomorphin 2HCl (A) Kruskall-Wallis test with Dunns method, (BCE) 2-way ANOVA with Sidak post hoc, group sizes: n?=?10 (vehicle), n?=?9C10 (fingolimod). *p??0.05, ns: not significant. Influence of fingolimod on serum cytokine expression Last, we investigated cytokine levels in serum samples taken at the end of the treatment period. Fingolimod treated and control mice showed no differences in the quantitative levels of Interferon- (IFN-), Tumor necrosis factor- (TNF-), Interleukin (IL)-1, IL-2, IL-10, IL-12p70 and IL-17 (Fig.?4ACD and FCH). However, there was a significant increase in Dorsomorphin 2HCl the IL-6 expression in the fingolimod treated mice compared to control (Mann-Whitney-U test, p?=?0.0229; Fig.?4E). Open in a separate window Physique 4 Influence of fingolimod on serum Rabbit Polyclonal to VTI1B cytokine expression. Serum samples were taken after an eight-week treatment period with fingolimod or vehicle. No differences in cytokine levels were observed for (A) Interferon- (IFN-), (B) Tumor necrosis factor- (TNF-), (C) Interleukin Dorsomorphin 2HCl (IL)-1b (IL-1b), (D) IL-2. (E) Fingolimod treated mice showed elevated levels of IL-6 compared to vehicle treated control animals, while (F) IL-10, (G) IL-12p70 and (H) IL-17 were not different between treatment groups. Statistical analysis: (A,C,D,E,G,H) Mann-Whitney-U test, (B,F) unpaired t-test, group sizes: n?=?5C9 (vehicle), n?=?3C8 (fingolimod). *p??0.05, ns: not significant. In conclusion, our data demonstrate that therapeutic fingolimod treatment does not improve clinical disease progression but rather worsens demyelination as assessed by electrophysiological parameters in this transgenic mouse model of CIDP. Discussion In this study, we describe functional and electrophysiological characteristics of a CD86 knockout in NOD mice which closely mimic clinical findings of CIDP. We were able to replicate the data from Salomon after peripheral nerve injury. We can in part substantiate this hypothesis by showing that MCV and F-wave latency were negatively affected in mice after fingolimod treatment compared to vehicle treatment. CD4+ FoxP3+ regulatory T cells are also of great importance in the pathogenesis of autoimmune neuropathies as depletion of these cells leads to a more severe phenotype and enhanced CD3+ T cell infiltration of peripheral nerves23. The positive influence of CD4+ FoxP3+ regulatory T cells on was confirmed in demyelinating central nervous system disorders such as multiple sclerosis24,25. While it was.