• International Journal of Oral Biology
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• v.31 no.3
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• pp.87-92
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• 2006

Schwann cells play an important role in peripheral nerve regeneration. Upon nerve injury, Schwann cells are activated and produce various proinflammatory mediators including IL-6, LIF and MCP-1, which result in the recruitment of macrophages and phagocytosis of myelin debris. However, it is unclear how the nerve injury induces Schwann cell activation. Recently, it was reported that necrotic cells induce immune cell activation via toll-like receptors (TLRs). This suggests that the TLRs expressed on Schwann cells may recognize nerve damage by binding to the endogenous ligands secreted by the damaged nerve, thereby inducing Schwann cell activation. To explore the possibility, we stimulated iSC, a rat Schwann cell line, with damaged neuronal cell extracts (DNCE). The stimulation of iSC with DNCE induced the expression of various inflammatory mediators including IL-6, LIF, MCP-1 and iNOS. Studies on the signaling pathway indicate that $NF-{\kappa}B$, p38 and JNK activation are required for the DNCE-induced inflammatory gene expression. Furthermore, treatment of either anti-TLR3 neutralizing antibody or ribonuclease inhibited the DNCE-induced proinflammatory gene expression in iSC. In summary, these results suggest that damaged neuronal cells induce inflammatory Schwann cell activation via TLR3, which might be involved in the Wallerian degeneration after a peripheral nerve injury.

• The Korea Journal of Herbology
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• v.23 no.2
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• pp.59-65
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• 2008

Objectives : HRHDT has been known as a useful prescription with antibiotic, anti-inflammatory, antioxidative and immunosuppressive activity. To evaluate anti-atopic dermatitis effect of HRHDT, we treated HRHDT in NC/Nga mice model skin induced contact hypersensitivity. Methods : Contact hypersensitivity, a local inflammatory response of skin, was induced by spreading the back skin of NC/Nga mice with 0.4${\sim}$1% DNCB. HRHDT was prepared by dissolving 3% HRHDT in solution and treated 3 weeks on the back skin. Results : HRHDT significantly reduced TEWL and erythema by 0.4${\sim}$1% of DNCB treatment compared to control group. HRHDT also reduced IgE on serum obtained from blood of DNCB-treated mice. Conclusions : These results showed that HRHDT could be used as a pharmaceutical material with anti-atopic dermatitis effect by reducing IgE in contact, hypersensitivity atopic dermatitis NC/Nga mice model by DNCB.