• The Korean Journal of Physiology and Pharmacology
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• v.8 no.5
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• pp.253-257
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• 2004

Schwann cells play an important role in peripheral nerve regeneration. Upon neuronal injury, activated Schwann cells clean up the myelin debris by phagocytosis, and promote neuronal survival and axon outgrowth by secreting various neurotrophic factors. However, it is unclear how the nerve injury induces Schwann cell activation. Recently, it was reported that certain cytoplasmic molecules, which are secreted by cells undergoing necrotic cell death, induce immune cell activation via the 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. Accordingly, this study was undertaken to examine the expression and the function of the TLRs on primary Schwann cells and iSC, a rat Schwann cell line. The transcripts of TLR2, 3, 4, and 9 were detected on the primary Schwann cells as well as on iSC. The stimulation of iSC with poly (I : C), a synthetic ligand for the TLR3, induced the expression of $TNF-{\alpha}$ and RANTES. In addition, poly (I : C) stimulation induced the iNOS expression and nitric oxide secretion in iSC. These results suggest that the TLRs may be involved in the inflammatory activation of Schwann cells, which is observed during Wallerian degeneration after a peripheral nerve injury.

• 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.

• Polymer(Korea)
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• v.38 no.2
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• pp.164-170
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• 2014

This study was designed to find an appropriate biomaterial to proliferate Schwann cell (SC). Poly(lactic-co-glycolic acid) (PLGA) films mixed with demineralized bone particle (DBP), small intestine submucosa (SIS), and silk were fabricated by a solvent casting method. Analysis of MTT, SEM and RT-PCR were performed to confirm adhesion and proliferation of SC. Contact angle of films was assayed for hydrophilicity of films. We confirmed that PLGA/DBP 20% film showed higher hydrophilicity, promoted adhesion and proliferation of SC than other films. It was concluded that PLGA/DBP film can be applied for the scaffold biomaterials for the regeneration of central nerve system.

• Polymer(Korea)
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• v.33 no.2
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• pp.118-123
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• 2009

Keratin contains regulatory molecules that can enhance neuronal cell activity. We fabricated keratin/ PLGA films using 0, 10, 20, and 50 wt% of keratin using solvent casting method. We measured the contact angle of each film and cell proliferation was assayed by counting the cells attached on the film. Adhered cell morphology was confirmed by scanning electron microscope. RT-PCR was conducted to evaluate the gene expression of NF, NSE, and S-100, the Schwann cell markers. The keratin content of 20 and 50 wt% provided higher wettability than PLGA. The 20 wt% keratin was better in cell adhesion and proliferation of SCs than other keratin/PLGA films. The phenotypic stability of SC was maintained with the keratin content of 10 and 20 wt%.

• Polymer(Korea)
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• v.32 no.1
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• pp.49-55
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• 2008

It is recognized that Schwann cells (SC) are essential for peripheral nerve development and regeneration. SIS (small intestinal submucosa) consists of some growth factors which can stimulate cell activity without immune rejection responges. SCs were harvested from the femurs and tibias of female Fischer rat and then suspended with $2{\times}10^6$ cell/sponge in SIS sponge. Fischer rat received an implant consisting of the SCs and the SIS sponge at the place of a 5 mm gap created by the sciatic nerve resection. Thin sections were stained with H &E staining and immunostaining of S-100, GFAP and NF after 1, 2, and 4 weeks. It was observed that the effects of the SIS sponge with SCs on neuroinduction(Group II, with scaffold & cell) are strong as much as uninjured model(Control I), and significantly stronger than SIS sponge model (Group 1, with scaffold only) and blank model (Control II). In conclusion, these results suggest that SIS sponge filled with SCs may have an important role for peripheral nerve regeneration of tissue engineering.