Figure 7.

Gene Therapy for Neuropathic Pain by IL-4 Expression with SP1 Homing Peptides to the Spinal Cord

(A) Scheme of SP1 peptide structure and binding of peptides with vectors. (B) Mechanical threshold of the hind paw before and after LPS injection with gene therapy in pBOS-IL4-YFP (IL-4, n = 7) and SP1 + pBOS-IL-4-YFP (SP1 + IL-4, n = 8) groups. (C) mRNA expression of IL-4 in the spinal cord after gene therapy by pBOS-YFP (CTR, n = 5), pBOS-IL4-YFP (IL-4, n = 5), or SP1 + pBOS-IL-4-YFP (SP1 + IL-4, n = 5). IL-4 mRNA expressions were standardized by GAPDH mRNA expression, and their relative expression ratios were calculated against the CTR group. (D) Immunohistochemistry of IL-4 in the spinal cord after gene therapy. Top shows YFP (green) and bottom shows IL-4 staining (blue). Scale bars, 100 μm. (E) IL-4 protein expression by ELISA analysis in spinal cord homogenized in PBS or RIPA buffer after the injection of pBOS-YFP (CTR, n = 5), pBOS-IL-4-YFP (IL-4, n = 5), or SP1 + pBOS-IL-4-YFP (SP1 + IL-4, n = 5). IL-4 protein contents were standardized by spinal cord protein weight. *p < 0.05 and **p < 0.01 versus others; ^#p < 0.01 in (E).