Expression and Mechanism of Interleukin 1 (IL-1), Interleukin 2 (IL-2), Interleukin 8 (IL-8), BMP, Fibroblast Growth Factor 1 (FGF1), and Insulin-Like Growth Factor (IGF-1) in Lumbar Disc Herniation

Abstract

BACKGROUND The expression and mechanism of IL-1, IL-2, IL-8, BMP, FGF1, and IGF-1 in Sprague-Dawley (SD) rats with lumbar disc herniation were investigated. MATERIAL AND METHODS Immunohistochemical methods were applied to identify IL-1, IL-2, IL-8, BMP, FGF1, and IGF-1. PI3K, AKT protein, and mRNA expression were detected and analyzed by Western blot analysis. We selected 30 healthy SD rats and divided them into 2 groups to construct an animal model that was validated by immediate CT scanning. Cartilage tissues from the lumbar disc herniation (experimental) group and control group were obtained and compared. RESULTS The expression of BMP was not significantly different between the control group and the experimental group (P>0.05). FGF1: There was no significant difference in the expression of FGF1 (P>0.05) between the control group and the experimental group. Compared with the control group, the expression of IGF-1 in the experimental group was significantly higher (P<0.05); the expression of IL-1 in the experimental group was significantly higher (P<0.05); and the expression of IL-2 in the experimental group was also significantly higher (P<0.05). There was no significant difference in IL-8 between the experimental group and the control group (P>0.05). The expression levels of PI3K and AKT protein and mRNA were significantly higher than those in healthy controls (P<0.05). CONCLUSIONS After lumbar disc herniation occurred, the IGF-1 was first activated; the PI3K/AKT signaling pathway was later activated, which resulted in the expression of IL-1 and IL-2 inflammation-related factors being increased.