Fig. 2
From: The inflammatory response in the regression of lumbar disc herniation
Representative proposed mechanism of LDH resorption. Both herniated IVD tissue and macrophages produce tumor necrosis factor alpha (TNF-α), monocyte chemoattractant protein (MCP)-1, matrix metalloproteinases (MMPs), interleukin (IL)-6, IL-8, prostaglandin E2 (PGE2), cyclooxygenase 2 (COX2), and nitric oxide (NO), which contribute to the inflammatory reaction and resorption of the herniated tissue. Vascular endothelial growth factor (VEGF) induces blood vessel ingrowth and neovascularization, which support immune cell mobilization to hernia site. Insert: in rat model of IVD herniation, CD68+ macrophages localized within hernia (delimitated by dashed line), which include a blood vessel (arrow). Scale bar: 100 μm. Image used elements from Servier Medical Art; insert: unpublished