interleukin-8 and Eye-Injuries--Penetrating

To investigate in vivo expression of chemokines in normal and inflamed human corneas, to determine whether chemokines are responsible for the recruitment of inflammatory cells.. In situ hybridization of the CXC chemokines growth-related oncogene-alpha (Gro-alpha) (CXCL-1), interleukin 8 (CXCL-8), macrophage interferon-gamma inducible gene (CXCL-9), and interferon-gamma inducible protein 10 (CXCL-10) and of the CC chemokines macrophage chemoattractant protein 1 (MCP-1) (CCL-2), macrophage inflammatory protein 1alpha (CCL-3), and regulated on activation, normal T-cell expressed and secreted (CCL-5) was performed to localize chemokine messenger RNA. Immunohistochemistry was used to identify the cellular infiltrate within the cornea. Three normal human eyes were compared with eyes enucleated because of chronic inflammation (n = 10), secondary to perforating injuries.. In normal corneas, no chemokine expression was detected. In inflamed lesions, a high intensity of signals from Gro-alpha (CXCL-1) and MCP-1 (CCL-2) messenger RNA was observed in limbal epithelium and from Gro-alpha (CXCL-1), interleukin 8 (CXCL-8), and MCP-1 (CCL-2) in corneal stroma. The Gro-alpha (CXCL-1) was the only chemokine expressed by central corneal epithelium. All other examined chemokines were only moderately expressed in limbus and corneal stroma, or barely detectable.. These cytokines are important agents in the cytokine network and contribute to the cell-specific and spatially restricted recruitment of neutrophils and mononuclear cells in acute inflammatory lesions of the human cornea. Clinical Relevance Understanding the role of chemokines in corneal inflammation may lead to the development of a selective receptor blockage of highly expressed chemokines to inhibit the recruitment of leukocyte subsets.

Topics: Antibodies, Monoclonal; Chemokine CCL2; Chemokine CCL4; Chemokine CXCL1; Chemokine CXCL10; Chemokine CXCL9; Chemokines; Chemokines, CXC; Chemotactic Factors; Cornea; Eye Injuries, Penetrating; Humans; Immunoenzyme Techniques; In Situ Hybridization; Inflammation; Intercellular Signaling Peptides and Proteins; Interleukin-8; Keratitis; Langerhans Cells; Macrophage Inflammatory Proteins; Macrophages; Neutrophils; RNA, Messenger; T-Lymphocytes

To explore the role of autocrine interleukin-1 alpha (IL-1 alpha) as a central regulator of the repair phenotype in corneal fibroblasts.. Disruption of the actin cytoskeleton with cytochalasin B (CB), which mimics changes in shape that occur in repair tissues, was used to stimulate repair gene expression in early-passage fibroblasts. Changes in expression of IL-1 alpha, IL-8, collagenase, and ENA-78 were determined by Northern blot analysis, radioimmunoassay, and an enzyme-amplified sensitivity immunoassay (EASIA). Expression of repair genes was also examined in repair fibroblasts, isolated from healing, penetrating keratectomy wounds in rabbits.. Blocking IL-1 alpha activity prevented both constitutive and stimulated increases in synthesis of IL-8 and collagenase in early-passage cultures of corneal fibroblasts, demonstrating the role of IL-1 alpha as a necessary intermediate for expression of these genes. Evidence is also presented that the IL-1 alpha autocrine controls expression of an IL-8 related factor, ENA-78. Unlike early-passage fibroblasts, fibroblasts freshly isolated from the uninjured cornea did not express IL-1 alpha. However, fibroblasts freshly isolated from remodeling corneal repair tissue 3 weeks after injury were found to express substantial levels of IL-1 alpha, regulated through an autocrine feedback loop. Neutralization experiments demonstrated that the IL-1 alpha autocrine is largely responsible for controlling both collagenase and IL-8 synthesis in repair fibroblasts, as it is in early-passage fibroblasts.. These findings provide evidence that activation of an autocrine IL-1 alpha feedback loop is an important mechanism by which fibroblasts adopt a repair phenotype during remodeling of the cornea.

Topics: Animals; Blotting, Northern; Chemokine CXCL5; Chemokines, CXC; Collagenases; Cornea; Corneal Injuries; Eye Injuries, Penetrating; Feedback; Fibroblasts; Immunoenzyme Techniques; Interleukin-1; Interleukin-8; Phenotype; Rabbits; Radioimmunoassay; RNA, Messenger; Wound Healing