Table 1.
Selected mediators of inflammation, their role, and corresponding expression in BPD.
| Mediators of inflammation | Role | Expression in BPD |
|---|---|---|
| Inflammatory cytokines | ||
| Interleukins: anti-inflammatory | ||
| IL-10 | Suppresses inflammatory response by inhibiting NF-κB | ↓/↔ |
| IL-4, IL-13 | Suppresses inflammation by inhibiting pro-inflammatory cytokine production | ↔ |
| Interleukins: pro-inflammatory | ||
| IL-1, IL-6 | Acute phase inflammatory response | ↑ |
| IL-8 (CXCL-8) | Main chemoattractant for neutrophils | ↑ |
| CC chemokines | ||
| Monocyte chemoattractant protein (MCP)-1, 1α, 1β, 2, 3 | Recruit inflammatory cells to area of injury | ↑ |
| Macrophage migration inhibitory factor (MIF) | Upstream regulator of innate immune response | ↓ |
| Tumor necrosis factor alpha (TNF-α) | Enhances expression of other pro-inflammatory cytokines | ↑ |
| Transforming growth factor-beta 1 (TGF-β1) | Pro-inflammatory | ↑ |
| Matrix proteins | ||
| Matrix metalloproteinase-8 | Disordered pulmonary remodeling after inflammation | ↑ |
| Matrix metalloproteinase-9 | Pro-inflammatory, interferon-gamma (IFN-γ) signaling | ↑ |
| Growth factors | ||
| Endothelin-1 | Pro-inflammatory | ↑ |
| Vascular endothelial growth factor | Pro-inflammatory | ↑/↓ |
| Connective tissue growth factor (CTGF) | Pro-inflammatory | ↑ |
| Bombesin-like peptide (BLP) | Increases mast cells in the lung | ↑ |
| Breast regression protein-39 (human analog is YKL-40) | Anti-inflammatory | ↓ |
| Pulmonary hepatocyte growth factor (HGF) | Alveolar septation, repair | ↓ |
| Keratinocyte growth factor (KGF) | Regulates proliferation of alveolar epithelial cells | ↓ |
| Miscellaneous | ||
| Interferon-inducible protein 9 (IP-9 – also known as CXCL11) | Pro-inflammatory, IFN-γ signaling | ↑ |
| Cyclooxygenase-2 (Cox-2) | Pro-inflammatory, IFN-γ signaling | ↑ |
| CCAAT/enhancer-binding protein (C/EBP) | Pro-inflammatory, IFN-γ signaling | ↑ |
| Endoglin | Pro-inflammatory | ↑ |
| Periostin | Pro-inflammatory | ↑ |
| Clara cell secretory protein | Modulates acute pulmonary inflammation | ↓ |
| Parathyroid hormone-related protein (PTHrP) | Alveolar growth | ↓ |
| Angiopoietin-2 | Pro-inflammatory | ↑ |
| Lactoferrin | Anti-inflammatory | ↓ |
↑ – increase; ↔ – no change; ↓ – decrease.