Table 2.
Select factors implicated in the development of PAH.
| Cytokine/Chemokine | Effect | Target effect | Location |
|---|---|---|---|
| Fractalkine (CX3CL1) | ↑ | Leukocyte recruitment | T cells |
| RANTES (CCL5) | ↑ | Attracts monocytes and T cells; induces ET - 1 | EC |
| Endothelin converting enzyme – 1 (ET-1) | ↑ | Vasoconstriction and mitogenic action | EC |
| Monocyte chemotactic protein – 1 (MCP – 1, CCL2) | ↑ | Monocyte recruitment | EC, SMC |
| Growth Factors | |||
| Platelet-derived growth factor (PDGF) | ↑ | Mitogen and chemoattractant for SMC, EC, fibroblasts; Resistance to apoptosis | EC |
| Epidermal growth factor (EGF) | ↑ | Induces proliferation and migration of SMC | EC, SMC, Macrophages |
| Vascular endothelial growth factor (VEGF) | ↑ | Induces proliferation and migration of SMC | EC |
| Seratonin (5-HT) | ↑ | Mitogenic effect on SMC, vasoconstriction | EC |
| Seratonin transporter (5-HTT) | ↑ | Co-mitogenic effect on SMC required for 5-HT action | SMC |
| Survivin | ↑ | Inhibitor of apoptosis | |
| Transcriptional Factors | |||
| Nuclear factor of activated T cells (NFAT) | ↑ | Increases inflammatory mediators including several interleukins and TNFα, and inhibits apoptosis | T cells, SMC |
EC: Endothelial cells, SMC: Smooth muscle cells, TNFα: Tumor necrosis factor α