Table 2.
PVR-Associated Growth Factors and Cytokines in Vitreous
| Growth factor/cytokine∗ | Rabbits† |
Humans† |
||
|---|---|---|---|---|
| Fibroblast-injection (n = 24) | RPE-injected (n = 12) | Non-traumatic (n = 21) | Traumatic (n = 15) | |
| VEGF | + + | + + | + | + + |
| PDGF-A | + + | + | + | + |
| PDGF-AB | + + | + | − | + |
| PDGF-B | + | + | − | − |
| PDGF-C | + + + | + + + | + + + | + + + |
| CTGF | + + + | + + + | + + | + |
| EGF | + | + | − | + |
| FGF-2 | + + | + + | + | + |
| G-CSF | − | + | − | + |
| HGF | + + | + | + + | + |
| IFN-γ | + + | + + | − | + + |
| IGF-1 | + + | + + | + | + |
| IL-6 | − | + | + + | + |
| MCP-1 | − | + | + + | + + |
| TGF-α | + | + | + | + + |
| TGF-β1 | + | + + | − | + |
| TGF-β2 | + + | + + | + | + |
| TGF-β3 | + | + | − | + |
Profiling data from two models of experimental PVR—the RPE-injection model (Figure 5) and the fibroblast-injection model24—together with clinical profiles from the vitreous of PVR patients,24 which is subdivided into traumatic and non-traumatic categories. All growth factors and cytokines listed are present in at least one type of vitreous from each species, and identify a core set of factors that putatively constitute PVR bioactivity in both experimental and clinical vitreous.
+, 0.1 to 2.5 ng/mL; ++, 2.5 to 10 ng/mL; +++, >10 ng/mL; −, <0.1 ng/mL (considered lower than detection).
The following three groups of growth factors and cytokines were omitted from this table: i) PDGF-D, GM-CSF, IL-9, and IL-10, each of which were lower than detection in all four types of vitreous (this was not due to a failure to detect the rabbit and/or human orthologs, as all four agents were detectable when tested in cells and/or serum from either species, data not shown); ii) IL-1β and IL-8, which were present (within the 0.1 to 2.5 ng/mL range) only in rabbit vitreous; and iii) TNF-α and TNF-β, which were present (within the 0.1 to 2.5 ng/mL range) only in traumatic human PVR vitreous. PDGF-B was detectable only in rabbit vitreous, although it was included as part of the core set because the presence of PDGF-AB in human vitreous suggests that some PDGF-B might exist; by including PDGF-B as part of the core set, we are able to ensure that all direct agonists of PDGFRα in vitreous are accounted for.
The + and − symbols indicate the concentration range at which growth factors and cytokines were present in each type of vitreous.