Abstract
Purpose: :
To evaluate the role of thrombopspondin-1 (TSP1), transforming growth factor (TGFβ) and connective tissue growth factor (CTGF) in advanced diabetic retinopathy.
Methods: :
A prospective study was conducted by collecting vitreous and plasma samples from diabetic and non-diabetic controls. PSEPCN profile has been determined by the use of Multiplexed Protein Profiling on Microarray by Rolling-Circle Amplification Technique. Western blot analysis has been used to assess the presence of TSP1 and CTGF in vitreous fluid.
Results: :
Pro-inflammatory cytokines such as TNFα and MIPβ were found elevated in patients with diabetes compared to non-diabetic controls. Interestingly, the PSEPCN profile indicated that baseline values of anti-angiogenic cytokines seen in the human control group, namely IL-4 and IL-13 were down-regulated in the diabetic patient group. Western blotting confirmed the presence of TSP1 in vitreous fluid in both the diabetic and the non-diabetic control group and for the first time to our knowledge the presence of CTGF in the vitreous of diabetic patients has been noted.
Conclusions: :
This prospective evaluation confirmed the pro-inflammatory axis of TSP1 and CTGF. These results also provide evidence that two important anti-angiogenic cytokines, IL-4 and IL-13, are diminished in diabetic patients when compared to controls. To the authors’ knowledge, this is the first time that the presence of CTGF was documented in vitreous fluid. There is little information in the literature related to the role of this pro-inflammatory axis in humans with diabetes to correlate the findings observed in the literature with mice and other experimental animal models.
Keywords: diabetic retinopathy • cytokines/chemokines • inflammation