Abstract | PURPOSE: METHODS: Vitreous samples from 32 PDR and 23 nondiabetic patients, epiretinal membranes from 10 patients with PDR, retinas of rats, and HRMEC were studied by enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, and Western blot analysis. An assay for in vitro cell migration angiogenesis was performed in HRMEC. RESULTS: In epiretinal membranes, PAR1 was expressed in vascular endothelial cells, CD45-expressing leukocytes, and myofibroblasts. ELISA and Western blot assays revealed significant increases in the expression levels of thrombin, MMP-1, and VEGF in vitreous samples from PDR patients compared to nondiabetic controls. Significant positive correlations were found between the levels of VEGF and the levels of thrombin (r = 0.41; p = 0.006) and MMP-1 (r = 0.66; p < 0.0001). Significant increases of cleaved PAR1 (approximately 50 kDa) and the proteolytically active thrombin (approximately 50 kDa) were detected in rat retinas after induction of diabetes. The proinflammatory cytokines IL-1β and TNF-α, but not high- glucose and CoCl2, induced upregulation of cleaved PAR1 (approximately 30 kDa) in HRMEC. In addition, thrombin and MMP-1 induced VEGF in HRMEC and vorapaxar, a PAR1 inhibitor, inhibited thrombin-induced migration in HRMEC. CONCLUSIONS: Interactions among thrombin, MMP-1, PAR1, and VEGF might facilitate angiogenesis in PDR.
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Authors | Ahmed M Abu El-Asrar, Kaiser Alam, Mohd Imtiaz Nawaz, Ghulam Mohammad, Kathleen Van den Eynde, Mohammad Mairaj Siddiquei, Ahmed Mousa, Gert De Hertogh, Ghislain Opdenakker |
Journal | Current eye research
(Curr Eye Res)
Vol. 41
Issue 12
Pg. 1590-1600
(12 2016)
ISSN: 1460-2202 [Electronic] England |
PMID | 27261371
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Receptor, PAR-1
- Thrombin
- Matrix Metalloproteinase 1
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Topics |
- Animals
- Blotting, Western
- Cell Movement
- Cells, Cultured
- Diabetes Mellitus, Experimental
- Diabetic Retinopathy
(metabolism, pathology)
- Enzyme-Linked Immunosorbent Assay
- Humans
- Immunohistochemistry
- Male
- Matrix Metalloproteinase 1
(biosynthesis)
- Rats
- Rats, Sprague-Dawley
- Receptor, PAR-1
(biosynthesis)
- Thrombin
(biosynthesis)
- Up-Regulation
- Vitreous Body
(metabolism, pathology)
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