Pigment epithelium-derived factor prevents advanced glycation end products-induced monocyte chemoattractant protein-1 production in microvascular endothelial cells by suppressing intracellular reactive oxygen species generation.
OBJECTIVE
Monocytes and macrophages accumulate in the lesion of the diabetic retina, which are most likely involved in the progression of diabetic retinopathy. The levels of monocyte chemoattractant protein-1 (MCP-1) in vitreous fluids were associated with the severity of proliferative diabetic retinopathy. Recently, pigment epithelium-derived factor has been shown to be involved in the pathogenesis of proliferative diabetic retinopathy. However, a role of pigment epithelium-derived factor in monocyte recruitments in diabetic retinopathy remains to be elucidated. In this study, we investigated effects of purified pigment epithelium-derived factor on AGE-induced reactive oxygen species generation, MCP-1 mRNA up-regulation and protein production in human cultured microvascular endothelial cells.


METHODS
The intracellular formation of reactive oxygen species was measured using the fluorescent probe CM-H(2)DCFDA. MCP-1 gene expression was analysed in quantitative reverse transcription-polymerase chain reaction. Monocyte chemoattractant protein-1 production by microvascular endothelial cells was measured with an ELISA system.


RESULTS
AGE increased intracellular reactive oxygen species generation in microvascular endothelial cells. Pigment epithelium-derived factor inhibited the AGE-induced reactive oxygen species generation in a dose-dependent manner. An anti-oxidant, N-acetylcysteine, or pigment epithelium-derived factor completely prevented the AGE-induced up-regulation of MCP-1 mRNA contents as well as protein production in microvascular endothelial cells.


CONCLUSIONS
Pigment epithelium-derived factor inhibits the AGE-induced reactive oxygen species generation and the subsequent increase in MCP-1 production in microvascular endothelial cells. Our study suggests that substitution of pigment epithelium-derived factor could prevent the progression of diabetic retinopathy by attenuating the deleterious effects of AGE.
Inagaki
Y
Y
Division of Endocrinology and Metabolism, Kurume University School of Medicine, Kurume 830-0011, Japan.
Yamagishi
S
S
Okamoto
T
T
Takeuchi
M
M
Amano
S
S
D002478:Cells, Cultured; D018932:Chemokine CCL2 / Q000037:antagonists & inhibitors* / Q000096:biosynthesis / Q000235:genetics; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005136:Eye Proteins; D015870:Gene Expression / Q000187:drug effects; D017127:Glycation End Products, Advanced / Q000494:pharmacology*; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism*; D009414:Nerve Growth Factors; D011506:Proteins / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors*; D015843:Serpins / Q000494:pharmacology*; D000099174:Pigment Epithelium-Derived Factor
D018932:Chemokine CCL2; D005136:Eye Proteins; D017127:Glycation End Products, Advanced; D009414:Nerve Growth Factors; D011506:Proteins; D017382:Reactive Oxygen Species; D015843:Serpins; D000099174:Pigment Epithelium-Derived Factor