Cilostazol attenuates ischemia-reperfusion-induced blood-brain barrier dysfunction enhanced by advanced glycation endproducts via transforming growth factor-β1 signaling

We investigated the effects of cilostazol, a selective inhibitor of phosphodiesterase 3, on blood-brain barrier (BBB) integrity against ischemia-reperfusion injury enhanced by advanced glycation endproducts (AGEs). We used in vitro BBB models with primarily cultured BBB-related cells from rats (brain capillary endothelial cells, astrocytes and pericytes), and subjected cells to either normoxia or 3-h oxygen glucose deprivation (OGD)/24h reoxygenation with or without AGEs. Treatment of AGEs did not affect the transendothelial electrical resistance (TEER) in the BBB model under normoxia, but there was a significant decrease in TEER under 3-h OGD/24-h reoxygenation conditions with AGEs. Cilostazol inhibited decreases in TEER induced by 3-h OGD/24-h reoxygenation with AGEs. Immunocytochemical and Western blot analyses showed that AGES reduced the expression of claudin-5, the main functional protein of tight junctions (TJs). In contrast, cilostazol increased the expression of claudin-5 under 3-h OGD/24-h reoxygenation with AGEs. Furthermore, while AGEs increased the production of extracellular transforming growth factor (TGF)-beta 1, cilostazol inhibited the production of extracellular TGF-beta 1 and restored the integrity of TJs. Thus, we found that AGEs enhanced ischemia-reperfusion injury, which mainly included decreases in the expression of proteins comprising TJs through the production of TGF-beta 1. Cilostazol appeared to limit ischemia-reperfusion injury with AGEs by improving the TJ proteins and inhibiting TGF-beta 1 signaling. (C) 2014 Elsevier Inc. All rights reserved.