Abstract
This work describes the pharmacological inhibition by cilostazol and its metabolites, OPC-13015 and OPC-13213, of the apoptosis in the human umbilical vein endothelial cells (HUVECs) damaged by lipopolysaccharide (LPS) in comparison with its analog, cilostamide. Cilostazol and OPC-31213 caused a significant suppression of cell death induced by LPS (1 μg/ml) in a concentration-dependent manner but a modest suppression by cilostamide and OPC-13015. These compounds potently inhibited the 5,5-dimethyl-1-pyrroline-1-oxide (DMPO)/⋅OH adduct formation and significantly reduced the increased intracellular reactive oxygen species (ROS) and tumor necrosis factor-α (TNF-α) production induced by LPS (1 μg/ml). An apoptotic death of HUVECs by 1 μg/ml LPS (DNA ladders on electrophoresis) was strongly suppressed by all these compounds. Incubation with LPS caused a marked decrease in Bcl-2 protein, which was significantly reversed by cilostazol and its analogs. The greatly increased Bax protein expression and cytochrome crelease by LPS were, in contrast, suppressed by cilostazol and, to a lesser degree, by others. In conclusion, cilostazol and its analogs exert a strong protection against apoptotic cell death by scavenging hydroxyl radicals and intracellular ROS with reduction in TNF-α formation and by increasing Bcl-2 protein expression and decreasing Bax protein and cytochrome c release.
Footnotes
-
This study was supported with funding from the Korea Science and Engineering Foundation, from the Research Institute of Genetic Engineering, Pusan National University, and from the Research Funds from Korea Otsuka Pharmaceutical Co. Ltd.
- Abbreviations:
- PDE
- phosphodiesterase
- ROS
- reactive oxygen species
- TNF-α
- tumor necrosis factor-α
- DMPO
- 5,5-dimethyl-1-pyrroline-1-oxide
- ELISA
- enzyme-linked immunosorbent assay
- EPR
- electron paramagnetic resonance
- HUVECs
- human umbilical vein endothelial cells
- LPS
- lipopolysaccharide
- MTT
- 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide
- PBS
- phosphate-buffered saline
- DCFH
- 2′,7′-dichlorofluorescein
- CREB
- cyclic AMP-response element-binding protein
- Received July 2, 2001.
- Accepted November 2, 2001.
- The American Society for Pharmacology and Experimental Therapeutics
JPET articles become freely available 12 months after publication, and remain freely available for 5 years.Non-open access articles that fall outside this five year window are available only to institutional subscribers and current ASPET members, or through the article purchase feature at the bottom of the page.
|