Related Experiment Videos
Involvement of NADH/NADPH oxidase in human platelet ROS production.
1Division of Cardiovascular and Respiratory Medicine, Department of Internal Medicine, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan.
Thrombosis Research
|September 13, 2001
Summary
Human platelets generate reactive oxygen species (ROS) through the NADH/NADPH oxidase system. This finding identifies a key enzymatic source of ROS in platelets, impacting vascular disease research.
Area of Science:
- Biochemistry
- Hematology
- Vascular Biology
Background:
- Platelets are crucial in vascular diseases like atherosclerosis.
- Reactive oxygen species (ROS) influence platelet function, and platelets can produce ROS.
- The specific enzymes responsible for ROS production in platelets remain largely unidentified.
Purpose of the Study:
- To investigate the presence and activity of the NADH/NADPH oxidase system in human platelets.
- To determine if NADH/NADPH oxidase is a significant source of ROS in platelets.
Main Methods:
- Lucigenin-enhanced chemiluminescence (L-CL) and electron spin resonance (ESR) assays to detect ROS.
- Enzymatic activity assays on platelet homogenates and MEG01 cells.
- Western blot analysis to identify specific protein components of NADH/NADPH oxidase.
Main Results:
- Human platelets release ROS, with increased production upon stimulation with TPA or calcium ionophore.
- Platelet homogenates and MEG01 cells exhibit NADH/NADPH-dependent superoxide production.
- This enzymatic activity is inhibited by diphenylene iodonium (DPI), and platelets express p22(phox) and p67(phox) proteins.
Conclusions:
- Human platelets possess functional p22(phox)-based NADH/NADPH oxidase activity.
- NADH/NADPH oxidase is identified as a likely major enzymatic source of ROS in human platelets.
- This discovery has implications for understanding platelet roles in vascular pathologies.