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Published on: July 16, 2013
UVA-induced calcium oscillations in rat mast cells
Yan Dong Zhou1, Xiao Feng Fang, Zong Jie Cui
1Institute of Cell Biology, Beijing Normal University, Beijing 100875, China.
Cell Calcium
|July 8, 2008
Summary
Ultraviolet A (UVA) light triggers reactive oxygen species (ROS) in rat mast cells, leading to calcium oscillations. This process involves NAD(P)H oxidase and phospholipase C signaling pathways.
Area of Science:
- Immunology
- Cell Biology
- Photobiology
Background:
- Ultraviolet A (UVA) is a component of solar irradiation with known immunomodulatory and anti-inflammatory effects.
- The precise molecular mechanisms underlying UVA's impact on calcium signaling in mast cells remain incompletely understood.
Purpose of the Study:
- To elucidate the molecular mechanisms of UVA-induced calcium signaling in rat mast cells.
- To investigate the role of reactive oxygen species (ROS) and specific signaling pathways in UVA's effects.
Main Methods:
- UVA irradiation of individual rat mast cells.
- Measurement of cytosolic calcium oscillations and ROS formation.
- Pharmacological inhibition of signaling pathways (e.g., phospholipase C, calcium channels) and enzymes (NAD(P)H oxidase).
- Spectral confocal imaging to analyze endogenous fluorophores.
Main Results:
- UVA irradiation induced ROS formation and regular cytosolic calcium oscillations in rat mast cells.
- Exogenous H2O2 and hypoxanthine/xanthine oxidase mimicked UVA's effect on calcium.
- Inhibition of phospholipase C (U73122) and calcium entry blockers abolished UVA-induced oscillations.
- Antioxidants (NAC) and NAD(P)H oxidase inhibitors (DPI) prevented both ROS production and calcium oscillations.
- Spectral analysis indicated the presence of NAD(P)H in mast cells.
Conclusions:
- UVA activates NAD(P)H oxidase in rat mast cells, leading to ROS production.
- ROS subsequently activates phospholipase C signaling.
- This cascade triggers regular cytosolic calcium oscillations, contributing to UVA's bioactivity.
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