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Updated: May 25, 2026
06:24
Minimal Erythema Dose (MED) Testing
Published on: May 28, 2013
Platelet-activating factor receptor agonists mediate xeroderma pigmentosum A photosensitivity
Yongxue Yao1, Kathleen A Harrison, Mohammed Al-Hassani
1Department of Dermatology, Indiana University School of Medicine, Indianapolis, Indiana 46202, USA.
The Journal of Biological Chemistry
|February 4, 2012
Summary
Oxidized glycerophosphocholines (Ox-GPCs) with platelet-activating factor (PAF) activity are key drivers of photosensitivity in xeroderma pigmentosum type A (XPA) deficiency. Antioxidants and PAF receptor antagonists mitigate these effects, revealing a novel therapeutic target.
Area of Science:
- Biochemistry
- Dermatology
- Genetics
Background:
- Xeroderma pigmentosum type A (XPA) deficiency impairs DNA repair, leading to increased photosensitivity.
- XPA-deficient cells exhibit reduced antioxidant defenses.
- Non-enzymatic oxidized glycerophosphocholines (Ox-GPCs) with platelet-activating factor (PAF) activity are implicated in disease but lack defined roles.
Purpose of the Study:
- To investigate the role of Ox-GPCs in the photosensitivity associated with XPA deficiency.
- To determine if Ox-GPCs mediate UVB-induced skin inflammation in XPA-deficient models.
Main Methods:
- Treatment of human XPA-deficient fibroblasts and Xpa-/- mice with ultraviolet B (UVB) radiation.
- Measurement of reactive oxygen species (ROS) and PAF receptor (PAF-R) agonistic activity.
- Inhibition studies using antioxidants and PAF-R antagonists.
- Mass spectrometry for structural characterization of Ox-GPCs.
Main Results:
- UVB irradiation increased ROS and PAF-R agonistic activity in XPA-deficient cells and mice.
- Antioxidants and PAF-R antagonists inhibited UVB-induced PAF-R agonistic activity and skin inflammation.
- Mass spectrometry identified increased sn-2 short-chain Ox-GPCs and PAF in UVB-irradiated XPA-deficient fibroblasts.
- UVB-induced skin inflammation and TNF-α production in Xpa-/- mice were significantly reduced by antioxidants and PAF-R antagonists.
Conclusions:
- Oxidized glycerophosphocholines (Ox-GPCs) play a critical role in the photosensitivity of xeroderma pigmentosum type A (XPA).
- UVB-induced Ox-GPCs activate the PAF receptor, contributing to skin inflammation.
- Targeting Ox-GPCs and the PAF receptor pathway offers a potential therapeutic strategy for XPA photosensitivity.
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