The Korean Journal of Physiology and Pharmacology

The Korean Society of Pharmacology (대한약리학회)
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P2X7 Receptor-mediated Membrane Blebbing in Salivary Epithelial Cells

  • Hwang, Sung-Min (Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute) ;
  • Koo, Na-Youn (Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute) ;
  • Choi, Se-Young (Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute) ;
  • Chun, Gae-Sig (Department of Oral Physiology, School of Dentistry, Dankook University) ;
  • Kim, Joong-Soo (Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute) ;
  • Park, Kyung-Pyo (Department of Physiology, School of Dentistry, Seoul National University and Dental Research Institute)
  • Published : 2009.06.30
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Abstract

High concentrations of ATP induce membrane blebbing. However, the underlying mechanism involved in epithelial cells remains unclear. In this study, we investigated the role of the P2X7 receptor (P2X7R) in membrane blebbing using Par C5 cells. We stimulated the cells with 5 mM of ATP for 1${\sim}$2 hrs and found the characteristics of membrane blebbing, a hallmark of apoptotic cell death. In addition, 500 ${\mu}M$ Bz-ATP, a specific P2X7R agonist, induced membrane blebbing. However, 300 ${\mu}M$ of Ox-ATP, a P2X7R antagonist, inhibited ATP-induced membrane blebbing, suggesting that ATP-induced membrane blebbing is mediated by P2X7R. We found that ATP-induced membrane blebbing was mediated by ROCK I activation and MLC phosphorylation, but not by caspase-3. Five mM of ATP evoked a biphasic $[Ca^{2+}]_i$ response; a transient $[Ca^{2+}]_i$ peak and sustained $[Ca^{2+}]_i$ increase secondary to ATP-stimulated $Ca^{2+}$ influx. These results suggest that P2X7R plays a role in membrane blebbing of the salivary gland epithelial cells.

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References

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