Involvement of Sodium in Early Phosphatidylserine Exposure and Phospholipid Scrambling Induced by P2X7 Purinoceptor Activation in Thymocytes
| Autor: | Jean-Claude Sulpice, Marie-Pierre Courageot, Françoise Giraud, Sandrine Lépine, Michel Hours |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Male
Cytoplasm Programmed cell death Time Factors CD8 Antigens Population Phospholipid Apoptosis Phosphatidylserines Thymus Gland Biochemistry Mice chemistry.chemical_compound Adenosine Triphosphate Cytosol Phospholipid scrambling Cations Ethidium Extracellular Animals education Molecular Biology Phospholipids Cell Nucleus Mice Inbred BALB C education.field_of_study Dose-Response Relationship Drug Receptors Purinergic P2 Cell Membrane Sodium Temperature Cell Biology Phosphatidylserine Flow Cytometry Protein Structure Tertiary Cell biology Kinetics Thymocyte chemistry CD4 Antigens Calcium Receptors Purinergic P2X7 Propidium |
| Zdroj: | Journal of Biological Chemistry. 279:21815-21823 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m401426200 |
| Popis: | Extracellular ATP (ATP(ec)), a possible effector in thymocyte selection, induces thymocyte death via purinoceptor activation. We show that ATP(ec) induced cell death by apoptosis, rather than lysis, and early phosphatidylserine (PS) exposure and phospholipid scrambling in a limited thymocyte population (35-40%). PS externalization resulted from the activation of the cationic channel P2X7 (formerly P2Z) receptor and was triggered in all thymocyte subsets although to different proportions in each one. Phospholipid movement was dependent on ATP(ec)-induced Ca(2+) and/or Na(+) influx. At physiological external Na(+) concentration, without external Ca(2+), PS was exposed in all ATP(ec)-responsive cells. In contrast, without external Na(+), physiological external Ca(2+) concentration promoted a submaximal response. Altogether these data show that Na(+) influx plays a major role in the rapid PS exposure induced by P2X7 receptor activation in thymocytes. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|