title: P2X7 receptors at adult neural progenitor cells of the mouse subventricular zone.
abstract: Neurogenesis requires the balance between the proliferation of newly formed progenitor cells and subsequent death of surplus cells. RT-PCR and immunocytochemistry demonstrated the presence of P2X7 receptor mRNA and immunoreactivity in cultured neural progenitor cells (NPCs) prepared from the adult mouse subventricular zone (SVZ). Whole-cell patch-clamp recordings showed a marked potentiation of the inward current responses both to ATP and the prototypic P2X7 receptor agonist dibenzoyl-ATP (Bz-ATP) at low Ca(2+) and zero Mg(2+) concentrations in the bath medium. The Bz-ATP-induced currents reversed their polarity near 0 mV; in NPCs prepared from P2X7(-/-) mice, Bz-ATP failed to elicit membrane currents. The general P2X/P2Y receptor antagonist PPADS and the P2X7 selective antagonists Brilliant Blue G and A-438079 strongly depressed the effect of Bz-ATP. Long-lasting application of Bz-ATP induced an initial current, which slowly increased to a steady-state response. In combination with the determination of YO-PRO uptake, these experiments suggest the dilation of a receptor-channel and/or the recruitment of a dye-uptake pathway. Ca(2+)-imaging by means of Fura-2 revealed that in a Mg(2+)-deficient bath medium Bz-ATP causes [Ca(2+)](i) transients fully depending on the presence of external Ca(2+). The MTT test indicated a concentration-dependent decrease in cell viability by Bz-ATP treatment. Correspondingly, Bz-ATP led to an increase in active caspase 3 immunoreactivity, indicating a P2X7-controlled apoptosis. In acute SVZ brain slices of transgenic Tg(nestin/EGFP) mice, patch-clamp recordings identified P2X7 receptors at NPCs with pharmacological properties identical to those of their cultured counterparts. We suggest that the apoptotic/necrotic P2X7 receptors at NPCs may be of particular relevance during pathological conditions which lead to increased ATP release and thus could counterbalance the ensuing excessive cell proliferation.
authors.affiliation: Rudolf Boehm Institute of Pharmacology and Toxicology, University of Leipzig, Haertelstrasse 16-18, 04107 Leipzig, Germany.
authors.forename: Nanette
authors.initials: N
authors.lastname: Messemer
authors.forename: Christin
authors.initials: C
authors.lastname: Kunert
authors.forename: Marcus
authors.initials: M
authors.lastname: Grohmann
authors.forename: Helga
authors.initials: H
authors.lastname: Sobottka
authors.forename: Karen
authors.initials: K
authors.lastname: Nieber
authors.forename: Herbert
authors.initials: H
authors.lastname: Zimmermann
authors.forename: Heike
authors.initials: H
authors.lastname: Franke
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Nörenberg
authors.forename: Isabelle
authors.initials: I
authors.lastname: Straub
authors.forename: Michael
authors.initials: M
authors.lastname: Schaefer
authors.forename: Thomas
authors.initials: T
authors.lastname: Riedel
authors.forename: Peter
authors.initials: P
authors.lastname: Illes
authors.forename: Patrizia
authors.initials: P
authors.lastname: Rubini
mesh_terms: D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000818:Animals; D001583:Benzoxazoles / Q000378:metabolism; D002118:Calcium / Q000378:metabolism / Q000494:pharmacology; D053148:Caspase 3 / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D020547:Lateral Ventricles / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D061251:Primary Cell Culture; D058911:Purinergic P2X Receptor Agonists / Q000494:pharmacology; D058920:Purinergic P2X Receptor Antagonists / Q000494:pharmacology; D011725:Pyridines / Q000494:pharmacology; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D011806:Quinolinium Compounds / Q000378:metabolism; D058486:Receptors, Purinergic P2X7 / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D012394:Rosaniline Dyes / Q000494:pharmacology; D013234:Stem Cells / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D013777:Tetrazoles / Q000494:pharmacology
chemical_list: C523668:3-(5-(2,3-dichlorophenyl)-1H-tetrazol-1-yl)methylpyridine; D001583:Benzoxazoles; D058911:Purinergic P2X Receptor Agonists; D058920:Purinergic P2X Receptor Antagonists; D011725:Pyridines; D011806:Quinolinium Compounds; D058486:Receptors, Purinergic P2X7; D012394:Rosaniline Dyes; D013777:Tetrazoles; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; C089813:YO-PRO 1; C033901:3'-O-(4-benzoyl)benzoyladenosine 5'-triphosphate; D011732:Pyridoxal Phosphate; D000255:Adenosine Triphosphate; D053148:Caspase 3; C004692:coomassie Brilliant Blue; D002118:Calcium
keywords: 2-MeSATP; 2-methylthio ATP; 2′(3′)-O-(4-benzoylbenzoyl)adenosine-5′-triphosphate; 2′,3′-O-(2,4,6-trinitrophenyl) adenosine 5′-triphosphate; 3-(4,5-dimethylthioazol-2-yl)-2,5-diphenyltetrazoliumbromid; 5-(3-bromophenyl)-1,3-dihydro-2H-benzofuro[3,2-e]-1,4-diazepin-2-one; 5-BDBD; Adult neural progenitor cells; BBG; Brain subventricular zone; Brilliant Blue G; Bz-ATP; CNS; E(max); EC(50); EGF; Extracellular ATP; FGF-2; GAPDH; GFAP; MTT; Msi1; NPC; P2X7 receptors; PPADS; SVZ; TNP-ATP; X(2) concentration; [Ca(2+)](i); central nervous system; concentration of agonist producing 50% of E(max); divalent cation concentration; epidermal growth factor; fibroblast growth factor-2; glial fibrillary acidic protein; glyceraldehyde 3-phosphate dehydrogenase; intracellular Ca(2+) concentration; maximal effect; musashi1; neural progenitor cell; pyridoxalphosphate-6-azophenyl-2′,4′-disulfonic acid; subventricular zone; wild-type; wt; α,β-meATP; α,β-methylene ATP