title: Ionotropic purinergic receptor P2X4 is involved in the regulation of chondrogenesis in chicken micromass cell cultures.
abstract: We have previously demonstrated that elevation of free cytosolic Ca(2+) concentration at the time of differentiation of chondroblasts was mainly due to a Ca(2+) influx and it was indispensable to cartilage formation in chicken high density mesenchymal cell cultures (HDC) [C. Matta, J. Fodor, Z. Szijgyarto, T. Juhasz, P. Gergely, L. Csernoch, R. Zakany, Cytosolic free Ca(2+) concentration exhibits a characteristic temporal pattern during in vitro cartilage differentiation: a possible regulatory role of calcineurin in Ca-signalling of chondrogenic cells, Cell Calcium 44 (2008) 310-323]. Here, we report that chondrogenic cells secreted ATP and administration of ATP to the culture medium evoked Ca(2+) transients exclusively in the presence of extracellular Ca(2+) and only on day 3 of culturing, when the final commitment of chondroblasts occurs. Moreover, ATP caused elevated protein expression of the chondrogenic transcription factor Sox9 and stimulated cartilage matrix production. Expression pattern of different types of both ionotropic and metabotropic purinergic receptors was detected. Agonists of metabotropic receptors, ADP and UDP did not evoke any Ca(2+) transients and had no influence on cartilage formation, while UTP caused transient elevation of cytosolic Ca(2+) concentration in 3-day-old HDC without stimulating matrix production. Suramin, which blocks all P2X receptors but not P2X(4) did not impede the effects of ATP, furthermore, P2X(4) appeared in the plasma membrane fraction and gave signals with immunocytochemistry only from day 3. In summary, we suggest a role of ionotropic purinergic signalling of P2X(4) in the generation of ATP-dependent Ca(2+) transients of differentiating chondroblasts.
authors.affiliation: Department of Physiology, Medical and Health Science Centre, University of Debrecen, Hungary.
authors.forename: János
authors.initials: J
authors.lastname: Fodor
authors.forename: Csaba
authors.initials: C
authors.lastname: Matta
authors.forename: Tamás
authors.initials: T
authors.lastname: Juhász
authors.forename: Tamás
authors.initials: T
authors.lastname: Oláh
authors.forename: Mónika
authors.initials: M
authors.lastname: Gönczi
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Szíjgyártó
authors.forename: Pál
authors.initials: P
authors.lastname: Gergely
authors.forename: László
authors.initials: L
authors.lastname: Csernoch
authors.forename: Róza
authors.initials: R
authors.lastname: Zákány
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D002642:Chick Embryo; D020219:Chondrogenesis / Q000502:physiology*; D003470:Culture Media / Q000737:chemistry; D005109:Extracellular Matrix / Q000378:metabolism; D008648:Mesoderm / Q000166:cytology; D018048:Receptors, Purinergic P2 / Q000235:genetics / Q000378:metabolism*; D058848:Receptors, Purinergic P2X4; D014530:Uridine Diphosphate / Q000378:metabolism; D014544:Uridine Triphosphate / Q000378:metabolism
chemical_list: D003470:Culture Media; D018048:Receptors, Purinergic P2; D058848:Receptors, Purinergic P2X4; D014530:Uridine Diphosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D002118:Calcium; D014544:Uridine Triphosphate