title: ATP stimulates Ca(2+)-waves and gene expression in cultured human pulmonary fibroblasts.
abstract: Given that extracellular ATP is markedly elevated in inflammation and is known to modulate fibroblast function, we examined the effects of exogenously added ATP on Ca(2+)-handling and gene expression in human pulmonary fibroblasts. Cells were loaded with the Ca(2+)-indicator dye fluo-4 and studied using confocal fluorimetry. Standard RT-PCR was used to probe gene expression. ATP (10(-5)M) evoked recurring Ca(2+)-waves which were completely occluded by cyclopiazonic acid (depletes the internal Ca(2+)-store) or the phospholipase inhibitor U73122. Pretreatment with ryanodine (10(-5)M), however, had no effect on the ATP-evoked responses. Regarding the receptor through which ATP acted, we found the ATP-response to be mimicked by UTP or ADP but not by adenosine or alpha,beta-methylene-ATP, and to be blocked by the purinergic receptor blocker PPADS. The ATP-evoked response was greater and longer lasting within the nucleus than in the non-nuclear portion of the cytosol. RT-PCR showed that ATP also rapidly and dramatically increased gene expression of P2Y(4) receptors, the cytokine TGF-beta (an important modulator of wound repair) and two matrix proteins (collagen A1 and fibronectin) approximately 4-5 times above baseline: this increase was not significantly affected by ryanodine but was abolished by PPADS. We conclude that, in human pulmonary fibroblasts, ATP acts upon P2Y receptors to liberate internal Ca(2+) through ryanodine-insensitive channels, leading to a Ca(2+)-wave which courses throughout the cell and modulates gene expression.
authors: Firestone Institute for Respiratory Health, St. Joseph's Hospital and the Departments of Medicine, Molecular Medicine and Pathology, McMaster University, Hamilton, Ontario, Canada L8N 3Z5. janssenl@mcmaster.ca
authors: Luke J
authors: LJ
authors: Janssen
authors: Laszlo
authors: L
authors: Farkas
authors: Tahseen
authors: T
authors: Rahman
authors: Martin R J
authors: MR
authors: Kolb
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000814:Aniline Compounds; D002110:Caffeine / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects*; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D003094:Collagen / Q000096:biosynthesis / Q000235:genetics; D004963:Estrenes / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005353:Fibronectins / Q000096:biosynthesis / Q000235:genetics; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D008168:Lung / Q000166:cytology; D058919:Purinergic P2 Receptor Antagonists; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D012433:Ryanodine / Q000494:pharmacology; D016212:Transforming Growth Factor beta / Q000096:biosynthesis / Q000235:genetics; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors; D014966:Xanthenes
chemical_list: D000814:Aniline Compounds; D004963:Estrenes; D005353:Fibronectins; C409648:Fluo 4; D007211:Indoles; D058919:Purinergic P2 Receptor Antagonists; D011760:Pyrrolidinones; D016212:Transforming Growth Factor beta; D014966:Xanthenes; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; C077792:pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid; D012433:Ryanodine; D002110:Caffeine; D011732:Pyridoxal Phosphate; D000255:Adenosine Triphosphate; D003094:Collagen; D010738:Type C Phospholipases; C000543:cyclopiazonic acid