Regulator of G-protein signaling protein 2 modulates purinergic calcium and ciliary beat frequency responses in airway epithelia.
In ciliated airway epithelial cells, purinergic stimulation increases both intracellular calcium ([Ca(2+)](i)) and ciliary beat frequency (CBF). Because regulator of G-protein signaling protein 2 (RGS2) terminates Galphaq-mediated phospholipase C activation, we examined its role in regulating purinergic signaling in human and ovine airway epithelial cells. RT-PCR of both human and ovine epithelial cell RNA yielded fragments of expected size ( approximately 491 bp) and sequence, confirming RGS2 message. Immunofluorescence demonstrated RGS2 protein expression in cultured airway epithelial cells of both species. Overexpression of an EGFP-RGS2 fusion protein (increasing RGS2 protein levels 1.8 times control, n = 28 cells) resulted in a reduced [Ca(2+)](i) and CBF response to 10 micro M ATP (human: 58 +/- 9% and 49 +/- 8% lower, respectively; n = 8 measurements, 4 cells; ovine: 56 +/- 12% and 53 +/- 16% lower, respectively; n = 5 measurements, 4 cells). Reducing RGS2 protein levels using antisense oligonucleotides increased the response of both [Ca(2+)](i) and CBF to ATP in human cells by 57 +/- 10% and 47 +/- 11%, respectively (n = 10 measurements, 6 cells), and in ovine cells by 88 +/- 13% and 48 +/- 9%, respectively (n = 10 measurements, 5 cells). These data provide functional evidence that RGS2 modulates purinergic signaling in human and ovine ciliated airway epithelial cells.
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D001980:Bronchi / Q000166:cytology*; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D006224:Cricetinae; D004847:Epithelial Cells / Q000378:metabolism; D006801:Humans; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010957:Plasmids / Q000378:metabolism; D020710:RGS Proteins / Q000378:metabolism / Q000502:physiology*; D012333:RNA, Messenger / Q000378:metabolism; D011983:Receptors, Purinergic / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012689:Sequence Homology, Nucleic Acid; D012756:Sheep; D015398:Signal Transduction; D012984:Software; D013997:Time Factors; D014132:Trachea / Q000166:cytology*; D014162:Transfection
D016376:Oligonucleotides, Antisense; D020710:RGS Proteins; D012333:RNA, Messenger; D011983:Receptors, Purinergic; C105345:Rgs2 protein, mouse; D000255:Adenosine Triphosphate; D002118:Calcium