Genetic profiling of alpha 1-adrenergic receptor subtypes by oligonucleotide microarrays: coupling to interleukin-6 secretion but differences in STAT3 phosphorylation and gp-130.
Alpha(1)-adrenoceptor subtypes (alpha(1A)-, alpha(1B)-, alpha(1D)-) are known to couple to similar signaling pathways, although differences among the subtypes do exist. As a more sensitive assay, we used oligonucleotide microarrays to identify gene expression changes in Rat-1 fibroblasts stably expressing each individual subtype. We report the gene expressions that change by at least a factor of 2 or more. Gene expression profiles significantly changed equally among all three subtypes, despite the unequal efficacy of the inositol phosphate response. Gene expressions were clustered into cytokines/growth factors, transcription factors, enzymes, and extracellular matrix proteins. There were also a number of individual subtype-specific changes in gene expression, suggesting a link to independent pathways. In addition, all three alpha(1)-AR subtypes robustly stimulated the transcription of the prohypertrophic cytokine interleukin (IL)-6, but differentially altered members of the IL-6 signaling pathway (gp-130 and STAT3). This was confirmed by measurement of secreted IL-6, activated STAT3, and gp-130 levels. Activation of STAT3 Tyr705 phosphorylation by the alpha(1)-ARs was not through IL-6 activation but was synergistic with IL-6, suggesting direct effects. Interestingly, alpha(1B)-AR stimulation caused the dimerization-dependent phosphorylation of Tyr705 on STAT3 but did not activate the transcriptional-dependent phosphorylation of Ser727. The alpha(1B)-AR also constitutively down-regulated the protein levels of gp-130. These results suggest that the alpha(1B)-AR has differential effects on the phosphorylation status of the STAT3 pathway and may not be as prohypertrophic as the other two subtypes.
Gonzalez-Cabrera
Pedro J
PJ
Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Gaivin
Robert J
RJ
Yun
June
J
Ross
Sean A
SA
Papay
Robert S
RS
McCune
Dan F
DF
Rorabaugh
Boyd R
BR
Perez
Dianne M
DM
D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D001667:Binding, Competitive; D015152:Blotting, Northern; D002478:Cells, Cultured; D050822:Cytokine Receptor gp130; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004837:Epinephrine / Q000494:pharmacology; D005347:Fibroblasts / Q000378:metabolism; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism*; D008562:Membrane Glycoproteins / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D010766:Phosphorylation; D051381:Rats; D018340:Receptors, Adrenergic, alpha-1 / Q000145:classification / Q000235:genetics*; D050796:STAT3 Transcription Factor; D012694:Serine / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D015534:Trans-Activators / Q000378:metabolism*; D014316:Tritium
C547716:ADRA1B protein, human; C547718:Adra1b protein, rat; D015703:Antigens, CD; D004268:DNA-Binding Proteins; C494199:IL6ST protein, human; C494201:Il6st protein, rat; D007295:Inositol Phosphates; D015850:Interleukin-6; D008562:Membrane Glycoproteins; D018340:Receptors, Adrenergic, alpha-1; D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human; C494088:Stat3 protein, rat; D015534:Trans-Activators; D014316:Tritium; D050822:Cytokine Receptor gp130; D012694:Serine; D004837:Epinephrine