CRE and SRE mediate LPA-induced CCN1 transcription in mouse aortic smooth muscle cells.
Lysophosphatidic acid (LPA), one component of oxidized low-density lipoprotein (ox-LDL), is a potent bioactive phospholipid. Our recent data reveal that LPA induces matricellular protein CCN1 (also known as Cyr61) expression in aortic smooth muscle cells (SMCs) and that CCN1 bridges LPA and integrin signaling pathways leading to SMC migration. Whether and how LPA regulates the transcriptional machinery of the CCN1 gene are unknown. In this study, we found that LPA markedly induces CCN1 mRNA expression in SMCs. Using deleting mutation and reporter gene strategies, we demonstrated regions from -2038 to -1787 and from -101 to +63 of the CCN1 promoter contain the essential regulatory elements. The serum response element (SRE) and cyclic AMP-response element (CRE) are located in these regions. LPA induced time-dependent phosphorylation of serum response factor (SRF) and CRE-binding protein (CREB) in mouse SMCs. Luciferase assays of a series of deleted, mutated CCN1 promoter-reporter gene constructs and dominant negative construct revealed the distal SRE and the proximal CRE in the CCN1 promoter are required for LPA-induced CCN1 gene expression. Our results imply that elevated LPA levels may trigger SMC migration and exacerbate restenosis and atherosclerotic lesions through the induced CCN1, which communicates with a set of plasma membrane proteins and intracellular kinases.
a Department of Biomedical & Diagnostic Sciences, University of Tennessee, Knoxville, Tennessee, USA.|b State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China 810016.
Quanlin
Q
Dou
a Department of Biomedical & Diagnostic Sciences, University of Tennessee, Knoxville, Tennessee, USA.
Feng
F
Hao
a Department of Biomedical & Diagnostic Sciences, University of Tennessee, Knoxville, Tennessee, USA.|c College of Animal Science and Technology, Yangzhou University, China 225009.
Longsheng
L
Sun
a Department of Biomedical & Diagnostic Sciences, University of Tennessee, Knoxville, Tennessee, USA.
Xuemin
X
Xu
a Department of Biomedical & Diagnostic Sciences, University of Tennessee, Knoxville, Tennessee, USA.
Mei-Zhen
MZ
Cui
D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D001665:Binding Sites; D002478:Cells, Cultured; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D055515:Cysteine-Rich Protein 61 / Q000235:genetics* / Q000378:metabolism; D017930:Genes, Reporter; D008246:Lysophospholipids / Q000494:pharmacology*; D051379:Mice; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D027602:Serum Response Element / Q000187:drug effects*; D026362:Serum Response Factor / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic / Q000187:drug effects*; D015533:Transcriptional Activation / Q000187:drug effects*; D014162:Transfection; D015854:Up-Regulation
C491850:CCN1 protein, mouse; C492004:Creb1 protein, mouse; D017362:Cyclic AMP Response Element-Binding Protein; D055515:Cysteine-Rich Protein 61; D008246:Lysophospholipids; D012333:RNA, Messenger; D026362:Serum Response Factor; C032881:lysophosphatidic acid
CCN1; acide lysophosphatidique; aortic smooth muscle cells; cellules musculaires lisses aortiques; gene regulation; lysophosphatidic acid; régulation génique; transcription