Protein Kinase A–Dependent Stimulation of Rat Type II Secreted Phospholipase A
            <sub>2</sub>
            Gene Transcription Involves C/EBP-β and -δ in Vascular Smooth Muscle Cells

Couturier, Cyril; Antonio, Valérie; Brouillet, Arthur; Béréziat, G.; Raymondjean, Michel; Andreani, Marise

doi:10.1161/01.atv.20.12.2559

Cited by 24 publications

(30 citation statements)

References 44 publications

(49 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Moreover, deletion to Ϫ156 or Ϫ42 bp abrogated the SAA induction of the promoter, indicating that the response elements reside in the promoter region between Ϫ488 and Ϫ156 bp. Two C/EBP binding sites in the region upstream of base pair Ϫ156 have been described previously (24). Western blot analysis was conducted on cell lysates from cultures treated with SAA to look for changes in C/EBP␤ expression.…”

Section: Resultsmentioning

confidence: 99%

“…In addition, site-directed mutant promoter constructs include those with mutations in the two C/EBP binding sites (C/EBP ⌬1 and C/EBP ⌬2 ) and one NFB binding site (NFB ⌬ ) previously identified within the 488 promoter fragment (23). A luciferase reporter construct (C-Luc) in which luciferase expression is driven by 4 repeats of C/EBP binding site 1 was used (24). Last, a luciferase reporter construct (N-Luc) in which luciferase expression is driven by 6 repeats of an NFB binding site was kindly provided by Dr. Gail Sonenshein, Boston University School of Medicine, Boston, MA.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Secretory Phospholipase A2, Group IIA Is a Novel Serum Amyloid A Target Gene

Sullivan

Seidl

Rich

et al. 2010

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

Atherosclerosis is a multifactorial vascular disease characterized by formation of inflammatory lesions. Elevated circulating acute phase proteins indicate disease risk. Serum amyloid A (SAA) is one such marker but its function remains unclear. To determine the role of SAA on aortic smooth muscle cell gene expression, a preliminary screen of a number of genes was performed and a strong up-regulation of expression of secretory phospholipase A 2 , group IIA (sPLA 2 ) was identified. The SAAinduced increase in sPLA 2 was validated by real time PCR, Western blot analysis, and enzyme activity assays. Demonstrating that SAA increased expression of sPLA 2 heteronuclear RNA and that inhibiting transcription eliminated the effect of SAA on sPLA 2 mRNA suggested that the increase was transcriptional. Transient transfections and electrophoretic mobility shift assays identified CAAT enhancer-binding protein (C/EBP) and nuclear factor B (NFB) as key regulatory sites mediating the induction of sPLA 2 . Moreover, SAA activated the inhibitor of NF-B kinase (IKK) in cultured smooth muscle cells. Previous reports showed that interleukin (IL)-1␤ up-regulates Pla2g2a gene transcription via C/EBP␤ and NFB. Interestingly, SAA activated smooth muscle cell IL-1␤ mRNA expression, however, blocking IL-1 receptors had no effect on SAA-mediated activation of sPLA 2 expression. Thus, the observed changes in sPLA 2 expression were not secondary to SAA-induced IL-1 receptor activation. The association of SAA with high density lipoprotein abrogated the SAA-induced increase in sPLA 2 expression. These data suggest that during atherogenesis, SAA can amplify the involvement of smooth muscle cells in vascular inflammation and that this can lead to deposition of sPLA 2 and subsequent local changes in lipid homeostasis.Elevated circulating acute phase proteins correlate with an increased risk for atherosclerosis (1-4). One such disease indicator is serum amyloid A (SAA) 2 (5). The SAA protein family consists of 12-14-kDa constitutive (SAA 4 ) and acute phase (SAA 1 , SAA 2 , and SAA 3 ) isoforms. During inflammation, there are large changes in liver-derived plasma levels of the acute phase isoforms, SAA 1 and SAA 2 (6, 7). The other acute phase isoform, SAA 3 , is extrahepatically inducible (8), and although the locus equivalent to SAA 3 was previously believed to be a pseudogene in humans, Larson and co-workers (9) demonstrated its expression by mammary gland epithelial cells. Proinflammatory stimuli induce SAA expression in liver; optimal expression is achieved with a combination of interleukin (IL)-1 and IL-6 (10, 11). Extrahepatic synthesis of SAA by synovial fibroblasts, macrophages, adipocytes, and smooth muscle cells has been documented (12-15). SAA is also expressed in atherosclerotic lesions (13,16,17). Although several roles have been suggested, the functions of SAA remain uncertain (7). Our laboratory demonstrated that in response to IL-1␣, cultured aortic smooth muscle cells synthesize SAA (18) leading to the hypothesis that during ather...

show abstract

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

Secretory Phospholipase A2, Group IIA Is a Novel Serum Amyloid A Target Gene

Sullivan

Seidl

Rich

et al. 2010

Journal of Biological Chemistry

Self Cite

View full text Add to dashboard Cite

show abstract

“…One was VSMCs isolated from rat aortas, previously used to study the interplay of transcription factors involved in the activation of the rat sPLA2-IIA promoter. 20,21 The other one was a line of human VSMCs (AU-1 cells), used as a species homologous model. We demonstrate here that sPLA2-IIA has paracrine/autocrine functions, independent of its catalytic activity and involving the PLA2 receptor and/or proteoglycans.…”

Section: Conclusion-wementioning

confidence: 99%

“…21 AU-1 cells are a cell line derived from a human aorta. Their morphology and the staining with monoclonal antibodies to ␣-actin and desmin confirmed the smooth muscle cell phenotype.…”

Section: Aortic Smooth Muscle Cellsmentioning

confidence: 99%

“…Nontransfected cells were incubated for 24 hours with medium alone (control), medium containing effectors known to induce sPLA2-IIA (IL-1␤ plus forskolin), 21 supernatant of control cells transfected with a Bluescript-KS plasmid (control supernatant), and supernatant of cells transfected with hsPLA2- Figure 1. Surexpression of human sPLA2-IIA proteins in VSMCs supernatants.…”

Section: Influence Of a Supernatant Containing Hspla2-iia Proteins Onmentioning

confidence: 99%

See 1 more Smart Citation

Autocrine and Paracrine Transcriptional Regulation of Type IIA Secretory Phospholipase A2 Gene in Vascular Smooth Muscle Cells

Jaulmes

Janvier

Andreani

et al. 2005

ATVB

Self Cite

View full text Add to dashboard Cite

Objective-The inflammation that occurs during the development of atherosclerosis is characterized by a massive release of sPLA2-IIA (group IIA secretory phospholipase A2) from vascular smooth muscle cells (VSMCs). We have investigated the autocrine function of sPLA2-IIA in rat aortic and human VSMCs. Methods and Results-We found that the transcription of the endogenous sPLA2-IIA gene increased by adding a cell supernatant containing human sPLA2-IIA proteins. We show that this effect was independent of the sPLA2 activity using sPLA2-IIA proteins lacking enzyme activity. Transient transfections with various sPLA2-IIA rat promoterluciferase constructs demonstrated that the C/EBP, NK-B, and Ets transcription factors are involved in the increase in sPLA2-IIA gene transcription. We also found the M-type sPLA2 receptor mRNA in VSMCs, and we showed that the sPLA2-luciferase reporter gene was induced by the specific agonist of the sPLA2 receptor, aminophenylmannopyranoside (APMP), and that this induction was mediated by the same transcription factor-binding sites. Finally, we used a sPLA2-IIA mutant unable to bind heparan-sulfate proteoglycans to show that the binding of wild-type sPLA2-IIA to proteoglycans is essential for the induction of an autocrine loop. Key Words: atherosclerosis Ⅲ autocrine/paracrine effects Ⅲ type IIA sPLA2 Ⅲ vascular smooth muscle cells P hospholipase A2 (PLA2) enzymes (EC 3.1.1.4) hydrolyze ester bonds at the sn-2 position of glyceroacylphospholipids to produce lysophospholipids and nonesterified fatty acids such as arachidonic acid (C20:4 n-6). The latter is further metabolized, contributing to the proinflammatory actions and later resolution. 1 PLA2 enzymes are present in most tissues and 4 groups are distinguished by subcellular location, molecular weight, and calcium dependence. One of these groups is secretory PLA2s (sPLA2s). The sPLA2s are extracellular low-molecular-mass (13 to 18 kDa) enzymes that have 6 to 8 disulfide bridges and require millimolar concentrations of Ca 2ϩ . 2 The isoform sPLA2-IIA is the most abundant sPLA2 in vascular smooth muscle cells (VSMCs). 3 Its synthesis is stimulated by inflammatory cytokines such as interleukin 1␤ (IL-1␤), IL-6, and tumor necrosis factor-1␣. 4 The plasma of patients with various inflammatory diseases, particularly atherosclerosis, contains high concentrations of sPLA2-IIA. 5,6 Transgenic mice that overproduce human sPLA2-IIA have confirmed its involvement in atherosclerosis. 7 sPLA2-IIA also functions as a messenger, and this latter function can be independent of its enzymatic activity. For example, sPLA2-IIA triggers a signaling cascade in monocytic cells that has features similar to those found in other cell types and seems to be unrelated to its catalytic activity. 8,9 The recent identification of membrane proteins binding sPLA2 has highlighted the biological effects of these enzymes. Several studies have shown that sPLA2-IB and sPLA2-IIA act via specific receptors characterized in several species (M-type receptors) to play roles that are...

show abstract

Upregulation of TNF‐α‐induced ICAM‐1 surface expression by adenylate cyclase‐dependent pathway in human endothelial cells

Bernot

Peiretti

Canault

et al. 2004

Journal Cellular Physiology

View full text Add to dashboard Cite

The level of adhesion molecules expressed at the endothelial cell surface is critical in the control of inflammation. Adenylate cyclase (AC) activity allowing cyclic adenosine monophosphate (cAMP) production can modulate the inflammatory process. We investigated the AC-dependent modulation of ICAM-1 surface expression in human umbilical venous endothelial cells (HUVEC). Pretreatment of HUVEC with forskolin significantly upregulated tumor necrosis factor alpha (TNF-alpha)- and interleukin-1 alpha (IL1-alpha)-induced ICAM-1 surface expression exclusively after a prolonged time of incubation with forskolin (at least 7-8 h). A poorly metabolizable analog of cAMP, dibutyryl-cAMP, mimicked forskolin effect on ICAM-1 surface expression. Protein kinase A (PKA) inhibitor H89 prevented forskolin effect on ICAM-1 surface expression. Upregulation of ICAM-1 surface level occurred through the increase in its mRNA levels and also to a subsequent activation of ICAM-1 intracellular trafficking towards cell surface. Stimulation by agonists of beta-adrenergic receptors did not alter the TNF-alpha-induced ICAM-1 surface expression. Pretreatment of HUVEC with pertussis toxin, which is known to activate AC through Gialpha inhibition, upregulated mRNA levels and surface expression of ICAM-1 induced by TNF-alpha. This effect was serum-dependent, since ICAM-1 expression was no more upregulated by pertussis toxin in cells cultured in 1% instead of 20% serum-enriched medium. However, forskolin treatment of HUVEC did not modify their overall adhesive properties. In conclusion, a persistent cAMP level elevation activating PKA is able to enhance ICAM-1 expression at the cell surface of endothelial cells placed under pro-inflammatory conditions. Combination of activation of gene transcription and membrane targeting may account for this augmentation.

show abstract

Protein Kinase A–Dependent Stimulation of Rat Type II Secreted Phospholipase A ₂ Gene Transcription Involves C/EBP-β and -δ in Vascular Smooth Muscle Cells

Cited by 24 publications

References 44 publications

Secretory Phospholipase A2, Group IIA Is a Novel Serum Amyloid A Target Gene

Secretory Phospholipase A2, Group IIA Is a Novel Serum Amyloid A Target Gene

Autocrine and Paracrine Transcriptional Regulation of Type IIA Secretory Phospholipase A2 Gene in Vascular Smooth Muscle Cells

Upregulation of TNF‐α‐induced ICAM‐1 surface expression by adenylate cyclase‐dependent pathway in human endothelial cells

Contact Info

Product

Resources

About

Protein Kinase A–Dependent Stimulation of Rat Type II Secreted Phospholipase A 2 Gene Transcription Involves C/EBP-β and -δ in Vascular Smooth Muscle Cells

Cited by 24 publications

References 44 publications

Secretory Phospholipase A2, Group IIA Is a Novel Serum Amyloid A Target Gene

Secretory Phospholipase A2, Group IIA Is a Novel Serum Amyloid A Target Gene

Autocrine and Paracrine Transcriptional Regulation of Type IIA Secretory Phospholipase A2 Gene in Vascular Smooth Muscle Cells

Upregulation of TNF‐α‐induced ICAM‐1 surface expression by adenylate cyclase‐dependent pathway in human endothelial cells

Contact Info

Product

Resources

About

Protein Kinase A–Dependent Stimulation of Rat Type II Secreted Phospholipase A ₂ Gene Transcription Involves C/EBP-β and -δ in Vascular Smooth Muscle Cells