scholarly journals Cytosolic phospholipase A2 gene expression in rat mesangial cells is regulated post-transcriptionally

1994 ◽  
Vol 304 (2) ◽  
pp. 417-422 ◽  
Author(s):  
A Tay ◽  
P Maxwell ◽  
Z G Li ◽  
H Goldberg ◽  
K Skorecki
Keyword(s):  
Gene Expression ◽  
Growth Factor ◽  
Phospholipase A2 ◽  
Mesangial Cells ◽  
Luciferase Activity ◽  
Cytosolic Phospholipase A2 ◽  
Mrna Levels ◽  
Glomerular Mesangial Cells ◽  
Coding Region ◽  
Cytosolic Phospholipase

Cytosolic phospholipase A2 (cPLA2) is thought to be the rate-limiting enzyme in the arachidonic acid/eicosanoid cascade. The ability of various agonists to increase steady-state cPLA2 mRNA levels has previously been reported. The current study delineates the contributions of transcriptional and post-transcriptional processes to the regulation of cPLA2 gene expression in response to a variety of agonists in cultured rat glomerular mesangial cells. Epidermal growth factor, platelet-derived growth factor, serum and phorbol myristate acetate all increase the half-life of cPLA2 mRNA transcripts, indicating a role for post-transcriptional modulation of gene expression. The presence of three ATTTA motifs in the 3′ untranslated region (3′UTR) of the rat cPLA2 cDNA is ascertained. Heterologous expression of chimeric constructs with different 3′UTRs ligated into the 3′ end of the luciferase coding region reveals that the presence of the cPLA2 3′UTR results in reduced luciferase activity compared with constructs without the cPLA2 3′UTR. Furthermore, the luciferase activity in the constructs with the cPLA2 3′UTR is increased in response to the same agonists which stabilize endogenous cPLA2 mRNA. A negligible effect of these agonists on transcriptional control of cPLA2 is evident using promoter-reporter constructs expressed in transient and stable transfectants. Taken together, these results indicate predominant post-transcriptional regulation of cPLA2 mRNA levels.

scholarly journals Epidermal growth factor and phorbol myristate acetate increase expression of the mRNA for cytosolic phospholipase A2 in glomerular mesangial cells

1993 ◽  
Vol 295 (3) ◽  
pp. 763-766 ◽  
Author(s):  
A P Maxwell ◽  
H J Goldberg ◽  
A H N Tay ◽  
Z G Li ◽  
G S Arbus ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Phospholipase A2 ◽  
Mesangial Cells ◽  
Mrna Levels ◽  
Glomerular Mesangial Cells ◽  
Pla2 Activity ◽  
Mrna Accumulation ◽  
Epidermal Growth

We have previously shown that phospholipase A2 (PLA2) activity is rapidly activated by epidermal growth factor (EGF) and phorbol 12-myristate 13-acetate (PMA) in renal mesangial cells and other cell systems in a manner that suggests a covalent modification of the PLA2 enzyme(s). This PLA2 activity is cytosolic (cPLA2) and is distinct from secretory forms of PLA2, which are also stimulated in mesangial cells in response to cytokines and other agonists. However, longer-term regulation of cPLA2 in renal cells may also occur at the level of gene expression. Cultured rat mesangial cells were used as a model system to test the effects of EGF and PMA on the regulation of cPLA2 gene expression. EGF and PMA both produced sustained increases in cPLA2 mRNA levels, with a parallel increase in enzyme activity over time. Inhibition of protein synthesis by cycloheximide increased basal cPLA2 mRNA accumulation in serum-starved mesangial cells, and the combination of EGF and cycloheximide resulted in super-induction of cPLA2 gene expression compared with EGF alone. Actinomycin D treatment entirely abrogated the effect of EGF on cPLA2 mRNA accumulation. These findings suggest that regulation of cPLA2 is achieved by factors controlling gene transcription and possibly mRNA stability, in addition to previously characterized posttranslational modifications.

scholarly journals Endothelin-1 stimulates cytosolic phospholipase A2 activity and gene expression in rat glomerular mesangial cells

1994 ◽  
Vol 46 (6) ◽  
pp. 1644-1652 ◽  
Author(s):  
Herbert Schramek ◽  
Yizheng Wang ◽  
Martha Konieczkowski ◽  
Michael S. Simonson ◽  
Michael J. Dunn
Keyword(s):  
Gene Expression ◽  
Phospholipase A2 ◽  
Mesangial Cells ◽  
Cytosolic Phospholipase A2 ◽  
Glomerular Mesangial Cells ◽  
Endothelin 1 ◽  
Cytosolic Phospholipase ◽  
Phospholipase A2 Activity

Gene expression profile of endothelin-1-induced growth in glomerular mesangial cells

2003 ◽  
Vol 285 (5) ◽  
pp. C1109-C1115 ◽  
Author(s):  
Rangnath Mishra ◽  
Patrick Leahy ◽  
Michael S. Simonson
Keyword(s):  
Gene Expression ◽  
Growth Factor ◽  
Cell Growth ◽  
Gene Expression Profile ◽  
Expression Profile ◽  
Kinase Inhibitor ◽  
Mesangial Cells ◽  
Growth Control ◽  
Glomerular Mesangial Cells ◽  
Regulated Gene Expression

Endothelin (ET)-1 is a vasoconstrictor and mitogen involved in vascular remodeling. Changes in gene expression that underlie control of cell growth by ET-1 remain poorly characterized. To identify pathways of growth control we used microarrays to analyze ET-1-regulated gene expression in human mesangial cells, an important ET-1 vascular target cell in vivo. Statistical assessment of differential expression (significance analysis of microarrays) revealed upregulated transcripts for growth factors [heparin-binding epidermal growth factor (EGF)-like growth factor (HB-EGF), fibroblast growth factor (FGF), interleukin (IL)-6] and downregulated transcripts for genes that inhibit growth (BAX, p27KIP1, DAD1). Consistent with the gene expression profile, quantitative RT-PCR and Western blotting confirmed induction of HB-EGF by ET-1. To test a functional role for HB-EGF in ET-1 signaling, we showed that exogenous HB-EGF stimulated phosphorylation of ErbB1 and growth of mesangial cells. ET-1-induced proliferation was blocked by an ErbB1 receptor-selective kinase inhibitor and by a specific ErbB1 receptor-neutralizing antibody. Proliferation in response to ET-1 was also inhibited by neutralizing antisera against human HB-EGF. Together, these results provide data for modeling ET-1 pathways for growth control and suggest a specific role for HB-EGF gene induction in mesangial cell growth in response to ET-1.

scholarly journals Enhancement of Cortisol-Induced 11β-Hydroxysteroid dehydrogenase Type 1 Expression by Interleukin 1β in Cultured Human Chorionic Trophoblast Cells

Endocrinology ◽  
2006 ◽  
Vol 147 (5) ◽  
pp. 2490-2495 ◽  
Author(s):  
Wenjiao Li ◽  
Lu Gao ◽  
Yan Wang ◽  
Tao Duan ◽  
Leslie Myatt ◽  
...  
Keyword(s):  
Gene Expression ◽  
Phospholipase A2 ◽  
Mrna Expression ◽  
Reporter Gene ◽  
Reductase Activity ◽  
Hydroxysteroid Dehydrogenase ◽  
Cytosolic Phospholipase A2 ◽  
Trophoblast Cells ◽  
Cytosolic Phospholipase

Chorion is the most abundant site of 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) expression within intrauterine tissues. It is important to study the regulation of 11β-HSD1 expression in the chorion in terms of local cortisol production during pregnancy. Using real-time PCR and enzyme activity assay, we found that cortisol (1 μm) and IL-1β (10 ng/ml) for 24 h significantly increased 11β-HSD1 mRNA expression and reductase activity in cultured human chorionic trophoblasts. A further significant increase of 11β-HSD1 mRNA expression and reductase activity was observed with cotreatment of cortisol and IL-1β. To explore the mechanism of induction, 11β-HSD1 promoter was cloned into pGL3 plasmid expressing a luciferase reporter gene. By transfecting the constructed vector into WISH cells, an amnion-derived cell line, we found that cortisol (1 μm) or IL-1β (10 ng/ml) significantly increased reporter gene expression. Likewise, an additional increase in reporter gene expression was observed with cotreatment of cortisol and IL-β. To explore the physiological significance of 11β-HSD1 induction in the chorion, we studied the effect of cortisol on cytosolic phospholipase A2 and cyclooxygenase 2 expression. We found that treatment of chorionic trophoblast cells with cortisol (1 μm) induced both cytosolic phospholipase A2 and cyclooxygenase 2 mRNA expression. We conclude that cortisol up-regulates 11β-HSD1 expression through induction of promoter activity, and the effect was enhanced by IL-1β, suggesting that more biologically active glucocorticoids could be generated in the fetal membranes in the presence of infection, which may consequently feed forward in up-regulation of prostaglandin synthesis.

A role for G-proteins in the epidermal growth factor stimulation of phospholipase A2 in rat kidney mesangial cells

1990 ◽  
Vol 10 (4) ◽  
pp. 353-362 ◽  
Author(s):  
Nashrudeen Hack ◽  
Paula Clayman ◽  
Karl Skorecki
Keyword(s):  
Arachidonic Acid ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Phospholipase A2 ◽  
G Protein ◽  
Mesangial Cells ◽  
Rat Kidney ◽  
Glomerular Mesangial Cells ◽  
Epidermal Growth ◽  
Stimulation Of

We have previously demonstrated phospholipase C (PLC) independent activation of phospholipase A2(PLA2) by epidermal growth factor (EGF) in glomerular mesangial cells in culture. In the current study using glass beads to permeabilize [3H]- or [14C]-arachidonate labelled mesangial cells we demonstrate that guanine nucleotides modulate the EGF-mediated stimulation of arachidonic acid release (75% inhibition with 100 μM GDPβS and 108% augmentation with 100 μM GTPγS). GTPγS alone stimulated both the release of free arachidonic acid and production of diacylglycerol (DAG), while EGF itself neither stimulated DAG nor augmented the DAG response to GTPγS. These findings suggest the intermediacy of a G-protein in PLC-independent stimulation of PLA2 by a growth factor, and provide a model system for determining the relationship between G-protein intermediacy and the intrinsic tyrosine kinase activity of the growth factor receptor.

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