scholarly journals Stimulation of prostaglandin E2 (PGE2) production by arachidonic acid, oestrogen and parathyroid hormone in MG-63 and MC3T3-E1 osteoblast-like cells

2005 ◽  
Vol 73 (6) ◽  
pp. 423-430 ◽  
Author(s):  
M. Coetzee ◽  
M. Haag ◽  
N. Claassen ◽  
M.C. Kruger
Keyword(s):  
Arachidonic Acid ◽  
Parathyroid Hormone ◽  
Prostaglandin E2 ◽  
Pge2 Production ◽  
Stimulation Of

Endocytosis by cultured mesangial cells and associated changes in prostaglandin E2 synthesis

1987 ◽  
Vol 252 (4) ◽  
pp. F627-F634
Author(s):  
P. C. Singhal ◽  
G. H. Ding ◽  
S. DeCandido ◽  
N. Franki ◽  
R. M. Hays ◽  
...  
Keyword(s):  
Prostaglandin E2 ◽  
Cytochalasin B ◽  
Mesangial Cells ◽  
Pge2 Production ◽  
Receptor Interaction ◽  
Coated Pits ◽  
Pge2 Synthesis ◽  
Gold Particles ◽  
Fresh Serum ◽  
Stimulation Of

The mechanism of macromolecule uptake by cultured mesangial cells was studied by use of transmission electron microscopy. In parallel, we investigated the effect of macromolecular uptake on prostaglandin E2 (PGE2) formation. Cultured rat mesangial cells were studied in their third passage. As model molecules, we used colloidal gold particles (10 nm diameter) coated either with polyethylene glycol (PEG) or fresh serum (SCG). Mesangial cells were incubated from 1 to 60 min and up to 12 h with either PEG or SCG particles. Endocytosis of SCG significantly exceeded that of PEG particles. The mechanism involved binding to coated pits, followed by formation of coated vesicles (endosomes), and eventually delivery of particles to lysosomes. Pretreatment with cytochalasin B virtually prevented endocytosis of SCG particles, indicating active participation of the cytoskeleton. Determination of PGE2 production in parallel showed that SCG significantly stimulated PGE2 synthesis within minutes, whereas PEG-coated gold had no effect. When gold particles were coated with decomplemented serum instead of fresh serum, the stimulation of PGE2 was partially, but not completely, prevented, indicating that complement may be one, but not the only ligand responsible for enhanced PGE2 production. Stimulation of PGE2 synthesis by SCG was not dependent on actual endocytosis, as it was not altered by cytochalasin B pretreatment. Thus, surface ligand-receptor interaction may be sufficient to trigger PGE2 synthesis. The interaction between mesangial endocytosis and PGE2 production may be important for glomerular pathophysiology.

scholarly journals Characterization of ATP receptor responsible for the activation of phospholipase A2 and stimulation of prostaglandin E2 production in thymic epithelial cells

1995 ◽  
Vol 308 (2) ◽  
pp. 399-404 ◽  
Author(s):  
P Liu ◽  
M Wen ◽  
J Hayashi
Keyword(s):  
Epithelial Cells ◽  
Prostaglandin E2 ◽  
Phospholipase A2 ◽  
Enzymic Activity ◽  
Pge2 Production ◽  
Thymic Epithelial Cells ◽  
Cross Linking ◽  
Atp Binding ◽  
Variant Cell ◽  
Stimulation Of

In TEA3A1 rat thymic epithelial cells, ATP stimulates prostaglandin E2 (PGE2) production through activation of phospholipase A2 (PLA2) enzymic activity. The stimulation of PGE2 production tested with other nucleotides indicated the agonist potency of adenosine 5′-[gamma-thio]triphosphate (ATP[S]) > or = UTP > ATP, with ED50 of about 10 microM for ATP[S]. In TEA3A1 cells, cross-linking studies with ATP[35S] revealed the presence of four cell-surface cross-linked bands of 42 kDa, 53 kDa, 83 kDa and 100 kDa in Triton X-100 extracts of TEA3A1 cells by fluorography. Guanosine 5′-[gamma-thio]triphosphate specifically blocked the cross-linking of ATP[35S] to the 53 kDa, 83 kDa and 100 kDa ATP-binding proteins, and inhibited the ATP[S]-mediated stimulation of PGE2 production with an ED50 of about 25 microM. On the other hand, 2-methylthioadenosine triphosphate (2MeSATP) blocked ATP[35S] cross-linking to the 42 kDa protein, but had no effect on ATP[S]-mediated stimulation of PGE2 production. In a variant cell line, TEAvarl, derived from TEA3A1 cells that lost their response to ATP in the activation of PLA2, the presence of 83 kDa ATP-binding protein was not detected. Results from our study suggest that ATP activates PLA2 enzymic activity in TEA3A1 cells by binding to an atypical ATP receptor that has not been described previously.

Effects of atrial natriuretic peptide on renal medullary prostaglandin E2 production

1989 ◽  
Vol 257 (3) ◽  
pp. F336-F340
Author(s):  
R. J. Bolterman ◽  
M. D. Bentley ◽  
S. M. Sandberg ◽  
M. J. Fiksen-Olsen ◽  
J. C. Romero
Keyword(s):  
Arachidonic Acid ◽  
Atrial Natriuretic Peptide ◽  
Prostaglandin E2 ◽  
Natriuretic Peptide ◽  
Inhibitory Effect ◽  
Pge2 Production ◽  
In Vitro Effects ◽  
Different Doses ◽  
Atrial Natriuretic

Like arachidonic acid (AA) and bradykinin (BK), the intrarenal administration of atrial natriuretic peptide (ANP) has been shown to increase the urinary excretion of prostaglandin E2 (PGE2). In the present study, the direct in vitro effects of ANP on PGE2 production were compared with those of AA and BK. Canine renal inner medullary slices were preincubated for 30 min and washed in aerated Krebs-Ringer buffer (37 degrees C). During the final incubation period, with the use of varied concentrations of AA, BK, or ANP in Krebs-Ringer buffer, samples were obtained at 0 and 30 min to be used for radioimmunoassay of PGE2. Although the rate of PGE2 production was significantly increased 11-fold with AA and threefold with BK, it was unaffected by four different doses of ANP (10(-5) to 10(-11) M). Furthermore, the production of PGE2 during basal and stimulated (BK or AA) conditions was significantly blocked by indomethacin but not by ANP. These results indicate that ANP had no direct stimulatory or inhibitory effect on the medullary production of PGE2.

scholarly journals Stimulation of creatine kinase BB activity by parathyroid hormone and by prostaglandin E2 in cultured bone cells

1985 ◽  
Vol 225 (3) ◽  
pp. 591-596 ◽  
Author(s):  
D Sömjen ◽  
A M Kaye ◽  
I Binderman
Keyword(s):  
Creatine Kinase ◽  
Parathyroid Hormone ◽  
Prostaglandin E2 ◽  
Bone Cells ◽  
Combined Treatment ◽  
Fold Increase ◽  
Bone Cell ◽  
Growth Promoters ◽  
Bone Cell Cultures ◽  
Stimulation Of

Bone cells in culture responded to parathyroid hormone (PTH) and prostaglandin E2 (PGE2) by a 2-fold increase in creatine kinase (CK) activity. Combined treatment resulted in a higher response than with PTH alone. Calcitonin (CT) failed to stimulate CK activity, did not affect the response of CK to PTH, but inhibited slightly the increase in CK activity by PGE2. Bone-cell cultures grown in low [Ca2+] (0.125 mM), enriched in PTH-responsive osteoblast-like cells, responded to PTH, but not to PGE2 or CT, by increased CK activity. In both normal and low-[Ca2+] cultures, 8-bromo cyclic AMP did not affect CK activity, nor did it change the response of the cells to PTH, PGE2 or CT. The increase in CK activity was time- and dose-dependent and inhibited both by cycloheximide and by actinomycin D. The isoenzyme of CK stimulated was the CKBB form, the isoenzyme induced by other hormones. This appears to be the first report of the stimulation of CK activity by a polypeptide hormone or a prostaglandin. We suggest that stimulation of CKBB can serve as a marker for the action of a variety of hormones and growth promoters.

Stimulation of leptin release by arachidonic acid and prostaglandin E2 in adipose tissue from obese humans

Metabolism ◽  
2001 ◽  
Vol 50 (8) ◽  
pp. 921-928 ◽  
Author(s):  
John N. Fain ◽  
Charles W. Leffler ◽  
George S.M. Cowan ◽  
Cynthia Buffington ◽  
Lisa Pouncey ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Arachidonic Acid ◽  
Prostaglandin E2 ◽  
Stimulation Of

Synthesis of prostaglandin E2 in different segments of isolated collecting tubules from adult and neonatal rabbits

1985 ◽  
Vol 248 (1) ◽  
pp. F134-F144 ◽  
Author(s):  
D. Schlondorff ◽  
J. A. Satriano ◽  
G. J. Schwartz
Keyword(s):  
Arachidonic Acid ◽  
Prostaglandin E2 ◽  
Feedback Loop ◽  
Pge2 Production ◽  
Large Variability ◽  
Pge2 Synthesis ◽  
Collecting Tubule ◽  
Concentrate Urine ◽  
Collecting Tubules

Prostaglandin E2 (PGE2) inhibits the action of the antidiuretic hormone (ADH) in isolated collecting tubules. A negative feedback loop has been postulated whereby ADH stimulates PGE2 synthesis. Furthermore, lysyl-bradykinin (LBK) inhibits the antidiuretic effect of ADH, probably via PGE2. Enhanced PGE2 synthesis has also been implicated as contributing to the inability to maximally concentrate urine during the neonatal period. We investigated PGE2 synthesis in microdissected cortical (CCT), medullary (MCT), and branched cortical (BCT) collecting tubules from adult and in corticomedullary collecting tubules (CT) from newborn rabbits. Isolated BCT produced significantly less PGE2 (12 +/- 2 pg X mm-1 X 20 min-1) than CCT (65 +/- 9) or MCT (76 +/- 8) from kidneys of adult rabbits. CT from newborn rabbits produced only 19 +/- 3 pg/mm, significantly less than either CCT or MCT from adults. A large variability in basal PGE2 production and hormonal response was observed from tubule to tubule. Under either basal conditions or in the presence of 2 microM arachidonic acid, LBK enhanced PGE2 synthesis in CCT and MCT from adults. ADH enhanced PGE2 production in MCT under basal conditions and in CCT in the presence of arachidonic acid. Neither LBK nor ADH stimulated PGE2 synthesis in neonatal CT. A23187 consistently stimulated PGE2 synthesis in CCT and MCT from adults and, to a lesser extent, in CT from newborn rabbits. Our results support the hypothesis that ADH and LBK enhance PGE2 synthesis in the collecting tubule. This response is, however, subject to large variations from tubule to tubule and depends on the in vitro incubation conditions.

Angiotensin II stimulates phospholipases C and A2 in cultured rat mesangial cells

1987 ◽  
Vol 253 (1) ◽  
pp. C113-C120 ◽  
Author(s):  
D. Schlondorff ◽  
S. DeCandido ◽  
J. A. Satriano
Keyword(s):  
Arachidonic Acid ◽  
Angiotensin Ii ◽  
Phospholipase A2 ◽  
Phospholipase C ◽  
Mesangial Cells ◽  
Inositol Trisphosphate ◽  
Pge2 Production ◽  
Diacylglycerol Lipase ◽  
Stimulation Of ◽  
In Cells

Angiotensin II stimulates prostaglandin (PG) E2 formation in mesangial cells cultured from rat renal glomeruli. The interactions between angiotensin II and PGE2 are important in modulating glomerular function. We examined the mechanism for stimulation of PGE2 production in mesangial cells using the putative diacylglycerol-lipase inhibitor RHC 80267 and trifluoperazine (TFP), an agent interfering with Ca2+-CaM-mediated processes. Although RHC 80267 inhibited diacylglycerol-lipase activity in mesangial cells, it did not influence PGE2 production in response to either angiotensin II or A23187. In contrast, TFP (50 microM) inhibited basal PGE2 production and stimulation by angiotensin II and A23187. TFP also decreased 14C release in response to angiotensin from cells prelabeled with [14C]arachidonic acid, which was associated with inhibition of 14C loss from phosphatidylinositol. In cells prelabeled with 32P, orthophosphate angiotensin II caused a rapid hydrolysis of phosphatidylinositol 4,5-bisphospate. TFP enhanced 32P labeling of phosphatidylinositides, but did not prevent the loss of phosphatidylinositol 4,5-bisphosphate in response to angiotensin. This was verified in cells prelabeled with myo-[3H]inositol where angiotensin stimulated formation of [3H]inositol trisphosphate. TFP enhanced formation of [3H]inositol trisphosphate both under basal- and angiotensin II-stimulated conditions. Thus TFP did not inhibit phospholipase C activation by angiotensin. Angiotensin II caused marked increases in [32P]lysophospholipids, indicating activation of also phospholipase A2. This process was inhibited by TFP. Taken together, these results are consistent with stimulation of both phospholipase C and A2 by angiotensin, the latter step responsible for the release of arachidonic acid and PGE2 formation. The activation of phospholipase A2, but not that of phospholipase C, is inhibited by TFP, perhaps by interference with calmodulin-dependent steps.

Bradykinin stimulates prostaglandin E2 formation in isolated human osteoblast-like cells

1990 ◽  
Vol 10 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Östen Ljunggren ◽  
Jan Rosenquist ◽  
Maria Ransjö ◽  
Ulf H. Lerner
Keyword(s):  
Parathyroid Hormone ◽  
Cyclic Amp ◽  
Prostaglandin E2 ◽  
Trabecular Bone ◽  
Human Osteoblast ◽  
Human Osteoblasts ◽  
Human Trabecular Bone ◽  
Stimulation Of ◽  
In Cells

The effect of bradykinin on prostaglandin E2 formation in cells from human trabecular bone has been studied. The cells responded to parathyroid hormone with enhanced cyclic AMP formation and were growing as cuboidal-shaped, osteoblast-like cells. In these isolated human osteoblast-like cells, bradykinin (1 μmol/l) caused a rapid (5 min) stimulation of prostaglandin E2 formation. This finding indicates that human osteoblasts are equipped with receptors for bradykinin linked to an increase in prostaglandin formation.

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