| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Service of Endocrinology, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, Sherbrooke, Québec, Canada J1H 5N4
Address all correspondence and requests for reprints to: Dr. Nicole Gallo-Payet, Service d’Endocrinologie, Faculté de Médecine et des Sciences de la Santé, Université de Sherbrooke, 3001, 12th Avenue North, Sherbrooke, Québec, Canada J1H 5N4. E-mail: nicole.gallo-payet{at}usherbrooke.ca.
Glomerulosa cells readily proliferate in primary culture. However, 3-d treatment with angiotensin II (Ang II) promotes cellular hypertrophy with a concomitant decrease in proliferation. The aim of the present study was to investigate the manner by which cytoskeleton and Rho-GTPase proteins may be involved in Ang II-induced growth and MAPK activation. Preincubation with Y27632 (an inhibitor of Rho-associated kinase) decreased basal proliferation, as did Ang II, whereas toxin B, which inhibits Rho-GTPases, enhanced the inhibitory effect of Ang II. Conversely, toxin B inhibited protein synthesis induced by Ang II, whereas Y27632 had no effect. Ang II induced a rapid but transient activation of RhoA/B, an effect abolished in Y27632-preincubated cells. Activation of Rac appeared biphasic, with an early activation at 1 min, followed by a more sustained effect at 10 min. Toxin B abolished Rac activation. Immunofluorescence studies revealed that Y27632 and toxin B disrupted the F-actin network similarly to Ang II. Y27632 also abolished the cortical F-actin ring induced by Ang II. Preincubation of cells with toxin B abolished p38 MAPK phosphorylation and early activation of p42mapk (ERK2) and decreased p44mapk (ERK1) induced by Ang II. In contrast, Y27632, abolished p44mapk (ERK1) but had no effect on p42mapk (ERK2) or p38. Together these results indicate that, in rat adrenal glomerulosa cells, specific Rho/Rho-associated kinase-dependent activation of p44mapk (ERK1) and an intact cytoskeletal organization are necessary in mediating basal cell proliferation, whereas activation of p42/p44mapk, p38 MAPK, and Rac are essential in mediating Ang II-induced protein synthesis (steroidogenic acute regulatory protein and 3ß-hydroxysteroid dehydrogenase).
This article has been cited by other articles:
 |
|
 |
|
  M. Otis, S. Campbell, M. D. Payet, and N. Gallo-Payet In Adrenal Glomerulosa Cells, Angiotensin II Inhibits Proliferation by Interfering with Fibronectin-Integrin Signaling Endocrinology, July 1, 2008; 149(7): 3435 - 3445. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Kilian, S. Campbell, L. Bilodeau, M.-O. Guimond, C. Roberge, N. Gallo-Payet, and M. D. Payet Angiotensin II Type 2 Receptor Stimulation Increases the Rate of NG108-15 Cell Migration via Actin Depolymerization Endocrinology, June 1, 2008; 149(6): 2923 - 2933. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. F Nogueira, C. A Vargas, M. Otis, N. Gallo-Payet, W. B Bollag, and W. E Rainey Angiotensin-II acute regulation of rapid response genes in human, bovine, and rat adrenocortical cells J. Mol. Endocrinol., December 1, 2007; 39(6): 365 - 374. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. J. Casal, S. Ryser, A. M. Capponi, and C. F. Wang-Buholzer Angiotensin II-Induced Mitogen-Activated Protein Kinase Phosphatase-1 Expression in Bovine Adrenal Glomerulosa Cells: Implications in Mineralocorticoid Biosynthesis Endocrinology, November 1, 2007; 148(11): 5573 - 5581. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Otis, S. Campbell, M. D Payet, and N. Gallo-Payet Expression of extracellular matrix proteins and integrins in rat adrenal gland: importance for ACTH-associated functions J. Endocrinol., June 1, 2007; 193(3): 331 - 347. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |
