Protein Kinase D Restrains Angiotensin II-Induced Aldosterone Secretion in Primary Adrenal Glomerulosa Cells

Hdl Handle:
http://hdl.handle.net/10675.2/575301
Title:
Protein Kinase D Restrains Angiotensin II-Induced Aldosterone Secretion in Primary Adrenal Glomerulosa Cells
Authors:
Shapiro, Brian A.
Abstract:
Misregulation of the renin-angiotensin II (Angll)-aldosterone (Aldo) system is a key feature of cardiovascular disease. A focus of study in this system is the Angll-elicited secretion of Aldo from the adrenocortical zona glomerulosa. An excellent model in which to study this phenomenon is primary cultures of bovine adrenal glomerulosa (AG) cells. These cells secrete detectable quantities of Aldo in response to secretagogues, such as Angll, elevated potassium (K+), adrenocorticotrophic hormone (ACTH) and phorbol 12-myristate 13-acetate (PMA), within 30 minutes. The serine (Ser)/threonine kinase protein kinase D (PKD) is reported to be activated by Angll in several systems, including the adrenocortical carcinoma cell line NCI H295R, and is thought to have a positive role in chronic (24 hours) Angll-evoked Aldo secretion. Because the role of PKD in acute Angll-elicited Aldo secretion has never been examined in a primary culture system, we undertook to study the role of PKD in acute (minutes to one hour) Aldo secretion. Thus, Angll (10 nM) and PMA (100 nM), but not elevated K+ (15 mM) and ACTH (10 nM), induced phosphorylation of PKD on Ser910, a marker of PKD activation, in primary bovine AG cells. This finding was confirmed by an in vitro kinase activity assay. Angll and PMA were also able to induce PKD activation in H295R cells. Furthermore, this activation was concentration dependent, and was rapidly induced (by 5 min). PKD activation was dependent on Angll type 1 (AT-1), but not AT-2 receptor, signaling, and was independent of tyrosine kinase signaling. Finally, we introduced, via adenovirus transduction, wild-type PKDwt and dominant negative PKDS738/742A constructs into primary AG cells and monitored Angll-evoked Aldo secretion. PKDwt -transduced AG cells exhibited decreased Angll-stimulated Aldo secretion, while in the PKDS738A742A - infected AG cells Angll-stimulated Aldo was enhanced. Thus, we hypothesize that PKD has an anti-secretory role in Angll-induced acute Aldo secretion.
Affiliation:
Department of Physiology
Issue Date:
Jul-2007
URI:
http://hdl.handle.net/10675.2/575301
Additional Links:
http://ezproxy.gru.edu/login?url=http://search.proquest.com/docview/304783503?accountid=12365
Type:
Dissertation
Appears in Collections:
Theses and Dissertations

Full metadata record

DC FieldValue Language
dc.contributor.authorShapiro, Brian A.en
dc.date.accessioned2015-08-19T21:30:29Zen
dc.date.available2015-08-19T21:30:29Zen
dc.date.issued2007-07en
dc.identifier.urihttp://hdl.handle.net/10675.2/575301en
dc.description.abstractMisregulation of the renin-angiotensin II (Angll)-aldosterone (Aldo) system is a key feature of cardiovascular disease. A focus of study in this system is the Angll-elicited secretion of Aldo from the adrenocortical zona glomerulosa. An excellent model in which to study this phenomenon is primary cultures of bovine adrenal glomerulosa (AG) cells. These cells secrete detectable quantities of Aldo in response to secretagogues, such as Angll, elevated potassium (K+), adrenocorticotrophic hormone (ACTH) and phorbol 12-myristate 13-acetate (PMA), within 30 minutes. The serine (Ser)/threonine kinase protein kinase D (PKD) is reported to be activated by Angll in several systems, including the adrenocortical carcinoma cell line NCI H295R, and is thought to have a positive role in chronic (24 hours) Angll-evoked Aldo secretion. Because the role of PKD in acute Angll-elicited Aldo secretion has never been examined in a primary culture system, we undertook to study the role of PKD in acute (minutes to one hour) Aldo secretion. Thus, Angll (10 nM) and PMA (100 nM), but not elevated K+ (15 mM) and ACTH (10 nM), induced phosphorylation of PKD on Ser910, a marker of PKD activation, in primary bovine AG cells. This finding was confirmed by an in vitro kinase activity assay. Angll and PMA were also able to induce PKD activation in H295R cells. Furthermore, this activation was concentration dependent, and was rapidly induced (by 5 min). PKD activation was dependent on Angll type 1 (AT-1), but not AT-2 receptor, signaling, and was independent of tyrosine kinase signaling. Finally, we introduced, via adenovirus transduction, wild-type PKDwt and dominant negative PKDS738/742A constructs into primary AG cells and monitored Angll-evoked Aldo secretion. PKDwt -transduced AG cells exhibited decreased Angll-stimulated Aldo secretion, while in the PKDS738A742A - infected AG cells Angll-stimulated Aldo was enhanced. Thus, we hypothesize that PKD has an anti-secretory role in Angll-induced acute Aldo secretion.en
dc.relation.urlhttp://ezproxy.gru.edu/login?url=http://search.proquest.com/docview/304783503?accountid=12365en
dc.rightsCopyright protected. Unauthorized reproduction or use beyond the exceptions granted by the Fair Use clause of U.S. Copyright law may violate federal law.en
dc.subjectPKDen
dc.subjectAldosteroneen
dc.subjectAngiotensin IIen
dc.subjectAdrenal Glomerulosa Cellsen
dc.titleProtein Kinase D Restrains Angiotensin II-Induced Aldosterone Secretion in Primary Adrenal Glomerulosa Cellsen
dc.typeDissertationen
dc.contributor.departmentDepartment of Physiologyen
dc.description.advisorBollag, Wendyen
dc.description.committeeChew, Catherine; Hill, David W. III; Liou, Gregory; McNeil, Paulen
dc.description.degreeDoctor of Philosophy (Ph.D.)en
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