Different effects of progesterone and estradiol on chimeric and wild type aldosterone synthase in vitro

dc.contributor.authorVecchiola Cárdenas, Andrea Paola
dc.contributor.authorLagos Arévalo, Carlos Fernando
dc.contributor.authorFuentes Zúñiga, Cristóbal Andrés
dc.contributor.authorAllende, Fidel
dc.contributor.authorCampino Johnson, María del Carmen
dc.contributor.authorValdivia, Carolina.
dc.contributor.authorTapia Castillo, Alejandra.
dc.contributor.authorOwen, Gareth Ivor
dc.contributor.authorSolari Gajardo, Sandra
dc.contributor.authorCarvajal Maldonado, Cristián Andrés
dc.contributor.authorFardella B., Carlos
dc.contributor.authorOgishima, Tadashi.
dc.contributor.authorMukai, Kuniaki.
dc.date.accessioned2019-10-17T15:35:55Z
dc.date.available2019-10-17T15:35:55Z
dc.date.issued2013
dc.date.updated2019-10-14T18:46:40Z
dc.description.abstractAbstract Background Familial hyperaldosteronism type I (FH-I) is caused by the unequal recombination between the 11beta-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) genes, resulting in the generation of a CYP11B1/B2 chimeric gene and abnormal adrenal aldosterone production. Affected patients usually show severe hypertension and an elevated frequency of stroke at a young age. Aldosterone levels rise during pregnancy, yet in pregnant women with FH-1, their hypertensive condition either remains unchanged or may even improve. The purpose of this study was to investigate in vitro whether female sex steroids modulate the activity of chimeric (ASCE) or wild type (ASWT) aldosterone synthase enzymes. Methods We designed an in vitro assay using HEK-293 cell line transiently transfected with vectors containing the full ASCE or ASWT cDNAs. Progesterone or estradiol effects on AS enzyme activities were evaluated in transfected cells incubated with deoxycorticosterone (DOC) alone or DOC plus increasing doses of these steroids. Results In our in vitro model, both enzymes showed similar apparent kinetic parameters (Km = 1.191 microM and Vmax = 27.08 microM/24 h for ASCE and Km = 1.163 microM and Vmax = 36.98 microM/24 h for ASWT; p = ns, Mann–Whitney test). Progesterone inhibited aldosterone production by ASCE- and ASWT-transfected cells, while estradiol demonstrated no effect. Progesterone acted as a competitive inhibitor for both enzymes. Molecular modelling studies and binding affinity estimations indicate that progesterone might bind to the substrate site in both ASCE and ASWT, supporting the idea that this steroid could regulate these enzymatic activities and contribute to the decay of aldosterone synthase activity in chimeric gene-positive patients. Conclusions Our results show an inhibitory action of progesterone in the aldosterone synthesis by chimeric or wild type aldosterone synthase enzymes. This is a novel regulatory mechanism of progesterone action, which could be involved in protecting pregnant women with FH-1 against hypertension. In vitro, both enzymes showed comparable kinetic parameters, but ASWT was more strongly inhibited than ASCE. This study implicates a new role for progesterone in the regulation of aldosterone levels that could contribute, along with other factors, to the maintenance of an adequate aldosterone-progesterone balance in pregnancy.Abstract Background Familial hyperaldosteronism type I (FH-I) is caused by the unequal recombination between the 11beta-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) genes, resulting in the generation of a CYP11B1/B2 chimeric gene and abnormal adrenal aldosterone production. Affected patients usually show severe hypertension and an elevated frequency of stroke at a young age. Aldosterone levels rise during pregnancy, yet in pregnant women with FH-1, their hypertensive condition either remains unchanged or may even improve. The purpose of this study was to investigate in vitro whether female sex steroids modulate the activity of chimeric (ASCE) or wild type (ASWT) aldosterone synthase enzymes. Methods We designed an in vitro assay using HEK-293 cell line transiently transfected with vectors containing the full ASCE or ASWT cDNAs. Progesterone or estradiol effects on AS enzyme activities were evaluated in transfected cells incubated with deoxycorticosterone (DOC) alone or DOC plus increasing doses of these steroids. Results In our in vitro model, both enzymes showed similar apparent kinetic parameters (Km = 1.191 microM and Vmax = 27.08 microM/24 h for ASCE and Km = 1.163 microM and Vmax = 36.98 microM/24 h for ASWT; p = ns, Mann–Whitney test). Progesterone inhibited aldosterone production by ASCE- and ASWT-transfected cells, while estradiol demonstrated no effect. Progesterone acted as a competitive inhibitor for both enzymes. Molecular modelling studies and binding affinity estimations indicate that progesterone might bind to the substrate site in both ASCE and ASWT, supporting the idea that this steroid could regulate these enzymatic activities and contribute to the decay of aldosterone synthase activity in chimeric gene-positive patients. Conclusions Our results show an inhibitory action of progesterone in the aldosterone synthesis by chimeric or wild type aldosterone synthase enzymes. This is a novel regulatory mechanism of progesterone action, which could be involved in protecting pregnant women with FH-1 against hypertension. In vitro, both enzymes showed comparable kinetic parameters, but ASWT was more strongly inhibited than ASCE. This study implicates a new role for progesterone in the regulation of aldosterone levels that could contribute, along with other factors, to the maintenance of an adequate aldosterone-progesterone balance in pregnancy.
dc.fuente.origenBiomed Central
dc.identifier.citationReproductive Biology and Endocrinology. 2013 Aug 13;11(1):76
dc.identifier.doi10.1186/1477-7827-11-76
dc.identifier.urihttps://repositorio.uc.cl/handle/11534/26778
dc.issue.numeroNo. 76
dc.language.isoen
dc.nota.accesoContenido completo
dc.pagina.final11
dc.pagina.inicio1
dc.revistaReproductive Biology and Endocrinologyes_ES
dc.rightsacceso abierto
dc.rights.holderVecchiola et al.; licensee BioMed Central Ltd.
dc.subject.ddc610
dc.subject.deweyMedicina y saludes_ES
dc.subject.otherHiperaldosteronismoes_ES
dc.subject.otherHipertensión En embarazoes_ES
dc.subject.otherMujeres embarazadases_ES
dc.titleDifferent effects of progesterone and estradiol on chimeric and wild type aldosterone synthase in vitroes_ES
dc.typeartículo
dc.volumenVol. 11
sipa.codpersvinculados123319
sipa.codpersvinculados1004550
sipa.codpersvinculados99519
sipa.codpersvinculados1000459
sipa.codpersvinculados1871
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