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Araujo CM, Hermidorff MM, Amancio GDCS, Lemos DDS, Silva ME, de Assis LVM, Isoldi MC. Rapid effects of aldosterone in primary cultures of cardiomyocytes - do they suggest the existence of a membrane-bound receptor? J Recept Signal Transduct Res 2015; 36:435-44. [PMID: 27305962 DOI: 10.3109/10799893.2015.1122042] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Aldosterone acts on its target tissue through a classical mechanism or through the rapid pathway through a putative membrane-bound receptor. Our goal here was to better understand the molecular and biochemical rapid mechanisms responsible for aldosterone-induced cardiomyocyte hypertrophy. We have evaluated the hypertrophic process through the levels of ANP, which was confirmed by the analysis of the superficial area of cardiomyocytes. Aldosterone increased the levels of ANP and the cellular area of the cardiomyocytes; spironolactone reduced the aldosterone-increased ANP level and cellular area of cardiomyocytes. Aldosterone or spironolactone alone did not increase the level of cyclic 3',5'-adenosine monophosphate (cAMP), but aldosterone plus spironolactone led to increased cAMP level; the treatment with aldosterone + spironolactone + BAPTA-AM reduced the levels of cAMP. These data suggest that aldosterone-induced cAMP increase is independent of mineralocorticoid receptor (MR) and dependent on Ca(2+). Next, we have evaluated the role of A-kinase anchor proteins (AKAP) in the aldosterone-induced hypertrophic response. We have found that St-Ht31 (AKAP inhibitor) reduced the increased level of ANP which was induced by aldosterone; in addition, we have found an increase on protein kinase C (PKC) and extracellular signal-regulated kinase 5 (ERK5) activity when cells were treated with aldosterone alone, spironolactone alone and with a combination of both. Our data suggest that PKC could be responsible for ERK5 aldosterone-induced phosphorylation. Our study suggests that the aldosterone through its rapid effects promotes a hypertrophic response in cardiomyocytes that is controlled by an AKAP, being dependent on ERK5 and PKC, but not on cAMP/cAMP-dependent protein kinase signaling pathways. Lastly, we provide evidence that the targeting of AKAPs could be relevant in patients with aldosterone-induced cardiac hypertrophy and heart failure.
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Affiliation(s)
- Carolina Morais Araujo
- a Laboratory of Hypertension , Research Center in Biological Science, Institute of Exact and Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
| | - Milla Marques Hermidorff
- a Laboratory of Hypertension , Research Center in Biological Science, Institute of Exact and Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
| | - Gabriela de Cassia Sousa Amancio
- a Laboratory of Hypertension , Research Center in Biological Science, Institute of Exact and Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
| | - Denise da Silveira Lemos
- b Laboratory of Immunoparasitology , Center for Research in Biological Sciences, Institute of Biological and Exact Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
| | - Marcelo Estáquio Silva
- c Laboratory of Experimental Nutrition , School of Nutrition, Federal University of Ouro Preto , Ouro Preto , Brazil , and
| | | | - Mauro César Isoldi
- a Laboratory of Hypertension , Research Center in Biological Science, Institute of Exact and Biological Sciences, Federal University of Ouro Preto , Ouro Preto , Brazil
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