The pathway of tissue aldosterone production may exist in the heart, and may be an important contributory factor to myocardial fibrosis and cardiac remodelling in the failing heart. CYP11B2 (aldosterone synthase) catalyses the final step of aldosterone production. The aim of the present study was to determine whether CYP11B2 and CYP11B1 (11beta-hydroxylase) are expressed in myocardial tissues, and whether these enzymes contribute to collagen accumulation and myocardial dysfunction in the failing human heart. Endomyocardial tissues were obtained from 23 patients with chronic heart failure (CHF) and 10 controls. CYP11B2 and CYP11B1 mRNA levels were measured by real-time quantitative reverse transcriptase-PCR. The myocardial collagen volume fraction (CVF) was determined by digital planimetry. CYP11B2 mRNA expression was greater in the CHF group than in the controls (P<0.05), while CYP11B1 mRNA was barely expressed in either group. There was a positive correlation between CYP11B2 mRNA levels and CVF (r=0.64, P=0.001). CYP11B2 mRNA was particularly highly expressed in subgroups of CHF patients with a large left ventricular end-systolic diameter (>55 mm) or a low left ventricular ejection fraction (<30%). CYP11B2 mRNA expression and CVF were lower in a CHF subgroup treated with a combination of spironolactone and angiotensin-converting enzyme inhibitors (ACEIs) than in a subgroup not treated with these drugs. In conclusion, this study has shown that increased myocardial expression of CYP11B2 mRNA is associated with increased myocardial fibrosis and with the severity of left ventricular dysfunction in human CHF. In addition, CYP11B2 expression and cardiac fibrosis are found to be decreased in CHF patients on drug therapy comprising spironolactone combined with ACEIs.
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Cell Mol Life Sci
December 2024
Department of Urology, Zhongnan Hospital of Wuhan University, Wuhan, China.
Aldosterone-producing adenoma (APA) is a leading cause of primary aldosteronism (PA), a condition marked by excessive aldosterone secretion. CYP11B2, the aldosterone synthase, plays a critical role in aldosterone biosynthesis and the development of APA. Despite its significance, encoding regulatory mechanisms governing CYP11B2, particularly its degradation, remain poorly understood.
View Article and Find Full Text PDFLab Med
December 2024
Department of Pediatrics, AIIMS Patna, Patna, Bihar, India.
Objective: Aldosterone synthase deficiency (ASD) is a rare autosomal recessive inherited disease with an overall clinical phenotype of failure to thrive, vomiting, severe dehydration, hyperkalemia, and hyponatremia. Mutations in the CYP11B2 gene encoding AS are responsible for the occurrence of ASD. Defects in CYP11B2 gene have only been reported in a limited number of cases worldwide.
View Article and Find Full Text PDFJ Clin Endocrinol Metab
December 2024
Université Paris Cité, INSERM CIC1418, 75015 Paris, France; Hypertension Department, AP-HP, Hôpital, Georges-Pompidou, 75015 Paris, France.
Inappropriate aldosterone excess plays a key role in the pathophysiology of various cardiovascular, endocrine and renal diseases. Mineralocorticoid receptor (MR) antagonists (MRAs) such as spironolactone block of the harmful effects of aldosterone and are recommended treatment in these various conditions. However, the sexual adverse effects of spironolactone due to its lack of specificity for the MR and the risk of hyperkalemia in patients with decreased renal function, limit its use.
View Article and Find Full Text PDFHypertension
December 2024
Center for Adrenal Disorders, Division of Endocrinology, Diabetes, and Hypertension (J.M.B., B.H., L.C.T., J.M., Y.N., A.J.N., A.V.).
Background: Renin-independent aldosterone production in normotensive people increases risk for developing hypertension. In parallel, normotensive adrenal glands frequently harbor aldosterone-producing micronodules with pathogenic somatic mutations known to induce primary aldosteronism (PA). A deeper understanding of these phenomena would inform the origins of PA and its role in hypertension pathogenesis.
View Article and Find Full Text PDFHypertens Res
November 2024
Department of Endocrinology, Metabolism, Rheumatology and Nephrology, Faculty of Medicine, Oita University, Oita, Japan.
Primary aldosteronism (PA) is a prevalent and curable secondary hypertensive disorder that accounts for 5-13% of all hypertension cases. The prevalence of resistant hypertension, cerebral and cardiovascular diseases, and renal complications is higher in PA patients than in those with essential hypertension. Appropriate diagnosis and treatment at an early stage may suppress cerebral and cardiovascular events.
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