Salt sensitivity of blood pressure and aldosterone: interaction between Lysine-specific demethylase 1 gene, sex, and age

Context Salt sensitivity of blood pressure (SSBP) is associated with increased cardiovascular risk, especially in individuals of African descent, although underlying mechanisms remain obscure. Lysine-specific demethylase 1 (LSD1) is a salt-sensitive epigenetic regulator associated with SSBP and aldosterone dysfunction. An LSD1 risk allele in humans is associated with SSBP and lower aldosterone levels in hypertensive African but not European descent. Heterozygous knockout LSD1 mice display SSBP and aldosterone dysregulation, but this effect is modified by age and biological sex. This might explain differences in cardiovascular risk with aging and biological sex in humans. Objective To determine if LSD1 risk allele (rs587618) carriers of African descent display a sex-by-age interaction with SSBP and aldosterone regulation. Methods We analyzed 297 individuals of African and European descent from the HyperPATH cohort. We performed multiple regression analyses for outcome variables related to SSBP and aldosterone. Results LSD1 risk allele carriers of African (but not European) descent had greater SSBP than non-risk homozygotes. Female LSD1 risk allele carriers of African descent had greater SSBP, mainly relationship-driven by women of low estrogen (postmenopausal). There was a significant LSD1 genotype-sex interaction in aldosterone response to angiotensin II stimulation in individuals ≤50 years, with female carriers displaying decreased aldosterone responsiveness. Conclusions SSBP associated with LSD1 risk allele status is driven by women of deplete estrogen state. Mechanisms related to a resistance to develop SSBP in females are uncertain but may relate to an estrogen modulating effect on mineralocorticoid receptor activation and/or LSD1 epigenetic regulation of the mineralocorticoid receptor.

New guidelines for the heart failure treatment (2021)

At this year’s ESC congress in London, it was announced an update of the guidelines for the treatment of chronic heart failure with reduced left ventricular ejection fraction. Key change compared to last guidelines is withdrawal the long-term titration strategy and introducing a simpler and faster regimen based on four groups of drugs: blocking the renin–angiotensin–aldosterone system (ACE-I, ARNI), sodium-glucose co-transporter inhibitors (dapagliflozin, empagliflozin), β-adrenolytic drugs, mineralocorticoid receptor inhibitors.

Rapid Shear Stress-dependent ENaC Membrane Insertion is Mediated by the Endothelial Glycocalyx and the Mineralocorticoid Receptor

The contribution of the shear-stress sensitive epithelial Na+ channel (ENaC) to the mechanical properties of the endothelial cell surface under (patho)physiological conditions is unclear. This issue was addressed in in vivo and in vitro models for endothelial dysfunction. Cultured human umbilical vein endothelial cells (HUVEC) were exposed to laminar (LSS) or non-laminar shear stress (NLSS). ENaC membrane insertion was quantified using Quantum-dot-based immunofluorescence staining and the mechanical properties of the cell surface were probed with the Atomic Force Microscope (AFM) in vitro and ex vivo in isolated aortae of C57BL/6 and ApoE/LDLR-/- mice. Flow- and acetylcholine-mediated vasodilation were measured in vivo using magnetic resonance imaging. Acute LSS led to a rapid mineralocorticoid receptor (MR)-dependent membrane insertion of ENaC and subsequent stiffening of the endothelial cortex caused by actin polymerization. Of note, NLSS stress further augmented the cortical stiffness of the cells. These effects strongly depend on the presence of the endothelial glycocalyx (eGC) and could be prevented by functional inhibition of ENaC and MR in vitro and ex vivo endothelial cells derived from C57BL/6 and ApoE/LDLR-/- vessel. As expected, in vivo in C57BL/6 vessels ENaC- and MR-inhibtion blunted flow- and acetylcholine-mediated vasodilation, while in the dysfunctional ApoE/LDLR-/- vessels this effect was absent. In conclusion, under physiological conditions, endothelial ENaC, together with the glycocalyx, was identified as an important shear stress sensor and mediator of endothelium-dependent vasodilation. In contrast, in pathophysiological conditions, ENaC-mediated mechanotransduction and endothelium-dependent vasodilation were lost, contributing to sustained endothelial stiffening and dysfunction.