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  • Author: Tham M Yao x
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Vincent Ricchiuti, Christine G Lian, Eveline M Oestreicher, Loc Tran, James R Stone, Tham Yao, Ellen W Seely, Gordon H Williams and Gail K Adler

We tested the hypothesis that 17β-estradiol (E2) has dual effects on the heart, increasing levels of proteins thought to have beneficial cardiovascular effects (e.g. endothelial nitric oxide (NO) synthase (eNOS)) as well as those thought to have detrimental cardiovascular effects (e.g. type 1 angiotensin II (AngII) receptor (AT1R)). Ovariectomized Wistar rats consuming a high-sodium diet received one of four treatments (n=7 per group): group 1, placebo pellets; group 2, E2 (0.5 mg/pellet, 21-day release); group 3, NOS inhibitor, N ω-nitro-l-arginine-methyl-ester (l-NAME; 40 mg/kg per day for 14 days) plus Ang II (0.225 mg/kg per day on days 11–14); group 4, E2 plus l-NAME/Ang II. E2 increased cardiac levels of estrogen receptors ESR1 and ESR2, an ESR-associated membrane protein caveolin-3, eNOS, and phosphorylated (p)eNOS, thus, exerting potentially beneficial cardiovascular effects on NO. However, E2 also increased cardiac levels of proteins associated with cardiovascular injury and inflammation including, AT1R, protein kinase C delta (PRKCD), phosphorylated PRKC, and phosphorylated extracellular signal regulated kinase (pMAPK)3/1, plasminogen activator inhibitor-1 (PAI-1), osteopontin and ED-1, a monocyte/macrophage-specific protein. E2 treatment led to similar protein changes in the hearts of l-NAME/Ang II-treated rats except that the increase in peNOS was prevented, and l-NAME/Ang II and E2 had additive effects in increasing cardiac PRKCD and PAI-1. Thus, the highest levels of cardiac PAI-1 and PRKCD occurred in l-NAME/Ang II-treated rats receiving E2. In summary, E2 treatment increased cardiac expression of AT1R as well as the expression of pro-inflammatory and prothrombotic factors.

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Yuefei Huang, Pei Yee Ting, Tham M Yao, Tsuyoshi Homma, Danielle Brooks, Isis Katayama Rangel, Gail K Adler, Jose R Romero, Jonathan S Williams, Luminita H Pojoga and Gordon H Williams

Human risk allele carriers of lysine-specific demethylase 1 (LSD1) and LSD1-deficient mice have salt-sensitive hypertension for unclear reasons. We hypothesized that LSD1 deficiency causes dysregulation of aldosterone’s response to salt intake resulting in increased cardiovascular risk factors (blood pressure and microalbumin). Furthermore, we determined the effect of biological sex on these potential abnormalities. To test our hypotheses, LSD1 male and female heterozygote-knockout (LSD1+/−) and WT mice were assigned to two age groups: 18 weeks and 36 weeks. Plasma aldosterone levels and aldosterone production from zona glomerulosa cells studied ex vivo were greater in both male and female LSD1+/− mice consuming a liberal salt diet as compared to WT mice consuming the same diet. However, salt-sensitive blood pressure elevation and increased microalbuminuria were only observed in male LSD1+/− mice. These data suggest that LSD1 interacts with aldosterone’s secretory response to salt intake. Lack of LSD1 causes inappropriate aldosterone production on a liberal salt diet; males appear to be more sensitive to this aldosterone increase as males, but not females, develop salt sensitivity of blood pressure and increased microalbuminuria. The mechanism responsible for the cardiovascular protective effect in females is uncertain but may be related to estrogen modulating the effect of mineralocorticoid receptor activation.