Mineralocorticoid Receptor Blocker Research Articles

Early Life Stress Increases Lipid Storage in Female Mice Fed a High Fat Diet via MR Activation in Adipocytes

We have previously shown that Maternal Separation and Early Weaning (MSEW), a mouse model of early life stress, exacerbates high fat diet (HF)‐induced obesity only in female offspring. Obese female MSEW mice display increased circulating and adrenal‐derived aldosterone and increased gWAT‐derived corticosterone compared with controls (C). Mineralocorticoid receptor (MR) activation has been shown to be critical in the regulation of the differentiation process of pre‐adipocytes into mature adipocytes and overall adipocyte homeostasis. The aim of this study was to determine the role of MR in the mechanism by which MSEW induces perigonadal hypertrophy in female mice fed a high fat diet (HF). MSEW and C mice were weaned onto a HF (60 % Kcal from fat). After 20 weeks, gonadal white adipose tissue (gWAT) was collected to conduct: 1) lipidomic analysis and markers of whitening, 2) collagenase digestion followed by magnetic activated cell sorting for isolation of preadipocytes for RNAseq, and 3) in vitro lipolysis assay. Another subset of mice was randomized to receive vehicle (50% Ora swift in water) or a MR blocker, spironolactone (Spiro, 100 mg/kg/day), for 2 weeks. Female MSEW mice showed increased adiposity along with reduced mitochondrial DNA density (0.81±0.09 and 1.08±0.07 mtDNA/gDNA, p<0.05 MSEW vs. C, respectively). Also, female MSEW mice displayed an increase of over 20 triacyclglycerols TAG, including a 6‐fold increase in 44:2/FA 18:2+NH4 (p<0.05 vs. C). Isolated mature adipocyte RNAseq revealed a 10‐fold downregulation of Aquaglycerolporin 3 (AQP3) in MSEW mice, a channel in adipocytes responsible for glycerol efflux (p<0.05 vs. C). Western blot analysis confirmed this reduction (0.40±0.08 and 1.0±0.14 AQP3/HSP90 p<0.05 MSEW vs. C, respectively). Spiro treatment induced a significant fat mass loss in obese MSEW females (‐3.5±0.9 and ‐1.0±0.5 delta fat mass (%BW) p<0.05 MSEW vs. C, respectively). Increased intracellular glycerol in vehicle‐treated MSEW mice was reduced to levels comparable to controls after Spiro treatment (1.08±0.2 and 1.64±0.12 mg glycerol/mg tissue, p<0.05 MSEW vs. C, respectively) while Spiro also decreased basal and stimulated released glycerol in MSEW mice (p<0.05). There were no differences in plasma glycerol between groups. It has been shown that aldosterone modulates AQP3 expression via MR signaling; however, Spiro treatment did not modify AQP3 protein expression. Overall, this data suggests that MR may play a role in adipose tissue hypertrophy as displayed by MSEW mice by preventing glycerol release in favor of triglyceride formation and storage, suggesting a role for impaired lipolysis that is independent of reduced AQP3 protein expression in adipocyte hypertrophy displayed by obese female MSEW mice.

Aldosterone Regulates Vasopressin Escape through Changes in Water and Urea Transporters

Vasopressin escape is a process that prevents the continuous decrease in serum sodium even under conditions of sustained high vasopressin. Previous reports suggest that this process is regulated by aldosterone but the mechanism is not fully defined. In this study, aldosterone synthase (Cyp11b2) knockout and wild‐type mice were implanted with 14‐day osmotic mini‐pumps delivering 5 ng/h dDAVP (desmopressin, type 2 vasopressin receptor agonist) to promote distal nephron water reabsorption. Urine osmolality was measured before and then daily (24‐h urine collections) throughout the experiment. After 4 days of increased urine osmolality, mice were given a gel diet to force additional fluid consumption. Urine osmolality of the wild type mice was significantly lower (successful escape) than that of aldosterone synthase knockout mice. Protein analysis showed that both AQP2 and UT‐A1 protein abundances were higher in the aldosterone synthase knockout than wild‐type mice at the end of the escape period. To confirm the findings from the aldosterone synthase knockout mice, the mineralocorticoid receptor blocker spironolactone (20mg/kg/day, s.c.) or vehicle was given to rats that were receiving vasopressin by mini‐pump in a comparable vasopressin escape protocol to the mice. The spironolactone‐treated rats displayed a higher urine osmolality and lower serum sodium level versus untreated escaping rats. Phosphoserine 256‐AQP2 (PS256‐AQP2) was significantly increased in the spironolactone‐treated rats. Our results indicate that: vasopressin escape is prevented if aldosterone or its receptor are not available; and increased abundance of AQP2 or UT‐A1, or PS256‐AQP2, contributes to deficient vasopressin escape in the absence of aldosterone.

Eplerenone‐induced natriuresis and hyperkalemia in mice lacking aldosterone results from aldosterone‐independent mineralocorticoid receptor occupancy

BackgroundMineralocorticoid receptor (MR) antagonists are recommended for patients with resistant hypertension independent of circulating aldosterone levels. Aldosterone, secreted in response to salt depletion or hyperkalemia, activates MR to increase epithelial sodium channel (ENaC) activity. While glucocorticoids can also activate MR, they are metabolized by 11β‐hydroxysteroid dehydrogenase type 2 (11β‐HSD2), protecting MR from illicit glucocorticoid occupation. 11β‐HSD2 is expressed at increasing levels from the DCT through the collecting duct. Here, we hypothesized that glucocorticoid occupies MR to stimulate ENaC in the DCT2 and early connecting tubule.MethodsWe studied aldosterone synthase knockout (AS−/−) mice provided by Dr. JM Luther. Kidney–specific MR knockout (MR−/−) mice were used for validation of Western blot for ENaC and immunofluorescence for MR. We measured plasma and urinary electrolytes at baseline, and following dietary salt restriction with or without administration of the MR antagonist eplerenone.ResultsAS−/− mice displayed higher plasma K+ levels than AS+/+ mice but not salt wasting under baseline. Under low salt (LS) diet, AS−/− mice exhibited higher urine Na+ excretion, but preserved body weight. Cleaved αENaC and γENaC abundances were lower in AS−/− than AS+/+ mice, and were not increased in AS−/− mice after LS diet. Notably, we found nuclear localization of MR was preserved in DCT2 of AS−/− mice. Administration of the MR blocker eplerenone to AS−/− mice fed LS diet led to hyperkalemia and decreased body weight with higher Na+ excretion, mimicking the phenotype of MR−/− mice.ConclusionsOur results provide evidence that MR is occupied in the absence of aldosterone, suggesting glucocorticoid‐binding to MR preserves sodium homeostasis in the DCT2 of AS−/− mice. This likely explains the milder phenotype of AS−/− mice compared with MR−/− mice.

Endothelial Mineralocorticoid Receptors Constrain Arteriogenesis and Perfusion Recovery Following Chronic Arterial Ligation in a Sex‐specific Manner

Vascular occlusive diseases are major contributors to cardiovascular morbidity and mortality. Prior work has implicated mineralocorticoid receptor (MR) signaling in perfusion recovery following arterial occlusion, however, cell‐specific MR signaling in the associated angiogenic and arteriogenic responses has not been elucidated. Further, accumulating evidence has revealed sex‐specific involvement of MR signaling in a number of cardiovascular disease states. Accordingly, we examined the hypothesis that MR signaling, specifically endothelial cell (EC) MR signaling, attenuates vascular compensation and perfusion recovery following femoral artery excision and that this effect would be more pronounced in females. Unilateral femoral artery ligation and excision was performed in male and female C57BL/6J mice treated with vehicle or the MR antagonist spironolactone (Spiro; 20 mg/kg/d, sc) as well as in male and female MR Intact and EC MR knockout (KO) mice. Serial assessment of hindlimb perfusion for 28 days following surgery revealed enhanced perfusion recovery following Spiro treatment in female, but not male, mice. Interestingly, Spiro increased gastrocnemius capillary density in both the ischemic and sham limb in males and females. Following perfusion fixation, collateral remodeling was assessed by micro‐computed tomography revealing enhanced collateral expansion following Spiro treatment in female, but not male, mice. Additional mechanistic experiments similarly revealed increased perfusion recovery and enhanced collateral expansion in female, not male, EC MR KO mice independent of capillary density. At 28 days post‐surgery, distribution analysis revealed larger overall arteriolar diameters only in the collateral zone of EC MR KO females. Further analysis revealed enhanced early (7 days post‐surgery) collateral expansion in male and female EC MR KO mice. In female, but not male, EC MR KO mice this was associated with increased CD68+ macrophages and CD206+ ‘M2’‐like macrophages in the collateral zone. Together, these data demonstrate that EC MR signaling constrains early arteriogenic collateralization following arterial excision in both sexes and constrains long‐term collateralization only in females involving limitation of pro‐arteriogenic CD206+ ‘M2’‐like macrophages in the collateral zone. To our knowledge, this is the first report of a role for EC MR signaling in arteriogenesis and highlights potential use of MR blockers in the treatment of vascular occlusive events.

Novel Therapies for Alport Syndrome.

Alport syndrome (AS) is a hereditary kidney disease associated with proteinuria, hematuria and progressive kidney failure. It is characterized by a defective glomerular basement membrane caused by mutations in type IV collagen genes COL4A3/A4/A5 which result in defective type IV collagen α3, α4, or α5 chains, respectively. Alport syndrome has three different patterns of inheritance: X-linked, autosomal and digenic. In a study of CKD of unknown etiology type IV collagen gene mutations accounted for the majority of the cases of hereditary glomerulopathies which suggests that AS is often underrecognized. The natural history and prognosis in patients with AS is variable and is determined by genetics and environmental factors. At present, no preventive or curative therapies exist for AS. Current treatment includes the use of renin-angiotensin-aldosterone system inhibitors which slow progression of kidney disease and prolong life expectancy. Ramipril was found in retrospective studies to delay the onset of ESKD and was recently demonstrated to be safe and effective in children and adolescents, supporting that early initiation of Renin Angiotensin Aldosterone System (RAAS) blockade is very important. Mineralocorticoid receptor blockers might be favorable for patients who develop “aldosterone breakthrough.” While the DAPA-CKD trial suggests a beneficial effect of SGLT2 inhibitors in CKD of non-metabolic origin, only a handful of patients had Alport in this cohort, and therefore conclusions can't be extrapolated for the treatment of AS with SGLT2 inhibitors. Advances in our understanding on the pathogenesis of Alport syndrome has culminated in the development of innovative therapeutic approaches that are currently under investigation. We will provide a brief overview of novel therapeutic targets to prevent progression of kidney disease in AS. Our review will include bardoxolone methyl, an oral NRf2 activator; lademirsen, an anti-miRNA-21 molecule; sparsentan, dual endothelin type A receptor (ETAR) and angiotensin 1 receptor inhibitor; atrasentan, oral selective ETAR inhibitor; lipid-modifying agents, including cholesterol efflux transporter ATP-binding cassette A1 (ABCA1) inducers, discoidin domain receptor 1 (DDR1) inhibitors and osteopontin blocking agents; the antimalarial drug hydroxychloroquine; the antiglycemic drug metformin and the active vitamin D analog paricalcitol. Future genomic therapeutic strategies such as chaperone therapy, genome editing and stem cell therapy will also be discussed.

Eplerenone inhibits UUO-induced lymphangiogenesis and cardiac fibrosis by attenuating inflammatory injury

Cardiorenal syndrome (CRS) is the leading cause of death associated with chronic kidney disease (CKD) and end-stage renal disease (ESRD). However, the underlying mechanisms of CRS are still poorly understood. Here, we studied a CKD model of unilateral ureteral obstruction (UUO) and observed pathological cardiac fibrosis and lymphangiogenesis in 180-day old UUO rats, in which inflammatory injury plays a major role. In addition, treatment of UUO rats with eplerenone, a mineralocorticoid receptor blocker (MRB), significantly reduced cardiac lymphangiogenesis and fibrosis. In conclusion, our experimental results showed that cardiac lymphangiogenesis in long-term UUO rats may be involved in the formation of cardiac fibrosis and that eplerenone can alleviate lymphangiogenesis and cardiac fibrosis by inhibiting inflammation.

Rationale and Design of the Efficacy and Safety of Esaxerenone in Hypertensive Patients With Left Ventricular Hypertrophy (ESES-LVH) Study ― Protocol for a Multicenter, Open-Label, Exploratory Interventional Study ―

Background: The complication of left ventricular (LV) hypertrophy (LVH) is associated with increased incidence of major cardiovascular events. Hypertension is an independent risk factor among several factors contributing to the development of LVH, and thus appropriate treatment of both hypertension and LVH reduces the risk of developing heart failure. Mineralocorticoid-receptor blockers (MRBs) have been reported to improve the prognosis of LVH, but use of currently available MRBs is limited by adverse events. Esaxerenone is a novel selective nonsteroidal MRB recently approved for treatment of hypertension. Although the renoprotective effect of esaxerenone has been demonstrated in both preclinical and clinical studies, little data is available in terms of its cardioprotective effects. Methods and Results: This multicenter, open-label, exploratory interventional study was designed to evaluate the safety and efficacy of esaxerenone in combination with renin-angiotensin system (RAS) inhibitors or calcium-channel blockers (CCBs). Eligible criteria are hypertensive patients with LVH, and target blood pressure (BP) not reached with an RAS inhibitor or a CCB. The primary endpoints are change from baseline in seated home BP (early morning systolic/diastolic BPs), and change and %change from baseline in the LV mass index at the end of treatment. Conclusions: This study will provide the first clinical evidence of the antihypertensive effect and safety of esaxerenone in hypertensive patients with LVH.

Therapeutic Effects of a Selective Mineralocorticoid Receptor Blocker as an Additional Combination Antihypertensive Drug in Hypertensive Patients

Therapeutic Effects of a Selective Mineralocorticoid Receptor Blocker as an Additional Combination Antihypertensive Drug in Hypertensive Patients

545 Cardiac protection by pirfenidone after myocardial infarction: a bioinformatic analysis

Abstract Aims Left ventricular (LV) remodelling after myocardial infarction (MI) is promoted by an intense fibrotic response, which could be targeted by an anti-fibrotic drug such as pirfenidone. Methods and results We explored the relationship between protein modulation by pirfenidone and post-MI remodelling, based on publicly available molecular information and transcriptomic data from a swine model of MI. We also compared the effects of pirfenidone and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers (ACEi/ARB), mineralocorticoid receptor blockers (MRA) and beta-blockers. We identified six causative motives of post-MI remodelling (cardiomyocyte cell death, impaired myocyte contractility, extracellular matrix remodelling and fibrosis, hypertrophy, renin–angiotensin–aldosterone system activation, and inflammation), 4 pirfenidone targets and 21 bioflags (indirect effectors). When considering both targets and bioflags, pirfenidone showed a broad relationship encompassing all six motives. p38γ-MAPK12 blockade inhibits cardiomyocyte apoptosis, cardiomyocyte hypertrophy and inflammation. Furthermore, pirfenidone can modulate extracellular matrix remodelling and cardiac fibrosis by targeting the TGFβ1-SMAD2/3 pathway and other effector proteins such as matrix metalloproteases 2 and 14, PDGFA/B, and IGF1, which promote myocardial fibrosis, cardiomyocyte hypertrophy and impaired contractility. All the gold standard drugs were found to be important for specific clinical motives, but pirfenidone had a more widespread action on the molecular pathways active in the post-MI setting. Conclusions A bioinformatic approach allowed to identify several possible mechanisms of action of pirfenidone with beneficial effects in the post-MI LV remodelling, and suggests additional effects over guideline-recommended therapies. These findings support clinical studies evaluating the beneficial effects of pirfenidone in patients with MI.

Abstract 9146: Efficacy and Safety of Esaxerenone in Hypertensive Patients with Heart Failure with Reduced Ejection Fraction

Introduction: Esaxerenone, a mineralocorticoid receptor blocker (MRB), is a new antihypertensive agent. However, esaxerenone-related data with respect to hypertension with heart failure are limited. Hypothesis: Esaxerenone is safe and effective for hypertensive patients with heart failure with reduced ejection fraction (HFrEF). Methods: Hypertensive patients with HFrEF treated with esaxerenone were retrospectively analyzed at two timepoints (short-term: 35±15 days; mid-term: 167±45 days) for hyperkalemia (K + >5.5 mEq/L), worsening renal function (WRF; estimated glomerular filtration rate (eGFR) reduction by >20%), and hypotension (systolic blood pressure <90 mmHg) along with brain natriuretic peptide (BNP) level. Patients administered esaxerenone as their first MRB (first-MRB cohort, n=20) and those who converted from another MRB (conversion cohort, n=30) were separately analyzed as sub analysis. Results: Fifty patients (56±10 years old, 37 males) were enrolled in this study. At the short-term assessment, hyperkalemia or hypotension was not observed at a dose of 2.0±0.9 mg/day. Seven patients (14%) showed WRF. K + and serum creatinine (Cre) were elevated (4.12±0.41 to 4.25±0.39 mmol/L, p =0.07, and 0.95±0.34 to 1.01±0.34 mg/dL, p =0.01, respectively), and eGFR was significantly reduced (66.9±19.6 to 62.4±19.7 mL/min/1.73 m 2 , p =0.006). At the mid-term assessment, there were no significant changes regarding K + , Cre and eGFR compared to those at the short-term. BNP levels were consistently lowered at the short-term and mid-term assessment. Sub analysis at the short-term assessment showed the changes in K + , Cre, and eGFR were significant in the first-MRB cohort, while they were not significant in the conversion cohort. Conclusions: Esaxerenone was safe for hypertensive patients with HFrEF. Hyperkalemia and hypotension were rarely noted while eGFR was significantly reduced. Moreover, esaxerenone was effective for HFrEF with respect to BNP levels.

Safety and efficacy of esaxerenone in Japanese hypertensive patients with heart failure with reduced ejection fraction: A retrospective study.

Esaxerenone, a mineralocorticoid receptor blocker (MRB), is a new antihypertensive agent. However, esaxerenone-related data with respect to hypertension with heart failure are limited. We investigated the safety and efficacy of esaxerenone in hypertensive patients with heart failure with reduced ejection fraction (HFrEF). Hypertensive patients with HFrEF treated with esaxerenone were retrospectively analyzed at two timepoints (short-term: 35±15 days; mid-term: 167±45 days). Adverse events including hyperkalemia (K+ >5.5 mEq/L), worsening renal function (WRF; estimated glomerular filtration rate (eGFR) reduction by ≥20%), and hypotension (systolic blood pressure <90 mmHg) were evaluated. eGFR and K+, serum creatinine, and brain natriuretic peptide (BNP) levels at baseline, short-term, and mid-term assessments were compared. Patients administered esaxerenone as their first MRB (first-MRB cohort) and those who converted from another MRB (conversion cohort) were separately analyzed. There were 50 (56±10 years old, 26% female) patients. At the short-term assessment, hyperkalemia or hypotension was not observed at a dose of 2.0±0.9 mg/day. Seven patients (14%) showed WRF. K+ was slightly elevated (4.12±0.41 to 4.25±0.39 mmol/L, p = 0.07) and eGFR was significantly reduced (66.9±19.6 mL/min/1.73 m2 to 62.4±19.7 mL/min/1.73 m2, p = 0.006). In the conversion cohort, significant changes in K+ and eGFR from baseline were not observed at the short-term assessment. BNP levels were consistently improved regardless of the cohorts (first-MRB cohort, 310 [110-370] pg/mL to 137 [47-152] pg/mL, p = 0.001; conversion cohort, 181 [30-203] pg/mL to 108 [26-146] pg/mL, p = 0.028). At the mid-term assessment, there were no significant changes in K+ and eGFR compared with the short-term assessment. In conclusion, esaxerenone was safe for hypertensive patients with HFrEF. Hyperkalemia and hypotension were rarely noted, while eGFR was marginally reduced. Moreover, esaxerenone might be beneficial for HFrEF in terms of BNP level reduction.

Effect of esaxerenone on nocturnal blood pressure and natriuretic peptide in different dipping phenotypes.

There are limited data on the nighttime blood pressure (BP)-lowering effect of esaxerenone and its effect on N-terminal pro b-type natriuretic peptide (NT-proBNP), a predictor of cardiovascular risk, according to different dipping patterns of nocturnal BP. This was a post hoc analysis of a multicenter, open-label, long-term phase 3 study of esaxerenone, a new highly selective mineralocorticoid receptor blocker, in patients with essential hypertension. Patients were classified by dipping pattern (extreme dippers, dippers, non-dippers, risers). Mean changes in BP, changes in dipping pattern, mean NT-proBNP levels, and percentage of patients with normal NT-proBNP levels (<55 pg/mL) at baseline and Weeks 12 and 28 were evaluated. Nighttime systolic BP decreased in all dipping pattern groups at Week 28, with the riser group showing the greatest change (−25.5 mmHg). A significant shift in dipping pattern and riser/non-dipper pattern changes to dipper/extreme dipper pattern were found from baseline to Week 28 (p < 0.0001). The prevalence of the riser pattern decreased from 14.4% to 9.8%, and that of the non-dipper pattern from 44.7% to 39.2%. The decrease in NT-proBNP from baseline to Week 28 was statistically significant in risers, non-dippers, dippers, and extreme dippers (p < 0.001, respectively). At baseline, the proportion of patients with NT-proBNP <55 pg/mL was lowest in risers versus the other dipping pattern types, but after reductions in NT-proBNP in all groups to Week 28, these differences disappeared. Long-term administration of esaxerenone may be a useful treatment option for nocturnal hypertension, especially in patients with a riser pattern.

Mineralocorticoid receptor signaling is implicated in carfilzomib-induced increase in blood pressure

Abstract Introduction Carfilzomib (Cfz), an irreversible proteasome inhibitor, is a first line antineoplastic agent indicated for relapsed/refractory multiple myeloma, with its clinical use being hampered by cardiovascular adverse effects. Hypertension, is the most common cardiovascular side effect of Cfz, remaining of unknown pathogenicity. Purpose Considering that management of Cfz-related hypertension remains an unmet clinical need and that renal function plays a pivotal role in blood pressure regulation we sought to investigate the renal contribution in Cfz-induced hypertension. Methods We have previously established a translational model of Cfz-induced cardiomyopathy, based on clinically applicable dose regimens and we have concluded that two and four dose protocols successfully resemble the clinical observations in vivo. Herein, sixty C57Bl/6 male mice (12–14 weeks old) were randomized to: 1. Two doses Protocol: i. Control (N/S 0.9%), ii. Cfz (8mg/kg) for two consecutive days; and 2. Four doses Protocol: i. Control (N/S 0.9%), ii. Cfz (8mg/kg) for seven days intraperitoneally. Systolic (SBP) and diastolic blood pressure (DBP) were measured by tail cuffs; the latter protocol was repeated and urine collection was performed via metabolic cages studies. Renal samples were collected for histological, proteomic, metabolomic and molecular signaling analyses. Finally, eplerenone, a mineralocorticoid receptor (MR) blocker, was orally co-administered with Cfz to the mice daily (165 mg/kg) in the four doses protocol. Results Cfz increased SBP only in the four doses protocol (78.50±2.05 vs 68.20±0.73 in the Control group, **P&amp;lt;0.01). Histological evaluation of the kidneys revealed a juxtaglomerular apparatus hyperplasia (JAH) in the same dose regimen. Proteomic analysis presented that metabolic and transport of small molecules pathways were differentially regulated in the Cfz treated murine kidneys. Metabolomic analysis revealed an increase in urea cycle metabolites (L-Alanine, L-Glutamine, glutamate, aspartate) and taurine content in the kidneys. Additionally, mice presented decreased diuresis without any differences in other metabolic parameters. In parallel an upregulation of β-ENaC expression and activation of MR/SGK-1 signaling in the kidneys was observed, indicating that Cfz activates MR signaling. Co-administration of eplerenone and Cfz, restored diuresis, decreased SBP and inhibited MR/SGK-1 signaling in the kidneys. Conclusions Activation of MR signaling by Cfz in the kidneys orchestrates renal water/salt retention and drives an increase in blood pressure in vivo. Histological and metabolomic analyses present that Cfz induces an acute kidney injury and a tonicity increase. Eplerenone reversed Cfz-induced blood pressure increase and restored diuresis by inhibiting MR/SGK-1 signaling. Therefore, MR blockade emerges as a potent therapeutic approach against Cfz-related cardiovascular adverse events. Funding Acknowledgement Type of funding sources: None.

Association Between Aldosterone and Parathyroid Hormone Levels in Patients With Adrenocortical Tumors

ObjectivePatients with primary aldosteronism (PA) can present with high PTH levels and negative calcium balance, with some studies speculating that aldosterone could directly stimulate PTH secretion. Either adrenalectomy or mineralocorticoid receptor blockers could reduce PTH levels in patients with PA. The aim of this study was to assess the relationship between aldosterone levels and parathyroid hormone (PTH)-vitamin D-calcium axis in a cohort of patients with PA, compared with patients with nonsecreting adrenocortical tumors in conditions of vitamin D sufficiency. MethodsWe enrolled a series of 243 patients retrospectively, of whom 66 had PA and 177 had nonsecreting adrenal tumors, and selected those with full mineral metabolism evaluation and 25(OH) vitamin D levels >20 ng/mL at the time of initial endocrine screening. The final cohort was composed of 26 patients with PA and 39 patients, used as controls, with nonsecreting adrenal tumors. The relationships between aldosterone, PTH levels, and biochemistries of mineral metabolism were assessed. ResultsAldosterone was positively associated with PTH levels (r = 0.260, P < .05) in the whole cohort and in the PA cohort alone (r = 0.450; P = .02). In the multivariate analysis, both aldosterone concentrations and urinary calcium excretion were significantly related to PTH levels, with no effect of 25(OH) vitamin D or other parameters of bone metabolism. ConclusionPTH level is associated with aldosterone, probably independent of 25(OH) vitamin D levels and urinary calcium. Whether aldosterone interacts directly with the parathyroid glands remains to be established.

Abstract 23: Body Fluid And Sodium Loss Leads To Aldosterone Hypersecretion And Muscle Catabolism In Hepatocellular Carcinoma Rats.

Background: The number of cancer survivors coincides with cardiovascular diseases is increasing, therefore, we are promoting the concept of “Onco-Hypertension” to clarify the mechanism linking cancer and blood pressure. In this study, we evaluated body osmolyte and water imbalance in hepatocellular cancer (HCC) model rats. Methods: Wistar rats were administered diethylnitrosamine (DEN) (1.5 μg/day, p.o.), a carcinogenic drug, for 8 weeks to establish liver cancer. Three weeks after the completion of DEN administration, we investigated blood pressure, tissue osmolyte and water content, and its association with aldosterone secretion. Results: HCC rats significantly reduced blood pressure, skin sodium, potassium, and water content. In the carcass (muscle + bone), dry weight, sodium, potassium, and water content were dramatically reduced without changing bone mass in HCC rats, suggesting that HCC causes muscle wasting to supply osmolyte and water for the dehydrated organs. These osmolytes and water loss were significantly associated with increased urinary aldosterone excretion. Supplementation of 0.25% salt water to drink improved body sodium and water loss and muscle wasting in HCC rats, which were completely suppressed by treatment with spironolactone (75 mg/kg/day, p.o.), a mineralocorticoid receptor (MR) blocker. Conclusion: These findings suggest that HCC causes body osmolyte and water loss, which leads to aldosterone hypersecretion and muscle catabolism to compensate for dehydration. A relatively small amount of salt supplement ameliorates the HCC-induced dehydration and muscle wasting via aldosterone/MR-mediated sodium and water restoration.

The mineralocorticoid receptor blocker spironolactone lowers plasma interferon-γ and interleukin-6 in patients with type 2 diabetes and treatment-resistant hypertension.

The mineralocorticoid receptor antagonist spironolactone lowers blood pressure in patients with resistant hypertension despite antihypertensive treatment with angiotensin-converting inhibitors (ACEi) and angiotensin-II receptor blockers (ARB). In preclinical studies, spironolactone suppresses pro-hypertensive interleukin 17A (IL-17A). Plasma samples were analysed from a randomized, double-blind placebo-controlled trial with spironolactone given to patients with type 2 diabetes mellitus (T2DM) and resistant hypertension on three antihypertensive drugs. We tested the hypothesis that spironolactone-induced antihypertensive effects are associated with suppression of IL-17A and related cytokines. Interferon-γ (IFN-γ), IL-17A, tumor necrosis factor-α (TNF-α), IL-6, IL-1β and IL-10 were assessed in plasma with immunoassay in samples before and after 16 weeks of treatment with placebo or spironolactone (12.5-25-50 mg/day). Spironolactone significantly reduced plasma IFN-γ and IL-6 while IL-17A, TNF-α, IL-1β and IL-10 were unchanged. IL-6 was more sensitive to higher doses of spironolactone. At baseline, serum aldosterone correlated positively with diastolic night blood pressure. Urine albumin/creatinine-ratios correlated positively with plasma IL-6 at baseline. There were no relations between aldosterone and cytokine concentrations at baseline; between cytokine concentration and blood pressure at baseline; and between cytokine concentration decrease and blood pressure decrease, except for IFN-γ, after treatment. The spironolactone-induced elevation in plasma potassium related inversely to blood pressure but not to changes in cytokines. In macrophages in vitro, spironolactone suppressed lipopolysaccharide (LPS)-induced TNF-α, IL-6, IL-1β and IL-10 levels. The antihypertensive action of spironolactone in resistant hypertensive patients is associated with suppressed IFN-γ and IL-6 and not IL-17A. Spironolactone exerts anti-inflammatory actions in vivo on macrophages and T-cells.

Huoxue Jiedu Huayu Formula Alleviates Cell Pyroptosis in Contralateral Kidneys of 6-Month-Old UUO Rats through the NLRP3/Caspase-1/IL-1β Pathway.

Objectives To study the protective effects and mechanisms of Huoxue Jiedu Huayu formula on cell pyroptosis through the NLRP3/caspase-1/IL-1β pathway in contralateral kidneys in 6-month-old unilateral ureteral obstruction (UUO) rats. Methods Wistar rats were randomly assigned to 5 groups: a Sham group, a unilateral nephrectomy group (UNX group), a UUO group, a UUO treated with spironolactone group (Spi group), and a UUO treated with Huoxue Jiedu Huayu formula group (HJHF group). After 6 months of oral drug intervention, blood and contralateral kidneys were collected for research. Results The morphology and function of the contralateral kidneys were essentially normal after unilateral nephrectomy. HJHF obviously decreased serum creatinine, urea, and inflammatory lesions and depressed cell pyroptosis based on the NLRP3/caspase-1/IL-1β pathway. Moreover, spironolactone, a mineralocorticoid receptor (MR) blocker, suppressed cell pyroptosis through SGK-1 and NF-кB. Conclusion HJHF and spirolactone inhibited excessive activation of MR and then reduced cell pyroptosis, which was dependent on the NLRP3/caspase-1/IL-1β pathway, to protect the contralateral kidneys of 6-month-old UUO rats.

Renal Injuries in Primary Aldosteronism: Quantitative Histopathological Analysis of 19 Patients With Primary Adosteronism.

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Characterization of Direct Perturbations on Voltage-Gated Sodium Current by Esaxerenone, a Nonsteroidal Mineralocorticoid Receptor Blocker.

Esaxerenone (ESAX; CS-3150, Minnebro®) is known to be a newly non-steroidal mineralocorticoid receptor (MR) antagonist. However, its modulatory actions on different types of ionic currents in electrically excitable cells remain largely unanswered. The present investigations were undertaken to explore the possible perturbations of ESAX on the transient, late and persistent components of voltage-gated Na+ current (INa) identified from pituitary GH3 or MMQ cells. GH3-cell exposure to ESAX depressed the transient and late components of INa with varying potencies. The IC50 value of ESAX required for its differential reduction in peak or late INa in GH3 cells was estimated to be 13.2 or 3.2 μM, respectively. The steady-state activation curve of peak INa remained unchanged during exposure to ESAX; however, recovery of peak INa block was prolonged in the presence 3 μM ESAX. In continued presence of aldosterone (10 μM), further addition of 3 μM ESAX remained effective at inhibiting INa. ESAX (3 μM) potently reversed Tef-induced augmentation of INa. By using isosceles-triangular ramp pulse with varying durations, the amplitude of persistent INa measured at high or low threshold was enhanced by the presence of tefluthrin (Tef), in combination with the appearance of the figure-of-eight hysteretic loop; moreover, hysteretic strength of the current was attenuated by subsequent addition of ESAX. Likewise, in MMQ lactotrophs, the addition of ESAX also effectively decreased the peak amplitude of INa along with the increased current inactivation rate. Taken together, the present results provide a noticeable yet unidentified finding disclosing that, apart from its antagonistic effect on MR receptor, ESAX may directly and concertedly modify the amplitude, gating properties and hysteresis of INa in electrically excitable cells.

Effects of Sodium Glucose Cotransporter 2 Inhibitor on Renal Renin-Angiotensin-Aldsoterone System

Objective: The renoprotective effect of sodium glucose cotransporter 2 inhibitor (SGL2i) has been reported in diabetic patients. Local renin-angiotensin-aldosterone system (RAAS) is activated in diabetes mellitus and hypertension. We examined the effects of SGL2i on the RAAS in the obese diabetic rats fed a high salt diet. Methods: Zucker-diabetic rats (ZDR) and control rats were fed a high or normal salt diet and were treated with canagliflozin for 8 weeks. Blood pressure (BP), blood glucose (BG), PRA, plasma aldosterone (PAC), urinary albumin excretion (UAE), urinary 8-hydroxy-2’-deoxyguanosine (8-OHdG), gene expression of angiotensinogen in the kidney were measured. Results: ZDR febd a high salt diet showed high BP, increased UAE and urinary 8-OHdG and elevated angiotensinogen mRNA levels. Treatment with canagliflozin significantly decreased BP, BG, UAE, urinary 8-OHdG and and renal angiotensinogen mRNA levels compared with control rats (p<0.05). Discussion and Conclusion: The closer mechanism of renoptotection of SGL2i in diabetes mellitus is unclear. We have reported that the repoprotective effects of type 2 angiotensin receptor antagonist or mineralocorticoid receptor blocker were partly due to the decreased RAAS in the kidney. Decreased renal RAAS by the treatment with canagliflozin may contribute to the renoprotection in DZR.