Mineralocorticoid Receptor Blocker Research Articles

Effect of Nonsteroidal Mineralocorticoid Receptor Blocker Esaxerenone on Vasoreactivity to an Endothelial Stimulator in Superior Mesenteric Arteries of Type 2 Diabetic Goto-Kakizaki Rat.

Endothelial dysfunction contributes to cardiometabolic disorders, including hypertension, obesity, and type 2 diabetes. Esaxerenone is a selective, nonsteroidal, high-affinity mineralocorticoid receptor blocker recently approved in Japan for the treatment of hypertension. Although imbalanced signaling between vasorelaxant and vasocontractile factors induced by endothelial stimulation is often observed in type 2 diabetic vessels, the effects of esaxerenone on endothelium-dependent responses in type 2 diabetes remain unclear. The aim of this study was to investigate the effect of esaxerenone on endothelium-dependent responses in superior mesenteric arteries isolated from type 2 diabetic Goto-Kakizaki (GK) rats. It was found that esaxerenone (3 mg/kg/d for 4 weeks, per os (p.o.)) partially ameliorated acetylcholine (ACh)-induced endothelium-derived hyperpolarizing factor (EDHF)-type relaxation and NS309, a potent activator of small- and intermediate-conductance Ca2+-activated K+ channels, -induced relaxation, and reduced ACh-induced endothelium-derived contracting factor (EDCF)-mediated contraction. These results suggest that esaxerenone ameliorates endothelial function through increased EDHF signaling and suppressed EDCF signaling.

Abstract 14001: Evaluation and Treatment of Patients With Low Ejection Fraction and Positive Troponin

Introduction: Patients with decreased LV ejection fraction (LVEF) presenting with elevated troponin incur high in-patient and follow-up mortality. Despite guidelines, testing for CAD and guideline-directed therapy in such patients has not been consistently utilized. To better understand this issue, we investigated hospital practice patterns in this vulnerable population. Methods: We conducted a tertiary single-center study of consecutive in-patients with abnormal troponin results on testing performed for clinical indications as requested by the treating physician. The study cohort included 432 patients, 67 +/- 14 years old with HTN in 75%, DM in 38%, smoking in 51%, dyslipidemia in 64%, family history of CAD in 28% and personal history of CAD or equivalent in 46%. Among them, 412 patients underwent echocardiographic LVEF assessment. Patients were then stratified according to the LVEF. The use of both ischemic evaluation and evidence-based medical therapy were compared. Hospital and long-term outcomes were analyzed. Results: Hospital mortality was 51/432 (11.8%) and during 28.1+/-13.8 months of follow-up additional 82/432 (18.9%) patients expired. Ischemia evaluation (both cardiac catheterization and non-invasive) was underutilized across all subgroups, including patients with decreased LVEF. Regarding guideline-directed medical therapy, only beta-blocker therapy was consistently utilized. Afterload reduction therapies such as angiotensin convertase enzyme inhibitors, angiotensin II receptor blockers, neprilysin inhibitors, hydralazine and nitrates were significantly underutilized. Statins and mineralocorticoid receptor blockers were also significantly underused (Table). Conclusions: Despite increased mortality, there continues to be room for improvement in the utilization of diagnostic evaluation and application of evidence-based therapy and in patients admitted with elevated cardiac biomarkers.

ODP442 Posaconazole-induced Pseudohyperaldosteronism (PIPH) in Patient Treated for Acute Myeloid Leukemia

Abstract Case summary A 62-year-old Caucasian female presented to our institute with mechanical fall complicated by cervical spine fracture. She had known history of essential hypertension and recently diagnosed acute myeloid leukemia with myelodysplasia related changes (AML-MRC). She had undergone induction chemotherapy with combination of daunorubicin and cytarabine, resulting in chemotherapy induced prolonged pancytopenia. She was initially started on primary prophylaxis with fluconazole, but was switched to voriconazole due to persistent neutropenia. Patient then developed bilateral upper and lower extremity erythematous popular rash on voriconazole. Decision at that time was to switch to Posaconazole 300 mg orally daily. Three months after initiating Posaconazole, patient presented with severe hypokalemia (2.1 mmol/L) and hypertension. Previously her blood pressure was under control with amlodipine, lisinopril and nadolol. Hypokalemia persisted despite aggressive oral and intermittent intravenous potassium replacement therapy. No sources of potassium loss were identified on clinical history. She had persistently elevated blood pressure (systolic blood pressure of 150-180 mmHg) despite being on her home anti-hypertensive regimen. Further work up showed undetectable plasma aldosterone of less than 1 ng/dL (normal < 28 ng/dL) and plasma renin activity level was suppressed to 0.14 ng/mL/h (normal 0.25–5.82 ng/mL/h) with concurrent potassium of 2.9 mmol/L (normal 3.5-5.3 mmol/l). Diagnosis of pseudohyperaldosteronism was made at this time. Posaconazole gradually stopped and eplerenone 25 mg daily was commenced to selectively block mineralocorticoids receptors to control blood pressure. Subsequently hypokalemia resolved after stopping posaconazole and blood pressure normalized with her original home anti-hypertensive regimen. Eplerenone was eventually stopped. Her potassium level and blood pressure remained normal 2 weeks after discharge. Discussion Recent studies have shown the presentation of hypokalemia and hypertension in nearly a quarter of patients on Posaconazole. The clinical presentation of hypokalemia and hypertension with apparent mineralocorticoid excess was evident in our patient and was consistent with posaconazole-induced pseudohyperaldosteronism (PIPH). Posaconazole interference with the steroid synthesis pathway has been described in various literature. Both cortisol and aldosterone activate aldosterone receptors. In the case of posaconazole, excess mineralocorticoid effect is due to relative selectivity of posaconazole for 11ΒHSD2 inhibition. 11ΒHSD2 inhibition causes increased serum cortisol level by preventing the conversion to inactive cortisone. The high cortisol level cross-reacts with the mineralocorticoid receptor leading to apparent mineralocorticoid excess with low serum aldosterone level and low plasma renin activity. The degree of pseudohyperaldosterone effect on systolic blood pressure and hypokalemia has been strongly associated with serum posaconazole level in some studies. Our patient had resolution of uncontrolled hypertension and hypokalemia after withholding the posaconazole and short term treatment with selective mineralocorticoid receptor blocker. Conclusion Early diagnosis and to allow for early intervention with cessation of the offending agent or treatment with mineralocorticoid antagonists, such as spironolactone and eplerenone is necessary in PIPH. Presentation: No date and time listed

Association between class of foundational medication for heart failure and prognosis in heart failure with reduced/mildly reduced ejection fraction

We clarified the association between changes in the number of foundational medications for heart failure (FMHF) during hospitalization for worsening heart failure (HF) and post-discharge prognosis. We retrospectively analyzed a combined dataset from three large-scale registries of hospitalized patients with HF in Japan (NARA-HF, WET-HF, and REALITY-AHF) and patients diagnosed with HF with reduced or mildly reduced left ventricular ejection fraction (HFr/mrEF) before admission. Patients were stratified by changes in the number of prescribed FMHF classes from admission to discharge: angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, beta-blockers, and mineralocorticoid receptor blockers. Primary endpoint was the combined endpoint of HF rehospitalization and all-cause death within 1 year of discharge. The cohort comprised 1113 patients, and 482 combined endpoints were observed. Overall, FMHF prescriptions increased in 413 (37.1%) patients (increased group), remained unchanged in 607 (54.5%) (unchanged group), and decreased in 93 (8.4%) (decreased group) at discharge compared with that during admission. In the multivariable analysis, the increased group had a significantly lower incidence of the primary endpoint than the unchanged group (hazard ratio 0.56, 95% confidence interval 0.45–0.60; P < 0.001). In conclusion, increase in FMHF classes during HF hospitalization is associated with a better prognosis in patients with HFr/mrEF.

Increasing the class of foundational medication for heart failure is associated with improved prognosis in hospitalized patients with heart failure with reduced or mildly reduced ejection fraction

Abstract Aim To clarify the association between changes in the number of foundational medications for heart failure (FMHF) during hospitalization for worsening heart failure and post-discharge prognosis. Methods and results We retrospectively analyzed a combined dataset of three large-scale registries of hospitalized patients with heart failure in Japan (NARA-HF, WET-HF, and REALITY-AHF) and included patients already diagnosed with heart failure with reduced or mildly reduced left ventricular ejection fraction (HFr/mrEF) before admission. Patients were stratified by changes in the number of prescribed FMHF classes, namely angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, beta blockers, and mineralocorticoid receptor blockers, from admission to discharge. The primary endpoint was defined as the combined endpoint of heart failure rehospitalization and all-cause death within 1-year of discharge. The cohort consisted of 1,113 patients, and 482 combined endpoints were observed. In total, 413 (37.1%) patients were on increased FMHF (increased group), 607 (54.5%) remained unchanged (unchanged group), and 93 (8.4%) had a decreased number of FMHF (decreased group) at discharge compared to the time of admission. In multivariable analysis, the increased group was associated with a significantly lower incidence of the primary endpoint compared with the unchanged group (hazard ratio 0.56, 95% confidence interval 0.45–0.60; P&amp;lt;0.001) and decreased group (hazard ratio 0.58, 95% confidence interval 0.40–0.84; P=0.004). Conclusion Increasing the number of FMHF cases during heart failure hospitalization is associated with a better prognosis in patients with HFr/mrEF. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): REALITY registry was funded by the Cardiovascular Research Fund of Japan.WET-HF registry was supported by a Grant-in-Aid for Young Scientists (Y.S. JSPS KAKENHI, 18K15860).

Combined antagonist treatment of glucocorticoid and mineralocorticoid receptor does not affect weight loss of fasting rainbow trout but inhibits a fasting-induced elevation of cortisol secretion

The gastrointestinal system of fish reacts rapidly to food deprivation. The relative masses of digestive organs and activities of digestive enzymes decrease within days of fasting. This is believed to be an energy-conserving strategy as the metabolic cost of maintaining digestive capacity is high. Cortisol is known for its role in energy mobilization following stress exposure, and prolonged elevated cortisol levels have been shown to reduce growth rates in fish. Fish experiencing chronic cortisol elevations show structural changes to their digestive tissues and overall reductions in relative digestive tissue masses. In fish fasting for prolonged periods, circulating cortisol levels have been reported to be downregulated, upregulated, or unchanged compared to feeding fish. This study aimed to investigate if RU486 and spironolactone, antagonists of the glucocorticoid receptor (GR), and mineralocorticoid receptor (MR), respectively, alone or in combination affect circulating cortisol levels during prolonged starvation. In addition, we tested the effects of blocking GR and MR, on the down-regulation of relative digestive tissue mass during starvation, and its effects on weight loss. Three treatment groups of rainbow trout were intraperitoneally implanted with either GR, MR, or GR and MR blockers. A fourth group was implanted with cortisol, while a fifth group served as a control. All treatment groups were sampled over a course of four weeks of food deprivation and compared against each other and fed control fish at day 0 of the trial. Starvation for 2 weeks and longer significantly increased circulating cortisol levels in all groups except for the group implanted with GR and MR antagonists. Loss of body mass occurred most rapidly during the first week of starvation. Spironolactone treatment resulted in significantly reduced loss of mass during the first week, however, over the following weeks, no differences in mass loss were observed in the groups implanted with blockers, while cortisol-treated fish showed the highest decrease in body mass over time. Relative digestive tissue mass decreased in all groups but apparently, the fasting-induced elevation in plasma cortisol levels did not affect the relative weight loss of digestive tissues as no differences were observed between control fish and GR + MR antagonist treated fish. Very high cortisol levels caused by cortisol treatment however caused a faster decrease in the relative mass of some digestive organs, particularly the stomach.

The renoprotective effect of esaxerenone independent of blood pressure lowering: a post hoc mediation analysis of the ESAX-DN trial

Angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) are recommended as first-line drugs for hypertension with diabetic nephropathy owing to their renoprotective effect; however, their effect beyond lowering blood pressure (BP) has not been confirmed. Recent studies have shown that aldosterone plays a key role in causing renal injury; therefore, it is likely that mineralocorticoid receptor (MR) blockers inhibit aldosterone-induced renal damage in different ways from ACE inhibitors and ARBs. Therefore, we investigated the mechanism of the effect of an MR blocker on reducing the urinary albumin-to-creatinine ratio (UACR) using data from a randomized, double-blind, placebo-controlled phase 3 study (ESAX-DN) of a new nonsteroidal MR blocker, esaxerenone. This post hoc analysis used a novel statistical method to quantitatively estimate the effect of esaxerenone on UACR reduction mediated, or not mediated, by changes in systolic BP (SBP) and/or estimated glomerular filtration rate (eGFR). The proportion of the mediated effect by SBP changes to the total effect on UACR reduction was 9.8–10.7%; the UACR was reduced to 0.903–0.911 times the baseline at the end of treatment through the SBP-related pathway and to 0.422–0.426 times the baseline through the non-SBP-related pathway. Even considering both SBP and eGFR simultaneously, the proportion of the mediated effect was 21.9–28.1%. These results confirm that esaxerenone has a direct UACR-lowering effect independent of BP lowering and that its magnitude is much larger than that of the BP-dependent effect. Thus, esaxerenone could be a UACR-reducing treatment option for patients with diabetic nephropathy.

Low-dose spironolactone ameliorates adipose tissue inflammation and apoptosis in letrozole-induced PCOS rat model

Background of studyGlobally, many reproductive aged women are affected by polycystic ovarian syndrome (PCOS), which is a common endocrine and metabolic disorder that is linked with adipose dysfunction and chronic low-grade inflammation. Spironolactone (SPL), a mineralocorticoid receptor blocker has been documented as a metabolic modulator. However, its immunomodulatory effect in PCOS is unknown. Therefore, the present study hypothesized that SPL would ameliorate adipose dysfunction and inflammation in experimental PCOS animals.Materials and methodsFemale Wistar rats that were 8 weeks old were allocated into three groups. Group 1 received vehicle (distilled water; p.o.), group 2 received letrozole (1 mg/kg; p.o.) and group 3 received letrozole plus SPL (0.25 mg/kg, p.o.). The administration was performed once daily for 21 days.ResultsThe experimental PCOS animals showed insulin resistance, hyperinsulinemia and hyperandrogenism as well as oxidative stress and elevated inflammatory biomarkers (NF-kB/TNF-/IL-6) as well as a significant decrease in triglycerides, total cholesterol, free fatty acids, GSH and G6PD in the adipose tissue of PCOS animals. In addition, immunohistochemical assessment of adipose tissue showed significant expression of BAX and inflammasome, indicating apoptosis and inflammation compared to control animals. Nevertheless, administration of SPL attenuated these perturbations.ConclusionAltogether, the present study suggests that low-dose spironolactone confers protection against adipose dysfunction in experimental PCOS animals by attenuating inflammation, oxidative stress and cellular apoptosis.

Esaxerenone inhibits the macrophage-to-myofibroblast transition through mineralocorticoid receptor/TGF-β1 pathway in mice induced with aldosterone.

Renal fibrosis is the inevitable pathway of the progression of chronic kidney disease to end-stage renal disease, which manifests as progressive glomerulosclerosis and renal interstitial fibrosis. In a previous study, we observed severe interstitial fibrosis in the contralateral kidneys of 6-month unilateral ureteral obstruction (UUO) rats, which was accompanied by increased macrophage infiltration and phenotypic transformation; after eplerenone administration, these effects were reduced. Therefore, we hypothesized that this effect was closely related to mineralocorticoid receptor (MR) activation induced by the increased aldosterone (ALD) level. In this study, we used uninephrectomy plus continuous aldosterone infusion in mice to observe whether aldosterone induced macrophage-to-myofibroblast transition (MMT) and renal fibrosis and investigated the signaling pathways. Notably, aldosterone induced predominantly M1 macrophage-to-myofibroblast transition by activating MR and upregulating TGF-β1 expression, which promoted renal fibrosis. These effects were antagonized by the MR blocker esaxerenone. These findings suggest that targeting the MR/TGF-β1 pathway may be an effective therapeutic strategy for renal fibrosis.

Therapie des metabolischen Syndroms

Metabolic syndrome is defined by the simultaneous presence of abdominal obesity, atherogenic dyslipoproteinemia, high blood pressure and increased fasting blood glucose. It is an important precursor of cardiovascular disease sequelae and shows epidemic proportions, not only in western countries. Modifications of lifestyle are central for treatment: negative energy balance with increased physical activity, a prudent balance of nutrients with carbohydrates, proteins and fats, considering atherogenic lipid profiles, blood pressure and the glycemic index of nutrients. Decisive for the implementation is the incorporation of long-term programs with continuous guidance, preferably in group therapy and targeting all individual risk factors. The introduction of sodium-glucose linked transporter 2 (SGLT2) inhibitors, glucagon-like peptide 1 (GLP1) receptor agonists and modern mineralocorticoid receptor blockers has resulted in new options for the effective prevention of sequelae.

Antihypertensive Effect of Long-Term Monotherapy with Esaxerenone in Patients with Essential Hypertension: Relationship Between Baseline Urinary Sodium Excretion and Its Antihypertensive Effect.

IntroductionThe blood pressure (BP) control mechanism for mineralocorticoid receptor blockers is unclear, and analysis of their use as a single agent in the clinical setting is required to resolve this uncertainty. There is a paucity of data on esaxerenone monotherapy assessing its long-term antihypertensive effect and urinary biomarkers.MethodsThis post hoc exploratory substudy of a long-term phase 3 study evaluated the effect of esaxerenone monotherapy (2.5 or 5 mg/day) in treatment-naïve patients who continued the therapy during the 52-week study period (n = 25). In addition to blood biomarkers, urinary biomarkers were also assessed in 24-h urine collection samples.ResultsEsaxerenone monotherapy was associated with consistent reductions in systolic/diastolic BP in the substudy population (− 23.5/− 13.1 mmHg at week 52, p < 0.001 vs baseline). Plasma aldosterone concentrations and plasma renin activity significantly increased during esaxerenone monotherapy at all time points. On the basis of the observations that both urine volume and urinary sodium excretion also decreased up to the end of the study, and were significantly lower at 12 weeks, patients were further categorized into higher/lower urinary sodium excretion subgroups according to whether their baseline values were above or below the median. In the group with higher baseline urinary sodium excretion, esaxerenone exhibited a significantly greater decrease in systolic/diastolic BP compared to the lower baseline group.ConclusionEsaxerenone exhibited sustained and stable antihypertensive activity even when administered as a single agent for 52 weeks in patients with essential hypertension. The additional urinary biomarker analysis suggests that the BP-lowering effects of esaxerenone may be partly exerted via mechanisms related to salt and water retention, and that the effect is particularly pronounced in patients with hypertension and higher baseline urinary sodium excretion, which may reflect a state of excessive salt intake.Trial registrationNCT02722265.Supplementary InformationThe online version contains supplementary material available at 10.1007/s12325-022-02282-3.

Eplerenone ameliorates lung fibrosis in unilateral ureteral obstruction rats by inhibiting lymphangiogenesis.

Chronic kidney disease (CKD) involves progressive and irreversible loss of renal function, often causing complications and comorbidities and impairing the function of various organs. In particular, lung injury is observed not only in advanced CKD but also in early-stage CKD. The present study investigated the potential involvement of mineralocorticoid receptors (MRs) and lymphatic vessels in lung injury using a 180-day unilateral ureteral obstruction (UUO) model for CKD. Changes in lung associated with lymphangiogenesis and inflammatory were analyzed in UUO rats. The pathology of the lung tissue was observed by hematoxylin and eosin and Masson's staining. Detection of the expression of lymphatic vessel endothelial hyaluronic acid receptor-1 (LYVE-1), Podoplanin, vascular endothelial growth factor receptor-3 (VEGFR-3) and VEGF C to investigate lymphangiogenesis. The mRNA and protein expression levels of IL-1β, monocyte chemotactic protein 1, tumor necrosis factor-α, nuclear factor κB, phosphorylated serum and glucocorticoid-induced protein kinase-1 and MR were evaluated using western blot, reverse transcription-quantitative PCR, immunohistochemical staining and immunofluorescence staining. In the present study, long-term UUO caused kidney damage, which also led to lung inflammation, accompanied by lymphangiogenesis. However, treatment with eplerenone, an MR blocker, significantly reduced the severity of lung injury and lymphangiogenesis. Therefore, lymphangiogenesis contributed to lung fibrosis in UUO rats due to activation of MRs. In addition, transdifferentiation of lymphatic epithelial cells into myofibroblasts may also be involved in lung fibrosis. Collectively, these findings provided a potential mechanism for lung fibrosis in CKD and suggested that the use of eplerenone decreased kidney damage and lung fibrosis.

Association of Antihypertensive Effects of Esaxerenone with the Internal Sodium Balance in Dahl Salt-Sensitive Hypertensive Rats.

Background: The nonsteroidal mineralocorticoid receptor blocker esaxerenone is effective in reducing blood pressure (BP). Objective: In this study, we investigated esaxerenone-driven sodium homeostasis and its association with changes in BP in Dahl salt-sensitive (DSS) hypertensive rats. Methods: In the different experimental setups, we evaluated BP by a radiotelemetry system, and sodium homeostasis was determined by an approach of sodium intake (food intake) and excretion (urinary excretion) in DSS rats with a low-salt diet (0.3% NaCl), high-salt diet (HSD, 8% NaCl), HSD plus 0.001% esaxerenone (w/w), and HSD plus 0.05% furosemide. Results: HSD-fed DSS rats showed a dramatic increase in BP with a non-dipper pattern, while esaxerenone treatment, but not furosemide, significantly reduced BP with a dipper pattern. The cumulative sodium excretion in the active period was significantly elevated in esaxerenone- and furosemide-treated rats compared with their HSD-fed counterparts. Sodium content in the skin, skinned carcass, and total body tended to be lower in esaxerenone-treated rats than in their HSD-fed counterparts, while these values were unchanged in furosemide-treated rats. Consistently, sodium balance tended to be reduced in esaxerenone-treated rats during the active period. Histological evaluation showed that esaxerenone, but not furosemide, treatment attenuated glomerulosclerosis, tubulointerstitial fibrosis, and urinary protein excretion induced by high salt loading. Conclusions: Collectively, these findings suggest that an esaxerenone treatment-induced reduction in BP and renoprotection are associated with body sodium homeostasis in salt-loaded DSS rats.

Esaxerenone, a selective mineralocorticoid receptor blocker, improves insulin sensitivity in mice consuming high-fat diet

BackgroundEsaxerenone is a novel, non-steroidal selective mineralocorticoid receptor (MR) blocker. MR activation plays a crucial role in the development of cardiovascular and metabolic diseases. In this study, we investigated the effects of esaxerenone on various metabolic parameters in mice. Materials and methodsEsaxerenone (3 mg/kg/day) was orally administered to high-fat diet (HFD)-fed male C57BL/6 mice. Mice fed a normal diet (ND) served as controls. Glucose and insulin tolerance, plasma lipid levels, and transaminase levels were assessed as metabolic parameters. Macrophage accumulation in the adipose tissue was evaluated using histological analysis. 3T3-L1 adipocytes, HepG2 cells, and C2C12 myotubes were used for in vitro experiments. Gene expression and insulin signaling were examined using quantitative RT-PCR and western blotting, respectively. ResultsHFD successfully induced insulin resistance compared with that in ND. Esaxerenone ameliorated insulin resistance (P < 0.05) without altering other metabolic parameters, such as the lipid profile. Esaxerenone administration tended to decrease plasma transaminase levels compared with those in the non-treated group. In the adipose tissue, esaxerenone decreased macrophage accumulation (P < 0.05) and increased the expression levels of adiponectin and PPARγ. Aldosterone significantly decreased the expression levels of PPARγ and adiponectin in 3T3-L1 adipocytes. Furthermore, aldosterone attenuated insulin-induced Akt phosphorylation in 3T3-L1 adipocytes, HepG2 cells, and C2C12 myotubes in a dose-dependent manner (P < 0.01). These effects were ameliorated by pretreatment with esaxerenone. ConclusionEsaxerenone ameliorated insulin resistance in HFD-fed mice. Reduction of inflammation and improvement in insulin signaling may underlie the beneficial effects of esaxerenone.

Upregulation of Mineralocorticoid Receptor Contributes to Development of Salt-Sensitive Hypertension after Ischemia-Reperfusion Injury in Rats.

The ischemia–reperfusion injury (IRI) of rat kidneys is used as a model of acute kidney injury. Salt-sensitive hypertension occurs in rats after IRI, and the distal nephrons play important roles in the development of this condition. We investigated the role of the mineralocorticoid receptor (MR) in the progression of IRI-induced salt-sensitive hypertension in rats. Fourteen days after right-side nephrectomy, IRI was induced by clamping the left renal artery, with sham surgery performed as a control. IRI rats were provided with normal water or water with 1.0% NaCl (IRI/NaCl), or they were implanted with an osmotic mini-pump to infuse vehicle or aldosterone (IRI/Aldo). Esaxerenone, a non-steroidal MR blocker (MRB), was administered to IRI/NaCl and IRI/Aldo rats for 6 weeks. MR expression increased by day 7 post-IRI. Blood pressure and urinary protein excretion increased in IRI/NaCl and IRI/Aldo rats over the 6-week period, but these effects were negated by MRB administration. The MRB attenuated the expression of the gamma-epithelial sodium channel (ENaC) and renal damage. The ENaC inhibitor, amiloride, ameliorated hypertension and renal damage in IRI/NaCl and IRI/Aldo rats. Our findings thus showed that MR upregulation may play a pivotal role in ENaC-mediated sodium uptake in rats after IRI, resulting in the development of salt-sensitive hypertension in response to salt overload or the activation of the renin–angiotensin–aldosterone system.

Mineralocorticoid receptor blockade attenuates hyperandrogenic metabolic dysregulation in letrozole-induced PCOS rat model.

Polycystic ovarian syndrome (PCOS) is a metabolic syndrome associated with mineralocorticoid receptor (MR) activation, which causes infertility in women of reproductive age. Spironolactone (SPL) is a MR blocker with inconclusive effect in the treatment of PCOS. Therefore, the present study hypothesized that low dose SPL would ameliorate metabolic dysfunction associated with PCOS. Female Wistar rats (8-week-old) were divided into 3 groups namely: Control, SPL, Letrozole (LET)-treated and LET + SPL-treated groups. The control group was given vehicle (distilled water), SPL-treated group received 0.25mg/kg, LET-treated group received 1mg/kg of LET and LET + SPL-treated group received a combination of LET and SPL. The administrations were done by oral gavage for 21days uninterruptedly. Biochemical parameters such as lipid profile, malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), γ-glutamyl transferase (GGT), lactate dehydrogenase (LDH), testosterone, 17-β estradiol and glutathione peroxidase (GPx) were determined with appropriate assay methods. Letrozole-treated group had a significant increase in ovarian weight, plasma and ovarian triglycerides, MDA/TNF-α, GGT/LDH and plasma testosterone while it decreased plasma 17-β estradiol and plasma/ovarian high-density lipoproteins and GPx when compared with control group. In addition, histomorphological changes were observed in LET-treated group compared with control group. Nevertheless, administration of low dose SPL attenuated these perturbations. The present study therefore demonstrates that inhibition of mineralocorticoid receptor by low dose SPL ameliorates hyperandrogenic metabolic dysfunction in a rat model of PCOS. Therefore, low dose SPL is hereby suggested as a promising therapeutic agent in the management of PCOS.

Early life stress exacerbates obesity in adult female mice via mineralocorticoid receptor-dependent increases in adipocyte triglyceride and glycerol content

Previously, we have shown that Maternal Separation and Early Weaning (MSEW) exacerbates high fat diet (HF)-induced visceral obesity in female offspring compared to normally reared female mice. Stress hormones such as glucocorticoids and mineralocorticoids are critical mediators in the process of fat expansion, and both can activate the mineralocorticoid receptor (MR) in the adipocyte. Therefore, this study aimed to, comprehend the specific effects of MSEW on adipose tissue basic homeostatic function, and investigate whether female MSEW mice show an exacerbated obesogenic response mediated by MR. Gonadal white adipose tissue (gWAT), a type of visceral fat, was collected to assess lipidomics, transcriptomics, and in vitro lipolysis assay. Obese female MSEW mice showed increased adiposity, elevated 44:2/FA 18:2 + NH4 lipid class and reduced mitochondrial DNA density compared to obese control counterparts. In addition, single-cell RNA sequencing in isolated pre- and mature adipocytes showed a ~9-fold downregulation of aquaglycerolporin 3 (Aqp3), a channel responsible for glycerol efflux in adipocytes. Obese MSEW mice showed high levels of circulating aldosterone and gWAT-derived corticosterone compared to controls. Further, the MR blocker spironolactone (Spiro, 100 mg/kg/day, 2 weeks) normalized the elevated intracellular glycerol levels, the greater in vitro lipolysis response, and the number of large size adipocytes in MSEW mice compared to the controls. Our data suggests that MR plays a role promoting adipocyte hypertrophy in female MSEW mice by preventing lipolysis via glycerol release in favor of triglyceride formation and storage.

Chronic intermittent hypoxia induces renal fibrosis through MR activation.

Obstructive sleep apnea syndrome (OSAS) is a disorder characterized by recurrent arousal from sleep and chronic intermittent hypoxia (CIH). OSAS-associated chronic kidney disease is mainly caused by CIH-induced tissue damage. Therefore, an OSAS model was established by CIH exposure in a hypoxic chamber for five weeks. In our study, macrophage infiltration and macrophage-myofibroblast transition (MMT) were observed in the kidneys of CIH rats and appeared to contribute to the development of renal fibrosis. However, the underlying mechanisms are not well defined. We also found that upon binding to the mineralocorticoid receptor (MR), aldosterone stimulated MMT and consequently led to renal fibrosis under hypoxic conditions. Additionally, an in vitro study of RAW264.7 macrophages demonstrated that MR activation may contribute to MMT, which resulted in a predominant M1 phenotype under hypoxic conditions. These effects were reversed by the MR blocker eplerenone. These results provide preliminary evidence that MR activation might be involved in the transdifferentiation of macrophages into myofibroblasts in the CIH model. The attenuation of renal injury demonstrates a protective role of MR blockade in CIH-induced renal disease.

P181 CARDIAC PROTECTION BY PIRFENIDONE AFTER MYOCARDIAL INFARCTION: A BIOINFORMATIC ANALYSIS

Abstract Purpose Left ventricular (LV) remodeling after myocardial infarction (MI) is promoted by an intense fibrotic response, which could be targeted by an anti–fibrotic drug such as pirfenidone. Methods We explored the relationship between protein modulation by pirfenidone and post–MI remodeling, 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. Results We identified 6 causative motives of post–MI remodeling (cardiomyocyte cell death, impaired myocyte contractility, extracellular matrix remodeling 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 6 motives. p38γ–MAPK12 blockade inhibits cardiomyocyte apoptosis, cardiomyocyte hypertrophy and inflammation. Furthermore, pirfenidone can modulate extracellular matrix remodeling 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. Conclusion A bioinformatic approach allowed to identify several possible mechanisms of action of pirfenidone with beneficial effects in the post–MI LV remodeling, and suggests additional effects over guideline–recommended therapies. These findings support clinical studies evaluating the beneficial effects of pirfenidone in patients with MI.

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&lt;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&lt;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&lt;0.05 vs. C). Western blot analysis confirmed this reduction (0.40±0.08 and 1.0±0.14 AQP3/HSP90 p&lt;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&lt;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&lt;0.05 MSEW vs. C, respectively) while Spiro also decreased basal and stimulated released glycerol in MSEW mice (p&lt;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.