Myeloid Mineralocorticoid Receptor Activation Contributes to Progressive Kidney Disease
01 Oct 2014-Journal of The American Society of Nephrology (American Society of Nephrology)-Vol. 25, Iss: 10, pp 2231-2240
TL;DR: Myeloid deficiency of MR provides protection similar to eplerenone in this disease, and MR signaling in myeloid cells, but not podocytes, contributes to the progression of renal injury in mouse GN.
Abstract: Clinical and experimental studies have shown that mineralocorticoid receptor (MR) antagonists substantially reduce kidney injury. However, the specific cellular targets and mechanisms by which MR antagonists protect against kidney injury must be identified. We used conditional gene deletion of MR signaling in myeloid cells (MR flox/flox LysM Cre mice; MyMRKO) or podocytes (MR flox/flox Pod Cre mice; PodMRKO) to establish the role of MR in these cell types in the development of mouse GN. Accelerated anti–glomerular basement membrane GN was examined in groups of mice: MyMRKO, PodMRKO, wild-type (WT) littermates, and WT mice receiving eplerenone (100 mg/kg twice a day; EPL-treated). At day 15 of disease, WT mice had glomerular crescents (37%±5%), severe proteinuria, and a 6-fold increase in serum cystatin-C. MyMRKO, PodMRKO, and EPL-treated mice with GN displayed proteinuria similar to that in these disease controls. However, MyMRKO and EPL-treated groups had a 35% reduction in serum cystatin-C levels and reduced crescent numbers compared with WT mice, whereas PodMRKO mice were not protected. The protection observed in MyMRKO mice appeared to result predominantly from reduced recruitment of macrophages and neutrophils into the inflamed kidney. Suppression of kidney leukocyte accumulation in MyMRKO mice correlated with reductions in gene expression of proinflammatory molecules (TNF- α , inducible nitric oxide synthase, chemokine (C-C motif) ligand 2, matrix metalloproteinase - 12), tubular damage, and renal fibrosis and was similar in EPL-treated mice. In conclusion, MR signaling in myeloid cells, but not podocytes, contributes to the progression of renal injury in mouse GN, and myeloid deficiency of MR provides protection similar to eplerenone in this disease.
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TL;DR: In this paper, the role of My-MR in leukocyte trafficking and the impact of sex was examined in mouse atherosclerosis and plaque inflammation by using intravital microscopy.
Abstract: Objective MR (mineralocorticoid receptor) activation associates with increased risk of cardiovascular ischemia while MR inhibition reduces cardiovascular-related mortality and plaque inflammation in mouse atherosclerosis. MR in myeloid cells (My-MR) promotes inflammatory cell infiltration into injured tissues and atherosclerotic plaque inflammation by unclear mechanisms. Here, we examined the role of My-MR in leukocyte trafficking and the impact of sex. Approach and Results We confirm in vivo that My-MR deletion (My-MR-KO) in ApoE-KO mice decreased plaque size. Flow cytometry revealed fewer plaque macrophages with My-MR-KO. By intravital microscopy, My-MR-KO significantly attenuated monocyte slow-rolling and adhesion to mesenteric vessels and decreased peritoneal infiltration of myeloid cells in response to inflammatory stimuli in male but not female mice. My-MR-KO mice had significantly less PSGL1 (P-selectin glycoprotein ligand 1) mRNA in peritoneal macrophages and surface PSGL1 protein on circulating monocytes in males. In vitro, MR activation with aldosterone significantly increased PSGL1 mRNA only in monocytes from MR-intact males. Similarly, aldosterone induced, and MR antagonist spironolactone inhibited, PSGL1 expression in human U937 monocytes. Mechanistically, aldosterone stimulated MR binding to a predicted MR response element in intron-1 of the PSGL1 gene by ChIP-qPCR. Reporter assays demonstrated that this PSGL1 MR response element is necessary and sufficient for aldosterone-activated, MR-dependent transcriptional activity. Conclusions These data identify PSGL1 as a My-MR target gene that drives leukocyte trafficking to enhance atherosclerotic plaque inflammation. These novel and sexually dimorphic findings provide insight into increased ischemia risk with MR activation, cardiovascular protection in women, and the role of MR in atherosclerosis and tissue inflammation.
7 citations
TL;DR: An overview of the pathophysiologic role of MR overactivation and preclinical evidence with the nonsteroidal MRA finerenone in a range of different disease models with respect to major components of the aggregate mode of action, including interfering with reactive oxygen species generation, inflammation, fibrosis, and hypertrophy is provided.
Abstract: Perception of the role of the aldosterone/mineralocorticoid receptor (MR) ensemble has been extended from a previously renal epithelial-centered focus on sodium and volume homeostasis to an understanding of their role as systemic modulators of reactive oxygen species, inflammation, and fibrosis. Steroidal MR antagonists (MRAs) are included in treatment paradigms for resistant hypertension and heart failure with reduced ejection fraction, while more recently, the nonsteroidal MRA finerenone was shown to reduce renal and cardiovascular outcomes in two large phase III trials (FIDELIO-DKD and FIGARO-DKD) in patients with chronic kidney disease and type 2 diabetes, respectively. Here, we provide an overview of the pathophysiologic role of MR overactivation and preclinical evidence with the nonsteroidal MRA finerenone in a range of different disease models with respect to major components of the aggregate mode of action, including interfering with reactive oxygen species generation, inflammation, fibrosis, and hypertrophy. We describe a time-dependent effect of these mechanistic components and the potential modification of major clinical parameters, as well as the impact on clinical renal and cardiovascular outcomes as observed in FIDELIO-DKD and FIGARO-DKD. Finally, we provide an outlook on potential future clinical indications and ongoing clinical studies with finerenone, including a combination study with a sodium–glucose cotransporter-2 inhibitor.
6 citations
TL;DR: Non-steroidal MRAs are currently under evaluation in heart failure and for synergistic treatment with sodium-glucose contransporter 2 inhibitors and could become an important therapy across the spectrum of cardiorenal disease.
Abstract: Despite existing treatments, patients with heart failure and chronic kidney disease (CKD) remain at high risk for adverse outcomes and progression to end-stage disease. Steroidal mineralocorticoid receptor antagonists (MRAs) such as spironolactone and eplerenone reduce mortality but remain under-prescribed due to the perceived risk of hyperkalaemia and hormonal side effects. The discovery of non-steroidal MRAs represents a major new dimension in cardiorenal disease therapy. Non-steroidal MRAs have high affinity and specificity for the mineralocorticoid receptor (MR) and differ from both steroidal agents and each other with respect to important physiochemical, pharmacodynamic, and pharmacokinetic parameters. Similar to their steroidal counterparts, they have beneficial anti-inflammatory, anti-remodelling, and anti-fibrotic properties in the kidneys, heart, and vasculature. There are several non-steroidal MRAs under development and clinical assessment; of these, only esaxerenone and finerenone are approved for treatment globally. In Japan, esaxerenone is approved for essential hypertension and has been studied in diabetic nephropathy. Compared with steroidal MRAs, finerenone more potently inhibits MR co-regulator recruitment and fibrosis and distributes more evenly between the heart and kidneys. The landmark Phase III trials FIGARO-DKD and FIDELIO-DKD demonstrated that finerenone-reduced major kidney and cardiovascular events on top of maximally tolerated renin-angiotensin-aldosterone system inhibition in patients with CKD associated with Type 2 diabetes. Non-steroidal MRAs are currently under evaluation in heart failure and for synergistic treatment with sodium-glucose contransporter 2 inhibitors. These ground-breaking agents could become an important therapy across the spectrum of cardiorenal disease.
6 citations
TL;DR: Aldosterona and the estimulación of the receptor mineralcorticoide (RM) in the genesis and progresion of the enfermedad renal cronica (ERC) and in el dano cardiovascular have been investigated as discussed by the authors.
Abstract: Resumen Hay abundantes datos experimentales que sustentan la participacion de la aldosterona y la estimulacion del receptor mineralcorticoide (RM) en la genesis y progresion de la enfermedad renal cronica (ERC) y en el dano cardiovascular. Muchos estudios han demostrado que en la ERC diabetica y no diabetica el bloqueo del sistema renina angiotensina-aldosterona (SRAA) con inhibidores de enzima de conversion (iECA) o antagonistas del receptor de angiotensina II (ARA2) disminuye la proteinuria, la progresion de la ERC y la mortalidad, pero persiste todavia un importante riesgo residual de desarrollo de estos eventos. En sujetos tratados con iECA o ARA2 puede haber un escape de la aldosterona cuya prevalencia en sujetos con ERC puede alcanzar el 50%. Diversos estudios han demostrado que, en la ERC, los farmacos antialdosteronicos clasicos (espironolactona, eplerenona) anadidos a iECA o ARA2 reducen la proteinuria, pero aumentan el riesgo de hipercaliemia. Otros estudios en sujetos tratados con dialisis sugieren un posible efecto beneficioso de los antialdosteronicos sobre eventos CV y mortalidad. Los nuevos ligadores intestinales de K+ pueden prevenir o reducir la hipercaliemia inducida por el bloqueo del SRAA y disminuir la desprescripcion o la reduccion de dosis de farmacos bloqueantes del SRAA. Los bloqueantes del RM no esteroideos, con mas potencia y selectividad que los clasicos, reducen la proteinuria y tienen menos riesgo de hipercaliemia. Varios ensayos clinicos, actualmente en realizacion, determinaran el efecto de los bloqueantes clasicos del RM sobre eventos CV y mortalidad en sujetos con ERC estadio 3b y en enfermos en dialisis, y si en enfermos con diabetes mellitus tipo 2 y ERC, optimamente tratados y con elevado riesgo de eventos CV y renales, la adicion de finerenona a su tratamiento produce beneficios cardiorrenales. Los inhibidores del cotransportador sodio-glucosa tipo 2 (iSGLT2) han demostrado reducir la mortalidad y el desarrollo y la progresion de la nefropatia diabetica y no diabetica. Hay argumentos fisiopatologicos que suscitan la posibilidad de que la triple combinacion iECA o ARA2, iSGLT2 y antagonista de aldosterona ofrezca mayor proteccion renal y vascular.
6 citations
TL;DR: In this article , the impact of finerenone treatment on the cardiovascular system in persons with type 2 diabetes and chronic kidney disease (CKD) is analyzed from a practical point of view.
Abstract: Abstract Persons with diabetes and chronic kidney disease (CKD) have a high residual risk of developing cardiovascular (CV) complications despite treatment with renin-angiotensin system blockers and sodium-glucose cotransporter type 2 inhibitors. Overactivation of mineralocorticoid receptors plays a key role in the progression of renal and CV disease, mainly by promoting inflammation and fibrosis. Finerenone is a nonsteroidal selective mineralocorticoid antagonist. Recent clinical trials, such as FIDELIO-DKD and FIGARO-DKD and the combined analysis FIDELITY have demonstrated that finerenone decreases albuminuria, risk of CKD progression, and CV risk in subjects with type 2 diabetes (T2D) and CKD. As a result, finerenone should thus be considered as part of a holistic approach to kidney and CV risk in persons with T2D and CKD. In this narrative review, the impact of finerenone treatment on the CV system in persons with type 2 diabetes and CKD is analyzed from a practical point of view. Key messages: Despite inhibition of renin-angiotensin system and sodium-glucose cotransporter type 2, persons with type 2 diabetes (T2D) and chronic kidney disease (CKD) remain on high cardiovascular (CV) residual risk. Overactivation of mineralocorticoid receptors plays a key role in the progression of renal and CV disease, mainly by promoting inflammation and fibrosis that is not targeted by traditional treatments. Finerenone is a nonsteroidal selective mineralocorticoid antagonist that decreases not only albuminuria, but also the risk of CKD progression, and CV risk in subjects with T2D and CKD.
6 citations
References
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TL;DR: The method was applicable also to newborn mice, which allows for the isolation of immature developmental stage glomeruli and makes feasible transcript profiling and proteomic analysis of the developing, healthy and diseased mouse glomerulus.
Abstract: Here we report a new isolation method for mouse glomeruli. The method is fast and simple and allows for the isolation of virtually all glomeruli present in the adult mouse kidney with minimal contamination of nonglomerular cells. Mice were perfused through the heart with magnetic 4.5- micro m diameter Dynabeads. Kidneys were minced into small pieces, digested by collagenase, filtered, and collected using a magnet. The number of glomeruli retrieved from one adult mouse was 20,131 +/- 4699 (mean +/- SD, n = 14) with a purity of 97.5 +/- 1.7%. The isolated glomeruli retained intact morphology, as confirmed by light and electron microscopy, as well as intact mRNA integrity, as confirmed by Northern blot analysis. The method was applicable also to newborn mice, which allows for the isolation of immature developmental stage glomeruli. This method makes feasible transcript profiling and proteomic analysis of the developing, healthy and diseased mouse glomerulus.
496 citations
TL;DR: It is shown that myeloid MR is an important control point in macrophage polarization and that the function of MR on myeloids cells likely represents a conserved ancestral MR function that is integrated in a transcriptional network with PPARgamma and glucocorticoid receptor.
Abstract: Inappropriate excess of the steroid hormone aldosterone, which is a mineralocorticoid receptor (MR) agonist, is associated with increased inflammation and risk of cardiovascular disease. MR antagonists are cardioprotective and antiinflammatory in vivo, and evidence suggests that they mediate these effects in part by aldosterone-independent mechanisms. Here we have shown that MR on myeloid cells is necessary for efficient classical macrophage activation by proinflammatory cytokines. Macrophages from mice lacking MR in myeloid cells (referred to herein as MyMRKO mice) exhibited a transcription profile of alternative activation. In vitro, MR deficiency synergized with inducers of alternatively activated macrophages (for example, IL-4 and agonists of PPARgamma and the glucocorticoid receptor) to enhance alternative activation. In vivo, MR deficiency in macrophages mimicked the effects of MR antagonists and protected against cardiac hypertrophy, fibrosis, and vascular damage caused by L-NAME/Ang II. Increased blood pressure and heart rates and decreased circadian variation were observed during treatment of MyMRKO mice with L-NAME/Ang II. We conclude that myeloid MR is an important control point in macrophage polarization and that the function of MR on myeloid cells likely represents a conserved ancestral MR function that is integrated in a transcriptional network with PPARgamma and glucocorticoid receptor. Furthermore, myeloid MR is critical for blood pressure control and for hypertrophic and fibrotic responses in the mouse heart and aorta.
332 citations
TL;DR: In this article, the effects of aldosterone on podocyte, a key player of the glomerular filtration barrier, were investigated in uninephrectomized rats and fed a high-salt diet, where the podocyte injury was accompanied by renal reduced nicotinamide-adenine dinucleotide phosphate oxidase activation, increased oxidative stress, and enhanced expression of Sgk1.
Abstract: Accumulating evidence suggests that mineralocorticoid receptor blockade effectively reduces proteinuria in hypertensive patients. However, the mechanism of the antiproteinuric effect remains elusive. In this study, we investigated the effects of aldosterone on podocyte, a key player of the glomerular filtration barrier. Uninephrectomized rats were continuously infused with aldosterone and fed a high-salt diet. Aldosterone induced proteinuria progressively, associated with blood pressure elevation. Notably, gene expressions of podocyte-associated molecules nephrin and podocin were markedly decreased in aldosterone-infused rats at 2 weeks, with a gradual decrease thereafter. Immunohistochemical studies and electron microscopy confirmed the podocyte damage. Podocyte injury was accompanied by renal reduced nicotinamide-adenine dinucleotide phosphate oxidase activation, increased oxidative stress, and enhanced expression of aldosterone effector kinase Sgk1. Treatment with eplerenone, a selective aldosterone receptor blocker, almost completely prevented podocyte damage and proteinuria, with normalization of elevated reduced nicotinamide-adenine dinucleotide phosphate oxidase activity. In addition, proteinuria, podocyte damage, and Sgk1 upregulation were significantly alleviated by tempol, a membrane-permeable superoxide dismutase, suggesting the pathogenic role of oxidative stress. Although hydralazine treatment almost normalized blood pressure, it failed to improve proteinuria and podocyte damage. In cultured podocytes with consistent expression of mineralocorticoid receptor, aldosterone stimulated membrane translocation of reduced nicotinamide-adenine dinucleotide phosphate oxidase cytosolic components and oxidative stress generation in podocytes. Furthermore, aldosterone enhanced the expression of Sgk1, which was inhibited by mineralocorticoid receptor antagonist and tempol. In conclusion, podocytes are injured at the early stage in aldosterone-infused rats, resulting in the occurrence of proteinuria. Aldosterone can directly modulate podocyte function, possibly through the induction of oxidative stress and Sgk1.
324 citations
TL;DR: A transgenic mouse line that expresses Cre recombinase exclusively in podocytes is reported, and Histological analysis of the kidneys showed that β‐gal expression was confined to podocytes.
Abstract: We report a transgenic mouse line that expresses Cre recombinase exclusively in podocytes. Twenty- four transgenic founders were generated in which Cre recombinase was placed under the regulation of a 2.5-kb fragment of the human NPHS2 promoter. Previously, this fragment was shown to drive beta-galactosidase (beta-gal) expression exclusively in podocytes of transgenic mice. For analysis, founder mice were bred with ROSA26 mice, a reporter line that expresses beta-gal in cells that undergo Cre recombination. Eight of 24 founder lines were found to express beta-gal exclusively in the kidney. Histological analysis of the kidneys showed that beta-gal expression was confined to podocytes. Cre recombination occurred during the capillary loop stage in glomerular development. No evidence for Cre recombination was detected in any of 14 other tissues examined.
296 citations
TL;DR: A critical role for the MR in cardiovascular disease has now been demonstrated by the beneficial response to MR blockade in 2 large clinical trials in patients with cardiac failure, needed for the development of antagonists that target the cardiovascular system while avoiding the undesirable side effects of renal MR blockade.
Abstract: Sodium transport in epithelial tissues is regulated by the physiological mineralocorticoid aldosterone. The response to aldosterone is mediated by the mineralocorticoid receptor (MR), for which the crystal structure of the ligand-binding domain has recently been established. The classical mode of action for this receptor involves the regulation of gene transcription. Several genes have now been shown to be regulated by aldosterone in epithelial tissues. Of these, the best characterized is serum- and glucocorticoid-regulated kinase, which increases sodium influx through the epithelial sodium channel. Turnover of these channels in the cell membrane is mediated by Nedd4-2, a ubiquitin protein ligase; serum- and glucocorticoid-regulated kinase interacts with and phosphorylates Nedd4-2, thereby rendering it unable to bind the sodium channels. In nonepithelial tissues, particularly the cardiovascular system, aldosterone also has direct effects, activating an inflammatory cascade, leading to cardiac fibrosis. A critical role for the MR in cardiovascular disease has now been demonstrated by the beneficial response to MR blockade in 2 large clinical trials in patients with cardiac failure. It is these nonepithelial actions of MR activation that need to be exploited for the development of antagonists that target the cardiovascular system while avoiding the undesirable side effects of renal MR blockade.
280 citations