The role of mineralocorticoid receptor activation in kidney inflammation and fibrosis

Non-steroidal mineralocorticoid receptor antagonist finerenone inhibits peritoneal fibrosis induced by high-glucose dialysate via regulating enhancer of zeste homolog 2 (EZH2) expression

Finerenone, a novel high-selective aldosterone receptor antagonist, exhibits powerful anti-inflammatory and antifibrotic effects in previous researches. The aim of our study was to investigate of it on peritoneal fibrosis. In our current research, we found that high glucose could induce epithelial mesothelial transformation (EMT) of peritoneal mesothelial cells (HPMCs). Under high glucose stimulation, the addition of finerenone could alleviate high glucose induced EMT and disordered cytoskeleton rearrangement in HPMCs. Moreover, finerenone decreased the expression of enhancer of zeste homolog 2 (EZH2). Results of rescue experiment showed that after overexpression of EZH2 in the presence of finerenone, the protective effect of finerenone on EMT, migration capacity and cytoskeleton rearrangement was counteracted by EZH2 overexpression. The above results have also been demonstrated in in vivo experiments. These findings imply that finerenone could alleviate EMT and peritoneal fibrosis via regulating EZH2. More studies are needed to validate it and explore further mechanism.

Mineralocorticoid receptor blockage in kidney transplantation: too much of a good thing or not?

Although, kidney transplantation (KT) is the best treatment option for patients with end-stage kidney disease, long-term complications including chronic kidney allograft disease (CKAD) and major adverse cardiovascular events (MACE) are common. To decrease these complications new therapeutic options are necessary. Mineralocorticoid receptor antagonists (MRAs) are one of the promising drugs in this context. In the general population, MRAs had favorable effects on blood pressure regulation, MACE, proteinuria and progression of chronic kidney disease. In the context of KT, there are limited studies showing beneficial effects such as reducing proteinuria and oxidative stress. In this review, we performed a narrative review to assess the use and impact of MRAs in kidney transplant recipients. We found that in KTRs, MRAs are safe and they have favorable or neutral impact on blood pressure, glomerular filtration rate, urinary protein/albumin excretion, and oxidative stress. No data was found regarding major cardiovascular adverse events.

Efficacy of Mineralocorticoid Receptor Antagonists on Kidney and Cardiovascular Outcomes in Patients With Chronic Kidney Disease: An Umbrella Review

Rationale & Objective

To comprehensively summarize the efficacy of mineralocorticoid receptor antagonists (MRAs) to improve kidney and cardiovascular (CV) outcomes in patients with chronic kidney disease (CKD).

Study Design

Relevant studies were identified from Medline and Scopus databases from their inception up to August 2023.

Setting & Study Populations

Patients with nondialysis or dialysis CKD.

Selection Criteria for Studies

Systematic reviews and meta-analyses (SR-MAs) of randomized controlled trials (RCTs) that investigated the efficacy of MRAs on kidney and CV outcomes in patients with nondialysis or dialysis CKD were included in this study.

Data Extraction

Characteristics of studies and participants, and treatment effects were extracted.

Analytic Approach

Efficacy of MRAs was qualitatively summarized according to types of patients and MRAs.

Results

Forty SR-MAs were included. When compared with placebo/usual care, steroidal MRAs (sMRAs) provided significant benefit in decreasing all-cause (pooled RRs of 0.38 [0.22-0.65] to 0.87 [0.77-0.98]) and CV mortality (pooled RRs of 0.34 [0.15-0.75] to 0.46 [0.28-0.76]) only in patients treated with dialysis, when compared with placebo. Nonsteroidal MRAs (nsMRAs) significantly lowered composite CV events in both nondialysis CKD (pooled RRs of 0.86 [0.79-0.94] to 0.92 [0.85-0.99]) and patients with diabetic kidney disease (DKD) (pooled RRs of 0.86 [0.78-0.95] to 0.88 [0.81-0.96]). In addition, nsMRAs showed significant benefit in reducing composite kidney outcomes in patients with either nondialysis CKD or DKD when compared with placebo. However, this efficacy was lower than sodium-glucose cotransporter-2 inhibitors (SGLT2i) in patients with DKD. Moreover, both sMRAs and nsMRAs significantly increased the risk of hyperkalemia in patients with nondialysis CKD and DKD.

Limitations

The comparison between nsMRAs and SGLT2i is based on network meta-analyses. Consequently, additional head-to-head RCTs are necessary to confirm the advantages of SGLT2i over nsMRAs.

Conclusions

sMRAs offer benefits in reducing all-cause and cardiovascular mortality and composite CV events in patients treated with dialysis. nsMRAs improve kidney outcomes in patients with nondialysis CKD and DKD but increase hyperkalemia risk.

Effect of spironolactone wash-out on albuminuria after long-term treatment in individuals with type 2 diabetes and high risk of kidney disease-An observational follow-up of the PRIORITY study

AIMS

This study aimed to explore the effect of discontinuation of long-term spironolactone treatment on markers of kidney function in individuals with type 2 diabetes (T2D) at high risk of kidney disease enrolled in the Proteomic prediction and Renin angiotensin aldosterone system Inhibition prevention Of early diabetic nephRopathy In TYpe 2 diabetic patients with normoalbuminuria (PRIORITY) study.

MATERIALS AND METHODS

An observational study following the nested randomised part of the PRIORITY study was conducted. A total of 115 individuals with T2D and normoalbuminuria but high risk for progression based on urinary proteomics, randomised to daily spironolactone (n = 50) or placebo (n = 65) for a median of 2.5 years, were re-examined approximately 6 weeks after the final visit in the PRIORITY study. Primary endpoint was relative change in geometric mean of urinary albumin-creatinine ratio (UACR) between the final visit in PRIORITY (baseline) and follow-up. Secondary endpoints were change in estimated glomerular filtration rate (eGFR), systolic blood pressure (SBP) and serum potassium.

RESULTS

No change in UACR was observed in neither the spironolactone (geometric mean change: 17%; 95% CI -12, 55; p = 0.28) nor the placebo (5%; 95% CI -13, 26; p = 0.63) group at follow-up. No difference in UACR between the groups was observed at follow-up (relative difference in geometric mean: 11%, 95% CI -26, 67; p = 0.60). For eGFR and SBP, an increase after discontinuation of spironolactone was observed, as well as for SBP after placebo discontinuation. Potassium levels were lower after discontinuation of spironolactone, but higher after placebo discontinuation (all p < 0.05).

CONCLUSIONS

UACR did not change after discontinuation of long-term treatment with spironolactone. However, an increase in eGFR was observed supporting a haemodynamic effect of spironolactone in the kidneys.

Intellectual landscapes and emerging trends of non-steroidal mineralocorticoid receptor antagonists: a bibliometric and visual analysis

PURPOSE

With increasing studies, non-steroidal mineralocorticoid receptor (MR) antagonists have been increasingly recognized as a major novel dimension in cardiorenal disease therapy. This bibliometric analysis aimed to uncover current research status and identify future research directions in the study of non-steroidal MR antagonists to inform subsequent investigations.

METHODS

Relevant English-language literature was retrieved from the Science Citation Index Expanded of the Web of Science Core Collection on January 10, 2024. Analyses of countries, institutions, authors, journals, documents, cited references and keywords were performed by the CiteSpace and VOSviewer software.

RESULTS

Overall, 498 documents, including 297 articles and 201 reviews, were included and analyzed. The United States (n = 188), Bayer AG (n = 78), and Professor Peter Kolkhof (n = 59) were the most prolific country, institution, and author in this field, respectively. Cluster analysis of cited references identified major clusters like cardiovascular disease, chronic kidney disease, and omecamtiv mecarbil. Keyword analysis indicated that sodium-glucose transport protein (SGLT)-2 inhibitors, pharmacotherapy, clinical trial, and guideline have emerged recently.

CONCLUSION

The field of non-steroidal MR antagonists is gradually gaining momentum as a novel pharmacotherapy in cardiorenal diseases, especially diabetic kidney disease, hypertension, and heart failure. Future studies will focus on add-on pharmacotherapy by combining non-steroidal MR antagonists with SGLT-2 inhibitors and the development and publication of clinical guidelines to facilitate patient management.

Decoding the role of aldosterone in glycation-induced diabetic complications

Diabetes-mediated development of micro and macro-vascular complications is a global concern. One of the factors is hyperglycemia induced the non-enzymatic formation of advanced glycation end products (AGEs). Accumulated AGEs bind with receptor of AGEs (RAGE) causing inflammation, oxidative stress and extracellular matrix proteins (ECM) modifications responsible for fibrosis, cell damage and tissue remodeling. Moreover, during hyperglycemia, aldosterone (Aldo) secretion increases, and its interaction with mineralocorticoid receptor (MR) through genomic and non-genomic pathways leads to inflammation and fibrosis. Extensive research on individual involvement of AGEs-RAGE and Aldo-MR pathways in the development of diabetic nephropathy (DN), cardiovascular diseases (CVDs), and impaired immune system has led to the discovery of therapeutic drugs. Despite mutual repercussions, the cross-talk between AGEs-RAGE and Aldo-MR pathways remains unresolved. Hence, this review focuses on the possible interaction of Aldo and glycation in DN and CVDs, considering the clinical significance of mutual molecular targets.

Epigenetic reprogramming driving successful and failed repair in acute kidney injury

Acute kidney injury (AKI) causes epithelial damage followed by subsequent repair. While successful repair restores kidney function, this process is often incomplete and can lead to chronic kidney disease (CKD) in a process called failed repair. To better understand the epigenetic reprogramming driving this AKI-to-CKD transition, we generated a single-nucleus multiomic atlas for the full mouse AKI time course, consisting of ~280,000 single-nucleus transcriptomes and epigenomes. We reveal cell-specific dynamic alterations in gene regulatory landscapes reflecting, especially, activation of proinflammatory pathways. We further generated single-nucleus multiomic data from four human AKI samples including validation by genome-wide identification of nuclear factor κB binding sites. A regularized regression analysis identifies key regulators involved in both successful and failed repair cell fate, identifying the transcription factor CREB5 as a regulator of both successful and failed tubular repair that also drives proximal tubular cell proliferation after injury. Our interspecies multiomic approach provides a foundation to comprehensively understand cell states in AKI.

Mineralocorticoid receptor antagonists in kidney transplantation

BACKGROUND

The fundamental role of the renin-angiotensin-aldosterone system in the pathophysiology of chronic kidney disease, congestive heart failure, hypertension and proteinuria is well established in pre-clinical and clinical studies. Mineralocorticoid receptor antagonists are among the primary options for renin-angiotensin-aldosterone system blockage, along with angiotensin-converting enzyme inhibitors and angiotensin receptor blockers.

METHODS

In this narrative review, we aim to evaluate the efficiency and safety of mineralocorticoid receptor antagonists in kidney transplant recipients, including the potential underlying pathophysiology.

RESULTS

The efficiency and safety of mineralocorticoid receptor antagonists in managing chronic kidney disease and proteinuria, either non-nephrotic or nephrotic range, have been demonstrated among nontransplanted patients, though studies investigating the role of mineralocorticoid receptor antagonists among kidney transplant recipients are scarce. Nevertheless, promising results have been reported in pre-clinical and clinical studies among kidney transplant recipients regarding the role of mineralocorticoid receptor antagonists in terms of ischaemia-reperfusion injury, proteinuria, or calcineurin inhibitor-mediated nephrotoxicity without considerable adverse events such as hypotension, hyperkalaemia or worsening renal functions.

CONCLUSION

Even though initial results regarding the role of mineralocorticoid receptor antagonist therapy for kidney transplant recipients are promising, there is clear need for large-scale randomized clinical trials with long-term follow-up data.

Target organ damage in untreated hypertensive patients with primary aldosteronism

An increased risk of target organ damage (TOD) has been reported in patients with primary aldosteronism (PA). However, there is relatively little related research on the correlation between the degree of TOD and those with and without PA in newly diagnosed hypertensive patients. The aim of this study was to assess the association between PA and TOD among patients with newly diagnosed hypertension. Newly diagnosed hypertensive patients were consecutively recruited from January 2015 to June 2020 at the University of Hong Kong-Shenzhen Hospital. Patients were stratified into those with and without PA. Data for left ventricular mass index (LVMI), carotid intima-media thickness (CIMT) and plaque, and microalbuminuria were systematically collected. A total of 1044 patients with newly diagnosed hypertension were recruited, 57 (5.5%) of whom were diagnosed with PA. Patients with PA had lower blood pressure, serum lipids, body mass index, and plasma renin activity and a higher incidence of hypokalemia than those without PA. In contrast, the prevalence of left ventricular hypertrophy, increased CIMT, and microalbuminuria was higher in patients with PA than in those without PA. Multivariable regression analysis demonstrated that PA was independently associated with increased LVMI, CIMT and microalbuminuria. Among patients with newly diagnosed hypertension, those with PA had more severe TOD, including a higher LVMI, CIMT and microalbuminuria, than those without PA. These findings emphasize the need for screening TOD in newly diagnosed hypertension due to underlying PA.

Chronic unpredictable mild stress increases serum aldosterone without affecting corticosterone levels and induces hepatic steatosis and renal injury in young adult male rats

Stress is often associated with anxiety and depressive symptoms in adolescents. Stress is associated with components of metabolic syndrome and inflammation. The present study hypothesizes that aldosterone, more than corticosterone, promotes chronic stress-hepatic steatosis and fibrosis, as well as renal inflammation and fibrosis in young adult rats. Thirty-two young adult male Wistar rats of 51 days old were divided into four groups (n = 8 per group): Control (C), chronic unpredictable mild stress (CUMS), control plus vehicle (C plus veh), CUMS plus eplerenone, a selective aldosterone blocker (CUMS plus EP). On postnatal day 51, eplerenone was administered orally through a gastric tube two hours before the start of the stress test. The CUMS paradigm was administered once daily at different times, with no repetition of the stressor sequence for four weeks. Renal inflammation and fibrosis were measured, as well as liver glycogen, triacylglycerol, and fibrosis levels. The serum concentrations of corticosterone, aldosterone, sodium, and creatinine were measured in urine and serum. The CUMS group showed a high level of serum aldosterone without affecting the level of corticosterone, increased urinary sodium, tubular atrophy, glomerular sclerosis, the presence of inflammation, and fibrosis, without affecting creatinine, increased glycogen content, triacylglycerol, and moderate fibrosis in the liver, and treatment with eplerenone prevented the inflammation, fibrosis, glycogen, and triacylglycerol. Our results show that chronic stress-induced aldosterone promotes hepatic steatosis and renal injury more than corticosterone. The prevention by eplerenone supports our hypothesis.

Lessons learned from early-stage clinical trials for diabetic nephropathy

INTRODUCTION

The evolution of treatment for diabetic nephropathy illustrates how basic biochemistry and physiology have led to new agents such as SGLT2 inhibitors and mineralocorticoid blockers. Conversely, clinical studies performed with these agents have suggested new concepts for investigational drug development. We reviewed currently available treatments for diabetic nephropathy and then analyzed early clinical trials of new agents to assess the potential for future treatment modalities.

AREAS COVERED

We searched ClinicalTrials.gov for new agents under study for diabetic nephropathy in the past decade. Once we have identified investigation trials of new agents, we then used search engines and Pubmed.gov to find publications providing insight on these drugs. Current treatments have shown benefit in both cardiac and renal disease. In our review, we found 51 trials and 43 pharmaceuticals in a number of drug classes: mineralocorticoid blockers, anti-inflammatory, anti-fibrosis, nitric oxide stimulatory, and podocyte protection, and endothelin inhibitors.

EXPERT OPINION

It is difficult to predict which early phase treatments will advance to confirmatory clinical trials. Current agents are thought to improve hemodynamic function. However, the coincident benefit of both myocardial function and the glomerulus argues for primary effects at the subcellular level, and we follow the evolution of agents which modify fundamental cellular processes.

Fibrosis in Chronic Kidney Disease: Pathophysiology and Therapeutic Targets

Chronic kidney disease (CKD) is a slowly progressive condition characterized by decreased kidney function, tubular injury, oxidative stress, and inflammation. CKD is a leading global health burden that is asymptomatic in early stages but can ultimately cause kidney failure. Its etiology is complex and involves dysregulated signaling pathways that lead to fibrosis. Transforming growth factor (TGF)-β is a central mediator in promoting transdifferentiation of polarized renal tubular epithelial cells into mesenchymal cells, resulting in irreversible kidney injury. While current therapies are limited, the search for more effective diagnostic and treatment modalities is intensive. Although biopsy with histology is the most accurate method of diagnosis and staging, imaging techniques such as diffusion-weighted magnetic resonance imaging and shear wave elastography ultrasound are less invasive ways to stage fibrosis. Current therapies such as renin-angiotensin blockers, mineralocorticoid receptor antagonists, and sodium/glucose cotransporter 2 inhibitors aim to delay progression. Newer antifibrotic agents that suppress the downstream inflammatory mediators involved in the fibrotic process are in clinical trials, and potential therapeutic targets that interfere with TGF-β signaling are being explored. Small interfering RNAs and stem cell-based therapeutics are also being evaluated. Further research and clinical studies are necessary in order to avoid dialysis and kidney transplantation.

Finerenone cardiovascular and kidney outcomes by age and sex: FIDELITY post hoc analysis of two phase 3, multicentre, double-blind trials

OBJECTIVES

This study aimed to evaluate the efficacy and safety of finerenone, a selective, non-steroidal mineralocorticoid receptor antagonist, on cardiovascular and kidney outcomes by age and/or sex.

DESIGN

FIDELITY post hoc analysis; median follow-up of 3 years.

SETTING

FIDELITY: a prespecified analysis of the FIDELIO-DKD and FIGARO-DKD trials.

PARTICIPANTS

Adults with type 2 diabetes and chronic kidney disease receiving optimised renin-angiotensin system inhibitors (N=13 026).

INTERVENTIONS

Randomised 1:1; finerenone or placebo.

PRIMARY AND SECONDARY OUTCOME MEASURES

Cardiovascular (cardiovascular death, non-fatal myocardial infarction, non-fatal stroke or hospitalisation for heart failure (HHF)) and kidney (kidney failure, sustained ≥57% estimated glomerular filtration rate (eGFR) decline or renal death) composite outcomes.

RESULTS

Mean age was 64.8 years; 45.2%, 40.1% and 14.7% were aged <65, 65-74 and ≥75 years, respectively; 69.8% were male. Cardiovascular benefits of finerenone versus placebo were consistent across age (HR 0.94 (95% CI 0.81 to 1.10) (<65 years), HR 0.84 (95% CI 0.73 to 0.98) (65-74 years), HR 0.80 (95% CI 0.65 to 0.99) (≥75 years); Pinteraction=0.42) and sex categories (HR 0.86 (95% CI 0.77 to 0.96) (male), HR 0.89 (95% CI 0.35 to 2.27) (premenopausal female), HR 0.87 (95% CI 0.73 to 1.05) (postmenopausal female); Pinteraction=0.99). Effects on HHF reduction were not modified by age (Pinteraction=0.70) but appeared more pronounced in males (Pinteraction=0.02). Kidney events were reduced with finerenone versus placebo in age groups <65 and 65-74 but not ≥75; no heterogeneity in treatment effect was observed (Pinteraction=0.51). In sex subgroups, finerenone consistently reduced kidney events (Pinteraction=0.85). Finerenone reduced albuminuria and eGFR decline regardless of age and sex. Hyperkalaemia increased with finerenone, but discontinuation rates were <3% across subgroups. Gynaecomastia in males was uncommon across age subgroups and identical between treatment groups.

CONCLUSIONS

Finerenone improved cardiovascular and kidney composite outcomes with no significant heterogeneity between age and sex subgroups; however, the effect on HHF appeared more pronounced in males. Finerenone demonstrated a similar safety profile across age and sex subgroups.

TRIAL REGISTRATION NUMBERS

NCT02540993, NCT02545049.

Aldosterone and aldosterone synthase inhibitors in cardiorenal disease

Modulation of the renin-angiotensin-aldosterone system is a foundation of therapy for cardiovascular and kidney diseases. Excess aldosterone plays an important role in cardiovascular disease, contributing to inflammation, fibrosis, and dysfunction in the heart, kidneys, and vasculature through both genomic and mineralocorticoid receptor (MR)-mediated as well as nongenomic mechanisms. MR antagonists have been a key therapy for attenuating the pathologic effects of aldosterone but are associated with some side effects and may not always adequately attenuate the nongenomic effects of aldosterone. Aldosterone is primarily synthesized by the CYP11B2 aldosterone synthase enzyme, which is very similar in structure to other enzymes involved in steroid biosynthesis including CYP11B1, a key enzyme involved in glucocorticoid production. Lack of specificity for CYP11B2, off-target effects on the hypothalamic-pituitary-adrenal axis, and counterproductive increased levels of bioactive steroid intermediates such as 11-deoxycorticosterone have posed challenges in the development of early aldosterone synthase inhibitors such as osilodrostat. In early-phase clinical trials, newer aldosterone synthase inhibitors demonstrated promise in lowering blood pressure in patients with treatment-resistant and uncontrolled hypertension. It is therefore plausible that these agents offer protection in other disease states including heart failure or chronic kidney disease. Further clinical evaluation will be needed to clarify the role of aldosterone synthase inhibitors, a promising class of agents that represent a potentially major therapeutic advance.

Renoprotective Effects of Mineralocorticoid Receptor Antagonists Against Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a growing epidemic worldwide and a leading cause of end-stage kidney disease. Mineralocorticoid receptor (MR) blockade using Finerenone is a recently approved therapeutic approach to slow down the progression of DKD in patients with type 2 diabetes in addition to other therapies such as angiotensin-II converting enzyme inhibitors (ACEIs), angiotensin II receptor blockers (ARBs), sodium-glucose co-transporter 2 (SGLT2) inhibitors, and glucagon-like peptide 1 (GLP-1) analogs. This review elaborates on the pathophysiologic pathways activated by aldosterone (the human mineralocorticoid) in DKD, the pharmacology of three different generations of mineralocorticoid receptor antagonists (MRAs), specifically, spironolactone, eplerenone, and finerenone, and the mechanisms by which these MRAs elicit their protective effects on the kidney under diabetic settings.

Epigenetic reprogramming driving successful and failed repair in acute kidney injury

Acute kidney injury (AKI) causes epithelial damage followed by subsequent repair. While successful repair restores kidney function, this process is often incomplete and can lead to chronic kidney disease (CKD) in a process called failed repair. To better understand the epigenetic reprogramming driving this AKI-to-CKD transition we generated a single nucleus multiomic atlas for the full mouse AKI time course, consisting of ~280,000 single nucleus transcriptomes and epigenomes. We reveal cell-specific dynamic alterations in gene regulatory landscapes reflecting especially activation of proinflammatory pathways. We further generated single nucleus multiomic data from four human AKI samples including validation by genome-wide identification of NF-kB binding sites. A regularized regression analysis identifies key regulators involved in both successful and failed repair cell fate, identifying the transcription factor CREB5 as a regulator of both successful and failed tubular repair that also drives proximal tubule cell proliferation after injury. Our interspecies multiomic approach provides a foundation to comprehensively understand cell states in AKI.

Molecular mechanisms of the stress-induced regulation of the inflammatory response in fish

Stressors in the environment of aquatic organisms can profoundly affect their immune system. The stress response in fish involves the activation of the hypothalamus-pituitary-interrenal (HPI) axis, leading to the release of several stress hormones, among them glucocorticoids, such as cortisol, which bind and activate corticosteroid receptors, namely the glucocorticoid receptor (GR) and mineralocorticoid receptor (MR). These receptors are highly expressed on immune cells, thereby allowing stress to have a potent effect that is classically considered to suppress immune function. In this review, we highlight the conserved structure and function of GR and MR among vertebrates and describe their role in modulating inflammation by regulating the expression of pro-inflammatory and anti-inflammatory genes. In particular, the involvement of MR during inflammation is reviewed, which in many studies has been shown to be immune-enhancing. In recent years, the use of zebrafish as a model organism has opened up new possibilities to study the effects of stress on inflammation, making it possible to investigate knockout lines for MR and/or GR, in combination with transgenic models with fluorescently labeled leukocyte subpopulations that enable the visualization and manipulation of these immune cells. The potential roles of other hormones of the HPI axis, such as corticotrophin-releasing hormone (Crh) and adrenocorticotropic hormone (Acth), in immune modulation are also discussed. Overall, this review highlights the need for further research to elucidate the specific roles of GR, MR and other stress hormones in regulating immune function in fish. Understanding these mechanisms will contribute to improving fish health and advancing our knowledge of stress signalling.

Heart Failure With Preserved Ejection Fraction With CKD: A Narrative Review of a Multispecialty Disorder

Heart failure with preserved ejection fraction (HFpEF) is a heterogenous syndrome with varying phenotypic expression. The phenotype chronic kidney disease (CKD) associated HFpEF is increasing in prevalence globally and is associated with increased morbidity and mortality compared to other HFpEF variants. These 2 conditions share common risk factors, including obesity, diabetes, and metabolic syndrome, as well as similar pathophysiology, including systemic inflammation, oxidative stress, elevated neurohormones, mineralocorticoid-receptor activation, and venous congestion. Given the coexistence of CKD and HFpEF, the diagnosis of HFpEF can be difficult. Moreover, treatment options for HFpEF have remained limited despite the success seen in its counterpart, heart failure with reduced ejection fraction. HFpEF encompasses complex multisystem pathophysiological perturbations beyond neurohormones, it is unlikely that a single agent can have significant benefit in this population. Recent data on sodium-glucose cotransporter 2 (SGLT2) inhibitors in HFpEF and CKD, and on glucagon-like peptide-1 (GLP-1) agonists and mineralocorticoid-receptor antagonists in metabolic syndrome, which target multiple pathways simultaneously, have led to promising therapeutics for HFpEF and CKD. In this perspective, our goal is to increase awareness of HFpEF as a multisystem disorder that shares the same disease processes seen in CKD and to emphasize that its management in individuals with CKD warrants a collective and multidisciplinary approach.

[The role of mineralocorticoid receptors hyperactivation in the development of cardiorenal complications in patients with diabetes mellitus, perspective of the selective nonsteroidal mineralocorticoid receptors antagonist's treatment: A review]

The renin-angiotensin-aldosterone system (RAAS) activation plays a key role in the chronic kidney disease (CKD) progression and in the cardiovascular complications (CVC) development in patients with diabetes mellitus (DM). RAAS blockers alone are not sufficient to prevent CVC and CVC progression. RAAS upregulation in CKD associated with DM triggers the mineralocorticoid receptors (MCR) hyperactivation which results in fibrosis and inflammation in the heart and kidneys. This review presents the current data about the variety of MCR hyperactivation manifestations, as well as about of multiplicity of MCR hyperactivation ways in DM. The efficacy and safety of finerenone, a new MCR nonsteroidal selective antagonist, are discussed.

Role of Sodium-Glucose Co-Transporter 2 Inhibitors in Chronic Kidney Disease, Congestive Heart Failure and Stroke-A Review and Clinical Guide for Healthcare Professionals

Diabetic kidney disease (DKD) causes a progressive decline in renal function, leading to end-stage kidney disease (ESKD), and increases the likelihood of cardiovascular events and mortality. The recent introduction of the sodium-glucose co-transporter 2 (SGLT-2) inhibitor has been a game changer in managing chronic kidney disease (CKD) and congestive heart failure (CHF). These agents not only slow down the progression of kidney disease but also have cardioprotective benefits, including for patients with congestive heart failure and atherosclerotic cardiovascular disease. Some evidence suggests that they can decrease the risk of stroke as well. This review aims to provide a comprehensive overview of the role of SGLT-2 inhibitors in CKD and CHF and their efficacy in stroke prevention. This review includes a comparison with glucagon-like peptide-1 (GLP-1) agonist and finerenone; focuses on safety data, the potential benefits beyond glycemic control, and a review of significant trials; and provides guidance in clinical practice.

The Mineralocorticoid Receptor Plays a Crucial Role in Macrophage Development and Function

Stress and the attendant rise in glucocorticoids (GCs) results in a potent suppression of the immune system. To date, the anti-inflammatory role of GCs, via activation of the glucocorticoid receptor, has been well-characterized. However, cortisol, the primary GC in both fish and humans, also signals through the high-affinity mineralocorticoid receptor (MR), of which the immunomodulatory role is poorly understood. Here, we tested the hypothesis that MR is a key modulator of leukocyte function during inflammation. Using transgenic MR knockout zebrafish with fluorescently labelled leukocytes, we show that a loss of MR results in a global reduction in macrophage number during key development stages. This reduction was associated with impaired macrophage proliferation and responsivity to developmental distribution signals, as well as increased susceptibility to cell death. Using a tail fin amputation in zebrafish larvae as a model for localized inflammation, we further showed that MR knockout larvae display a reduced ability to produce more macrophages under periods of inflammation (emergency myelopoiesis). Finally, we treated wild-type larvae with an MR antagonist (eplerenone) during definitive hematopoiesis, when the macrophages had differentiated normally throughout the larvae. This pharmacological blockade of MR reduced the migration of macrophages toward a wound, which was associated with reduced macrophage Ccr2 signalling. Eplerenone treatment also abolished the cortisol-induced inhibition of macrophage migration, suggesting a role for MR in cortisol-mediated anti-inflammatory action. Taken together, our work reveals that MR is a key modulator of the innate immune response to inflammation under both basal and stressed conditions.

Diabetic Kidney Disease: An Update

Diabetes is a major public health challenge and diabetic kidney disease (DKD), a broader diagnostic term than diabetic nephropathy, is the leading cause of chronic kidney disease and end-stage kidney disease in the United States and worldwide. A better understanding of the underlying pathophysiological mechanisms of DKD, and recent clinical trials testing new therapeutic interventions, have shown promising results to curb this epidemic. Given the global health burden of DKD, it is extremely important to prioritize prevention, early recognition, referral, and aggressive management of DKD in the primary care setting.

Mineralocorticoid Receptor Antagonists for Preventing Chronic Kidney Disease Progression: Current Evidence and Future Challenges

Regulation and action of the mineralocorticoid receptor (MR) have been the focus of intensive research over the past 80 years. Genetic and physiological/biochemical analysis revealed how MR and the steroid hormone aldosterone integrate the responses of distinct tubular cells in the face of environmental perturbations and how their dysregulation compromises fluid homeostasis. In addition to these roles, the accumulation of data also provided unequivocal evidence that MR is involved in the pathophysiology of kidney diseases. Experimental studies delineated the diverse pathological consequences of MR overactivity and uncovered the multiple mechanisms that result in enhanced MR signaling. In parallel, clinical studies consistently demonstrated that MR blockade reduces albuminuria in patients with chronic kidney disease. Moreover, recent large-scale clinical studies using finerenone have provided evidence that the non-steroidal MR antagonist can retard the kidney disease progression in diabetic patients. In this article, we review experimental data demonstrating the critical importance of MR in mediating renal injury as well as clinical studies providing evidence on the renoprotective effects of MR blockade. We also discuss areas of future investigation, which include the benefit of non-steroidal MR antagonists in non-diabetic kidney disease patients, the identification of surrogate markers for MR signaling in the kidney, and the search for key downstream mediators whereby MR blockade confers renoprotection. Insights into these questions would help maximize the benefit of MR blockade in subjects with kidney diseases.

Primary Aldosteronism and the Role of Mineralocorticoid Receptor Antagonists for the Heart and Kidneys

Primary aldosteronism (PA) is the most common cause of secondary hypertension but is frequently underrecognized and undertreated. Patients with PA are at a markedly increased risk for target organ damage to the heart and kidneys. While patients with unilateral PA can be treated surgically, many patients with PA are not eligible or willing to undergo surgery. Steroidal mineralocorticoid receptor antagonists (MRAs) are highly effective for treating PA and reducing the risk of target organ damage. However, steroidal MRAs are often underprescribed and can be poorly tolerated by some patients due to side effects. Nonsteroidal MRAs reduce adverse renal and cardiovascular outcomes among patients with diabetic kidney disease and are bettertolerated than steroidal MRAs. While their blood pressure-lowering effects remain unclear, these agents may have a potential role in reducing target organ damage in patients with PA.

Finerenone in type 2 diabetes and renal outcomes: A random-effects model meta-analysis

BACKGROUND

The nonsteroidal mineralocorticoid antagonist finerenone is a new addition to the list of agents (angiotensin converting enzyme inhibitors and sodium glucose cotransporter 2 inhibitors) conferring renal protection to patients with diabetic kidney disease. Two recent meta-analyses using the fixed effect model in patients with chronic kidney disease (both diabetic and nondiabetic populations) came to a conflicting conclusion on the effect of finerenone on eGFR decline. This meta-analysis was undertaken exclusively in the type 2 diabetes (T2D) population to explore the robustness and heterogeneity of the effect size by conducting a random effects model meta-analysis along with draft plots and prediction intervals.

MATERIALS AND METHODS

A database search was conducted using the Cochrane library, PubMed, and Embase to identify relevant citations. Analysis was conducted on the 14^th of September 2022, using RevMan 5.4.1 and RStudio (2022.07.1, Build 554). The hazard ratio was used as the effect size for the renal composite, while the standardized mean difference (SMD) was used to estimate the effect size of eGFR decline and reduction in the urine albumin creatinine ratio (UACR). The Cochrane risk-of-bias was used to assess the quality of the studies. The primary outcome assessed was the renal composite defined as kidney failure, a sustained decrease of at least 40% in the eGFR from baseline, or death from renal causes.

RESULTS

A pooled population of 13,943 patients from four citations was included for analysis. The Cochrane risk of bias was used to assess the quality of the studies. There was a significant 16% reduction in the renal composite (kidney failure, a sustained decrease of at least 40% in the eGFR from baseline, or death from renal causes) [HR: 0.84, 95% CI 0.77-0.92, ²: 0, I²: 0%). Finerenone was also associated with reduction in UACR (SMD: -0.49, 95% CI -0.53 to -0.46, τ²: < 0.0001, I²: 0%, prediction interval: -0.57 to -0.41) and prevention of decline in eGFR (SMD: -0.32, 95% CI -0.37 to -0.27, τ²: < 0.0001, I²: 0%, prediction interval: -0.43 to -0.21) without any evidence for significant heterogeneity. Except for an increase in hyperkalaemia (RR: 2.22, 95% CI 1.93-2.24), adverse events were observed with fineronone compared to placebo (RR: 1.00, 95% CI 0.98-1.01).

CONCLUSION

There are significant benefits in renal outcomes associated with finerenone treatment in T2D patients with established chronic kidney disease with a side effect profile comparable to placebo.

Eplerenone inhibits the macrophage-to-myofibroblast transition in rats with UUO-induced type 4 cardiorenal syndrome through the MR/CTGF pathway

Cardiovascular complications are the leading causes of death in patients with chronic kidney disease (CKD), accounting for approximately 50% of deaths. Despite significant advances in the understanding of cardiac disease due to CKD, the underlying mechanisms involved in many pathological changes have not been fully elucidated. In our previous study, we observed severe fibrosis in the contralateral kidney of a 6-month-old rat UUO model. In the present experiment, we also observed severe fibrosis in the hearts of rats subjected to UUO and the macrophage-to-myofibroblast transition (MMT). These effects were inhibited by the mineralocorticoid receptor (MR) blocker eplerenone. Notably, in vitro, aldosterone-activated MR induced the MMT and subsequently promoted the secretion of CTGF, the target of MR, from macrophages; these changes were inhibited by eplerenone. The CTGF also induced the MMT and both the aldosterone and CTGF-induced MMT could be alleviated by the CTGF blocker. In conclusion, our results suggest that targeting the MR/CTGF pathway to inhibit the MMT may be an effective therapeutic strategy for the treatment of cardiac fibrosis.

Chronic kidney disease in patients with type 2 diabetes: new targets of medicine action

Diabetes mellitus type 2 (DM2) is socially important disease, becoming non-infectious epidemic due to increasing prevalence. Chronic kidney disease (CKD) is one of the most common diabetic complications. Kidney injury signs and/or estimated glomerular filtration rate (eGFR) decrease are seen in 40-50% of patients with DM2. Three groups of factors are considered to be the basis of CKD development and progression in DM2: metabolic, hemodynamic, inflammation and fibrosis. Existing drugs that are used in patients with CKD and DM2 first of all target hemodynamic and metabolic disturbances, but their action against inflammation and fibrosis is indirect. Hyperactivation of mineralocorticoid receptors (MR) is considered as one of the main trigger factors of end-organ damage in patients with DM2 due to inflammation and fibrosis. Development of selective nonsteroidal MR antagonists (MRA) as a new class of medications is directed to demonstrate positive effects from blocking this pathophysiological pathway of CKD development and overcome the steroidal MRAs’ shortcomings. Hence pathophysiological hyperactivation of MR with subsequent inflammation and fibrosis in patients with CKD in DM2 is considered a promising therapeutic target for the new drugs with cardionephroprotective effect.

Macrophages in Renal Injury, Repair, Fibrosis Following Acute Kidney Injury and Targeted Therapy

Acute kidney injury (AKI) is a renal disease with a high incidence and mortality. Currently, there are no targeted therapeutics for preventing and treating AKI. Macrophages, important players in mammalian immune response, are involved in the multiple pathological processes of AKI. They are dynamically activated and exhibit a diverse spectrum of functional phenotypes in the kidney after AKI. Targeting the mechanisms of macrophage activation significantly improves the outcomes of AKI in preclinical studies. In this review, we summarize the role of macrophages and the underlying mechanisms of macrophage activation during kidney injury, repair, regeneration, and fibrosis and provide strategies for macrophage-targeted therapies.

The innate immune response, microenvironment proteinases, and the COVID-19 pandemic: pathophysiologic mechanisms and emerging therapeutic targets

The coronavirus disease 2019 (COVID-19) pandemic, causing considerable mortality and morbidity worldwide, has fully engaged the biomedical community in attempts to elucidate the pathophysiology of COVID-19 and develop robust therapeutic strategies. To this end, the predominant research focus has been on the adaptive immune response to COVID-19 infections stimulated by mRNA and protein vaccines and on the duration and persistence of immune protection. In contrast, the role of the innate immune response to the viral challenge has been underrepresented. This overview focuses on the innate immune response to COVID-19 infection, with an emphasis on the roles of extracellular proteases in the tissue microenvironment. Proteinase-mediated signaling caused by enzymes in the extracellular microenvironment occurs upstream of the increased production of inflammatory cytokines that mediate COVID-19 pathology. These enzymes include the coagulation cascade, kinin-generating plasma kallikrein, and the complement system, as well as angiotensin-generating proteinases of the renin-angiotensin system. Furthermore, in the context of several articles in this Supplement elucidating and detailing the trajectory of diverse profibrotic pathways, we extrapolate these insights to explore how fibrosis and profibrotic pathways participate importantly in the pathogenesis of COVID-19. We propose that the lessons garnered from understanding the roles of microenvironment proteinases in triggering the innate immune response to COVID-19 pathology will identify potential therapeutic targets and inform approaches to the clinical management of COVID-19. Furthermore, the information may also provide a template for understanding the determinants of COVID-19-induced tissue fibrosis that may follow resolution of acute infection (so-called "long COVID"), which represents a major new challenge to our healthcare systems.