Mineralocorticoid receptor antagonists in patients with chronic kidney disease

Repurposing the familiar: Future treatment options against chronic kidney disease

OBJECTIVES

Chronic kidney disease (CKD) is a serious health issue with rising morbidity and mortality rates. Despite advances in understanding its pathophysiology, effective therapeutic options are limited, necessitating innovative treatment approaches. Also, current frontline treatments that are available against CKD are not uniformly effective and often come with significant side effects. Therefore, identifying new therapeutic targets or improving existing treatments for CKD is crucial. Drug repurposing is a promising strategy in the drug discovery process that involves screening existing approved drugs for new therapeutic applications.

KEY FINDINGS

This review discusses the pharmacological mechanisms and clinical evidence that support the efficacy of these repurposed drugs. Various drugs classes such as inodilators, endothelin-1 type A (ET-1A) receptor antagonists, bisphosphonates, mineralocorticoid receptor (MR) antagonists, DNA demethylating agents, nuclear factor erythroid 2-related factor 2 (NRF2) activators, P2X7 inhibitors, autophagy modulators, hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHI) are discussed that could remarkably contribute against CKD.

SUMMARY

The review critically examines the potential for repurposing well-established drugs to slow the progression of CKD and enhance patient outcomes. This review emphasizes the importance of a multidisciplinary approach in advancing the field of drug repurposing, ultimately paving the way for innovative and effective therapies for patients suffering from CKD.

RXRα/MR signaling promotes diabetic kidney disease by facilitating renal tubular epithelial cells senescence and metabolic reprogramming

Cell senescence and metabolic reprogramming are significant features of diabetic kidney disease (DKD). However, the underlying mechanisms between cell senescence and metabolic reprogramming are poorly defined. Here, we report that retinoid X receptor α (RXRα), a key nuclear receptor transcription factor, regulates cell senescence and metabolic reprogramming in DKD. Through high-throughput sequencing, bioinformatic analysis and experimental validation, we confirmed the critical role of RXRα in promoting cell senescence and metabolic dysregulation in renal tubular epithelial cells (RTECs) induced by lipid overload. In vivo, in situ injection of AAV9-shRxra into the kidney reduced proteinuria, RTECs senescence and insulin resistance in DKD mice. In vitro, knockdown of RXRα markedly improved G2/M phase arrest and suppressed the expression of senescence-associated secretory phenotypes (SASPs). Protein-protein interaction (PPI) analysis and unbiased bioinformatics were employed to identify the direct interactions between RXRα and the mineralocorticoid receptor (MR), which were subsequently validated through coimmunoprecipitation. Gene network analysis revealed the collaborative regulatory role of RXRα and MR in RTECs senescence. In an accelerated aging mouse model, treatment with a MR antagonist has been shown to inhibite the RXRα/MR signaling, improve RTECs senescence, and reduce interstitial fibrosis and lipid deposition in the kidneys. These findings indicate that inhibition of RXRα/MR signaling could alleviate cell senescence during metabolic disorders. Thus, our study revealed that RXRα/MR signaling serves as a critical regulatory factor mediating the crosstalk between cell senescence and metabolic reprogramming, shedding light on a novel mechanism for targeting cell senescence and metabolic dysregulation in DKD.

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.

Associated lifestyle factors of elevated plasma aldosterone concentration in community population, gender-stratified analysis of a cross-sectional survey

BACKGROUND

Aldosterone plays important parts in development of cardio-metabolic diseases as end product of renin-angiotensin-aldosterone system. However, factors elevating circulating aldosterone are not clear, and lifestyle-related factors are suggested to be involved, whereas less studied. Therefore, we aimed to explore the association of lifestyle factors with plasma aldosterone concentration (PAC) in community population.

METHODS

In this cross-sectional study, we recruited participants using multistage random sampling from Emin China in 2019, and collected data and fasting blood samples. The considered lifestyle factors included obesity parameters (neck circumference, abdominal circumference), alcohol consumption, blood pressure (BP), physical activity, sleep duration, sleep quality, mental state (depression and anxiety), fasting blood glucose (FBG), and lipid profiles (total cholesterol and triglyceride). PAC was measured using radioimmunoassay. We performed sex-stratified linear and logistic regressions to explore associated factors of PAC. Component analysis was further performed to identify the main factors affecting PAC.

RESULTS

Twenty-seven thousand four hundred thirty-six participants with 47.1% men were included. Obesity parameters (neck circumference, abdominal circumference), glucose metabolism (FBG), psychological status (anxiety status in men and women, depression status in men), BP, liver function (in men), lipid metabolism (TC and TG in men), sleep parameters (sleep quality in women), and renal function (in women) are the main factors associated with elevated PAC.

CONCLUSION

lower physical activity, alcohol consumption, higher BP, fat accumulation, dyslipidemia, higher fasting blood glucose, and presence of depression and anxiety were the main factors associated with eleveated PAC.

Spironolactone for Preventing Contrast-Induced Nephropathy After Percutaneous Coronary Intervention in Patients With Acute Myocardial Infarction and Chronic Kidney Disease

Patients with acute myocardial infarction (AMI) and chronic kidney disease (CKD) are at high risk of contrast-induced nephropathy (CIN), which can subsequently worsen the overall prognosis. To evaluate the efficacy of spironolactone for CIN prevention, 410 patients with AMI and CKD receiving percutaneous coronary intervention (PCI) were retrospectively analyzed. Among them, 240 and 170 patients were enrolled in the standard treatment and spironolactone groups (spironolactone was administered 2 days before and 3 days after PCI), respectively. The primary endpoint of CIN was defined as a 0.5 mg/dL or >25% increase from the baseline serum creatinine level within 48-72 h post-PCI. CIN incidence was significantly lower in the spironolactone group than in the standard treatment group (11.2 vs 26.7%, P < .001). Further, cardiac re-hospitalization (hazard ratio [HR]: 0.515; 95% CI: 0.382-0.694; P < .001) and cardiac death (HR: 0.612; 95% CI: 0.429-0.872; P = .007) risks were significantly lower in patients who received long-term spironolactone with a median treatment duration of 42 months after discharge. Spironolactone might lower the risk of CIN, and long-term use of spironolactone reduces the risk of cardiac re-hospitalization and cardiac death in patients with AMI and CKD undergoing PCI.

An Update on Current Therapeutic Options in IgA Nephropathy

Immunoglobulin A nephropathy (IgAN) remains the leading cause of primary glomerular disease worldwide. Outcomes are poor with high rates of progressive chronic kidney disease and kidney failure, which contributes to global healthcare costs. Although this disease entity has been described, there were no disease-specific treatments until recently, with the current standard of care focusing on optimal supportive measures including lifestyle modifications and optimization of the renin-angiotensin-aldosterone blockade. However, with significant advances in the understanding of the pathogenesis of IgAN in the past decade, and the acceptance of surrogate outcomes for accelerated drug approval, there have been many new investigational agents tested to target this disease. As these agents become available, we envision a multi-pronged treatment strategy that simultaneously targets the consequences of ongoing nephron loss, stopping any glomerular inflammation, inhibiting pro-fibrotic signals in the glomerulus and tubulo-interstitium, and inhibiting the production of pathogenic IgA molecules. This review is an update on a previous review published in 2021, and we aim to summarize the developments and updates in therapeutic strategies in IgAN and highlight the promising discoveries that are likely to add to our armamentarium.

Expanding options of supportive care in IgA nephropathy

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide, with a potentially serious prognosis. At present, management of IgAN is primarily based on therapeutic lifestyle changes, and excellent blood pressure control and maximized supportive treatment with the combination of inhibition of the renin-angiotensin-aldosterone system with either inhibitors of angiotensin-converting enzyme or angiotensin II receptor blockers and inhibitors of sodium-glucose cotransporter-2, and possibly in the future also with endothelin antagonists. Supportive care currently represents the cornerstone of treatment of IgAN. Targeted-release formulation of budesonide should replace systemic corticosteroids in patients with higher proteinuria and active histological lesions. New treatment options are aimed at immunopathogenesis of IgAN including depletion or modulation of Galactose-deficient-Immunoglobulin A1-producing B cells, plasma cells, and the alternate and/or lectin pathway of complement. The exact place of monoclonal antibodies and complement inhibitors will need to be determined. This article reviews potential supportive therapies currently available for patients with IgAN.

Chronic kidney disease begets heart failure and vice versa: temporal associations between heart failure events in relation to incident chronic kidney disease in type 2 diabetes

AIM

To investigate the interplay of incident chronic kidney disease (CKD) and/or heart failure (HF) and their associations with prognosis in a large, population-based cohort with type 2 diabetes (T2DM).

METHODS

Patients aged ≥18 years with new-onset T2DM, without renal disease or HF at baseline, were identified from the territory-wide Clinical Data Analysis Reporting System between 2000 and 2015. Patients were followed up until December 31, 2020 for incident CKD and/or HF and all-cause mortality.

RESULTS

Among 102 488 patients (median age 66 years, 45.7% women, median follow-up 7.5 years), new-onset CKD occurred in 14 798 patients (14.4%), in whom 21.7% had HF. In contrast, among 9258 patients (9.0%) with new-onset HF, 34.6% had CKD. The median time from baseline to incident CKD or HF (4.4 vs. 4.1 years) did not differ. However, the median (interquartile range) time until incident HF after CKD diagnosis was 1.7 (0.5-3.6) years and was 1.2 (0.2-3.4) years for incident CKD after HF diagnosis (P < 0.001). The crude incidence of CKD was higher than that of HF: 17.6 (95% confidence interval [CI] 17.3-17.9) vs. 10.6 (95% CI 10.4-10.9)/1000 person-years, respectively, but incident HF was associated with a higher adjusted-mortality than incident CKD. The presence of either condition (vs. CKD/HF-free status) was associated with a three-fold hazard of death, whereas concomitant HF and CKD conferred a six to seven-fold adjusted hazard of mortality.

CONCLUSION

Cardiorenal complications are common and are associated with high mortality risk among patients with new-onset T2DM. Close surveillance of these dual complications is crucial to reduce the burden of disease.

Diabetic nephropathy: Focusing on pathological signals, clinical treatment, and dietary regulation

Diabetic nephropathy (DN) is one of the most severe complications of diabetes. However, due to its complex pathological mechanisms, no effective therapeutic methods (other than ACEIs and ARBs) have been applied, which have been used for many years in clinical practice. Recent studies have shown that emerging therapeutics, including novel target-based pharmacotherapy, cell therapies, and dietary regulation, are leading to new hopes for DN management. This review aims to shed new light on the treatment of DN by describing the important pathological mechanisms of DN and by analysing recent advances in clinical treatment, including drug therapy, cell therapy, and dietary regulation. In pathological mechanisms, RAAS activation, AGE accumulation, and EMT are involved in inflammation, cellular stress, apoptosis, pyroptosis, and autophagy. In pharmacotherapy, several new therapeutics, including SGLT2 inhibitors, GLP-1 agonists, and MRAs, are receiving public attention. In addition, stem cell therapies and dietary regulation are also being emphasized. Herein, we highlight the importance of combining therapy and dietary regulation in the treatment of DN and anticipate more basic research or clinical trials to verify novel strategies.

Efficacy and safety of non-steroidal mineralocorticoid receptor antagonists for renal outcomes: A systematic review and meta-analysis

BACKGROUND

Novel nonsteroidal mineralocorticoid receptor antagonists (MRAs) are noted for their potential cardiorenal benefits for patients with type 2 diabetes mellitus and chronic kidney diseases; however, the effect of this regimen on renal outcomes remains uncertain.

METHODS

We performed a systematic review and meta-analysis of nonsteroidal MRAs focusing primarily on renal outcomes and safety in randomized, controlled trials. The MEDLINE, Embase, and Cochrane databases were systemically searched for trials published through April 2022. We included randomized, controlled trials assessing the effects of nonsteroidal MRAs on renal outcomes, as well as cardiovascular disease (CVD) effects in patients with chronic kidney disease (CKD). Summary estimates of risk ratios (RRs) reductions were calculated with a random-effects model. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to evaluate the certainty of evidence. This study is registered with PROSPERO under number CRD42022335464.

FINDINGS

In total, 11 trials and 1 pooled analysis including a total of 17,517 participants were enrolled. Nonsteroidal MRAs reduced renal composite endpoints by 17 % [HR = 0.83, 95 % (0.75, 0.91); low quality] with 16 % in kidney failure (high quality), 23 % in ESRD (high quality), 20 % in eGFR decreased to less than 15 mL/min/1.73 m² (high quality), and 17 % with more than a 40 % decrease in eGFR (high quality); 14 % with cardiovascular composite endpoints [HR = 0.86, 95 % (0.78, 0.94); moderate quality]; and 13 % of all-cause mortality [HR = 0.87, 95 % (0.76, 0.98); moderate quality]. Nonsteroidal MRAs were also associated with additional benefits in lowering UACR levels (moderate quality) and lowering BP levels (moderate quality) compared with the control groups. However, nonsteroidal MRAs did not show a statistically significant effect on the risk of renal death (moderate quality), hospitalization for any cause (moderate quality) or change in GFR (low quality). Regarding safety, there was no significant difference in the risk of adverse events between the participants receiving nonsteroidal MRAs and the control group.

INTERPRETATION

Nonsteroidal MRAs had a statistically beneficial effect on reducing the risk of the composite kidney outcome, the composite of cardiovascular outcomes, and all-cause mortality. Nonsteroidal MRAs were also associated with benefits of proteinuria remission and blood pressure lowering. Although these findings provided positive evidence for the use of nonsteroidal MRAs for cardiorenal protection in patients with or without CKD, the quality of this evidence is potentially uncertain.

Novel pathogenic variants in CUBN uncouple proteinuria from renal function

BACKGROUND

Proteinuria is an unfavorable clinical condition highly associated with a risk of renal and cardiovascular disease in chronic kidney disease (CKD). However, whether all proteinuria forms are linked to renal impairment are still unclear. Cubilin is an endocytic receptor highly expressed in renal proximal tubules mediating uptake of albumin, transferrin and α1-microglobulin.

METHODS

Exome sequencing method initially identified candidate genes. With the application of exome sequencing combined with Sanger sequencing, we further focused on CUBN through bioinformatics analysis. The pathogenic effects of the potentially causative variants were verified utilizing complementary analysis of clinical data and systematic characterization of the variants' expression and function with clinical samples and in vitro experiments in HEK293T cell lines along with in vivo experiments in mice.

RESULTS

In this study, we identified four novel variants locating after the vitamin B12 (vitB12)-binding domain of Cubilin (encoded by CUBN, NM_001081.3: c.4397G > A (p.C1466Y), c.6796C > T (p.R2266X), c.6821 + 3A > G and c.5153_5154delCT (p.S1718X)) in two families. Moreover, the variants severely affected the expression and function of Cubilin in renal proximal tubules and caused albuminuria, increasing levels in urine transferrin and α1-microglobulin, but without progressive glomerular filtration barrier (GFB) impairment, vitB12 deficiencies or abnormal blood levels of HDL and albumin. Further mechanistic insights showed that the variants after the vitB12-binding domain of CUBN merely disrupted the association with Amnionless (AMN) that exhibited aberrant localization in cell cytoplasm rather than membrane.

CONCLUSIONS

Here, our findings suggested that different mutation types after the vitB12-binding domain of CUBN uncouple proteinuria from glomerular filtration barrier, that may be an unexpectedly common benign condition in humans and may not require any proteinuria-lowering treatment or renal biopsy.

An overview of mineralocorticoid receptor antagonists as a treatment option for patients with heart failure: the current state-of-the-art and future outlook

INTRODUCTION

Mineralocorticoid receptor antagonists (MRAs) improve cardiovascular outcomes in patients with heart failure. These benefits of MRAs vary in different heart failure populations based on left ventricular ejection fraction and associated comorbidities.

AREAS COVERED

We define the pharmacologic properties of MRAs and the pathophysiological rationale for their utility in heart failure. We outline the current literature on the use of MRAs in different heart failure populations, including reduced and preserved ejection fraction (HFrEF/ HFpEF), and acute heart failure decompensation. Finally, we describe the limitations of currently available data and propose future directions of study.

EXPERT OPINION

While there is strong evidence supporting the use of MRAs in HFrEF, evidence in patients with HFpEF or acute heart failure is less definitive. Comorbidities such as obesity or atrial fibrillation could be clinical modifiers of the response to MRAs and potentially alter the risk/benefit ratio in these subpopulations. Emerging evidence for new non-steroidal MRAs reveal promising preliminary results that, if confirmed in large randomized clinical trials, could favor a change in clinical practice.

Targeted inhibition of TGF-β type I receptor by AZ12601011 protects against kidney fibrosis

Renal fibrosis, a common feature of chronic kidney disease, causes the progressive loss of renal function, in which TGF-β₁ plays a critical role. In this study, we found that expression levels of TGF-β₁ and its receptor 1 (TGF-βR1) were both significantly increased in obstructive fibrosis kidneys. AZ12601011 is a small molecular inhibitor of TGF-βR1; however, its therapeutic potential for renal fibrosis remains unclear. During the experiments, AZ12601011 was applied to various models of renal fibrosis followed by unilateral ureteral obstruction (UUO) and ischemia/reperfusion (I/R) in vivo, in addition to renal tubular epithelial cells (TECs) challenged by hypoxia/reoxygenation (H/R) and TGF-β₁in vitro. Our results revealed that AZ12601011 ameliorated renal injuries and fibrosis shown by PAS, HE, and Masson staining, which was consistent with the decrease in Col-1 and α-SMA expression in the kidneys from UUO and I/R mice. Similarly, in vitro data showed that AZ12601011 inhibited the induction of Col-1 and α-SMA in both TECs treated with TGF-β₁ and H/R. In addition, the results of cellular thermal shift assay (CETSA), molecular docking, and western bolt indicated that AZ12601011 could directly bind to TGF-βR1 and block activation of the downstream Smad3. Taken together, our findings suggest that AZ12601011 can attenuate renal fibrosis by blocking the TGF-β/Smad3 signaling pathway and it might serve as a promising clinical candidate in the fight against fibrotic kidney diseases.

Mineralocorticoid Receptor Antagonist Use and Hard Renal Outcomes in Real-World Patients With Chronic Kidney Disease

BACKGROUND

Real-world evidence about mineralocorticoid receptor antagonist (MRA) use has been limited in chronic kidney disease, particularly regarding its association with hard renal outcomes.

METHODS

In this retrospective cohort study, adult chronic kidney disease outpatients referred to the department of nephrology at an academic hospital between January 2005 and December 2018 were analyzed. The main inclusion criteria were estimated glomerular filtration rate ≥10 and <60 mL/min per 1.73 m² and follow-up ≥90 days. The exposure of interest was MRA use, defined as the administration of spironolactone, eplerenone, or potassium canrenoate. The primary outcome was renal replacement therapy initiation, defined as the initiation of chronic hemodialysis, peritoneal dialysis, or kidney transplantation. A marginal structural model using inverse probability of weighting was applied to account for potential time-varying confounders.

RESULTS

Among a total of 3195 patients, the median age and estimated glomerular filtration rate at baseline were 66 years and 38.4 mL/min per 1.73 m², respectively. During follow-up (median, 5.9 years), 770 patients received MRAs, 211 died, and 478 started renal replacement therapy. In an inverse probability of weighting-weighted pooled logistic regression model, MRA use was significantly associated with a 28%-lower rate of renal replacement therapy initiation (hazard ratio, 0.72 [95% CI, 0.53-0.98]). The association between MRA use and renal replacement therapy initiation was dose-dependent (P for trend <0.01) and consistent across patient subgroups. The incidence of hyperkalemia (>5.5 mEq/L) was somewhat higher in MRA users but not significant (hazard ratio, 1.14 [95% CI, 0.88-1.48]).

CONCLUSIONS

MRA users showed a better renal prognosis across various chronic kidney disease subgroups in a real-world chronic kidney disease population.

Mineralocorticoid Receptor Antagonists-Use in Chronic Kidney Disease

Mineralocorticoid receptor antagonists (MRA) are drugs with a potentially broad spectrum of action. They have been reported to have healing effects in many diseases, such as chronic heart failure, hypertension, or nephrotic syndrome. Numerous studies suggest that mineralocorticoid receptor activation is pathogenic and a progression factor of chronic kidney disease (CKD); however, results of studies on the use of MRA in the treatment of CKD are inconclusive. Current guidelines recommend against the use of MRA in patients with advanced CKD. Although, there is growing interest on their use in this population due to treatment benefits. In this review, we summarize studies which were purposed to evaluate the impact of MRA therapy on CKD patients. Despite many benefits of this treatment e.g., reducing cardiovascular mortality or alleviating proteinuria, steroidal MRA (such as spironolactone or eplerenone) have a low safety profile. They often lead to hyperkalemia complications which are dangerous in patients with CKD, and diabetic nephropathy, especially in hemodialysis patients. Studies on recently developed nonsteroidal MRA showed that they have fewer side effects. In our review, we discuss steroidal and nonsteroidal MRA treatment effects on the estimated glomerular filtration rate (eGFR), proteinuria, the cardiovascular system, and hyperkalemia in CKD patients. We present new content and recent publications in this field.