Aldosterone, Mineralocorticoid Receptor Activation, and CKD: A Review of Evolving Treatment Paradigms

Steroid hormones in pain: Mechanistic underpinnings and therapeutic perspectives

Pain is a complex sensory and emotional experience that severely affects an individual's quality of life and health status. Steroid hormones, as important regulatory substances in the human body, are extensively involved in various physiological and pathological processes. In recent years, remarkable progress has been made in the research of steroid hormones in the field of pain. They play a crucial role in the occurrence, development, and treatment of pain. This review comprehensively elaborates on the roles and therapeutic mechanisms of steroid hormones in pain, explores the performances of glucocorticoids, mineralocorticoids, sex hormones, etc. in different pain models, as well as the molecular mechanisms by which they regulate pain through genomic and non-genomic effects, aiming to provide a theoretical basis for the clinical treatment of pain.

Coenzyme Q10 alleviates oxidative stress, inflammation and fibrosis via activation of TGFβ1/TNF-α in FCA-Salt hypertensive rats

Hypertension is one of the most common factors contributing to cardiac remodeling that links to changes in both heart and kidney functions. Several studies have reported the beneficial effects of Coenzyme Q10 (CoQ10) in reducing oxidative stress due to its antioxidant properties. However, the cardioprotective and nephroprotective roles of CoQ10 against the toxicity induced by fludrocortisone acetate (FCA) have yet to be investigated. Therefore, we evaluated the CoQ10 effects on FCA-induced cardiotoxicity and nephrotoxicity in a rat model (FCA-Salt). We analyzed various oxidative stress parameters and antioxidant enzyme activities using biochemical assays. In addition, we examined inflammatory and fibrosis via histological staining of heart and kidney tissues. CoQ10 significantly reduced lipid peroxidation product-malondialdehyde (MDA) while increased nitric oxide (NO) in the FCA-Salt rats. Antioxidant enzyme activities were also enhanced by CoQ10 in these rats. Histopathological examination detected tissue damage and fibrosis in the FCA-Salt group, which was significantly reduced by CoQ10. Furthermore, enzyme-linked immunosorbent assay (ELISA) indicated the activation of Transforming growth factor-β1/Tumor necrosis factor-α (TGF-β1/TNF-α) by CoQ10. Consequently, our study suggests that CoQ10 can effectively protect heart and kidney health against cardiotoxicity and nephrotoxicity in FCA-Salt hypertensive rats via TGF-β1/TNF-α pathway.

The potential for improving cardio-renal outcomes in chronic kidney disease with the aldosterone synthase inhibitor vicadrostat (BI 690517): a rationale for the EASi-KIDNEY trial

Patients with chronic kidney disease (CKD) are at risk of progressive loss of kidney function, heart failure, and cardiovascular death despite current proven therapies, including renin-angiotensin system inhibitors (RASi), sodium glucose co-transporter-2 inhibitors (SGLT2i), and statin-based regimens. RASi and SGLT2i reduce risk of CKD progression irrespective of primary cause of kidney disease, suggesting they target final common pathways. Targeting aldosterone overactivity with a nonsteroidal mineralocorticoid receptor antagonist (MRA) also reduces cardiorenal risk in patients with albuminuric diabetic kidney disease already treated with RASi. Together, these observations provide the rationale for trials to assess effects of inhibiting the aldosterone pathway in a broader range of patients with CKD, including those with non-diabetic causes of CKD or low albuminuria. Aldosterone synthase inhibitors (ASi) have emerged as an alternative to MRAs for aldosterone pathway inhibition. Phase II data from 586 patients with albuminuric CKD have shown that 10 mg of an ASi, vicadrostat (BI 690517), reduced urine albumin-to-creatinine ratio by ∼40% compared with placebo, with or without concurrent empagliflozin treatment. MRA and ASi increase risk of hyperkalaemia. Combining their use with an SGLT2i may mitigate some of this risk, improving tolerability, and allowing a wider range of patients to be treated (including those with higher levels of blood potassium than in previous trials). The EASi-KIDNEY (NCT06531824) double-blind placebo-controlled trial will test this approach by assessing the safety and cardiorenal efficacy of vicadrostat in combination with empagliflozin in ∼11 000 patients with CKD. It will be sufficiently large to assess effects in patients with and without diabetes separately.

Mineralocorticoid Receptor Antagonist Use in Hypertension to Prevent Heart Failure

Mineralocorticoid receptor antagonists (MRAs) reduce cardiovascular mortality and heart failure (HF) hospitalizations across the spectrum of HF. Beyond their recognized benefits in patients with established HF, the value of MRA therapy may be undervalued for the prevention of HF in patients with hypertension. Emerging evidence indicates that a substantial proportion of patients considered to have "idiopathic" or "essential" hypertension have mineralocorticoid receptor overactivation by under-recognized mechanisms (such as, primary aldosteronism pathophysiology, cortisol dysregulation, and ligand-independent activation). The recognition that MRAs may address an operative mechanism of HF pathogenesis, and that implementation of therapy early in the course of hypertension may prevent the incidence of HF, suggests a new strategy to prevent HF that warrants further investigation. This review summarizes new evidence and theories which suggest that increased use of MRAs in hypertension may decrease incident HF by addressing common and under-recognized mechanisms of mineralocorticoid receptor overactivation.

Advances and challenges in kidney fibrosis therapeutics

Chronic kidney disease (CKD) is a major global health burden that affects more than 10% of the adult population. Current treatments, including dialysis and transplantation, are costly and not curative. Kidney fibrosis, defined as an abnormal accumulation of extracellular matrix in the kidney parenchyma, is a common outcome in CKD, regardless of disease aetiology, and is a major cause of loss of kidney function and kidney failure. For this reason, research efforts have focused on identifying mediators of kidney fibrosis to inform the development of effective anti-fibrotic treatments. Given the prominent role of the transforming growth factor-β (TGFβ) family in fibrosis, efforts have focused on inhibiting TGFβ signalling. Despite hopes raised by the efficacy of this approach in preclinical models, translation into clinical practice has not met expectations. Antihypertensive and antidiabetic drugs slow the decline in kidney function and could slow fibrosis but, owing to the lack of technologies for in vivo renal imaging, their anti-fibrotic effect cannot be truly assessed at present. The emergence of new drugs targeting pro-fibrotic signalling, or enabling cell repair and cell metabolic reprogramming, combined with better stratification of people with CKD and the arrival of nanotechnologies for kidney-specific drug delivery, open up new perspectives for the treatment of this major public health challenge.

Water and electrolyte abnormalities in novel pharmacological agents for kidney disease and cancer

This review article series on water and electrolyte disorders is based on the 'Electrolyte Winter Seminar' held annually for young nephrologists in Japan. This is the third article in this series that focuses on water and electrolyte disturbances caused by novel pharmacological agents for kidney disease and cancer. The advent of novel pharmacological agents in cardiorenal medicine and oncology has introduced both therapeutic benefits and challenges in managing medication-induced water and electrolyte disturbances. These medications, including sodium-glucose cotransporter-2 (SGLT2) inhibitors, non-steroidal mineralocorticoid receptor antagonists (ns-MRAs), and immune checkpoint inhibitors (ICIs), significantly impact water and electrolyte homeostasis. SGLT2 inhibitors used widely in diabetes mellitus, heart failure, and chronic kidney disease mitigate hyperkalemia and hypomagnesemia but increase the risk of hypernatremia in patients on fluid restriction. Conversely, they are beneficial for managing hyponatremia in the syndrome of inappropriate antidiuresis (SIAD). ns-MRAs, prescribed for diabetic kidney disease, exhibit a high risk of hyperkalemia, particularly when combined with renin-angiotensin system inhibitors. ICIs, a breakthrough in oncology, frequently induce hyponatremia through immune-related adverse events, such as hypophysitis and non-immune-related adverse events like SIAD. Understanding the pathophysiology of these disturbances and implementing timely interventions, including hormone replacement and water and electrolyte management, is critical for optimizing treatment outcomes.

Development of mass spectrometric methods for determination of desoxycorticosterone pivalate and its esterase product in canine serum

Hypoadrenocorticism is a serious condition in dogs that results from autoimmune adrenalitis and depletion of mineralocorticoids and glucocorticoids. Affected dogs respond well to glucocorticoid supplementation and treatment with the synthetic mineralocorticoid desoxycorticosterone pivalate (DOCP). DOCP injected once monthly resolves serum Na/K abnormalities and normalizes water balance, but therapy is expensive. Cost abatement involves prolongation of the 30-day dosage interval or decreasing the 2.2 mg/kg dosage. These approaches are not based on DOCP pharmacokinetics. A full assessment of the practicality of either approach would benefit from understanding drug pharmacokinetics, requiring measurement of DOCP and its esterase product desoxycorticosterone (DOC) in canine serum while avoiding toxic endpoints from overdosing. Mass spectrometric methods were developed including gas chromatography-tandem mass spectrometry of DOCP and DOC-methoxime trimethylsilyl derivatives, an approach sensitive to 2 ng/mL. Greater sensitivity was desired, so liquid chromatography-tandem mass spectrometry (LC-MS/MS) with ESI+ ionization was investigated. Supported liquid extraction was devised for serum with recoveries ∼100%. The LC-MS/MS method was validated for linearity, precision, accuracy and limits of detection (0.029 and 0.019 ng/mL for DOC and DOCP, respectively). A pilot experiment with DOCP-treated hypoadrenocorticism dogs over one-month revealed DOC baseline values as 0.183+/-0.090 ng/mL, which increased to the 1.0 - 2.2 ng/mL range. DOCP was not visible in any samples suggesting 100% conversion. Halving the dosage to 1.1 mg/kg still showed clear increases over the DOC baseline. MS fragmentation involved ring cleavages, dehydrations and double-charged fragments. The methodology was robust and suitable for studying DOC/DOCP pharmacokinetics in future studies of hypoadrenocorticism dogs.

Guideline-Directed Medical Therapy for Heart Failure in Transthyretin Amyloid Cardiomyopathy

Cardiac amyloidosis is an underdiagnosed cause of infiltrative cardiomyopathy, leading to heart failure across the spectrum of ejection fractions. Although there are approved disease-modulating therapies for the transthyretin subtype (transthyretin amyloid cardiomyopathy [ATTR-CM]), the role of heart failure medications remains uncertain and challenging in clinical practice. Their effects on clinical outcomes, such as mortality and hospitalization, are unknown for ATTR-CM. This review aims to explore the use of these medications in ATTR-CM, considering the disease's stage and patient-specific issues, such as fluid homeostasis, autonomic dysfunction, conduction disorders, low and fixed stroke volumes, and decreased functional capacity. As our understanding of this condition deepens, it is important to reassess the impact of contemporary heart failure medication in ATTR-CM. Finally, the relevance of guideline recommendations for heart failure drugs based on left ventricular ejection fraction should be reconsidered in the context of ATTR-CM.

Involvement of Mineralocorticoid Receptor Activation by High Mobility Group Box 1 and Receptor for Advanced Glycation End Products in the Development of Acute Kidney Injury

Key Points

Our study revealed that high mobility group box 1 activates the mineralocorticoid receptor (MR) through the receptor for advanced glycation end products (RAGE) in AKI. MR antagonists and RAGE aptamers inhibited high mobility group box 1–induced Rac1/MR activation and downstream inflammatory molecules in endothelial cells. MR antagonists and RAGE aptamers may represent promising therapeutic strategies for preventing AKI and CKD progression.

Background

Although AKI is associated with an increased risk of CKD, the underlying mechanisms remain unclear. High mobility group box 1 (HMGB1), one of the ligands for the receptor for advanced glycation end products (RAGE), is elevated in patients with AKI. We recently demonstrated that the mineralocorticoid receptor (MR) is activated by the RAGE/Rac1 pathway, contributing to chronic renal damage in hypertensive mice. Therefore, this study investigated the role of the HMGB1/RAGE/MR pathway in AKI and progression to CKD.

Methods

We performed a mouse model of renal ischemia–reperfusion (I/R) with or without MR antagonist (MRA). In vitro experiments were conducted using cultured endothelial cells to examine the interaction between the HMGB1/RAGE and Rac1/MR pathways.

Results

In renal I/R injury mice, renal MR activation was associated with elevated serum HMGB1, renal RAGE, and activated Rac1, all of which were suppressed by MRA. Renal I/R injury led to renal dysfunction, tubulointerstitial injury, and increased expressions of inflammation and fibrosis mediators, which were ameliorated by MRA. In vitro , RAGE aptamer or MRA inhibited HMGB1-induced Rac1/MR activation and upregulation of monocyte chemoattractant protein 1 and NF-κB expressions. Seven days after I/R injury, renal I/R injury mice developed CKD, whereas MRA prevented renal injury progression and decreased the mortality rate. Furthermore, in case of MRA treatment even after I/R injury, attenuated renal dysfunction compared with untreated mice was also observed.

Conclusions

Our findings suggest that HMGB1 may play a crucial role in AKI and CKD development by activating the Rac1/MR pathway through interactions with RAGE.

Clinical implications of mineralocorticoid receptor overactivation

The mineralocorticoid receptor (MR) is a nuclear transcription factor that plays a critical role in regulating fluid, electrolytes, blood pressure, and hemodynamic stability. In conditions such as chronic kidney disease (CKD) and heart failure (HF), MR overactivation leads to increased salt and water retention, inflammatory and fibrotic gene expression, and organ injury. The MR is essential for transcriptional regulation and is implicated in metabolic, proinflammatory, and pro-fibrotic pathways. It is widely expressed in various cell types throughout the body, including the gastrointestinal tract, heart, brain, kidneys, immune cells, and vasculature. Animal studies suggest that MR activation induces oxidative stress in the kidneys and mediates renal inflammation and fibrosis. Immune cell-specific deletion of MR has shown protection against cardiac fibrosis, indicating the MR's role in pathological remodeling. In vascular smooth muscle cells, the MR regulates vascular tone and vasoconstriction. Mineralocorticoid receptor antagonists (MRAs) can be categorized based on their chemical structure as either steroidal or nonsteroidal. Steroidal MRAs (sMRA), such as spironolactone and eplerenone, have demonstrated cardiovascular benefits but are limited by hyperkalemia, gynecomastia, and sexual dysfunction. Nonsteroidal MRAs (nsMRA) have shown promise in preclinical studies and clinical trials. They offer a promising alternative by effectively blocking MR without hormone-like effects, potentially improving cardiovascular and renal disease management. Further education is necessary regarding the significance of MRA utilization in CKD and HF, balancing benefits with the risk of hyperkalemia. This risk could be mitigated by combining MRAs with potassium-binding agents. Studies are underway to explore the synergistic effects between nsMRAs and other agents, such as SGLT-2i inhibitors and Glucagon-like peptide-1 agonists, to optimize cardiorenal outcomes. Overall, MR overactivation remains a significant therapeutic target, with nsMRAs showing promise as pivotal therapies in CKD and HF management. This review highlights the evolving landscape of MR-targeted therapies, their molecular mechanisms, and clinical implications in cardiorenal diseases.

Recent Advances and Perspectives on the Use of Mineralocorticoid Receptor Antagonists for the Treatment of Hypertension and Chronic Kidney Disease: A Review

Chronic kidney disease (CKD) is a major public health concern around the world. It is a significant risk factor for cardiovascular disease (CVD), and, as it progresses, the risk of cardiovascular events increases. Furthermore, end-stage kidney disease severely affects life expectancy and quality of life. Type 2 diabetes and hypertension are not only primary causes of CKD but also independent risk factors for CVD, which underscores the importance of effective treatment strategies for these conditions. The current therapies, including angiotensin-converting enzyme inhibitors, angiotensin II receptor blockers, and sodium-glucose co-transporter 2 inhibitors, are administered to control hypertension, slow the progression of CKD, and reduce cardiovascular risk. However, their efficacy remains suboptimal in certain instances. Mineralocorticoid receptor (MR), a nuclear receptor found in various tissues, such as the kidney and heart, plays a pivotal role in the progression of CKD. Overactivation of MR triggers inflammation and fibrosis, which exacerbates kidney damage and accelerates disease progression. MR antagonists (MRAs) have substantial beneficial effects in patients with cardiac and renal conditions; however, their use has been constrained because of adverse effects, such as hyperkalemia and kidney dysfunction. Recently, novel non-steroidal MRAs are more efficacious and have superior safety profiles to steroidal MRAs, making them promising potential components of future treatment strategies. Here, we discuss recent findings and the roles of MRAs in the management of hypertension and CKD, with a focus on the evidence obtained from fundamental research and major clinical trials.

Pharmacological Nephroprotection in Chronic Kidney Disease Patients with Type 2 Diabetes Mellitus-Clinical Practice Position Statement of the Polish Society of Nephrology

Both chronic kidney disease (CKD) and type 2 diabetes (T2D) are modern epidemics worldwide and have become a severe public health problem. Chronic kidney disease progression in T2D patients is linked to the need for dialysis or kidney transplantation and represents the risk factor predisposing to serious cardiovascular complications. In recent years, important progress has occurred in nephroprotective pharmacotherapy in CKD patients with T2D. In the current position paper, we described a nephroprotective approach in CKD patients with T2D based on the five following pillars: effective antihyperglycemic treatment, SGLT2 inhibitor or semaglutide, antihypertensive therapy, use of RASi (ARB or ACEi), and in selected patients, finerenone, as well as sodium bicarbonate in patients with metabolic acidosis. We thought that the current statement is comprehensive and up-to-date and addresses multiple pathways of nephroprotection in patients with CKD and T2D.

Elucidating the complex interplay between chronic kidney disease and hypertension

Chronic kidney disease (CKD) and hypertension share a complex relationship, each exacerbating the progression of the other. CKD contributes to hypertension by decreasing renal function, leading to fluid retention and increased plasma volume, whereas hypertension exacerbates CKD by increasing glomerular pressure and causing renal damage. This review examines the intertwined nature of CKD and hypertension, exploring the factors driving hypertension in CKD and how hypertension accelerates CKD progression. It discusses the role of the renin-angiotensin system and inflammatory cytokines in this relationship, as well as the potential of blood pressure management to slow renal decline. While studies suggest that meticulous blood pressure control can help attenuate CKD progression, optimal management strategies remain unclear and require further investigation. This review also evaluates the evidence surrounding strict antihypertensive therapy in patients with CKD, considering both diabetic and non-diabetic cases. It recommends blood pressure targets based on CKD stage and presence of diabetes, emphasizing the importance of individualized treatment approaches. Renin-angiotensin system inhibitors are highlighted as a key pharmacological intervention due to their renal protective effects, particularly in patients with CKD with proteinuria. However, evidence regarding their efficacy in patients with CKD but without proteinuria is inconclusive. This review underscores the need for comprehensive approaches to effectively address the intertwined nature of CKD and hypertension and calls for further research to optimize clinical management strategies in this complex interplay.

The renin-angiotensin-aldosterone system: An old tree sprouts new shoots

The intricate physiological and pathological diversity of the Renin-Angiotensin-Aldosterone System (RAAS) underpins its role in maintaining bodily equilibrium. This paper delves into the classical axis (Renin-ACE-Ang II-AT1R axis), the protective arm (ACE2-Ang (1-7)-MasR axis), the prorenin-PRR-MAP kinases ERK1/2 axis, and the Ang IV-AT4R-IRAP cascade of RAAS, examining their functions in both physiological and pathological states. The dysregulation or hyperactivation of RAAS is intricately linked to numerous diseases, including cardiovascular disease (CVD), renal damage, metabolic disease, eye disease, Gastrointestinal disease, nervous system and reproductive system diseases. This paper explores the pathological mechanisms of RAAS in detail, highlighting its significant role in disease progression. Currently, in addition to traditional drugs like ACEI, ARB, and MRA, several novel therapeutics have emerged, such as angiotensin receptor-enkephalinase inhibitors, nonsteroidal mineralocorticoid receptor antagonists, aldosterone synthase inhibitors, aminopeptidase A inhibitors, and angiotensinogen inhibitors. These have shown potential efficacy and application prospects in various clinical trials for related diseases. Through an in-depth analysis of RAAS, this paper aims to provide crucial insights into its complex physiological and pathological mechanisms and offer valuable guidance for developing new therapeutic approaches. This comprehensive discussion is expected to advance the RAAS research field and provide innovative ideas and directions for future clinical treatment strategies.

Dual blockade of endothelin A and angiotensin II type 1 receptors with sparsentan as a novel treatment strategy to alleviate IgA nephropathy

INTRODUCTION

Although immunoglobulin A nephropathy (IgAN) had been discovered more than 50 years ago, 30-40% of IgAN patients still have primary glomerular disease that progresses to end-stage renal disease. However, various treatment strategies for IgAN have rapidly expanded in recent years to include endothelin (ET) receptor antagonists.

AREAS COVERED

In this review, we discuss the role of the ET-1/ETA receptor axis in the development of IgAN, especially focusing on the potential of sparsentan, a dual ET and angiotensin receptor antagonist as a novel therapy for IgAN.

EXPERT OPINION

Evaluation of the MEST-C score at the time of renal biopsy in IgAN is important in determining treatment strategies. If lesions are mainly in the acute phase, such as crescents, steroid therapy should be continued. However, if lesions are mainly in the chronic phase, such as glomerulosclerosis, sparsentan rather than steroid or angiotensin II receptor blocker alone may improve renal outcomes. Although further clinical studies are needed to back up these assumptions, appropriate combination of new drugs containing sparsentan and conventional drugs for IgAN treatment at the appropriate disease stage is expected to further inhibit the progression of renal damage.

Dysregulation of the 3β-hydroxysteroid dehydrogenase type 2 enzyme and steroid hormone biosynthesis in chronic kidney disease

Introduction

Chronic kidney disease (CKD) presents a critical global health challenge, marked by the progressive decline of renal function. This study explores the role of the 3β-hydroxysteroid dehydrogenase type 2 enzyme (HSD3B2) and the steroid hormone biosynthesis pathway in CKD pathogenesis and progression.

Methods

Using an adenine-induced CKD mouse model, we conducted an untargeted metabolomic analysis of plasma samples to identify key metabolite alterations associated with CKD. Immunohistochemistry, Western blotting, and qPCR analyses were performed to confirm HSD3B2 expression in both human and mouse tissues. Additionally, Nephroseq and Human Protein Atlas data were utilized to assess the correlation between HSD3B2 and kidney function. Functional studies were conducted on HK2 cells with HSD3B2 knockdown to evaluate the impact on cell proliferation and apoptosis.

Results

Metabolic characteristics revealed significant shifts in CKD, with 61 metabolites increased and 65 metabolites decreased, highlighting the disruption in steroid hormone biosynthesis pathways influenced by HSD3B2. A detailed examination of seven key metabolites underscored the enzyme's central role. HSD3B2 exhibited a strong correlation with kidney function, supported by data from Nephroseq and the Human Protein Atlas. Immunohistochemistry, Western blotting, and qPCR analyses confirmed a drastic reduction in HSD3B2 expression in CKD-affected kidneys. Suppressed proliferation and increased apoptosis rates in HSD3B2 knocked down HK2 cells further demonstrated the enzyme's significance in regulating renal pathophysiology.

Discussion

These findings underscore the potential of HSD3B2 as a clinical diagnostic and therapeutic target in CKD. While further studies are warranted to fully elucidate the mechanisms, our results provide valuable insights into the intricate interplay between steroid hormone biosynthesis and CKD. This offers a promising avenue for precision medicine approaches and personalized treatment strategies.

Salidroside Pre-Treatment Inhibits Hypertensive Renal Injury and Fibrosis Through Inhibiting Wnt/β-Catenin Pathway

Objectives

This study aimed to explore the protective effects and underlying mechanisms of salidroside (SAL) in angiotensin II (Ang II)-induced hypertensive renal injury and fibrosis, using in vivo and in vitro models.

Methods

In this study, we generated Ang II-induced hypertensive renal injury and fibrosis in mice and the recombinant interferon-gamma (IFN-γ)-stimulated murine podocyte clone 5 (MPC5) model in vitro. Histological and oxidative stress analyses were performed to evaluate the renal injury.

Results

SAL pre-treatment reduced systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), and attenuated serum creatinine (Scr), blood urea nitrogen (BUN), and serum cystatin C (Cys-C) levels in Ang II-infused mice (all, P < 0.001). SAL reduced renal fibrosis and related molecules expression, including Collagen I, Collagen III, and α-smooth muscle actin (α-SMA) (all, P < 0.001). SAL decreased the content of malondialdehyde (MDA) while increasing superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in Ang II-treated mice (all, P < 0.001). In addition, SAL pre-treatment inhibited AT1R, Wnt1, Wnt3a, and β-catenin expressions (all, P < 0.001), both in vivo and in vitro.

Conclusion

Our experimental data demonstrate that SAL pre-treatment protects against Ang II-induced hypertensive renal injury and fibrosis by suppressing the Wnt/β-catenin pathway in vivo and in vitro.

Mechanism of protective actions of sparsentan in the kidney: lessons from studies in models of chronic kidney disease

Simultaneous inhibition of angiotensin II AT1 and endothelin ETA receptors has emerged as a promising approach for treatment of chronic progressive kidney disease. This therapeutic approach has been advanced by the introduction of sparsentan, the first dual AT1 and ETA receptor antagonist. Sparsentan is a single molecule with high affinity for both receptors. It is US Food and Drug Administration approved for immunoglobulin A nephropathy (IgAN) and is currently being developed as a treatment for rare kidney diseases, such as focal segmental glomerulosclerosis. Clinical studies have demonstrated the efficacy and safety of sparsentan in these conditions. In parallel with clinical development, studies have been conducted to elucidate the mechanisms of action of sparsentan and its position in the context of published evidence characterizing the nephroprotective effects of dual ETA and AT1 receptor inhibition. This review summarizes this evidence, documenting beneficial anti-inflammatory, antifibrotic, and hemodynamic actions of sparsentan in the kidney and protective actions in glomerular endothelial cells, mesangial cells, the tubulointerstitium, and podocytes, thus providing the rationale for the use of sparsentan as therapy for focal segmental glomerulosclerosis and IgAN and suggesting potential benefits in other renal diseases, such as Alport syndrome.

Management of chronic kidney disease: The current novel and forgotten therapies

Chronic kidney disease (CKD) is a progressive and incurable condition that imposes a significant burden on an aging society. Although the exact prevalence of this disease is unknown, it is estimated to affect at least 800 million people worldwide. Patients with diabetes or hypertension are at a higher risk of developing chronic kidney damage. As the kidneys play a crucial role in vital physiological processes, damage to these organs can disrupt the balance of water and electrolytes, regulation of blood pressure, elimination of toxins, and metabolism of vitamin D. Early diagnosis is paramount to prevent potential complications. Treatment options such as dietary modifications and medications can help slow disease progression. In our narrative review, we have summarized the available therapeutic options to slow the progression of chronic kidney disease. Many new drug treatments have recently become available, offering a beacon of hope and optimism in CKD management. Nonetheless, disease prevention remains the most critical step in disease management. Given the significant impact of CKD on public health, there is a pressing need for further research. With the development of new technologies and advancements in medical knowledge, we hope to find more effective diagnostic tools and treatments for CKD patients.

Use of Fludrocortisone for Hyperkalemia in Chronic Kidney Disease Not Yet on Dialysis

Background

Hyperkalemia is a frequent and potentially lethal complication of chronic kidney disease (CKD). We retrospectively examined the potassium-lowering effect of oral fludrocortisone and its adverse effects in hyperkalemic CKD patients not yet on dialysis.

Methods

Thirty-three patients (23 men and 10 women, ages 69±14 years) were included. To control hyperkalemia at the outpatient clinic, twenty-one patients (Group 1) received fludrocortisone (0.05-0.1 mg/day) without changes in angiotensin II receptor blockers (ARBs) and calcium polystyrene sulfonate (CPS), while twelve patients (Group 2) were treated with fludrocortisone in addition to stopping ARBs and/or adding low-dose CPS.

Results

Fludrocortisone was administered for a median of 169 days (interquartile range, 47-445). At the first follow-up after fludrocortisone administration, serum potassium dropped from 6.14±0.32 mEq/L to 4.52±1.06 mEq/L (p<0.001) in Group 1 and from 6.37±0.35 mEq/L to 4.08±0.74 mEq/L (p<0.01) in Group 2. Ten patients in Group 1 and five patients in Group 2 measured serum potassium levels at four outpatient visits before and after fludrocortisone administration, respectively. The frequency of serum potassium ≥6.0 mEq/L decreased from 19/40 (48%) to 2/40 (5%) (p<0.001) in Group 1 and from 11/20 (55%) to 0/20 (0%) (p<0.001) in Group 2. Eleven patients experienced sodium retention-related problems after fludrocortisone administration: 7 with worsening leg edema, 2 with pleural effusions, and 2 with pulmonary edema.

Conclusion

In pre-dialysis CKD patients, fludrocortisone at low doses effectively reduced serum potassium levels; however, sodium retention was a common adverse effect.

The potential for improved outcomes in the prevention and therapy of diabetic kidney disease through 'stacking' of drugs from different classes

Aggressive therapy of diabetic kidney disease (DKD) can not only slow the progression of DKD to renal failure but, if utilized at an early enough stage of DKD, can also stabilize and/or reverse the decline in renal function. The currently recognized standard of therapy for DKD is blockade of the renin-angiotensin system with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs). However, unless utilized at a very early stage, monotherapy with these drugs in DKD will only prevent or slow the progression of DKD and will neither stabilize nor reverse the progression of DKD to renal decompensation. Recently, the addition of a sodium-glucose cotransporter-2 inhibitor and/or a mineralocorticoid receptor blocker to ACE inhibitors or ARBs has been clearly shown to further decelerate the decline in renal function. The use of glucagon-like peptide-1 (GLP-1) agonists shown promise in decelerating the progression of DKD. Other drugs that may aid in the deceleration the progression of DKD are dipeptidyl peptidase-4 inhibitors, pentoxifylline, statins, and vasodilating beta blockers. Therefore, aggressive therapy with combinations of these drugs (stacking) should improve the preservation of renal function in DKD.

Use of bailing capsules (cordyceps sinensis) in the treatment of chronic kidney disease: a meta-analysis and network pharmacology

The Bailing Capsule is a commonly used traditional Chinese medicine for the treatment of chronic kidney disease (CKD). However, its therapeutic effects and pharmacological mechanisms have not been fully explored. In this study, we integrated meta-analysis and network pharmacology to provide scientific evidence for the efficacy and pharmacological mechanism of Bailing Capsule in treating CKD. We conducted searches for randomized controlled studies matching the topic in PubMed, the Cochrane Library, Embase, Web of Science, and the Wanfang Database, and screened them according to predefined inclusion and exclusion criteria. Dates from the included studies were extracted for meta-analysis, including renal function indicators, such as 24-h urinary protein (24UP), blood urea nitrogen (BUN), and serum creatinine (Scr), as well as inflammatory indicators like high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α). Network pharmacology was employed to extract biological information, including active drug ingredients and potential targets of the drugs and diseases, for network construction and gene enrichment. Our findings indicated that 24UP, BUN, and Scr in the treatment group containing Bailing Capsule were lower than those in the control group. In terms of inflammatory indicators, hs-CRP, IL-6, and TNF-α, the treatment group containing Bailing Capsule also exhibited lower levels than the control group. Based on network pharmacology analysis, we identified 190 common targets of Bailing Capsule and CKD. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses suggested that the pharmacological mechanism of Bailing Capsule might be related to immune response, inflammatory response, vascular endothelial damage, cell proliferation, and fibrosis. This demonstrates that Bailing Capsule can exert therapeutic effects through multiple targets and pathways, providing a theoretical basis for its use.

A New Hope on the Horizon for Kidney and Cardiovascular Protection with SGLT2 Inhibitors, GLP-1 Receptor Agonists, and Mineralocorticoid Receptor Antagonists in Type 2 Diabetic and Chronic Kidney Disease Patients

Type 2 diabetes (T2D) is the leading cause of chronic kidney disease (CKD). In addition, the cardiovascular prevalence in diabetic patients is around 32.2%, with a two-fold increased mortality risk compared to those without diabetes. Recent investigations have shed light on the promising cardioprotective and nephroprotective benefits of sodium-glucose cotransporter-2 inhibitors (SGLT2i), glucagon-like peptide-1 receptor agonists (GLP-1RA), and nonsteroidal mineralocorticoid receptor antagonists (nsMRAs) for individuals with T2D. The evidence robustly indicates that SGLT2i and GLP-1RA significantly reduce the risk of CKD and cardiovascular disease (CVD), all while effectively managing blood glucose levels. Furthermore, combining SGLT2i with nsMRAs amplifies the benefits, potentially offering a more profound reduction in cardiovascular and renal outcomes. The data analysis strongly supports the integration of these pharmacological agents in the management strategies for CKD and CVD prevention among T2D patients, highlighting the importance of awareness among nephrologists, especially in regions with limited healthcare resources.

Evidence for the druggability of aldosterone targets in heart failure: A bioinformatics and data science-driven decision-making approach

BACKGROUND

Aldosterone plays a key role in the neurohormonal drive of heart failure. Systematic prioritization of drug targets using bioinformatics and database-driven decision-making can provide a competitive advantage in therapeutic R&D. This study investigated the evidence on the druggability of these aldosterone targets in heart failure.

METHODS

The target disease predictability of mineralocorticoid receptors (MR) and aldosterone synthase (AS) in cardiac failure was evaluated using Open Targets target-disease association scores. The Open Targets database collections were downloaded to MongoDB and queried according to the desired aggregation level, and the results were retrieved from the Europe PMC (data type: text mining), ChEMBL (data type: drugs), Open Targets Genetics Portal (data type: genetic associations), and IMPC (data type: genetic associations) databases. The target tractability of MR and AS in the cardiovascular system was investigated by computing activity scores in a curated ChEMBL database using supervised machine learning.

RESULTS

The medians of the association scores of the MR and AS groups were similar, indicating a comparable predictability of the target disease. The median of the MR activity scores group was significantly lower than that of AS, indicating that AS has higher target tractability than MR [Hodges-Lehmann difference 0.62 (95%CI 0.53-0.70, p < 0.0001]. The cumulative distributions of the overall multiplatform association scores of cardiac diseases with MR were considerably higher than with AS, indicating more advanced investigations on a wider range of disorders evaluated for MR (Kolmogorov-Smirnov D = 0.36, p = 0.0009). In curated ChEMBL, MR had a higher cumulative distribution of activity scores in experimental cardiovascular assays than AS (Kolmogorov-Smirnov D = 0.23, p < 0.0001). Documented clinical trials for MR in heart failures surfaced in database searches, none for AS.

CONCLUSIONS

Although its clinical development has lagged behind that of MR, our findings indicate that AS is a promising therapeutic target for the treatment of cardiac failure. The multiplatform-integrated identification used in this study allowed us to comprehensively explore the available scientific evidence on MR and AS for heart failure therapy.

Efficacy and safety of aldosterone synthase inhibition with and without empagliflozin for chronic kidney disease: a randomised, controlled, phase 2 trial

BACKGROUND

Excess aldosterone accelerates chronic kidney disease progression. This phase 2 clinical trial assessed BI 690517, an aldosterone synthase inhibitor, for efficacy, safety, and dose selection.

METHODS

This was a multinational, randomised, controlled, phase 2 trial. People aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 30 to less than 90 mL/min/1·73 m2, a urine albumin to creatinine ratio (UACR) of 200 to less than 5000 mg/g, and serum potassium of 4·8 mmol/L or less, taking an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, were enrolled. Participants were randomly assigned (1:1) to 8 weeks of empagliflozin or placebo run-in, followed by a second randomisation (1:1:1:1) to 14 weeks of treatment with once per day BI 690517 at doses of 3 mg, 10 mg, or 20 mg, or placebo. Study participants, research coordinators, investigators, and the data coordinating centre were masked to treatment assignment. The primary endpoint was the change in UACR measured in first morning void urine from baseline (second randomisation) to the end of treatment. This study is registered with ClinicalTrials.gov (NCT05182840) and is completed.

FINDINGS

Between Feb 18 and Dec 30, 2022, of the 714 run-in participants, 586 were randomly assigned to receive BI 690517 or placebo. At baseline, 33% (n=196) were women, 67% (n=390) were men, 42% (n=244) had a racial identity other than White, and mean participant age was 63·8 years (SD 11·3). Mean baseline eGFR was 51·9 mL/min/1·73 m2 (17·7) and median UACR was 426 mg/g (IQR 205 to 889). Percentage change in first morning void UACR from baseline to the end of treatment at week 14 was -3% (95% CI -19 to 17) with placebo, -22% (-36 to -7) with BI 690517 3 mg, -39% (-50 to -26) with BI 690517 10 mg, and -37% (-49 to -22) with BI 690517 20 mg monotherapy. BI 690517 produced similar UACR reductions when added to empagliflozin. Investigator-reported hyperkalaemia occurred in 10% (14/146) of those in the BI 690517 3 mg group, 15% (22/144) in the BI 690517 10 mg group, and 18% (26/146) in the BI 690517 20 mg group, and in 6% (nine of 147) of those receiving placebo, with or without empagliflozin. Most participants with hyperkalaemia did not require intervention (86% [72/84]). Adrenal insufficiency was an adverse event of special interest reported in seven of 436 study participants (2%) receiving BI 690517 and one of 147 participants (1%) receiving matched placebo. No treatment-related deaths occurred during the study.

INTERPRETATION

BI 690517 dose-dependently reduced albuminuria with concurrent renin-angiotensin system inhibition and empagliflozin, suggesting an additive efficacy for chronic kidney disease treatment without unexpected safety signals.

FUNDING

Boehringer Ingelheim.

Potential of Modulating Aldosterone Signaling and Mineralocorticoid Receptor with microRNAs to Attenuate Diabetic Kidney Disease

Diabetic Kidney Disease (DKD) is a significant complication of diabetes and primary cause of end-stage renal disease globally. The exact mechanisms underlying DKD remain poorly understood, but multiple factors, including the renin-angiotensin-aldosterone system (RAAS), play a key role in its progression. Aldosterone, a mineralocorticoid steroid hormone, is one of the key components of RAAS and a potential mediator of renal damage and inflammation in DKD. miRNAs, small noncoding RNA molecules, have attracted interest due to their regulatory roles in numerous biological processes. These processes include aldosterone signaling and mineralocorticoid receptor (MR) expression. Numerous miRNAs have been recognized as crucial regulators of aldosterone signaling and MR expression. These miRNAs affect different aspects of the RAAS pathway and subsequent molecular processes, which impact sodium balance, ion transport, and fibrosis regulation. This review investigates the regulatory roles of particular miRNAs in modulating aldosterone signaling and MR activation, focusing on their impact on kidney injury, inflammation, and fibrosis. Understanding the complex interaction between miRNAs and the RAAS could lead to a new strategy to target aldosterone signaling and MR activation using miRNAs. This highlights the potential of miRNA-based interventions for DKD, with the aim of enhancing kidney outcomes in individuals with diabetes.

Biomarkers to Guide Medical Therapy in Primary Aldosteronism

Primary aldosteronism (PA) is an endocrinopathy characterized by dysregulated aldosterone production that occurs despite suppression of renin and angiotensin II, and that is non-suppressible by volume and sodium loading. The effectiveness of surgical adrenalectomy for patients with lateralizing PA is characterized by the attenuation of excess aldosterone production leading to blood pressure reduction, correction of hypokalemia, and increases in renin-biomarkers that collectively indicate a reversal of PA pathophysiology and restoration of normal physiology. Even though the vast majority of patients with PA will ultimately be treated medically rather than surgically, there is a lack of guidance on how to optimize medical therapy and on key metrics of success. Herein, we review the evidence justifying approaches to medical management of PA and biomarkers that reflect endocrine principles of restoring normal physiology. We review the current arsenal of medical therapies, including dietary sodium restriction, steroidal and nonsteroidal mineralocorticoid receptor antagonists, epithelial sodium channel inhibitors, and aldosterone synthase inhibitors. It is crucial that clinicians recognize that multimodal medical treatment for PA can be highly effective at reducing the risk for adverse cardiovascular and kidney outcomes when titrated with intention. The key biomarkers reflective of optimized medical therapy are unsurprisingly similar to the physiologic expectations following surgical adrenalectomy: control of blood pressure with the fewest number of antihypertensive agents, normalization of serum potassium without supplementation, and a rise in renin. Pragmatic approaches to achieve these objectives while mitigating adverse effects are reviewed.

Sex-dependent effects of finerenone on hemostasis in normoglycemic and streptozotocin-induced diabetic mice

Diabetes is associated with aldosterone excess and the overactivation of its mineralocorticoid receptor (MR) which leads to the development of many cardiovascular dysfunctions. Therefore, MR antagonists have been found to exert favorable effects on the cardiovascular system. Finerenone is a new nonsteroidal MR antagonist approved for the treatment of chronic kidney disease associated with type 2 diabetes. Clinical studies have demonstrated that finerenone improves cardiovascular outcomes. However, its influence on hemostasis in the cardioprotective effect is unknown. Therefore, the main aim of our study was to evaluate the effects of finerenone (10 mg/kg, p.o.) on selected hemostasis parameters in streptozotocin (180 mg/kg, i.p.)-induced diabetes. Since regulation of the MR activity is sex-dependent, the study was conducted in both female and male mice. The most beneficial effects of finerenone were observed in diabetic female mice which included a decrease in thrombus formation, attenuation of platelet activity, inhibition of the coagulation system, and activation of fibrinolysis. In contrast, in male diabetic mice only an attenuation of the coagulation system was observed. Furthermore, finerenone also exerted unfavorable effects, but only in normoglycemic mice, manifested as a slight increase in platelet activity in males and an enhancement of the coagulation system activity in females. Our study is the first to show the sex-dependent and glycemia-dependent effects of finerenone on hemostasis in diabetes. The occurrence of beneficial effects only in female diabetic mice requires in-depth study.

Advances in the management of chronic kidney disease

Chronic kidney disease (CKD) represents a global public health crisis, but awareness by patients and providers is poor. Defined as persistent abnormalities in kidney structure or function for more than three months, manifested as either low glomerular filtration rate or presence of a marker of kidney damage such as albuminuria, CKD can be identified through readily available blood and urine tests. Early recognition of CKD is crucial for harnessing major advances in staging, prognosis, and treatment. This review discusses the evidence behind the general principles of CKD management, such as blood pressure and glucose control, renin-angiotensin-aldosterone system blockade, statin therapy, and dietary management. It additionally describes individualized approaches to treatment based on risk of kidney failure and cause of CKD. Finally, it reviews novel classes of kidney protective agents including sodium-glucose cotransporter-2 inhibitors, glucagon-like peptide-1 receptor agonists, non-steroidal selective mineralocorticoid receptor antagonists, and endothelin receptor antagonists. Appropriate, widespread implementation of these highly effective therapies should improve the lives of people with CKD and decrease the worldwide incidence of kidney failure.

Higher plasma aldosterone concentrations in patients with aortic diseases and hypertension: a retrospective observational study

BACKGROUND

Aortic diseases remain a highly perilous macrovascular condition. The relationship between circulating aldosterone and aortic diseases is rarely explored, thus we investigated the difference in plasma aldosterone concentration (PAC) between patients with and without aortic disease in hypertensive people.

METHODS

We analyzed 926 patients with hypertension, ranging in age from 18 to 89 years, who had their PAC measured from the hospital's electronic database. The case group and control group were defined based on inclusion and exclusion criteria. The analysis included general information, clinical data, biochemical data, and medical imaging examination results as covariates. To further evaluate the difference in PAC between primary hypertension patients with aortic disease and those without, we used multivariate logistic regression analysis and also employed propensity score matching to minimize the influence of confounding factors.

RESULTS

In total, 394 participants were included in the analysis, with 66 individuals diagnosed with aortic diseases and 328 in the control group. The participants were predominantly male (64.5%) and over the age of 50 (68.5%), with an average PAC of 19.95 ng/dL. After controlling for confounding factors, the results showed hypertension patients with aortic disease were more likely to have high PAC levels than those without aortic disease (OR = 1.138, 95% CI [1.062 to 1.238]). Subgroup analysis revealed consistent relationship between PAC and primary hypertensive patients with aortic disease across the different stratification variables. Additionally, hypertensive patients with aortic disease still have a risk of higher PAC levels than those without aortic disease, even after propensity score matching.

CONCLUSIONS

The results of this study suggest that primary hypertensive patients with aortic diseases have elevated levels of PAC, but the causal relationship between PAC and aortic disease requires further study.

Finerenone and other future therapeutic options for Alport syndrome

Alport syndrome is a rare genetic disease that results in disordered basement membrane type IV collagen resulting in haematuria, proteinuria and often development of renal fibrosis leading to progressive kidney disease. The therapeutic blockage of the renin-angiotensin-aldosterone system, which slows the progression to kidney failure, is supported by strong evidence. Recent clinical trials using sodium-glucose co-transporter-2 (SGLT2) inhibitors and mineralocorticoid receptor antagonists (MRA) in patients with chronic kidney disease have changed the therapeutic landscape. Patients with Alport syndrome and progressive kidney disease may benefit from treatment with MRAs because research has shown that these drugs are nephroprotective through a variety of mechanisms, including by preventing fibrosis. Ongoing clinical trials show great promise in order to help establish the long-term safety and efficacy of Finerenone, a MRA. This review discusses the evidence for the use of MRAs as a potential treatment in Alport syndrome that may slow the progression of chronic kidney disease and prevent patients reaching kidney failure.

A biomimetic renal fibrosis progression model on-chip evaluates anti-fibrotic effects longitudinally in a dynamic fibrogenic niche

Although renal fibrosis can advance chronic kidney disease and progressively lead to end-stage renal failure, no effective anti-fibrotic drugs have been clinically approved. To aid drug development, we developed a biomimetic renal fibrosis progression model on-chip to evaluate anti-fibrotic effects of natural killer cell-derived extracellular vesicles and pirfenidone (PFD) across different fibrotic stages. First, the dynamic interplay between fibroblasts and kidney-derived extracellular matrix (ECM) resembling the fibrogenic niche on-chip demonstrated that myofibroblasts induced by stiff ECM in 3 days were reversed to fibroblasts by switching to soft ECM, which was within 2, but not 7 days. Second, PFD significantly down-regulated the expression of α-SMA in NRK-49F in medium ECM, as opposed to stiff ECM. Third, a study in rats showed that early administration of PFD significantly inhibited renal fibrosis in terms of the expression levels of α-SMA and YAP. Taken together, both on-chip and animal models indicate the importance of early anti-fibrotic intervention for checking the progression of renal fibrosis. Therefore, this renal fibrosis progression on-chip with a feature of recapitulating dynamic biochemical and biophysical cues can be readily used to assess anti-fibrotic candidates and to explore the tipping point when the fibrotic fate can be rescued for better medical intervention.

Primary Aldosteronism in Chronic Kidney Disease: Blood Pressure Control and Kidney and Cardiovascular Outcomes After Surgical Versus Medical Management

BACKGROUND

Diagnosis and treatment of primary aldosteronism (PA) in chronic kidney disease (CKD) may be deferred due to limited evidence supporting safety and efficacy of treatment. Our goal was to assess clinical outcomes in patients with PA and CKD who received surgical or medical management.

METHODS

We conducted a multicenter, retrospective cohort study of patients with PA and CKD who underwent adrenal vein sampling from 2009-2019. We characterized clinical outcomes and evaluated differences by surgical versus medical management. Primary outcomes were systolic blood pressure and number of antihypertensive medications. Secondary outcomes were diastolic blood pressure, serum potassium, estimated glomerular filtration rate (eGFR), and kidney and cardiovascular events. Analyses were adjusted for age, sex, race, cardiovascular disease, diabetes, and eGFR.

RESULTS

Of 239 participants with PA and CKD, 158 (66%) underwent adrenalectomy, and 81 (34%) were treated medically. Mean age was 57±10 years, 67% were female, mean eGFR was 45±12 mL/min per 1.73 m2, and 49% were on potassium supplementation. At 5 years, mean blood pressure decreased from 149±22/85±14 to 131±28/78±16 mm Hg and mean number of antihypertensive medications decreased from 4.0±1.5 to 2.4±1.4. Adrenalectomy, compared to medical management, was associated with similar systolic blood pressure (-0.90 mm Hg [95% CI, -6.99 to 5.07]) but fewer medications (1.7 [95% CI, -2.24 to -1.10]), and no difference in potassium levels or kidney or cardiovascular outcomes.

CONCLUSIONS

Patients with PA and CKD are likely to benefit from either surgical adrenalectomy or medical management. Detection and treatment of PA may help to reduce blood pressure and medication burden in patients with CKD.

Pharmacological Nephroprotection in Non-Diabetic Chronic Kidney Disease-Clinical Practice Position Statement of the Polish Society of Nephrology

Chronic kidney disease (CKD) is a modern epidemic worldwide. Introducing renin-angiotensin system (RAS) inhibitors (i.e., ACEi or ARB) not only as blood-pressure-lowering agents, but also as nephroprotective drugs with antiproteinuric potential was a milestone in the therapy of CKD. For decades, this treatment remained the only proven strategy to slow down CKD progression. This situation changed some years ago primarily due to the introduction of drugs designed to treat diabetes that turned into nephroprotective strategies not only in diabetic kidney disease, but also in CKD unrelated to diabetes. In addition, several drugs emerged that precisely target the pathogenetic mechanisms of particular kidney diseases. Finally, the role of metabolic acidosis in CKD progression (and not only the sequelae of CKD) came to light. In this review, we aim to comprehensively discuss all relevant therapies that slow down the progression of non-diabetic kidney disease, including the lowering of blood pressure, through the nephroprotective effects of ACEi/ARB and spironolactone independent from BP lowering, as well as the role of sodium-glucose co-transporter type 2 inhibitors, acidosis correction and disease-specific treatment strategies. We also briefly address the therapies that attempt to slow down the progression of CKD, which did not confirm this effect. We are convinced that our in-depth review with practical statements on multiple aspects of treatment offered to non-diabetic CKD fills the existing gap in the available literature. We believe that it may help clinicians who take care of CKD patients in their practice. Finally, we propose the strategy that should be implemented in most non-diabetic CKD patients to prevent disease progression.

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.

Renin-independent aldosteronism and chronic kidney disease in diabetes: Observational and Mendelian randomization analyses

BACKGROUND

Renin-independent aldosteronism (RIA) describes the spectrum of autonomous aldosterone secretion from mild to overt. We aimed to explore whether RIA is causally associated with chronic kidney disease (CKD) in patients with diabetes.

METHODS

We cross-sectionally included 1027, 402 and 39,709 patients with any type of diabetes from cohorts of EIMDS, CONPASS and UK Biobank, respectively. In EIMDS, we defined RIA and renin-dependent aldosteronism based on plasma aldosterone and renin concentrations. We performed captopril challenge test to confirm renin-dependent or independent aldosteronism in CONPASS. In UK Biobank, we generated genetic instruments for RIA based on the genome-wide association studies (GWAS). We extracted the corresponding single nucleotide polymorphisms (SNPs) information from the GWAS data of CKD in diabetes. We harmonized the SNP-RIA and SNP-CKD data to conduct the two-sample Mendelian randomization analyses.

FINDINGS

In EIMDS and CONPASS, when compared to subjects with normal aldosterone concentration or renin-dependent aldosteronism, participants with RIA had a lower estimated glomerular filtration rate, a higher prevalence of CKD, and a higher multivariate-adjusted odds ratio (OR) of CKD (OR 2.62 [95%CI 1.09-6.32] in EIMDS, and 4.31 [1.39-13.35] in CONPASS). The two-sample Mendelian randomization analysis indicated that RIA was significantly associated with a higher risk of CKD (inverse variance weighted OR 1.10 [95 % CI 1.05-1.14]), with no evidence of significant heterogeneity or substantial directional pleiotropy.

INTERPRETATION

Among patients with diabetes, renin-independent aldosteronism is causally associated with a higher risk of CKD. Targeted treatment of autonomous aldosterone secretion may benefit renal function in diabetes.

Impact of Baseline Clinical Variables on SGLT2i's Antiproteinuric Effect in Diabetic Kidney Disease

INTRODUCTION

Proteinuria is a major risk factor for the progression of chronic kidney disease (CKD). Sodium-glucose cotransporter 2 inhibitors (SGLT2i) demonstrated a nephroprotective and antiproteinuric effect in people with type 2 diabetes (T2DM) and proteinuric CKD. We conducted a retrospective study to evaluate clinical and laboratory variables that can help predict proteinuria reduction with SGLT2i therapy.

MATERIALS AND METHODS

Patients affected by T2DM and CKD who started any SGLT2i were included in the study. Patients were stratified into two subgroups, Responder (R) and non-Responder (nR), based upon the response to the therapy with SGLT2i, namely the reduction in a 24 h urine proteins test (uProt) of ≥30% from baseline levels. The aim of the study is to analyse differences in baseline characteristics between the two groups and to investigate the relationship between them and the proteinuria reduction. A Kruskal-Wallis test, unpaired t-test and Chi² test were used to test the difference in means and the percentage (%) between the two groups. Linear and logistic regressions were utilized to analyse the relationship between proteinuria reduction and basal characteristics.

RESULTS

A total of 58 patients were enrolled in the study: 32 patients (55.1%) were in the R group and 26 patients (44.9%) in the nR group. R's patients had a significant higher uProt at baseline (1393 vs. 449 mg/24 h, p = 0.010). There was a significant correlation between baseline uProt and proteinuria reduction with SGLT2i in both univariate (β = -0.43, CI -0.55 to -031; p < 0.001) and multivariate analyses (β = -0.46, CI -0.57 to -0.35, p < 0.001). In the multivariate analysis, there was a significant positive correlation between the estimated glomerular filtration rate (eGFR) and proteinuria reduction (β = -17, CI -31 to -3.3, p = 0.016) and a significant negative correlation with body mass index (BMI) (β = 81, CI 13 to 50, p = 0.021). The multivariate logistic regressions show a positive correlation of being in the R group with diabetic retinopathy at baseline (Odds Ratio (OR) 3.65, CI 0.97 to 13.58, p = 0.054), while the presence of cardiovascular disease (CVD) at baseline is associated with being in the nR group (OR 0.34, CI 0.09 to 1.22, p = 0.1), even if these statements did not reach statistical significance.

CONCLUSIONS

In this real-life experience, following the administration of SGLT2i, a reduction of more than 30% in proteinuria was observed in more than half of the patients, and these patients had a significantly higher baseline proteinuria value. Variables such as eGFR and BMI are variables that, considered in conjunction with proteinuria, can help predict treatment response before therapy initiation. Different phenotypes of diabetic kidney disease may have an impact on the antiproteinuric response.

Integrative single-cell characterization of frugivory adaptations in the bat kidney and pancreas

Frugivory evolved multiple times in mammals, including bats. However, the cellular and molecular components driving it remain largely unknown. Here, we used integrative single-cell sequencing on insectivorous and frugivorous bat kidneys and pancreases and identified key cell population, gene expression and regulatory element differences associated with frugivorous adaptation that also relate to human disease, particularly diabetes. We found an increase in collecting duct cells and differentially active genes and regulatory elements involved in fluid and electrolyte balance in the frugivore kidney. In the frugivorous pancreas, we observed an increase in endocrine and a decrease in exocrine cells and differences in genes and regulatory elements involved in insulin regulation. Combined, our work provides novel insights into frugivorous adaptation that also could be leveraged for therapeutic purposes.