Finerenone Reduces Renal RORγt γδ T Cells and Protects against Cardiorenal Damage

INTRODUCTION

Chronic activation of the mineralocorticoid receptor (MR) leads to pathological processes like inflammation and fibrosis during cardiorenal disease. Modulation of immunological processes in the heart or kidney may serve as a mechanistic and therapeutic interface in cardiorenal pathologies. In this study, we investigated anti-inflammatory/-fibrotic and immunological effects of the selective nonsteroidal MR antagonists finerenone (FIN) in the deoxycorticosterone acetate (DOCA)-salt model.

METHODS

Male C57BL6/J mice were uninephrectomized and received a DOCA pellet implantation (2.4 mg/day) plus 0.9% NaCl in drinking water (DOCA-salt) or received a sham operation and were orally treated with FIN (10 mg/kg/day) or vehicle in a preventive study design. Five weeks after the procedure, blood pressure (BP), urinary albumin/creatinine ratio (UACR), glomerular and tubulointerstitial damage, echocardiographic cardiac function, as well as cardiac/renal inflammatory cell content by FACS analysis were assessed.

RESULTS

BP was significantly reduced by FIN. FACS analysis revealed a notable immune response due to DOCA-salt exposure. Especially, infiltrating renal RORγt γδ-positive T cells were upregulated, which was significantly ameliorated by FIN treatment. This was accompanied by a significant reduction of UACR in FIN-treated mice. In the heart, FIN reduced DOCA-salt-induced cardiac hypertrophy, cardiac fibrosis and led to an improvement of the global longitudinal strain. Cardiac actions of FIN were not associated with a regulation of cardiac RORγt γδ-positive T cells.

DISCUSSION/CONCLUSION

The present study shows cardiac and renal protective effects of FIN in a DOCA-salt model. The cardiorenal protection was accompanied by a reduction of renal RORγt γδ T cells. The observed actions of FIN may provide a potential mechanism of its efficacy recently observed in clinical trials.

Finerenone reduces renal RORgt gd T-Cells and protects against cardiorenal damage

 

Chronic activation of the mineralocorticoid receptor (MR) through the agonist aldosterone leads to pathological processes like inflammation, fibrosis, and increased blood pressure. Therefore, MR antagonists (MRA) belong to guideline-based therapy for hypertension and heart failure with reduced ejection fraction. The nonsteroidal, selective MRA finerenone (FIN) induces distinct pharmacological actions when compared to steroidal MRAs including less adverse effects and improved efficacy (e.g. anti-fibrosis). In this study, we investigated the effects of FIN in a deoxycorticosterone acetate (DOCA)-salt model which induces an increase of blood pressure and end organ damage including hypertrophy, fibrosis, and inflammatory cell infiltration in heart and kidney.

Male C57BL6/J mice were either uni-nephrectomized in addition to DOCA-pellet application (2.4mg/d) and 0.9% NaCl in the drinking water (DOCA/UNX) or received a sham operation. One week prior to the surgery, oral treatment with FIN (10mg/kg/d) or vehicle (VEH) started and lasted throughout the experiment. Five weeks after the procedure, final examinations including blood pressure (BP) measurement, urine analysis, speckle-tracking echocardiography (STE), and FACS analysis of the heart and kidney were performed.

BP was significantly reduced by FIN treatment. FACS analysis revealed a notable immune response due to DOCA/ UNX exposure. Especially infiltrating renal RORγt γδ T-Cells were upregulated, which was significantly ameliorated by the FIN-treatment. This was accompanied by an improvement of kidney function shown by a reduction of the urinary albumin/creatinine ratio in FIN-treated mice. In the heart, FIN reduced DOCA/ UNX-induced cardiac hypertrophy, cardiac fibrosis and led to an improvement of the global longitudinal strain (GLS) in the STE-analysis. Cardiac actions of FIN were not associated with a regulation of cardiac RORγt γδ T-Cells.

The present study shows cardiac and renal protective effects of FIN in a DOCA/UNX model. The cardiorenal protection was accompanied by a reduction of renal RORγt γδ T-Cells. Anti-inflammatory actions of FIN may provide a potential mechanism of its clinical efficacy recently observed in clinical trials.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Bayer AG

Liver X Receptor Agonist AZ876 Induces Beneficial Endogenous Cardiac Lipid Reprogramming and Protects Against Isoproterenol-Induced Cardiac Damage

Background

It is known that dietary intake of polyunsaturated fatty acids may improve cardiac function. However, relatively high daily doses are required to achieve sufficient cardiac concentrations of beneficial omega‐3 fatty acids. The liver X receptor (LXR) is a nuclear hormone receptor and a crucial regulator of lipid homeostasis in mammals. LXR activation has been shown to endogenously reprogram cellular lipid profiles toward increased polyunsaturated fatty acids levels. Here we studied whether LXR lipid reprogramming occurs in cardiac tissue and exerts cardioprotective actions.

Methods and Results

Male 129SV mice were treated with the LXR agonist AZ876 (20 µmol/kg per day) for 11 days. From day 6, the mice were injected with the nonselective β‐agonist isoproterenol for 4 consecutive days to induce diastolic dysfunction and subendocardial fibrosis while maintaining systolic function. Treatment with isoproterenol led to a marked impairment of global longitudinal strain and the E/e' ratio of transmitral flow to mitral annular velocity, which were both significantly improved by the LXR agonist. Histological examination showed a significant reduction in isoproterenol‐induced subendocardial fibrosis by AZ876. Analysis of the cardiac lipid composition by liquid chromatography‐high resolution mass spectrometry revealed a significant increase in cardiac polyunsaturated fatty acids levels and a significant reduction in saturated fatty acids by AZ876.

Conclusions

The present study provides evidence that the LXR agonist AZ876 prevents subendocardial damage, improves global longitudinal strain and E/e' in a mouse model of isoproterenol‐induced cardiac damage, accompanied by an upregulation of cardiac polyunsaturated fatty acids levels. Cardiac LXR activation and beneficial endogenous cardiac lipid reprogramming may provide a new therapeutic strategy in cardiac disease with diastolic dysfunction.

Pharmacological inhibition of adipose tissue adipose triglyceride lipase by Atglistatin prevents catecholamine-induced myocardial damage

AIMS

Heart failure (HF) is characterized by an overactivation of β-adrenergic signalling that directly contributes to impairment of myocardial function. Moreover, β-adrenergic overactivation induces adipose tissue lipolysis, which may further worsen the development of HF. Recently, we demonstrated that adipose tissue-specific deletion of adipose triglyceride lipase (ATGL) prevents pressure-mediated HF in mice. In this study, we investigated the cardioprotective effects of a new pharmacological inhibitor of ATGL, Atglistatin, predominantly targeting ATGL in adipose tissue, on catecholamine-induced cardiac damage.

METHODS AND RESULTS

Male 129/Sv mice received repeated injections of isoproterenol (ISO, 25 mg/kg BW) to induce cardiac damage. Five days prior to ISO application, oral Atglistatin (2 mmol/kg diet) or control treatment was started. Two and twelve days after the last ISO injection cardiac function was analysed by echocardiography. The myocardial deformation was evaluated using speckle-tracking-technique. Twelve days after the last ISO injection, echocardiographic analysis revealed a markedly impaired global longitudinal strain, which was significantly improved by the application of Atglistatin. No changes in ejection fraction were observed. Further studies included histological-, WB-, and RT-qPCR-based analysis of cardiac tissue, followed by cell culture experiments and mass spectrometry-based lipidome analysis. ISO application induced subendocardial fibrosis and a profound pro-apoptotic cardiac response, as demonstrated using an apoptosis-specific gene expression-array. Atglistatin treatment led to a dramatic reduction of these pro-fibrotic and pro-apoptotic processes. We then identified a specific set of fatty acids (FAs) liberated from adipocytes under ISO stimulation (palmitic acid, palmitoleic acid, and oleic acid), which induced pro-apoptotic effects in cardiomyocytes. Atglistatin significantly blocked this adipocytic FA secretion.

CONCLUSION

This study demonstrates cardioprotective effects of Atglistatin in a mouse model of catecholamine-induced cardiac damage/dysfunction, involving anti-apoptotic and anti-fibrotic actions. Notably, beneficial cardioprotective effects of Atglistatin are likely mediated by non-cardiac actions, supporting the concept that pharmacological targeting of adipose tissue may provide an effective way to treat cardiac dysfunction.