Kidney International Supplements最新文献

Aldosterone controls salt–water homeostasis by acting on the mineralocorticoid receptor (MR), a ligand-activated transcription factor, in kidney epithelial cells. However, it is now evident that the MR is expressed in multiple cell types and tissues, acting as a key driver of cardiovascular disease. MR antagonists have proven to be highly efficient in patients with heart failure and reduced ejection fraction, and they are a cornerstone of contemporary therapy. In the past decade, a series of experimental studies using models with cell type–specific MRs uncovered the cellular and molecular mechanisms underlying its detrimental effect on left ventricular remodeling. Based on these findings, the potential of MR antagonists has been evaluated in other cardiovascular diseases, including coronary artery disease, arterial hypertension, heart failure with preserved ejection fraction, pulmonary hypertension, atrial fibrillation, and heart valve disease. The present review summarizes the current knowledge on MR activation and antagonism in cardiovascular disease.

The recent successful demonstrations that the nonsteroidal mineralocorticoid receptor (MR) antagonist finerenone provides effective kidney and cardiovascular (CV) protection in patients with chronic kidney disease (CKD) and type 2 diabetes constitutes a platform for considering and implementing an array of future clinical trials in patients with nondiabetic CKD. Activation of the MR, with consequent inflammation and fibrosis, should be operative as a pathogenetic mediator not only in patients with diabetic CKD but also in those with nondiabetic kidney disease. Consequently, it is proposed that MR antagonism therapy will be equally efficacious in patients with nondiabetic CKD. Recently, a major new clinical trial has been initiated testing finerenone in patients with nondiabetic kidney disease (FIND-CKD; NCT05047263). A second clinical development program, FIONA, is dedicated to studies of finerenone in children with glomerular and nonglomerular CKD. Finally, the interrelationship of fibroblast growth factor 23 (FGF23), membrane αKlotho (hereafter called Klotho), and aldosterone may be a propitious subject for future investigation. The interplay and intersection of these seemingly disparate yet intricate relationships may unmask novel, and indeed compelling, opportunities for therapeutic interventions that are capable of interrupting the vicious cycle of excess aldosterone/MR activation and FGF23 secretion with concomitant Klotho insufficiency characteristically present in patients with CKD.

Chronic kidney disease is a major global health challenge, and mineralocorticoid receptor (MR) signaling is thought to play a role in disease progression. The classic role of the MR is the regulation of fluid and electrolyte homeostasis via differential gene expression, and recently its role in modulating inflammation and fibrosis has been identified. In addition to expression of the MR in renal epithelial cells, it is also found in nonepithelial cells, such as endothelial cells, vascular smooth muscle cells, podocytes, and fibroblasts. Targeting the MR in these cells may play a role in offering protection against inflammation and fibrosis in the kidneys and the cardiovascular system. Herein, data from preclinical cell-specific MR knockout mouse models and in vitro studies that help uncover the role of the MR in nonepithelial cells are presented. This review also discusses several potential targets that offer opportunities for the targeting of MR signaling in nonepithelial cells.

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

Chronic kidney disease is characterized by progressive scarring that results in loss of normal tissue in the kidney and eventually end-stage kidney disease. Interstitial fibrosis and tubular atrophy have been most closely correlated with decline in renal function. Potential mechanisms include profibrotic changes in tubules, influx of profibrotic rather than healing reparative macrophages, and an increase in activated myofibroblasts. Aldosterone activates the mineralocorticoid receptor in the collecting duct to increase sodium reabsorption, resulting in increased blood pressure. Aldosterone also promotes inflammation and fibrosis in the kidney by activating the mineralocorticoid receptor in other cellular compartments, including podocytes, mesangial cells, epithelial cells, and myeloid cells. Aldosterone also may act indirectly by stimulating factors in epithelial tissues that contribute to inflammatory macrophage polarization, myofibroblast differentiation, and progressive fibrosis. This review discusses the potential mechanisms by which aldosterone and mineralocorticoid receptor activation promotes inflammation and fibrosis via nonclassical pathways in the kidney.