Aldosterone and mineralocorticoid receptor signaling as determinants of cardiovascular and renal injury: an extraordinary paradigm shift

Alport Syndrome

Alport syndrome (AS) is characterized by progressive kidney failure, hematuria, sensorineural hearing loss, and ocular abnormalities. Pathogenic variants in the COL4A3-5 genes result in a defective deposition of the collagen IV α3α4α5 protomers in the basement membranes of the glomerulus in the kidney, the cochlea in the ear and the cornea, lens capsule and retina in the eye. The presence of a large variety of COL4A3-5 gene(s) pathogenetic variants irrespective of the mode of inheritance (X-linked, autosomal recessive, autosomal dominant, or digenic) with and without syndromic features is better defined as the "Alport spectrum disorder", and represents the most common cause of genetic kidney disease and the second most common cause of genetic kidney failure. The clinical course and prognosis of individuals with AS is highly variable. It is influenced by gender, mode of inheritance, affected gene(s), type of genetic mutation, and genetic modifiers. This review article will discuss the epidemiology, classification, pathogenesis, diagnosis, clinical course with genotype-phenotype correlations, and current and upcoming treatment of patients with AS. It will also review current recommendations with respect to when to evaluate for hearing loss or ophthalmologic abnormalities.

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

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

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

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

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

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