Reduced Expression of Extracellular Matrix Proteins in the Heart and Kidneys of Rats with Endotoxemia under the Effect of Actinonin

Meprin A in Patients with Acute Decompensation of Heart Failure

Plasma levels of meprin A, IL-6, and IL-18 were measured in 68 patients with acute decompensated heart failure at the time of admission to the hospital and after 1 year. The patients were assigned to groups depending on renal function disorder which was assessed by glomerular filtration rate (GFR). During hospital stay, the plasma levels of meprin A in patients with normal GFR (≥90 ml/min/1.73 m²) were considerably higher than in patients with reduced GFR (<90 ml/min/1.73 m²): 1.80 (0.86; 2.65) and 1.04 (0.56; 1.60) ng/ml, respectively. The levels of IL-6 and IL-18 did not differ significantly. After 1 year, plasma levels of meprin A and interleukins markedly decreased in patients with normal GFR (0.33 (0.20; 0.86) ng/ml) and remained high in patients with reduced GFR (0.92 (0.39; 1.33) ng/ml). Thus, the dynamics of meprin A levels in patients with acute decompensated heart failure depends on functional state of the kidneys, which may affect the course of heart failure.

Meprin and ADAM proteases as triggers of systemic inflammation in sepsis

Systemic inflammatory disorders (SIDs) comprise a broad range of diseases characterized by dysregulated excessive innate immune responses. Severe forms of SIDs can lead to organ failure and death, and their increasing incidence represents a major issue for the healthcare system. Protease-mediated ectodomain shedding of cytokines and their receptors represents a central mechanism in the regulation of inflammatory responses. The metalloprotease A disintegrin and metalloproteinase (ADAM) 17 is the best-characterized ectodomain sheddase capable of releasing TNF-α and soluble IL-6 receptor, which are decisive factors of systemic inflammation. Recently, meprin metalloproteases were also identified as IL-6 receptor sheddases and activators of the pro-inflammatory cytokines IL-1β and IL-18. In different mouse models of SID, particularly those mimicking a sepsis-like phenotype, ADAM17 and meprins have been found to promote disease progression. In this review, we summarize the role of ADAM10, ADAM17, and meprins in the onset and progression of sepsis and discuss their potential as therapeutic targets.

Extracellular Matrix Components of Rat Lungs after Direct and Indirect Lung Injury

We studied the effects of direct intratracheal and indirect intravenous administration of pathogen on the concentrations of types I, III, and IV collagens and fibronectin and expression of the corresponding genes at the early stages of LPS-induced lung injury. Direct and indirect administration of LPS increased the level of type III collagen and decreased the expression of genes encoding types I and III collagens. Expression of type IV collagen remained unchanged. Considerable decrease in fibronectin gene expression was observed after direct LPS administration. Thus, changes in the extracellular matrix of the lungs at the early stages of acute lung injury differ depending on the way of pathogen administration.