Mesenchymal stem/stromal cells alleviate early-stage pulmonary fibrosis in a uPAR-dependent manner.

Pulmonary fibrosis, a debilitating lung disorder characterised by excessive fibrous tissue accumulation in lung parenchyma, compromises respiratory function leading to a life-threatening respiratory failure. While its origins are multifaceted and poorly understood, the urokinase system, including urokinase-type plasminogen activator (uPA) and its receptor (uPAR), plays a significant role in regulating fibrotic response, extracellular matrix remodelling, and tissue repair. Mesenchymal stem/stromal cells (MSCs) hold promise in regenerative medicine for treating pulmonary fibrosis. Our study aimed to investigate the potential of MSCs to inhibit pulmonary fibrosis as well as the contribution of uPAR expression to this effect. We found that intravenous MSC administration significantly reduced lung fibrosis in the bleomycin-induced pulmonary fibrosis model in mice as revealed by MRI and histological evaluations. Notably, administering the MSCs isolated from adipose tissue of uPAR knockout mice (Plaur-/- MSCs) attenuated lung fibrosis to a lesser extent as compared to WT MSCs. Collagen deposition, a hallmark of fibrosis, was markedly reduced in lungs treated with WT MSCs versus Plaur-/- MSCs. Along with that, endogenous uPA levels were affected differently; after Plaur-/- MSCs were administered, the uPA content was specifically decreased within the blood vessels. Our findings support the potential of MSC treatment in attenuating pulmonary fibrosis. We provide evidence that the observed anti-fibrotic effect depends on uPAR expression in MSCs, suggesting that uPAR might counteract the uPA accumulation in lungs.

T-Cadherin Deficiency Is Associated with Increased Blood Pressure after Physical Activity.

T-cadherin is a regulator of blood vessel remodeling and angiogenesis, involved in adiponectin-mediated protective effects in the cardiovascular system and in skeletal muscles. GWAS study has previously demonstrated a SNP in the Cdh13 gene to be associated with hypertension. However, the role of T-cadherin in regulating blood pressure has not been experimentally elucidated. Herein, we generated Cdh13∆Exon3 mice lacking exon 3 in the Cdh13 gene and described their phenotype. Cdh13∆Exon3 mice exhibited normal gross morphology, life expectancy, and breeding capacity. Meanwhile, their body weight was considerably lower than of WT mice. When running on a treadmill, the time spent running and the distance covered by Cdh13∆Exon3 mice was similar to that of WT. The resting blood pressure in Cdh13∆Exon3 mice was slightly higher than in WT, however, upon intensive physical training their systolic blood pressure was significantly elevated. While adiponectin content in the myocardium of Cdh13∆Exon3 and WT mice was within the same range, adiponectin plasma level was 4.37-fold higher in Cdh13∆Exon3 mice. Moreover, intensive physical training augmented the AMPK phosphorylation in the skeletal muscles and myocardium of Cdh13∆Exon3 mice as compared to WT. Our data highlight a critically important role of T-cadherin in regulation of blood pressure and stamina in mice, and may shed light on the pathogenesis of hypertension.

Urokinase System in Pathogenesis of Pulmonary Fibrosis: A Hidden Threat of COVID-19.

Pulmonary fibrosis is a common and threatening post-COVID-19 complication with poorly resolved molecular mechanisms and no established treatment. The plasminogen activator system, including urokinase (uPA) and urokinase receptor (uPAR), is involved in the pathogenesis of COVID-19 and contributes to the development of lung injury and post-COVID-19 pulmonary fibrosis, although their cellular and molecular underpinnings still remain obscure. The aim of the current study was to assess the role of uPA and uPAR in the pathogenesis of pulmonary fibrosis. We analyzed uPA and uPAR expression in human lung tissues from COVID-19 patients with pulmonary fibrosis using single-cell RNA-seq and immunohistochemistry. We modeled lung fibrosis in Plau-/- and Plaur-/- mice upon bleomycin instillation and explored the effect of uPAR downregulation in A549 and BEAS-2B lung epithelial cells. We found that uPAR expression drastically decreased in the epithelial airway basal cells and monocyte/macrophage cells, whereas uPA accumulation significantly increased in tissue samples of COVID-19 patients. Lung injury and fibrosis in Plaur-/- vs. WT mice upon bleomycin instillation revealed that uPAR deficiency resulted in pro-fibrogenic uPA accumulation, IL-6 and ACE2 upregulation in lung tissues and was associated with severe fibrosis, weight loss and poor survival. uPAR downregulation in A549 and BEAS-2B was linked to an increased N-cadherin expression, indicating the onset of epithelial-mesenchymal transition and potentially contributing to pulmonary fibrosis. Here for the first time, we demonstrate that plasminogen treatment reversed lung fibrosis in Plaur-/- mice: the intravenous injection of 1 mg of plasminogen on the 21st day of bleomycin-induced fibrosis resulted in a more than a two-fold decrease in the area of lung fibrosis as compared to non-treated mice as evaluated by the 42nd day. The expression and function of the plasminogen activator system are dysregulated upon COVID-19 infection, leading to excessive pulmonary fibrosis and worsening the prognosis. The potential of plasminogen as a life-saving treatment for non-resolving post-COVID-19 pulmonary fibrosis warrants further investigation.

Mitochondrial peptide Mtln contributes to oxidative metabolism in mice.

Mitoregulin (Mtln) is a recently identified 56 amino acid long mitochondrial peptide conserved in vertebrates. Mtln is known to enhance function of respiratory complex I, which is likely mediated by modulation of lipid composition. To address an influence of Mtln gene on the metabolism we created knockout mice deficient in Mtln gene. In line with accumulation of triglycerides observed earlier on a model of Mtln knockout cell lines, we observed Mtln KO mice to develop obesity on a high fat diet. An increased weight gain could be attributed to enhanced fat accumulation according to the magnetic resonance live imaging. In addition, Mtln KO mice demonstrate elevated serum triglycerides and other oxidation substrates accompanied by an exhaustion of tricarboxylic acids cycle intermediates, suggesting suboptimal oxidation of respiration substrates by mitochondria lacking Mtln.

Seasonal peculiarities of PCDD/Fs levels in bank voles inhabiting sites in the vicinity of the landfill with municipal wastes (Moscow, Russia).

Differences in PCDD/Fs concentrations were registered among adult bank voles (Myodes glareolus) inhabiting forest in the vicinity of the Landfill Salariyevo (Moscow, Russia) and caught in early spring (over-winter survivors) and late summer. The levels of highly toxic congeners and WHO-TEQ05 in samples of wintering voles were much lower than those in samples got in summer. This difference was investigated analyzing PCDD/Fs in sexually matured animals and offspring obtained in vivarium. Practically, no significant differences of PCDD/Fs concentrations and general toxicity were revealed among sexes. The main impact to these seasonal differences in PCDD/Fs accumulation was assigned to the types of functional development and activity, diet variation as natural growth of all voles occurs on the same territory but in seasonally diverse conditions. So, the species functional ecology (lifestyle and seasonal features) should be considered in practical application of animal models from natural populations for local monitoring of PCDD/Fs body burden, and individual functional type of ontogenesis among cyclomorphic mammalian species, especially. Thus, the results obtained during monitoring should be carefully interpreted for a proper environmental management.

Urokinase Receptor uPAR Downregulation in Neuroblastoma Leads to Dormancy, Chemoresistance and Metastasis.

uPAR is a membrane receptor that binds extracellular protease urokinase, contributes to matrix remodeling and plays a crucial role in cellular adhesion, proliferation, survival, and migration. uPAR overexpression in tumor cells promotes mitogenesis, opening a prospective avenue for targeted therapy. However, uPAR targeting in cancer has potential risks. We have recently shown that uPAR downregulation in neuroblastoma promotes epithelial-mesenchymal transition (EMT), potentially associated with metastasis and chemoresistance. We used data mining to evaluate the role of uPAR expression in primary and relapsed human neuroblastomas. To model the decreased uPAR expression, we targeted uPAR using CRISPR/Cas9 and shRNA in neuroblastoma Neuro2a cells and evaluated their chemosensitivity in vitro as well as tumor growth and metastasis in vivo. We demonstrate that the initially high PLAUR expression predicts poor survival in human neuroblastoma. However, relapsed neuroblastomas have a significantly decreased PLAUR expression. uPAR targeting in neuroblastoma Neuro2a cells leads to p38 activation and an increased p21 expression (suggesting a dormant phenotype). The dormancy in neuroblastoma cells can be triggered by the disruption of uPAR-integrin interaction. uPAR-deficient cells are less sensitive to cisplatin and doxorubicin treatment and exhibit lower p53 activation. Finally, low uPAR-expressing Neuro2a cells formed smaller primary tumors, but more frequent metastasis in mice. To the best of our knowledge, this is the first study revealing the pathological role of dormant uPAR-deficient cancer cells having a chemoresistant and motile phenotype.

Early Induction of Neurotrophin Receptor and miRNA Genes in Mouse Brain after Pentilenetetrazole-Induced Neuronal Activity.

Neurotrophin receptors regulate neuronal survival and network formation, as well as synaptic plasticity in the brain via interaction with their ligands. Here, we examined early changes in the expression of neurotrophin receptor genes Ntk1 (TrkA), Ntrk2 (TrkB), Ntrk3 (TrkC), Ngfr (p75NTR) and miRNAs that target theses gens in the mouse brain after induction of seizure activity by pentylenetetrazol. We found that expression of Ntrk3 and Ngfr was upregulated in the cortex and the hippocampus 1-3 hours after the seizures, while Ntrk2 expression increased after 3-6 hours in the anterior cortex and after 1 and 6 hours in the hippocampus. At the same time, the ratio of Bcl-2/Bax signaling proteins increased in the anterior and posterior cortex, but not in the hippocampus, suggesting the activation of anti-apoptotic signaling. Expression of miRNA-9 and miRNA-29a, which were predicted to target Ntrk3, was upregulated in the hippocampus 3 hours after pentylenetetrazol injection. Therefore, early cellular response to seizures in the brain includes induction of the Ntrk2, Ntrk3, Ngfr, miRNA-9, and miRNA-29a expression, as well as activation of Bcl-2 and Bax signaling pathways, which may characterize them as important mediators of neuronal adaptation and survival upon induction of the generalized brain activity.

The content of dioxins and furans in soils, bottom sediments of water bodies, and tissues of small mammals near the landfill site with municipal solid wastes (Moscow, Russia).

For the first time, the levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were characterized in the tissues of wild small mammals living in contaminated sites near a municipal solid waste landfill (Moscow, Russia). The Ural field mice Sylvaemus uralensis, the bank voles Clethrionomys glareolus, and the common shrews Sorex araneus were trapped at 1- and 5-km distances from the landfield "Salariyevo." High-resolution chromatography-mass spectrometry was used to measure the levels of 17 PCDD/Fs congeners in the animal organisms and natural objects (soils, bottom sediments). The values of the total toxic equivalencies (WHO-TEQ05) for animals were many times higher than those for soils and bottom sediments. The octo-substituted congeners dominated in the samples from the habitat, whereas the highly toxic 2,3,7,8-substituted ones - in the mammalian tissues. The levels of WHO-TEQ05 were comparable in the soil samples collected at 1- and 5-km distances from the dump body. The levels of WHO-TEQ05 in tissues of mammals caught 1 km from the dump were much higher than those of the distant territory inhabitants. The maximum WHO-TEQ05 levels were found in the shrews, and this has been considered in terms of nutrition characteristics. The data obtained will be used to assess the risks of chronic exposure to low doses of PCDD/Fs contaminating the environment near landfills.

Sensory evaluation of pralines containing different honey products.

In this study, pralines manufactured by hand were evaluated sensorially. These pralines were obtained from dark chocolate containing 60% cocoa components, filled with Apis mellifera carnica Poll drone larvae, blossom honey and a blossom honey/pollen mixture from the protected region of Stara Planina-Eastern Serbia (a specific botanical region). The objectives of this study were investigations related to the use of sensory analysis for quality assessment of new functional products with potential benefits for human health, in particular of desserts based on dark chocolate pralines filled with different bee products characterized by a specific botanical and geographic origin, as well as of their storage properties and expected shelf life. Sensory quality (appearance, texture, odor and taste were evaluated by a group of experienced panelists immediately after the production (day 0), and then after 30, 90 and 180 days of storage under ambient conditions (temperature 18-20 °C). The results were statistically analyzed by the two-factorial analysis of variance (MANOVA) and with the LSD-test. It is possible to conclude that the storage time and composition of dark chocolate pralines containing different honey-bee products have statistically highly significant (p < 0.01) influence on the sensorially evaluated properties of pralines.

Investigations of bread production with postponed staling applying instrumental measurements of bread crumb color.

Crumb color quality characteristics of bread of different compositions (whole grain, rye, barley and diet bread) at 24 hours intervals during three days after bread preparation were investigated by means of a MOM-color 100 tristimulus photo colorimeter, in CIE, CIELab, ANLAB and Hunter systems. The highest value of average reflectance y (%) was found for barley bread (immediately after preparation), so that can be said that this sample was "conditionally" the lightest. The lowest values of y (%) were found for diet bread, so that it can be considered as the "conditionally" the darkest product. Colors of all investigated bread samples were lighter after three days of keeping compared to day 0. Changes of average reflectance of bread samples packed in polyethylene packaging with keeping time can be described by linear equation (correlation coefficient 0.99). The dominant wavelength of barley and diet bread confirm the presence of yellow pigment. Color qualities of the mentioned kinds of bread depend on processes during bread staling and raw material composition of bread (flour). Color quality measurements can be used as easy auxiliary method for screening in the development of slower staling bread.