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Chitosan (partially deacetylated chitin), a component of fungal cell walls, caused epidermal cell (EC) death in the leaves of pea ( Pisum sativum L.) and tobacco Nicotiana tabacum or Nicotiana benthamiana detected by destruction of cell nuclei. The mitochondria-targeted quinone SkQ1 prevented the destruction of EC nuclei induced by chitosan. Chitosan increased and SkQ1 suppressed the activity of protein kinases in N. benthamiana and P. sativum and eliminated the effect of chitosan. Chitosan induced the generation of reactive oxygen species (ROS) in the guard cells (GC) of pea plants. Treatment with chitosan or H 2 O 2 did not cause destruction of GC nuclei; however, it resulted in disruption of the permeability barrier of the plasma membrane detected by propidium iodide fluorescence. Treatment with bacterial lipopolysaccharide but not peptidoglycan caused destruction of pea EC nuclei, which was prevented by SkQ1. Leaves of tobacco plants containing the N gene responsible for resistance to tobacco mosaic virus (TMV) were infiltrated with Agrobacterium tumefaciens cells. These cells contained a genetic construct with the gene of the helicase domain of TMV replicase ( p50 ); its protein product p50 is a target for the N -gene product. As a result, the hypersensitive response (HR) was initiated. The HR manifested itself in the death of leaves and was suppressed by SkQ3. Treatment of tobacco epidermal peels with the A. tumefaciens cells for the p50 gene expression stimulated the destruction of EC nuclei, which was inhibited by SkQ1 or SkQ3. The p50 -lacking A. tumefaciens cells did not induce the destruction of EC nuclei. The protective effect of mitochondria-targeted antioxidants SkQ1 and SkQ3 demonstrates the involvement of mitochondria and their ROS in programmed cell death caused by pathogen elicitors.

Programmed cell death (PCD) is the main defense mechanism in plants to fight various pathogens including viruses. The best-studied example of virus-induced PCD in plants is Tobacco mosaic virus (TMV)-elicited hypersensitive response in tobacco plants containing the N resistance gene. It was previously reported that the animal mitochondrial protein Bcl-xL, which lacks a homolog in plants, effectively suppresses plant PCD induced by TMV p50 — the elicitor of hyper-sensitive response in Nicotiana tabacum carrying the N gene. Our studies show that the mitochondria-targeted antioxidant SkQ1 effectively suppresses p50-induced PCD in tobacco plants. On the other hand, SkQ1 did not affect Poa semilatent virus TGB3-induced endoplasmic reticulum stress, which is followed by PCD, in Nicotiana benthamiana epidermal cells. These data suggest that mitochondria-targeted antioxidant SkQ1 can be used to study molecular mechanisms of PCD suppression in plants.

Pectin methylesterase (PME) is a cell-wall enzyme that acts as a growth and morphogenesis factor in higher plants and is involved in gene silencing, plant virus reproduction, and transgenesis. A study was made of the role of PME as a stress protein in host plant-virus interactions. PME enzymatic activity was induced, not only by an additional PME gene copy, but also by an empty vector. PME suppressed tobacco mosaic virus (TMV) reproduction, including short-and long-distance virus movement in plants. Surprisingly, elevated PME activity was observed in intact stably transformed transgenic plants. For example, PME activity was increased in transgenic Nicotiana tabacum and N. benthamiana plants expressing the genes for the TMV movement protein and GFP and in tomato plants with cosuppression of the polygalacturonase gene. Activation of light-inducible psb O induced transcription of the PME gene. It was suggested that PME is involved in maintaining the stability of the plant transcriptome and restores its status quo upon viral infection, transformation with a foreign gene, or excess transcription of the cell genome.

(ProQuest: Abstract omitted; see image)[PUBLICATION ABSTRACT]

The response to stress involves the activation of pathways leading either to protection from the stress origin, eventually resulting in development of stress resistance, or activation of the rapid death of the organism. Here we hypothesize that mitochondrial reactive oxygen species (mtROS) play a key role in stress-induced programmed death of the organism, which we called “phenoptosis” in 1997. We demonstrate that the synthetic mitochondria-targeted antioxidant SkQ1 (which specifically abolishes mtROS) prevents rapid death of mice caused by four mechanistically very different shocks: (a) bacterial lipopolysaccharide (LPS) shock, (b) shock in response to intravenous mitochondrial injection, (c) cold shock, and (d) toxic shock caused by the penetrating cation C 12 TPP. Importantly, under all these stresses mortality was associated with a strong elevation of the levels of pro-inflammatory cytokines and administration of SkQ1 was able to switch off the cytokine storms. Since the main effect of SkQ1 is the neutralization of mtROS, this study provides evidence for the role of mtROS in the activation of innate immune responses mediating stress-induced death of the organism. We propose that SkQ1 may be used clinically to support patients in critical conditions, such as septic shock, extensive trauma, cooling, and severe infection by bacteria or viruses.

Viruses are obligate parasites, that use the host’s internal metabolic systems for their own reproduction. This complicates the search for molecular targets to prevent the spread of viral infection without disrupting the vital functions of human cells. Defective interfering particles (DIPs) are natural competitors of viruses for important resources of viral reproduction. DIPs emerge during infection, originate from the normal viral replication process and inhibit its progression, making them an interesting candidate for antiviral therapy. Here we describe the biology of DIPs, advances in DIP-based antiviral technology, analyze their therapeutic potential and provide a systemic overview of existing preventive and therapeutic antiviral strategies.

An essential requirement for single-cell RNA sequencing in cancer is the preparation of high-quality single-cell suspensions from the tumor tissue. In this work, various methods of dissociation of tumor biopsy specimens were analyzed and developed to obtain a cell suspension with at least 80% viability. It was found that the optimal conditions for sample preparation are mechanical dissociation followed by incubation with a collagenase/hyaluronidase mixture with addition of DNAase I for 60 min. Thus, we optimize the approach for preparing single-cell suspensions from the tumor biopsy tissue for single-cell RNA sequencing.

Semen quality was assessed and lipid spectrum of seminal plasma was determined in 42 stallions of different breeds aged from 5 to 16 years (average 9.8±5.4 years). The concentration of total cholesterol, triglycerides, high density lipoproteins and low-density lipoproteins were determined in semen plasma. We found a negative correlation between the concentration of low- and high-density lipoproteins and progressive sperm motility in both fresh (p<0.05) and thawed (p<0.05) semen. We also found a negative correlation between the concentration of low-density lipoproteins in sperm plasma with total sperm motility in fresh (p<0.05) and frozen (p<0.01) semen, and the concentration of high-density lipoproteins in sperm plasma with total sperm motility in fresh and frozen semen (p<0.05). We found a significant negative correlation between ejaculate volume and concentration of triglycerides (p<0.05), cholesterol (p<0.01) and high-density lipoproteins (p<0.05). There was a positive correlation between sperm concentration and triglycerides (p<0.05), cholesterol (p<0.001) and high-density lipoprotein (p<0.01) content.

This is the first petrophysical study of extrusive rocks (dacites to andesites) discharged by Bezymianny Volcano. We provide a comparative description of properties for extrusive rocks in accordance with identified age groups. We show the dynamics in the variation of extrusive rock properties in relation to their ages, with the result that the older a rock the higher are its density, strength, and elastic parameters. Rocks petrophysical features are compared between extrusive domes and lava flows. We argue for petrophysical properties to be applicable for deriving more accurate results for the genesis of rocks having similar petrophysical properties, in particular, rocks of extrusive and effusive origin.

The boron-10 ion implantation in layers on the core components can provide lower nuclear reactivity due to an abnormally large neutron-capture cross-section during the initial stage of the reactor operation. It is shown that after the boron-10 ion implantation at 22 keV energy with 7∙10 16 ion/cm 2 fluence, the surface microhardness of E110 zirconium alloy increases from 3 to 3.7 GPa. After the boron-10 ion implantation in the indicated conditions (22 keV energy and 7∙10 16 ion/cm 2 fluence), the corrosion rate of E110 zirconium alloy in a 1% hydrofluoric acid solution is 1.2–1.4 times lower than that of the nonimplanted alloy. The boron-10 ion implantation is accompanied by such processes as the formation of a subgrain structure in the surface layer of the alloy, the grain size of which ranges within 100–200 nm; the increase in the scalar dislocation density; and the formation of 1.8–2.3 nm nanoparticles of zirconium boride.