Effect of Inducers and Inhibitors of the Keap1/Nrf2/ARE System on the Viability and Functional Activity of Model Neuronal-Like and Glial Cells

On mouse neuroblastoma (Neuro-2a) and human glioblastoma (U-87 MG) cell lines, we studied the effect of inducers and inhibitors of redox-sensitive signaling system of the antioxidant-responsive element Keap1/Nrf2/ARE on the main processes that determine nerve cell viability and vital activity (proliferative activity, apoptosis, autophagy, and activation of the Keap1/Nrf2/ARE system). Inhibitors of the Keap1/Nrf2/ARE system stimulate apoptosis more pronouncedly than inducers, have a weaker effect on autophagy, and do not change the nuclear to cytoplasmic Nrf2 ratio. In general, the revealed effects testify in favor of the potential effectiveness of stimulating the Keap1/Nrf2/ARE system for the prevention and adjuvant therapy of neurodegenerative diseases.

Protective Effect of a New Monophenolic Antioxidant TS-13 in a Mouse Model of Parkinson's Disease

The development of means of the prevention and treatment of age-related neurodegenerative diseases, as well as geroprotectors, among other things, is based on the inflammatory and free radical theories of aging. In this context, we studied the effect of sodium monophenol 3-(3'-tert-butyl-4'-hydroxyphenyl)propyl thiosulfonate (TS-13) on the behavioral and locomotor activity of C57BL/6 mice in modeling Parkinson's disease by MPTP neurotoxin injection. TS-13 administration significantly improved orientation and exploratory activity and emotional response of the animals in the open field test, but did not affect the increase in anxiety caused by MPTP injection. Long-term (6 months) TS-13 administration did not suppress spontaneous motor activity in BALB/c mice and slightly increased their exploratory activity.

Knockout of mutant TP53 in the HaCaT cells enhances their migratory activity

The HaCaT cell line represents the spontaneously immortalized non-carcinogenic human keratinocytes that are used as a model for studying the function of normal human keratinocytes. There are two TP53 alleles in the HaCaT cell genome, which comprise two gain-of-function (GOF) mutations acquired through spontaneous immortalization (mutTP53). Mutations result in the increased proliferation rate and violation of the stratification program. The study was aimed to assess the effects of the mutTP53 gene knockout on the HaCaT keratinocytes capability of proliferation and migration in the in vitro model of epidermal injury and regeneration (scratch test), and on the ability to form stratified epithelium in the organotypic epidermal model. To perform the scratch-test, cells were cultured until monolayer was formed, then the standardized injury was created. The organotypic model was obtained by growing keratinocytes in the polycarbonate membrane inserts with the pore size of 0.4 μm at the interface between the phases (air-liquid). It has been shown that the mutant TP53 gene knockout results in the increased migration capability of the HaCaT keratinocytes: in the HaCaT with the mutTP53 knockout, the defect closure occurred faster than in the appropriate group of the WT HaCaT (p < 0.05), on day three the defect size was 12% ± 3% and 66% ± 5% of the initial size. There is evidence that mutant TP53 in the HaCaT cells is a negative regulator of the laminin 5 expression (LAMC2 expression was 9.96 ± 1.92 times higher in the cells with the mutTP53 knockout, p < 0.05), however, this does not promote normalization of the program of epithelial differentiation and stratification followed by formation of the stratum corneum in the organotypic model.

Impact of p53 knockdown on protein dataset of HaCaT cells

The HaCaT line of immortalized non-tumor cells is a popular model of keratinocytes used for dermatological studies, in the practice of toxicological tests, and in the study of skin allergic reactions. These cells maintain a stable keratinocyte phenotype, do not require specific growth factors during cultivation, and respond to keratinocyte differentiation stimuli. HaCaT cells bear two mutant p53 alleles - R282Q and H179Y. At least two mechanisms of GOF (gain-of-function) of mutant p53 are known: it affects functions of p63/p73 by inhibiting their binding to DNA; or it binds to new DNA sites by interacting with other transcription factors (NF-Y, E2F1, NF-KB, VDR, p63). Proteins of the P53 family play an important role in the regulation of proliferation and differentiation processes of human keratinocytes. Proteomic study of HaCaT cells with TP53 gene knockdown provides new data for understanding the limitations of HaCaT cells when using them as an experimental model of normal human keratinocytes.

In this article we present datasets obtained through the high-throughput shotgun proteomics analysis of human immortalized HaCaT keratinocytes and p53 knockdown HaCaT keratinocytes. As a protocol for proteomic profiling of cells, we used the approach of obtaining LC-MS/MS measurements followed by their processing with MaxQuant software (version 1.6.3.4). The “RAW” files were deposited to the ProteomeXchange with identifier PXD033538.

Proteome Profiling of PMJ2-R and Primary Peritoneal Macrophages

In vitro models are often used for studying macrophage functions, including the process of phagocytosis. The application of primary macrophages has limitations associated with the individual characteristics of animals, which can lead to insufficient standardization and higher variability of the obtained results. Immortalized cell lines do not have these disadvantages, but their responses to various signals can differ from those of the living organism. In the present study, a comparative proteomic analysis of immortalized PMJ2-R cell line and primary peritoneal macrophages isolated from C57BL/6 mice was performed. A total of 4005 proteins were identified, of which 797 were quantified. Obtained results indicate significant differences in the abundances of many proteins, including essential proteins associated with the process of phagocytosis, such as Elmo1, Gsn, Hspa8, Itgb1, Ncf2, Rac2, Rack1, Sirpa, Sod1, C3, and Msr1. These findings indicate that outcomes of studies utilizing PMJ2-R cells as a model of peritoneal macrophages should be carefully validated. All MS data are deposited in ProteomeXchange with the identifier PXD022133.

Impact of p53 modulation on interactions between p53 family members during HaCaT keratinocytes differentiation

HaCaT cell line is a widely used model for studying normal human keratinocytes. However, mutations of TP53 gene are typical for this cell line, which have a substantial impact on functions of the encoded protein. The features of this regulatory circuit should be considered when using HaСaT cells for assessment of human skin physiology and pathology in vitro. The study was aimed to assess the features of differentiation realization in HaCaT cells with modulated activity of p53 protein. The expression of p53 was reduced by knockdown of TP53 gene by shRNA (by 2.2 times, p < 0.05), and the elevated concentration of the p53 active forms was achieved via exposure of cells to Nutlin-3a, the MDM2 inhibitor and the major negative regulator of p53. It has been found that regulation of at least three differentiation markers, СASP14, IVL (expression increase by 3.9 and 3.7 times respectively in the p53-knockdown cells, p < 0.05) and TGM1 (twofold expression decrease in the p53-knockdown cells, and 1.7-fold expression increase under exposure to Nutlin-3a, p < 0.05) in HaCaT cells is p53-mediated. The positive correlation has been revealed for expression of TGM1 and p53 that might be realized indirectly via ΔNp63 expression alteration. At the same time, modulation of p53 does not result in significant alterations in expression of cytokeratins.

Telomerized fibroblasts as a candidate 3d in vitro model of pathological hypertrophic scars

The search for the optimal cell model for studying the pathogenesis of pathological scars is a pressing challenge. This study aimed at evaluating the feasibility of using telomerized fibroblasts for the in vitro 3D modeling of pathological hypertrophic scars. NF and Fb-hTERT cells were cultured as monolayers and spheroids in the absence and in the presence of TGFβ1. The metabolic activity of the cultured cells was assessed using the MTT assay. Cell migration was estimated using the scratch assay. The expression of genes associated with fibrous scar tissue growth was measured by qRT-PCR. Fb-hTERT cells were more metabolically active than NF cells in the presence of TGFβ1 (for 1 ng/ml: 179 ± 12% vs. 135 ± 13% respectively; p < 0,05). Spheroids grown from Fb-hTERT cells were significantly larger than those derived from NF cells. In the presence of TGFβ1, the expression of proteins associated with extracellular matrix production (COL1A1, COL3A1, FN1) was lower in Fb-hTERT cells than in NF cells (more than 25, 20 and 2-fold, respectively; p < 0.05). Intact NF cells were more active in closing the scratch than Fb-hTERT cells: on day 2, the gap closure rate was 2.28 times higher in NF cells (p < 0.05). Exposure to TGFβ1 stimulated Fb-hTERT, unlike NF cells, to close the gap 2 times faster on day 2 (p < 0.05). Thus, telomerized fibroblasts have a few phenotypic traits observed in keloid fibroblasts; still there are some limitations that should be accounted for when using Fb-hTERT cells for the modeling of pathological hypertrophic scars.

[Oxidative stress in aging.]

The free-radical theory of aging, advanced more than 50 years ago by D.Harman, remains popular today. The review analyzes age-related changes in the main endogenous mechanisms of reactive oxygen species (ROS) production and antioxidant defense mechanisms. With age, ROS generation by mitochondria, peroxisomes, and NAD(P)H oxidases is enhanced, while the transcriptional activity of the important system Keap1/Nrf2/ARE maintaining redox balance decreases. In old animals, autophagy activity is also low, which removes damaged organelles and aggregated structures from cells. The age-related shift of the redox balance towards oxidative stress can cause the development of age-associated neurodegenerative, autoimmune and inflammatory pathologies.

Pathology of A(H5N8) (Clade 2.3.4.4) Virus in Experimentally Infected Chickens and Mice

The emergence of novel highly pathogenic avian influenza viruses (HPAIVs) in migratory birds raises serious concerns as these viruses have the potential to spread during fall migration. We report the identification of novel HPAIV A(H5N8) clade 2.3.4.4 virus that was isolated from sick domestic duck at commercial farm during the second wave of spread that began in October and affected poultry (ducks; chiсkens) in several European regions of Russia and Western Siberia in 2016. The strain was highly lethal in experimental infection of chickens and mice with IVPI = 2.34 and MLD50 = 1.3log10⁡ EID50, accordingly. Inoculation of chickens with the HPAIV A/H5N8 demonstrated neuroinvasiveness, multiorgan failure, and death of chickens on the 3rd day post inoculation. Virus replicated in all collected organ samples in high viral titers with the highest titer in the brain (6.75±0.1 log10TCID50/ml). Effective virus replication was found in the following cells: neurons and glial cells of a brain; alveolar cells and macrophages of lungs; epithelial cells of a small intestine; hepatocytes and Kupffer cells of a liver; macrophages and endothelial cells of a spleen; and the tubular epithelial cells of kidneys. These findings advance our understanding of histopathological effect of A(H5N8) HPAIV infection.

Plant Phenols and Autophagy

Many plant phenols (stilbenes, curcumins, catechins, flavonoids, etc.) are effective antioxidants and protect cells during oxidative stress. Extensive clinical studies on the potential of phenolic compounds for treatment of cardiovascular, neurodegenerative, oncological, and inflammatory diseases are now being conducted. In addition to direct antioxidant effect, plant phenols may provide a protective effect via activation of the Keap1/Nrf2/ARE redox-sensitive signaling system and regulation of autophagy. In this review, mechanisms of effects of the most common plant phenols on autophagy are presented.

[Age-related dynamics of the main extracellular matrix components in residents of the Russian Arctic]

The main extracellular matrix components in Arctic residents were studied. Northerners had increased levels of total glycosaminoglycans, hyaluronan, and collagen IV in plasma and both general and peptide-bound hydroxyproline in urine, which indicates an accelerated metabolism of the main extracellular matrix components compared with comparison group (residents of Siberia). Age-related remodeling of extracellular matrix in northerners manifested in changing ratio and quantity of its main components. Levels of total glycosaminoglycans, hyaluronan, fibronectin, hydroxyproline and its fractions increased with age while the level of collagen IV changed insignificantly. Average positive correlation between extracellular matrix components and biological aging indicators is suggestive of relationship between these two processes: aging - which is accelerated in the Arctic and pathological remodeling of extracellular matrix as it is associated with accelerated aging. Changes in local regulation system including those related to matrix metalloproteinases and their tissue inhibitors may be one of the reasons for pathological remodeling of extracellular matrix.

Oxidized Dextran Enhances Alternative Activation of Macrophages in Mice of Opposite Lines

Differences in peritoneal macrophage polarization in mice of opposite lines CBA and C57Bl/6 and the effects of 60 kDa oxidized dextran were studied. Macrophages of C57Bl/6 mice demonstrated a phenotype close to M1, with increasing expression of CD86 costimulatory molecule and unchanged CD206 expression in response to activation. Macrophages of CBA mice demonstrated higher plasticity in response to activating agents; expression of the markers increased irrespectively on stimulated receptor (TLR-4 or mannose receptor) and both CD86 (classical activation) and CD206 (alternative activation) increased. Macrophage response to addition of oxidized dextran (60 kDa) to the culture medium could be characterized as potentiation of their alternative activation: expression of CD86 in CBA mice in response to LPS and LPS+IL-4 and in C57Bl/6 mice in response to IFN-γ and LPS+IFN-γ decreased, while expression of CD206 by intact macrophages of CBA mice and by macrophages stimulated by IFN-γ and IL-4 increased under the effect of 60 kDa oxidized dextran.

[STUDYING THE ACUTE TOXICITY OF DEXTRAN POLYALDEHYDE CONJUGATE WITH ISONICOTINIC ACID HYDRAZIDE.]

The acute toxicity of a new antubercular drug, dextran polyaldehyde conjugate with isonicotinic acid hydrazide (dextrazide), has been studied on animals, HepaRG cell line, and FRSN human skin fibroblasts. Average tolerable doses (LD(10), LD(16)), half-lethal doses (LD(50)), and lethal doses (LD(84)) of dextrazide have been determined for intraperitoneal introduction in mice and rats and intravenous injection in rabbits.

[Quality of life for men of different ages in the russian European North and its relationship with self-reported health and hormonal status]

Assessment of the quality of life for male inhabitants of the Russian European North demonstrated decreased indices of physical health component (the scale of role functioning determined by physical condition) and mental health component (the scales of social functioning and role functioning determined by emotional state and mental health) compared to the inhabitants of Siberia as a comparison group. Men aged up to 29 had the highest values at all scales. The values decreased with age. The most prominent decrease was observed for the scales of general well-being and pain intensity. There was a moderate decrease for the scales of physical functioning, role functioning determined by emotional state, and role functioning determined by physical condition. Quality of life was closely related to self-reported health of northerners, pathological index, molecular marker of aging, and biological age. Negative correlation between these values implies the deterioration of physical and mental health with biological age. The quality of life for northerners also correlated with hormonal status. There was a relationship between testosterone and three scales of physical health components; between cortisol and one scale of physical component; and between both dehydroepiandrosterone sulfate and insulin and the scales of physical and mental components of health. The effect of various hormones on different age groups of northerners was demonstrated.

Expression of stress-dependent genes in hepatocytes spheroids after cisplatin treatment

Effects of cisplatin on the hepatic HepaRG cells cultured in spheroids were estimated using biochemical, cytofluorometric, and molecular methods. Hepatocyte viability and expression of mRNA of stress-dependent genes involved in the cell response to toxic agent cisplatin underwent time- and dose-dependent changes. Activation of oxidative stress was observed at the early stages of incubation (3 h) followed by induction of apoptosis after prolonging the incubation to 24 h. The prospects of using HepaRG cells cultured in spheroids for estimation of drug toxicity by variations in the expression of stress-dependent genes were demonstrated. An increase in expression of genes of GSR and HSPA1A proteins at the early stages of incubation with cisplatin can serve as a marker of the cytotoxic effects of cisplatin and other agents with similar mechanisms of action.