Physiological Stress Conditions Research Articles

Chromogranin B Protects Human Umbilical Endothelial Cells against Oxidative Stress

Chromogranin B (CgB) is involved in the control of the cardiovascular system through the regulation of catecholamine release. Whether CgB can exert direct actions on the endothelium has not yet been clarified. Here, we aimed to investigate the effects of CgB on cell viability, mitochondrial membrane potential, reactive oxygen species (ROS), glutathione (GSH), nitric oxide (NO) release, and the cytosolic calcium concentration ([Ca2+]c) in human vascular endothelial cells (HUVECs) cultured under both physiological and peroxidative conditions. In HUVECs, experiments were conducted to establish the proper concentration and timing of CgB stimulation. Thereafter, specific assays were used to evaluate the response of HUVECs cultured in physiologic or oxidative stress conditions to CgB in the presence or absence of β-adrenergic receptor agonists and antagonists and intracellular pathways blockers. Analysis of cell viability, mitochondrial membrane potential, and NO release revealed that CgB was able to cause increased effects in HUVECs cultured in physiological conditions. Additionally, the same analyses performed in HUVECs cultured with H2O2, showed protective effects exerted by CgB, which was also able to counteract ROS release and maintain GSH levels. Furthermore, CgB played a dual role on the [Ca2+]c depending on the physiological or peroxidative cell culturing conditions. In conclusion, our data provide new information about the direct role of CgB in the physiological regulation of endothelial function and highlight its potential as a protective agent against peroxidative conditions, such as those found in cardiovascular diseases.

SIK2 Controls the Homeostatic Character of the POMC Secretome Acutely in Response to Pharmacological ER Stress Induction.

The neuronal etiology of obesity is centered around a diet-induced inflammatory state in the arcuate nucleus of the hypothalamus, which impairs the functionality of pro-opiomelanocortine neurons (POMCs) responsible for whole-body energy homeostasis and feeding behavior. Intriguingly, systemic salt inducible kinase 2 (SIK2) knockout mice demonstrated reduced food intake and energy expenditure along with modestly dysregulated metabolic parameters, suggesting a causal link between the absence of SIK2 activity in POMCs and the observed phenotype. To test this hypothesis, we conducted a comparative secretomics study from POMC neurons following pharmacologically induced endoplasmic reticulum (ER) stress induction, a hallmark of metabolic inflammation and POMC dysregulation in diet-induced obese (DIO) mice. Our data provide significant in vitro evidence for the POMC-specific SIK2 activity in controlling energy metabolism and feeding in DIO mice by regulating the nature of the related POMC secretome. Our data also suggest that under physiological stress conditions, SIK2 may act as a gatekeeper for the secreted inflammatory factors and signaling molecules critical for cellular survival and energy homeostasis. On the other hand, in the absence of SIK2, the gate opens, leading to a surge of inflammatory cytokines and apoptotic cues concomitant with the dysregulation of POMC neurons.

PHB And Its Role In Salt Acclimatization In Halotolerant Azotobacter Salinestris Species

Poly β-hydroxybutyrate (PHB) are important storage compounds of carbon and energy. Bacteria usually produce PHB apparently in response to the limitation of an essential nutrient and conditions of physiological stress. Therefore, it is assumed that the function of PHB is to serve as an available carbon repository when bacteria face carbon limitation, supporting their survival. Recent findings indicate that PHB plays a protective role against stress-like conditions such as thermal and oxidative shock. The objective of the review is to look at the role of PHB in the salt acclimation process. Salinity is considered to be the most serious abiotic stress affecting crop productivity. It is an active process, spreading globally and a reason for land degradation. Several strategies have been assumed to be used in order to deal with soil salinity. Salt tolerant plant growth promoting rhizobacteria (ST- PGPR) used as a biofertilizer has known to increase the crop yield under stressed condition. Azotobacter salinestris species is known to tolerate 8% salt concentration and can be studied as a model organism to understand the role of PHB in salt acclimatization. Thus, a sustainable approach under saline condition.

Production of nutritionally active compounds from Spirulina platensis under various stress conditions

The free-floating, filamentous cyanobacteria Spirulina platensis is highly valued and in great demand worldwide for its high-value colors and phytonutrients. These compounds find use in health foods, feed, medicines, and diagnostics. The primary objective of this work was to enhance the growth of Spirulina under both oxidative and physiological stress conditions in order to maximize the synthesis of phycocyanin and carotenoid pigments. Cultures were subjected to different concentrations of hydrogen peroxide (H2O2) and sodium chloride for varying temperatures and pH levels. Under lower concentrations of H2O2 (4mM), the maximum carotenoid content was increased, but the phycocyanin content was found to be stimulated at 10mM. Moreover, the synthesis of both pigments was shown to be highest under physiological stress circumstances (40mM and 60mM NaCl concentration) and at an optimal pH of 8-9, helped by a temperature range of 25-30℃. The experimental results demonstrate that both carotenoid and phycocyanin exhibit antioxidant properties even in the presence of oxidative stress. This suggests that the aforementioned circumstances can be applied in future investigations to extract different antioxidants from S. platensis.

Duplex Fluorinated and Atomic Layer Deposition-Derived ZrO2 Coatings Improve the Corrosion Resistance and Mechanical Properties of Mg-2Zn-0.46Y-0.5Nd (wt.%) Alloy Plates and Screws.

This study investigated the corrosion resistance and mechanical properties of Mg-2Zn-0.46Y-0.5Nd (wt.%) alloy plates and screws with fluorinated coatings and atomic layer deposition (ALD)-derived zirconia (ZrO2) coatings in vitro under physiological stress conditions. Synthetic polyurethane hemimandible replicas were split and fixed as the following three groups of magnesium alloy plates and screws: no additional surface coating treatment (Group A), with fluorinated coatings (Group B), and with duplex fluorinated and ALD-derived 100 nm ZrO2 coatings (Group C). A circulating stress of 1-10 N was applied to the distal bone segment, and a 4-week simulated body fluid immersion test was employed to study the remaining material volume and the mechanical properties of the different groups. Compared with Group A and Group B, the degradation rate of magnesium alloy plates and screws' head regions was significantly slowed down under the protection of duplex MgF2/ZrO2 coatings (p < 0.01). There was no significant difference in the degradation rate of the screw shaft region between groups (p = 0.077). In contrast to fluoride coatings, duplex MgF2/ZrO2 coatings maintained the mechanical strength of magnesium alloy plates and screws after a 14 day in vitro SBF immersion test. We conclude that duplex MgF2/ZrO2 coatings exhibited a certain protective effect on the Mg alloy plates and screws under physiological stress conditions.

Wearable Ring-Shaped Biomedical Device for Physiological Monitoring through Finger-Based Acquisition of Electrocardiographic, Photoplethysmographic, and Galvanic Skin Response Signals: Design and Preliminary Measurements.

Wearable health devices (WHDs) are rapidly gaining ground in the biomedical field due to their ability to monitor the individual physiological state in everyday life scenarios, while providing a comfortable wear experience. This study introduces a novel wearable biomedical device capable of synchronously acquiring electrocardiographic (ECG), photoplethysmographic (PPG), galvanic skin response (GSR) and motion signals. The device has been specifically designed to be worn on a finger, enabling the acquisition of all biosignals directly on the fingertips, offering the significant advantage of being very comfortable and easy to be employed by the users. The simultaneous acquisition of different biosignals allows the extraction of important physiological indices, such as heart rate (HR) and its variability (HRV), pulse arrival time (PAT), GSR level, blood oxygenation level (SpO2), and respiratory rate, as well as motion detection, enabling the assessment of physiological states, together with the detection of potential physical and mental stress conditions. Preliminary measurements have been conducted on healthy subjects using a measurement protocol consisting of resting states (i.e., SUPINE and SIT) alternated with physiological stress conditions (i.e., STAND and WALK). Statistical analyses have been carried out among the distributions of the physiological indices extracted in time, frequency, and information domains, evaluated under different physiological conditions. The results of our analyses demonstrate the capability of the device to detect changes between rest and stress conditions, thereby encouraging its use for assessing individuals' physiological state. Furthermore, the possibility of performing synchronous acquisitions of PPG and ECG signals has allowed us to compare HRV and pulse rate variability (PRV) indices, so as to corroborate the reliability of PRV analysis under stationary physical conditions. Finally, the study confirms the already known limitations of wearable devices during physical activities, suggesting the use of algorithms for motion artifact correction.

Non-canonical mRNA translation initiation in cell stress and cancer.

The now well described canonical mRNA translation initiation mechanism of m7G 'cap' recognition by cap-binding protein eIF4E and assembly of the canonical pre-initiation complex consisting of scaffolding protein eIF4G and RNA helicase eIF4A has historically been thought to describe all cellular mRNA translation. However, the past decade has seen the discovery of alternative mechanisms to canonical eIF4E mediated mRNA translation initiation. Studies have shown that non-canonical alternate mechanisms of cellular mRNA translation initiation, whether cap-dependent or independent, serve to provide selective translation of mRNAs under cell physiological and pathological stress conditions. These conditions typically involve the global downregulation of canonical eIF4E1/cap-mediated mRNA translation, and selective translational reprogramming of the cell proteome, as occurs in tumor development and malignant progression. Cancer cells must be able to maintain physiological plasticity to acquire a migratory phenotype, invade tissues, metastasize, survive and adapt to severe microenvironmental stress conditions that involve inhibition of canonical mRNA translation initiation. In this review we describe the emerging, important role of non-canonical, alternate mechanisms of mRNA translation initiation in cancer, particularly in adaptation to stresses and the phenotypic cell fate changes involved in malignant progression and metastasis. These alternate translation initiation mechanisms provide new targets for oncology therapeutics development.

Comprehensive Transcriptome Profiling of Antioxidant Activities by Glutathione in Human HepG2 Cells.

Glutathione (GSH) has long been recognised for its antioxidant and detoxifying effects on the liver. The hepatoprotective effect of GSH involves the activation of antioxidative systems such as NRF2; however, details of the mechanisms remain limited. A comparative analysis of the biological events regulated by GSH under physiological and oxidative stress conditions has also not been reported. In this study, DNA microarray analysis was performed with four experiment arms including Control, GSH, hydrogen peroxide (HP), and GSH + HP treatment groups. The GSH-treated group exhibited a significant upregulation of genes clustered in cell proliferation, growth, and differentiation, particularly those related to MAPK, when compared with the Control group. Additionally, liver functions such as alcohol and cholesterol metabolic processes were significantly upregulated. On the other hand, in the HP-induced oxidative stress condition, GSH (GSH + HP group) demonstrated a significant activation of cell proliferation, cell cycle, and various signalling pathways (including TGFβ, MAPK, PI3K/AKT, and HIF-1) in comparison to the HP group. Furthermore, several disease-related pathways, such as chemical carcinogenesis-reactive oxygen species and fibrosis, were significantly downregulated in the GSH + HP group compared to the HP group. Collectively, our study provides a comprehensive analysis of the effects of GSH under both physiological and oxidative stress conditions. Our study provides essential insights to direct the utilisation of GSH as a supplement in the management of conditions associated with oxidative stress.

Effect of Native Trichoderma as Seed Treatment on Germination and Seedling Performance of Lentil Under Biotic and Abiotic Stress Conditions

Physiological and water stress conditions substantially impede seed germination and the establishment of plant population. In 2020, a study was conducted in a completely randomized design (CRD) to identify potential Trichoderma strains that could alleviate physiological and water stress in germinating seeds. To create physiological stress, seeds were kept in an incubator at high relative humidity (90%) and temperature (40ºC) for 20 days. Similarly, to induce water stress on germinating seeds, Polyethylene glycol (PEG) was applied in four concentrations (0, 5, 10, and 15%). Nine different isolates of Trichoderma were isolated from forest and agricultural soil and conidial suspension was applied to lentil seeds to deposit 107cfu per gram of seeds. For each treatment, a total of one hundred seeds were placed on three layered moist blotter paper and incubated at 25±2°C. Germination was measured after every 24 hours. Under stress conditions, seeds treated with Trichoderma exhibited enhanced germination, root and shoot length, dry and fresh weight of root and shoot of seedlings as compared to untreated seeds. Highest seed germination under physiological stress and water stress was observed with Trichoderma isolates T87, Forest soil and T62, Darchula respectively. Isolate T87, Forest soil demonstrated the highest vigor index of seedlings in stress conditions. Seed treated with Trichoderma isolates also displayed significant improvement in germination under biotic stress induced by Sclerotium rolfsii. Trichoderma isolate T31, Banke showed highest germination under biotic stress. These findings highlight the potential of Trichoderma to enhance plant resilience and promote healthier growth under challenging environmental conditions. SAARC J. Agric., 21(2): 145-156 (2023)

The Effect of Diaphragm Breathing Exercises on Physiological and Psychological Stress

Physiological and psychological stress causes changes in homeostasis characterized by an imbalance of activity between the autonomic nervous systems. Overactivity of the sympathetic nervous system leads to physical, psychological, and behavioral disorders.&#x0D; Diaphragmatic breathing exercises routinely have been shown to suppress sympathetic nerve activity through activation of the parasympathetic nervous system and an increase in tidal volume that creates a change in the cell membrane potential to hyperpolarization, with the result being an improvement in physiological and psychological stress conditions, which appear in various parameters. This paper reviews the anatomy, physiology, and biomechanics of the diaphragm muscle, as well as the mechanism of diaphragmatic breathing exercises in improving physiological and psychological stress conditions from a Physical Medicine and Rehabilitation point of view.&#x0D; Keywords: breathing, diaphragm, exercise, physiological stress, psychological stress

PENINGKATAN PENGETAHUAN PENCEGAHAN SINDROM METABOLIK MELALUI PEMANFAATAN TANAMAN ROSELLA PADA LANSIA DI WILAYAH PUSKESMAS SETABELAN SURAKARTA DI MASSA COVID-19

The elderly is a process in life that is characterized by a decrease in one's body function to maintain balance against physiological stress conditions. The decline in health in the elderly is most often caused by non-communicable diseases. One of the non-communicable diseases is metabolic syndrome. Metabolic syndrome is a metabolic disorder that originates from a collection of various diseases such as cardiovascular disease, stroke, central obesity, impaired glucose tolerance, and dyslipidemia which may develop into diabetes. Rosella flowers have the benefit of lowering blood pressure, HbA1c, and other factors that cause metabolic syndrome because they contain organic acids, anthocyanins and flavonoids. The main problem faced by partners is the ignorance of the elderly to prevent complications of cardiovascular disease so that it becomes metabolic syndrome. This limitation causes the eating behavior of the elderly to often pay no attention to the type of food that can increase the risk of hypertension, obesity, and diabetes mellitus. Community service activities are carried out at the Waras Mulyo Posbindu in the Setabelan Health Center work area in October 2022 in Setabelan Village, Banjarsari District, Surakarta City. There were 20 elderly who took part in Posbindu Waras Mulyo. Held from 13.00-14.00. The results of the pretest and posttest were compared to find out if there was an increase in knowledge among the elderly. Based on the comparison results, it was found that 20 elderly people (100%) had increased knowledge. Increased knowledge of the elderly about understanding, risk factors, signs and symptoms, and how to prevent them.&#x0D; Keywords: Elderly; Metabolic Syndrome; Knowledge; Rosella.

Sensing of H2O2-induced oxidative stress by the UPF factor complex is crucial for activation of catalase-3 expression in Neurospora.

UPF-1-UPF-2-UPF-3 complex-orchestrated nonsense-mediated mRNA decay (NMD) is a well-characterized eukaryotic cellular surveillance mechanism that not only degrades aberrant transcripts to protect the integrity of the transcriptome but also eliminates normal transcripts to facilitate appropriate cellular responses to physiological and environmental changes. Here, we describe the multifaceted regulatory roles of the Neurospora crassa UPF complex in catalase-3 (cat-3) gene expression, which is essential for scavenging H2O2-induced oxidative stress. First, losing UPF proteins markedly slowed down the decay rate of cat-3 mRNA. Second, UPF proteins indirectly attenuated the transcriptional activity of cat-3 gene by boosting the decay of cpc-1 and ngf-1 mRNAs, which encode a well-studied transcription factor and a histone acetyltransferase, respectively. Further study showed that under oxidative stress condition, UPF proteins were degraded, followed by increased CPC-1 and NGF-1 activity, finally activating cat-3 expression to resist oxidative stress. Together, our data illustrate a sophisticated regulatory network of the cat-3 gene mediated by the UPF complex under physiological and H2O2-induced oxidative stress conditions.

Relationship between proton/ potassium fluxes and central carbon catabolic pathways in different Saccharomyces cerevisiae strains under osmotic stress conditions

Ion homeostasis is pivotal for numerous cellular functions and adaptation. Investigation of the relationship between K+ and H+ transporters and energy exchange processes of S. cerevisiae ATCC 9804 and ATCC 13007 strains will be crucial to enhance resistance to osmotic stress and improve industrial processes. Specific growth rate (SGR), pH and oxidation-reduction potential (ORP), K+ and H+ fluxes, mitochondrial H+-ATPase activity changes, and metabolites were studied in physiological and osmotic stress conditions. Strictly neutral conditions are needed for yeast biomass production under osmotic stress (microaerophilic growth), where the SGR of ATCC 9804 is suppressed ∼85% and in ATCC 13007 ∼60% compared to physiological conditions. The addition of N′N’-dicyclohexylcarbodiimide (DCCD) completely abolishes K+ and H+ transport. High affinity to K+ ions were registered in aerobic growth, which decreased during the transition to microaerophilic growth, as well as under stress, and was especially low in DCCD-inhibited samples. Mitochondrial H+-ATPase activity was suppressed ∼5-fold under osmotic stress conditions, compared with the physiological one. Taken together it can be concluded that cell membrane transporters and the mitochondrial proton-potassium exchange systems, are crucial in maintaining cell physiological functions, regulating the energy balance via FOF1-ATPase, as well as in stress responding processes.

Tetramethylalloxazines as efficient singlet oxygen photosensitizers and potential redox-sensitive agents

Tetramethylalloxazines (TMeAll) have been found to have a high quantum yield of singlet oxygen generation when used as photosensitizers. Their electronic structure and transition energies (S0 → Si, S0 → Ti, T1 → Ti) were calculated using DFT and TD-DFT methods and compared to experimental absorption spectra. Generally, TMeAll display an energy diagram similar to other derivatives belonging to the alloxazine class of compounds, namely π,π* transitions are accompanied by closely located n,π* transitions. Photophysical data such as quantum yields of fluorescence, fluorescence lifetimes, and nonradiative rate constants were also studied in methanol (MeOH), acetonitrile (ACN), and 1,2-dichloroethane (DCE). The transient absorption spectra were also analyzed. To assess cytotoxicity of new compounds, a hemolytic assay was performed using human red blood cells (RBC) in vitro. Subsequently, fluorescence lifetime imaging experiments (FLIM) were performed on RBC under physiological and oxidative stress conditions alone or in the presence of TMeAll allowing for pinpointing changes caused by those compounds on the intracellular environment of these cells.

Aortic Stenosis: A New Physiologic Approach With the Stress Aortic Valve Index

The stress aortic valve index is a new validated way for grading the severity of aortic stenosis. These measurements are based on physiologic (stress) conditions, rather than the traditional resting indices, used in echocardiography. The essence of these measurements is described in this case report.

Neuronal cells co-ordinate myeloid-epithelial cell interaction to regulate intestinal inflammation

Abstract Epithelial response to injury is coordinated through an intricate interaction with neuronal and myeloid cells, however the signaling modules involved are not well understood. In humans, somatic mutations in Tet methylcytosine dioxygenase 2 (TET2), a DNA demethylase, are commonly observed during ageing in myeloid cells and known to modulate inflammatory responses. Using a mouse model that lacks TET2 in myeloid cells (Tet2 ΔLysM), we show that myeloid cells and sympathetic neurons form a signaling nexus that controls differentiation of enterochromaffin cells and serotonin production during colonic inflammation. Under physiological conditions, TET2 restricts IL-1β production by myeloid cells which in turn controls the intestinal sympathetic architecture. During inflammation, IL1R signaling limits sympathetic cues that drive differentiation of enterochromaffin cells through α1-adrenergic signaling. As a result, enterochromaffin differentiation and colitis progression in response to mucosal injury is attenuated in Tet2 ΔLysMmice. Further, protection from colitis in Tet2 ΔLysMmice is mediated by its catalytic activity, and dependent on sympathetic neurons and IL1R signaling. Adrenergic control of epithelial response and pro-colitic serotonin production is also evident under conditions of physiological stress that leads to increased colitis susceptibility. Overall, our study reveals a sympathetic-epithelial axis that controls the severity of colitis and is modulated by myeloid-derived IL-1β and physiological stress. Our findings may also explain why inflammatory bowel disease in the elderly, where TET2 mutations in myeloid cells are common, is less severe and suggests TET2 activity as an attractive target for IBD. Supported by the US National Institutes of Health (DK067180) to B.J, the University of Chicago's Center for Interdisciplinary Study of Inflammatory Intestinal Disorders (C-IID) Pilot &amp; Feasibility Award (NIDDK P30 DK042086) to A.M. and D.S, Crohn’s and Colitis Foundation Career Development Award #964209 to A.M. and G.I. Research Foundation Associates Board Award to A.M. and D.S.

Identification of Appropriate Endogenous Controls for Circulating miRNA Quantification in Working Dogs under Physiological Stress Conditions

Cell-free miRNAs, called circulating miRNAs (cmiRNAs), can act in a paracrine manner by facilitating a diversity of signaling mechanisms between cells. Real-time qPCR is the most accepted method for quantifying miRNA expression levels. The use of stable miRNA endogenous control (EC) for qPCR data normalization allows an accurate cross-sample gene expression comparison. The appropriate selection of EC is a crucial step because qPCR data can change drastically when normalization is performed using an unstable versus a stable EC. To find EC cmiRNA with stable expression in search and rescue (SAR) working dogs, we explored the serum miRNome by Next-Generation Sequencing (NGS) at T0 (resting state) and T1 immediately after SAR performance (state of physiologically recovered stress). The cmiRNAs selected in the NGS circulating miRNome as probable ECs were validated by qPCR, and miRNA stability was evaluated using the Delta Ct, BestKeeper, NormFinder, and GeNorm algorithms. Finally, RefFinder was used to rank the stability orders at both T0 and T1 by establishing miR-320 and miR-191 as the best-circulating ECs. We are confident that this study not only provides a helpful result in itself but also an experimental design for selecting the best endogenous controls to normalize gene expression for genes beyond circulating miRNAs.

Shear Stress Markedly Alters the Proteomic Response to Hypoxia in Human Pulmonary Endothelial Cells.

Blood flow produces shear stress that homeostatically regulates the phenotype of pulmonary endothelial cells, exerting antiinflammatory and antithrombotic actions and maintaining normal barrier function. Hypoxia due to diseases, such as chronic obstructive pulmonary disease (COPD), causes vasoconstriction, increased vascular resistance, and pulmonary hypertension. Hypoxia-induced changes in endothelial function play a central role in the development of pulmonary hypertension. However, the interactive effects of hypoxia and shear stress on the pulmonary endothelial phenotype have not been studied. Human pulmonary microvascular endothelial cells were cultured in normoxia or hypoxia while subjected to physiological shear stress or in static conditions. Unbiased proteomics was used to identify hypoxia-induced changes in protein expression. Using publicly available single-cell RNA sequencing datasets, differences in gene expression between the alveolar endothelial cells from COPD and healthy lungs were identified. Sixty proteins were identified whose expression changed in response to hypoxia in conditions of physiological shear stress but not in static conditions. These included proteins that are crucial for endothelial homeostasis (e.g., JAM-A [junctional adhesion molecule A], ERG [ETS transcription factor ERG]) or implicated in pulmonary hypertension (e.g., thrombospondin-1). Fifty-five of these 60 have not been previously implicated in the development of hypoxic lung diseases. mRNA for 5 of the 60 (ERG, MCRIP1 [MAPK regulated corepressor interacting protein 1], EIF4A2 [eukaryotic translation initiation factor 4A2], HSP90AA1 [heat shock protein 90 alpha family class A member 1], and DNAJA1 [DnaJ Hsp40 (heat shock protein family) member A1]) showed similar changes in the alveolar endothelial cells of COPD compared with healthy lungs in females but not in males. These data show that the proteomic responses of the pulmonary microvascular endothelium to hypoxia are significantly altered by shear stress and suggest that these shear-hypoxia interactions are important in the development of hypoxic pulmonary vascular disease.

PQBP5/NOL10 maintains and anchors the nucleolus under physiological and osmotic stress conditions

Polyglutamine binding protein 5 (PQBP5), also called nucleolar protein 10 (NOL10), binds to polyglutamine tract sequences and is expressed in the nucleolus. Using dynamic imaging of high-speed atomic force microscopy, we show that PQBP5/NOL10 is an intrinsically disordered protein. Super-resolution microscopy and correlative light and electron microscopy method show that PQBP5/NOL10 makes up the skeletal structure of the nucleolus, constituting the granule meshwork in the granular component area, which is distinct from other nucleolar substructures, such as the fibrillar center and dense fibrillar component. In contrast to other nucleolar proteins, which disperse to the nucleoplasm under osmotic stress conditions, PQBP5/NOL10 remains in the nucleolus and functions as an anchor for reassembly of other nucleolar proteins. Droplet and thermal shift assays show that the biophysical features of PQBP5/NOL10 remain stable under stress conditions, explaining the spatial role of this protein. PQBP5/NOL10 can be functionally depleted by sequestration with polyglutamine disease proteins in vitro and in vivo, leading to the pathological deformity or disappearance of the nucleolus. Taken together, these findings indicate that PQBP5/NOL10 is an essential protein needed to maintain the structure of the nucleolus.

ERGONOMICS OF PROFESSIONAL RISKS MANAGEMENT

In the modern working environment, the performance of professional tasks mostly depends on the physiological and cognitive abilities of employees, adaptive and mental processes. From these abilities and processes depend on information processing. Emphasized attention is placed on the fact that acceptable working conditions, high work productivity and a high level of well-being of employees are interconnected elements. Therefore, it is important to manage the conditions of cognitive and physiological stress in order to reduce their harmful consequences for individual employees, teams, organizations, etc. To improve the effectiveness of risk management, a four-step approach is proposed, which involves accounting for occupational hazards, dangerous and harmful occupational factors at the workplace; providing the opportunity of any employee to contact the group of rapid response to hazards in case of occurrence or change of dangerous and harmful occupational factors, growth of occupational risks, appearance of new hazards, etc. during the work shift; introducing a discussion with justification of preventive and protective actions to reduce professional risks; application of measures for the prevention of dangerous situations (conducting supervision, audits and self-assessment of the activities of employees at workplaces). Systematicity is the main principle of ergonomics used to develop an algorithm for the step-by-step implementation of the process of managing professional risks. It`s consists of defining as a complete system - the set of all components of the labor activity of employees, which would reduce the impact on the physiological and cognitive potential of the employee. Forms of a hazard guide, a hazard notification card and a safety audit report have been developed. It will reduce the time to learn the specified procedures due to a conscious attitude to one's own activities at the workplace. Reasonable measures to increase the effectiveness of professional risks management based on the step-by-step performance of certain actions by employees are oriented to increasing awareness of safety at the workplace. Keywords: risk, management, ergonomics, preventive measures, cognitive stress.