Stress Stimuli Research Articles

On the significance of estimating cardiorespiratory coupling strength in sports medicine.

The estimation of cardiorespiratory coupling (CRC) is attracting interest in sports physiology as an important tool to characterize cardiac neural regulation genuinely driven by respiration. When applied in sports medicine, cardiorespiratory coupling measurements can provide information on the effects of training, pre-competition stress, as well as cardiovascular adjustments during stressful stimuli. Furthermore, since the cardiorespiratory coupling is strongly affected by physical activity, the study of the cardiorespiratory coupling can guide the application of specific training methods to optimize the coupling between autonomic activity and heart with possible effects on performance. However, a consensus about the physiological mechanisms, as well as methodological gold standard methods to quantify the cardiorespiratory coupling, has not been reached yet, thus limiting its application in experimental settings. This review supports the relevance of assessing cardiorespiratory coupling in the sports medicine, examines the possible physiological mechanisms involved, and lists a series of methodological approaches. cardiorespiratory coupling strength seems to be increased in athletes when compared to sedentary subjects, in addition to being associated with positive physiological outcomes, such as a possible better interaction of neural subsystems to cope with stressful stimuli. Moreover, cardiorespiratory coupling seems to be influenced by specific training modalities, such as inspiratory muscle training. However, the impact of cardiorespiratory coupling on sports performance still needs to be better explored through ad hoc physical exercise tests and protocols. In addition, this review stresses that several bivariate and multivariate methods have been proposed to assess cardiorespiratory coupling, thus opening new possibilities in estimating cardiorespiratory interactions in athletes.

Effects of chronic stress on bladder morphology of rats and impact of comfort food diet as an ameliorating agent

Objectives To investigate the effects of chronic stress on bladder morphology and the impact of food preference (standard or comfort foods) on the bladder of stressed rats. Methods In total, 32 Wistar male rats (3 months old) were divided into four groups: control (C), stressed (S), control + comfort food (C + CF), and stressed + comfort food (S + CF). Groups C and C + CF were maintained under normal conditions, while groups S and S + CF were subjected to chronic stress by the restraint method. Groups C and S received standard rat chow, while groups C + CF and S + CF received comfort food (Froot Loops®) and standard chow. The stress stimuli were induced daily for 2 h over 8 weeks. After 8 weeks, all animals were killed, and the bladders were removed and used for histomorphometric analysis. Results Body mass was similar among the groups. Stress did not promote differences regarding food intake, but animals receiving comfort food showed higher calories intake (in kcal/Kg) than animals receiving only standard chow. The C + CF and S + CF groups preferred comfort food over the standard chow; this preference was higher in the S + CF than in the C + CF group. The surface density of smooth muscle was reduced in stressed animals, while connective tissue and elastic system fiber content were increased in stressed groups. Further, epithelial height was increased in rats submitted to chronic stress. The surface density of elastic system fibers was decreased by the consumption of comfort food. Conclusions Chronic stress induces morphological modifications on the bladder wall and epithelium. These modifications may be related to lower urinary tract symptoms. Additionally, chronic stress caused a higher preference for comfort food intake which did not ameliorate or aggravate the stress-induced bladder alterations.

ANGPTL8 links inflammation and poor differentiation, which are characteristics of malignant renal cell carcinoma.

Inflammation is observed in many tumors, which affects metastasis, infiltration, and immune escape and causes poor differentiation of the cancer cells. However, the molecular basis underlying the relationship between inflammation and poor differentiation in tumors has not been identified. In this study, we demonstrate that angiopoietin-like protein-8 (ANGPTL8), which is induced by stress stimuli such as inflammation, is involved in the maintenance of the undifferentiated state of clear cell renal cell carcinoma (ccRCC) cells. ANGPTL8 is also involved in the production of chemokines that attract immune suppressor cells to the tumor microenvironment. ANGPTL8 sustains the continuous production of chemokines by activating the NF-κB signaling pathway and maintains the undifferentiated state of ccRCC cells. Finally, ANGPTL8 is induced by STAT3 signaling, which is activated by immune cells in the tumor microenvironment. These results support a role for ANGPTL8 in determining the properties of ccRCC by hampering tumor cell differentiation and establishing the tumor microenvironment.

Effects of chronic restraint stress in the prostate of prepubertal and adult rats.

To investigate the effects of chronic stress in the prostate of prepubertal and adult rats. Thirty-two male rats were assigned into four groups depending on the type of treatment (control or stressed) and the age at which stress was initiated (prepubertal or adult). Restraint stress stimuli were applied for six weeks. Stressed prepubertal and adult rats evaluated immediately after the last stress stimuli were named SP and SA groups, respectively. Age-matched rats were used as control groups (CP and CA). At the end of the experiment, the rats were euthanized, and prostate morphological parameters were evaluated and statistically compared. Application of stress stimuli to the SP group resulted in reduced body weight, but no prostate morphological modification was noted. The SA group showed reduced testosterone level and prostatic epithelium surface density, in comparison to CA group. Further, the prostatic lumen surface density was increased in adult stressed animals, in comparison to adult controls. The stress stimuli promoted changes in hormonal and morphological parameters in the prostate of adult stressed rats. Prepubertal stressed animals did not presented modifications of prostate morphology.

Synaptic alterations as a common phase in neurological and neurodevelopmental diseases: JNK is a key mediator in synaptic changes.

Synaptic alterations as a common phase in neurological and neurodevelopmental diseases: JNK is a key mediator in synaptic changes.

Physiological and psychological factors assessment in the process of professional self-determination

The article deals with physiological (adaptive potential, resistance to hypoxia and stress stimuli) and psycho physiological (level of sociability) factors that contribute to the formation of the student's personality. As part of presented study, first-year students of Sevastopol State University were diagnosed (28 people, of which: 14 girls and 14 boys) according to the following indicators: level of adaptive potential; human resistance to hypoxia; attention and speed of information processing; resistance of a person to the action of stressful stimuli; level of person’s communication skills. A comparative analysis of the components of the adaptive potential of the individual and the levels of psychological well-being among first-year students of a higher educational institution was carried out. The paper also presents the results of a study of first-year students in terms of their sociability (not sociable, average level of sociability, normal sociability, very sociable, hyperactive. Based on the results of given study, a comprehensive description was given to first-year students (the number of students who underwent diagnostics is 28 people). In conclusion the authors say that a high students’ adaptive potential ensures their successful adaptation to the group and learning activities because of appropriate neuropsychic stability, and developed communication skills.

An organic-inorganic hybrid thermochromic ferroelastic with multi-channel switches

Multifunctional switchable materials are attracting tremendous interest because of their great application potential in signal processing, information encryption, and smart devices. Here, we reported an organic-inorganic hybrid thermochromic ferroelastic crystal, [TMIm][CuCl4] (TMIm = 1,1,3,3-tetramethylimidazolidinium), which undergoes two reversible phase transitions at 333 K and 419 K, respectively. Intriguingly, these three phases experience a remarkable ferroelastic-paraelastic-ferroelastic (2/m-mmm-2/m) transition, which remains relatively unexplored in ferroelastics. Moreover, the ferroelastic domains can be simultaneously switched under temperature and stress stimuli. Meanwhile, [TMIm][CuCl4] exhibits thermochromic phenomenon, endowing it with extra spectral encryption possibilities during information processing. Combined with dielectric switching behavior, [TMIm][CuCl4] are promising for practical applications in memory devices, next-generation sensors, and encryption technology.

Protein phosphatases and their targets: Comprehending the interactions in plant signaling pathways.

Protein phosphorylation is a vital reversible post-translational modification. This process is established by two classes of enzymes: protein kinases and protein phosphatases. Protein kinases phosphorylate proteins while protein phosphatases dephosphorylate phosphorylated proteins, thus, functioning as 'critical regulators' in signaling pathways. The eukaryotic protein phosphatases are classified as phosphoprotein phosphatases (PPP), metallo-dependent protein phosphatases (PPM), protein tyrosine (Tyr) phosphatases (PTP), and aspartate (Asp)-dependent phosphatases. The PPP and PPM families are serine (Ser)/threonine (Thr) specific phosphatases (STPs) that dephosphorylate Ser and Thr residues. The PTP family dephosphorylates Tyr residues while dual-specificity phosphatases (DsPTPs/DSPs) dephosphorylate Ser, Thr, and Tyr residues. The composition of these enzymes as well as their substrate specificity are important determinants of their functional significance in a number of cellular processes and stress responses. Their role in animal systems is well-understood and characterized. The functional characterization of protein phosphatases has been extensively covered in plants, although the comprehension of their mechanistic basis is an ongoing pursuit. The nature of their interactions with other key players in the signaling process is vital to our understanding. The substrates or targets determine their potential as well as magnitude of the impact they have on signaling pathways. In this article, we exclusively overview the various substrates of protein phosphatases in plant signaling pathways, which are a critical determinant of the outcome of various developmental and stress stimuli.

Relationship Between Left-Right Dominancy of Prefrontal Cortex Activity and Heart Rate During Rest and Task Periods: An fNIRS Study.

BackgroundFunctional near-infrared spectroscopy (fNIRS) studies demonstrated that regulation of stress response of the autonomic nervous system is mediated by the left-right asymmetry of prefrontal cortex (PFC) activity. However, it is not yet clear whether PFC regulation of stress response is functioning only when the subject was under stress or even at rest without stress. In addition, the temporal responsivity of PFC regulation of stress response is not known.AimThis study aims to investigate the relationship between the left-right asymmetry of PFC activity and heart rate during both resting state and stressful state while performing a working memory task.ApproachTwenty-nine subjects were recruited to rest and conduct 2-back task, during which fNIRS and ECG were measured simultaneously.ResultsWe found weak correlation (r=0.28, p=0.137) between laterality index (LI) and heart rate in the task session, but no correlation in rest sessions at a group level. Moreover, weak but significant correlation was found only in the task session for all analysis intervals ranged from 2s to 1 min.ConclusionIt is suggested that regulation of stress responses was mediated by the left-right asymmetry of PFC activity only when the subject was under stress stimuli and embody stress response did not affect PFC in reverse. This regulation can be observed at an analysis interval of no less than 2s.

Omic analysis of anthocyanin synthesis in wine grape leaves under low-temperature

• Low-temperature promotes the accumulation of anthocyanins in grape leaves by up-regulating the expression of structural genes that induce anthocyanin synthesis, related transcription factors and LRR-type receptor-like protein kinases. • Under the same low-temperature environment, the more anthocyanin accumulated in the leaves, the less damage they suffered. • The synthesis and accumulation of anthocyanins promoted the adaptation and resistance of grape leaves to low-temperature environmental conditions. Anthocyanins can be induced by environmental factors such as low- temperature, and play an important role in adapting to abiotic stress. In this study, the leaves of 'Cabernet Gernischt' grapes with different colors under natural low-temperature in autumn were collected and grouped into Green (Gre), Light-red (L-Red), Red (Red), and Dark-red (D-Red). Results showed that the total anthocyanin content and anthocyanin components were increased in turn from Gre to D-red. Under the same low-temperature, Gre was substantially damaged, L-Red was mildly damaged, Red and D-Red had no visible damage. RNA-seq data showed that a total of 3666 DEGs were screened out of all 28,306 genes detected, of which 1936 DEGs were upregulated and 1730 DEGs were downregulated in D-Red vs Gre. Transcriptomics and metabolomics showed that DEGs were significantly enriched in GO terms, such as in defense response, defense response to oomycetes, and response to reactive oxygen species, hydrogen peroxide, heat, salt stress, and biotic stimulus pathways. The KEGG analysis showed that DEGs were mainly enriched in secondary metabolism, carbohydrate metabolism, energy metabolism, and lipid metabolism. Anthocyanin synthesis genes may be regulated by transcription factors such as ERF, MYB, NAC, bHLH and various LRR-type receptor-like protein kinase (LRR-RLK) family genes. In conclusion, the accumulation of anthocyanins significantly increased from green to red in grape leaves during autumn low-temperature, improving the cold resistance of grape leaves.

Protective and Adverse Roles of DDX3X in Different Cell Types in Nonalcoholic Steatohepatitis Progression

Persistent hepatic cellular metabolic stress and liver inflammatory stimuli are key signatures of nonalcoholic steatohepatitis (NASH). DDX3X is a vital molecule involved in cell fate decisions in both pro-survival stress granule (SG) and pro-death NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome assembly in response to stress signals. However, the role of DDX3X in NASH remains unclear. We characterized the cell type-specific roles of DDX3X in NASH. Human liver tissues from NASH patients and normal control subjects were collected to assess DDX3X expression and distribution. Nutritional steatohepatitis models were constructed by feeding macrophage-specific DDX3X knockout (DDX3X ΔMφ ), hepatocyte-specific DDX3X knockout (DDX3X Δhep ), and wild-type control (DDX3X fl/fl ) mice a high-fat and high-cholesterol (HFHC) diet, a methionine- and choline-deficient (MCD) diet, and a high-fat/high-iron/high-fructose/high-cholesterol, low-methionine, and choline-deficient (HFHIHFHC-MCD) diet. The study demonstrated that DDX3X was predominantly expressed in macrophages and hepatocytes in control liver tissues, and its expression was down-regulated in patients or mice with NASH. Compared to DDX3X fl/fl littermates, DDX3X ΔMφ mice showed improved liver histology in nutritional steatohepatitis models. Loss of macrophage DDX3X inhibited NLRP3 inflammasome-mediated pyroptosis, causing anti-inflammatory M2 polarization and alleviating hepatocyte steatohepatitic changes. DDX3X Δhep mice developed marked steatohepatitis in multiple nutritional steatohepatitis models compared to DDX3X fl/fl littermates. DDX3X-deleted hepatocytes showed impaired SG assembly, leading to increased sensitivity and intolerance to metabolic stimulation and resultant steatohepatitis. In conclusion, DDX3X plays opposite roles in different cell types during the progression of NASH. A better understanding of the cell-specific differences in the crosstalk between SG formation and NLRP3 activation is crucial for developing prospective targeted DDX3X inhibitors for the treatment of NASH.

Chronic stress-induced apoptosis is mitigated by young mitochondria transplantation in the prefrontal cortex of aged rats.

Apoptosis is common and often comorbid with aging and stress-related mood disorders. Evidence suggests that fresh mitochondria could reverse age-related dysfunctions in organs, especially in the brain. Therefore, this study investigated the effect of young mitochondria administration on the apoptosis process in the prefrontal cortex (PFC) of aged rats exposed to chronic stress. Aged (22 months old) male rats were randomly assigned into four groups: aged control (AC), aged rats treated with young mitochondria (A+M), aged rats subjected to chronic stress for four weeks (A+St), and aged rats subjected to chronic stress and treated with young mitochondria (A+St+M). A+M and A+St+M groups received a single ICV injection (10 μl) of fresh mitochondria isolated from the brain of young rats for five minutes (2 µl/min). Finally, the levels of Malondialdehyde (MDA), Cytochrome c (Cyt c), Bax, Bcl-2, and Caspase-3 expression were investigated in the PFC. Young mitochondria administration reduced neuronal apoptosis in the PFC, associated with down-regulation of MDA, Bax, and Caspase-3 and up-regulation of Bcl-2. Moreover, fresh mitochondria partially improved the chronic stress-induced mitochondrial dysfunction in aged rats, as indicated by reduced cytochrome c (Cyt c) release from the mitochondria. These results suggest mitotherapy could reverse cell viability and mitochondrial dysfunction-induced apoptosis in the PFC tissue of aged rats subjected to stressful stimuli.

Tomada de Decisão sob Estresse: O Efeito “Esconder-se atrás de um Bolo Pequeno”

ABSTRACT Objective: we analyzed decision-making under stress by manipulating salivary cortisol levels. Theoretical background: literature dedicated to the relationship between stress and decision-making is still inconclusive. Studies have found that when dealing with stressful decisions, people will respond with a greater propensity for opportunistic behavior. However, stress might also decrease the potential for deception when the decision requires strategic/analytical responses. Method: we implemented a laboratory experiment using the ultimatum game with asymmetric information, in which only the first mover was fully informed about the size of the endowment. Our experiment compared the decisions of subjects who received a stress stimulus from an adapted Trier social stress test for groups (TSST-G) protocol with a control group. Results: we found that under stress, proposers transferred more to responders. In contrast, non-stressed players were more likely to take advantage of information asymmetry by choosing lower strategic offers, which is consistent with the so-called ‘hide behind a small cake’ effect. Regression analysis also indicated that larger offers are not necessarily associated with increased prosocial motives since stressed proposers became more confident about the responder’s ability to guess the true endowment, which decreased their incentive to take advantage of the aforementioned effect. Conclusions: one possible effect of stress could be an increase in risk perception, decreasing the ability to make strategic decisions. The stressful condition might have rendered our participants less capable of realizing the ‘hide behind a small cake’ potential of the game, leading them to make more conservative offers when compared to the control group.

Birds living near airports do not show consistently higher levels of feather corticosterone.

Noise represents a threat to human and wildlife health, triggering physiological and behavioral challenges to individuals living close to sources of extreme noise. Here, we considered airport environments as sources of potentially stressful stimuli for birds and tested if those living near airports are under higher physiological stress than birds living in quiet sites. We used measurements of CORT in feathers (CORTf) as a proxy of chronic stress. We evaluated 14 passerine and 1 non-passerine species, living near three Brazilian airports. We found that, across species, individuals with a better body condition had lower CORTf concentration. At the species level, we found that CORTf concentration was not consistently affected by airport noise. Comparing individuals living in quiet sites with those living near airports, we found that 2 species had higher and 2 had lower CORTf concentrations near airports, while 11 species presented no significant differences between sites. At the population level, model selection indicated that the direction and strength of these differences are weakly related to species' song frequency (peak frequency), as lower-frequency singers tended to present higher CORTf levels at airport-affected sites. In summary, we were unable to find a consistent response among species, probably due to species-specific differences in their response to anthropogenic disturbances. Instead, we found that species might be affected differently according to their singing spectral frequency and that individuals in good body condition show lower CORTf, suggesting that this measure is consistent with lower physiological stress.

Evolutionary analysis of p38 stress-activated kinases in unicellular relatives of animals suggests an ancestral function in osmotic stress.

p38 kinases are key elements of the cellular stress response in animals. They mediate the cell response to a multitude of stress stimuli, from osmotic shock to inflammation and oncogenes. However, it is unknown how such diversity of function in stress evolved in this kinase subfamily. Here, we show that the p38 kinase was already present in a common ancestor of animals and fungi. Later, in animals, it diversified into three JNK kinases and four p38 kinases. Moreover, we identified a fifth p38 paralog in fishes and amphibians. Our analysis shows that each p38 paralog has specific amino acid substitutions around the hinge point, a region between the N-terminal and C-terminal protein domains. We showed that this region can be used to distinguish between individual paralogs and predict their specificity. Finally, we showed that the response to hyperosmotic stress in Capsaspora owczarzaki, a close unicellular relative of animals, follows a phosphorylation-dephosphorylation pattern typical of p38 kinases. At the same time, Capsaspora's cells upregulate the expression of GPD1 protein resembling an osmotic stress response in yeasts. Overall, our results show that the ancestral p38 stress pathway originated in the root of opisthokonts, most likely as a cell's reaction to salinity change in the environment. In animals, the pathway became more complex and incorporated more stimuli and downstream targets due to the p38 sequence evolution in the docking and substrate binding sites around the hinge region. This study improves our understanding of p38 evolution and opens new perspectives for p38 research.

Calcium decoders and their targets: The holy alliance that regulate cellular responses in stress signaling.

Calcium (Ca2+) signaling is versatile communication network in the cell. Stimuli perceived by cells are transposed through Ca2+-signature, and are decoded by plethora of Ca2+ sensors present in the cell. Calmodulin, calmodulin-like proteins, Ca2+-dependent protein kinases and calcineurin B-like proteins are major classes of proteins that decode the Ca2+ signature and serve in the propagation of signals to different parts of cells by targeting downstream proteins. These decoders and their targets work together to elicit responses against diverse stress stimuli. Over a period of time, significant attempts have been made to characterize as well as summarize elements of this signaling machinery. We begin with a structural overview and amalgamate the newly identified Ca2+ sensor protein in plants. Their ability to bind Ca2+, undergo conformational changes, and how it facilitates binding to a wide variety of targets is further embedded. Subsequently, we summarize the recent progress made on the functional characterization of Ca2+ sensing machinery and in particular their target proteins in stress signaling. We have focused on the physiological role of Ca2+, the Ca2+ sensing machinery, and the mode of regulation on their target proteins during plant stress adaptation. Additionally, we also discuss the role of these decoders and their mode of regulation on the target proteins during abiotic, hormone signaling and biotic stress responses in plants. Finally, here, we have enumerated the limitations and challenges in the Ca2+ signaling. This article will greatly enable in understanding the current picture of plant response and adaptation during diverse stimuli through the lens of Ca2+ signaling.

Quantifying faecal cortisol metabolites in rescued orphaned koala joeys undergoing rehabilitation†

Mortality is prevalent in koala joeys being hand reared/rehabilitated, with little knowledge about the causes of such high rates of mortality. Wildlife hospitals/rehabilitation expose koala joeys to novel husbandry environments that create stressful stimulus for these animals. Furthermore, loss of the mother and/or being raised by a human can be threatening and/or stressful. The hypothalamic–pituitary–adrenal axis plays a vital role in mediating the stress endocrine response of vertebrate species including marsupials (by adrenocortical release of glucocorticoids such as cortisol), however, there are no studies that quantify cortisol metabolites in koala joeys. To contribute to this dearth of knowledge, the primary aim of this study was to quantify the levels of faecal cortisol metabolites (as an index of physiological stress) in koala joeys undergoing rehabilitation. A total of 39 faecal samples were collected from four koala joeys admitted at a wildlife hospital in New South Wales, Australia. The samples were processed and analysed for faecal cortisol metabolites (FCM) using a polyclonal R4866 cortisol enzyme-immunoassay which has been previously biologically validated in adult koalas. The results indicated that there was significant inter-individual variation in FCM concentrations among the joeys, however, these differences were not based on the sex of the joeys. The average FCM concentration among joeys varied from 18.34 to 44.18 ng/g. Our study provides the first record of physiological stress in male and female rescued koala joeys by indexing FCM concentrations during rehabilitation.

Transcriptome Analysis of Hepatoprotection of Traditional Medicines Against Acute CCl4 and Chronic Alcohol-Induced Liver Injury in Mice

Hua-Feng-Dan produced adaptive mechanisms in the liver to render it to tolerant to CCl4-induced oxidative stress stimuli. Thus, transcriptome analysis is a powerful tool to reveal the molecular mechanisms of hepatoprotection by traditional medicines.

Stress granules dynamics: benefits in cancer

Stress granules (SGs) are stress-induced subcellular compartments, which carry out a particular function to cope with stress. These granules protect cells from stress-related damage and cell death through dynamic sequestration of numerous ribonucleoproteins (RNPs) and signaling proteins, thereby promoting cell survival under both physiological and pathological condition. During tumorigenesis, cancer cells are repeatedly exposed to diverse stress stimuli from the tumor microenvironment, and the dynamics of SGs is often modulated due to the alteration of gene expression patterns in cancer cells, leading to tumor progression as well as resistance to anticancer treatment. In this mini review, we provide a brief discussion about our current understanding of the fundamental roles of SGs during physiological stress and the effect of dysregulated SGs on cancer cell fitness and cancer therapy. [BMB Reports 2022; 55(12): 577-586].

Insomnia in response to stress in pregnant women: description of the problem, complications, identification of risk groups and therapeutic options

Insomnia is a major clinical problem in pregnant population, with almost 40% of women in the third trimester being affected. If left untreated, insomnia reduces the quality of life and increases the risk of other disorders, both somatic and mental. Sleep disorders can affect the course of pregnancy, delivery, and perinatal outcomes, as well as prevent the formation of a proper bond between mother and infant, which is crucial for the child’s further development. The term “sleep reactivity,” defining a certain tendency to exhibit sleep disturbance in response to a stressful stimulus, increasingly appears in literature. Sleep reactivity is a part of the body’s overall response to stress. It has been shown that high sleep reactivity can be a risk factor for chronic insomnia, which confirms its clinical significance. Ford Insomnia Response to Stress Test (FIRST) is an available and easy-to-use tool to measure this tendency. Due to the high prevalence and multiple complications of pregnancy insomnia, it is worth using appropriate screening tools to diagnose the disorder during prenatal checkups with the attending physician. In the light of current medical knowledge, cognitive-behavioural therapy of insomnia is the method of choice and should be used in every symptomatic patient. The latest data also indicate its efficacy and safety in advanced pregnancy patients.