Stress-induced Responses Research Articles

Abstract C033: Identifying and targeting prostate cancer therapy resistance mechanisms driven by the tumor microenvironment

Abstract Background: Prostate cancer is a prevalent malignancy in men, with treatment resistance posing a significant challenge to successful cure. Acquired Resistance to Therapy (ART) arises from two main components: (1) Tumor Microenvironment (TME) and (2) mutations or epigenetic changes at gene level within the tumor cells themselves. While most cancer therapies target the intrinsic biology of cancer cells, growing evidence indicates that these treatments can also harm the stromal cells within TME, potentially driving ART. The biology of ART may vary based on the types of treatments, cell types, and organ locations. Thus, this study aims to dissect ART components driven by TME-mediated cellular processes in a comprehensive manner. Hypothesis: We propose that cancer therapies induce stress responses in non-cancerous cells within the TME. These stress responses involve the secretion of cytokines, mediators, and growth factors, which we term Stress Response Secretory Programs (SRSPs). We further hypothesize that targeting SRSPs could overcome ART that helps to improve treatment specificity and efficacy. Materials and Methods: We employed comprehensive single-cell profiling of common metastatic sites included liver, prostate, lung, bone, lymph node and spleen in preclinical models to identify secreted proteins and dysregulated pathways caused by genotoxic therapies. In vitro, we evaluated treatment resistance in murine prostate epithelial cell lines (Myc-CAP) by exposing them to conditioned media (CM) from irradiated murine fibroblasts (F4M2), using cell growth assays. Results: Single-cell RNA sequencing of organ samples revealed significant expressions of SRSPs and increased inflammatory responses in liver and prostate fibroblasts as well as other stromal cells treated with carboplatin. In vitro, CM from irradiated F4M2 cells enhanced cell proliferation and survival of Myc-CAP cells in response to docetaxel treatment. Conclusion: Our findings highlight the crucial role of SRSPs in mediating ART through interactions within the TME, which alter tumor cell phenotypes. Targeting these SRSPs holds potential for overcoming treatment resistance and improving therapeutic outcomes, underscoring the need to consider TME complexity in cancer treatment strategies. Citation Format: Tony Lok Heng Chu, Armand Bankhead, Ilsa Coleman, Sander Frank, Peter S. Nelson, Tarana Arman. Identifying and targeting prostate cancer therapy resistance mechanisms driven by the tumor microenvironment [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C033.

Effects of MMP2 and its inhibitor TIMP2 on DNA damage, apoptosis and senescence of human lens epithelial cells induced by oxidative stress.

Oxidative stress-induced lens epithelial cells (LECs) death plays a pivotal role in pathogenesis of age-related cataract (ARC), causing significant visual impairment. Apoptosis of porcine granulosa cells mediated by MMP2 is linked to DNA damage. The current study aimed to investigate the potential mechanism of MMP2 in DNA damage, apoptosis and senescence of lens epithelial cells caused by oxidative stress. HLE-B3 cells were treated with different doses of H2O2 for 24h, and CCK-8 was used to detect cell viability. Furthermore, western blotting was used to detect the expressions of MMP2, Bcl2, Bax, cleaved caspase3, γ-H2AX, p16, p21, and TIMP2. DCFH-DA staining was used to assess ROS levels. Moreover, EdU staining was used to detect cell proliferation, and flow cytometry was used to detect cell apoptosis. Then, 15A3 immunofluorescence staining and γ-H2AX staining were used to detect DNA damage. In addition, SA-β-gal staining was used to observe cell senescence. The present findings suggest that oxidative stress triggers damage to LECs viability and elevates the expression of MMP2. Furthermore, MMP2 interference attenuates H2O2-induced active damage, apoptosis, DNA damage, and cellular senescence in LECs. Additionally, TIMP2 expression is down-regulated in H2O2-induced LECs, which suppresses the expression of MMP2 induced by H2O2. These findings highlight the crucial role of MMP2 and TIMP2 in the modulation of oxidative stress-induced cellular responses in LECs. Collectively, TIMP2 alleviates H2O2-induced lens epithelial cell viability damage, apoptosis, DNA damage and cell senescence in LECs by inhibiting MMP2.

Molecular basis of neurodegeneration in a mouse model of Polr3-related disease

Pathogenic variants in subunits of RNA polymerase (Pol) III cause a spectrum of Polr3-related neurodegenerative diseases including 4H leukodystrophy. Disease onset occurs from infancy to early adulthood and is associated with a variable range and severity of neurological and non-neurological features. The molecular basis of Polr3-related disease pathogenesis is unknown. We developed a postnatal whole-body mouse model expressing pathogenic Polr3a mutations to examine the molecular mechanisms by which reduced Pol III transcription results primarily in central nervous system phenotypes. Polr3a mutant mice exhibit behavioral deficits, cerebral pathology and exocrine pancreatic atrophy. Transcriptome and immunohistochemistry analyses of cerebra during disease progression show a reduction in most Pol III transcripts, induction of innate immune and integrated stress responses and cell-type-specific gene expression changes reflecting neuron and oligodendrocyte loss and microglial activation. Earlier in the disease when integrated stress and innate immune responses are minimally induced, mature tRNA sequencing revealed a global reduction in tRNA levels and an altered tRNA profile but no changes in other Pol III transcripts. Thus, changes in the size and/or composition of the tRNA pool have a causal role in disease initiation. Our findings reveal different tissue- and brain region-specific sensitivities to a defect in Pol III transcription.

Molecular basis of neurodegeneration in a mouse model of Polr3-related disease.

Pathogenic variants in subunits of RNA polymerase (Pol) III cause a spectrum of Polr3-related neurodegenerative diseases including 4H leukodystrophy. Disease onset occurs from infancy to early adulthood and is associated with a variable range and severity of neurological and non-neurological features. The molecular basis of Polr3-related disease pathogenesis is unknown. We developed a postnatal whole-body mouse model expressing pathogenic Polr3a mutations to examine the molecular mechanisms by which reduced Pol III transcription results primarily in central nervous system phenotypes. Polr3a mutant mice exhibit behavioral deficits, cerebral pathology and exocrine pancreatic atrophy. Transcriptome and immunohistochemistry analyses of cerebra during disease progression show a reduction in most Pol III transcripts, induction of innate immune and integrated stress responses and cell-type-specific gene expression changes reflecting neuron and oligodendrocyte loss and microglial activation. Earlier in the disease when integrated stress and innate immune responses are minimally induced, mature tRNA sequencing revealed a global reduction in tRNA levels and an altered tRNA profile but no changes in other Pol III transcripts. Thus, changes in the size and/or composition of the tRNA pool have a causal role in disease initiation. Our findings reveal different tissue- and brain region-specific sensitivities to a defect in Pol III transcription.

A Review of Visual Estimation Research on Live Pig Weight.

The weight of live pigs is directly related to their health, nutrition management, disease prevention and control, and the overall economic benefits to livestock enterprises. Direct weighing can induce stress responses in pigs, leading to decreased productivity. Therefore, modern livestock industries are increasingly turning to non-contact techniques for estimating pig weight, such as automated monitoring systems based on computer vision. These technologies provide continuous, real-time weight-monitoring data without disrupting the pigs' normal activities or causing stress, thereby enhancing breeding efficiency and management levels. Two methods of pig weight estimation based on image and point cloud data are comprehensively analyzed in this paper. We first analyze the advantages and disadvantages of the two methods and then discuss the main problems and challenges in the field of pig weight estimation technology. Finally, we predict the key research areas and development directions in the future.

Metabolic and Physiological Effects of Antibiotic-Induced Dysbiosis in Citrus

Streptomycin (Str) and oxytetracycline (Otc) are widely used antibiotics to manage bacterial diseases in citrus and other crops. However, their impacts on the rhizosphere bacterial assembly and plant physiology are poorly understood. The aim of this study was to examine the effects of Str and Otc on the physiology (assimilation, transpiration rate, intracellular CO2, and stomatal conductance to water vapor), rhizosphere bacterial assemblages (16S rRNA gene high-throughput amplicon sequencing), and rhizosphere metabolite profiles in healthy Citrus reticulata trees. The results indicated a reduction in photosynthesis after Str and Otc treatments, whereas CO2 outflow stayed constant. Both antibiotics decreased the culturable numbers of bacteria. Analysis of the microbiome showed changes in relative abundance of bacterial groups, specifically Pseudomonas, Agrobacterium, and Streptomyces, in response to the antibiotics. Metabolite profiles changed in streptomycin- and oxytetracycline-treated citrus plants suggesting response to microbe targets or induction of stress responses. This study advances knowledge of antibiotic-driven effects on the rhizosphere microbiome, rhizosphere metabolome, and plant physiology, which is essential for managing plant diseases while safeguarding rhizosphere ecology and long-term plant health.

Stress-induced cortisol response predicts empathy for pain: The role of task-based connectivity between the insula and sensorimotor cortex during acute stress

Empathy for pain is a key driver of prosocial behavior and is influenced by acute psychosocial stress. However, the role of task-based brain connectivity during acute stress have been neglected. Hence, we aimed to explore the relationship between the magnitude of cortisol response to acute stress and empathy for pain, as well as the neural connectivity mechanisms involved. In this study, 80 healthy participants (37 women and 43 men) were exposed to the acute psychosocial stress paradigm (ScanSTRESS) and were scanned by functional magnetic resonance imaging. Saliva samples were collected to measure the magnitude of cortisol stress response. Subsequently, the participants took part in a pain-video task to assess their empathy for pain. Six participants were excluded because of physical discomfort or excessive head movement in all runs during the task-dependent fMRI scan. Therefore, 33 women and 41 men were included in data analysis. We found that empathy for pain was negatively correlated with the magnitude of cortisol stress response (r = -0.268, p = 0.018) and that the task-based connectivity between the salience network and sensorimotor network, including its sub-network and sub-region, was negatively correlated with the magnitude of cortisol stress response, and positively correlated with empathy for pain. Furthermore, task-based connectivity between the insula and the paracentral lobule mediates the effect of the stress-induced cortisol response on empathy for pain (indirect effect = -0.0152, 95% CI = [- 0.036, -0.001], p = 0.036). Our research suggests that empathy is not only correlated with stress-induced glucocorticoids but also tied to the stress-induced reduced communication between basic and higher brain regions.

Enhanced pollen tube performance at high temperature contributes to thermotolerant fruit and seed production in tomato.

Rising temperature extremes during critical reproductive periods threaten the yield of major grain and fruit crops. Flowering plant reproduction depends on the ability of pollen grains to generate a pollen tube, which elongates through the pistil to deliver sperm cells to female gametes for double fertilization. We used tomato as a model fruit crop to determine how high temperature affects the pollen tube growth phase, taking advantage of cultivars noted for fruit production in exceptionally hot growing seasons. We found that exposure to high temperature solely during the pollen tube growth phase limits fruit biomass and seed set more significantly in thermosensitive cultivars than in thermotolerant cultivars. Importantly, we found that pollen tubes from the thermotolerant Tamaulipas cultivar have enhanced growth invivo and invitro under high temperature. Analysis of the pollen tube transcriptome's response to high temperature allowed us to define two response modes (enhanced induction of stress responses and higher basal levels of growth pathways repressed by heat stress) associated with reproductive thermotolerance. Importantly, we define key components of the pollen tube stress response, identifying enhanced reactive oxygen species (ROS) homeostasis and pollen tube callose synthesis and deposition as important components of reproductive thermotolerance in Tamaulipas. Our work identifies the pollen tube growth phase as a viable target to enhance reproductive thermotolerance and delineates key pathways that are altered in crop varieties capable of fruiting under high-temperature conditions.

Pubertal- and stress-dependent changes in cellular activation and expression of excitatory amino acid receptor subunits in the paraventricular nucleus of the hypothalamus in male and female rats.

Pubertal maturation is marked by significant changes in stress-induced hormonal responses mediated by the hypothalamic-pituitary-adrenal (HPA) axis, with prepubertal male and female rats often exhibiting greater HPA reactivity compared to adult males and females. Though the implications of these changes are unclear, elevated stress responsiveness might contribute to the stress-related vulnerabilities often associated with puberty. The current experiments sought to determine whether differences in cellular activation, as measured by FOS immunohistochemistry, or excitatory ionotropic glutamate receptor subunit expression, as measured by qRT-PCR, in the paraventricular nucleus (PVN) were associated with these noted pubertal shifts in stress reactivity in male and female rats. As the PVN is the key nucleus responsible for activating the hormonal stress response, we predicted greater cellular activation and higher expression levels of glutamate receptor subunits in the PVN of prepubertal males and females compared to their adult counterparts. Our FOS data revealed that while prepubertal males showed greater stress-induced activation in the PVN than adult males, prepubertal females showed less activation than adult females. Moreover, many of the NMDA, AMPA, and kainate receptor subunits measured, including Grin1, Grin2b, Gria1, Gria2, Grik1, and Grik2, had higher expression levels in adults, particularly in males. Though not supporting our initial predictions, these data do indicate that age and stress influence the activation of the PVN and the expression of glutamate receptor subunits important in its function. These data also suggest that the effects of age and stress are different in males and females. Though still far from a clear understanding of what mechanism(s) mediate pubertal shift in stress reactivity, these data add to our growing understanding of how age, stress, and sex influence HPA function.

Mechanisms of Staphylococcus aureus survival of trimethoprim-sulfamethoxazole-induced thymineless death.

Trimethoprim-sulfamethoxazole (SXT) is commonly used to treat diverse Staphylococcus aureus infections, including those associated with cystic fibrosis (CF) pulmonary disease. Studies with Escherichia coli found that SXT impairs tetrahydrofolate production, leading to DNA damage, stress response induction, and accumulation of reactive oxygen species (ROS) in a process known as thymineless death (TLD). TLD survival can occur through the uptake of exogenous thymidine, countering the effects of SXT; however, a growing body of research has implicated central metabolism as another potentially important determinant of bacterial survival of SXT and other antibiotics. Here, we conducted studies to better understand the mechanisms of TLD survival in S. aureus. We found that thymidine abundances in CF sputum were insufficient to prevent TLD of S. aureus, highlighting the importance of alternative survival mechanisms in vivo. In S. aureus cultured in vitro with SXT and low thymidine, we frequently identified adaptive mutations in genes encoding carbohydrate, nucleotide, and amino acid metabolism, supporting reduced metabolism as a common survival mechanism. Although intracellular ROS levels rose with SXT treatment in vitro, survival was not improved in the presence of ROS scavengers, unlike in E. coli. SXT challenge induced the SOS response, which was alleviated by added thymidine. Finally, an inactivating mutation in the phosphotransferase gene ptsI conferred both limitation in cellular ATP and improved survival against TLD. Collectively, these results suggest that alterations in core metabolic functions, particularly those that reduce ATP levels, predominantly confer S. aureus survival and persistence during SXT treatment, potentially identifying novel targets for co-treatment.IMPORTANCEStaphylococcus aureus is a ubiquitous organism and one of the leading causes of human infections, many of which are difficult to treat due to persistence, antibiotic resistance, or antibiotic tolerance. As our arsenal of effective antibiotics dwindles, the need for improved treatments becomes increasingly urgent, necessitating a better understanding of the precise mechanisms by which pathogens evade our most critical antimicrobial agents. Here, we report a systematic characterization of the mechanisms of S. aureus survival to treatment with the first-line antistaphylococcal antibiotic trimethoprim-sulfamethoxazole, identifying pathways and candidate targets for enhancing the efficacy of available antimicrobial agents.

The predictive value of stress-induced hyperglycemia parameters for delayed healing after tibial fracture post-surgery

PurposeThe objective of this retrospective cohort study was to investigate the predictive value of stress-induced hyperglycemia parameters for delayed healing after tibial fracture post-surgery.MethodsA cohort of 108 participants who underwent surgical intervention for tibial fractures caused by trauma was included in this retrospective study. Data collected from electronic medical records encompassed demographic characteristics, bone healing assessments, stress-induced hyperglycemia parameters, inflammatory markers, and stress-related hormones. Comparative analyses, correlation analyses, univariate logistic regression analyses, and receiver operating characteristic (ROC) curve analyses were conducted to assess the predictive value of the studied parameters.ResultsThe delayed healing group exhibited higher levels of fasting blood glucose, postprandial glucose, and HbA1c, as well as elevated levels of inflammatory markers and stress-related hormones compared to the normal healing group. Correlation analysis and logistic regression demonstrated positive associations between stress-induced hyperglycemia parameters, inflammatory markers, stress-related hormones, and delayed union of tibial fractures (R2: 0.183 ~ 0.403;OR: 1.091 ~ 16.332). ROC curve analysis revealed high area under the curve (AUC = 0.911) values for stress-induced hyperglycemia parameters, indicating their potential as predictive markers for delayed healing. Multivariate regression analysis further substantiated the predictive capability of stress-induced hyperglycemia parameters.ConclusionThe study findings highlight the complex interplay between stress-induced hyperglycemia, inflammatory response, and bone healing outcomes in patients undergoing surgical intervention for tibial fractures. The identification of stress-induced hyperglycemia parameters as potential predictive markers for delayed healing after tibial fracture surgery offers insights for risk assessment and patient management, emphasizing the need for comprehensive understanding of these factors to optimize postoperative recovery in orthopedic patients.

Effects of traffic noise on the psychophysiological responses of college students: An EEG study

Traffic noise harms public health, but the specific mechanisms are not fully understood. To understand how traffic noise at different sound pressure levels (SPLs) affects psychophysiological responses, this study examined five SPLs of traffic noise: 40, 45, 50, 55, and 60 dB. 38 young college students were recruited for Profile of Mood States (POMS) evaluations and measurements of electrocardiogram and electroencephalogram. The study found that traffic noise exposure led to a 0.95–1.64-fold increase in mood disturbance compared to no sound, with 60 dB traffic noise causing a significantly greater increase compared to other SPLs. As SPL increased, ΔLF/HF increased by 0.01–0.83, indicating heightened stress levels. Traffic noise also induced stress responses in the brain, with α power reduced by 13.08–24.15 % compared to no sound. High SPL traffic noise significantly harmed brain comfort. Compared to 40–45 dB, exposure to 50–60 dB traffic noise significantly increased α power by 28.66–85.80 % (p < 0.05). Additionally, 60 dB traffic noise increased the likelihood of supercritical brain activity by 32.49 % compared to no sound. Psychological response changes were closely related to physiological response changes. Δα power, particularly in the frontal and parietal lobes, was the strongest predictor of the increase in total mood disturbance, suggesting these lobes should be the focus of future traffic noise-brain studies. The study emphasizes the need for a comprehensive evaluation of the negative effects of traffic noise from a psychophysiological perspective, highlighting the harm of high SPLs. The findings provide valuable insights for developing indoor acoustic environment standards.

Co-transcribed genes SA1833-SA1832 promote persister formation by regulating the transcription of holin-like gene lrgA in methicillin-resistant Staphylococcus aureus strain N315

Staphylococcus aureus, a facultative anaerobic gram-positive bacterial pathogen, has posed major threat to public health worldwide. Upon S. aureus infection, the host immune system is activated for clearance. However, intracellular S. aureus, which remains viable for an extended time, has evolved the ability to escape from immune response and extracellular antibiotics. One of possible strategies is the formation of persisters. Persistence is one of the major causes of S. aureus relapse infection but the underlying mechanisms remain obscure. Here, we identified two co-transcribed genes SA1833-SA1832 that are involved in persister formation in S. aureus. Dysfunction of SA1833 and/or SA1832 significantly reduces persister formation in the presence of ceftizoxime. Additionally, we found that the expression of SA1833 and SA1832 under the induction of oxidative stress and SOS response is strictly regulated by the LexA-RecA pathway. Interestingly, SA1833-SA1832 contributes to persister formation in an lrgA-dependent manner. Moreover, the mouse RAW264.7 macrophage infection model indicated that disrupting SA1833-SA1832 inhibits S. aureus from infecting macrophages and impairs its ability to survive in the intracellular environment.

ER stress aggravates NOD1-mediated inflammatory response leading to impaired nutrient metabolism in hepatoma cells

Nucleotide-binding Oligomerization Domain 1 (NOD1) is a cytosolic pattern recognition receptor that senses specific bacterial peptidoglycan moieties, leading to the induction of inflammatory response. Besides, sensing peptidoglycan, NOD1 has been reported to sense metabolic disturbances including the ER stress-induced unfolded protein response (UPR). However, the underpinning crosstalk between the NOD1 activating microbial ligands and the metabolic cues to alter metabolic response is not yet comprehensively defined. Here, we show that underlying ER stress aggravated peptidoglycan-induced NOD1-mediated inflammatory response in hepatoma cells. The HepG2 cells, undergoing ER stress induced by thapsigargin exhibited an amplified inflammatory response induced by peptidoglycan ligand of NOD1 (i.e. iE-DAP). This aggravated inflammatory response disrupted lipid and glucose metabolism, characterized by de novo lipogenic response, and increased gluconeogenesis in HepG2 cells. Further, we characterized that the aggravation of NOD1-induced inflammatory response was dependent on inositol-requiring enzyme 1-α (IRE1-α) and protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) activation, in conjunction with calcium flux. Altogether, our findings suggest that differential UPR activation makes liver cells more sensitive towards bacterial-derived ligands to pronounce inflammatory response in a NOD1-dependent manner that impairs hepatic nutrient metabolism.

Effects of water immersion on immune, intestinal flora and metabolome of Chinese mitten crab (Eriocheir sinensis) after air exposure

Air exposure stress can induce stress response of Eriocheir sinensis and affect its normal life activities. The goal of this study was to investigate the effects of water immersion on the recovery of hepatopancreas immune-related enzyme activity, intestinal microbial diversity and metabolic level of Chinese mitten crabs after exposure to air. The results show that immersion can effectively alleviate the adverse effects of air exposure on the antioxidant capacity and immune capacity of Chinese mitten crabs, and the longer the time of immersion, the more obvious the recovery effect. Among them, the levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase and acid phosphatase significantly increased after exposure to air (P < 0.05), reached a peak at 3 h, began to decline after immersion, and returned to a level close to the initial value at 24 h (P < 0.05). In addition, after exposure to air, the glucose and total cholesterol in haemolymph of Eriocheir sinensis were significantly different from the initial values (P < 0.05), gradually recovered to the initial level after re-immersion. However, changes in intestinal flora and hepatopancreas metabolism caused by air exposure did not fully recover after water exposure, and its negative effects did not completely disappear. The sequencing results showed that the species composition and diversity of intestinal microorganisms of Chinese mitten crab changed after air exposure and immersion treatment. The relative abundance of Actinomycetes increased significantly, while that of Proteobacteria and Firmicutes decreased significantly. Metabolomics analysis showed that air exposure and immersion destroyed the metabolic balance of amino acids and carnitine, reduced the level of carnitine metabolism, hindered the absorption of nutrients, and led to the accumulation of harmful substances.

Response of Mycobacterium avium subsp. paratuberculosis isolates to reactive oxygen stress generated by treatment with copper ions

Copper (Cu) ions have been recognized for their efficacy in inactivating bacteria, including Mycobacterium avium subsp. paratuberculosis (MAP), the causative agent of Johne’s disease (JD) known for its resilience to unfavorable conditions. However, the response of MAP isolates isolated from cows to Cu exposure remains inadequately understood, as their responses may differ from those of laboratory-adapted reference strains. In this study, we examined the response of MAP isolates obtained from MAP-infected and affected cows to Cu ion treatment, comparing that with the response of the reference strain ATCC 19698 to the same treatment. Three MAP field isolates and the MAP reference strain were exposed to Cu ions, and their viability, protein/lipid damage, ROS production, and gene expression were evaluated in triplicate. Survival differed among isolates, with an isolate from a cow with clinical JD exhibiting increased tolerance to Cu exposure. While Cu treatment induced lipid peroxidation and ROS production across all isolates, genes associated with Cu detoxification and virulence were upregulated, particularly in the reference strain. Whole genome sequencing analysis revealed that, despite genomic similarities between field isolates and the reference strain ATCC 19698, there were differences regarding the presence/absence of genes related with certain virulence factors. Further research on Cu exposure with larger numbers of MAP isolates is needed to explain the stress-induced responses that influence MAP survival during natural infections and in challenging environments.

Regulation of corticosteroid-binding globulin release in murine leydig tumor cell line mLTC-1 by luteinizing hormone and interleukin-6

Exogenous assaults interfere with homeostatic processes in the body by inducing stress responses. Corticosteroid-binding globulin (CBG) binds to stress hormone glucocorticoids to transport and dynamically control their availability to target tissues. In our previous study, we confirmed that CBG is locally produced by Leydig cells in the testes. Here, we explored the potential regulators of CBG using a murine Leydig tumor cell line (mLTC-1). Results indicated that luteinizing hormone (LH) and interleukin-6 (IL-6) were important factors stimulating the release of CBG from mLTC-1 cells. In addition, IL-6 stimulated mLTC-1 cells to release alpha-1 antitrypsin (AAT), a serine proteinase inhibitor (serpin) that affects CBG conformation. The results implied that any challenge that altered LH or IL-6 levels also changed the release and binding status of CBG with steroid hormones in the testicular microenvironment and modulated cellular responses to these stress hormones. In addition, secretory proteomic analysis indicated that the extracellular matrix (ECM), cytoskeleton, and proteasomes were essentially produced by the mLTC-1 cells, and LH evoked the secretion of proteins involved in binding and metabolism. These results emphasize that Leydig cells may undertake more functions than just steroidogenesis, and the regulation of Leydig cells by LH is versatile.

PCSK1N as a tumor size marker and an ER stress response protein in corticotroph pituitary adenomas.

Silent corticotroph adenoma (SCA) exhibits more tumor aggressiveness features than functioning adenomas (FCA). We aimed to investigate PCSK1N expression in CA and examine if ER stress-induced responses affect cell survival in a corticotroph tumor cell model. Clinical and imaging characteristics were recorded in 33 patients with FCA (20 women, 11 macroadenomas) and 18 SCA (8 women, all macroadenomas). Gene expression of proopiomelanocortin (POMC), T-box transcription factor 19(TBX19)/TPIT, proprotein convertase subtilisin/kexin type 1(PCSK1)/PC1/3, and its inhibitor PCSK1N, was measured by RT-qPCR in adenoma tissue.Mouse pituitary corticotroph tumor (AtT-20) cells were treated with tanespimycin (17-AAG), a HSP90 chaperone inhibitor, to induce ER stress, followed by gene and protein analyses. POMC, TPIT, and PCSK1 expression were higher, whereas PCSK1N was lower in FCA compared to SCA. PCSK1N correlated with POMC (rs= -0.514, p <0.001), TPIT (rs= -0.386, p = 0.005), PCSK1 (rs= -0.3691, p = 0.008), and tumor largest diameter (rs= 0.645, p <0.001), in all CA. Induction of ER stress by 17-AAG in AtT-20 cells led to a decrease of POMC and an increase of PCSK1N gene expression at 24h. Moreover, a downregulation of cell cycle, apoptosis, and senescence pathways, and alterations in cell adhesion and cytoskeleton were observed at the protein level. PCSK1N is higher in SCA compared with FCA, and associated with corticotroph cell markers and tumor size. PCSK1N is likely to be part of the adaptive response to ER stress, potentially conferring a survival advantage to the corticotroph tumor cell in conjunction with other proteins.

Acute stress and blockade of mineralocorticoid or glucocorticoid receptors: Effects on working memory

Although early studies were able to demonstrate a negative impact of stress on working memory performance, present research findings are heterogeneous. Numerous further studies found no effects or even improved performance, with the direction of these stress effects likely depending on the underlying biological mechanisms. The aim of this study was to investigate receptor-specific effects, as part of the stress-induced cortisol response, on working memory performance. Healthy, male participants (N=318, mean age 25.4 ± 5.1y) were exposed to the Trier Social Stress Test (TSST), a social-evaluative stress manipulation, or a non-stress control condition after they had received either spironolactone (blockade of the mineralocorticoid receptor, MR) or mifepristone (blockade of the glucocorticoid receptor, GR) or a placebo. Both substances are potent antagonists with high affinity for the respective receptors. To assess working memory, we implemented the n-back task subsequent to stress exposure, number of correct responses and reaction times served as outcome measures. We did not find effects of stress on working memory for any outcome measure, i.e. correct responses and reaction times. Yet, post hoc tests revealed that the group that received mifepristone exhibited longer reaction times under medium load conditions when compared to the placebo group, which might be an indication of the GR’s involvement in task performance. We conclude that working memory performance is not affected by acute stress, at least under these prevalent conditions.

The impact of irrigation with harvested rainwater containing asbestos cement matrix on the germination characteristics of Solanum lycopersicum

AbstractThe study aims to investigate how the transfer of matrix materials from eroded asbestos cement products induces stress responses in plants. The paper evaluates the exposure and risk factors of plants, water, and soil to asbestos cement materials. Additionally, the experimental results provide empirical evidence for plant stress responses based on physiological and germination parameters. Contamination of irrigation water with asbestos cement raises environmental concerns due to its potential toxicity to plants and soil quality. Asbestos in irrigation water can lead to toxic stress for plants, affecting germination processes and growth. The paper analyzes the effects of preset doses of irrigation water containing asbestos cement matrix on the germination process and physiological parameters of Solanum lycopersicum in a controlled experiment setting. This research proposes methodological developments that could be valuable for environmental plant protection professionals.