Stress Response Research Articles

SpWRKY71 is required for drought tolerance in tomato

ABSTRACT Drought has a profound impact on the growth, development and quality yield of crops. It has been demonstrated that WRKY transcription factors (TFs) play an important role in abiotic stress responses. Previously, numerous studies have documented the functional role of these TFs in a range of plant species. In this study, the SpWRKY71 gene from the wild tomato specie, Solanum. pennellii, was identified and its role in drought stress tolerance was investigated. Subcellular localisation showed that SpWRKY71 is predominantly nuclear in localisation and exhibited elevated transcript levels following PEG6000 and abscisic acid (ABA) treatments. Furthermore, we employed virus-induced gene silencing (VIGS) technology to examine the function of SpWRKY71 in tomato under stress conditions. The plants in which SpWRKY71 had been silenced demonstrated a high sensitivity to drought conditions, exhibiting accelerated and more severe stem and leaf wilting compared to the control plants. The results indicated that SpWRKY71 silencing resulted in a significant exacerbation of drought-induced oxidative damage, as evidenced by an increase in the accumulation of hydrogen peroxide (H₂O₂), superoxide anion (O₂–) and malondialdehyde (MDA) and reduction in the antioxidant enzyme activities and stress-related genes compared to the control. These results indicate that SpWRKY71 plays a significant role in the mechanism of drought stress tolerance in tomato, thereby providing theoretical foundation for the study of the SpWRKY71-mediated drought tolerance in plants.

Genome wide identification of Dof transcription factors in Carmine radish reveals RsDof33 role in cadmium stress and anthocyanin biosynthesis

Carmine radish (Raphanus sativus L.) is cultivated in Fuling, Chongqing, for its red color. Dof-TFs are critical in regulating plant growth, development, stress responses, and signal transduction.This work comprehensively examined the structure, evolution, and expression of the carmine radish Dof gene and its behavior under cadmium (Cd) stress. The radish genome has 59 RsDofs, which are divided into nine clusters (A: 8, B1: 10, B2: 10, C1: 3, C2.1: 5, C2.2: 4, C3: 11, D1: 4, and D2: 4). Phylogenetic tree analysis revealed significant Dof gene family resemblance between Arabidopsis thaliana and Brassica napus. Perhaps segment duplication resulted in RsDof gene family expansion. Cd stress-induced RsDof expression patterns were studied using an RNA-seq atlas and qRT-PCR. The majority of RsDofs were tissue-specific and Cd-sensitive. The involvement of RsDof genes in Cd stress response and anthocyanin synthesis was verified using qRT-PCR. RsDof33 is involved in Cd stress response and anthocyanin synthesis. A. thaliana overexpressed the recombinant fusion protein RsDof33-GFP, which was localized to the nucleus, resulting in fewer rosette leaves, delayed flowering, and higher anthocyanin concentration. RsDof33-expressing plants had significantly higher transcript levels of the auxin biosynthetic genes YUCCA (AtYUC2), auxin efflux carrier (AtPIN4), and AtKNAT2, which are involved in leaf shape development, as well as AtPAL, AtCHS, AtCHI, AtDFR, AtLDOX, and AtUF3GT. These findings indicate that RsDofs are critical to plant development and stress responses.

Sirtuin1 Deficiency Could Exacerbate Melanocyte Apoptosis Under Endoplasmic Reticulum Stress.

Vitiligo is a depigmentation disease caused by the targeted destruction of melanocytes, resulting in skin and hair depigmentation and significant psychological stress. However, the mechanisms underlying its onset and progression remain unclear. Endoplasmic reticulum (ER) stress, which is linked with oxidative stress and autoimmunity, is involved in the development of vitiligo, and prolonged ER stress induces apoptosis. Sirtuin 1 (Sirt1) might be a key regulator of ER stress. Thus, we explored how Sirt1 modulates ER stress-induced melanocyte apoptosis in vitro and in vivo. Our results showed that Sirt1 affected ER stress-induced apoptosis of melanocyte apoptosis when upon to ER stress in vitro. Sirt1 inhibition aggravated the vitiligo phenotype in mice; thereby protecting against the stress response, and abating the unfolded protein response. These results suggest that Sirt1 impairment could accelerate melanocyte apoptosis in vitiligo.

Lipid transfer protein VAS inhibits the hypersensitive response via reactive oxygen species signaling in Nicotiana benthamiana.

Lipid transfer proteins (LTPs) are small cysteine-rich soluble proteins that affect flower and seed development, cuticular wax deposition, and biotic and abiotic stress responses. We isolated an LTP-encoding gene homologous to LTPVAS in Nicotiana benthamiana and designated it LTP-VASCULAR TISSUE SIZE (NbLTPVAS). This gene was expressed in seeds, leaves, roots, and stems. Additionally, NbLTPVAS expression was induced by hypersensitive response (HR)-inducing agents. Cell death was accelerated and the phytopathogenic bacterial population decreased significantly in NbLTPVAS-silenced plants infected with the incompatible Ralstonia solanacearum strain 8107. The expression of HR marker gene hin1 in NbLTPVAS-silenced plants was markedly induced by R. solanacearum 8107, indicative of the acceleration of HR. HR cell death in NbLTPVAS-silenced plants was also promoted by the Agrobacterium-mediated expression of HR-inducing proteins including INF1, AvrA, and PopP1. Excessive production of reactive oxygen species (ROS) was detected in NbLTPVAS-silenced plants. The expression of NbrbohB (encoding a ROS-generating enzyme) also increased in NbLTPVAS-silenced plants, but the expression of the antioxidant enzyme-encoding genes NbSOD and NbAPX decreased. The silencing of both NbLTPVAS and NbrbohB adversely affected HR induction. Moreover, NbLTPVAS was secreted into the intercellular washing fluid. The transient expression of the full-length NbLTPVAS induced the expression of antioxidant genes, attenuated ROS production, and suppressed the induction of HR cell death. This is the first functional analysis of LTPVAS in plant-microbe interactions. Our study provides novel insights into the role of NbLTPVAS as a negative regulator of HR via ROS homeostasis in N. benthamiana.

Understanding and Treating Obsessive-compulsive Disorder: The Interplay of Genetic, Environmental, and Therapeutic Factors

Millions worldwide suffer from OCD, which begins in adolescence and impairs daily life. Many genetic and environmental variables induce OCD. It examines heredity and environment as OCD causes. OCD is connected to serotonin and dopamine gene polymorphisms. Serotonin and glutamate transporter gene polymorphisms increase OCD risk. OCD is caused by a neurochemical imbalance that affects emotional control and behavior, according to these genetics. Childhood trauma, stress, poor life experiences, and genetics promote OCD symptoms. Neurodevelopment and the stress response system are affected by emotional, physical, or sexual abuse, rendering youngsters more prone to OCD. Early unpleasant experiences can dysregulate the stress-regulating hypothalamic-pituitary-adrenal (HPA) axis, generating anxiety and compulsivity. Life experiences and biological stresses may induce OCD, including prenatal effects, maternal stress, and infections. Genetics and environment complicate OCD's biochemical and experiential factors. This knowledge is essential for OCD therapy and prevention. Early detection of at-risk individuals, especially those with a genetic predisposition to OCD or trauma, permits concentrated therapy. CBT, especially exposure and response prevention, can cure OCD by changing maladaptive cognitive processes and behaviors. Some people's OCD symptoms improve with SSRIs' neurochemical balance. OCD treatment should incorporate genetic and environmental factors, according to this paper. Researchers and doctors can improve patient-specific treatment strategies by analyzing these complex relationships. Genetic testing, environmental assessments, and therapy tactics affect OCD treatment outcomes and quality of life. Genetic and environmental research is needed to understand OCD and develop new treatments and preventative methods.

CRISPuRe-seq: pooled screening of barcoded ribonucleoprotein reporters reveals regulation of RNA polymerase III transcription by the integrated stress response via mTOR.

Genetic screens usingCRISPR (Clustered Regularly Interspaced Palindromic Repeats)provide valuable information about gene function. Nearly all pooled screening technologies rely on the cell to link genotype to phenotype, making it challenging to assay mechanistically informative, biochemically defined phenotypes. Here, we present CRISPuRe-seq(CRISPR PuRification), a novel pooled screening strategy that expands the universe of accessible phenotypes through the purification of ribonucleoprotein complexes that link genotypes to expressed RNA barcodes. While screening for regulators of the integrated stress response (ISR), we serendipitously discovered that the ISR represses transfer RNA (tRNA) production under conditions of reduced protein synthesis. This regulation is mediated through inhibition of mTORC1 and corresponding activation of the RNA polymerase III inhibitor MAF1. These data demonstrate that coherent downregulation of tRNA expression and protein synthesis is achieved through cross-talk between the ISR and mTOR, two master integrators of cell state.

The neurobiological impact of oxytocin in mental health disorders: a comprehensive review

Oxytocin, a neuropeptide, plays a significant role in modulating social behavior and has been widely studied for its potential impact on mental health disorders. This review examines the neurobiological mechanisms through which oxytocin influences mental health and its therapeutic potential in conditions such as autism spectrum disorder, schizophrenia, PTSD, anxiety, and depression. Oxytocin enhances social bonding, trust, and empathy by modulating neural circuits linked to social interactions. Studies indicate that oxytocin’s ability to regulate the hypothalamic-pituitary-adrenal (HPA) axis plays a vital role in stress response and emotional regulation. Therapeutic applications, particularly intranasal administration of oxytocin, have shown promise in alleviating symptoms and improving patient outcomes. However, personalized approaches are essential to optimize treatment effectiveness. Despite its potential, challenges remain in understanding the mechanisms underlying its effects and identifying the patient populations that would benefit most from such therapies. Future research should focus on elucidating these mechanisms, exploring the long-term efficacy of oxytocin-based interventions, and advancing personalized medicine to maximize its clinical utility.

Vagal circuits in the heart and gut can regulate cardiometabolism and stress responses.

Vagal circuits in the heart and gut can regulate cardiometabolism and stress responses.

The genomic and epigenomic landscapes of hemizygous genes across crops with contrasting reproductive systems

Hemizygous genes, which are present on only one of the two homologous chromosomes of diploid organisms, have been mainly studied in the context of sex chromosomes and sex-linked genes. However, these genes can also occur on the autosomes of diploid plants due to structural variants (SVs), such as a deletion/insertion of one allele, and this phenomenon largely unexplored in plants. Here, we investigated the genomic and epigenomic landscapes of hemizygous genes across 22 genomes with varying propagation histories: eleven clonal lineages, seven outcrossed samples, and four inbred and putatively homozygous genomes. We identified SVs leading to genic hemizygosity. As expected, very few genes (0.01 to 1.2%) were hemizygous in the homozygous genomes, representing negative controls. Hemizygosity was appreciable among outcrossed lineages, averaging 8.7% of genes, but consistently elevated for the clonal samples at 13.8% genes, likely reflecting heterozygous SV accumulation during clonal propagation. Compared to diploid genes, hemizygous genes were more often situated in centromeric than telomeric regions and experienced weaker purifying selection. They also had reduced levels of expression, averaging ~20% of the expression levels of diploid genes, violating the evolutionary model of dosage compensation. We also detected higher DNA methylation levels in hemizygous genes and transposable elements, which may contribute to their reduced expression. Finally, expression profiles showed that hemizygous genes were more specifically expressed in contexts related to fruit development, organ differentiation, and stress responses. Overall, hemizygous genes accumulate in clonally propagated lineages and display distinct genetic and epigenetic features compared to diploid genes, shedding unique insights into genetic studies and breeding programs of clonal crops.

Deciphering Regulatory Networks Governing Seedling Emergence in Deep-Sown Direct-Seeded Rice Cultivation

The rise of direct-seeded rice cultivation as a suitable alternative to transplanted puddled rice depends on developing genotypes with high seedling emergence under deep sown conditions. Two rice genotypes (IRGC 128442 and PR126) were screened for contrasting seedling emergence and subjected to high-throughput RNA sequencing under varying sowing depths (4 cm and 10 cm) and time intervals (5, 10, and 15 days after sowing). On average, a total of 2702 differentially expressed genes were identified across twelve inter- and intra-genotypic pairwise differential expression analyses, with a false discovery rate ≤ 0.05 and log2 fold change ≥ ± 2. The DEGs specifically showing differential expression under deep-sowing stress were prioritized and further refined based on their corresponding gene ontology terms, gene set enrichment analysis and KEGG and plant reactome pathway. From this pool of DEGs, 24 genes were validated using qRT-PCR. Among these, two genes (LOC_Os04g51460 and LOC_Os02g45450) contribute to cell wall remodelling and membrane stability, while three genes (LOC_Os04g48484, LOC_Os06g04399, and LOC_Os07g15440) play key roles in mitigating abiotic stress. Transcriptional regulators (LOC_Os06g33940 and LOC_Os01g45730) drive stress responses and growth. Notably, high fold changes in LOC_Os03g22720 and LOC_Os07g01960 underscore their importance in early stress responses and metabolic adjustments. The transcriptome analysis also highlighted the role of 29 heat shock proteins in response to deep sowing stress. Differential expression of key components in the abscisic acid (ABA)-mediated signalling pathway such as OsABI5 (LOC_Os01g64000), phosphatase 2C-like (PP2C) (LOC_Os09g15670) and OsPYL (LOC_Os06g36670) indicated downregulation of ABA signalling in the genotype IRGC 128442. Additionally, a role for miRNA-mediated regulation of auxin response factors was hypothesized in seedling emergence regulation. The study brings us closer to understanding the genetic control of seedling emergence under deep sown conditions. Functional validation of the key candidate genes and pathways could provide new targets for genetic improvement, potentially contributing to the development of rice cultivars optimized for direct-seeded rice cultivation.

Metabolic profiling reveals distinctive ripening dynamics in ethylene-treatedMusa balbisiana cv. 'Pisang Klutuk Wulung' comparedtocommercial Cavendish banana.

As an important crop, bananas still encounter fruit quality and shelf-life problems that are affected by the ripening process. Improving postharvest technologies may effectively address these challenges, such as by studying the ripening mechanism of banana cultivars with a slow ripening process. A banana cultivar that exhibits this characteristic is Musa balbisiana cv. 'Pisang Klutuk Wulung' (BB Group) or Pisang Klutuk Wulung (PKW), which has a ripening duration of 14-28 days. However, the metabolomics study on the ripening mechanism of this banana is still limited. This study aimed to analyze metabolite changes in ethylene-treated Pisang Klutuk Wulung during ripening in comparison to commercial bananas (Cavendish). Both bananas were subjected to exogenous ethylene treatment and analyzed using gas chromatography-mass spectrometry to perform metabolite profiling throughout the ripening process. The principal component analysis showed sample separation based on the ripening stages and banana species in pulp and peel. Orthogonal projection to latent structure analysis suggested that metabolite changes accompanied the ripening stages. Potential metabolite markers that distinguished the ripening of PKW and Cavendish were found, such as quinic acid, inositol, and 2-aminoethanol. This study shows differences in metabolite profiles between these bananas, especially the metabolites involved in sugar metabolism, cell wall metabolism, stress response, and biosynthesis of aromatic compounds. This study provides novel insights into the metabolic changes occurring during PKW ripening, contributing to the improvement of banana postharvest strategies.

A C2H2 Zinc Finger Protein, OsZOS2-19, Modulates ABA Sensitivity and Cold Response in Rice.

Cold stress is a major factor limiting rice (Oryza sativa L.) productivity, making it crucial to understand the molecular mechanisms underlying stress responses to develop resilient crops. In this study, we characterized OsZOS2-19, a cold- and abscisic acid (ABA) -responsive C2H2 zinc finger protein, which functions as a transcriptional repressor. Overexpression of OsZOS2-19 in rice lines increases sensitivity both cold and ABA, reducing cold tolerance, disrupting osmotic balance, and impairing reactive oxygen species (ROS) scavenging. RNA sequencing revealed that OsZOS2-19 overexpression interfered with key stress-response pathways, including those associated with sugar metabolism and glutathione biosynthesis. These findings suggest that OsZOS2-19 negatively regulates cold tolerance and ABA sensitivity by modulating ROS accumulation and osmotic balance, offering new insights into cold adaptation in rice.

Backbone resonance assignment of the catalytic and ATP-binding domain of CpxA from Escherichia coli.

CpxA is an extensively studied histidine kinase implicated in cellular stress responses. The highly conserved CA domain of CpxA (CpxACA) is an essential domain for the hydrolysis of ATP and the binding of inhibitors and considered to be a promising target for broad-spectrum antimicrobial drugs development. The ATP-binding pocket in the CA domain contains a flexible ATP lid motif. Although the crystal structure of CA domain has been defined, the structure of the ATP lid remains uncertain, posing a challenge to the study of its catalytic mechanism. In this study, we report the backbone 1H, 13C and 15N chemical shift assignments of CpxACA by heteronuclear multidimensional spectroscopy and predict its secondary structure in solution using TALOS+. The residues of ATP lid motif are well-assigned. Therefore, this study provides a foundation for understanding the role of CpxACA in cellular signaling and the development of novel antimicrobial therapies.

Harnessing the fundamental roles of vitamins: the potent anti-oxidants in longevity.

Aging is a complex and heterogeneous biological process characterized by telomere attrition, genomic instability, mitochondrial dysfunction, and disruption in nutrient sensing. Besides contributing to the progression of cancer, metabolic disorders, and neurodegenerative diseases, these manifestations of aging also adversely affect organ function. It is crucial to understand these mechanisms and identify interventions to modulate them to promote healthy aging and prevent age-related diseases. Vitamins have emerged as potential modulators of aging beyond their traditional roles in health maintenance. There is an increasing body of evidence that hormetic effects of vitamins are responsible for activating cellular stress responses, repair mechanisms, and homeostatic processes when mild stress is induced by certain vitamins. It is evident from this dual role that vitamins play a significant role in preventing frailty, promoting resilience, and mitigating age-related cellular damage. Moreover, addressing vitamin deficiencies in the elderly could have a significant impact on slowing aging and extending life expectancy. A review of recent advances in the role of vitamins in delaying aging processes and promoting multiorgan health is presented in this article. The purpose of this paper is to provide a comprehensive framework for using vitamins as strategic tools for fostering longevity and vitality. It offers a fresh perspective on vitamins' role in aging research by bridging biological mechanisms and clinical opportunities.

Effects of Moringa oleifera seed extract on growth and immunophysiology of whisker catfish (Mystus gulio) fingerlings.

In aquaculture, phytobiotics are used as growth promoters, immunomodulators, antioxidants, and stress mitigators in several fish species. Herein, we assess the impact of Moringa oleifera seeds petroleum ether extracts (MSE) on growth, hematological, and biochemical responses in whisker catfish (Mystus gulio). A total of 120 M. gulio fingerlings (mean weight 2.09 ± 0.16 g) were randomly distributed in four different experimental groups. Fish were fed to satiation with the experimental diets [T1 (control, 0% MSE), T2 (0.05% MSE), T3 (0.10% MSE), and T4 (0.15% MSE)] for 60 days. Results demonstrated that fingerlings fed with 0.05 and 0.10% MSE-supplemented diet significantly enhanced weight gain, specific growth rate, protein efficiency ratio, hemato-immunological indices (erythrocyte count, leucocyte count, hemoglobin, globulin, serum protein, and respiratory burst activity) and survival compared to other groups (P < 0.05). However, at the higher dose of MSE (0.15%), a significant reduction in the above parameters was observed (P < 0.05). Feeding MSE at 0.05 and 0.10% significantly minimizes the stress responses (blood glucose, cortisol, and catalase). Dose-dependent reduction in serum cholesterol and high-density lipid and an increase in triglyceride were recorded (P < 0.05). Histopathological observation of liver tissue showed congestion of hepatic vein at 0.15% MSE supplementation. Overall, the study suggests that the dietary supplementation of MSE up to 0.10% improves growth, biochemical, and innate immune response in M. gulio fingerlings.

The Usefulness of physiological and biochemical stress response of soil collembola (Xenylla welchi Folsom, 1916) as a biomarker in a lead-amended garden soil

The Usefulness of physiological and biochemical stress response of soil collembola (Xenylla welchi Folsom, 1916) as a biomarker in a lead-amended garden soil

REDD1 expression in podocytes facilitates renal inflammation and pyroptosis in streptozotocin-induced diabetic nephropathy

Sterile inflammation resulting in an altered immune response is a key determinant of renal injury in diabetic nephropathy (DN). In this investigation, we evaluated the hypothesis that hyperglycemic conditions augment the pro-inflammatory immune response in the kidney by promoting podocyte-specific expression of the stress response protein regulated in development and DNA damage response 1 (REDD1). In support of the hypothesis, streptozotocin (STZ)-induced diabetes increased REDD1 protein abundance in the kidney concomitant with renal immune cell infiltration. In diabetic mice, administration of the SGLT2 inhibitor dapagliflozin was followed by reductions in blood glucose concentration, renal REDD1 protein abundance, and immune cell infiltration. In contrast with diabetic REDD1+/+ mice, diabetic REDD1−/− mice did not exhibit albuminuria, increased pro-inflammatory factors, or renal macrophage infiltration. In cultured human podocytes, exposure to hyperglycemic conditions promoted REDD1-dependent activation of NF-κB signaling. REDD1 deletion in podocytes attenuated both the increase in chemokine expression and macrophage chemotaxis under hyperglycemic conditions. Notably, podocyte-specific REDD1 deletion prevented the pro-inflammatory immune cell infiltration in the kidneys of diabetic mice. Furthermore, exposure of podocytes to hyperglycemic conditions promoted REDD1-dependent pyroptotic cell death, evidenced by an NLRP3-mediated increase in caspase-1 activity and LDH release. REDD1 expression in podocytes was also required for an increase in pyroptosis markers in the glomeruli of diabetic mice. The data support that podocyte-specific REDD1 is necessary for chronic NF-κB activation in the context of diabetes and raises the prospect that therapies targeting podocyte-specific REDD1 may be helpful in DN.

Investigating the Interplay Between the Nrf2/Keap1/HO-1/SIRT-1 Pathway and the p75NTR/PI3K/Akt/MAPK Cascade in Neurological Disorders: Mechanistic Insights and Therapeutic Innovations.

Neurological illnesses are debilitating diseases that affect brain function and balance. Due to their complicated aetiologies and progressive nature, neurodegenerative and neuropsychiatric illnesses are difficult to treat. These incurable conditions damage brain functions like mobility, cognition, and emotional regulation, but medication, gene therapy, and physical therapy can manage symptoms. Disruptions in cellular signalling pathways, especially those involving oxidative stress response, memory processing, and neurotransmitter modulation, contribute to these illnesses. This review stresses the interplay between key signalling pathways involved in neurological diseases, such as the Nrf2/Keap1/HO-1/SIRT-1 axis and the p75NTR/PI3K/Akt/MAPK cascade. To protect neurons from oxidative damage and death, the Nrf2 transcription factor promotes antioxidant enzyme production. The Keap1 protein releases Nrf2 during oxidative stress for nuclear translocation and gene activation. The review also discusses how neurotrophin signalling through the p75 neurotrophin receptor (p75NTR) determines cell destiny, whether pro-survival or apoptotic. The article highlights emerging treatment approaches targeting these signalling pathways by mapping these connections. Continued research into these molecular pathways may lead to new neurological disease treatments that restore cellular function and neuronal survival. In addition to enhanced delivery technologies, specific modulators and combination therapies should be developed to fine-tune signalling responses. Understanding these crosstalk dynamics is crucial to strengthening neurological illness treatment options and quality of life.

Assessment of laparotomy-induced stress response in opium- and morphine-addicted rats by measuring serum glucose and corticosterone levels: an animal experiment

Background: Surgical procedures induce stress responses similar to severe illnesses, activating the metabolic and neuroendocrine systems, especially the hypothalamic-pituitary-adrenal (HPA) axis. The resulting cortisol surge maintains homeostasis but can adversely affect recovery by elevating blood glucose levels and increasing the risk of complications. Given the high prevalence of opium use, especially in the Middle East and southwestern Asia, and its suspected impact on HPA axis function, this study assesses corticosterone (CS) and glucose as indicators of impaired neuroendocrine responses to surgical stress in an animal model with chronic opioid use. Materials and methods: Thirty-six male Wistar rats were randomly assigned to three groups: morphine-addicted, opium-addicted, and control. Addiction was induced by administering increasing doses of morphine or opium in drinking water, as verified by naloxone injections. Laparotomy was performed under ketamine and xylazine anesthesia. Blood samples were collected post-surgery and post-recovery to measure the CS and glucose levels. Results: This study included 30 rats, with ten rats per group. Post-surgery, mean CS levels were higher in the control group compared to the addicted groups, although not significantly higher. Thirty minutes post-recovery, CS levels remained elevated in the addicted groups. Mean glucose levels were significantly higher in the control group both immediately and thirty minutes post-recovery, indicating a sustained hyperglycemic response. No significant differences were observed between addicted groups in glucose levels. Conclusion: Our study suggests that chronic opioid use may reduce the neuroendocrine response to surgical stress, as shown by lower CS levels in addicted rats. This aligns with existing research on opioids and stress responses. However, the small sample size and lack of baseline measurements limit the findings. Future studies should use larger, more diverse samples and additional biomarkers. This pilot study highlights the need for further research on altered stress responses in opioid-addicted patients undergoing surgery, emphasizing the importance of tailored postoperative care.

Brain and cardiovascular responses to acute stress in remitted and recurrent late-life depression.

In individuals with remitted late-life depression (LLD), stress exposure can increase the likelihood of a new, recurrent depressive episode. Variability in the effect of stress on recurrence risk may reflect underlying brain and physiological processes mediating the stress response. We examined how subjective, physiological, and brain responses to an experimental stressor differs in older adults with and without remitted depression, and how these stress responses relate to future relapse. Participants were recruited through 3 sites and included 76 older adults with remitted LLD and 36 age-matched healthy comparison (HC) adults. Participants completed an acute stressor task during functional brain imaging with behavioral and cardiovascular monitoring. Remitted LLD participants were followed longitudinally to evaluate depression recurrence. Compared to HC, the remitted LLD group exhibited reduced stressor-evoked systolic blood pressure and heart rate responses, as well as reduced stressor-evoked posterior insula activity. This blunted stress response phenotype appeared more specific to the stable remitter group than the relapsing LLD group. Survival analyses demonstrated that greater stressor-evoked bed nucleus of the stria terminalis (BNST) activity was associated with faster time to recurrence. These findings add to a growing literature reporting so-called "blunted" stressor-evoked cardiovascular and brain reactivity in remitted depression. Moreover, they link the stress response in visceral interoceptive brain circuits with relapse vulnerability. Future work involving longer follow-up periods may reveal additional stress-related brain and behavioral predictors of recurrence in remitted LLD.