Biological stress response terminology: Integrating the concepts of adaptive response and preconditioning stress within a hormetic dose-response framework

Laminaria digitata Extract Improved Leaf Meristem Protection Under Drought and Nitrogen Uptake After Rehydration Through Hormesis-Based Chemical Priming in Lolium perenne

Drought is among the most damaging stress for plants, impacting crop yield and grassland sustainability. This study aimed to evaluate the biostimulant effect of an algal extract from Laminaria digitata on Lolium perenne cultivated in a growth chamber. Leaves were sprayed at different concentrations 7 days before stopping irrigation. This priming period was followed by fourteen days of drought and ten days of recovery. Algal extract supplied at 2 and 5 L.ha-1 stimulated nitrogen uptake during recovery, while higher doses were deleterious. During drought, algal extract 2 L.ha-1 increased water content in leaves and shoot 0-3 cm housing the leaf meristems. The improvement in water content arose from the smaller decline in leaf relative water content (RWC), suggesting better osmotic adjustment. Cell membrane stability was less impaired during drought and quickly returned to pre-drought levels during recovery, indicating better membrane protection. The higher fructan content may contribute to osmotic adjustment and membrane protection. The results show that algal extract improved leaf meristem protection under drought and N uptake after rehydration through hormesis-based chemical priming. The treatment limited sucrose accumulation during drought, so that sucrose content can be used as an indicator of biostimulation together with RWC and cell membrane stability.

Ex Situ Thermal Preconditioning Modulates Coral Physiology and Enhances Heat Tolerance: A Multispecies Perspective for Active Restoration

Global warming threatens reef-building corals by challenging their adaptive capacity. Therefore, interventions such as stress-hardening by thermal preconditioning could become crucial for their survival. This study aimed to systematically assess the effects of distinct thermal preconditioning regimes (stable-high at 29 °C, variable-high at 29 ± 1.5 °C, and stable-ambient control at 26 °C) on the baseline physiology and thermal tolerance of six stony coral species (Galaxea fascicularis, Porites rus, Acropora muricata, Montipora digitata, Pocillopora verrucosa, and Stylophora pistillata) to determine commonalities in the stress-hardening responses that transcend species-specific signatures. For this, we quantified changes in photosynthetic efficiency and bleaching intensity before and after a short-term heat stress assay and up to 30 days later. Stress-hardening was successful in all preconditioned corals, with the variable-high regime slightly outperforming the stable-high regime. Preconditioning reduced the heat stress response by up to 90%, yet species differed in receptiveness. It also improved resilience (survival and recovery), and corals with high inherent thermal tolerance recovered better than susceptible species. Notably, both preconditioning regimes affected baseline physiology, exclusively of the branching species, causing tissue paling and decreased photosynthetic efficiency. We conclude that implementing thermal stress-hardening protocols requires consideration of the species-specific receptiveness and potential physiological trade-offs.

Effect of graded inclusion of black soldier fly (Hermetia illucens, Linnaeus, 1758) pre-pupae meal in diets for gilthead seabream (Sparus aurata, Linnaeus, 1758) on gut microbiome and liver morphology

Over the last decades, an insect meal has received great attention for finfish diets, due to its nutritional composition and low ecological footprint. In the present study, we assessed the response of gut microbiota composition and liver histology of gilthead seabream (Sparus aurata) fed four experimental diets including the black soldier fly (Hermetia illucens) meal (HI) used to replace 0 (HI0), 25 (HI25), 35 (HI35) and 50 (HI50) percent of fish meal in a 131-day feeding trial. At the end of the experiment, a remarkable change in gut microbiota composition related to HI inclusion was observed, with a preponderance of Cyanobacteriain the control and low HI groups (HI0, HI25) while Chloroflexi became prevalent in the higher HI inclusion groups (HI35, HI50). Predictive analysis on bacterial metabolic pathways showed a clear separation between HI0-HI25 and HI35-HI50 groups. The microbiota shifts observed suggest a pivotal role of HI in inducing a bacterial-mediated physiological response in this fish species, probably due to chitin content and the fatty acid profile of this ingredient. Liver histology showed a higher hepatocyte size in fish from the HI50 group, suggesting lipid dysmetabolism due to the HI meal fatty acid profile, while a marginal adaptive response was observed in the HI25 group. In conclusion, while up to 25% inclusion of black soldier fly meal showed limited adverse effects, 50% HI dietary inclusion is not recommended in gilthead seabream diet, since possible alteration in lipid deposition, particularly at hepatic level, were highlighted in this fish species.

The lifelong effects of anoxia hormesis in solitary bees

The stimulatory and protective response known as hormesis elicits an often over compensatory response resulting in life-history trait improvements. There are an array of abiotic and biotic agents that have been shown to trigger hormesis; most commonly studied are chemicals, temperature, and low oxygen. Investigations into low-oxygen exposures that activate the hormetic response reveal that insect performance can be dramatically improved by single short low-oxygen events, but the focus of this work has been primarily on short-term, transitory protection afforded by hormesis. Few reports examine whether the effect is longer lasting or lifelong. We previously reported that one hour of anoxia was enough to induce a hormetic response in the alfalfa leafcutting bee, Megachile rotundata (Hymenoptera: Megachilidae). Here, we investigated the long-term effects of this response by looking at starvation resistance, flight, and locomotory activity throughout the life of the adult bees. In addition, we studied the effects of anoxia hormesis on multiple reproductive metrics. Anoxia hormesis had lifelong positive effects for flight in both sexes. We also recorded higher starvation survival in bees that experienced hormesis. This improvement in performance came at a steep reproductive cost (ie reduction in fecundity). However, no costs or benefits were passed to the next generation. We hypothesize that using anoxia hormesis in the context of pollination services by this species should result in bees that are more active in the field, thereby increasing the numbers of visits to flowers throughout their entire life.

Reserpine Causes Neuroendocrine Toxicity, Inducing Impairments in Cognition via Disturbing Hypothalamic-Pituitary-Thyroid Axis in Zebrafish

Reserpine is used as a cheap and effective first-line antihypertensive, and presently, it is applied as treatment for difficult-to-control cases of hypertension. Despite its significance, reserpine's neuroendocrine toxicity remains largely underexplored. Here, we investigated the effects of reserpine on development, locomotion, central nervous system (CNS) neurons, thyroid development, and the expression of genes related to neurodevelopment, endocrine, learning and memory, and depression in zebrafish exposed to different doses of reserpine ranging from 0.5 mg/L to 16 mg/L. The results of our study demonstrated that reserpine exerts dose-dependent toxicity on the neuroendocrine system (NES). An investigation into its underlying mechanism suggests that reserpine disrupted the hypothalamic-pituitary-thyroid (HPT) axis via down-regulating hhex, tg, and tshβ genes, impairing thyroid hormone synthesis and endocrine balance. Meanwhile, it affected neurodevelopment, as evidenced by the reduced expression of gfap, gap43, mbp, syn2a, and tuba1b genes, which compromised neuronal structure and function, while impaired neurotransmitter release and uptake could occur due to the suppression of crhb and mao genes. To conclude, these findings illustrate the interconnected impact of pathways involved in endocrine and neurodevelopment in reserpine-induced toxicity.

Transcriptomic and chromatin accessibility profiling unveils new regulators of heat hormesis in Caenorhabditis elegans

Heat hormesis describes the beneficial adaptations from transient exposure to mild heat stress, which enhances stress resilience and promotes healthy aging. It is thought to be the underlying basis of popular wellness practices like sauna therapy. Despite extensive documentation across species, the molecular basis of the long-term protective effects of heat hormesis remain poorly understood. This study bridges that critical gap through a comprehensive multiomic analysis, providing key insights into the transcriptomic and chromatin accessibility landscapes throughout a heat hormesis regimen adapted in C. elegans. We uncover highly dynamic dose-dependent molecular responses to heat stress and reveal that while most initial stress-induced changes revert to baseline, key differences in response to subsequent heat shock challenge are directly linked to physiological benefits. We identify new regulators of heat hormesis, including MARS-1/MARS1, SNPC-4/SNAPc, ELT-2/GATA4, FOS-1/c-Fos, and DPY-27/SMC4, which likely orchestrate gene expression programs that enhance stress resilience through distinct biological pathways. This study advances our understanding of stress resilience mechanisms, points to multiple new avenues of future investigations, and suggests potential strategies for promoting healthy aging through mid-life stress management.

Positive allosteric modulation of AMPA receptors via PF4778574 leads to reduced demyelination and clinical disability in experimental models of multiple sclerosis

Introduction

Multiple Sclerosis (MS), a debilitating central nervous system (CNS) disorder, is characterized by inflammation, demyelination, and neuronal degeneration. Despite advancements in immunomodulatory treatments, neuroprotective or restorative strategies remain inadequate. Our research is focusing on the potential of the positive allosteric modulator of AMPA receptors (AMPA-PAM), PF4778574, in addressing MS symptoms.

Methods

We utilized the MOG35-55 induced experimental autoimmune encephalomyelitis (EAE) model in C57BL6J mice to examine PF4778574's therapeutic and prophylactic efficacy. Our comprehensive approach included clinical scoring, optical coherence tomography (OCT), optomotor response (OMR) and histological assessments. Additionally, we explored the effects of PF4778574 in comparison and in combination with the immunomodulatory agent fingolimod, and investigated the impact on Cuprizone induced toxic demyelination.

Results

Prophylactic administration of PF4778574 showed notable improvement in clinical EAE indices and reduction in neuronal loss. While it did not diminish microglial activity, it reduced demyelinated areas in optic nerves and in the corpus callosum. Both PF4778574 and fingolimod significantly enhanced clinical EAE scores and decreased demyelination. However, their combination did not yield additional benefits. In the cuprizone model, PF4778574 increased oligodendrocyte precursor and mature myelin-forming cells, suggesting a pro-remyelinating effect.

Discussion

PF4778574 demonstrates promise in mitigating EAE effects, especially in terms of clinical disability and demyelination. These results suggest AMPA-PAMs as potential targets of interest for MS treatment beyond immunomodulatory approaches.

Modulation of the Adaptive Capacity of Growing Rats through Modification of the Protein Content in the Diet

Hematological and morphological studies of the liver were carried out in a subacute experiment on rats receiving a model toxicant against the background of diets with decreasing protein content during the most important period of ontogenesis characterized by intensive growth and sexual maturation. It was found that the stimulating effect of hormesis manifested in the blood and liver under conditions of sufficient protein supply (⩾ 9% of total caloric content). Growing animals chronically exposed to protein deficiency (3-6%) were characterized by suppressed hemopoiesis and decreased size of hepatocytes; against the background of a toxic load, the suppression of hematopoiesis was even more pronounced. The toxicant had a stimulating influence on the liver even in the presence of protein deficiency, which indicates the priorities in distribution of resource under conditions of adaptation to stress.

Comparative bioactivity analysis of latex and water extract of Euphorbia gaillardotii: chemical profile, antioxidant capacity, effects on water quality, in vitro antimicrobial-cytotoxic activities, and in silico molecular docking studies

The genus Euphorbia, belonging to the family Euphorbiaceae, represents a significant ethnobotanical heritage due to the diverse bioactive properties exhibited. In this study, the phytochemical composition and biological activities of latex and aerial parts of the water extract of Euphorbia gaillardotii were investigated. Phytochemical analyses were performed using gas chromatography-mass spectrometry and high-performance liquid chromatography techniques and total antioxidants, phenolics, sugars, organic acids, and aroma components were quantitatively determined. The effects of the test compounds on physicochemical parameters in aqueous media were evaluated by electrical conductivity, dissolved oxygen concentration, and pH measurements. Antimicrobial activity was evaluated on Gram-positive and Gram-negative bacteria and yeast strains using the disk diffusion method. The cytotoxic activity on the MCF-7 human breast cancer cell line was measured spectrophotometrically using the Cell Counting Kit-8 proliferation/apoptosis detection kit. The results showed that E. gaillardotii latex and aerial parts water extract significantly affected the physicochemical parameters of aqueous media, especially at high concentrations. The test substances displayed antimicrobial activity, with the latex-impregnated disks demonstrating larger inhibition zones than the aerial parts extract. The results showed that both the latex and extract treatments exhibited concentration-dependent effects on MCF-7 cell viability (P < 0.001). Furthermore, in silico docking analyses revealed a robust binding affinity of succinic acid, the most prevalent bioactive compound in the extract, towards the B-cell lymphoma 2 (Bcl-2) molecule, with a binding energy of -6.16 kcal/mol. This may be associated with the observed cytotoxicity. These results suggest that E. gaillardotii may be a valuable source for potential pharmacological applications.

Radiophobia Harm, Its Main Cause, and a Proposed Solution

Background: We are exposed to natural ionizing radiation and other genomic stressors throughout life and radiophobia has caused much harm to society. The main basis for radiophobia is the invalid linear no-threshold (LNT) hypothesis for cancer induction, which the System of Radiological Protection (SRP) is linked to. Largely unknown to the public, evolution-associated genomic stress adaptation (gensadaptation) over many previous generations now provides protection to all lifeforms from low radiation doses. Objective: To help bring about an improved SRP not linked to the invalid LNT hypothesis for radiation-caused health detriment and to promote low-dose radiation therapy for different diseases. Methods: All-solid-cancer mortality risk dose-response relationships for A-bomb survivors were generated based on published LNT-modeling-related results. Dose-response relationships for lung cancer prevention by low-dose radiation were generated by linear interpolation based on published data from a study using > 15,000 mice. Uncertainty characterization was based on Monte Carlo calculations for binomial and Poisson distributions. New dose characterization tools were used for threshold dose-response relationships for radiation-caused cancer mortality. Results: The all-solid-cancer mortality risk for A-bomb survivors transitioned from LNT to threshold-linear when adjusted for key missing uncertainty at low doses. The prevention of lung cancer in mice by low radiation doses depends on the radiation absorbed dose and type. Conclusions: The SRP should be linked to population dose thresholds rather than the invalid LNT hypothesis and small likely harmless radiation doses could possibly be used in treating different diseases.

Effects of anthranilic diamide insecticides on metamorphosis in the common toad Rhinella arenarum (Hensel, 1867) at concentrations found in aquatic environments

Anthranilic diamides (AD) are a modern class of insecticides used as alternatives to pyrethroids and neonicotinoids, particularly against lepidopteran pests. Despite their widespread use and presence in surface waters, little is known regarding their effects on amphibians. The aim of this study was to examine the effects of environmentally-relevant concentrations of AD insecticides chlorantraniliprole (CHLO) and cyantraniliprole (CYAN) on metamorphosis of the toad Rhinella arenarum. Tadpoles were exposed to CHLO or CYAN at concentrations ranging from 5 and 5000 µg/L from stage 27 until metamorphosis completion. Both insecticides produced a non-monotonic acceleration of the time required for individuals to progress through development and a decrease in the proportion of individuals completing metamorphosis, although a delay in metamorphosis was also observed at 5 µg/L of CHLO. Snout-vent length and body weight of metamorphosed toads were not markedly affected by either insecticide. CHLO was more toxic than CYAN, with a lowest observed effect concentration (LOEC) for CHLO on time to metamorphosis defined as 5 µg/L compared to 5000 µg/L for CYAN. The LOEC for reduced metamorphic success defined as 50 µg/L for CHLO compared to 500 µg/L for CYAN. As most effects occurred after stage 39, when metamorphosis depends upon thyroid hormones, it is conceivable that that AD insecticides act as endocrine disruptors. These findings suggest that contamination of surface waters with CHLO and CYAN may disrupt amphibian development in the wild and warrant further research to investigate the possibility of endocrine-disruption by ADs.

Coniferaldehyde activates autophagy and enhances oxidative stress resistance and lifespan of Caenorhabditis elegans via par-4/aak-2/skn-1 pathway

Aging represents the gradual accumulation of alterations within an organism over time. The physical and chemical characteristics of our cells gradually change as we age, making it more difficult for our tissues and organs to self-regulate, regenerate, and maintain their structural and functional integrity. AMP- activated protein kinase (AMPK), a well-known sensor of cellular energy status acts as a central regulator of an integrated signalling network that control homeostasis, metabolism, stress resistance, cell survival and autophagy. Coniferaldehyde (CFA), a phenolic compound found in many edible plants, has multiple biological and pharmacological functions. Our findings demonstrated that 50 µM CFA could significantly activate autophagy and reduce oxidative stress, which enhanced the activity of antioxidant enzymes and increased resistance under oxidative stress. CFA treatment could efficiently decrease reactive oxygen species (ROS) levels and positively enhance the expression of antioxidant genes in Caenorhabditis elegans (C. elegans). On the other hand, CFA did not have any role in the lifespan extension of the several mutants linked to the AAK-2/AMPK pathway and it promotes SKN-1 (Skinhead-1) localization into the nucleus, which modulates downstream gene gst-4 (Glutathione S-transferase). In depth investigations revealed that CFA could lower oxidative stress and enhance the lifespan of C. elegans by activating the PAR-4/LKB-1-AAK-2/AMPK-SKN-1/NRF-2 pathway, with crucial involvement of bec-1 and lgg-1 genes for autophagy mediated lifespan extension. This study might contribute to understanding the interactions and mechanisms that allow natural compounds like CFA to treat age-related disorders among several species.

Risk factors for hospitalization-associated disability among older patients: A systematic review and meta-analysis

BACKGROUND

The outcomes of older patients are significantly limited by hospitalization-associated disability (HAD), and there are currently few available management options for HAD. This review aimed to identify and quantify the risk factors for HAD, to provide reliable evidence for developing a HAD prevention program centered on risk factor management among older patients.

METHODS

The MEDLINE, Embase, PsycINFO, CINAHL, and PubMed databases were searched in March 2024 to identify cross-sectional and cohort studies that used multivariable analysis to examine risk factors for HAD among older patients.

RESULTS

We screened 883 studies, 21 of which met our inclusion criteria. Our findings revealed a substantial association between various risk factors and HAD among older patients. Specifically, advanced age, female sex, Caucasian ethnicity, comorbidity burden, better activities of daily living at admission, dementia diagnosis, and longer lengths of stay were significant risk factors for HAD. Furthermore, frailty, poor physical function, immobility, and delirium were identified as confirmed risk factors for HAD among older patients.

CONCLUSIONS

This review provided a comprehensive synthesis of available evidence on risk factors for HAD among older patients, serving as a valuable guide for the development of HAD prevention strategies both prior to and during hospitalization.

The lipid side of unfolded protein response

Although our current knowledge of the molecular crosstalk between the ER stress, the unfolded protein response (UPR), and lipid homeostasis remains limited, there is increasing evidence that dysregulation of either protein or lipid homeostasis profoundly affects the other. Most research regarding UPR signaling in human diseases has focused on the causes and consequences of disrupted protein folding. The UPR itself consists of very complex pathways that function to not only maintain protein homeostasis, but just as importantly, modulate lipid biogenesis to allow the ER to adjust and promote cell survival. Lipid dysregulation is known to activate many aspects of the UPR, but the complexity of this crosstalk remains a major research barrier. ER lipid disequilibrium and lipotoxicity are known to be important contributors to numerous human pathologies, including insulin resistance, liver disease, cardiovascular diseases, neurodegenerative diseases, and cancer. Despite their medical significance and continuous research, however, the molecular mechanisms that modulate lipid synthesis during ER stress conditions, and their impact on cell fate decisions, remain poorly understood. Here we summarize the current view on crosstalk and connections between altered lipid metabolism, ER stress, and the UPR.

Metformin ameliorates neuroinflammatory environment for neurons and astrocytes during in vitro and in vivo stroke and tobacco smoke chemical exposure: Role of Nrf2 activation

Despite the protective nature of the blood-brain barrier (BBB) and brain-protecting tissues, some types of CNS injury or stress can cause cerebral cytokine production and profound alterations in brain function. Neuroinflammation, which can also be accompanied by increased cerebral cytokine production, has a remarkable impact on the pathogenesis of many neurological illnesses, including loss of BBB integrity and ischemic stroke, yet effective treatment choices for these diseases are currently lacking. Although little is known about the brain effects of Metformin (MF), a commonly prescribed first-line antidiabetic drug, prior research suggested that it may be useful in preventing BBB deterioration and the increased risk of stroke caused by tobacco smoking (TS). Therefore, reducing neuroinflammation by escalating anti-inflammatory cytokine production and declining pro-inflammatory cytokine production could prove an effective therapeutic strategy for ischemic stroke. Hence, the current investigation was planned to explore the potential role of MF against stroke and TS-induced neuroinflammation and reactive oxygen species (ROS) production. Our studies revealed that MF suppressed releasing pro-inflammatory mediators like tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) by aiming at the nuclear factor kappa B (NF-κB) signaling pathway in primary neurons and astrocytes. MF also upregulated anti-inflammatory mediators, like interleukin-10 (IL-10), and interleukin-4 (IL-4), by upregulating the Nrf2-ARE signaling pathway. Adolescent mice receiving MF along with TS exposure also showed a notable decrease in NF-κB expression compared to the mice not treated with MF and significantly decreased the level of TNF-α, IL-1β, MCP-1, and MIP-2 and increased the levels of IL-10 and IL-4 through the activation of Nrf2-ARE signaling pathway. These results suggest that MF has anti-neuroinflammatory effects via inhibiting NF-κB signaling by activating Nrf2-ARE. These studies support that MF could be a strong candidate drug for treating and or preventing TS-induced neuroinflammation and ischemic stroke.

Developmental Thermal Conditioning Regulates Oxidative State and Beak Coloration in Response to Thermal Stressors in Adulthood

AbstractAt certain intensities and durations, environmental stressors during development can result in changes in physiology that prepare organisms for future stressful conditions. Such plasticity can allow organisms to maintain good condition when confronted with a poor environment, potentially conferring an advantage in fitness. However, the physiological changes underlying these adaptive phenotypic adjustments are understudied. Using captive male zebra finches (Taeniopygia castanotis), we tested whether exposure to a prolonged mild stressor during development would adaptively modify their antioxidant enzyme expression, reducing oxidative damage when exposed to a high-intensity stressor in adulthood and allowing the maintenance of a secondary sexual trait. To do this, we exposed juvenile finches to either a prolonged mild heat stressor treatment (38°C) or a control temperature treatment (22°C). As adults, these finches were then exposed to either an acute high-intensity heat stressor treatment (42°C) or control temperature treatment (22°C). The beak color of males-a sexually selected trait-was quantified, as were oxidative stress parameters in the testes and liver tissues. We saw that the mild-heat-conditioned males had beaks with higher saturation and lower brightness at baseline in adulthood but that the changes in beak color in response to the high heat stressor varied. After exposure to the high heat stressor as adults, finches had higher levels of superoxide dismutase 1 and 2 in the testes and lower levels of lipid damage in the liver if they were also exposed to the mild heat conditioning as juveniles, indicating an adaptive phenotypic change.

Transcriptome analysis reveals high concentration of resveratrol promotes lipid synthesis and induces apoptosis in Siberian sturgeon (Acipenser baerii)

Resveratrol has been reported to promote immunity and decrease oxidative stress, but which demonstrates biphasic effects relied on the use concentration. In this study, the effects of diet supplement with a relative high concentration of resveratrol (0.32 mg/kg) on metabolism, antioxidation and apoptosis of liver were investigated in Siberian sturgeon. The results showed that resveratrol significantly increased the lipid synthesis and the apoptosis, but did not either activate the antioxidant NRF2/KEAP1 pathway or enhance the antioxidant enzyme activity. Transcriptome analysis revealed significant changes in regulatory pathways related to glycolipid, including PPAR signaling pathway, Insulin signaling pathway, Fatty acid biosynthesis, and Glycolysis/Gluconeogenesis. In addition, resveratrol significantly increased the lipid synthesis genes (accα and fas), fatty acid transport gene (fatp 6) and gluconeogenesis gene (gck), but decreased the survival-promoting genes (gadd45β and igf 1). These findings highlight a significant effect of resveratrol on glycolipid metabolism in Siberian sturgeon. Moreover, this study also demonstrated that 0.32 mg/kg resveratrol has physiological toxicity to the liver of Siberian sturgeon, indicating that this dose is too high for Siberian sturgeon. Thus, our study provides a valuable insight for future research and application of resveratrol in fish.

Bioenergetic mapping of 'healthy microbiomes' via compound processing potential imprinted in gut and soil metagenomes

Despite mounting evidence of their importance in human health and ecosystem functioning, the definition and measurement of 'healthy microbiomes' remain unclear. More advanced knowledge exists on health associations for compounds used or produced by microbes. Environmental microbiome exposures (especially via soils) also help shape, and may supplement, the functional capacity of human microbiomes. Given the synchronous interaction between microbes, their feedstocks, and micro-environments, with functional genes facilitating chemical transformations, our objective was to examine microbiomes in terms of their capacity to process compounds relevant to human health. Here we integrate functional genomics and biochemistry frameworks to derive new quantitative measures of in silico potential for human gut and environmental soil metagenomes to process a panel of major compound classes (e.g., lipids, carbohydrates) and selected biomolecules (e.g., vitamins, short-chain fatty acids) linked to human health. Metagenome functional potential profile data were translated into a universal compound mapping 'landscape' based on bioenergetic van Krevelen mapping of function-level meta-compounds and corresponding functional relative abundances, reflecting imprinted genetic capacity of microbiomes to metabolize an array of different compounds. We show that measures of 'compound processing potential' associated with human health and disease (examining atherosclerotic cardiovascular disease, colorectal cancer, type 2 diabetes and anxious-depressive behavior case studies), and displayed seemingly predictable shifts along gradients of ecological disturbance in plant-soil ecosystems (three case studies). Ecosystem quality explained 60-92 % of variation in soil metagenome compound processing potential measures in a post-mining restoration case study dataset. With growing knowledge of the varying proficiency of environmental microbiota to process human health associated compounds, we might design environmental interventions or nature prescriptions to modulate our exposures, thereby advancing microbiota-oriented approaches to human health. Compound processing potential offers a simplified, integrative approach for applying metagenomics in ongoing efforts to understand and quantify the role of microbiota in environmental- and human-health.

Mirikizumab Exposure-Response Relationships in Patients with Moderately-to-Severely Active Ulcerative Colitis in Randomized Phase II and III Studies

Mirikizumab is a humanized anti-interleukin-23p19 monoclonal antibody being developed for ulcerative colitis (UC) and Crohn's disease. We characterized the relationship of mirikizumab systemic exposure with efficacy and safety end points in patients with UC using phase II (NCT02589665) and III (NCT03518086, NCT03524092) trial data. Exposure-response models were developed for clinical remission, clinical response, endoscopic remission, and change in modified Mayo score following induction (50-1,000 mg i.v. every 4 weeks) and maintenance (200 mg s.c. every 4 or 12 weeks) treatment. These models evaluated observed and pharmacokinetic model-predicted mirikizumab exposures as the exposure measure. Key safety event rates were compared across mirikizumab exposure quartiles in the phase III trial. Mirikizumab efficacy in patients with UC showed an apparent positive association with systemic exposure following both induction and maintenance. However, further analysis found this relationship to be overstated by the presence of confounding factors that were not among the tested patient covariates. While prior biologic experience and baseline disease severity showed statistically significant influences on estimated placebo effect, no patient factors affected the mirikizumab effect parameters in any of the phase III exposure-response models. There was no apparent mirikizumab concentration relationship with any adverse event of special interest. When the phase II and III data and confounding are considered together, efficacy was unlikely to be strongly affected by variation in exposures across individual patients at the phase III dose. Together with the previously demonstrated mirikizumab exposure insensitivity to patient factors, these findings indicate that mirikizumab dose adjustment to patient characteristics is not required.

The relationship of redox signaling with the risk for atherosclerosis

Oxidative balance plays a pivotal role in physiological homeostasis, and many diseases, particularly age-related conditions, are closely associated with oxidative imbalance. While the strategic role of oxidative regulation in various diseases is well-established, the specific involvement of oxidative stress in atherosclerosis remains elusive. Atherosclerosis is a chronic inflammatory disorder characterized by plaque formation within the arteries. Alterations in the oxidative status of vascular tissues are linked to the onset, progression, and outcome of atherosclerosis. This review examines the role of redox signaling in atherosclerosis, including its impact on risk factors such as dyslipidemia, hyperglycemia, inflammation, and unhealthy lifestyle, along with dysregulation, vascular homeostasis, immune system interaction, and therapeutic considerations. Understanding redox signal transduction and the regulation of redox signaling will offer valuable insights into the pathogenesis of atherosclerosis and guide the development of novel therapeutic strategies.

Current advances and future trends of hormesis in disease

Hormesis, an adaptive response, occurs when exposure to low doses of a stressor potentially induces a stimulatory effect, while higher doses may inhibit it. This phenomenon is widely observed across various organisms and stressors, significantly advancing our understanding and inspiring further exploration of the beneficial effects of toxins at doses both below and beyond traditional thresholds. This has profound implications for promoting biological regulation at the cellular level and enhancing adaptability throughout the biosphere. Therefore, conducting bibliometric analysis in this field is crucial for accurately analyzing and summarizing its current research status. The results of the bibliometric analysis reveal a steady increase in the number of publications in this field over the years. The United States emerges as the leading country in both publication and citation numbers, with the journal Dose-Response publishing the highest number of papers in this area. Calabrese E.J. is a prominent person with significant contributions and influence among authors. Through keyword co-occurrence and trend analysis, current hotspots in this field are identified, primarily focusing on the relationship between hormesis, oxidative stress, and aging. Analysis of highly cited references predicts that future research trends may center around the relationship between hormesis and stress at different doses, as well as exploring the mechanisms and applications of hormesis. In conclusion, this review aims to visually represent hormesis-related research through bibliometric methods, uncovering emerging patterns and areas of focus within the field. It provides a summary of the current research status and forecasts trends in hormesis-related research.

Ameliorative anti-coagulant, anti-oxidative and anti-ferroptotic activities of nanocurcumin and donepezil on coagulation, oxidation and ferroptosis in Alzheimer's disease

Alzheimer's disease (ad) is a neurological condition that worsens over time and is characterized by the buildup of amyloid (Aβ) plaques in the brain parenchyma. Neuroprotection and cholinesterase inhibition have been the two primary techniques used in the creation of medications to date. In ad, a novel sort of programmed cell death known as ferroptosis takes place along with iron buildup, lipid peroxidation, and glutathione deficiency. The objective of the current investigation was to examine the neuroprotective and anti-ferroptotic role of nanocurcumin and Donepezil against model of aluminum chloride AlCl3 and D-galactose induced ad. The experiment was performed on 70 rats divided into (G1: control, G2: NCMN, G3: Donepezil, G4: ad-model, G5: Donepezil co-treatment, G6: NCMN co-treatment and G7: NCMN+Donepezil co-treatment). Hematological parameters and biochemical investigations as oxidative stress, liver function, kidney function, iron profile and plasma fibrinogen were evaluated. Treatment with Nanocurcumin alone or in combination with Donepezil improved oxidative stress, liver functions, and kidney functions, improve iron profile and decreased plasma fibrinogen.

Hormesis, the Individual and Combined Phytotoxicity of the Components of Glyphosate-Based Formulations on Algal Growth and Photosynthetic Activity

The occurrence of the market-leading glyphosate active ingredient in surface waters is a globally observed phenomenon. Although co-formulants in pesticide formulations were considered inactive components from the aspects of the required main biological effect of the pesticide, several studies have proven the high individual toxicity of formulating agents, as well as the enhanced combined toxicity of the active ingredients and other components. Since the majority of active ingredients are present in the form of chemical mixtures in our environment, the possible combined toxicity between active ingredients and co-formulants is particularly important. To assess the individual and combined phytotoxicity of the components, glyphosate was tested in the form of pure active ingredient (glyphosate isopropylammonium salt) and herbicide formulations (Roundup Classic and Medallon Premium) formulated with a mixture of polyethoxylated tallow amines (POEA) or alkyl polyglucosides (APG), respectively. The order of acute toxicity was as follows for Roundup Classic: glyphosate < herbicide formulation < POEA. However, the following order was demonstrated for Medallon Premium: herbicide formulation < glyphosate < APG. Increased photosynthetic activity was detected after the exposure to the formulation (1.5-5.8 mg glyphosate/L and 0.5-2.2 mg POEA/L) and its components individually (glyphosate: 13-27.2 mg/L, POEA: 0.6-4.8 mg/L), which indicates hormetic effects. However, decreased photosynthetic activity was detected at higher concentrations of POEA (19.2 mg/L) and Roundup Classic (11.6-50.6 mg glyphosate/L). Differences were demonstrated in the sensitivity of the selected algae species and, in addition to the individual and combined toxicity of the components presented in the glyphosate-based herbicides. Both of the observed inhibitory and stimulating effects can adversely affect the aquatic ecosystems and water quality of surface waters.

Glyphosate hormesis effects on the vegetative and reproductive development of glyphosate-susceptible and -resistant Conyza sumatrensis biotypes

Low glyphosate doses that produce hormesis may alter the susceptibility to herbicides of weeds or enhance their propagation and dispersal. The objective of this work was to evaluate the hormetic effects of glyphosate on the vegetative, phenological and reproductive development in resistant (R) and susceptible (S) Conyza sumatrensis biotypes. The glyphosate resistance level of biotype R was 11.2-fold compared to the S biotype. Glyphosate doses <11.25 g ae ha-1 induced temporary and permanent hormetic effects for the number of leaves, plant height and dry mass accumulation up to 28 d after application in both R and S biotypes. The S biotype required 15-19% fewer thermal units at 1.4 and 2.8 g ae ha-1 glyphosate than untreated plants to reach the bolting stage. Also, this biotype had less thermal units associated with the appearance (1225 vs 1408 units) and opening (1520 vs 1765 units) of the first capitulum than the R biotype. In addition, glyphosate affected reproductive traits of both biotypes compared to their controls, increasing the number of capitulum's and seeds per plant up to 37 and 41% (at 2.8 and 0.7 g ae h-1, respectively) in the S biotype, and by 48 and 114% (both at 5.6 g ae ha-1) in the R biotype. Depending on environmental parameters, glyphosate may or may not cause hormetic effects on the vegetative and phenological development of C. sumatrenis biotypes; however, this herbicide increases the speed and fecundity of reproduction, regardless of the glyphosate susceptibility level, which can alter the population dynamics and glyphosate susceptibility of future generations.

The hormesis principle of neuroplasticity and neuroprotection

Animals live in habitats fraught with a range of environmental challenges to their bodies and brains. Accordingly, cells and organ systems have evolved stress-responsive signaling pathways that enable them to not only withstand environmental challenges but also to prepare for future challenges and function more efficiently. These phylogenetically conserved processes are the foundation of the hormesis principle, in which single or repeated exposures to low levels of environmental challenges improve cellular and organismal fitness and raise the probability of survival. Hormetic principles have been most intensively studied in physical exercise but apply to numerous other challenges known to improve human health (e.g., intermittent fasting, cognitive stimulation, and dietary phytochemicals). Here we review the physiological mechanisms underlying hormesis-based neuroplasticity and neuroprotection. Approaching natural resilience from the lens of hormesis may reveal novel methods for optimizing brain function and lowering the burden of neurological disorders.

NQO1 Mediates Lenvatinib Resistance by Regulating ROS-induced Apoptosis in Hepatocellular Carcinoma

OBJECTIVE

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-associated death worldwide. As a first-line drug for advanced HCC treatment, lenvatinib faces a significant hurdle due to the development of both intrinsic and acquired resistance among patients, and the underlying mechanism remains largely unknown. The present study aims to identify the pivotal gene responsible for lenvatinib resistance in HCC, explore the potential molecular mechanism, and propose combinatorial therapeutic targets for HCC management.

METHODS

Cell viability and colony formation assays were conducted to evaluate the sensitivity of cells to lenvatinib and dicoumarol. RNA-Seq was used to determine the differences in transcriptome between parental cells and lenvatinib-resistant (LR) cells. The upregulated genes were analyzed by GO and KEGG analyses. Then, qPCR and Western blotting were employed to determine the relative gene expression levels. Afterwards, the intracellular reactive oxygen species (ROS) and apoptosis were detected by flow cytometry.

RESULTS

PLC-LR and Hep3B-LR were established. There was a total of 116 significantly upregulated genes common to both LR cell lines. The GO and KEGG analyses indicated that these genes were involved in oxidoreductase and dehydrogenase activities, and reactive oxygen species pathways. Notably, NAD(P)H:quinone oxidoreductase 1 (NQO1) was highly expressed in LR cells, and was involved in the lenvatinib resistance. The high expression of NQO1 decreased the production of ROS induced by lenvatinib, and subsequently suppressed the apoptosis. The combination of lenvatinib and NQO1 inhibitor, dicoumarol, reversed the resistance of LR cells.

CONCLUSION

The high NQO1 expression in HCC cells impedes the lenvatinib-induced apoptosis by regulating the ROS levels, thereby promoting lenvatinib resistance in HCC cells.

Changes in thermal sensitivity of Rhinella arenarum tadpoles (Anura: Bufonidae) exposed to sublethal concentrations of different pesticide fractions (Lorsban® 75WG)

The intensive use of agrochemicals and the rapid increase of global temperatures have modified the thermal conditions of aquatic environments, thus increasing amphibians' vulnerability to global warming and positioning them at great risk. Commercial formulations of chlorpyrifos (COM) are the pesticides most widely used in agricultural activities, with a high toxic potential on amphibians. However, little is known about the separate effects of the active ingredient (CPF) and adjuvants (AD). We studied the thermal sensitivity at different concentrations and pesticide fractions in Rhinella arenarum tadpoles, on thermal tolerance limits (CTmax = Critical thermal maximum and CTmin = Critical thermal minimum), swimming speed (Ss), Optimum temperature (Top), and Thermal breadth 50 (B50). Our results demonstrate that the pesticide active ingredient, the adjuvants, and the commercial formulation of chlorpyrifos differentially impair the thermal sensitivity of R. arenarum tadpoles. The pesticide fractions affected the heat and the cold tolerance (CTmax and CTmin), depending on the concentrations they were exposed to. The locomotor performance (Ss, Top, and B50) of tadpoles also varied among fractions, treatments, and environmental temperatures. In the context of climate change, the outcomes presented are particularly relevant, as mean temperatures are increasing at unprecedented rates, which suggests that tadpoles inhabiting warming and polluted ponds are currently experiencing deleterious conditions. Considering that larval stages of amphibians are the most susceptible to changing environmental conditions and the alarming predictions about environmental temperatures in the future, it is likely that the synergism between high temperatures and pesticide exposure raise the threat of population deletions in the coming years.

Circadian Rhythms, Chrononutrition, Physical Training, and Redox Homeostasis-Molecular Mechanisms in Human Health

A multitude of physiological processes, human behavioral patterns, and social interactions are intricately governed by the complex interplay between external circumstances and endogenous circadian rhythms. This multidimensional regulatory framework is susceptible to disruptions, and in contemporary society, there is a prevalent occurrence of misalignments between the circadian system and environmental cues, a phenomenon frequently associated with adverse health consequences. The onset of most prevalent current chronic diseases is intimately connected with alterations in human lifestyle practices under various facets, including the following: reduced physical activity, the exposure to artificial light, also acknowledged as light pollution, sedentary behavior coupled with consuming energy-dense nutriments, irregular eating frameworks, disruptions in sleep patterns (inadequate quality and duration), engagement in shift work, and the phenomenon known as social jetlag. The rapid evolution of contemporary life and domestic routines has significantly outpaced the rate of genetic adaptation. Consequently, the underlying circadian rhythms are exposed to multiple shifts, thereby elevating the susceptibility to disease predisposition. This comprehensive review endeavors to synthesize existing empirical evidence that substantiates the conceptual integration of the circadian clock, biochemical molecular homeostasis, oxidative stress, and the stimuli imparted by physical exercise, sleep, and nutrition.

Adverse outcome pathways of PBDEs inducing male reproductive toxicity

Polybrominated diphenyl ethers (PBDEs) are widely used brominated flame retardants, they are easily released into environment and causing adverse effects to the ecosystem and human health. This review aims to summarize the research status of PBDEs-induced male reproductive toxicity and its mechanisms at various levels such as molecular/cellular, tissue/organ and individual/population. The Adverse Outcome Pathways (AOPs) diagram showed that PBDEs-induced reactive oxygen species (ROS) production, disruptions of estrogen receptor-α (ERα) and antagonism of androgen receptor (AR) were defined as critical molecular initiating events (MIEs). They caused key events (KEs) at the molecular and cellular levels, including oxidative stress, increased DNA damage, damaging mitochondria, increased glycolipid levels and apoptosis, depletion of ectoplasmic specialization and decreased Leydig cells numbers. These in turn lead to followed KEs at the tissue or organ levels, such as the impaired spermatogenesis, impaired blood-testis barrier and reduced testosterone synthesis and function. As a result, reproductive system-related adverse outcomes (AOs) were reported, such as the decreased sperm quantity or quality, shorten male anogenital distance and cryptorchidism in individual and reduced reproduction of the population. This review assembled information on the mechanisms of male reproductive toxicity induced by PBDEs, and constructed a causal mechanism relationship diagram from different levels using the an AOP framework to provide theoretical basis for ecological risk assessment and environmental management of PBDEs. The AOP framework makes it possible to develop risk management strategies based on toxicity mechanisms and support for development of Integrated Approach to Testing and Assessment (IATA) which are available for regulatory purposes.

Novel Insights on Ferroptosis Modulation as Potential Strategy for Cancer Treatment: When Nature Kills

Significance: The multifactorial nature of the mechanisms implicated in cancer development still represents a major issue for the success of established antitumor therapies. The discovery of ferroptosis, a novel form of programmed cell death distinct from apoptosis, along with the identification of the molecular pathways activated during its execution, has led to the uncovering of novel molecules characterized by ferroptosis-inducing properties. Recent advances: As of today, the ferroptosis-inducing properties of compounds derived from natural sources have been investigated and interesting findings have been reported both in vitro and in vivo. Critical Issues: Despite the efforts made so far, only a limited number of synthetic compounds have been identified as ferroptosis inducers, and their utilization is still limited to basic research. In this review, we analyzed the most important biochemical pathways involved in ferroptosis execution, with particular attention to the newest literature findings on canonical and non-canonical hallmarks, together with mechanisms of action of natural compounds identified as novel ferroptosis inducers. Compounds have been classified based on their chemical structure, and modulation of ferroptosis-related biochemical pathways has been reported. Future Directions: The outcomes herein collected represent a fascinating starting point from which to take hints for future drug discovery studies aimed at identifying ferroptosis-inducing natural compounds for anticancer therapies. Antioxid. Redox Signal. 40, 40-85.

Allelochemicals: A source for developing economically and environmentally friendly plant growth regulators

Allelochemicals are specific secondary metabolites that can exhibit autotoxicity by inhibiting the growth of the same plant species that produced them. These metabolites have been found to affect various physical processes during plant growth and development, including inhibition of seed germination, photosynthesis, respiration, root growth, and nutrient uptake, with diverse mechanisms involving cell destruction, oxidative homeostasis and photoinhibition. In some cases, allelochemicals can also have positive effects on plant growth and development. In addition to their ecological significance, allelochemicals also possess potential as plant growth regulators (PGRs) due to their extensive physiological effects. However, a comprehensive summary of the development and applications of allelochemicals as PGRs is currently lacking. In this review, we present an overview of the sources and categories of allelochemicals, discuss their effects and the underlying mechanisms on plant growth and development. We showcase numerous instances of key phytohormonal allelochemicals and non-phytohormonal allelochemicals, highlighting their potential as candidates for the development of PGRs. This review aims to provide a theoretical basis for the development of economical, safe and effective PGRs utilizing allelochemicals, and emphasizes the need for further research in this area.

Investigation on toxicity and mechanism to Daphnia magna for 14 disinfection by-products: Enzyme activity and molecular docking

Exposure to disinfection by-products (DBPs) has been found to induce a range of toxic effects in aquatic organism. Previous studies have consistently demonstrated that a majority of DBPs have the ability to induce in vivo toxicity in aquatic organisms. However, the impact of DBPs on the metabolic processes of Daphnia magna (D. magna) and the underlying molecular toxicity mechanisms are still not well understood. Therefore, we investigated the effects of 14 DBPs on two oxidative stress enzymes and malondialdehyde (MDA) levels in D. magna. Additionally, we employed molecular docking to simulate the toxicity of DBPs to D. magna at the molecular level. This comprehensive analysis allowed us to gain further insights into the toxicity of DBPs on D. magna. The results showed that among the aliphatic DBPs, the more bromine substituents, the lower the toxicity effect, and it's opposite in the aromatic DBPs. In the detection of oxidative stress level, catalase (CAT) enzyme and superoxide dismutase (SOD) enzyme in D. magna under compound stress showed a low increase and decrease with the increase of concentration. The level of MDA showed a positive correlation with the concentration. In the last, molecular docking simulations have shown promise in predicting the toxicity of DBPs and providing insights into their toxic effects to a certain extent, and the docking situation of P53 is slightly different. Hence, it is imperative to further regulate the presence of aromatic DBPs due to their pronounced toxic effects on D. magna, and these simulations can be complemented with actual experiments to enhance our understanding of the toxicity mechanisms of DBPs.

Oral Administration of Silybin Protects Against MPTP-Induced Neurotoxicity by Reducing Pro-inflammatory Cytokines and Preserving BDNF Levels in Mice

Parkinson's disease (PD) is the second most frequent neurodegenerative disease associated with motor dysfunction secondary to the loss of dopaminergic neurons in the nigrostriatal axis. Actual therapy consists mainly of levodopa; however, its long-term use promotes secondary effects. Consequently, finding new therapeutic alternatives, such as neuroprotective molecules, is necessary. Among these alternatives is silybin (Sb), the major bioactive flavonolignan in silymarin. Both exert neuroprotective effects, preserving dopamine levels and dopaminergic neurons when administered in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse PD model, being probably Sb the potential therapeutic molecule behind this effect. To elucidate the role of Sb in the PD model, we determined the dose-dependent conservation of striatal dopamine content following Sb oral administration. Then, we evaluated motor deficit tests using the best dopamine conservative dose of Sb and determined a cytokine-dependent inflammatory profile status, malondialdehyde as an oxidative stress product, and neurotrophic factors content in the MPTP-induced mouse PD model. Our results show that oral Sb at 100 mg/kg dose conserved about 60% dopamine levels. Also, Sb improved motor deficits, preserved neurotrophic factors content and mitochondrial function, reduced lipid peroxidation, diminished proinflammatory cytokines to basal levels, enhanced fractalkine production in the striatum and substantia nigra, and increased IL-10 and IL-4 levels in the substantia nigra in the MPTP mice. Thus, oral Sb may be a potential pharmacological PD treatment alternative.

Adjuvant Effect of Cinnamon Polyphenolic Components in Colorectal Cancer Cell Lines

Colorectal cancer (CRC) is the second-leading cause of cancer death, with a worldwide incidence rate constantly increasing; thus, new strategies for its prevention or treatment are needed. Here, we describe the adjuvant effect of the polyphenol-enriched fractions of cinnamon, from cinnamon bark and buds, when co-administered with a potent anticancer drug, cetuximab, used for CRC therapy. The co-administration significantly reduces the cetuximab dose required for the antiproliferative activity against colorectal cancer cell line E705, which is sensitive to EGFR-targeted therapy. The anticancer activity of these cinnamon-derived fractions, whose major components (as assessed by UPLC-HRMS analysis) are procyanidins and other flavonoids, strictly correlates with their ability to induce apoptosis in cancer cell lines through ERK activation and the mitochondrial membrane potential impairment. Due to the severe side effects of cetuximab administration, our results suggest the use of nutraceuticals based on the polyphenolic fractions of cinnamon extracts as adjuvants in the therapy of CRC.

Screening of tolerance of Atriplex vulgatissima under zinc or lead experimental conditions. An integrative perspective by using the integrated biological response index (IBRv2)

The search for plants with a high capacity to tolerate and accumulate metals is an important issue in phytoremediation. In this sense, this study was conducted in the halophyte Atriplex vulgatissima to evaluate the effects of different concentrations of lead (Pb, 50 and 100 μM) or zinc (Zn, 100 and 200 μM) on morphological, physiological, and biochemical parameters as well as the accumulation patterns of this species. The results indicated that while essential metal Zn showed high translocation from roots to shoots (TF > 1), non-essential Pb was mainly accumulated in the roots (BCF>1). Regarding shape, both metals induced slenderness of the blade, but only Zn treatment reduced leaf size. No difference in biomass production and photosynthetic parameters was found between Pb and Zn treatments. Pb treatments did not show significant differences between treatments regarding water content (WC), pigment concentration, and the activity of superoxide dismutase (SOD) and guaiacol peroxidase (GPx), but did result in a decrease in catalase activity at 100 μM Pb. On the other hand, 200 μM Zn leads to a clear reduction in WC and pigment concentrations, along with an increase in SOD and GPx activities. In addition, ascorbate peroxidase (APx) activity showed a hormesis effect at 50 μM Pb and 100 μM Zn. Malondialdehyde increased with both Pb and Zn treatments. The integrated biological index (IBRv2) indicated that 200 μM Zn was the most affected treatment (IBRv2 = 19.02) and that under the same concentrations of metals (100 μM Pb or Zn), Pb treatments presented major stress (IBRv2 = 11.55). A. vulgatissima is a metallophyte with the potential for Pb phytostabilization and Zn phytoextraction, as well as a bioindicator of these metals. Its high biomass and deep roots, combined with its halophytic traits, make it suitable for bioremediation and monitoring programs.

How super is supersulfide?: Reconsidering persulfide reactivity in cellular biology

In an attempt to understand the cellular mechanisms of H2S signalling, recent research has focused on supersulfide (i.e., alkyl and inorganic hydropersulfide) formation and subsequent reactivity. While our understanding of supersulfides in biology has rapidly advanced, there are some chemical features of this unique functional group that require re-evaluation. Persulfides, such as glutathione hydropersulfide, have been called "supersulfide" as it is assumed that the alkyl hydropersulfide (RSSH) functional group is a superior nucleophile compared to the corresponding thiol (RSH) due to the alpha effect. However, recent quantum mechanical calculations and experimental data show that persulfides are not "super" nucleophiles, but rather potent electrophiles in cellular biology. It is proposed here that persulfides, via their electrophilic signalling effects, induces a cellular hormesis effect, which may explain the observed effects of altered RSSH production. Therefore, the electrophilic and thiol oxidant properties of persulfides should considered in cellular biology.

Low Antioxidant Glutathione Levels Lead to Longer Telomeres: A Sex-Specific Link to Longevity?

Telomeres are repetitive DNA sequences at the end of chromosomes that protect them from degradation. They have been the focus of intense research because short telomeres would predict accelerated ageing and reduced longevity in vertebrates. Oxidative stress is considered a physiological driver of the telomere shortening and, consequently, short lifespan. Among molecules fighting against oxidative stress, glutathione is involved in many antioxidant pathways. Literature supports that oxidative stress may trigger a compensatory "hormetic" response increasing glutathione levels and telomere length. Here, we tested the link between total glutathione concentration and telomere length in captive birds (zebra finches; Taeniopygia guttata). Total glutathione levels were experimentally decreased during birds' growth using a specific inhibitor of glutathione synthesis (buthionine sulfoximine; BSO). We monitored the birds' reproductive performance in an outdoor aviary during the first month of life, and their longevity for almost 9 years. Among control individuals, erythrocyte glutathione levels during development positively predicted erythrocyte telomere length in adulthood. However, BSO-treated females, but not males, showed longer telomeres than control females in adulthood. This counterintuitive finding suggests that females mounted a compensatory response. Such compensation agrees with precedent findings in the same population where the BSO treatment increased growth and adult body mass in females but not males. BSO did not influence longevity or reproductive output in any sex. However, early glutathione levels and adult telomere length interactively predicted longevity only among control females. Those females with "naturally" low (non-manipulated) glutathione levels at the nestling age but capable of producing longer telomeres in adulthood seem to live longer. The results suggest that the capability to mount a hormetic response triggered by low early glutathione levels can improve fitness via telomere length. Overall, the results may indicate a sex-specific link between glutathione and telomere values. Telomerase activity and sexual steroids (estrogens) are good candidates to explain the sex-biased mechanism underlying the early-life impact of oxidative stress on adult telomere length.

Dual RNase activity of IRE1 as a target for anticancer therapies

The unfolded protein response (UPR) is a cellular mechanism that protects cells during stress conditions in which there is an accumulation of misfolded proteins in the endoplasmic reticulum (ER). UPR activates three signaling pathways that function to alleviate stress conditions and promote cellular homeostasis and cell survival. During unmitigated stress conditions, however, UPR activation signaling changes to promote cell death through apoptosis. Interestingly, cancer cells take advantage of this pathway to facilitate survival and avoid apoptosis even during prolonged cell stress conditions. Here, we discuss different signaling pathways associated with UPR and focus specifically on one of the ER signaling pathways activated during UPR, inositol-requiring enzyme 1α (IRE1). The rationale is that the IRE1 pathway is associated with cell fate decisions and recognized as a promising target for cancer therapeutics. Here we discuss IRE1 inhibitors and how they might prove to be an effective cancer therapeutic.

Quantum Electrodynamics Coherence and Hormesis: Foundations of Quantum Biology

BACKGROUND

"Quantum biology" (QB) is a promising theoretical approach addressing questions about how living systems are able to unfold dynamics that cannot be solved on a chemical basis or seem to violate some fundamental laws (e.g., thermodynamic yield, morphogenesis, adaptation, autopoiesis, memory, teleology, biosemiotics). Current "quantum" approaches in biology are still very basic and "corpuscular", as these rely on a semi-classical and approximated view. We review important considerations of theory and experiments of the recent past in the field of condensed matter, water, physics of living systems, and biochemistry to join them by creating a consistent picture applicable for life sciences. Within quantum field theory (QFT), the field (also in the matter field) has the primacy whereby the particle, or "quantum", is a derivative of it. The phase of the oscillation and not the number of quanta is the most important observable of the system. Thermodynamics of open systems, symmetry breaking, fractals, and quantum electrodynamics (QED) provide a consistent picture of condensed matter, liquid water, and living matter. Coherence, resonance-driven biochemistry, and ion cyclotron resonance (Liboff-Zhadin effect) emerge as crucial hormetic phenomena. We offer a paradigmatic approach when dealing with living systems in order to enrich and ultimately better understand the implications of current research activities in the field of life sciences.

Heat-induced maternal effects shape avian eggshell traits and embryo development and phenotype at high incubation temperatures

Phenotypic plasticity is an important avenue by which organisms may persist in the face of rapid environmental change. Environmental cues experienced by the mother can also influence the phenotype of offspring, a form of plasticity called maternal effects. Maternal effects can adaptively prepare offspring for the environmental conditions they will likely experience; however, their ability to buffer offspring against environmental stressors as embryos is understudied. Using captive zebra finches, we performed a maternal-offspring environmental match-mismatch experiment utilizing a 2 × 2 × 2 factorial design. Mothers were exposed to a mild heat conditioning (38°C) or control (22°C) treatment as juveniles, an acute high heat (42°C) or control (22°C) treatment as adults, then paired for breeding. The eggs produced by those females were incubated at a hyperthermic (38.5°C) or optimal temperature (37.2°C). We found that when mothers were exposed to a mild heat conditioning as juveniles, their embryos exhibited reduced water loss, longer development times, and produced hatchlings with heavier pectoralis muscles when incubated at high incubation temperatures, compared to embryos from control mothers. Mothers exposed to both the mild heat conditioning as juveniles and a high heat stressor as adults produced eggs with a higher density of shell pores and embryos with lower heart rates during development. However, there was a cost when there was a mismatch between maternal and embryo environment. Embryos from these conditioned and heat-stressed mothers had reduced survival at control incubation temperatures, indicating the importance of offspring environment when interpreting potential adaptive effects.

The Unfolded Protein Response: A Double-Edged Sword for Brain Health

Efficient brain function requires as much as 20% of the total oxygen intake to support normal neuronal cell function. This level of oxygen usage, however, leads to the generation of free radicals, and thus can lead to oxidative stress and potentially to age-related cognitive decay and even neurodegenerative diseases. The regulation of this system requires a complex monitoring network to maintain proper oxygen homeostasis. Furthermore, the high content of mitochondria in the brain has elevated glucose demands, and thus requires a normal redox balance. Maintaining this is mediated by adaptive stress response pathways that permit cells to survive oxidative stress and to minimize cellular damage. These stress pathways rely on the proper function of the endoplasmic reticulum (ER) and the activation of the unfolded protein response (UPR), a cellular pathway responsible for normal ER function and cell survival. Interestingly, the UPR has two opposing signaling pathways, one that promotes cell survival and one that induces apoptosis. In this narrative review, we discuss the opposing roles of the UPR signaling pathways and how a better understanding of these stress pathways could potentially allow for the development of effective strategies to prevent age-related cognitive decay as well as treat neurodegenerative diseases.

Kinetic Effects of Transferrin-Conjugated Gold Nanoparticles on the Antioxidant Glutathione-Thioredoxin Pathway

Nanoparticle-based therapeutics are being clinically translated for treating cancer. Even when thought to be biocompatible, nanoparticles are being increasingly identified as altering cell regulation and homeostasis. Antioxidant pathways are important for maintaining cell redox homeostasis and play important roles by maintaining ROS levels within tolerable ranges. Here, we sought to understand how a model of a relatively inert nanoparticle without any therapeutic agent itself could antagonize a cancer cell lines' antioxidant mechanism. A label-free protein expression approach was used to assess the glutathione-thioredoxin antioxidative pathway in a prostate cancer cell line (PC-3) after exposure to gold nanoparticles conjugated with a targeting moiety (transferrin). The impact of the nanoparticles was also corroborated through morphological analysis with TEM and classification of pro-apoptotic cells by way of the sub-G0/G1 population via the cell cycle and annexin V apoptosis assay. After a two-hour exposure to nanoparticles, major proteins associated with the glutathione-thioredoxin antioxidant pathway were downregulated. However, this response was acute, and in terms of protein expression, cells quickly recovered within 24 h once nanoparticle exposure ceased. The impact on PRDX-family proteins appears as the most influential factor in how these nanoparticles induced an oxidative stress response in the PC-3 cells. An apparent adaptive response was observed if exposure to nanoparticles continued. Acute exposure was observed to have a detrimental effect on cell viability compared to continuously exposed cells. Nanoparticle effects on cell regulation likely provide a compounding therapeutic advantage under some circumstances, in addition to the action of any cytotoxic agents; however, any therapeutic advantage offered by nanoparticles themselves with regard to vulnerabilities specific to the glutathione-thioredoxin antioxidative pathway is highly temporal.

Optogenetic control of the integrated stress response reveals proportional encoding and the stress memory landscape

The integrated stress response (ISR) is a conserved signaling network that detects aberrations and computes cellular responses. Dissecting these computations has been difficult because physical and chemical inducers of stress activate multiple parallel pathways. To overcome this challenge, we engineered a photo-switchable control over the ISR sensor kinase PKR (opto-PKR), enabling virtual, on-target activation. Using light to control opto-PKR dynamics, we traced information flow through the transcriptome and for key downstream ISR effectors. Our analyses revealed a biphasic, proportional transcriptional response with two dynamic modes, transient and gradual, that correspond to adaptive and terminal outcomes. We then constructed an ordinary differential equation (ODE) model of the ISR, which demonstrated the dependence of future stress responses on past stress. Finally, we tested our model using high-throughput light-delivery to map the stress memory landscape. Our results demonstrate that cells encode information in stress levels, durations, and the timing between encounters. A record of this paper's transparent peer review process is included in the supplemental information.

Low-dose chemical stimulation and pest resistance threaten global crop production

Pesticide resistance increases and threatens crop production sustainability. Chemical contamination contributes to the development of pest resistance to pesticides, in part by causing stimulatory effects on pests at low sub-toxic doses and facilitating the spread of resistance genes. This article discusses hormesis and low-dose biological stimulation and their relevance to crop pest resistance. It highlights that a holistic approach is needed to tackle pest resistance to pesticides and reduce imbalance in accessing food and improving food security in accordance with the UN's Sustainable Development Goals. Among others, the effects of sub-toxic doses of pesticides should be considered when assessing the impact of synthetic and natural pesticides, while the promotion of alternative agronomical practices is needed to decrease the use of agrochemicals. Potential alternative solutions include camo-cropping, exogenous application of phytochemicals that are pest-suppressing or -repelling and/or attractive to carnivorous arthropods and other pest natural enemies, and nano-technological innovations. Moreover, to facilitate tackling of pesticide resistance in poorer countries, less technology-demanding and low-cost practices are needed. These include mixed cropping systems, diversification of cultures, use of 'push-pull cropping', incorporation of flower strips into cultivations, modification of microenvironment, and application of beneficial microorganisms and insects. However, there are still numerous open questions, and more research is needed to address the ecological and environmental effects of many of these potential solutions, with special reference to trophic webs.

Central and Peripheral Inflammation: A Common Factor Causing Addictive and Neurological Disorders and Aging-Related Pathologies

Many diseases and degenerative processes affecting the nervous system and peripheral organs trigger the activation of inflammatory cascades. Inflammation can be triggered by different environmental conditions or risk factors, including drug and food addiction, stress, and aging, among others. Several pieces of evidence show that the modern lifestyle and, more recently, the confinement associated with the COVID-19 pandemic have contributed to increasing the incidence of addictive and neuropsychiatric disorders, plus cardiometabolic diseases. Here, we gather evidence on how some of these risk factors are implicated in activating central and peripheral inflammation contributing to some neuropathologies and behaviors associated with poor health. We discuss the current understanding of the cellular and molecular mechanisms involved in the generation of inflammation and how these processes occur in different cells and tissues to promote ill health and diseases. Concomitantly, we discuss how some pathology-associated and addictive behaviors contribute to worsening these inflammation mechanisms, leading to a vicious cycle that promotes disease progression. Finally, we list some drugs targeting inflammation-related pathways that may have beneficial effects on the pathological processes associated with addictive, mental, and cardiometabolic illnesses.

Hormesis Responses of Photosystem II in Arabidopsis thaliana under Water Deficit Stress

Since drought stress is one of the key risks for the future of agriculture, exploring the molecular mechanisms of photosynthetic responses to water deficit stress is, therefore, fundamental. By using chlorophyll fluorescence imaging analysis, we evaluated the responses of photosystem II (PSII) photochemistry in young and mature leaves of Arabidopsis thaliana Col-0 (cv Columbia-0) at the onset of water deficit stress (OnWDS) and under mild water deficit stress (MiWDS) and moderate water deficit stress (MoWDS). Moreover, we tried to illuminate the underlying mechanisms in the differential response of PSII in young and mature leaves to water deficit stress in the model plant A. thaliana. Water deficit stress induced a hormetic dose response of PSII function in both leaf types. A U-shaped biphasic response curve of the effective quantum yield of PSII photochemistry (Φ_PSII) in A. thaliana young and mature leaves was observed, with an inhibition at MiWDS that was followed by an increase in Φ_PSII at MoWDS. Young leaves exhibited lower oxidative stress, evaluated by malondialdehyde (MDA), and higher levels of anthocyanin content compared to mature leaves under both MiWDS (+16%) and MoWDS (+20%). The higher Φ_PSII of young leaves resulted in a decreased quantum yield of non-regulated energy loss in PSII (Φ_NO), under both MiWDS (-13%) and MoWDS (-19%), compared to mature leaves. Since Φ_NO represents singlet-excited oxygen (¹O₂) generation, this decrease resulted in lower excess excitation energy at PSII, in young leaves under both MiWDS (-10%) and MoWDS (-23%), compared to mature leaves. The hormetic response of PSII function in both young and mature leaves is suggested to be triggered, under MiWDS, by the intensified reactive oxygen species (ROS) generation, which is considered to be beneficial for activating stress defense responses. This stress defense response that was induced at MiWDS triggered an acclimation response in A. thaliana young leaves and provided tolerance to PSII when water deficit stress became more severe (MoWDS). We concluded that the hormesis responses of PSII in A. thaliana under water deficit stress are regulated by the leaf developmental stage that modulates anthocyanin accumulation in a stress-dependent dose.

Evidences of metabolic alterations and cellular damage in different tissues of scallops Aequipecten tehuelchus exposed to cadmium

Scallops Aequipecten tehuelchus (Patagonia, Argentina) were exposed to 0, 2, 5 and 12 μg Cd/L for 7 and 14 days, causing in digestive gland a significant production of reactive oxygen and nitrogen species (RONS), induction of catalase (CAT) and glutathione S-transferase (GST) activities and metallothioneins (MT) synthesis. In gills, there was inhibition of GST and induction of CAT, MT and α-tocopherol (α-Toc). In muscle, a significant increment of MT was also registered and inhibition of CAT. Lipid peroxidation, measured as TBARS, was not promoted in any tissue. More significant effects were observed in digestive gland than in gills and muscle, evidencing the critical role of digestive gland in Cd accumulation and metabolisation. This research would evidence dose-dependent effects of Cd on MT, GST, CAT and α-Toc in the three organs assayed, as well as a time-dependent effect of Cd on the response of CAT, GST and TBARS in digestive gland.

Low-level laser selectively inhibiting colorectal cancer cell metabolic activity and inducing apoptosis for delaying the development of intestinal cancer

Low-level laser irradiation (LLLI) is a novel approach that shows promise for the treatment of colorectal cancer (CRC). However, the molecular mechanisms underlying its biochemical effects and gene expression remain unclear. Here, LLLI (632.8 nm) was used to treat CRC RKO cells and normal small intestinal NCM460 cells. LLLI showed a significant dose- and time-dependent effect on cell viability, in which a single dose of irradiation at 15 J/cm² selectively inhibited the growth of RKO cells but largely unaffected the activity of NCM460 cells. And then, LLLI produced an internal response, effectively reducing the level of H₂O₂ in tumor cells, downregulating the mitochondrial membrane potential, and improving the efficiency of apoptosis in CRC, but no internal response was observed in NCM460 cells under the same conditions. Furthermore, the expression of several important genes in the classical WNT pathway was significantly downregulated, and the pathway was inactivated after LLLI intervention, thereby inhibiting tumor cell growth. Simultaneously, TNF-α was effectively activated to stimulate the caspase family members of the death effector to initiate apoptosis led by the extrinsic pathway. LLLI successfully achieves tumor cell normalization while delivering a potent anticancer effect, expected to be a novel therapeutic modality for CRC.

Unpredictable fasting transiently alters corticosterone and feeding behavior but not body mass or later HPA axis function in zebra finches (Taeniopygia guttata)

The hypothalamic-pituitary-adrenal (HPA) axis is commonly activated in response to unpredictable conditions, including unstable or inadequate food supply. Extended exposure to unpredictable food resources can alter HPA axis function, with the potential for negative fitness consequences. We addressed the interrelationships of unpredictable food resources, HPA axis activity, and food intake in adult and juvenile zebra finches (Taeniopygia guttata). Finches exposed to prolonged periods of unpredictable food elevate corticosterone (the primary avian glucocorticoid) when food is unavailable; however, whether they experience chronic elevation in baseline corticosterone during periods of unpredictability, even when food is available, is unclear. We subjected adults and juveniles to an extended period of temporally unpredictable food (consisting of a random daily fast) or predictable food supply. We investigated baseline corticosterone under fed conditions and in response to an acute fast (mimicking the daily fasting periods in the unpredictable treatment), and assessed differences in body mass, food intake, and corticosterone responses to restraint. Regardless of sex and age, individuals in both treatment groups elevated corticosterone when fasted, and baseline corticosterone under fed conditions was indistinguishable between groups. Thus, corticosterone levels were not persistently elevated in the unpredictably fed group. Treatment groups did not differ in body mass or corticosterone responses to restraint, but unpredictably fed birds consumed food more rapidly when food was available. Our findings suggest that the unpredictably fed birds experienced repeated, moderate elevations in corticosterone. Such elevations may aid birds in coping with unpredictable food sources, in part by activating compensatory changes in foraging behavior.