Cellular Stress Responses: Cell Survival and Cell Death. Hindawi Publishing Corporation. Int J Cell Biol. 2010;214074. [PMID: 20182529 PMCID: PMC2825543 DOI: 10.1155/2010/214074]

The arginine metabolism and its deprivation in cancer therapy

Arginine deprivation has emerged as a promising therapeutic strategy in cancer treatment due to the auxotrophy of certain tumors. Many cancers, such as pancreatic, colorectal, and hepatocellular carcinoma, exhibit downregulated argininosuccinate synthetase, making them reliant on external arginine sources. This dependency allows targeted therapies that deplete arginine, inhibiting tumor growth while sparing normal cells. Arginine is crucial for various cellular processes, including protein synthesis and immune function. Its deprivation affects both tumor metabolism and immune responses, potentially enhancing cancer therapy. Studies have explored using enzymes like arginine deiminase and arginase, often modified for increased stability and reduced immunogenicity, to effectively lower arginine levels in the tumor microenvironment. These approaches show promise, particularly in tumors with low argininosuccinate synthetase expression. However, the impact on immune cells and the potential for resistance highlight the need for further research. Combining arginine deprivation with other treatments might improve outcomes, offering a novel approach to combat arginine-dependent cancers.

Loss of non-muscle myosin II Zipper leads to apoptosis-induced compensatory proliferation in Drosophila

Drosophila Non-muscle myosin II Zipper (Zip) belongs to a functionally divergent class of molecular motors that play a vital role in various cellular processes including cell adhesion, cell migration, cell protrusion, and maintenance of polarity via its cross-linking property with actin. To further determine its role in cell proliferation and apoptosis, we carried out Zip loss of function studies that led to compromised epithelial integrity in Drosophila wing imaginal discs as evident from the perturbed expression pattern of cell-cell junction proteins Cadherin, Actin, and Armadillo. Disruption of these adhesion proteins resulted in the cells undergoing apoptosis as evident from the increased level of effector caspase, cDcp-1. The induction of cell death due to the loss of function of Zip was accompanied by proliferation as apparent from increased PH3 staining. The control of apoptosis-induced compensatory proliferation lies under the caspase cascade. We carried out experiments that suggested that the apical caspase Dronc is responsible for the apoptosis-induced compensatory proliferation due to the loss of Zip function and not the effector caspase Drice/Dcp-1. Further, it was observed that Dronc leads to the subsequent activation of Jun N-terminal kinase pathway (JNK) pathway and Wingless (Wg) mitogen that diffuse to the neighboring cells and prompt them to undergo cell division. Taken together, our results suggest that loss of function of Zip leads to apoptosis-induced compensatory proliferation.

Targeting p53-p21 signaling to enhance mesenchymal stem cell regenerative potential

Mesenchymal stem cells (MSCs) are properties of self-renewal and differentiation potentials and thus are very appealing to regenerative medicine. Nevertheless, their therapeutic potential is frequently constrained by senescence, limited proliferation, and stress-induced apoptosis. The key role of the p53-p21 biology in MSC biology resides in safeguarding genomic stability while promoting senescence and limiting regenerative capacity upon over-activation demonstrated. This pathway is a key point for improving MSC function and exploiting the inherent limitations. Recent advances indicate that senescence can be delayed by targeting the p53-p21 signaling and improved MSC proliferation and differentiation capacity. PFT-α pharmacological agents transiently inhibit p53 from increasing proliferation and lineage-specific differentiation, while antioxidants such as hydrogen-rich saline and epigallocatechin 3 gallate (EGCG) suppress oxidative stress and attenuate p53 p21 signaling. Genetic tools like CRISPR-Cas9 and RNA interference also precisely modulate TP53 and CDKN1A expression to optimize MSC functionality. The interplay of p53-p21 with pathways like Wnt/β-catenin and MAPK further highlights opportunities for combinatorial therapies to enhance MSC resilience and regenerative outcomes. This review aims to offer a holistic view of how p53-p21 targeting can further the regenerative potential of MSCs, resolving senescence, proliferation, and stress resilience towards advanced therapeutics built on MSCs.

Antiplatelet therapy as a novel approach in Parkinson's disease: Repositioning Ticagrelor to alleviate rotenone-induced parkinsonism via modulation of ER stress, apoptosis, and autophagy

Cardiovascular diseases, such as myocardial infarction, ischemic stroke, and coronary heart ailments have been closely associated with Parkinson's disease (PD). Despite this established link, the potential neuroprotective impact of the potent antiplatelet agent ticagrelor (Tica) remains unexplored against PD. Thus, we hypothesized that Tica could be repurposed as a therapeutic agent against PD. Rotenone experimental model was adopted in Wistar male rats by administering rotenone subcutaneously on alternate days during a 21-day experimental period and treating a subset of rats with Tica orally for the last 11 consecutive days. The administration of Tica improved motor function (open field test, hanging wire test) and restored striatal histological features. Additionally, Tica opposed the rotenone effect and markedly obliterated the striatal α-synuclein content but enhanced the protein expression of tyrosine hydroxylase and dopamine content. On the molecular level, Tica inhibited striatal endoplasmic reticulum stress (ERS) as evidenced by the downregulation of the ER-resident transmembrane sensor inositol-requiring enzyme 1 alpha and its downstream molecular targets, TNF receptor-associated factor 2 and c-Jun N-terminal kinase, along with a reduction in caspase-3 activity. On the other hand, Tica augmented the autophagy machinery by upregulating the autophagosome markers Beclin-1 and light chain 3-II, while inhibiting the content of cathepsin D. Therefore, the current study is the first to accentuate the neuroprotective potential of Tica in a rat model of PD via modulating the crosstalk between ERS, apoptosis, and autophagy to represent a potential novel therapeutic candidate for managing PD, particularly in patients with or prone to cardiovascular diseases.

Arginine Deprivation Induces Quiescence and Confers Vulnerability to Ferroptosis in Colorectal Cancer

Metabolic reprogramming is a hallmark of cancer. Rewiring of amino acid metabolic processes provides the basis for amino acid deprivation therapies. In this study, we found that arginine biosynthesis is limited in colorectal cancer because of the deficiency of ornithine transcarbamylase. Accordingly, colorectal cancer cells met the demand for arginine by increasing external uptake. The addiction to environmental arginine resulted in the susceptibility of colorectal cancer to arginine deprivation, which dramatically decreased proliferation in colorectal cancer cells and promoted these cells to enter a reversible quiescence state. Arginine deprivation induced quiescence by activating the AMPK-p53-p21 pathway. RNA sequencing data indicated that colorectal cancer cells may be vulnerable to ferroptosis during arginine deprivation and the combination of ferroptosis inducers and arginine deprivation strongly impeded tumor growth in vivo. These findings suggest that dietary modification combined with ferroptosis induction could be a potential therapeutic strategy for colorectal cancer. Significance: Colorectal cancer dependency on arginine uptake creates a metabolic vulnerability to arginine deficiency that causes cell cycle arrest and ferroptosis sensitivity, highlighting arginine deprivation plus ferroptosis induction as a promising treatment.

Cooperation of R and Rab5 regulates crayfish anti-disease immune response by triggering apoptosis

Toll-like receptors (TLRs) are involved in innate immunity in aquatic animals. The comprehensive regulation characteristic of TLRs in the immune of crayfish (Procambarus clarkii) has been less elucidated. In this study, we investigated the regulatory pathways of TLRs in the crayfish by identifying the proteins interacting with TLRs encoded by the resistance (R)-gene identified in our previous study. In vivo pull-down analysis indicated an interaction between the R protein and myeloid differentiation factor 88 (MyD88) and the Ras-like small GTPase Rab5. In vitro pull-down assays verified that R directly interacted with MyD88, but not with Rab5. Many differentially expressed genes involved in the Toll signaling pathway were identified using transcriptomes analysis of RNAi-Rab5 and RNAi-GFP crayfish hemocytes. Tumor susceptibility gene 101 and CD9 (encoding a tetraspanin protein) related to exosomes were identified, and their protein expression was validated using western blotting. We hypothesize that the R protein receives a signal upon pathogen challenge and triggers apoptosis during immune responses by interacting with MyD88, with the cooperation of Rab5-secreting exosomes. We anticipate this study to provide preliminary evidence for the involvement of exosomes in the TLR-mediated immune regulatory pathway and advance the understanding of this pathway in crayfish immune resistance.

Biochanin‑A as SIRT‑1 modulator in preventing statin‑associated diabetogenesis: An in vitro study

The widespread use of statin therapy for hypercholesterolemia has raised concerns due to its associated risk of inducing diabetes. Biochanin-A (BA), an isoflavone, exhibits potential in preventing diabetes and hyperlipidemia, yet its efficacy in mitigating statin-induced diabetes remains unexplored. This gap prompts a crucial inquiry: Can BA reduce the risk of diabetes associated with statin therapy? The present study investigated the molecular mechanisms behind atorvastatin's diabetogenic nature and evaluated the potential of BA to counteract these effects. Insulin resistance was assessed using L6 skeletal muscle cells and pancreatic beta cell apoptosis in MIN-6 cells. Our hypothesis posits that atorvastatin exacerbates free fatty acid accumulation, leading to the downregulation of sirtuin-1 (SIRT-1) and decreased uncoupling protein (UCP) 3 expression, culminating in insulin resistance. Conversely, BA is assumed to positively modulate SIRT-1 and downregulate UCP2, thus offering a protective effect. In vitro studies using L6 and MIN-6 cells revealed that BA has increased cell viability and shown optimal protection against the toxicity induced by atorvastatin in both cell lines at different concentrations. BA effectively inhibited the reduction in glucose uptake caused by atorvastatin. Pre-treatment with BA upregulated proteins that are involved in the insulin-signaling pathway and reversed the expression levels of UCPs induced by atorvastatin. BA also enhanced insulin release, preserved mitochondrial function, and prevented atorvastatin-induced apoptosis. Furthermore, BA improved SIRT-1 expression, potentially through the nicotinamide phospho-ribosyl-transferase-nicotinamide adenine dinucleotide + SIRT1-pathway, revealing that BA may play a role in modulating cellular processes in statin-associated SIRT-1 downregulation. BA can be considered a promising molecule to counteract statin-induced diabetes, suggesting a prospective therapeutic role in enhancing the safety profile of statin therapy. This research lays the groundwork for future clinical evaluations of BA as an adjunctive treatment for patients at risk of statin-induced diabetes.

Pro-apoptotic and mitochondria-disrupting effects of 4-methylthiazole in K562 leukemia cells: A mechanistic investigation

Thiazole derivatives have garnered attention for their anticancer potential. This study investigates the antileukemic effects of 4-methylthiazole on K562 chronic myeloid leukemia (CML) cells, focusing on apoptosis induction and mitochondrial dysfunction. Cell viability was assessed using MTS assays; apoptosis and necrosis were analyzed via Annexin V/PI staining and flow cytometry; mitochondrial membrane potential changes were evaluated with JC-1 dye; gene expression levels were measured by qRT-PCR; and levels of apoptosis- and cytokine-related proteins were quantified using ELISA. Treatment with 4-methylthiazole led to selective cytotoxicity in K562 cells while sparing healthy peripheral blood mononuclear cells (PBMNCs). Apoptotic induction was evidenced by Caspase-3 (CASP-3) activation, Cytochrome-C (CYT-C), release, and mitochondrial depolarization. Gene expression analysis showed upregulation of pro-apoptotic markers such as TP53 (tumor suppressor protein 53), BAX and BAK (pro-apoptotic Bcl-2 family proteins), while upregulation of CASP3 (caspase-3) expression was not statistically significant. Conversely, levels of GPX4 (glutathione peroxidase 4, involved in oxidative stress protection) remained unchanged, indicating an apoptosis mechanism independent of oxidative stress. Additionally, SEMA3A (Semaphorin 3 A, involved in tumor progression and cell signaling) was significantly downregulated. Cytokine profiling revealed a dose-dependent modulation of IL-6, while TNF-α and IL-10 levels remained unaffected. These findings suggest that 4-methylthiazole induces apoptosis through mitochondrial pathways, affects cytokine signaling, and selectively targets leukemia cells, supporting its potential as a therapeutic candidate for CML treatment.

Activation of PANoptosis and Ferroptosis during Ex Vivo Lung Perfusion in Human Lungs

A recent study demonstrated upregulation of PANoptosis related genes during reperfusion in human lung transplants. However, the impact of ex vivo lung perfusion (EVLP) on different cell death pathways and their relationship with inflammatory genes and clinical characteristics remains unknown. We conducted transcriptomic analyses on pre- and post-EVLP biopsies from 49 donation after brain death (DBD) and 39 donation after circulatory death (DCD) lungs. Gene set enrichment analysis (GSEA) and single-sample GSEA (ssGSEA) were used to assess the enrichment of cell death and inflammatory pathways. We further explored the relationships between these pathways, donor characteristics, and clinical outcomes. DBD lungs showed significant enrichment of apoptosis and ferroptosis gene sets compared to DCD lungs. During EVLP, pyroptosis, apoptosis, necroptosis, and ferroptosis gene sets were significantly upregulated and strongly correlated with inflammatory pathways in both DBD and DCD donor lungs. Donor age, sex and smoking history were associated with specific cell death pathways. In DCD lungs, the expression of ferroptosis-related genes was associated with recipient early outcomes. In conclusion, the expression of cell death gene sets is donor-type specific. The identification of multiple cell death and inflammatory pathways during EVLP provides potential therapeutic targets to improve donor lung quality and enhance clinical outcomes.

Salinomycin and oxaliplatin synergistically enhances cytotoxic effect on human colorectal cancer cells in vitro and in vivo

Oxaliplatin (OXA) is widely used for colorectal cancer (CRC) as a first-line chemotherapy. However, drug resistance and peripheral neurotoxicity prevail in colorectal cancer therapy. Salinomycin (SAL) makes cancer cells sensitive to ionizing radiation and chemotherapeutic drugs. Chemotherapy regimens that combine more than two drugs can improve the outcome of patients. In the present study, we detected apoptosis and mitochondrial function in CRC cells through MTT assays, Annexin V-FITC/PI staining, colony-forming assays, intracellular reactive oxygen species (ROS) measurements, western blotting and so on. We used CompuSyn software to calculate combination index (CI). The effect of SAL and OXA was synergistic. The combination treatment inhibited cell proliferation, migration and colony formation but increased the expression of proapoptotic proteins and promoted cell apoptosis of CRC cells. In vitro experiments demonstrated that the SAL and OXA cotreatment increased intracellular ROS levels in CRC cell lines, decreased the MMP and activated the mitogen-activated protein kinase (MAPK) pathway, thus inhibiting the proliferation of CRC cells and promoting the apoptosis of CRC cells. Pretreatment with N-acetylcysteine (NAC) reversed this effect. Cotreatment with SAL and OXA increases the apoptotic effects in OXA-treated CRC cell lines. In vivo, combined treatment of SAL and OXA markedly inhibited the tumor growth compared to either drug alone. SAL enhances OXA-induced antitumor effects in CRC both in vitro and in vivo by ROS-mediated mitochondrial apoptosis and activation of the MAPK pathway. These results may provide a rationale for combining SAL with OXA for CRC treatment.

Auto-sumoylation of the yeast Ubc9 E2 SUMO-conjugating enzyme extends cellular lifespan

Calorie restriction (CR) provides anti-aging benefits through diverse processes, such as reduced metabolism and growth and increased mitochondrial activity. Although controversy still exists regarding CR-mediated lifespan effects, many researchers are seeking interventions that mimic the effects of CR. Yeast has proven to be a useful model system for aging studies, including CR effects. We report here that yeast adapted through in vitro evolution to the severe cellular stress caused by loss of the Ulp2 SUMO-specific protease exhibit both enhanced growth rates and replicative lifespan, and they have altered gene expression profiles similar to those observed in CR. Notably, in certain evolved ulp2Δ lines, an increase in the auto-sumoylation of Ubc9 E2 SUMO-conjugating enzyme results in altered regulation of multiple targets involved in energy metabolism and translation at both transcriptional and post-translational levels. This increase is essential for the survival of aged cells and CR-mediated lifespan extension. Thus, we suggest that high Ubc9 auto-sumoylation exerts potent anti-aging effects by promoting efficient energy metabolism-driven improvements in cell replication abilities. This potential could be therapeutically explored for the development of promising CR-mimetic strategies.

Inhibitor-based modulation of huntingtin aggregation mechanisms mitigates fibril-induced cellular stress

Huntington's disease (HD) is a neurodegenerative disorder in which mutated fragments of the huntingtin protein (Htt) undergo misfolding and aggregation. Since aggregated proteins can cause cellular stress and cytotoxicity, there is an interest in the development of small molecule aggregation inhibitors as potential modulators of HD pathogenesis. Here, we study how a polyphenol modulates the aggregation mechanism of huntingtin exon 1 (HttEx1) even at sub-stoichiometric ratios. Sub-stoichiometric amounts of curcumin impacted the primary and/or secondary nucleation events, extending the pre-aggregation lag phase. Remarkably, the disrupted aggregation process changed both the aggregate structure and its cell metabolic properties. When administered to neuronal cells, the 'break-through' protein aggregates induced significantly reduced cellular stress compared to aggregates formed in absence of inhibitors. Structural analysis by electron microscopy, small angle X-ray scattering (SAXS), and solid-state NMR spectroscopy identified changes in the fibril structures, probing the flanking domains in the fuzzy coat and the fibril core. We propose that changes in the latter relate to the presence or absence of polyglutamine (polyQ) β-hairpin structures. Our findings highlight multifaceted consequences of small molecule inhibitors that modulate the protein misfolding landscape, with potential implications for treatment strategies in HD and other amyloid disorders.

Unravelling the role of protein kinase R (PKR) in neurodegenerative disease: a review

Protein Kinase R is an essential regulator of many cell activities and belongs to one of the largest and most functionally complex gene families. These are found all over the body, and by adding phosphate groups to the substrate proteins, they regulate their activity and coordinate the action of almost all cellular processes. Recent research has illuminated the involvement of PKR in the pathogenesis of neurodegenerative disorders (NDs), thereby expanding our understanding of intricate molecular mechanisms underlying disease progression. Through their inhibition or activation, they hold potential therapeutic targets for the pathogenesis or protection of NDs. In the case of AD (AD), PKR contributes to the protection or elevation of Aβ accumulation, neuroinflammation, synaptic plasticity alterations, and neuronal excitability. Similarly, in Parkinson's disease (PD), PKR again has a dual role in dopaminergic neuronal loss, gene mutations, and mitochondrial dysfunction via various pathways. Notably, neuronal excitotoxicity, as well as genetic mutations, have been linked to ALS. In Huntington's disease (HD), PKR is associated with decreased or increased mutated genes, striatal neuron degeneration, neuroinflammation, and excitotoxicity. This review emphasizes strategies that target PKR for the treatment of neurodegenerative disorders. Doing so offers valuable insights that can guide future research endeavors and the development of innovative therapeutic approaches.

Self-assembly and 3D Bioprinting of Neurospheres and Evaluation of Caffeine and Photobiomodulation Effects in an Alzheimer's Disease In Vitro Model

Several in vitro models of Alzheimer's disease (AD) rely on 2D cell culture, and, more recently, 3D cultures represented by free-floating neurospheres have been used as models for the disease. The advantage of 3D over 2D cell culture is that cell-extracellular matrix and cell-cell interactions can be assessed, better representing the molecular and cellular hallmarks of the disease. In the current study, we developed two complementary 3D neurosphere models using SH-SY5Y human neuroblastoma cells to investigate AD pathology and evaluate potential therapies. First, self-assembled neurospheres were exposed to hydrogen peroxide (H₂O₂) and amyloid-beta oligomers (AβOs), inducing AD-like features such as increased production of reactive oxygen species (ROS), amyloid aggregation, and apoptosis. Treatment with caffeine or photobiomodulation (PBM) using LED irradiation significantly reduced Aβ1-42 accumulation, ROS generation, and decreased apoptosis markers. Second, 3D bioprinting of SH-SY5Y cells resulted in neurospheres with enhanced cellular organization and differentiation. These findings emphasize the advantages of 3D models for studying neurodegeneration and evaluating therapeutic strategies, bridging the gap between traditional 2D cultures and complex in vitro systems.

Chronic stress and depression impact on tongue and major sublingual gland histology and the potential protective role of Thymus vulgaris: An animal study

OBJECTIVES

Reporting the histological effects of chronic stress on certain oral tissues, as well as the capacity of Thymus vulgaris (thyme) to protect tissues from stress and link both serum cortisol and serotonin levels.

METHODS

30 rats were randomly divided into a trio of groups: normal control (no treatment), stress group (chronic stress without treatment), and treatment group (chronic stress treated with thyme at a dose of 200 mg/kg BW orally via needle gavage daily for 21 days). At the end of the experiment, tongues and major sublingual glands (SLGs) were surgically removed and processed for histological and histochemical studies. Blood samples were taken shortly before scarification for the biochemical study of cortisol and serotonin serum levels.

RESULTS

Examination of tongue and SLG sections of the stress group indicated significant alterations in histology and changes in SLG secretion. An examination of tongue and SLG histological sections of the thyme-treated group are showed an improvement. Chronic stress raises cortisol serum levels and lowers serotonin serum levels.

CONCLUSIONS

Chronic stress causes alteration of the tongue and major SLG histology, as well as changes in SLG secretion. Thyme may protect tissues from stress, and there is a relation between cortisol and serotonin levels.

Consensus on the key characteristics of metabolism disruptors

Metabolism-disrupting agents (MDAs) are chemical, infectious or physical agents that increase the risk of metabolic disorders. Examples include pharmaceuticals, such as antidepressants, and environmental agents, such as bisphenol A. Various types of studies can provide evidence to identify MDAs, yet a systematic method is needed to integrate these data to help to identify such hazards. Inspired by work to improve hazard identification of carcinogens using key characteristics (KCs), we developed 12 KCs of MDAs based on our knowledge of processes underlying metabolic diseases and the effects of their causal agents: (1) alters function of the endocrine pancreas; (2) impairs function of adipose tissue; (3) alters nervous system control of metabolic function; (4) promotes insulin resistance; (5) disrupts metabolic signalling pathways; (6) alters development and fate of metabolic cell types; (7) alters energy homeostasis; (8) causes inappropriate nutrient handling and partitioning; (9) promotes chronic inflammation and immune dysregulation in metabolic tissues; (10) disrupts gastrointestinal tract function; (11) induces cellular stress pathways; and (12) disrupts circadian rhythms. In this Consensus Statement, we present the logic that revealed the KCs of MDAs and highlight evidence that supports the identification of KCs. We use chemical, infectious and physical agents as examples to illustrate how the KCs can be used to organize and use mechanistic data to help to identify MDAs.

A Network Approach to White Band Disease Challenged Staghorn Coral Acropora cervicornismicroRNAs and Their Targets

Coral reefs are increasingly threatened by disease outbreaks, yet little is known about the genetic mechanisms underlying disease resistance. Since the 1970s, White Band Disease (WBD) has decimated the Caribbean staghorn coral Acropora cervicornis. However, 15% or more of individuals are highly disease-resistant, and the genes controlling the production of Argonaut proteins, involved in microRNA (miRNA) post-transcriptional gene silencing, are up-regulated in WBD-resistant corals. This suggests that miRNAs may be key regulators of coral immunity. In this study, we conducted an in situ disease transmission experiment with five healthy-exposed control tanks and five WBD-exposed tanks, each containing 50 A. cervicornis genotypes, sampled over 7 days and then sequenced miRNAs from 12 replicate genotypes, including 12 WBD-exposed and 12 healthy-exposed control fragments from two time points. We identified 67 bona fide miRNAs in A. cervicornis, 3 of which are differentially expressed in disease-resistant corals. We performed a phylogenetic comparison of miRNAs across cnidarians and found greater conservation of miRNAs in more closely related taxa, including all three differentially expressed miRNAs being conserved in more than one Acropora coral. One of the three miRNAs has putative genomic targets involved in the cnidarian innate immunity. In addition, community detection coupled with over-representation analysis of our miRNA-messenger RNA (mRNA) target network found two key unique A. cervicornis miRNAs regulating multiple important immune-related pathways such as Toll-like receptor pathway, endocytosis, and apoptosis. These findings highlight how multiple miRNAs may help the coral host maintain immune homeostasis in the presence of environmental stress including disease.

New insights into reductive stress responses and its clinical relation in cancer

Cells are susceptible to both oxidative and reductive stresses, with reductive stress being less studied and potentially therapeutic in cancer. Reductive stress, characterized by an excess of reducing equivalents exceeding the activity of endogenous oxidoreductases, can lead to an imbalance in homeostasis, causing an increase in reactive oxygen species induction, affecting cellular antioxidant load and flux. Unlike oxidative stress, reductive stress has been understudied and poorly understood, and there is still much to learn about its mechanisms in cancer, its therapeutic potential, and how cancer cells react to it. Changes in redox balance and interference with redox signaling are linked to cancer cell growth, metastasis, and resistance to chemotherapy and radiation. Overconsumption of reducing equivalents can reduce metabolism, alter protein disulfide bond formation, disrupt mitochondrial homeostasis, and disrupt cancer cell signaling pathways. Novel approaches to delivering or using cancer medicines and techniques to influence redox biology have been discovered. Under reductive stress, cancer cells may coordinate separate pools of redox pairs, potentially impacting biology.

Chaetoglobosin A induces apoptosis in T-24 human bladder cancer cells through oxidative stress and MAPK/PI3K-AKT-mTOR pathway

Chaetoglobosin A (ChA) is an antitumor compound produced by Chaetomium globosum. However, the mechanism of its antitumor effect has been rarely reported. In this study, we evaluated the anti-proliferative effect of ChA on T-24 human bladder cancer cells and explored its mechanism of action. ChA was found to have a good inhibitory effect on T-24 cells by MTT assay with an IC50 value of 48.14 ± 10.25 μΜ. Moreover, it was found to have a migration inhibitory ability and a sustained proliferation inhibitory effect on tumor cells by cell aggregation assay and cell migration assay. The cells morphological changes were determined by Hoechst33342 assay. While Annexin V-FITC/PI double-staining assay also demonstrated that the number of apoptotic cells increased with the increase of drug concentration. Flow cytometry results showed that ChA treatment increased reactive oxygen species (ROS) and decreased mitochondrial membrane potential (MMP) in T-24 cells and inhibited cell mitosis, resulting in an increase in the number of sub-G1 phase cells. Further western blot experiments demonstrated that MAPK and PI3K-AKT-mTOR pathways were activated after drug treatment in addition to endogenous and exogenous apoptotic pathways. The addition of the ROS inhibitor N-acetylcysteine (NAC) upregulated the expression level of Bcl-2 protein, decreased p38 phosphorylation, increased ERK phosphorylation and restored the levels of PI3K and p-mTOR after ChA treatment. These suggest that ChA induces apoptosis by regulating oxidative stress, MAPK, and PI3K-AKT-mTOR signaling pathways in T-24 cells.

Preliminary Insights into the Acute Molecular Responses in C2C12 Myotubes to Hyperthermia and Insulin Treatment

This study investigates the differential gene expression in an immortalized cell line of mouse skeletal myoblasts (C2C12)-derived myotube cells subjected to hyperthermia (40°C) with and without insulin treatment to elucidate the impact of thermal stress on skeletal muscle physiology. Hyperthermia, which occurs during intense physical activity or environmental heat exposure, is known to challenge muscle homeostasis and influence metabolic function. mRNA sequencing revealed that hyperthermia robustly altered gene expression-upregulating key genes involved in glycolysis, oxidative phosphorylation, heat shock response, and apoptosis. These changes are suggestive of an elevated metabolic state and enhanced cellular stress; however, these results remain preliminary without complementary protein or metabolic assays. Notably, insulin treatment moderated many of the hyperthermia-induced transcriptional alterations, particularly affecting genes linked to glucose uptake and metabolism. Together, these findings provide hypothesis-generating insights into the interplay between thermal stress and insulin signaling in C2C12 myotubes, and they underscore potential targets for future mechanistic studies.

Radiation exposure induces genome-wide alternative splicing events in Aedes aegypti mosquitoes

Sterile insect technique is a method to control insect pest populations by sterilizing males with ionizing radiation. However, radiation sickness lowers the fitness of sterilized males. In this study, we investigate impacts of ionizing radiation on gene transcription, specifically alternative splicing events in irradiated male Aedes aegypti mosquitoes. We compared RNA sequencing data from mosquitoes irradiated with a single standard X-ray dose of 50 Grey and un-irradiated control mosquitoes using the Multivariate Analysis of Transcript Splicing computational tool. We found that radiation exposure caused alternative splicing events in 197 genes that are involved in a variety of biological processes including the Hippo and Notch cell signaling pathways. Our results suggest that radiation damage produced by ionizing radiation can alter the splicing of genes involved in important biological functions in male Ae. aegypti mosquitoes. These findings identify several new leads for new projects aimed at understanding the impact of radiation-induced alternative splicing on mosquito fitness and improving sterile insect technique by the development of radio-resistant mosquito strains.

Cellular Stress Responses and Associated Diseases: A Focus on Heat Shock Proteins

Cellular stress response is the response of the cell at molecular level in order to combat various environmental stressors / viral infections. These stressors can be either intra or extracellular. In the beginning of the insult cell tries to recoup from these adverse events by various mechanism like heat shock protein response, unfolded protein response, mitochondrial stress signaling, DNA damage response etc. However, if these stressors exceed the cellular capacity to coup with it, it leads to programmed cell death and senescence. Also, chronic stress and cortisol released in response to cellular stress decreases telomerase activity which is needed to replenish telomeres which are protective casing at the end of a strand of DNA. Too low telomeres lead to cell death or cell become pro-inflammatory leading to aging process and other health associated risks like cardiovascular diseases neurodegenerative diseases, autoimmune diseases, cancers etc.

Old drugs, new challenges: reassigning drugs for cancer therapies

The "War on Cancer" began with the National Cancer Act of 1971 and despite more than 50 years of effort and numerous successes, there still remains much more work to be done. The major challenge remains the complexity and intrinsic polygenicity of neoplastic diseases. Furthermore, the safety of the antitumor therapies still remains a concern given their often off-target effects. Although the amount of money invested in research and development required to introduce a novel FDA-approved drug has continuously increased, the likelihood for a new cancer drug's approval remains limited. One interesting alternative approach, however, is the idea of repurposing of old drugs, which is both faster and less costly than developing new drugs. Repurposed drugs have the potential to address the shortage of new drugs with the added benefit that the safety concerns are already established. That being said, their interactions with other new drugs in combination therapies, however, should be tested. In this review, we discuss the history of repurposed drugs, some successes and failures, as well as the multiple challenges and obstacles that need to be addressed in order to enhance repurposed drugs' potential for new cancer therapies.

The cytotoxic and hemolytic potential of karmitoxin from Karlodinium armiger and how it interacts with sterols

Karmitoxin, produced by Karlodinium armiger, is structurally related to karlotoxin and amphidinols, two potent ichthyotoxic hemolysins with high affinity for sterols. Given these structural similarities, karmitoxin is believed to exhibit comparable toxic effects. Cytotoxicity was assessed in the fish gill cell line RTgill-W1 and the human epithelial colon cell line HCEC-1CT. The hemolytic potential with and without added sterols was tested on fish erythrocytes to investigate possible impacts of toxin-sterol interactions. Sterol interactions were further evaluated using surface plasmon resonance. A 3-h incubation returned an EC50 of 111 and 175 nM in RTgill-W1 and in HCEC-1CT cells, respectively. Lactate dehydrogenase (LDH) release increased with toxin concentration, reaching 11 % in the fish and 40 % in the human cell line. Extended exposure (24 h) increased the toxicity in RTgill-W1 cells (EC50 74 nM, 40 % LDH release). In parallel, hemolytic potential of karmitoxin was confirmed, as well as its interaction with free sterols. Interaction kinetics revealed complex stabilities with kd(s-1) constants of 1.13 × 10-2 (cholesterol), 5.48 × 10-3 (epicholesterol), and 4.72 × 10-3 (ergosterol). Interaction with cholesterol followed the single-exponential model well, while data indicated more complex binding with epicholesterol and ergosterol. Altering the RTgill-W1 cholesterol content did not impact cytotoxicity at the tested concentration. Overall, karmitoxin showed potent cytotoxic and hemolytic properties in human and fish models. Complex formation with sterols may play a role in membrane targeting, yet cellular cholesterol quantity might not affect cytotoxicity.

Could the cell nucleus be a new destination for QSOX1 under thermal stress?

Quiescin/sulfhydryl oxidase 1 (QSOX1) is a thiol oxidase that exists in two isoforms, QSOX1a, which contains a transmembrane (TM) domain, a short extraluminal domain, and a luminal catalytic domain, and QSOX1b, which lacks the TM domain and remains soluble. QSOX1 is localized in the ER, Golgi, secretory vesicles, endosomes, and the extracellular environment. In this study, we demonstrate via immunofluorescence that QSOX1 translocates to the nucleus in response to heat (43 °C) and cold (4 °C) stress, occurring as early as 15 min post-exposure in L929 fibroblasts. Orthogonal views of confocal microscopy images reveal that QSOX1 is predominantly nucleoplasmic. This nuclear translocation was further confirmed through cell fractionation followed by immunoblotting, which also identified QSOX1a as the primary isoform present in nuclear fractions. RT-qPCR analysis revealed an increase in QSOX1a mRNA levels, with a significant upregulation observed specifically after cold stress. Finally, QSOX1 knockdown sensitized fibroblasts to cold stress-induced cell death, indicating a potential cytoprotective role for QSOX1a under these conditions. Our findings suggest that the cell nucleus may serve as a novel subcellular destination for QSOX1a during cold stress. Based on existing literature, we proposed a hypothesis to explain the nuclear translocation, possibly via a lateral diffusion-retention mechanism. The biological significance and molecular mechanisms underlying this translocation, however, warrant further investigation.

Exposure to Selenomethionine and Selenocystine Induces Redox-Mediated ER Stress in Normal Breast Epithelial MCF-10A Cells

Selenium is an essential trace element co-translationally incorporated into selenoproteins with important biological functions. Health benefits have long been associated with selenium supplementation. However, cytotoxicity is observed upon excessive selenium intake. The aim of this study is to investigate the metabolic pathways underlying the response to the selenium-containing amino acids selenomethionine and selenocysteine in a normal human breast epithelial cell model. We show that both selenomethionine and selenocystine inhibit the proliferation of non-cancerous MCF-10A cells in the same concentration range as cancerous MCF-7 and Hela cells, which results in apoptotic cell death. Selenocystine exposure in MCF-10A cells caused a severe depletion of free low molecular weight thiols, which might explain the observed upregulation of the expression of the oxidative stress pathway transcription factor NRF2. Both selenomethionine and selenocystine induced the expression of target genes of the unfolded protein response (GRP78, ATF4, CHOP). Using a redox-sensitive fluorescent probe targeted to the endoplasmic reticulum (ER), we show that both selenoamino acids shifted the ER redox balance towards an even more oxidizing environment. These results suggest that alteration of the redox state of the ER may disrupt protein folding and cause ER stress-induced apoptosis in MCF-10A cells exposed to selenoamino acids.

Stress-Induced Response and Adaptation Mechanisms in Bacillus licheniformis PSKA1 Exposed With Abiotic and Antibiotic Stresses

Soil ecosystems consist of diverse microbial communities with great potential for ecological and biotechnological applications. These communities encounter various abiotic stresses, which expedite the activation of transient overexpression of heat shock proteins (HSPs). In the present study, a soil bacterium was isolated and identified as Bacillus licheniformis strain PSK.A1, and its growth parameters were optimized before exposing it to heat, salt, pH, and antibiotic stress conditions. Comparative protein expression was analyzed using SDS-PAGE, protein stabilization via protein aggregation assays, and survival through single spot dilution and colony-counting methods under various stress conditions. The pre-treatment of short stress dosage showed endured overall tolerance of bacterium to lethal conditions, as evidenced by moderately enhanced total soluble intracellular protein content, better protein stabilization, comparatively over-expressed HSPs, and relatively enhanced cell survival. The findings highlighted that cells grown under optimal conditions were more susceptible to lethal environments than stressed cells, with their enhanced tolerance linked to the overexpression of 20 distinct HSPs of 17-91 kD. These insights offer the potential for developing strategies to enhance microbial resilience for various applications including bacterial bioprocessing, bio-remediation, and infectious disease management.

State of thermal tolerance in an endangered himalayan fish Tor putitora revealed by expression modulation in environmental stress related genes

Increasing temperature due to global warming in the Himalayan regions has severe implications for the survival of aquatic ectotherms. To study the thermal acclimation and heat tolerance of an endangered Himalayan fish species, Tor putitora, we examined tissue-specific mRNA expression patterns of heat-shock proteins (HSP90β; HSP70, HSP60, HSP47, HSP30, and HSP20), warm-temperature acclimation proteins (WAP65-1) and cyclin-dependent kinase inhibitor 1B (CDKN1B) genes in liver, brain, gill, kidney, muscle, and gonad tissues at the intervals of 10, 20, and 30 days during a high-temperature treatment (34.0 °C) for 30 days. All the tested genes have exhibited tissue-specific and time-dependent expression patterns. Heat shock proteins' differential expression and modulation across examined tissues indicate their role in long-term cellular adaptation, protection against the cytotoxic effect of hyperthermia, and species acclimation to higher temperatures. WAP65-1 and CDKN1B expression in treatment groups suggests its involvement in maintaining homeostasis, long-term temperature acclimation, and thermotolerance during chronic thermal exposure. The response of studied genes under heat stress indicates their potential use as environmental stress biomarkers in this species. The present study elucidates molecular mechanisms regulating the thermal acclimation capacity and thermotolerance of T. putitora and its survival under future projections of widespread warming in the Himalayan region.

Promoting the transition from pyroptosis to apoptosis in endothelial cells: a novel approach to alleviate methylglyoxal-induced vascular damage

BACKGROUND

Methylglyoxal (MGO)-induced cell death in vascular endothelial cells (VECs) plays a critical role in the progression of diabetic vascular complications (DVCs). Previous studies have shown that MGO can induce inflammatory pyroptosis, leading to VEC damage. However, the underlying mechanism remains unclear, and effective interventions are yet to be developed.

METHODS

Human umbilical vein endothelial cells (HUVECs) were used for in vitro experiments. Cell death modes were assessed through morphological observations. Mechanistic investigations were performed using immunofluorescence, flow cytometry, Western blotting, and ELISA. Inhibitors and adenoviruses were employed to validate the mechanisms. Vascular organoids in conjunction with AngioTool plug-in assays were used to evaluate VEC damage and angiogenic capacity. Mouse blood pressure was measured using the tail-cuff method, and vascular morphology was examined through hematoxylin and eosin (H&E) staining as well as immunofluorescence staining. Data were analyzed using the GraphPad Prism software.

RESULTS

Our study revealed that MGO induces pyroptosis in VECs via the Caspase3/gasdermin E (GSDME) pathway. Furthermore, the saponin monomer 13 of dwarf lilyturf tuber (DT-13), inhibited MGO-induced pyroptosis and promoted the generation of apoptotic bodies, facilitating the transition from pyroptosis to apoptosis. Mechanistically, DT-13 suppressed the Caspase3-mediated cleavage of GSDME and non-muscle myosin heavy chain IIA (NMMHC IIA), while increasing the phosphorylation of myosin light chain 2 (MLC2), which facilitated apoptotic body formation. Additionally, DT-13 was shown to mitigate VEC damage, inhibit angiogenesis, reduce vascular remodeling, and alleviate MGO-induced hypertension.

CONCLUSIONS

This study uncovers a novel mechanism through which MGO induces VEC damage, highlighting the therapeutic significance of the transition from pyroptosis to apoptosis in this process. These findings suggest potential therapeutic strategies for managing diabetic angiopathy. Furthermore, DT-13 emerges as a promising compound for therapeutic intervention, offering new possibilities for clinical applications.

Optimal duration of ex vivo lung perfusion for heat stress-mediated therapeutic reconditioning of damaged rat donor lungs

OBJECTIVES

Transient heat stress (HS) application during experimental ex vivo lung perfusion (EVLP) of warm ischaemic (WI) rat lungs produces a range of therapeutic benefits. Here, we explored whether different EVLP durations after HS application would influence its therapeutic effects.

METHODS

In protocol 1, WI rat lungs were exposed to HS (41.5°C, 60-90 min EVLP), and EVLP was maintained for 3, 4.5 or 6 h (n = 5/group), followed by physiological measurements (compliance, oedema, oxygenation capacity). In protocol 2, WI rat lungs treated with (HS groups) or without HS (control groups) were maintained for 3 or 4.5 h EVLP (n = 5/group), followed by physiological evaluation and measurements (lung tissue) of heat shock proteins (HSP70, HSP27, HS90, GRP78), endogenous proteins (surfactant protein-D, CC16, platelet endothelial cell adhesion molecule-1), anti-apoptotic (Bcl2, Bcl-xL) and pro-apoptotic proteins (Bcl2-associated X protein, CCAAT/enhancer binding-protein homologous protein), antioxidant enzymes (heme-oxygenase-1, nicotinamide di-phospho-nucleotide dehydrogenase quinone-1) and nitrotyrosine (oxidative stress biomarker).

RESULTS

In protocol 1, physiological variables were stable after 3 and 4.5 h but deteriorated after 6 h. In protocol 2, at 3 h EVLP, HS-treated lungs differed from controls by higher expression of HSP70 and heme-oxygenase-1, and lower CC16 expression. In contrast, at 4.5 h EVLP, HS-treated lungs displayed improved physiology, higher levels of all HSPs, preserved or increased expression of surfactant protein-D, CC-16 and platelet endothelial cell adhesion molecule-1, increased antioxidant and anti-apoptotic proteins, and reduced pro-apoptotic proteins and nitrotyrosine.

CONCLUSIONS

The protective effects of HS application during EVLP of WI-damaged rat lungs strictly depend on the duration of post-HS recovery. An EVLP duration of 4.5 h appears to optimize the therapeutic potential of HS, while maintaining lungs in a stable physiological state.

Regulation of Granzymes A and B by High-Risk HPV: Impact on Immune Evasion and Carcinogenesis

The number of new cancer cases is soaring, and currently, there are 440.5 per 100,000 new cases reported every year. A quarter of these are related to human papillomavirus (HPV) infections, particularly types 16 and 18. These include oropharyngeal, anal, vaginal, and penile cancers. A critical aspect of their oncogenic potential lies in their ability to manipulate host immune responses, facilitating immune evasion and carcinogenesis. High-risk HPVs target key immune components like granzymes A and B and MHC-I, which are crucial for the elimination of virus-infected and transformed cells, thereby weakening immune surveillance. Evidence suggests that high-risk HPVs downregulate the expression of tumor suppressors, such as p53 and pRB, and the activity of these immune components, weakening CTL and NK cell responses, thus enabling persistent infection and carcinogenesis. We discuss the implications of granzyme and MHC-I dysregulation for immune evasion, tumor progression, and potential therapeutic strategies. This review further explores the regulation of granzyme A, B, and MHC-I by high-risk HPVs, focusing on how viral oncoproteins, E6 and E7, interfere with granzyme-mediated cytotoxicity and antigen presentation. The complex interplay between high-risk HPVs, granzyme A, granzyme B, and MHC-I may provide insights into novel approaches for targeting HPV-associated cancers.

Genomic 8-oxoguanine modulates gene transcription independent of its repair by DNA glycosylases OGG1 and MUTYH

8-oxo-7,8-dihydroguanine (OG) is one of the most abundant oxidative lesions in the genome and is associated with genome instability. Its mutagenic potential is counteracted by a concerted action of 8-oxoguanine DNA glycosylase (OGG1) and mutY homolog DNA glycosylase (MUTYH). It has been suggested that OG and its repair has epigenetic-like properties and mediates transcription, but genome-wide evidence of this interdependence is lacking. Here, we applied an improved OG-sequencing approach reducing artificial background oxidation and RNA-sequencing to correlate genome-wide distribution of OG with gene transcription in OGG1 and/or MUTYH-deficient cells. Our data identified moderate enrichment of OG in the genome that is mainly dependent on the genomic context and not affected by DNA glycosylase-initiated repair. Interestingly, no association was found between genomic OG deposition and gene expression changes upon loss of OGG1 and MUTYH. Regardless of DNA glycosylase activity, OG in promoter regions correlated with expression of genes related to metabolic processes and damage response pathways indicating that OG functions as a cellular stress sensor to regulate transcription. Our work provides novel insights into the mechanism underlying transcriptional regulation by OG and DNA glycosylases OGG1 and MUTYH and suggests that oxidative DNA damage accumulation and its repair utilize different pathways.

Characterization of heat, salt, acid, alkaline, and antibiotic stress response in soil isolate Bacillus subtilis strain PSK.A2

Microbes play an essential role in soil fertility by replenishing the nutrients; they encounter various biotic and abiotic stresses disrupting their cellular homeostasis, which expedites activating a conserved signaling pathway for transient over-expression of heat shock proteins (HSPs). In the present study, a versatile soil bacterium Bacillus subtilis strain PSK.A2 was isolated and characterized. Further, the isolated bacterium was exposed with several stresses, viz., heat, salt, acid, alkaline, and antibiotics. Stress-attributed cellular morphological modifications such as swelling, shrinkage, and clump formation were observed under the scanning electron microscope. The comparative protein expression pattern was studied by SDS-PAGE, relative protein stabilization was assessed by protein aggregation assay, and relative survival was mapped by single spot dilution and colony-counting method under control, stressed, lethal, and stressed lethal conditions of the isolate. The findings demonstrated that bacterial stress tolerance was maintained via the activation of various HSPs of molecular weight ranging from 17 to 115 kD to respective stimuli. The treatment of subinhibitory dose of antibiotics not interfering protein synthesis (amoxicillin and ciprofloxacin) resulted in the expression of eight HSPs of molecular weight ranging from 18 to 71 kD. The pre-treatment of short stress dosage showed endured overall tolerance of bacterium to lethal conditions, as evidenced by moderately enhanced total soluble intracellular protein content, better protein stabilization, comparatively over-expressed HSPs, and relatively enhanced cell survival. These findings hold an opportunity for developing novel approaches towards enhancing microbial resilience in a variety of conditions, including industrial bioprocessing, environmental remediation, and infectious disease management.

Secreted extracellular heat shock protein gp96 and inflammatory cytokines are markers of severe malaria outcome

Malaria caused by Plasmodium spp., is a major public health issue in sub-Saharan Africa. The fight against malaria has stalled due to increasing resistance to treatments and insecticides. There is an urgent need to focus on new therapeutic targets to combat malaria effectively. This study aimed to measure the secreted heat shock protein gp96 levels in both malaria patients and controls. Indeed, gp96 plays a crucial role in parasite survival within the host and in establishing a successful infection. Therefore, gp96 could be a promising target for antimalarial drugs. In our study, we included 60 malaria patients, 30 with severe malaria (SM) and 30 with uncomplicated malaria (UM). Additionally, 28 controls were included. Using the ELISA method, we measured gp96 levels in the participants' blood samples. We then used the Mann-Whitney or analyse of variance tests to calculate descriptive statistics and determined the correlation between gp96 level and parasitemia using Spearman's rank correlation test. The study found that gp96 levels in the plasma significantly increased in malaria patients (23.86 ng/mL) compared to control (5.88 ng/mL), with a P < 0.0001. Interestingly, there was a significant difference between SM (27.56 ng/mL) and UM (13.9 ng/mL), with a P-value of 0.001. These findings are accompanied by significantly higher parasitemia and elevated proinflammatory cytokines such as IL-17A and IL-1β levels in SM patients compared to UM and controls. Furthermore, there was no significant positive correlation between gp96 levels and parasitemia/proinflammatory cytokines. Our research has revealed, for the first time, that individuals with SM have significantly higher levels of gp96 in the context of high parasitemia and proinflammatory cytokines. Our preliminary results will be taken further to evaluate gp96 as a valuable biomarker for the diagnosis of SM and a potential target for antimalarial drug discovery.

Caspase 3 and caspase 7 promote cytoprotective autophagy and the DNA damage response during non-lethal stress conditions in human breast cancer cells

Cell stress adaptation plays a key role in normal development and in various diseases including cancer. Caspases are activated in response to cell stress, and growing evidence supports their function in non-apoptotic cellular processes. A role for effector caspases in promoting stress-induced cytoprotective autophagy was demonstrated in Drosophila, but has not been explored in the context of human cells. We found a functionally conserved role for effector caspase 3 (CASP3) and caspase 7 (CASP7) in promoting starvation or proteasome inhibition-induced cytoprotective autophagy in human breast cancer cells. The loss of CASP3 and CASP7 resulted in an increase in PARP1 cleavage, reduction in LC3B and ATG7 transcript levels, and a reduction in H2AX phosphorylation, consistent with a block in autophagy and DNA damage-induced stress response pathways. Surprisingly, in non-lethal cell stress conditions, CASP7 underwent non-canonical processing at two calpain cleavage sites flanking a PARP1 exosite, resulting in stable CASP7-p29/p30 fragments. Expression of CASP7-p29/p30 fragment(s) could rescue H2AX phosphorylation in the CASP3 and CASP7 double knockout background. Strikingly, yet consistent with these phenotypes, the loss of CASP3 and CASP7 exhibited synthetic lethality with BRCA1 loss. These findings support a role for human caspases in stress adaptation through PARP1 modulation and reveal new therapeutic avenues for investigation.

Transcriptomics Unveil Canonical and Non-Canonical Heat Shock-Induced Pathways in Human Cell Lines

The cellular stress response (CSR) is a conserved mechanism that protects cells from -environmental and physiological stressors. The heat shock response (HSR), a critical component of the CSR, utilizes molecular chaperones to mitigate proteotoxic stress caused by elevated temperatures. We hypothesized that while the canonical HSR pathways are conserved across cell types, specific cell lines may exhibit unique transcriptional responses to heat shock. To test this, we compared the transcriptomic responses of HEK293, HepG2, and HeLa cells under control conditions immediately following heat shock and after an 8-h recovery period. RNA sequencing revealed the conserved activation of canonical HSR pathways, including the unfolded protein response, alongside the -enrichment of the non-canonical "Receptor Ligand Activity" pathway across all cell lines. Cell-line-specific variations were observed, with HepG2 cells exhibiting significantly higher ex-pression levels of certain genes compared to other cell lines under stress conditions, as well as greater fold changes in gene expression relative to its control conditions. Validation by qPCR confirmed the activation of key genes within the "Receptor Ligand Activity" pathway across time points. These findings provide insights into conserved and context-specific aspects of the HSR, contributing to a more comprehensive understanding of stress response mechanisms across mammalian cells.

Adaptive Plasticity Tumor Cells Modulate MAPK-Targeting Therapy Response in Colorectal Cancer

MAPK pathway inhibitors (MAPKi) are increasingly used in the treatment of advanced colorectal cancer, but often produce short-lived responses in patients. Although acquired resistance by de novo mutations in tumors have been found to reduce response in some patients, additional mechanisms underlying the limited response durability of MAPK targeting therapy remain unknown. Here, we denote new contributory tumor biology and provide insight on the impact of tumor plasticity on therapy response. Analysis of MAPKi treated patients revealed activation of stemness programs and increased ASCL2 expression, which are associated with poor outcomes. Greater ASCL2 with MAPKi treatment was also seen in patient-derived CRC models, independent of driver mutations. We find ASCL2 denotes a distinct cell population, arising from phenotypic plasticity, with a proliferative, stem-like phenotype, and decreased sensitivity to MAPKi therapy, which were named adaptive plasticity tumor (APT) cells. MAPK pathway suppression induces the APT phenotype in cells, resulting in APT cell enrichment in tumors and limiting therapy response in preclinical and clinical data. APT cell depletion improved MAPKi treatment efficacy and extended MAPKi response durability in mice. These findings uncover a cellular program that mitigates the impact of MAPKi therapies and highlights the importance of addressing tumor plasticity to improve clinical outcomes.

Donor Variability Alters the Characteristics of Human Brain Microvascular Endothelial Cells

Primary brain microvascular endothelial cells (BMECs) are widely used in a large number of in vitro studies each year to better mimic their physiological characteristics in vivo. However, potential changes in primary endothelial cells stemming from donor variability or culture conditions may affect the reliability and reproducibility of the experiments. While working on a project regarding BMEC senescence, we noticed behavioral differences between two different batches of cells. Comparative analyses of cellular characteristics revealed that while one batch of BMECs developed a typical cobblestone morphology, the other batch displayed a spindle-shape morphology. Despite showing similar tubulogenic and barrier-forming capacities, the spindle-shaped BMECs displayed greater proliferation rates, stronger staining for CD34, a marker of stemness and higher resistance to oxidative stress-induced senescence and replicative senescence. Conversely, the spindle-shaped cells demonstrated a much weaker staining for the endothelial marker CD31. Taken together, these findings indicate that it is important to scrutinize endothelial characteristics to ensure experimental accuracy when cellular responses markedly vary between the so-called endothelial cells.

The role of circadian rhythm regulator PERs in oxidative stress, immunity, and cancer development

The complex interaction between circadian rhythms and physiological functions is essential for maintaining human health. At the heart of this interaction lies the PERIOD proteins (PERs), pivotal to the circadian clock, influencing the timing of physiological and behavioral processes and impacting oxidative stress, immune functionality, and tumorigenesis. PER1 orchestrates the cooperation of the enzyme GPX1, modulating mitochondrial dynamics in sync with daily rhythms and oxidative stress, thus regulating the mechanisms managing energy substrates. PERs in innate immune cells modulate the temporal patterns of NF-κB and TNF-α activities, as well as the response to LPS-induced toxic shock, initiating inflammatory responses that escalate into chronic inflammatory conditions. Crucially, PERs modulate cancer cell behaviors including proliferation, apoptosis, and migration by influencing the levels of cell cycle proteins and stimulating the expression of oncogenes c-Myc and MDM2. PER2/3, as antagonists in cancer stem cell biology, play important roles in differentiating cancer stem cells and in maintaining their stemness. Importantly, the expression of Pers serve as a significant factor for early cancer diagnosis and prognosis. This review delves into the link between circadian rhythm regulator PERs, disruptions in circadian rhythm, and oncogenesis. We examine the evidence that highlights how dysfunctions in PERs activities initiate cancer development, aid tumor growth, and modify cancer cell metabolism through pathways involved in oxidative stress and immune system. Comprehending these connections opens new pathways for the development of circadian rhythm-based therapeutic strategies, with the aims of boosting immune responses and enhancing cancer treatments.

HSF1 at the crossroads of chemoresistance: from current insights to future horizons in cell death mechanisms

Heat Shock Factor 1 (HSF1) is a major transcriptional factor regulating the heat shock response and has become a potential target for overcoming cancer chemoresistance. This review comprehensively examines HSF1's role in chemoresistance and its potential as a therapeutic target in cancer. We explore the complex, intricate mechanism that regulates the activation of HSF1, HSF1's function in promoting resistance to chemotherapy, and the strategies used to manipulate HSF1 for therapeutic benefit. In addition, we discuss emerging research implicating HSF1's roles in autophagy, apoptosis, DNA damage repair, drug efflux, and thus chemoresistance. This article highlights the significance of HSF1 in cancer chemoresistance and its potential as a target for enhancing cancer treatment efficacy.

Live and let die: analyzing ultrastructural features in cell death

Cell death is an important process that supports morphogenesis during development and tissue homeostasis during adult life by removing damaged or unwanted cells and its dysregulation is associated with numerous disease states. There are different pathways through which a cell can undergo cell death, each relying on peculiar molecular mechanisms and morpho-ultrastructural features. To date, however, while molecular and genetic approaches have been successfully integrated into the field, cell death studies rarely incorporate ultrastructural data from electron microscopy. This review article reports a gallery of original transmission electron microscopy images to describe the ultrastructural features of cells undergoing different types of cell death programs, including necrosis, apoptosis, autophagy, mitotic catastrophe, ferroptosis, methuosis, and paraptosis. TEM has been an important technology in cell biology for well over 50 years and still continues to offer significant advantages in the area of cell death research. TEM allows detailed characterization of the ultrastructural changes within the cell, such as the alteration of organelles and subcellular structures, the nuclear reorganization, and the loss of membrane integrity that enable a distinction between the different forms of cell death based on morphological criteria. Possible pitfalls are also described.

Heat shock protein HSPA8 impedes hemin-induced cellular-toxicity in liver

Accumulation of hemin in cells, tissues, and organs is one of the major pathological conditions linked to hemolytic diseases like malaria. Pro-oxidant hemin confers high toxicity following its accumulation. We tested the cellular toxicity of hemin on HepG2 cells by exploring modulation in various cellular characteristics. Hemin reduces the viability of HepG2 cells and brings about visible morphological changes. Hemin causes perforations on the surface of HepG2 cells observed through SEM. Hemin leads to the extracellular release of liver enzymes and reduces the wound-healing potential of HepG2 cells. Hemin leads to the fragmentation of HepG2 DNA, arrests the cell cycle progression in the S-phase and induces apoptosis in these cells. Western blot analysis revealed that hemin triggers both the extrinsic and intrinsic pathways of apoptosis in HepG2 cells. We have already shown that the cytoprotective protein HSPA8 can polymerize hemin and minimize its toxicity. Similar experiments with hemin in the presence and absence of HSPA8 showed that HSPA8 reverses all the tested toxic effects of hemin on HepG2 cells. The protection from hemin toxicity in HepG2 cells appeared to be due to the extracellular polymerization of hemin by HSPA8.

Perfluorooctane sulfonate causes DNA damage and apoptosis via oxidative stress in umbilical cord fibroblast cells of Yangtze finless porpoise

Yangtze finless porpoise (YFP) is a critically endangered species in China. It has been found that YFP is constantly exposed to perfluorooctane sulfonate (PFOS) in aquatic environments, leading to significant bioaccumulation. However, the impacts of PFOS on YFP health and survival are still unknown. To circumvent the limitations in YFP research, this study used YFP umbilical cord fibroblast cell line and exposed the cells to PFOS for 48 h, with objectives to uncover the cytotoxicity and mechanisms of PFOS in YFP. A high-throughput proteomics assay showed that PFOS exposure at 50 μM for 48 h perturbed the proteome structure in YFP umbilical cord fibroblast cells. Functional annotation found the high relevance of oxidative stress, mitochondrial oxidative phosphorylation, and DNA damage to PFOS cytotoxic mechanisms. Concordantly, PFOS exposure significantly increased the deposition of reactive oxygen species (ROS) in YFP cells. The potential of mitochondria to produce ATP was also compromised by PFOS, which was accompanied by the higher permeability of mitochondrial membrane. In addition, exposure of YFP umbilical cord fibroblast cells to 50 μM PFOS damaged the DNA assembly as evidenced by the increase in the percentage of DNA fragmentation. Gene transcription and enzymatic activity of caspases were up-regulated by PFOS, subsequently favoring the occurrence of early and late apoptosis. It was notable that ROS scavenger could successfully mitigate the cytotoxicity of PFOS on oxidative stress and apoptosis, thus pinpointing ROS as the molecular initiating event in apoptosis endpoints. To our knowledge, this is the first study that investigates the detrimental effects of PFOS using YFP umbilical cord fibroblast cells. The data will support an accurate assessment of ecological risks imposed by environmental pollutants on the health and sustainability of YFP, which is especially important under the context of sharp decline in YFP population and national initiative in YFP conservation.

Developmental and molecular effects of pure-tone sine wave exposure on early zebrafish embryo development: Implications for reproductive health

Noise pollution has become a significant concern for human health, yet its effects on early embryonic development remain underexplored. Specifically, data on the impact of sine wave noise on newly fertilized embryos is limited. This study aimed to address this gap by using zebrafish embryos at the 1-cell stage as a model to assess the toxicity of sine waves, following OECD Test No. 236. We exposed embryos to sound levels of 90 decibels (dB) and above, observing increased deformity rates, delayed development, and reductions in body length, heart rate and brain size. To elucidate the molecular mechanisms underlying these effects, we employed transcriptomics, metabolomics, and epigenomics (m6A-MeRIP-seq). KEGG enrichment analysis revealed significant alterations in arachidonic acid metabolism, axon guidance, and ubiquitin-mediated proteolysis. In conclusion, our findings demonstrate that high levels of sine wave noise adversely affect early embryo development. These results provide crucial insights for developing strategies to mitigate noise pollution and protect early developmental stages.

Oscillatory autophagy induction is enabled by an updated AMPK-ULK1 regulatory wiring

Autophagy-dependent survival relies on a crucial oscillatory response during cellular stress. Although oscillatory behaviour is typically associated with processes like the cell cycle or circadian rhythm, emerging experimental and theoretical evidence suggests that such periodic dynamics may explain conflicting experimental results in autophagy research. In this study, we demonstrate that oscillatory behaviour in the regulation of the non-selective, stress-induced macroautophagy arises from a series of interlinked negative and positive feedback loops within the mTORC1-AMPK-ULK1 regulatory triangle. While many of these interactions have been known for decades, recent discoveries have revealed how mTORC1, AMPK, and ULK1 are truly interconnected. Although these new findings initially appeared contradictory to established models, additional experiments and our systems biology analysis clarify the updated regulatory structure. Through computational modelling of the autophagy oscillatory response, we show how this regulatory network governs autophagy induction. Our results not only reconcile previous conflicting experimental observations but also offer insights for refining autophagy regulation and advancing understanding of its mechanisms of action.

Trehalose Cryopreservation of Human Mesenchymal Stem Cells from Cord Tissue

Adequate hypothermic storage of human mesenchymal stem cells (hMSCs) is of fundamental importance since they have been explored in several regenerative medicine initiatives. However, the actual clinical application of hMSCs necessitates hypothermic storage for long periods, a process that requires the use of non-toxic and efficient cryo-reagents capable of maintaining high viability and differentiating properties after thawing. Current cryopreservation methods are based on cryoprotectant agents (CPAs) containing dimethylsulphoxide (DMSO), which have been shown to be toxic for clinical applications. In this study, we describe a simple and effective trehalose (TRE)-based solution to cryo-store human umbilical cord-derived MSCs (UC-MSCs) in liquid nitrogen. Cells viability, identity, chromosomal stability, proliferative and migration capacity, and stress response were assessed after cryopreservation in TRE as CPA, testing different concentrations by itself or in combination with ethylene glycol (EG). Here we show that TRE-stored UC-MSCs provided lower cell recovery rates compared with DMSO-based solution, but maintained good functional properties, stability, and differentiating potential. The best cell recovery was obtained using 0.5 M TRE with 10% EG showing no differences in the osteogenic, adipogenic, and chondrogenic differentiation capacity. A second cycle of cryopreservation in this TRE-based solution had no additional impact on the viability and morphology, although slightly affected cell migration. Furthermore, the expression of the stress-related genes, HSPA1A, SOD2, TP53, BCL-2, and BAX, did not show a higher response in UC-MSCs cryopreserved in 0.5 M TRE + 10% EG compared with DMSO. Together these results, in addition to ascertained therapeutic properties of TRE, provide sufficient evidence to consider TRE-based medium as a low-cost and efficient solution for the storage of human UC-MSCs cells and potentially substitute DMSO-based cryo-reagents.

Transcriptomics Unveil Canonical and Non-Canonical Heat Shock-Induced Pathways in Human Cell Lines

The cellular stress response (CSR) is a conserved mechanism that protects cells from environmental and physiological stressors. The heat shock response (HSR), a critical component of the CSR, utilizes molecular chaperones to mitigate proteotoxic stress caused by elevated temperatures. We hypothesized that while the canonical HSR pathways are conserved across cell types, specific cell lines may exhibit unique transcriptional responses to heat shock. To test this, we compared the transcriptomic responses of HEK293, HepG2, and HeLa cells under control conditions immediately following heat shock and after an 8-hour recovery period. RNA sequencing revealed conserved activation of canonical HSR pathways, including the unfolded protein response, alongside enrichment of the non-canonical "Receptor Ligand Activity" pathway across all cell lines. Cell line-specific variations were also observed, with HepG2 cells displaying more uniquely expressed genes and elevated expression levels (fold changes) of shared genes under stress conditions. Validation by qPCR confirmed the activation of key genes within the "Receptor Ligand Activity" pathway across time points. These findings provide insights into conserved and context-specific aspects of the HSR, contributing to a more comprehensive understanding of stress response mechanisms across mammalian cells.

Life History Differences Between Lepidoptera Larvae and Blattodea Nymphs Lead to Different Energy Allocation Strategies and Cellular Qualities

Different life histories result in different strategies to allocate energy in biosynthesis, including growth and reproduction, and somatic maintenance. One of the most notable life history differences between Lepidoptera and Blattodea species is that the former grow much faster than the latter, and during metamorphosis, a large amount of tissue in Lepidoptera species disintegrates. In this review, using Lepidoptera caterpillars and cockroach nymphs as examples, we show that, due to these differences in growth processes, cockroach nymphs spend 20 times more energy on synthesizing one unit of biomass (indirect cost of growth) than butterfly caterpillars. Because of the low indirect cost of growth in caterpillars, the fraction of metabolic energy allocated to growth is six times lower, and that for maintenance is seven times higher in caterpillars, compared to cockroach nymphs, despite caterpillar's higher growth rates. Moreover, due to the higher biosynthetic energy cost in cockroach nymphs, they have better cellular qualities, including higher proteasomal activity for protein quality control and higher resistance to oxidative stress. We also show that under food restriction conditions, the fraction of assimilated energy allocated to growth was reduced by 120% in cockroach nymphs, as they lost body weight under food restriction, while this reduction was only 14% in hornworms, and the body mass increased at a lower rate. Finaly, we discuss future research, especially the difference in adult lifespans associated with the energetic differences.

The Emerging Role of p21 in Diabetes and Related Metabolic Disorders

In the context of cell cycle inhibition, anti-proliferation, and the dysregulation observed in certain cancer pathologies, the protein p21 assumes a pivotal role. p21 links DNA damage responses to cellular processes such as apoptosis, senescence, and cell cycle arrest, primarily functioning as a regulator of the cell cycle. However, accumulating empirical evidence suggests that p21 is both directly and indirectly linked to a number of different metabolic processes. Intriguingly, recent investigations indicate that p21 significantly contributes to the pathogenesis of diabetes. In this review, we present a comprehensive evaluation of the scientific literature regarding the involvement of p21 in metabolic processes, diabetes etiology, pancreatic function, glucose homeostasis, and insulin resistance. Furthermore, we provide an encapsulated overview of therapies that target p21 to alleviate metabolic disorders. A deeper understanding of the complex interrelationship between p21 and diabetes holds promise for informing current and future therapeutic strategies to address this rapidly escalating health crisis.

Stress Granules in Infectious Disease: Cellular Principles and Dynamic Roles in Immunity and Organelles

Stress granules (SGs) are membrane-less aggregates that form in response to various cellular stimuli through a process called liquid-liquid phase separation (LLPS). Stimuli such as heat shock, osmotic stress, oxidative stress, and infections can induce the formation of SGs, which play crucial roles in regulating gene expression to help cells adapt to stress conditions. Various mRNAs and proteins are aggregated into SGs, particularly those associated with the protein translation machinery, which are frequently found in SGs. When induced by infections, SGs modulate immune cell activity, supporting the cellular response against infection. The roles of SGs differ in viral versus microbial infections, and depending on the type of immune cell involved, SGs function differently in response to infection. In this review, we summarize our current understanding of the implication of SGs in immunity and cellular organelles in the context of infectious diseases. Importantly, we explore insights into the regulatory functions of SGs in the context of host cells under infection.