Cell Stress最新文献

Fungal infections pose a significant global health threat with rising morbidity and mortality rates. However, the repertoire of effective antifungal drugs remains narrow, a challenge that is further exacerbated by the increasing emergence of (multi)drug-resistant strains. This underscores the urgent need for novel therapeutic strategies. Among them, antifungal peptides (AFPs) have emerged as a promising alternative. AFPs are small, naturally occurring peptides produced by a wide range of organisms, including plants, animals, fungi, and bacteria, as part of their innate immune defense. In addition, synthetic and semisynthetic variants have also been engineered. We here underscore the potential of AFPs as viable candidates for the development of next-generation antifungal therapies. In particular, we advocate their multimodal advantage that spans beyond standalone activity, including their synergistic and immune-regulatory potential.

Cushing syndrome (CS) is caused by an increase in endogenous or exogenous glucocorticoids, leading to major alterations in body composition, including visceral obesity, sarcopenia, osteoporosis, type 2 diabetes, and dyslipidemia. Cardiovascular complications resulting from CS are often lethal. We previously demonstrated that CS induced by oral corticosterone (CORT) supplementation in mice can be prevented by inhibition of the peptide hormone acyl-CoA binding protein (ACBP), encoded by the gene diazepam binding inhibitor (DBI). Here, we investigated whether ACBP/DBI inhibition could be used to treat, rather than prevent, CS. To this end, we initiated treatment with anti-ACBP/DBI monoclonal antibodies (mAbs) in mice three weeks after the start of CORT supplementation, when hyperphagia and body weight gain were already established. Two anti-ACBP/DBI mAbs, 7G4a (specific for mouse ACBP/DBI only) and 82 (which recognizes both mouse and human ACBP/DBI), were able to normalize food intake and halt weight gain in mice under continuous CORT treatment. In addition, both mAbs attenuated CORT-induced sarcopenia, adiposity in inguinal, perigonadal, and visceral fat depots, and fully restored metabolic parameters, including type-2 diabetes, insulinemia, free fatty acids, triglycerides, and liver transaminases. In conclusion, neutralization of ACBP/DBI may serve as an effective therapeutic strategy for the treatment of established CS.

Removing certain essential amino acids from the diet is known to promote weight loss in rodents via effects on food intake and energy expenditure. Two complementary articles by Varghese et al [Nature 643(8072)] and Lee et al [Nature Metabolism 7(6)] now show that cysteine depletion through combined dietary and genetic means in mice evokes a unique stress response in the liver to amplify these metabolic outcomes and offer a potentially new treatment option for obesity.

Replication stress (RS) is a major driver of genomic instability and cancer development through impaired DNA replication that can lead to chromosomal instability (CIN). Although RS is mechanistically linked to CIN, its relationship with cellular proliferation is complex. Depending on the context, RS can either promote or suppress cell growth. Existing RS gene expression signatures overlook this complexity, relying on the overexpression of oncogenes such as MYC, which introduces a proliferation bias. To disentangle genuine RS from confounding cell cycle and proliferation transcriptional profiles, we developed and validated a novel gene expression signature that accurately predicts RS independently of oncogene activity. This tumorigenic RS signature (TRSS) captures RS-related transcriptional changes across diverse cellular contexts, enabling a more robust and proliferation-independent measure of RS in both experimental and clinical samples. Applying our signature to patient data, we discovered a link between RS and the non-homologous end-joining (NHEJ) DNA repair pathway. Specifically, we observed that MSH2 and MSH6 - core components of mismatch repair - are associated with elevated RS and may indicate a shift toward NHEJ-mediated repair under stress conditions. Our study provides a refined approach to quantify RS and sheds light on its broader impact on DNA repair network dynamics.

Antibody-drug conjugates (ADCs) offer a strategy for targeted delivery of cytotoxic agents to cancer cells. In this study, we investigated the mechanism of action of datopotamab deruxtecan, an ADC composed of a monoclonal antibody targeting tumor-associated calcium signal transducer 2 (TACSTD2, also known as trophoblast cell-surface antigen-2 (TROP2)) conjugated to the topoisomerase I inhibitor DXd. Datopotamab deruxtecan reduced the viability of human osteosarcoma U2OS cells engineered to express TROP2, but had no effect on their parental counterparts, which only expressed the CALR-GFP biosensor. In TROP2-expressing cells, it triggered the translocation of CALR-GFP from the ER to the cell periphery. Both datopotamab deruxtecan and its DXd payload elicited several features characteristic of immunogenic cell death (ICD), including detectable calreticulin exposure on the cell surface, release of high-mobility group box 1 (HMGB1), and ATP secretion into the culture medium. Importantly, the TROP2-targeted ADC also exerted a bystander antitumor effect on parental U2OS cells (lacking TROP2 expression) co-cultured with TROP2-expressing U2OS cells. These findings demonstrate that datopotamab deruxtecan delivers a cytotoxic payload capable of inducing hallmark features of ICD in vitro.

An imbalanced production of reactive oxygen species (ROS) is linked to various aspects of cancer development, including cytoskeletal remodelling. However, the relationship between ROS, actin and cellular stiffness remains controversial. Here, we show that oxidative stress increases cortical stiffness in pre-apoptotic colon and pancreatic cancer cells via localized F-actin polymerization in the apical cortex - independent of changes in total F-actin levels. Using atomic force microscopy and flow cytometry, we demonstrate this effect across multiple ROS inducers: the combination of arsenic trioxide and D-enantiomer of vitamin C, hydrogen peroxide, and rotenone. These findings explain previously debated relationships on how ROS influence actin organization, which may affect cellular stiffness. By separating total from cortical actin effects, our study reveals a redox-sensitive mechanism that governs cytoskeletal remodelling and may impair cancer cell migration.

The dysfunction of mitochondria, the "energy factories" of cells, not only causes an insufficiency of energy production but also leads to various pathological alterations in cells such as the accumulation of reactive oxygen species, inflammatory responses and mitochondrial DNA damage, all of which were involved in the onset or deterioration of diseases. The presence of mitochondrial dysfunction has been confirmed in many ocular surface diseases such as dry eye, Fuchs corneal endothelial dystrophy and diabetic keratopathy. However, its role in the pathogenesis of ocular surface diseases and underlying molecular mechanisms have not been fully elucidated. Moreover, mitochondrial therapies for ocular surface diseases are currently still under investigation. This mini-review summarizes the pathological features of mitochondrial dysfunction and its mechanisms that have been identified in the pathogenesis of ocular surface diseases, and discusses the potential of mitochondrial therapies in the treatment of these diseases.

High carbohydrate intake, a characteristic of many Western diets, is a major contributor to age-associated pathologies. Here, we explored the molecular consequences of sugar overload during chronological aging in the yeast Saccharomyces cerevisiae. High levels of glucose and fructose resulted in a decrease of chronological lifespan as well as an increase of cell death, ROS and neutral lipids. Interestingly, these changes were accompanied by significantly altered ceramide profiles. Deletion of either the kinase Tor1, a master regulator of growth and autophagy in response to nutrients, or the vacuole-anchored receptor Vac8, an important player in various autophagy pathways, improved survival and normalized ceramide profiles. This suggests that ceramides might play a role in sugar stress-induced cell death. In line, pharmacological inhibition of sphingolipid synthesis normalized ceramide profiles and improved chronological lifespan, whereas pharmacologically induced ceramide accumulation decreased chronological lifespan. In sum, our findings causally link nutrient signaling and an altered ceramide profile to sugar cytotoxicity in aging yeast, providing a basis for further search of feasible interventions against sugar-induced cell death.

Genetically identical cells in a population show cell-to-cell variability because of fluctuation in transcription, epigenetics, post-translational modifications, and stochastic or extrinsically triggered non-genetic alterations. The change in the interaction state of proteins also emerges as an additional layer of cell signaling that influences cell cycle and cell death. However, the interrelation between cell cycle progression and cell death under the influence of spatio-temporal changes in protein-protein interaction is difficult to demonstrate in growing cells. This requires tools for cell cycle phase-resolved visualization of macromolecular interactions in live cells. We describe an approach to visualize the interaction of pro- and anti-death signaling partners, Bax and Bcl-xL, during cell cycle progression and cell death in live cells. Cells were stably expressed with Bax and Bcl-xL with FRET pairs and real-time cell cycle indicator probes. Acceptor photobleaching and Fluorescence lifetime imaging revealed interaction dynamics between Bax and Bcl-xL in isogenic stable cells. While Bcl-xL inhibited cell cycle progression, Bax promoted the cell cycle. The study highlighted an increased Bax-Bcl-xL interaction in the G1 phase compared to the non-G1 phase. Increased interaction is seen under stressed conditions and Bax-activated cells with FLIM-FRET, highlighting the nature of Bax-Bcl-xL interaction during cellular stress. In conclusion, our study explains Bax-Bcl-xL interaction dynamics in real-time and the potential utility of the approach to study macromolecular interactions along with cell cycle and cell death.

Differential and even opposing functions of two major antioxidant transcription factors Nrf1 and Nrf2 (encoded by Nfe2l1 and Nfe2l2, respectively) are determined by distinctions in their tempospatial positioning, topological repartitioning, proteolytic processing, and biochemical modification, as well as in their shared evolutionary origin. As a matter of fact, the allelopathic potentials of Nrf1 and Nrf2 (both resembling two entangled 'Yin-Yang' quanta that comply with a dialectic law of the unity of opposites) are fulfilled to coordinately control redox physiological homeostasis so as to be maintained within the presetting thresholds. By putative exponential curves of redox stress and intrinsic anti-redox capability, there is inferable to exist a set point at approaching zero with the 'Golden Mean' for the healthy survival (i.e., dubbed the 'zero theory'). A bulk of the hitherto accumulating evidence demonstrates that the set point of redox homeostasis is dictated selectively by multi-hierarchical threshold settings, in which the living fossil-like Nrf1 acts as a robust indispensable determinon, whereas Nrf2 serves as a versatile chameleon-like master regulon, in governing the redox homeodynamic ranges. This is attributable to the facts that Nrf2 has exerted certain 'double-edged sword' effects on life process, whereas Nrf1 executes its essential physiobiological functions, along with unique pathophysiological phenotypes, by integrating its 'three-in-one' roles elicited as a specific triplet of direct sensor, transducer and effector within multi-hierarchical stress responsive signaling to redox metabolism and target gene reprogramming. Here, we also critically reviewed redox regulation of physio-pathological functions from the eco-evo-devo perspectives, through those coding rules (redox code, stress-coping code, and topogenetic code). The evolving concepts on stress and redox stress were also further revisited by scientific principles of physics and chemistry. Besides, several novel concepts such as oncoprotists, Reverse Central Dogma, and Grand Redox-Unifying Theory' (GRUT) of life, together with diffusive reactive species (DRS)-based murburn concept integrating all stochastic electron-, proton- and/or moiety-transfer reactive and interactive processes (e.g., PCHEMS), are introduced in this interdisciplinary and synthetic review.