Search Results (120)

BST2 has emerged as a multifunctional molecule that bridges antiviral defense, membrane architecture, and tumor immunity. Originally characterized as an interferon-inducible restriction factor that tethers virions to the plasma membrane, BST2 is now recognized as an oncogenic driver and immunoregulatory hub in diverse malignancies. In cancer, BST2 expression is frequently upregulated through promoter hypomethylation and transcriptional activation. Functionally, BST2 promotes proliferation, epithelial–mesenchymal transition, anoikis resistance, and chemoresistance, whereas its loss sensitizes tumor cells to proteotoxic and metabolic stresses. Beyond tumor cells, BST2 modulates the tumor microenvironment by promoting M2 macrophage infiltration, dendritic cell exhaustion, and natural killer (NK)-cell resistance, thereby contributing to immune evasion. Elevated BST2 expression correlates with poor prognosis in glioblastoma, breast, nasopharyngeal, and pancreatic cancers, and it serves as a circulating biomarker within small extracellular vesicles. In conclusion, BST2 is a dual-function molecule that integrates oncogenic signaling and immune regulation, making it an attractive diagnostic and therapeutic target for hematological and solid tumors. Full article

Neurodegenerative diseases such as Alzheimer’s, Parkinson’s, amyotrophic lateral sclerosis, and Huntington’s disease represent a major challenge in neuroscience due to their complex, multifactorial nature and the absence of curative treatments. These disorders share common molecular mechanisms, including oxidative stress, mitochondrial dysfunction, proteostasis collapse, calcium dyshomeostasis, chronic neuroinflammation, and the prion-like propagation of misfolded proteins. Together, these processes trigger a cascade of cellular damage that culminates in synaptic dysfunction and programmed neuronal death. This review integrates current evidence on the sequential stages of neurodegeneration, emphasizing the convergence of oxidative, inflammatory, and proteotoxic pathways that drive neuronal vulnerability. Moreover, it explores emerging therapeutic strategies aimed at restoring cellular homeostasis, such as Nrf2 activation, modulation of the unfolded protein response (UPR), enhancement of autophagy, immunotherapy against pathological proteins, and gene therapy approaches. The dynamic interplay among mitochondria, endoplasmic reticulum, and glial cells is highlighted as a central element in disease progression. Understanding these interconnected mechanisms provides a foundation for developing multi-targeted interventions capable of halting or delaying neuronal loss and improving clinical outcomes in neurodegenerative disorders. This work provides an integrative and introductory overview of the convergent mechanisms underlying neurodegeneration rather than an exhaustive mechanistic analysis. Full article

Water alkalinization is a critical global stressor for freshwater fish, yet the systemic patterns of multi-organ responses and injury remain insufficiently understood. This study integrates histopathology, biochemistry, and multi-organ transcriptomics to provide an integrated, time-resolved assessment of stress responses in European perch (Perca fluviatilis) exposed to acute alkaline stress (20 mmol/L). The analysis indicated that alkaline stress initially causes structural disturbance of gill tissue (lamellar fusion, necrosis) within 96 h, associated with impaired osmoregulatory functions. This primary dysfunction was followed by progressive hepatic impairment, characterized by uncontrolled oxidative stress (elevated levels in Malondialdehyde, MDA) and widespread hepatocyte necrosis. Transcriptomic analysis identified extensive transcriptional shifts associated with these alterations: large-scale differential expression in the liver (3629 Differentially Expressed Genes, DEGs) and kidney (478 DEGs). Notably, the liver exhibited a stress-responsive transcriptional profile involving activation of the HIF-1 signaling pathway and mobilizing protein quality control systems (e.g., ‘Proteasome,’ ‘Lysosome’) consistent with mitigation of proteotoxic stress. This compensatory response appeared insufficient to prevent severe metabolic disruption and cellular injury. This study presents a time-associated sequence of organ-specific stress responses under acute alkalinity, identifying candidate stress-associated genes (slc7a11, egln3, klhl38b) as potential targets for future functional studies and breeding alkali-tolerant strains. Full article

Background/Objectives: Cathepsins, lysosomal proteases crucial for neuronal proteostasis, mediate the clearance of misfolded and aggregated proteins. Their dysregulation is implicated in neurodegenerative and neuropsychiatric disorders such as Alzheimer’s, Parkinson’s, and Huntington’s diseases. These conditions are characterized by toxic protein accumulation and impaired clearance, which exacerbate cellular stress responses, including the unfolded protein response (UPR), oxidative damage, and mitochondrial dysfunction. This review aims to summarize current knowledge on cathepsin roles in these pathways and assess their therapeutic potential. Methods: A comprehensive literature review was conducted, focusing on recent in vitro and in vivo studies investigating cathepsin function, inhibition, and modulation. Mechanistic insights and pharmacological approaches targeting cathepsins were analyzed, with attention to challenges in translating preclinical findings to clinical settings. Results: Cathepsins demonstrate a dual role: their proteolytic activity supports neuronal health by degrading toxic aggregates, but altered or insufficient activity may worsen proteotoxic stress. Studies reveal that cathepsins regulate autophagy, apoptosis, and neuroinflammation both intracellularly and extracellularly. Despite promising mechanistic data, clinical translation is hindered by issues such as poor inhibitor selectivity, limited brain penetration, and variability across preclinical models. Conclusions: Targeting cathepsins presents a promising strategy for treating neurodegenerative and neuropsychiatric disorders, but significant challenges remain. Future research should focus on improving drug specificity and delivery, and on developing standardized models to better predict clinical outcomes. Full article

Heat hardening induces complex biochemical reprogramming that enhances thermal resilience in marine bivalves. Despite this technique’s promising results in marine animals, the molecular basis of heat hardening is far from understood. This study elucidates the molecular mechanisms underlying the hardening process in Mytilus galloprovincialis exposed to a 4-day sublethal heat treatment. Induction of hsf-1, hsp70, and hsp90 genes revealed the activation of the heat shock response and proteostasis machinery, ensuring proper protein folding and preventing oxidative and proteotoxic stress. Simultaneous upregulation of mitochondrial (atpase6, cox1, nadh) and glycolytic (pk, cs) genes reflects enhanced oxidative phosphorylation and glycolytic flux, maintaining ATP supply and metabolic flexibility under elevated temperatures. Increased hif-1α expression suggests transient hypoxia signaling, coordinating oxygen utilization with redox control. Reinforcement of antioxidant defenses, together with elevated autophagy-related transcription, denotes a shift toward oxidative stress mitigation and damaged organelle clearance. Balanced expression of pro- (bax) and anti-apoptotic (bcl-2) factors, along with nf-κb modulation, supports tight regulation of cell survival and inflammatory responses. These findings underscore a highly integrated biochemical network linking proteostasis, intermediary metabolism, redox balance, and antioxidant defense with cellular quality control, which together underpin the physiological plasticity of heat-hardened M. galloprovincialis, enhancing survival under transient thermal stress. Full article

Background: Multiple myeloma (MM) is essentially an incurable cancer, but treatments with proteasome inhibitors are widely used clinically to extend patient survival. While the mechanisms of proteasome inhibition by Bortezomib are well known, the cellular responses to this proteotoxic stress that leads to sensitivity by MM are not fully elucidated. This study reports on the application of an emerging method to investigate proteostasis by proteomics. Methods: We utilized metabolic labeling with azidohomoalanine (AHA) in a MM cell line in combination with Bortezomib treatment. AHA labeling facilitates the selective isolation and identification of proteins for investigations of protein synthesis or protein degradation. Results: The data collected reveals significant changes in gene protein synthesis upon Bortezomib treatment, including protein neddylation. The data also reveals a global increase in protein degradation, which suggests the induction of an autophagy-related process. The resulting data collected reveals significant changes upon Bortezomib treatment in protein synthesis of genes, including protein neddylation, and protein degradation data reveals a global increase in protein degradation, suggesting an induction of an autophagy-related process. Subsequent cellular and proteomic analysis investigated the additional treatment of an autophagy inhibitor, hydroxychloroquine, in combination with Bortezomib treatment by label-free proteomics to further characterize the proteome-wide changes in these two proteotoxic stresses. Conclusions: AHA metabolic labeling proteomics to investigate protein synthesis and degradation enables novel complementary insights into complex cellular responses compared to that of traditional label-free proteomics. Full article

Amyloid cardiomyopathy (ACM), driven by transthyretin (TTR) and immunoglobulin light chain (LC) amyloid fibrils, remains a major clinical challenge due to limited mechanistic understanding and insufficient preclinical models. Human-induced pluripotent stem cells (iPSCs) have emerged as a transformative platform to model ACM, offering patient-specific and genetically controlled systems. In this review, we summarize recent advances in the use of iPSC-derived cardiomyocytes (iPSC-CMs) in both two-dimensional (2D) monolayer cultures and three-dimensional (3D) constructs—including spheroids, organoids, cardiac microtissues, and engineered heart tissues (EHTs)—for disease modeling, mechanistic research, and drug discovery. While 2D culture of iPSC-CMs reproduces hallmark proteotoxic phenotypes such as sarcomeric disorganization, oxidative stress, and apoptosis in ACM, 3D models provide enhanced physiological relevance through incorporating multicellularity, extracellular matrix interactions, and mechanical load-related features. Genome editing with Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas9 further broadens the scope of iPSC-based models, enabling isogenic comparisons and the dissection of mutation-specific effects, particularly in transthyretin-related amyloidosis (ATTR). Despite limitations such as cellular immaturity and challenges in recapitulating aging-associated phenotypes, ongoing refinements in differentiation, maturation, and dynamic training of iPSC-cardiac models hold great promise for overcoming these barriers. Together, these advances position iPSC-based systems as powerful human-relevant platforms for modeling and elucidating disease mechanisms and accelerating therapeutic development to prevent ACM. Full article

Steatotic liver disease (SLD) has become one of the most prevalent chronic liver diseases, representing a significant health burden worldwide. The complex pathogenesis of SLD results in a lack of specific therapeutic targets and effective drug treatment modalities. Copper (Cu) is a trace element that plays a critical role in various physiological processes, particularly hepatic metabolism. Meanwhile, Cu overload can induce cellular toxicity, which is generally explained by its capacity to induce oxidative damage. In 2022, a novel form of programmed cell death, designated as cuproptosis, was identified. In essence, excess Cu ions bind to the lipoylated components of the tricarboxylic acid cycle, resulting in proteotoxic stress and subsequent cell death. The role of cuproptosis in the pathologies of Cu overload-induced diseases has gained considerable attention. However, the association between SLD and Cu overload, particularly cuproptosis, remains to be elucidated. This review provides a concise overview of cuproptosis. The significance of Cu overload in SLD, as well as the potential association between cuproptosis and SLD, is explored. This review aims to offer insights into the potential of cuproptosis as a therapeutic target for SLD. Full article

Food safety hazards induce diverse cellular damages including DNA damage, oxidative stress, proteotoxic stress, and membrane disruption, ultimately contributing to various human diseases. Conventional toxicity assays, while effective, are often resource-intensive and lack the capacity to distinguish among these different damage types, thereby limiting insight into toxic responses and the development of effective strategies for targeted risk mitigation. Here, we constructed a panel of Escherichia coli whole-cell biosensors capable of distinguishing distinct categories of cellular damage. Specifically, an optimized RecA-LexA-based DNA damage biosensor that precisely controls the exogenous expression of the transcriptional repressor LexA achieved a 35.5% reduction in baseline signal and a 36.6-fold induction of fluorescence. In parallel, systematic promoter screening identified P_fpr, P_katG, P_grpE, and P_fabA as effective modules for constructing oxidative, proteotoxic, and membrane stress biosensors. These biosensors exhibited high specificity and sensitivity, generating dose-dependent responses to model toxicants and enabling discrimination of cellular damage induced by typical hazards such as norfloxacin and ciprofloxacin. Notably, the DNA damage biosensor detected norfloxacin with a limit of detection (LOD) of 1.3 ng/mL in standard solution and 3.0 ng/mL in milk, comparable to that of high-performance liquid chromatography (HPLC). Together, our work not only provides a versatile, cost-effective, and sensitive tool for assessing diverse cellular damages induced by food safety hazards, but also demonstrates potential utility for practical food safety monitoring. Full article

Background/Objective: Proteotoxic stress induced by inhibitors of the ubiquitin–proteasome system has been successful in multiple myeloma but not in solid cancers such as prostate cancer. Our objective is to find a combination with proteasome inhibitors that increases apoptotic cell death in all types of prostate cancer without harming non-cancer cells. Methods: The effectiveness of rencofilstat, a pan-cyclophilin inhibitor, combined with the ixazomib proteasome inhibitor, was investigated in multiple prostate cancer and non-cancer cells. Inducible knockdown of stress response XBP1s and cyclophilins A/B and inducible expression of XBP1s and cyclophilin B were developed in prostate cancer to determine functional roles. Results: Rencofilstat + ixazomib increased apoptotic cell death in prostate cancer but not in non-cancer cells. We investigated the effects on XBP1s and PERK, important unfolded protein response factors required for cells to survive proteotoxic stress. The results revealed that XBP1s had a pro-survival role early, but maintenance at later times of rencofilstat + ixazomib treatment resulted in cell death. In addition, decreased PERK and phospho-eIF2α likely maintained protein synthesis to further enhance proteotoxic stress. In contrast, rencofilstat + ixazomib did not alter XBP1s or PERK in non-cancer cells. Additional genetic experiments showed that the RCF targets cyclophilins A, B, and D had protective effects. Rencofilstat increased extracellular secretion of cyclophilin B, but rencofilstat + ixazomib reduced glycosylation and, likely, the biological function of CD147 (CypB receptor) and decreased downstream ERK signaling. Conclusions: Rencofilstat + ixazomib may be a new strategy for increasing proteotoxic stress and apoptotic cell death in advanced prostate cancer cells with less toxic side effects. Full article

Objectives: Retinitis pigmentosa (RP) is commonly initiated by rod photoreceptor degeneration due to genetic mutations, followed by secondary cone loss and progressive blindness. Preserving rod function during the earlier stages of RP is a key therapeutic goal, as rod survival supports cone maintenance and delays vision loss. In this study, we investigated the therapeutic potential of transient knockdown of retinoid-related orphan receptor beta (RORB) using a cell-penetrating asymmetric small interfering RNA (cp-asiRORB) in Rho^P23H mice, a model of autosomal dominant RP. While the role of RORB in the adult retina remains unclear, prior studies of related nuclear receptors suggest potential involvement in proteostasis. Based on this, we hypothesized that persistent RORB expression may influence photoreceptor homeostasis under degenerative stress. Methods: We first optimized the cp-asiRORB design to enhance gene silencing and cellular uptake. In vitro studies were conducted under proteotoxic stress. In vivo studies involved intravitreal administration of cp-asiRORB in Rho^P23H mice. Furthermore, single-cell RNA sequencing of rod photoreceptors was performed. Results: In vitro studies demonstrated that RORB knockdown improved cell viability, reduced apoptosis, and diminished aggresome formation under proteotoxic stress. Intravitreal administration of cp-asiRORB in Rho^P23H mice effectively reduced RORB expression in the retina, leading to improved photoreceptor survival and preserved visual function. Single-cell RNA sequencing revealed upregulation of proteasomal subunit genes in cp-asiRORB-treated eyes, indicating enhanced proteostasis. Conclusions: Together, these results demonstrate that transient suppression of RORB mitigates proteotoxic stress and slows RP progression, highlighting a novel RNAi-based therapeutic strategy for retinal degeneration. Full article

Cellular stress triggers the formation of diverse RNA–protein aggregates, which can be associated with physiological responses, pathological conditions, or even detrimental outcomes. Under stress-induced proteostasis disruption, these RNA–protein assemblies are known as stress granules (SGs). Targeting such condensates—while sparing functional RNAs and proteins—remains a major therapeutic challenge in protein aggregation disorders such as myopathies and neuropathies. In this study, we investigated the cellular response to various stress conditions in the context of the TIA1 E384K mutation, a founder variant implicated in both Welander distal myopathy (WDM) and amyotrophic lateral sclerosis (ALS). Cells were exposed to different stressors, including proteotoxic, proteostatic, chemotoxic, and osmotic insults, and the behavior of TIA1-related SGs was analyzed. Our findings reveal a distinct yet conserved pattern in the dynamics of TIA1-dependent SG formation and clearance, influenced by the specific type of stressor and modulated by eIF2α Ser35 phosphorylation. These results indicate that the WDM-associated TIA1 mutation leads to aberrant SG dynamics across different stress conditions. Collectively, these observations support the idea that TIA1 E384K-associated SG dysregulation plays a role in WDM and ALS pathogenesis and underscores the importance of multiple stress contexts in disease progression. Full article

Duchenne muscular dystrophy (DMD) is a severe X-linked recessive disorder caused by mutations in the DMD gene, leading to progressive muscle degeneration and fibrosis. A key pathological feature of DMD is mitochondrial dysfunction driven by calcium overload, which disrupts oxidative phosphorylation and triggers cell death pathways. This study shows the therapeutic potential of VBIT-4, a novel inhibitor of the mitochondrial voltage-dependent anion channel (VDAC), in two dystrophin-deficient mouse models: the mild mdx and the severe D2.DMDel8-34 strains. VBIT-4 administration (20 mg/kg) reduced mitochondrial calcium overload, enhanced resistance to permeability transition pore induction, and improved mitochondrial ultrastructure in D2.DMDel8-34 mice, while showing negligible effects in mdx mice. VBIT-4 suppressed mitochondrial and total calpain activity and reduced endoplasmic reticulum stress markers, suggesting a role in mitigating proteotoxic stress. However, it did not restore oxidative phosphorylation or reduce oxidative stress. Functional assays revealed limited improvements in muscle strength and fibrosis reduction, exclusively in the severe model. These findings underscore VDAC as a promising target for severe DMD and highlight the critical role of mitochondrial calcium homeostasis in DMD progression. Full article

RNA modifications regulate diverse aspects of transcripts’ function and stability. Among these, N1-methyladenine (m¹A) is a reversible mark primarily installed by the TRMT6/TRMT61A methyltransferase on tRNA, though it is also found on other RNA types. m¹A has been implicated in protecting mRNAs during acute protein misfolding stress. However, the role of m¹A under chronic proteotoxic conditions, such as intracellular amyloid aggregation, remains poorly understood. To address this gap, we examined the effects of reduced N1-adenine methylation in human cells undergoing amyloidogenesis. Suppression of the methyltransferase TRMT61A or overexpression of the m¹A-specific demethylase ALKBH3 enhanced amyloid aggregation. A deficiency of N1-adenine methylation also impaired the expression of a reporter mRNA-encoded protein, highlighting the protective role of m¹A in safeguarding transcript functionality. Proteomic analysis of amyloid aggregates from TRMT61A-deficient cells revealed increased co-aggregation of bystander proteins, particularly those with known RNA-binding activity. At the same time, the aggregates from methylation-deficient cells contained elevated levels of mRNAs. Collectively, our findings support a role for m¹A in preventing RNA entanglement within aggregates and limiting RNA-mediated propagation of protein co-aggregation. Full article

A dietary supplement, trans-resveratrol and hesperetin (tRES+HESP)—also known as GlucoRegulate—induces increased expression of glyoxalase 1 (Glo1) by activation of transcription factor Nrf2, countering accumulation of the reactive dicarbonyl glycating agent, methylglyoxal. tRES+HESP corrected insulin resistance and decreased fasting and postprandial plasma glucose and low-grade inflammation in overweight and obese subjects in a clinical trial. The aim of this study was to explore, for the first time, health-beneficial gene expression other than Glo1 induced by tRES+HESP in human endothelial cells and fibroblasts in primary culture and HepG2 hepatoma cell line and activity of cis-resveratrol (cRES) as a Glo1 inducer. We measured antioxidant response element-linked gene expression in these cells in response to 5 µM tRES+HESP by the NanoString method. tRES+HESP increases gene expression linked to the prevention of dicarbonyl stress, lipid peroxidation, oxidative stress, proteotoxicity and hyperglycemia-linked glycolytic overload. Downstream benefits were improved regulation of glucose and lipid metabolism and decreased inflammation, extracellular matrix remodeling and senescence markers. The median effective concentration of tRES was ninefold lower than cRES in the Glo1 inducer luciferase reporter assay. The GlucoRegulate supplement provides a new treatment option for the prevention of type 2 diabetes and metabolic dysfunction–associated steatotic liver disease and supports healthy aging. Full article