Lysosomal Zn2+ release triggers rapid, mitochondria-mediated, non-apoptotic cell death in metastatic melanoma

Extensive iron accumulation in the digestive gland of Turbo sazae and characterization of iron distribution and chemical structure

Metal accumulation in marine invertebrates has attracted significant attention owing to its toxicity to human health. Although T. sazae is a major edible fish resource in Japan, metal accumulation in the soft body of T. sazae has not been examined. In this study, the metal concentrations, chemical forms, and distributions in soft tissues of T. sazae were characterized. We observed the extensive iron accumulation i.e. over 10,000 μg/g dw in the digestive gland of T. sazae. The iron accumulator in the digestive gland was ferritin, an iron storage protein. Analysis of elemental distribution revealed that ferritin in the digestive gland contains phosphorus, and that μm-sized brown granular cells were responsible for iron storage, with over 70,000 μg/g ww of iron accumulated at the most concentrated point. T. sazae probably contributes to the ocean's iron cycle by grazing on iron-rich algae and rocks and storing iron using unique ferritin.

MCOLN1/TRPML1-MCOLN3/TRPML3 heteromer and its coupling to Ca2+ sensor SYT5 regulates autophagosome-lysosome fusion in a PtdIns4P-dependent manner

Macroautophagy/autophagy progresses through Ca2+-dependent multiple fusion events. Recently, we reported that the intracellular Ca2+ channel MCOLN3/TRPML3 provides Ca2+ for membrane fusion during autophagosome formation as a downstream effector of phosphatidylinositol-3-phosphate (PtdIns3P). However, the molecular mechanism of Ca2+ signaling in the late stage of autophagy remains unknown. Here, we show that the MCOLN1/TRPML1-MCOLN3/TRPML3 heteromer is the Ca2+ provider for autophagosome-lysosome fusion. MCOLN1-MCOLN3 functions downstream of PtdIns4P to release Ca2+ from autophagosomes, and the Ca2+ signal via PtdIns4P-MCOLN1-MCOLN3 is decoded by the Ca2+ sensor SYT5 (synaptotagmin 5). The binding of Ca2+ and PtdIns4P to SYT5 is critical for autophagosome-lysosome fusion by forming a fusion complex. Collectively, these results reveal that PtdIns4P-MCOLN1-MCOLN3-SYT5 constitutes the Ca2+ signaling complex in autophagosome-lysosome fusion and that MCOLN3 also regulates the late stage of autophagy through heteromerization with MCOLN1 in a phosphoinositide (PI)-dependent manner.Abbreviations: ATG, autophagy related; CPA, cyclopiazonic acid; DN, dominant-negative; GPN, glycyl-L-phenylalanine-beta-naphthylamide; KO, knockout; NH4Cl, ammonium chloride; PtdIns3K, phosphatidylinositol 3-kinase; PtdIns3P, phosphatidylinositol-3-phosphate; PI, phosphoinositide; SYT5, synaptotagmin 5; tfLC3, mRFP-GFP tandem fluorescent-tagged LC3; WT, wild-type.

Targeting TRPML3 inhibits proliferation and invasion, and enhances doxorubicin sensitivity by disrupting lysosomal acidification and mitochondrial function in triple-negative breast cancer

TNBC remains the most aggressive and therapy-resistant type of breast cancer, for which efficient targeted therapies have not been developed yet. Here, we identified TRPML3 (ML3) as a potential therapeutic target in TNBC. Our data showed that ML3 is significantly upregulated in TNBC cells compared with nontumorigenic control cells. ML3 knockdown (KD) impairs TNBC cell proliferation by inducing cell cycle arrest and caspase-dependent apoptosis. ML3 KD also inhibits TNBC cell migration and invasion. Mechanistically, ML3 KD reduces lysosomal number and enhances lysosomal acidification, which in turn activates mTORC1, thereby inhibiting autophagy initiation and flux. This disruption negatively impacts mitochondrial function, as evidenced by reduced ATP production, increased ROS and NO production, and mitochondrial fragmentation. Importantly, ML3 KD enhances TNBC cell sensitivity to doxorubicin and paclitaxel. The finding suggests that targeting ML3 disrupts lysosomal and mitochondrial homeostasis and enhance chemosensitivity, presenting ML3 as a potential therapeutic vulnerability in TNBC enhancing chemosensitivity.

Lysosomal Ion Channels and Transporters: Recent Findings, Therapeutic Potential, and Technical Approaches

In recent years, there has been a growing interest in lysosomal ion channels and transporters due to their critical role in maintaining lysosomal function and their involvement in a variety of diseases, particularly lysosomal storage diseases, cancer, and neurodegenerative disorders. Recent advancements in research techniques, including manual and automated patch clamp (APC) electrophysiology, solid-supported membrane-based electrophysiology (SSME), and fluorescence-based ion imaging, have further enhanced our ability to investigate lysosomal ion channels and transporters in both physiological and pathological conditions, spurring drug discovery efforts. Several pharmaceutical companies are now developing therapies aimed at modulating these channels and transporters to improve lysosomal function in disease. Small molecules targeting channels like transient receptor potential mucolipin (TRPML) 1 and TMEM175, as well as drugs modulating lysosomal pH, are currently in preclinical and clinical development. This review provides an overview of the role of lysosomal ion channels and transporters in health and disease, highlights the cutting-edge techniques used to study them, and discusses the therapeutic potential of targeting these channels and transporters in the treatment of various diseases. Furthermore, in addition to summarizing recent discoveries, we contribute novel functional data on cystinosin, TRPML1, and two-pore channel 2 (TPC2), utilizing both SSME and APC approaches.

Quantification of lysosomal labile Zn2+ and monitoring of Zn2+ efflux using a small-molecule-protein hybrid fluorescent probe

Lysosomal labile Zn2+ levels have been unclear. By targeting a small-molecule fluorescent Zn2+ probe, ZnDA-3H, to lysosomes via VAMP7-Halo, the lysosomal labile Zn2+ concentration was determined to be 1.9 nM in HeLa cells. Furthermore, ZnDA-3H enabled direct visualization of the Zn2+ efflux from the lysosomes to cytosol upon TRPMLs activation.

Global trends and emerging insights in BRAF and MEK inhibitor resistance in melanoma: a bibliometric analysis

Objective

This study aims to perform a comprehensive bibliometric analysis of global research on BRAF and MEK inhibitor resistance in melanoma, identifying key research trends, influential contributors, and emerging themes from 2003 to 2024.

Methods

A systematic search was conducted in the Web of Science Core Collection (WoSCC) database to retrieve publications related to BRAF and MEK inhibitor resistance from 1 January 2003, to 1 September 2024. Bibliometric analyses, including publication trends, citation networks, and keyword co-occurrence patterns, were performed using VOSviewer and CiteSpace. Collaborative networks, co-cited references, and keyword burst analyses were mapped to uncover shifts in research focus and global cooperation.

Results

A total of 3,503 documents, including 2,781 research articles and 722 review papers, were analyzed, highlighting significant growth in this field. The United States, China, and Italy led in publication volume and citation impact, with Harvard University and the University of California System among the top contributing institutions. Research output showed three phases of growth, peaking in 2020. Keyword and co-citation analyses revealed a transition from early focus on BRAF mutations and MAPK pathway activation to recent emphasis on immunotherapy, combination therapies, and non-apoptotic cell death mechanisms like ferroptosis and pyroptosis. These trends reflect the evolving priorities and innovative approaches shaping the field of resistance to BRAF and MEK inhibitors in melanoma.

Conclusion

Research on BRAF and MEK inhibitor resistance has evolved significantly. This analysis provides a strategic framework for future investigations, guiding the development of innovative, multi-modal approaches to improve treatment outcomes for melanoma patients.

Role of copper homeostasis and cuproptosis in heart failure pathogenesis: implications for therapeutic strategies

Copper is an essential micronutrient involved in various physiological processes in various cell types. Consequently, dysregulation of copper homeostasis-either excessive or deficient-can lead to pathological changes, such as heart failure (HF). Recently, a new type of copper-dependent cell death known as cuproptosis has drawn increasing attention to the impact of copper dyshomeostasis on HF. Notably, copper dyshomeostasis was associated with the occurrence of HF. Hence, this review aimed to investigate the biological processes involved in copper uptake, transport, excretion, and storage at both the cellular and systemic levels in terms of cuproptosis and HF, along with the underlying mechanisms of action. Additionally, the role of cuproptosis and its related mitochondrial dysfunction in HF pathogenesis was analyzed. Finally, we reviewed the therapeutic potential of current drugs that target copper metabolism for treating HF. Overall, the conclusions of this review revealed the therapeutic potential of copper-based therapies that target cuproptosis for the development of strategies for the treatment of HF.

Activation of lysosomal Ca2+ channels mitigates mitochondrial damage and oxidative stress

Elevated levels of plasma-free fatty acids and oxidative stress have been identified as putative primary pathogenic factors in endothelial dysfunction etiology, though their roles are unclear. In human endothelial cells, we found that saturated fatty acids (SFAs)-including the plasma-predominant palmitic acid (PA)-cause mitochondrial fragmentation and elevation of intracellular reactive oxygen species (ROS) levels. TRPML1 is a lysosomal ROS-sensitive Ca2+ channel that regulates lysosomal trafficking and biogenesis. Small-molecule agonists of TRPML1 prevented PA-induced mitochondrial damage and ROS elevation through activation of transcriptional factor EB (TFEB), which boosts lysosome biogenesis and mitophagy. Whereas genetically silencing TRPML1 abolished the protective effects of TRPML1 agonism, TRPML1 overexpression conferred a full resistance to PA-induced oxidative damage. Pharmacologically activating the TRPML1-TFEB pathway was sufficient to restore mitochondrial and redox homeostasis in SFA-damaged endothelial cells. The present results suggest that lysosome activation represents a viable strategy for alleviating oxidative damage, a common pathogenic mechanism of metabolic and age-related diseases.

Mechanisms and therapeutic potential of disulphidptosis in cancer

SLC7A11 plays a pivotal role in tumour development by facilitating cystine import to enhance glutathione synthesis and counteract oxidative stress. Disulphidptosis, an emerging form of cell death observed in cells with high expression of SLC7A11 under glucose deprivation, is regulated through reduction-oxidation reactions and disulphide bond formation. This process leads to contraction and collapse of the F-actin cytoskeleton from the plasma membrane, ultimately resulting in cellular demise. Compared to other forms of cell death, disulphidptosis exhibits distinctive characteristics and regulatory mechanisms. This mechanism provides novel insights and innovative strategies for cancer treatment while also inspiring potential therapeutic approaches for other diseases. Our review focuses on elucidating the molecular mechanism underlying disulphidptosis and its connection with the actin cytoskeleton, identifying alternative metabolic forms of cell death, as well as offering insights into disulphidptosis-based cancer therapy. A comprehensive understanding of disulphidptosis will contribute to our knowledge about fundamental cellular homeostasis and facilitate the development of groundbreaking therapies for disease treatment.

Targeting ion channels: innovative approaches to combat cancer drug resistance

Ion channels, as functional molecules that regulate the flow of ions across cell membranes, have emerged as a promising target in cancer therapy due to their pivotal roles in cell proliferation, metastasis, apoptosis, drug resistance, and so on. Recently, increasing evidence suggests that dysregulation of ion channels is a common characteristic of cancer cells, contributing to their survival and the resistance to conventional therapies. For example, the aberrant expression of sodium (Na+) and potassium ion (K+) channels is significantly correlated with the sensitivity of chemotherapy drugs. The endogenous calcium (Ca2+) channels contribute to the acquired resistance of osimertinib in epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer cell lines. Ferrous ions (Fe2+) enhance the sensitivity of breast cancer cells to doxorubicin treatment. Preclinical models have also demonstrated the effect of specific ion channel blockers or modulators on anticancer drug resistance. This review describes the current understanding about the interaction between ion channels and the therapeutic efficacy of anticancer drugs. Then, the therapeutic potential of ion channel blockers or modulators in enhancing the sensitivity or overcoming the resistance of cancer cells to anticancer therapies is discussed. Targeting ion channels will hopefully offer a novel and promising strategy for overcoming cancer drug resistance.

Metal-Dependent Cell Death in Renal Fibrosis: Now and in the Future

Renal fibrosis is a common final pathway underlying nearly almost all progressive kidney diseases. Metal ions are essential trace elements in organisms and are involved in important physiological activities. However, aberrations in intracellular metal ion metabolism may disrupt homeostasis, causing cell death and increasing susceptibility to various diseases. Accumulating evidence suggests a complex association between metal-dependent cell death and renal fibrosis. In this article, we provide a comprehensive overview of the specific molecular mechanisms of metal-dependent cell death and their crosstalk, up-to-date evidence supporting their role in renal fibrosis, therapeutic targeting strategies, and research needs, aiming to offer a rationale for future clinical treatment of renal fibrosis.

Exploration and breakthrough in the mode of intervertebral disc cell death may lead to significant advances in treatments for intervertebral disc degeneration

Low back pain caused by intervertebral disc degeneration (IDD) has emerged as a significant global public health concern, with far-reaching consequences for patients' quality of life and healthcare systems. Although previous research have revealed that the mechanisms of intervertebral disc cell apoptosis, pyroptosis and necroptosis can aggravate IDD damage by mediating inflammation and promoting extracellular matrix degradation, but they cannot explain the connection between different cell death mechanisms and ion metabolism disorders. The latest study shows that cell death mechanisms such as cellular senescence, ferroptosis, and cuproptosis, and PANopotosis have similar roles in the progression of intervertebral disc degeneration, but not exactly the same damage mechanism. This paper summarizes the effects of various cell death patterns on the disease progression of IDD, related molecular mechanisms and signaling pathways, providing new perspectives and potential clinical intervention strategies for the prevention and treatment of IDD.

TPC2: From Blond Hair to Melanoma?

Two-pore channel 2 (TPC2) is expressed in endolysosomes throughout the human body, as well as in melanosomes of melanocytes. Melanocytes produce pigment, i.e., melanin, which determines hair and skin color but also protects from UV light. Extensive exposure to UV light is one of the major risk factors for the development of melanoma, which develops from pigment-producing cells, i.e., melanocytes. In recent years, several human TPC2 single nucleotide polymorphisms have been identified to increase the likelihood of carriers presenting with blond hair and hypopigmentation. These variants were all characterized as gain-of-function versions of TPC2. Vice versa, the loss of function of TPC2 increases melanin production and reduces cancer hallmarks such as proliferation, migration, invasion, tumor growth, and metastasis formation. The activity of TPC2 is controlled in a complex manner, with several endogenous ligands as well as a number of interacting proteins being involved. We will discuss here the role of TPC2 in pigmentation and its potential to impact melanoma development and progression and highlight recent findings on Rab7a as an enhancer of TPC2 activity.

Novel insights into cuproptosis inducers and inhibitors

Cuproptosis is a new pattern of Cu-dependent cell death distinct from classic cell death pathways and characterized by aberrant lipoylated protein aggregation in TCA cycle, Fe-S cluster protein loss, HSP70 elevation, proteotoxic and oxidative stress aggravation. Previous studies on Cu homeostasis and Cu-induced cell death provide a great basis for the discovery of cuproptosis. It has gradually gathered enormous research interests and large progress has been achieved in revealing the metabolic pathways and key targets of cuproptosis, due to its role in mediating some genetic, neurodegenerative, cardiovascular and tumoral diseases. In terms of the key targets in cuproptosis metabolic pathways, they can be categorized into three types: oxidative stress, mitochondrial respiration, ubiquitin-proteasome system. And strategies for developing cuproptosis inducers and inhibitors involved in these targets have been continuously improved. Briefly, based on the essential cuproptosis targets and metabolic pathways, this paper classifies some relevant inducers and inhibitors including small molecule compounds, transcription factors and ncRNAs with the overview of principle, scientific and medical application, in order to provide reference for the cuproptosis study and target therapy in the future.

Targeting lysosomal quality control as a therapeutic strategy against aging and diseases

Previously, lysosomes were primarily referred to as the digestive organelles and recycling centers within cells. Recent discoveries have expanded the lysosomal functional scope and revealed their critical roles in nutrient sensing, epigenetic regulation, plasma membrane repair, lipid transport, ion homeostasis, and cellular stress response. Lysosomal dysfunction is also found to be associated with aging and several diseases. Therefore, function of macroautophagy, a lysosome-dependent intracellular degradation system, has been identified as one of the updated twelve hallmarks of aging. In this review, we begin by introducing the concept of lysosomal quality control (LQC), which is a cellular machinery that maintains the number, morphology, and function of lysosomes through different processes such as lysosomal biogenesis, reformation, fission, fusion, turnover, lysophagy, exocytosis, and membrane permeabilization and repair. Next, we summarize the results from studies reporting the association between LQC dysregulation and aging/various disorders. Subsequently, we explore the emerging therapeutic strategies that target distinct aspects of LQC for treating diseases and combatting aging. Lastly, we underscore the existing knowledge gap and propose potential avenues for future research.

The causal relationship between trace element status and upper gastrointestinal ulcers: a Mendelian randomization study

Background

This study aimed to investigate the bidirectional causal relationships between trace elements (such as zinc, magnesium, phosphate, and folate) and upper gastrointestinal ulcers (including gastric and duodenal ulcers). We utilized a two-sample Mendelian randomization (MR) analysis to achieve this.

Methods

We conducted a two-sample MR analysis using summary-level data from genome-wide association studies (GWAS) obtained from public genomics repositories. We utilized a range of MR methods, including inverse-variance weighted (IVW), MR-Egger, and weighted median methods, and conducted a meta-analysis to synthesize results across different datasets. To ensure the robustness of our findings, we performed extensive sensitivity analyses, including pleiotropy assessment, heterogeneity tests, and leave-one-out analysis.

Results

Our findings are significant, indicating a positive causal relationship between increased zinc levels and the risk of gastric ulcers. Moreover, magnesium and folate appear to offer potential protective effects against gastroduodenal ulcers (p < 0.05). The meta-analysis further supports the causal relationship between zinc and gastric ulcers (p < 0.05), confirming zinc's significant causal impact on this condition.

Conclusion

The study confirms a positive causal relationship between zinc and gastric ulcers and highlights the complexity of how trace elements regulate the progression of upper gastrointestinal ulcers. These results provide a scientific basis for dietary recommendations regarding trace element intake in clinical and public health practices. They also offer new insights into effective prevention and treatment strategies for gastric and duodenal ulcers.

Recent progress of methods for cuproptosis detection

Varying from other identified cell death pathways, cuproptosis is a new type of regulated cell death characterized by excess Cu ions, abnormal aggregation of lipoylated proteins in TCA cycle, loss of Fe-S cluster proteins, upregulation of HSP70, leading to proteotoxic and oxidative stress. Cuproptosis is highly concerned by scientific community and as the field of cuproptosis further develops, remarkable progress has been made in the verification and mechanism of cuproptosis, and methods used to detect cuproptosis have been continuously improved. According to the characteristic changes of cuproptosis, techniques based on cell death verification, Cu content, morphology, molecular biology of protein levels of cuproptosis-related molecules and biochemical pathways of cuproptosis-related enzyme activity and metabolites of oxidative stress, lipoic acid, TCA cycle, Fe-S cluster proteins, oxidative phosphorylation, cell respiration intensity have been subject to cuproptosis verification and research. In order to further deepen the understanding of detecting cuproptosis, the principle and application of common cuproptosis detection methods are reviewed and categorized in cellular phenomena and molecular mechanism in terms of cell death, Cu content, morphology, molecular biology, biochemical pathways with a flow chart. All the indicating results have been displayed in response to the markers of cuproptosis, their advantages and limitations are summaried, and comparison of cuproptosis and ferroptosis detection is performed in this study. Our collection of methods for cuproptosis detection will provide a great basis for cuproptosis verification and research in the future.

Metabolic cell death in cancer: ferroptosis, cuproptosis, disulfidptosis, and beyond

Cell death resistance represents a hallmark of cancer. Recent studies have identified metabolic cell death as unique forms of regulated cell death resulting from an imbalance in the cellular metabolism. This review discusses the mechanisms of metabolic cell death-ferroptosis, cuproptosis, disulfidptosis, lysozincrosis, and alkaliptosis-and explores their potential in cancer therapy. Our review underscores the complexity of the metabolic cell death pathways and offers insights into innovative therapeutic avenues for cancer treatment.

Triptolide-induced cuproptosis is a novel antitumor strategy for the treatment of cervical cancer

BACKGROUND

Cuproptosis is a unique copper-dependent form of cell death that is highly correlated with the metabolic state of cells. Triptolide exerts pharmacological activity by altering the regulation of metal ions. Cuproptosis is poorly understood in cancer, so in this study, we explored whether triptolide could induce cuproptosis in cervical cancer cells.

METHODS

The human cervical cancer cell lines HeLa and SiHa, which primarily rely on oxidative phosphorylation, were treated with triptolide. Cell viability, proliferation and migration, copper levels and cuproptosis-related protein levels were evaluated in these cell lines. The copper ion chelator tetrathiomolybdate (TTM) was administered to determine whether it could reverse the cuproptosis induced by triptolide. In addition, a nude mouse cervical cancer xenograft model was established to determine the effects of triptolide on cuproptosis in isolated tumor tissues.

RESULTS

The copper concentration increased with triptolide treatment. The levels of cuproptosis -related proteins, such as FDX1, LIAS, and DLAT, in the HeLa and SiHa cell lines decreased with triptolide treatment. XIAP, the target of triptolide, played a role in cuproptosis by regulating COMMD1. The level of copper exporters (ATP7A/B) decreased, but the level of the copper importer (CTR1) did not change with triptolide treatment. Furthermore, triptolide inhibited cervical cancer growth and induced cuproptosis in vivo.

CONCLUSIONS

In summary, we report a new antitumor mechanism by which triptolide disrupted intracellular copper homeostasis and induced cuproptosis in cervical cancer by regulating the XIAP/COMMD1/ATP7A/B axis.

Lysosomal exocytosis: From cell protection to protumoral functions

Lysosomes are single membrane bounded group of acidic organelles that can be involved in a process called lysosomal exocytosis which leads to the extracellular release of their content. Lysosomal exocytosis is required for plasma membrane repair or remodeling events such as bone resorption, antigen presentation or mitosis, and for protection against toxic agents such as heavy metals. Recently, it has been showed that to fulfill this protective role, lysosomal exocytosis needs some autophagic proteins, in an autophagy-independent manner. In addition to these crucial physiological roles, lysosomal exocytosis plays a major protumoral role in various cancers. This effect is exerted through tumor microenvironment modifications, including extracellular matrix remodeling, acidosis, oncogenic and profibrogenic signals. This review provides a comprehensive overview of the different elements released in the microenvironment during lysosomal exocytosis, i.e. proteases, exosomes, and protons, and their effects in the context of tumor development and treatment.

MCOLN1/TRPML1 in the lysosome: a promising target for autophagy modulation in diverse diseases

MCOLN1/TRPML1 is a nonselective cationic channel specifically localized to the late endosome and lysosome. With its property of mediating the release of several divalent cations such as Ca2+, Zn2+ and Fe2+ from the lysosome to the cytosol, MCOLN1 plays a pivotal role in regulating a variety of cellular events including endocytosis, exocytosis, lysosomal biogenesis, lysosome reformation, and especially in Macroautophagy/autophagy. Autophagy is a highly conserved catabolic process that maintains cytoplasmic integrity by removing superfluous proteins and damaged organelles. Acting as the terminal compartments, lysosomes are crucial for the completion of the autophagy process. This review delves into the emerging role of MCOLN1 in controlling the autophagic process by regulating lysosomal ionic homeostasis, thereby governing the fundamental functions of lysosomes. Furthermore, this review summarizes the physiological relevance as well as molecular mechanisms through which MCOLN1 orchestrates autophagy, consequently influencing mitochondria turnover, cell apoptosis and migration. In addition, we have illustrated the implications of MCOLN1-regulated autophagy in the pathological process of cancer and myocardial ischemia-reperfusion (I/R) injury. In summary, given the involvement of MCOLN1-mediated autophagy in the pathogenesis of cancer and myocardial I/R injury, targeting MCOLN1 May provide clues for developing new therapeutic strategies for the treatment of these diseases. Exploring the regulation of MCOLN1-mediated autophagy in diverse diseases contexts will surely broaden our understanding of this pathway and offer its potential as a promising drug target.Abbreviation: CCCP:carbonyl cyanide3-chlorophenylhydrazone; CQ:chloroquine; HCQ: hydroxychloroquine;I/R: ischemia-reperfusion; MAP1LC3/LC3:microtubule associated protein 1 light chain 3; MCOLN1/TRPML1:mucolipin TRP cation channel 1; MLIV: mucolipidosis type IV; MTORC1:MTOR complex 1; ROS: reactive oxygenspecies; SQSTM1/p62: sequestosome 1.

Mutation of TRPML1 Channel and Pathogenesis of Neurodegeneration in Haimeria

Neurodegenerative diseases, a group of debilitating disorders, have garnered increasing attention due to their escalating prevalence, particularly among aging populations. Alzheimer's disease (AD) reigns as a prominent exemplar within this category, distinguished by its relentless progression of cognitive impairment and the accumulation of aberrant protein aggregates within the intricate landscape of the brain. While the intricate pathogenesis of neurodegenerative diseases has been the subject of extensive investigation, recent scientific inquiry has unveiled a novel player in this complex scenario-transient receptor potential mucolipin 1 (TRPML1) channels. This comprehensive review embarks on an exploration of the intricate interplay between TRPML1 channels and neurodegenerative diseases, with an explicit spotlight on Alzheimer's disease. It immerses itself in the intricate molecular mechanisms governing TRPML1 channel functionality and elucidates their profound implications for the well-being of neurons. Furthermore, the review ventures into the realm of therapeutic potential, pondering the possibilities and challenges associated with targeting TRPML1 channels as a promising avenue for the amelioration of neurodegenerative disorders. As we traverse this multifaceted terrain of neurodegeneration and the enigmatic role of TRPML1 channels, we embark on a journey that not only broadens our understanding of the intricate machinery governing neuronal health but also holds promise for the development of innovative therapeutic interventions in the relentless battle against neurodegenerative diseases.

Emerging mechanisms and promising approaches in pancreatic cancer metabolism

Pancreatic cancer is an aggressive cancer with a poor prognosis. Metabolic abnormalities are one of the hallmarks of pancreatic cancer, and pancreatic cancer cells can adapt to biosynthesis, energy intake, and redox needs through metabolic reprogramming to tolerate nutrient deficiency and hypoxic microenvironments. Pancreatic cancer cells can use glucose, amino acids, and lipids as energy to maintain malignant growth. Moreover, they also metabolically interact with cells in the tumour microenvironment to change cell fate, promote tumour progression, and even affect immune responses. Importantly, metabolic changes at the body level deserve more attention. Basic research and clinical trials based on targeted metabolic therapy or in combination with other treatments are in full swing. A more comprehensive and in-depth understanding of the metabolic regulation of pancreatic cancer cells will not only enrich the understanding of the mechanisms of disease progression but also provide inspiration for new diagnostic and therapeutic approaches.

The ion channels of endomembranes

The endomembrane system consists of organellar membranes in the biosynthetic pathway [endoplasmic reticulum (ER), Golgi apparatus, and secretory vesicles] as well as those in the degradative pathway (early endosomes, macropinosomes, phagosomes, autophagosomes, late endosomes, and lysosomes). These endomembrane organelles/vesicles work together to synthesize, modify, package, transport, and degrade proteins, carbohydrates, and lipids, regulating the balance between cellular anabolism and catabolism. Large ion concentration gradients exist across endomembranes: Ca2+ gradients for most endomembrane organelles and H+ gradients for the acidic compartments. Ion (Na+, K+, H+, Ca2+, and Cl-) channels on the organellar membranes control ion flux in response to cellular cues, allowing rapid informational exchange between the cytosol and organelle lumen. Recent advances in organelle proteomics, organellar electrophysiology, and luminal and juxtaorganellar ion imaging have led to molecular identification and functional characterization of about two dozen endomembrane ion channels. For example, whereas IP3R1-3 channels mediate Ca2+ release from the ER in response to neurotransmitter and hormone stimulation, TRPML1-3 and TMEM175 channels mediate lysosomal Ca2+ and H+ release, respectively, in response to nutritional and trafficking cues. This review aims to summarize the current understanding of these endomembrane channels, with a focus on their subcellular localizations, ion permeation properties, gating mechanisms, cell biological functions, and disease relevance.

Driving factors of neuronal ferroptosis

Ferroptosis is an oxidative form of iron-dependent cell death characterized by the accumulation of lipid peroxides on membranes. Iron and lipids containing polyunsaturated fatty acids are essential for this process. Ferroptosis is central to several neurological diseases and underlies the importance of balanced iron and polyunsaturated fatty acid metabolism in the brain, particularly in neurons. Here, we reflect on the potential links between neuronal physiology and the accumulation of iron and peroxidated lipids, the mechanisms neurons use to protect themselves from ferroptosis, and the relationship between pathogenic protein deposition and ferroptosis in neurodegenerative disease. We propose that the unique physiology of neurons makes them especially vulnerable to ferroptosis.

From ferroptosis to cuproptosis, and calcicoptosis, to find more novel metals-mediated distinct form of regulated cell death

Regulated cell death (RCD), also known as programmed cell death (PCD), plays a critical role in various biological processes, such as tissue injury/repair, development, and homeostasis. Dysregulation of RCD pathways can lead to the development of many human diseases, such as cancer, neurodegenerative disorders, and cardiovascular diseases. Maintaining proper metal ion homeostasis is critical for human health. However, imbalances in metal levels within cells can result in cytotoxicity and cell death, leading to a variety of diseases and health problems. In recent years, new types of metal overload-induced cell death have been identified, including ferroptosis, cuproptosis, and calcicoptosis. This has prompted us to examine the three defined metal-dependent cell death types, and discuss other metals-induced ferroptosis, cuproptosis, and disrupted Ca2+ homeostasis, as well as the roles of Zn2+ in metals' homeostasis and related RCD. We have reviewed the connection between metals-induced RCD and various diseases, as well as the underlying mechanisms. We believe that further research in this area will lead to the discovery of novel types of metal-dependent RCD, a better understanding of the underlying mechanisms, and the development of new therapeutic strategies for human diseases.

Inhibition of lysosomal TRPML1 channel eliminates breast cancer stem cells by triggering ferroptosis

Cancer stem cells (CSCs) are a sub-population of cells possessing high tumorigenic potential, which contribute to therapeutic resistance, metastasis and recurrence. Eradication of CSCs is widely recognized as a crucial factor in improving patient prognosis, yet the effective targeting of these cells remains a major challenge. Here, we show that the lysosomal cation channel TRPML1 represents a promising target for CSCs. TRPML1 is highly expressed in breast cancer cells and exhibits sensitivity to salinomycin, a drug known to selectively eliminate CSCs. Pharmacological inhibition and genetic depletion of TRPML1 promote ferroptosis in breast CSCs, reduce their stemness, and enhance the sensitivity of breast cancer cells to chemotherapy drug doxorubicin. The inhibition and knockout of TRPML1 also demonstrate significant suppression of tumor formation and growth in the mouse xenograft model. These findings suggest that targeting TRPML1 to eliminate CSCs may be an effective strategy for the treatment of breast cancer.

Widespread transcriptomic alterations of transient receptor potential channel genes in cancer

Ion channels, in particular transient-receptor potential (TRP) channels, are essential genes that play important roles in many physiological processes. Emerging evidence has demonstrated that TRP genes are involved in a number of diseases, including various cancer types. However, we still lack knowledge about the expression alterations landscape of TRP genes across cancer types. In this review, we comprehensively reviewed and summarised the transcriptomes from more than 10 000 samples in 33 cancer types. We found that TRP genes were widespreadly transcriptomic dysregulated in cancer, which was associated with clinical survival of cancer patients. Perturbations of TRP genes were associated with a number of cancer pathways across cancer types. Moreover, we reviewed the functions of TRP family gene alterations in a number of diseases reported in recent studies. Taken together, our study comprehensively reviewed TRP genes with extensive transcriptomic alterations and their functions will directly contribute to cancer therapy and precision medicine.

Mechanism of metal ion-induced cell death in gastrointestinal cancer

Gastrointestinal (GI) cancer is one of the most severe types of cancer, with a significant impact on human health worldwide. Due to the urgent demand for more effective therapeutic strategies against GI cancers, novel research on metal ions for treating GI cancers has attracted increasing attention. Currently, with accumulating research on the relationship between metal ions and cancer therapy, several metal ions have been discovered to induce cell death. In particular, the three novel modes of cell death, including ferroptosis, cuproptosis, and calcicoptosis, have become focal points of research in the field of cancer. Meanwhile, other metal ions have also been found to trigger cell death through various mechanisms. Accordingly, this review focuses on the mechanisms of metal ion-induced cell death in GI cancers, hoping to provide theoretical support for further GI cancer therapies.

The crosstalk between mitochondrial quality control and metal-dependent cell death

Mitochondria are the centers of energy and material metabolism, and they also serve as the storage and dispatch hubs of metal ions. Damage to mitochondrial structure and function can cause abnormal levels and distribution of metal ions, leading to cell dysfunction and even death. For a long time, mitochondrial quality control pathways such as mitochondrial dynamics and mitophagy have been considered to inhibit metal-induced cell death. However, with the discovery of new metal-dependent cell death including ferroptosis and cuproptosis, increasing evidence shows that there is a complex relationship between mitochondrial quality control and metal-dependent cell death. This article reviews the latest research results and mechanisms of crosstalk between mitochondrial quality control and metal-dependent cell death in recent years, as well as their involvement in neurodegenerative diseases, tumors and other diseases, in order to provide new ideas for the research and treatment of related diseases.

Lucanthone, a Potential PPT1 Inhibitor, Perturbs Stemness, Reduces Tumor Microtube Formation, and Slows the Growth of Temozolomide-Resistant Gliomas In Vivo

Glioblastoma (GBM) is the most frequently diagnosed primary central nervous system tumor in adults. Despite the standard of care therapy, which includes surgical resection, temozolomide chemotherapy, radiation and the newly added tumor-treating fields, median survival remains only ∼20 months. Unfortunately, GBM has a ∼100% recurrence rate, but after recurrence there are no Food and Drug Administration-approved therapies to limit tumor growth and enhance patient survival, as these tumors are resistant to temozolomide (TMZ). Recently, our laboratory reported that lucanthone slows GBM by inhibiting autophagic flux through lysosome targeting and decreases the number of Olig2+ glioma stem-like cells (GSC) in vitro and in vivo. We now additionally report that lucanthone efficiently abates stemness in patient-derived GSC and reduces tumor microtube formation in GSC, an emerging hallmark of treatment resistance in GBM. In glioma tumors derived from cells with acquired resistance to TMZ, lucanthone retains the ability to perturb tumor growth, inhibits autophagy by targeting lysosomes, and reduces Olig2 positivity. We also find that lucanthone may act as an inhibitor of palmitoyl protein thioesterase 1. Our results suggest that lucanthone may function as a potential treatment option for GBM tumors that are not amenable to TMZ treatment. SIGNIFICANCE STATEMENT: We report that the antischistosome agent lucanthone impedes tumor growth in a preclinical model of temozolomide-resistant glioblastoma and reduces the numbers of stem-like glioma cells. In addition, it acts as an autophagy inhibitor, and its mechanism of action may be via inhibition of palmitoyl protein thioesterase 1. As there are no defined therapies approved for recurrent, TMZ-resistant tumor, lucanthone could emerge as a treatment for glioblastoma tumors that may not be amenable to TMZ both in the newly diagnosed and recurrent settings.

Contribution of zinc accumulation to ischemic brain injury and its mechanisms about oxidative stress, inflammation, and autophagy: an update

Ischemic stroke is a leading cause of death and disability worldwide, and presently, there is no effective neuroprotective therapy. Zinc is an essential trace element that plays important physiological roles in the central nervous system. Free zinc concentration is tightly regulated by zinc-related proteins in the brain under normal conditions. Disruption of zinc homeostasis, however, has been found to play an important role in the mechanism of brain injury following ischemic stroke. A large of free zinc releases from storage sites after cerebral ischemia, which affects the functions and survival of nerve cells, including neurons, astrocytes, and microglia, resulting in cell death. Ischemia-triggered intracellular zinc accumulation also disrupts the function of blood-brain barrier via increasing its permeability, impairing endothelial cell function, and altering tight junction levels. Oxidative stress and neuroinflammation have been reported to be as major pathological mechanisms in cerebral ischemia/reperfusion injury. Studies have showed that the accumulation of intracellular free zinc could impair mitochondrial function to result in oxidative stress, and form a positive feedback loop between zinc accumulation and reactive oxygen species production, which leads to a series of harmful reactions. Meanwhile, elevated intracellular zinc leads to neuroinflammation. Recent studies also showed that autophagy is one of the important mechanisms of zinc toxicity after ischemic injury. Interrupting the accumulation of zinc will reduce cerebral ischemia injury and improve neurological outcomes. This review summarizes the role of zinc toxicity in cellular and tissue damage following cerebral ischemia, focusing on the mechanisms about oxidative stress, inflammation, and autophagy.

Magnetic modulation of lysosomes for cancer therapy

Lysosomes play a central role in biochemical signal transduction and oxidative stress in cells. Inducing lysosome membrane penetration (LMP) to cause lysosomal-dependent cell death (LCD) in tumor cells is an effective strategy for cancer therapy. Chemical drugs can destroy the stability of lysosomes by neutralizing protons within the lysosomes or enhancing the fragility of the lysosomal membranes. However, there remain several unsolved problems of traditional drugs in LMP induction due to insufficient lysosomal targeting, fast metabolism, and toxicity in normal cells. With the development of nanotechnology, magnetic nanoparticles have been demonstrated to target lysosomes naturally, providing a versatile tool for lysosomal modulation. Combined with excellent tissue penetration and spatiotemporal manipulability of magnetic fields, magnetic modulation of lysosomes progresses rapidly in inducing LMP and LCD for cancer therapy. This review comprehensively discussed the strategies of magnetic modulation of lysosomes for cancer therapy. The intrinsic mechanisms of LMP-induced LCD were first introduced. Then, the modulation of lysosomes by diverse physical outputs of magnetic fields was emphatically discussed. Looking forward, this review will shed the light on the prospect of magnetic modulation of lysosomes, inspiring future research of magnetic modulation strategy in cancer therapy. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

Advances in Nanodelivery Systems Based on Metabolism Reprogramming Strategies for Enhanced Tumor Therapy

Tumor development and metastasis are closely related to the complexity of the metabolism network. Recently, metabolism reprogramming strategies have attracted much attention in tumor metabolism therapy. Although there is preliminary success of metabolism therapy agents, their therapeutic effects have been restricted by the effective reaching of the tumor sites of drugs. Nanodelivery systems with unique physical properties and elaborate designs can specifically deliver to the tumors. In this review, we first summarize the research progress of nanodelivery systems based on tumor metabolism reprogramming strategies to enhance therapies by depleting glucose, inhibiting glycolysis, depleting lactic acid, inhibiting lipid metabolism, depleting glutamine and glutathione, and disrupting metal metabolisms combined with other therapies, including chemotherapy, radiotherapy, photodynamic therapy, etc. We further discuss in detail the advantages of nanodelivery systems based on tumor metabolism reprogramming strategies for tumor therapy. As well as the opportunities and challenges for integrating nanodelivery systems into tumor metabolism therapy, we analyze the outlook for these emerging areas. This review is expected to improve our understanding of modulating tumor metabolisms for enhanced therapy.

TRPML1 as a potential therapeutic target for triple-negative breast cancer: a review

Triple-negative breast cancer (TNBC) is the most refractory subtype of breast cancer, and effective treatments are urgently needed owing to its poor prognosis. Surgery, radiotherapy, and chemotherapy, alone or in combination, are the leading choices for TNBC therapy. Although promising approaches and procedures have emerged, several challenges, such as off-target effects, drug resistance, and severe side effects, remain to be addressed. Recently, transient receptor potential channel mucolipin 1 (TRPML1) has attracted the attention of researchers because its expression has been implicated in numerous diseases, including cancer. TRPML1 regulates biological events and signaling pathways, including autophagic flux, exocytosis, ionic homeostasis, and lysosomal biogenesis, all contributing to tumorigenesis and cancer progression. TRPML1 also functions as a building block for cancer cell growth, mitogenic signaling, priming tissues for metastasis, and activation of transcriptional programs, processes involved in several malignant tumors. This review provides an overview of breast cancer epidemiology and diagnostic techniques and then discusses the existing therapeutics. Additionally, we elaborate on the development of, and associated challenges to, TNBC diagnostics and treatment and the feasibility of TRPML1 as a therapeutic target for TNBC.

Unlocking the potential of platinum drugs: organelle-targeted small-molecule platinum complexes for improved anticancer performance

Platinum-based drugs have revolutionized cancer chemotherapy; however, their therapeutic efficacy has been limited by severe side effects and drug resistance. Recently, approaches that target specific organelles in cancer cells have emerged as attractive alternatives to overcome these challenges. Many studies have validated these strategies and highlighted that organelle-targeted platinum complexes demonstrate increased anticancer activity, the ability to overcome drug resistance, novel molecular mechanisms, or even lower toxicity. This review provides a brief summary of various organelle-targeting strategies that promote the accumulation of platinum complexes in certain intracellular areas, such as the nucleus, mitochondria, endoplasmic reticulum (ER), and lysosomes. Moreover, the mechanisms through which these strategies improve anticancer performance, overcome drug resistance, and alter the action mode of conventional platinum drugs are discussed. By providing an extensive account of platinum complexes targeting different organelles, this review aims to assist researchers in understanding the design principles, identifying potential targets, and fostering innovative ideas for the development of platinum complexes.

Amphibian-Derived Natural Anticancer Peptides and Proteins: Mechanism of Action, Application Strategies, and Prospects

Cancer is one of the major diseases that seriously threaten human life. Traditional anticancer therapies have achieved remarkable efficacy but have also some unavoidable side effects. Therefore, more and more research focuses on highly effective and less-toxic anticancer substances of natural origin. Amphibian skin is rich in active substances such as biogenic amines, alkaloids, alcohols, esters, peptides, and proteins, which play a role in various aspects such as anti-inflammatory, immunomodulatory, and anticancer functions, and are one of the critical sources of anticancer substances. Currently, a range of natural anticancer substances are known from various amphibians. This paper aims to review the physicochemical properties, anticancer mechanisms, and potential applications of these peptides and proteins to advance the identification and therapeutic use of natural anticancer agents.

The therapeutic potential of targeting regulated non-apoptotic cell death

Cell death is critical for the development and homeostasis of almost all multicellular organisms. Moreover, its dysregulation leads to diverse disease states. Historically, apoptosis was thought to be the major regulated cell death pathway, whereas necrosis was considered to be an unregulated form of cell death. However, research in recent decades has uncovered several forms of regulated necrosis that are implicated in degenerative diseases, inflammatory conditions and cancer. The growing insight into these regulated, non-apoptotic cell death pathways has opened new avenues for therapeutic targeting. Here, we describe the regulatory pathways of necroptosis, pyroptosis, parthanatos, ferroptosis, cuproptosis, lysozincrosis and disulfidptosis. We discuss small-molecule inhibitors of the pathways and prospects for future drug discovery. Together, the complex mechanisms governing these pathways offer strategies to develop therapeutics that control non-apoptotic cell death.

Zn2+ decoration of microtubules arrests axonal transport and displaces tau, doublecortin, and MAP2C

Intracellular Zn2+ concentrations increase via depolarization-mediated influx or intracellular release, but the immediate effects of Zn2+ signals on neuron function are not fully understood. By simultaneous recording of cytosolic Zn2+ and organelle motility, we find that elevated Zn2+ (IC50 ≈ 5-10 nM) reduces both lysosomal and mitochondrial motility in primary rat hippocampal neurons and HeLa cells. Using live-cell confocal microscopy and in vitro single-molecule TIRF imaging, we reveal that Zn2+ inhibits activity of motor proteins (kinesin and dynein) without disrupting their microtubule binding. Instead, Zn2+ directly binds to microtubules and selectively promotes detachment of tau, DCX, and MAP2C, but not MAP1B, MAP4, MAP7, MAP9, or p150glued. Bioinformatic predictions and structural modeling show that the Zn2+ binding sites on microtubules partially overlap with the microtubule binding sites of tau, DCX, dynein, and kinesin. Our results reveal that intraneuronal Zn2+ regulates axonal transport and microtubule-based processes by interacting with microtubules.

The role of Zn2+ in shaping intracellular Ca2+ dynamics in the heart

Increasing evidence suggests that Zn2+ acts as a second messenger capable of transducing extracellular stimuli into intracellular signaling events. The importance of Zn2+ as a signaling molecule in cardiovascular functioning is gaining traction. In the heart, Zn2+ plays important roles in excitation-contraction (EC) coupling, excitation-transcription coupling, and cardiac ventricular morphogenesis. Zn2+ homeostasis in cardiac tissue is tightly regulated through the action of a combination of transporters, buffers, and sensors. Zn2+ mishandling is a common feature of various cardiovascular diseases. However, the precise mechanisms controlling the intracellular distribution of Zn2+ and its variations during normal cardiac function and during pathological conditions are not fully understood. In this review, we consider the major pathways by which the concentration of intracellular Zn2+ is regulated in the heart, the role of Zn2+ in EC coupling, and discuss how Zn2+ dyshomeostasis resulting from altered expression levels and efficacy of Zn2+ regulatory proteins are key drivers in the progression of cardiac dysfunction.

Lysosomal Ca2+ as a mediator of palmitate-induced lipotoxicity

While the mechanism of lipotoxicity by palmitic acid (PA), an effector of metabolic stress in vitro and in vivo, has been extensively investigated, molecular details of lipotoxicity are still not fully characterized. Since recent studies reported that PA can exert lysosomal stress in addition to well-known ER and mitochondrial stress, we studied the role of lysosomal events in lipotoxicity by PA, focusing on lysosomal Ca²⁺. We found that PA induced accumulation of mitochondrial ROS and that mitochondrial ROS induced release of lysosomal Ca²⁺ due to lysosomal Ca²⁺ exit channel activation. Lysosomal Ca²⁺ release led to increased cytosolic Ca²⁺ which induced mitochondrial permeability transition (mPT). Chelation of cytoplasmic Ca²⁺ or blockade of mPT with olesoxime or decylubiquinone (DUB) suppressed lipotoxicity. Lysosomal Ca²⁺ release led to reduced lysosomal Ca²⁺ content which was replenished by ER Ca²⁺, the largest intracellular Ca²⁺ reservoir (ER → lysosome Ca²⁺ refilling), which in turn activated store-operated Ca²⁺ entry (SOCE). Inhibition of ER → lysosome Ca²⁺ refilling by blockade of ER Ca²⁺ exit channel using dantrolene or inhibition of SOCE using BTP2 inhibited lipotoxicity in vitro. Dantrolene or DUB also inhibited lipotoxic death of hepatocytes in vivo induced by administration of ethyl palmitate together with LPS. These results suggest a novel pathway of lipotoxicity characterized by mPT due to lysosomal Ca²⁺ release which was supplemented by ER → lysosome Ca²⁺ refilling and subsequent SOCE, and also suggest the potential role of modulation of ER → lysosome Ca²⁺ refilling by dantrolene or other blockers of ER Ca²⁺ exit channels in disease conditions characterized by lipotoxicity such as metabolic syndrome, diabetes, cardiomyopathy or nonalcoholic steatohepatitis.

Dual inhibition of MYC and SLC39A10 by a novel natural product STAT3 inhibitor derived from Chaetomium globosum suppresses tumor growth and metastasis in gastric cancer

Gastric cancer remains one of the most common deadly diseases and lacks effective targeted therapies. In the present study, we confirmed that the signal transducer and activator of transcription 3 (STAT3) is highly expressed and associated with a poor prognosis in gastric cancer. We further identified a novel natural product inhibitor of STAT3, termed XYA-2, which interacts specifically with the SH2 domain of STAT3 (K_d= 3.29 μM) and inhibits IL-6-induced STAT3 phosphorylation at Tyr705 and nuclear translocation. XYA-2 inhibited the viability of seven human gastric cancer cell lines with 72-h IC₅₀ values ranging from 0.5 to 0.7 μΜ. XYA-2 at 1 μΜ inhibited the colony formation and migration ability of MGC803 (72.6% and 67.6%, respectively) and MKN28 (78.5% and 96.6%, respectively) cells. In the in vivo studies, intraperitoneal administration of XYA-2 (10 mg/kg/day, 7 days/week) significantly suppressed 59.8% and 88.8% tumor growth in the MKN28-derived xenograft mouse model and MGC803-derived orthotopic mouse model, respectively. Similar results were obtained in a patient-derived xenograft (PDX) mouse model. Moreover, XYA-2 treatment extended the survival of mice bearing PDX tumors. The molecular mechanism studies based on transcriptomics and proteomics analyses indicated that XYA-2 might exert its anticancer activity by synergistically inhibiting the expression of MYC and SLC39A10, two downstream genes of STAT3 in vitro and in vivo. Together, these findings suggested that XYA-2 may be a potent STAT3 inhibitor for treating gastric cancer, and dual inhibition of MYC and SLC39A10 may be an effective therapeutic strategy for STAT3-activated cancer.

Die hard: cell death mechanisms and their implications in nanotoxicology

Cell death is a fundamental biological process, and its fine-tuned regulation is required for life. However, the complexity of regulated cell death is often reduced to a matter of live-dead discrimination. Here, we provide a perspective on programmed or regulated cell death, focusing on apoptosis, pyroptosis, necroptosis, and ferroptosis (the latter three cell death modalities are examples of regulated necrosis). We also touch on other, recently described manifestations of (pathological) cell death including cuproptosis. Furthermore, we address how engineered nanomaterials impact on regulated cell death. We posit that an improved understanding of nanomaterial-induced perturbations of cell death may allow for a better prediction of the consequences of human exposure and could also yield novel approaches by which to mitigate these effects. Finally, we provide examples of the harnessing of nanomaterials to achieve cancer cell killing through the induction of regulated cell death.

Zinc oxide nanoparticles trigger autophagy-mediated cell death through activating lysosomal TRPML1 in normal kidney cells

Zinc oxide nanoparticles (ZnO NPs) have been widely used in various materials including sunscreens, cosmetics, over-the-counter topical skin products, and pigments. As traces of the used ZnO NPs have been found in the kidney, it is crucial to uncover their potential risks. The aim of this study is to elucidate detrimental effects of ZnO NPs and the molecular mechanism behind their renal toxicity. Cytotoxic effects were measured by MTT assay after HK2 cells were exposed to ZnO NPs for 24 h and IC₅₀ value was determined. ROS and intracellular Zn²⁺ levels were detected by flow cytometry, and localization of Zn²⁺ and lysosome was determined by confocal microscopy. Occurrence of autophagy and detection of autophagic flux were determined by Western blot and confocal microscopy, respectively. We performed unpaired student t test for two groups, and one-way ANOVA with Tukey's post hoc for over three groups. ZnO NPs induced cell death in human renal proximal tubule epithelial cells, HK2. Cytosolic Zn²⁺ caused autophagy-mediated cell death rather than apoptosis. Cytosolic Zn²⁺ processed in lysosome was released by TRPML1, and inhibition of TRPML1 significantly decreased autophagic flux and cell death. The findings of this study suggest that ZnO NPs strongly induce autophagy-mediated cell death in human kidney cells. Controlling TRPML1 can be potentially used to prevent the kidney from ZnO NPs-induced toxicity.

Myeloid-derived suppressor cells ameliorate liver mitochondrial damage to protect against autoimmune hepatitis by releasing small extracellular vesicles

BACKGROUND

Autoimmune hepatitis (AIH) is an inflammatory liver disease that is associated with impaired self-tolerance. Myeloid-derived supprfessor cells (MDSCs) have been considered to exert counterregulatory effects on AIH. However, the specific mechanism underlying these effects is unclear. Herein, we investigated the efficacy and safety of MDSCs in protecting against AIH and explored the underlying mechanism.

METHODS

Circulating and liver MDSC expression levels in 71 AIH patients and 47 healthy control (HC) individuals were detected by flow cytometry and immunohistochemistry. The adoptive transfer of induced bone marrow-derived MDSCs (BM MDSCs) to AIH mice was used to explore the function of MDSCs. Hepatic injury and mitochondrial damage were evaluated by transaminase levels, histopathology, immunohistochemistry, transmission electron microscopy and western blotting. MDSCs were pretreated with the small extracellular vesicle (sEV) generation inhibitor GW4869 to explore the mechanism. Importantly, sEVs derived from MDSCs and MDSCs-GW4869 were injected into model mice to monitor mitochondrial function and biogenesis.

RESULTS

Circulating and liver MDSCs were expanded in AIH patients and mouse model. Furthermore, the follow-up data of AIH patients showed that immunosuppressive therapy further promoted the expansion of MDSCs. More importantly, the adoptive transfer of BM MDSCs to AIH mice effectively ameliorated liver injury and regulated the imbalance of the immune microenvironment. Additionally, BM MDSCs reduced liver mitochondrial damage and improved mitochondrial biogenesis. Mechanistically, sEVs derived from BM MDSCs showed the same biological effects as cells, and blocking sEV production weakened the function of BM MDSCs. Finally, multiple long-term administrations of BM MDSCs were proven to be safe in general.

CONCLUSION

In conclusion, MDSCs ameliorate liver mitochondrial damage to protect against autoimmune hepatitis by releasing small extracellular vesicles.

A Novel Cuproptosis-Related Prognostic Model and the Hub Gene FDX1 Predict the Prognosis and Correlate with Immune Infiltration in Clear Cell Renal Cell Carcinoma

Clear cell renal cell carcinoma (ccRCC) is a common malignancy of the urological system with poor prognosis. Cuproptosis is a recently discovered novel manner of cell death, and the hub gene FDX1 could promote cuproptosis. However, the potential roles of cuproptosis-related genes (CRGs) and FDX1 for predicting prognosis, the immune microenvironment, and therapeutic response have been poorly studied in ccRCC. In the present study, The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) data were downloaded. CRGs were subjected to prognosis analysis, and three of them were used to construct the prognostic model by least absolute shrinkage and selection operator (LASSO) regression. The CRGs prognostic model showed excellent performance. Moreover, based on the risk score of the model, the nomogram was developed to predict 1-year, 3-year, and 5-year survival. Furthermore, the hub gene of cuproptosis, FDX1, was an independent prognostic biomarker in multivariate Cox regression analysis. The pan-cancer analysis showed that FDX1 was significantly downregulated and closely related to prognosis in ccRCC among 33 cancer types. Lower FDX1 was also correlated with worse clinicopathologic features. The lower expression of FDX1 in ccRCC was verified in the external database and our own database, which may be caused by DNA methylation. We further demonstrated that the tumor mutational burden (TMB) and immune cell infiltration were related to the expression of FDX1. Immune response and drug sensitivity analysis revealed that immunotherapy or elesclomol may have a favorable treatment effect in the high FDX1 expression group and sunitinib or axitinib may work better in the low FDX1 expression group. In conclusion, we constructed a CRGs prognostic model and revealed that FDX1 could serve as a prognostic biomarker and predict therapeutic response in ccRCC. The study will provide a novel, precise, and individual treatment strategy for ccRCC patients.

Identification of key cuproptosis-related genes and their targets in patients with IgAN

BACKGROUND

IgA nephropathy (IgAN) is one of the most common forms of chronic glomerulonephritis, but the aetiology and pathogenesis remain unclear. Cuproptosis is a newly identified form of cell death that plays an important role in many diseases. Researchers have not clearly determined whether the expression of cuproptosis-related genes (CRGs) is involved in the pathogenesis of IgAN.

METHODS

The GSE93798, GSE50469 and GSE37460 datasets containing microarray data from patients with IgAN (63) and healthy controls (31) were downloaded from the GEO database. Immune cells and immune-related functions were analysed in patients with IgAN and controls, and genes were identified that may be related to cuproptosis. A logistic regression model was established according to the results, and then GO and KEGG enrichment analyses were performed. Finally, possible drugs were selected using the DSigDB database.

RESULTS

The subjects in the different groups showed significantly different fractions of immune cells and immune-related functions, and 11 genes related to cuproptosis may be involved in these processes. Based on these 11 genes, the ROC curve was plotted, and the AUC value was calculated (0.898, 95% CI: 0.839-0.958). The result revealed good predictability. Then, genes with P &lt; 0.05 (lipoyltransferase 1, LIPT1) were selected to plot an ROC curve, and the AUC value was calculated (0.729, 95% CI: 0.636-0.821). Enrichment analyses showed that the TCA cycle and multiple metabolic pathways may also be involved in the occurrence of IgAN. Finally, 293 potential drugs that may be used to treat IgAN were identified based on these genes.

CONCLUSION

In this study, we identified some novel CRGs that may be involved in IgAN, among which LIPT1 was significantly differentially expressed. It may predict the risk of IgAN and provides a possible target for the treatment of IgAN. Further experimental studies are needed to explore how these CRGs mediate the occurrence and development of IgAN.

Deregulated calcium signaling in blood cancer: Underlying mechanisms and therapeutic potential

Intracellular calcium signaling regulates diverse physiological and pathological processes. In solid tumors, changes to calcium channels and effectors via mutations or changes in expression affect all cancer hallmarks. Such changes often disrupt transport of calcium ions (Ca2+) in the endoplasmic reticulum (ER) or mitochondria, impacting apoptosis. Evidence rapidly accumulates that this is similar in blood cancer. Principles of intracellular Ca2+ signaling are outlined in the introduction. We describe different Ca2+-toolkit components and summarize the unique relationship between extracellular Ca2+ in the endosteal niche and hematopoietic stem cells. The foundational data on Ca2+ homeostasis in red blood cells is discussed, with the demonstration of changes in red blood cell disorders. This leads to the role of Ca2+ in neoplastic erythropoiesis. Then we expand onto the neoplastic impact of deregulated plasma membrane Ca2+ channels, ER Ca2+ channels, Ca2+ pumps and exchangers, as well as Ca2+ sensor and effector proteins across all types of hematologic neoplasms. This includes an overview of genetic variants in the Ca2+-toolkit encoding genes in lymphoid and myeloid cancers as recorded in publically available cancer databases. The data we compiled demonstrate that multiple Ca2+ homeostatic mechanisms and Ca2+ responsive pathways are altered in hematologic cancers. Some of these alterations may have genetic basis but this requires further investigation. Most changes in the Ca2+-toolkit do not appear to define/associate with specific disease entities but may influence disease grade, prognosis, treatment response, and certain complications. Further elucidation of the underlying mechanisms may lead to novel treatments, with the aim to tailor drugs to different patterns of deregulation. To our knowledge this is the first review of its type in the published literature. We hope that the evidence we compiled increases awareness of the calcium signaling deregulation in hematologic neoplasms and triggers more clinical studies to help advance this field.

A comprehensive analysis and validation of cuproptosis-associated genes across cancers: Overall survival, the tumor microenvironment, stemness scores, and drug sensitivity

Background: Cuproptosis is a novel type of cell death induced by copper. Cuproptosis-associated genes play a crucial part in oncogenesis and the growth and metastasis of tumors. However, the correlations among cuproptosis-associated genes, overall survival, the tumor microenvironment, and drug sensitivity remain unclear. Therefore, we performed an analysis of cuproptosis-associated genes across cancers.

Methods: We downloaded RNA sequence expression data, clinical and survival data, stemness score data, and immune subtype data of cuproptosis-associated genes from the UCSC Xena. Next, we conducted differential analysis, expression analysis and correlation analysis across cancers with various R packages. Moreover, survival analysis and Cox hazard analysis were conducted to investigate the relationships between cuproptosis-associated genes and survival outcomes in various cancer types. Finally, we also analyzed the relationship among the levels of cuproptosis-associated genes across cancers, immune types, the tumor microenvironment, stemness scores, and drug sensitivity. Expression validation of cuproptosis-associated genes in renal cancer and normal tissues by immunohistochemical staining.

Results: We found that 10 cuproptosis-associated genes (FDX1, LIAS, LIPT1, DLD, DLAT, PDHA1, PDHB, MTF1, GLS, and CDKN2A) were differently expressed in 18 tumors and normal tissues. Survival outcomes showed that cuproptosis-associated genes had prognostic value in various cancer types. Moreover, we identified that cuproptosis-associated genes had different levels in six immune subtypes. The study also indicated that the levels of most cuproptosis-associated genes were positively correlated with the RNAss and DNAss. FDX1, LIAS, LIPT1, DLD, DLAT, PDHA1, and PDHB were negatively correlated with immune scores and ESTIMATE scores. In addition, we identified the top 16 drugs strongly sensitivity to cuproptosis-associated genes according to the correlation coefficient. Finally, we also found that cuproptosis-associated genes were significantly correlated with immune subtype, clinical features, the tumor microenvironment, and drug sensitivity in Kidney renal clear cell carcinoma. And the results of immunohistochemical staining analysis was very consistent with the previous analysis.

Conclusion: We performed an overall analysis to uncover the roles of cuproptosis-associated genes in differential expression, survival outcomes, immune subtypes, the tumor microenvironment, stemness scores, and cancer drug sensitivity across cancers.

A protocol to measure lysosomal Zn2+ release through a genetically encoded Zn2+ indicator

Intracellular vesicles such as lysosomes contain micromolar to millimolar concentrations of Zn2+, and disturbing lysosomal Zn2+ homeostasis via lysosomal Zn2+ release leads to mitochondria damage and consequent lytic cell death. Methods have been developed to image cellular Zn2+ dynamics. Here, we present a protocol using GZnP3, a genetically encoded fluorescent Zn2+ indicator, to assess lysosomal Zn2+ release in cultured cells by fluorescence microscopy imaging. For complete details on the use and execution of this protocol, please refer to Du et al. (2021) or Minckley et al. (2019).