Mitochondria-mediated ferroptosis contributes to the inflammatory responses of bovine viral diarrhea virus (BVDV) in vitro.

Bovine viral diarrhea virus (BVDV) belongs to the family Flaviviridae and includes two biotypes in cell culture: cytopathic (CP) or non-cytopathic (NCP) effects. Ferroptosis is a non-apoptotic form of programmed cell death that contributes to inflammatory diseases. However, whether BVDV induces ferroptosis and the role of ferroptosis in viral infection remain unclear. Here, we provide evidence that both CP and NCP BVDV can induce ferroptosis in Madin-Darby bovine kidney cells at similar rate. Mechanistically, biotypes of BVDV infection downregulate cytoplasmic and mitochondrial GPX4 via Nrf2-GPX4 pathway, thereby resulting in lethal lipid peroxidation and promoting ferroptosis. In parallel, BVDV can degrade ferritin heavy chain and mitochondrial ferritin via NCOA4-mediated ferritinophagy to promote the accumulation of Fe2+ and initiate ferroptosis. Importantly, CP BVDV-induced ferroptosis is tightly associated with serious damage of mitochondria and hyperactivation of inflammatory responses. In contrast, mild or unapparent damage of mitochondria and slight inflammatory responses were detected in NCP BVDV-infected cells. More importantly, different mitophagy pathways in response to mitochondria damage by both biotypes of BVDV are involved in inflammatory responses. Overall, this study is the first to show that mitochondria may play key roles in mediating ferroptosis and inflammatory responses induced by biotypes of BVDV in vitro.IMPORTANCEBovine viral diarrhea virus (BVDV) threatens a wide range of domestic and wild cattle population worldwide. BVDV causes great economic loss in cattle industry through its immunosuppression and persistent infection. Despite extensive research, the mechanism underlying the pathogenesis of BVDV remains elusive. Our data provide the first direct evidence that mitochondria-mediated ferroptosis and mitophagy are involved in inflammatory responses in both biotypes of BVDV-infected cells. Importantly, we demonstrate that the different degrees of injury of mitochondria and inflammatory responses may attribute to different mitophagy pathways induced by biotypes of BVDV. Overall, our findings uncover the interaction between BVDV infection and mitochondria-mediated ferroptosis, which shed novel light on the physiological impacts of ferroptosis on the pathogenesis of BVDV infection, and provide a promising therapeutic strategy to treat this important infectious disease with a worldwide distribution.

Low-Dose Exposure of WS2 Nanosheets Induces Differential Apoptosis in Lung Epithelial Cells.

Escalating the production and application of tungsten disulfide (WS2) nanosheets inevitably increases environmental human exposure and warrants the necessity of studies to elucidate their biological impacts. Herein, we assessed the toxicity of WS2 nanosheets and focused on the impacts of low doses (≤10 µg/mL) on normal (BEAS-2B) and tumorigenic (A549) lung epithelial cells. The low doses, which approximate real-world exposures, were found to induce cell apoptosis, while doses ≥ 50 µg/mL cause necrosis. Focused studies on low-dose exposure to WS2 nanosheets revealed more details of the impacts on both cell lines, including reduction of cell metabolic activity, induction of lipid peroxidation in cell membranes, and uncoupling of mitochondrial oxidative phosphorylation that led to the loss of ATP production. These phenomena, along with the expression situations of a few key proteins involved in apoptosis, point toward the occurrence of mitochondria-dependent apoptotic signaling in exposed cells. Substantial differences in responses to WS2 exposure between normal and tumorigenic lung epithelial cells were noticed as well. Specifically, BEAS-2B cells experienced more adverse effects and took up more nanosheets than A549 cells. Our results highlight the importance of dose and cell model selection in the assessment of nanotoxicity. By using doses consistent with real-world exposures and comparing normal and diseased cells, we can gain knowledge to guide the development of safety precautions for mitigating the adverse impacts of nanomaterial exposure on human health.

NaAsO2 decreases GSH synthesis by inhibiting GCLC and induces apoptosis through Hela cell mitochondrial damage, mediating the activation of the NF-κB/miR-21 signaling pathway.

BACKGROUND: Cervical cancer is the fourth most common cancer in women worldwide, and arsenic has a certain effect in solid tumor chemotherapy. As the rate-limiting enzyme subunit of GSH synthesis, GCLC may be an important target for arsenic to induce apoptosis through mitochondrial apoptosis pathway to exert anti-tumor effect. NF-κB plays an important role in the occurrence and development of cervical cancer and can regulate the expression of GCLC. miR-21 is a potential biomarker of cervical cancer, which can induce apoptosis through ROS regulated the mitochondrial pathway of cells. However, the role of miR-21 in the mitochondrial pathway of cervical cancer cells induced by NaAsO2 through NF-κB/GCLC and GSH synthesis regulated oxidative stress is rarely reported. Therefore, the purpose of this study was to investigate whether NaAsO2 might induce mitochondrial damage and apoptosis of cervical cancer cells through NF-κB/ miR-21 /GCLC induced oxidative stress, and play the anti-tumor role of arsenic as a potential drug for the treatment of cervical cancer. METHODS: Hela cells were treated with different concentrations of NaAsO2, D, L-Buthionine-(SR)-sulfoximine (BSO), IκBα inhibitor (BAY 11-7082) and miR-21 Inhibitor. CCK-8 assay, Western Blot, qRT PCR, immunofluorescence, transmission electron microscopy, mitochondrial Membrane Potential Assay Kit with JC-1,2',7'-Dichlorofluorescin diacetate fluorescent probe and Annexin V-FITC were used to measure cell activity, GSH and ROS, mitochondrial morphology and membrane potential (ΔΨm), protein and mRNA expression of GCLC, GCLM, p65, IκBα, p-P65, p-I κBα, Bcl-2, BAX, Caspase3, cleaved-caspase3 and miR-21. RESULTS: Compared with the control group, with the gradual increasing dose of NaAsO2, cell viability was considerable reduced, and increased rate of apoptosis, intracellular GSH level was decreased significantly, ROS was increased, mitochondrial structure was damaged, mitochondrial membrane potential ΔΨm and Bcl2/BAX lowered, the expression of Caspase3 and cleaved-caspase3 were significantly increased, resulting in mitochondrial apoptosis. When Hela cells were treated with 15, 20, and 25 µmol/L NaAsO2, the mRNA and protein levels of GCLC and GCLM were reduced, the expression of p65 in the nucleus was increased, the expression of p-p65/p65, p-IκBα/IκBα and miR-21 were significantly increased. When BSO increased the inhibitory effect of NaAsO2 on GCLC, Compared with NaAsO2 group, the ΔΨm and protein of Bcl-2/BAX, caspase3 and cleaved-capsase3 were increased. When BAY 11-7082 combined with NaAsO2 co-treated, compared with the NaAsO2 group, the protein and mRNA expression of GCLC was increased, NaAsO2-increased expression level of miR-21 was suppressed, and the ΔΨm and cell viability were higher. In addition, compared with the combination of NaAsO2 and miR-21NC, the protein expression of GCLC was increased, the ΔΨm and cell viability reduction were alleviated by miR-21 Inhibitor combined with NaAsO2. CONCLUSION: NaAsO2 may lead to ROS accumulation in Hela cells and trigger mitochondrial apoptosis. The mechanism may be related to the activation of NF-κB signaling pathway and the promotion of miR-21 expression which leads to the inhibition of GCLC expression and the significant decrease of intracellular reductive GSH synthesis.

Zearalenone Induces MLKL-Dependent Necroptosis in Goat Endometrial Stromal Cells via the Calcium Overload/ROS Pathway.

Zearalenone (ZEA) is a fungal mycotoxin known to exert strong reproductive toxicity in animals. As a newly identified type of programmed cell death, necroptosis is regulated by receptor-interacting protein kinase 1 (RIPK1), receptor-interacting protein kinase 3 (RIPK3), and mixed-lineage kinase domain-like pseudokinase (MLKL). However, the role and mechanism of necroptosis in ZEA toxicity remain unclear. In this study, we confirmed the involvement of necroptosis in ZEA-induced cell death in goat endometrial stromal cells (gESCs). The release of lactate dehydrogenase (LDH) and the production of PI-positive cells markedly increased. At the same time, the expression of RIPK1 and RIPK3 mRNAs and P-RIPK3 and P-MLKL proteins were significantly upregulated in ZEA-treated gESCs. Importantly, the MLKL inhibitor necrosulfonamide (NSA) dramatically attenuated gESCs necroptosis and powerfully blocked ZEA-induced reactive oxygen species (ROS) generation and mitochondrial dysfunction. The reactive oxygen species (ROS) scavengers and N-acetylcysteine (NAC) inhibited ZEA-induced cell death. In addition, the inhibition of MLKL alleviated the intracellular Ca2+ overload caused by ZEA. The calcium chelator BAPTA-AM markedly suppressed ROS production and mitochondrial damage, thus inhibiting ZEA-induced necroptosis. Therefore, our results revealed the mechanism by which ZEA triggers gESCs necroptosis, which may provide a new therapeutic strategy for ZEA poisoning.

Dexmedetomidine inhibits mitochondria damage and apoptosis of enteric glial cells in experimental intestinal ischemia/reperfusion injury via SIRT3-dependent PINK1/HDAC3/p53 pathway.

BACKGROUND: Intestinal ischemia/reperfusion (I/R) injury commonly occurs during perioperative periods, resulting in high morbidity and mortality on a global scale. Dexmedetomidine (Dex) is a selective α2-agonist that is frequently applied during perioperative periods for its analgesia effect; however, its ability to provide protection against intestinal I/R injury and underlying molecular mechanisms remain unclear. METHODS: To fill this gap, the protection of Dex against I/R injury was examined in a rat model of intestinal I/R injury and in an inflammation cell model, which was induced by tumor necrosis factor-alpha (TNF-α) plus interferon-gamma (IFN-γ) stimulation. RESULTS: Our data demonstrated that Dex had protective effects against intestinal I/R injury in rats. Dex was also found to promote mitophagy and inhibit apoptosis of enteric glial cells (EGCs) in the inflammation cell model. PINK1 downregulated p53 expression by promoting the phosphorylation of HDAC3. Further studies revealed that Dex provided protection against experimentally induced intestinal I/R injury in rats, while enhancing mitophagy, and suppressing apoptosis of EGCs through SIRT3-mediated PINK1/HDAC3/p53 pathway in the inflammation cell model. CONCLUSION: Hence, these findings provide evidence supporting the protective effect of Dex against intestinal I/R injury and its underlying mechanism involving the SIRT3/PINK1/HDAC3/p53 axis.

Calcitriol alleviates ethanol-induced hepatotoxicity via AMPK/mTOR-mediated autophagy.

Excessive ethanol consumption causes cellular damage, leading to fetal alcohol syndrome and alcohol liver diseases, which are frequently seen with vitamin D (VD) deficiency. A great deal of progress has been achieved in the mechanisms of ethanol-induced hepatocyte damage. However, there are limited intervention means to reduce or rescue hepatocytes damage caused by ethanol. On the basis of our preliminary limited screen process, calcitriol showed a positive effect on protecting hepatocyte viability. Therefore, the molecular basis is worth elucidating. We found that calcitriol pretreatment markedly improved the cell viability, decreased cell apoptosis and oxidative stress and alleviated the abnormal mitochondrial morphology and membrane potential of hepatocytes induced by ethanol. Notably, autophagy was significantly enhanced by calcitriol, as evident by the increasing number of autophagosomes and autolysosomes, upregulated LC3B-Ⅱ and ATG5 levels, and promotion of p62 degradation. Furthermore, calcitriol pretreatment increased the colocalization of GFP-LC3-labeled autophagosomes with mitochondria, suggesting that calcitriol effectively promoted ethanol-induced mitophagy in hepatocytes. In addition, the inhibition of autophagy attenuated the protective and preventive effect of calcitriol. Furthermore, the effect of calcitriol on autophagy was regulated by AMPK/mTOR signaling, and signaling transduction was dependent on the Vitamin D receptor (VDR). In conclusion, calcitriol ameliorates ethanol-induced hepatocyte damage by enhancing autophagy. It may offer a convenient preventive and hepatoprotective mean for people on occasional social drink.

Sennoside A restores colonic barrier function through protecting colon enterocytes from ROS-induced mitochondrial damage in diet-induced obese mice.

The intestinal barrier dysfunction is closely implicated in low-grade chronic inflammation for insulin resistance in diet-induced obesity (DIO). It is generally believed that degradation of colon enterocytes contributes to intestinal barrier dysfunction in the pathological process of obesity. Sennoside A (SA) is reported to improve metabolic disorders, but the effect and mechanism of SA on colonic barrier function of DIO remains unknown. In this study, SA was found to restore colonic barrier function by protecting the continuity and integrity of colon enterocytes in DIO mice. An increase in mRNA expression of tight junction proteins Occludin, Claudin-2 and ZO-1 provides another mechanism of restoring colonic barrier function in SA-treated group. In the research of mechanism, mitophagy was inhibited by SA via a protection of mitochondrial structure and function in colon. A reduction was found in production of reactive oxygen species (ROS) in the colon, and the benefical effect was attributed to an inhibition of activity in complex I and III with a reduction of protein expression and an increase of Mn-SOD activity. The results indicate that SA can restores colonic barrier function through protecting colon enterocytes from ROS-induced mitochondrial damage in DIO mice.

Induction of hepatic portal fibrosis, mitochondria damage, and extracellular vesicle formation in Sprague-Dawley rats exposed to copper, manganese, and mercury, alone and in combination.

Increased anthropogenic activity and subsequent environmental exposure to heavy metals induce the production of reactive oxygen species (ROS), which increases oxidative stress and the risk of associated diseases. The aim of this study, in a subacute model of toxicity, was to investigate the effects of copper (Cu), manganese (Mn), and mercury (Hg) alone and in combination on the liver tissue of male Sprague-Dawley rats, exposed orally to 100 times the World Health Organization's acceptable water limits of each metal. General histological alterations as well as ultrastructural changes were investigated using light microscopy and transmission electron microscopy (TEM) respectively. Exposure to Cu, Mn, and Hg, alone and in combinations, caused hydropic swelling of the hepatocytes, dilation of the sinusoids, formation of binucleated hepatocytes with an increased inflammatory cell accumulation at the portal triad. Increased collagen deposition with associated fibrosis was also observed. Evaluation of hepatocyte ultrastructure revealed mitochondrial membrane damage and inner membrane swelling especially for hepatocytes exposed to Mn. Extracellular vesicle (EV) formation was observed in the liver tissue of all exposed rats. Furthermore, increased damage observed for metal combinations was possibly due to synergism. In conclusion, Cu, Mn, and Hg alone and as part of a mixture cause cellular damage, inflammation, and fibrosis increasing the risk of associated diseases.

Reactive oxygen and nitrogen species induce cell apoptosis via a mitochondria-dependent pathway in hyperoxia lung injury.

Hyperoxia-induced lung injury limits the application of mechanical ventilation on rescuing the lives of premature infants and seriously ill and respiratory failure patients, and its mechanisms are not completely understood. In this article, we focused on the relationship between hyperoxia-induced lung injury and reactive oxygen species (ROS), reactive nitrogen species (RNS), mitochondria damage, as well as apoptosis in the pulmonary epithelial II cell line RLE-6TN. After exposure to hyperoxia, the cell viability was significantly decreased, accompanied by the increase in ROS, nitric oxide (NO), inflammatory cytokines, and cell death. Furthermore, hyperoxia triggered the loss of mitochondrial membrane potential (▵Ψm), thereby promoting cytochrome c to release from mitochondria to cytoplasm. Further studies conclusively showed that the Bax/Bcl-2 ratio was enlarged to activate the mitochondria-dependent apoptotic pathway after hyperoxia treatment. Intriguingly, the effects of hyperoxia on the level of ROS, NO and inflammation, mitochondrial damage, as well as cell death were reversed by free radical scavengers N-acetylcysteine and hemoglobin. In addition, a hyperoxia model of neonatal Sprague-Dawley (SD) rats presented the obvious characteristics of lung injury, such as a decrease in alveolar numbers, alveolar mass edema, and disorganized pulmonary structure. The effects of hyperoxia on ROS, RNS, inflammatory cytokines, and apoptosis-related proteins in lung injury tissues of neonatal SD rats were similar to that in RLE-6TN cells. In conclusion, mitochondria are a primary target of hyperoxia-induced free radical, whereas ROS and RNS are the key mediators of hyperoxia-induced cell apoptosis via the mitochondria-dependent pathway in RLE-6TN cells.

SHP-2 restricts apoptosis induced by chemotherapeutic agents via Parkin-dependent autophagy in cervical cancer.

BACKGROUND: Autophagy is a cell degradation pathway that eliminates damaged or unwanted proteins and organelles. Autophagy protects cells from chemotherapeutic agents by scavenging damaged mitochondria. METHODS: Plasmid transfection and shRNA were used to regulate SHP-2 expression. Annexin V/PI staining were employed to analysis apoptosis. Flow cytometry was used to analyse intracellular calcium level and ROS. Immunofluorescence was used to detect mitochondria membrane potential, autophagy and Parkin translocation. RESULTS: In cervical cancer, we found that SHP-2 suppressed apoptosis induced by Oxaliplatin and 5-FU. Further studies have found that SHP-2 protects against mitochondrial damage. This role of SHP-2 is associated with the activation of autophagy. In addition, SHP-2 degraded impaired mitochondria dependent on the ubiquitin ligase function of Parkin. CONCLUSIONS: These results suggest that SHP-2 inhibits the apoptosis induced by chemotherapeutic drugs through activating autophagy to degrade damaged mitochondria and ubiquitin ligase Parkin involved in SHP-2 induced autophagy.

Protective Effect of Edaravone Against Aß25-35-Induced Mitochondrial Oxidative Damage in SH-SY5Y Cells.

Amyloid-ß (Aß)-induced oxidative stress plays an important role in the pathogenesis of Alzheimer's disease (AD). Recent studies show that Aß accumulation may lead to mitochondrial oxidative damage. In the present study, we investigated the protective effect of edaravone on mitochondrial damage in SH-SY5Y cells treated with Aß25-35. SH-SY5Y cells were pre-treated with 20, 40 or 80 µM edaravone before treatment with 25 µM Aß25-35. After 24h cell culture, cellular apoptosis, intracellular reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨm), ATP levels and mitochondrial morphology were evaluated. SH-SY5Y cells exposed to Aß25-35 had high levels of apoptosis and ROS; loss of ΔΨm, decreased ATP levels and presence of mitochondrial swelling. However, these effects were significantly inhibited by edaravone pre-treatment. These results indicate that edaravone prevents mitochondria oxidative damage caused by Aß in SH-SY5Y cells, which suggests that it may have potential clinical application in AD therapy.

PpIX induces mitochondria-related apoptosis in murine leukemia L1210 cells.

CONTEXT: Protoporphyrin IX (PpIX), a well-known sensitizer that can enhance laser light or ultrasound induced cytotoxicity in photodynamic and sonodynamic therapy. However, PpIX alone could effectively cause anti-tumor effect and the underlying mechanisms are rarely been reported. Therefore, this study was to investigate the possible mechanism by which PpIX revealed anti-proliferative effect on murine leukemia L1210 cells. MATERIALS AND METHODS: The accumulation of PpIX in L1210 cells and normal peripheral blood mononuclear cells (PBMCs) was evaluated with flow cytometry. The subcellular localization of PpIX and apoptosis-inducing factor (AIF) translocation were determined by confocal microscope. The cell viability was examined by MTT assay. Annexin V-PE/7-AAD and DAPI staining were used to detect apoptotic cells. The mitochondrial membrane potential (MMP) changes were tested by rhodamine123 staining. DNA damage was measured by comet assay. RESULTS: PpIX preferentially accumulated in L1210 cells compared to PBMCs and PpIX mainly located in the mitochondria of L1210 cells. PpIX at a concentration of 1 µg/ml or above exerted significant anti-tumor effect and the cell viability loss presented PpIX dose-dependent manner. Typical apoptotic features such as chromatin condensation were observed by DAPI staining. Annexin V-PE/7-AAD analysis showed 5 µg/ml PpIX could induce about 24% cell apoptosis, which was inhibited by cyclosporin A (CsA), an inhibitor of mitochondrial permeability transition pore. In addition, the PpIX caused MMP loss, AIF translocation to nucleus and serious DNA damage were also suppressed by CsA. CONCLUSION: The results indicate mitochondria-dependent apoptosis were involved in PpIX caused cell damage on L1210 cells.

The role of mitochondrial damage-associated molecular patterns in acute pancreatitis.

Acute pancreatitis (AP) is one of the most common gastrointestinal tract diseases with significant morbidity and mortality. Current treatments remain unspecific and supportive due to the severity and clinical course of AP, which can fluctuate rapidly and unpredictably. Mitochondria, cellular power plant to produce energy, are involved in a variety of physiological or pathological activities in human body. There is a growing evidence indicating that mitochondria damage-associated molecular patterns (mtDAMPs) play an important role in pathogenesis and progression of AP. With the pro-inflammatory properties, released mtDAMPs may damage pancreatic cells by binding with receptors, activating downstream molecules and releasing inflammatory factors. This review focuses on the possible interaction between AP and mtDAMPs, which include cytochrome c (Cyt c), mitochondrial transcription factor A (TFAM), mitochondrial DNA (mtDNA), cardiolipin (CL), adenosine triphosphate (ATP) and succinate, with focus on experimental research and potential therapeutic targets in clinical practice. Preventing or diminishing the release of mtDAMPs or targeting the mtDAMPs receptors might have a role in AP progression.

Combination of biotransformation and metabolomics reveals tolfenpyrad-induced hepatocytotoxicity.

Tolfenpyrad (TFP) is an extensively used pesticide that inevitably leads to human exposure to both TFP and its transformation product residues. However, the biotransformation of TFP in humans has not been elucidated, and the toxicity of TFP along with its biotransformation products remains largely unknown. In this study, the biotransformation process of TFP was investigated using human liver microsomes and human hepatic cells. Endogenous metabolic changes in the cells were studied to investigate the hepatocytotoxicity of TFP at environmentally relevant concentrations. Fourteen phase I biotransformation products and four phase II TFP products were characterized, among which twelve products were identified for the first time. The oxidative product tolfenpyrad-benzoic acid (PT-CA) was particularly abundant and stable. Further hepatotoxicity assessments and metabolic studies demonstrated comparable metabolic profiles for TFP and PT-CA in HepG2 cells, with both significantly disrupting purine and glutathione metabolism. These processes are closely associated with oxidative stress, mitochondrial damage, and cell death. Our results provide novel perspectives on the biotransformation, metabolism, and hepatotoxicity of TFP, thereby highlighting the non-negligible toxicity of its crucial biotransformation product PT-CA in environmental risk assessments.

VDAC1, as a downstream molecule of MLKL, participates in OGD/R-induced necroptosis by inducing mitochondrial damage.

Ischemia-reperfusion (I/R) injury constitutes a significant risk factor for a range of diseases, including ischemic stroke, myocardial infarction, and trauma. Following the restoration of blood flow post-tissue ischemia, oxidative stress can lead to various forms of cell death, including necrosis, apoptosis, autophagy, and necroptosis. Recent evidence has highlighted the crucial role of mitochondrial dysfunction in I/R injury. Nevertheless, there remains much to be explored regarding the molecular signaling network governing cell death under conditions of oxidative stress. Voltage-dependent anion channel 1 (VDAC1), a major component in the outer mitochondrial membrane, is closely involved in the regulation of cell death. In a cellular model of oxygen-glucose deprivation and reoxygenation (OGD/R), which effectively simulates I/R injury in vitro, our study reveals that OGD/R induces VDAC1 oligomerization, consequently exacerbating cell death. Furthermore, we have revealed the translocation of mixed lineage kinase domain-like protein (MLKL) to the mitochondria, where it interacts with VDAC1 following OGD/R injury, leading to an increased mitochondrial membrane permeability. Notably, the inhibition of MLKL by necrosulfonamide hinders the binding of MLKL to VDAC1, primarily by affecting the membrane translocation of MLKL, and reduces OGD/R-induced VDAC1 oligomerization. Collectively, our findings provide preliminary evidence of the functional association between MLKL and VDAC1 in the regulation of necroptosis.

Effects of Dityrosine on Lactic Acid Metabolism in Mice Gastrocnemius Muscle During Endurance Exercise via the Oxidative Stress-Induced Mitochondria Damage.

Dityrosine (Dityr) has been detected in commercial food as a product of protein oxidation and has been shown to pose a threat to human health. This study aims to investigate whether Dityr causes a decrease in lactic acid metabolism in the gastrocnemius muscle during endurance exercise. C57BL/6 mice were administered Dityr or saline by gavage for 13 weeks and underwent an endurance exercise test on a treadmill. Dityr caused a severe reduction in motion displacement and endurance time, along with a significant increase in lactic acid accumulation in the blood and gastrocnemius muscle in mice after exercise. Dityr induced significant mitochondrial defects in the gastrocnemius muscle of mice. Additionally, Dityr induced serious oxidative stress in the gastrocnemius muscle, accompanied by inflammation, which might be one of the causes of mitochondrial dysfunction. Moreover, significant apoptosis in the gastrocnemius muscle increased after exposure to Dityr. This study confirmed that Dityr induced oxidative stress in the gastrocnemius muscle, which further caused significant mitochondrial damage in the gastrocnemius muscle cell, resulting in decreased capacity of lactic acid metabolism and finally affected performance in endurance exercise. This may be one of the possible mechanisms by which highly oxidized foods cause a decreased muscle energy metabolism.

Nano-hydroxyapatite promotes cell apoptosis by co-activating endoplasmic reticulum stress and mitochondria damage to inhibit glioma growth.

Despite a growing body of studies demonstrating the specific anti-tumor effect of nano-hydroxyapatite (n-HA), the underlying mechanism remained unclear. Endoplasmic reticulum (ER) and mitochondria are two key players in intracellular Ca2+ homeostasis and both require Ca2+ to participate. Moreover, the ER-mitochondria interplay coordinates the maintenance of cellular Ca2+ homeostasis to prevent any negative consequences from excess of Ca2+, hence there needs in-depth study of n-HA effect on them. In this study, we fabricated needle-like n-HA to investigate the anti-tumor effectiveness as well as the underlying mechanisms from cellular and molecular perspectives. Data from in vitro experiments indicated that the growth and invasion of glioma cells were obviously reduced with the aid of n-HA. It is interesting to note that the expression of ER stress biomarkers (GRP78, p-IRE1, p-PERK, PERK, and ATF6) were all upregulated after n-HA treatment, along with the activation of the pro-apoptotic transcription factor CHOP, showing that ER stress produced by n-HA triggered cell apoptosis. Moreover, the increased expression level of intracellular reactive oxygen species and the mitochondrial membrane depolarization, as well as the downstream cell apoptotic signaling activation, further demonstrated the pro-apoptotic roles of n-HA induced Ca2+ overload through inducing mitochondria damage. The in vivo data provided additional evidence that n-HA caused ER stress and mitochondria damage in cells and effectively restrain the growth of glioma tumors. Collectively, the work showed that n-HA co-activated intracellular ER stress and mitochondria damage are critical triggers for cancer cells apoptosis, offering fresh perspectives on ER-mitochondria targeted anti-tumor therapy.

Self-Reinforced Bimetallic Mito-Jammer for Ca2+ Overload-Mediated Cascade Mitochondrial Damage for Cancer Cuproptosis Sensitization.

Overproduction of reactive oxygen species (ROS), metal ion accumulation, and tricarboxylic acid cycle collapse are crucial factors in mitochondria-mediated cell death. However, the highly adaptive nature and damage-repair capabilities of malignant tumors strongly limit the efficacy of treatments based on a single treatment mode. To address this challenge, a self-reinforced bimetallic Mito-Jammer is developed by incorporating doxorubicin (DOX) and calcium peroxide (CaO2) into hyaluronic acid (HA) -modified metal-organic frameworks (MOF). After cellular, Mito-Jammer dissociates into CaO2 and Cu2+ in the tumor microenvironment. The exposed CaO2 further yields hydrogen peroxide (H2O2) and Ca2+ in a weakly acidic environment to strengthen the Cu2+-based Fenton-like reaction. Furthermore, the combination of chemodynamic therapy and Ca2+ overload exacerbates ROS storms and mitochondrial damage, resulting in the downregulation of intracellular adenosine triphosphate (ATP) levels and blocking of Cu-ATPase to sensitize cuproptosis. This multilevel interaction strategy also activates robust immunogenic cell death and suppresses tumor metastasis simultaneously. This study presents a multivariate model for revolutionizing mitochondria damage, relying on the continuous retention of bimetallic ions to boost cuproptosis/immunotherapy in cancer.

Layer-by-Layer Nanoparticles for Calcium Overload in situ Enhanced Reactive Oxygen Oncotherapy.

Background: Challenges such as poor drug selectivity, non-target reactivity, and the development of drug resistance continue to pose significant obstacles in the clinical application of cancer therapeutic drugs. To overcome the limitations of drug resistance in chemotherapy, a viable treatment strategy involves designing multifunctional nano-platforms that exploit the unique physicochemical properties of tumor microenvironment (TME). Methods: Herein, layer-by-layer nanoparticles with polyporous CuS as delivery vehicles, loaded with a sonosensitizer (tetra-(4-aminophenyl) porphyrin, TAPP) and sequentially functionalized with pH-responsive CaCO3, targeting group hyaluronic acid (HA) were designed and synthesized for synergistic treatment involving chemodynamic therapy (CDT), sonodynamic therapy (SDT), photothermal therapy (PTT), and calcium overload. Upon cleavage in an acidic environment, CaCO3 nanoparticles released TAPP and Ca2+, with TAPP generating 1O2 under ultrasound trigger. Exposed CuS produced highly cytotoxic ·OH in response to H2O2 and also exhibited a strong PTT effect. Results: CuS@TAPP-CaCO3/HA (CTCH) delivered an enhanced ability to release more Ca2+ under acidic conditions with a pH value of 6.5, which in situ causes damage to HeLa mitochondria. In vitro and in vivo experiments both demonstrated that mitochondrial dysfunction greatly amplified the damage caused by reactive oxygen species (ROS) to tumor, which strongly confirms the synergistic effect between calcium overload and reactive oxygen therapy. Conclusion: Collectively, the development of CTCH presents a novel therapeutic strategy for tumor treatment by effectively responding to the acidic TME, thus holding significant clinical implications.

GSH/pH Dual Activatable Cross-linked and Fluorinated PEI for Cancer Gene Therapy Through Endogenous Iron De-Hijacking and in Situ ROS Amplification.

Ferroptosis-related cancer therapy is limited by insufficient Fe2+ /Fe3+ redox pair and hydrogen peroxide (H2 O2 ) for producing lethal hydroxyl radicals (·OH). Although exogenous iron or ROS-producing drugs can enhance ferroptosis, exploiting endogenous iron (labile iron pool, LIP) stored in ferritin and promoting ROS generation may be safer. Herein, a metal/drug-free nanomedicine is developed for responsive LIP release and H2 O2 generation on the mitochondria membranes, amplifying hydroxyl radical production to enhance ferroptosis-mediated antitumor effects. A glutathione(GSH)/pH dual activatable fluorinated and cross-linked polyethyleneimine (PEI) with dialdehyde polyethylene glycol layer nanocomplex loaded with MTS-KR-SOD (Mitochondria-targeting-sequence-KillerRed-Superoxide Dismutase) and CRISPR/Cas9-CA IX (Carbonic anhydrase IX (CA IX)) plasmids (FP@MC) are developed for enhanced ferroptosis through endogenous iron de-hijacking and in situ ROS amplification. Two plasmids are constructed to knockdown CA IX and translate KillerRed-SOD recombinant protein specifically on mitochondria membranes, respectively. The CA IX knockdown acidifies the intracellular environment, leading the release of LIP from ferritin as a "flare" to initiate endogenous chemodynamic therapy. Meanwhile, MTS-KR-SOD generates H2 O2 when irradiated by a 590 nm laser to assist chemodynamic therapy, leading to ROS amplification for mitochondria damage and lipid peroxide accumulation. The combined therapeutic effects aggravate cancer ferroptosis and suppress tumor growth, providing a new paradigm for amplifying ROS and iron ions to promote ferroptosis-related cancer therapy.