Cell death: All roads lead to mitochondria

Thiolutin Is a Potential Fungicide for Controlling Phytophthora nicotianae and Its Mechanistic Study

Phytophthora nicotianae is a destructive plant pathogen that causes significant agricultural losses, with current chemical control strategies leading to resistance and environmental concerns. This study identified thiolutin, a dithiopyrrolone antibiotic from Streptomyces luteireticuli ASG80, as a potent antifungal agent against multiple Phytophthora species. Thiolutin exhibited strong in vitro activity, with an EC50 value of 0.8266 μg/mL, significantly reduced disease incidence and Phytophthora abundance in vivo, outperforming conventional fungicides such as metalaxyl. Transcriptomic analysis revealed significant downregulation of key genes in energy metabolism pathways, including mitochondrial function and oxidative phosphorylation, indicating impaired energy production and cellular metabolism. Microscopic and biochemical analyses further demonstrated that thiolutin disrupts cell membrane integrity, induces reactive oxygen species accumulation, and damages mitochondria, ultimately leading to energy metabolism disruption and fungal programmed cell death. These findings highlight thiolutin's potential as an environmentally friendly alternative for managing Phytophthora-induced plant diseases.

Molecular mechanism of programmed cell death in drug-induced neuronal damage: A special focus on ketamine-induced neurotoxicity

In recent years, the abuse of ketamine as a recreational drug has been growing, and has become one of the most widely abused drugs. Continuous using ketamine poses a risk of drug addiction and complications such as attention deficit disorder, memory loss and cognitive decline. Ketamine-induced neurotoxicity is thought to play a key role in the development of these neurological complications. In this paper, we focus on the molecular mechanisms of ketamine-induced neurotoxicity. According to our analyses, drugs in causing neurotoxicity are closely associated with programmed cell death (PCD) such as apoptosis, autophagy, necroptosis, pyroptosis, and Ferroptosis. Therefore, this review will collate the existing mechanisms of programmed death in ketamine-induced neurotoxicity as well as explore the possible mechanisms by outlining the mechanisms of programmed death in other drug-induced neurotoxicity, which may be helpful in identifying potential therapeutic targets for neurotoxicity induced by ketamine abuse.

Identification of mitochondrial function and programmed cell death associated key biomarkers and the circRNA-miRNA-mRNA regulatory network in systemic lupus erythematosus

Objectives

Systemic Lupus Erythematosus (SLE) is a highly heterogeneous autoimmune disease with complex pathogenic mechanisms. Mitochondrial function and programmed cell death (PCD) play important roles in SLE. This study aims to screen biomarkers related to mitochondrial function and programmed cell death in SLE and analyze their underlying mechanisms.

Methods

SLE-related databases were derived from the GEO database, where three SLE databases were merged into one database as the training set. Genes related to mitochondrial function and PCD were sourced from the MitoCarta 3.0 database. Key genes were identified through bioinformatics and machine learning, and their expression levels and diagnostic efficacy were validated using two SLE-related datasets as the validation set. The relationship between diagnostic genes and immune cells was analyzed through CIBERSORT immune infiltration analysis. Diagnostic genes-related miRNAs were predicted using online databases. Differential circRNAs were screened in SLE circRNA datasets, and the relationship between circRNAs and miRNAs is predicted through circbank, finally constructing a circRNA-miRNA-mRNA ceRNA regulatory network.

Results

From the 448 differential genes in the SLE training set, two key genes, IFI27 and LAMP3, were identified through machine learning and WGCNA. Enrichment analysis revealed that they were mainly enriched in pathways such as cell cycle, systemic lupus erythematosus, cytosolic DNA sensing pathway, toll-like receptor (TLR) signaling pathway and nod-like receptor (NLR) signaling pathway. Immune infiltration analysis found that compared with normal group, 11 immune cells were differentially expressed, with IFI27 related 9 types of immune cells and LAMP3 related 10 types of immune cells. The final constructed circRNA-miRNA-mRNA ceRNA regulatory network consists of 2 mRNAs, 5 miRNAs, and 4 circRNAs.

Conclusion

Our study ultimately identified two biomarkers (IFI27 and LAMP3) related to mitochondrial function and programmed cell death that play an important role in SLE. In the future, IFI27 and LAMP3 have the potential to become important biomarkers in the diagnosis and treatment of SLE. Their role in the immune response may provide new strategies for the treatment of SLE.

Harnessing natural saponins: Advancements in mitochondrial dysfunction and therapeutic applications

BACKGROUND

Mitochondrial dysfunction plays a crucial role in the development of a variety of diseases, notably neurodegenerative disorders, cardiovascular diseases, metabolic syndrome, and cancer. Natural saponins, which are intricate glycosides characterized by steroidal or triterpenoid structures, have attracted interest due to their diverse pharmacological benefits, including anti-inflammatory, antiviral, and anti-aging effects.

PURPOSE

This review synthesizes recent advancements in understanding mitochondrial dysfunction and explores how saponins can modulate mitochondrial function. It focuses on their potential applications in neuroprotection, cardiovascular health, and oncology.

STUDY DESIGN

The review incorporates a comprehensive literature analysis, highlighting the interplay between saponins and mitochondrial signaling pathways. Specific attention is given to the effects of saponins like ginsenoside Rg2 and 20(S)-protopanaxatriol on mitophagy and their neuroprotective, anti-aging, and synergistic therapeutic effects when combined.

METHODS

We conducted a comprehensive review of current research and clinical trials using PubMed, Google Scholar, and SciFinder databases. The search focused on saponins' role in mitochondrial function and their therapeutic effects, including "saponins", "mitochondria" and "mitochondrial function". The analysis primarily focused on articles published between 2011 and 2024.

RESULTS

The findings indicate that certain saponins can enhance mitophagy and modulate mitochondrial signaling pathways, showing promise in neuroprotection and anti-aging. Additionally, combinations of saponins have demonstrated synergistic effects in myocardial protection and cancer therapy, potentially improving therapeutic outcomes.

CONCLUSION

Although saponins exhibit significant potential in modulating mitochondrial functions and developing innovative therapeutic strategies, their clinical applications are constrained by low bioavailability. Rigorous clinical trials are essential to translate these findings into effective clinical therapies, ultimately improving patient outcomes through a deeper understanding of saponins' impact on mitochondrial function.

1-Bromopropane induces mitochondrial damage and lipid metabolism imbalance in respiratory epithelial cells through the PGC-1α/PPARα pathway

1-Bromopropane (1-BP) has become a new air pollutant in occupational and living environments due to its advantages in industrial applications and as a representative compound of volatile organic compounds (VOCs). As an irritant, its damaging effects on respiratory epithelium are worthy of further study. This study aimed to explore the damage effects of 1-BP on respiratory epithelial cells and reveal its underlying mechanisms. We found that exposure to 1-BP markedly reduced the viability of respiratory epithelial cells in a dose-dependent manner, and induced oxidative stress and vacuolation changes in respiratory epithelial cells. Subsequently, through RNA-seq analysis, we identified that the 1-BP-induced damage of respiratory epithelial cells was related to the mitochondrial function pathway and further verified that 1-BP caused mitochondrial damage of respiratory epithelial cells, which was manifested as ultrastructural damage, decreased membrane potential, ATP, and MFN2 levels. These damages were associated with cellular oxidative stress responses. Pretreating cells with the agonists of PGC-1α and PPARα, we revealed that 1-BP affected the expression of PGC-1α and interfered with its coactivator PPARα levels, causing an increase in the expression of lipid-producing genes and a decrease in the expression of lipid-decomposing genes, thus leading to a lipid accumulation in respiratory epithelial cells. Meanwhile, the imbalance of lipid metabolism in respiratory epithelial cells induced by 1-BP further caused mitochondrial damage, and the effect was bidirectional. These findings suggested that 1-BP has a potential role in inducing respiratory epithelial cell damage and is associated with the PGC-1α/PPARα signaling pathway.

Charge Separation-Engineered Piezoelectric Ultrathin Nanorods Modulate Tumor Stromal Microenvironment and Enhance Cell Immunogenicity for Synergistically Piezo-Thermal-Immune Therapy

The tumor microenvironment (TME) is characterized by hypoxia and low immunogenicity, with a dense and rigid extracellular matrix (ECM) that impedes the diffusion of therapeutic agents and immune cells, thereby limiting the efficacy of immunotherapy. To overcome these challenges, an oxygen defect piezoelectric-photothermal sensitizer, bismuth vanadate nanorod-supported platinum nanodots (BVP) is developed. The integration of platinum enhances the photothermal effect and improves charge separation efficiency under ultrasound, leading to increased heat generation and the production of reactive oxygen species (ROS) and oxygen. Platinum also catalyzes the conversion of hydrogen peroxide in the TME to oxygen, which serves as both a ROS source and a means to alleviate tumor hypoxia, thereby reversing the immunosuppressive TME. Moreover, the coordination of bismuth ions with glutathione further amplifies cellular oxidative stress. The generated heat and ROS not only denature the collagen in the ECM, facilitating the deeper penetration of BVP into the tumor but also induce immunogenic cell death in tumor cells. Through the "degeneration and penetration" strategy, photoacoustic therapy effectively activates immune cells, inhibiting both tumor growth and metastasis. This study introduces a pioneering approach in the design of antitumor nanomedicines aimed at reversing the immunosuppressive characteristics of the TME.

A genetically encoded fluorescent protein sensor for mitochondrial membrane damage detection

Mitochondria are essential cellular organelles; detecting mitochondrial damage is crucial in cellular biology and toxicology. Compared with existing chemical probe detection methods, genetically encoded fluorescent protein sensors can directly indicate cellular and molecular events without involving exogenous reagents. In this study, we introduced a molecular sensor system, MMD-Sensor, for monitoring mitochondrial membrane damage. The sensor consists of two molecular modules. Module I is a fusion structure of the mitochondrial localization sequence (MLS), AIF cleavage site sequence (CSS), nuclear localization sequence (NLS), N-terminus of mNeonGreen and mCherry. Module II is a fusion structure of the C-terminus of mNeonGreen, NLS sequence, and mtagBFP2. Under normal condition, Module I is constrained in the inner mitochondrial membrane anchored by MLS, while Module II is restricted to the nucleus by its NLS fusion component. If the mitochondrial membrane is damaged, CSS is cut from the inner membrane, causing Module I to shift into the nucleus guided by the NLS fusion component. After Module I enters the nucleus, the N- and C-terminus of mNeonGreen meet each other and rebuild its intact 3D structure through fragment complementation and thus generates green fluorescence in the nucleus. Dynamic migration of red fluorescence from mitochondria to the nucleus and generation of green fluorescence in the nucleus indicate mitochondrial membrane damage. Using the MMD-Sensor, mitochondrial membrane damage induced by various reagents, such as uncoupling agents, ATP synthase inhibitors, monovalent cationic carriers, and ROS, in HeLa and 293T cells are directly observed and evaluated.

Selenadiazole-Induced Hela Cell Apoptosis through the Redox Oxygen Species-Mediated JAK2/STAT3 Signaling Pathway

Cervical cancer is a significant global health concern, and novel therapeutic strategies are continually being sought to combat this disease. In recent years, selenadiazole found latent therapeutic effects on tumors. Herein, investigating the mechanism of selenadiazole in Hela cells holds promise for advancing cervical cancer treatment. Hela cells, a widely utilized model for studying cervical cancer, were treated with selenadiazole, and cell viability was assessed by using the cell counting kit-8 (CCK-8) assay. Changes in mitochondrial membrane potential were evaluated using JC-1 staining, while apoptosis induction was examined using AnnexinV-PI double staining. Intracellular ROS levels were measured by using specific fluorescent probes and the ELIASA system. Additionally, Western blotting was performed to assess the activation of related proteins in response to selenadiazole. Data analysis was performed using GraphPad. Exposure to selenadiazole led to a substantial increase in intracellular redox oxygen species (ROS) levels in Hela cells. Importantly, the induction of ROS by selenadiazole was associated with a marked increase in mitochondrial apoptosis, as evidenced by elevated levels of AnnexinV-positive cells, the JC-1 monomer, caspase-9, and Bcl-2. Furthermore, activation of the JAK2/STAT3 pathway was observed following the selenadiazole treatment. Selenadiazole holds the potential to suppress tumor growth in cervical cancer cells by increasing reactive oxygen species (ROS) levels and inducing mitochondrial apoptosis via the JAK2/STAT3 pathway. This study offers valuable insights into potential cervical cancer therapies and underscores the need for further research into the specific mechanisms of selenadiazole.

CyHV-2 infection triggers mitochondrial-mediated apoptosis in GiCF cells by upregulating the pro-apoptotic gene ccBAX

Apoptosis is a physiological cell death phenomenon, representing one of the fundamental physiological mechanisms for maintaining homeostasis in living organisms. Previous studies have observed typical apoptotic features in Carassius auratus gibelio caudal fin cell (GiCF) infected with Cyprinid herpesvirus 2 (CyHV-2), and found a significant up-regulation of ccBAX expression in these infected cells. However, the specific apoptotic mechanism involved remains unclear. In this study, we utilized the GiCF cell line to investigate the apoptotic mechanism during CyHV-2 infection. Immunofluorescence staining revealed translocation of ccBAX into mitochondria upon CyHV-2 infection. Flow cytometry analysis demonstrated that overexpression of ccBAX expedited virus-induced apoptosis, characterized by heightened mitochondrial depolarization, increased transcriptional levels of Cytochrome c (Cyto c) in both the cytoplasm and mitochondria, and augmented Caspase 3/7 enzyme activity. Bax inhibitor peptide V5 (BIP-V5), an inhibitor interfering with the function of Bax proteins, inhibited Bax-mediated apoptotic events through the mitochondrial pathway and attenuated apoptosis induced by CyHV-2. In this study, it was identified for the first time that CyHV-2 induces apoptosis via the mitochondrial pathway in GiCF cells, bridging an important gap in our understanding regarding cell death mechanisms induced by herpesvirus infections in fish species. These findings provide a theoretical basis for comprehending viral apoptotic regulation mechanisms and the prevention and control of cellular pathologies caused by CyHV-2 infection.

Mitochondria-targetable small molecule fluorescent probes for the detection of cancer-associated biomarkers: A review

Cancer represents a global threat to human health, and effective strategies for improved cancer early diagnosis and treatment are urgently needed. The detection of tumor biomarkers has been one of the important auxiliary means for tumor screening and diagnosis. Mitochondria are crucial subcellular organelles that produce most chemical energy used by cells, control metabolic processes, and maintain cell function. Evidence suggests the close involvement of mitochondria with cancer development. As a consequence, the identification of cancer-associated biomarker expression levels in mitochondria holds significant importance in the diagnosis of early-stage diseases and the monitoring of therapy efficacy. Small-molecule fluorescent probes are effective for the identification and visualization of bioactive entities within biological systems, owing to their heightened sensitivity, expeditious non-invasive analysis and real-time detection capacities. The design principles and sensing mechanisms of mitochondrial targeted fluorescent probes are summarized in this review. Additionally, the biomedical applications of these probes for detecting cancer-associated biomarkers are highlighted. The limitations and challenges of fluorescent probes in vivo are also considered and some future perspectives are provided. This review is expected to provide valuable insights for the future development of novel fluorescent probes for clinical imaging, thereby contributing to the advancement of cancer diagnosis and treatment.

Jianpi Shengqing Huazhuo Formula improves abnormal glucose and lipid metabolism in obesity by regulating mitochondrial biogenesis

ETHNOPHARMACOLOGICAL RELEVANCE

Jianpi Shengqing Huazhuo Formula (JSH) is a modified prescription based on traditional Chinese medicine theory and classic prescriptions (Buzhong Yiqi Decoction and Yuye Decoction). It has been found that JSH has a good effect on obese patients with early abnormal glucose and lipid metabolism. Therefore, this experiment was conducted to study its clinical efficacy and pharmacological effect.

AIM OF THE STUDY

To observe the clinical efficacy of JSH and explore the mechanism of the formula to improve glucose and lipid metabolism in obese rats.

MATERIALS AND METHODS

1.

CLINICAL OBSERVATION

10 overweight/obese patients with abnormal glucose and lipid metabolism were selected to observe the indicators of serum glucose, serum lipids and liver damage of the patients before and after treatment with JSH. 2. Animal experiments: Fifty Sprague-Dawley (SD) rats were randomly divided into control group, model group, Metformin group (120 mg/kg/day), JSH-L group (5 g/kg/day) and JSH-H group (20 g/kg/day), with 10 rats in each group. The obese SD rat model was produced by feeding 60% high-fat diet for 8 weeks, and the drug group was given prophylactic administration for 8 weeks. At the end of the experiment, body weight, abdominal fat, plasma glucose, plasma lipids, plasma alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were measured. The levels of interleukin-6 (IL-6), interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) in plasma were detected by Elisa, and the changes of malondialdehyde (MDA), glutathione (GSH) and catalase (CAT) in plasma and liver tissue were detected by kits. The pathological changes and lipid deposition in liver were observed by HE staining and oil red O staining, and the changes in the number of mitochondria in liver cells were observed by transmission electron microscopy. RT-qPCR and Western Blot (WB) were used to detect the mitochondrial regulation-related indicators PGC-1α, NRF1, TFAM, MFN2, DRP1 and apoptosis-related indicators Bcl-2, Bax, caspase 8 in liver tissue.

RESULTS

1.

CLINICAL OBSERVATION

After one month administration, the patient's body weight, BMI, 2 h oral glucose tolerance test (2hOGTT), glycated hemoglobin (HbA1c), triglyceride (TG), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C) decreased significantly, and the indicators of liver damage AST and ALT also decreased significantly. 2. Animal experiments: JSH can significantly reduce body weight and abdominal fat area, improve glucose and lipid metabolism, and also reduce plasma IL-6, IL-1β and TNF-α content in obese rats, and improve oxidative stress; HE staining and oil red O staining also showed that JSH can alleviate liver damage and lipid deposition in the liver. Further observations of liver cell ultrastructure showed that JSH can ameliorate the reduction of liver mitochondria caused by a high-fat diet and promote the expression of indicators of mitochondrial biogenesis related to PGC-1α, NRF1, and TFAM. Moreover, JSH could promote the expression of MFN2 and DRP1, decrease Bcl-2 and increase Bax in the liver.

CONCLUSIONS

1.

CLINICAL OBSERVATION

JSH can reduce body weight, serum glucose, serum lipid, and liver injury in overweight/obese patients. 2. Animal experiments: JSH regulates PGC-1α/NRF1/TFAM signaling pathway promotes liver mitochondrial biogenesis, improves glucose and lipid metabolism in obese rats, and regulates mitochondrial dependent apoptosis indicators Bcl-2/Bax to reduce liver injury.