Role of Mitochondrial Calcium and the Permeability Transition Pore in Regulating Cell Death

Utilizing engineered extracellular vesicles as delivery vectors in the management of ischemic stroke: a special outlook on mitochondrial delivery

Ischemic stroke is a secondary cause of mortality worldwide, imposing considerable medical and economic burdens on society. Extracellular vesicles, serving as natural nano-carriers for drug delivery, exhibit excellent biocompatibility in vivo and have significant advantages in the management of ischemic stroke. However, the uncertain distribution and rapid clearance of extracellular vesicles impede their delivery efficiency. By utilizing membrane decoration or by encapsulating therapeutic cargo within extracellular vesicles, their delivery efficacy may be greatly improved. Furthermore, previous studies have indicated that microvesicles, a subset of large-sized extracellular vesicles, can transport mitochondria to neighboring cells, thereby aiding in the restoration of mitochondrial function post-ischemic stroke. Small extracellular vesicles have also demonstrated the capability to transfer mitochondrial components, such as proteins or deoxyribonucleic acid, or their sub-components, for extracellular vesicle-based ischemic stroke therapy. In this review, we undertake a comparative analysis of the isolation techniques employed for extracellular vesicles and present an overview of the current dominant extracellular vesicle modification methodologies. Given the complex facets of treating ischemic stroke, we also delineate various extracellular vesicle modification approaches which are suited to different facets of the treatment process. Moreover, given the burgeoning interest in mitochondrial delivery, we delved into the feasibility and existing research findings on the transportation of mitochondrial fractions or intact mitochondria through small extracellular vesicles and microvesicles to offer a fresh perspective on ischemic stroke therapy.

Mechanism of Ca2+ overload caused by STIM1/ORAI1 activation of store-operated Ca2+ entry (SOCE) in hydrogen peroxide-induced mitochondrial damage and apoptosis in human primary melanocytes

BACKGROUND

Vitiligo is a common depigmentation disorder. Oxidative stress in melanocytes is thought to be the primary cause of vitiligo. Imbalances in cellular calcium ion (Ca2+) levels may be associated with the onset and progression of various diseases through a process that has been linked to oxidative stress. The purpose of this study was to investigate the regulatory mechanism by which Ca2+ levels change in normal human melanocytes (NHMs) under oxidative stress, thereby providing new insights and potential clinical therapeutic targets for the pathogenesis and treatment of vitiligo.

METHODS AND RESULTS

Single-cell RNA sequencing data from vitiligo patients were analyzed using bioinformatics techniques. NHMs were treated with hydrogen peroxide (H2O2), store-operated Ca2+ entry (SOCE) blocker BTP2, and SOCE agonist cyclopiazonic acid. Flow cytometry was used to detect Ca2+ levels, apoptosis rates, intra-mitochondrial reactive oxygen species (ROS) levels, and mitochondrial membrane potential (MMP) damage. The expression levels of target proteins were detected using immunofluorescence, quantitative real-time PCR, and western blotting. We found that H2O2-induced oxidative stress resulted in significantly increased intracellular Ca2+ levels, upregulation of stromal interaction molecule 1 (STIM1) and calcium release-activated calcium channel protein (ORAI1), and mitochondrial dysfunction. Inhibition of SOCE and small interfering RNA-mediated silencing of STIM1/ORAI1 expression lowered mitochondrial levels of ROS and oxidative stress-induced intracellular Ca2+ overload and restored MMP, ultimately terminating oxidative stress-induced apoptosis.

CONCLUSIONS

Oxidative stress upregulates STIM1/ORAI1 expression, leading to melanocyte apoptosis via increased Ca2+ influx, whereas inhibition of SOCE protects melanocytes against oxidative stress-induced damage.

Donafenib Induces Mitochondrial Dysfunction in Liver Cancer Cells via DRP1

Hepatocellular carcinoma (HCC) represents a significant global health challenge, characterized by a high incidence rate. Mitochondria have emerged as an important therapeutic target for HCC. Donafenib, a multi-receptor tyrosine kinase inhibitor, has been approved for the treatment of advanced HCC. However, the underlying mechanisms remain to be elucidated. In this study, we aim to investigate the effects of Donafenib on mitochondrial function in HCC cells. Firstly, we show that Donafenib induces mitochondrial oxidative stress in SNU-449 liver cancer cells by increasing mitochondrial ROS while reducing glutathione peroxidase (GPx) activity and the expression of Mn-SOD. We also demonstrate that Donafenib decreases mitochondrial membrane potential (MMP) and induces the opening of the mitochondrial permeability transition pore (mPTP). Furthermore, Donafenib reduces mitochondrial respiratory rate, COX IV activity, and ATP production. Notably, Donafenib induces mitochondrial fragmentation and reduces mitochondrial length by increasing the expression of DRP1, without affecting Mfn1 or Mfn2. Silencing of DRP1 protects against mitochondrial dysfunction induced by Donafenib, indicating that DRP1 plays a key role in mediating Donafenib's effects on mitochondrial function in HCC cells.

Calcium-mediated regulation of mitophagy: implications in neurodegenerative diseases

Calcium signaling plays a pivotal role in diverse cellular processes through precise spatiotemporal regulation and interaction with effector proteins across distinct subcellular compartments. Mitochondria, in particular, act as central hubs for calcium buffering, orchestrating energy production, redox balance and apoptotic signaling, among others. While controlled mitochondrial calcium uptake supports ATP synthesis and metabolic regulation, excessive accumulation can trigger oxidative stress, mitochondrial membrane permeabilization, and cell death. Emerging findings underscore the intricate interplay between calcium homeostasis and mitophagy, a selective type of autophagy for mitochondria elimination. Although the literature is still emerging, this review delves into the bidirectional relationship between calcium signaling and mitophagy pathways, providing compelling mechanistic insights. Furthermore, we discuss how disruptions in calcium homeostasis impair mitophagy, contributing to mitochondrial dysfunction and the pathogenesis of common neurodegenerative diseases.

The Mitochondria-Targeted Micelle Inhibits Alzheimer's Disease Progression by Alleviating Neuronal Mitochondrial Dysfunction and Neuroinflammation

Mitochondrial dysfunction plays an important role in neuroinflammation and cognitive impairment in Alzheimer's disease (AD). Herein, this work designs a mitochondria-targeted micelle CsA-TK-SS-31 (CTS) to block the progression of AD by simultaneously alleviating mitochondrial dysfunction in microglia and neurons. The mitochondria-targeted peptide SS-31 drives cyclosporin A (CsA) to penetrate the blood-brain barrier (BBB) and delivers CsA to mitochondria of microglia and neurons in the brains of 5 × FAD mice. Under the high level of reactive oxygen species (ROS) environment in damaged mitochondria of microglia and neurons, the linker (thioketal, TK) between CsA and SS-31 is broken and CsA and SS-31 are released while consuming ROS in the microenvironment. The released CsA and SS-31 synergistically restore the mitochondrial membrane potential and the balance between the fission and fusion of mitochondria, which subsequently protect neurons from apoptosis and reduce the activation of microglia in the brains of 5 × FAD mice. Ultimately, the neuroinflammation and cognitive impairment of 5 × FAD mice are ameliorated. This research provides a synergistic treatment strategy for AD through alleviating mitochondrial dysfunction to reduce neuroinflammation and restore the function of neurons simultaneously.

Insights into mitochondrial creatine kinase: examining preventive role of creatine supplement in doxorubicin-induced cardiotoxicity

Doxorubicin (Dox) is an effective and commonly used anticancer drug; however, it leads to several side effects including cardiotoxicity which contributes to poor quality of life for cancer patients. Creatine (Cr) is a promising intervention to alleviate Dox-induced cardiotoxicity. This study aimed to examine the effects of Cr beforeDox on cardiac mitochondrial creatine kinase (MtCK). Male rats were randomly assigned to one of two 4-week Cr feeding interventions (standard Cr diet or Cr loading diet) or a control diet (Con, n = 20). Rats in the standard Cr diet (Cr1, n = 20) were fed 2% Cr for 4-weeks. Rats in the Cr loading diet (Cr2, n = 20) were fed 4% Cr for 1-week followed by 2% Cr for 3-weeks. After 4-weeks, rats received either a bolus injection of 15 mg/kg Dox or a placebo saline injection (Sal). Five days post-injections left ventricle (LV) was excised and analyzed for MtCK expression using Western blot and ELISA. A significant drug effect was observed for LV mass (p < 0.05), post hoc testing revealed LV mass of Con + Dox and Cr2 + Dox was significantly lower than Con + Sal (p < 0.05). A significant drug effect was observed for MtCK (p = 0.03) through Western blot. A significant drug effect (p = 0.03) and interaction (p = 0.02) was observed for MtCK using ELISA. Post hoc testing revealed that Cr2 + Dox had significantly higher MtCK than Cr1 + Sal and Cr2 + Sal. Data suggest that a reduction in LV mass and MtCK may contribute to Dox-induced cardiotoxicity, and Cr supplementation may play a potential role in mitigating cardiotoxicity by preserving mitochondrial CK.

The Role of P53 in Myocardial Ischemia-Reperfusion Injury

PURPOSE

P53 is one of the key tumor suppressors. In normal cells, p53 is maintained at low levels by the ubiquitination of the ubiquitinated ligase MDM2. In contrast, under stress conditions such as DNA damage and ischemia, the interaction between p53 and MDM2 is blocked and activated by phosphorylation and acetylation, thereby mediating the trans-activation of p53 through its target genes to regulate a variety of cellular responses. Previous studies have shown that the expression of p53 is negligible in normal myocardium, tends to increase in myocardial ischemia and is maximally induced in ischemia-reperfused myocardium, demonstrating a possible key role of p53 in the development of MIRI. In this review, we detail and summarize recent studies on the mechanism of action of p53 in MIRI and describe the therapeutic agents targeting the relevant targets to provide new strategies for the prevention and treatment of MIRI.

METHODS

We collected 161 relevant papers mainly from Pubmed and Web of Science (search terms "p53" and "myocardial ischemia-reperfusion injury"). After that, we selected pathway studies related to p53 and classified them according to their contents. We eventually analyzed and summarized them.

RESULTS AND CONCLUSION

In this review, we detail and summarize recent studies on the mechanism of action of p53 in MIRI and validate its status as an important intermediate affecting MIRI. On the one hand, p53 is regulated and modified by multiple factors, especially non-coding RNAs; on the other hand, p53 regulates apoptosis, programmed necrosis, autophagy, iron death and oxidative stress in MIRI through multiple pathways. More importantly, several studies have reported medications targeting p53-related therapeutic targets. These medications are expected to be effective options for the alleviation of MIRI, but further safety and clinical studies are needed to convert them into clinical applications.

Unraveling the role of the P2X7 receptor in cancer radioresistance: Molecular insights and therapeutic implications

The P2X7 receptor, a key player in purinergic signaling, is a crucial factor in modulating the response of cancer cells to radiotherapy. The aim of this study was to elucidate the molecular mechanisms by which P2X7 receptor activation contributes to radioresistance in different cancer types. P2X7 receptor signaling influences cellular processes such as DNA damage repair and inflammatory responses, thereby improving tumor survival after radiation exposure. Activation of the P2X7 receptor leads to changes in the tumor microenvironment and promotes an adaptive response that enables cancer cells to resist therapeutic interventions. Therefore, targeting the P2X7 receptor could represent a new therapeutic strategy against cancer. By linking molecular insights with therapeutic implications, this research highlights the P2X7 receptor as a promising target for overcoming radioresistance in cancer therapy and paves the way for novel combination approaches that could significantly improve patient outcomes.

Synaptotagmin-1 attenuates myocardial programmed necrosis and ischemia/reperfusion injury through the mitochondrial pathway

Programmed necrosis/necroptosis greatly contributes to the pathogenesis of cardiac disorders including myocardial infarction, ischemia/reperfusion (I/R) injury and heart failure. However, the fundamental mechanism underlying myocardial necroptosis, especially the mitochondria-dependent death pathway, is poorly understood. Synaptotagmin-1 (Syt1), a Ca2+ sensor, is originally identified in nervous system and mediates synchronous neurotransmitter release. The later findings of Syt1 expressions in many non-neuronal tissues including muscles suggest that Syt1 may exert important functions beyond regulation of neurotransmitter release. Syt1 is highly expressed in cardiomyocytes and has been used as an extracellular molecular probe for SPECT imaging of cardiac cell death in acute myocardial infarction. However, whether Syt1 functions in the pathogenesis of cardiac disorders and what is the molecular etiology have not yet been clarified. We showed here that Syt1 expression was significantly down-regulated in mice I/R injured heart tissues, H2O2-challenged cardiomyocytes and hypoxia/reoxygenation (H/R)-damaged cardiomyocytes. Enforced expression of Syt1 significantly inhibited myocardial necrotic cell death and interstitial fibrosis, and improved cardiac function in mice subjected to I/R operation. In exploring the underlying mechanisms, we found that Syt1 interacted with Parkin and promoted Parkin-catalyzed CypD ubiquitination, thus inhibited mitochondrial membrane permeability transition pore (mPTP) opening and ultimately suppressed cardiomyocyte necrosis. We further found that Syt1 expression was negatively regulated by miR-193b-3p. MiR-193b-3p regulated cardiomyocyte necrosis and mPTP opening by targeting Syt1. Our present work revealed a novel regulatory model of myocardial necrosis composed of miR-193b-3p, Syt1, Parkin, and CypD, which may provide potential therapeutic targets and strategies for heart protection.

Microenvironment-induced programmable nanotherapeutics restore mitochondrial dysfunction for the amelioration of non-alcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a metabolic liver disorder with severe complications. Mitochondrial dysfunction due to over-opening of the mitochondrial permeability transition pore (mPTP) in liver cells plays a central role in the development and progression of NAFLD. Restoring mitochondrial function is a promising strategy for NAFLD therapy. Herein, we designed and developed a microenvironment-induced programmable nanotherapeutic to restore mitochondrial function and ameliorate NAFLD. Cyclosporine A (CsA), as a highly effective inhibitors of the opening of mPTP, was chosen in the present work. Nanotherapeutics were prepared by assembling two structurally simple multifunctional glucosamine derivatives: dextran-grafted galactose (Dex-Gal) and Dex-triphenylphosphine (Dex-TPP). Galactose units in the nanotherapeutics guide the hepatocyte-specific uptake. Detachment of galactose from acidic lysosomes via Schiff base cleavage exposes the TPP moieties, which subsequently steers the nanotherapeutics to escape from lysosomes and target mitochondria through an enhanced positive charge, enabling precise in situ drug delivery. Simultaneously, the nanotherapeutics improved mitochondrial dysfunction by inhibiting palmitic acid-induced opening of the mitochondrial permeability transition pore in HepG2 cells, maintaining mitochondrial membrane potential, and decreasing reactive oxygen species production. Furthermore, CsA@Dex-Gal/TPP accumulated in the livers of NAFLD mice, restored mitochondrial autophagy, regulated abnormalities in glucose and lipid metabolism, and improved hepatic lipid deposition. This study offers a new cascading strategy for targeting liver cell mitochondria to treat NAFLD and other mitochondria-associated diseases. STATEMENT OF SIGNIFICANCE: We design microenvironment-induced programmable nanotherapeutics for NAFLD Nanotherapeutics has the capabilities of lysosomal escape and mitochondrial targeting Nanotherapeutics improves mitochondrial dysfunction and ameliorates NAFLD This study offers a new cascading strategy for other mitochondria-associated diseases.

Curcumin Improves Hippocampal Cell Bioenergetics, Redox and Inflammatory Markers, and Synaptic Proteins, Regulating Mitochondrial Calcium Homeostasis

Mitochondria produces energy through oxidative phosphorylation (OXPHOS), maintaining calcium homeostasis, survival/death cell signaling mechanisms, and redox balance. These mitochondrial functions are especially critical for neurons. The hippocampus is crucial for memory formation in the brain, which is a process with high mitochondrial function demand. Loss of hippocampal function in aging is related to neuronal damage, where mitochondrial impairment is critical. Synaptic and mitochondrial dysfunction are early events in aging; both are regulated reciprocally and contribute to age-associated memory loss together. We previously showed that prolonged treatment with Curcumin or Mitoquinone (MitoQ) improves mitochondrial functions in aged mice, exerting similar neuroprotective effects. Curcumin has been described as an anti-inflammatory and antioxidant compound, and MitoQ is a potent antioxidant directly targeting mitochondria; however, whether Curcumin exerts a direct impact on the mitochondria is unclear. In this work, we study whether Curcumin could have a mechanism similar to MitoQ targeting the mitochondria. We utilized hippocampal slices of 4-6-month-old C57BL6 mice to assess the cellular changes induced by acute Curcumin treatment ex-vivo compared to MitoQ. Our results strongly suggest that both compounds improve the synaptic structure, oxidative state, and energy production in the hippocampus. Nevertheless, Curcumin and MitoQ modify mitochondrial function differently; MitoQ improves the mitochondrial bioenergetics state, reducing ROS production and increasing ATP generation. In contrast, Curcumin reduces mitochondrial calcium levels and prevents calcium overload related to mitochondrial swelling. Thus, Curcumin is described as a new regulator of mitochondrial calcium homeostasis and could be used in pathological events involving calcium deregulation and excitotoxicity, such as aging and neurodegenerative diseases.

How does mitochondrial Ca2+ change during ischemia and reperfusion? Implications for activation of the permeability transition pore

Cardiac ischemia followed by reperfusion results in cardiac cell death, which has been attributed to an increase of mitochondrial Ca2+ concentration, resulting in activation of the mitochondrial permeability transition pore (PTP). Evaluating this hypothesis requires understanding of the mechanisms responsible for control of mitochondrial Ca2+ in physiological conditions and how they are altered during both ischemia and reperfusion. Ca2+ influx is thought to occur through the mitochondrial Ca2+ uniporter (MCU). However, with deletion of the MCU, an increase in mitochondrial Ca2+ still occurs, suggesting an alternative Ca2+ influx mechanism during ischemia. There is less certainty about the mechanisms responsible for Ca2+ efflux, with contributions from both Ca2+/H+ exchange and a Na+-dependent Ca2+ efflux pathway. The molecular details of both mechanisms are not fully resolved. We discuss this and the contributions of both pathways to the accumulation of mitochondrial Ca2+ during ischemia and reperfusion. We further discuss the role of mitochondrial Ca2+ in activation of the PTP.

Mechanisms of postischemic cardiac death and protection following myocardial injury

Acute myocardial infarction (MI) is a leading cause of death worldwide. Although with current treatment, acute mortality from MI is low, the damage and remodeling associated with MI are responsible for subsequent heart failure. Reducing cell death associated with acute MI would decrease the mortality associated with heart failure. Despite considerable study, the precise mechanism by which ischemia and reperfusion (I/R) trigger cell death is still not fully understood. In this Review, we summarize the changes that occur during I/R injury, with emphasis on those that might initiate cell death, such as calcium overload and oxidative stress. We review cell-death pathways and pathway crosstalk and discuss cardioprotective approaches in order to provide insight into mechanisms that could be targeted with therapeutic interventions. Finally, we review cardioprotective clinical trials, with a focus on possible reasons why they were not successful. Cardioprotection has largely focused on inhibiting a single cell-death pathway or one death-trigger mechanism (calcium or ROS). In treatment of other diseases, such as cancer, the benefit of targeting multiple pathways with a "drug cocktail" approach has been demonstrated. Given the crosstalk between cell-death pathways, targeting multiple cardiac death mechanisms should be considered.

Prognostic signature and therapeutic drug identification for dilated cardiomyopathy based on necroptosis via bioinformatics and experimental validation

Necroptosis, a type of programmed cell death, has been increasingly linked to cardiovascular disease development, yet its role in dilated cardiomyopathy (DCM) remains unclear. In this study, we analyzed the GSE5406 dataset from the GEO database to explore necroptosis-related prognostic signatures in DCM using LASSO regression. We identified five necroptosis-related genes (BID, CAMK2B, GLUL, HSP90AB1, CHMP5) that define a necroptosis-related signature with strong predictive value, evidenced by ROC curve areas of 0.852 and 0.957 in training and test sets, respectively. Our analyses, including GO and GSEA enrichment, focused on pathways associated with high necroptosis-related scores (NRS) and revealed significant immune cell infiltration. Notably, nTreg and iTreg cells were enriched in the high NRS group, while CD8 naive T cells and CD8 T cells positively correlated with NRS. Small molecule drugs fenofibrate, procyclidine, and tienilic acid emerged as potential therapeutic agents for high-risk patients, with fenofibrate showing efficacy in inhibiting DCM progression in an inflammatory animal model. These findings underscore the clinical relevance of necroptosis-related genes in assessing DCM progression and prognosis and highlight their potential for targeted therapeutic development.

Perturbation of calcium homeostasis invokes eryptosis-like cell death in enucleated bone marrow stem cells

Enucleated cells, also known as cytoplasts, are valuable tools with a wide range of applications. However, their potential for bio-engineering is greatly restricted by the short lifespan. We postulated that the enucleation process damages the integrity of the plasma membrane and thus activates a cell death program(s). The results showed that a tiny hole was generated transiently on the plasma membrane when the nucleus was spun off, while force-gated ion channels were activated in response to the pulling by the nucleus. Influx of extracellular calcium stimulated the opening of calcium channels and the release of calcium from endoplasmic reticulum and mitochondria. Long lasting calcium transient increased protein phosphorylation and activated caspase 9 and calpain proteinase activities. Subsequently, mitochondria membrane permeability and Reactive Oxygen Species (ROS) levels were significantly elevated, which eventually led to eryptosis-like cell death. When extracellular calcium was maintained at optimal concentration, the lifespan of enucleated cells was extended; however, huge amounts of vacuoles appeared in the cytoplasm, possibly derived from enlarged autophagosomes. Inhibition of vacuolation by inhibitors of autophagy or in co-culture with primary muscle cells did not rescue cells dying from the paraptosis-like pathway. These results offer valuable insights for further investigation into the intricate mechanisms underlying enucleated cell death.

Role of VDAC1 in hepatocyte apoptosis during acute liver injury in rats induced by obstructive jaundice

Objectives

Exploring the role of VDAC1 in hepatocyte apoptosis during acute liver injury induced by obstructive jaundice.

Materials and Methods

Animal and cell models were established to investigate possible mechanisms during acute liver injury induced by OJ. Blood was collected for liver function assessment. H&E and TEM were employed to observe pathological changes in the liver tissues. Flow cytometry was used to measure the hepatocyte apoptosis. The mitochondrial MPTP assay was employed to assess the mitochondrial function of hepatocytes. IHC, western blot, and qRT-PCR were employed to determine the expression levels of VDAC1. Then, VDAC-siRNA was used to establish a knockdown model. Flow cytometry was used again to measure hepatocyte apoptosis following VDAC1 knockdown.

Results

The serum of rats in the OJ group exhibited a significant increase in liver function. Irregular tissue structure and mitochondrial morphology were observed in the liver tissues of OJ rats. A significant increase in mitochondrial permeability in hepatocytes. The expression levels of VDAC1 were significantly increased in the liver tissue of OJ rats. They were also significantly increased in the hepatocytes, primarily within mitochondrial membranes, determined by western blot in vivo and in vitro. Significant increases in the rates of hepatocyte apoptosis, particularly early apoptosis, were observed in the OJ groups. However, there was a reverse in the rates of hepatocyte apoptosis after knockdown regulation of VDAC1 only within the cells of the OJ group.

Conclusion

The up-regulation of VDAC in liver injury caused by obstructive jaundice may lead to increased early apoptosis of hepatocytes.

The Impact of Calcium Overload on Cellular Processes: Exploring Calcicoptosis and Its Therapeutic Potential in Cancer

The key role of calcium in various physiological and pathological processes includes its involvement in various forms of regulated cell death (RCD). The concept of 'calcicoptosis' has been introduced as a calcium-induced phenomenon associated with oxidative stress and cellular damage. However, its definition remains controversial within the research community, with some considering it a general form of calcium overload stress, while others view it as a tumor-specific calcium-induced cell death. This review examines 'calcicoptosis' in the context of established RCD mechanisms such as apoptosis, necroptosis, ferroptosis, and others. It further analyzes the intricate relationship between calcium dysregulation and oxidative stress, emphasizing that while calcium overload often triggers cell death, it may not represent an entirely new type of RCD but rather an extension of known pathways. The purpose of this paper is to discuss the implications of this perspective for cancer therapy focusing on calcium-based nanoparticles. By investigating the connections between calcium dynamics and cell death pathways, this review contributes to the advancement of our understanding of calcicoptosis and its possible therapeutic uses.

A physical perspective on lithium therapy

Lithium salts have strong medical properties in neurological disorders such as bipolar disorder and lithium-responsive headaches. They have recently gathered attention due to their potential preventive effect in viral infections. Though the therapeutic effect of lithium was documented by Cade in the late 1940s, its underlying mechanism of action is still disputed. Acute lithium exposure has an activating effect on excitable organic tissue and organisms, and is highly toxic. Lithium exposure is associated with a strong metabolic response in the organism, with large changes in phospholipid and cholesterol expression. Opposite to acute exposure, this metabolic response alleviates excessive cellular activity. The presence of lithium ions strongly affects lipid conformation and membrane phase unlike other alkali ions, with consequences for membrane permeability, buffer property and excitability. This review investigates how lithium ions affect lipid membrane composition and function, and how lithium response might in fact be the body's attempt to counteract the physical presence of lithium ions at cell level. Ideas for further research in microbiology and drug development are discussed.

Role of AMP deaminase in diabetic cardiomyopathy

Diabetes mellitus is one of the major causes of ischemic and nonischemic heart failure. While hypertension and coronary artery disease are frequent comorbidities in patients with diabetes, cardiac contractile dysfunction and remodeling occur in diabetic patients even without comorbidities, which is referred to as diabetic cardiomyopathy. Investigations in recent decades have demonstrated that the production of reactive oxygen species (ROS), impaired handling of intracellular Ca2+, and alterations in energy metabolism are involved in the development of diabetic cardiomyopathy. AMP deaminase (AMPD) directly regulates adenine nucleotide metabolism and energy transfer by adenylate kinase and indirectly modulates xanthine oxidoreductase-mediated pathways and AMP-activated protein kinase-mediated signaling. Upregulation of AMPD in diabetic hearts was first reported more than 30 years ago, and subsequent studies showed similar upregulation in the liver and skeletal muscle. Evidence for the roles of AMPD in diabetes-induced fatty liver, sarcopenia, and heart failure has been accumulating. A series of our recent studies showed that AMPD localizes in the mitochondria-associated endoplasmic reticulum membrane as well as the sarcoplasmic reticulum and cytosol and participates in the regulation of mitochondrial Ca2+ and suggested that upregulated AMPD contributes to contractile dysfunction in diabetic cardiomyopathy via increased generation of ROS, adenine nucleotide depletion, and impaired mitochondrial respiration. The detrimental effects of AMPD were manifested at times of increased cardiac workload by pressure loading. In this review, we briefly summarize the expression and functions of AMPD in the heart and discuss the roles of AMPD in diabetic cardiomyopathy, mainly focusing on contractile dysfunction caused by this disorder.

Simultaneous use of venlafaxine and calcium channel blockers on tolerance to morphine: The role of mitochondrial damage and oxidative stress in the brain

BACKGROUND

One of the reasons for tolerance to morphine is increased oxidative stress and dysfunction of cell mitochondria in the hippocampus. Venlafaxine and calcium channel blockers can protect mitochondrial function. The investigation of the role of mitochondrial damage and oxidative stress in the simultaneous use of venlafaxine and calcium channel blockers on the acute analgesic effects of morphine and the induction of tolerance to its effects in mice was assessed.

METHOD

In this experimental study, to induce tolerance to morphine, NMRI mice were treated with 50 mg/kg morphine for three consecutive days and 5 mg/kg morphine on the fourth day. Venlafaxine (20 mg/kg) alone or in combination with calcium channel blockers, nimodipine (10 mg/kg), and diltiazem (40 mg/kg) was administered 30 min before morphine, and the hot plate test was used. Then, hippocampal mitochondria were isolated by differential centrifugation method, and the levels of mitochondrial dehydrogenase activity, mitochondrial membrane potential, mitochondrial ROS production rate, as well as the content of glutathione and malondialdehyde in hippocampal mitochondria, were measured.

RESULTS

The administration of venlafaxine-nimodipine and venlafaxine-diltiazem increased morphine's acute analgesic effects (P < 0.05) and reduced the induction and expression of tolerance to the analgesic effects of morphine (P < 0.05). Morphine significantly decreased MTT and GSH and increased MDA, mitochondrial membrane damage, and ROS compared to the control group (P < 0.01). Injection of venlafaxine-nimodipine and also venlafaxine-diltiazem 30 min before morphine can improve these alterations (P < 0.05).

DISCUSSION AND CONCLUSION

Our data showed that the simultaneous use of venlafaxine with calcium channel blockers could increase the acute analgesic effects of morphine and reduce the induction and expression of tolerance to it. Also, the preventive and protective roles of simultaneous administration of venlafaxine and calcium channel blockers on morphine-induced mitochondrial oxidative stress and damage during the tolerance test were achieved.

Newcastle disease virus infection induces parthanatos in tumor cells via calcium waves

Parthanatos is distinct from caspase-dependent apoptosis in that it does not necessitate the activation of caspase cascades; Instead, it relies on the translocation of Apoptosis-inducing Factor (AIF) from the mitochondria to the nucleus, resulting in nuclear DNA fragmentation. Newcastle Disease Virus (NDV) is an oncolytic virus that selectively targets and kills tumor cells by inducing cell apoptosis. It has been reported that NDV triggers classic apoptosis through the mitochondrial pathway. In this study, we observed that NDV infection induced endoplasmic reticulum stress (ERS), which caused a rapid release of endogenous calcium ions (Ca2+). This cascade of events resulted in mitochondrial depolarization, loss of mitochondrial membrane potential, and structural remodeling of the mitochondria. The overload of Ca2+ also initiated an increase in mitochondrial membrane permeability, facilitating the transfer of AIF to the nucleus to induce apoptosis. Damaged mitochondria produced excessive reactive oxygen species (ROS), which further exacerbated mitochondrial damage and increased mitochondrial membrane permeability, thus promoting additional intracellular Ca2+ accumulation and ultimately triggering an ROS burst. Collectively, these findings indicate that NDV infection promotes excessive calcium accumulation and ROS generation, leading to mitochondrial damage that releases more calcium and ROS, creating a feedback loop that exacerbates AIF-dependent parthanatos. This study not only provides a novel perspective on the oncolytic mechanism of NDV but also highlights new targets for antiviral research.

Mitochondrial Calcium Signaling Regulates Branched-Chain Amino Acid Catabolism in Fibrolamellar Carcinoma

Metabolic adaptations in response to changes in energy supply and demand are essential for survival. The mitochondrial calcium uniporter plays a key role in coordinating metabolic homeostasis by regulating TCA cycle activation, mitochondrial fatty acid oxidation, and cellular calcium signaling. However, a comprehensive analysis of uniporter-regulated mitochondrial pathways has remained unexplored. Here, we investigate metabolic consequences of uniporter loss- and gain-of-function using uniporter knockout cells and the liver cancer fibrolamellar carcinoma (FLC), which we demonstrate to have elevated mitochondrial calcium levels. Our results reveal that branched-chain amino acid (BCAA) catabolism and the urea cycle are uniporter-regulated metabolic pathways. Reduced uniporter function boosts expression of BCAA catabolism genes, and the urea cycle enzyme ornithine transcarbamylase (OTC). In contrast, high uniporter activity in FLC suppresses their expression. This suppression is mediated by reduced expression of the transcription factor KLF15, a master regulator of liver metabolism. Thus, uniporter responsive calcium signaling plays a central role in FLC-associated metabolic changes, including hyperammonemia. Our study identifies an important role for mitochondrial calcium signaling in metabolic adaptation through transcriptional regulation of metabolism and elucidates its importance for BCAA and ammonia metabolism in FLC.

Regulation of adult neurogenesis: the crucial role of astrocytic mitochondria

Neurogenesis has emerged as a promising therapeutic approach for central nervous system disorders. The role of neuronal mitochondria in neurogenesis is well-studied, however, recent evidence underscores the critical role of astrocytic mitochondrial function in regulating neurogenesis and the underlying mechanisms remain incompletely understood. This review highlights the regulatory effects of astrocyte mitochondria on neurogenesis, focusing on metabolic support, calcium homeostasis, and the secretion of neurotrophic factors. The effect of astrocytic mitochondrial dysfunction in the pathophysiology and treatment strategies of Alzheimer's disease and depression is discussed. Greater attention is needed to investigate the mitochondrial autophagy, dynamics, biogenesis, and energy metabolism in neurogenesis. Targeting astrocyte mitochondria presents a potential therapeutic strategy for enhancing neural regeneration.

NF-κB Signaling Pathway in Rheumatoid Arthritis: Mechanisms and Therapeutic Potential

Rheumatoid arthritis (RA) is an autoimmune chronic inflammatory disease that imposes a heavy economic burden on patients and society. Bone and cartilage destruction is considered an important factor leading to RA, and inflammation, oxidative stress, and mitochondrial dysfunction are closely related to bone erosion and cartilage destruction in RA. Currently, there are limitations in the clinical treatment methods for RA, which urgently necessitates finding new effective treatments for patients. Nuclear transcription factor-κB (NF-κB) is a signaling transcription factor that is widely present in various cells. It plays an important role as a stress source in the cellular environment and regulates gene expression in processes such as immunity, inflammation, cell proliferation, and apoptosis. NF-κB has long been recognized as a pathogenic factor of RA, and its activation can exacerbate RA by promoting inflammation, oxidative stress, mitochondrial dysfunction, and bone destruction. Conversely, inhibiting the activity of the NF-κB pathway effectively inhibits these pathological processes, thereby alleviating RA. Therefore, NF-κB may be a potential therapeutic target for RA. This article describes the physiological structure of NF-κB and its important role in RA through the regulation of oxidative stress, inflammatory response, mitochondrial function, and bone destruction. Meanwhile, we also summarized the impact of NF-κB crosstalk with other signaling pathways on RA and the effect of related drugs or inhibitors targeting NF-κB on RA. The purpose of this article is to provide evidence for the role of NF-κB in RA and to emphasize its significant role in RA by elucidating the mechanisms, so as to provide a theoretical basis for targeting the NF-κB pathway as a treatment for RA.

From dysfunction to healing: advances in mitochondrial therapy for Osteoarthritis

Osteoarthritis (OA) is a chronic degenerative joint condition characterised by cartilage deterioration and changes in bone morphology, resulting in pain and impaired joint mobility. Investigation into the pathophysiological mechanisms underlying OA has highlighted the significance of mitochondrial dysfunction in its progression. Mitochondria, which are cellular organelles, play a crucial role in regulating energy metabolism, generating reactive oxygen species, and facilitating essential biological processes including apoptosis. In recent years, the utilisation of exogenous drugs and MT to improve mitochondrial function in chondrocytes has shown great promise in OA treatment. Numerous studies have investigated the potential of stem cells and extracellular vesicles in mitochondrial transfer. This review aims to explore the underlying mechanisms of mitochondrial dysfunction in OA and assess the progress in utilising mitochondrial transfer as a therapeutic approach for this disease.

S1P regulates intervertebral disc aging by mediating endoplasmic reticulum-mitochondrial calcium ion homeostasis

As the aging process progresses, age-related intervertebral disc degeneration (IVDD) is becoming an emerging public health issue. Site-1 protease (S1P) has recently been found to be associated with abnormal spinal development in patients with mutations and has multiple biological functions. Here, we discovered a reduction of S1P in degenerated and aging intervertebral discs, primarily regulated by DNA methylation. Furthermore, through drug treatment and siRNA-mediated S1P knockdown, nucleus pulposus cells were more prone to exhibit degenerative and aging phenotypes. Conditional KO of S1P in mice resulted in spinal developmental abnormalities and premature aging. Mechanistically, S1P deficiency impeded COP II-mediated transport vesicle formation, which leads to protein retention in the endoplasmic reticulum (ER) and subsequently ER distension. ER distension increased the contact between the ER and mitochondria, disrupting ER-to-mitochondria calcium flow and resulting in mitochondrial dysfunction and energy metabolism disturbance. Finally, using 2-APB to inhibit calcium ion channels and the senolytic drug dasatinib and quercetin (D + Q) partially rescued the aging and degenerative phenotypes caused by S1P deficiency. In conclusion, our findings suggest that S1P is a critical factor in causing IVDD in the process of aging and highlight the potential of targeting S1P as a therapeutic approach for age-related IVDD.

Inhibition of SGLT2 protects podocytes in diabetic kidney disease by rebalancing mitochondria-associated endoplasmic reticulum membranes

BACKGROUND

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have changed the therapeutic landscape for diabetic kidney disease (DKD) patients, but their underlying mechanisms are complicated and not fully understood. Mitochondria-associated endoplasmic reticulum membranes (MAMs), the dynamic contact sites between mitochondria and the endoplasmic reticulum (ER), serve as intracellular platforms important for regulating cellular fate and function. This study explored the roles and mechanisms of SGLT2 inhibitors in regulating MAMs formation in diabetic podocytes.

METHODS

We assessed MAMs formation in podocytes from DKD patients' renal biopsy samples and induced an increase in MAMs formation in cultured human podocytes by transfecting OMM-ER linker plasmid to investigate the effects of MAMs imbalance on podocyte injury. Empagliflozin-treated diabetic mice and podocyte-specific SGLT2 knockout diabetic mice (diabetic states were induced by streptozotocin and a high-fat diet), empagliflozin-treated podocytes, SGLT2-downregulated podocytes, and SGLT2-overexpressing podocytes were used to investigate the effects and mechanisms of SGLT2 inhibitors on MAMs formation in diabetic podocytes.

RESULTS

MAMs were increased in podocytes and were associated with renal dysfunction in DKD patients. Increased MAMs aggravated HG-induced podocyte injury. The expression of SGLT2 was increased in diabetic podocytes. In addition, empagliflozin-treatment and podocyte-specific SGLT2 knockout attenuated MAMs formation and podocyte injury in diabetic mice. Empagliflozin treatment and SGLT2 knockdown decreased podocyte MAMs formation by activating the AMP-activated protein kinase (AMPK) pathway, while SGLT2 overexpression had the opposite effect.

CONCLUSIONS

Inhibition of SGLT2 attenuates MAMs imbalance in diabetic podocytes by activating the AMPK pathway. This study expands our knowledge of the roles of SGLT2 inhibitors in improving DKD podocyte injury and provides new insights into DKD treatment.

Endogenous complement 1q binding protein (C1qbp) regulates mitochondrial permeability transition and post-myocardial infarction remodeling and dysfunction

The mitochondrial permeability transition (MPT) pore regulates necrotic cell death following diverse cardiac insults. While the componentry of the pore itself remains controversial, Cyclophilin D (CypD) has been well-established as a positive regulator of pore opening. We have previously identified Complement 1q-binding protein (C1qbp) as a novel CypD-interacting molecule and a negative regulator of MPT-dependent cell death in vitro. However, its effects on the MPT pore and sensitivity to cell death in the heart remain untested. We therefore hypothesized that C1qbp would inhibit MPT in cardiac mitochondria and protect cardiac myocytes against cell death in vivo. To investigate the effects of C1qbp in the myocardium we generated gain- and loss-of-function mice. Transgenic C1qbp overexpression resulted in decreased complex protein expression and reduced mitochondrial respiration and ATP production but MPT was unaffected. In contrast, while C1qbp+/- mice did not exhibit any changes in mitochondrial protein expression, respiration, or ATP, the MPT pore was markedly sensitized to Ca2+ in these animals. Neither overexpression nor depletion of C1qbp significantly affected baseline heart morphology or function at 3 months of age. When subjected to myocardial infarction, C1qbp transgenic mice exhibited similar infarct sizes and cardiac remodeling to non-transgenic mice, consistent with the lack of an effect on MPT. In contrast, cardiac scar formation and dysfunction were significantly increased in the C1qbp+/- mice compared to C1qbp+/+ controls. Our results suggest that C1qbp is required for normal regulation of the MPT pore and mitochondrial function, and influences cardiac remodeling following MI, the latter more likely being independent of C1qbp effects on the MPT pore.

Salvaging myocardial infarction with nanoenzyme-loaded hydrogels: Targeted scavenging of mitochondrial reactive oxygen species

Myocardial infarction resulting from coronary artery atherosclerosis is the leading cause of heart failure, which represents a significant global health burden. The limitations of conventional pharmacologic thrombolysis and flow reperfusion procedures highlight the urgent need for new therapeutic strategies to effectively treat myocardial infarction. In this study, we present a novel biomimetic approach that integrates polyphenols and metal nanoenzymes, inspired by the structure of pomegranates. We developed tannic acid-coated Mn-Co3O4 (MCT) nanoparticles in combination with an injectable collagen hydrogel for the effective treatment of myocardial infarction. The hydrogel enhanced the infarct microenvironment, while the slow-released MCT targets mitochondria to inhibit the post-infarction surge of reactive oxygen species, providing anti-apoptotic and anti-inflammatory effects. RNA sequencing revealed the potential of hydrogels to serve as an interventional mechanism during the post-infarction inflammatory phase. Notably, we found that the hydrogel, when combined with the nanopomegranate-based therapy, significantly improves adverse ventricular remodeling and restores cardiac function in early infarction management. The MCT hydrogel leverages the unique benefits of both MCT nanopomegranates and collagen, demonstrating a synergistic effect. This approach provides a promising example of the potential cooperation between nanomimetic structures and natural biomaterials in therapeutic applications.

Regulated cell death in chronic kidney disease: current evidence and future clinical perspectives

Chronic kidney disease (CKD) is the progressive loss of kidney function/structure over a period of at least 3 months. It is characterised histologically by the triad of cell loss, inflammation and fibrosis. This literature review focuses on the forms of cell death that trigger downstream inflammation and fibrosis, collectively called regulated cell death (RCD) pathways. Discrete forms of RCD have emerged as central mediators of CKD pathology. In particular, pathways of regulated necrosis - including mitochondrial permeability transition pore (mPTP)-mediated necrosis, necroptosis, ferroptosis and pyroptosis - have been shown to mediate kidney pathology directly or through the release of danger signals that trigger a pro-inflammatory response, further amplifying tissue injury in a cellular process called necroinflammation. Despite accumulating evidence in pre-clinical models, no clinical studies have yet targeted these RCD modes in human CKD. The review summarizes recent advances in our understanding of RCD pathways in CKD, looks at inter-relations between the pathways (with the emphasis on propagation of death signals) and the evidence for therapeutic targeting of molecules in the RCD pathways to prevent or treat CKD.

Role of layilin in regulating mitochondria-mediated apoptosis: a study on B cell lymphoma (BCL)-2 family proteins

BACKGROUND

Malignant gliomas exhibit rapid tumor progression and resistance to treatment, leading to high lethality. One of the causes is the reduced progression of apoptosis in glioma cells. Layilin is a type 1 transmembrane protein with a C-type lectin motif in its extracellular domain. We previously reported that layilin is mainly localized to mitochondria or their close proximity and that layilin is essential for maintaining of the fragmented type of mitochondria. This study investigates the effects of layilin on mitochondria-mediated apoptosis, focusing on B cell lymphoma (BCL)-2 family proteins in a glioma cell line of A172 cells.

RESULTS

We compared the levels of pro-apoptotic BCL-2 family proteins of BAD, BAK, BAX, and BIM and anti-apoptotic BCL-2 family proteins of BCL-2 and BCL-XL between layilin- knockdown (KD) cells and control cells using western blot. The protein levels of BAD were significantly smaller in layilin-KD cells than in control cells, while those of BCL-2 were significantly larger. We then compared the mitochondrial membrane potential (ΔΨm) under p-trifluoromethoxyphenyl hydrazone (FCCP)-treated conditions using MT-1 staining. In layilin-KD cells, ΔΨm was significantly larger and FCCP-induced ΔΨm reduction was significantly lower than in control cells. Furthermore, we examined the levels of cell membrane-bound Annexin V and DNA-bound propidium idodide (PI) in layilin-KD cells with/without staurosporine (STS) treatment. Layilin-KD significantly decreased levels of cell membrane-bound Annexin V with/without STS treatment. On the other hand, PI levels were not changed by layilin-KD. We also investigated the amounts of the active caspase (CASP)-3, CASP-6, CASP-7, and poly (ADP-ribose) polymerase-1 (PARP1, cleaved form), as well as DNA fragmentation in layilin-KD cells under apoptotic conditions induced by STS, using western blot and the DNA ladder method, respectively. Under STS-treated conditions, the amounts of active CASP-3, CASP-7, and poly (ADP-ribose) PARP1 were significantly smaller in layilin-KD cells than in control cells. Accordingly, DNA fragmentation was significantly suppressed in layilin-KD cells compared to control cells under STS-treated conditions.

CONCLUSION

This study demonstrates that layilin contributes to ΔΨm reduction to promote apoptosis by up-regulating BAD and down-regulating BCL-2 in glioma cells. Our data elucidates a new function of layilin: regulation of mitochondria-mediated apoptosis.

The Role of Mitochondrial Permeability Transition in Bone Metabolism, Bone Healing, and Bone Diseases

Bone is a dynamic organ with an active metabolism and high sensitivity to mitochondrial dysfunction. The mitochondrial permeability transition pore (mPTP) is a low-selectivity channel situated in the inner mitochondrial membrane (IMM), permitting the exchange of molecules of up to 1.5 kDa in and out of the IMM. Recent studies have highlighted the critical role of the mPTP in bone tissue, but there is currently a lack of reviews concerning this topic. This review discusses the structure and function of the mPTP and its impact on bone-related cells and bone-related pathological states. The mPTP activity is reduced during the osteogenic differentiation of mesenchymal stem cells (MSCs), while its desensitisation may underlie the mechanism of enhanced resistance to apoptosis in neoplastic osteoblastic cells. mPTP over-opening triggers mitochondrial swelling, regulated cell death, and inflammatory response. In particular, mPTP over-opening is involved in dexamethasone-induced osteoblast dysfunction and bisphosphonate-induced osteoclast apoptosis. In vivo, the mPTP plays a significant role in maintaining bone homeostasis, with many bone disorders linked to its excessive opening. Genetic deletion or pharmacological inhibition of the over-opening of mPTP has shown potential in enhancing bone injury recovery and alleviating bone diseases. Here, we review the findings on the relationship of the mPTP and bone at both the cellular and disease levels, highlighting novel avenues for pharmacological approaches targeting mitochondrial function to promote bone healing and manage bone-related disorders.

The Interplay of Mitochondrial Bioenergetics and Dopamine Agonists as an Effective Disease-Modifying Therapy for Parkinson's Disease

Parkinson's disease (PD) is a progressive neurological ailment with a slower rate of advancement that is more common in older adults. The biggest risk factor for PD is getting older, and those over 60 have an exponentially higher incidence of this condition. The failure of the mitochondrial electron chain, changes in the dynamics of the mitochondria, and abnormalities in calcium and ion homeostasis are all symptoms of Parkinson's disease (PD). Increased mitochondrial reactive oxygen species (mROS) and an energy deficit are linked to these alterations. Levodopa (L-DOPA) is a medication that is typically used to treat most PD patients, but because of its negative effects, additional medications have been created utilizing L-DOPA as the parent molecule. Ergot and non-ergot derivatives make up most PD medications. PD is successfully managed with the use of dopamine agonists (DA). To get around the motor issues produced by L-DOPA, these dopamine derivatives can directly excite DA receptors in the postsynaptic membrane. In the past 10 years, two non-ergoline DA with strong binding properties for the dopamine D2 receptor (D2R) and a preference for the dopamine D3 receptor (D3R) subtype, ropinirole, and pramipexole (PPx) have been developed for the treatment of PD. This review covers the most recent research on the efficacy and safety of non-ergot drugs like ropinirole and PPx as supplementary therapy to DOPA for the treatment of PD.

Cardiomyocyte Adaptation to Exercise: K+ Channels, Contractility and Ischemic Injury

Cardiovascular disease is a leading cause of morbidity and mortality, and exercise-training (TRN) is known to reduce risk factors and protect the heart from ischemia and reperfusion injury. Though the cardioprotective effects of exercise are well-documented, underlying mechanisms are not well understood. This review highlights recent findings and focuses on cardiac factors with emphasis on K+ channel control of the action potential duration (APD), β-adrenergic and adenosine regulation of cardiomyocyte function, and mitochondrial Ca2+ regulation. TRN-induced prolongation and shortening of the APD at low and high activation rates, respectively, is discussed in the context of a reduced response of the sarcolemma delayed rectifier potassium channel (IK) and increased content and activation of the sarcolemma KATP channel. A proposed mechanism underlying the latter is presented, including the phosphatidylinositol-3kinase/protein kinase B pathway. TRN induced increases in cardiomyocyte contractility and the response to adrenergic agonists are discussed. The TRN-induced protection from reperfusion injury is highlighted by the increased content and activation of the sarcolemma KATP channel and the increased phosphorylated glycogen synthase kinase-3β, which aid in preventing mitochondrial Ca2+ overload and mitochondria-triggered apoptosis. Finally, a brief section is presented on the increased incidences of atrial fibrillation associated with age and in life-long exercisers.

Understanding coenzyme Q

Coenzyme Q (CoQ), also known as ubiquinone, comprises a benzoquinone head group and a long isoprenoid side chain. It is thus extremely hydrophobic and resides in membranes. It is best known for its complex function as an electron transporter in the mitochondrial electron transport chain (ETC) but is also required for several other crucial cellular processes. In fact, CoQ appears to be central to the entire redox balance of the cell. Remarkably, its structure and therefore its properties have not changed from bacteria to vertebrates. In metazoans, it is synthesized in all cells and is found in most, and maybe all, biological membranes. CoQ is also known as a nutritional supplement, mostly because of its involvement with antioxidant defenses. However, whether there is any health benefit from oral consumption of CoQ is not well established. Here we review the function of CoQ as a redox-active molecule in the ETC and other enzymatic systems, its role as a prooxidant in reactive oxygen species generation, and its separate involvement in antioxidant mechanisms. We also review CoQ biosynthesis, which is particularly complex because of its extreme hydrophobicity, as well as the biological consequences of primary and secondary CoQ deficiency, including in human patients. Primary CoQ deficiency is a rare inborn condition due to mutation in CoQ biosynthetic genes. Secondary CoQ deficiency is much more common, as it accompanies a variety of pathological conditions, including mitochondrial disorders as well as aging. In this context, we discuss the importance, but also the great difficulty, of alleviating CoQ deficiency by CoQ supplementation.

Oxidative stress in alcoholic liver disease, focusing on proteins, nucleic acids, and lipids: A review

Oxidative stress is one of the important factors in the development of alcoholic liver disease. The production of reactive oxygen species and other free radicals is an important feature of alcohol metabolism in the liver and an important substance in liver injury. When large amounts of ROS are produced, the homeostasis of the liver REDOX system will be disrupted and liver injury will be caused. Oxidative stress can damage proteins, nucleic acids and lipids, liver dysfunction. In addition, damaging factors produced by oxidative damage to liver tissue can induce the occurrence of inflammation, thereby aggravating the development of ALD. This article reviews the oxidative damage of alcohol on liver proteins, nucleic acids, and lipids, and provides new insights and summaries of the oxidative stress process. We also discussed the relationship between oxidative stress and inflammation in alcoholic liver disease from different perspectives. Finally, the research status of antioxidant therapy in alcoholic liver disease was summarized, hoping to provide better help for learning and developing the understanding of alcoholic liver disease.

Theoretical insights into a turn-on fluorescence probe based on naphthalimide for peroxynitrite detection

Compared with other reactive oxygen species, peroxynitrite (ONOO-) has diversified reactions and transformations in organisms, and its specific action mechanism is not very clear. The study of reactive oxygen species is of great significance in the field of physiology and pathology. Recently an effective on/off fluorescent probe HCA-OH was designed by Liu et al. through tethering p-aminophenol to 1,8-naphthalimide directly. The probe HCA-OH could release the fluorophore HCA-NH2 with good photostability and high fluorescence quantum yield under oxidation of ONOO- via dearylation process. In this work, the sensing mechanism and spectrum character of probe HCA-OH were studied in detail under quantum chemistry calculation. The electronic structures, reaction sites and fluorescent properties of the probe were theoretically analyzed to benefit us for in-depth understanding the principle of detection on reactive oxygen species (ONOO-) with the fluorescent probe HCA-OH. These theoretical results could inspire the medical research community to design and synthesize highly efficient fluorescent probe for reactive oxygen species detection.

Induction of DEPP1 by HIF Mediates Multiple Hallmarks of Ischemic Cardiomyopathy

BACKGROUND

HIF (hypoxia inducible factor) regulates many aspects of cardiac function. We and others previously showed that chronic HIF activation in the heart in mouse models phenocopies multiple features of ischemic cardiomyopathy in humans, including mitochondrial loss, lipid accumulation, and systolic cardiac dysfunction. In some settings, HIF also causes the loss of peroxisomes. How, mechanistically, HIF promotes cardiac dysfunction is an open question.

METHODS

We used mice lacking cardiac pVHL (von Hippel-Lindau protein) to investigate how chronic HIF activation causes multiple features of ischemic cardiomyopathy, such as autophagy induction and lipid accumulation. We performed immunoblot assays, RNA sequencing, mitochondrial and peroxisomal autophagy flux measurements, and live cell imaging on isolated cardiomyocytes. We used CRISPR-Cas9 gene editing in mice to validate a novel mediator of cardiac dysfunction in the setting of chronic HIF activation.

RESULTS

We identify a previously unknown pathway by which cardiac HIF activation promotes the loss of mitochondria and peroxisomes. We found that DEPP1 (decidual protein induced by progesterone 1) is induced under hypoxia in a HIF-dependent manner and localizes inside mitochondria. DEPP1 is both necessary and sufficient for hypoxia-induced autophagy and triglyceride accumulation in cardiomyocytes ex vivo. DEPP1 loss increases cardiomyocyte survival in the setting of chronic HIF activation ex vivo, and whole-body Depp1 loss decreases cardiac dysfunction in hearts with chronic HIF activation caused by VHL loss in vivo.

CONCLUSIONS

Our findings identify DEPP1 as a key component in the cardiac remodeling that occurs with chronic ischemia.

PCSK9 Inhibitors and Anthracyclines: The Future of Cardioprotection in Cardio-Oncology

The field of cardio-oncology is an expanding frontier within cardiovascular medicine, and the need for evidence-based guidelines is apparent. One of the emerging focuses within cardio-oncology is the concomitant use of medications for cardioprotection in the setting of chemotherapy regimens that have known cardiovascular toxicity. While clinical trials focusing on cardioprotection during chemotherapy are sparse, an inaugural trial exploring the prophylactic potential of Sodium-Glucose Cotransporter-2 inhibitors (SGLT2is) for anthracycline (ANT)-induced cardiotoxicity has recently commenced. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors, though less studied in this oncology demographic, have exhibited promise in preclinical studies for conferring cardiac protection during non-ischemic toxic insults. While primarily used to reduce low-density lipoprotein, PCSK9 inhibitors exhibit pleiotropic effects, including the attenuation of inflammation, reactive oxygen species, and endothelial dysfunction. In ANT-induced cardiotoxicity, these same processes are accelerated, resulting in premature termination of treatment, chronic cardiovascular sequelae, heart failure, and/or death. This review serves a dual purpose: firstly, to provide a concise overview of the mechanisms implicated in ANT-induced cardiotoxicity, and, finally, to summarize the existing preclinical data supporting the theoretical possibility of the cardioprotective effects of PCSK9 inhibition in ANT-induced cardiotoxicity.

Understanding the intersection between placental development and cancer: Lessons from the tumor suppressor BAP1

The placenta, a pivotal organ in mammalian reproduction, allows nutrient exchange and hormonal signaling between the mother and the developing fetus. Understanding its molecular intricacies is essential for deciphering normal embryonic development and pathological conditions such as tumorigenesis. Here, we explore the multifaceted role of the tumor suppressor BRCA1-associated protein 1 (BAP1) in cancer and placentation. Initially recognized for its tumor-suppressive properties, BAP1 has emerged as a key regulator at the intersection of tumorigenesis and placental development. BAP1 influences crucial cellular processes such as cell death, proliferation, metabolism, and response to hypoxic conditions. By integrating insights from tumor and developmental biology, we illuminate the complex molecular pathways orchestrated by BAP1. This perspective highlights BAP1's significant impact on both cancer and placental development, and suggests novel therapeutic strategies that could improve outcomes for pregnancy disorders and cancer.

Therapeutic Potential of Natural Resources Against Endometriosis: Current Advances and Future Perspectives

Endometriosis (EMS) is defined as the appearance, growth, infiltration, and repeated bleeding of endometrioid tissue (glands and stroma) outside the uterus cavity, which can form nodules and masses. Endometriosis is a chronic inflammatory estrogen-dependent disease and occurs in women of reproductive age. This disorder may significantly affect the quality of life of patients. The pathogenic processes involved in the development and maintenance of endometriosis remain unclear. Current treatment options for endometriosis mainly include drug therapy and surgery. Drug therapy mainly ties to the use of non-steroidal anti-inflammatory drugs (NSAIDs) and hormonal drugs. However, these drugs may produce adverse effects when used for long-term treatment of endometriosis, such as nausea, vomiting gastrointestinal reactions, abnormal liver and kidney function, gastric ulcers, and thrombosis. Although endometriosis lesions can be surgically removed, the disease has a high recurrence rate after surgical resection, with a recurrence rate of 21.5% within 2 years and 40% to 50% within 5 years. Thus, there is an urgent need to develop alternative or additional therapies for the treatment of endometriosis. In this review, we give a systematic summary of therapeutic multiple component prescriptions (including traditional Chinese medicine and so on), bioactive crude extracts of plants/herbs and purified compounds and their newly found mechanisms reported in literature in recent years against endometriosis.

Exploring the multifaceted role of adenosine nucleotide translocase 2 in cellular and disease processes: A comprehensive review

Adenosine nucleotide translocases (ANTs) are a family of proteins abundant in the inner mitochondrial membrane, primarily responsible for shuttling ADP and ATP across the mitochondrial membrane. Additionally, ANTs are key players in balancing mitochondrial energy metabolism and regulating cell death. ANT2 isoform, highly expressed in undifferentiated and proliferating cells, is implicated in the development and drug resistance of various tumors. We conduct a detailed analysis of the potential mechanisms by which ANT2 may influence tumorigenesis and drug resistance. Notably, the significance of ANT2 extends beyond oncology, with roles in non-tumor cell processes including blood cell development, gastrointestinal motility, airway hydration, nonalcoholic fatty liver disease, obesity, chronic kidney disease, and myocardial development, making it a promising therapeutic target for multiple pathologies. To better understand the molecular mechanisms of ANT2, this review summarizes the structural properties, expression patterns, and basic functions of the ANT2 protein. In particular, we review and analyze the controversy surrounding ANT2, focusing on its role in transporting ADP/ATP across the inner mitochondrial membrane, its involvement in the composition of the mitochondrial permeability transition pore, and its participation in apoptosis.

Environmental endocrine disruptor-induced mitochondrial dysfunction: a potential mechanism underlying diabetes and its complications

Diabetes and its complications significantly affect individuals' quality of life. The etiology of diabetes mellitus and its associated complications is complex and not yet fully understood. There is an increasing emphasis on investigating the effects of endocrine disruptors on diabetes, as these substances can impact cellular processes, energy production, and utilization, ultimately leading to disturbances in energy homeostasis. Mitochondria play a crucial role in cellular energy generation, and any impairment in these organelles can increase susceptibility to diabetes. This review examines the most recent epidemiological and pathogenic evidence concerning the link between endocrine disruptors and diabetes, including its complications. The analysis suggests that endocrine disruptor-induced mitochondrial dysfunction-characterized by disruptions in the mitochondrial electron transport chain, dysregulation of calcium ions (Ca2+), overproduction of reactive oxygen species (ROS), and initiation of signaling pathways related to mitochondrial apoptosis-may be key mechanisms connecting endocrine disruptors to the development of diabetes and its complications.

Mitochondrial Dysfunction is a Crucial Immune Checkpoint for Neuroinflammation and Neurodegeneration: mtDAMPs in Focus

Neuroinflammation is a pivotal factor in the progression of both age-related and acute neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, and stroke. Mitochondria, essential for neuronal health due to their roles in energy production, calcium buffering, and oxidative stress regulation, become increasingly susceptible to dysfunction under conditions of metabolic stress, aging, or injury. Impaired mitophagy in aged or injured neurons leads to the accumulation of dysfunctional mitochondria, which release mitochondrial-derived damage-associated molecular patterns (mtDAMPs). These mtDAMPs act as immune checkpoints, activating pattern recognition receptors (PRRs) and triggering innate immune signaling pathways. This activation initiates inflammatory responses in neurons and brain-resident immune cells, releasing cytokines and chemokines that damage adjacent healthy neurons and recruit peripheral immune cells, further amplifying neuroinflammation and neurodegeneration. Long-term mitochondrial dysfunction perpetuates a chronic inflammatory state, exacerbating neuronal injury and contributing additional immunogenic components to the extracellular environment. Emerging evidence highlights the critical role of mtDAMPs in initiating and sustaining neuroinflammation, with circulating levels of these molecules potentially serving as biomarkers for disease progression. This review explores the mechanisms of mtDAMP release due to mitochondrial dysfunction, their interaction with PRRs, and the subsequent activation of inflammatory pathways. We also discuss the role of mtDAMP-triggered innate immune responses in exacerbating both acute and chronic neuroinflammation and neurodegeneration. Targeting dysfunctional mitochondria and mtDAMPs with pharmacological agents presents a promising strategy for mitigating the initiation and progression of neuropathological conditions.

CKB Promotes Mitochondrial ATP Production by Suppressing Permeability Transition Pore

Creatine kinases are essential for maintaining cellular energy balance by facilitating the reversible transfer of a phosphoryl group from ATP to creatine, however, their role in mitochondrial ATP production remains unknown. This study shows creatine kinases, including CKMT1A, CKMT1B, and CKB, are highly expressed in cells relying on the mitochondrial F1F0 ATP synthase for survival. Interestingly, silencing CKB, but not CKMT1A or CKMT1B, leads to a loss of sensitivity to the inhibition of F1F0 ATP synthase in these cells. Mechanistically, CKB promotes mitochondrial ATP but reduces glycolytic ATP production by suppressing mitochondrial calcium (mCa2+) levels, thereby preventing the activation of mitochondrial permeability transition pore (mPTP) and ensuring efficient mitochondrial ATP generation. Further, CKB achieves this regulation by suppressing mCa2+ levels through the inhibition of AKT activity. Notably, the CKB-AKT signaling axis boosts mitochondrial ATP production in cancer cells growing in a mouse tumor model. Moreover, this study also uncovers a decline in CKB expression in peripheral blood mononuclear cells with aging, accompanied by an increase in AKT signaling in these cells. These findings thus shed light on a novel signaling pathway involving CKB that directly regulates mitochondrial ATP production, potentially playing a role in both pathological and physiological conditions.

Bongkrekic acid alleviates airway inflammation via breaking the mPTP/mtDAMPs/RAGE feedback loop in a steroid-insensitive asthma model

Mitochondrial dysfunction is critical in the pathogenesis of asthma. Mitochondrial permeability transition pore (mPTP) regulates the release of mitochondrial damage-associated molecular patterns (mtDAMPs) to maintain mitochondrial homeostasis. Bongkrekic acid (BKA) is a highly selective inhibitor of mPTP opening, participates the progression of various diseases. This research investigated the exact roles of BKA and mPTP in the pathogenesis of asthma and elucidated its underlying mechanisms. In the present study, cytochrome c, one of the mtDAMPs, levels were elevated in asthmatic patients, and associated to airway inflammation and airway obstruction. BKA, the inhibitor of mPTP markedly reversed TDI-induced airway hyperresponsiveness, airway inflammation, and mitochondrial dysfunction. Pretreatment with mitochondrial precipitation, to simulate the release of mtDAMPs, further increased TDI-induced airway inflammation and the expression of RAGE in mice. Administration of the inhibitor of RAGE, FPS-ZM1, alleviated the airway inflammation, the abnormal open of mPTP and mitochondrial dysfunction induced by mtDAMPs and TDI. Furthermore, stimulation with different mtDAMPs activated RAGE signaling in human bronchial epithelial cells. Accordingly, our study indicated that mPTP was important and BKA was efficient in alleviating inflammation in TDI-induced asthma. A positive feedback loop involving mPTP, mtDAMPs and RAGE was present in TDI-induced asthma, indicating that mPTP might serve as a potential therapeutic target for asthma.

Mitochondrial pathway of programmed cell death in Paeonia lactiflora pollen cryopreservation

Programmed cell death (PCD) is an important factor to reduces the viability of plant germplasm after cryopreservation. However, the pathways by which PCD occurs is not fully understood. To investigate whether there is a mitochondrial pathway for pollen PCD after cryopreservation, the pollen of Paeonia lactiflora two cultivars with different PCD levels after cryopreservation was used as test material and the changes of mitochondrial calcium ions (Ca2+), structure, function and their relationship with PCD were compared. The results showed that compared with fresh pollen, the PCD of 'Feng Huang Nie Pan' was significantly reduced after cryopreservation. Their mitochondrial Ca2+ content decreased by 74.27%, mitochondrial permeability transition pore (MPTP) opening reduced by 25.41%, mitochondrial membrane potential slightly decreased by 5.02%, cardiolipin oxidation decreased by 65.31%, and oxygen consumption remained stable, with a slightly ATP production increase. On the contrary, compared with fresh pollen, 'Zi Feng Chao Yang' showed severe PCD after cryopreservation. The decline in mitochondrial Ca2+-ATPase activity led to an accumulation of excessive Ca2+ within mitochondria, triggering widespread opening of MPTP, significantly affecting mitochondrial respiration and energy synthesis. These results suggest the mitochondrial pathway of PCD exists in pollen cryopreservation.

Targeting Mitochondrial Dysfunction and Reactive Oxygen Species for Neurodegenerative Disease Treatment

Alzheimer's disease (AD) and Parkinson's disease (PD) are the most common neurodegenerative diseases, and they affect millions of people worldwide, particularly older individuals. Therefore, there is a clear need to develop novel drug targets for the treatment of age-related neurodegenerative diseases. Emerging evidence suggests that mitochondrial dysfunction and reactive oxygen species (ROS) generation play central roles in the onset and progression of neurodegenerative diseases. Mitochondria are key regulators of respiratory function, cellular energy adenosine triphosphate production, and the maintenance of cellular redox homeostasis, which are essential for cell survival. Mitochondrial morphology and function are tightly regulated by maintaining a balance among mitochondrial fission, fusion, biogenesis, and mitophagy. In this review, we provide an overview of the main functions of mitochondria, with a focus on recent progress highlighting the critical role of ROS-induced oxidative stress, dysregulated mitochondrial dynamics, mitochondrial apoptosis, mitochondria-associated inflammation, and impaired mitochondrial function in the pathogenesis of age-related neurodegenerative diseases, such as AD and PD. We also discuss the potential of mitochondrial fusion and biogenesis enhancers, mitochondrial fission inhibitors, and mitochondria-targeted antioxidants as novel drugs for the treatment of these diseases.

Application of Calcium Kinetics Characterization in Cardiac Disease Modeling and Drug Discovery

Calcium regulation is essential in virtually any cell due to its critical role as a second messenger in multiple signaling pathways [...].