Mitochondria as a therapeutic target for common pathologies

Update on the correlation between mitochondrial function and osteonecrosis of the femoral head osteocytes

Mitochondrial health is maintained in a steady state through mitochondrial dynamics and autophagy processes. Recent studies have identified healthy mitochondria as crucial regulators of cellular function and survival. This process involves adenosine triphosphate (ATP) synthesis by mitochondrial oxidative phosphorylation (OXPHOS), regulation of calcium metabolism and inflammatory responses, and intracellular oxidative stress management. In the skeletal system, they participate in the regulation of cellular behaviors and the responses of osteoblasts, osteoclasts, chondrocytes, and osteocytes to external stimuli. Indeed, mitochondrial damage or dysfunction occurs in the development of a few bone diseases. For example, mitochondrial damage may lead to an imbalance in osteoblasts and osteoclasts, resulting in osteoporosis, osteomalacia, or poor bone production, and chondrocyte death and inflammatory infiltration in osteoarthritis are the main causes of cartilage degeneration due to mitochondrial damage. However, the opposite exists for osteosarcoma, where overactive mitochondrial metabolism is able to accelerate the proliferation and migration of osteosarcoma cells, which is a major disease feature. Bone is a dynamic organ and osteocytes play a fundamental role in all regions of bone tissue and are involved in regulating bone integrity. This review examines the impact of mitochondrial physiological function on osteocyte health and summarizes the microscopic molecular mechanisms underlying its effects. It highlights that targeted therapies focusing on osteocyte mitochondria may be beneficial for osteocyte survival, providing a new insight for the diagnosis, prevention, and treatment of diseases associated with osteocyte death.

Regional uterine contractility differences during pregnancy: The role of hypoxia and ferroptosis in vitro

Regional variations in uterine contractility during pregnancy have been well-documented. However, the molecular mechanisms underlying these differences remain unclear. To address this, isotonic contraction experiments were conducted on pregnant rat uteri, revealing significantly lower contractility on the placenta-attached side compared to the non-attached side. Interestingly, lactic acid accumulation was higher in the placenta-attached tissue, suggesting metabolic differences between these regions. Muscle contraction requires substantial energy, with adenosine triphosphate (ATP) serving as the direct source of energy, which is predominantly supplied by mitochondria, the cellular energy production centers. Mitochondrial energy generation relies heavily on oxygen availability. To explore the impact of oxygen conditions on uterine smooth muscle cell (USMC) contraction, we cultured these cells under hypoxic conditions. Hypoxia was found to reduce cell contraction and disrupt mitochondrial integrity. Specifically, mitochondria exhibited shrinkage and deformation, characterized by reduced cristae and a collapse of the mitochondrial membrane potential. These structural and functional changes align with hallmarks of ferroptosis. Furthermore, hypoxia stimulated the translocation of dynamic related protein 1 (Drp1) to mitochondria, a process linked to mitochondrial fragmentation. Ferroptosis was downregulated when Drp1 activity was inhibited, highlighting its regulatory role in this process. Collectively, these findings demonstrate that hypoxia induced-ferroptosis impairs mitochondria, leading to reduced energy production and cell viability. This ultimately decreases the contractility of pregnant USMC, providing new insights into the molecular mechanisms underlying regional differences in uterine contractility during pregnancy.

Pre-clinical evidence for mitochondria as a therapeutic target for luteolin: A mechanistic view

Pre-clinical evidence indicates that mitochondria may be a therapeutic target for luteolin (3',4',5,7-tetrahydroxyflavone; LUT) in different conditions. LUT modulates mitochondrial physiology in in vitro, ex vivo, and in vivo experimental models. This flavone exerted mitochondria-related antioxidant and anti-apoptotic effects, stimulated mitochondrial fusion and fission, induced mitophagy, and promoted mitochondrial biogenesis in human and animal cells and tissues. Moreover, LUT modulated the activity of components of the oxidative phosphorylation (OXPHOS) system, improving the ability of mitochondria to produce adenosine triphosphate (ATP) in certain circumstances. The mechanism of action by which LUT promoted mitochondrial benefits and protection are not completely clear yet. Nonetheless, LUT is a potential candidate to be utilized in mitochondrial therapy in the future. In this work, it is explored the mechanisms of action by which LUT modulates mitochondrial physiology in different pre-clinical experimental models.

Kirenol alleviates cerebral ischemia-reperfusion injury by reducing oxidative stress and ameliorating mitochondrial dysfunction via activating the CK2/AKT pathway

Ischemic stroke represents a predominant cause of morbidity and mortality globally, resulting from abrupt vascular occlusion or rupture, which precipitates considerable neuronal damage. This study aims to shed more light on the specific neuroprotective mechanisms of Kirenol, a bioactive diterpene derived from traditional herbal medicine, with a particular focus on its regulation of mitochondrial dynamics via the CK2/AKT signalling pathway and its impact on the mitochondrial fusion protein Optic atrophy 1 (Opa1). The effects of Kirenol on neuronal viability, mitochondrial function, and pertinent signalling pathways were evaluated by employing a middle cerebral artery occlusion (MCAO) model in rats and subjecting HT22 neuronal cells to oxidative stress. Treatment with Kirenol significantly improved neurological outcomes, augmented Opa1 expression, and restored apoptotic-related protein markers, antioxidative factors, mitochondrial membrane potential, and adenosine triphosphate (ATP) levels (P < 0.01). Mechanistically, Kirenol elevated CK2 levels and phosphorylated AKT while inhibiting CK2/AKT signalling attenuated Kirenol's protective effects on Opa1 expression. Furthermore, silencing Opa1 using siRNA diminished the neuroprotective effects of Kirenol on oxidative stress and apoptosis-related markers, underscoring the critical role of Opa1. In vitro assessments demonstrated that Kirenol effectively mitigated oxidative stress-induced neuronal damage, restoring cell morphology and viability. Kirenol exhibited dose-dependent neuroprotective effects in the MCAO model (P < 0.01). These findings elucidate the neuroprotective role of Kirenol in ischemic stroke through Opa1-mediated mitochondrial fusion and highlight the CK2/AKT pathway as a promising therapeutic target.

Discovery and antitumor evaluation of a mitochondria-targeting ruthenium complex for effective cancer therapy

Ruthenium-based metallodrugs have garnered attention as a promising alternative for anticancer therapy, aiming to overcome chemoresistance and severe side effects linked to platinum-based drugs. However, ruthenium complexes tested in clinical trials to date have yielded unsatisfactory results. This study synthesized a positively charged ruthenium complex (Ru-2) that effectively penetrated cancer cells and exhibited superior cytotoxicity to cisplatin in vitro against cancer cell lines and organoids. Ru-2 selectively targeted mitochondria, disrupting their function by depolarizing mitochondrial membrane potential, elevating reactive oxygen species production, and impairing both oxidative phosphorylation and the tricarboxylic acid cycle. Furthermore, Ru-2 triggered endoplasmic reticulum (ER) stress and apoptosis. Integrative transcriptomic and proteomic analyses, performed using RNA sequencing and mass spectrometry, identified key molecular changes in cancer cells treated with Ru-2. For enhanced in vivo application, we developed a transferrin-based nanomedicine formulation, TF/Ru-2, incorporating Ru-2 into transferrin. In vivo studies demonstrated that both Ru-2 and TF/Ru-2 exhibited superior antitumor efficacy and improved biosafety compared to cisplatin. This study presents a novel ruthenium complex and a transferrin-based drug delivery platform with significant potential for future cancer therapies.

CNS Mitochondria-Derived Vesicle in Blood: Potential Biomarkers for Brain Mitochondria Dysfunction

OBJECTIVE

Mitochondrial dysfunction is a hallmark of neurodegenerative diseases like Alzheimer's (AD) and Parkinson's (PD). Our goal was to develop practical, noninvasive methods to assess mitochondrial status through the detection of mitochondria-derived vesicles (MDVs).

METHODS

We explored blood-borne MDVs, a recently identified class of extracellular vesicles, as potential biomarkers for CNS mitochondrial status.

RESULTS

The study identified MDVs from neurons, astrocytes, and oligodendrocytes specifically in human plasma. A novel nanoflow cytometry was developed to evaluate the level of neuron-, astrocyte-, and oligodendrocyte-derived MDVs in plasma in AD and PD patients. Importantly, analyses of discovery and validation cohorts revealed significantly lower brain cell-specific MDVs in AD and PD patients compared to healthy controls.

INTERPRETATION

This study suggests that blood MDVs could serve as noninvasive biomarkers for mitochondrial dysfunction in AD, PD, and beyond, potentially aiding in monitoring mitochondrial-focused therapies for neurological disorders.

Introducing TAPY as a Versatile Alternative to TPP for Selective Mitochondrial Targeting in Cancer Cells

The understanding of diseases such as cancer and Alzheimer's, along with natural aging processes, heavily relies on the study of mitochondrial function. Optical techniques like fluorescence imaging microscopy are pivotal for this purpose, enabling precise mapping of subcellular structures, including mitochondria. In this study, we explored TAPY (triarylpyridinium) cations, a novel family of mitochondrial carriers resembling the well-known triphenylphosphonium cation (TPP). Six TAPY-bodipy (BDP) dyads were prepared and chemically characterized. Confocal Laser Scanning Microscopy (CLSM) studies demonstrated that the systems were delivered selectively to the mitochondria of cancer cells (MCF-7, A549, HT-29). Remarkably, these dyads did not target the mitochondria of normal cells (HEK-293, HMEC-1), suggesting their potential use in distinguishing cancerous cells from healthy ones. A model compound comprised of the same bodipy cargo but attached to TPP was also synthesized and tested. Notably, in preliminary comparative assays with MCF-7 cells, the dyad TAPY(OMe)-BDP outperformed the TPP derivative in mitochondrial imaging, achieving twice the final fluorescence intensity. The potential chemical diversity achievable with TAPY cations is considerable, with many derivatives being accessible starting from readily available commercial products. This implies that, based on the strategy outlined in this study, carefully optimized TAPY derivatives for targeted mitochondrial delivery could potentially be developed in the future as alternatives or complements to TPP, with the present work acting as a proof of concept.

Massage-Mimicking Nanosheets Mechanically Reorganize Inter-organelle Contacts to Restore Mitochondrial Functions in Parkinson's Disease

Parkinson's disease (PD) is exacerbated by dysfunction of inter-organelle contact, which depends on cellular responses to the mechanical microenvironment and can be regulated by external mechanical forces. Delivering dynamic mechanical forces to neural cells proves challenging due to the skull. Inspired by the effects of massage; here PEGylated black phosphorus nanosheets (PEG-BPNS), known for their excellent biocompatibility, biodegradability, specific surface area, mechanical strength, and flexibility, are introduced, which are capable of adhering to neural cell membrane and generating mechanical stimulation with their lateral size of 200 nm, exhibiting therapeutic potential in a 1-methyl-4-phenyl-1,2,3,6-te-trahydropyridine-induced PD mouse model by regulating inter-organelle contacts. Specifically, it is found that 200 nm PEG-BPNS, acting as "NanoMassage," significantly increase  plasma membrane tension, as evidenced by fluorescent lipid tension reporter fluorescence lifetime analysis. This mechanical force modulates actin reorganization, subsequently regulating the contacts between actin, mitochondria, and endoplasmic reticulum, further controlling mitochondrial fission and mitigating mitochondrial dysfunction in PD, exhibiting therapeutic efficacy via intranasal administration. These findings provide a noninvasive strategy for applying mechanical stimulation to deep brain areas and elucidate the mechanism of NanoMassage mediating inter-organelle contacts, suggesting the rational design of "NanoMassage" to remodel inter-organelle communications in neurodegenerative disease treatment.

Effects of co-exposure to microplastics and perfluorooctanoic acid on the Caco-2 cells

As plastics are produced and used, humans are inevitably exposed to microplastics (MPs) on a daily basis. The pollution of MPs has aroused widespread human concern. Perfluorooctanoic acid (PFOA), a persistent organic pollutant (POP), can be adsorbed by microplastics and may exacerbate human health hazards. In this study, we investigated the effects of co-exposure of PET MPs and PFOA on the human intestinal tract in terms of both cytotoxicity and intestinal barrier through in vitro experiments. The results showed that PFOA induced cellular oxidative stress, mitochondrial dysfunction exerted cytotoxic effects, and inhibited tight junction (TJ) protein expression causing intestinal barrier damage. PET MPs can synergize with PFOA to exacerbate the deleterious effects on the intestinal tract by decreasing cell membrane permeability to increase PFOA accumulation in the cell and enhancing the ability of PFOA to inhibit zonula occludens-1 (ZO-1) proteins.

HNGF6A ameliorates oxidative stress-mediated mitochondrial dysfunction in degenerative meniscus

Aims

Meniscus injury can lead to knee synovitis and cartilage deterioration, ultimately resulting in osteoarthritis (OA). Mitochondrial dysfunction has been identified as an induction factor in OA development, owing to an imbalance between the production of reactive oxygen species (ROS) and the antioxidant capacity of cells. However, the contribution of mitochondrial function in the meniscus to OA remains unclear. The purpose of this work was to elucidate the impact of HNGF6A, a mitochondrial-derived protective peptide, on meniscus senescence and degeneration to clarify the underlying mechanisms of ROS-induced OA pathogenesis.

Methods

Primary human meniscus cells were subjected to oxidative stress using tert-butyl hydrogen peroxide (TBHP). Mitochondrial function and ROS levels were evaluated using transmission electron microscopy (TEM), cytometry, and immunofluorescence. C57BL/6 mice subjected to destabilization of the medial meniscus (DMM) were either administered or not administered HNGF6A, and gait analysis was performed at eight weeks after surgery. Knee joints were collected for graft micro-CT and histological staining.

Results

Mitochondrial function was found to be impaired in the degraded menisci in OA. Pretreatment with HNGF6A significantly restored the matrix degradation and cell apoptosis induced by TBHP, and maintained mitochondrial redox homeostasis, which corresponded with the activation of autophagy and FUN14 domain containing 1 (FUNDC1) upon HNGF6A treatment. The animal studies also revealed that HNGF6A alleviates meniscus degeneration and osteophyte volume, and ameliorates the OA phenotype in vivo.

Conclusion

HNGF6A was found to protect meniscus cells by restoring FUNDC1-mediated mitochondrial redox homeostasis and autophagy. Thus, HNGF6A may have therapeutic applications in the prevention and treatment of meniscal degeneration and OA progression.

Association of Mitochondrial DNA Copy Number in Peripheral Blood with Risk and Prognosis in Acute Aortic Syndrome

Previous studies have reported that mitochondrial DNA copy number (mtDNA-CN) of blood was associated with a series of aging-related diseases. However, it remains unknown whether mtDNA-CN can be a potential biomarker of acute aortic syndromes (AASs). The mtDNA-CN in blood of 190 male patients with AAS and 207 healthy controls were detected by standardized real-time quantitative PCR-based assay. The mtDNA sequencing data of blood and myocardial muscle in 134 individuals were used to analyze mtDNA somatic mutations in blood. mtDNA-CN in peripheral blood was negatively correlated with age of individuals. Further analysis based on next-generation sequencing data demonstrated numbers and heteroplasmy of mtDNA mutations were positively correlated with age. Remarkably, mtDNA-CN of patients with AAS was lower than that of healthy controls. Logistic regression also showed that mtDNA-CN was independently associated with risk of AAS. During follow-up, patients with the lowest mtDNA-CN quartile had a hazard ratio of 2.543 for all-cause-mortality and 1.964 for composite end points compared with the other patients. Moreover, multivariate Cox regression indicated that lowest mtDNA-CN quartile was independently associated with all-cause mortality in patients with AAS. Our study demonstrated a negative correlation between mtDNA-CN and age. Moreover, lower mtDNA-CN in peripheral blood was significantly associated with higher risk and worse prognosis of AAS. It provided crucial evidence supporting the potential of mtDNA-CN as a novel biomarker of AAS.

Mitochondrial quality control: A promising target of traditional Chinese medicine in the treatment of cardiovascular disease

Cardiovascular disease remains the leading cause of death globally, and drugs for new targets are urgently needed. Mitochondria are the primary sources of cellular energy, play crucial roles in regulating cellular homeostasis, and are tightly associated with pathological processes in cardiovascular disease. In response to physiological signals and external stimuli in cardiovascular disease, mitochondrial quality control, which mainly includes mitophagy, mitochondrial dynamics, and mitochondrial biogenesis, is initiated to meet cellular requirements and maintain cellular homeostasis. Traditional Chinese Medicine (TCM) has been shown to have pharmacological effects on alleviating cardiac injury in various cardiovascular diseases, including myocardial ischemia/reperfusion, myocardial infarction, and heart failure, by regulating mitochondrial quality control. Recently, several molecular mechanisms of TCM in the treatment of cardiovascular disease have been elucidated. However, mitochondrial quality control by TCM for treating cardiovascular disease has not been investigated. In this review, we aim to decipher the pharmacological effects and molecular mechanisms of TCM in regulating mitochondrial quality in various cardiovascular diseases. We also present our perspectives regarding future research in this field.

A turn-on mitochondria-targeted iridium (Ⅲ) Complex-Based probe for glutathione detection and photodynamic therapy of cancer cells

As one of the most abundant biothiols in cells, glutathione (GSH) usually exists in a dynamic equilibrium of oxidized glutathione (GSSG) and reduces glutathione redox, and plays an essential reducing substance to maintain the REDOX balance of the microenvironment. So, the development of a reliable GSH sensor will be important for living cells and organisms. We fabricated a mitochondria targeted "turn-on" fluorescent sensor based on Ir (III) complex and successfully detected endogenous and exogenous GSH in living cells and zebrafish. For the probe Ir-DINI, a robust electron-withdrawing group 2,4-dinitrobenzoyl was introduced to quench the fluorescence, which could be broken through electrostatic interaction with GSH, following exposing a strong fluorescent Ir (Ⅲ) complex Ir-OH. On the other hand, photodynamic therapy (PDT) has attracted much attention in recent years due to its minimally invasive treatment. We found that singlet oxygen yields of probe Ir-DINI displayed an enhancement before and after the detection of GSH. Additionally, photodynamic studies in living cells illustrated that after reacting with GSH, probe Ir-DINI exhibited more obvious phototoxicity than before the detection of GSH. So the probe Ir-DINI could be served as a GSH sensor and potential GSH-activated photosensitizer for photodynamic therapy.

An endoplasmic reticulum and lipid droplets dual-localized strategy to develop small molecular photosensitizers that induce ferroptosis during photodynamic therapy

Organelle-localized photosensitizers have been well-developed to enhance the photodynamic therapy (PDT) efficacy through triggering given cell death. The endoplasmic reticulum (ER) and lipid droplets (LDs) are two key organelles mutually regulating ferroptosis. Thus, in this study, small molecular photosensitizer CAR PSs were developed through fragment integration strategy and the heavy-atom modification. It was showed that the integration strategy did not affect the organelle localization and CAR PSs successfully achieved ER/LDs dual location. Besides, the heavy-atom modification help CAR PSs display good ROS generation efficiency. Importantly, ER/LDs dual-localized CAR PSs exhibited superior photo-toxicity and lower dark-toxicity against multiple breast cancer cell lines than the only ER-targeting Ce6, which further explained the superposition effect of dual organelle targeting. Preliminary studies revealed that CAR PSs induced enhanced ferroptosis via simultaneously triggering the ER stress and lipid peroxidation during PDT. Moreover, CAR-2 demonstrated significant in vivo PDT activity to suppress the tumor growth in 4T1 tumor bearing mice. These findings not only provide a promising photosensitizer CAR-2 exerting excellent in vitro and in vivo PDT effect through stimulating ferroptosis, but also propose a design strategy for the development of ER/LDs dual localized PSs.

Transcriptional dynamics in type 2 diabetes progression is linked with circadian, thermogenic, and cellular stress in human adipose tissue

The prevalence of type 2 diabetes (T2D) has increased significantly over the past three decades, with an estimated 30-40% of cases remaining undiagnosed. Brown and beige adipose tissues are known for their remarkable catabolic capacity, and their ability to diminish blood glucose plasma concentration. Beige adipose tissue can be differentiated from adipose-derived stem cells or through transdifferentiation from white adipocytes. However, the impact of T2D progression on beige adipocytes' functional capacity remains unclear. Transcriptomic profiling of subcutaneous adipose tissue biopsies from healthy normal-weight, obese, prediabetic obese, and obese subjects diagnosed with T2D, reveals a progressive alteration in cellular processes associated with catabolic metabolism, circadian rhythms, thermogenesis-related signaling pathways, cellular stress, and inflammation. MAX is a potential transcription factor that links inflammation with the circadian clock and thermogenesis during the progression of T2D. This study unveils an unrecognized transcriptional circuit that increasingly disrupts subcutaneous adipose tissue oxidative capacity during the progression of T2D. These findings could open new research venues for developing chrono-pharmaceutical strategies to treat and prevent T2D.

Formononetin ameliorates DSS-induced colitis by inhibiting the MAPK/PPAR-γ/NF-κB/ROS signaling pathways

BACKGROUND AND AIM

Formononetin (FMN) is a compound isolated from Astragalus membranaceus, that exhibits a range of pharmacological activities, including antitumor, anti-inflammatory, hypolipidemic, and antioxidant effects. Although preliminary study suggests that FMN have a therapeutic role in Inflammatory Bowel Disease (IBD), its specific mechanism of action requires further investigation. This study aimed to investigate the mechanism by which FMN treats DSS-induced colitis in mice.

METHODS

RAW264.7 and Bone marrow-derived macrophages (BMDMs) were treated with LPS to establish an inflammatory cell model. Biochemical parameters and morphological characteristics were assessed in the present or absent of FMN. 4 % solution of DSS was administered to C57BL/6 mice to induce IBD, which served as an animal model for investigating the pharmacodynamics of FMN.

RESULTS

FMN significantly reduced colitis-associated injury, as evidenced by a decrease in the disease activity index (DAI), weight gain, and restoration of colon length. Furthermore, FMN inhibits protein expression of NLRP3 inflammasome, suppressed the nuclear translocation of NF-κB/p65, and prevented mitochondrial damage, this process results in a reduction in the accumulation of reactive oxygen species (ROS). Additionally, FMN inhibited the mitogen-activated protein kinase (MAPK) signaling pathway, upregulated peroxisome proliferator-activated receptor gamma (PPAR-γ) in the nucleus, and decreased the release of inflammatory factors, thereby exerting anti-inflammatory effects.

CONCLUSION

By inhibiting mitochondrial damage, activating the MAPK/PPAR-γ/ROS signaling pathway, reducing the nuclear translocation of NF-κB, and suppressing the expression of NLRP3 inflammasome-associated proteins, FMN exerts anti-inflammatory effects.

Mitochondria-targeted nanotherapeutics: A new frontier in neurodegenerative disease treatment

Mitochondria are the seat of cellular energy and play key roles in regulating several cellular processes such as oxidative phosphorylation, respiration, calcium homeostasis and apoptotic pathways. Mitochondrial dysfunction results in error in oxidative phosphorylation, redox imbalance, mitochondrial DNA mutations, and disturbances in mitochondrial dynamics, all of which can lead to several metabolic and degenerative diseases. A plethora of studies have provided evidence for the involvement of mitochondrial dysfunction in the pathogenesis of neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, Huntington's disease, and amyotrophic lateral sclerosis. Hence mitochondria have been used as possible therapeutic targets in the regulation of neurodegenerative diseases. However, the double membranous structure of mitochondria poses an additional barrier to most drugs even if they are able to cross the plasma membrane. Most of the drugs acting on mitochondria also required very high doses to exhibit the desired mitochondrial accumulation and therapeutic effect which in-turn result in toxic effects. Mitochondrial targeting has been improved by direct conjugation of drugs to mitochondriotropic molecules like dequalinium (DQA) and triphenyl phosphonium (TPP) cations. But being cationic in nature, these molecules also exhibit toxicity at higher doses. In order to further improve the mitochondrial localization with minimal toxicity, TPP was conjugated with various nanomaterials like liposomes. inorganic nanoparticles, polymeric nanoparticles, micelles and dendrimers. This review provides an overview of the role of mitochondrial dysfunction in neurodegenerative diseases and various nanotherapeutic strategies for efficient targeting of mitochondria-acting drugs in these diseases.

Pharmacological approaches to enhance mitochondrial biogenesis: focus on PGC-1Α, AMPK, and SIRT1 in cellular health

BACKGROUND

Mitochondrial biogenesis is essential for cellular energy balance and metabolic stability. Its dysregulation is linked to various metabolic and neurodegenerative diseases, making it a significant therapeutic target. Pharmacological approaches aimed at enhancing mitochondrial function have gained attention for their potential to restore cellular metabolism.

OBJECTIVES

This review examines recent advancements in pharmacological strategies targeting mitochondrial biogenesis, focusing on the roles of PGC-1α, AMPK, and SIRT1, alongside novel therapeutic agents and drug delivery systems.

METHODS

A systematic review of studies published between 2018 and 2023 was conducted using databases such as PubMed, Web of Science, and Elsevier. Keywords related to mitochondrial biogenesis and pharmacological modulation were used to identify relevant literature.

RESULTS

Various pharmacological agents, including resveratrol, curcumin, and metformin, activate mitochondrial biogenesis through different pathways. SIRT1 activators and AMPK agonists have shown promise in improving mitochondrial function. Advances in mitochondria-targeted drug delivery systems enhance therapeutic efficacy, yet challenges remain in clinical translation due to the complexity of mitochondrial regulation.

CONCLUSION

Pharmacological modulation of mitochondrial biogenesis holds therapeutic potential for metabolic and neurodegenerative diseases. While preclinical studies are promising, further research is needed to optimize drug efficacy, delivery methods, and personalized treatment strategies.

Transgenic iPSC Lines with Genetically Encoded MitoTimer to Study Mitochondrial Biogenesis in Dopaminergic Neurons with Tauopathy

Background: Tauopathy has been identified as a prevalent causative agent of neurodegenerative diseases, including frontotemporal dementia with parkinsonism-17 (FTDP-17). This rare hereditary neurodegenerative condition is characterised by the manifestation of parkinsonism and behavioural changes. The majority of cases of FTDP-17 are associated with mutations in the MAPT gene, which encodes the tau protein. MAPT mutations lead to disruption of the balance between 3R and 4R tau forms, which causes destabilisation of microtubules and impairment of cellular organelle functions, particularly mitochondrial dysfunction. The development of model systems and tools for studying the molecular, genetic, and biochemical mechanisms underlying FTDP-17 and testing therapies at the cellular level is an urgent necessity. Methods: In this study, we generated transgenic lines of induced pluripotent stem cells (iPSCs) from a patient carrying the pathogenic mutation c.2013T > G (rs63750756, p.N279K) of MAPT and a healthy donor. A doxycycline-controlled transgene of the genetically encoded biosensor MitoTimer was integrated into the AAVS1 locus of these cells. The MitoTimer biosensor allows for lifetime monitoring of the turnover of mitochondria in neuronal cells derived from directed iPSC differentiation. The fact that transcription of the transgene can be induced by doxycycline provides additional possibilities for pulse labelling of newly formed mitochondria. Results: Transgenic iPSC lines provide a unique tool to study the molecular and genetic mechanisms of FTDP-17 caused by the presence of the c.2013T > G (p.N279K) mutation, as well as to test potential drugs in vitro.

Mitochondrial uncoupler 2,4-dinitrophenol (DNP) confers protection from the acute effect of ionizing radiation by regulating redox homeostasis in radio-sensitive organs of C57BL/6 mice

PURPOSE

The development of radiation countermeasures is an unmet need. Several cytoprotective approaches have been demonstrated to minimize ionizing radiation-induced tissue toxicity. Previously, our research indicated that mild mitochondrial uncoupling by 2,4-dinitrophenol (DNP) potentially counteract the IR-induced cell death. Herein, our investigation delves into the radio-protective efficacy of DNP following total-body irradiation (TBI) in C57BL/6 mice.

METHOD

DNP was administered orally 2 h prior to TBI (7.6 Gy gamma (γ)-radiation) as a prophylactic approach against acute radiation syndrome (ARS), and survival analysis was performed for 30 days in C57BL/6 mice. Radiation-induced reactive oxygen species (ROS) and macromolecular oxidation (lipid and protein) were examined in radiation-sensitive organs, including the spleen, bone marrow, liver, and gastrointestinal tract (GI). GI damage was examined using tissue histology and correlated with the level of antioxidant catalase, superoxide dismutase, and reduced glutathione (GSH).

RESULTS

DNP conferred radioprotection in mice, as evidenced by a 41% increase in survival. DNP pretreatment facilitates a substantial regulation of TBI-induced ROS production and macromolecular oxidation as early as 30 min to 24 h post-irradiation across various radiation-sensitive organs. Moreover, antioxidant analysis in GI tissue showed that DNP played a crucial role in maintaining redox homeostasis. This was evident through the elevation of catalase, superoxide dismutase, and GSH, eventually protecting from radiation-induced GI damage.

CONCLUSION

The study confirms that DNP-mediated regulation of redox homeostasis in the hematopoietic and GI systems enhances survival efficacy while mitigating the risk of acute tissue damage and provides protection against ARS in C57BL/6 mice.

Cellular Senescence in Health, Disease, and Lens Aging

Background: Cellular senescence is a state of irreversible cell cycle arrest that serves as a critical regulator of tissue homeostasis, aging, and disease. While transient senescence contributes to development, wound healing, and tumor suppression, chronic senescence drives inflammation, tissue dysfunction, and age-related pathologies, including cataracts. Lens epithelial cells (LECs), essential for maintaining lens transparency, are particularly vulnerable to oxidative stress-induced senescence, which accelerates lens aging and cataract formation. This review examines the dual role of senescence in LEC function and its implications for age-related cataractogenesis, alongside emerging senotherapeutic interventions. Methods: This review synthesizes findings on the molecular mechanisms of senescence, focusing on oxidative stress, mitochondrial dysfunction, and the senescence-associated secretory phenotype (SASP). It explores evidence linking LEC senescence to cataract formation, highlighting key studies on stress responses, DNA damage, and antioxidant defense. Recent advances in senotherapeutics, including senolytics and senomorphics, are analyzed for their potential to mitigate LEC senescence and delay cataract progression. Conclusions: LEC senescence is driven by oxidative damage, mitochondrial dysfunction, and impaired redox homeostasis. These factors activate senescence path-ways, including p53/p21 and p16/Rb, resulting in cell cycle arrest and SASP-mediated inflammation. The accumulation of senescent LECs reduces regenerative capacity, disrupts lens homeostasis, and contributes to cataractogenesis. Emerging senotherapeutics, such as dasatinib, quercetin, and metformin, show promise in reducing the senescent cell burden and modulating the SASP to preserve lens transparency.

["Mitochondrial medicine" in the light of the fourth national plan for rare diseases (PNMR4): The example of the MITOMICS project]

The aim of the MITOMICS project is to establish a clinical database of patients diagnosed with mitochondrial diseases, combined with a « multiomics » integrated approach in order to gain a better understanding of the molecular mechanisms underlying these diseases, and ultimately, to offer better patient care. The MITOMICS project thus contributes to the consolidation of a French "mitochondrial medicine", a notion that deserves to be examined. With the upcoming launch of the fourth national plan for rare diseases, it is an example of the study and management of rare and ultrarare diseases in France. This article traces the emergence of mitochondrial medicine since the early 1960s. It presents its main characteristics (genocentrism, strong techno-dependence), as well as its major technical and theoretical limitations, with a view to developing personalized mitochondrial medicine for the years to come.

Single-cell atlas reveals multi-faced responses of losartan on tubular mitochondria in diabetic kidney disease

BACKGROUND AND OBJECTIVE

Mitochondria are crucial to the function of renal tubular cells, and their dynamic perturbation in many aspects is an important mechanism of diabetic kidney disease (DKD). Single-nucleus RNA sequencing (snRNA-seq) technology is a high-throughput sequencing analysis technique for RNA at the level of a single cell nucleus. Here, our DKD mouse kidney single-cell RNA sequencing conveys a more comprehensive mitochondrial profile, which helps us further understand the therapeutic response of this unique organelle family to drugs.

METHODS

After high fat diet (HFD), mice were intraperitoneally injected with streptozotocin (STZ) to induce DKD, and then divided into three subsets: CON (healthy) subset, DKD (vehicle) subset, and LST (losartan; 25 mg/kg/day) subset. Divide HK-2 cell into LG (low glucose; 5 mM) and HG (high glucose; 30 mM) and HG + LST (losartan; 1 µ M) subsets. snRNA-seq was performed on the renal tissues of LST and DKD subset mice. To reveal the effects of losartan on gene function and pathway changes in renal tubular mitochondria, Gene Ontology (GO) enrichment analysis and GSEA/GSVA scoring were performed to analyze the specific response of proximal tubular (PT) cell mitochondria to losartan treatment, including key events in mitochondrial homeostasis such as mitochondrial morphology, dynamics, mitophagy, autophagic flux, mitochondrial respiratory chain, apoptosis, and ROS generation. Preliminary validation through in vitro and in vivo experiments, including observation of changes in mitochondrial morphology and dynamics using probes such as Mitotracker Red, and evaluation of the effect of losartan on key events of mitochondrial homeostasis perturbation using electron microscopy, laser confocal microscopy, immunofluorescence, and Western blotting. Detection of autophagic flux in cells by transfecting Ad-mCherry-GFP-LC3B dual fluorescence labeled adenovirus. Various fluorescent probes and energy detector are used to detect mitochondrial apoptosis, ROS, and respiration of mitochondrion.

RESULTS

Through the single-cell atlas of DKD mouse kidneys, it was found that losartan treatment significantly increased the percentage of PT cells. Gene Ontology (GO) enrichment analysis of differentially expressed genes showed enrichment of autophagy of mitochondrion pathway. Further GSEA analysis and GSVA scoring revealed that mitophagy and other key mitochondrial perturbation events, such as ROS production, apoptosis, membrane potential, adenosine triphosphate (ATP) synthesis, and mitochondrial dynamics, were involved in the protective mechanism of losartan on PT cells, thereby improving mitochondrial homeostasis. Consistent results were also obtained in mice and cellular experiments. In addition, we highlighted a specific renal tubular subpopulation with mitophagy phenotype found in single-cell data, and preliminarily validated it with co-localization and increased expression of Pink1 and Gclc in kidney specimens of DKD patients treated with losartan.

CONCLUSIONS

Our research suggests that scRNA-seq can reflect the multifaceted mitochondrial landscape of DKD renal tubular cells after drug treatment, and these findings may provide new targets for DKD therapy at the organelle level.

A review of the pathogenesis of mitochondria in breast cancer and progress of targeting mitochondria for breast cancer treatment

With breast cancer being the most common tumor among women in the world today, it is also the leading cause of cancer-related deaths. Standard treatments include chemotherapy, surgery, endocrine therapy, and targeted therapy. However, the heterogeneity, drug resistance, and poor prognosis of breast cancer highlight an urgent need for further exploration of its underlying mechanisms. Mitochondria, highly dynamic intracellular organelles, play a pivotal role in maintaining cellular energy metabolism. Altered mitochondrial function plays a critical role in various diseases, and recent studies have elucidated its pathophysiological mechanisms in breast carcinogenesis. This review explores the role of mitochondrial dysfunction in breast cancer pathogenesis and assesses potential mitochondria-targeted therapies.

Low Phosphorus Causes Hepatic Energy Metabolism Disorder Through Dynamin-Related Protein 1-Mediated Mitochondrial Fission in Fish

BACKGROUND

Low phosphorus (LP) diets perturb hepatic energy metabolism homeostasis in fish. However, the specific mechanisms in LP-induced hepatic energy metabolism disorders remain to be fully elucidated.

OBJECTIVES

This study sought to elucidate the underlying mechanisms of mitochondria involved in LP-induced energy metabolism disorders.

METHODS

Spotted seabass were fed diets with 0.72% (S-AP, control) or 0.36% (S-LP) available phosphorus for 10 wk. Drp1 was knocked down or protein kinase (PK) A was activated using 8Br-cAMP (5 μM, a PKA activator) in spotted seabass hepatocytes under LP medium. Zebrafish were fed Z-LP diets (0.30% available phosphorus) containing Mdivi-1 (5 mg/kg, a Drp1 inhibitor) or 8Br-cAMP (0.5 mg/kg) for 6 wk. Biochemical and molecular parameters, along with transmission electron microscopy and immunofluorescence, were used to assess hepatic glycolipid metabolism, mitochondrial function, and morphology.

RESULTS

Spotted seabass fed S-LP diets showed reduced ATP (52%) and cAMP (52%) concentrations, along with reduced Drp1 (s582) (38%) and PKA (61%) phosphorylation concentrations in the liver compared with those fed S-AP diets (P < 0.05). Drp1 knockdown elevated ATP concentrations (1.99-fold), decreased mitochondrial DRP1 protein amounts (45%), and increased mitochondrial aspect ratio (1.82-fold) in LP-treated hepatocytes (P < 0.05). Furthermore, 8Br-cAMP-treated hepatocytes exhibited higher PKA phosphorylation (2.85-fold), ATP concentrations (1.60-fold), and mitochondrial aspect ratio (2.00-fold), along with decreased mitochondrial DRP1 protein concentrations (29%) under LP medium (P < 0.05). However, mutating s582 to alanine mimic Drp1 dephosphorylation decreased ATP concentrations (63%) and mitochondrial aspect ratio (53%) in 8Br-cAMP-treated hepatocytes (P < 0.05). In addition, zebrafish fed Z-LP diets containing Mdivi-1 or 8Br-cAMP had higher ATP concentrations (3.44-fold or 1.98-fold) than those fed Z-LP diets (P < 0.05).

CONCLUSIONS

These findings provide a potential mechanistic elucidation for LP-induced energy metabolism disorders through the cAMP/PKA/Drp1-mediated mitochondrial fission signaling pathway.

Targeting Caveolin-1 in Multiple Myeloma Cells Enhances Chemotherapy and Natural Killer Cell-Mediated Immunotherapy

The cell membrane transport capacity and surface targets of multiple myeloma (MM) cells heavily influence chemotherapy and immunotherapy. Here, it is found that caveolin-1 (CAV1), a primary component of membrane lipid rafts and caveolae, is highly expressed in MM cells and is associated with MM progression and drug resistance. CAV1 knockdown decreases MM cell adhesion to stromal cells and attenuates cell adhesion-mediated drug resistance to bortezomib. CAV1 inhibition in MM cells enhances natural killer cell-mediated cytotoxicity through increasing CXCL10, SLAMF7, and CD112. CAV1 suppression reduces mitochondrial membrane potential, increases reactive oxygen species, and inhibits autophagosome-lysosome fusion, resulting in the disruption of redox homeostasis. Additionally, CAV1 knockdown enhances glutamine addiction by increasing ASCT2 and LAT1 and dysregulates glutathione metabolism. As a result of CAV1 inhibition, MM cells are more sensitive to starvation, glutamine depletion, and glutamine transporter inhibition, and grow more slowly in vivo in a mouse model treated with bortezomib. The observation that CAV1 inhibition modulated by 6-mercaptopurine, daidzin, and statins enhances the efficacy of bortezomib in vitro and in vivo highlights the translational significance of these FDA-approved drugs in improving MM outcomes. These data demonstrate that CAV1 serves as a potent therapeutic target for enhancing chemotherapy and immunotherapy for MM.

Gas Empowered Dual-Cascade Strategy for Augmented Single-Atom Nanotherapies

Single-atom nanotherapies have received numerous attention in malignant oncotherapy. However, the insufficient enzyme substrate and the upregulation of heat shock proteins during therapeutic interventions are seldom concurrently noticed. Herein, a novel gas empowered dual-cascade synergistic treatment strategy is demonstrated with domino effect, which can sequentially reinforce single-atom nanozyme (SAzyme)-based enzymatic therapeutics and mild photothermal therapy (PTT) (< 45 °C). In the proof-of-concept study, Fe single atom nanozyme (Fe/SAzyme) loaded with hydrogen sulfide (H2S) donor NaHS is developed for HSPs-silencing mediated mild PTT. The generated H2S suppresses the catalase activity to achieve "intracellular H2O2 conservation", thereby furnishing the enzyme substrate to Fe/SAzyme to produce abundant cytotoxic hydroxyl radicals (·OH) for augmented enzymatic therapeutics. Then, excess ·OH induced mitochondrial dysfunction blocks adenosine triphosphate (ATP) energy supply to realize cellular energy remodeling, which hinders overexpression of HSPs and enhances mild PTT of Fe/SAzyme both in vitro and vivo. Consequently, the gas-triggered dual-cascade strategy achieves domino H2S/·OH/mitochondrial dysfunction synergistic effect, endowing SAzymes with maximum antitumor efficacy via enzymatic therapeutics combined with mild PTT. This dual-cascaded gas/enzymatic/mild PTT synergistic oncotherapy not only exhibits a new pathway for gas-facilitated mild PTT, but also offers a valuable paradigm for the application of "1 + 1 + 1 > 3" multimodal synergistic tumor therapy.

A Review over Mitochondrial Diseases Due to mtDNA Mutations: Recent Advances and Remedial Aspects

Mitochondria, also called 'powerhouse of the cell', is meant for energy generation in eukaryotic cells. This action is performed by mitochondria through the oxidative phosphorylation (OXPHOS) of the respiratory chain (RC). Based on the functioning of the cell, the number of mitochondria varies up to thousands in number. Mutations in the mitochondrial DNA (mtDNA) and/or nuclear DNA (nDNA) genes may lead to the generation of primary mitochondrial disease (PMD) that affects the structure and function of mitochondria. The diagnosis of such mitochondrial diseases occurs in early childhood and it can lead to serious, fetal and multi-organ diseases. Understanding epigenetic events and changes in the pathway can help improve the effectiveness of treatment. However, there are several reasons lack of the disease symptoms (age, sign, symptoms, morbidity and lethality), restricted availability of preclinical models along with extensive phenotypes that hamper the development of efficient drugs. Despite the introduction of new treatments and the encouraging results of treatments and therapies, there is no effective cure for PMD. This article contains information about the changes associated with cytopathic diseases that make possible the analysis of various diseases by genetic techniques. Increasing our understanding of how mitochondrial DNA mutations affect mitochondrial metabolism and subsequently result in neurodegenerative disease will prove vital to the development of targeted therapies and treatments.

Functional utility of gold complexes with phosphorus donor ligands in biological systems

Metallo-phosphines are ubiquitous in organometallic chemistry with widespread applications as catalysts in various chemical transformations, precursors for organic electronics, and chemotherapeutic agents or chemical probes. Here, we provide a comprehensive review of the exploration of the current biological applications of Au complexes bearing phosphine donor ligands. The goal is to deepen our understanding of the synthetic utility and reactivity of Au-phosphine complexes to provide insights that could lead to the design of new molecules and enhance the cross-application or repurposing of these complexes.

Triphenylphosphine-Modified IridiumIII, RhodiumIII, and RutheniumII Complexes to Achieve Enhanced Anticancer Selectivity by Targeting Mitochondria

The incorporation of an organelle-targeting moiety into compounds has proven to be an effective strategy in the development of targeted anticancer drugs. We herein report the synthesis, characterization, and biological evaluation of novel triphenylphosphine-modified half-sandwich iridiumIII, rhodiumIII, and rutheniumII complexes. The primary goal was to enhance anticancer selectivity through mitochondrial targeting. All these triphenylphosphine-modified complexes exhibited promising cytotoxicity in the micromolar range (5.13-23.22) against A549 and HeLa cancer cell lines, surpassing the activity of comparative complexes that lack the triphenylphosphine moiety. Noteworthy is their good selectivity toward cancer cells compared to normal BEAS-2B cells, underscored by selectivity index ranging from 7.3 to >19.5. Mechanistically, these complexes primarily target mitochondria rather than interacting with DNA. The targeting of mitochondria and triggering mitochondrial dysfunction were confirmed using both confocal microscopy and flow cytometry. Their ability to depolarize mitochondrial membrane potential (MMP) and enhance reactive oxygen species (ROS) was observed, thereby leading to intrinsic apoptotic pathways. Moreover, these complexes lead to cell cycle arrest in the G2/M phase and demonstrated antimigration effects, significantly inhibiting the migration of A549 cells in wound-healing assays.

Z-Ligustilide: A Potential Therapeutic Agent for Atherosclerosis Complicating Cerebrovascular Disease

Atherosclerosis (AS) is one of the major catalysts of ischemic cerebrovascular disease, and the death and disease burden from AS and its cerebrovascular complications are increasing. Z-ligustilide (Z-LIG) is a key active ingredient in Angelica sinensis (Oliv.) Diels and Ligusticum chuanxiong Hort. In this paper, we first introduced LIG's physicochemical properties and pharmacokinetics. Then, we reviewed Z-LIG's intervention and therapeutic mechanisms on AS and its cerebrovascular complications. The mechanisms of Z-LIG intervention in AS include improving lipid metabolism, antioxidant and anti-inflammatory effects, protecting vascular endothelium, and inhibiting vascular endothelial fibrosis, pathological thickening, and plaque calcification. In ischemic cerebrovascular diseases complicated by AS, Z-LIG exerts practical neuroprotective effects in ischemic stroke (IS), transient ischemic attack (TIA), and vascular dementia (VaD) through anti-neuroinflammatory, anti-oxidation, anti-neuronal apoptosis, protection of the blood-brain barrier, promotion of mitochondrial division and angiogenesis, improvement of cholinergic activity, inhibition of astrocyte proliferation, and endoplasmic reticulum stress. This paper aims to provide a basis for subsequent studies of Z-LIG in the prevention and treatment of AS and its cerebrovascular complications and, thus, to promote the development of interventional drugs for AS.

Nanoengineered mitochondria enable ocular mitochondrial disease therapy via the replacement of dysfunctional mitochondria

Leber's hereditary optic neuropathy (LHON) is an ocular mitochondrial disease that involves the impairment of mitochondrial complex I, which is an important contributor to blindness among young adults across the globe. However, the disorder has no available cures, since the approved drug idebenone for LHON in Europe relies on bypassing complex I defects rather than fixing them. Herein, PARKIN mRNA-loaded nanoparticle (mNP)-engineered mitochondria (mNP-Mito) were designed to replace dysfunctional mitochondria with the delivery of exogenous mitochondria, normalizing the function of complex I for treating LHON. The mNP-Mito facilitated the supplementation of healthy mitochondria containing functional complex I via mitochondrial transfer, along with the elimination of dysfunctional mitochondria with impaired complex I via an enhanced PARKIN-mediated mitophagy process. In a mouse model induced with a complex I inhibitor (rotenone, Rot), mNP-Mito enhanced the presence of healthy mitochondria and exhibited a sharp increase in complex I activity (76.5%) compared to the group exposed to Rot damage (29.5%), which greatly promoted the restoration of ATP generation and mitigation of ocular mitochondrial disease-related phenotypes. This study highlights the significance of nanoengineered mitochondria as a promising and feasible tool for the replacement of dysfunctional mitochondria and the repair of mitochondrial function in mitochondrial disease therapies.

Electroacupuncture pretreatment maintains mitochondrial quality control via HO-1/MIC60 signaling pathway to alleviate endotoxin-induced acute lung injury

Electroacupuncture has been demonstrated to mitigate endotoxin-induced acute lung injury by enhancing mitochondrial function. This study investigates whether electroacupuncture confers lung protection through the regulation of mitochondrial quality control mediated by heme oxygenase-1 (HO-1) and the mitochondrial inner membrane protein MIC60. HO-1, an inducible stress protein, is crucial for maintaining mitochondrial homeostasis and protecting against lung injury. MIC60, a key component of the mitochondrial contact site and cristae organizing system, supports mitochondrial integrity. We employed genetic knockout/silencing and cell transfection techniques to model lipopolysaccharide (LPS)-induced lung injury, assessing changes in mitochondrial structure, reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP), and the expression of proteins essential for mitochondrial quality control. Our findings reveal that electroacupuncture alleviates endotoxin-induced acute lung injury and associated mitochondrial dysfunction, as evidenced by reductions in lung injury scores, decreased ROS production, and suppressed expression of proteins involved in mitochondrial fission and mitophagy. Additionally, electroacupuncture enhanced MMP and upregulated proteins that facilitate mitochondrial fusion and biogenesis. Importantly, the protective effects of electroacupuncture were reduced in models with Hmox1 knockout or Mic60 silencing, and in macrophages transfected with Hmox1-siRNA or Mic60-siRNA. Moreover, HO-1 was found to influence MIC60 expression during electroacupuncture preconditioning and LPS challenge, demonstrating that these proteins not only co-localize but also interact directly. In conclusion, electroacupuncture effectively modulates mitochondrial quality control through the HO-1/MIC60 signaling pathway, offering an adjunctive therapeutic strategy to ameliorate endotoxin-induced acute lung injury in both in vivo and in vitro settings.

Role of mitochondria in renal ischemia-reperfusion injury

Acute kidney injury (AKI) induced by renal ischemia-reperfusion injury (IRI) has a high morbidity and mortality, representing a worldwide problem. The kidney is an essential organ of metabolism that has high blood perfusion and is the second most mitochondria-rich organ after the heart because of the high ATP demands of its essential functions of nutrient reabsorption, acid-base and electrolyte balance, and hemodynamics. Thus, these energy-intensive cells are particularly vulnerable to mitochondrial dysfunction. As the bulk of glomerular ultrafiltrate reabsorption by proximal tubules occurs via active transport, the mitochondria of proximal tubules must be equipped for detecting and responding to fluctuations in energy availability to guarantee efficient basal metabolism. Any insults to mitochondrial quality control mechanisms may lead to biological disruption, blocking the clearance of damaged mitochondria and resulting in morphological change and tissue dysfunction. Extensive research has shown that mitochondria have pivotal roles in acute kidney disease, so in this article, we discuss the role of mitochondria, their dynamics and mitophagy in renal ischemia-reperfusion injury.

Design and synthesis of novel mitochondria-targeted ergosterol peroxide derivatives as potential anti-cancer agents

Ergosterol peroxide (EP) is a natural steroid compound that has been reported to have significant antitumor activity. However, its poor water solubility and cellular uptake mean that it has weak efficacy against tumor cells. Herein, we designed and synthesized a series of EP derivatives with mitochondrial targeting properties. Of these, compound 15a showed an IC50 value of 0.32 μM against MCF-7 cells, which was 67-fold higher than that of the parental EP (IC50 = 21.46 μM), and was better than cisplatin (IC50 = 4.23 μM), had a selectivity index of 25.28 (IC50MCF-10A/IC50MCF-7). Additionally, compound 15a promoted an increase in intracellular reactive oxygen species levels and a decrease in mitochondrial membrane potential, and blocked the cell cycle in the G0/G1 phase. In a mouse model of breast cancer, 15a showed 89.85 % tumor inhibition at a dose of 20 mg/kg, which is similar to the therapeutic effect of the cisplatin. On the basis of these results, 15a could be considered for further preclinical evaluation for cancer therapy.

Ruthenium(ii)-Arene Complex Triggers Immunogenic Ferroptosis for Reversing Drug Resistance

Chemoresistance remains an arduous challenge in oncology, but ferroptosis shows potential for overcoming it by stimulating the immune system. Herein, a novel high-performance ruthenium(II)-based arene complex [Ru(η6-p-cym)(BTBpy)Cl] (RuBTB) is developed for ferroptosis-enhanced antitumor immunity and drug resistance reversal via glutathione (GSH) metabolism imbalance. RuBTB shows significantly enhanced antiproliferation activity against cisplatin (CDDP)-resistant lung cancer cells (A549R), with 26.35-fold better anticancer effects than CDDP. Immunogenic ferroptosis is induced by GSH depletion/glutathione peroxidase 4 (GPX4) inactivation, mitochondrial dysfunction, and endoplasmic reticulum (ER) stress in RuBTB-treated cells. Mechanism studies indicate that RuBTB regulates ferroptosis and immune-related pathways, coordinating with GSH metabolism-mediated glutathione S-transferase (GST) inhibition to reverse drug resistance in platinum-combined therapy. Tumor vaccination experiments demonstrate the intensified antitumor effects endowed by highly immunogenic ferroptosis in vivo. This study provides the first example of a metal-arene complex for achieving satisfactory ferroptosis therapeutic effects with efficient immunogenicity to overcome drug resistance in metal-based immunochemotherapy.

A peptide alleviated oxidative damages in the L02 cells and mice liver

The liver is vitally metabolic for a multitude of biochemical reactions. Consequently, it generates many free radicals and reactive oxygen species, rendering it more susceptible to oxidative stress-induced damage. Oxidative stress represents a pivotal factor in the pathogenesis of liver diseases. We screened some antioxidant peptides previously. Here we investigated whether the peptides could attenuate oxidative damage with APPH in L02 cells. The results showed that one of the peptides, sequence FETLMPLWGNK, could decrease the excessive reactive oxygen species, increase antioxidant enzyme activity and protect mitochondrial function, reduce the ratio of apoptosis and S phase cycle arrest, and improve the survival rate of L02 cells damaged by APPH compared to cells of the control group. Then the peptide was evaluated in mice that CCl4 injured. We found that CCl4-injured mice had significantly increased serum inflammatory factors and liver injury markers, a large number of inflammatory cell infiltration, and local necrosis in the liver. The peptide could reduce inflammation, and improve liver pathological changes. This phenomenon may be associated with the activation of the Nrf2 signaling pathway. Concurrently, the peptide protects the liver by regulating the expression of proteins related to the mitochondrial apoptosis pathway (p53, Bax, Bcl-2, and Caspase3) and mitophagy-related proteins (PINK1, Parkin, and AMPKα). Therefore, the results indicated that the peptide is an active substance with antioxidant activity and anti-inflammatory effects.

Pioneering Advances and Innovative Applications of Mesoporous Carriers for Mitochondria-Targeted Therapeutics

Mitochondria, known as the cell's powerhouse, play a critical role in energy production, cellular maintenance, and stemness regulation in non-cancerous cells. Despite their importance, using drug delivery systems to target the mitochondria presents significant challenges due to several barriers, including cellular uptake limitations, enzymatic degradation, and the mitochondrial membranes themselves. Additionally, barriers in the organs to be targetted, along with extracellular barriers formed by physiological processes such as the reticuloendothelial system, contribute to the rapid elimination of nanoparticles designed for mitochondrial-based drug delivery. Overcoming these challenges has led to the development of various strategies, such as molecular targeting using cell-penetrating peptides, genomic editing, and nanoparticle-based systems, including porous carriers, liposomes, micelles, and Mito-Porters. Porous carriers stand out as particularly promising candidates as drug delivery systems for targeting the mitochondria due to their large pore size, surface area, and ease of functionalisation. Depending on the pore size, they can be classified as micro-, meso-, or macroporous and are either ordered or non-ordered based on both size and pore uniformity. Several methods are employed to target the mitochondria using porous carriers, such as surface modifications with polyethylene glycol (PEG), incorporation of targeting ligands like triphenylphosphonium, and capping the pores with gold nanoparticles or chitosan to enable controlled and triggered drug delivery. Photodynamic therapy is another approach, where drug-loaded porous carriers generate reactive oxygen species (ROS) to enhance mitochondrial targeting. Further advancements have been made in the form of functionalised porous silica and carbon nanoparticles, which have demonstrated potential for effective drug delivery to mitochondria. This review highlights the various approaches that utilise porous carriers, specifically focusing on silica-based systems, as efficient vehicles for targeting mitochondria, paving the way for improved drug delivery strategies in mitochondrial therapies.

A Spatiotemporally Controlled and Mitochondria-Targeted Prodrug of Hydrogen Sulfide Enables Mild Mitochondrial Uncoupling for the Prevention of Lipid Deposition

Mild mitochondrial uncoupling offers therapeutic benefits for various diseases like obesity by regulating cellular energy metabolism. However, effective chemical intervention tools for inducing mild mitochondria-targeted uncoupling are limited. Herein, we have developed a mitochondria-targeted H2S prodrug M1 with a unique property of on-demand photoactivated generation of H2S accompanied by self-reporting fluorescence for real-time tracking. Upon photoirradiation, M1 decomposes in mitochondria to generate H2S and a turn-on fluorescent coumarin derivative for the visualization and quantification of H2S. M1 is confirmed to induce reactive oxygen species (ROS)-dependent mild mitochondrial uncoupling, activating mitochondria-associated adenosine monophosphate-activated protein kinase (AMPK) to suppress palmitic acid (PA)-induced lipid deposition in hepatocytes. The uncoupling functions induced by M1 are strictly controlled in mitochondria, representing a fresh strategy to prevent lipid deposition and improve metabolic syndrome by increasing cellular energy expenditure.

The cyano positional isomerism strategy for constructing mitochondria-targeted AIEgens with type I reactive oxygen species generation capability

In this work, a series of cationic luminogens (designated as PSMP isomers) were developed based on the cyano positional isomerism strategy. The isomerism of the cyano substituent on the molecular skeleton can finely regulate the optical behaviour, the type of photoinduced reactive oxygen species (ROS), and mitochondria-targeted capability of isomers. Interestingly, PSMP-4, with the cyano group installed at an appropriate location, exhibits a special aggregation-induced emission effect and potent O2˙- generation efficacy through the type I photochemistry pathway. Notably, PSMP-4 can accumulate in mitochondria with high specificity. Taking advantage of its excellent photostability, PSMP-4 realizes in situ mitochondria imaging in a washing-free manner and sensitive response to the change of mitochondrial membrane potential. The integration of comprehensive photophysical properties and mitochondrial specificity enable PSMP-4 to successfully trigger the death of cancer cells through an efficient type I photodynamic therapy process both in vitro and in multicellular tumor spheroid models.

Orthogonal Persulfide Generation through Precision Tools Provides Insights into Mitochondrial Sulfane Sulfur

The sulfane sulfur pool, comprised of persulfide (RS-SH) and polysulfide (RS-SnH) derived from hydrogen sulfide (H2S), has emerged as a major player in redox biochemistry. Mitochondria, besides energy generation, serve as significant cellular redox hubs, mediate stress response and cellular health. However, the effects of endogenous mitochondrial sulfane sulfur (MSS) remain largely uncharacterized as compared with their cytosolic counterparts, cytosolic sulfane sulfur (CSS). To investigate this, we designed a novel artificial substrate for mitochondrial 3-mercaptopyruvate sulfurtransferase (3-MST), a key enzyme involved in MSS biosynthesis. Using cells expressing a mitochondrion-localized persulfide biosensor, we demonstrate this tool's ability to selectively enhance MSS. While H2S was previously known to suppress human immunodeficiency virus (HIV-1), we found that MSS profoundly affected the HIV-1 life cycle, mediating viral reactivation from latency. Additionally, we provide evidence for the role of the host's mitochondrial redox state, membrane potential, apoptosis, and respiration rates in managing HIV-1 latency and reactivation. Together, dynamic fluctuations in the MSS pool have a significant and possibly conflicting effect on HIV-1 viral latency. The precision tools developed herein allow for orthogonal generation of persulfide within both mitochondria and the cytosol and will be useful in interrogating disease biology.

A Coupling-Induced Assembly Strategy for Constructing Artificial Shell on Mitochondria in Living Cells

The strategy of in vivo self-assembly has been developed for improved enrichment and long-term retention of anticancer drug in tumor tissues. However, most self-assemblies with non-covalent bonding interactions are susceptible to complex physiological environments, leading to weak stability and loss of biological function. Here, we develop a coupling-induced assembly (CIA) strategy to generate covalently crosslinked nanofibers, which is applied for in situ constructing artificial shell on mitochondria. The oxidation-responsive peptide-porphyrin conjugate P1 is synthesized, which self-assemble into nanoparticles. Under the oxidative microenvironment of mitochondria, the coupling of thiols in P1 causes the formation of dimers, which is further ordered and stacked into crosslinked nanofibers. As a result, the artificial shell is constructed on the mitochondria efficiently through multivalent cooperative interactions due to the increased binding sites. Under ultrasound (US) irradiation, the porphyrin molecules in the shell produce a large amount of reactive oxygen species (ROS) that act on the adjacent mitochondrial membrane, exhibiting ~2-fold higher antitumor activity than nanoparticles in vitro and in vivo. Therefore, the mitochondria-targeted CIA strategy provides a novel perspective on improved sonodynamic therapy (SDT) and shows potential applications in antitumor therapies.

Severe hypoxaemic hypercapnia compounds cerebral oxidative-nitrosative stress during extreme apnoea: Implications for cerebral bioenergetic function

We examined the extent to which apnoea-induced extremes of oxygen demand/carbon dioxide production impact redox regulation of cerebral bioenergetic function. Ten ultra-elite apnoeists (six men and four women) performed two maximal dry apnoeas preceded by normoxic normoventilation, resulting in severe end-apnoea hypoxaemic hypercapnia, and hyperoxic hyperventilation designed to ablate hypoxaemia, resulting in hyperoxaemic hypercapnia. Transcerebral exchange of ascorbate radicals (by electron paramagnetic resonance spectroscopy) and nitric oxide metabolites (by tri-iodide chemiluminescence) were calculated as the product of global cerebral blood flow (by duplex ultrasound) and radial arterial (a) to internal jugular venous (v) concentration gradients. Apnoea duration increased from 306 ± 62 s during hypoxaemic hypercapnia to 959 ± 201 s in hyperoxaemic hypercapnia (P ≤ 0.001). Apnoea generally increased global cerebral blood flow (all P ≤ 0.001) but was insufficient to prevent a reduction in the cerebral metabolic rates of oxygen and glucose (P = 0.015-0.044). This was associated with a general net cerebral output (v > a) of ascorbate radicals that was greater in hypoxaemic hypercapnia (P = 0.046 vs. hyperoxaemic hypercapnia) and coincided with a selective suppression in plasma nitrite uptake (a > v) and global cerebral blood flow (P = 0.034 to <0.001 vs. hyperoxaemic hypercapnia), implying reduced consumption and delivery of nitric oxide consistent with elevated cerebral oxidative-nitrosative stress. In contrast, we failed to observe equidirectional gradients consistent with S-nitrosohaemoglobin consumption and plasma S-nitrosothiol delivery during apnoea (all P ≥ 0.05). Collectively, these findings highlight a key catalytic role for hypoxaemic hypercapnia in cerebral oxidative-nitrosative stress. KEY POINTS: Local sampling of blood across the cerebral circulation in ultra-elite apnoeists determined the extent to which severe end-apnoea hypoxaemic hypercapnia (prior normoxic normoventilation) and hyperoxaemic hypercapnia (prior hyperoxic hyperventilation) impact free radical-mediated nitric oxide bioavailability and global cerebral bioenergetic function. Apnoea generally increased the net cerebral output of free radicals and suppressed plasma nitrite consumption, thereby reducing delivery of nitric oxide consistent with elevated oxidative-nitrosative stress. The apnoea-induced elevation in global cerebral blood flow was insufficient to prevent a reduction in the cerebral metabolic rates of oxygen and glucose. Cerebral oxidative-nitrosative stress was greater during hypoxaemic hypercapnia compared with hyperoxaemic hypercapnia and coincided with a lower apnoea-induced elevation in global cerebral blood flow, highlighting a key catalytic role for hypoxaemia. This applied model of voluntary human asphyxia might have broader implications for the management and treatment of neurological diseases characterized by extremes of oxygen demand and carbon dioxide production.

Hypoxia and aging: molecular mechanisms, diseases, and therapeutic targets

Aging is a complex biological process characterized by the gradual decline of cellular functions, increased susceptibility to diseases, and impaired stress responses. Hypoxia, defined as reduced oxygen availability, is a critical factor that influences aging through molecular pathways involving hypoxia-inducible factors (HIFs), oxidative stress, inflammation, and epigenetic modifications. This review explores the interconnected roles of hypoxia in aging, highlighting how hypoxic conditions exacerbate cellular damage, promote senescence, and contribute to age-related pathologies, including cardiovascular diseases, neurodegenerative disorders, cancer, metabolic dysfunctions, and pulmonary conditions. By examining the molecular mechanisms linking hypoxia to aging, we identify key pathways that serve as potential therapeutic targets. Emerging interventions such as HIF modulators, antioxidants, senolytics, and lifestyle modifications hold promise in mitigating the adverse effects of hypoxia on aging tissues. However, challenges such as the heterogeneity of aging, lack of reliable biomarkers, and safety concerns regarding hypoxia-targeted therapies remain. This review emphasizes the need for personalized approaches and advanced technologies to develop effective antiaging interventions. By integrating current knowledge, this review provides a comprehensive framework that underscores the importance of targeting hypoxia-induced pathways to enhance healthy aging and reduce the burden of age-related diseases.

Mitochondrial-Derived Peptide MOTS-c Suppresses Ovarian Cancer Progression by Attenuating USP7-Mediated LARS1 Deubiquitination

Mitochondrial-nuclear communication plays a vital role in maintaining cellular homeostasis. MOTS-c, a short peptide derived from the 12S rRNA of mitochondrial DNA, has been suggested as a retrograde mitochondrial signal. Although recent clinical studies have suggested a possible link between MOTS-c and human cancer, the role of MOTS-c in tumorigenesis has yet to be investigated. Here, MOTS-c levels are found to be reduced in both serum and tumor tissues from ovarian cancer (OC) patients, which are associated with poor patients' prognosis. Exogenous MOTS-c inhibits the proliferation, migration and invasion of OC cells, and induces cell cycle arrest and apoptosis. Mechanistically, MOTS-c interacts with LARS1 and promotes its ubiquitination and proteasomal degradation. In addition, USP7 was identified as a deubiquitinase of LARS1, and MOTS-c can attenuates USP7-mediated LARS1 deubiquitination by competing with USP7 for binding to LARS1. Besides, LARS1 was found to be increased and play an important oncogenic function in OC. More importantly, MOTS-c displays a marked anti-tumor effect on OC growth without systemic toxicity in vivo. In conclusion, this study reveals a crucial role of MOTS-c in OC and provides a possibility for MOTS-c as a therapeutic target for the treatment of this manlignacy.

Xanthohumol Protects Against Neuronal Excitotoxicity and Mitochondrial Dysfunction in APP/PS1 Mice: An Omics-Based Study

Background: Neuronal excitotoxicity and metabolic decline, which begin in the early stages of Alzheimer's disease (AD), pose challenges for effective amelioration. Our previous work suggested that the natural compound xanthohumol, the most abundant prenylated flavonoid in hops, prevents memory deficits in APP/PS1 mice; however, the underlying mechanisms remain unclear. Methods: This study utilized APP/PS1 mice and cutting-edge omics techniques to investigate the effects of xanthohumol on hippocampal proteome, serum metabolome, and microbiome. Results: Our findings revealed that xanthohumol reduces the postsynaptic overexpression of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, N-methyl-D-aspartate, and metabotropic glutamate receptors, but enhances ATP synthesis and mitophagy in the young AD hippocampus. Further mechanistic analyses suggested systemic regulatory effects, particularly on the decreasing glutamate synthesis in the blood and intestines of AD mice following xanthohumol administration. Conclusions: These results underscore the potential of xanthohumol in mitigating AD pathology through multifaceted mechanisms, sparking interest and curiosity in its preventive and therapeutic potential in AD.

Mitochondrial dynamics and energy metabolism interference therapy for promoting photothermal sensitization

Photothermal therapy (PTT) is minimally invasive, precisely controlled, and therapeutically effective treatment method. However, its efficacy is limited by the overexpression of heat shock proteins (HSP), which leads to cellular thermal blockade. Targeting mitochondria with PTT can enhance anticancer efficacy, as mitochondria encode genes related to HSP and provide energy for their production. Nevertheless, mitochondrial dynamics confer resistance to damage from external stimuli. Therefore, disrupting the balance of mitochondrial dynamics is essential to impede HSP production. Herein, we synthesized degradable Cu3BiS3 (CBS) nanosheets (NSs) with one face modified by carboxylated triphenylphosphonium (TPP) to target mitochondria. This modification increases the production of exogenous reactive oxygen species (ROS) and induces the overexpression of dynamin-related protein 1 (Drp1), disrupting mitochondrial dynamic homeostasis. The other face was modified with carboxylated β-cyclodextrin (CD) to load the glycolysis inhibitor (2-deoxyglucose, 2DG), thereby reducing adenosine triphosphate (ATP) production in the extra-mitochondrial space, as glycolysis also occurs in the cytoplasm. The resulting TPP-CBS-2DG Janus NSs (JNSs) not only disrupt mitochondrial energy production, leading to cell starvation, but also inhibit HSP production. Consequently, TPP-CBS-2DG JNSs can enhance tumor thermal sensitivity in PTT, improving its efficacy. This work holds great promise for overcoming tumor heat resistance in PTT and provides a feasible method for fabricating selectively modified multifunctional NSs.

Attenuating mitochondrial dysfunction-derived reactive oxygen species and reducing inflammation: the potential of Daphnetin in the viral pneumonia crisis

Amidst the global burden of viral pneumonia, mitigating the excessive inflammatory response induced by viral pneumonia has emerged as a significant challenge. Pneumovirus infections can lead to the persistent activation of M1 macrophages, culminating in cytokine storms that exacerbate pulmonary inflammation and contribute to the development of pulmonary fibrosis. Mitochondria, beyond their role as cellular powerhouses, are pivotal in integrating inflammatory signals and regulating macrophage polarization. Mitochondrial damage in alveolar macrophages is postulated to trigger excessive release of reactive oxygen species (ROS), thereby amplifying macrophage-mediated inflammatory pathways. Recent investigations have highlighted the anti-inflammatory potential of Daphnetin, particularly in the context of cardiovascular and renal disorders. This review elucidates the mechanisms by which viral infection-induced mitochondrial damage promotes ROS generation, leading to the phenotypic shift of alveolar macrophages towards a pro-inflammatory state. Furthermore, we propose a mechanism whereby Daphnetin attenuates inflammatory signaling by inhibiting excessive release of mitochondrial ROS, thus offering mitochondrial protection. Daphnetin may represent a promising pharmacological intervention for viral pneumonia and could play a crucial role in addressing future pandemics.

Integrative study of skeletal muscle mitochondrial dysfunction in a murine pancreatic cancer-induced cachexia model

Pancreatic ductal adenocarcinoma (PDAC), the most common pancreatic cancer, is a deadly cancer, often diagnosed late and resistant to current therapies. PDAC patients are frequently affected by cachexia characterized by muscle mass and strength loss (sarcopenia) contributing to patient frailty and poor therapeutic response. This study assesses the mechanisms underlying mitochondrial remodeling in the cachectic skeletal muscle, through an integrative exploration combining functional, morphological, and omics-based evaluation of gastrocnemius muscle from KIC genetically engineered mice developing autochthonous pancreatic tumor and cachexia. Cachectic PDAC KIC mice exhibit severe sarcopenia with loss of muscle mass and strength associated with reduced muscle fiber's size and induction of protein degradation processes. Mitochondria in PDAC atrophied muscles show reduced respiratory capacities and structural alterations, associated with deregulation of oxidative phosphorylation and mitochondrial dynamics pathways. Beyond the metabolic pathways known to be altered in sarcopenic muscle (carbohydrates, proteins, and redox), lipid and nucleic acid metabolisms are also affected. Although the number of mitochondria per cell is not altered, mitochondrial mass shows a twofold decrease and the mitochondrial DNA threefold, suggesting a defect in mitochondrial genome homeostasis. In conclusion, this work provides a framework to guide toward the most relevant targets in the clinic to limit PDAC-induced cachexia.

Potent BODIPY-based photosensitisers for selective mitochondrial dysfunction and effective photodynamic therapy

The development of new and improved mitochondria-targeting photosensitisers (PSs) for photodynamic therapy (PDT) remains highly desirable, due to the critical role the mitochondria play in maintaining healthy cellular function. Here, we report the design, synthesis, photophysical properties and biological characterisation of a series of di-iodinated BODIPY-based PSs, BODIPY-Mito-I-n, for mitochondria-targeted PDT applications. Six BODIPY-Mito-I-n analogues were synthesised in good yields, with fast reaction times of between 30 and 60 min under mild conditions. The di-iodination of the BODIPY scaffold enabled highly efficient population of the triplet state, leading to high singlet oxygen (1O2) photosensitisation efficiencies (ΦΔ = 0.55-0.65). All BODIPY-Mito-I-n compounds exhibited very high photocytotoxic activity towards HeLa cells, with IC50,light values of between 1.30 and 6.93 nM, due to photoinduced 1O2 generation. Notably, the poly(ethylene glycol) (PEG)-modified BODIPY-Mito-I-6 showed remarkably lower dark cytotoxicity (IC50,dark = 6.68-7.25 μM) than the non-PEGylated analogues BODIPY-Mito-I-1 to BODIPY-Mito-I-5 (IC50,dark = 0.58-1.09 μM), resulting in photocytotoxicity indices up to 2120. Mechanistic studies revealed that BODIPY-Mito-I-6 induced reactive oxygen species overproduction and mitochondrial dysfunction in cells upon irradiation, leading to significant cell death through a combination of apoptosis and necrosis. It is anticipated that our design will contribute to the development of more effective mitochondria-targeting PSs for cancer therapy.