The power and potential of mitochondria transfer

Peripheral mitochondrial DNA as a neuroinflammatory biomarker for major depressive disorder

In the pathogenesis of major depressive disorder, chronic stress-related neuroinflammation hinders favorable prognosis and antidepressant response. Mitochondrial DNA may be an inflammatory trigger, after its release from stress-induced dysfunctional central nervous system mitochondria into peripheral circulation. This evidence supports the potential use of peripheral mitochondrial DNA as a neuroinflammatory biomarker for the diagnosis and treatment of major depressive disorder. Herein, we critically review the neuroinflammation theory in major depressive disorder, providing compelling evidence that mitochondrial DNA release acts as a critical biological substrate, and that it constitutes the neuroinflammatory disease pathway. After its release, mitochondrial DNA can be carried in the exosomes and transported to extracellular spaces in the central nervous system and peripheral circulation. Detectable exosomes render encaged mitochondrial DNA relatively stable. This mitochondrial DNA in peripheral circulation can thus be directly detected in clinical practice. These characteristics illustrate the potential for mitochondrial DNA to serve as an innovative clinical biomarker and molecular treatment target for major depressive disorder. This review also highlights the future potential value of clinical applications combining mitochondrial DNA with a panel of other biomarkers, to improve diagnostic precision in major depressive disorder.

Youthful Stem Cell Microenvironments: Rejuvenating Aged Bone Repair Through Mitochondrial Homeostasis Remodeling

Extracellular matrix (ECM) derived from mesenchymal stem cells regulates antioxidant properties and bone metabolism by providing a favorable extracellular microenvironment. However, its functional role and molecular mechanism in mitochondrial function regulation and aged bone regeneration remain insufficiently elucidated. This proteomic analysis has revealed a greater abundance of proteins supporting mitochondrial function in the young ECM (Y-ECM) secreted by young bone marrow-derived mesenchymal stem cells (BMMSCs) compared to the aged ECM (A-ECM). Further studies demonstrate that Y-ECM significantly rejuvenates mitochondrial energy metabolism in adult BMMSCs (A-BMMSCs) through the promotion of mitochondrial respiratory functions and amelioration of oxidative stress. A-BMMSCs cultured on Y-ECM exhibited enhanced multi-lineage differentiation potentials in vitro and ectopic bone formation in vivo. Mechanistically, silencing of silent information regulator type 3 (SIRT3) gene abolished the protective impact of Y-ECM on A-BMMSCs. Notably, a novel composite biomaterial combining hyaluronic acid methacrylate hydrogel microspheres with Y-ECM is developed, which yielded substantial improvements in the healing of bone defects in an aged rat model. Collectively, these findings underscore the pivotal role of Y-ECM in maintaining mitochondrial redox homeostasis and present a promising therapeutic strategy for the repair of aged bone defects.

Recommendations for mitochondria transfer and transplantation nomenclature and characterization

Intercellular mitochondria transfer is an evolutionarily conserved process in which one cell delivers some of their mitochondria to another cell in the absence of cell division. This process has diverse functions depending on the cell types involved and physiological or disease context. Although mitochondria transfer was first shown to provide metabolic support to acceptor cells, recent studies have revealed diverse functions of mitochondria transfer, including, but not limited to, the maintenance of mitochondria quality of the donor cell and the regulation of tissue homeostasis and remodelling. Many mitochondria-transfer mechanisms have been described using a variety of names, generating confusion about mitochondria transfer biology. Furthermore, several therapeutic approaches involving mitochondria-transfer biology have emerged, including mitochondria transplantation and cellular engineering using isolated mitochondria. In this Consensus Statement, we define relevant terminology and propose a nomenclature framework to describe mitochondria transfer and transplantation as a foundation for further development by the community as this dynamic field of research continues to evolve.

Protocol for mitochondrial variant enrichment from single-cell RNA sequencing using MAESTER

Single-cell RNA sequencing (scRNA-seq) enables detailed characterization of cell states but often lacks insights into tissue clonal structures. Here, we present a protocol to probe cell states and clonal information simultaneously by enriching mitochondrial DNA (mtDNA) variants from 3'-barcoded full-length cDNA. We describe steps for input library preparation, mtDNA enrichment, PCR product cleanup, and paired-end sequencing. We then detail computational steps for running maegatk, variant calling, and data integration to illuminate cell states and clonal dynamics in primary human tissues. For complete details on the use and execution of this protocol, please refer to Miller et al.1.

Targeting mitophagy in neurodegenerative diseases

Mitochondrial dysfunction is a hallmark of idiopathic neurodegenerative diseases, including Parkinson disease, amyotrophic lateral sclerosis, Alzheimer disease and Huntington disease. Familial forms of Parkinson disease and amyotrophic lateral sclerosis are often characterized by mutations in genes associated with mitophagy deficits. Therefore, enhancing the mitophagy pathway may represent a novel therapeutic approach to targeting an underlying pathogenic cause of neurodegenerative diseases, with the potential to deliver neuroprotection and disease modification, which is an important unmet need. Accumulating genetic, molecular and preclinical model-based evidence now supports targeting mitophagy in neurodegenerative diseases. Despite clinical development challenges, small-molecule-based approaches for selective mitophagy enhancement - namely, USP30 inhibitors and PINK1 activators - are entering phase I clinical trials for the first time.

Mitochondrial diseases: from molecular mechanisms to therapeutic advances

Mitochondria are essential for cellular function and viability, serving as central hubs of metabolism and signaling. They possess various metabolic and quality control mechanisms crucial for maintaining normal cellular activities. Mitochondrial genetic disorders can arise from a wide range of mutations in either mitochondrial or nuclear DNA, which encode mitochondrial proteins or other contents. These genetic defects can lead to a breakdown of mitochondrial function and metabolism, such as the collapse of oxidative phosphorylation, one of the mitochondria's most critical functions. Mitochondrial diseases, a common group of genetic disorders, are characterized by significant phenotypic and genetic heterogeneity. Clinical symptoms can manifest in various systems and organs throughout the body, with differing degrees and forms of severity. The complexity of the relationship between mitochondria and mitochondrial diseases results in an inadequate understanding of the genotype-phenotype correlation of these diseases, historically making diagnosis and treatment challenging and often leading to unsatisfactory clinical outcomes. However, recent advancements in research and technology have significantly improved our understanding and management of these conditions. Clinical translations of mitochondria-related therapies are actively progressing. This review focuses on the physiological mechanisms of mitochondria, the pathogenesis of mitochondrial diseases, and potential diagnostic and therapeutic applications. Additionally, this review discusses future perspectives on mitochondrial genetic diseases.

The adaptor protein Miro1 modulates horizontal transfer of mitochondria in mouse melanoma models

Recent research has shown that mtDNA-deficient cancer cells (ρ0 cells) acquire mitochondria from tumor stromal cells to restore respiration, facilitating tumor formation. We investigated the role of Miro1, an adaptor protein involved in movement of mitochondria along microtubules, in this phenomenon. Inducible Miro1 knockout (Miro1KO) mice markedly delayed tumor formation after grafting ρ0 cancer cells. Miro1KO mice with fluorescently labeled mitochondria revealed that this delay was due to hindered mitochondrial transfer from the tumor stromal cells to grafted B16 ρ0 cells, which impeded recovery of mitochondrial respiration and tumor growth. Miro1KO led to the perinuclear accumulation of mitochondria and impaired mobility of the mitochondrial network. In vitro experiments revealed decreased association of mitochondria with microtubules, compromising mitochondrial transfer via tunneling nanotubes (TNTs) in mesenchymal stromal cells. Here we show the role of Miro1 in horizontal mitochondrial transfer in mouse melanoma models in vivo and its involvement with TNTs.

Safety and efficacy of mesenchymal stromal cells mitochondria transplantation as a cell-free therapy for osteoarthritis

OBJECTIVE

The inflammatory responses from synovial fibroblasts and macrophages and the mitochondrial dysfunction in chondrocytes lead to oxidative stress, disrupt extracellular matrix (ECM) homeostasis, and accelerate the deterioration process of articular cartilage in osteoarthritis (OA). In recent years, it has been proposed that mesenchymal stromal cells (MSC) transfer their functional mitochondria to damaged cells in response to cellular stress, becoming one of the mechanisms underpinning their therapeutic effects. Therefore, we hypothesize that a novel cell-free treatment for OA could involve direct mitochondria transplantation, restoring both cellular and mitochondrial homeostasis.

METHODS

Mitochondria were isolated from Umbilical Cord (UC)-MSC (Mito-MSC) and characterized based on their morphology, phenotype, functions, and their ability to be internalized by different articular cells. Furthermore, the transcriptional changes following mitochondrial uptake by chondrocytes were evaluated using an Affymetrix analysis, Lastly, the dose dependence therapeutic efficacy, biodistribution and immunogenicity of Mito-MSC were assessed in vivo, through an intra-articular injection in male C57BL6 mice in a collagenase-induced OA (CIOA) model.

RESULTS

Our findings demonstrate the functional integrity of Mito-MSC and their ability to be efficiently transferred into chondrocytes, synovial macrophages, and synovial fibroblasts. Moreover, the transcriptomic analysis showed the upregulation of genes involved in stress such as DNA reparative machinery and inflammatory antiviral responses. Finally, Mito-MSC transplantation yielded significant reductions in joint mineralization, a hallmark of OA progression, as well as improvements in OA-related histological signs, with the lower dose exhibiting better therapeutic efficacy. Furthermore, Mito-MSC was detected within the knee joint for up to 24 h post-injection without eliciting an inflammatory response in CIOA mice.

CONCLUSION

Collectively, our results reveal that mitochondria derived from MSC are transferred to key articular cells and are retained in the joint without generating an inflammatory immune response mitigating articular cartilage degradation in OA, probably through a restorative effect triggered by the stress antiviral response within OA chondrocytes.

Lymphocytes-Associated Extracellular Vesicles Activate Natural Killer Cells in HNSCC

Small extracellular vesicles (sEVs) facilitate intercellular communication and play a pivotal role in tumor progression. Accumulated evidence has indicated the diversity of sEVs but with limited results revealing the landscape of heterogeneity of sEVs. The heterogeneity of cargo RNA in sEVs presents the different cell origins and indicates different functions. Here, we analyzed the heterogeneity of sEVs at droplet levels from single-cell RNA sequencing results of head and neck squamous cell carcinoma (HNSCC) with the previously reported algorithm SEVtras. With the sEVs secretion activity calculated by SEVtras, we also found that the T cells held the major role of sEVs secretion. In addition, we found these sEVs secreted by T cells increased the cytotoxic ability of natural killer cells (NK cells), which illustrated an indirect manner for the anti-tumor function of T cells. These results revealed the heterogeneity of cargo RNA of sEVs in HNSCC and underlined a sEVs-dependent manner in which T cells act on NK cells and anti-tumor immunity.

A subcellular sampling instrument allows spatial resolution of amyloid deposit-derived organelle-specific effects in microglia

Methodological developments in biomedical research are currently moving towards single-cell approaches. This allows for a much better spatial and functional characterization of, for example, the deterioration of cells within a tissue in response to noxae. However, subcellular resolution is also essential to elucidate whether observed impairments are driven by an explicit organelle. Here, we use the Single Cellome™ System SS2000 (Yokogawa) to investigate the local effects of Aβ plaque-like deposits (characteristic for Alzheimer's disease) on mitochondria in the mouse microglial cell line SIM-A9. First, the specificity of subcellular extraction is demonstrated by detecting subcellular staining and RT-qPCR concerning marker genes by comparing nuclear and mitochondrial samples. Oxygen consumption and gene expression is then assessed in cells near and far from peptide deposits. Mostly, all analyses confirm the high specificity and integrity of the sampled material. In addition, impact of the peptide deposits occur concerning spatial distribution of the cells: e.g., oxygen consumption is only reduced in cells close to Aβ deposits but not in proximity to deposits of biologically inactive Aβ (scrambled) or in far distance. Moreover, a distance-related gene expression pattern occurs, demonstrating the local initiation of mitochondrial changes of microglia when approaching toxic peptide deposits.

Mitochondrial DNA damage, repair, and replacement in cancer

Mitochondria are vital organelles with their own DNA (mtDNA). mtDNA is circular and composed of heavy and light chains that are structurally more accessible than nuclear DNA (nDNA). While nDNA is typically diploid, the number of mtDNA copies per cell is higher and varies considerably during development and between tissues. Compared with nDNA, mtDNA is more prone to damage that is positively linked to many diseases, including cancer. Similar to nDNA, mtDNA undergoes repair processes, although these mechanisms are less well understood. In this review, we discuss the various forms of mtDNA damage and repair and their association with cancer initiation and progression. We also propose horizontal mitochondrial transfer as a novel mechanism for replacing damaged mtDNA.

Intercellular Mitochondrial transfer: Therapeutic implications for energy metabolism in heart failure

Heart failure (HF) remains one of the leading causes of high morbidity and mortality globally. Impaired cardiac energy metabolism plays a critical role in the pathological progression of HF. Various forms of HF exhibit marked differences in energy metabolism, particularly in mitochondrial function and substrate utilization. Recent studies have increasingly highlighted that improving energy metabolism in HF patients as a crucial treatment strategy. Mitochondrial transfer is emerging as a promising and precisely regulated therapeutic strategy for treating metabolic disorders. This paper specifically reviews the characteristics of mitochondrial energy metabolism across different types of HF and explores the modes and mechanisms of mitochondrial transfer between different cell types in the heart, such as cardiomyocytes, fibroblasts, and immune cells. We focused on the therapeutic potential of intercellular mitochondrial transfer in improving energy metabolism disorders in HF. We also discuss the role of signal transduction in mitochondrial transfer, highlighting that mitochondria not only function as energy factories but also play crucial roles in intercellular communication, metabolic regulation, and tissue repair. This study provides new insights into improving energy metabolism in heart failure patients and proposes promising new therapeutic strategies.

Targeting mitochondrial transfer: a new horizon in cardiovascular disease treatment

Cardiovascular diseases (CVDs) are the leading cause of mortality among individuals with noncommunicable diseases worldwide. Obesity is associated with an increased risk of developing cardiovascular disease (CVD). Mitochondria are integral to the cardiovascular system, and it has been reported that mitochondrial transfer is associated with the pathogenesis of multiple CVDs and obesity. This review offers a comprehensive examination of the relevance of mitochondrial transfer to cardiovascular health and disease, emphasizing the critical functions of mitochondria in energy metabolism and signal transduction within the cardiovascular system. This highlights how disruptions in mitochondrial transfer contribute to various CVDs, such as myocardial infarction, cardiomyopathies, and hypertension. Additionally, we provide an overview of the molecular mechanisms governing mitochondrial transfer and its potential implications for CVD treatment. This finding underscores the therapeutic potential of mitochondrial transfer and addresses the various mechanisms and challenges in its implementation. By delving into mitochondrial transfer and its targeted modulation, this review aims to advance our understanding of cardiovascular disease treatment, presenting new insights and potential therapeutic strategies in this evolving field.

Pan-cancer association of a mitochondrial function score with genomic alterations and clinical outcome

Mitochondria are pivotal in cellular energy metabolism and have garnered significant attention for their roles in cancer progression and therapy resistance. Despite this, the functional diversity of mitochondria across various cancer types remains inadequately characterized. This study seeks to fill this knowledge gap by introducing and validating MitoScore-a novel metric designed to quantitatively assess mitochondrial function across a wide array of cancers. Our investigation evaluates the capacity of MitoScore not only to distinguish between tumor and adjacent normal tissues but also to serve as a predictive marker for clinical outcomes. We analyzed gene expression data from 24 cancer types and corresponding normal tissues using the TCGA database. MitoScore was calculated by summing the normalized expression levels of six mitochondrial genes known to be consistently altered across multiple cancers. Differential gene expression was assessed using DESeq2, with a focus on identifying significant changes in mitochondrial function. MitoScore's associations with tumor proliferation, hypoxia, aneuploidy, and clinical outcomes were evaluated using Spearman's correlation, linear regression, and Kaplan-Meier survival analyses. MitoScore was significantly higher in tumor tissues compared to normal tissues across most cancer types (p < 0.001). It positively correlated with tumor proliferation rates (r = 0.46), hypoxia scores (r = 0.61), and aneuploidy (r = 0.44), indicating its potential as a marker of aggressive tumor behavior. High MitoScore was also associated with poorer prognosis in several cancer types, suggesting its utility as a predictive biomarker for clinical outcomes. This study introduces MitoScore, a metric for mitochondrial activity often elevated in tumors and linked to poor prognosis. It correlates positively with hypoxia and negatively with stromal and immune infiltration, highlighting mitochondria's role in the tumor microenvironment. MitoScore's association with genomic instability, such as aneuploidy, suggests mitochondrial dysfunction contributes to cancer progression. Despite challenges in mitochondrial-targeted therapies, MitoScore may identify tumors responsive to such treatments, warranting further research for clinical application.

Mitochondrial transplantation rescues Ca2+ homeostasis imbalance and myocardial hypertrophy in SLC25A3-related hypertrophic cardiomyopathy

SLC25A3 encodes mitochondrial phosphate carrier (PiC), which is involved in inorganic phosphate transport. Clinical reports have found that most patients with homozygous or complex heterozygous mutations in SLC25A3 exhibit lactic acidosis, cardiac hypertrophy, and premature death. However, the potential molecular mechanisms underlying these associations remain unclear. Using CRISPR-Cas9 technology, we generated human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) carrying SLC25A3-knockout (KO) or missense mutations (c.C544T, c.A547G, c.C349T) to elucidate the pathogenic mechanisms of SLC25A3-related hypertrophic cardiomyopathy (HCM) and evaluate potential therapeutic interventions. These SLC25A3-KO or missense mutation hiPSC-CMs recapitulated the disease phenotype associated with myocardial hypertrophy, including diastolic dysfunction, Ca2+ homeostasis imbalance, and mitochondrial energy metabolism dysfunction. Further studies suggested the potential link between the accumulation of glycolytic byproducts and Ca2+ homeostasis imbalance in SLC25A3-KO hiPSC-CMs. Finally, we explored the prospective therapeutic implications of mitochondrial transplantation in rescuing SLC25A3-related HCM.

3D culture inhibits replicative senescence of SCAPs via UQCRC2-mediated mitochondrial oxidative phosphorylation

Stem cells derived from the apical papilla (SCAPs) play a crucial role in tooth root development and dental pulp regeneration. They are important seed cells for bone/tooth tissue engineering. However, replicative senescence remains an unavoidable issue as in vitro amplification increases. This study investigated the effect of a three-dimensional (3D) culture environment constructed with methylcellulose on SCAPs senescence. It was observed that 3D culture conditions can delay cellular senescence, potentially due to changes in mitochondrial function and oxidative phosphorylation. Transcriptome high-throughput sequencing technology revealed that the different mitochondrial states may be related to UQCRC2. Knocking down UQCRC2 expression in the 3D culture group resulted in increased production of mitochondrial reactive oxygen species, decreased mitochondrial membrane potential, and a decline in the oxygen consumption rate for oxidative phosphorylation, accelerating cell senescence. The results of this study indicated that 3D culture can mitigate SCAPs aging by maintaining UQCRC2-mediated mitochondrial homeostasis. These findings provide a new solution for the senescence of SCAPs during in vitro amplification and can promote the applications of SCAPs-based clinical translation.

Synergistic enhancement of low-dose radiation therapy via cuproptosis and metabolic reprogramming for radiosensitization in in situ hepatocellular carcinoma

BACKGROUND

Radiotherapy (RT) is a primary clinical approach for cancer treatment, but its efficacy is often hindered by various challenges, especially radiation resistance, which greatly compromises the therapeutic effectiveness of RT. Mitochondria, central to cellular energy metabolism and regulation of cell death, play a critical role in mechanisms of radioresistance. In this context, cuproptosis, a novel copper-induced mitochondria-respiratory-dependent cell death pathway, offers a promising avenue for radiosensitization.

RESULTS

In this study, an innovative theranostic nanoplatform was designed to induce cuproptosis in synergy with low-dose radiation therapy (LDRT, i.e., 0.5-2 Gy) for the treatment of in situ hepatocellular carcinoma (HCC). This approach aims to reverse the hypoxic tumor microenvironment, promoting a shift in cellular metabolism from glycolysis to oxidative phosphorylation (OXPHOS), thereby enhancing sensitivity to cuproptosis. Concurrently, the Fenton-like reaction ensures a sustained supply of copper and depletion of glutathione (GSH), inducing cuproptosis, disrupting mitochondrial function, and interrupting the energy supply. This strategy effectively overcomes radioresistance and enhances the therapeutic efficacy against tumors.

CONCLUSIONS

In conclusion, this study elucidates the intricate interactions among tumor hypoxia reversal, cuproptosis, metabolic reprogramming, and radiosensitization, particularly in the context of treating in situ hepatocellular carcinoma, thereby providing a novel paradigm for radiotherapy.

Understanding Post-COVID-19: Mechanisms, Neurological Complications, Current Treatments, and Emerging Therapies

COVID-19, a highly infectious disease, caused a worldwide pandemic in early 2020. According to the World Health Organization (WHO), COVID-19 has resulted in approximately 774 million cases and around 7 million deaths. The effects of COVID-19 are well known; however, there is a lack of information on the pathophysiological mechanisms underlying the symptoms that comprise Post-Acute COVID-19 Syndrome (PACS) or Long COVID-19. Neurological sequelae are common, with cognitive dysfunction being one of the foremost symptoms. Research indicates that elevated inflammatory levels and increased oxidative stress may play a role in the etiology and severity of PACS. Treatment options are extremely limited, and there is no consensus among the medical and scientific communities on how to manage the disease. Nevertheless, many scientists advocate for using antioxidants for symptomatic therapy and cognitive behavior therapy for supportive care. Additionally, current research aims to ameliorate several aspects of the inflammatory cascade. This review highlights the intracellular and extracellular pathways crucial to the neurological manifestations of PACS, providing valuable information for healthcare professionals and scientists. Given the complex nature of PACS, understanding these pathways is essential for developing new treatment options. Assessing PACS is challenging, and reviewing current therapeutic options while proposing a triad of potential therapeutic elements will add value to clinical assays and guidelines. Current therapeutic strategies, such as antioxidants/vitamin supplements, neurogenic stem cell therapy, and mitochondrial therapy, could be combined to enhance their effectiveness. Future research should focus on validating these approaches and exploring new avenues for the effective treatment of PACS.

Frequent genetic exchanges revealed by a pan-mitogenome graph of a fungal plant pathogen

Mitochondria are present in almost all eukaryotic lineages. The mitochondrial genomes (mitogenomes) evolve separately from nuclear genomes, and they can therefore provide relevant insights into the evolution of their host species. Fusarium oxysporum is a major fungal plant pathogen that is assumed to reproduce clonally. However, horizontal chromosome transfer between strains can occur through heterokaryon formation, and recently, signs of sexual recombination have been observed. Similarly, signs of recombination in F. oxysporum mitogenomes challenged the prevailing assumption of clonal reproduction in this species. Here, we construct, to our knowledge, the first fungal pan-mitogenome graph of nearly 500 F. oxysporum mitogenome assemblies to uncover the variation and evolution. In general, the gene order of fungal mitogenomes is not well conserved, yet the mitogenome of F. oxysporum and related species are highly colinear. We observed two strikingly contrasting regions in the F. oxysporum pan-mitogenome, comprising a highly conserved core mitogenome and a long variable region (6-16 kb in size), of which we identified three distinct types. The pan-mitogenome graph reveals that only five intron insertions occurred in the core mitogenome and that the long variable regions drive the difference between mitogenomes. Moreover, we observed that their evolution is neither concurrent with the core mitogenome nor with the nuclear genome. Our large-scale analysis of long variable regions uncovers frequent recombination between mitogenomes, even between strains that belong to different taxonomic clades. This challenges the common assumption of incompatibility between genetically diverse F. oxysporum strains and provides new insights into the evolution of this fungal species.IMPORTANCEInsights into plant pathogen evolution is essential for the understanding and management of disease. Fusarium oxysporum is a major fungal pathogen that can infect many economically important crops. Pathogenicity can be transferred between strains by the horizontal transfer of pathogenicity chromosomes. The fungus has been thought to evolve clonally, yet recent evidence suggests active sexual recombination between related isolates, which could at least partially explain the horizontal transfer of pathogenicity chromosomes. By constructing a pan-genome graph of nearly 500 mitochondrial genomes, we describe the genetic variation of mitochondria in unprecedented detail and demonstrate frequent mitochondrial recombination. Importantly, recombination can occur between genetically diverse isolates from distinct taxonomic clades and thus can shed light on genetic exchange between fungal strains.

Hidden role of microglia during neurodegenerative disorders and neurocritical care: A mitochondrial perspective

The incidence of aging-related neurodegenerative disorders and neurocritical care diseases is increasing worldwide. Microglia, the main inflammatory cells in the brain, could be potential viable therapeutic targets for treating neurological diseases. Interestingly, mitochondrial functions, including energy metabolism, mitophagy and transfer, fission and fusion, and mitochondrial DNA expression, also change in activated microglia. Notably, mitochondria play an active and important role in the pathophysiology of neurodegenerative disorders and neurocritical care diseases. This review briefly summarizes the current knowledge on mitochondrial dysfunction in microglia in neurodegenerative disorders and neurocritical care diseases and comprehensively discusses the prospects of the application of neurological injury prevention and treatment targets by mitochondria.

A promising therapeutic: Exosome-mediated mitochondrial transplantation

Mitochondrial dysfunction has been identified as a trigger for cellular autophagy dysfunction and programmed cell death. Emerging studies have revealed that, in pathological contexts, intercellular transfer of mitochondria takes place, facilitating the restoration of mitochondrial function, energy metabolism, and immune homeostasis. Extracellular vesicles, membranous structures released by cells, exhibit reduced immunogenicity and enhanced stability during the transfer of mitochondria. Thus, this review provides a concise overview of mitochondrial dysfunction related diseases and the mechanism of mitochondrial dysfunction in diseases progression, and the composition and functions of the extracellular vesicles, along with elucidating the principal mechanisms underlying intercellular mitochondrial transfer. In this article, we will focus on the advancements in both animal models and clinical trials concerning the therapeutic efficacy of extracellular vesicle-mediated mitochondrial transplantation across various systemic diseases in neurodegenerative diseases and cardiovascular diseases. Additionally, the review delves into the multifaceted roles of extracellular vesicle-transplanted mitochondria, encompassing anti-inflammatory actions, promotion of tissue repair, enhancement of cellular function, and modulation of metabolic and immune homeostasis within diverse pathological contexts, aiming to provide novel perspectives for extracellular vesicle transplantation of mitochondria in the treatment of various diseases.

Mitophagy in gynecological malignancies: roles, advances, and therapeutic potential

Mitophagy is a process in which impaired or dysfunctional mitochondria are selectively eliminated through the autophagy mechanism to maintain mitochondrial quality control and cellular homeostasis. Based on specific target signals, several mitophagy processes have been identified. Defects in mitophagy are associated with various pathological conditions, including neurodegenerative disorders, cardiovascular diseases, metabolic diseases, and cancer. Mitophagy has been shown to play a critical role in the pathogenesis of gynecological malignancies and the development of drug resistance. In this review, we have summarized and discussed the role and recent advances in understanding the therapeutic potential of mitophagy in the development of gynecological malignancies. Therefore, the valuable insights provided in this review may serve as a basis for further studies that contribute to the development of novel treatment strategies and improved patient outcomes.

Autologous mitochondrial transplant for acute cerebral ischemia: Phase 1 trial results and review

The results of a Phase 1 trial of autologous mitochondrial transplantation for the treatment of acute ischemic stroke during mechanical thrombectomy are presented. Standardized methods were used to isolate viable autologous mitochondria in the acute clinical setting, allowing for timely transplantation within the ischemic window. No significant adverse events were observed with the endovascular approach during reperfusion therapy. Safety outcomes in study participants were comparable to those of matched controls who did not undergo transplantation. This study represents the first use of mitochondrial transplantation in the human brain, highlighting specific logistical challenges related to the acute clinical setting, such as limited tissue samples and constrained time for isolation and transplantation. We also review the opportunities and challenges associated with further clinical translation of mitochondrial transplantation in the context of acute cerebral ischemia and beyond.

Hypoxia regulates small extracellular vesicle biogenesis and cargo sorting through HIF-1α/HRS signaling pathway in head and neck squamous cell carcinoma

Small extracellular vesicles (sEVs) act as crucial messengers that transmit biological signals in hypoxic tumor microenvironment (TME), significantly impacting cancer progression. However, the precise mechanism by which hypoxia influences sEV biogenesis remains poorly understood. In this study, we observed increased sEV secretion and alterations in cargo composition in head and neck squamous cell carcinoma (HNSCC) cells under hypoxic conditions. We found that hepatocyte growth factor-regulated tyrosine kinase substrate (HRS), a key component of the endosomal sorting complexes required for transport (ESCRT), was upregulated during hypoxia. This upregulation activated the endosomal system and reduced degradation of multivesicular bodies (MVBs). HRS depletion altered the packaging of protein cargoes such as mitochondria-related proteins into sEVs under hypoxia, and these cargoes promoted a pro-tumorigenic phenotype of macrophages. Importantly, we demonstrated that HRS is transcriptionally activated by hypoxia inducible factor-1α (HIF-1α). Spatial transcriptomics and immunohistochemistry revealed a positive correlation between HRS and HIF-1α. These findings establish a link between the hypoxic response, sEV biogenesis, and cargo packaging, enhancing our understanding of how the hypoxic TME influences sEV biogenesis in HNSCC cells.

The role of mitochondria in tumor metastasis and advances in mitochondria-targeted cancer therapy

Mitochondria are central actors in diverse physiological phenomena ranging from energy metabolism to stress signaling and immune modulation. Accumulating scientific evidence points to the critical involvement of specific mitochondrial-associated events, including mitochondrial quality control, intercellular mitochondrial transfer, and mitochondrial genetics, in potentiating the metastatic cascade of neoplastic cells. Furthermore, numerous recent studies have consistently emphasized the highly significant role mitochondria play in coordinating the regulation of tumor-infiltrating immune cells and immunotherapeutic interventions. This review provides a comprehensive and rigorous scholarly investigation of this subject matter, exploring the intricate mechanisms by which mitochondria contribute to tumor metastasis and examining the progress of mitochondria-targeted cancer therapies.

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.

Development of a novel SupraChoroidal-to-Optic-NervE (SCONE) drug delivery system

PURPOSE

Targeted drug delivery to the optic nerve head may be useful in the preclinical study and later clinical management of optic neuropathies, however, there are no FDA-approved drug delivery systems to achieve this. The purpose of this work was to develop an optic nerve head drug delivery technique.

METHODS

Different strategies to approach the optic nerve head were investigated, including standard intravitreal and retroorbital injections. A novel SupraChoroidal-to-Optic-NervE (SCONE) delivery was optimized by creating a sclerotomy and introducing a catheter into the suprachoroidal space. Under direct visualization, the catheter was guided to the optic nerve head. India ink was injected. The suprachoroidal approach was performed in New Zealand White rabbit eyes in vivo (25 animals total). Parameters, including microneedle size and design, catheter design, and catheter tip angle, were optimized ex vivo and in vivo.

RESULTS

Out of the candidate optic nerve head approaches, intravitreal, retroorbital, and suprachoroidal approaches were able to localize India ink to within 2 mm of the optic nerve. The suprachoroidal approach was further investigated, and after optimization, was able to deposit India ink directly within the optic nerve head in up to 80% of attempts. In eyes with successful SCONE delivery, latency and amplitude of visual evoked potentials was not different than the naïve untreated eye.

CONCLUSIONS

SCONE delivery can be used for targeted drug delivery to the optic nerve head of rabbits without measurable toxicity measured anatomically or functionally. Successful development of this system may yield novel opportunities to study optic nerve head-specific drug delivery in animal models, and paradigm-shifting management strategies for treating optic neuropathies.

TRANSLATIONAL RELEVANCE

Here we demonstrate data on a new method for targeted delivery to the optic nerve head, addressing a significant unmet need in therapeutics for optic neuropathies.

Mitochondrial transfer in the progression and treatment of cardiac disease

Mitochondria are the primary site for energy production and play a crucial role in supporting normal physiological functions of the human body. In cardiomyocytes (CMs), mitochondria can occupy up to 30 % of the cell volume, providing sufficient energy for CMs contraction and relaxation. However, some pathological conditions such as ischemia, hypoxia, infection, and the side effect of drugs, can cause mitochondrial dysfunction in CMs, leading to various myocardial injury-related diseases including myocardial infarction (MI), myocardial hypertrophy, and heart failure. Self-control of mitochondria quality and conversion of metabolism pathway in energy production can serve as the self-rescue measure to avoid autologous mitochondrial damage. Particularly, mitochondrial transfer from the neighboring or extraneous cells enables to mitigate mitochondrial dysfunction and restore their biological functions in CMs. Here, we described the homeostatic control strategies and related mechanisms of mitochondria in injured CMs, including autologous mitochondrial quality control, mitochondrial energy conversion, and especially the exogenetic mitochondrial donation. Additionally, this review emphasizes on the therapeutic effects and potential application of utilizing mitochondrial transfer in reducing myocardial injury. We hope that this review can provide theoretical clues for the developing of advanced therapeutics to treat cardiac diseases.

Astragaloside IV alleviates septic myocardial injury through DUSP1-Prohibitin 2 mediated mitochondrial quality control and ER-autophagy

INTRODUCTION

Septic cardiomyopathy (SCM) is a complication of myocardial injury in patients with severe sepsis.

OBJECTIVES

This study highlights the potential of Astragaloside IV(AS) in the treatment of septic cardiomyopathy and provides a reference for developing cardioprotective drugs targeting DUSP1-PHB2-related mitochondria-ER interaction.

METHODS

Dual specificity phosphatase-1 (DUSP1)/Prohibitin 2 cardiomyocyte-specific knockout mice (DUSP1/PHB2CKO) /DUSP1 transgenic mice (DUSP1/PHB2TG) were used to generate LPS-induced sepsis models. The pathological mechanism by which AS-IV improves heart injury was detected using cardiac ultrasound, fluorescence staining, transmission electron microscopy, and western blotting. After siRNA treatment of cardiomyocytes with DUSP-1/PHB2, changes in mitochondrial function and morphology were determined using qPCR, western blotting, ELISA, and laser confocal microscopy, and the targeted therapeutic effects of AS-IV were further examined.

RESULTS

SCM treatment leads to severe mitochondrial dysfunction. However, Astragaloside IV (AS) treatment normalizes mitochondrial homeostasis and ER function. Notably, the protective effect was blocked in DUSP1/Prohibitin 2 cardiomyocyte-specific knockout mice (DUSP1/PHB2CKO) but remained unaffected in DUSP1 transgenic mice (DUSP1/PHB2TG).

CONCLUSION

This study highlights the potential of AS in the treatment of septic cardiomyopathy and provides a reference for developing cardioprotective drugs targeting DUSP1-PHB2 related mitochondria-ER interaction.

Intercellular nanotube-mediated mitochondrial transfer enhances T cell metabolic fitness and antitumor efficacy

Mitochondrial loss and dysfunction drive T cell exhaustion, representing major barriers to successful T cell-based immunotherapies. Here, we describe an innovative platform to supply exogenous mitochondria to T cells, overcoming these limitations. We found that bone marrow stromal cells establish nanotubular connections with T cells and leverage these intercellular highways to transplant stromal cell mitochondria into CD8+ T cells. Optimal mitochondrial transfer required Talin 2 on both donor and recipient cells. CD8+ T cells with donated mitochondria displayed enhanced mitochondrial respiration and spare respiratory capacity. When transferred into tumor-bearing hosts, these supercharged T cells expanded more robustly, infiltrated the tumor more efficiently, and exhibited fewer signs of exhaustion compared with T cells that did not take up mitochondria. As a result, mitochondria-boosted CD8+ T cells mediated superior antitumor responses, prolonging animal survival. These findings establish intercellular mitochondrial transfer as a prototype of organelle medicine, opening avenues to next-generation cell therapies.

Molecular and cellular mechanisms of mitochondria transfer in models of central nervous system disease

In the central nervous system (CNS), neuronal function and dysfunction are critically dependent on mitochondrial integrity and activity. In damaged or diseased brains, mitochondrial dysfunction reduces adenosine triphosphate (ATP) levels and impairs ATP-dependent neural firing and neurotransmitter dynamics. Restoring mitochondrial capacity to generate ATP may be fundamental in restoring neuronal function. Recent studies in animals and humans have demonstrated that endogenous mitochondria may be released into the extracellular environment and transported or exchanged between cells in the CNS. Under pathological conditions in the CNS, intercellular mitochondria transfer contributes to new classes of signaling and multifunctional cellular activities, thereby triggering deleterious effects or promoting beneficial responses. Therefore, to take full advantage of the beneficial effects of mitochondria, it may be useful to transplant healthy and viable mitochondria into damaged tissues. In this review, we describe recent findings on the mechanisms of mitochondria transfer and provide an overview of experimental methodologies, including tissue sourcing, mitochondrial isolation, storage, and modification, aimed at optimizing mitochondria transplantation therapy for CNS disorders. Additionally, we examine the clinical relevance and potential strategies for the therapeutic application of mitochondria transplantation.

Advances in research on the relationship between mitochondrial function and colorectal cancer: a bibliometric study from 2013 to 2023

The study provides a thorough examination of literature from 2013 to 2023, delving into the intricate relationship between mitochondrial function and colorectal cancer (CRC). It offers a concise overview of the current landscape and emerging trends in this rapidly evolving research area. The findings indicate a consistent rise in annual publications, reflecting growing interest and significant potential in the field. China emerges as the leading contributor, followed by the United States and India. However, despite China's dominance in output, its average citation rate is lower than that of the US, which leads in citations per publication, highlighting a noticeable disparity. In the realm of research institutions, Shanghai Jiao Tong University and China Medical University are identified as major contributors, yet the potential for inter-institutional collaboration remains largely untapped, suggesting avenues for future synergy. Internationally, China-US collaborations are particularly robust, fostering cross-border knowledge exchange. Hyun Jin Won and Li Wei are recognized as prolific authors, while Ahmedin Jemal is an influential co-cited scholar, noted for his seminal contributions. Keyword analysis reveals research focus areas, such as the complex CRC tumor microenvironment, molecular mechanisms of oxidative stress, and key multidrug resistance pathways. It also highlights the promising potential of mitochondria-targeted therapies and nanomolecular technologies in clinical practice, signaling their growing significance in addressing complex health challenges. The study underscores the imperative to validate complex mitochondrial mechanisms and signaling pathways in CRC, with a particular emphasis on translating these insights into drug targets for clinical trials. Advancing this research is expected to refine and enhance CRC treatment strategies. Additionally, it highlights the urgency of validating mitochondrial complexities in CRC, advocating for collaborative efforts to link these mechanisms with tailored therapeutic interventions for clinical testing. This integrated approach promises significant advancements in developing effective, targeted CRC treatments, ultimately improving patient outcomes.

LncRNA mediated metabolic reprogramming: the chief culprits of solid tumor malignant progression: an update review

Metabolism reprogramming (MR) is one of the top ten hallmarks of malignant tumors. The aberrant activation of MR has been recognized as a critical contributory factor to the malignant progression of solid tumors. Moreover, various long non-coding RNAs (lncRNAs) are implicated in the aberrant activation of MR in solid tumor cells. Therefore, in this review, we mainly focus on summarizing the functional relevance and molecular mechanistic underpinnings of lncRNAs in modulating MR of solid tumors by targeting glucose metabolism, lipid metabolism, affecting mitochondrial function, and regulating interactions between tumor and non-tumor cells in tumor microenvironment. Besides, we also underscore the potential for constructing lncRNAs-centered tumor metabolic regulation networks and developing novel anti-tumor strategies by targeting lncRNAs and abnormal MR. Ultimately, this review seeks to offer new targets and avenues for the clinical treatment of solid tumors in the future.

Synthetic Nanoassemblies for Regulating Organelles: From Molecular Design to Precision Therapeutics

Each organelle referring to a complex multiorder architecture executes respective biological processes via its distinct spatial organization and internal microenvironment. As the assembly of biomolecules is the structural basis of living cells, creating synthetic nanoassemblies with specific physicochemical and morphological properties in living cells to interfere or couple with the natural organelle architectures has attracted great attention in precision therapeutics of cancers. In this review, we give an overview of the latest advances in the synthetic nanoassemblies for precise organelle regulation, including the formation mechanisms, triggering strategies, and biomedical applications in precision therapeutics. We summarize the emerging material systems, including polymers, peptides, and deoxyribonucleic acids (DNAs), and their respective intermolecular interactions for intercellular synthetic nanoassemblies, and highlight their design principles in constructing precursors that assemble into synthetic nanoassemblies targeting specific organelles in the complex cellular environment. We further showcase the developed intracellular synthetic nanoassemblies targeting specific organelles including mitochondria, the endoplasmic reticulum, lysosome, Golgi apparatus, and nucleus and describe their underlying mechanisms for organelle regulation and precision therapeutics for cancer. Last, the essential challenges in this field and prospects for future precision therapeutics of synthetic nanoassemblies are discussed. This review should facilitate the rational design of organelle-targeting synthetic nanoassemblies and the comprehensive recognition of organelles by materials and contribute to the deep understanding and application of the synthetic nanoassemblies for precision therapeutics.

Mechanisms Regulating Mitochondrial Transfer in Human Corneal Epithelial Cells

Purpose

The intraepithelial corneal nerves (ICNs) innervating the cornea are essential to corneal epithelial cell homeostasis. Rho-associated kinase (ROCK) inhibitors (RIs) have been reported to play roles in neuron survival after injury and in mitochondrial transfer between corneal epithelial cells. In this study, the mechanisms human corneal limbal epithelial (HCLE) cells use to control intercellular mitochondrial transfer are assessed.

Methods

Mitotracker and AAV1 mitotag eGFPmCherry were used to allow us to study mitochondrial transfer between HCLE cells and neurons in co-cultures and in HCLE cultures. A mitochondrial transfer assay was developed using HCLE cells to quantify the impact of cell stress and inhibition of phagocytosis, gap junctions, and ROCK on mitochondrial transfer, cell adhesion, migration, matrix deposition, and mitochondrial content.

Results

Bidirectional mitochondrial transfer occurs between HCLE cells and neurons. Mitochondrial transfer among HCLE cells is inhibited when gap junction function is reduced and enhanced by acid stress and by inhibition of either phagocytosis or ROCK. Media conditioned by RI-treated cells stimulates cell adhesion and mitochondrial transfer.

Conclusions

Maximal mitochondrial transfer takes place when gap junctions are functional, when ROCK and phagocytosis are inhibited, and when cells are stressed by low pH media. Treatments that reduce mitochondrial content increase HCLE cell mitochondrial transfer. ROCK inhibition in co-cultures causes the release and adhesion of mitochondria to substrates where they can be engulfed by migrating HCLE cells and growing axons and their growth cones.

Mitochondrial derived vesicles- Quo Vadis?

Mitochondria are dynamic, intracellular organelles with a separate genome originating from prokaryotes. They perform numerous functions essential for cellular metabolism and energy production. Mitochondrial-derived vesicles (MDVs) are single or double membrane-enclosed vesicles, formed and released from the mitochondrial sub-compartments into the cytosol, in response to various triggers. MDVs interact with other organelles such as lysosomes and peroxisomes or may be incorporated and excreted via extracellular vesicles (EVs). MDVs selectively incorporate diverse protein and lipid cargoes and are involved in various functions such as mitochondrial quality control, immunomodulation, energy complementation, and compartmentalization and transport. This review aims to provide a summary of the current knowledge of MDVs biogenesis, release, cargoes, and roles.

Knocking down EGR1 inhibits nucleus pulposus cell senescence and mitochondrial damage through activation of PINK1-Parkin dependent mitophagy, thereby delaying intervertebral disc degeneration

Mitophagy plays a crucial role in maintaining the homeostasis of intervertebral disc (IVD). Early Growth Response 1 (EGR1), a conservative transcription factor, is commonly upregulated under oxidative stress conditions and participates in regulating cellular senescence, apoptosis, and inflammatory responses. However, the specific role of EGR1 in nucleus pulposus (NP) cell senescence and mitophagy remains unclear. In this study, through bioinformatics analysis and validation using human tissue specimens, we found that EGR1 is significantly upregulated in IVD degeneration (IDD). Further experimental results demonstrate that knockdown of EGR1 inhibits TBHP-induced NP cell senescence and mitochondrial dysfunction while promoting the activation of mitophagy. The protective effect of EGR1 knockdown on NP cell senescence and mitochondrion disappears upon inhibition of mitophagy with mdivi1. Mechanistic studies reveal that EGR1 suppresses NP cell senescence and mitochondrial dysfunction by modulating the PINK1-Parkin dependent mitophagy pathway. Additionally, EGR1 knockdown delays acupuncture-induced IDD in rats. In conclusion, our study demonstrates that under TBHP-induced oxidative stress, EGR1 knockdown mitigates NP cell senescence and mitochondrial dysfunction through the PINK1-Parkin dependent mitophagy pathway, thereby alleviating IDD.

Mitochondrial Extracellular Vesicles (mitoEVs): Emerging mediators of cell-to-cell communication in health, aging and age-related diseases

Mitochondria are metabolic and signalling hubs that integrate a plethora of interconnected processes to maintain cell homeostasis. They are also dormant mediators of inflammation and cell death, and with aging damages affecting mitochondria gradually accumulate, resulting in the manifestation of age-associated disorders. In addition to coordinate multiple intracellular functions, mitochondria mediate intercellular and inter-organ cross talk in different physiological and stress conditions. To fulfil this task, mitochondrial signalling has evolved distinct and complex conventional and unconventional routes of horizontal/vertical mitochondrial transfer. In this regard, great interest has been focused on the ability of extracellular vesicles (EVs), such as exosomes and microvesicles, to carry selected mitochondrial cargoes to target cells, in response to internal and external cues. Over the past years, the field of mitochondrial EVs (mitoEVs) has grown exponentially, revealing unexpected heterogeneity of these structures associated with an ever-expanding mitochondrial function, though the full extent of the underlying mechanisms is far from being elucidated. Therefore, emerging subsets of EVs encompass exophers, migrasomes, mitophers, mitovesicles, and mitolysosomes that can act locally or over long-distances to restore mitochondrial homeostasis and cell functionality, or to amplify disease. This review provides a comprehensive overview of our current understanding of the biology and trafficking of MitoEVs in different physiological and pathological conditions. Additionally, a specific focus on the role of mitoEVs in aging and the onset and progression of different age-related diseases is discussed.

Mitochondrial transfer from mesenchymal stem cells: Mechanisms and functions

Mesenchymal stem cells based therapy has been used in clinic for almost 20 years and has shown encouraging effects in treating a wide range of diseases. However, the underlying mechanism is far more complicated than it was previously assumed. Mitochondria transfer is one way that recently found to be employed by mesenchymal stem cells to exert its biological effects. As one way of exchanging mitochondrial components, mitochondria transfer determines both mesenchymal stem cells and recipient cell fates. In this review, we describe the factors that contribute to MSCs-MT. Then, the routes and mechanisms of MSCs-MT are summarized to provide a theoretical basis for MSCs therapy. Besides, the advantages and disadvantages of MSCs-MT in clinical application are analyzed.

Unraveling the roles and mechanisms of mitochondrial translation in normal and malignant hematopoiesis

Due to spatial and genomic independence, mitochondria possess a translational mechanism distinct from that of cytoplasmic translation. Several regulators participate in the modulation of mitochondrial translation. Mitochondrial translation is coordinated with cytoplasmic translation through stress responses. Importantly, the inhibition of mitochondrial translation leads to the inhibition of cytoplasmic translation and metabolic disruption. Therefore, defects in mitochondrial translation are closely related to the functions of hematopoietic cells and various immune cells. Finally, the inhibition of mitochondrial translation is a potential therapeutic target for treating multiple hematologic malignancies. Collectively, more in-depth insights into mitochondrial translation not only facilitate our understanding of its functions in hematopoiesis, but also provide a basis for the discovery of new treatments for hematological malignancies and the modulation of immune cell function.

Mitochondrion-based organellar therapies for central nervous system diseases

As most traditional drugs used to treat central nervous system (CNS) diseases have a single therapeutic target, many of them cannot treat complex diseases or diseases whose mechanism is unknown and cannot effectively reverse the root changes underlying CNS diseases. This raises the question of whether multiple functional components are involved in the complex pathological processes of CNS diseases. Organelles are the core functional units of cells, and the replacement of damaged organelles with healthy organelles allows the multitargeted and integrated modulation of cellular functions. The development of therapies that target independent functional units in the cell, specifically, organelle-based therapies, is rapidly progressing. This article comprehensively discusses the pathogenesis of mitochondrial homeostasis disorders, which involve mitochondria, one of the most important organelles in CNS diseases, and the machanisms of mitochondrion-based therapies, as well as current preclinical and clinical studies on the efficacy of therapies targeting mitochondrial to treat CNS diseases, to provide evidence for use of organelle-based treatment strategies in the future.

The mitochondrial protein Bcs1A regulates antifungal drug tolerance by affecting efflux pump expression in the filamentous pathogenic fungus Aspergillus fumigatus

Aspergillus fumigatus is the predominant pathogen responsible for aspergillosis infections, with emerging drug-resistant strains complicating treatment strategies. The role of mitochondrial functionality in fungal resistance to antifungal agents is well-documented yet not fully understood. In this study, the mitochondrial protein Bcs1A, a homolog of yeast Bcs1, was found to regulate colony growth, ion homeostasis, and the response to antifungal drugs in A. fumigatus. Microscopic observations revealed substantial colocalization of Bcs1A-GFP fusion protein fluorescence with mitochondria. Bcs1A deletion compromised colony growth and the utilization of non-fermentable carbon sources, alongside causing abnormal mitochondrial membrane potential and reduced reactive oxygen species production. These findings underscore Bcs1A's vital role in maintaining mitochondrial integrity. Phenotypic analysis and determinations of minimum inhibitory concentrations indicated that the Δbcs1A mutant was more resistant to various antifungal agents, such as azoles, terbinafine, and simvastatin, compared to wild-type strain. RNA sequencing and RT-qPCR analysis highlighted an upregulation of multiple efflux pumps in the Δbcs1A mutant. Furthermore, loss of the principal drug efflux pump, mdr1, decreased azole tolerance in the Δbcs1A mutant, suggesting that Bcs1A's modulated of azoles response via efflux pump expression. Collectively, these results establish Bcs1A as essential for growth and antifungal drug responsiveness in A. fumigatus mediated through mitochondrial regulation.IMPORTANCEDrug resistance presents a formidable obstacle in the clinical management of aspergillosis. Mitochondria are integral to various biochemical pathways, including those involved in fungi drug response, making mitochondrial proteins promising therapeutic targets for drug therapy. This study confirms that Bcs1A, a mitochondrial respiratory chain protein, is indispensable for mitochondrial functionality and multidrug tolerance in Aspergillus fumigatus. Mutation of Bcs1A not only leads to a series of drug efflux pumps upregulated but also shows that loss of the primary efflux pump, mdr1, partial reduction in drug tolerance in the Bcs1A mutant, highlighting that Bcs1A's significant influence on mitochondria-mediated drug resistance.

Differences in cellular and molecular processes in exposure to PM2.5 and O3

Epidemiological and toxicological studies have shown that PM2.5 and O3 could pose significant risks to human health, such as an increased incidence of respiratory and cardiovascular diseases. Usually, the adverse health outcomes induced by PM2.5 and O3 exposure are similar. However, PM2.5 and O3 have distinct physical and chemical properties, with PM2.5 being a solid-liquid mixture and O3 being a strongly oxidizing gaseous pollutant. Therefore, we speculated that there are some differences in biological processes induced by PM2.5 and O3 exposure. In the present study, we investigated the differences induced by PM2.5 and O3 exposure from the perspective of cellular and molecular processes. Firstly, the pulmonary epithelial cells (BEAS-2B) were exposed to different concentrations of PM2.5 or O3 at different durations. Then, we chose experimental models with the concentrations and duration at which the cell survival rate was 50 % after exposure to PM2.5 and O3, which were 100 μg/mL for 24 h for PM2.5, and 200 ppb for 4 h for O3. Our findings indicate that PM2.5 infiltrates cells via endocytosis without causing significant damage to cell membranes, while O3 induces lipid peroxidation at the cell surface. Moreover, the detection of mitochondrial function showed that the content of ATP was significantly reduced after exposure to both PM2.5 and O3. However, we found a significant difference in mtDNA copy number. PM2.5 exposure increased the mtDNA copy number by up-regulating the expression of fission genes (Fis1, Mff, Dnm1). O3 exposure decreased it by up-regulating the expression of fusion gene (Mfn1, Mfn2) and down-regulating the expression of fission gene (Fis1, Dnm1). These results indicate that although both PM2.5 and O3 exposure induced almost exactly similar adverse health outcomes, significant differences do exist in cellular and molecular processes.

Mitochondria transfer-based therapies reduce the morbidity and mortality of Leigh syndrome

Mitochondria transfer is a recently described phenomenon in which donor cells deliver mitochondria to acceptor cells1-3. One possible consequence of mitochondria transfer is energetic support of neighbouring cells; for example, exogenous healthy mitochondria can rescue cell-intrinsic defects in mitochondrial metabolism in cultured ρ0 cells or Ndufs4-/- peritoneal macrophages4-7. Exposing haematopoietic stem cells to purified mitochondria before autologous haematopoietic stem cell transplantation allowed for treatment of anaemia in patients with large-scale mitochondrial DNA mutations8,9, and mitochondria transplantation was shown to minimize ischaemic damage to the heart10-12, brain13-15 and limbs16. However, the therapeutic potential of using mitochondria transfer-based therapies to treat inherited mitochondrial diseases is unclear. Here we demonstrate improved morbidity and mortality of the Ndufs4-/- mouse model of Leigh syndrome (LS) in multiple treatment paradigms associated with mitochondria transfer. Transplantation of bone marrow from wild-type mice, which is associated with release of haematopoietic cell-derived extracellular mitochondria into circulation and transfer of mitochondria to host cells in multiple organs, ameliorates LS in mice. Furthermore, administering isolated mitochondria from wild-type mice extends lifespan, improves neurological function and increases energy expenditure of Ndufs4-/- mice, whereas mitochondria from Ndufs4-/- mice did not improve neurological function. Finally, we demonstrate that cross-species administration of human mitochondria to Ndufs4-/- mice also improves LS. These data suggest that mitochondria transfer-related approaches can be harnessed to treat mitochondrial diseases, such as LS.

Is mitochondrial morphology important for cellular physiology?

Mitochondria are double membrane-bound organelles the network morphology of which in cells is shaped by opposing events of fusion and fission executed by dynamin-like GTPases. Mutations in these genes can perturb the form and functions of mitochondria in cell and animal models of mitochondrial diseases. An expanding array of chemical, mechanical, and genetic stressors can converge on mitochondrial-shaping proteins and disrupt mitochondrial morphology. In recent years, studies aimed at disentangling the multiple roles of mitochondrial-shaping proteins beyond fission or fusion have provided insights into the homeostatic relevance of mitochondrial morphology. Here, I review the pleiotropy of mitochondrial fusion and fission proteins with the aim of understanding whether mitochondrial morphology is important for cell and tissue physiology.

Stress triggers gut dysbiosis via CRH-CRHR1-mitochondria pathway

Stress can lead to gut dysbiosis in brain-gut axis disordered diseases as irritable bowel syndrome (IBS), yet the mechanisms how stress transfer from the brain to the gut and disrupt gut microbiota remain elusive. Here we describe a stress-responsive brain-to-gut axis which impairs colonocytes' mitochondria to trigger gut dysbiosis. Patients with IBS exhibit significantly increased facultative anaerobes and decreased obligate anaerobes, related to increased serum corticotropin-releasing hormone (CRH) level and defected colonocytes' mitochondria ultrastructure. Mice exposed to acute stress experienced enhanced CRH-CRH receptor type 1 (CRHR1) signaling, which impaired mitochondria and epithelium hypoxia in the colon, subsequently triggered gut dysbiosis. Antagonizing CRHR1 expression to inhibit cAMP/Ras/MAPK signaling or activating mitochondria respiration conferred resilience against stress-induced mitochondria damaging and epithelium hypoxia impairment, ultimately improving gut dysbiosis. These results suggest that the CRH-CRHR1-mitochondria pathway plays a pivotal role in stress-induced gut dysbiosis that could be therapeutically targeted for stress-induced gastrointestinal diseases. Yiming Zhang et.al report that psychological stress activated Corticotropin-releasing hormone (CRH)-CRH receptor type 1 (CRHR1)-mitochondria pathway to trigger gut dysbiosis and reveal CRHR1 upregulation damages mitochondria via cAMP/Ras/MAPK signaling in colonocytes.

Brain-body mitochondrial distribution patterns lack coherence and point to tissue-specific and individualized regulatory mechanisms

Energy transformation capacity is generally assumed to be a coherent individual trait driven by genetic and environmental factors. This predicts that some individuals should have high and others low mitochondrial oxidative phosphorylation (OxPhos) capacity across organ systems. Here, we test this assumption using multi-tissue molecular and enzymatic activities in mice and humans. Across up to 22 mouse tissues, neither mitochondrial OxPhos capacity nor mtDNA density were correlated between tissues (median r = -0.01-0.16), indicating that animals with high mitochondrial capacity in one tissue can have low capacity in other tissues. Similarly, the multi-tissue correlation structure of RNAseq-based indices of mitochondrial gene expression across 45 tissues from 948 women and men (GTEx) showed small to moderate coherence between only some tissues (regions of the same brain), but not between brain-body tissue pairs in the same person (median r = 0.01). Mitochondrial DNA copy number (mtDNAcn) also lacked coherence across organs and tissues. Mechanistically, tissue-specific differences in mitochondrial gene expression were attributable in part to i) tissue-specific activation of canonical energy sensing pathways including the transcriptional coactivator PGC-1 and the integrated stress response (ISR), and ii) proliferative activity across tissues. Finally, we identify subgroups of individuals with high mitochondrial gene expression in some tissues (e.g., heart) but low expression in others (e.g., skeletal muscle) who display different clinical phenotypic patterns. Taken together, these data raise the possibility that tissue-specific energy sensing pathways may contribute to the idiosyncratic mitochondrial distribution patterns associated with the inter-organ heterogeneity and phenotypic diversity among individuals.

Enhanced osteogenic differentiation in 3D hydrogel scaffold via macrophage mitochondrial transfer

To assess the efficacy of a novel 3D biomimetic hydrogel scaffold with immunomodulatory properties in promoting fracture healing. Immunomodulatory scaffolds were used in cell experiments, osteotomy mice treatment, and single-cell transcriptomic sequencing. In vitro, fluorescence tracing examined macrophage mitochondrial transfer and osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs). Scaffold efficacy was assessed through alkaline phosphatase (ALP), Alizarin Red S (ARS) staining, and in vivo experiments. The scaffold demonstrated excellent biocompatibility and antioxidant-immune regulation. Single-cell sequencing revealed a shift in macrophage distribution towards the M2 phenotype. In vitro experiments showed that macrophage mitochondria promoted BMSCs' osteogenic differentiation. In vivo experiments confirmed accelerated fracture healing. The GAD/Ag-pIO scaffold enhances osteogenic differentiation and fracture healing through immunomodulation and promotion of macrophage mitochondrial transfer.