Mitochondrial transplantation therapy for ischemia reperfusion injury: a systematic review of animal and human studies

Mitochondrial Transplantation: A Novel Therapy for Liver Ischemia/Reperfusion Injury

OBJECTIVE

To investigate the hepatoprotective effects of mitochondrial transplantation (MTx) in a murine liver ischemia/reperfusion (I/R) model.

BACKGROUND

Sequential liver ischemia, followed by reperfusion (I/R), is a pathophysiological process underlying hepatocellular injury in a number of clinical contexts, such as hemorrhagic shock/resuscitation, major elective liver surgery, and organ transplantation. A unifying pathogenic consequence of I/R is mitochondrial dysfunction. Restoration of mitochondria through transplantation (MTx) has emerged as a potential therapeutic in I/R. However, its role in liver I/R and its mechanisms of action remain poorly defined.

METHODS

We investigated the hepatoprotective effects of MTx in an in vivo mouse model of liver I/R and used in vivo imaging and various knockout and transgenic mouse models to determine the mechanism of protection.

RESULTS

We found that I/R-induced hepatocellular injury was prevented by MTx, as measured by plasma ALT, AST, and liver histology. In addition, I/R-induced pro-inflammatory cytokine release (IL-6, TNFα) was dampened by MTx, and anti-inflammatory IL-10 was enhanced. Moreover, MTx lowered neutrophil infiltration into both the liver sinusoids and lung bronchoalveolar lavage fluid, suggesting a local and distant reduction in inflammation. Using in vivo intravital imaging, we found that I/R-subjected Kupffer cells (KCs), rapidly sequestered transplanted mitochondria, and acidified mitochondria within lysosomal compartments. To specifically interrogate the role of KCs, we depleted KCs using the diphtheria toxin-inducible Clec4f/iDTR transgenic mouse, then induced I/R, and discovered that KCs are necessary for the beneficial effects of MTx. Finally, we induced I/R in the complement receptor of the immunoglobulin (CRIg) superfamily knockout mice and found that CRIg was required for mitochondria capture by KCs and mitochondria-mediated hepatoprotection.

CONCLUSIONS

In this study, we demonstrated that CRIg-dependent capture of mitochondria by I/R-subjected KCs is a hepatoprotective mechanism in vivo . These data progress knowledge on the mechanisms of MTx and open new avenues for clinical translation.

Targeting mitochondrial transfer as a promising therapeutic strategy

Despite the primary impression of mitochondria as energy factories, these organelles are increasingly recognized for their multifaceted roles beyond energy production. Intriguingly, mitochondria can transfer between cells, influencing physiological and pathological processes through intercellular trafficking termed 'mitochondrial transfer.' This phenomenon is important in maintaining metabolic homeostasis, enhancing tissue regeneration, exacerbating cancer progression, and facilitating immune modulation, depending on the cell type and microenvironment. Recently, mitochondrial transfer has emerged as a promising therapeutic target for tissue repair and antitumor therapy. Here, we summarize and critically review recent advances in this field. We aim to provide an updated overview of the mechanisms and potential therapeutic avenues associated with mitochondrial transfer in various diseases from the perspective of different donor cells.

An engineered mitoCBE facilitates efficient mitochondrial DNA editing and modified mitochondrial transfer

Double-stranded DNA cytosine deaminase DddA orthologs from multiple types of bacteria have been fused with the transcription-activator-like effector system for mitochondrial DNA (mtDNA) base editing, while the efficiencies remain limited and its nuclear off-targeting activity cannot be ignored yet. Here we identified a DddA ortholog from Burkholderia gladioli (BgDddA) and generated nuclear or mtDNA cytosine base editors (mitoCBEs), exhibiting higher C⋅G-to-T⋅A editing frequencies compared with canonical DdCBE, and fusion with transactivator Rta remarkably improved editing efficiencies by up to 6.4-fold at non-TC targets. Referring to DddA11, we further introduced six substitutions into BgDddA and generated mitoCBE3.2, which efficiently induced disease-associated mtDNA mutations in mouse and human cell lines at both TC and non-TC targets with efficiency reaching up to 99.2%. Using mitoCBE3.2, single clones containing homoplasmic mtDNA mutations or premature stop codons associated with human diseases were generated, and the functions of these mutations have been evaluated upon the treatment of reactive oxygen species inducers. Importantly, mitochondria harboring these homoplasmic mutations were transplanted into wild-type cells, enabling precise base conversions, without the risk of nuclear gene off-targets. Thus, we have engineered an efficient mitoCBE using BgDddA, facilitating mitochondrial disease modeling and potential mutation correction with the aid of mitochondrial transplantation.

Biomimetic MOF Nanocarrier-Mediated Synergistic Delivery of Mitochondria and Anti-Inflammatory miRNA to Alleviate Acute Lung Injury

Acute lung injury (ALI) is a clinically critical disease characterized by overwhelming inflammatory response and significant tissue damage with no specific treatment available currently. As a key player in the pathogenesis of ALI, macrophages are aberrantly activated and polarize toward the pro-inflammatory phenotypes, leading to overzealous inflammation and lung injury. Mitochondria is recognized as a crucial signaling hub governing macrophage function and polarization, deregulation of which is causatively related with defective metabolism of macrophages, deregulated inflammation, and hence ALI. Herein, an inflammation-responsive, biomimetic metal-organic framework (MOF) nanoplatform, termed a127/mito@ZIF@Ma is developed, which is sophistically designed for synergistic delivery of macrophage-derived mitochondria and anti-inflammatory miRNA-127 antagonist to resume pulmonary macrophages homeostasis and alleviate lung inflammation and injury. Notably, macrophage membrane encapsulation conferred the biomimetic MOF with enhanced transport efficacy both in vitro and in vivo. Therefore, the administration of the nanoparticles accordingly conferred a profound protection of mice against lung inflammation and injury induced by either bacterial or viral infection with unnoticeable tissue toxicity. The study thus devises a novel MOF-based nanosystem that integrates mitochondria transplantation and miRNA therapeutics, which may open a new avenue for treating ALI and relevant critical diseases.

Recent advances in mitochondrial transplantation to treat disease

Mitochondrial transplantation (MT), an innovative regenerative technique widely used to treat diseases caused by mitochondrial dysfunction, shows great promise for clinical application. This procedure can increase the number of mitochondria and improve the function of damaged mitochondria, resulting in increased adenosine triphosphate levels, decreased reactive oxygen species production, improved Ca2+ buffering capacity, modulated inflammatory response, and reduced apoptosis to protect cells, thus promoting tissue repair. In this review, we describe research advances in MT over the last five years, focusing on its application in treating various diseases, including ischaemic injuries (of the kidney, heart, lung, and liver), neurodegenerative disorders, spinal cord injury, sepsis, diabetes mellitus, stroke, and ultraviolet radiation injuries, as well as in procedures such as organ transplantation, focusing on instances where MT demonstrated good efficacy. We also cover the application of engineered mitochondria and mitochondrial combination therapies and present the latest advances in improving MT efficiency, as well as the current clinical applications and shortcomings of MT, aiming to provide a theoretical foundation for enhanced MT utilisation in the future.

Mitochondrial transplantation improves outcomes after cardiac arrest and resuscitation in mice

INTRODUCTION

Mitochondrial transplantation (MTx) is an emerging strategy for restoring cellular bioenergetics and mitigating ischemia-reperfusion (IR) injury. We previously demonstrated that MTx improved neurological outcomes and survival in a rat model of cardiac arrest (CA). However, the mechanisms underlying these benefits, particularly regarding immune modulation and transcriptional regulation, remain unclear.

METHODS

Adult C57BL/6 mice and Sprague-Dawley rats underwent CA and resuscitation protocols, followed by intravenous MTx with species-matched donor mitochondria. Survival and neurological outcomes were assessed up to 72 h. Biodistribution and cellular uptake of fluorescent dye-labeled mitochondria were analyzed via in vivo imaging and flow cytometry. Gene expression related to mitochondrial dynamics, inflammation, and immune regulation was evaluated using qPCR.

RESULTS

MTx improved 72-hour survival (33.3% vs. 0%, P = 0.006) and neurological scores compared to vehicle treatment. Reduced brain edema was observed in MTx-treated animals. Mitochondrial uptake was significantly enhanced in the brain and spleen post-CA, with key infiltrating and resident immune cell populations-including monocytes, macrophages, microglia, astrocytes, and endothelial cells-preferentially internalizing transplanted mitochondria. Circulating myeloid cells rapidly internalized functional mitochondria, with 53.9% uptake in MTx-treated CA animals versus 10.6% in controls (P < 0.001). MTx also modulated immune profiles, reducing pro-inflammatory macrophages and enhancing cytotoxic T cell numbers. Gene expression analysis showed that MTx downregulated Fission 1, preserved Mitofusin 2, and upregulated protective genes, including Hmox1, Sirt1, and Entpd1.

CONCLUSIONS

MTx improves outcomes after CA, accompanied by mitochondrial uptake by immune cells and redistribution to injured tissues. This process likely modulates immune responses, enhances mitochondrial fusion, and activates cytoprotective gene expression.

Xenotransplantation of mitochondria: A novel strategy to alleviate ischemia-reperfusion injury during ex vivo lung perfusion

BACKGROUND

Ischemia-reperfusion injury (IRI) plays a crucial role in the development of primary graft dysfunction (PGD) following lung transplantation. A promising novel approach to optimize donor organs before transplantation and reduce the incidence of PGD is mitochondrial transplantation.

METHODS

In this study, we explored the delivery of isolated mitochondria in 4 hours ex vivo lung perfusion (EVLP) before transplantation as a means to mitigate IRI. To provide a fresh and viable source of mitochondria, as well as to streamline the workflow without the need for donor muscle biopsies, we investigated the impact of autologous, allogeneic, and xenogeneic mitochondrial transplantation. In the xenogeneic settings, isolated mitochondria from mouse liver were utilized while autologous and allogeneic sources came from pig skeletal muscle biopsies.

RESULTS

Treatment with mitochondrial transplantation increased the P/F ratio and reduced pulmonary peak pressure of the lungs during EVLP, compared to lungs without any mitochondrial transplantation, indicating IRI mitigation. Extensive investigations using advanced light and scanning electron microscopy did not reveal evidence of acute rejection in any of the groups, indicating safe xenotransplantation of mitochondria.

CONCLUSIONS

Future work is needed to further explore this novel therapy for combating IRI in lung transplantation, where xenotransplantation of mitochondria may serve as a fresh, viable source to reduce IRI.

The role of homogenization cycles and Poloxamer 188 on the quality of mitochondria isolated for use in mitochondrial transplantation therapy

Mitochondrial transplantation (MTx) offers a promising therapeutic approach to mitigate mitochondrial dysfunction in conditions such as ischemia-reperfusion (IR) injury. The quality and viability of donor mitochondria are critical to MTx success, necessitating the optimization of isolation protocols. This study aimed to assess a rapid mitochondrial isolation method, examine the relationship between mitochondrial size and membrane potential, and evaluate the potential benefits of Poloxamer 188 (P-188) in improving mitochondrial quality during the isolation process. Mitochondria were isolated from pectoral muscle biopsies of adult male Sprague-Dawley rats using an automated homogenizer. MitoTracker Deep Red (MTDR) staining and flow cytometry were used to assess mitochondrial purity, while the JC-1 assay evaluated membrane potential. Mitochondrial size groups were compared for membrane potential differences. Homogenization frequency and P-188 supplementation (1 mM) were assessed for their effects on mitochondrial membrane potential and particle size, and particle counts. The rapid isolation method yielded mitochondria that retained sufficient membrane potential to be effectively inhibited by carbonyl cyanide 3-chlorophenylhydrazone (CCCP), a disruptor of mitochondrial membrane potential. Larger mitochondria exhibited significantly higher JC-1 ratios, indicating greater membrane potential. Excessive homogenization (10 cycles) reduced membrane potential compared to 3 cycles homogenization (P = 0.026). P-188 significantly increased the JC-1 ratio from 10.26 ± 2.57 to 33.78 ± 17.78 (P = 0.023). Particle size and count analysis revealed that 10 cycles homogenization significantly increased particle count compared to 3 cycles homogenization (P = 0.0001), but was associated with smaller particle sizes (P = 0.0031). The rapid mitochondrial isolation method produced viable mitochondria, with larger mitochondria exhibiting superior membrane potential. Reducing homogenization frequency and incorporating P-188 improved mitochondrial quality and preserved particle size. These strategies offer promising strategies for optimizing MTx protocols. Further refinement of these techniques is necessary for their clinical application in MTx therapy.

Effects of combo therapy with coenzyme Q10 and mitochondrial transplantation on myocardial ischemia/reperfusion-induced arrhythmias in aged rats

Objectives

Ischemia/reperfusion (IR)-induced ventricular arrhythmia, which mainly occurs after the opening of coronary artery occlusion, poses a clinical problem. This study aims to investigate the effectiveness of pretreatment with coenzyme Q10 (CoQ10) in combination with mitochondrial transplantation on IR-induced ventricular arrhythmias in aged rats.

Materials and Methods

Myocardial IR induction was performed by left anterior descending coronary artery occlusion for 30 min, followed by re-opening for 24 hr. CoQ10 was administered intraperitoneally at a dosage of 10 mg/kg/day for two weeks before inducing IR. At the start of reperfusion, 500 µl of the respiration buffer containing 6×106±5×105 mitochondria/ml of respiration buffer harvested from the pectorals major muscle of young donor rats were injected intramyocardially. To investigate arrhythmias, the heart's electrical activity during ischemia and the first 30 min of reperfusion were recorded by electrocardiogram. After 24 hr of reperfusion, cardiac histopathological changes, creatine kinase-MB, nitric oxide metabolites (NOx), oxidative stress markers (malondialdehyde, total anti-oxidant, superoxide dismutase, and glutathione peroxidase), and the expression of genes regulating mitochondrial fission/fusion were measured.

Results

Pretreatment with CoQ10 in combination with mitochondrial transplantation reduced ventricular arrhythmias, cardiac histopathological changes, and creatine kinase-MB levels. Simultaneously, this combined therapeutic approach increased myocardial NOx levels, fostering an improved oxidative balance. It also triggered the down-regulation of mitochondrial fission genes, coupled with the up-regulation of mitochondrial fusion genes.

Conclusion

The combination of CoQ10 and mitochondrial transplantation demonstrated a notable anti-arrhythmic effect by elevating NOx levels, reducing oxidative stress, and improving mitochondrial fission/fusion in aged rats with myocardial IRI.

The Mitochondrial Transplantation: A New Frontier in Plastic Surgery

Challenges such as difficult wound healing, ischemic necrosis of skin flaps, and skin aging are prevalent in plastic surgery. Previous research has indeed suggested that these challenges in plastic surgery are often linked to cellular energy barriers. As the powerhouses of the cell, mitochondria play a critical role in sustaining cellular vitality and health. Fundamentally, issues like ischemic and hypoxic damage to organs and tissues, as well as aging, stem from mitochondrial dysfunction, which leads to a depletion of cellular energy. Hence, having an adequate number of high-quality, healthy mitochondria is vital for maintaining tissue stability and cell survival. In recent years, there has been preliminary exploration into the protective effects of mitochondrial transplantation against cellular damage in systems such as the nervous, cardiovascular, and respiratory systems. For plastic surgery, mitochondrial transplantation is an extremely advanced research topic. This review focuses on the novel applications and future prospects of mitochondrial transplantation in plastic surgery, providing insights for clinicians and researchers, and offering guidance to patients seeking innovative and effective treatment options.

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.

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.

The role of mitochondria in iron overload-induced damage

Iron overload is a pathological condition characterized by the abnormal accumulation of iron within the body, which may result from excessive iron intake, disorders of iron metabolism, or specific disease states. This condition can lead to significant health complications and may pose life-threatening risks. The excessive accumulation of iron can induce cellular stress, adversely affecting the structure and function of mitochondria, thereby compromising overall organ function. Given the critical role of mitochondria in cellular metabolism and homeostasis, it is imperative to investigate how mitochondrial dysfunction induced by iron overload contributes to disease progression, as well as to explore mitochondrial-related pathways as potential therapeutic targets for various iron overload disorders. This review examines the mechanisms by which mitochondria are implicated in iron overload-induced damage, including increased oxidative stress, mitochondrial DNA damage, and disruptions in energy metabolism. Additionally, it addresses the relationship between these processes and various forms of programmed cell death, as well as alterations in mitochondrial dynamics. Furthermore, the review discusses strategies aimed at alleviating and mitigating the complications associated with iron overload in patients by targeting mitochondrial pathways.

Acute lung injury and post-cardiac arrest syndrome: a narrative review

BACKGROUND

Post-cardiac arrest syndrome (PCAS) presents a multifaceted challenge in clinical practice, characterized by severe neurological injury and high mortality rates despite advancements in management strategies. One of the important critical aspects of PCAS is post-arrest lung injury (PALI), which significantly contributes to poor outcomes. PALI arises from a complex interplay of pathophysiological mechanisms, including trauma from chest compressions, pulmonary ischemia-reperfusion (IR) injury, aspiration, and systemic inflammation. Despite its clinical significance, the pathophysiology of PALI remains incompletely understood, necessitating further investigation to optimize therapeutic approaches.

METHODS

This review comprehensively examines the existing literature to elucidate the epidemiology, pathophysiology, and therapeutic strategies for PALI. A comprehensive literature search was conducted to identify preclinical and clinical studies investigating PALI. Data from these studies were synthesized to provide a comprehensive overview of PALI and its management.

RESULTS

Epidemiological studies have highlighted the substantial prevalence of PALI in post-cardiac arrest patients, with up to 50% of survivors experiencing acute lung injury. Diagnostic imaging modalities, including chest X-rays, computed tomography, and lung ultrasound, play a crucial role in identifying PALI and assessing its severity. Pathophysiologically, PALI encompasses a spectrum of factors, including chest compression-related trauma, pulmonary IR injury, aspiration, and systemic inflammation, which collectively contribute to lung dysfunction and poor outcomes. Therapeutically, lung-protective ventilation strategies, such as low tidal volume ventilation and optimization of positive end-expiratory pressure, have emerged as cornerstone approaches in the management of PALI. Additionally, therapeutic hypothermia and emerging therapies targeting mitochondrial dysfunction hold promise in mitigating PALI-related morbidity and mortality.

CONCLUSION

PALI represents a significant clinical challenge in post-cardiac arrest care, necessitating prompt diagnosis and targeted interventions to improve outcomes. Mitochondrial-related therapies are among the novel therapeutic strategies for PALI. Further clinical research is warranted to optimize PALI management and enhance post-cardiac arrest care paradigms.

Effect of umbilical cord mesenchymal stem cell-derived mitochondrial transplantation on ischemia-reperfusion injury in a rat model

BACKGROUND

Despite advancements in reconstructive procedures, ischemia-reperfusion (I/R) injury remains a significant challenge in reconstructive surgery, with mitochondrial dysfunction playing a pivotal role. Mitochondrial transplantation has emerged as a promising therapeutic strategy to address this issue. This study aims to evaluate the impact of umbilical cord mesenchymal stem cell-derived mitochondrial transplantation on skin flap I/R models in rats.

MATERIAL AND METHODS

Twenty male rats underwent I/R injury on skin flaps, with or without mitochondrial transplantation administered via intravenous or subcutaneous routes. Analysis encompassed histopathology, inflammatory, apoptotic, oxidative stress, and hypoxia markers.

RESULTS

Results revealed a reduction in inflammation, apoptosis, oxidative stress, and hypoxia in the transplantation group compared to controls.

CONCLUSION

The findings suggest that umbilical cord mesenchymal stem cell-derived mitochondrial transplantation shows promise in enhancing flap viability and attenuating I/R injury, offering valuable insights for improved outcomes in reconstructive surgery. However, further exploration in larger animal models and refinement of delivery methods and dosage are warranted to fully elucidate its clinical translatability.

Mitotherapy with Fresh Isolated Cardiac Mitochondria Via Injection Into Blood Reduces Aluminum Phosphide-Induced Mortality and Protects Cardiac Tissue Against Oxidative Stress and Mitochondrial Damages

The hallmark of aluminum phosphide (AlP) poisoning is heart failure in victims which is associated with reactive oxygen species (ROS), mitochondrial dysfunction, oxidative stress, alteration in antioxidant defense system and depletion of ATP in cardiomyocytes. In the present study, we hypothesized that the injection of isolated mitochondria into blood or mitochondrial transplantation can likely create a primary target for phosphine released from AlP and inhibit AlP-induced mortality and cardiotoxicity in rat. Male, Wistar, healthy and adult rats were randomly divided into 5 groups as control, AlP (12.5 mg/kg, orally), AlP + mitochondria (125 µg/kg), AlP + mitochondria (250 µg/kg) and mitochondria (250 µg/kg) alone. Functional and intact mitochondria isolated from rat heart and transplantation was carried out via tail vein, 30 min after exposure to AlP. Survival rate, histopathological alterations, cardiac biochemical markers, oxidative stress and mitochondrial toxicity parameters were monitored and analyzed during 30 days. We found that injection of healthy mitochondria into blood at concentrations of 125 and 250 125 µg/ml significantly increased the survival of rats up to 40% and 56.25% respectively, during 30 days. Moreover, we observed that mitochondria injection into blood decreased histopathological damages, cardiac biochemical markers, oxidative stress and mitochondrial toxicity parameters. To our knowledge, the current study is the first report in the literature that demonstrated good therapeutic effects of mitochondrial transplantation in AlP-induced mortality and cardiotoxicity. The findings of the present study suggests that injection of exogenous mitochondria into blood could be an effective therapeutic strategy in treating AlP poisoning.

Extracellular vesicles: opening up a new perspective for the diagnosis and treatment of mitochondrial dysfunction

Mitochondria are crucial organelles responsible for energy generation in eukaryotic cells. Oxidative stress, calcium disorders, and mitochondrial DNA abnormalities can all cause mitochondrial dysfunction. It is now well documented that mitochondrial dysfunction significantly contributes to the pathogenesis of numerous illnesses. Hence, it is vital to investigate innovative treatment methods targeting mitochondrial dysfunction. Extracellular vesicles (EVs) are cell-derived nanovesicles that serve as intercellular messengers and are classified into small EVs (sEVs, < 200 nm) and large EVs (lEVs, > 200 nm) based on their sizes. It is worth noting that certain subtypes of EVs are rich in mitochondrial components (even structurally intact mitochondria) and possess the ability to transfer them or other contents including proteins and nucleic acids to recipient cells to modulate their mitochondrial function. Specifically, EVs can modulate target cell mitochondrial homeostasis as well as mitochondria-controlled apoptosis and ROS generation by delivering relevant substances. In addition, the artificial modification of EVs as delivery carriers for therapeutic goods targeting mitochondria is also a current research hotspot. In this article, we will focus on the ability of EVs to modulate the mitochondrial function of target cells, aiming to offer novel perspectives on therapeutic approaches for diverse conditions linked to mitochondrial dysfunction.

Analysis of the prognostic value of mitochondria-related genes in patients with acute myocardial infarction

BACKGROUND

Acute myocardial infarction (AMI) is a leading cause of death worldwide. Mitochondrial dysfunction is a key determinant of cell death post-AMI. Preventing mitochondrial dysfunction is thus a key therapeutic strategy. This study aimed to explore key genes and target compounds related to mitochondrial dysfunction in AMI patients and their association with major adverse cardiovascular events (MACE).

METHODS

Differentially expressed genes in AMI were identified from the Gene Expression Omnibus (GEO) datasets (GSE166780 and GSE24519), and mitochondria-related genes were obtained from MitoCarta3.0 database. By intersection of the two gene groups, mitochondria-related genes in AMI were identified. Next, the identified genes related to mitochondria were subject to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses. Protein-protein interaction (PPI) network was constructed, and key genes were screened. Then, targeted drug screening and molecular docking were performed. Blood samples from AMI patients and healthy volunteers were analyzed for the key genes expressions using quantitative real time polymerase chain reaction (qRT-PCR). Later, receiver operating characteristic (ROC) curves assessed the diagnostic value of key genes, and univariate and multivariate COX analyses identified risk factors and protective factors for MACE in AMI patients.

RESULTS

After screening and identification, 138 mitochondria-related genes were identified, mainly enriched in the processes and pathways of cellular respiration, redox, mitochondrial metabolism, apoptosis, amino acid and fatty acid metabolism. According to the PPI network, 5 key mitochondria-related genes in AMI were obtained: translational activator of cytochrome c oxidase I (TACO1), cytochrome c oxidase subunit Va (COX5A), PTEN-induced putative kinase 1 (PINK1), SURF1, and NDUFA11. Molecular docking showed that Cholic Acid, N-Formylmethionine interacted with COX5A, nicotinamide adenine dinucleotide + hydrogen (NADH) and NDUFA11. Subsequent basic experiments revealed that COX5A and NDUFA11 expressions were significantly lower in the blood of patients with AMI than those in the corresponding healthy volunteers; also, AMI patients with MACE had lower COX5A and NDUFA11 expressions in the blood than those without MACE (P < 0.01). ROC analysis also showed high diagnostic value for COX5A and NDUFA11 [area under the curve (AUC) > 0.85]. In terms of COX results, COX5A, NDUFA11 and left ventricular ejection fraction (LVEF) were protective factors for MACE in AMI, while C-reactive protein (CRP) was a risk factor.

CONCLUSION

COX5A and NDUFA11, key mitochondria-related genes in AMI, may be used as biomarkers to diagnose AMI and predict MACE.

Cardioprotection in cardiovascular surgery

Since the invention of cardiopulmonary bypass, cardioprotective strategies have been investigated to mitigate ischemic injury to the heart during aortic cross-clamping and reperfusion injury with cross-clamp release. With advances in cardiac surgical and percutaneous techniques and post-operative management strategies including mechanical circulatory support, cardiac surgeons are able to operate on more complex patients. Therefore, there is a growing need for improved cardioprotective strategies to optimize outcomes in these patients. This review provides an overview of the basic principles of cardioprotection in the setting of cardiac surgery, including mechanisms of cardiac injury in the context of cardiopulmonary bypass, followed by a discussion of the specific approaches to optimizing cardioprotection in cardiac surgery, including refinements in cardiopulmonary bypass and cardioplegia, ischemic conditioning, use of specific anesthetic and pharmaceutical agents, and novel mechanical circulatory support technologies. Finally, translational strategies that investigate cardioprotection in the setting of cardiac surgery will be reviewed, with a focus on promising research in the areas of cell-based and gene therapy. Advances in this area will help cardiologists and cardiac surgeons mitigate myocardial ischemic injury, improve functional post-operative recovery, and optimize clinical outcomes in patients undergoing cardiac surgery.

Differential Mitochondrial Bioenergetics in Neurons and Astrocytes Following Ischemia-Reperfusion Injury and Hypothermia

The close interaction between neurons and astrocytes has been extensively studied. However, the specific behavior of these cells after ischemia-reperfusion injury and hypothermia remains poorly characterized. A growing body of evidence suggests that mitochondria function and putative transference between neurons and astrocytes may play a fundamental role in adaptive and homeostatic responses after systemic insults such as cardiac arrest, which highlights the importance of a better understanding of how neurons and astrocytes behave individually in these settings. Brain injury is one of the most important challenges in post-cardiac arrest syndrome, and therapeutic hypothermia remains the single, gold standard treatment for neuroprotection after cardiac arrest. In our study, we modeled ischemia-reperfusion injury by using in vitro enhanced oxygen-glucose deprivation and reperfusion (eOGD-R) and subsequent hypothermia (HPT) (31.5 °C) to cell lines of neurons (HT-22) and astrocytes (C8-D1A) with/without hypothermia. Using cell lysis (LDH; lactate dehydrogenase) as a measure of membrane integrity and cell viability, we found that neurons were more susceptible to eOGD-R when compared with astrocytes. However, they benefited significantly from HPT, while the HPT effect after eOGD-R on astrocytes was negligible. Similarly, eOGD-R caused a more significant reduction in adenosine triphosphate (ATP) in neurons than astrocytes, and the ATP-enhancing effects from HPT were more prominent in neurons than astrocytes. In both neurons and astrocytes, measurement of reactive oxygen species (ROS) revealed higher ROS output following eOGD-R, with a non-significant trend of differential reduction observed in neurons. HPT after eOGD-R effectively downregulated ROS in both cells; however, the effect was significantly more effective in neurons. Lipid peroxidation was higher after eOGD-R in neurons, while in astrocytes, the increase was not statistically significant. Interestingly, HPT had similar effects on the reduction in lipoperoxidation after eOGD-R with both types of cells. While glutathione (GSH) levels were downregulated after eOGD-R in both cells, HPT enhanced GSH in astrocytes, but worsened GSH in neurons. In conclusion, neuron and astrocyte cultures respond differently to eOGD-R and eOGD-R + HTP treatments. Neurons showed higher sensitivity to ischemia-reperfusion insults than astrocytes; however, they benefited more from HPT therapy. These data suggest that given the differential effects from HPT in neurons and astrocytes, future therapeutic developments could potentially enhance HPT outcomes by means of neuronal and astrocytic targeted therapies.

Bridging the gap between in vitro and in vivo models: a way forward to clinical translation of mitochondrial transplantation in acute disease states

Mitochondrial transplantation and transfer are being explored as therapeutic options in acute and chronic diseases to restore cellular function in injured tissues. To limit potential immune responses and rejection of donor mitochondria, current clinical applications have focused on delivery of autologous mitochondria. We recently convened a Mitochondrial Transplant Convergent Working Group (CWG), to explore three key issues that limit clinical translation: (1) storage of mitochondria, (2) biomaterials to enhance mitochondrial uptake, and (3) dynamic models to mimic the complex recipient tissue environment. In this review, we present a summary of CWG conclusions related to these three issues and provide an overview of pre-clinical studies aimed at building a more robust toolkit for translational trials.

Mitochondrial dysfunction: mechanisms and advances in therapy

Mitochondria, with their intricate networks of functions and information processing, are pivotal in both health regulation and disease progression. Particularly, mitochondrial dysfunctions are identified in many common pathologies, including cardiovascular diseases, neurodegeneration, metabolic syndrome, and cancer. However, the multifaceted nature and elusive phenotypic threshold of mitochondrial dysfunction complicate our understanding of their contributions to diseases. Nonetheless, these complexities do not prevent mitochondria from being among the most important therapeutic targets. In recent years, strategies targeting mitochondrial dysfunction have continuously emerged and transitioned to clinical trials. Advanced intervention such as using healthy mitochondria to replenish or replace damaged mitochondria, has shown promise in preclinical trials of various diseases. Mitochondrial components, including mtDNA, mitochondria-located microRNA, and associated proteins can be potential therapeutic agents to augment mitochondrial function in immunometabolic diseases and tissue injuries. Here, we review current knowledge of mitochondrial pathophysiology in concrete examples of common diseases. We also summarize current strategies to treat mitochondrial dysfunction from the perspective of dietary supplements and targeted therapies, as well as the clinical translational situation of related pharmacology agents. Finally, this review discusses the innovations and potential applications of mitochondrial transplantation as an advanced and promising treatment.

Novel Role for Cardiolipin as a Target of Therapy to Mitigate Myocardial Injury Caused by Venoarterial Extracorporeal Membrane Oxygenation

BACKGROUND

Cardiolipin is a mitochondrial-specific phospholipid that maintains integrity of the electron transport chain (ETC) and plays a central role in myocardial ischemia/reperfusion injury. Tafazzin is an enzyme that is required for cardiolipin maturation. Venoarterial extracorporeal membrane oxygenation (VA-ECMO) use to provide hemodynamic support for acute myocardial infarction has grown exponentially, is associated with poor outcomes, and is under active clinical investigation, yet the mechanistic effect of VA-ECMO on myocardial damage in acute myocardial infarction remains poorly understood. We hypothesized that VA-ECMO acutely depletes myocardial cardiolipin and exacerbates myocardial injury in acute myocardial infarction.

METHODS

We examined cardiolipin and tafazzin levels in human subjects with heart failure and healthy swine exposed to VA-ECMO and used a swine model of closed-chest myocardial ischemia/reperfusion injury to evaluate the effect of VA-ECMO on cardiolipin expression, myocardial injury, and mitochondrial function.

RESULTS

Cardiolipin and tafazzin levels are significantly reduced in the left ventricles of individuals requiring VA-ECMO compared with individuals without VA-ECMO before heart transplantation. Six hours of exposure to VA-ECMO also decreased left ventricular levels of cardiolipin and tafazzin in healthy swine compared with sham controls. To explore whether cardiolipin depletion by VA-ECMO increases infarct size, we performed left anterior descending artery occlusion for a total of 120 minutes followed by 180 minutes of reperfusion in adult swine in the presence and absence of MTP-131, an amphipathic molecule that interacts with cardiolipin to stabilize the inner mitochondrial membrane. Compared with reperfusion alone, VA-ECMO activation beginning after 90 minutes of left anterior descending artery occlusion increased infarct size (36±8% versus 48±7%; P<0.001). VA-ECMO also decreased cardiolipin and tafazzin levels, disrupted mitochondrial integrity, reduced electron transport chain function, and promoted oxidative stress. Compared with reperfusion alone or VA-ECMO before reperfusion, delivery of MTP-131 before VA-ECMO activation reduced infarct size (22±8%; P=0.03 versus reperfusion alone and P<0.001 versus VA-ECMO alone). MTP-131 restored cardiolipin and tafazzin levels, stabilized mitochondrial function, and reduced oxidative stress in the left ventricle.

CONCLUSIONS

We identified a novel mechanism by which VA-ECMO promotes myocardial injury and further identify cardiolipin as an important target of therapy to reduce infarct size and to preserve mitochondrial function in the setting of VA-ECMO for acute myocardial infarction.

Organ-Specific Mitochondrial Alterations Following Ischemia-Reperfusion Injury in Post-Cardiac Arrest Syndrome: A Comprehensive Review

BACKGROUND

Mitochondrial dysfunction, which is triggered by systemic ischemia-reperfusion (IR) injury and affects various organs, is a key factor in the development of post-cardiac arrest syndrome (PCAS). Current research on PCAS primarily addresses generalized mitochondrial responses, resulting in a knowledge gap regarding organ-specific mitochondrial dynamics. This review focuses on the organ-specific mitochondrial responses to IR injury, particularly examining the brain, heart, and kidneys, to highlight potential therapeutic strategies targeting mitochondrial dysfunction to enhance outcomes post-IR injury.

METHODS AND RESULTS

We conducted a narrative review examining recent advancements in mitochondrial research related to IR injury. Mitochondrial responses to IR injury exhibit considerable variation across different organ systems, influenced by unique mitochondrial structures, bioenergetics, and antioxidative capacities. Each organ demonstrates distinct mitochondrial behaviors that have evolved to fulfill specific metabolic and functional needs. For example, cerebral mitochondria display dynamic responses that can be both protective and detrimental to neuronal activity and function during ischemic events. Cardiac mitochondria show vulnerability to IR-induced oxidative stress, while renal mitochondria exhibit a unique pattern of fission and fusion, closely linked to their susceptibility to acute kidney injury. This organ-specific heterogeneity in mitochondrial responses requires the development of tailored interventions. Progress in mitochondrial medicine, especially in the realms of genomics and metabolomics, is paving the way for innovative strategies to combat mitochondrial dysfunction. Emerging techniques such as mitochondrial transplantation hold the potential to revolutionize the management of IR injury in resuscitation science.

CONCLUSIONS

The investigation into organ-specific mitochondrial responses to IR injury is pivotal in the realm of resuscitation research, particularly within the context of PCAS. This nuanced understanding holds the promise of revolutionizing PCAS management, addressing the unique mitochondrial dysfunctions observed in critical organs affected by IR injury.

Therapeutic potential of mitochondrial transplantation in modulating immune responses post-cardiac arrest: a narrative review

BACKGROUND

Mitochondrial transplantation (MTx) has emerged as a novel therapeutic strategy, particularly effective in diseases characterized by mitochondrial dysfunction. This review synthesizes current knowledge on MTx, focusing on its role in modulating immune responses and explores its potential in treating post-cardiac arrest syndrome (PCAS).

METHODS

We conducted a comprehensive narrative review of animal and human studies that have investigated the effects of MTx in the context of immunomodulation. This included a review of the immune responses following critical condition such as ischemia reperfusion injury, the impact of MTx on these responses, and the therapeutic potential of MTx in various conditions.

RESULTS

Recent studies indicate that MTx can modulate complex immune responses and reduce ischemia-reperfusion injury post-CA, suggesting MTx as a novel, potentially more effective approach. The review highlights the role of MTx in immune modulation, its potential synergistic effects with existing treatments such as therapeutic hypothermia, and the need for further research to optimize its application in PCAS. The safety and efficacy of autologous versus allogeneic MTx, particularly in the context of immune reactions, are critical areas for future investigation.

CONCLUSION

MTx represents a promising frontier in the treatment of PCAS, offering a novel approach to modulate immune responses and restore cellular energetics. Future research should focus on long-term effects, combination therapies, and personalized medicine approaches to fully harness the potential of MTx in improving patient outcomes in PCAS.

A break in mitochondrial endosymbiosis as a basis for inflammatory diseases

Mitochondria retain bacterial traits due to their endosymbiotic origin, but host cells do not recognize them as foreign because the organelles are sequestered. However, the regulated release of mitochondrial factors into the cytosol can trigger cell death, innate immunity and inflammation. This selective breakdown in the 2-billion-year-old endosymbiotic relationship enables mitochondria to act as intracellular signalling hubs. Mitochondrial signals include proteins, nucleic acids, phospholipids, metabolites and reactive oxygen species, which have many modes of release from mitochondria, and of decoding in the cytosol and nucleus. Because these mitochondrial signals probably contribute to the homeostatic role of inflammation, dysregulation of these processes may lead to autoimmune and inflammatory diseases. A potential reason for the increased incidence of these diseases may be changes in mitochondrial function and signalling in response to such recent phenomena as obesity, dietary changes and other environmental factors. Focusing on the mixed heritage of mitochondria therefore leads to predictions for future insights, research paths and therapeutic opportunities. Thus, whereas mitochondria can be considered 'the enemy within' the cell, evolution has used this strained relationship in intriguing ways, with increasing evidence pointing to the recent failure of endosymbiosis being critical for the pathogenesis of inflammatory diseases.

Explore novel molecular mechanisms of FNDC5 in ischemia-reperfusion (I/R) injury by analyzing transcriptome changes in mouse model of skeletal muscle I/R injury with FNDC5 knockout

BACKGROUND

Irisin, a myokine derived from proteolytic cleavage of the fibronectin type III domain-containing protein 5 (FNDC5) protein, is crucial in protecting tissues and organs from ischemia-reperfusion (I/R) injury. However, the underlying mechanism of its action remains elusive. In this study, we investigated the expression patterns of genes associated with FNDC5 knockout to gain insights into its molecular functions.

METHODS

We employed a mouse model of skeletal muscle I/R injury with FNDC5 knockout to examine the transcriptional profiles using RNA sequencing. Differentially expressed genes (DEGs) were identified and subjected to further analyses, including gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, protein-protein interaction (PPI) network analysis, and miRNA-transcription factor network analysis. The bioinformatics findings were validated using qRT-PCR and Western blotting.

RESULTS

Comparative analysis of skeletal muscle transcriptomes between wild-type (WT; C57BL/6), WT-I/R, FNDC5 knockout (KO), and KO-I/R mice highlighted the significance of FNDC5 in both physiological conditions and I/R injury. Through PPI network analysis, we identified seven key genes (Col6a2, Acta2, Col4a5, Fap, Enpep, Mmp11, and Fosl1), which facilitated the construction of a TF-hub genes-miRNA regulatory network. Additionally, our results suggested that the PI3K-Akt pathway is predominantly involved in FNDC5 deletion-mediated I/R injury in skeletal muscle. Animal studies revealed reduced FNDC5 expression in skeletal muscle following I/R injury, and the gastrocnemius muscle with FNDC5 knockout exhibited larger infarct size and more severe tissue damage after I/R. Moreover, Western blot analysis confirmed the upregulation of Col6a2, Enpep, and Mmp11 protein levels following I/R, particularly in the KO-I/R group. Furthermore, FNDC5 deletion inhibited the PI3K-Akt signaling pathway.

CONCLUSION

This study demonstrates that FNDC5 deletion exacerbates skeletal muscle I/R injury, potentially involving the upregulation of Col6a2, Enpep, and Mmp11. Additionally, the findings suggest the involvement of the PI3K-Akt pathway in FNDC5 deletion-mediated skeletal muscle I/R injury, providing novel insights into the molecular mechanisms underlying FNDC5's role in this pathological process.

Mitochondrial transplantation: the advance to therapeutic application and molecular modulation

Mitochondrial transplantation provides a novel methodology for rescue of cell viability and cell function following ischemia-reperfusion injury and applications for other pathologies are expanding. In this review we present our methods and acquired data and evidence accumulated to support the use of mitochondrial transplantation.

Allogeneic mitochondrial transplantation ameliorates cardiac dysfunction due to doxorubicin: An in vivo study

Damage to the mitochondria may lead to serious conditions that are difficult to treat. Doxorubicin is one of the most widely used chemotherapeutic drugs for the treatment of malignancies in children and adults, and reportedly causes damage to the mitochondria. Unfortunately, the dangerous cardiac side effects of doxorubicin appear when the patient is in the midst of a vigorous fight against the disease, either by taking doxorubicin alone or in combination with other drugs. This study aimed to determine whether exogenous healthy and functional mitochondria are internalized by cells, can it help the survival of these cells, and can reduce cardiotoxicity. For this purpose, isolated, pure, and functional exogenous mitochondria were injected into the tail vein of a rat model of doxorubicin-induced cardiotoxicity. After that, the heart function of the rats and their antioxidant status, inflammatory markers, and histopathological examination were investigated. Our findings show that intravenous mitochondrial transplantation provided efficient mitochondrial uptake and reduced cardiotoxicity by reducing ROS production, lipid peroxidation, and inflammation. In addition, the levels of ATP and antioxidant enzymes increased after mitochondrial transplantation; therefore all of these complex processes resulted in the reduction of apoptosis and necrosis in rat heart tissue. These promising results open the way to more effective cancer treatment without the side effects of related drugs. Transplanting exogenous mitochondria probably enhances the cell's mitochondrial network, potentially treating mitochondria-related disorders such as cardiovascular and neurodegenerative diseases, although the exact relationship between mitochondrial damage and these conditions remains unclear.

Advances in the study of B cells in renal ischemia-reperfusion injury

Renal ischemia-reperfusion injury (IRI) is a non-negligible clinical challenge for clinicians in surgeries such as renal transplantation. Functional loss of renal tubular epithelial cell (TEC) in IRI leads to the development of acute kidney injury, delayed graft function (DGF), and allograft rejection. The available evidence indicates that cellular oxidative stress, cell death, microvascular dysfunction, and immune response play an important role in the pathogenesis of IRI. A variety of immune cells, including macrophages and T cells, are actively involved in the progression of IRI in the immune response. The role of B cells in IRI has been relatively less studied, but there is a growing body of evidence for the involvement of B cells, which involve in the development of IRI through innate immune responses, adaptive immune responses, and negative immune regulation. Therefore, therapies targeting B cells may be a potential direction to mitigate IRI. In this review, we summarize the current state of research on the role of B cells in IRI, explore the potential effects of different B cell subsets in the pathogenesis of IRI, and discuss possible targets of B cells for therapeutic aim in renal IRI.

Mitochondrial transfer restores impaired liver functions by AMPK/ mTOR/PI3K-AKT pathways in metabolic syndrome

AIM

We investigated the effect of mitochondria transfer in high fat diet and streptozotocin (HFD + STZ) induced metabolic syndrome (MeS) in rats. The effect of mitochondria transfer in MeS with co-existing hypertension, hyperlipidaemia, diabetes and fatty liver together, has not been reported.

MATERIALS AND METHODS

Heathy mitochondria was transferred intravenously and the effect on several physiological parameters and biochemical parameters were examined in HFD + STZ rats. In addition, RNA-sequencing of healthy liver tissues was performed to elucidate the molecular pathways affected by mitochondria transfer in restoring metabolic health.

KEY FINDINGS

We observed reduction in both systolic and diastolic blood pressure levels, reduced blood glucose levels, and a marked reduction in serum lipid profiles. The levels of alanine transaminase (ALT) and aspartate transaminase (AST) also improved along with evident restoration of liver morphology demonstrated by histopathological analysis. Enhanced mitochondrial biogenetics and reduction in oxidative stress and inflammatory markers was also observed. The pathway enrichment analysis revealed reduction in insulin resistance, inflammatory markers, regulation of mitochondrial bioenergetics, calcium ion homeostasis, fatty-acid β-oxidation, cytokine immune regulators, and enhanced lipid solubilisation. The significant effect of healthy mitochondria transfer in restoration of metabolic functions was observed by the activation of PI3K-AKT, AMPK/mTOR pathways and cytokine immune regulators, suggesting that inflammatory mediators were also significantly affected after mitochondria transfer.

SIGNIFICANCE

This study, provides insights on molecular processes triggered by mitochondria transfer in fatty liver regeneration and improvement of overall metabolic health.

Therapeutic Effects of Mesenchymal Stromal Cells Require Mitochondrial Transfer and Quality Control

Due to their beneficial effects in an array of diseases, Mesenchymal Stromal Cells (MSCs) have been the focus of intense preclinical research and clinical implementation for decades. MSCs have multilineage differentiation capacity, support hematopoiesis, secrete pro-regenerative factors and exert immunoregulatory functions promoting homeostasis and the resolution of injury/inflammation. The main effects of MSCs include modulation of immune cells (macrophages, neutrophils, and lymphocytes), secretion of antimicrobial peptides, and transfer of mitochondria (Mt) to injured cells. These actions can be enhanced by priming (i.e., licensing) MSCs prior to exposure to deleterious microenvironments. Preclinical evidence suggests that MSCs can exert therapeutic effects in a variety of pathological states, including cardiac, respiratory, hepatic, renal, and neurological diseases. One of the key emerging beneficial actions of MSCs is the improvement of mitochondrial functions in the injured tissues by enhancing mitochondrial quality control (MQC). Recent advances in the understanding of cellular MQC, including mitochondrial biogenesis, mitophagy, fission, and fusion, helped uncover how MSCs enhance these processes. Specifically, MSCs have been suggested to regulate peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC1α)-dependent biogenesis, Parkin-dependent mitophagy, and Mitofusins (Mfn1/2) or Dynamin Related Protein-1 (Drp1)-mediated fission/fusion. In addition, previous studies also verified mitochondrial transfer from MSCs through tunneling nanotubes and via microvesicular transport. Combined, these effects improve mitochondrial functions, thereby contributing to the resolution of injury and inflammation. Thus, uncovering how MSCs affect MQC opens new therapeutic avenues for organ injury, and the transplantation of MSC-derived mitochondria to injured tissues might represent an attractive new therapeutic approach.

The Effects of Mitochondrial Transplantation on Sepsis Depend on the Type of Cell from Which They Are Isolated

Previously, we have shown that mitochondrial transplantation in the sepsis model has immune modulatory effects. The mitochondrial function could have different characteristics dependent on cell types. Here, we investigated whether the effects of mitochondrial transplantation on the sepsis model could be different depending on the cell type, from which mitochondria were isolated. We isolated mitochondria from L6 muscle cells, clone 9 liver cells and mesenchymal stem cells (MSC). We tested the effects of mitochondrial transplantation using in vitro and in vivo sepsis models. We used the LPS stimulation of THP-1 cell, a monocyte cell line, as an in vitro model. First, we observed changes in mitochondrial function in the mitochondria-transplanted cells. Second, we compared the anti-inflammatory effects of mitochondrial transplantation. Third, we investigated the immune-enhancing effects using the endotoxin tolerance model. In the in vivo polymicrobial fecal slurry sepsis model, we examined the survival and biochemical effects of each type of mitochondrial transplantation. In the in vitro LPS model, mitochondrial transplantation with each cell type improved mitochondrial function, as measured by oxygen consumption. Among the three cell types, L6-mitochondrial transplantation significantly enhanced mitochondrial function. Mitochondrial transplantation with each cell type reduced hyper-inflammation in the acute phase of in vitro LPS model. It also enhanced immune function during the late immune suppression phase, as shown by endotoxin tolerance. These functions were not significantly different between the three cell types of origin for mitochondrial transplantation. However, only L6-mitochondrial transplantation significantly improved survival compared to the control in the polymicrobial intraabdominal sepsis model. The effects of mitochondria transplantation on both in vitro and in vivo sepsis models differed depending on the cell types of origin for mitochondria. L6-mitochondrial transplantation might be more beneficial in the sepsis model.

Independent and sensory human mitochondrial functions reflecting symbiotic evolution

The bacterial origin of mitochondria has been a widely accepted as an event that occurred about 1.45 billion years ago and endowed cells with internal energy producing organelle. Thus, mitochondria have traditionally been viewed as subcellular organelle as any other - fully functionally dependent on the cell it is a part of. However, recent studies have given us evidence that mitochondria are more functionally independent than other organelles, as they can function outside the cells, engage in complex "social" interactions, and communicate with each other as well as other cellular components, bacteria and viruses. Furthermore, mitochondria move, assemble and organize upon sensing different environmental cues, using a process akin to bacterial quorum sensing. Therefore, taking all these lines of evidence into account we hypothesize that mitochondria need to be viewed and studied from a perspective of a more functionally independent entity. This view of mitochondria may lead to new insights into their biological function, and inform new strategies for treatment of disease associated with mitochondrial dysfunction.

Machine perfusion of the liver and bioengineering

With the increasing number of accepted candidates on waiting lists worldwide, there is an urgent need to expand the number and the quality of donor livers. Dynamic preservation approaches have demonstrated various benefits, including improving liver function and graft survival, and reducing liver injury and post-transplant complications. Consequently, organ perfusion techniques are being used in clinical practice in many countries. Despite this success, a proportion of livers do not meet current viability tests required for transplantation, even with the use of modern perfusion techniques. Therefore, devices are needed to further optimise machine liver perfusion - one promising option is to prolong machine liver perfusion for several days, with ex situ treatment of perfused livers. For example, stem cells, senolytics, or molecules targeting mitochondria or downstream signalling can be administered during long-term liver perfusion to modulate repair mechanisms and regeneration. Besides, today's perfusion equipment is also designed to enable the use of various liver bioengineering techniques, to develop scaffolds or for their re-cellularisation. Cells or entire livers can also undergo gene modulation to modify animal livers for xenotransplantation, to directly treat injured organs or to repopulate such scaffolds with "repaired" autologous cells. This review first discusses current strategies to improve the quality of donor livers, and secondly reports on bioengineering techniques to design optimised organs during machine perfusion. Current practice, as well as the benefits and challenges associated with these different perfusion strategies are discussed.

Mitochondrial transplantation as a possible therapeutic option for sarcopenia

With advancing age, the skeletal muscle phenotype is characterized by a progressive loss of mass, strength, and quality. This phenomenon, known as sarcopenia, has a negative impact on quality of life and increases the risk of morbidity and mortality in older adults. Accumulating evidence suggests that damaged and dysfunctional mitochondria play a critical role in the pathogenesis of sarcopenia. Lifestyle modifications, such as physical activity, exercise, and nutrition, as well as medical interventions with therapeutic agents, are effective in the management of sarcopenia and offer solutions to maintain and improve skeletal muscle health. Although a great deal of effort has been devoted to the identification of the best treatment option, these strategies are not sufficient to overcome sarcopenia. Recently, it has been reported that mitochondrial transplantation may be a possible therapeutic approach for the treatment of mitochondria-related pathological conditions such as ischemia, liver toxicity, kidney injury, cancer, and non-alcoholic fatty liver disease. Given the role of mitochondria in the function and metabolism of skeletal muscle, mitochondrial transplantation may be a possible option for the treatment of sarcopenia. In this review, we summarize the definition and characteristics of sarcopenia and molecular mechanisms associated with mitochondria that are known to contribute to sarcopenia. We also discuss mitochondrial transplantation as a possible option. Despite the progress made in the field of mitochondrial transplantation, further studies are needed to elucidate the role of mitochondrial transplantation in sarcopenia. KEY MESSAGES: Sarcopenia is the progressive loss of skeletal muscle mass, strength, and quality. Although the specific mechanisms that lead to sarcopenia are not fully understood, mitochondria have been identified as a key factor in the development of sarcopenia. Damaged and dysfunctional mitochondria initiate various cellular mediators and signaling pathways, which largely contribute to the age-related loss of skeletal muscle mass and strength. Mitochondrial transplantation has been reported to be a possible option for the treatment/prevention of several diseases. Mitochondrial transplantation may be a possible therapeutic option for improving skeletal muscle health and treating sarcopenia. Mitochondrial transplantation as a possible treatment option for sarcopenia.

Mitochondria Have Made a Long Evolutionary Path from Ancient Bacteria Immigrants within Eukaryotic Cells to Essential Cellular Hosts and Key Players in Human Health and Disease

Mitochondria have made a long evolutionary path from ancient bacteria immigrants within the eukaryotic cell to become key players for the cell, assuming crucial multitasking skills critical for human health and disease. Traditionally identified as the powerhouses of eukaryotic cells due to their central role in energy metabolism, these chemiosmotic machines that synthesize ATP are known as the only maternally inherited organelles with their own genome, where mutations can cause diseases, opening up the field of mitochondrial medicine. More recently, the omics era has highlighted mitochondria as biosynthetic and signaling organelles influencing the behaviors of cells and organisms, making mitochondria the most studied organelles in the biomedical sciences. In this review, we will especially focus on certain 'novelties' in mitochondrial biology "left in the shadows" because, although they have been discovered for some time, they are still not taken with due consideration. We will focus on certain particularities of these organelles, for example, those relating to their metabolism and energy efficiency. In particular, some of their functions that reflect the type of cell in which they reside will be critically discussed, for example, the role of some carriers that are strictly functional to the typical metabolism of the cell or to the tissue specialization. Furthermore, some diseases in whose pathogenesis, surprisingly, mitochondria are involved will be mentioned.

The Role of Alternative Mitophagy in Heart Disease

Autophagy is essential for maintaining cellular homeostasis through bulk degradation of subcellular constituents, including misfolded proteins and dysfunctional organelles. It is generally governed by the proteins Atg5 and Atg7, which are critical regulators of the conventional autophagy pathway. However, recent studies have identified an alternative Atg5/Atg7-independent pathway, i.e., Ulk1- and Rab9-mediated alternative autophagy. More intensive studies have identified its essential role in stress-induced mitochondrial autophagy, also known as mitophagy. Alternative mitophagy plays pathophysiological roles in heart diseases such as myocardial ischemia and pressure overload. Here, this review discusses the established and emerging mechanisms of alternative autophagy/mitophagy that can be applied in therapeutic interventions for heart disorders.

Exogenous mitochondrial transplantation improves survival and neurological outcomes after resuscitation from cardiac arrest

BACKGROUND

Mitochondrial transplantation (MTx) is an emerging but poorly understood technology with the potential to mitigate severe ischemia-reperfusion injuries after cardiac arrest (CA). To address critical gaps in the current knowledge, we test the hypothesis that MTx can improve outcomes after CA resuscitation.

METHODS

This study consists of both in vitro and in vivo studies. We initially examined the migration of exogenous mitochondria into primary neural cell culture in vitro. Exogenous mitochondria extracted from the brain and muscle tissues of donor rats and endogenous mitochondria in the neural cells were separately labeled before co-culture. After a period of 24 h following co-culture, mitochondrial transfer was observed using microscopy. In vitro adenosine triphosphate (ATP) contents were assessed between freshly isolated and frozen-thawed mitochondria to compare their effects on survival. Our main study was an in vivo rat model of CA in which rats were subjected to 10 min of asphyxial CA followed by resuscitation. At the time of achieving successful resuscitation, rats were randomly assigned into one of three groups of intravenous injections: vehicle, frozen-thawed, or fresh viable mitochondria. During 72 h post-CA, the therapeutic efficacy of MTx was assessed by comparison of survival rates. The persistence of labeled donor mitochondria within critical organs of recipient animals 24 h post-CA was visualized via microscopy.

RESULTS

The donated mitochondria were successfully taken up into cultured neural cells. Transferred exogenous mitochondria co-localized with endogenous mitochondria inside neural cells. ATP content in fresh mitochondria was approximately four times higher than in frozen-thawed mitochondria. In the in vivo survival study, freshly isolated functional mitochondria, but not frozen-thawed mitochondria, significantly increased 72-h survival from 55 to 91% (P = 0.048 vs. vehicle). The beneficial effects on survival were associated with improvements in rapid recovery of arterial lactate and glucose levels, cerebral microcirculation, lung edema, and neurological function. Labeled mitochondria were observed inside the vital organs of the surviving rats 24 h post-CA.

CONCLUSIONS

MTx performed immediately after resuscitation improved survival and neurological recovery in post-CA rats. These results provide a foundation for future studies to promote the development of MTx as a novel therapeutic strategy to save lives currently lost after CA.

Mitochondrial transplantation in cardiac surgical patients: optimism, caveats, and outstanding questions

PURPOSE OF REVIEW

Mitochondria satisfy the high metabolic demand of the heart, and also play major roles in reactive oxygen species signaling, calcium buffering, and regulation of cell death. Mitochondrial damage or dysfunction can drive diseases seen in cardiac surgical patients, including heart failure and ischemia/reperfusion injury. Exogenous transplantation of isolated mitochondria has been proposed as one way to augment mitochondrial function and mitigate a number of pathologic processes, with a heavy focus on ischemia/reperfusion injury.

RECENT FINDINGS

Animal models of cardiac ischemia/reperfusion injury have shown functional benefits after mitochondrial transplantation. Many of the mechanisms underlying this therapy's effect; optimal dosing, delivery, and timing; and how it will translate to cardiac surgical patients are yet unknown.

SUMMARY

Mitochondrial transplantation is a potential therapeutic strategy for cardiac ischemia/reperfusion injury. Effective application to selected cardiac surgical patients can be informed by further mechanistic investigations.

Mitochondrial transplant after ischemia reperfusion promotes cellular salvage and improves lung function during ex-vivo lung perfusion

BACKGROUND

In lung transplantation, ischemia-reperfusion injury associated with mitochondrial damage can lead to graft rejection. Intact, exogenous mitochondria provide a unique treatment option to salvage damaged cells within lung tissue.

METHODS

We developed a novel method to freeze and store allogeneic mitochondria isolated from porcine heart tissue. Stored mitochondria were injected into a model of induced ischemia-reperfusion injury using porcine ex-vivo lung perfusion. Treatment benefits to immune modulation, antioxidant defense, and cellular salvage were evaluated. These findings were corroborated in human lungs undergoing ex-vivo lung perfusion. Lung tissue homogenate and primary lung endothelial cells were then used to address underlying mechanisms.

RESULTS

Following cold ischemia, mitochondrial transplant reduced lung pulmonary vascular resistance and tissue pro-inflammatory signaling and cytokine secretion. Further, exogenous mitochondria reduced reactive oxygen species by-products and promoted glutathione synthesis, thereby salvaging cell viability. These results were confirmed in a human model of ex-vivo lung perfusion wherein transplanted mitochondria decreased tissue oxidative and inflammatory signaling, improving lung function. We demonstrate that transplanted mitochondria induce autophagy and suggest that bolstered autophagy may act upstream of the anti-inflammatory and antioxidant benefits. Importantly, chemical inhibitors of the MEK autophagy pathway blunted the favorable effects of mitochondrial transplant.

CONCLUSIONS

These data provide direct evidence that mitochondrial transplant improves cellular health and lung function when administered during ex-vivo lung perfusion and suggest the mechanism of action may be through promotion of cellular autophagy. Data herein contribute new insights into the therapeutic potential of mitochondrial transplant to abate ischemia-reperfusion injury during lung transplant, and thus reduce graft rejection.

Understanding the Therapeutic Approaches for Neuroprotection

The term "neurodegenerative disorders" refers to a group of illnesses in which deterioration of nerve structure and function is a prominent feature. Cognitive capacities such as memory and decision-making deteriorate as a result of neuronal damage. The primary difficulty that remains is safeguarding neurons since they do not proliferate or regenerate spontaneously and are therefore not substituted by the body after they have been damaged. Millions of individuals throughout the world suffer from neurodegenerative diseases. Various pathways lead to neurodegeneration, including endoplasmic reticulum stress, calcium ion overload, mitochondrial dysfunction, reactive oxygen species generation, and apoptosis. Although different treatments and therapies are available for neuroprotection after a brain injury or damage, the obstacles are inextricably connected. Several studies have revealed the pathogenic effects of hypothermia, different breathed gases, stem cell treatments, mitochondrial transplantation, multi-pharmacological therapy, and other therapies that have improved neurological recovery and survival outcomes after brain damage. The present review highlights the use of therapeutic approaches that can be targeted to develop and understand significant therapies for treating neurodegenerative diseases.

Mitochondrial transplantation attenuates traumatic neuropathic pain, neuroinflammation, and apoptosis in rats with nerve root ligation

Traumatic neuropathic pain (TNP) is caused by traumatic damage to the somatosensory system and induces the presentation of allodynia and hyperalgesia. Mitochondrial dysfunction, neuroinflammation, and apoptosis are hallmarks in the pathogenesis of TNP. Recently, mitochondria-based therapy has emerged as a potential therapeutic intervention for diseases related to mitochondrial dysfunction. However, the therapeutic effectiveness of mitochondrial transplantation (MT) on TNP has rarely been investigated. Here, we validated the efficacy of MT in treating TNP. Both in vivo and in vitro TNP models by conducting an L5 spinal nerve ligation in rats and exposing the primary dorsal root ganglion (DRG) neurons to capsaicin, respectively, were applied in this study. The MT was operated by administrating 100 µg of soleus-derived allogeneic mitochondria into the ipsilateral L5 DRG in vivo and the culture medium in vitro. Results showed that the viable transplanted mitochondria migrated into the rats' spinal cord and sciatic nerve. MT alleviated the nerve ligation-induced mechanical and thermal pain hypersensitivity. The nerve ligation-induced glial activation and the expression of pro-inflammatory cytokines and apoptotic markers in the spinal cord were also repressed by MT. Consistently, exogenous mitochondria reversed the capsaicin-induced reduction of mitochondrial membrane potential and expression of pro-inflammatory cytokines and apoptotic markers in the primary DRG neurons in vitro. Our findings suggest that MT mitigates the spinal nerve ligation-induced apoptosis and neuroinflammation, potentially playing a role in providing neuroprotection against TNP.

The Therapeutic Potential of Mitochondria Transplantation Therapy in Neurodegenerative and Neurovascular Disorders

Neurodegenerative and neurovascular disorders affect millions of people worldwide and account for a large and increasing health burden on the general population. Thus, there is a critical need to identify potential disease-modifying treatments that can prevent or slow the disease progression. Mitochondria are highly dynamic organelles and play an important role in energy metabolism and redox homeostasis, and mitochondrial dysfunction threatens cell homeostasis, perturbs energy production, and ultimately leads to cell death and diseases. Impaired mitochondrial function has been linked to the pathogenesis of several human neurological disorders. Given the significant contribution of mitochondrial dysfunction in neurological disorders, there has been considerable interest in developing therapies that can attenuate mitochondrial abnormalities and proffer neuroprotective effects. Unfortunately, therapies that target specific components of mitochondria or oxidative stress pathways have exhibited limited translatability. To this end, mitochondrial transplantation therapy (MTT) presents a new paradigm of therapeutic intervention, which involves the supplementation of healthy mitochondria to replace the damaged mitochondria for the treatment of neurological disorders. Prior studies demonstrated that the supplementation of healthy donor mitochondria to damaged neurons promotes neuronal viability, activity, and neurite growth and has been shown to provide benefits for neural and extra-neural diseases. In this review, we discuss the significance of mitochondria and summarize an overview of the recent advances and development of MTT in neurodegenerative and neurovascular disorders, particularly Parkinson's disease, Alzheimer's disease, and stroke. The significance of MTT is emerging as they meet a critical need to develop a diseasemodifying intervention for neurodegenerative and neurovascular disorders.

Perspectives on mitochondrial relevance in cardiac ischemia/reperfusion injury

Cardiovascular disease is the most common cause of death worldwide and in particular, ischemic heart disease holds the most considerable position. Even if it has been deeply studied, myocardial ischemia-reperfusion injury (IRI) is still a side-effect of the clinical treatment for several heart diseases: ischemia process itself leads to temporary damage to heart tissue and obviously the recovery of blood flow is promptly required even if it worsens the ischemic injury. There is no doubt that mitochondria play a key role in pathogenesis of IRI: dysfunctions of these important organelles alter cell homeostasis and survival. It has been demonstrated that during IRI the system of mitochondrial quality control undergoes alterations with the disruption of the complex balance between the processes of mitochondrial fusion, fission, biogenesis and mitophagy. The fundamental role of mitochondria is carried out thanks to the finely regulated connection to other organelles such as plasma membrane, endoplasmic reticulum and nucleus, therefore impairments of these inter-organelle communications exacerbate IRI. This review pointed to enhance the importance of the mitochondrial network in the pathogenesis of IRI with the aim to focus on potential mitochondria-targeting therapies as new approach to control heart tissue damage after ischemia and reperfusion process.

Mitochondrial Dysfunction in Cyanotic Congenital Heart Disease: A Promising Therapeutic Approach for the Future

Congenital heart disease (CHD) is one of the most specific and yet challenging fields of heart surgery. Apart from the known clinical approaches, including surgery, a significant scale of regenerative therapeutic options is available, which increase the number of cardiomyocytes and restore cardiac function. Although it has been revealed in recent years that mitochondrial transplantation can be used as a promising treatment option in this disease group, there is no clinical evidence for the significance of mitochondrial function in myocardial tissue of patients with CHD regarding cardiac surgery. In this study, mitochondrial morphology and function, myocardial fibrosis, and myocyte atypia were evaluated in myocardial biopsy tissue of pediatric patients with cyanotic and acyanotic CHD, five from each group. After histopathological evaluation of myocardial tissue specimens, mitochondrial morphology and network were analyzed by immunofluorescence staining using an anti-Tom20 antibody, electron transport chain complexes of myocardium were examined by cytochrome c oxidase/succinate dehydrogenase staining, and the amount of ATP was measured by bioluminescence assay. In addition, cardiac markers have been tested to be reviewed as a potential indicator for postoperative follow-up. Myocyte atypia and fibrosis were classified on a scale of 1 to 4. In this study, unlike patients with acyanotic CHD, alterations in mitochondrial network and reduction in ATP production were detected in all pediatric patients with cyanotic CHD. A statistically significant correlation was also determined between mitochondrial dysfunction and cardiac markers. These findings may be assumed as a promising pathway for evaluating the relationship between mitochondrial dysfunction and cyanotic CHD.

Mitochondria and ischemia reperfusion injury

PURPOSE OF REVIEW

This review describes the role of mitochondria in ischemia-reperfusion-injury (IRI).

RECENT FINDINGS

Mitochondria are the power-house of our cells and play a key role for the success of organ transplantation. With their respiratory chain, mitochondria are the main energy producers, to fuel metabolic processes, control cellular signalling and provide electrochemical integrity. The mitochondrial metabolism is however severely disturbed when ischemia occurs. Cellular energy depletes rapidly and various metabolites, including Succinate accumulate. At reperfusion, reactive oxygen species are immediately released from complex-I and initiate the IRI-cascade of inflammation. Prior to the development of novel therapies, the underlying mechanisms should be explored to target the best possible mitochondrial compound. A clinically relevant treatment should recharge energy and reduce Succinate accumulation before organ implantation. While many interventions focus instead on a specific molecule, which may inhibit downstream IRI-inflammation, mitochondrial protection can be directly achieved through hypothermic oxygenated perfusion (HOPE) before transplantation.

SUMMARY

Mitochondria are attractive targets for novel molecules to limit IRI-associated inflammation. Although dynamic preservation techniques could serve as delivery tool for new therapeutic interventions, their own inherent mechanism should not only be studied, but considered as key treatment to reduce mitochondrial injury, as seen with the HOPE-approach.

An Overview on Mitochondrial-Based Therapies in Sepsis-Related Myocardial Dysfunction: Mitochondrial Transplantation as a Promising Approach

Sepsis is defined as a life-threatening organ failure due to dysregulated host response to infection. Despite current advances in our knowledge about sepsis, it is still considered as a major global health challenge. Myocardial dysfunction is a well-defined manifestation of sepsis which is related to worse outcomes in septic patients. Given that the heart is a mitochondria-rich organ and the normal function of mitochondria is essential for successful modulation of septic response, the contribution of mitochondrial damage in sepsis-related myocardial dysfunction has attracted the attention of many scientists. It is widely accepted that mitochondrial damage is involved in sepsis-related myocardial dysfunction; however, effective and potential treatment modalities in clinical setting are still lacking. Mitochondrial-based therapies are potential approaches in sepsis treatment. Although various therapeutic strategies have been used for mitochondrial function improvement, their effects are limited when mitochondria undergo irreversible alterations under septic challenge. Therefore, application of more effective approaches such as mitochondrial transplantation has been suggested. This review highlights the crucial role of mitochondrial damage in sepsis-related myocardial dysfunction, then provides an overview on mitochondrial-based therapies and current approaches to mitochondrial transplantation as a novel strategy, and proposes future directions for more researches in this field.

Mitochondrial therapy: a vision of the outlooks for treatment of main twenty-first-century diseases

Mitochondria are dynamic organelles which constantly change their shape, size, and location within the cells. Mitochondrial dynamics is associated with mesenchymal metabolism or epithelial-mesenchymal transition to regulate the stem cell differentiation, proliferation, migration, and apoptosis. The transfer of mitochondria from one cell to another is necessary to improve and maintain homeostasis in an organism. Mitochondrial transplantation is a therapeutic approach that involves an introduction of healthy mitochondria into damaged organs. Recent evidence data have shown that the physiological properties of healthy mitochondria provide their ability to replace damaged mitochondria, with suggesting that replacing damaged mitochondria with healthy mitochondria may protect cells from further damage. Moreover, mitochondria can also be actively released into the extracellular space and potentially be transferred between the cells in the central nervous system. This increased interest in mitochondrial therapy calls for a deeper understanding of the mechanisms, which build the basis for mitochondrial transfer, uptake, and cellular defense. In this review, questions related to the involvement of mitochondria in the pathogenesis of cancer will be discussed. Particular attention will be paid to mitochondrial transplantation as a therapeutic approach to treat the mitochondrial dysfunction under some pathological conditions.

A new hope: Mitochondria, a critical factor in the war against prions

Prion diseases encompass a group of incurable neurodegenerative disorders that occur due to the misfolding and aggregation of infectious proteins. The most well-known prion diseases are Creutzfeldt-Jakob disease (CJD), bovine spongiform encephalopathy (also known as mad cow disease), and kuru. It is estimated that around 1-2 persons per million worldwide are affected annually by prion disorders. Infectious prion proteins propagate in the brain, clustering in the cells and rapidly inducing tissue degeneration and death. Prion disease alters cell metabolism and energy production damaging mitochondrial function and dynamics leading to a fast accumulation of damage. Dysfunction of mitochondria could be considered as an early precursor and central element in the pathogenesis of prion diseases such as in sporadic CJD. Preserving mitochondria function may help to resist the rapid spread and damage of prion proteins and even clearance. In the war against prions and other degenerative diseases, studying how to preserve the function of mitochondria by using antioxidants and even replacing them with artificial mitochondrial transfer/transplant (AMT/T) may bring a new hope and lead to an increase in patients' survival. In this perspective review, we provide key insights about the relationship between the progression of prion disease and mitochondria, in which understanding how protecting mitochondria function and viability by using antioxidants or AMT/T may help to develop novel therapeutic interventions.