MitoQ Is Able to Modulate Apoptosis and Inflammation

The role of mitochondrial DNA variants and dysfunction in the pathogenesis and progression of multiple sclerosis

Multiple sclerosis (MS) is a chronic autoimmune disease that affects the central nervous system (CNS). The etiology of MS remains elusive, with a complex interplay of genetic and environmental factors contributing to its pathogenesis. Recent studies showed mitochondrial DNA (mtDNA) as a potential player in the development and progression of MS. These studies encompassed mtDNA variants, copy number variations, and haplogroups. This narrative review aims to synthesize the current understanding of the role of mtDNA's in MS. The findings of this review suggest that mtDNA may indeed play a role in the development and progression of MS. Several studies have reported an association between mtDNA variants and increased susceptibility to MS, while others have found a link between mtDNA copy number variations and disease severity. Furthermore, specific mtDNA haplogroups have been demonstrated to confer protection against MS. MtDNA alterations may make neurons and oligodendrocytes more susceptible to inflammatory and oxidative stress, causing demyelination and axonal degeneration in MS patients. In conclusion, this review underscores the potential significance of mtDNA in the pathogenesis of MS and highlights the need for further research to fully elucidate its role. A deeper understanding of mtDNA's involvement in MS may pave the way for the development of novel therapeutic strategies to combat this debilitating disease.

Deoxynivalenol induces spleen damage, apoptosis, and inflammation in mice by increasing mitochondrial reactive oxygen species: Protective effects of curcumin

Deoxynivalenol (DON), a Fusarium mycotoxin, causes spleen apoptosis and inflammation, which damage the organ. Curcumin (Cur) is a member of the ginger family. It has anti-apoptotic and anti-inflammatory effects that maintain the health of the organism's immune system. Here, the protective effects of Cur against DON-induced spleen damage were explored. First, we found DON (2.4 mg/kg body weight) decreased the expression of manganese superoxide dismutase, mitochondrial membrane potential, adenosine triphosphate, and disturbed hematoxylin and eosin staining in mice spleen. The results confirmed that DON causes mitochondrial reactive oxygen species (mtROS) overproduction leading to spleen damage. Second, we found DON decreased the expression of mitochondrial apoptosis-inducing factor (AIF) and B-cell lymphoma-2 (Bcl-2), and increased the expression of nuclear AIF, Bcl2-associated X (Bax), cysteine-aspartate protease-3 (caspase-3), caspase-9. Mitoquinone is a mitochondria-targeted antioxidant that can prevent of mitochondrial oxidative damage. These expression increases were not observed in the mitoquinone-treated group, confirming that mtROS was an upstream regulatory target of apoptosis and inflammation in DON-exposed mice spleens. Finally, we confirmed that Cur (50 or 100 mg/kg body weight) attenuated DON-induced apoptosis and inflammation by inactivating mtROS. Collectively, these results confirm that DON causes spleen damage by increasing mtROS, and the protective effects of curcumin.

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

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

Safeguarding the brain from oxidative damage

Oxidative stress imposes a substantial cellular burden on the brain and contributes to diverse neurodegenerative diseases. Various antioxidant signaling pathways have been implicated in oxidative stress and have a protective effect on brain cells by increasing the release of numerous enzymes and through anti-inflammatory responses to oxidative damage caused by abnormal levels of reactive oxygen species (ROS). Although many molecules evaluated as antioxidants have shown therapeutic potentials in preclinical studies, the results of clinical trials have been less than satisfactory. This review focuses on several signaling pathways involved in oxidative stress that are associated with antioxidants. These pathways have a protective effect against stressors by increasing the release of various enzymes and also exert anti-inflammatory responses against oxidative damage. There is no doubt that oxidative stress is a crucial therapeutic target in the treatment of neurological diseases. Therefore, it is essential to understand the discovery of multiple routes that can efficiently repair the damage caused by ROS and prevent neurodegenerative disorders. This paper aims to provide a concise and objective review of the oxidative and antioxidant pathways and their potential therapeutic applications in treating oxidative injury in the brain.

Location and interaction of idebenone and mitoquinone in a membrane similar to the inner mitochondrial membrane. Comparison with ubiquinone 10

Oxygen is essential for aerobic life on earth but it is also the origin of harmful reactive oxygen species (ROS). Ubiquinone is par excellence the endogenous cellular antioxidant, but a very hydrophobic one. Because of that, other molecules have been envisaged, such as idebenone (IDE) and mitoquinone (MTQ), molecules having the same redox active benzoquinone moiety but higher solubility. We have used molecular dynamics to determine the location and interaction of these molecules, both in their oxidized and reduced forms, with membrane lipids in a membrane similar to that of the mitochondria. Both IDE and reduced IDE (IDOL) are situated near the membrane interface, whereas both MTQ and reduced MTQ (MTQOL) locate in a position adjacent to the phospholipid hydrocarbon chains. The quinone moieties of both ubiquinone 10 (UQ10) and reduced UQ10 (UQOL10) in contraposition to the same moieties of IDE, IDOL, MTQ and MTQOL, located near the membrane interphase, whereas the isoprenoid chains remained at the middle of the hydrocarbon chains. These molecules do not aggregate and their functional quinone moieties are located in the membrane at different depths but near the hydrophobic phospholipid chains whereby protecting them from ROS harmful effects.

The role of local inflammation in complications associated with intubation in pediatric patients: A narrative review

Although the most important primary local inflammatory response factor to intubation is not yet clear, it is known that it may be directly attributed to the presence of trauma during intubation or the response of oral bacterial flora present in the trachea. It is known that prolonged intubation is associated with worse outcomes, but other underlying systemic issues, such as sepsis and trauma, are also associated with this result. Likewise, patients who require advanced airway management and excessive manipulation are more likely to experience complications. There are various inflammatory mediators that are generated during orotracheal intubation, many of which can be considered targets for therapies to help reduce inflammation caused by intubation. However, there is little evidence on the management of the inflammatory response induced by orotracheal intubation in pediatric patients. Therefore, the aim of this narrative review is to highlight the intubation associated complications that can arise from poorly controlled inflammation in intubated pediatric patients, review the proposed pathophysiology behind this, and discuss the current treatments that exist. Finally, taking into account the discussion on pathophysiology, we describe the current therapies being developed and future directions that can be taken in order to create more treatment options within this patient population.

Mitochondria-targeted antioxidant MitoQ ameliorates ROS production and improves cell viability in cryopreserved buffalo fibroblasts

Cryopreservation commonly decreases the cellular functionality and post-thaw viability of cells. Reactive oxygen species (ROS) generated during cryopreservation degrade mitochondrial activity and promote the release of cytochrome C which activates caspases required for apoptosis. Antioxidants have the potential to improve the recovery efficiency of cells by reducing ROS production and maintaining mitochondrial membrane potential (MMP). The present study was conducted to explore the role of MitoQ, a derivative of coenzyme Q10 on cryopreserved fibroblasts derived from buffalo skin. To achieve our goal, buffalo skin fibroblasts were treated with varying concentrations of MitoQ (0, 0.1, 0.5, 1, 2, and 10 μM) for 24, 48, and 72 h. The MMP, ROS generation, cell viability was measured by flow cytometry. Furthermore, expression of genes related to mitochondrial oxidative stress (NRF2, GPX, and SOD), apoptosis (BAK and caspase 3) and cell proliferation (AKT) were also assessed. The results showed that over a period of 72 h lower concentrations of MitoQ (0.1-0.5 μM) decrease the ROS production, improves MMP and cell viability whilst the high concentration of MitoQ (2-10 μM) increased the oxidative damage to the cells. Taken together, our study provide important insights into the novel role of MitoQ in cryopreserved buffalo skin fibroblasts. In conclusion, we demonstrated the dose-dependent functional role of MitoQ on cryopreserved fibroblasts for improving post-thaw cell viability and cellular function.

Mitochondria-Targeted Antioxidants, an Innovative Class of Antioxidant Compounds for Neurodegenerative Diseases: Perspectives and Limitations

Neurodegenerative diseases comprise a wide spectrum of pathologies characterized by progressive loss of neuronal functions and structures. Despite having different genetic backgrounds and etiology, in recent years, many studies have highlighted a point of convergence in the mechanisms leading to neurodegeneration: mitochondrial dysfunction and oxidative stress have been observed in different pathologies, and their detrimental effects on neurons contribute to the exacerbation of the pathological phenotype at various degrees. In this context, increasing relevance has been acquired by antioxidant therapies, with the purpose of restoring mitochondrial functions in order to revert the neuronal damage. However, conventional antioxidants were not able to specifically accumulate in diseased mitochondria, often eliciting harmful effects on the whole body. In the last decades, novel, precise, mitochondria-targeted antioxidant (MTA) compounds have been developed and studied, both in vitro and in vivo, to address the need to counter the oxidative stress in mitochondria and restore the energy supply and membrane potentials in neurons. In this review, we focus on the activity and therapeutic perspectives of MitoQ, SkQ1, MitoVitE and MitoTEMPO, the most studied compounds belonging to the class of MTA conjugated to lipophilic cations, in order to reach the mitochondrial compartment.

The neuroprotective effects of targeting key factors of neuronal cell death in neurodegenerative diseases: The role of ER stress, oxidative stress, and neuroinflammation

Neuronal loss is one of the striking causes of various central nervous system (CNS) disorders, including major neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), and Amyotrophic lateral sclerosis (ALS). Although these diseases have different features and clinical manifestations, they share some common mechanisms of disease pathology. Progressive regional loss of neurons in patients is responsible for motor, memory, and cognitive dysfunctions, leading to disabilities and death. Neuronal cell death in neurodegenerative diseases is linked to various pathways and conditions. Protein misfolding and aggregation, mitochondrial dysfunction, generation of reactive oxygen species (ROS), and activation of the innate immune response are the most critical hallmarks of most common neurodegenerative diseases. Thus, endoplasmic reticulum (ER) stress, oxidative stress, and neuroinflammation are the major pathological factors of neuronal cell death. Even though the exact mechanisms are not fully discovered, the notable role of mentioned factors in neuronal loss is well known. On this basis, researchers have been prompted to investigate the neuroprotective effects of targeting underlying pathways to determine a promising therapeutic approach to disease treatment. This review provides an overview of the role of ER stress, oxidative stress, and neuroinflammation in neuronal cell death, mainly discussing the neuroprotective effects of targeting pathways or molecules involved in these pathological factors.

Robust intervention for oxidative stress-induced injury in periodontitis via controllably released nanoparticles that regulate the ROS-PINK1-Parkin pathway

Oxidative stress in periodontitis has emerged as one of the greatest barriers to periodontal tissue restoration. In this study, we synthesized controlled drug release nanoparticles (MitoQ@PssL NPs) by encasing mitoquinone (MitoQ; an autophagy enhancer) into tailor-made reactive oxygen species (ROS)-cleavable amphiphilic polymer nanoparticles (PssL NPs) to regulate the periodontitis microenvironment. Once exposed to reactive oxygen species, which were substantially overproduced under oxidative stress conditions, the ROS-cleavable PssL was disintegrated, promoting the release of the encapsulated MitoQ. The released mitoquinone efficiently induced mitophagy through the PINK1-Parkin pathway and successfully reduced oxidative stress by decreasing the amount of reactive oxygen species. With the gradual decrease in the reactive oxygen species level, which was insufficient to disintegrate PssL, the release of mitoquinone was reduced and eventually eliminated, which contributed to a redox homeostasis condition and facilitated the regeneration of periodontal tissue. MitoQ@PssL NPs have great potential in the treatment of periodontitis via microenvironment-controlled drug release, which will provide a new avenue for periodontal regeneration and diseases related to imbalanced redox metabolism.

Endurance training and MitoQ supplementation improve spatial memory, VEGF expression, and neurogenic factors in hippocampal tissue of rats

Background and Aim

The hippocampus has a key role in memory and learning, which means that this brain structure has high-energy demand. Accordingly, mitochondrial dysfunction in the hippocampus has deleterious effects on brain function. MitoQ is an antioxidant that accumulates selectively in mitochondria at high concentration. In this study, the effect of MitoQ alone and in combination with endurance training (ET) was investigated on spatial memory (distance, time, and number of passes in the target quarter), antioxidant status (superoxide dismutase [SOD] and glutathione peroxidase [GPx]), and neurogenic factor levels (vascular endothelial growth factor [VEGF] and brain-derived neurotrophic factor [BDNF]) in male Wistar rats.

Methods

Rats were assigned to a control (CTL) group, ET group, ET+MitoQ group, and a MitoQ group. Rats were trained on a treadmill for 8 weeks, 5 days/week, and 50 min/day. MitoQ (250 μM daily) was administered through drinking water for 8 weeks. Spatial memory (Morris water maze test), gene expression (real-time PCR), protein expression (Western blotting), and antioxidants (ELISA method) were determined.

Results

Distance and number of passes in the target quarter in the ET, MitoQ, and ET+MitoQ groups were higher than in the CTL group (P=0.001). MitoQ+ET had more impact on the abovementioned indices than MitoQ or ET alone. Simultaneous use of MitoQ and ET significantly increased gene and protein expression of VEGF (P=0.0001) and gene expression of BDNF (P=0.004) and Sestrin 2 (SESN2) (P=0.0001) in hippocampal tissue. The expression of VEGF (P=0.007) and SESN2 (P=0.001) was higher in the MitoQ group compared to the CTL group. Tissue GPx levels were increased following all three interventions (P≤0.013) compared to the CTL group while SOD levels remained unchanged in all groups.

Conclusions

The combination of ET and MitoQ has additive effects on spatial memory in rats by modulating parameters that are involved in hippocampal neurogenesis. In addition, MitoQ may have positive effects on the antioxidant defense by improving GPx activity.

Relevance for Patients

Considering the positive effects of MitoQ on improving the memory and the antioxidant defense, it seems that it can play a positive role in improving the diseases associated with memory loss in the long term, and ET along with this supplement can increase the possible positive effects.

Does Antioxidant Mitoquinone (MitoQ) Ameliorate Oxidative Stress in Frozen-Thawed Rooster Sperm?

In this study, we aimed to determine the benefit of mitoquinone (MitoQ) in rooster semen extenders on sperm quality, motility parameters, antioxidant capacities, and apoptotic changes in post-thawed rooster semen. A total of 85 ejaculates from 18 roosters were collected and then divided into five equal aliquots and cryopreserved in extenders with 1.0% soy lecithin nanoparticles that contained various concentrations of MitoQ (0 nM (M0), 50 nM (M50), 100 nM (M100), 150 nM (M150), and 200 nM (M200)). By using a computer-assisted semen analyzer, sperm motility parameters were assessed after freeze thawing. The M150 group had significantly higher percentages of total motility, progressive motility, viability, acrosome membrane integrity, and mitochondrial activity than the other groups (p < 0.05). Compared to other groups, M100 and M150 groups produced a higher percentage of plasma membrane integrity and ATP contents (p < 0.05). Additionally, the lowest levels of ROS and MDA in spermatozoa were observed in M150 group (p < 0.05), whereas the highest levels of ROS and MDA were observed in sperm in the controls or the M200 group (p < 0.05). Significantly higher values of SOD, GPx, and Cas-3 were found in the M150 group compared to other groups (p < 0.05). Overall, these results demonstrate that MitoQ at 150 nM not only ameliorates post-thawed sperm quality and motility parameters by restoring ATP levels and preventing membrane damage, but also improves redox balance and antiapoptotic activities.

The Effect of Antioxidant Added to Preservation Solution on the Protection of Kidneys before Transplantation

Ischemia–reperfusion injury is a key clinical problem of transplantology. Current achievements in optimizing organ rinse solutions and storage techniques have significantly influenced the degree of graft damage and its survival after transplantation. In recent years, intensive research has been carried out to maintain the viability of tissues and organs outside the integral environment of the body. Innovative solutions for improving the biochemical functions of the stored organ have been developed. The article discusses directions for modifying preservation solutions with antioxidants. Clinical and experimental studies aimed at optimizing these fluids, as well as perfusion and organ preservation techniques, are presented.

Novel experimental and early investigational drugs for the treatment of bipolar disorder

INTRODUCTION

The quest toward more effective treatments for bipolar disorder (BD) solicits novel drugs and further research on the underpinning neurobiology. The present review aims to critically appraise the existing evidence about the pharmacological treatment of BD toward the development of novel treatment avenues.

AREAS COVERED

The present review appraises animal and human studies concerning both the currently available psychotropic drugs, and the general medicine drugs which may represent a path toward the development of novel drugs for BD. PubMed and Scopus were last accessed on February 20^th, 2021 for records indexed upon inception relevant to the pharmacological treatment of BD. Immune-modulating agents, anti-inflammatory agents, and glutamate antagonists represent the most intriguing potential targets for the development of new drugs for BD, thus receiving critical appraisal in the present text.

EXPERT OPINION

Regardless of the neurobiological pathways worthy of investigation toward the development of experimental drugs for BD, several unmet needs need to be addressed first. In particular, several biomarkers are altered in BD. However, it is the opinion herein expressed by the authors that it remains uncertain what comes first, that is peripheral changes or the disease.