Electron carriers and energy conservation in mitochondrial respiration

Karnozin EXTRA® causes changes in mitochondrial bioenergetics response in MCF-7 and MRC-5 cell lines

Numerous studies reported about potential effects of L-carnosine in regulation of tumor growth and metabolism. We evaluated the effects of different concentrations of L-carnosine from Karnozin EXTRA® supplement on mitochondrial respiratory chain complexes of human embryo lung fibroblasts (MRC-5) and human breast cancer cells (MCF-7), with different energy pathways. Also, we analyzed the proliferation index and expression of various markers of oxidative stress. Treatment with Karnozin EXTRA® (concentration of L-carnosine were 2, 5 and 10 mM) for 24 hours gradually decreased the number of cells and changed their morphological features. In both cell lines, a dose-dependent reduction of cell viability was recorded compared to the control group. Also, experimental groups showed a concentration-dependent decrease in fluorescence intensity of SOD2 expressions in MCF-7, while in MRC-5 we noticed higher fluorescence intensity in Carnosine 2 mM group. Treated cells, in both cell lines, showed different intensity of iNOS cytoplasmic immunopositivity in a concentration-dependent manner. In all experimental groups, we noticed an increased expression of marker of oxidative stress-cytochrome P450 2E1 (CYP2E1). The effects of Karnozin EXTRA® capsule on mitochondrial respiration, assessed with the Clark-type electrode, were manifested as a reduction of: basal cell respiration, maximum capacity of electron transport chain and mitochondrial ATP-linked respiration. Also, significant decrease in the activity of complex I (NADH-ubiquinone oxidoreductase), complex II (succinate dehydrogenase) and complex IV (cytochrome c oxidase) was observed in both cell lines. Bearing in mind that Karnozin EXTRA® is a potential regulator of energy metabolism of MCF-7 and MRC-5, these results provide a good basis for further preclinical and clinical research.

MDM2 up-regulates the energy metabolism in NSCLC in a p53-independent manner

Although an E3 ligase MDM2 is the major negative regulator of the p53 tumor suppressor, a growing body of evidence suggests its p53-independent oncogenic properties. In particular, MDM2 has been shown to regulate serine metabolism independently of p53 status in several types of neoplasia, including NSCLC. Using the GSEA approach and publicly available molecular data on NSCLC tumors, our bioinformatics data suggest that MDM2 affects a number of metabolic genes, particularly those encoding components of the electron transport chain (ETC). To experimentally elucidate the role of MDM2 in respiration and energy metabolism of NSCLC cell models, we established NSCLC cell lines (WT p53+ A549 and p53-null H1299) overexpressing wild-type MDM2, or its catalytically deficient (C464A) mutant (MUT), or the control vector. Using TMRE staining and SeaHorse energy profiling, we demonstrated that wild-type MDM2, but not its catalytically inactive mutant, significantly increased mitochondrial membrane potential (MMP), glycolysis, respiration, and ATP production in a p53-independent manner. Further, we compared MDM2-associated effects of two natural compounds that, according to our docking experiment data, bind MDM2 with affinities similar to nutlin-3A, ganoderic acid A and berberine. Despite the fact that both nutlin-3A and berberine stabilized the MDM2 protein, they displayed differential effects on energy metabolism. Taken together, our data argue that MDM2 affects energy metabolism likely in a p53-independent manner. These results also highlight another pharmacological dimension of using MDM2-targeting compounds as potent inhibitors of glycolysis and respiration in tumor cells.

The Neural Palette of Heme: Altered Heme Homeostasis Underlies Defective Neurotransmission, Increased Oxidative Stress, and Disease Pathogenesis

Heme, a complex iron-containing molecule, is traditionally recognized for its pivotal role in oxygen transport and cellular respiration. However, emerging research has illuminated its multifaceted functions in the nervous system, extending beyond its canonical roles. This review delves into the diverse roles of heme in the nervous system, highlighting its involvement in neural development, neurotransmission, and neuroprotection. We discuss the molecular mechanisms by which heme modulates neuronal activity and synaptic plasticity, emphasizing its influence on ion channels and neurotransmitter receptors. Additionally, the review explores the potential neuroprotective properties of heme, examining its role in mitigating oxidative stress, including mitochondrial oxidative stress, and its implications in neurodegenerative diseases. Furthermore, we address the pathological consequences of heme dysregulation, linking it to conditions such as Alzheimer's disease, Parkinson's disease, and traumatic brain injuries. By providing a comprehensive overview of heme's multifunctional roles in the nervous system, this review underscores its significance as a potential therapeutic target and diagnostic biomarker for various neurological disorders.

Hydrogen-Rich Gas Enhanced Sprint-Interval Performance: Metabolomic Insights into Underlying Mechanisms

(1) Background: The diversity of blood biomarkers used to assess the metabolic mechanisms of hydrogen limits a comprehensive understanding of its effects on improving exercise performance. This study evaluated the impact of hydrogen-rich gas (HRG) on metabolites following sprint-interval exercise using metabolomics approaches, aiming to elucidate its underlying mechanisms of action. (2) Methods: Ten healthy adult males participated in the Wingate Sprint-interval test (SIT) following 60 min of HRG or placebo (air) inhalation. Venous blood samples were collected for metabolomic analysis both before and after gas inhalation and subsequent to completing the SIT. (3) Results: Compared with the placebo, HRG inhalation significantly improved mean power, fatigue index, and time to peak for the fourth sprint and significantly reduced the attenuation values of peak power, mean power, and time to peak between the first and fourth. Metabolomic analysis highlighted the significant upregulation of acetylcarnitine, propionyl-L-carnitine, hypoxanthine, and xanthine upon HRG inhalation, with enrichment pathway analysis suggesting that HRG may foster fat mobilization by enhancing coenzyme A synthesis, promoting glycerophospholipid metabolism, and suppressing insulin levels. (4) Conclusions: Inhaling HRG before an SIT enhances end-stage anaerobic sprint capabilities and mitigates fatigue. Metabolomic analysis suggests that HRG may enhance ATP recovery during interval stages by accelerating fat oxidation, providing increased energy replenishment for late-stage sprints.

On the fundamentals of quantum rate theory and the long-range electron transport in respiratory chains

It has been shown that both the electron-transfer rate constant of an electrochemical reaction and the conductance quantum are correlated with the concept of quantum capacitance. This simple association between the two separate concepts has an entirely quantum rate basis that encompasses the electron-transfer rate theory as originally proposed by Rudolph A. Marcus whether statistical mechanics is appropriately taken into account. I have prepared a concise review of the quantum mechanical rate theory principles focused on its quantum electrodynamics character to demonstrate that it can reconcile the conflicting views established on attempting to use the super-exchange (supported on electron transfer) or 'metallic-like' (supported on conductance quantum) mechanisms separately to explain the highly efficient long-range electron transport observed in the respiratory processes of living cells. The unresolved issues related to long-range electron transport are clarified in light of the quantum rate theory with a discussion focused on Geobacter sulfurreducens films as a reference standard of the respiration chain. Theoretical analyses supported by experimental data suggest that the efficiency of respiration within a long-range electron transport path is intrinsically a quantum mechanical event that follows relativistic quantum electrodynamics principles as addressed by quantum rate theory.

Free radicals and oxidative stress: Mechanisms and therapeutic targets

BACKGROUND

Free radicals are small extremely reactive species that have unpaired electrons. Free radicals include subgroups of reactive species, which are all a product of regular cellular metabolism. Oxidative stress happens when the free radicals production exceeds the capacity of the antioxidant system in the body's cells.

OBJECTIVE

The current review clarifies the prospective role of antioxidants in the inhibition and healing of diseases.

METHODS

Information on oxidative stress, free radicals, reactive oxidant species, and natural and synthetic antioxidants was obtained by searching electronic databases like PubMed, Web of Science, and Science Direct, with articles published between 1987 and 2023 being included in this review.

RESULTS

Free radicals exhibit a dual role in living systems. They are toxic byproducts of aerobic metabolism that lead to oxidative injury and tissue disorders and act as signals to activate appropriate stress responses. Endogenous and exogenous sources of reactive oxygen species are discussed in this review. Oxidative stress is a component of numerous diseases, including diabetes mellitus, atherosclerosis, cardiovascular disease, Alzheimer's disease, Parkinson's disease, and cancer. Although various small molecules assessed as antioxidants have shown therapeutic prospects in preclinical studies, clinical trial outcomes have been inadequate. Understanding the mechanisms through which antioxidants act, where, and when they are active may reveal a rational approach that leads to more tremendous pharmacological success. This review studies the associations between oxidative stress, redox signaling, and disease, the mechanisms through which oxidative stress can donate to pathology, the antioxidant defenses, the limits of their effectiveness, and antioxidant defenses that can be increased through physiological signaling, dietary constituents, and probable pharmaceutical interference. Prospective clinical applications of enzyme mimics and current progress in metal- and non-metal-based materials with enzyme-like activities and protection against chronic diseases have been discussed.

CONCLUSION

This review discussed oxidative stress as one of the main causes of illnesses, as well as antioxidant systems and their defense mechanisms that can be useful in inhibiting these diseases. Thus, the positive and deleterious effects of antioxidant molecules used to lessen oxidative stress in numerous human diseases are discussed. The optimal level of vitamins and minerals is the amount that achieves the best feed benefit, best growth rate, and health, including immune efficiency, and provides sufficient amounts to the body.

Changing ROS, NAD and AMP: A path to longevity via mitochondrial therapeutics

Lifespan of many organisms, from unicellular yeast to extremely complex human organism, strongly depends on the genetic background and environmental factors. Being among most influential target energy metabolism is affected by macronutrients, their caloric values, and peculiarities of catabolism. Mitochondria are central organelles that respond for energy metabolism in eukaryotic cells. Mitochondria generate reactive oxygen species (ROS), which are lifespan modifying metabolites and a kind of biological clock. Oxidized nicotinamide adenine dinucleotide (NAD⁺) and adenosine monophosphate (AMP) are important metabolic intermediates and molecules that trigger or inhibit several signaling pathways involved in gene silencing, nutrient allocation, and cell regeneration and programmed death. A part of NAD⁺ and AMP metabolism is tied to mitochondria. Using substances that able to target mitochondria, as well as allotopic expression of specific enzymes, are envisioned to be innovative approaches to prolong lifespan by modulation of ROS, NAD⁺, and AMP levels. Among substances, an anti-diabetic drug metformin is believed to increase NAD⁺ and AMP levels, indirectly influencing histone deacetylases, involved in gene silencing, and AMP-activated protein kinase, an energy sensor of cells. Mitochondrially targeted derivatives of ubiquinone were found to interact with ROS. A mitochondrially targeted non-proton-pumping NADH dehydrogenase may influence both ROS and NAD⁺ levels. Chapter describes putative how mitochondria-targeted drugs and NADH dehydrogenase extend lifespan, perspectives of creating drugs with similar properties and their usage as senotherapeutic pills are discussed in the chapter.

Benefits of electrochemistry studies for the majority of students who will not become electrochemists

In teaching electrochemistry, it is of primary importance to make students always aware of the relations between electrochemistry and all the non-electrochemical topics, which are taught. The vast majority of students will not specialise in electrochemistry, but they all can very much benefit from the basics and concepts of electrochemistry. This paper is aimed to give suggestions how the teaching of electrochemistry can easily be interrelated to topics of inorganic, organic, analytical, environmental chemistry, biochemistry and biotechnology.

Recent Overview of Potent Antioxidant Activity of Coordination Compounds

During recent decades, the complexation of organic ligands toward several metal ions of s-p and d-block has been applied as a plan to enhance its antioxidant performance. Due to their wide range of beneficial impacts, coordination compounds are widely used in industries, specifically in the medicinal and pharmaceutical fields. The activity is generally improved by chelation consequently knowing that the characteristics of both ligands and metals can lead to the development of greatly active compounds. Chelation compounds are a substitute for using the traditional synthetic antioxidants, because metal chelates present benefits, including a variety in geometry, oxidation states, and coordination number, that assist and favor the redox methods associated with antioxidant action. As well as understanding the best studied anti-oxidative assets of these compounds, coordination compounds are involved in the free radical scavenging process and protecting human organisms from the opposing effects of these radicals. The antioxidant ability can be assessed by various interrelated systems. The methodological modification offers the most knowledge on the antioxidant property of metal chelates. Colorimetric techniques are the most used, though electron paramagnetic resonance (EPR) is an alternative for metallic compounds, since color does not affect the results. Information about systems, with their benefits, and restrictions, permits a dependable valuation of the antioxidant performance of coordination compounds, as well as assisting application in various states wherever antioxidant drugs are required, such as in food protection, appropriate good-packaged foods, dietary supplements, and others. Because of the new exhaustive analysis of organic ligands, it has become a separate field of research in chemistry. The present investigation will be respected for providing a foundation for the antioxidant properties of organic ligands, future tests on organic ligands, and building high-quality antioxidative compounds.

Ketones: potential to achieve brain energy rescue and sustain cognitive health during ageing

Alzheimer’s disease (AD) is the most common major neurocognitive disorder of ageing. Although largely ignored until about a decade ago, accumulating evidence suggests that deteriorating brain energy metabolism plays a key role in the development and/or progression of AD-associated cognitive decline. Brain glucose hypometabolism is a well-established biomarker in AD but was mostly assumed to be a consequence of neuronal dysfunction and death. However, its presence in cognitively asymptomatic populations at higher risk of AD strongly suggests that it is actually a pre-symptomatic component in the development of AD. The question then arises as to whether progressive AD-related cognitive decline could be prevented or slowed down by correcting or bypassing this progressive ‘brain energy gap’. In this review, we provide an overview of research on brain glucose and ketone metabolism in AD and its prodromal condition – mild cognitive impairment (MCI) – to provide a clearer basis for proposing keto-therapeutics as a strategy for brain energy rescue in AD. We also discuss studies using ketogenic interventions and their impact on plasma ketone levels, brain energetics and cognitive performance in MCI and AD. Given that exercise has several overlapping metabolic effects with ketones, we propose that in combination these two approaches might be synergistic for brain health during ageing. As cause-and-effect relationships between the different hallmarks of AD are emerging, further research efforts should focus on optimising the efficacy, acceptability and accessibility of keto-therapeutics in AD and populations at risk of AD.

Bioactivity of Inhaled Methane and Interactions With Other Biological Gases

A number of studies have demonstrated explicit bioactivity for exogenous methane (CH₄), even though it is conventionally considered as physiologically inert. Other reports cited in this review have demonstrated that inhaled, normoxic air-CH₄ mixtures can modulate the in vivo pathways involved in oxidative and nitrosative stress responses and key events of mitochondrial respiration and apoptosis. The overview is divided into two parts, the first being devoted to a brief review of the effects of biologically important gases in the context of hypoxia, while the second part deals with CH₄ bioactivity. Finally, the consequence of exogenous, normoxic CH₄ administration is discussed under experimental hypoxia- or ischaemia-linked conditions and in interactions between CH₄ and other biological gases, with a special emphasis on its versatile effects demonstrated in pulmonary pathologies.

Analysis of Mitochondrial Dysfunction by Microplate Reader in hiPSC-Derived Neuronal Cell Models of Neurodegenerative Disorders

Mitochondria are responsible for many vital pathways governing cellular homeostasis, including cellular energy management, heme biosynthesis, lipid metabolism, cellular proliferation and differentiation, cell cycle regulation, and cellular viability. Electron transport and ADP phosphorylation coupled with proton pumping through the mitochondrial complexes contribute to the preservation of mitochondrial membrane potential (ΔΨ_m). Importantly, mitochondrial polarization is essential for reactive oxygen species (ROS) production and cytosolic calcium (Ca²⁺) handling. Thus, changes in mitochondrial oxidative phosphorylation (OXPHOS), ΔΨ_m, and ATP/ADP may occur in parallel or stimulate each other. Brain cells like neurons are heavily reliant on mitochondrial OXPHOS for its high-energy demands, and hence improper mitochondrial function is detrimental for neuronal survival. Indeed, several neurodegenerative disorders are associated with mitochondrial dysfunction. Modeling this disease-relevant phenotype in neuronal cells differentiated from patient-derived human induced pluripotent stem cells (hiPSCs) provide an appropriate cellular platform for studying the disease pathology and drug discovery. In this review, we describe high-throughput analysis of crucial parameters related to mitochondrial function in hiPSC-derived neurons. These methodologies include measurement of ΔΨ_m, intracellular Ca²⁺, oxidative stress, and ATP/ADP levels using fluorescence probes via a microplate reader. Benefits of such an approach include analysis of mitochondrial parameters on a large population of cells, simultaneous analysis of different cell lines and experimental conditions, and for drug screening to identify compounds restoring mitochondrial function.

Characterizing the Electron Transport Chain: Functional Approach Using Extracellular Flux Analyzer on Mouse Tissue Samples

The Seahorse Extracellular Flux Analyzer enables the high-throughput characterization of oxidative phosphorylation capacity based on the electron transport chain organization and regulation with relatively small amount of material. This development over the traditional polarographic Clark-type electrode approaches make it possible to analyze the respiratory features of mitochondria isolated from tissue samples of particular animal models. Here we provide a description of an optimized approach to carry out multi-well measurement of O2 consumption, with the Agilent Seahorse XFe96 analyzer on mouse brain and muscles to determine the tissue-specific oxidative phosphorylation properties. Protocols include the preparation of the tissue samples, isolation of mitochondria, and analysis of their function; in particular, the preparation and optimization of the reagents and samples.

Phosphorus Supplementation Mitigates Perivascular Adipose Inflammation-Induced Cardiovascular Consequences in Early Metabolic Impairment

Background

The complexity of the interaction between metabolic dysfunction and cardiovascular complications has long been recognized to extend beyond simple perturbations of blood glucose levels. Yet, structured interventions targeting the root pathologies are not forthcoming. Growing evidence implicates the inflammatory changes occurring in perivascular adipose tissue (PVAT) as early instigators of cardiovascular deterioration.

Methods and Results

We used a nonobese prediabetic rat model with localized PVAT inflammation induced by hypercaloric diet feeding, which dilutes inorganic phosphorus (Pi) to energy ratio by 50%, to investigate whether Pi supplementation ameliorates the early metabolic impairment. A 12‐week Pi supplementation at concentrations equivalent to and twice as much as that in the control diet was performed. The localized PVAT inflammation was reversed in a dose‐dependent manner. The increased expression of UCP1 (uncoupling protein1), HIF‐1α (hypoxia inducible factor‐1α), and IL‐1β (interleukin‐1β), representing the hallmark of PVAT inflammation in this rat model, were reversed, with normalization of PVAT macrophage polarization. Pi supplementation restored the metabolic efficiency consistent with its putative role as an UCP1 inhibitor. Alongside, parasympathetic autonomic and cerebrovascular dysfunction function observed in the prediabetic model was reversed, together with the mitigation of multiple molecular and histological cardiovascular damage markers. Significantly, a Pi‐deficient control diet neither induced PVAT inflammation nor cardiovascular dysfunction, whereas Pi reinstatement in the diet after a 10‐week exposure to a hypercaloric low‐Pi diet ameliorated the dysfunction.

Conclusions

Our present results propose Pi supplementation as a simple intervention to reverse PVAT inflammation and its early cardiovascular consequences, possibly through the interference with hypercaloric‐induced increase in UCP1 expression/activity.

Therapeutic Approach of Flavonoid in Ameliorating Diabetic Cardiomyopathy by Targeting Mitochondrial-Induced Oxidative Stress

Diabetes cardiomyopathy is one of the key factors of mortality among diabetic patients around the globe. One of the prior contributors to the progression of diabetic cardiomyopathy is cardiac mitochondrial dysfunction. The cardiac mitochondrial dysfunction can induce oxidative stress in cardiomyocytes and was found to be the cause of majority of the heart morphological and dynamical changes in diabetic cardiomyopathy. To slow down the occurrence of diabetic cardiomyopathy, it is crucial to discover therapeutic agents that target mitochondrial-induced oxidative stress. Flavonoid is a plentiful phytochemical in plants that shows a wide range of biological actions against human diseases. Flavonoids have been extensively documented for their ability to protect the heart from diabetic cardiomyopathy. Flavonoids' ability to alleviate diabetic cardiomyopathy is primarily attributed to their antioxidant properties. In this review, we present the mechanisms involved in flavonoid therapies in ameliorating mitochondrial-induced oxidative stress in diabetic cardiomyopathy.

Overview of the Antioxidant and Anti-Inflammatory Activities of Selected Plant Compounds and Their Metal Ions Complexes

Numerous plant compounds and their metal-ion complexes exert antioxidative, anti-inflammatory, anticancer, and other beneficial effects. This review highlights the different bioactivities of flavonoids, chromones, and coumarins and their metal-ions complexes due to different structural characteristics. In addition to insight into the most studied antioxidative properties of these compounds, the first part of the review provides a comprehensive overview of exogenous and endogenous sources of reactive oxygen and nitrogen species, oxidative stress-mediated damages of lipids and proteins, and on protective roles of antioxidant defense systems, including plant-derived antioxidants. Additionally, the review covers the anti-inflammatory and antimicrobial activities of flavonoids, chromones, coumarins and their metal-ion complexes which support its application in medicine, pharmacy, and cosmetology.

Reviving mitochondrial bioenergetics: A relevant approach in epilepsy

Epileptogenesis is most commonly associated with neurodegeneration and a bioenergetic defect attributing to the fact that mitochondrial dysfunction plays a key precursor for neuronal death. Mitochondria are the essential organelle of neuronal cells necessary for certain neurophysiological processes like neuronal action potential activity and synaptic transmission. The mitochondrial dysfunction disrupts calcium homeostasis leading to inhibitory interneuron dysfunction and increasing the excitatory postsynaptic potential. In epilepsy, the prolonged repetitive neuronal activity increases the excessive demand for energy and acidosis in the brain further increasing the intracellular calcium causing neuronal death. Similarly, the mitochondrial damage also leads to the decline of energy by dysfunction of the electron transport chain and abnormal production of the ROS triggering the apoptotic neuronal death. Thus, the elevated level of cytosolic calcium causes the mitochondria DNA damage coinciding with mtROS and releasing the cytochrome c binding to Apaf protein further initiating the apoptosis resulting in epileptic encephalopathies. The various genetic and mRNA studies of epilepsy have explored the various pathogenic mutations of genes affecting the mitochondria functioning further initiating the neuronal excitotoxicity. Based on the results of previous studies, the recent therapeutic approaches are targeting basic mitochondrial processes, such as energy metabolism or free-radical generation, or specific interactions of disease-related proteins with mitochondria and hold great promise to attenuate epileptogenesis. Therefore, the current review emphasizes the emerging insights to uncover the relation between mitochondrial dysfunction and ROS generation contributing to mechanisms underlying epileptic seizures.

A thermostable Fe/Mn SOD of Geobacillus sp. PCH100 isolated from glacial soil of Indian trans-Himalaya exhibits activity in the presence of common inhibitors

Superoxide dismutases are the enzymes involved in dismutation of superoxide radicals into oxygen and hydrogen peroxide. The present work reports a thermostable Fe/Mn SOD of Geobacillus sp. strain PCH100 (GsSOD) isolated from glacial soil. Purified recombinant GsSOD is a dimeric protein of ~57 kDa that exhibited highest activity at a temperature of 10 °C and pH of 7.8. Maximum enzyme velocity and Michaelis constant of the GsSOD were 1098.90 units/mg and 0.62 μM, respectively. At 80 °C, thermal inactivation rate constant and half-life of GsSOD were 3.33 × 10^-3 min^-1 and 208 min, respectively. Interestingly, GsSOD tolerated a temperature of 100 °C and 130 °C up to 15 min and 5 min, respectively. Circular dichroism and differential scanning calorimetry confirmed thermostable nature of GsSOD. Apoenzyme of GsSOD regained enzymatic activity in the presence of Fe²⁺ and Mn²⁺ as metal ion cofactors. GsSOD was stable under varying concentrations of chemicals, namely ethylenediaminetetraacetic acid, potassium cyanide, hydrogen peroxide, chloroform-ethanol, 3-[(3-cholamidopropyl)-dimethylammonio]-1-propanesulfonate, Tween-20, Triton X-100, urea, and guanidine hydrochloride. The enzyme exhibited >70% activity in presence of 10 mM metal ions. Owing to its thermostable nature and resistance to chemical inhibitors, GsSOD is a potential enzyme for industrial applications.

Mitochondrial reactive oxygen species in physiology and disease

Mitochondrial reactive oxygen species (mROS) are routinely produced at several sites within the organelle. The balance in their formation and elimination is maintained by a complex and robust antioxidant system. mROS may act as second messengers and regulate a number of physiological processes, such as insulin signaling, cell differentiation and proliferation, wound healing, etc. Nevertheless, when a sudden or sustained increase in ROS formation is not efficiently neutralized by the endogenous antioxidant defense system, the detrimental impact of high mROS levels on cell function and viability eventually results in disease development. In this review, we will focus on the dual role of mROS in pathophysiology, emphasizing the physiological role exerted by a regulated mROS production/elimination, and discussing the detrimental effects evoked by an imbalance in mitochondrial redox state. Furthermore, we will touch upon the interplay between mROS and Ca²⁺ homeostasis.

Mitochondrial Dysfunction in Diabetic Cardiomyopathy: The Possible Therapeutic Roles of Phenolic Acids

As the powerhouse of the cells, mitochondria play a very important role in ensuring that cells continue to function. Mitochondrial dysfunction is one of the main factors contributing to the development of cardiomyopathy in diabetes mellitus. In early development of diabetic cardiomyopathy (DCM), patients present with myocardial fibrosis, dysfunctional remodeling and diastolic dysfunction, which later develop into systolic dysfunction and eventually heart failure. Cardiac mitochondrial dysfunction has been implicated in the development and progression of DCM. Thus, it is important to develop novel therapeutics in order to prevent the progression of DCM, especially by targeting mitochondrial dysfunction. To date, a number of studies have reported the potential of phenolic acids in exerting the cardioprotective effect by combating mitochondrial dysfunction, implicating its potential to be adopted in DCM therapies. Therefore, the aim of this review is to provide a concise overview of mitochondrial dysfunction in the development of DCM and the potential role of phenolic acids in combating cardiac mitochondrial dysfunction. Such information can be used for future development of phenolic acids as means of treating DCM by alleviating the cardiac mitochondrial dysfunction.

Mitochondrial Inheritance in Phytopathogenic Fungi-Everything Is Known, or Is It?

Mitochondria are important organelles in eukaryotes that provide energy for cellular processes. Their function is highly conserved and depends on the expression of nuclear encoded genes and genes encoded in the organellar genome. Mitochondrial DNA replication is independent of the replication control of nuclear DNA and as such, mitochondria may behave as selfish elements, so they need to be controlled, maintained and reliably inherited to progeny. Phytopathogenic fungi meet with special environmental challenges within the plant host that might depend on and influence mitochondrial functions and services. We find that this topic is basically unexplored in the literature, so this review largely depends on work published in other systems. In trying to answer elemental questions on mitochondrial functioning, we aim to introduce the aspect of mitochondrial functions and services to the study of plant-microbe-interactions and stimulate phytopathologists to consider research on this important organelle in their future projects.

Glutathione in Brain: Overview of Its Conformations, Functions, Biochemical Characteristics, Quantitation and Potential Therapeutic Role in Brain Disorders

Glutathione (GSH) is an important antioxidant found abundantly and synthesized intracellularly in the cytosol in a tightly regulated fashion. It has diverse physiological functions, including protection against reactive oxygen species and nitrogen species, antioxidant defense as well as maintenance of cellular thiol status. The human brain due to the high oxygen consumption is extremely susceptible to the generation of reactive oxygen species. GSH plays a paramount role in brain antioxidant defense, maintaining redox homeostasis. The depletion of brain GSH has also been observed from both autopsies as well as in vivo MRS studies with aging and varied neurological disorders (Alzheimer's disease, Parkinson's disease, etc.). Therefore, GSH enrichment using supplementation is a promising avenue in the therapeutic development for these neurological disorders. This review will enrich the information on the importance of GSH synthesis, metabolism, functions, compartmentation and inter-organ transport, structural conformations and its quantitation via different techniques. The transportation of GSH in the brain via different interventional routes and its potential role in the development of therapeutic strategies for various brain disorders is also addressed. Very recent study found significant improvement of behavioral deficits including cognitive decline, depressive-like behaviors, in APP (NL-G-F/NL-G-FG-) mice due to oral GSH administration. This animal model study put an emergent need to complete GSH supplementation trial in MCI and AD patients for cognitive improvement as proposed earlier.

Mitochondrial ROS Formation in the Pathogenesis of Diabetic Cardiomyopathy

Diabetic cardiomyopathy is a result of diabetes-induced changes in the structure and function of the heart. Hyperglycemia affects multiple pathways in the diabetic heart, but excessive reactive oxygen species (ROS) generation and oxidative stress represent common denominators associated with adverse tissue remodeling. Indeed, key processes underlying cardiac remodeling in diabetes are redox sensitive, including inflammation, organelle dysfunction, alteration in ion homeostasis, cardiomyocyte hypertrophy, apoptosis, fibrosis, and contractile dysfunction. Extensive experimental evidence supports the involvement of mitochondrial ROS formation in the alterations characterizing the diabetic heart. In this review we will outline the central role of mitochondrial ROS and alterations in the redox status contributing to the development of diabetic cardiomyopathy. We will discuss the role of different sources of ROS involved in this process, with a specific emphasis on mitochondrial ROS producing enzymes within cardiomyocytes. Finally, the therapeutic potential of pharmacological inhibitors of ROS sources within the mitochondria will be discussed.