Alterations In Oxidative Metabolism Research Articles

The damage caused by Cd toxicity to photosynthesis, cellular ultrastructure, antioxidant metabolism, and gene expression in young cacao plants are mitigated by high Mn doses in soil.

Manganese (Mn) is one of the essential mineral micronutrients most demanded by cacao. Cadmium (Cd) is highly toxic to plants and other living beings. There are indications that Mn can interact with Cd and mitigate its toxicity. The objective of this study was to evaluate the action of Mn on the toxic effect of Cd in young plants of the CCN 51 cacao genotype, subjected to different doses of Mn, Cd, and Mn+Cd in soil, through physiological, biochemical, molecular, and micromorphological and ultrastructural changes. High soil Mn doses favored the maintenance and performance of adequate photosynthetic processes in cacao. However, high doses of Cd and Mn+Cd in soil promoted damage to photosynthesis, alterations in oxidative metabolism, and the uptake, transport, and accumulation of Cd in roots and leaves. In addition, high Cd concentrations in roots and leaf tissues caused irreversible damage to the cell ultrastructure, compromising cell function and leading to programmed cell death. However, there was a mitigation of Cd toxicity when cacao was grown in soils with low Cd doses and in the presence of Mn. Thus, damage to the root and leaf tissues of cacao caused by Cd uptake from contaminated soils can be attenuated or mitigated by the presence of high Mn doses in soil.

The possible role of the endocrine disrupting chemicals on the premature and early menopause associated with the altered oxidative stress metabolism.

The possible role of the endocrine disrupting chemicals on the premature and early menopause associated with the altered oxidative stress metabolism.

Regulation of Oxidative Energy Metabolism By G0S2 in FLT3+ AML

Introduction: Acute myeloid leukemia (AML) patients with mutations in the FMS-like tyrosine kinase 3 (FLT3) gene represent 20-30% of all AML cases. These patients can be treated with tyrosine kinase inhibitors (TKIs) targeting FLT3; however, up to 60% of patients develop resistance or experience adverse side effects, which makes identifying mechanisms of drug resistance a priority. Our previous work demonstrated a tumor suppressor role for G0/G1 switch gene 2 (G0S2) in chronic myeloid leukemia (CML), which is profoundly downregulated in TKI resistance (Gonzalez MA, et al. under review). However, the role of G0S2 in FLT3+ AML is unknown. G0S2 regulates multiple cellular functions, including lipolysis, de novo lipogenesis, and oxidative phosphorylation; therefore, we hypothesized that reduced G0S2 expression in FLT3+ AML results in altered oxidative energy metabolism, promoting therapy resistance. Methods: To address this hypothesis, we first used shRNA lentiviral vectors to transduce the FLT3+ AML cell lines, MOLM-13 and MOLM-14, with a non-targeting control vector (shNT), a G0S2 knockdown vector (shG0S2), and an ectopic G0S2 expression vector (pLVX G0S2). In primary FLT3+ AML MNCs, we used an empty vector (EV) and pLVX G0S2. We assessed colony formation ability by plating cells in 0.9% Methocult plus cytokines for primary cells, and measured apoptosis using AnnexinV and 7-aminoactinomycin D (7AAD). Cell lines were treated with Doxycycline (100 ng/ml) ± FLT3 inhibitors, either Quizartinib (20nM) or Midostaurin (50nM). We performed immunoblotting using SDS-page, PVDF membranes, and a human antibody cocktail for the 5-electron transport chain (ETC) complexes. For the in vivo experiments, NOD-scid IL2Rgammanull (NSG) mice received intravenous injections of 3 million cells/mouse of the MOLM-14 cell lines with the shNT, shG0S2, and pLVX G0S2 vectors, and all mice were immediately placed in doxycycline hyclate chow to induce vector expression. To assess the role of G0S2 in FTL3+ AML cells, we used the correlation feature available at UALCAN to calculate the genes co-expressed with G0S2 in The Cancer Genome Atlas (TCGA) AML data. Finally, we measured oxygen consumption rates (OCR) using the Cell Mito Stress Test kit for the Agilent Seahorse XFp Bioanalyzer. Results: Using publically available data, we found that G0S2 mRNA expression does not correlate with overall survival (OS) in AML, but is significantly downregulated in AML versus normal mononuclear cells (MNCs, p<0.001), and further reduced in AML patients with mutated FLT3 (p=0.006). In colony formation assays, the FLT3 TKI Midostaurin reduced colony number in the presence of G0S2 ectopic expression when compared to its control. In contrast, FLT3 TKIs had less of an effect on apoptosis in the presence of G0S2 ectopic expression. In primary FLT3+ AML MNCs, ectopic G0S2 expression resulted in a significant reduction of colony formation, which correlated with increased induction of apoptosis when compared to the empty vector control. Importantly, pathway enrichment analysis using data from The Cancer Genome Atlas (TCGA) revealed that the genes co-expressed with G0S2 in AML implicated a role in energy metabolism. After confirming G0S2 ectopic expression in the MOLM-13 cell line, immunoblotting showed reduced expression of complexes III and V of the ETC, which correlated with reductions in oxygen consumption rates using the Agilent Seahorse Bioanalyzer. In vivo, G0S2 knockdown in FLT3+ AML cell lines resulted in a significant reduction in overall survival of NSG mice compared with controls (Figure 1). Conclusion: Altogether, our data demonstrate that loss of G0S2 expression in FLT3+ AML dysregulates oxygen metabolism by altering expression of ETC components. Ultimately, we showed that G0S2 is a tumor suppressor that is downregulated in FLT3+ AML, which might promote therapy resistance by altering oxidative energy metabolism. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Rnd3 Expression is Necessary to Maintain Mitochondrial Homeostasis but Dispensable for Autophagy.

Autophagy is a highly conserved process that mediates the targeting and degradation of intracellular components to lysosomes, contributing to the maintenance of cellular homeostasis and to obtaining energy, which ensures viability under stress conditions. Therefore, autophagy defects are common to different neurodegenerative disorders. Rnd3 belongs to the family of Rho GTPases, involved in the regulation of actin cytoskeleton dynamics and important in the modulation of cellular processes such as migration and proliferation. Murine models have shown that Rnd3 is relevant for the correct development and function of the Central Nervous System and lack of its expression produces several motor alterations and neural development impairment. However, little is known about the molecular events through which Rnd3 produces these phenotypes. Interestingly we have observed that Rnd3 deficiency correlates with the appearance of autophagy impairment profiles and irregular mitochondria. In this work, we have explored the impact of Rnd3 loss of expression in mitochondrial function and autophagy, using a Rnd3 KO CRISPR cell model. Rnd3 deficient cells show no alterations in autophagy and mitochondria turnover is not impaired. However, Rnd3 KO cells have an altered mitochondria oxidative metabolism, resembling the effect caused by oxidative stress. In fact, lack of Rnd3 expression makes these cells strictly dependent on glycolysis to obtain energy. Altogether, our results demonstrate that Rnd3 is relevant to maintain mitochondria function, suggesting a possible relationship with neurodegenerative diseases.

The Relationship Between Resting Cerebral Blood Flow, Neurometabolites, Cardio-Respiratory Fitness and Aging-Related Cognitive Decline.

Older adults typically experience a decline in cognitive function, but improvements in physical health and lifestyle can be neuroprotective across the human lifespan. The primary objective of this study is to advance our basic understanding of how cardiorespiratory fitness and neurophysiological attributes relate to cognitive decline. While cerebral blood flow (CBF) is critical for the supply of nutrients to the tissue, the brain’s major neurotransmitters (i.e., gamma-aminobutyric acid, GABA, and glutamate-glutamine complex, Glx) are closely linked to oxidative metabolism. Within the context of flow-metabolism coupling, the critical question is how these neurophysiological parameters interplay, resulting in cognitive decline. Further, how cardiorespiratory fitness may impact aging neurophysiology and cognition is not well understood. To address these questions, we recruited 10 younger and 12 older cognitively intact participants to collect GABA and Glx using magnetic resonance spectroscopy (MRS), CBF using pseudo-continuous arterial spin labeling Magnetic Resonance Imaging (MRI), VO2max as a measure of cardiorespiratory fitness using the YMCA submax test, and cognitive and motor-cognitive measures using a battery of behavioral assessments. We observed expected differences in GABA+, Glx, and CBF between younger and older participants in pre-SMA, a frontal domain-general region. When GABA+ and Glx were related to CBF via multiple linear regression, Glx was identified as the main contributor to the model. For higher-order executive function (i.e., inhibition versus color naming), GABA*Glx*CBF interaction was critical in younger, while only Glx was involved in older participants. For unimanual motor dexterity, GABA*Glx interaction was the common denominator across both groups, but younger participants’ brain also engages CBF. In terms of selective motor inhibition, CBF from younger participants was the only major neurophysiological factor. In terms of fitness, cardiorespiratory fitness was significantly related to GABA, Glx, and motor performance when combining cohorts, but no group-specific relationships were observed. Taken together, our results indicate that Glx and CBF coupling decreases with aging, perhaps due to altered glial oxidative metabolism. Our data suggest that GABA, Glx, and CBF are engaged and weighted differently for different cognitive measures sensitized to aging, and higher fitness allows for a more efficient metabolic shift that facilitates improved performance on cognitive-motor tasks.

Exploiting the tumor immune microenvironment and immunometabolism using mitochondria-targeted drugs: Challenges and opportunities in racial disparity and cancer outcome research.

Black and Hispanic cancer patients have a higher incidence of cancer mortality. Many factors (e.g., socioeconomic differences, insufficient access to healthcare) contribute to racial disparity. Emerging research implicates biological disparity in cancer outcomes. Studies show distinct differences in the tumor immune microenvironment (TIME) in Black cancer patients. Studies also have linked altered mitochondrial metabolism to changes in immune cell activation in TIME. Recent publications revealed a novel immunomodulatory role for triphenylphosphonium‐based mitochondrial‐targeted drugs (MTDs). These are synthetically modified, naturally occurring molecules (e.g., honokiol, magnolol, metformin) or FDA‐approved small molecule drugs (e.g., atovaquone, hydroxyurea). Modifications involve conjugating the parent molecule via an alkyl linker chain to a triphenylphosphonium moiety. These modified molecules (e.g., Mito‐honokiol, Mito‐magnolol, Mito‐metformin, Mito‐atovaquone, Mito‐hydroxyurea) accumulate in tumor cell mitochondria more effectively than in normal cells and inhibit mitochondrial respiration, induce reactive oxygen species, activate AMPK and redox transcription factors, and inhibit cancer cell proliferation. Besides these intrinsic effects of MTDs in redox signaling and proliferation in tumors, MTDs induced extrinsic effects in the TIME of mouse xenografts. MTD treatment inhibited tumor‐suppressive immune cells, myeloid‐derived suppressor cells, and regulatory T cells, and activated T cells and antitumor immune effects. One key biological disparity in Black cancer patients was related to altered mitochondrial oxidative metabolism; MTDs targeting vulnerabilities in tumor cells and the TIME may help us understand this biological disparity. Clinical trials should include an appropriate number of Black and Hispanic cancer patients and should validate the intratumoral, antihypoxic effects of MTDs with imaging.

The genetics of pediatric cutaneous autoimmunity: The sister diseases vitiligo and alopecia areata

Autoimmunity, the reaction of the host against self, is a complex pattern of immunologic response that allows the immune system to react to “normal” tissue. Many such diseases exist in the skin, but in particular, two stand out as visible manifestations of autoimmune cutaneous attack. These are vitiligo, the immune attack on the melanocyte, and alopecia areata, the immune attack of the hair unit. These two illnesses include the prototypes of "simple" attacks on specific components of the skin. Other such illnesses are psoriasis—a complex series of immunologic responses resulting in a characteristic pattern of keratinocyte hyperproliferation—and lichen planus, which is similarly associated with a typical cutaneous skin disease pattern, but these will not be included in this review. In comparison, autoimmune polyendocrinopathies have defined pathways of disease based on single-gene mutations that can result in a variety of autoimmune skin features including vitiligo and alopecia areata. This contribution reviews known patterns of autoimmunity in childhood skin disease with a particular focus on single-gene disorders where they exist, and the more common multifactorial genes that contribute to this breach of the immune system's regulatory checks and balances. Genetic mechanisms that will be covered include innate and adaptive immunity, major histocompatibility complex II class associations, genetic polymorphisms, and major histocompatibility complex I class associations that bridge autoinflammatory and autoimmunity states, as well as alterations in oxidative metabolism promoting tissue destruction. End-organ tissue destruction appears to occur via interferon gamma and cytotoxic mediated activity and is a promising new therapeutic target. Janus kinase inhibitors also have the benefit clinically of both affecting the immune cascade at the cytotoxic T cell level and allowing triggering of melanocyte and hair follicular activity through the signal transducer and activator of transcription pathway, representing an attractive therapeutic with dial activity, among other cytokines implicated in end-organ destruction. Transplacental autoimmunity will not be covered herein. Greater insight into mechanisms of pediatric cutaneous autoimmunity in vitiligo and alopecia areata has yielded better therapeutic options and interventions. Understanding the basis of autoimmune triggering in our patients, that is, personalized medicine, may allow for targeted therapeutics with a goal of induction of remission, regeneration, or rejuvenation of the end-organ with the least toxic side effect profile.

Nutritional and phytochemical profile of pomegranate ("Wonderful variety") peel and its effects on hepatic oxidative stress and metabolic alterations.

The peel of pomegranate fruit contains antioxidant phytochemicals that may potentiate health benefits but remain under-explored. We evaluated the antioxidant, nutritional and phytochemical profiles of the peel of the "Wonderful" variety pomegranate and its influence on oxidative metabolic alterations in hepatic tissue. The peel contained appreciable amounts of some beneficial trace minerals and both essential and non-essential amino acids. Mostly Omega 3 and 6 fatty acids were found. The peel extracts exhibited in vitro radical scavenging and Fe3+ reducing antioxidant activities and dose-dependently prevented oxidative stress-induced lipid peroxidation increase and GSH depletion in both Chang liver cells (IC50 = 18.0 ± 1.46 and 11.2 ± 0.99 µg/mL, respectively) and isolated rat liver (IC50 = 96.7 ± 3.34 and 19.4 ± 3.36 µg/mL, respectively). The antioxidant effects were comparable to that of ascorbic and correlated with their phenolic profile. HPLC analysis further identified antioxidant phenolic acids (gallic acid, syringic acid ferulic acid p-coumaric acid or trans-4-hydroxycinnamic acid, etc.). The peel did not cause notable cytotoxicity in liver and kidney cells, which suggest minimal safety concerns. Metabolomics analysis revealed alterations in fatty acid, amino acids, and nucleic acid metabolisms following the induction of oxidative stress. These alterations were improved in the acetone extract-treated tissues, with concomitant activation of vitamin and selonocompound metabolisms. Data suggest that the fruit peel of "Wonderful" pomegranate may be an underutilized source of functional nutrients and antioxidants phenolic acids for optimum body function and mitigation hepatic oxidative damage and metabolic alterations as well as associated diseases. PRACTICAL APPLICATIONS: Although underutilized, documented evidence have shown that the wastes, like peels from fruits contain more phytochemicals than the edible pulp, making them potential sources of bioactive principles. In this study we exposed the nutritional, phytochemical and oxidative stress-related medicinal benefits of the peel of "Wonderful" pomegranate variety. The peel could ameliorate oxidative hepatic metabolic alterations. The peel of this fruit could be a source of beneficial micro and macro nutrients, as well as bioactive phenolics to improve oxidative health and mitigate oxidative hepatic damage and associated disease states. Medicinally utilizing the fruit's peel could reduce underutilized fruit wastes, increase the value of the fruit and benefit the bioeconomy.

Molecular Signature of HFpEF: Systems Biology in a Cardiac-Centric Large Animal Model

In this study the authors used systems biology to define progressive changes in metabolism and transcription in a large animal model of heart failure with preserved ejection fraction (HFpEF). Transcriptomic analysis of cardiac tissue, 1-month post-banding, revealed loss of electron transport chain components, and this was supported by changes in metabolism and mitochondrial function, altogether signifying alterations in oxidative metabolism. Established HFpEF, 4months post-banding, resulted in changes in intermediary metabolism with normalized mitochondrial function. Mitochondrial dysfunction and energetic deficiencies were noted in skeletal muscle at early and late phases of disease, suggesting cardiac-derived signaling contributes to peripheral tissue maladaptation in HFpEF. Collectively, these results provide insights into the cellular biology underlying HFpEF progression.

Abstract IA-025: Exploiting Redox Biology for Selectively Targeting Cancer Cells

Abstract Relative to normal cells, cancer cells have been shown to demonstrate fundamental alterations in oxidative metabolism leading to increased steady-state levels of superoxide, hydrogen peroxide, and labile iron pools. Alterations in cancer cell oxidative metabolism in turn lead to disruptions in many redox sensitive signaling and gene expression pathways that impact cell growth, differentiation, genomic instability, and cancer progression. Cancer cells adapt to this altered metabolic state by activating many signaling and gene expression pathways that allow them to survive and continue to progress to malignancy. The current talk will discuss how pharmacological ascorbate and superoxide dismutase mimics can be used to target the oxidative metabolic frailties of cancer versus normal cells to enhance therapeutic outcomes to radio-chemo-therapies both in pre-clinical and clinical trials. The long-term goal is to utilize a detailed mechanistic understanding of alterations in cancer versus normal cell oxidative metabolism and redox biology to develop rapidly implementable new strategies that can enhance tumor responses while protecting normal tissues during standard radio-chemo-therapy protocols. (Supported by P01 CA217797, R01 CA182804, T32 CA078586). Citation Format: Douglas R Spitz. Exploiting Redox Biology for Selectively Targeting Cancer Cells [abstract]. In: Proceedings of the AACR Virtual Special Conference on Radiation Science and Medicine; 2021 Mar 2-3. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(8_Suppl):Abstract nr IA-025.

Alterations in oxidative metabolism in liver of female rats: Effects of long-term vitamin A deficiency

Background: The latest estimate by 5 UN agencies is that 821 million people globally are undernourished, which puts them at risk of vitamin and other nutrient deficiencies. Vitamin A deficiency remains a widespread public health problem among women and children in the developing world the role of vitamin A and its active metabolites in pathways involved in antioxidant protection and in the inhibition of important pathways that promote oxidative stress. Objectives: Determine if vitamin A deficiency could influence oxidative metabolism in 6-month-old female wistar rats. Materials and Methods: Determine the concentration of carbonyl proteins, as a marker of protein oxidation; TBARS, as a lipoperoxidation marker; and nitrotyrosine as a marker of oxidative stress dependent on nitric oxide. Quantify the expression of CAT, SOD, eNOS and iNOS in the liver and wistar rats deficient in vitamin A for 6 months. Results: An increase in the concentration of carbonyl protein and nitrotyrosine in the liver tissue deficient in vitamin A is observed. The expression of SOD, eNOS and iNOS decreased in the group with a private diet of vitamin A. From the regression analysis a positive correlation was established between hepatic retinoic acid levels and gene expression of eNOS, iNOS and SOD. A positive correlation between serum retinoic acid levels and gene expression of eNOS and iNOS was also observed. Conclusions: It is possible to ratify the relationship between the development of stress and vitamin A levels; improving the understanding of hepatic metabolism and its response to the absence of this vitamin.

Alterations in oxidative metabolism in liver of female rats: Effects of long-term vitamin A deficiency

Alterations in oxidative metabolism in liver of female rats: Effects of long-term vitamin A deficiency

The Potential for Natural Antioxidant Supplementation in the Early Stages of Neurodegenerative Disorders.

The neurodegenerative process is characterized by the progressive ultrastructural alterations of selected classes of neurons accompanied by imbalanced cellular homeostasis, a process which culminates, in the later stages, in cell death and the loss of specific neurological functions. Apart from the neuronal cell impairment in selected areas of the central nervous system which characterizes many neurodegenerative diseases (e.g., Alzheimer’s Disease, Parkinson’s Disease, Huntington’s Disease, etc.), some alterations may be found in the early stages including gliosis and the misfolding or unfolding accumulation of proteins. On the other hand, several common pathophysiological mechanisms can be found early in the course of the disease including altered oxidative metabolism, the loss of cross-talk among the cellular organelles and increased neuroinflammation. Thus, antioxidant compounds have been suggested, in recent years, as a potential strategy for preventing or counteracting neuronal cell death and nutraceutical supplementation has been studied in approaching the early phases of neurodegenerative diseases. The present review will deal with the pathophysiological mechanisms underlying the early stages of the neurodegenerative process. In addition, the potential of nutraceutical supplementation in counteracting these diseases will be assessed.

Changes in heat stress tolerance in a freshwater amphipod following starvation: The role of oxygen availability, metabolic rate, heat shock proteins and energy reserves

The ability of organisms to cope with environmental stressors depends on the duration and intensity of the stressor, as well as the type of stress. For aquatic organisms, oxygen limitation has been implicated in limiting heat tolerance. Here we examine how starvation affects heat tolerance in the amphipod Gammarus fossarum (Koch, 1836) and whether observed changes can be explained from alterations in oxidative metabolism, depletion of energy reserves, upregulation of heat shock proteins or susceptibility to oxygen limitation. Starved amphipods showed impaired survival compared to fed amphipods during prolonged exposure to mild heat. In contrast, under acute, high-intensity heat exposure they actually showed improved survival. We observed a lower demand for oxygen in starved amphipods which could make them less susceptible to oxygen limitation. Such a role for oxygen in limiting heat tolerance was verified as hypoxia impaired the heat tolerance of amphipods, especially starved ones. Fed amphipods likely rely more on anaerobic metabolism to maintain energy status during heat stress, whereas for starved amphipods aerobic metabolism appears to be more important. The depletion of their energy reserves constrains their ability to maintain energy status via anaerobic metabolism. We did not find evidence that alterations in heat tolerance following starvation were related to the upregulation of heat shock proteins. In conclusion, starvation can have opposite effects on heat tolerance, acting via pathways that are operating on different time scales.

Harnessing altered oxidative metabolism in cancer by augmented prooxidant therapy.

Deregulated metabolism of oxygen with increased generation of reactive oxygen species (ROS) is characteristic for a majority of cancers. The elevated ROS levels are in part responsible for further progression of cancer, but when produced in large excess, they endanger the viability of the cancer cells. To protect themselves from ROS-mediated toxicity, many types of cancers enhance the intrinsic antioxidant defenses, which make them dependent on the efficacy of a given ROS-detoxifying system. This poses an attractive target for anticancer therapy by two main approaches: the use of ROS-generating agents (i.e., prooxidants) or by inhibition of a chosen antioxidant system. However, the clinical efficacy of either of these approaches used alone is modest at best. The solution may rely on combining these strategies into an advanced prooxidant therapy (APoT) in order to produce a synergistic and cancer-specific effect. Indeed, such strategies have proven efficient in preclinical models, e.g., in B cell malignancies and breast cancer. Following promising experimental reports on APoT, this approach needs to be further extensively tested in order to become a potential alternative or an enhancement for classical chemotherapy.

A DEFICIÊNCIA DE TIAMINA E NIACINA COMO FATOR DE RISCO PARA DE DOENÇAS NEUROLÓGICAS

Niacina e tiamina, vitaminas obtidas por meio da dieta, são precursoras de coenzimas do metabolismo intermediário. O objetivo do presente trabalho foi realizar uma revisão da literatura a respeito dessas vitaminas no metabolismo oxidativo e suas implicações em doenças neurológicas. A metodologia consistiu na realização de uma busca bibliográfica nas bases de dados Medline e Science Direct, utilizando os descritores “oxidative stress”, deficiency, “basal metabolism”, “nervous system”, “thiamine” e “niacin”. Ao final, foram destacados dez artigos para a produção da revisão. Os estudos demonstraram que a deficiência das vitaminas niacina e tiamina pode causar disfunções no sistema nervoso central devido a falhas no metabolismo oxidativo.

BOLA (BolA Family Member 3) Deficiency Controls Endothelial Metabolism and Glycine Homeostasis in Pulmonary Hypertension

Deficiencies of iron-sulfur (Fe-S) clusters, metal complexes that control redox state and mitochondrial metabolism, have been linked to pulmonary hypertension (PH), a deadly vascular disease with poorly defined molecular origins. BOLA3 (BolA Family Member 3) regulates Fe-S biogenesis, and mutations in BOLA3 result in multiple mitochondrial dysfunction syndrome, a fatal disorder associated with PH. The mechanistic role of BOLA3 in PH remains undefined. In vitro assessment of BOLA3 regulation and gain- and loss-of-function assays were performed in human pulmonary artery endothelial cells using siRNA and lentiviral vectors expressing the mitochondrial isoform of BOLA3. Polymeric nanoparticle 7C1 was used for lung endothelium-specific delivery of BOLA3 siRNA oligonucleotides in mice. Overexpression of pulmonary vascular BOLA3 was performed by orotracheal transgene delivery of adeno-associated virus in mouse models of PH. In cultured hypoxic pulmonary artery endothelial cells, lung from human patients with Group 1 and 3 PH, and multiple rodent models of PH, endothelial BOLA3 expression was downregulated, which involved hypoxia inducible factor-2α-dependent transcriptional repression via histone deacetylase 1-mediated histone deacetylation. In vitro gain- and loss-of-function studies demonstrated that BOLA3 regulated Fe-S integrity, thus modulating lipoate-containing 2-oxoacid dehydrogenases with consequent control over glycolysis and mitochondrial respiration. In contexts of siRNA knockdown and naturally occurring human genetic mutation, cellular BOLA3 deficiency downregulated the glycine cleavage system protein H, thus bolstering intracellular glycine content. In the setting of these alterations of oxidative metabolism and glycine levels, BOLA3 deficiency increased endothelial proliferation, survival, and vasoconstriction while decreasing angiogenic potential. In vivo, pharmacological knockdown of endothelial BOLA3 and targeted overexpression of BOLA3 in mice demonstrated that BOLA3 deficiency promotes histological and hemodynamic manifestations of PH. Notably, the therapeutic effects of BOLA3 expression were reversed by exogenous glycine supplementation. BOLA3 acts as a crucial lynchpin connecting Fe-S-dependent oxidative respiration and glycine homeostasis with endothelial metabolic reprogramming critical to PH pathogenesis. These results provide a molecular explanation for the clinical associations linking PH with hyperglycinemic syndromes and mitochondrial disorders. These findings also identify novel metabolic targets, including those involved in epigenetics, Fe-S biogenesis, and glycine biology, for diagnostic and therapeutic development.

Hyperhomocysteinemia, Suppressed Immunity, and Altered Oxidative Metabolism Caused by Pathogenic Microbes in Atherosclerosis and Dementia.

Many pathogenic microorganisms have been demonstrated in atherosclerotic plaques and in cerebral plaques in dementia. Hyperhomocysteinemia, which is a risk factor for atherosclerosis and dementia, is caused by dysregulation of methionine metabolism secondary to deficiency of the allosteric regulator, adenosyl methionine. Deficiency of adenosyl methionine results from increased polyamine biosynthesis by infected host cells, causing increased activity of ornithine decarboxylase, decreased nitric oxide and peroxynitrate formation and impaired immune reactions. The down-regulation of oxidative phosphorylation that is observed in aging and dementia is attributed to deficiency of thioretinaco ozonide oxygen complexed with nicotinamide adenine dinucleotide and phosphate, which catalyzes oxidative phosphorylation. Adenosyl methionine biosynthesis is dependent upon thioretinaco ozonide and adenosine triphosphate (ATP), and the deficiency of adenosyl methionine and impaired immune function in aging are attributed to depletion of thioretinaco ozonide from mitochondrial membranes. Allyl sulfides and furanonaphthoquinones protect against oxidative stress and apoptosis by increasing the endogenous production of hydrogen sulfide and by inhibiting electron transfer to the active site of oxidative phosphorylation. Diallyl trisulfide and napabucasin inhibit the signaling by the signal transducer and activator of transcription 3 (Stat3), potentially enhancing immune function by effects on T helper lymphocytes and promotion of apoptosis. Homocysteine promotes endothelial dysfunction and apoptosis by the unfolded protein response and endoplasmic reticulum stress through activation of the N-methyl D-aspartate (NMDA) receptor, causing oxidative stress, calcium influx, apoptosis and endothelial dysfunction. The prevention of atherosclerosis and dementia may be accomplished by a proposed nutritional metabolic homocysteine-lowering protocol which enhances immunity and corrects the altered oxidative metabolism in atherosclerosis and dementia.

Hypothyroid myopathy: A peculiar clinical presentation of thyroid failure. Review of the literature.

Abnormalities in thyroid function are common endocrine disorders that affect 5-10% of the general population, with hypothyroidism occurring more frequently than hyperthyroidism. Clinical symptoms and signs are often nonspecific, particularly in hypothyroidism. Muscular symptoms (stiffness, myalgias, cramps, easy fatigability) are mentioned by the majority of patients with frank hypothyroidism. Often underestimated is the fact that muscle symptoms may represent the predominant or the only clinical manifestation of hypothyroidism, raising the issue of a differential diagnosis with other causes of myopathy, which sometimes can be difficult. Elevated serum creatine kinase, which not necessarily correlates with the severity of the myopathic symptoms, is certainly suggestive of muscle impairment, though it does not explain the cause. Rare muscular manifestations, associated with hypothyroidism, are rhabdomyolysis, acute compartment syndrome, Hoffman's syndrome and Kocher-Debré-Sémélaigne syndrome. Though the pathogenesis of hypothyroid myopathy is not entirely known, proposed mechanisms include altered glycogenolytic and oxidative metabolism, altered expression of contractile proteins, and neuro-mediated damage. Correlation studies of haplotype, muscle gene expression and protein characterization, could help understanding the pathophysiological mechanisms of this myopathic presentation of hypothyroidism.

Oxidative metabolism and Ca2+ handling in isolated brain mitochondria and striatal neurons from R6/2 mice, a model of Huntington's disease.

Alterations in oxidative metabolism and defects in mitochondrial Ca2+ handling have been implicated in the pathology of Huntington's disease (HD), but existing data are contradictory. We investigated the effect of human mHtt fragments on oxidative metabolism and Ca2+ handling in isolated brain mitochondria and cultured striatal neurons from the R6/2 mouse model of HD. Non-synaptic and synaptic mitochondria isolated from the brains of R6/2 mice had similar respiratory rates and Ca2+ uptake capacity compared with mitochondria from wild-type (WT) mice. Respiratory activity of cultured striatal neurons measured with Seahorse XF24 flux analyzer revealed unaltered cellular respiration in neurons derived from R6/2 mice compared with neurons from WT animals. Consistent with the lack of respiratory dysfunction, ATP content of cultured striatal neurons from R6/2 and WT mice was similar. Mitochondrial Ca2+ accumulation was also evaluated in cultured striatal neurons from R6/2 and WT animals. Our data obtained with striatal neurons derived from R6/2 and WT mice show that both glutamate-induced increases in cytosolic Ca2+ and subsequent carbonilcyanide p-triflouromethoxyphenylhydrazone-induced increases in cytosolic Ca2+ were similar between WT and R6/2, suggesting that mitochondria in neurons derived from both types of animals accumulated comparable amounts of Ca2+ Overall, our data argue against respiratory deficiency and impaired Ca2+ handling induced by human mHtt fragments in both isolated brain mitochondria and cultured striatal neurons from transgenic R6/2 mice.