Therapeutic targeting of oxidative stress with coenzyme Q10 counteracts exaggerated diabetic cardiomyopathy in a mouse model of diabetes with diminished PI3K(p110α) signaling

Diabetes-induced cardiac complications include left ventricular (LV) dysfunction and heart failure. We previously demonstrated that LV phosphoinositide 3-kinase p110α (PI3K) protects the heart against diabetic cardiomyopathy, associated with reduced NADPH oxidase expression and activity. Conversely, in dominant negative PI3K(p110α) transgenic mice (dnPI3K), reduced cardiac PI3K signaling exaggerated diabetes-induced cardiomyopathy, associated with upregulated NADPH oxidase. The goal was to examine whether chronic supplementation with the antioxidant coenzyme Q₁₀ (CoQ₁₀) could attenuate LV superoxide and diabetic cardiomyopathy in a setting of impaired PI3K signaling. Diabetes was induced in 6-week-old nontransgenic and dnPI3K male mice via streptozotocin. After 4 weeks of diabetes, CoQ₁₀ supplementation commenced (10 mg/kg ip, 3 times/week, 8 weeks). At study end (12 weeks of diabetes), markers of LV function, cardiomyocyte hypertrophy, collagen deposition, NADPH oxidase, oxidative stress (3-nitrotyrosine), and concentrations of CoQ₉ and CoQ₁₀ were determined. LV NADPH oxidase (Nox2 gene expression and activity, and lucigenin-enhanced chemiluminescence), as well as oxidative stress, were increased by diabetes, exaggerated in diabetic dnPI3K mice, and attenuated by CoQ₁₀. Diabetes-induced LV diastolic dysfunction (prolonged deceleration time, elevated end-diastolic pressure, impaired E/A ratio), cardiomyocyte hypertrophy and fibrosis, expression of atrial natriuretic peptide, connective tissue growth factor, and β-myosin heavy chain were all attenuated by CoQ₁₀. Chronic CoQ₁₀ supplementation attenuates aspects of diabetic cardiomyopathy, even in a setting of reduced cardiac PI3K protective signaling. Given that CoQ₁₀ supplementation has been suggested to have positive outcomes in heart failure patients, chronic CoQ₁₀ supplementation may be an attractive adjunct therapy for diabetic heart failure.     

Effects of dietary L-carnitine and coenzyme Q10 supplementation on performance and ascites mortality of broilers

The study was conducted to determine the effects of dietary L-carnitine and coenzyme Q₁₀ (CoQ₁₀) supplementation on growth performance and ascites mortality of broilers. A 3 × 3 factorial arrangement was employed with three levels (0, 75 and 150 mg/kg) of L-carnitine and three levels of CoQ₁₀ (0, 20 and 40 mg/kg) supplementation during the experiment. Five hundred and forty one-day-old Arbor Acre male broiler chicks were randomly allocated into nine groups with six replicates each. All birds were fed with the basal diets from day 1 to 7 and changed to the experimental diets from day 8. During day 15 to 21 all the birds were exposed to low ambient temperature (15 - 18°C) to induce ascites. The results showed that under this condition, growth performance of broilers were not significantly affected by CoQ₁₀ or L-carnitine + CoQ₁₀ supplementation during week 0 - 3 and 0 - 6, but body weight gain (BWG) of broilers was significantly reduced by 150 mg/kg L-carnitine during week 0 - 6. Packed cell volume (PCV) of broilers was significantly decreased by L-carnitine and L-carnitine + CoQ₁₀ supplementation (P < 0.05). Erythrocyte osmotic fragility (EOF), ascites heart index (AHI) and ascites mortality of broilers were significantly decreased by L-carnitine, CoQ₁₀ and L-carnitine + CoQ₁₀ supplementation. Though no significant changes were observed in total antioxidative capability (T-AOC), total superoxide dismutase (T-SOD) was increased by L-carnitine, CoQ₁₀ and L-carnitine + CoQ₁₀ supplementation (P < 0.05). Malonaldehyde (MDA) content was significantly decreased by CoQ₁₀ and L-carnitine + CoQ₁₀ supplementation. The results indicate that dietary L-carnitine and CoQ₁₀ supplementation reduce ascites mortality of broilers; the reason may be partially associated with their antioxidative effects.     

Lactate increases coenzyme Q10 production by Agrobacterium tumefaciens

By the optimization of nitrogen source for coenzyme Q₁₀ (ubiquinone, CoQ₁₀) production in Agrobacterium tumefaciens KCCM 10413 culture, the highest CoQ₁₀ production was achieved in medium containing corn steep powder (CSP). Components for a stimulatory effect on the production of CoQ₁₀ in CSP were screened, and lactate was found to increase dry cell weight (DCW) and the specific CoQ₁₀ content. In a fed-batch culture of A. tumefaciens, supplementation with 1.5 g of lactate l⁻¹ further improved DCW, the specific CoQ₁₀ content, and CoQ₁₀ production by 16.0, 5.8, and 22.8%, respectively. It has been reported that lactate stimulates cell growth and acts as an accelerator driving the tricarboxylic acid (TCA) cycle (Roberto et al. 2002, Biotechnol Let 24:427–431; Matsuoka et al. 1996, Biosci Biotechnol Biochem 60:575–579). In this study, lactate supplementation increased DCW and the specific CoQ₁₀ content in A. tumefaciens culture, probably by accelerating TCA cycle and energy production as reported previously, leading to the increase of CoQ₁₀ production.     

Effect of dietary coenzyme Q and fatty acids on the antioxidant status of rat tissues

Summary.  Wistar rats were fed with different diets with or without supplement coenzyme Q₁₀ (CoQ₁₀) and with oil of different sources (sunflower or virgin olive oil) for six or twelve months. Ubiquinone contents (CoQ₉ and CoQ₁₀) were quantified in homogenates of livers and brains from rats fed with the four diets. In the brain, younger rats showed a 3-fold higher amount of ubiquinone than older ones for all diets. In the liver, however, CoQ₁₀ supplementation increased the amount of CoQ₉ and CoQ₁₀ in both total homogenates and plasma membranes. Rats fed with sunflower oil as fat source showed higher amounts of ubiquinone content than those fed with olive oil, in total liver homogenates, but the total ubiquinone content in plasma membranes was similar with both fat sources. Older rats showed a higher amount of ubiquinone after diets supplemented with CoQ₁₀. Two ubiquinone-dependent antioxidant enzyme activities were measured. NADH-ferricyanide reductase activity in hepatocyte plasma membranes was unaltered by ubiquinone accumulation, but this activity increased slightly with age. Both cytosolic and membrane-bound dicumarol-sensitive NAD(P)H:(quinone acceptor) oxidoreductase (DT-diaphorase, EC 1.6.99.2) activities were decreased by diets supplemented with CoQ₁₀. Animals fed with olive oil presented lower DT-diaphorase activity than those fed with sunflower oil, suggesting that the CoQ₁₀ antioxidant protection is strengthened by olive oil as fat source. Received May 22, 2002; accepted September 20, 2002; published online May 21, 2003 RID="*" ID="*" Correspondence and reprints: Departamento de Biología Celular, Fisiología e Inmunología, Universidad de Córdoba Edificio Severo Ochoa, Campus de Rabanales, 14071 Córdoba, Spain.     

Bioenergetic and Antioxidant Properties of Coenzyme Q<Subscript>10</Subscript>: Recent Developments

For a number of years, coenzyme Q (CoQ₁₀ in humans) was known for its key role in mitochondrial bioenergetics; later studies demonstrated its presence in other subcellular fractions and in plasma, and extensively investigated its antioxidant role. These two functions constitute the basis on which research supporting the clinical use of CoQ₁₀ is founded. Also at the inner mitochondrial membrane level, coenzyme Q is recognized as an obligatory co-factor for the function of uncoupling proteins and a modulator of the transition pore. Furthermore, recent data reveal that CoQ₁₀ affects expression of genes involved in human cell signalling, metabolism, and transport and some of the effects of exogenously administered CoQ₁₀ may be due to this property. Coenzyme Q is the only lipid soluble antioxidant synthesized endogenously. In its reduced form, CoQH₂, ubiquinol, inhibits protein and DNA oxidation but it is the effect on lipid peroxidation that has been most deeply studied. Ubiquinol inhibits the peroxidation of cell membrane lipids and also that of lipoprotein lipids present in the circulation. Dietary supplementation with CoQ₁₀ results in increased levels of ubiquinol-10 within circulating lipoproteins and increased resistance of human low-density lipoproteins to the initiation of lipid peroxidation. Moreover, CoQ₁₀ has a direct anti-atherogenic effect, which has been demonstrated in apolipoprotein E-deficient mice fed with a high-fat diet. In this model, supplementation with CoQ₁₀ at pharmacological doses was capable of decreasing the absolute concentration of lipid hydroperoxides in atherosclerotic lesions and of minimizing the size of atherosclerotic lesions in the whole aorta. Whether these protective effects are only due to the antioxidant properties of coenzyme Q remains to be established; recent data point out that CoQ₁₀ could have a direct effect on endothelial function. In patients with stable moderate CHF, oral CoQ₁₀ supplementation was shown to ameliorate cardiac contractility and endothelial dysfunction. Recent data from our laboratory showed a strong correlation between endothelium bound extra cellular SOD (ecSOD) and flow-dependent endothelial-mediated dilation, a functional parameter commonly used as a biomarker of vascular function. The study also highlighted that supplementation with CoQ₁₀ that significantly affects endothelium-bound ecSOD activity. Furthermore, we showed a significant correlation between increase in endothelial bound ecSOD activity and improvement in FMD after CoQ₁₀ supplementation. The effect was more pronounced in patients with low basal values of ecSOD. Finally, we summarize the findings, also from our laboratory, on the implications of CoQ₁₀ in seminal fluid integrity and sperm cell motility.     

Effects of dietary L-carnitine and coenzyme Q10 at different supplemental ages on growth performance and some immune response in ascites-susceptible broilers

Abstract

Effects of dietary L-carnitine and coenzyme Q₁₀ (CoQ₁₀) at different supplemental ages on performance and some immune response were investigated in ascites-susceptible broilers. A 3 × 2 × 2 factorial design was used consisting of L-carnitine supplementation (0, 75, and 100 mg/kg), CoQ₁₀ supplementation (0 and 40 mg/kg) and different supplemental ages (from day 1 on and from day 10 on). A total of 480 one-day-old Arbor Acre male broiler chicks were randomly allocated to 12 groups, every group had five replicates, each with eight birds. The birds were fed a corn-soybean based diet for six weeks. From day 10 – 21, all the birds were exposed to a low ambient temperature (12 – 15°C) to increase the susceptibility to ascites. No significant effects were observed on growth performance by L-carnitine, CoQ₁₀ supplementation, and different supplemental ages. Packed cell volume was significantly decreased by L-carnitine supplementation alone, and ascites heart index and ascites mortality were decreased by L-carnitine, CoQ₁₀ supplementation alone, and L-carnitine + CoQ₁₀ supplementation together (p < 0.05). Heart index of broilers was significantly improved by L-carnitine, CoQ₁₀ supplementation alone during 0 – 3 week. Serum IgG content was improved by L-carnitine supplementation alone (p < 0.05), but lysozyme activity was increased by L-carnitine + CoQ₁₀ supplementation together (p < 0.05). A significant L-carnitine by supplemental age interaction was observed in lysozyme activity. L-carnitine supplementation alone had no effects on the peripheral blood lymphocyte (PBL) proliferation in response to concanavalin A (ConA) and lipopolysaccharide, but supplemental CoQ₁₀ alone and L-carnitine + CoQ₁₀ together decreased the PBL proliferation in response to ConA (p < 0.05). The present study suggested that L-carnitine + CoQ₁₀ supplementation together had positive effects on some immune response of ascites-susceptible broilers, which might benefit for the reduction of broilers' susceptibility to ascites.     

Ca<Superscript>2+</Superscript> increases the specific coenzyme Q<Subscript>10</Subscript> content in <Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>

Of various metal ions (Ca²⁺, Cr³⁺, Cu²⁺, Fe²⁺, Mg²⁺, Mn²⁺, Ni²⁺ and Zn²⁺) added to the culture medium of Agrobacterium tumefaciens at 1 mM, only Ca²⁺ increased Coenzyme Q10 (CoQ₁₀) content in cells without the inhibition of cell growth. In a pH-stat fed-batch culture, supplementation with 40 mM of CaCO₃ increased the specific CoQ₁₀ content and oxidative stress by 22.4 and 48%, respectively. Also, the effect of Ca²⁺ on the increase of CoQ₁₀ content was successfully verified in a pilot-scale (300 L) fermentor. In this study, the increased oxidative stress in A. tumefaciens culture by the supplementation of Ca²⁺ is hypothesized to stimulate the increase of specific CoQ₁₀ content in order to protect the membrane against lipid peroxidation. Our results improve the understanding of Ca²⁺ effect on CoQ₁₀ biosynthesis in A. tumefaciens and should contribute to better industrial production of CoQ₁₀ by biological processes.     

A water soluble CoQ10 formulation improves intracellular distribution and promotes mitochondrial respiration in cultured cells

Background

Mitochondria are both the cellular powerhouse and the major source of reactive oxygen species. Coenzyme Q₁₀ plays a key role in mitochondrial energy production and is recognized as a powerful antioxidant. For these reasons it can be argued that higher mitochondrial ubiquinone levels may enhance the energy state and protect from oxidative stress. Despite the large number of clinical studies on the effect of CoQ₁₀ supplementation, there are very few experimental data about the mitochondrial ubiquinone content and the cellular bioenergetic state after supplementation. Controversial clinical and in vitro results are mainly due to the high hydrophobicity of this compound, which reduces its bioavailability.

Principal Findings

We measured the cellular and mitochondrial ubiquinone content in two cell lines (T67 and H9c2) after supplementation with a hydrophilic CoQ₁₀ formulation (Qter®) and native CoQ₁₀. Our results show that the water soluble formulation is more efficient in increasing ubiquinone levels. We have evaluated the bioenergetics effect of ubiquinone treatment, demonstrating that intracellular CoQ₁₀ content after Qter supplementation positively correlates with an improved mitochondrial functionality (increased oxygen consumption rate, transmembrane potential, ATP synthesis) and resistance to oxidative stress.

Conclusions

The improved cellular energy metabolism related to increased CoQ₁₀ content represents a strong rationale for the clinical use of coenzyme Q₁₀ and highlights the biological effects of Qter®, that make it the eligible CoQ₁₀ formulation for the ubiquinone supplementation.     

Treatment of CoQ10 Deficient Fibroblasts with Ubiquinone,CoQ Analogs,and Vitamin C: Time- and Compound-Dependent Effects

Background

Coenzyme Q₁₀ (CoQ₁₀) and its analogs are used therapeutically by virtue of their functions as electron carriers, antioxidant compounds, or both. However, published studies suggest that different ubiquinone analogs may produce divergent effects on oxidative phosphorylation and oxidative stress.

Methodology/Principal Findings

To test these concepts, we have evaluated the effects of CoQ₁₀, coenzyme Q₂ (CoQ₂), idebenone, and vitamin C on bioenergetics and oxidative stress in human skin fibroblasts with primary CoQ₁₀ deficiency. A final concentration of 5 µM of each compound was chosen to approximate the plasma concentration of CoQ₁₀ of patients treated with oral ubiquinone. CoQ₁₀ supplementation for one week but not for 24 hours doubled ATP levels and ATP/ADP ratio in CoQ₁₀ deficient fibroblasts therein normalizing the bioenergetics status of the cells. Other compounds did not affect cellular bioenergetics. In COQ2 mutant fibroblasts, increased superoxide anion production and oxidative stress-induced cell death were normalized by all supplements.

Conclusions/Significance

These results indicate that: 1) pharmacokinetics of CoQ₁₀ in reaching the mitochondrial respiratory chain is delayed; 2) short-tail ubiquinone analogs cannot replace CoQ₁₀ in the mitochondrial respiratory chain under conditions of CoQ₁₀ deficiency; and 3) oxidative stress and cell death can be counteracted by administration of lipophilic or hydrophilic antioxidants. The results of our in vitro experiments suggest that primary CoQ₁₀ deficiencies should be treated with CoQ₁₀ supplementation but not with short-tail ubiquinone analogs, such as idebenone or CoQ₂. Complementary administration of antioxidants with high bioavailability should be considered if oxidative stress is present.     

Ubiquinol-10 ameliorates mitochondrial encephalopathy associated with CoQ deficiency

Coenzyme Q10 (CoQ₁₀) deficiency (MIM 607426) causes a mitochondrial syndrome with variability in the clinical presentations. Patients with CoQ₁₀ deficiency show inconsistent responses to oral ubiquinone-10 supplementation, with the highest percentage of unsuccessful results in patients with neurological symptoms (encephalopathy, cerebellar ataxia or multisystemic disease). Failure in the ubiquinone-10 treatment may be the result of its poor absorption and bioavailability, which may be improved by using different pharmacological formulations. In a mouse model (Coq9^X/X) of mitochondrial encephalopathy due to CoQ deficiency, we have evaluated oral supplementation with water-soluble formulations of reduced (ubiquinol-10) and oxidized (ubiquinone-10) forms of CoQ₁₀. Our results show that CoQ₁₀ was increased in all tissues after supplementation with ubiquinone-10 or ubiquinol-10, with the tissue levels of CoQ₁₀ with ubiquinol-10 being higher than with ubiquinone-10. Moreover, only ubiquinol-10 was able to increase the levels of CoQ₁₀ in mitochondria from cerebrum of Coq9^X/X mice. Consequently, ubiquinol-10 was more efficient than ubiquinone-10 in increasing the animal body weight and CoQ-dependent respiratory chain complex activities, and reducing the vacuolization, astrogliosis and oxidative damage in diencephalon, septum–striatum and, to a lesser extent, in brainstem. These results suggest that water-soluble formulations of ubiquinol-10 may improve the efficacy of CoQ₁₀ therapy in primary and secondary CoQ₁₀ deficiencies, other mitochondrial diseases and neurodegenerative diseases.     

Effect of vanillic acid on COQ6 mutants identified in patients with coenzyme Q10 deficiency

Human COQ6 encodes a monooxygenase which is responsible for the C5-hydroxylation of the quinone ring of coenzyme Q (CoQ). Mutations in COQ6 cause primary CoQ deficiency, a condition responsive to oral CoQ₁₀ supplementation. Treatment is however still problematic given the poor bioavailability of CoQ10. We employed S. cerevisiae lacking the orthologous gene to characterize the two different human COQ6 isoforms and the mutations found in patients. COQ6 isoform a can partially complement the defective yeast, while isoform b, which lacks part of the FAD-binding domain, is inactive but partially stable, and could have a regulatory/inhibitory function in CoQ₁₀ biosynthesis. Most mutations identified in patients, including the frameshift Q461fs478X mutation, retain residual enzymatic activity, and all patients carry at least one hypomorphic allele, confirming that the complete block of CoQ biosynthesis is lethal. These mutants are also partially stable and allow the assembly of the CoQ biosynthetic complex. In fact treatment with two hydroxylated analogues of 4-hydroxybenzoic acid, namely, vanillic acid or 3-4-hydroxybenzoic acid, restored the respiratory growth of yeast Δcoq6 cells expressing the mutant huCOQ6-isoa proteins. These compounds, and particularly vanillic acid, could therefore represent an interesting therapeutic option for COQ6 patients.     

IDENTIFICATION OF COENZYME Q10 FROM PORPHYRIDIUM PURPUREUM (RHODOPHYTA) BY MATRIX‐ASSISTED LASER DESORPTION IONIZATION CURVED FIELD REFLECTRON MASS SPECTROMETRY1

Antioxidant agents from natural sources are currently the focus of scientific interest and are part of several natural product screenings. Coenzymes Q (CoQ, ubiquinones) are integral parts of the electron transport chain of the inner mitochondrial membrane. As antioxidants they protect phospholipids against peroxidation and are also involved in various processes of tissue protection. Their natural occurrence was validated for Saccharomyces cerevisiae as CoQ₆, for Escherichia coli as CoQ₈, and for humans as CoQ₁₀. After carrying out a preparative reversed‐phase (RP)–HPLC separation of extracts isolated from unicellular red alga Porphyridium purpureum (Bory) K. M. Drew et R. Ross, it was possible to identify a 2,3‐dimethoxy‐5‐methyl‐6‐decaprenyl‐1,4‐benzoquinone (CoQ₁₀) within these extracts using a matrix‐assisted laser desorption ionization (MALDI) curved field reflectron (CFR) mass spectrometer. Detected mass fragments showed a high significance and could be structurally interpreted for both commercialized standard and CoQ₁₀ isolated from P. purpureum.     

Increasing coenzyme Q10 yield from Rhodopseudomonas palustris by expressing rate-limiting enzymes and blocking carotenoid and hopanoid pathways

Coenzyme Q₁₀ (CoQ₁₀), a strong antioxidant, is used extensively in food, cosmetic and medicine industries. A natural producer, Rhodopseudomonas palustris, was engineered to overproduce CoQ₁₀. For increasing the CoQ₁₀ content, crtB gene was deleted to block the carotenoid pathway. crtB gene deletion led to 33% improvement of CoQ₁₀ content over the wild type strain. However, it was found that the yield of hopanoids was also increased by competing for the precursors from carotenoid pathway with CoQ₁₀ pathway. To further increase the CoQ₁₀ content, hopanoid pathway was blocked by deleting shc gene, resulting in R. palustris [Δshc, ΔcrtB] to produce 4·7 mg g⁻¹ DCW CoQ₁₀, which was 1·2 times higher than the CoQ₁₀ content in the wild type strain. The common strategy of co-expression of rate-limiting enzymes (DXS, DPS and UbiA) was combined with the pathway blocking method resulted in 8·2 mg g⁻¹ DCW of CoQ₁₀, which was 2·9 times higher than that of wild type strain. The results suggested a synergistic effect among different metabolic engineering strategies. This study demonstrates the potential of R. palustris for CoQ₁₀ production and provides viable strategies to increase CoQ₁₀ titer.     

Preparation and characterization of novel coenzyme Q<Subscript>10</Subscript> nanoparticles engineered from microemulsion precursors

The purpose of these studies was to prepare and characterize nanoparticles into which Coenzyme Q₁₀ (CoQ₁₀) had been incorporated (CoQ₁₀-NPs) using a simple and potentially scalable method. CoQ₁₀-NPs were prepared by cooling warm microemulsion precursors composed of emulsifying wax, CoQ₁₀, Brij 78, and/or Tween 20. The nanoparticles were lyophilized, and the stability of CoQ₁₀-NPs in both lyophilized form and aqueous suspension was monitored over 7 days. The release of CoQ₁₀ from the nanoparticles was investigated at 37°C. Finally, an in vitro study of the uptake of CoQ₁₀-NPs by mouse macrophage, J774A.1, was completed. The incorporation efficiency of CoQ₁₀ was approximately 74%±5%. Differential Scanning Calorimetry (DSC) showed that the nanoparticle was not a physical mixture of its individual components. The size of the nanoparticles increased over time if stored in aqueous suspension. However, enhanced stability was observed when the nanoparticles were stored at 4°C. Storage in lyophilized form demonstrated the highest stability. The in vitro release profile of CoQ₁₀ from the nanoparticles showed an initial period of rapid release in the first 9 hours followed by a period of slower and extended release. The uptake of CoQ₁₀-NPs by the J774A.1 cells was over 4-fold higher than that of the CoQ₁₀-free nanoparticles (P<.05). In conclusion, CoQ₁₀-NPs with potential application for oral CoQ₁₀ delivery were engineered readily from microemulsion precursors.     

Oxidative stress correlates with headache symptoms in fibromyalgia: coenzyme Q₁₀ effect on clinical improvement

Background

Fibromyalgia (FM) is a chronic pain syndrome with unknown etiology and a wide spectrum of symptoms such as allodynia, debilitating fatigue, joint stiffness and migraine. Recent studies have shown some evidences demonstrating that oxidative stress is associated to clinical symptoms in FM of fibromyalgia. We examined oxidative stress and bioenergetic status in blood mononuclear cells (BMCs) and its association to headache symptoms in FM patients. The effects of oral coenzyme Q₁₀ (CoQ₁₀) supplementation on biochemical markers and clinical improvement were also evaluated.

Methods

We studied 20 FM patients and 15 healthy controls. Clinical parameters were evaluated using the Fibromyalgia Impact Questionnaire (FIQ), visual analogues scales (VAS), and the Headache Impact Test (HIT-6). Oxidative stress was determined by measuring CoQ₁₀, catalase and lipid peroxidation (LPO) levels in BMCs. Bioenergetic status was assessed by measuring ATP levels in BMCs.

Results

We found decreased CoQ₁₀, catalase and ATP levels in BMCs from FM patients as compared to normal control (P<0.05 and P<0.001, respectively) We also found increased level of LPO in BMCs from FM patients as compared to normal control (P<0.001). Significant negative correlations between CoQ₁₀ or catalase levels in BMCs and headache parameters were observed (r = −0.59, P<0.05; r = −0.68, P<0.05, respectively). Furthermore, LPO levels showed a significant positive correlation with HIT-6 (r = 0.33, P<0.05). Oral CoQ₁₀ supplementation restored biochemical parameters and induced a significant improvement in clinical and headache symptoms (P<0.001).

Discussion

The results of this study suggest a role for mitochondrial dysfunction and oxidative stress in the headache symptoms associated with FM. CoQ10 supplementation should be examined in a larger placebo controlled trial as a possible treatment in FM.     

CoQ10 supplementation rescues nephrotic syndrome through normalization of H2S oxidation pathway

Nephrotic syndrome (NS), a frequent chronic kidney disease in children and young adults, is the most common phenotype associated with primary coenzyme Q₁₀ (CoQ₁₀) deficiency and is very responsive to CoQ₁₀ supplementation, although the pathomechanism is not clear. Here, using a mouse model of CoQ deficiency-associated NS, we show that long-term oral CoQ₁₀ supplementation prevents kidney failure by rescuing defects of sulfides oxidation and ameliorating oxidative stress, despite only incomplete normalization of kidney CoQ levels and lack of rescue of CoQ-dependent respiratory enzymes activities. Liver and kidney lipidomics, and urine metabolomics analyses, did not show CoQ metabolites. To further demonstrate that sulfides metabolism defects cause oxidative stress in CoQ deficiency, we show that silencing of sulfide quinone oxido-reductase (SQOR) in wild-type HeLa cells leads to similar increases of reactive oxygen species (ROS) observed in HeLa cells depleted of the CoQ biosynthesis regulatory protein COQ8A. While CoQ₁₀ supplementation of COQ8A depleted cells decreases ROS and increases SQOR protein levels, knock-down of SQOR prevents CoQ₁₀ antioxidant effects. We conclude that kidney failure in CoQ deficiency-associated NS is caused by oxidative stress mediated by impaired sulfides oxidation and propose that CoQ supplementation does not significantly increase the kidney pool of CoQ bound to the respiratory supercomplexes, but rather enhances the free pool of CoQ, which stabilizes SQOR protein levels rescuing oxidative stress.     

Intracellular cholesterol accumulation and coenzyme Q10 deficiency in Familial Hypercholesterolemia

Familial Hypercholesterolemia (FH) is an autosomal co-dominant genetic disorder characterized by elevated low-density lipoprotein (LDL) cholesterol levels and increased risk for premature cardiovascular disease. Here, we examined FH pathophysiology in skin fibroblasts derived from FH patients harboring heterozygous mutations in the LDL-receptor.Fibroblasts from FH patients showed a reduced LDL-uptake associated with increased intracellular cholesterol levels and coenzyme Q₁₀ (CoQ₁₀) deficiency, suggesting dysregulation of the mevalonate pathway.Secondary CoQ₁₀ deficiency was associated with mitochondrial depolarization and mitophagy activation in FH fibroblasts. Persistent mitophagy altered autophagy flux and induced inflammasome activation accompanied by increased production of cytokines by mutant cells. All the pathological alterations in FH fibroblasts were also reproduced in a human endothelial cell line by LDL-receptor gene silencing.Both increased intracellular cholesterol and mitochondrial dysfunction in FH fibroblasts were partially restored by CoQ₁₀ supplementation. Dysregulated mevalonate pathway in FH, including increased expression of cholesterogenic enzymes and decreased expression of CoQ₁₀ biosynthetic enzymes, was also corrected by CoQ₁₀ treatment.Reduced CoQ₁₀ content and mitochondrial dysfunction may play an important role in the pathophysiology of early atherosclerosis in FH. The diagnosis of CoQ₁₀ deficiency and mitochondrial impairment in FH patients may also be important to establish early treatment with CoQ₁₀.     

Optimization of culture conditions and scale-up to pilot and plant scales for coenzyme Q<Subscript>10</Subscript> production by <Emphasis Type="Italic">Agrobacterium tumefaciens</Emphasis>

This report describes the optimization of culture conditions for coenzyme Q₁₀ (CoQ₁₀) production by Agrobacterium tumefaciens KCCM 10413, an identified high-CoQ₁₀-producing strain (Kim et al., Korean patent. 10-0458818, 2002b). Among the conditions tested, the pH and the dissolved oxygen (DO) levels were the key factors affecting CoQ₁₀ production. When the pH and DO levels were controlled at 7.0 and 0–10%, respectively, a dry cell weight (DCW) of 48.4 g l⁻¹ and a CoQ₁₀ production of 320 mg l⁻¹ were obtained after 96 h of batch culture, corresponding to a specific CoQ₁₀ content of 6.61 mg g-DCW⁻¹. In a fed-batch culture of sucrose, the DCW, specific CoQ₁₀ content, and CoQ₁₀ production increased to 53.6 g l⁻¹, 8.54 mg g-DCW⁻¹, and 458 mg l⁻¹, respectively. CoQ₁₀ production was scaled up from a laboratory scale (5-l fermentor) to a pilot scale (300 l) and a plant scale (5,000 l) using the impeller tip velocity (V _tip) as a scale-up parameter. CoQ₁₀ production at the laboratory scale was similar to those at the pilot and plant scales. This is the first report of pilot- and plant-scale productions of CoQ₁₀ in A. tumefaciens.     

Update on the application of magnetic fields to microalgal cultures

Coenzyme Q₁₀ (CoQ₁₀) is the main CoQ species in human and is used extensively in food, cosmetic and medicine industries because of its antioxidant properties and its benefit in prophylactic medicine and therapy for a variety of diseases. Among various approaches to increase the production of CoQ₁₀, microbial fermentation is the most effective. As knowledge of the biosynthetic enzymes and regulatory mechanisms modulating CoQ₁₀ production increases, opportunities arise for metabolic engineering of CoQ₁₀ in microbial hosts. In this review, we present various strategies used up to date to improve CoQ₁₀ production and focus on metabolic engineering of CoQ₁₀ overproduction in microbes. General strategies of metabolic engineering include providing sufficient precursors for CoQ₁₀, increasing metabolic fluxes, and expanding storage capacity for CoQ₁₀. Based on these strategies, CoQ₁₀ production has been significantly improved in natural CoQ₁₀ producers, as well as in heterologous hosts.

     

Pediatric reference intervals for muscle coenzyme Q10

Coenzyme Q₁₀ (CoQ₁₀) is present in humans in both the reduced (ubiquinol, CoQ₁₀H₂) and oxidized (ubiquinone, CoQ₁₀) forms. CoQ₁₀ is an essential cofactor in mitochondrial oxidative phosphorylation, and is necessary for ATP production. Total, reduced and oxidized CoQ₁₀ levels in skeletal muscle of 148 children were determined by HPLC coupled with electrochemical detection, and we established three level thresholds for total CoQ₁₀ in muscle. We defined as “severe deficiency”, CoQ₁₀ levels falling in the range between 0.82 and 4.88 μmol/g tissue; as “intermediate deficiency”, those ranging between 5.40 and 9.80 μmol/g tissue, and as “mild deficiency”, the amount of CoQ₁₀ included between 10.21 and 19.10 μmol/g tissue. Early identification of CoQ₁₀ deficiency has important implications in children, not only for those with primary CoQ₁₀ defect, but also for patients with neurodegenerative disorders, in order to encourage earlier supplementation with this agent also in mild and intermediate deficiency.