Project description:Coenzyme Q10 deficiency is a clinically and genetically heterogeneous disorder, with manifestations that may range from fatal neonatal multisystem failure, to adult-onset encephalopathy. We report a patient who presented at birth with severe lactic acidosis, proteinuria, dicarboxylic aciduria, and hepatic insufficiency. She also had dilation of left ventricle on echocardiography. Her neurological condition rapidly worsened and despite aggressive care she died at 23 h of life. Muscle histology displayed lipid accumulation. Electron microscopy showed markedly swollen mitochondria with fragmented cristae. Respiratory-chain enzymatic assays showed a reduction of combined activities of complex I+III and II+III with normal activities of isolated complexes. The defect was confirmed in fibroblasts, where it could be rescued by supplementing the culture medium with 10 μM coenzyme Q10. Coenzyme Q10 levels were reduced (28% of controls) in these cells. We performed exome sequencing and focused the analysis on genes involved in coenzyme Q10 biosynthesis. The patient harbored a homozygous c.545T>G, p.(Met182Arg) alteration in COQ2, which was validated by functional complementation in yeast. In this case the biochemical and morphological features were essential to direct the genetic diagnosis. The parents had another pregnancy after the biochemical diagnosis was established, but before the identification of the genetic defect. Because of the potentially high recurrence risk, and given the importance of early CoQ10 supplementation, we decided to treat with CoQ10 the newborn child pending the results of the biochemical assays. Clinicians should consider a similar management in siblings of patients with CoQ10 deficiency without a genetic diagnosis.
Project description:For a number of years, coenzyme Q10 (CoQ10) was known for its key role in mitochondrial bioenergetics; later studies demonstrated its presence in other subcellular fractions and in blood plasma, and extensively investigated its antioxidant role. These 2 functions constitute the basis for supporting the clinical use of CoQ10. Also, at the inner mitochondrial membrane level, CoQ10 is recognized as an obligatory cofactor for the function of uncoupling proteins and a modulator of the mitochondrial transition pore. Furthermore, recent data indicate that CoQ10 affects the expression of genes involved in human cell signaling, metabolism and transport, and some of the effects of CoQ10 supplementation may be due to this property. CoQ10 deficiencies are due to autosomal recessive mutations, mitochondrial diseases, aging-related oxidative stress and carcinogenesis processes, and also statin treatment. Many neurodegenerative disorders, diabetes, cancer, and muscular and cardiovascular diseases have been associated with low CoQ10 levels as well as different ataxias and encephalomyopathies. CoQ10 treatment does not cause serious adverse effects in humans and new formulations have been developed that increase CoQ10 absorption and tissue distribution. Oral administration of CoQ10 is a frequent antioxidant strategy in many diseases that may provide a significant symptomatic benefit.
Project description:Ubiquinone (coenzyme Q(10) or CoQ(10)) is a lipid-soluble component of virtually all cell membranes and has multiple metabolic functions. Deficiency of CoQ(10) (MIM 607426) has been associated with five different clinical presentations that suggest genetic heterogeneity, which may be related to the multiple steps in CoQ(10) biosynthesis. Patients with all forms of CoQ(10) deficiency have shown clinical improvements after initiating oral CoQ(10) supplementation. Thus, early diagnosis is of critical importance in the management of these patients. This year, the first molecular defect causing the infantile form of primary human CoQ(10) deficiency has been reported. The availability of genetic testing will allow for a better understanding of the pathogenesis of this disease and early initiation of therapy (even presymptomatically in siblings of patients) in this otherwise life-threatening infantile encephalomyopathy.
Project description:BackgroundCoenzyme Q10 (CoQ10) is essential for mitochondrial energy production and serves as an antioxidants in extra mitochondrial membranes. The genetics of primary CoQ10 deficiency has been described in several studies, whereas the influence of common genetic variants on CoQ10 status is largely unknown. Here we tested for non-synonymous single-nucleotidepolymorphisms (SNP) in genes involved in the biosynthesis (CoQ3G272S , CoQ6M406V, CoQ7M103T), reduction (NQO1P187S, NQO2L47F) and metabolism (apoE3/4) of CoQ10 and their association with CoQ10 status. For this purpose, CoQ10 serum levels of 54 healthy male volunteers were determined before (T0) and after a 14 days supplementation (T14) with 150 mg/d of the reduced form of CoQ10.FindingsAt T0, the CoQ10 level of heterozygous NQO1P187S carriers were significantly lower than homozygous S/S carriers (0.93 ± 0.25 μM versus 1.34 ± 0.42 μM, p = 0.044). For this polymorphism a structure homology-based method (PolyPhen) revealed a possibly damaging effect on NQO1 protein activity. Furthermore, CoQ10 plasma levels were significantly increased in apoE4/E4 genotype after supplementation in comparison to apoE2/E3 genotype (5.93 ± 0.151 μM versus 4.38 ± 0.792 μM, p = 0.034). Likewise heterozygous CoQ3G272S carriers had higher CoQ10 plasma levels at T14 compared to G/G carriers but this difference did not reach significance (5.30 ± 0.96 μM versus 4.42 ± 1.67 μM, p = 0.082).ConclusionsIn conclusion, our pilot study provides evidence that NQO1P187S and apoE polymorphisms influence CoQ10 status in humans.
Project description:OBJECTIVES:The goal of this investigation was to determine if acute influenza infection is associated with depletion of CoQ10 compared to healthy controls and to determine any associations between CoQ10 levels and illness severity and inflammatory biomarkers. PATIENTS AND METHODS:We analyzed serum CoQ10 concentrations of patients with acute influenza enrolled in a randomized clinical trial prior to study drug administration. Patients were enrolled at a single urban tertiary care center over 3 influenza seasons (December 27, 2013 to March 31, 2016). Wilcoxon rank sum test was used to compare CoQ10 levels between influenza patients and healthy controls. Correlations with inflammatory biomarkers and severity of illness were assessed using Spearman correlation coefficient. RESULTS:We analyzed CoQ10 levels from 50 patients with influenza and 29 controls. Overall, patients with acute influenza had lower levels of CoQ10 (.53 ?g/mL, IQR .37-.75 vs .72, IQR .58-.90, P = .004). Significantly more patients in the influenza group had low CoQ10 levels (<.5 ?g/mL) compared to controls (48% vs 7%, P < .001). Among influenza patients, there were significant but weak correlations between CoQ10 levels and IL-2 (r = -.30, P = .04), TNF-alpha (r = -.35, P = .01) and VEGF (r = .38, P = .007), but no correlation with IL-6, IL-10, VCAM or influenza severity of illness score (all P > .05). CONCLUSIONS:We found that CoQ10 levels were significantly lower in patients with acute influenza infection and that these levels had significant although weak correlations with several inflammatory biomarkers.
Project description:Coenzyme Q10 (CoQ10) is an essential cofactor in the mitochondrial respiratory chain, and as a dietary supplement it has recently gained attention for its potential role in the treatment of neurodegenerative disease. Evidence for mitochondrial dysfunction in neurodegenerative disorders derives from animal models, studies of mitochondria from patients, identification of genetic defects in patients with neurodegenerative disease, and measurements of markers of oxidative stress. Studies of in vitro models of neuronal toxicity and animal models of neurodegenerative disorders have demonstrated potential neuroprotective effects of CoQ10. With this data in mind, several clinical trials of CoQ10 have been performed in Parkinson's disease and atypical Parkinson's syndromes, Huntington's disease, Alzheimer disease, Friedreich's ataxia, and amyotrophic lateral sclerosis, with equivocal findings. CoQ10 is widely available in multiple formulations and is very well tolerated with minimal adverse effects, making it an attractive potential therapy. Phase III trials of high-dose CoQ10 in large sample sizes are needed to further ascertain the effects of CoQ10 in neurodegenerative diseases.
Project description:The human syndrome of coenzyme Q (CoQ) deficiency is a heterogeneous mitochondrial disease characterized by a diminution of CoQ content in cells and tissues that affects all the electron transport processes CoQ is responsible for, like the electron transference in mitochondria for respiration and ATP production and the antioxidant capacity that it exerts in membranes and lipoproteins. Supplementation with external CoQ is the main attempt to address these pathologies, but quite variable results have been obtained ranging from little response to a dramatic recovery. Here, we present the importance of modeling human CoQ deficiencies in animal models to understand the genetics and the pathology of this disease, although the election of an organism is crucial and can sometimes be controversial. Bacteria and yeast harboring mutations that lead to CoQ deficiency are unable to grow if they have to respire but develop without any problems on media with fermentable carbon sources. The complete lack of CoQ in mammals causes embryonic lethality, whereas other mutations produce tissue-specific diseases as in humans. However, working with transgenic mammals is time and cost intensive, with no assurance of obtaining results. Caenorhabditis elegans and Drosophila melanogaster have been used for years as organisms to study embryonic development, biogenesis, degenerative pathologies, and aging because of the genetic facilities and the speed of working with these animal models. In this review, we summarize several attempts to model reliable human CoQ deficiencies in invertebrates, focusing on mutant phenotypes pretty similar to those observed in human patients.
Project description:Coenzyme Q (CoQ) is an essential component of the respiratory chain but also participates in other mitochondrial functions such as regulation of the transition pore and uncoupling proteins. Furthermore, this compound is a specific substrate for enzymes of the fatty acids beta-oxidation pathway and pyrimidine nucleotide biosynthesis. Furthermore, CoQ is an antioxidant that acts in all cellular membranes and lipoproteins. A complex of at least ten nuclear (COQ) genes encoded proteins synthesizes CoQ but its regulation is unknown. Since 1989, a growing number of patients with multisystemic mitochondrial disorders and neuromuscular disorders showing deficiencies of CoQ have been identified. CoQ deficiency caused by mutation(s) in any of the COQ genes is designated primary deficiency. Other patients have displayed other genetic defects independent on the CoQ biosynthesis pathway, and are considered to have secondary deficiencies. This review updates the clinical and molecular aspects of both types of CoQ deficiencies and proposes new approaches to understanding their molecular bases.
Project description:Our present study reveals significant decelerating effects on senescence processes in middle-aged SAMP1 mice supplemented for 6 or 14 months with the reduced form (QH2, 500 mg/ kg BW/ day) of coenzyme Q10 (CoQ10). To unravel molecular mechanisms of these CoQ10 effects, a genome-wide transcript profiling in liver, heart, brain and kidney of SAMP1 mice supplemented with the reduced (QH2) or oxidized form of CoQ10 (Q10) was performed. Liver seems to be the main target tissue of CoQ10 intervention, followed by kidney, heart and brain. Stringent evaluation of the resulting data revealed that QH2 has a stronger impact on gene expression than Q10, which was primarily due to differences in the bioavailability. Indeed, we found that QH2 supplementation was more effective than Q10 to increase levels of CoQ10 in the liver of SAMP1 mice (54.92-fold and 30.36-fold, respectively). To identify functional and regulatory connections of the “top 50” (p < 0.05) up- and down-regulated QH2-sensitive transcripts in liver (fold changes ranging from 21.24 to -6.12), text mining analysis (Genomatix BiblioSphere, GFG level B3) was used. Hereby, we identified 11 QH2-sensitive genes which are regulated by PPAR-α and are primarily involved in cholesterol synthesis (e.g. HMGCS1, HMGCL, HMGCR), fat assimilation (FABP5), lipoprotein metabolism (PLTP) and inflammation (STAT-1). Thus, we provide evidence that QH2 is involved in the reduction of fat and cholesterol synthesis via modulation of the PPAR-α signalling pathway. These data may explain, at least in part, the observed effects on decelerated age-dependent degeneration processes in QH2-supplemented SAMP1 mice.
Project description:Our present study reveals significant decelerating effects on senescence processes in middle-aged SAMP1 mice supplemented for 6 or 14 months with the reduced form (QH2, 500 mg/ kg BW/ day) of coenzyme Q10 (CoQ10). To unravel molecular mechanisms of these CoQ10 effects, a genome-wide transcript profiling in liver, heart, brain and kidney of SAMP1 mice supplemented with the reduced (QH2) or oxidized form of CoQ10 (Q10) was performed. Liver seems to be the main target tissue of CoQ10 intervention, followed by kidney, heart and brain. Stringent evaluation of the resulting data revealed that QH2 has a stronger impact on gene expression than Q10, which was primarily due to differences in the bioavailability. Indeed, we found that QH2 supplementation was more effective than Q10 to increase levels of CoQ10 in the liver of SAMP1 mice (54.92-fold and 30.36-fold, respectively). To identify functional and regulatory connections of the âtop 50â (p < 0.05) up- and down-regulated QH2-sensitive transcripts in liver (fold changes ranging from 21.24 to -6.12), text mining analysis (Genomatix BiblioSphere, GFG level B3) was used. Hereby, we identified 11 QH2-sensitive genes which are regulated by PPAR-α and are primarily involved in cholesterol synthesis (e.g. HMGCS1, HMGCL, HMGCR), fat assimilation (FABP5), lipoprotein metabolism (PLTP) and inflammation (STAT-1). Thus, we provide evidence that QH2 is involved in the reduction of fat and cholesterol synthesis via modulation of the PPAR-α signalling pathway. These data may explain, at least in part, the observed effects on decelerated age-dependent degeneration processes in QH2-supplemented SAMP1 mice. Whole genome expression profiles were analysed from liver, heart, brain and kidney (each analyzed separately) of SAMP1 mice supplemented with QH2, Q10 or a control diet. From every experimental group, three mice each were sacrificed 6 or 14 months after supplementation, resulting in a total of 72 microarrays.