1
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Sun L, Ren Y, Su B, Wang S, Zhong X, Jiang Y, Wang F. Glomerular basement membrane ultrastructural changes in a patient with COQ2 glomerulopathy: A case report. Nephrology (Carlton) 2024. [PMID: 38838054 DOI: 10.1111/nep.14329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/20/2024] [Accepted: 05/21/2024] [Indexed: 06/07/2024]
Abstract
Primary coenzyme Q10 deficiency-1, caused by COQ2 disease-causing variants, is an autosomal recessive disorder, and genetic testing is the gold standard for diagnosing this condition. A Chinese boy with steroid-resistant nephrotic syndrome, focal segmental glomerulosclerosis, and progressive kidney insufficiency was included in the study. Electron microscopy revealed the glomerular basement membrane with irregular thickness and lamellation with diffuse effacement of foot processes in the podocytes, and swollen mitochondria with abnormal cristae in the podocytes. Coenzyme Q10 supplementation started about 3 weeks after the onset of mild kidney dysfunction did not improve the proband's kidney outcome. Proband-only whole-exome sequencing and Sanger sequencing revealed two heteroallelic COQ2 variants: a maternally inherited novel variant c.1013G > A[p.(Gly338Glu)] in exon 6 and a variant of unknown origin c.1159C > T[p.(Arg387*)] in exon 7. Subsequent long-read sequencing demonstrated these two variants were located on different alleles. Our report extends the phenotypic and genotypic spectrum of COQ2 glomerulopathy.
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Affiliation(s)
- Liuyu Sun
- Department of Pediatrics, Peking University First Hospital, Beijing, People's Republic of China
| | - Yali Ren
- Department of Electron Microscopy, Peking University First Hospital, Beijing, People's Republic of China
| | - Baige Su
- Department of Pediatrics, Peking University First Hospital, Beijing, People's Republic of China
| | - Suxia Wang
- Department of Electron Microscopy, Peking University First Hospital, Beijing, People's Republic of China
| | - Xuhui Zhong
- Department of Pediatrics, Peking University First Hospital, Beijing, People's Republic of China
| | - Yuwu Jiang
- Department of Pediatrics, Peking University First Hospital, Beijing, People's Republic of China
| | - Fang Wang
- Department of Pediatrics, Peking University First Hospital, Beijing, People's Republic of China
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2
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Staiano C, García-Corzo L, Mantle D, Turton N, Millichap LE, Brea-Calvo G, Hargreaves I. Biosynthesis, Deficiency, and Supplementation of Coenzyme Q. Antioxidants (Basel) 2023; 12:1469. [PMID: 37508007 PMCID: PMC10375973 DOI: 10.3390/antiox12071469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/17/2023] [Accepted: 07/19/2023] [Indexed: 07/30/2023] Open
Abstract
Originally identified as a key component of the mitochondrial respiratory chain, Coenzyme Q (CoQ or CoQ10 for human tissues) has recently been revealed to be essential for many different redox processes, not only in the mitochondria, but elsewhere within other cellular membrane types. Cells rely on endogenous CoQ biosynthesis, and defects in this still-not-completely understood pathway result in primary CoQ deficiencies, a group of conditions biochemically characterised by decreased tissue CoQ levels, which in turn are linked to functional defects. Secondary CoQ deficiencies may result from a wide variety of cellular dysfunctions not directly linked to primary synthesis. In this article, we review the current knowledge on CoQ biosynthesis, the defects leading to diminished CoQ10 levels in human tissues and their associated clinical manifestations.
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Affiliation(s)
- Carmine Staiano
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - Laura García-Corzo
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | | | - Nadia Turton
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Merseyside L3 5UX, UK
| | - Lauren E Millichap
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Merseyside L3 5UX, UK
| | - Gloria Brea-Calvo
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA, 41013 Sevilla, Spain
- Centro de Investigación Biomédica en Red en Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, 28029 Madrid, Spain
- Departamento de Fisiología, Anatomía y Biología Celular, Universidad Pablo de Olavide, 41013 Sevilla, Spain
| | - Iain Hargreaves
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Merseyside L3 5UX, UK
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Wang S, Jain A, Novales NA, Nashner AN, Tran F, Clarke CF. Predicting and Understanding the Pathology of Single Nucleotide Variants in Human COQ Genes. Antioxidants (Basel) 2022; 11:antiox11122308. [PMID: 36552517 PMCID: PMC9774615 DOI: 10.3390/antiox11122308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 11/11/2022] [Accepted: 11/14/2022] [Indexed: 11/23/2022] Open
Abstract
Coenzyme Q (CoQ) is a vital lipid that functions as an electron carrier in the mitochondrial electron transport chain and as a membrane-soluble antioxidant. Deficiencies in CoQ lead to metabolic diseases with a wide range of clinical manifestations. There are currently few treatments that can slow or stop disease progression. Primary CoQ10 deficiency can arise from mutations in any of the COQ genes responsible for CoQ biosynthesis. While many mutations in these genes have been identified, the clinical significance of most of them remains unclear. Here we analyzed the structural and functional impact of 429 human missense single nucleotide variants (SNVs) that give rise to amino acid substitutions in the conserved and functional regions of human genes encoding a high molecular weight complex known as the CoQ synthome (or Complex Q), consisting of the COQ3-COQ7 and COQ9 gene products. Using structures of COQ polypeptides, close homologs, and AlphaFold models, we identified 115 SNVs that are potentially pathogenic. Further biochemical characterizations in model organisms such as Saccharomyces cerevisiae are required to validate the pathogenicity of the identified SNVs. Collectively, our results will provide a resource for clinicians during patient diagnosis and guide therapeutic efforts toward combating primary CoQ10 deficiency.
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Effects of CoQ10 Replacement Therapy on the Audiological Characteristics of Pediatric Patients with COQ6 Variants. BIOMED RESEARCH INTERNATIONAL 2022; 2022:5250254. [PMID: 36124066 PMCID: PMC9482153 DOI: 10.1155/2022/5250254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 08/17/2022] [Indexed: 11/21/2022]
Abstract
Primary coenzyme Q10 (CoQ10) deficiency refers to a group of mitochondrial cytopathies caused by genetic defects in CoQ10 biosynthesis. Primary coenzyme Q10 deficiency-6 (COQ10D6) is an autosomal recessive disorder attributable to biallelic COQ6 variants; the cardinal phenotypes are steroid-resistant nephrotic syndrome (SRNS), which inevitably progresses to kidney failure, and sensorineural hearing loss (SNHL). Here, we describe the phenotypes and genotypes of 12 children with COQ10D6 from 11 unrelated Korean families and quantitatively explore the beneficial effects of CoQ10 replacement therapy on SNHL. A diagnosis of SRNS generally precedes SNHL documentation. COQ10D6 is associated with progressive SNHL. Four causative COQ6 variants were identified in either homozygotes or compound heterozygotes: c.189_191delGAA, c.484C>T, c.686A>C, and c.782C>T. The response rate (no further hearing loss or improvement) was 42.9%; CoQ10 replacement therapy may thus limit and even improve hearing loss. Notably, the audiological benefit appeared to be genotype-specific, suggesting a genotype–phenotype correlation. The results of cochlear implantation were generally favorable, and the effects were sustained over time. Our results thus propose the beneficial effects of CoQ10 replacement therapy on hearing loss. Our work with COQ10D6 patients is a good example of personalized, genetically tailored, audiological rehabilitation of patients with syndromic deafness.
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Wang N, Zheng Y, Zhang L, Tian X, Fang Y, Qi M, Du J, Chen S, Chen S, Li J, Shen B, Wang L. A Family Segregating Lethal Primary Coenzyme Q10 Deficiency Due to Two Novel COQ6 Variants. Front Genet 2022; 12:811833. [PMID: 35111204 PMCID: PMC8802230 DOI: 10.3389/fgene.2021.811833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 12/06/2021] [Indexed: 01/28/2023] Open
Abstract
Primary coenzyme Q10 deficiency-6 (COQ10D6), as a rare autosomal recessive disease caused by COQ6 mutations, is characterized by progressive infantile-onset nephrotic syndrome resulting in end-stage renal failure and sensorineural hearing loss. Here, we report two Chinese siblings with COQ10D6 who primarily presented with severe metabolic acidosis, proteinuria, hypoalbuminemia, growth retardation, and muscle hypotonia and died in early infancy. Using whole-exome sequencing and Sanger sequencing, we identified two rare recessive nonsense mutations in the COQ6 gene segregating with disease in affected family members: c.249C > G (p.Tyr83Ter) and c.1381C > T (p.Gln461Ter), resulting in two truncated protein products. Both mutations are located in a highly conserved area and are predicted to be pathogenic. Indeed, the death of our patients in early infancy indicates the pathogenicity of the p.Tyr83Ter and p.Gln461Ter variants and highlights the significance of the two variants for COQ6 enzyme function, which is necessary for the biosynthesis of coenzyme Q10. In conclusion, we discovered a novel compound heterozygous pathogenic variant of the COQ6 gene as a cause of severe COQ10D6 in the two siblings. Based on the clinical history and genetic characteristics of the patients, our cases expand the genotypic spectrum of COQ10D6 and highlight the heterogeneity and severity of clinical features associated with COQ6 mutations. For patients with clinical manifestations suggestive of COQ10D6, early testing for COQ6 mutations is beneficial for disease diagnosis and therapeutic interventions as well as disease prevention in future generations.
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Affiliation(s)
- Na Wang
- Department of Clinical Laboratory, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
| | - Youmin Zheng
- Department of Pediatrics, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
| | - Lingzi Zhang
- Department of Pediatrics, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
| | - Xiong Tian
- Department of Public Research Platform, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
| | - Yicheng Fang
- Department of Radiology, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
| | - Ming Qi
- Sir Run Run Shaw Hospital Affiliated to Zhejiang University School of Medicine, Hangzhou, China
- DIAN Diagnostics, Hangzhou, China
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, United States
| | - Juping Du
- Department of Clinical Laboratory, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
| | - Shuaishuai Chen
- Department of Clinical Laboratory, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
| | - Shiyong Chen
- Department of Clinical Laboratory, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
| | - Jun Li
- Department of Clinical Laboratory, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
| | - Bo Shen
- Department of Clinical Laboratory, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
- *Correspondence: Bo Shen, ; Lizhen Wang,
| | - Lizhen Wang
- Department of Pediatrics, Taizhou Hospital of Zhejiang Province Affiliated to Wenzhou Medical University, Linhai, China
- *Correspondence: Bo Shen, ; Lizhen Wang,
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6
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Primary coenzyme Q10 nephropathy, a potentially treatable form of steroid-resistant nephrotic syndrome. Pediatr Nephrol 2021; 36:3515-3527. [PMID: 33479824 PMCID: PMC8295399 DOI: 10.1007/s00467-020-04914-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/28/2020] [Accepted: 12/31/2020] [Indexed: 12/18/2022]
Abstract
Steroid-resistant nephrotic syndrome (SRNS) is a genetically heterogeneous kidney disease that is the second most frequent cause of kidney failure in the first 2 decades of life. Despite the identification of mutations in more than 39 genes as causing SRNS, and the localization of its pathogenesis to glomerular podocytes, the disease mechanisms of SRNS remain poorly understood and no universally safe and effective therapy exists to treat patients with this condition. Recently, genetic research has identified a subgroup of SRNS patients whose kidney pathology is caused by primary coenzyme Q10 (CoQ10) deficiency due to recessive mutations in genes that encode proteins in the CoQ10 biosynthesis pathway. Clinical and preclinical studies show that primary CoQ10 deficiency may be responsive to treatment with CoQ10 supplements bypassing the biosynthesis defects. Coenzyme Q10 is an essential component of the mitochondrial respiratory chain, where it transports electrons from complexes I and II to complex III. Studies in yeast and mammalian model systems have recently identified the molecular functions of the individual CoQ10 biosynthesis complex proteins, validated these findings, and provided an impetus for developing therapeutic compounds to replenish CoQ10 levels in the tissues/organs and thus prevent the destruction of tissues due to mitochondrial OXPHOS deficiencies. In this review, we will summarize the clinical findings of the kidney pathophysiology of primary CoQ10 deficiencies and discuss recent advances in the development of therapies to counter CoQ10 deficiency in tissues.
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Cellular Models for Primary CoQ Deficiency Pathogenesis Study. Int J Mol Sci 2021; 22:ijms221910211. [PMID: 34638552 PMCID: PMC8508219 DOI: 10.3390/ijms221910211] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/17/2021] [Accepted: 09/18/2021] [Indexed: 02/07/2023] Open
Abstract
Primary coenzyme Q10 (CoQ) deficiency includes a heterogeneous group of mitochondrial diseases characterized by low mitochondrial levels of CoQ due to decreased endogenous biosynthesis rate. These diseases respond to CoQ treatment mainly at the early stages of the disease. The advances in the next generation sequencing (NGS) as whole-exome sequencing (WES) and whole-genome sequencing (WGS) have increased the discoveries of mutations in either gene already described to participate in CoQ biosynthesis or new genes also involved in this pathway. However, these technologies usually provide many mutations in genes whose pathogenic effect must be validated. To functionally validate the impact of gene variations in the disease’s onset and progression, different cell models are commonly used. We review here the use of yeast strains for functional complementation of human genes, dermal skin fibroblasts from patients as an excellent tool to demonstrate the biochemical and genetic mechanisms of these diseases and the development of human-induced pluripotent stem cells (hiPSCs) and iPSC-derived organoids for the study of the pathogenesis and treatment approaches.
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Li M, Yue Z, Lin H, Wang H, Chen H, Sun L. COQ2 mutation associated isolated nephropathy in two siblings from a Chinese pedigree. Ren Fail 2021; 43:97-101. [PMID: 33397173 PMCID: PMC7801106 DOI: 10.1080/0886022x.2020.1864402] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Backgroud Coenzyme Q10 (CoQ10) is involved in the biosynthesis of adenosine triphosphate (ATP), and is most abundant in the mitochondrial membrane. The primary CoQ10 deficiency caused by COQ2 defect is mostly manifested as encephalopathy, encephalopathy with nephropathy, and rarely as an isolated nephrotic syndrome. Methods Clinical and pathological data and peripheral blood samples of 2 siblings with steroid-resistant nephrotic syndrome (SRNS) and their family members of a Chinese pedigree were collected. DNA was extracted and subjected to next-generation sequencing of target genes of hereditary nephropathy. Results Compound heterozygous mutations of COQ2 (c.1058A > G, p.Y353C, paternal and c.973A > G, p.T325A, maternal)were identified in both siblings of the pedigree. Mutation of p.Y353C was novel. The proband was a girl, who presented with SRNS at the age of 7 months. CoQ10 was administered after the gene sequencing results came out. Proteinuria decreased gradually to 1+, occasionally negative. The child was normal in growth and intelligence. She is now 4 years old. The second patient was her elder brother. He was found to have SRNS at the age of 2 years old. Renal pathology indicated focal segmental glomerulosclerosis (FSGS). Electronic microcopy revealed that a large quantity of mitochondria with normal contour was accumulated within the podocytes. Both patients were in normal intelligence without convulsion. Conclusion The 2 cases harboring COQ2compound heterozygous mutations presented with isolated SRNS, with a renal pathology of FSGS and a large quantity of mitochondria with normal contour accumulated within the podocytes. CoQ10 was efficacy in eliminating proteinuria.
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Affiliation(s)
- Min Li
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Zhihui Yue
- Department of Pediatrics, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hongrong Lin
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Haiyan Wang
- Department of Pediatrics, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Huamu Chen
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Liangzhong Sun
- Department of Pediatrics, Nanfang Hospital, Southern Medical University, Guangzhou, China
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Alcázar-Fabra M, Rodríguez-Sánchez F, Trevisson E, Brea-Calvo G. Primary Coenzyme Q deficiencies: A literature review and online platform of clinical features to uncover genotype-phenotype correlations. Free Radic Biol Med 2021; 167:141-180. [PMID: 33677064 DOI: 10.1016/j.freeradbiomed.2021.02.046] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 02/13/2021] [Accepted: 02/26/2021] [Indexed: 12/13/2022]
Abstract
Primary Coenzyme Q (CoQ) deficiencies are clinically heterogeneous conditions and lack clear genotype-phenotype correlations, complicating diagnosis and prognostic assessment. Here we present a compilation of all the symptoms and patients with primary CoQ deficiency described in the literature so far and analyse the most common clinical manifestations associated with pathogenic variants identified in the different COQ genes. In addition, we identified new associations between the age of onset of symptoms and different pathogenic variants, which could help to a better diagnosis and guided treatment. To make these results useable for clinicians, we created an online platform (https://coenzymeQbiology.github.io/clinic-CoQ-deficiency) about clinical manifestations of primary CoQ deficiency that will be periodically updated to incorporate new information published in the literature. Since CoQ primary deficiency is a rare disease, the available data are still limited, but as new patients are added over time, this tool could become a key resource for a more efficient diagnosis of this pathology.
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Affiliation(s)
- María Alcázar-Fabra
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA and CIBERER, Instituto de Salud Carlos III, Seville, 41013, Spain
| | | | - Eva Trevisson
- Clinical Genetics Unit, Department of Women's and Children's Health, University of Padova, Padova, 35128, Italy; Istituto di Ricerca Pediatrica, Fondazione Città della Speranza, Padova, 35128, Italy.
| | - Gloria Brea-Calvo
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC-JA and CIBERER, Instituto de Salud Carlos III, Seville, 41013, Spain.
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Lee JM, Kronbichler A, Shin JI, Oh J. Current understandings in treating children with steroid-resistant nephrotic syndrome. Pediatr Nephrol 2021; 36:747-761. [PMID: 32086590 PMCID: PMC7910243 DOI: 10.1007/s00467-020-04476-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 12/22/2019] [Accepted: 01/07/2020] [Indexed: 12/27/2022]
Abstract
Steroid-resistant nephrotic syndrome (SRNS) remains a challenge for paediatric nephrologists. SRNS is viewed as a heterogeneous disease entity including immune-based and monogenic aetiologies. Because SRNS is rare, treatment strategies are individualized and vary among centres of expertise. Calcineurin inhibitors (CNI) have been effectively used to induce remission in patients with immune-based SRNS; however, there is still no consensus on treating children who become either CNI-dependent or CNI-resistant. Rituximab is a steroid-sparing agent for patients with steroid-sensitive nephrotic syndrome, but its efficacy in SRNS is controversial. Recently, several novel monoclonal antibodies are emerging as treatment option, but their efficacy remains to be seen. Non-immune therapies, such as angiotensin-converting enzyme inhibitors or angiotensin II receptor blockers, have been proven efficacious in children with SRNS and are recommended as adjuvant agents. This review summarizes and discusses our current understandings in treating children with idiopathic SRNS.
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Affiliation(s)
- Jiwon M. Lee
- Department of Pediatrics, Chungnam National University Hospital, Daejeon, South Korea
| | - Andreas Kronbichler
- Department of Internal Medicine IV (Nephrology and Hypertension), Medical University Innsbruck, Innsbruck, Austria
| | - Jae Il Shin
- Department of Pediatrics, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, C.P.O. Box 8044, Seoul, 120-752 South Korea ,Division of Pediatric Nephrology, Severance Children’s Hospital, Seoul, South Korea ,Institute of Kidney Disease Research, Yonsei University College of Medicine, Seoul, South Korea
| | - Jun Oh
- Department of Pediatrics Nephrology, University Hamburg-Eppendorf, Martinistrasse, 52 20246, Hamburg, Germany.
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Fernandez-Vizarra E, Zeviani M. Mitochondrial disorders of the OXPHOS system. FEBS Lett 2020; 595:1062-1106. [PMID: 33159691 DOI: 10.1002/1873-3468.13995] [Citation(s) in RCA: 99] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 10/21/2020] [Accepted: 11/01/2020] [Indexed: 12/13/2022]
Abstract
Mitochondrial disorders are among the most frequent inborn errors of metabolism, their primary cause being the dysfunction of the oxidative phosphorylation system (OXPHOS). OXPHOS is composed of the electron transport chain (ETC), formed by four multimeric enzymes and two mobile electron carriers, plus an ATP synthase [also called complex V (cV)]. The ETC performs the redox reactions involved in cellular respiration while generating the proton motive force used by cV to synthesize ATP. OXPHOS biogenesis involves multiple steps, starting from the expression of genes encoded in physically separated genomes, namely the mitochondrial and nuclear DNA, to the coordinated assembly of components and cofactors building each individual complex and eventually the supercomplexes. The genetic cause underlying around half of the diagnosed mitochondrial disease cases is currently known. Many of these cases result from pathogenic variants in genes encoding structural subunits or additional factors directly involved in the assembly of the ETC complexes. Here, we review the historical and most recent findings concerning the clinical phenotypes and the molecular pathological mechanisms underlying this particular group of disorders.
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Affiliation(s)
- Erika Fernandez-Vizarra
- Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, UK
| | - Massimo Zeviani
- Venetian Institute of Molecular Medicine, Padova, Italy.,Department of Neurosciences, University of Padova, Italy
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12
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Compound heterozygous inheritance of two novel COQ2 variants results in familial coenzyme Q deficiency. Orphanet J Rare Dis 2020; 15:320. [PMID: 33187544 PMCID: PMC7662744 DOI: 10.1186/s13023-020-01600-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 10/26/2020] [Indexed: 12/20/2022] Open
Abstract
Background Primary coenzyme Q10 deficiency is a rare disease that results in diverse and variable clinical manifestations. Nephropathy, myopathy and neurologic involvement are commonly associated, however retinopathy has also been observed with certain pathogenic variants of genes in the coenzyme Q biosynthesis pathway. In this report, we describe a novel presentation of the disease that includes nephropathy and retinopathy without neurological involvement, and which is the result of a compound heterozygous state arising from the inheritance of two recessive potentially pathogenic variants, previously not described. Materials and methods Retrospective report, with complete ophthalmic examination, multimodal imaging, electroretinography, and whole exome sequencing performed on a family with three affected siblings. Results We show that affected individuals in the described family inherited two heterozygous variants of the COQ2 gene, resulting in a frameshift variant in one allele, and a predicted deleterious missense variant in the second allele (c.288dupC,p.(Ala97Argfs*56) and c.376C > G,p.(Arg126Gly) respectively). Electroretinography results were consistent with rod-cone dystrophy in the affected individuals. All affected individuals in the family exhibited the characteristic retinopathy as well as end-stage nephropathy, without evidence of any neurological involvement. Conclusions We identified two novel compound heterozygous variants of the COQ2 gene that result in primary coenzyme Q deficiency. Targeted sequencing of coenzyme Q biosynthetic pathway genes may be useful in diagnosing oculorenal clinical presentations syndromes not explained by more well known syndromes (e.g., Senior-Loken and Bardet-Biedl syndromes).
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Yuruk Yildirim Z, Toksoy G, Uyguner O, Nayir A, Yavuz S, Altunoglu U, Turkkan ON, Sevinc B, Gokcay G, Kurkcu Gunes D, Kiyak A, Yilmaz A. Primary coenzyme Q10 Deficiency-6 (COQ10D6): Two siblings with variable expressivity of the renal phenotype. Eur J Med Genet 2019; 63:103621. [PMID: 30682496 DOI: 10.1016/j.ejmg.2019.01.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 11/22/2018] [Accepted: 01/19/2019] [Indexed: 11/26/2022]
Abstract
Primary coenzyme Q10 deficiency-6 (COQ10D6) is a rare autosomal recessive disorder caused by COQ6 mutations. The main clinical manifestations are infantile progressive nephrotic syndrome (NS) leading to end-stage renal disease and sensorineural deafness. A 7-year-old girl was diagnosed with steroid-resistant NS (SRNS) and an audiological work-up revealed bilateral sensorineural deafness. A renal biopsy demonstrated focal segmental glomerulosclerosis. Despite immunosuppressive therapy, her serum levels of creatinine increased and haemodialysis was indicated within 1 year after the diagnosis. Living-donor kidney transplantation was performed in the eighth month of haemodialysis. A diagnostic custom-designed panel-gene test including 30 genes for NS revealed homozygous c.1058C > A [rs397514479] in exon nine of COQ6. Her older brother, who had sensorineural hearing loss with no renal or neurological involvement, had the same mutation in homozygous form. COQ6 mutations should be considered not only in patients with SRNS with sensorineural hearing loss but also in patients with isolated sensorineural hearing loss with a family history of NS. The reported p.His174 variant of COQ8B was suggested to be a risk factor for secondary CoQ deficiency, while p.Arg174 appeared to improve the condition in a yeast model. Family segregation and the co-occurrence of biallelic p.Arg174 of COQ8B in a brother with hearing loss implied that the interaction of the altered COQ8B with the mutant COQ6 alleviated the symptoms in this family. CoQ10 replacement therapy should be initiated for these patients, as primary CoQ10 deficiency is considered the only known treatable mitochondrial disease.
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Affiliation(s)
- Zeynep Yuruk Yildirim
- Istanbul University, Istanbul Faculty of Medicine, Pediatric Nephrology Department, Istanbul, Turkey.
| | - Guven Toksoy
- Istanbul University, Istanbul Faculty of Medicine, Department of Medical Genetics, Istanbul, Turkey
| | - Oya Uyguner
- Istanbul University, Istanbul Faculty of Medicine, Department of Medical Genetics, Istanbul, Turkey
| | - Ahmet Nayir
- Istanbul University, Istanbul Faculty of Medicine, Pediatric Nephrology Department, Istanbul, Turkey
| | - Sevgi Yavuz
- Kanuni Sultan Suleyman Research and Training Hospital, Pediatric Nephrology Department, Istanbul, Turkey
| | - Umut Altunoglu
- Istanbul University, Istanbul Faculty of Medicine, Department of Medical Genetics, Istanbul, Turkey
| | - Ozde Nisa Turkkan
- Istanbul University, Istanbul Faculty of Medicine, Pediatric Nephrology Department, Istanbul, Turkey
| | - Burcu Sevinc
- Istanbul University, Istanbul Faculty of Medicine, Department of Medical Genetics, Istanbul, Turkey
| | - Gulden Gokcay
- Istanbul University, Istanbul Faculty of Medicine, Pediatric Nutrition and Metabolism Department, Istanbul, Turkey
| | - Dilek Kurkcu Gunes
- Istanbul University, Istanbul Faculty of Medicine, Pediatric Nutrition and Metabolism Department, Istanbul, Turkey
| | - Aysel Kiyak
- Kanuni Sultan Suleyman Research and Training Hospital, Pediatric Nephrology Department, Istanbul, Turkey
| | - Alev Yilmaz
- Istanbul University, Istanbul Faculty of Medicine, Pediatric Nephrology Department, Istanbul, Turkey
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14
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Hidalgo-Gutiérrez A, Barriocanal-Casado E, Bakkali M, Díaz-Casado ME, Sánchez-Maldonado L, Romero M, Sayed RK, Prehn C, Escames G, Duarte J, Acuña-Castroviejo D, López LC. β-RA reduces DMQ/CoQ ratio and rescues the encephalopathic phenotype in Coq9R239X mice. EMBO Mol Med 2019; 11:e9466. [PMID: 30482867 PMCID: PMC6328940 DOI: 10.15252/emmm.201809466] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 10/23/2018] [Accepted: 10/26/2018] [Indexed: 01/15/2023] Open
Abstract
Coenzyme Q (CoQ) deficiency has been associated with primary defects in the CoQ biosynthetic pathway or to secondary events. In some cases, the exogenous CoQ supplementation has limited efficacy. In the Coq9R239X mouse model with fatal mitochondrial encephalopathy due to CoQ deficiency, we have tested the therapeutic potential of β-resorcylic acid (β-RA), a structural analog of the CoQ precursor 4-hydroxybenzoic acid and the anti-inflammatory salicylic acid. β-RA noticeably rescued the phenotypic, morphological, and histopathological signs of the encephalopathy, leading to a significant increase in the survival. Those effects were due to the decrease of the levels of demethoxyubiquinone-9 (DMQ9) and the increase of mitochondrial bioenergetics in peripheral tissues. However, neither CoQ biosynthesis nor mitochondrial function changed in the brain after the therapy, suggesting that some endocrine interactions may induce the reduction of the astrogliosis, spongiosis, and the secondary down-regulation of astrocytes-related neuroinflammatory genes. Because the therapeutic outcomes of β-RA administration were superior to those after CoQ10 supplementation, its use in the clinic should be considered in CoQ deficiencies.
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Affiliation(s)
- Agustín Hidalgo-Gutiérrez
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, Granada, Spain
- Instituto de Biotecnología, Centro de Investigación Biomédica, Universidad de Granada, Granada, Spain
| | - Eliana Barriocanal-Casado
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, Granada, Spain
- Instituto de Biotecnología, Centro de Investigación Biomédica, Universidad de Granada, Granada, Spain
| | - Mohammed Bakkali
- Departamento de Genética, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - M Elena Díaz-Casado
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, Granada, Spain
- Instituto de Biotecnología, Centro de Investigación Biomédica, Universidad de Granada, Granada, Spain
| | - Laura Sánchez-Maldonado
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, Granada, Spain
- Instituto de Biotecnología, Centro de Investigación Biomédica, Universidad de Granada, Granada, Spain
| | - Miguel Romero
- Departamento de Farmacología, Facultad de Farmacia, Universidad de Granada, Granada, Spain
| | - Ramy K Sayed
- Instituto de Biotecnología, Centro de Investigación Biomédica, Universidad de Granada, Granada, Spain
- Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Sohag University, Sohag, Egypt
| | - Cornelia Prehn
- Institute of Experimental Genetics, Genome Analysis Center, Helmholtz Zentrum München, Neuherberg, Germany
| | - Germaine Escames
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, Granada, Spain
- Instituto de Biotecnología, Centro de Investigación Biomédica, Universidad de Granada, Granada, Spain
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Granada, Spain
| | - Juan Duarte
- Departamento de Farmacología, Facultad de Farmacia, Universidad de Granada, Granada, Spain
| | - Darío Acuña-Castroviejo
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, Granada, Spain
- Instituto de Biotecnología, Centro de Investigación Biomédica, Universidad de Granada, Granada, Spain
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Granada, Spain
| | - Luis C López
- Departamento de Fisiología, Facultad de Medicina, Universidad de Granada, Granada, Spain
- Instituto de Biotecnología, Centro de Investigación Biomédica, Universidad de Granada, Granada, Spain
- Centro de Investigación Biomédica en Red de Fragilidad y Envejecimiento Saludable (CIBERFES), Granada, Spain
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15
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Kleiner G, Barca E, Ziosi M, Emmanuele V, Xu Y, Hidalgo-Gutierrez A, Qiao C, Tadesse S, Area-Gomez E, Lopez LC, Quinzii CM. CoQ 10 supplementation rescues nephrotic syndrome through normalization of H 2S oxidation pathway. Biochim Biophys Acta Mol Basis Dis 2018; 1864:3708-3722. [PMID: 30251690 DOI: 10.1016/j.bbadis.2018.09.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 08/03/2018] [Accepted: 09/05/2018] [Indexed: 12/11/2022]
Abstract
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.
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Affiliation(s)
- Giulio Kleiner
- Department of Neurology, Columbia University Medical Center, New York, NY, United States
| | - Emanuele Barca
- Department of Neurology, Columbia University Medical Center, New York, NY, United States
| | - Marcello Ziosi
- Department of Neurology, Columbia University Medical Center, New York, NY, United States
| | - Valentina Emmanuele
- Department of Neurology, Columbia University Medical Center, New York, NY, United States
| | - Yimeng Xu
- Department of Pathology, Columbia University Medical Center, New York, NY, United States
| | | | - Changhong Qiao
- Irving Institute for Clinical and Translational Research, Columbia University Medical Center, New York, NY, United States
| | - Saba Tadesse
- Department of Neurology, Columbia University Medical Center, New York, NY, United States
| | - Estela Area-Gomez
- Department of Neurology, Columbia University Medical Center, New York, NY, United States
| | - Luis C Lopez
- Department of Physiology, Faculty of Medicine, University of Granada, Granada, Spain
| | - Catarina M Quinzii
- Department of Neurology, Columbia University Medical Center, New York, NY, United States.
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16
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Clinical syndromes associated with Coenzyme Q10 deficiency. Essays Biochem 2018; 62:377-398. [DOI: 10.1042/ebc20170107] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/02/2018] [Accepted: 05/15/2018] [Indexed: 12/27/2022]
Abstract
Primary Coenzyme Q deficiencies represent a group of rare conditions caused by mutations in one of the genes required in its biosynthetic pathway at the enzymatic or regulatory level. The associated clinical manifestations are highly heterogeneous and mainly affect central and peripheral nervous system, kidney, skeletal muscle and heart. Genotype–phenotype correlations are difficult to establish, mainly because of the reduced number of patients and the large variety of symptoms. In addition, mutations in the same COQ gene can cause different clinical pictures. Here, we present an updated and comprehensive review of the clinical manifestations associated with each of the pathogenic variants causing primary CoQ deficiencies.
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17
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Coenzyme Q 10 deficiencies: pathways in yeast and humans. Essays Biochem 2018; 62:361-376. [PMID: 29980630 PMCID: PMC6056717 DOI: 10.1042/ebc20170106] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 04/08/2018] [Accepted: 05/14/2018] [Indexed: 12/23/2022]
Abstract
Coenzyme Q (ubiquinone or CoQ) is an essential lipid that plays a role in mitochondrial respiratory electron transport and serves as an important antioxidant. In human and yeast cells, CoQ synthesis derives from aromatic ring precursors and the isoprene biosynthetic pathway. Saccharomyces cerevisiae coq mutants provide a powerful model for our understanding of CoQ biosynthesis. This review focusses on the biosynthesis of CoQ in yeast and the relevance of this model to CoQ biosynthesis in human cells. The COQ1–COQ11 yeast genes are required for efficient biosynthesis of yeast CoQ. Expression of human homologs of yeast COQ1–COQ10 genes restore CoQ biosynthesis in the corresponding yeast coq mutants, indicating profound functional conservation. Thus, yeast provides a simple yet effective model to investigate and define the function and possible pathology of human COQ (yeast or human gene involved in CoQ biosynthesis) gene polymorphisms and mutations. Biosynthesis of CoQ in yeast and human cells depends on high molecular mass multisubunit complexes consisting of several of the COQ gene products, as well as CoQ itself and CoQ intermediates. The CoQ synthome in yeast or Complex Q in human cells, is essential for de novo biosynthesis of CoQ. Although some human CoQ deficiencies respond to dietary supplementation with CoQ, in general the uptake and assimilation of this very hydrophobic lipid is inefficient. Simple natural products may serve as alternate ring precursors in CoQ biosynthesis in both yeast and human cells, and these compounds may act to enhance biosynthesis of CoQ or may bypass certain deficient steps in the CoQ biosynthetic pathway.
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18
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Hernández-Camacho JD, Bernier M, López-Lluch G, Navas P. Coenzyme Q 10 Supplementation in Aging and Disease. Front Physiol 2018; 9:44. [PMID: 29459830 PMCID: PMC5807419 DOI: 10.3389/fphys.2018.00044] [Citation(s) in RCA: 216] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Accepted: 01/12/2018] [Indexed: 12/21/2022] Open
Abstract
Coenzyme Q (CoQ) is an essential component of the mitochondrial electron transport chain and an antioxidant in plasma membranes and lipoproteins. It is endogenously produced in all cells by a highly regulated pathway that involves a mitochondrial multiprotein complex. Defects in either the structural and/or regulatory components of CoQ complex or in non-CoQ biosynthetic mitochondrial proteins can result in a decrease in CoQ concentration and/or an increase in oxidative stress. Besides CoQ10 deficiency syndrome and aging, there are chronic diseases in which lower levels of CoQ10 are detected in tissues and organs providing the hypothesis that CoQ10 supplementation could alleviate aging symptoms and/or retard the onset of these diseases. Here, we review the current knowledge of CoQ10 biosynthesis and primary CoQ10 deficiency syndrome, and have collected published results from clinical trials based on CoQ10 supplementation. There is evidence that supplementation positively affects mitochondrial deficiency syndrome and the symptoms of aging based mainly on improvements in bioenergetics. Cardiovascular disease and inflammation are alleviated by the antioxidant effect of CoQ10. There is a need for further studies and clinical trials involving a greater number of participants undergoing longer treatments in order to assess the benefits of CoQ10 treatment in metabolic syndrome and diabetes, neurodegenerative disorders, kidney diseases, and human fertility.
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Affiliation(s)
- Juan D Hernández-Camacho
- Centro Andaluz de Biología del Desarrollo and CIBERER, Instituto de Salud Carlos III, Universidad Pablo de Olavide-CSIC-JA, Sevilla, Spain
| | - Michel Bernier
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Guillermo López-Lluch
- Centro Andaluz de Biología del Desarrollo and CIBERER, Instituto de Salud Carlos III, Universidad Pablo de Olavide-CSIC-JA, Sevilla, Spain
| | - Plácido Navas
- Centro Andaluz de Biología del Desarrollo and CIBERER, Instituto de Salud Carlos III, Universidad Pablo de Olavide-CSIC-JA, Sevilla, Spain
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19
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Stańczyk M, Bałasz-Chmielewska I, Lipska-Ziętkiewicz B, Tkaczyk M. CoQ10-related sustained remission of proteinuria in a child with COQ6 glomerulopathy-a case report. Pediatr Nephrol 2018; 33:2383-2387. [PMID: 30232548 PMCID: PMC6208703 DOI: 10.1007/s00467-018-4083-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 09/04/2018] [Accepted: 09/05/2018] [Indexed: 12/30/2022]
Abstract
BACKGROUND Treatment of steroid resistant nephrotic syndrome is still a challenge for physicians. There are a growing number of studies exploring genetic background of steroid-resistant glomerulopathies. CASE DIAGNOSIS/TREATMENT We present the case of a 4-year-old girl with steroid-resistant glomerulopathy due to a COQ6 defect with no additional systemic symptoms. The disease did not respond for second-line therapy with calcineurin inhibitor, but it remitted completely after oral treatment with 30 mg/kg/d of coenzyme Q10 (CoQ10). The patient was identified to be a compound heterozygote for two pathogenic variants in COQ6 gene: a known missense substitution c.1078C > T (p.R360W) and a novel frameshift c.804delC mutation. After 12 months of CoQ10 therapy, the child remains in full remission, her physical development accelerated, frequent respiratory airways diseases subsided. CONCLUSIONS Genetic assessment of children with steroid-resistant nephrotic proteinuria enables therapy optimization. Proteinuria caused by a COQ6 gene defect can be successfully treated with CoQ10.
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Affiliation(s)
- Małgorzata Stańczyk
- Department of Pediatrics, Immunology and Nephrology, Polish Mother's Memorial Hospital Research Institute of Lodz, Rzgowska St. 281/289, 93-338, Lodz, Poland.
| | - Irena Bałasz-Chmielewska
- Department of Nephrology and Hypertension of Children and Adolescents, Medical University of Gdansk, Gdansk, Poland
| | - Beata Lipska-Ziętkiewicz
- Department of Biology and Medical Genetics, Clinical Genetics Unit, Medical University of Gdansk, Gdansk, Poland
| | - Marcin Tkaczyk
- Department of Pediatrics, Immunology and Nephrology, Polish Mother’s Memorial Hospital Research Institute of Lodz, Rzgowska St. 281/289, 93-338 Lodz, Poland ,Department of Pediatrics, Immunology and Nephrology, Polish Mother’s Memorial Hospital Research Institute of Lodz, Division of Didactics in Pediatrics, Medical University of Lodz, Lodz, Poland
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20
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Vazquez Fonseca L, Doimo M, Calderan C, Desbats MA, Acosta MJ, Cerqua C, Cassina M, Ashraf S, Hildebrandt F, Sartori G, Navas P, Trevisson E, Salviati L. Mutations in COQ8B (ADCK4) found in patients with steroid-resistant nephrotic syndrome alter COQ8B function. Hum Mutat 2017; 39:406-414. [PMID: 29194833 PMCID: PMC5838795 DOI: 10.1002/humu.23376] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 11/20/2017] [Accepted: 11/26/2017] [Indexed: 01/08/2023]
Abstract
Mutations in COQ8B cause steroid-resistant nephrotic syndrome with variable neurological involvement. In yeast, COQ8 encodes a protein required for coenzyme Q (CoQ) biosynthesis, whose precise role is not clear. Humans harbor two paralog genes: COQ8A and COQ8B (previously termed ADCK3 and ADCK4). We have found that COQ8B is a mitochondrial matrix protein peripherally associated with the inner membrane. COQ8B can complement a ΔCOQ8 yeast strain when its mitochondrial targeting sequence (MTS) is replaced by a yeast MTS. This model was employed to validate COQ8B mutations, and to establish genotype-phenotype correlations. All mutations affected respiratory growth, but there was no correlation between mutation type and the severity of the phenotype. In fact, contrary to the case of COQ2, where residual CoQ biosynthesis correlates with clinical severity, patients harboring hypomorphic COQ8B alleles did not display a different phenotype compared with those with null mutations. These data also suggest that the system is redundant, and that other proteins (probably COQ8A) may partially compensate for the absence of COQ8B. Finally, a COQ8B polymorphism, present in 50% of the European population (NM_024876.3:c.521A > G, p.His174Arg), affects stability of the protein and could represent a risk factor for secondary CoQ deficiencies or for other complex traits.
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Affiliation(s)
- Luis Vazquez Fonseca
- Clinical Genetics Unit, Department of Women and Children's Health, IRP Città della Speranza, University of Padova, Padova, Italy
| | - Mara Doimo
- Clinical Genetics Unit, Department of Women and Children's Health, IRP Città della Speranza, University of Padova, Padova, Italy.,Department of Medical Biochemistry and Biophysics, Umeå University, Umeå, Sweden
| | - Cristina Calderan
- Clinical Genetics Unit, Department of Women and Children's Health, IRP Città della Speranza, University of Padova, Padova, Italy
| | - Maria Andrea Desbats
- Clinical Genetics Unit, Department of Women and Children's Health, IRP Città della Speranza, University of Padova, Padova, Italy
| | - Manuel J Acosta
- Clinical Genetics Unit, Department of Women and Children's Health, IRP Città della Speranza, University of Padova, Padova, Italy
| | - Cristina Cerqua
- Clinical Genetics Unit, Department of Women and Children's Health, IRP Città della Speranza, University of Padova, Padova, Italy
| | - Matteo Cassina
- Clinical Genetics Unit, Department of Women and Children's Health, IRP Città della Speranza, University of Padova, Padova, Italy
| | - Shazia Ashraf
- Division of Nephrology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Friedhelm Hildebrandt
- Division of Nephrology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Geppo Sartori
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Placido Navas
- Centro Andaluz de Biología del Desarrollo, Universidad Pablo de Olavide-CSIC, CIBERER Instituto de Salud Carlos III, Seville, Spain
| | - Eva Trevisson
- Clinical Genetics Unit, Department of Women and Children's Health, IRP Città della Speranza, University of Padova, Padova, Italy
| | - Leonardo Salviati
- Clinical Genetics Unit, Department of Women and Children's Health, IRP Città della Speranza, University of Padova, Padova, Italy
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