Cardiac involvement (CI) in phosphomannomutase 2-congenital disorders of glycosylation (PMM2-CDG) is part of the multisystemic presentation contributing to high mortality rates. The most common cardiac manifestations are pericardial effusion, cardiomyopathy, and structural heart defects. A genotype-phenotype correlation with organ involvement has not yet been described. We analyzed clinical, biochemical, and molecular genetic data of 222 patients from eight European centers and characterized the natural course of patients with CI. Fifty-seven patients (45 children) presented with CI, of whom 24 died (median age 21 months, standard deviation 49.8). Pericardial effusion was the most frequent manifestation (55.4%), occurring mostly within the first 6 months of life. The most common pathogenic variants in patients with CI were p.(Arg141His) in 74%, followed by p.(Val231Met) in 36%, which is 3.5 times higher than in PMM2-CDG patients without CI (p < 0.0001). Twenty-one out of 36 patients with p.(Val231Met) had CI; among them, 15 died, compared to 33 out of 166 patients without p.(Val231Met) who had CI (p < 0.0001). Nine out of 33 patients died (p = 0.0015), indicating greater clinical severity. Furthermore, the p.(Val231Met) variant is predominant in Eastern Europe, suggesting a founder effect. Cardiac complications in PMM2-CDG patients are common and serious. The variant p.(Val231Met) profoundly influences the extent of CI and mortality rates. Therefore, we recommend cardiac surveillance be included in the follow-up protocols for PMM2-CDG.
- MeSH
- dítě MeSH
- fenotyp * MeSH
- fosfotransferasy (fosfomutasy) * genetika nedostatek MeSH
- genetické asociační studie MeSH
- kardiomyopatie genetika MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- mutace MeSH
- novorozenec MeSH
- předškolní dítě MeSH
- stupeň závažnosti nemoci MeSH
- vrozené poruchy glykosylace * genetika MeSH
- Check Tag
- dítě MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- novorozenec MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
BACKGROUND: Transport protein particle (TRAPP) is a multiprotein complex that functions in localising proteins to the Golgi compartment. The TRAPPC11 subunit has been implicated in diseases affecting muscle, brain, eye and to some extent liver. We present three patients who are compound heterozygotes for a missense variant and a structural variant in the TRAPPC11 gene. TRAPPC11 structural variants have not yet been described in association with a disease. In order to reveal the estimated genesis of identified structural variants, we performed sequencing of individual breakpoint junctions and analysed the extent of homology and the presence of repetitive elements in and around the breakpoints. METHODS: Biochemical methods including isoelectric focusing on serum transferrin and apolipoprotein C-III, as well as mitochondrial respiratory chain complex activity measurements, were used. Muscle biopsy samples underwent histochemical analysis. Next-generation sequencing was employed for identifying sequence variants associated with neuromuscular disorders, and Sanger sequencing was used to confirm findings. RESULTS: We suppose that non-homologous end joining is a possible mechanism of deletion origin in two patients and non-allelic homologous recombination in one patient. Analyses of mitochondrial function performed in patients' skeletal muscles revealed an imbalance of mitochondrial metabolism, which worsens with age and disease progression. CONCLUSION: Our results contribute to further knowledge in the field of neuromuscular diseases and mutational mechanisms. This knowledge is important for understanding the molecular nature of human diseases and allows us to improve strategies for identifying disease-causing mutations.
- MeSH
- delece genu MeSH
- dítě MeSH
- dospělí MeSH
- kosterní svaly patologie metabolismus MeSH
- lidé MeSH
- missense mutace genetika MeSH
- svalové dystrofie * genetika patologie MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- kazuistiky MeSH
BACKGROUND: Cystathionine β-synthase (CBS)-deficient homocystinuria (HCU) is an inherited disorder of sulfur amino acid metabolism with varying severity and organ complications, and a limited knowledge about underlying pathophysiological processes. Here we aimed at getting an in-depth insight into disease mechanisms using a transgenic mouse model of HCU (I278T). METHODS: We assessed metabolic, proteomic and sphingolipidomic changes, and mitochondrial function in tissues and body fluids of I278T mice and WT controls. Furthermore, we evaluated the efficacy of methionine-restricted diet (MRD) in I278T mice. RESULTS: In WT mice, we observed a distinct tissue/body fluid compartmentalization of metabolites with up to six-orders of magnitude differences in concentrations among various organs. The I278T mice exhibited the anticipated metabolic imbalance with signs of an increased production of hydrogen sulfide and disturbed persulfidation of free aminothiols. HCU resulted in a significant dysregulation of liver proteome affecting biological oxidations, conjugation of compounds, and metabolism of amino acids, vitamins, cofactors and lipids. Liver sphingolipidomics indicated upregulation of the pro-proliferative sphingosine-1-phosphate signaling pathway. Liver mitochondrial function of HCU mice did not seem to be impaired compared to controls. MRD in I278T mice improved metabolic balance in all tissues and substantially reduced dysregulation of liver proteome. CONCLUSION: The study highlights distinct tissue compartmentalization of sulfur-related metabolites in normal mice, extensive metabolome, proteome and sphingolipidome disruptions in I278T mice, and the efficacy of MRD to alleviate some of the HCU-related biochemical abnormalities.
- MeSH
- cystathionin-beta-synthasa * metabolismus nedostatek genetika MeSH
- homocystinurie * metabolismus genetika MeSH
- játra * metabolismus MeSH
- lipidomika metody MeSH
- metabolomika * metody MeSH
- mitochondrie metabolismus MeSH
- modely nemocí na zvířatech * MeSH
- myši transgenní * MeSH
- myši MeSH
- proteom metabolismus MeSH
- proteomika * metody MeSH
- sfingolipidy * metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Dolichol is a lipid critical for N-glycosylation as a carrier for activated sugars and nascent oligosaccharides. It is commonly thought to be directly produced from polyprenol by the enzyme SRD5A3. Instead, we found that dolichol synthesis requires a three-step detour involving additional metabolites, where SRD5A3 catalyzes only the second reaction. The first and third steps are performed by DHRSX, whose gene resides on the pseudoautosomal regions of the X and Y chromosomes. Accordingly, we report a pseudoautosomal-recessive disease presenting as a congenital disorder of glycosylation in patients with missense variants in DHRSX (DHRSX-CDG). Of note, DHRSX has a unique dual substrate and cofactor specificity, allowing it to act as a NAD+-dependent dehydrogenase and as a NADPH-dependent reductase in two non-consecutive steps. Thus, our work reveals unexpected complexity in the terminal steps of dolichol biosynthesis. Furthermore, we provide insights into the mechanism by which dolichol metabolism defects contribute to disease.
- MeSH
- 3-oxo-5-alfa-steroid-4-dehydrogenasa metabolismus genetika MeSH
- dolichol * metabolismus biosyntéza MeSH
- glykosylace MeSH
- lidé MeSH
- membránové proteiny metabolismus genetika MeSH
- missense mutace MeSH
- vrozené poruchy glykosylace metabolismus genetika MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
INTRODUCTION: Monoallelic variants in the ALG5 gene encoding asparagine-linked glycosylation protein 5 homolog (ALG5) have been recently shown to disrupt polycystin-1 (PC1) maturation and trafficking via underglycosylation, causing an autosomal dominant polycystic kidney disease-like (ADPKD-like) phenotype and interstitial fibrosis. In this report, we present clinical, genetic, histopathologic, and protein structure and functional correlates of a new ALG5 variant, p.R79W, that we identified in 2 distant genetically related Irish families displaying an atypical late-onset ADPKD phenotype combined with tubulointerstitial damage. METHODS: Whole exome and targeted sequencing were used for segregation analysis of available relatives. This was followed by immunohistochemistry examinations of kidney biopsies, and targeted (UMOD, MUC1) and untargeted plasma proteome and N-glycomic studies. RESULTS: We identified a monoallelic ALG5 variant [GRCh37 (NM_013338.5): g.37569565G>A, c.235C>T; p.R79W] that cosegregates in 23 individuals, of whom 18 were clinically affected. We detected abnormal localization of ALG5 in the Golgi apparatus of renal tubular cells in patients' kidney specimens. Further, we detected the pathological accumulation of uromodulin, an N-glycosylated glycosylphosphatidylinositol (GPI)-anchored protein, in the endoplasmic reticulum (ER), but not mucin-1, an O- and N-glycosylated protein. Biochemical investigation revealed decreased plasma and urinary uromodulin levels in clinically affected individuals. Proteomic and glycoproteomic profiling revealed the dysregulation of chronic kidney disease (CKD)-associated proteins. CONCLUSION: ALG5 dysfunction adversely affects maturation and trafficking of N-glycosylated and GPI anchored protein uromodulin, leading to structural and functional changes in the kidney. Our findings confirm ALG5 as a cause of late-onset ADPKD and provide additional insight into the molecular mechanisms of ADPKD-ALG5.
- Publikační typ
- časopisecké články MeSH
This study presents an in-depth analysis of mitochondrial enzyme activities in Friedreich's ataxia (FA) patients, focusing on the Electron Transport Chain complexes I, II, and IV, the Krebs Cycle enzyme Citrate Synthase, and Coenzyme Q10 levels. It examines a cohort of 34 FA patients, comparing their mitochondrial enzyme activities and clinical parameters, including disease duration and cardiac markers, with those of 17 healthy controls. The findings reveal marked reductions in complexes II and, specifically, IV, highlighting mitochondrial impairment in FA. Additionally, elevated Neurofilament Light Chain levels and cardiomarkers were observed in FA patients. This research enhances our understanding of FA pathophysiology and suggests potential biomarkers for monitoring disease progression. The study underscores the need for further clinical trials to validate these findings, emphasizing the critical role of mitochondrial dysfunction in FA assessment and treatment.
- MeSH
- biologické markery * metabolismus MeSH
- citrátsynthasa metabolismus MeSH
- dospělí MeSH
- Friedreichova ataxie * diagnóza MeSH
- kohortové studie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mitochondrie metabolismus MeSH
- mladiství MeSH
- mladý dospělý MeSH
- ubichinon * analogy a deriváty MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Multiple system atrophy (MSA) is generally a sporadic neurodegenerative disease which ranks among atypical Parkinson's syndromes. The main clinical manifestation is a combination of autonomic dysfunction and parkinsonism and/or cerebellar disability. The disease may resemble other Parkinsonian syndromes, such as Parkinson's disease (PD) or progressive supranuclear palsy (PSP), from which MSA could be hardly distinguishable during the first years of progression. Due to the lack of a reliable and easily accessible biomarker, the diagnosis is still based primarily on the clinical picture. Recently, reduced levels of coenzyme Q10 (CoQ10) were described in MSA in various tissues, including the central nervous system. The aim of our study was to verify whether the level of CoQ10 in plasma and lymphocytes could serve as an easily available diagnostic biomarker of MSA. The study reported significantly lower levels of CoQ10 in the lymphocytes of patients with MSA compared to patients with PD and controls. The reduction in CoQ10 levels in lymphocytes correlated with the increasing degree of clinical involvement of patients with MSA. CoQ10 levels in lymphocytes seem to be a potential biomarker of disease progression.
- Publikační typ
- časopisecké články MeSH
Závěrečná zpráva o řešení grantu Agentury pro zdravotnický výzkum MZ ČR
nestr.
Mitochondrial diseases are caused by insufficient function of energy provision apparatus and they belong among the most severe inborn errors of metabolism. Whole exome sequencing helped to characterise many causal mutations, but as of yet, almost 40% of cases remain without defined genetic cause. Thorough non-invasive biochemical characterisation remains the centrepiece for successful interpretation of identified genetic variants. Aim of the project is to develop and optimise cryopreservation technique for blood elements, which will be compatible with subsequent functional analyses of mitochondrial function. Subsequently, they will be analysed through high resolution respirometry in permeabilised cells and by the analysis of preferred metabolic pathways in intact cells. In patients with biochemically verified mitochondrial dysfunction, causal genetic variant will be identified by exome sequencing and newly characterised variants will be functionally validated.
Mitochondriální onemocnění jsou vyvolané nedostatečnou funkcí energetického aparátu a patří k závažným dědičným poruchám metabolismu. Řada kauzálních mutací již byla identifikována díky rozvoji exomového sekvenování, ale stále se nedaří nalézt genetickou příčinu u téměř 40% případů. Kvalitní neinvazivní biochemická charakterizace pacientů s podezdřením na mitochondriální onemocnění zásadní pro úspěšnou interpretaci exomových dat. Cílem projektu je využití krevních elementů jako materiálu pro standardizovanou a reprodukovatelnou biochemickou charakterizaci pacientů. Bude optimalizována metodika kryoprezervace krevních elementů kompatibilní s následnou analýzou mitochondriálních funkcí. Ty budou poté analyzovány pomocí vysoce citlivé respirometrie u permeabilizovaných buněk a analýzou preferovaných metabolických drah u buněk intaktních. U pacientů s biochemicky potvrzeným nálezem bude provedeno exomové sekvenování pro určení genetické příčiny a nově nalezené varianty budou dále funkčně validovány.
- Klíčová slova
- Metabolism, metabolizmus, oxidační fosforylace, Mitochondrie, oxidative phosphorylation, Mitochondria, mitochondriální onemocnění, Mitochondrial diseases,
- NLK Publikační typ
- závěrečné zprávy o řešení grantu AZV MZ ČR
Huntington's disease (HD) is an autosomal dominant neurodegenerative disease caused by a mutation in the HTT gene. To generate human-induced pluripotent stem cells (hiPSCs), we used dermal fibroblasts from 1 healthy adult control (K-Pic2), 1 HD manifest patient (M-T2), 1 healthy juvenile control (jK-N1), and 1 juvenile HD patient (jHD-V1). HD stage of patients was assessed by neurological tests and donors were without comorbidities and were non-smokers. Characterization showed that the obtained hiPSCs have the same number of CAG repeats as the parental fibroblast lines, express pluripotency markers and have the ability to differentiate into all 3 germ layers.
Leber hereditary optic neuropathy is a primary mitochondrial disease characterized by acute visual loss due to the degeneration of retinal ganglion cells. In this study, we describe a patient carrying a rare missense heteroplasmic variant in MT-ND1, NC_012920.1:m.4135T>C (p.Tyr277His) manifesting with a typical bilateral painless decrease of the visual function, triggered by physical exercise or higher ambient temperature. Functional studies in muscle and fibroblasts show that amino acid substitution Tyr277 with His leads to only a negligibly decreased level of respiratory chain complex I (CI), but the formation of supercomplexes and the activity of the enzyme are disturbed noticeably. Our data indicate that although CI is successfully assembled in the patient's mitochondria, its function is hampered by the m.4135T>C variant, probably by stabilizing CI in its inactive form. We conclude that the m.4135T>C variant together with a combination of external factors is necessary to manifest the phenotype.
- Publikační typ
- kazuistiky MeSH
