Deficit kobalaminu (Cbl, B12) se projevuje v kojeneckém věku neprospíváním, makrocytární anemií, hypotonií, opožděním/regresem vývoje, mikrocefalií a epilepsií. Jednou z příčin deficitu B12 u novorozenců je in utero získaný deficit maternálního původu. Po vzoru jiných zemí EU představujeme průběžné výsledky pilotního projektu novorozeneckého laboratorního screeningu (NLS) deficitu Cbl probíhajícího na spolupracujících pražských pracovištích. Metody: Pro podezření na deficit B12 stačí odchylka alespoň 1 primárního markeru: propionylkarnitin > 3,8 μmol/l, poměr propionylkarnitin/acetylkarnitin > 0,3, methionin < 7 μmol/l, poměr propionylkarnitin/methionin > 0,5 (stanoveno tandemovou hmotnostní spektrometrií). Jako druhostupňové markery využíváme kyselinu methylmalonovou (MMA) > 2,5 μmol/l a celkový homocystein (tHcy) > 12 μmol/l. U pozitivních nálezů provádíme u novorozence i matky test vstřebávání Cbl a stanovujeme celkový B12 (stanoveno elektrochemiluminiscenční imunoanalýzou), holoTC (stanoveno chemiluminiscenční imunoanalýzou), foláty (stanoveno elektrochemiluminiscenční imunoanalýzou), sérovou MMA (stanoveno kapalinovou chromatografií s tandemovou hmotnostní spektrometrií), tHcy (stanoveno vysokoúčinnou kapalinovou chromatografií) a vybrané sirné metabolity. U matek dále stanovujeme markery chronické gastritidy. Výsledky: K 21. 02. 2024 byl deficit B12 vyšetřen v 20 419 krevních kapkách (86,1 % z celkového počtu odebraných vzorků). 863 novorozenců mělo pozitivní alespoň 1 z prvostupňových markerů (2nd tier 4,2 %). Celkově jsme zachytili 6 novorozenců s elevovanými hodnotami MMA, ve 4 případech se jednalo o pravou pozitivitu, 1 případ byl falešně pozitivní, 1 případ byl záchyt kombinované malonové/methylmalonové acidurie. V našich předběžných výsledcích dosahoval neonatální deficit B12 incidenci 1 : 5105 (95% CI 1 : 1994 – 1 : 8735). Závěr: Předběžná data z naší studie prokazují vysokou incidenci neonatálního deficitu B12 ve spolupracujících pražských porodnicích. Výsledky mohou sloužit jako vědecký podklad k rozšíření NLS v České republice. Práce vznikla s podporou grantového projektu AZV NU22-07-00126, RVO-VFN64165 a programu Cooperatio, vědní oblasti „Pediatrie“ a „Metabolické a endokrinní nemoci“.
Cobalamin (Cbl, B12) deficiency manifests in infancy as failure to thrive, macrocytic anemia, hypotonia, developmental delay/regression, microcephaly, and epilepsy. One of the causes of B12 deficiency in newborns is in-utero acquired deficiency caused by maternal deficiency. Following the example of other EU countries, we present interim data from a pilot project of newborn laboratory screening (NLS) for Cbl deficiency, which has been conducted at cooperating Prague hospitals. Methods: At least one abnormal primary marker is required for suspected B12 deficiency: propionylcarnitine > 3.8 μmol/l, propionylcarnitine/acetylcarnitine ratio > 0.3, methionine < 7 μmol/l, propionylcarnitine/methionine ratio > 0.5 (determined by tandem mass spectrometry). Secondary markers include methylmalonic acid (MMA) > 2.5 μmol/l and total homocysteine (tHcy) > 12 μmol/l. In the case of NLS positivity, both the newborn and the mother undergo a Cbl absorption test. We determine total B12 (measured by electrochemiluminescence immunoassay), holoTC (measured by chemiluminescence immunoassay), folates (measured by electrochemiluminescence immunoassay), serum MMA
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
BACKGROUND: In animals, dietary sulfur amino acid restriction (SAAR) improves metabolic health, possibly mediated by altering sulfur amino acid metabolism and enhanced anti-obesogenic processes in adipose tissue. AIM: To assess the effects of SAAR over time on the plasma and urine SAA-related metabolites (sulfurome) in humans with overweight and obesity, and explore whether such changes were associated with body weight, body fat and adipose tissue gene expression. METHODS: Fifty-nine subjects were randomly allocated to SAAR (∼2 g SAA, n = 31) or a control diet (∼5.6 g SAA, n = 28) consisting of plant-based whole-foods and supplemented with capsules to titrate contents of SAA. Sulfurome metabolites in plasma and urine at baseline, 4 and 8 weeks were measured using HPLC and LC-MS/MS. mRNA-sequencing of subcutaneous white adipose tissue (scWAT) was performed to assess changes in gene expression. Data were analyzed with mixed model regression. Principal component analyses (PCA) were performed on the sulfurome data to identify potential signatures characterizing the response to SAAR. RESULTS: SAAR led to marked decrease of the main urinary excretion product sulfate (p < 0.001) and plasma and/or 24-h urine concentrations of cystathionine, sulfite, thiosulfate, H2S, hypotaurine and taurine. PCA revealed a distinct metabolic signature related to decreased transsulfuration and H2S catabolism that predicted greater weight loss and android fat mass loss in SAAR vs. controls (all pinteraction < 0.05). This signature correlated positively with scWAT expression of genes in the tricarboxylic acid cycle, electron transport and β-oxidation (FDR = 0.02). CONCLUSION: SAAR leads to distinct alterations of the plasma and urine sulfurome in humans, and predicted increased loss of weight and android fat mass, and adipose tissue lipolytic gene expression in scWAT. Our data suggest that SAA are linked to obesogenic processes and that SAAR may be useful for obesity and related disorders. TRIAL IDENTIFIER: https://clinicaltrials.gov/study/NCT04701346.
- MeSH
- aminokyseliny sírové * metabolismus krev MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- metabolom MeSH
- nadváha * metabolismus genetika MeSH
- obezita * metabolismus genetika MeSH
- regulace genové exprese MeSH
- tuková tkáň * metabolismus MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- randomizované kontrolované studie MeSH
Elevated total plasma homocysteine (hyperhomocysteinemia) is a marker of cardiovascular, thrombotic, and neuropsychological disease. It has multiple causes, including the common nutritional vitamin B12 or folate deficiency. However, some rare but treatable, inborn errors of metabolism (IEM) characterized by hyperhomocysteinemia can be missed due to variable presentations and the lack of awareness. The aim of this study is to identify undiagnosed IEM in adults with significantly elevated homocysteine using key existing clinical data points, then IEM specific treatment can be offered to improve outcome. We conducted a retrospective study with data mining and chart review of patients with plasma total homocysteine >30 μmol/L over a two-year period. We offer biochemical and genetic testing to patients with significant hyperhomocysteinemia without a clear explanation to diagnose IEM. We identified 22 subjects with significant hyperhomocysteinemia but no clear explanation. Subsequently, we offered genetic testing to seven patients and diagnosed one patient with classic homocystinuria due to cystathionine beta-synthase deficiency. With treatment, she lowered her plasma homocysteine and improved her health. This study stresses the importance of a thorough investigation of hyperhomocysteinemia in adults to identify rare but treatable IEM. We propose a metabolic evaluation algorithm for elevated homocysteine levels.
- MeSH
- dospělí MeSH
- homocystein MeSH
- homocystinurie * diagnóza genetika MeSH
- hyperhomocysteinemie * diagnóza genetika MeSH
- kyselina listová MeSH
- lidé MeSH
- retrospektivní studie MeSH
- vitamin B 12 terapeutické užití MeSH
- vrozené poruchy metabolismu * diagnóza genetika MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Decreasing the dietary intake of methionine exerts robust anti-adiposity effects in rodents but modest effects in humans. Since cysteine can be synthesized from methionine, animal diets are formulated by decreasing methionine and eliminating cysteine. Such diets exert both methionine restriction (MR) and cysteine restriction (CR), that is, sulfur amino acid restriction (SAAR). Contrarily, SAAR diets formulated for human consumption included cysteine, and thus might have exerted only MR. Epidemiological studies positively correlate body adiposity with plasma cysteine but not methionine, suggesting that CR, but not MR, is responsible for the anti-adiposity effects of SAAR. Whether this is true, and, if so, the underlying mechanisms are unknown. Using methionine- and cysteine-titrated diets, we demonstrate that the anti-adiposity effects of SAAR are due to CR. Data indicate that CR increases serinogenesis (serine biosynthesis from non-glucose substrates) by diverting substrates from glyceroneogenesis, which is essential for fatty acid reesterification and triglyceride synthesis. Molecular data suggest that CR depletes hepatic glutathione and induces Nrf2 and its downstream targets Phgdh (the serine biosynthetic enzyme) and Pepck-M. In mice, the magnitude of SAAR-induced changes in molecular markers depended on dietary fat concentration (60% fat >10% fat), sex (males > females), and age-at-onset (young > adult). Our findings are translationally relevant as we found negative and positive correlations of plasma serine and cysteine, respectively, with triglycerides and metabolic syndrome criteria in a cross-sectional epidemiological study. Controlled feeding of low-SAA, high-polyunsaturated fatty acid diets increased plasma serine in humans. Serinogenesis might be a target for treating hypertriglyceridemia.
- MeSH
- aminokyseliny sírové * metabolismus MeSH
- cystein * metabolismus MeSH
- lidé MeSH
- metabolismus lipidů MeSH
- methionin metabolismus MeSH
- myši MeSH
- obezita metabolismus MeSH
- průřezové studie MeSH
- serin metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Regulation of H2S homeostasis in humans is poorly understood. Therefore, we assessed the importance of individual enzymes in synthesis and catabolism of H2S by studying patients with respective genetic defects. We analyzed sulfur compounds (including bioavailable sulfide) in 37 untreated or insufficiently treated patients with seven ultrarare enzyme deficiencies and compared them to 63 controls. Surprisingly, we observed that patients with severe deficiency in cystathionine β-synthase (CBS) or cystathionine γ-lyase (CSE) - the enzymes primarily responsible for H2S synthesis - exhibited increased and normal levels of bioavailable sulfide, respectively. However, an approximately 21-fold increase of urinary homolanthionine in CBS deficiency strongly suggests that lacking CBS activity is compensated for by an increase in CSE-dependent H2S synthesis from accumulating homocysteine, which suggests a control of H2S homeostasis in vivo. In deficiency of sulfide:quinone oxidoreductase - the first enzyme in mitochondrial H2S oxidation - we found normal H2S concentrations in a symptomatic patient and his asymptomatic sibling, and elevated levels in an asymptomatic sibling, challenging the requirement for this enzyme in catabolizing H2S under physiological conditions. Patients with ethylmalonic encephalopathy and sulfite oxidase/molybdenum cofactor deficiencies exhibited massive accumulation of thiosulfate and sulfite with formation of large amounts of S-sulfocysteine and S-sulfohomocysteine, increased renal losses of sulfur compounds and concomitant strong reduction in plasma total cysteine. Our results demonstrate the value of a comprehensive assessment of sulfur compounds in severe disorders of homocysteine/cysteine metabolism and provide evidence for redundancy and compensatory mechanisms in the maintenance of H2S homeostasis.
- MeSH
- cystein MeSH
- homeostáza MeSH
- homocystein MeSH
- lidé MeSH
- síra MeSH
- sulfan * metabolismus MeSH
- sulfidy metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Cystathionine β-synthase (CBS) deficiency has a wide clinical spectrum, ranging from neurodevelopmental problems, lens dislocation and marfanoid features in early childhood to adult onset disease with predominantly thromboembolic complications. We have analysed clinical and laboratory data at the time of diagnosis in 328 patients with CBS deficiency from the E-HOD (European network and registry for Homocystinurias and methylation Defects) registry. We developed comprehensive criteria to classify patients into four groups of pyridoxine responsivity: non-responders (NR), partial, full and extreme responders (PR, FR and ER, respectively). All groups showed overlapping concentrations of plasma total homocysteine while pyridoxine responsiveness inversely correlated with plasma/serum methionine concentrations. The FR and ER groups had a later age of onset and diagnosis and a longer diagnostic delay than NR and PR patients. Lens dislocation was common in all groups except ER but the age of dislocation increased with increasing responsiveness. Developmental delay was commonest in the NR group while no ER patient had cognitive impairment. Thromboembolism was the commonest presenting feature in ER patients, whereas it was least likely at presentation in the NR group. This probably is due to the differences in ages at presentation: all groups had a similar number of thromboembolic events per 1000 patient-years. Clinical severity of CBS deficiency depends on the degree of pyridoxine responsiveness. Therefore, a standardised pyridoxine-responsiveness test in newly diagnosed patients and a critical review of previous assessments is indispensable to ensure adequate therapy and to prevent or reduce long-term complications.
- MeSH
- cystathionin-beta-synthasa nedostatek MeSH
- dítě MeSH
- dospělí MeSH
- fenotyp MeSH
- homocystinurie diagnóza farmakoterapie enzymologie MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- lineární modely MeSH
- methionin krev MeSH
- mladiství MeSH
- mladý dospělý MeSH
- opožděná diagnóza MeSH
- předškolní dítě MeSH
- pyridoxin terapeutické užití MeSH
- registrace MeSH
- senioři MeSH
- stupeň závažnosti nemoci MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
- Publikační typ
- abstrakt z konference MeSH
- MeSH
- buněčné klony MeSH
- buňky K562 MeSH
- CRISPR-Cas systémy MeSH
- genový knockout MeSH
- homozygot MeSH
- hyperhomocysteinemie farmakoterapie genetika MeSH
- kultivované buňky MeSH
- kyselina listová terapeutické užití MeSH
- lidé MeSH
- megaloblastová anemie farmakoterapie genetika MeSH
- mladiství MeSH
- posunová mutace MeSH
- recidiva MeSH
- sekvenční delece MeSH
- sekvenování exomu MeSH
- sodíko-vodíkový výměnný transportér 1 nedostatek genetika MeSH
- vitamin B 12 terapeutické užití MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- mužské pohlaví MeSH
- Publikační typ
- dopisy MeSH
- kazuistiky MeSH
- práce podpořená grantem MeSH
BACKGROUND AND PURPOSE: Homocystinurias are rare genetic defects characterized by altered fluxes of sulfur compounds including homocysteine and cysteine. We explored whether the severely perturbed sulfur amino acid metabolism in patients with homocystinurias affects the metabolism of hydrogen sulfide. EXPERIMENTAL APPROACH: We studied 10 treated patients with a block in the conversion of homocysteine to cysteine due to cystathionine β-synthase deficiency (CBSD) and six treated patients with remethylation defects (RMD) and an enhanced flux of sulfur metabolites via transsulfuration. Control groups for CBSD and RMD patients consisted of 22 patients with phenylketonuria on a low-protein diet and of 12 healthy controls respectively. Plasma and urine concentrations of selected sulfur compounds were analysed by HPLC and LC-MS/MS. KEY RESULTS: Patients with CBSD exhibited plasma concentrations of monobromobimane-detected sulfide similar to appropriate controls. Urinary homolanthionine and thiosulfate in CBSD were increased significantly 1.9 and 3 times suggesting higher hydrogen sulfide synthesis by γ-cystathionase and detoxification respectively. Surprisingly, patients with RMD had significantly lower plasma sulfide levels (53 and 64% of controls) with lower sulfite concentrations, and higher taurine and thiosulfate levels suggesting enhanced cysteine oxidation and hydrogen sulfide catabolism respectively. CONCLUSION AND IMPLICATIONS: The results from this study suggest that severe inherited defects in sulfur amino acid metabolism may be accompanied by only moderately perturbed hydrogen sulfide metabolism and lends support to the hypothesis that enzymes in the transsulfuration pathway may not be the major contributors to the endogenous hydrogen sulfide pool. LINKED ARTICLES: This article is part of a themed section on Chemical Biology of Reactive Sulfur Species. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.4/issuetoc.
- MeSH
- dítě MeSH
- dospělí MeSH
- homocystinurie krev metabolismus moč MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- předškolní dítě MeSH
- sloučeniny síry krev metabolismus moč MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
