The molecular mechanisms linking obstructive sleep apnea syndrome (OSA) to obesity and the development of metabolic diseases are still poorly understood. The role of hypoxia (a characteristic feature of OSA) in excessive fat accumulation has been proposed. The present study investigated the possible effects of hypoxia (4% oxygen) on de novo lipogenesis by tracking the major carbon sources in differentiating 3T3-L1 adipocytes. Gas-permeable cultuware was employed to cultivate 3T3-L1 adipocytes in hypoxia (4%) for 7 or 14 days of differentiation. We investigated the contribution of glutamine, glucose or acetate using 13C or 14C labelled carbons to the newly synthesized lipid pool, changes in intracellular lipid content after inhibiting citrate- or acetate-dependent pathways and gene expression of involved key enzymes. The results demonstrate that, in differentiating adipocytes, hypoxia decreased the synthesis of lipids from glucose (44.1 ± 8.8 to 27.5 ± 3.0 pmol/mg of protein, p < 0.01) and partially decreased the contribution of glutamine metabolized through the reverse tricarboxylic acid cycle (4.6% ± 0.2-4.2% ± 0.1%, p < 0.01). Conversely, the contribution of acetate, a citrate- and mitochondria-independent source of carbons, increased upon hypoxia (356.5 ± 71.4 to 649.8 ± 117.5 pmol/mg of protein, p < 0.01). Further, inhibiting the citrate- or acetate-dependent pathways decreased the intracellular lipid content by 58% and 73%, respectively (p < 0.01) showing the importance of de novo lipogenesis in hypoxia-exposed adipocytes. Altogether, hypoxia modified the utilization of carbon sources, leading to alterations in de novo lipogenesis in differentiating adipocytes and increased intracellular lipid content.
- MeSH
- acetáty * metabolismus farmakologie MeSH
- buněčná diferenciace * účinky léků MeSH
- buňky 3T3-L1 * MeSH
- citrátový cyklus MeSH
- glukosa * metabolismus MeSH
- glutamin * metabolismus MeSH
- hypoxie buňky MeSH
- lipidy biosyntéza MeSH
- lipogeneze * účinky léků MeSH
- metabolismus lipidů účinky léků MeSH
- myši MeSH
- tukové buňky * metabolismus účinky léků MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Obstructive sleep apnea syndrome, characterized by repetitive episodes of tissue hypoxia, is associated with several metabolic impairments. Role of fatty acids and lipids attracts attention in its pathogenesis for their metabolic effects. Parallelly, hypoxia-induced activation of reverse tricarboxylic acid cycle (rTCA) with reductive glutamine metabolism provides precursor molecules for de novo lipogenesis. Gas-permeable cultureware was used to culture L6-myotubes in chronic hypoxia (12%, 4% and 1% O2) with 13C labelled glutamine and inhibitors of glutamine uptake or rTCA-mediated lipogenesis. We investigated changes in lipidomic profile, 13C appearance in rTCA-related metabolites, gene and protein expression of rTCA-related proteins and glutamine transporters, glucose uptake and lactate production. Lipid content increased by 308% at 1% O2, predominantly composed of saturated fatty acids, while triacylglyceroles containing unsaturated fatty acids and membrane lipids (phosphatidylcholines, phosphatidylethanolamines, phosphatidylinositol) decreased by 20-70%. rTCA labelling of malate, citrate and 2-hydroxyglutarate increased by 4.7-fold, 2.2-fold and 1.9-fold in 1% O2, respectively. ATP-dependent citrate lyase inhibition in 1% O2 decreased lipid amount by 23% and increased intensity of triacylglyceroles containing unsaturated fatty acids by 56-80%. Lactate production increased with hypoxia. Glucose uptake dropped by 75% with progression of hypoxia from 4% to 1% O2. Protein expression remained unchanged. Altogether, hypoxia modified cell metabolism leading to lipid composition alteration and rTCA activation.
The 'gold standard' treatment of severe neonatal jaundice is phototherapy with blue-green light, which produces more polar photo-oxidation products that are easily excreted via the bile or urine. The aim of this study was to compare the effects of bilirubin (BR) and its major photo-oxidation product lumirubin (LR) on the proliferation, differentiation, morphology, and specific gene and protein expressions of self-renewing human pluripotent stem cell-derived neural stem cells (NSC). Neither BR nor LR in biologically relevant concentrations (12.5 and 25 µmol/L) affected cell proliferation or the cell cycle phases of NSC. Although none of these pigments affected terminal differentiation to neurons and astrocytes, when compared to LR, BR exerted a dose-dependent cytotoxicity on self-renewing NSC. In contrast, LR had a substantial effect on the morphology of the NSC, inducing them to form highly polar rosette-like structures associated with the redistribution of specific cellular proteins (β-catenin/N-cadherin) responsible for membrane polarity. This observation was accompanied by lower expressions of NSC-specific proteins (such as SOX1, NR2F2, or PAX6) together with the upregulation of phospho-ERK. Collectively, the data indicated that both BR and LR affect early human neurodevelopment in vitro, which may have clinical relevance in phototherapy-treated hyperbilirubinemic neonates.
- Publikační typ
- časopisecké články MeSH
Mitochondrial production of 2-hydroxyglutarate (2HG) can be catalyzed by wild-type isocitrate dehydrogenase 2 (IDH2) and alcohol dehydrogenase, iron-containing 1 (ADHFE1). We investigated whether biochemical background and substrate concentration in breast cancer cells promote 2HG production. To estimate its role in 2HG production, we quantified 2HG levels and its enantiomers in breast cancer cells using analytical approaches for metabolomics. By manipulation of mitochondrial substrate fluxes using genetic and pharmacological approaches, we demonstrated the existence of active competition between 2HG producing enzymes, i.e., IDH2 and ADHFE1. Moreover, we showed that distinct fractions of IDH2 enzyme molecules operate in distinct oxido-reductive modes, providing NADPH and producing 2HG simultaneously. We have also detected 2HG release in the urine of breast cancer patients undergoing adjuvant therapy and detected a correlation with stages of breast carcinoma development. In summary, we provide a background for vital mitochondrial production of 2HG in breast cancer cells with outcomes towards cancer biology and possible future diagnosis of breast carcinoma.
- Publikační typ
- časopisecké články MeSH
For severe unconjugated hyperbilirubinemia the gold standard treatment is phototherapy with blue-green light, producing more polar photo-oxidation products, believed to be non-toxic. The aim of the present study was to compare the effects of bilirubin (BR) and lumirubin (LR), the major BR photo-oxidation product, on metabolic and oxidative stress markers. The biological activities of these pigments were investigated on several human and murine cell lines, with the focus on mitochondrial respiration, substrate metabolism, reactive oxygen species production, and the overall effects on cell viability. Compared to BR, LR was found to be much less toxic, while still maintaining a similar antioxidant capacity in the serum as well as suppressing activity leading to mitochondrial superoxide production. Nevertheless, due to its lower lipophilicity, LR was less efficient in preventing lipoperoxidation. The cytotoxicity of BR was affected by the cellular glycolytic reserve, most compromised in human hepatoblastoma HepG2 cells. The observed effects were correlated with changes in the production of tricarboxylic acid cycle metabolites. Both BR and LR modulated expression of PPARα downstream effectors involved in lipid and glucose metabolism. Proinflammatory effects of BR, evidenced by increased expression of TNFα upon exposure to bacterial lipopolysaccharide, were observed in murine macrophage-like RAW 264.7 cells. Collectively, these data point to the biological effects of BR and its photo-oxidation products, which might have clinical relevance in phototherapy-treated hyperbilirubinemic neonates and adult patients.
- Publikační typ
- časopisecké články MeSH
Úvod: Lékové alergie představují terapeutický problém, který může komplikovat volbu farmakoterapie. V případě nepřesné nebo falešně pozitivní anamnézy může být pacient zbytečně vystaven lékům druhé linie, které mohou zvyšovat terapeutické riziko či představovat zvýšené náklady pro zdravotní systém. Metoda: Prospektivní analýza zdravotnické dokumentace hospitalizovaných pacientů doplněná strukturovaným rozhovorem s odebráním podrobné anamnézy. V období 11/2018 až 04/2019 bylo zařazeno 92 hospitalizovaných pacientů na vybraných klinikách FN Olomouc.Výsledky: Prevalence lékových alergií ve vzorku hospitalizovaných pacientů byla 21,2 %. U 92 pacientů bylo zjištěno 163 léko-vých alergií (průměr 1,8 alergie na pacienta). Nejčastěji postiženým orgánovým systémem byla kůže (39 % reakcí) a gastroin-testinální trakt (16 %). Mezi lékovými alergiemi dominují alergie na antimikrobní přípravky (36 %), analgetika (16 %), přípravky s obsahem jódu (11 %) a lokální anestetika (7 %). Z antimikrobních látek byly nejčastěji uváděny betalaktamová antibiotika (55 %) a sulfonamidy (24 %). U 10 % alergických reakcí byl zjištěn rozpor mezi dokumentací a anamnézou zjištěnou od pacien-ta. Celkem 18 % uváděných alergických reakcí bylo autory vyhodnoceno jako nežádoucí účinky jiné než alergické etiologie.Závěr: Prevalence anamnesticky udávaných lékových alergií mezi hospitalizovanými pacienty je vysoká, mezi nejčastější léčiva patří antibiotika a analgetika. Kvalita a správnost alergologické anamnézy jsou klíčové pro racionální a bezpečnou farmakote-rapii, ověření a doplnění alergologické anamnézy by měla být věnována zvýšená pozornost.Klíčová slova: lékové alergie, anamnéza, antibiotika, analgetika, racionální farmakote
Introduction: Drug allergies may complicate choice of pharmacotherapy. In the case of an invalid of false-positive allergy history the patient may be exposed to second-line drugs that may present higher risk of side effects or increase cost of care. Methods: Prospective analysis of health records of hospitalized patients followed by a structured interview with detailed history. Between 11/2018 and 4/2019 we examined 92 hospitalized patients at selected clinics of the University Hospital in Olomouc. Results: The prevalence of drug allergies in our sample of hospitalized patients was 21.2%. In 92 patients we identified a total of 163 drug allergies (a mean of 1.8 allergy per patient). The most common manifestations were cutaneous (39% of reactions) and gastrointestinal (16%). Allergies to antimicrobial agents were most commonly reported (36%), followed by analgesics (16%), iodine (11%) and local anesthetics (7%). Betalactam antibiotics (55%) and sulfonamides (24%) were the most common antibiotics with reported allergies. In 10% of reported allergies a mismatch between the patients history and his documentation was identified. Approximately 18% of reactions were evaluated by the authors to be likely non-allergic adverse effects. Conclusion: The prevalence of drug allergies among hospitalized patients is high, the most commonly reported drugs are antibiotics and analgesics. Validity of allergic history is key for rational and safe pharmacotherapy. Effort should be made to properly verify and document any drug allergies and intolerance.
Akcelerácia vývoja a najmä registrácie nových očkovacích látok a ich kombinácií významne zvýšili preventívny potenciál lekárov. Na druhej strane si však situácia vyžaduje od zdravotníckych pracovníkov oveľa viac vedomostí o vakcínach a ich účinkoch. Do roku 2006 sa v rámci povinného očkovania detí robil zásah proti 10 prenosným ochoreniam: TBC, záškrt, tetanus, čierny kašeľ, osýpky, ružienky, príušnice, VHB, HiB, detská obrna. Očkovanie sa vykonáva dlhodobo v tzv. „škandinávskej“ schéme, ktorá je odlišná od štátov väčšiny krajín EÚ. Optimalizácia očkovacieho kalendára detí v Slovenskej republike a možnosti zaradenia nových očkovaní do systému preventívnej starostlivosti o deti a dorast zvyšuje požiadavky na rozhodovací proces lekárov-pediatrov.
The acceleration in the development and mainly in the registration of new vaccines and the combinations of vaccination antigens substantially increased the preventive potential of medical doctors. On the other hand these possibilities require from health care workers much more information and knowledge. Until 2006 the regular compulsory vaccination encountered 10 transmissible diseases: Tbc, diphtheria, tetanus, pertussis, morbilli - measles, rubella - German measles, parotitis – mumps, hepatitis B, and Haemophilus influenzae type B infections. The vaccination schedule in the Slovak Republic is performed according to the „Scandinavian“ scheme that differs from the schedule in the majority of EU countries. Optimization of the vaccination schedule for children in the Slovak Republic and possible implementation of new vaccinations to the system of preventive health care of children and adolescents increases requirements in the process of decision of paediatricians.
