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
Kazuistika popisuje případ 68letého muže, u kterého se několik měsíců před stanovením diagnózy karcinomu pankreatu objevil jako časný příznak úbytek hmotnosti a diabetes mellitus. Diagnóza byla stanovena bohužel pozdě, až ve stadiu generalizovaného onemocnění, kdy nebylo možné pacienta léčit jinak než symptomaticky. Cílem článku je upozornit na tuto možnost manifestace karcinomu pankreatu. Pouze diagnóza stanovená včas v době lokalizovaného nádoru umožňuje resekci tumoru, která je jedinou kurativní léčebnou metodu. Z tohoto důvodu je nutné při netypické manifestaci diabetu pomýšlet také na možnou přítomnost karcinomu pankreatu.
The case report is about a 68-years-old man who developed a weight loss and diabetes mellitus as early symptoms of pancreatic cancer several months before the diagnosis. Unfortunately, the diagnosis was made too late, at the stage of generalized disease, when symptomatic treatment was the only possible way. The aim of the article is to warn about this possible way of pancreatic cancer manifestation, because only the diagnosis determined in time, when the tumor is localized, allows its resection - the only curative treatment method. For this reason, it is necessary to consider the presence of pancreatic cancer in the case of an atypical manifestation of diabetes.
- MeSH
- diabetes mellitus diagnóza etiologie MeSH
- hmotnostní úbytek MeSH
- lidé MeSH
- nádory slinivky břišní * diagnóza terapie MeSH
- senioři MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- Publikační typ
- kazuistiky 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.
Fluorescein is a fluorescent dye used as a diagnostic tool in various fields of medicine. Although fluorescein itself possesses low toxicity, after photoactivation, it releases potentially toxic molecules, such as singlet oxygen (1O2) and, as we demonstrate in this work, also carbon monoxide (CO). As both of these molecules can affect physiological processes, the main aim of this study was to explore the potential biological impacts of fluorescein photochemistry. In our in vitro study in a human hepatoblastoma HepG2 cell line, we explored the possible effects on cell viability, cellular energy metabolism, and the cell cycle. We observed markedly lowered cell viability (≈30%, 75-2400 μM) upon irradiation of intracellular fluorescein and proved that this decrease in viability was dependent on the cellular oxygen concentration. We also detected a significantly decreased concentration of Krebs cycle metabolites (lactate and citrate < 30%; 2-hydroxyglutarate and 2-oxoglutarate < 10%) as well as cell cycle arrest (decrease in the G2 phase of 18%). These observations suggest that this photochemical reaction could have important biological consequences and may account for some adverse reactions observed in fluorescein-treated patients. Additionally, the biological activities of both 1O2 and CO might have considerable therapeutic potential, particularly in the treatment of cancer.
- MeSH
- angiografie MeSH
- antitumorózní látky chemie farmakologie MeSH
- buňky Hep G2 MeSH
- citrátový cyklus účinky léků účinky záření MeSH
- fluorescein chemie farmakologie MeSH
- fotochemické procesy MeSH
- kontrolní body buněčného cyklu účinky léků účinky záření MeSH
- lidé MeSH
- oxid uhelnatý analýza MeSH
- plynová chromatografie s hmotnostně spektrometrickou detekcí MeSH
- singletový kyslík analýza MeSH
- světlo MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Metabolic transformation of cancer cells leads to the accumulation of lactate and significant acidification in the tumor microenvironment. Both lactate and acidosis have a well-documented impact on cancer progression and negative patient prognosis. Here, we report that cancer cells adapted to acidosis are significantly more sensitive to oxidative damage induced by hydrogen peroxide, high-dose ascorbate, and photodynamic therapy. Higher lactate concentrations abrogate the sensitization. Mechanistically, acidosis leads to a drop in antioxidant capacity caused by a compromised supply of nicotinamide adenine dinucleotide phosphate (NADPH) derived from glucose metabolism. However, lactate metabolism in the Krebs cycle restores NADPH supply and antioxidant capacity. CPI-613 (devimistat), an anticancer drug candidate, selectively eradicates the cells adapted to acidosis through inhibition of the Krebs cycle and induction of oxidative stress while completely abrogating the protective effect of lactate. Simultaneous cell treatment with tetracycline, an inhibitor of the mitochondrial proteosynthesis, further enhances the cytotoxic effect of CPI-613 under acidosis and in tumor spheroids. While there have been numerous attempts to treat cancer by neutralizing the pH of the tumor microenvironment, we alternatively suggest considering tumor acidosis as the Achilles' heel of cancer as it enables selective therapeutic induction of lethal oxidative stress.
- MeSH
- acidóza patofyziologie MeSH
- antitumorózní látky farmakologie MeSH
- citrátový cyklus účinky léků MeSH
- energetický metabolismus MeSH
- fyziologická adaptace MeSH
- glukosa metabolismus MeSH
- glykolýza MeSH
- kapryláty farmakologie MeSH
- koncentrace vodíkových iontů MeSH
- kyselina mléčná metabolismus MeSH
- lidé MeSH
- mitochondrie účinky léků metabolismus patologie MeSH
- nádorové buňky kultivované MeSH
- nádorové mikroprostředí * MeSH
- nádory farmakoterapie metabolismus patologie MeSH
- oxidační stres MeSH
- sulfidy farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
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
Statiny se využívají pro léčbu primární hypercholesterolemie a dyslipidemie. Významně snižují kardiovaskulární riziko v primární i sekundární prevenci. V České republice se nejvíce používají atorvastatin a rosuvastatin, méně simvastatin a fluvastatin. Při léčbě statiny je třeba stanovit cílové hodnoty HDL cholesterolu, zvolit vhodný režim (případně s doplňkovou léčbou ezetimibem). Po jejich nasazení se také mohou vyskytovat nežádoucí účinky (nevolnost, únava, myalgie, vzácně statinová myopatie). Řadou studií je prokázáno, že statiny mají neuroprotektivní účinky na mozkovou tkáň. Mohou přestupovat hematoencefalickou bariéru a snížit aktivaci mikroglie i následné vyplavování prozánětlivých mediátorů. Za patologických podmínek navozují v mozku vazodilataci, inhibici proliferace buněk hladkého svalu ve stěně cév, zlepšují funkci endoteliálních buněk, stabilizují aterosklerotický plát. Mají antiagregační, antioxidativní a protizánětlivý účinek.
Statins are used to treat primary hypercholesterolemia and dyslipidemia. They significantly reduce cardiovascular risk in primary and secondary prevention. In the Czech Republic, atorvastatin and rosuvastatin are the most used drugs, otherwise simvastatin and fluvastatin are less prescribed. For statin therapy, appropriate HDL cholesterol target values should be established, and special regimen with adjunctive therapy with ezetimibe in selected patients. Drug side effects may occur with statin therapy, such as nausea, fatigue, myalgia, rarely statin myopathy. A number of studies have shown that statins have neuroprotective effects on the brain tissue. They can cross the blood-brain barrier and reduce microglia activation followed by subsequent leaching of proinflammatory mediators. Under pathological conditions, statins induce vasodilation in the brain, inhibit the proliferation of smooth muscle cells in the vessel wall, improve endothelial cell function, and stabilize the atherosclerotic plaque. They have antiplatelet, antioxidant and anti-inflammatory effect.
- MeSH
- hypercholesterolemie farmakoterapie MeSH
- lidé MeSH
- nemoci nervového systému * farmakoterapie prevence a kontrola MeSH
- neuroprotektivní látky farmakologie MeSH
- nežádoucí účinky léčiv MeSH
- statiny * farmakologie škodlivé účinky terapeutické užití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Invasive bilirubin measurements remain the gold standard for the diagnosis and treatment of infants with severe neonatal hyperbilirubinemia. The present paper describes different methods currently available to assess hyperbilirubinemia in newborn infants. Novel point-of-care bilirubin measurement methods, such as the BiliSpec and the Bilistick, would benefit many newborn infants, especially in low-income and middle-income countries where the access to costly multi-analyzer in vitro diagnostic instruments is limited. Total serum bilirubin test results should be accurate within permissible limits of measurement uncertainty to be fit for clinical purposes. This implies correct implementation of internationally endorsed reference measurement systems as well as participation in external quality assessment programs. Novel analytic methods may, apart from bilirubin, include the determination of bilirubin photoisomers and bilirubin oxidation products in blood and even in other biological matrices. IMPACT: Key message: Bilirubin measurements in blood remain the gold standard for diagnosis and treatment of severe neonatal hyperbilirubinemia (SNH). External quality assessment (EQA) plays an important role in revealing inaccuracies in diagnostic bilirubin measurements. What does this article add to the existing literature? We provide analytic performance data on total serum bilirubin (TSB) as measured during recent EQA surveys. We review novel diagnostic point-of-care (POC) bilirubin measurement methods and analytic methods for determining bilirubin levels in biological matrices other than blood. Impact: Manufacturers should make TSB test results traceable to the internationally endorsed total bilirubin reference measurement system and should ensure permissible limits of measurement uncertainty.
- MeSH
- bilirubin krev MeSH
- biologické markery krev MeSH
- lidé MeSH
- novorozenec MeSH
- novorozenecká hyperbilirubinemie krev diagnóza terapie MeSH
- novorozenecká žloutenka krev diagnóza terapie MeSH
- novorozenecký screening * MeSH
- point of care testing * MeSH
- prediktivní hodnota testů MeSH
- prognóza MeSH
- reprodukovatelnost výsledků MeSH
- stupeň závažnosti nemoci MeSH
- upregulace MeSH
- Check Tag
- lidé MeSH
- novorozenec MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Severe neonatal hyperbilirubinemia (SNH) is a serious condition that occurs worldwide. Timely recognition with bilirubin determination is key in the management of SNH. Visual assessment of jaundice is unreliable. Fortunately, transcutaneous bilirubin measurement for screening newborn infants is routinely available in many hospitals and outpatient settings. Despite a few limitations, the use of transcutaneous devices facilitates early recognition and appropriate management of neonatal jaundice. Unfortunately, however, advanced and often costly screening modalities are not accessible to everyone, while there is an urgent need for inexpensive yet accurate instruments to assess total serum bilirubin (TSB). In the near future, novel icterometers, and in particular optical bilirubin estimates obtained with a smartphone camera and processed with a smartphone application (app), seem promising methods for screening for SNH. If proven reliable, these methods may empower outpatient health workers as well as parents at home to detect jaundice using a simple portable device. Successful implementation of ubiquitous bilirubin screening may contribute substantially to the reduction of the worldwide burden of SNH. The benefits of non-invasive bilirubin screening notwithstanding, any bilirubin determination obtained through non-invasive screening must be confirmed by a diagnostic method before treatment. IMPACT: Key message: Screening methods for neonatal hyperbilirubinemia facilitate early recognition and timely treatment of severe neonatal hyperbilirubinemia (SNH). Any bilirubin screening result obtained must be confirmed by a diagnostic method. What does this article add to the existing literature? Data on optical bilirubin estimation are summarized. Niche research strategies for prevention of SNH are presented. Impact: Transcutaneous screening for neonatal hyperbilirubinemia contributes to the prevention of SNH. A smartphone application with optical bilirubin estimation seems a promising low-cost screening method, especially in low-resource settings or at home.
- MeSH
- bilirubin krev MeSH
- biologické markery krev MeSH
- časná diagnóza MeSH
- chytrý telefon MeSH
- lidé MeSH
- mobilní aplikace MeSH
- novorozenec MeSH
- novorozenecká hyperbilirubinemie krev diagnóza terapie MeSH
- novorozenecká žloutenka krev diagnóza terapie MeSH
- novorozenecký screening * přístrojové vybavení MeSH
- prediktivní hodnota testů MeSH
- prognóza MeSH
- reprodukovatelnost výsledků MeSH
- stupeň závažnosti nemoci MeSH
- upregulace MeSH
- Check Tag
- lidé MeSH
- novorozenec MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
BACKGROUND: Unconjugated hyperbilirubinemia, a feature of neonatal jaundice or Crigler-Najjar syndrome, can lead to neurotoxicity and even death. We previously demonstrated that unconjugated bilirubin (UCB) can be eliminated via transintestinal excretion in Gunn rats, a model of unconjugated hyperbilirubinemia, and that this is stimulated by enhancing fecal fatty acid excretion. Since transintestinal excretion also occurs for cholesterol (TICE), we hypothesized that increasing fecal cholesterol excretion and/or TICE could also enhance fecal UCB disposal and subsequently lower plasma UCB concentrations. METHODS: To determine whether increasing fecal cholesterol excretion could ameliorate unconjugated hyperbilirubinemia, we treated hyperbilirubinemic Gunn rats with ezetimibe (EZE), an intestinal cholesterol absorption inhibitor, and/or a liver X receptor (LXR) and farnesoid X receptor (FXR) agonist (T0901317 (T09) and obeticholic acid (OCA), respectively), known to stimulate TICE. RESULTS: We found that EZE treatment alone or in combination with T09 or OCA increased fecal cholesterol disposal but did not lower plasma UCB levels. CONCLUSIONS: These findings do not support a link between the regulation of transintestinal excretion of cholesterol and bilirubin. Furthermore, induction of fecal cholesterol excretion is not a potential therapy for unconjugated hyperbilirubinemia. IMPACT: Increasing fecal cholesterol excretion is not effective to treat unconjugated hyperbilirubinemia. This is the first time a potential relation between transintestinal excretion of cholesterol and unconjugated bilirubin is investigated. Transintestinal excretion of cholesterol and unconjugated bilirubin do not seem to be quantitatively linked. Unlike intestinal fatty acids, cholesterol cannot "capture" unconjugated bilirubin to increase its excretion. These results add to our understanding of ways to improve and factors regulating unconjugated bilirubin disposal in hyperbilirubinemic conditions.
- MeSH
- bilirubin chemie MeSH
- cholesterol metabolismus MeSH
- Criglerův-Najjarův syndrom metabolismus terapie MeSH
- dietní tuky farmakokinetika MeSH
- ezetimib farmakologie terapeutické užití MeSH
- feces chemie MeSH
- fluorované uhlovodíky farmakologie terapeutické užití MeSH
- haptoglobiny analýza MeSH
- hyperbilirubinemie terapie MeSH
- jaterní receptor X metabolismus MeSH
- krysa rodu rattus MeSH
- kyselina chenodeoxycholová analogy a deriváty farmakologie terapeutické užití MeSH
- lipidy krev MeSH
- náhodné rozdělení MeSH
- potkani Gunn MeSH
- PPAR delta metabolismus MeSH
- receptory cytoplazmatické a nukleární metabolismus MeSH
- střeva účinky léků metabolismus MeSH
- sulfonamidy farmakologie terapeutické užití MeSH
- žluč chemie MeSH
- žlučové kyseliny a soli metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
