Mitochondrial metabolic remodeling is a hallmark of the Trypanosoma brucei digenetic life cycle because the insect stage utilizes a cost-effective oxidative phosphorylation (OxPhos) to generate ATP, while bloodstream cells switch to aerobic glycolysis. Due to difficulties in acquiring enough parasites from the tsetse fly vector, the dynamics of the parasite's metabolic rewiring in the vector have remained obscure. Here, we took advantage of in vitro-induced differentiation to follow changes at the RNA, protein, and metabolite levels. This multi-omics and cell-based profiling showed an immediate redirection of electron flow from the cytochrome-mediated pathway to an alternative oxidase (AOX), an increase in proline consumption, elevated activity of complex II, and certain tricarboxylic acid (TCA) cycle enzymes, which led to mitochondrial membrane hyperpolarization and increased reactive oxygen species (ROS) levels. Interestingly, these ROS molecules appear to act as signaling molecules driving developmental progression because ectopic expression of catalase, a ROS scavenger, halted the in vitro-induced differentiation. Our results provide insights into the mechanisms of the parasite's mitochondrial rewiring and reinforce the emerging concept that mitochondria act as signaling organelles through release of ROS to drive cellular differentiation.
- MeSH
- adenosintrifosfát biosyntéza MeSH
- buněčná diferenciace účinky léků MeSH
- buněčné dýchání účinky léků MeSH
- buněčné linie MeSH
- elektrony MeSH
- glukosa farmakologie MeSH
- membránový potenciál mitochondrií účinky léků MeSH
- metabolické sítě a dráhy účinky léků MeSH
- metabolomika * MeSH
- mitochondriální proteiny metabolismus MeSH
- mitochondrie účinky léků metabolismus MeSH
- oxidace-redukce MeSH
- oxidoreduktasy metabolismus MeSH
- prolin metabolismus MeSH
- proteom metabolismus MeSH
- protozoální proteiny metabolismus MeSH
- reaktivní formy kyslíku metabolismus MeSH
- rostlinné proteiny metabolismus MeSH
- signální transdukce MeSH
- transkriptom genetika MeSH
- transport elektronů účinky léků MeSH
- Trypanosoma brucei brucei účinky léků genetika růst a vývoj metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
AIMS: Increased plasma soluble endoglin concentrations (sEng) are frequently detected in metabolic disorders accompanied with hypercholesterolemia in serum, but effect of sEng on the cholesterol biochemistry is unknown. Cholesterol and bile acids (BA) are important products of liver metabolism with numerous functions within the organism. Turnover of these substances requires precise regulation due to potential toxicities during their cumulation. In this study, we hypothesized that high sEng levels affect cholesterol homeostasis and BA turnover in mice liver. MAIN METHODS: Nine-month-old transgenic male mice overexpressing human sEng and wild-type mice underwent plasma, bile, stool, and organ samples analysis by analytical, qRT-PCT and Western blot methods. KEY FINDINGS: sEng mice demonstrated decreased plasma total and LDL cholesterol concentrations due to upregulation of hepatic Sr-b1 and Ldlr receptors, increased liver cholesterol content, and increased Abcg8-mediated cholesterol efflux into bile. sEng also increased conversion of cholesterol into bile acids (BA) via upregulation of Cyp7a1 and increased Mdr1 expression. Plasma concentrations of BA were increased in sEng mice due to their enhanced reabsorption via ileum. Increased hepatic disposition of BA led to their increased biliary excretion coupled with choleretic activity. SIGNIFICANCE: For the first time, we have shown that high sEng plasma levels affect cholesterol and BA homeostasis on the basis of complex liver and intestinal effects. The significance of these findings for pathophysiology of diseases associated with increased sEng concentrations remains to be elucidated in prospective studies.
- MeSH
- cholesterol krev metabolismus MeSH
- endoglin krev fyziologie MeSH
- feces MeSH
- homeostáza * MeSH
- játra metabolismus MeSH
- LDL-receptory metabolismus MeSH
- myši transgenní MeSH
- myši MeSH
- oxidační stres MeSH
- přenašeče organických aniontů závislé na sodíku metabolismus MeSH
- protein SREBP2 metabolismus MeSH
- symportéry metabolismus MeSH
- upregulace MeSH
- zánět krev MeSH
- žlučové kyseliny a soli krev metabolismus MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Due to toxicity and compliance issues and the emergence of resistance to current medications new drugs for the treatment of Human African Trypanosomiasis are needed. A potential approach to developing novel anti-trypanosomal drugs is by inhibition of the 6-oxopurine salvage pathways which synthesise the nucleoside monophosphates required for DNA/RNA production. This is in view of the fact that trypanosomes lack the machinery for de novo synthesis of the purine ring. To provide validation for this approach as a drug target, we have RNAi silenced the three 6-oxopurine phosphoribosyltransferase (PRTase) isoforms in the infectious stage of Trypanosoma brucei demonstrating that the combined activity of these enzymes is critical for the parasites' viability. Furthermore, we have determined crystal structures of two of these isoforms in complex with several acyclic nucleoside phosphonates (ANPs), a class of compound previously shown to inhibit 6-oxopurine PRTases from several species including Plasmodium falciparum. The most potent of these compounds have Ki values as low as 60 nM, and IC50 values in cell based assays as low as 4 μM. This data provides a solid platform for further investigations into the use of this pathway as a target for anti-trypanosomal drug discovery.
- MeSH
- hypoxanthinfosforibosyltransferasa antagonisté a inhibitory chemie genetika metabolismus MeSH
- inhibitory enzymů chemie farmakologie MeSH
- katalytická doména MeSH
- lidé MeSH
- metabolické sítě a dráhy účinky léků MeSH
- molekulární modely MeSH
- objevování léků MeSH
- pentosyltransferasy antagonisté a inhibitory chemie genetika metabolismus MeSH
- purinony metabolismus MeSH
- RNA interference MeSH
- trypanocidální látky chemie farmakologie MeSH
- Trypanosoma brucei brucei účinky léků enzymologie genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
AIM: To investigate the effect of resveratrol on biliary secretion of cholephilic compounds in healthy and bile duct-obstructed rats. METHODS: Resveratrol (RSV) or saline were administered to rats by daily oral gavage for 28 d after sham operation or reversible bile duct obstruction (BDO). Bile was collected 24 h after the last gavage during an intravenous bolus dose of the Mdr1/Mrp2 substrate azithromycin. Bile acids, glutathione and azithromycin were measured in bile to quantify their level of biliary secretion. Liver expression of enzymes and transporters relevant for bile production and biliary secretion of major bile constituents and drugs were analyzed at the mRNA and protein levels using qRT-PCR and Western blot analysis, respectively. The TR-FRET PXR Competitive Binding Assay kit was used to determine the agonism of RSV at the pregnane X receptor. RESULTS: RSV increased bile flow in sham-operated rats due to increased biliary secretion of bile acids (BA) and glutathione. This effect was accompanied by the induction of the hepatic rate-limiting transporters for bile acids and glutathione, Bsep and Mrp2, respectively. RSV also induced Cyp7a1, an enzyme that is crucial for bile acid synthesis; Mrp4, a transporter important for BA secretion from hepatocytes to blood; and Mdr1, the major apical transporter for xenobiotics. The findings were supported by increased biliary secretion of azithromycin. The TR-FRET PXR competitive binding assay confirmed RSV as a weak agonist of the human nuclear receptor PXR, which is a transcriptional regulator of Mdr1/Mrp2. RSV demonstrated significant hepatoprotective properties against BDO-induced cirrhosis. RSV also reduced bile flow in BDO rats without any corresponding change in the levels of the transporters and enzymes involved in RSV-mediated hepatoprotection. CONCLUSION: Resveratrol administration for 28 d has a distinct effect on bile flow and biliary secretion of cholephilic compounds in healthy and bile duct-obstructed rats.
- MeSH
- ABC transportéry metabolismus MeSH
- antiflogistika nesteroidní farmakologie terapeutické užití MeSH
- antioxidancia farmakologie terapeutické užití MeSH
- aplikace orální MeSH
- azithromycin farmakokinetika MeSH
- cholestáza farmakoterapie etiologie patofyziologie MeSH
- glutathion sekrece MeSH
- hepatocyty účinky léků metabolismus sekrece MeSH
- játra účinky léků metabolismus patofyziologie MeSH
- krysa rodu rattus MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- potkani Wistar MeSH
- steroidní receptory agonisté MeSH
- stilbeny farmakologie terapeutické užití MeSH
- žlučové kyseliny a soli chemie sekrece MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
AIMS: Statins are known to influence the status of adipokines, which play a key role in the pathophysiology of cardiometabolic diseases. As the effect of ezetimibe as an add-on to statin therapy on the impact of statins on plasma adipokines levels is currently unclear, the aim of the present study was to investigate this through a meta-analysis of controlled trials. METHODS: A systematic review was performed, followed by a bibliographic search in PubMed, Medline, SCOPUS, Web of Science and Google Scholar databases. Quantitative data synthesis was performed using a fixed- or random-effects model (based on the level of interstudy heterogeneity) and the generic inverse variance weighting method. Effect sizes were expressed as standardized mean difference (SMD) and 95% confidence interval (CI). RESULTS: Meta-analysis of 23 controlled trials did not suggest any significant effect of adding ezetimibe on top of statin therapy on plasma concentrations of adiponectin (SMD 0.34, 95% CI -0.28, 0.96; P = 0.288), leptin (SMD -0.75, 95% CI: -2.35, 0.85; P = 0.360), plasminogen activator inhibitor 1 (SMD -1.06, 95% CI: -2.81, 0.69; P = 0.236) and interleukin 6 (SMD 0.30, 95% CI: -0.08, 0.67; P = 0.124). However, significantly greater reductions in plasma concentrations of tumour necrosis factor α (TNF-α) (SMD -0.48, 95% CI -0.87, -0.08; P = 0.018) were achieved with ezetimibe/statin combination therapy. CONCLUSIONS: The results suggested that ezetimibe add-on to statin therapy is associated with an enhanced TNF-α-lowering effect compared with statin monotherapy. Owing to the emerging role of TNF-α in the pathogenesis of metabolic disorders, further investigations are required to unveil the translational relevance of this TNF-α-lowering effect.
- MeSH
- adiponektin krev MeSH
- anticholesteremika farmakologie terapeutické užití MeSH
- ateroskleróza krev farmakoterapie MeSH
- ezetimib farmakologie terapeutické užití MeSH
- inhibitor aktivátoru plazminogenu 1 krev MeSH
- interleukin-6 krev MeSH
- kombinovaná farmakoterapie metody MeSH
- leptin krev MeSH
- lidé MeSH
- randomizované kontrolované studie jako téma MeSH
- statiny farmakologie terapeutické užití MeSH
- TNF-alfa krev MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- metaanalýza MeSH
- přehledy MeSH
- srovnávací studie MeSH
