Decreased inflammatory status has been reported in subjects with mild unconjugated hyperbilirubinemia. However, mechanisms of the anti-inflammatory actions of bilirubin (BR) are not fully understood. The aim of this study is to assess the role of BR in systemic inflammation using hyperbilirubinemic Gunn rats as well as their normobilirubinemic littermates and further in primary hepatocytes. The rats were treated with lipopolysaccharide (LPS, 6 mg/kg intraperitoneally) for 12 h, their blood and liver were collected for analyses of inflammatory and hepatic injury markers. Primary hepatocytes were treated with BR and TNF-α. LPS-treated Gunn rats had a significantly decreased inflammatory response, as evidenced by the anti-inflammatory profile of white blood cell subsets, and lower hepatic and systemic expressions of IL-6, TNF-α, IL-1β, and IL-10. Hepatic mRNA expression of LPS-binding protein was upregulated in Gunn rats before and after LPS treatment. In addition, liver injury markers were lower in Gunn rats as compared to in LPS-treated controls. The exposure of primary hepatocytes to TNF-α with BR led to a milder decrease in phosphorylation of the NF-κB p65 subunit compared to in cells without BR. In conclusion, hyperbilirubinemia in Gunn rats is associated with an attenuated systemic inflammatory response and decreased liver damage upon exposure to LPS.

• Klíčová slova
• Gunn rats, LPS, NF-κB, bilirubin, hyperbilirubinemia, inflammation,
• MeSH
• apoptóza účinky léků   MeSH
• bilirubin farmakologie   MeSH
• biologické markery krev   MeSH
• cytokiny krev   genetika   metabolismus   MeSH
• cytoprotekce účinky léků   MeSH
• fosforylace účinky léků   MeSH
• hepatocyty metabolismus   MeSH
• hyperbilirubinemie krev   komplikace   MeSH
• játra metabolismus   MeSH
• kultivované buňky MeSH
• leukocyty metabolismus   MeSH
• lipopolysacharidy MeSH
• messenger RNA genetika   metabolismus   MeSH
• NF-kappa B metabolismus   MeSH
• potkani Gunn MeSH
• signální transdukce MeSH
• zánět komplikace   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bilirubin MeSH
• biologické markery MeSH
• cytokiny MeSH
• lipopolysacharidy MeSH
• messenger RNA MeSH
• NF-kappa B MeSH

Oxidative stress and inflammation are predominant features of several chronic diseases. The nuclear factor erythroid 2-related factor 2 (Nrf2) is a major arbiter in counteracting these insults via up-regulation of several defensive proteins, including heme oxygenase-1 (HO-1). HO-1-derived carbon monoxide (CO) exhibits anti-inflammatory actions and can be delivered to tissues by CO-releasing agents. In this study we assessed the pharmacological and anti-inflammatory properties of HYCO-3, a dual activity compound obtained by conjugating analogues of the CO-releasing molecule CORM-401 and dimethyl fumarate (DMF), an immunomodulatory drug known to activate Nrf2. HYCO-3 induced Nrf2-dependent genes and delivered CO to cells in vitro and tissues in vivo, confirming that the two expected pharmacological properties of this agent are achieved. In mice challenged with lipopolysaccharide, orally administered HYCO-3 reduced the mRNA levels of pro-inflammatory markers (TNF-α, IL-1β and IL-6) while increasing the expression of the anti-inflammatory genes ARG1 and IL-10 in brain, liver, lung and heart. In contrast, DMF or CORM-401 alone or their combination decreased the expression of pro-inflammatory genes but had limited influence on anti-inflammatory markers. Furthermore, HYCO-3 diminished TNF-α and IL-1β in brain and liver but not in lung and heart of Nrf2-/- mice, indicating that the CO-releasing part of this hybrid contributes to reduction of pro-inflammation and that this effect is organ-specific. These data demonstrate that the dual activity of HYCO-3 results in enhanced efficacy compared to the parent compounds indicating the potential exploitation of hybrid compounds in the development of effective anti-inflammatory therapies.

• Klíčová slova
• Carbon monoxide (CO), Dual-activity molecules, Inflammation, Macrophage phenotype, Nrf2 activators,
• MeSH
• antiflogistika farmakologie   MeSH
• antioxidancia metabolismus   MeSH
• cytokiny genetika   metabolismus   MeSH
• exprese genu MeSH
• faktor 2 související s NF-E2 genetika   metabolismus   MeSH
• hemoxygenasa-1 genetika   metabolismus   MeSH
• kultivované buňky MeSH
• lipopolysacharidy škodlivé účinky   MeSH
• makrofágy účinky léků   imunologie   metabolismus   MeSH
• mediátory zánětu metabolismus   MeSH
• mikroglie účinky léků   metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• myši knockoutované MeSH
• myši MeSH
• oxid uhelnatý metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• zánět farmakoterapie   etiologie   metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• antiflogistika MeSH
• antioxidancia MeSH
• cytokiny MeSH
• faktor 2 související s NF-E2 MeSH
• hemoxygenasa-1 MeSH
• lipopolysacharidy MeSH
• mediátory zánětu MeSH
• oxid uhelnatý MeSH

Heme oxygenase 1 (Hmox1), a ubiquitous enzyme degrading heme to carbon monoxide, iron, and biliverdin, is one of the cytoprotective enzymes induced in response to a variety of stimuli, including cellular oxidative stress. Gangliosides, sialic acid-containing glycosphingolipids expressed in all cells, are involved in cell recognition, signalling, and membrane stabilization. Their expression is often altered under many pathological and physiological conditions including cell death, proliferation, and differentiation. The aim of this study was to assess the possible role of Hmox1 in ganglioside metabolism in relation to oxidative stress. The content of liver and brain gangliosides, their cellular distribution, and mRNA as well as protein expression of key glycosyltransferases were determined in Hmox1 knockout mice as well as their wild-type littermates. To elucidate the possible underlying mechanisms between Hmox1 and ganglioside metabolism, hepatoblastoma HepG2 and neuroblastoma SH-SY5Y cell lines were used for in vitro experiments. Mice lacking Hmox1 exhibited a significant increase in concentrations of liver and brain gangliosides and in mRNA expression of the key enzymes of ganglioside metabolism. A marked shift of GM1 ganglioside from the subsinusoidal part of the intracellular compartment into sinusoidal membranes of hepatocytes was shown in Hmox1 knockout mice. Induction of oxidative stress by chenodeoxycholic acid in vitro resulted in a significant increase in GM3, GM2, and GD1a gangliosides in SH-SY5Y cells and GM3 and GM2 in the HepG2 cell line. These changes were abolished with administration of bilirubin, a potent antioxidant agent. These observations were closely related to oxidative stress-mediated changes in sialyltransferase expression regulated at least partially through the protein kinase C pathway. We conclude that oxidative stress is an important factor modulating synthesis and distribution of gangliosides in vivo and in vitro which might affect ganglioside signalling in higher organisms.

• MeSH
• gangliosidy metabolismus   MeSH
• hemoxygenasa-1 metabolismus   MeSH
• játra metabolismus   MeSH
• lidé MeSH
• mozek metabolismus   MeSH
• myši knockoutované MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• oxidační stres fyziologie   MeSH
• signální transdukce fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• gangliosidy MeSH
• hemoxygenasa-1 MeSH

Estrogen-induced cholestasis is characterized by impaired hepatic uptake and biliary bile acids secretion because of changes in hepatocyte transporter expression. The induction of heme oxygenase-1 (HMOX1), the inducible isozyme in heme catabolism, is mediated via the Bach1/Nrf2 pathway, and protects livers from toxic, oxidative and inflammatory insults. However, its role in cholestasis remains unknown. Here, we investigated the effects of HMOX1 induction by heme on ethinylestradiol-induced cholestasis and possible underlying mechanisms. Wistar rats were given ethinylestradiol (5 mg/kg s.c.) for 5 days. HMOX1 was induced by heme (15 μmol/kg i.p.) 24 hrs prior to ethinylestradiol. Serum cholestatic markers, hepatocyte and renal membrane transporter expression, and biliary and urinary bile acids excretion were quantified. Ethinylestradiol significantly increased cholestatic markers (P ≤ 0.01), decreased biliary bile acid excretion (39%, P = 0.01), down-regulated hepatocyte transporters (Ntcp/Oatp1b2/Oatp1a4/Mrp2, P ≤ 0.05), and up-regulated Mrp3 (348%, P ≤ 0.05). Heme pre-treatment normalized cholestatic markers, increased biliary bile acid excretion (167%, P ≤ 0.05) and up-regulated hepatocyte transporter expression. Moreover, heme induced Mrp3 expression in control (319%, P ≤ 0.05) and ethinylestradiol-treated rats (512%, P ≤ 0.05). In primary rat hepatocytes, Nrf2 silencing completely abolished heme-induced Mrp3 expression. Additionally, heme significantly increased urinary bile acid clearance via up-regulation (Mrp2/Mrp4) or down-regulation (Mrp3) of renal transporters (P ≤ 0.05). We conclude that HMOX1 induction by heme increases hepatocyte transporter expression, subsequently stimulating bile flow in cholestasis. Also, heme stimulates hepatic Mrp3 expression via a Nrf2-dependent mechanism. Bile acids transported by Mrp3 to the plasma are highly cleared into the urine, resulting in normal plasma bile acid levels. Thus, HMOX1 induction may be a potential therapeutic strategy for the treatment of ethinylestradiol-induced cholestasis.

• Klíčová slova
• 17α- ethinylestradiol, bile acids, heme, multidrug resistance-associated protein 3, nuclear factor erythroid-2-related factor-2,
• MeSH
• ABC transportéry genetika   MeSH
• alkalická fosfatasa krev   MeSH
• bilirubin krev   farmakologie   MeSH
• cholestáza krev   chemicky indukované   enzymologie   MeSH
• enzymová indukce účinky léků   MeSH
• ethinylestradiol MeSH
• exprese genu účinky léků   MeSH
• hem farmakologie   MeSH
• hemová oxygenasa (decyklizující) biosyntéza   genetika   MeSH
• hepatocyty účinky léků   enzymologie   MeSH
• krysa rodu Rattus MeSH
• kultivované buňky MeSH
• kyselina taurocholová farmakologie   MeSH
• ochranné látky farmakologie   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• potkani Wistar MeSH
• primární buněčná kultura MeSH
• proteiny spojené s mnohočetnou rezistencí k lékům genetika   MeSH
• žlučové kyseliny a soli krev   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ABC transportéry MeSH
• Abcc2 protein, rat MeSH Prohlížeč
• Abcc4 protein, rat MeSH Prohlížeč
• alkalická fosfatasa MeSH
• bilirubin MeSH
• ethinylestradiol MeSH
• hem MeSH
• hemová oxygenasa (decyklizující) MeSH
• kyselina taurocholová MeSH
• ochranné látky MeSH
• proteiny spojené s mnohočetnou rezistencí k lékům MeSH
• žlučové kyseliny a soli MeSH