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1.
Cell Death Dis ; 12(7): 698, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34257282

RESUMO

Sorafenib, a protein kinase inhibitor approved for the treatment of hepatocellular carcinoma and advanced renal cell carcinoma, has been repeatedly reported to induce ferroptosis by possibly involving inhibition of the cystine/glutamate antiporter, known as system xc-. Using a combination of well-defined genetically engineered tumor cell lines and canonical small molecule ferroptosis inhibitors, we now provide unequivocal evidence that sorafenib does not induce ferroptosis in a series of tumor cell lines unlike the cognate system xc- inhibitors sulfasalazine and erastin. We further show that only a subset of tumor cells dies by ferroptosis upon sulfasalazine and erastin treatment, implying that certain cell lines appear to be resistant to system xc- inhibition, while others undergo ferroptosis-independent cell death. From these findings, we conclude that sorafenib does not qualify as a bona fide ferroptosis inducer and that ferroptosis induced by system xc- inhibitors can only be achieved in a fraction of tumor cell lines despite robust expression of SLC7A11, the substrate-specific subunit of system xc-.


Assuntos
Antineoplásicos/farmacologia , Ferroptose/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Sorafenibe/farmacologia , Sistema y+ de Transporte de Aminoácidos/antagonistas & inibidores , Sistema y+ de Transporte de Aminoácidos/genética , Sistema y+ de Transporte de Aminoácidos/metabolismo , Animais , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Células HEK293 , Humanos , Camundongos , Neoplasias/genética , Neoplasias/metabolismo , Neoplasias/patologia , Piperazinas/farmacologia , Sulfassalazina/farmacologia
2.
J Nutr ; 151(9): 2835-2842, 2021 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-34191031

RESUMO

BACKGROUND: Brain iron accumulation is a feature of Alzheimer disease (AD) but whether a chronic dietary iron overload contributes to AD induction is unknown. We previously showed that young mice fed a high iron diet did not display cognitive impairment despite the AD pathological markers in hippocampus. OBJECTIVES: We aim to compare the impact of high dietary iron on brain pathologic changes and cognitive function in young and old mice. METHODS: Male C57BL/6J mice at 1 mo and 13 mo of age were fed with either a control diet (66 mg Fe/kg; Young-Ctrl and Old-Ctrl) or a high iron diet (14 g Fe/kg; Young-High Fe and Old-High Fe) for 7 mo, and outcomes were evaluated at 8 mo and 20 mo of age. Iron concentrations in brain regions were measured by atomic absorption spectrophotometry. Perls's Prussian blue staining and amyloid-ß (Aß) immunostaining were performed. Protein expression in the cerebral cortex and hippocampus was determined by immunoblotting. Superoxide dismutase activity and malondialdehyde concentration were examined. Cognitive functions were tested with the Morris water maze system. Two-factor ANOVA was used to analyze most data. RESULTS: Compared with Old-Ctrl mice, Old-High Fe mice showed significantly higher iron concentrations in cerebral cortex (60% higher), cerebellum (60% higher), and hippocampus (90% higher), paralleled by lower superoxide dismutase activity and greater malondialdehyde concentration in cerebral cortex and hippocampus and worse cognitive function. In contrast, these variables did not significantly differ between the 2 young groups. Nevertheless, ferritin, phospho-tau, and Aß1-42 expression in hippocampus and ferritin and Aß1-42 expression in cerebral cortex were induced by the high iron diet irrespective of the age of mice (40-200% greater). CONCLUSIONS: High dietary iron induced cognitive defects in old mice but not young mice, suggesting that elderly people should avoid consuming abnormally high concentrations of iron.

3.
Eur J Immunol ; 51(5): 1234-1245, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33454984

RESUMO

Pyroptosis is a type of acute cell death that mainly occurs in immune cells. It is characterized with robust release of inflammatory cytokines and has emerged to play a critical role in the pathogenesis of sepsis-associated immune disorders. In this study, we screened for pyroptotic inhibitors with the ultimate goal to benefit sepsis treatments. Accidentally, we identified that nitrosonisoldipine (NTS), a photodegradation product of calcium channel inhibitor nisoldipine, inhibits noncanonical pyroptosis. Using murine immortalized BM-derived macrophage and human THP-1 cell line, we further discovered that NTS not only inhibits noncanonical pyroptosis mediated by caspase-11 or caspase-4 but also canonical pyroptosis mediated by caspase-1. Mechanistically, NTS directly inhibits the enzyme activities of these inflammatory caspases, and these inhibitory effects persist despite extensive washout of the drug. By contrast, apoptosis mediated by caspase-3/-7 was not affected by NTS. Mice pretreated with NTS intraperitoneally displayed improved survival rate and extended survival time in LPS- and polymicrobe-induced septic models, respectively. In conclusion, NTS is a selective inhibitor of inflammatory caspases that blocks both the noncanonical and canonical pyroptotic pathways. It is safe for intraperitoneal administration and might be used as a prototype to develop drugs for sepsis treatments.


Assuntos
Inibidores de Caspase/farmacologia , Piroptose/efeitos dos fármacos , Choque Séptico/tratamento farmacológico , Choque Séptico/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Apoptose/efeitos dos fármacos , Bloqueadores dos Canais de Cálcio/farmacologia , Bloqueadores dos Canais de Cálcio/uso terapêutico , Inibidores de Caspase/uso terapêutico , Modelos Animais de Doenças , Humanos , Camundongos , Prognóstico , Choque Séptico/etiologia , Choque Séptico/mortalidade , Resultado do Tratamento
4.
Cell Metab ; 32(6): 920-937, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33217331

RESUMO

Acute or chronic cellular stress resulting from aberrant metabolic and biochemical processes may trigger a pervasive non-apoptotic form of cell death, generally known as ferroptosis. Ferroptosis is unique among the different cell death modalities, as it has been mostly linked to pathophysiological conditions and because several metabolic pathways, such as (seleno)thiol metabolism, fatty acid metabolism, iron handling, mevalonate pathway, and mitochondrial respiration, directly impinge on the cells' sensitivity toward lipid peroxidation and ferroptosis. Additionally, key cellular redox systems, such as selenium-dependent glutathione peroxidase 4 and the NAD(P)H/ferroptosis suppressor protein-1/ubiquinone axis, are at play that constantly surveil and neutralize oxidative damage to cellular membranes. Since this form of cell death emerges to be the root cause of a number of diseases and since it offers various pharmacologically tractable nodes for therapeutic intervention, there has been overwhelming interest in the last few years aiming for a better molecular understanding of the ferroptotic death process.


Assuntos
Ferroptose , Ferro/metabolismo , Metabolismo dos Lipídeos , Peroxidação de Lipídeos , Animais , Humanos , Mitocôndrias/metabolismo
5.
PeerJ ; 8: e8380, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32095320

RESUMO

Pancreatic adenocarcinoma (PAAD), the most common subtype of pancreatic cancer, is a highly lethal disease. In this study, we integrated the expression profiles of splicing factors (SFs) of PAAD from RNA-sequencing data to provide a comprehensive view of the clinical significance of SFs. A prognostic index (PI) based on SFs was developed using the least absolute shrinkage and selection operator (LASSO) COX analysis. The PI exhibited excellent performance in predicting the status of overall survival of PAAD patients. We also used the percent spliced in (PSI) value obtained from SpliceSeq software to quantify different types of alternative splicing (AS). The prognostic value of AS events was explored using univariate COX and LASSO COX analyses; AS-based PIs were also proposed. The integration of prognosis-associated SFs and AS events suggested the potential regulatory mechanisms of splicing processes in PAAD. This study defined the markedly clinical significance of SFs and provided novel insight into their potential regulatory mechanisms.

6.
Cell Death Differ ; 27(2): 466-481, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31209359

RESUMO

Hypomagnesemia is a significant risk factor for critically ill patients to develop sepsis, a life-threatening disease with a mortality rate over 25%. Our clinic data analysis showed that hypomagnesemia is associated with a decreased monocyte count in septic patients. At the cellular level, we found that Mg2+ inhibits pyroptosis. Specifically, Mg2+ limits the oligomerization and membrane localization of gasdermin D N-terminal (GSDMD-NT) upon the activation of either the canonical or noncanonical pyroptotic pathway. Mechanistically, we demonstrated that Ca2+ influx is a prerequisite for the function of GSDMD-NT. Mg2+ blocks Ca2+ influx by inhibiting the ATP-gated Ca2+ channel P2X7, thereby impeding the function of GSDMD-NT and inhibiting lipopolysaccharide (LPS)-induced noncanonical pyroptosis. Furthermore, Mg2+ administration protects mice from LPS-induced lethal septic shock. Together, our data reveal the underlying mechanism of how Mg2+ inhibits pyroptosis and suggest potential clinic applications of magnesium supplementation for sepsis prevention and treatment.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Magnésio/farmacologia , Proteínas de Ligação a Fosfato/antagonistas & inibidores , Piroptose/efeitos dos fármacos , Sepse/tratamento farmacológico , Animais , Células Cultivadas , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Lipopolissacarídeos/administração & dosagem , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Magnésio/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Ligação a Fosfato/metabolismo , Sepse/metabolismo , Sepse/patologia
7.
Eur J Immunol ; 50(3): 464-467, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31756255

RESUMO

Pyroptosis is a type of programmed lytic cell death that could be activated by either the canonical or noncanonical inflammasome pathway. In this study, we aimed to examine the effect of hypertonic solution on noncanonical pyroptosis in macrophage. We found that although hypertonic solution had a general inhibitory effect on noncanonical pyroptosis, the underlying mechanism varied by the solute causing hypertonicity. Specifically, hypertonic NaCl or KCl solution inhibited the cleavage of gasdermin D, the pore-forming protein in pyroptosis, whereas hypertonic saccharide solution did not affect the cleavage or membrane binding of gasdermin D. In this case, nevertheless, pyroptosis was still inhibited as evidenced by the preserved mitochondria activity and cell membrane permeability.


Assuntos
Soluções Hipertônicas/química , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Macrófagos/metabolismo , Proteínas de Ligação a Fosfato/metabolismo , Piroptose/fisiologia , Animais , Camundongos
8.
J Nutr ; 149(12): 2247-2254, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31373375

RESUMO

BACKGROUND: Brain iron deposition is a feature of Alzheimer disease and may contribute to its development. However, the relative contribution of dietary iron remains unclear. OBJECTIVES: We investigated the impact of high dietary iron on brain pathological changes and cognitive function in adult wild-type (WT) mice and amyloid precursor protein/presenilin 1 (APP/PS1) double transgenic mice. METHODS: Male WT mice and APP/PS1 mice aged 10 wk were fed either a control diet (66 mg Fe/kg) (WT-Ctrl and APP/PS1-Ctrl) or a high iron diet (14 g Fe/kg) (WT-High Fe and APP/PS1-High Fe) for 20 wk. Iron concentrations in brain regions were measured by atomic absorption spectrophotometry. Brain iron staining and amyloid-ß (Aß) immunostaining were performed. Protein expressions in the hippocampus were determined by immunoblotting. Superoxide dismutase (SOD) activity and malondialdehyde concentration were examined. Cognitive functions were tested with the Morris water maze system. RESULTS: In the hippocampus, APP/PS1-High Fe mice had significantly higher iron concentration (2.5-fold) and ferritin (2.0-fold) than APP/PS1-Ctrl mice (P < 0.001), and WT-High Fe mice had significantly higher ferritin (2.0-fold) than WT-Ctrl mice (P < 0.001). Interestingly, APP/PS1 mice had significantly higher iron concentration (2-3-fold) and ferritin (2-2.5-fold) than WT mice fed either diet (P < 0.001). Histological analysis indicated that iron accumulated in the hippocampal dentate gyrus region in APP/PS1 mice, consistent with the pattern of Aß deposition. For both mouse strains, iron treatment induced Aß and phospho-τ expression (1.5-3-fold) in the hippocampus, but had little impact on oxidative stress and cognitive function. Furthermore, APP/PS1 mice had significantly lower SOD activity and higher malondialdehyde concentration than WT mice in the hippocampus (P < 0.0001), paralleled by apparent cognitive dysfunction. CONCLUSIONS: Dietary iron overload induces iron disorder and Aß and phospho-τ expression in the hippocampus of adult WT and APP/PS1 transgenic mice.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Hipocampo/metabolismo , Homeostase , Ferro/administração & dosagem , Ferro/metabolismo , Presenilina-1/metabolismo , Proteínas tau/metabolismo , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/genética , Animais , Dieta , Crescimento , Masculino , Camundongos , Camundongos Transgênicos , Estresse Oxidativo , Fosforilação , Proteínas tau/genética
9.
Sci Rep ; 9(1): 9437, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31263155

RESUMO

Accumulation of iron has been associated with the pathobiology of various disorders of the central nervous system. Our previous work has shown that hephaestin (Heph) and ceruloplasmin (Cp) double knockout (KO) mice induced iron accumulation in multiple brain regions and that this was paralleled by increased oxidative damage and deficits in cognition and memory. In this study, we enriched astrocytes and oligodendrocytes from the cerebral cortex of neonatal wild-type (WT), Heph KO and Cp KO mice. We demonstrated that Heph is highly expressed in oligodendrocytes, while Cp is mainly expressed in astrocytes. Iron efflux was impaired in Cp KO astrocytes and Heph KO oligodendrocytes and was associated with increased oxidative stress. The expression of Heph, Cp, and other iron-related genes was examined in astrocytes and oligodendrocytes both with and without iron treatment. Interestingly, we found that the expression of the mRNA encoding ferroportin 1, a transmembrane protein that cooperates with CP and HEPH to export iron from cells, was positively correlated with Cp expression in astrocytes, and with Heph expression in oligodendrocytes. Our findings collectively demonstrate that HEPH and CP are important for the prevention of glial iron accumulation and thus may be protective against oxidative damage.


Assuntos
Ceruloplasmina/genética , Ferro/metabolismo , Proteínas de Membrana/genética , Estresse Oxidativo , Animais , Astrócitos/citologia , Astrócitos/metabolismo , Ceruloplasmina/deficiência , Proteínas de Membrana/deficiência , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oligodendroglia/citologia , Oligodendroglia/metabolismo , Estresse Oxidativo/genética
10.
EBioMedicine ; 41: 497-508, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30878597

RESUMO

BACKGROUND: Gut integrity is compromised in abdominal sepsis with increased cellular apoptosis and altered barrier permeability. Intestinal epithelial cells (IEC) form a physiochemical barrier that separates the intestinal lumen from the host's internal milieu and is strongly involved in the mucosal inflammatory response and immune response. Recent research indicates the involvement of the stimulator of interferons genes (STING) pathway in uncontrolled inflammation and gut mucosal immune response. METHODS: We investigated the role of STING signaling in sepsis and intestinal barrier function using intestinal biopsies from human patients with abdominal sepsis and with an established model of abdominal sepsis in mice. FINDINGS: In human abdominal sepsis, STING expression was elevated in peripheral blood mononuclear cells and intestinal biopsies compared with healthy controls, and the degree of STING expression in the human intestinal lamina propria correlated with the intestinal inflammation in septic patients. Moreover, elevated STING expression was associated with high levels of serum intestinal fatty acid binding protein that served as a marker of enterocyte damage. In mice, the intestinal STING signaling pathway was markedly activated following the induction of sepsis induced by cecal ligation perforation (CLP). STING knockout mice showed an alleviated inflammatory response, attenuated gut permeability, and decreased bacterial translocation. Whereas mice treated with a STING agonist (DMXAA) following CLP developed greater intestinal apoptosis and a more severe systemic inflammatory response. We demonstrated that mitochondrial DNA (mtDNA) was released during sepsis, inducing the intestinal inflammatory response through activating the STING pathway. We finally investigated DNase I administration at 5 hours post CLP surgery, showing that it reduced systemic mtDNA and inflammatory cytokines levels, organ damage, and bacterial translocation, suggesting that inhibition of mtDNA-STING signaling pathway protects against CLP-induced intestinal barrier dysfunction. INTERPRETATION: Our results indicate that the STING signaling pathway can contribute to lethal sepsis by promoting IEC apoptosis and through disrupting the intestinal barrier. Our findings suggest that regulation of the mtDNA-STING pathway may be a promising therapeutic strategy to promote mucosal healing and protect the intestinal barrier in septic patients. FUND: National Natural Science Foundation of China.


Assuntos
Intestinos/patologia , Proteínas de Membrana/metabolismo , Sepse/patologia , Animais , Apoptose , Bactérias/isolamento & purificação , Bactérias/metabolismo , Citocinas/análise , Citocinas/sangue , DNA Mitocondrial/metabolismo , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Humanos , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/citologia , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/metabolismo , Proteínas de Membrana/agonistas , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NF-kappa B/metabolismo , Sepse/tratamento farmacológico , Xantonas/uso terapêutico
11.
Zhonghua Wei Chang Wai Ke Za Zhi ; 22(1): 17-21, 2019 Jan 25.
Artigo em Chinês | MEDLINE | ID: mdl-30703788

RESUMO

The published clinical research in 2018 in surgical infection are changing current opinions in the management of acute appendicitis, antibiotics usage, resuscitation of septic shock, and choice of nutritional therapy in critically ill patients. In the management of uncomplicated acute appendicitis, antibiotic therapy can be successful in selected patients who wish to avoid surgery. Delayed primary wound closure can not reduce superficial surgical site infection rates compared to primary wound closure for complicated appendicitis. Infusion of antibiotics 30 minutes before the start of operation may influence their prophylactic effect on surgical site infection. After adequate source control, long-course antibiotic therapy in critically ill post-operative patients is not associated with any clinical benefit. Although susceptible in the test, piperacillin-tazobactam can not replace carbapenems in patients with Escherichia coli and Klebsiella pneumoniae bloodstream infection that produce extended-spectrum beta-lactamase for definitive treatment. Deresuscitation of critically ill patients is associated with reduced mortality. Hydrocortisone therapy has potential role in the patients with septic shock and worth further evidence. The use of an energy-dense formulation for enteral delivery of nutrition can not improve 90-day survival rate in patients undergoing mechanical ventilation. Compared with early isocaloric parenteral nutrition, early enteral nutrition did not reduce mortality or the risk of secondary infections, but was associated with a greater risk of digestive complications in critically ill adults with septic shock.


Assuntos
Antibacterianos/uso terapêutico , Apendicite/terapia , Apoio Nutricional , Choque Séptico/terapia , Infecção da Ferida Cirúrgica/terapia , Antibacterianos/administração & dosagem , Apendicite/complicações , Estado Terminal , Humanos , Choque Séptico/etiologia , Infecção da Ferida Cirúrgica/etiologia , Infecção da Ferida Cirúrgica/prevenção & controle
12.
Acta Physiol (Oxf) ; 225(3): e13194, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30269441

RESUMO

Stimulator of interferons genes (STING) is an adaptor protein that plays a critical role in the secretion of type I interferons and pro-inflammatory cytokines in response to cytosolic nucleic acid. Recent research indicates the involvement of the STING pathway in uncontrolled inflammation, sepsis, and shock. STING signaling is significantly up-regulated in human sepsis, and STING agonists are suggested to contribute to the pathogenesis of sepsis and shock. Nevertheless, little is known about the consequences of activated STING-mediated signaling during sepsis. It has been shown that aberrant activation of the STING-dependent way can result in increased inflammation, type I interferons responses, and cell death (including apoptosis, necroptosis, and pyroptosis). In addition, autophagy modulation has been demonstrated to protect against multiple organs injuries in animal sepsis model. However, impaired autophagy may contribute to the aberrant activation of STING signaling, leading to uncontrolled inflammation and cell death. Here we present a comprehensive review of recent advances in the understanding of STING signaling, focusing on the regulatory mechanisms and the roles of this pathway in sepsis.


Assuntos
Autofagia/fisiologia , Morte Celular/fisiologia , Inflamação/metabolismo , Interferons/metabolismo , Sepse/metabolismo , Animais , Humanos , Transdução de Sinais/fisiologia
13.
Biochem Biophys Res Commun ; 503(3): 1905-1910, 2018 09 10.
Artigo em Inglês | MEDLINE | ID: mdl-30060949

RESUMO

Multi-copper ferroxidases (MCFs) play important roles in cellular iron metabolism and homeostasis. In this study, we generated the hephaestin (Heph), ceruloplasmin (Cp) single and Heph/Cp double knockout (KO) mice to investigate the roles of MCFs in iron transport among system and vital organs in mice at 4 weeks and 6 months of age. Compared with wild-type (WT) mice, Heph/Cp mice at both ages presented with severe anemia and significantly lower iron level in the serum and spleen, but with significantly higher iron level in the liver, heart, kidney, and duodenal enterocytes. Furthermore, Heph/Cp mice displayed significantly lower level of hepcidin mRNA and transferrin receptor 1 (TFR1) protein expression, but significantly higher level of ferroportin 1 (FPN1) protein expression in the liver than WT mice at 6 months of age. Liver superoxide dismutase (SOD) and glutathione peroxidase (GPx) enzyme activities were significantly lower in Heph/Cp KO mice than WT mice at 6 months of age. Together, our results suggest that ablation of HEPH and CP could lead to severe systemic iron deficiency and local tissue iron overload, which disrupt the whole body iron homeostasis and impact on tissue functions.


Assuntos
Anemia Ferropriva/genética , Anemia Ferropriva/metabolismo , Ceruloplasmina/deficiência , Deleção de Genes , Homeostase/genética , Ferro/metabolismo , Proteínas de Membrana/deficiência , Animais , Ceruloplasmina/genética , Ceruloplasmina/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
14.
Redox Biol ; 17: 432-439, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29883959

RESUMO

Little is known about the iron efflux from the pancreas, but it is likely that multicopper ferroxidases (MCFs) are involved in this process. We thus used hephaestin (Heph) and ceruloplasmin (Cp) single-knockout mice and Heph/Cp double-knockout mice to investigate the roles of MCFs in pancreatic iron homeostasis. We found that both HEPH and CP were expressed in the mouse pancreas, and that ablation of either MCF had limited effect on the pancreatic iron levels. However, ablation of both MCFs together led to extensive pancreatic iron deposition and severe oxidative damage. Perls' Prussian blue staining revealed that this iron deposition was predominantly in the exocrine pancreas, while the islets were spared. Consistent with these results, plasma lipase and trypsin were elevated in Heph/Cp knockout mice, indicating damage to the exocrine pancreas, while insulin secretion was not affected. These data indicate that HEPH and CP play mutually compensatory roles in facilitating iron efflux from the exocrine pancreas, and show that MCFs are able to protect the pancreas against iron-induced oxidative damage.


Assuntos
Ceruloplasmina/genética , Ferro/metabolismo , Proteínas de Membrana/genética , Estresse Oxidativo/genética , Animais , Ceruloplasmina/metabolismo , Homeostase/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Knockout , Oxirredução , Oxirredutases/genética , Oxirredutases/metabolismo , Pâncreas Exócrino/metabolismo , Pâncreas Exócrino/patologia
15.
J Nutr ; 148(4): 643-649, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29659961

RESUMO

Background: The accumulation of iron occurs in the central nervous system (CNS) in several neurodegenerative diseases. Although multi-copper ferroxidases (MCFs) play an important role in cellular iron metabolism and homeostasis, the mechanism of MCFs in the CNS remains unclear. Objective: The aim was to study the role of MCFs in CNS iron metabolism and homeostasis by using hephaestin/ceruloplasmin (Heph/Cp) double knockout (KO) mice. Methods: Heph/Cp double KO male mice were generated by crossing both single KO mice. In Heph/Cp KO and wild-type (WT) control mice at 4 wk and 6 mo of age, iron concentrations of selected brain regions were measured by atomic absorption spectrophotometry, and gene expressions of Heph, Cp, ferroportin 1 (Fpn1) [+ iron responsive element (IRE)], L-ferritin, H-ferritin, transferrin receptor 1 (Tfrc), and divalent metal transporter 1 (Dmt1) (+IRE) were quantitated by quantitative reverse transcriptase-polymerase chain reaction. Brain region L-ferritin protein concentration, superoxide dismutase (SOD), and glutathione peroxidase (GPx) activities and malondialdehyde (MDA) concentration were also determined. Learning and memory abilities in Heph/Cp KO and WT control mice at 6 mo of age were tested by the IntelliCage system (New Behavior). Results: Iron concentration was significantly higher in Heph/Cp KO mice than in WT control mice at 4 wk of age in the cortex (50%), hippocampus (120%), brainstem (35%), and cerebellum (220%) and at 6 mo of age in the cortex (140%), hippocampus (420%), brainstem (560%), and cerebellum (340%). L-Ferritin and MDA concentrations were significantly higher and SOD and GPx activities were significantly lower in the cortex, hippocampus, brainstem, and cerebellum of KO mice than in those of WT controls at both 4 wk and 6 mo of age. Iron-related gene expressions also differed significantly between groups. Learning and memory deficits occurred in Heph/Cp KO mice at 6 mo of age. Conclusion: Mutation of both MCFs in mice induces iron accumulation in brain regions, oxidative damage, and learning and memory defects.


Assuntos
Encéfalo/metabolismo , Ceruloplasmina/deficiência , Cobre/metabolismo , Ferro/metabolismo , Deficiências da Aprendizagem/etiologia , Transtornos da Memória/etiologia , Estresse Oxidativo , Animais , Comportamento Animal , Proteínas de Transporte de Cátions/metabolismo , Ceruloplasmina/metabolismo , Ferritinas/metabolismo , Glutationa Peroxidase/metabolismo , Aprendizagem , Masculino , Malondialdeído/metabolismo , Memória , Camundongos Knockout , Receptores da Transferrina/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Superóxido Dismutase/metabolismo
16.
FEBS Lett ; 592(3): 394-401, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29355933

RESUMO

Little is known about the iron efflux mechanism in adipocytes. Here, we used hephaestin (Heph) and ceruloplasmin (Cp) single-knockout (KO) mice and Heph/Cp double-KO mice to investigate the roles of multicopper ferroxidases (MCFs) in this process. We show that both HEPH and CP are expressed in subcutaneous adipose tissue. Ablation of either MCF leads to a compensatory increase in the other, which contributes to the balance of iron status. However, ablation of both MCFs together induces severe iron deposition in adipocytes which is associated with decreased adiponectin and leptin mRNA expression. Furthermore, Heph/Cp KO mice display disordered carbohydrate metabolism characterized as type 2 diabetes. Together, these results demonstrate the protective roles of HEPH and CP in preventing iron overload in adipocytes.


Assuntos
Adipócitos/metabolismo , Ceruloplasmina/genética , Diabetes Mellitus Tipo 2/metabolismo , Ferro/metabolismo , Proteínas de Membrana/genética , Adiponectina/genética , Animais , Ceruloplasmina/metabolismo , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/veterinária , Técnicas de Inativação de Genes , Leptina/genética , Masculino , Proteínas de Membrana/metabolismo , Camundongos
17.
Sci Rep ; 6: 39470, 2016 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-27991585

RESUMO

Multicopper ferroxidases (MCFs) play an important role in cellular iron homeostasis. However, the role of MCFs in renal metabolism remains unclear. We used Hephaestin (Heph) and Ceruloplasmin (Cp) single or double (Heph/Cp) knockout (KO) mice to study the roles of MCFs in the kidney. Renal iron levels and the expression of iron metabolism genes were examined. The non-heme iron content both in the renal cortex and medulla of Heph/Cp KO mice was significantly increased. Perls' Prussian blue staining showed iron accumulation on the apical side of renal tubular cells in Heph/Cp KO mice. A significant increase in ferritin protein expression was also observed in the renal medulla and cortex of Heph/Cp KO mice. Both DMT1 and TfR1 protein expression were significantly decreased in the renal medulla of Heph/Cp KO mice, while the expression of DMT1 protein was significantly increased in the renal cortex of these animals. Significant increase in proteinuria and total urinary iron was observed in the double knockout mice, and this was associated with compromised structural integrity. These results suggest that KO of both the HEPH and CP genes leads to kidney iron deposition and toxicity, MCFs could protect kidney against a damage from iron excess.


Assuntos
Ceruloplasmina/genética , Ceruloplasmina/metabolismo , Ferro/metabolismo , Rim/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Animais , Cobre/química , Ferritinas/metabolismo , Ferrocianetos , Genótipo , Homeostase , Córtex Renal , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
18.
J Nutr ; 145(5): 1003-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25788583

RESUMO

BACKGROUND: Iron accumulation in the central nervous system (CNS) is a common feature of many neurodegenerative diseases. Multicopper ferroxidases (MCFs) play an important role in cellular iron metabolism. However, the role of MCFs in the CNS in health and disease remains poorly characterized. OBJECTIVE: The aim was to study the role of hephaestin (HEPH) and ceruloplasmin (CP) in CNS iron metabolism and homeostasis. METHODS: Iron concentrations and L-ferritin protein levels of selected brain regions were determined in global hephaestin knockout (Heph KO), global ceruloplasmin knockout (Cp KO), and wild-type (WT) male mice at 6-7 mo of age. Gene expression of divalent metal transporter 1 (Dmt1), ferroportin 1 (Fpn1), Heph, Cp, and transferrin receptor 1 (Tfrc) and HEPH protein level was quantitated in the same brain regions. RESULTS: Iron and L-ferritin protein levels were significantly increased in Heph KO mouse brain cortex (iron: 30%, P < 0.05; L-ferritin: 200%, P < 0.05), hippocampus (iron: 80%, P < 0.05; L-ferritin: 300%, P < 0.05), brainstem (iron: 20%, P < 0.05; L-ferritin: 150%, P < 0.05), and cerebellum (iron: 20%, P < 0.05; L-ferritin: 100%, P < 0.05) regions than in WT and Cp KO mouse brain regions at 6 mo of age. Expression of the Heph gene was significantly increased in the Cp KO mouse cortex (100%; P < 0.01), hippocampus (350%; P < 0.001), brainstem (30%; P < 0.01), and cerebellum (150%; P < 0.001) than in WT controls, and Cp gene expression was significantly decreased in the Heph KO mouse hippocampus (20%; P < 0.05) than in WT control mice at 6 mo of age. CONCLUSIONS: Ablation of HEPH or CP results in disordered brain iron homeostasis in mice. Heph KO may provide a novel model for neurodegenerative disorders.


Assuntos
Encéfalo/metabolismo , Ceruloplasmina/metabolismo , Regulação da Expressão Gênica , Homeostase , Ferro/metabolismo , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Tronco Encefálico/metabolismo , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Cerebelo/metabolismo , Córtex Cerebral/metabolismo , Ceruloplasmina/genética , Hipocampo/metabolismo , Masculino , Proteínas de Membrana/genética , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Neurônios/metabolismo , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo
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