Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 11.842
Filtrar
1.
Ecotoxicol Environ Saf ; 203: 110928, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32888618

RESUMO

Hexavalent chromium [Cr(VI)] is seriously harmful to ecosystems and living organisms due to its strong toxicity. Role of dynamin-related protein 1 (Drp1) and Drp1-associated mitochondrial fragmentation in mitophagy and cytotoxicity after Cr(VI) exposure has not been clarified so far. We confirmed that Cr(VI) caused mitochondrial fission by up-regulating Drp1 expression and enhancing Drp1 mitochondrial translocation. By applying the intracellular Ca2+ antagonist BAPTA-AM and mitochondrial Ca2+ antagonist Ru360, we demonstrated that Cr(VI)-induced excessive mitochondrial fission was in a Ca2+-Drp1 dependent manner. The administration of Drp1 siRNA significantly suppressed the overactivation of mitophagy in Cr(VI)-induced hepatotoxicity. The specific Drp1 inhibitor mitochondrial division inhibitor-1 (Mdivi-1) blocked the overactive mitophagy and subsequently ameliorated hepatotoxicity caused by Cr(VI) in vivo. We reached the conclusion that Drp1-dependent mitochondrial fission contributes to Cr(VI)-induced mitophagy and hepatotoxicity, which may provide experimental basis for the study of chromium-associated toxicity, especially for the prevention of health damage in chromium-exposed population.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/etiologia , Cromo/toxicidade , Dinaminas/metabolismo , Poluentes Ambientais/toxicidade , Hepatócitos/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , Mitofagia/efeitos dos fármacos , Animais , Linhagem Celular , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Ecossistema , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Mitocôndrias Hepáticas/patologia , RNA Interferente Pequeno/metabolismo
2.
PLoS One ; 15(9): e0237809, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32915792

RESUMO

Chimeric mice with humanized livers are considered a useful animal model for predicting human (h-) drug metabolism and toxicity. In this study, the characteristics of fresh h-hepatocytes (cFHHs, PXB-cells®) isolated from chimeric mice (PXB-mice®) were evaluated in vitro to confirm their utility for drug development. cFHHs cultured at high density (2.13 × 105 cells/cm2) displayed stable production of h-albumin and cytochrome P450 (CYP) 3A activities for at least 21 days. The mRNA expression levels of 10 of 13 CYP, UDP-glucuronosyltransferase (UGT), and transporters were maintained at >10% of the levels of freshly isolated cFHHs after 21 days. From 1 week, many bile canaliculi were observed between cFHHs, and the accumulation of the multidrug resistance-associated protein and bile salt export pump substrates in these bile canaliculi was clearly inhibited by cyclosporin A. Microarray analysis of cFHHs cultured at high density and at low density (0.53 × 105 cells/cm2) revealed that high density culture maintained high expressions of some transcription factors (HNF4α, PXR, and FXR) perhaps involved in the high CYP, UGT and transporter gene expressions of cFHHs. These results strongly suggest that cFHHs could be a novel in vitro tool for drug development studies.


Assuntos
Canalículos Biliares/efeitos dos fármacos , Desenvolvimento de Medicamentos/métodos , Hepatócitos/efeitos dos fármacos , Cultura Primária de Células/métodos , Quimeras de Transplante , Animais , Canalículos Biliares/citologia , Canalículos Biliares/metabolismo , Células Cultivadas , Criança , Pré-Escolar , Ciclosporina/farmacologia , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Feminino , Glucuronosiltransferase/genética , Glucuronosiltransferase/metabolismo , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , Masculino , Camundongos , Camundongos SCID , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
3.
Ecotoxicol Environ Saf ; 205: 111326, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32961495

RESUMO

Hexavalent chromium [Cr(VI)] is ubiquitous in the environment and is commonly used in various industrial processes. Clusterin (CLU) is an extracellular chaperone protein which exerts the anti-apoptotic function. In this study, we aimed to explore the effect of CLU on Cr(VI)-induced mitochondrial fission and apoptosis. We revealed that the apoptosis rate of L02 hepatocytes treated with Cr (VI) was increased. CLU over-expression could protect the hepatocytes from Cr(VI)-induced mitochondrial apoptosis. Furthermore, Cr(VI) triggered the intracellular calcium overload, resulting in the activation of xanthine oxidase (XO). Cr(VI) induced reactive oxygen species (ROS) overproduction, led to dynamin-related protein 1 (Drp1) translocation to mitochondria and the subsequent mitochondrial fission, contributing to the caspase-3-dependent mitochondrial apoptosis as evidenced by higher mitochondrial permeability transition pore (mPTP) opening rate, lower mitochondrial membrane potential (MMP), and more alanine transaminase (ALT)/aspartate transaminase (AST) leakage into the culture medium. However, CLU over-expression could trigger the AMP-activated protein kinase (AMPK) pathway, which was followed by the increase of sarcoplasmic reticulum Ca2+-ATPase (SERCA2a) expression. CLU-induced AMPK/SERCA2a activation attenuated calcium overload, caspase-3 activation, and ultimate mitochondrial apoptosis. All in all, the present study demonstrated that Cr(VI) induced hepatocytes apoptosis via Ca2+-ROS-Drp1-mitochondrial fission axis and CLU alleviated the mitochondrial apoptosis through activation of the AMPK/SERCA2a pathway.


Assuntos
Cromo/toxicidade , Clusterina/metabolismo , Poluentes Ambientais/toxicidade , Apoptose/efeitos dos fármacos , Caspase 3 , Dinaminas , Hepatócitos/efeitos dos fármacos , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
4.
Aquat Toxicol ; 227: 105586, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32882451

RESUMO

Estrogenic effects triggered by androgens have been previously shown in a few studies. Aromatization and direct binding to estrogen receptors (ERs) are the most proposed mechanisms. For example, previously, a modulation of vitellogenin A (VtgA) by testosterone (T), an aromatizable androgen, was reported in brown trout primary hepatocytes. The effect was reversed by an ER antagonist. In this study, using the same model the disruption caused by T and by the non-aromatizable androgen - dihydrotestosterone (DHT), was assessed in selected estrogenic targets. Hepatocytes were exposed (96 h) to six concentrations of each androgen. The estrogenic targets were VtgA, ERα, ERß1 and two zona pellucida genes, ZP2.5 and ZP3a.2. The aromatase CYP19a1 gene and the androgen receptor (AR) were also included. Modulation of estrogenic targets was studied by quantitative real-time PCR and immunohistochemistry, using an HScore system. VtgA and ERα were up-regulated by DHT (1, 10, 100 µM) and T (10, 100 µM). In contrast, ERß1 was down-regulated by DHT (10, 100 µM), and T (100 µM). ZP2.5 mRNA levels were increased by DHT and T (1, 10, 100 µM), while ZP3a.2 was up-regulated by DHT (100 µM) and T (10, 100 µM). Positive correlations were found between VtgA and ERα mRNA levels and ZPs and ERα, after exposure to both androgens. The mRNA levels of CYP19a1 were not changed, while AR expression tended to increase after micromolar DHT exposures. HScores for Vtg and ZPs corroborated the molecular findings. Both androgens triggered estrogen signaling through direct binding to ERs, most probably ERα.


Assuntos
Androgênios/toxicidade , Di-Hidrotestosterona/toxicidade , Estrogênios/metabolismo , Hepatócitos/efeitos dos fármacos , Testosterona/toxicidade , Truta/metabolismo , Poluentes Químicos da Água/toxicidade , Androgênios/metabolismo , Animais , Células Cultivadas , Di-Hidrotestosterona/metabolismo , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Receptor beta de Estrogênio/genética , Receptor beta de Estrogênio/metabolismo , Estrogênios/genética , Expressão Gênica/efeitos dos fármacos , Hepatócitos/metabolismo , Masculino , Cultura Primária de Células , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Testosterona/metabolismo , Vitelogeninas/genética , Vitelogeninas/metabolismo , Poluentes Químicos da Água/metabolismo
5.
Mol Pharmacol ; 98(3): 267-279, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32817462

RESUMO

Human cytochrome P450 (P450) CYP2B6 undergoes nitric oxide (NO)-dependent proteasomal degradation in response to the NO donor dipropylenetriamine NONOate (DPTA) and biologic NO in HeLa and HuH7 cell lines. CYP2B6 is also downregulated by NO in primary human hepatocytes. We hypothesized that NO or derivative reactive nitrogen species may generate adducts of tyrosine and/or cysteine residues, causing CYP2B6 downregulation, and selected Tyr and Cys residues for mutation based on predicted solvent accessibility. CYP2B6V5-Y317A, -Y380A, and -Y190A mutant proteins expressed in HuH7 cells were less sensitive than wild-type (WT) enzyme to degradation evoked by DPTA, suggesting that these tyrosines are targets for NO-dependent downregulation. The Y317A or Y380A mutants did not show increases in high molecular mass (HMM) species after treatment with DPTA or bortezomib + DPTA, in contrast to the WT enzyme. Carbon monoxide-releasing molecule 2 treatment caused rapid suppression of 2B6 enzyme activity, significant HMM species generation, and ubiquitination of CYP2B6 protein but did not stimulate CYP2B6 degradation. The CYP2B6 inhibitor 4-(4-chlorophenyl)imidazole blocked NO-dependent CYP2B6 degradation, suggesting that NO access to the active site is important. Molecular dynamics simulations predicted that tyrosine nitrations of CYP2B6 would cause significant destabilizing perturbations of secondary structure and remove correlated motions likely required for enzyme function. We propose that cumulative nitrations of Y190, Y317, and Y380 by reactive nitrogen species cause destabilization of CYP2B6, which may act synergistically with heme nitrosylation to target the enzyme for degradation. SIGNIFICANCE STATEMENT: This work provides novel insight into the mechanisms by which nitric oxide, which is produced in hepatocytes in response to inflammation, triggers the ubiquitin-dependent proteasomal degradation of the cytochrome P450 (P450) enzyme CYP2B6. Our data demonstrate that both nitration of specific tyrosine residues and interaction of nitric oxide (NO) with the P450 heme are necessary for NO to trigger ubiquitination and protein degradation.


Assuntos
Citocromo P-450 CYP2B6/química , Citocromo P-450 CYP2B6/metabolismo , Doadores de Óxido Nítrico/farmacologia , Tirosina/química , Linhagem Celular , Citocromo P-450 CYP2B6/genética , Regulação para Baixo , Células HeLa , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Cultura Primária de Células , Proteólise
6.
Ecotoxicol Environ Saf ; 205: 111166, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32827966

RESUMO

N, N-Dimethylformamide (DMF) is a universal organic solvent which widely used in various industries, and a considerable amount of DMF is detected in industrial effluents. Accumulating animal and epidemiological studies have identified liver injury as an early toxic effect of DMF exposure; however, the detailed mechanisms remain poorly understood. In this study, we systematically integrated the quantitative proteomics, lipidomics, and metabolomics data obtained from the primary human hepatocytes exposed to DMF, to depict the complicated biochemical reactions correlated to liver damage. Eventually, we identified 284 deregulated proteins (221 downregulated and 63 upregulated) and 149 deregulated lipids or metabolites (99 downregulated and 50 upregulated) induced by DMF exposure. Further, the integration of the protein-metabolite (lipid) interactions revealed that N-glycan biosynthesis (involved in the endoplasmic reticulum stress and the unfolded protein response), bile acid metabolism (involved in the lipid metabolism and the inflammatory process), and mitochondrial dysfunction and glutathione depletion (both contributed to reactive oxygen species) were the typical biochemical reactions disturbed by DMF exposure. In summary, our study identified the versatile protein, lipid, and metabolite molecules in multiple signaling and metabolic pathways involved in DMF induced liver injury, and provided new insights to elucidate the toxic mechanisms of DMF.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Dimetilformamida/toxicidade , Poluentes Ambientais/toxicidade , Hepatócitos/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Metaboloma/efeitos dos fármacos , Proteoma/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Glutationa/metabolismo , Hepatócitos/metabolismo , Humanos , Lipidômica , Metabolômica , Cultura Primária de Células , Proteômica , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais , Testes de Toxicidade/métodos
7.
Cardiovasc Ther ; 2020: 9397109, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32821285

RESUMO

Chronic systemic inflammation contributes to cardiovascular disease (CVD) and correlates with the abundance of acute phase response (APR) proteins in the liver and plasma. Bromodomain and extraterminal (BET) proteins are epigenetic readers that regulate inflammatory gene transcription. We show that BET inhibition by the small molecule apabetalone reduces APR gene and protein expression in human hepatocytes, mouse models, and plasma from CVD patients. Steady-state expression of serum amyloid P, plasminogen activator inhibitor 1, and ceruloplasmin, APR proteins linked to CVD risk, is reduced by apabetalone in cultured hepatocytes and in humanized mouse liver. In cytokine-stimulated hepatocytes, apabetalone reduces the expression of C-reactive protein (CRP), alpha-2-macroglobulin, and serum amyloid P. The latter two are also reduced by apabetalone in the liver of endotoxemic mice. BET knockdown in vitro also counters cytokine-mediated induction of the CRP gene. Mechanistically, apabetalone reduces the cytokine-driven increase in BRD4 BET occupancy at the CRP promoter, confirming that transcription of CRP is BET-dependent. In patients with stable coronary disease, plasma APR proteins CRP, IL-1 receptor antagonist, and fibrinogen γ decrease after apabetalone treatment versus placebo, resulting in a predicted downregulation of the APR pathway and cytokine targets. We conclude that CRP and components of the APR pathway are regulated by BET proteins and that apabetalone counters chronic cytokine signaling in patients.


Assuntos
Anti-Inflamatórios/farmacologia , Proteína C-Reativa/metabolismo , Doenças Cardiovasculares/tratamento farmacológico , Citocinas/metabolismo , Endotoxemia/tratamento farmacológico , Epigênese Genética/efeitos dos fármacos , Proteínas Nucleares/metabolismo , Quinazolinonas/farmacologia , Fatores de Transcrição/metabolismo , Animais , Sítios de Ligação , Proteína C-Reativa/genética , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/metabolismo , Células Cultivadas , Ceruloplasmina/genética , Ceruloplasmina/metabolismo , Citocinas/genética , Modelos Animais de Doenças , Endotoxemia/genética , Endotoxemia/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Proteínas Nucleares/genética , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Regiões Promotoras Genéticas , Componente Amiloide P Sérico/metabolismo , Transdução de Sinais , Fatores de Transcrição/genética , alfa-Macroglobulinas/genética , alfa-Macroglobulinas/metabolismo
8.
PLoS One ; 15(8): e0236392, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32780735

RESUMO

In clinical trials, animal and cell line models are often used to evaluate the potential toxic effects of a novel compound or candidate drug before progressing to human trials. However, relating the results of animal and in vitro model exposures to relevant clinical outcomes in the human in vivo system still proves challenging, relying on often putative orthologs. In recent years, multiple studies have demonstrated that the repeated dose rodent bioassay, the current gold standard in the field, lacks sufficient sensitivity and specificity in predicting toxic effects of pharmaceuticals in humans. In this study, we evaluate the potential of deep learning techniques to translate the pattern of gene expression measured following an exposure in rodents to humans, circumventing the current reliance on orthologs, and also from in vitro to in vivo experimental designs. Of the applied deep learning architectures applied in this study the convolutional neural network (CNN) and a deep artificial neural network with bottleneck architecture significantly outperform classical machine learning techniques in predicting the time series of gene expression in primary human hepatocytes given a measured time series of gene expression from primary rat hepatocytes following exposure in vitro to a previously unseen compound across multiple toxicologically relevant gene sets. With a reduction in average mean absolute error across 76 genes that have been shown to be predictive for identifying carcinogenicity from 0.0172 for a random regression forest to 0.0166 for the CNN model (p < 0.05). These deep learning architecture also perform well when applied to predict time series of in vivo gene expression given measured time series of in vitro gene expression for rats.


Assuntos
Aprendizado Profundo , Regulação da Expressão Gênica/efeitos dos fármacos , Aprendizado de Máquina , Algoritmos , Animais , Ensaios Clínicos como Assunto/estatística & dados numéricos , Regulação da Expressão Gênica/genética , Hepatócitos/efeitos dos fármacos , Humanos , Redes Neurais de Computação , Ratos
9.
Anticancer Res ; 40(8): 4491-4504, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32727779

RESUMO

BACKGROUND: Peroxiredoxin II (PRDX2) performs unique roles in cells. It can reduce peroxides through cysteine residues, and helps prevent the effects of oxidative stress on cells. It is closely related to the occurrence and development of various diseases, especially alcoholic liver injury and even liver cancer. The metabolism of alcohol in hepatocytes leads to the increase in the levels of reactive oxygen species (ROS), oxidative stress, injury, and apoptosis. Therefore, this study focused on the investigating the protection conferred by PRDX2 against alcohol-induced apoptosis of hepatocytes. MATERIALS AND METHODS: PRDX2 inhibition of alcohol-induced apoptosis in L02 hepatocytes was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, fluorescence microscopy, flow cytometry, western blotting and hematoxylin and eosin staining. RESULTS: The results showed that the levels of reactive oxygen species, protein kinase B, ß-catenin, B-cell lymphoma-2 (BCL2), BCL-XL, BCL2-associated X, cleaved caspase-3, and cleaved poly (ADP-ribose) polymerase in PRDX2-silenced cells were increased significantly after the treatment of cells with ethanol. Similar results were obtained in an in vivo Prdx2-knockout mouse model of alcoholic liver injury. Therefore, PRDX2 may regulate the phosphorylation of the AKT signal protein by eliminating reactive oxygen species from cells, and it inhibits the downstream mitochondria-dependent apoptosis pathway, and, thereby, the apoptosis of cells. CONCLUSION: Thus, PRDX2 may be a potential molecular target for the prevention and treatment of alcoholic liver injury.


Assuntos
Etanol/efeitos adversos , Hepatócitos/citologia , Peroxirredoxinas/genética , Transdução de Sinais , Apoptose , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Inativação Gênica , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Fosforilação/efeitos dos fármacos , Poli(ADP-Ribose) Polimerases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , beta Catenina/metabolismo
10.
Nat Commun ; 11(1): 3360, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620763

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is considered the next major health epidemic with an estimated 25% worldwide prevalence. No drugs have yet been approved and NAFLD remains a major unmet need. Here, we identify MCJ (Methylation-Controlled J protein) as a target for non-alcoholic steatohepatitis (NASH), an advanced phase of NAFLD. MCJ is an endogenous negative regulator of the respiratory chain Complex I that acts to restrain mitochondrial respiration. We show that therapeutic targeting of MCJ in the liver with nanoparticle- and GalNAc-formulated siRNA efficiently reduces liver lipid accumulation and fibrosis in multiple NASH mouse models. Decreasing MCJ expression enhances the capacity of hepatocytes to mediate ß-oxidation of fatty acids and minimizes lipid accumulation, which results in reduced hepatocyte damage and fibrosis. Moreover, MCJ levels in the liver of NAFLD patients are elevated relative to healthy subjects. Thus, inhibition of MCJ emerges as an alternative approach to treat NAFLD.


Assuntos
Ácidos Graxos/metabolismo , Proteínas de Choque Térmico HSP40/metabolismo , Fígado/patologia , Mitocôndrias/efeitos dos fármacos , Proteínas Mitocondriais/metabolismo , Chaperonas Moleculares/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Adulto , Idoso , Animais , Conjuntos de Dados como Assunto , Dieta Hiperlipídica/efeitos adversos , Modelos Animais de Doenças , Feminino , Proteínas de Choque Térmico HSP40/antagonistas & inibidores , Proteínas de Choque Térmico HSP40/genética , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Fígado/citologia , Fígado/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Proteínas Mitocondriais/antagonistas & inibidores , Proteínas Mitocondriais/genética , Chaperonas Moleculares/antagonistas & inibidores , Chaperonas Moleculares/genética , Nanopartículas/administração & dosagem , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Oxirredução/efeitos dos fármacos , Cultura Primária de Células , RNA Interferente Pequeno/administração & dosagem , RNA-Seq
11.
Artigo em Inglês | MEDLINE | ID: mdl-32660993

RESUMO

Previously, ivermectin (1 to 10 mg/kg of body weight) was shown to inhibit the liver-stage development of Plasmodium berghei in orally dosed mice. Here, ivermectin showed inhibition of the in vitro development of Plasmodium cynomolgi schizonts (50% inhibitory concentration [IC50], 10.42 µM) and hypnozoites (IC50, 29.24 µM) in primary macaque hepatocytes when administered as a high dose prophylactically but not when administered in radical cure mode. The safety, pharmacokinetics, and efficacy of oral ivermectin (0.3, 0.6, and 1.2 mg/kg) with and without chloroquine (10 mg/kg) administered for 7 consecutive days were evaluated for prophylaxis or radical cure of P. cynomolgi liver stages in rhesus macaques. No inhibition or delay to blood-stage P. cynomolgi parasitemia was observed at any ivermectin dose (0.3, 0.6, and 1.2 mg/kg). Ivermectin (0.6 and 1.2 mg/kg) and chloroquine (10 mg/kg) in combination were well-tolerated with no adverse events and no significant pharmacokinetic drug-drug interactions observed. Repeated daily ivermectin administration for 7 days did not inhibit ivermectin bioavailability. It was recently demonstrated that both ivermectin and chloroquine inhibit replication of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vitro Further ivermectin and chloroquine trials in humans are warranted to evaluate their role in Plasmodium vivax control and as adjunctive therapies against COVID-19 infections.


Assuntos
Antimaláricos/farmacologia , Cloroquina/farmacologia , Ivermectina/farmacologia , Fígado/efeitos dos fármacos , Malária/tratamento farmacológico , Plasmodium cynomolgi/efeitos dos fármacos , Animais , Antimaláricos/sangue , Antimaláricos/farmacocinética , Disponibilidade Biológica , Cloroquina/sangue , Cloroquina/farmacocinética , Esquema de Medicação , Combinação de Medicamentos , Sinergismo Farmacológico , Feminino , Hepatócitos/efeitos dos fármacos , Hepatócitos/parasitologia , Ivermectina/sangue , Ivermectina/farmacocinética , Fígado/parasitologia , Macaca mulatta , Malária/parasitologia , Masculino , Parasitemia/tratamento farmacológico , Plasmodium cynomolgi/crescimento & desenvolvimento , Plasmodium cynomolgi/patogenicidade , Cultura Primária de Células , Esquizontes/efeitos dos fármacos , Esquizontes/crescimento & desenvolvimento
12.
Toxicol Lett ; 332: 222-234, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32679240

RESUMO

The relative toxicity of three legacy and six emerging brominated flame retardants* was studied in the male Harlan Sprague Dawley rat. The hepatocellular and thyroid toxicity of each flame retardant was evaluated following five-day exposure to each of the nine flame retardants (oral gavage in corn oil) at 0.1-1000 µmol/kg body weight per day. Histopathology and transcriptomic analysis were performed on the left liver lobe. Centrilobular hypertrophy of hepatocytes and increases in liver weight were seen following exposure to two legacy (PBDE-47, HBCD) and to one emerging flame retardant (HCDBCO). Total thyroxine (TT4) concentrations were reduced to the greatest extent after PBDE-47 exposure. The PBDE-47, decaBDE, and HBCD liver transcriptomes were characterized by upregulation of liver disease-related and/or metabolic transcripts. Fewer liver disease or metabolic transcript changes were detected for the other flame retardants studied (TBB, TBPH, TBBPA-DBPE, BTBPE, DBDPE, or HCDBCO). PBDE-47 exhibited the most disruption of hepatocellular toxic endpoints, with the Nrf2 antioxidant pathway transcripts upregulated to the greatest extent, although some activation of this pathway also occurred after decaBDE, HBCD, TBB, and HCBCO exposure. These studies provide information that can be used for prioritizing the need for more in-depth brominated flame retardant toxicity studies.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas/patologia , Retardadores de Chama/toxicidade , Hidrocarbonetos Bromados/toxicidade , Fígado/metabolismo , Transcriptoma/efeitos dos fármacos , Animais , Tamanho Celular/efeitos dos fármacos , Monitoramento Ambiental , Hepatócitos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Doenças da Glândula Tireoide/induzido quimicamente , Doenças da Glândula Tireoide/patologia , Tiroxina/metabolismo , Toxicogenética
13.
PLoS Comput Biol ; 16(6): e1007622, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32484845

RESUMO

Interpretations of elevated blood levels of alanine aminotransferase (ALT) for drug-induced liver injury often assume that the biomarker is released passively from dying cells. However, the mechanisms driving that release have not been explored experimentally. The usefulness of ALT and related biomarkers will improve by developing mechanism-based explanations of elevated levels that can be expanded and elaborated incrementally. We provide the means to challenge the ability of closely related model mechanisms to generate patterns of simulated hepatic injury and ALT release that scale (or not) to be quantitatively similar to the wet-lab validation targets, which are elevated plasma ALT values following acetaminophen (APAP) exposure in mice. We build on a published model mechanism that helps explain the generation of characteristic spatiotemporal features of APAP hepatotoxicity within hepatic lobules. Discrete event and agent-oriented software methods are most prominent. We instantiate and leverage a small constellation of concrete model mechanisms. Their details during execution help bring into focus ways in which particular sources of uncertainty become entangled with cause-effect details within and across several levels. We scale ALT amounts in virtual mice directly to target plasma ALT values in individual mice. A virtual experiment comprises a set of Monte Carlo simulations. We challenge the sufficiency of four potentially explanatory theories for ALT release. The first of the tested model theories failed to achieve the initial validation target, but each of the three others succeeded. Results for one of the three model mechanisms matched all target ALT values quantitatively. It explains how ALT externalization is the combined consequence of lobular-location-dependent drug-induced cellular damage and hepatocyte death. Falsification of one (or more) of the model mechanisms provides new knowledge and incrementally shrinks the constellation of model mechanisms. The modularity and biomimicry of our explanatory models enable seamless transition from mice to humans.


Assuntos
Alanina Transaminase/sangue , Biomarcadores/sangue , Hepatócitos/efeitos dos fármacos , Necrose , Acetaminofen/toxicidade , Animais , Doença Hepática Induzida por Substâncias e Drogas , Biologia Computacional , Simulação por Computador , Hepatócitos/enzimologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Camundongos , Método de Monte Carlo , Software
14.
Aquat Toxicol ; 225: 105528, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32569996

RESUMO

Abamectin (ABM) has been extensively used in Chinese aquaculture systems for parasite control, but no information is available regarding its effects on the important freshwater commercial fish species Schizothorax prenanti. We performed an acute toxicity test to determine the effects of ABM on S. prenanti, and the 48- and 96-h median lethal concentration values were 33.32 and 15.98 µg/L, respectively. In a second test, animals were exposed to sublethal concentrations of ABM (0.5, 2 or 8 µg/L) for 8 days, and various cytological and biochemical parameters were measured. ABM caused DNA damage in hepatocytes, with significant increases in Olive Tail Moment values and 8-hydroxy-2'-deoxyguanosine levels. Hepatocytic apoptosis occurred following all treatments, and was accompanied by an increase in reactive oxygen species (ROS) generation and caspase activity in a dose- and time-dependent manner. In addition, there were significant decreases in glutathione peroxidase levels and superoxide dismutase and catalase activity and increases in malonaldehyde levels. ABM-induced hepatocytic apoptosis in S. prenanti was probably triggered by ROS generation following a cascade reaction of caspases in mitochondrial or death receptor pathways, which caused antioxidant inhibition, oxidative product accumulation, and DNA damage in the liver.


Assuntos
Cyprinidae/metabolismo , Dano ao DNA , Ivermectina/análogos & derivados , Estresse Oxidativo/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Apoptose/efeitos dos fármacos , Cyprinidae/genética , Cyprinidae/crescimento & desenvolvimento , Relação Dose-Resposta a Droga , Água Doce/química , Glutationa Peroxidase/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Ivermectina/toxicidade , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Malondialdeído/metabolismo , Oxirredução , Superóxido Dismutase/metabolismo
15.
PLoS One ; 15(6): e0234038, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32492075

RESUMO

Extracellular adenosine triphosphate (eATP) released by damaged cells, and its purinergic receptors, comprise a crucial signaling network after injury. Purinergic receptor P2X7 (P2RX7), a major driver of NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome activation and IL-1ß processing, has been shown to play a role in liver injury in murine diet- and chemically-induced liver injury models. It is unclear, however, whether P2RX7 plays a role in non-alcoholic steatohepatitis (NASH) and which cell type is the main target of P2RX7 pharmacological inhibition. Here, we report that P2RX7 is expressed by infiltrating monocytes and resident Kupffer cells in livers from NASH-affected individuals. Using primary isolated human cells, we demonstrate that P2RX7 expression in CD14+ monocytes and Kupffer cells primarily mediates IL-1ß release. In addition, we show that pharmacological inhibition of P2RX7 in monocytes and Kupffer cells, blocks IL-1ß release, reducing hepatocyte caspase 3/7 activity, IL-1ß-mediated CCL2 and CCL5 chemokine gene expression and secretion, and hepatic stellate cell (HSC) procollagen secretion. Consequently, in a chemically-induced nonhuman primate model of liver fibrosis, treatment with a P2RX7 inhibitor improved histological characteristics of NASH, protecting from liver inflammation and fibrosis. Taken together, these findings underscore the critical role of P2RX7 in the pathogenesis of NASH and implicate P2RX7 as a promising therapeutic target for the management of this disease.


Assuntos
Inflamação/prevenção & controle , Cirrose Hepática/tratamento farmacológico , Antagonistas do Receptor Purinérgico P2X/uso terapêutico , Receptores Purinérgicos P2X7/metabolismo , Animais , Caspase 3/metabolismo , Células Cultivadas , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Células Estreladas do Fígado/citologia , Células Estreladas do Fígado/efeitos dos fármacos , Células Estreladas do Fígado/metabolismo , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Inflamação/patologia , Interleucina-1beta/metabolismo , Macrófagos do Fígado/citologia , Macrófagos do Fígado/efeitos dos fármacos , Macrófagos do Fígado/metabolismo , Lipopolissacarídeos/farmacologia , Fígado/metabolismo , Fígado/patologia , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/patologia , Macaca fascicularis , Masculino , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Hepatopatia Gordurosa não Alcoólica/patologia , Pró-Colágeno/metabolismo , Antagonistas do Receptor Purinérgico P2X/farmacologia , Receptores Purinérgicos P2X7/química , Receptores Purinérgicos P2X7/genética
16.
Toxicol Lett ; 331: 65-74, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32492475

RESUMO

Although disturbance of the methionine cycle and sequent decrease in hepatic methylation capacity are known to be important factors in the development of alcoholic liver injury, the underlying mechanisms are not fully understood. Here, we investigated the importance of the methylation of protein phosphatase 2A (PP2A) in alcoholic liver disease (ALD). We found that the severity of ethanol-induced liver injury and the extent of demethylation of PP2A catalytic C subunit (PP2Ac) were reduced after treatment with betaine, a methyl donor involved in the methionine-homocysteine cycle. These results suggest that PP2Ac methylation is decreased due to a broad decrease in hepatic methylation capacity after exposure to ethanol. Moreover, we found that the reduction in PP2Ac methylation led to increased degradation of the regulatory Bα subunit, thus promoting the phosphorylation and nuclear exclusion of Forkhead box O1 (FOXO1) and reducing FOXO1 transcriptional activity. Ultimately, the reduced activity of FOXO1 led to increased expression of TXNIP, which caused hepatic lipid accumulation. Our findings suggest that the reduction of PP2A methylation, a result of decrease hepatic methylation capacity, played an important role in ethanol-induced lipid accumulation via down-regulation of PP2A/Bα and FOXO1 phosphorylation.


Assuntos
Etanol/toxicidade , Proteína Forkhead Box O1/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatopatias Alcoólicas/metabolismo , Fígado/efeitos dos fármacos , Proteína Fosfatase 2/metabolismo , Animais , Linhagem Celular , Hepatócitos/metabolismo , Fígado/metabolismo , Fígado/patologia , Hepatopatias Alcoólicas/patologia , Masculino , Metilação , Camundongos , Camundongos Endogâmicos C57BL , Fosforilação
17.
Toxicol Lett ; 331: 242-253, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32579994

RESUMO

Dysregulated bile acid (BA) homeostasis is an extremely significant pathological phenomenon of intrahepatic cholestasis, and the accumulated BA could further trigger hepatocyte injury. Here, we showed that the expression of sphingosine-1-phosphate receptor 1 (S1PR1) was down-regulated by α-naphthylisothiocyanate (ANIT) in vivo and in vitro. The up-regulated S1PR1 induced by SEW2871 (a specific agonist of S1PR1) could improve ANIT-induced deficiency of hepatocyte tight junctions (TJs), cholestatic liver injury and the disrupted BA homeostasis in mice. BA metabolic profiles showed that SEW2871 not only reversed the disruption of plasma BA homeostasis, but also alleviated BA accumulation in the liver of ANIT-treated mice. Further quantitative analysis of 19 BAs showed that ANIT increased almost all BAs in mice plasma and liver, all of which were restored by SEW2871. Our data demonstrated that the top performing BAs were taurine conjugated bile acids (T-), especially taurocholic acid (TCA). Molecular mechanism studies indicated that BA transporters, synthetase, and BAs nuclear receptors (NRs) might be the important factors that maintained BA homeostasis by SEW2871 in ANIT-induced cholestasis. In conclusion, these results demonstrated that S1PR1 selective agonists might be the novel and potential effective agents for the treatment of intrahepatic cholestasis by recovering dysregulated BA homeostasis.


Assuntos
1-Naftilisotiocianato/toxicidade , Ácidos e Sais Biliares/sangue , Colestase/prevenção & controle , Fígado/efeitos dos fármacos , Oxidiazóis/farmacologia , Receptores de Esfingosina-1-Fosfato/agonistas , Tiofenos/farmacologia , Animais , Ácidos e Sais Biliares/metabolismo , Colestase/induzido quimicamente , Colestase/metabolismo , Regulação para Baixo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Homeostase , Fígado/metabolismo , Fígado/patologia , Masculino , Camundongos Endogâmicos C57BL , Receptores de Esfingosina-1-Fosfato/genética , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo , Junções Íntimas/patologia
18.
Aquat Toxicol ; 224: 105516, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32485495

RESUMO

Summer outbreaks of the hepatobiliary syndrome in fish impose a heavy burden on aquaculture in China. Curcumin is a polyphenol with antioxidant activity that has been used to protect the health of fish livers, but the mechanism underlying its protective effect is unclear. In this study, an in vitro model of hepatocyte oxidative damage in Oreochromis niloticus was established using H2O2. Treatment with 5 mM H2O2 for 2.5 h markedly reduced cell viability and antioxidant activity and elevated lactate dehydrogenase (LDH) activity, indicating conditions that can be used to establish an oxidative stress model. Under H2O2 stress, curcumin pretreatment significantly maintained cell viability, reduced malondialdehyde (MDA) levels, and increased superoxide dismutase (SOD) activity. RNA-seq results showed that acute H2O2 treatment resulted in minor changes in gene expression, whereas curcumin changed the expression profile and affected cytochrome P450 (Cyp 450), glutathione (GSH) metabolism, and the peroxisome proliferator-activated receptor (PPAR) signaling pathway. Several critical antioxidant defense signaling pathways were identified, and altered expression was confirmed by q-PCR. These results indicate that curcumin might upregulate PPAR expression by increasing Cyp2J2 expression. Further experiments showed that curcumin can upregulate the Nrf2-Keap1 signaling pathway at the transcriptional level, and this upregulation can induce downstream defense genes, including glutamate cysteine ligase catalytic subunit(GCLC) and glutamate cysteine ligase modifier subunit (GCLM), and thereby promote GSH synthesis and the expression of related antioxidases. This study might shed light on the effects of curcumin on the prevention and alleviation of liver diseases in fish.


Assuntos
Antioxidantes/farmacologia , Curcumina/farmacologia , Hepatócitos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Tilápia/metabolismo , Transcriptoma/efeitos dos fármacos , Animais , Antioxidantes/metabolismo , Células Cultivadas , Curcumina/metabolismo , Glutamato-Cisteína Ligase/genética , Glutamato-Cisteína Ligase/metabolismo , Hepatócitos/metabolismo , Peróxido de Hidrogênio/toxicidade , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/genética , Cultura Primária de Células , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Tilápia/genética , Poluentes Químicos da Água/toxicidade
19.
J Toxicol Sci ; 45(6): 339-347, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32493876

RESUMO

The metabolomic profiles of rat primary hepatocytes following treatment with rotenone, FCCP, or (+)-usnic acid were determined using liquid chromatography-mass spectrometry/mass spectrometry and gas chromatography-mass spectrometry. Significant and similar changes in the levels of 283 biochemical metabolites were associated with the three treatments compared with solvent control samples. Overall, the three treatments generated similar global biochemical profiles, with some minor differences associated with rotenone treatment. All three treatments resulted in a shift in energy metabolism as demonstrated by decreased glycogen stores and glycolysis. A reduced antioxidant response was detected in cells following all treatments. In addition, bile acid biosynthesis decreased as a potential consequence of increased oxidative stress by all three treatments. Conversely, rotenone treatment induced a number of changes after 1 hr, which were not detected in FCCP- or (+)-usnic acid-treated samples; these changes were not sustained over time and included increased NAD+ salvage and lysine degradation. In conclusion, these biochemical profiles could provide new insights into the mechanism(s) of mitochondrial toxicity.


Assuntos
Benzofuranos/efeitos adversos , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/efeitos adversos , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Rotenona/efeitos adversos , Animais , Ácidos e Sais Biliares/metabolismo , Células Cultivadas , Cromatografia Líquida , Metabolismo Energético/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Glicogênio/metabolismo , Glicólise/efeitos dos fármacos , Metabolômica , Mitocôndrias Hepáticas/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Ratos Endogâmicos F344
20.
Life Sci ; 257: 117889, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32502541

RESUMO

PURPOSE: Gestational diabetes mellitus (GDM) has many adverse effects on offspring, such as abnormal glycolipid metabolism, obesity, insulin resistance, mental retardation, schizophrenia and so on. METHODS: We established a GDM rat model by injecting 1% streptozotocin associated with a high-fat diet one week before pregnancy, and offspring rats were sacrificed at 8 weeks of age to obtain liver tissue for study. We used hematoxylin-eosin (HE) staining to observe liver morphological changes, Tunel staining for hepatocyte apoptosis, transmission electron microscope for liver ultrastructure, and western blot for protein expression in liver tissue. RESULTS: Compared with normal offspring rats, hepatocytes of GDM offspring rats showed obvious edema, liver organ index increased, and hepatocyte apoptosis and autophagosome in the liver were significantly increased; Bax, cleaved-caspase3/caspase3, LCII, Beclin 1, P-IKBα/IKBα and P-p65/p6 protein expression in the liver were significantly increased; Bcl2, p62 and PPARγ protein expression in the liver were significantly decreased. Tau prevented the GDM-related effects in the offspring: Tau decreased hepatocyte edema (or even disappears), liver organ index, hepatocyte apoptosis and the number of autophagosomes in the liver. In addition, Tau also decreased Bax, cleaved-caspase3/caspase3, LCII, Beclin 1, P-IKBα/IKBα and P-p65/p6 protein expression, and increased Bcl2, p62 and PPARγ protein expression in the liver of GDM offspring rats. CONCLUSION: Taurine should be considered as a potential gestational nutritional supplement to prevent liver damage in GDM offspring.


Assuntos
Diabetes Gestacional/tratamento farmacológico , Taurina/farmacologia , Animais , Autofagia/efeitos dos fármacos , Diabetes Mellitus Experimental , Dieta Hiperlipídica/efeitos adversos , Suplementos Nutricionais , Feminino , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Resistência à Insulina/fisiologia , Metabolismo dos Lipídeos/fisiologia , Fígado/efeitos dos fármacos , Masculino , Obesidade/metabolismo , Gravidez , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Ratos , Ratos Sprague-Dawley , Taurina/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA