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1.
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
2.
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
3.
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
4.
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
5.
PLoS One ; 15(6): e0234002, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32497071

RESUMO

Human primary hepatocytes (PHs) are critical to studying liver functions, drug metabolism and toxicity. PHs isolated from livers that are unacceptable for transplantation have limited expansion and culture viability in vitro, in addition to rapidly deteriorating enzymatic functions. The unsuitability of immortalized hepato-carcinoma cell lines for this function has prompted studies to develop hepatocyte-like cells from alternative sources like ESC, iPS, and other stem cell types using differentiation protocols. This study describes a novel technique to produce expandable and functional hepatocyte-like cells from the fusion of an immortalized human umbilical cord blood derived cell line (E12 MLPC) to normal human primary hepatocytes. Multi-lineage progenitor cells (MLPC) comprise a small subset of mesenchymal-like cells isolated from human umbilical cord blood. MLPC are distinguishable from other mesenchymal-like cells by their extended expansion capacity (up to 80 cell doublings before senescence) and the ability to be differentiated into cells representative of endo-, meso- and ectodermal origins. Transfection of MLPC with the gene for telomerase reverse transcriptase (TERT) resulted in clonal cell lines that were capable of differentiation to different cellular outcomes while maintaining their functional immortality. A methodology for the development of immortalized hepatocyte-like hybrid cells by the in vitro fusion of human MLPC with normal human primary hepatocytes is reported. The resultant hybrid cells exhibited homology with hepatocytes by morphology, immunohistochemistry, urea and albumin production and gene expression. A medium that allows stable long-term expansion of hepatocyte-like fusion cells is described.


Assuntos
Fusão Celular , Hepatócitos/citologia , Células Híbridas/citologia , Células-Tronco/citologia , Diferenciação Celular , Células Cultivadas , Hepatócitos/metabolismo , Humanos , Células Híbridas/metabolismo , Células-Tronco/metabolismo , Telomerase/genética , Transfecção
6.
Nat Commun ; 11(1): 3084, 2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32555153

RESUMO

Tumor-initiating stem-like cells (TICs) are defective in maintaining asymmetric cell division and responsible for tumor recurrence. Cell-fate-determinant molecule NUMB-interacting protein (TBC1D15) is overexpressed and contributes to p53 degradation in TICs. Here we identify TBC1D15-mediated oncogenic mechanisms and tested the tumorigenic roles of TBC1D15 in vivo. We examined hepatocellular carcinoma (HCC) development in alcohol Western diet-fed hepatitis C virus NS5A Tg mice with hepatocyte-specific TBC1D15 deficiency or expression of non-phosphorylatable NUMB mutations. Liver-specific TBC1D15 deficiency or non-p-NUMB expression reduced TIC numbers and HCC development. TBC1D15-NuMA1 association impaired asymmetric division machinery by hijacking NuMA from LGN binding, thereby favoring TIC self-renewal. TBC1D15-NOTCH1 interaction activated and stabilized NOTCH1 which upregulated transcription of NANOG essential for TIC expansion. TBC1D15 activated three novel oncogenic pathways to promote self-renewal, p53 loss, and Nanog transcription in TICs. Thus, this central regulator could serve as a potential therapeutic target for treatment of HCC.


Assuntos
Proteínas Ativadoras de GTPase/metabolismo , Células-Tronco Neoplásicas/citologia , Receptor Notch1/metabolismo , Adulto , Idoso , Animais , Carcinogênese/patologia , Carcinoma Hepatocelular/metabolismo , Divisão Celular , Linhagem Celular Tumoral , Transferência Ressonante de Energia de Fluorescência , Hepacivirus , Hepatócitos/citologia , Humanos , Fígado/metabolismo , Neoplasias Hepáticas/metabolismo , Camundongos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Fosforilação , Receptores Notch/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/metabolismo
7.
Nat Commun ; 11(1): 2362, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32398673

RESUMO

Due to their bacterial ancestry, many components of mitochondria share structural similarities with bacteria. Release of molecular danger signals from injured cell mitochondria (mitochondria-derived damage-associated molecular patterns, mito-DAMPs) triggers a potent inflammatory response, but their role in fibrosis is unknown. Using liver fibrosis resistant/susceptible mouse strain system, we demonstrate that mito-DAMPs released from injured hepatocyte mitochondria (with mtDNA as major active component) directly activate hepatic stellate cells, the fibrogenic cell in the liver, and drive liver scarring. The release of mito-DAMPs is controlled by efferocytosis of dying hepatocytes by phagocytic resident liver macrophages and infiltrating Gr-1(+) myeloid cells. Circulating mito-DAMPs are markedly increased in human patients with non-alcoholic steatohepatitis (NASH) and significant liver fibrosis. Our study identifies specific pathway driving liver fibrosis, with important diagnostic and therapeutic implications. Targeting mito-DAMP release from hepatocytes and/or modulating the phagocytic function of macrophages represents a promising antifibrotic strategy.


Assuntos
Alarminas/imunologia , Células Estreladas do Fígado/imunologia , Hepatócitos/metabolismo , Cirrose Hepática/imunologia , Hepatopatia Gordurosa não Alcoólica/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Alarminas/metabolismo , Animais , Apoptose/imunologia , Modelos Animais de Doenças , Progressão da Doença , Feminino , Hepatócitos/citologia , Hepatócitos/imunologia , Humanos , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/imunologia , Fígado/patologia , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/patologia , Macrófagos/imunologia , Masculino , Camundongos , Pessoa de Meia-Idade , Mitocôndrias/metabolismo , Hepatopatia Gordurosa não Alcoólica/imunologia , Fagocitose/imunologia , Tioacetamida/toxicidade , Adulto Jovem
8.
J Vis Exp ; (159)2020 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-32449710

RESUMO

Liver disease is an escalating global health issue. While liver transplantation is an effective mode of therapy, patient mortality has increased due to shortages in donor organ availability. Organ scarcity also affects the routine supply of human hepatocytes for basic research and the clinic. Therefore, the development of renewable sources of human liver progenitor cells is desirable and is the goal of this study. To be able to effectively generate and deploy human liver progenitors on a large scale, a reproducible hepatic progenitor differentiation system was developed. This protocol aids experimental reproducibility between users in a range of cell cultureware formats and permits differentiations using both, human embryonic and induced pluripotent stem cell lines. These are important advantages over current differentiation systems that will enhance the basic research and may pave the way towards clinical product development.


Assuntos
Diferenciação Celular , Fígado/citologia , Células-Tronco Pluripotentes/citologia , Contagem de Células , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Endoderma/citologia , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Humanos , Processamento de Imagem Assistida por Computador , Laminina/farmacologia , Células-Tronco Pluripotentes/efeitos dos fármacos , Reprodutibilidade dos Testes
9.
Nat Commun ; 11(1): 2461, 2020 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-32424153

RESUMO

It is well established that pluripotent stem cells in fetal and postnatal liver (LPCs) can differentiate into both hepatocytes and cholangiocytes. However, the signaling pathways implicated in the differentiation of LPCs are still incompletely understood. Transcription Factor EB (TFEB), a master regulator of lysosomal biogenesis and autophagy, is known to be involved in osteoblast and myeloid differentiation, but its role in lineage commitment in the liver has not been investigated. Here we show that during development and upon regeneration TFEB drives the differentiation status of murine LPCs into the progenitor/cholangiocyte lineage while inhibiting hepatocyte differentiation. Genetic interaction studies show that Sox9, a marker of precursor and biliary cells, is a direct transcriptional target of TFEB and a primary mediator of its effects on liver cell fate. In summary, our findings identify an unexplored pathway that controls liver cell lineage commitment and whose dysregulation may play a role in biliary cancer.


Assuntos
Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Linhagem da Célula , Fígado/citologia , Fígado/fisiologia , Regeneração/fisiologia , Animais , Neoplasias dos Ductos Biliares/patologia , Ductos Biliares/metabolismo , Diferenciação Celular , Proliferação de Células , Colangiocarcinoma/patologia , Regulação para Baixo/genética , Hepatócitos/citologia , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Modelos Biológicos , Fenótipo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Fatores de Transcrição SOX9/genética , Fatores de Transcrição SOX9/metabolismo , Esferoides Celulares/citologia , Células-Tronco/citologia , Células-Tronco/metabolismo , Regulação para Cima/genética
10.
Mutat Res ; 852: 503169, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32265043

RESUMO

The phycotoxins, okadaic acid (OA) and dinophysistoxins 1 and 2 (DTX-1 and -2), are protein phosphatase PP2A and PP1 inhibitors involved in diarrhetic shellfish poisoning (DSP) in humans. Data on the in vivo acute toxicity of the OA-group toxins show some differences and the European Food Safety Authority (EFSA) has determined toxicity equivalent factors (TEFs) of one for the reference toxin, OA, as well as for DTX-1 and 0.6 for DTX-2. However, recent in vitro studies indicated that DTX-1 seems to be more toxic than OA. As OA was described as apoptotic and aneugenic compound, we analyzed the DNA damage responses induced by the 3 toxins through γH2AX and pH3 biomarkers on proliferative HepaRG cells using High Content Analysis. We quantitatively examined the responses for γH2AX and pH3 by benchmark dose analyzing (BMD) using PROAST software. We found that the three toxins increased both γH2AX- and pH3-positive cells populations in a concentration-dependent manner. The 3 toxins induced mitotic arrest, characteristic of aneugenic compounds, as well as DNA strand-breaks concomitantly to cytotoxicity. BMD analysis showed that DTX-1 is the most potent inducer of DNA damage, followed by OA and DTX-2. The quantitative genotoxic data provided in this study are additional findings for reconsidering the estimated TEFs of this group of phycotoxins.


Assuntos
Inibidores Enzimáticos/toxicidade , Histonas/genética , Mutagênicos/toxicidade , Ácido Okadáico/toxicidade , Piranos/toxicidade , Benchmarking , Biomarcadores/metabolismo , Linhagem Celular Transformada , Proliferação de Células/efeitos dos fármacos , Dano ao DNA , Relação Dose-Resposta a Droga , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Histonas/metabolismo , Humanos , Interações Hidrofóbicas e Hidrofílicas , Mitose/efeitos dos fármacos , Testes de Mutagenicidade , Fosforilação/efeitos dos fármacos , Software
11.
Med Sci (Paris) ; 36(3): 261-263, 2020 Mar.
Artigo em Francês | MEDLINE | ID: mdl-32228845

RESUMO

Organoids offer an elegant approach to model human diseases and test new drugs. Nonalcoholic fatty liver disease (NAFLD) whose incidence has dramatically increased in recent years with the rise of obesity, is defined by triglyceride accumulation in hepatocytes, inflammation, liver injury, and progression to fibrosis. There is currently no approved therapy but many pathways are being explored. Two American teams have created mini-steatotic livers using different approaches, both using induced pluripotent stem cells (iPS), thus offering new tools to test developing drugs.


Assuntos
Bioengenharia/tendências , Ciência de Laboratório Médico/tendências , Hepatopatia Gordurosa não Alcoólica/patologia , Técnicas de Cultura de Tecidos/tendências , Animais , Bioengenharia/métodos , Células Cultivadas , Progressão da Doença , Hepatócitos/citologia , Hepatócitos/patologia , Hepatócitos/fisiologia , Humanos , Fígado/patologia , Fígado/fisiologia , Cirrose Hepática/patologia , Ciência de Laboratório Médico/métodos , Modelos Biológicos , Técnicas de Cultura de Tecidos/métodos , Tecidos Suporte
12.
Nat Chem Biol ; 16(7): 725-730, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32284602

RESUMO

Anti-CRISPR (Acr) proteins are powerful tools to control CRISPR-Cas technologies. However, the available Acr repertoire is limited to naturally occurring variants. Here, we applied structure-based design on AcrIIC1, a broad-spectrum CRISPR-Cas9 inhibitor, to improve its efficacy on different targets. We first show that inserting exogenous protein domains into a selected AcrIIC1 surface site dramatically enhances inhibition of Neisseria meningitidis (Nme)Cas9. Then, applying structure-guided design to the Cas9-binding surface, we converted AcrIIC1 into AcrIIC1X, a potent inhibitor of the Staphylococcus aureus (Sau)Cas9, an orthologue widely applied for in vivo genome editing. Finally, to demonstrate the utility of AcrIIC1X for genome engineering applications, we implemented a hepatocyte-specific SauCas9 ON-switch by placing AcrIIC1X expression under regulation of microRNA-122. Our work introduces designer Acrs as important biotechnological tools and provides an innovative strategy to safeguard CRISPR technologies.


Assuntos
Proteína 9 Associada à CRISPR/genética , Sistemas CRISPR-Cas , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Edição de Genes/métodos , MicroRNAs/genética , Engenharia de Proteínas/métodos , Sequência de Aminoácidos , Proteína 9 Associada à CRISPR/metabolismo , Linhagem Celular Tumoral , Genoma Humano , Células HEK293 , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , MicroRNAs/metabolismo , Modelos Moleculares , Mutagênese Insercional , Neisseria meningitidis/enzimologia , Neisseria meningitidis/genética , Plasmídeos/química , Plasmídeos/metabolismo , Domínios Proteicos , Estrutura Secundária de Proteína , RNA Guia/genética , RNA Guia/metabolismo , Staphylococcus aureus/enzimologia , Staphylococcus aureus/genética
13.
J Biosci Bioeng ; 130(2): 212-216, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32312490

RESUMO

To clinically apply bioartificial livers (BALs), an effective liver cell cryopreservation method is required for a stable cell supply. In this study, we performed tissue-engineered construct (TEC) cryopreservation of fetal liver cells (FLCs) in which FLCs cultured within a porous polymer scaffold were cryopreserved. Growth and albumin secretion in TEC-cryopreserved FLCs after thawing were compared to freshly isolated FLCs (control experiments). The effect of preculture duration prior to cryopreservation (0-3 weeks) on these functions was also examined. In the three-dimensional cultures, the TEC-cryopreserved FLCs with preculturing showed constant growth, and this growth was comparable to controls. On the contrary, the TEC-cryopreserved FLCs without preculturing did not proliferate after thawing. Albumin secretion of TEC-cryopreserved FLCs with preculturing rapidly increased up to day 12 and high secretory activity comparable to controls was maintained thereafter in FLCs with 1- or 2-week preculturing, suggesting this as an appropriate preculture duration. Compared to conventionally cryopreserved FLCs, growth and albumin secretion in the TEC-cryopreserved FLCs were significantly higher, indicating their usefulness as a potent cell source for BALs.


Assuntos
Albuminas/metabolismo , Hepatócitos/citologia , Fígado Artificial , Polímeros/química , Engenharia Tecidual/métodos , Tecidos Suporte/química , Animais , Sobrevivência Celular , Células Cultivadas , Criopreservação/normas , Feto , Fígado/citologia , Camundongos , Polímeros/farmacologia , Porosidade
14.
Gene ; 744: 144632, 2020 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-32240777

RESUMO

IGF2BPs, a subclass of RNA-binding proteins, regulate cellular differentiation, proliferation and migration during multiple organs development, but their functions in liver development still remain unclear. Here, in this study, whole-mount in situ hybridization showed that igf2bp1 was constantly and stably expressed at early stages of embryo development in zebrafish. Both the morpholino-induced knockdown and CRISPR/Cas9-mediated knockout of igf2bp1 led to a reduced-size liver phenotype. Further analysis revealed that igf2bp1 is required for hepatic outgrowth, but not for hepatoblast specification and budding. Deficiency of igf2bp1 resulted in reduced cell proliferation, but had no effect on apoptosis. Therefore, we concluded that igf2bp1 is a critical factor to regulate hepatic outgrowth via cell proliferation during early liver development in zebrafish.


Assuntos
Fígado/embriologia , Proteínas de Ligação a RNA/fisiologia , Proteínas de Peixe-Zebra/fisiologia , Animais , Proliferação de Células , Hepatócitos/citologia , Fígado/anatomia & histologia , Fígado/metabolismo , Morfolinos , Tamanho do Órgão , Fenótipo , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/genética , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/antagonistas & inibidores , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
15.
Zhonghua Gan Zang Bing Za Zhi ; 28(3): 254-258, 2020 Mar 20.
Artigo em Chinês | MEDLINE | ID: mdl-32306659

RESUMO

Objective: To investigate the feasibility of cationic antimicrobial peptide cathelicidin-PY(PY) therapy through a mouse model of acute liver failure. Methods: The ability of different concentrations of antimicrobial peptide PY to neutralize endotoxin / lipopolysaccharide (LPS) in vitro was detected by Limulus Amebocyte Lysate (LAL) assay. Cell counting kit-8 (CCK-8) was used to detect the toxic effect of different concentrations of antimicrobial peptide PY on mouse monocyte macrophages (RAW264.7). An in vitro hemolysis experiment was used to evaluate the activity of antimicrobial peptide PY on healthy human erythrocytes. D-galactosamine combined with LPS- induced mouse model of acute liver failure was constructed. The antimicrobial peptide PY effect on survival rate of mouse model was observed. HE staining was used to observe the pathological changes of liver tissue. Immunohistochemistry and Western blotting were used to detect the expression of apoptosis-associated protein caspase-3. Intra-group comparisons were performed using t-test and analysis of variance. χ (2) test was used for the comparison of rates. Results: An in vitro experiment showed that the endotoxin neutralization rate was higher at very low dose (0.01 µmol/L), and exceeded 70% at medium-dose (10-40 µmol/L), and the difference between groups with different concentration was statistically significant (F = 569.22, P < 0.05). Medium-dose antimicrobial peptide PY had strong endotoxin neutralizing effect, low cytotoxicity and hemolytic activity. Moreover, in vivo experiments showed that the degree of liver injury and survival rate of mouse model was significantly improved with the medium-dose of antimicrobial peptide PY. Immunohistochemistry results showed that the expression of caspase-3 in the liver tissue was significantly depleted in the medium-dose group than that of the liver failure group, and the results were consistent with protein immunoblotting testing. Conclusion: Antimicrobial peptide PY possesses a strong ability to neutralize endotoxin and few toxic side effects. A specific dose of antimicrobial peptide PY can attenuate hepatocyte apoptosis and significantly improve the survival rate of animal model, and thus provides a new idea for the liver failure treatment.


Assuntos
Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Falência Hepática Aguda/tratamento farmacológico , Neuropeptídeo Y/uso terapêutico , Animais , Apoptose , Células Cultivadas , Eritrócitos/citologia , Hepatócitos/citologia , Humanos , Lipopolissacarídeos , Camundongos , Células RAW 264.7
16.
Nat Cell Biol ; 22(3): 321-331, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32123335

RESUMO

CRISPR-Cas9 technology has revolutionized genome editing and is applicable to the organoid field. However, precise integration of exogenous DNA sequences into human organoids is lacking robust knock-in approaches. Here, we describe CRISPR-Cas9-mediated homology-independent organoid transgenesis (CRISPR-HOT), which enables efficient generation of knock-in human organoids representing different tissues. CRISPR-HOT avoids extensive cloning and outperforms homology directed repair (HDR) in achieving precise integration of exogenous DNA sequences into desired loci, without the necessity to inactivate TP53 in untransformed cells, which was previously used to increase HDR-mediated knock-in. CRISPR-HOT was used to fluorescently tag and visualize subcellular structural molecules and to generate reporter lines for rare intestinal cell types. A double reporter-in which the mitotic spindle was labelled by endogenously tagged tubulin and the cell membrane by endogenously tagged E-cadherin-uncovered modes of human hepatocyte division. Combining tubulin tagging with TP53 knock-out revealed that TP53 is involved in controlling hepatocyte ploidy and mitotic spindle fidelity. CRISPR-HOT simplifies genome editing in human organoids.


Assuntos
Sistemas CRISPR-Cas , Edição de Genes , Técnicas de Introdução de Genes/métodos , Organoides/citologia , Hepatócitos/citologia , Hepatócitos/ultraestrutura , Humanos , Intestinos/citologia , Fígado/citologia , Organoides/ultraestrutura , Fuso Acromático/ultraestrutura , Proteína Supressora de Tumor p53/fisiologia
17.
Phytomedicine ; 69: 153198, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32151917

RESUMO

BACKGROUND: Induced pluripotent stem cells (iPSCs) are regarded as the best potential cell source for cell-based regenerative medicine. To develop a safe and efficient iPSC-based cell therapy, it is very important to avoid possible teratoma formation, which can arise from undifferentiated iPSCs (USCs) remaining among differentiated cell products. Dried bark of Magnolia officinalis (Magnolia cortex, MC) has long been used in traditional medicine to treat gastrointestinal ailments and allergic diseases, and has shown have various pharmacological activities, including anti-bacterial, anti-inflammatory, and anti-cancer effects. However, its effects on iPSCs have not yet been examined. PURPOSE: In this study, we investigated the selective cytotoxic effects of ethanol extract of MC (EEMC) on undifferentiated iPSCs and elucidated the underlying apoptotic mechanisms in detail. We also investigated the inhibitory effects of EEMC on teratoma formation via in ovo experiments. RESULTS: We found that EEMC greatly reduced cell growth and induced apoptotic cell death in USCs, but not in differentiated or normal cells. EEMC caused G2/M cell cycle arrest, mitochondrial damage, and caspase activation of USCs, accompanied by p53 accumulation. In p53KO human iPSCs, EEMC had no cytotoxicity, reinforcing that EEMC-mediated apoptosis of USCs is p53-dependent. EEMC did not cause DNA damage in iPSC-derived differentiated cells. In ovo teratoma formation assay revealed that EEMC treatment before injection efficiently eliminated USCs and prevented teratoma formation. CONCLUSIONS: These results collectively indicate that EEMC has potent anti-teratoma activity, and therefore can be used for the development of safe iPSC-based therapy.


Assuntos
Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/efeitos dos fármacos , Magnolia/química , Extratos Vegetais/farmacologia , Teratoma/prevenção & controle , Animais , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Embrião de Galinha , Etanol/química , Hepatócitos/citologia , Hepatócitos/fisiologia , Humanos , Células-Tronco Pluripotentes Induzidas/patologia , Células-Tronco Pluripotentes Induzidas/fisiologia , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Extratos Vegetais/química , Teratoma/patologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
18.
J Biosci Bioeng ; 129(6): 741-748, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32014416

RESUMO

Functional artificial livers (FALs), with embedded hepatocytes that perform the functions of a normal liver, have been developed during the past decades. It is important to note that the liver scaffold, which is a biologically functional core of bioartificial livers, plays a vital role in the bio-cartridge within a bioartificial liver. In this study, a three-dimensional (3D) liver scaffold for in vitro cultures was fabricated by freeze-drying a chitosan/gelatin (CG) solution. A CG scaffold has advantages such as (i) inexpensive and easy-to-make; (ii) easy to fabricate with varying compressive modulus by changing the concentration of glutaraldehyde; (iii) non-cytotoxicity; and (iv) porous structure is similar to extracellular matrix (ECM), thus facilitating hepatocyte adhesion and proliferation. The results revealed that the compressive modulus and maintainability of a CG scaffold was correlated to the increase in glutaraldehyde. Furthermore, hepatocyte viability and hepatic functions showed the best performances with a 0.61% glutaraldehyde-CG scaffold. This CG scaffold not only had higher hepatocyte biocompatibility and mechanical strength, but also maintained hepatic functions and viability in vitro cultures; especially, the mechanical properties of 0.61% glutaraldehyde-CG scaffold were very similar to those in normal liver. The CG scaffold as a liver scaffold may have high potential for further bioartificial liver design in the near future.


Assuntos
Quitosana/química , Gelatina/química , Hepatócitos/citologia , Fígado/citologia , Animais , Células Cultivadas , Liofilização , Glutaral/metabolismo , Fígado Artificial , Masculino , Porosidade , Ratos Sprague-Dawley
19.
J Agric Food Chem ; 68(9): 2673-2683, 2020 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-32050765

RESUMO

Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming the leading cause of chronic liver diseases throughout the world. The deficit of pharmacotherapy for NAFLD calls for an urgent need for a new drug discovery and lifestyle management. Black tea is the most popular and functional drink consumed worldwide. Its main bioactive constituent theaflavin helps to prevent obesity-a major risk factor for NAFLD. To find new targets for the development of effective and safe therapeutic drugs from natural plants for NAFLD, we found a theaflavin monomer theaflavin-3,3'-digallate (TF3), which significantly reduced lipid droplet accumulation in hepatocytes, and directly bound and inhibited the activation of plasma kallikrein (PK), which was further proved to stimulate adenosine monophosphate activated protein kinase (AMPK) and its downstream targets. Taken together, we proposed that the TF3-PK-AMPK regulatory axis is a novel mechanism of lipid deposition mitigation, and PK could be a new target for NAFLD treatment.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Biflavonoides/farmacologia , Catequina/farmacologia , Hepatócitos/metabolismo , Gotículas Lipídicas/metabolismo , Hepatopatia Gordurosa não Alcoólica/metabolismo , Extratos Vegetais/farmacologia , Calicreína Plasmática/metabolismo , Proteínas Quinases Ativadas por AMP/genética , Apoptose/efeitos dos fármacos , Camellia sinensis/química , Células Hep G2 , Hepatócitos/citologia , Hepatócitos/efeitos dos fármacos , Humanos , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Transdução de Sinais/efeitos dos fármacos
20.
Cell Mol Life Sci ; 77(15): 2887-2898, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32060582

RESUMO

Liver regeneration (LR) capacity in vertebrates developed through natural selection over a hundred million years of evolution. To maintain homeostasis or recover from various injuries, liver cells must regenerate; this process includes the renewal of parenchymal and nonparenchymal cells as well as the formation of liver structures. The cellular origin of newly grown tissue is one of the critical questions in this area and has been a subject of prolonged debate. The regenerative tissue may derive from either hepatocyte self-duplication or liver stem/progenitor cells (LSPCs). Recently, hepatocyte subpopulations and cholangiocytes were also described as important founder cells. The niche that triggers the proliferation of hepatocytes and the differentiation of LSPCs has been extensively studied. Meanwhile, in vitro culture systems for liver founder cells and organoids have been developed rapidly for mechanistic studies and potential therapeutic purposes. This review summarizes the cellular sources and niches that give rise to renewed hepatocytes during LR, and it also describes in vitro culture studies of those founder cells for future applications, as well as current reports for stem cell-based therapies for liver diseases.


Assuntos
Hepatócitos/citologia , Regeneração Hepática/fisiologia , Animais , Diferenciação Celular , Terapia Baseada em Transplante de Células e Tecidos , Doença Hepática Induzida por Substâncias e Drogas/patologia , Doença Hepática Induzida por Substâncias e Drogas/terapia , Células Estreladas do Fígado/citologia , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/transplante , Hepatócitos/metabolismo , Hepatócitos/transplante , Humanos , Células-Tronco/citologia , Células-Tronco/metabolismo
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