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1.
Acta Pharmacol Sin ; 44(1): 157-168, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35655095

RESUMO

Hepatic steatosis plays a detrimental role in the onset and progression of alcohol-associated liver disease (ALD). Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an evolutionarily conserved protein related to the unfolded protein response. Recent studies have demonstrated that MANF plays an important role in liver diseases. In this study, we investigated the role of MANF in ethanol-induced steatosis and the underlying mechanisms. We showed that the hepatic MANF expression was markedly upregulated in mouse model of ALD by chronic-plus-single-binge ethanol feeding. Moreover, after chronic-plus-binge ethanol feeding, hepatocyte-specific MANF knockout (HKO) mice displayed more severe hepatic steatosis and liver injury than wild-type (WT) control mice. Immunoprecipitation-coupled MS proteomic analysis revealed that arginosuccinate synthase 1 (ASS1), a rate-limiting enzyme in the urea cycle, resided in the same immunoprecipitated complex with MANF. Hepatocyte-specific MANF knockout led to decreased ASS1 activity, whereas overexpression of MANF contributed to enhanced ASS1 activity in vitro. In addition, HKO mice displayed unique urea cycle metabolite patterns in the liver with elevated ammonia accumulation after ethanol feeding. ASS1 is known to activate AMPK by generating an intracellular pool of AMP from the urea cycle. We also found that MANF supplementation significantly ameliorated ethanol-induced steatosis in vivo and in vitro by activating the AMPK signaling pathway, which was partly ASS1 dependent. This study demonstrates a new mechanism in which MANF acts as a key molecule in maintaining hepatic lipid homeostasis by enhancing ASS1 activity and uncovers an interesting link between lipid metabolism and the hepatic urea cycle under excessive alcohol exposure.


Assuntos
Fígado Gorduroso , Hepatopatias Alcoólicas , Animais , Camundongos , Proteínas Quinases Ativadas por AMP/metabolismo , Astrócitos/metabolismo , Etanol/toxicidade , Fígado Gorduroso/induzido quimicamente , Hepatócitos/metabolismo , Fígado/metabolismo , Camundongos Knockout , Fatores de Crescimento Neural/metabolismo , Proteômica , Ureia/metabolismo
2.
Acta Pharmacol Sin ; 44(6): 1175-1190, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36635421

RESUMO

Mesencephalic astrocyte-derived neurotrophic factor (MANF), an endoplasmic reticulum stress-inducible secreting protein, has evolutionarily conserved immune-regulatory function that contributes to the negative regulation of inflammation in macrophages. In this study, we investigated the profiles of MANF in the macrophages of the patients with active inflammatory bowel disease (IBD) and the mice with experimental colitis, which was induced in both myeloid cell-specific MANF knockout mice and wild-type mice by 3% dextran sodium sulfate (DSS) for 7 days. We found that MANF expression was significantly increased in intestinal macrophages from both the mice with experimental colitis and patients with active IBD. DSS-induced colitis was exacerbated in myeloid cell-specific MANF knockout mice. Injection of recombinant human MANF (rhMANF, 10 mg·kg-1·d-1, i.v.) from D4 to D6 significantly ameliorated experimental colitis in DSS-treated mice. More importantly, MANF deficiency in myeloid cells resulted in a dramatic increase in the number of Ly6ChiCX3CRint proinflammatory macrophages in colon lamina propria of DSS-treated mice, and the proinflammatory cytokines and chemokines were upregulated as well. Meanwhile, we demonstrated that MANF attenuated Th17-mediated immunopathology by inhibiting BATF2-mediated innate immune response and downregulating CXCL9, CXCL10, CXCL11 and IL-12p40; MANF functioned as a negative regulator in inflammatory macrophages via inhibiting CHOP-BATF2 signaling pathway, thereby protecting against DSS-induced mouse colitis. These results suggest that MANF ameliorates colon injury by negatively regulating inflammatory macrophage transformation, which shed light on a potential therapeutic target for IBD.


Assuntos
Colite , Doenças Inflamatórias Intestinais , Humanos , Camundongos , Animais , Colite/induzido quimicamente , Colite/tratamento farmacológico , Doenças Inflamatórias Intestinais/patologia , Transdução de Sinais , Macrófagos/metabolismo , Colo/metabolismo , Fatores de Crescimento Neural/genética , Camundongos Knockout , Sulfato de Dextrana/toxicidade , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , Receptor 1 de Quimiocina CX3C
3.
Mol Cell ; 60(6): 914-29, 2015 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-26687600

RESUMO

Multicellular organisms have multiple homologs of the yeast ATG8 gene, but the differential roles of these homologs in autophagy during development remain largely unknown. Here we investigated structure/function relationships in the two C. elegans Atg8 homologs, LGG-1 and LGG-2. lgg-1 is essential for degradation of protein aggregates, while lgg-2 has cargo-specific and developmental-stage-specific roles in aggregate degradation. Crystallography revealed that the N-terminal tails of LGG-1 and LGG-2 adopt the closed and open form, respectively. LGG-1 and LGG-2 interact differentially with autophagy substrates and Atg proteins, many of which carry a LIR motif. LGG-1 and LGG-2 have structurally distinct substrate binding pockets that prefer different residues in the interacting LIR motif, thus influencing binding specificity. Lipidated LGG-1 and LGG-2 possess distinct membrane tethering and fusion activities, which may result from the N-terminal differences. Our study reveals the differential function of two ATG8 homologs in autophagy during C. elegans development.


Assuntos
Autofagia , Proteínas de Caenorhabditis elegans/química , Caenorhabditis elegans/metabolismo , Proteínas Associadas aos Microtúbulos/química , Animais , Família da Proteína 8 Relacionada à Autofagia , Sítios de Ligação , Caenorhabditis elegans/química , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Cristalografia por Raios X , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Modelos Moleculares , Mutação , Conformação Proteica , Proteínas Serina-Treonina Quinases/metabolismo , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética
4.
Nucleic Acids Res ; 48(11): 5799-5813, 2020 06 19.
Artigo em Inglês | MEDLINE | ID: mdl-32399566

RESUMO

Transcription and pre-mRNA splicing are coupled to promote gene expression and regulation. However, mechanisms by which transcription and splicing influence each other are still under investigation. The ATPase Prp5p is required for pre-spliceosome assembly and splicing proofreading at the branch-point region. From an open UV mutagenesis screen for genetic suppressors of prp5 defects and subsequent targeted testing, we identify components of the TBP-binding module of the Spt-Ada-Gcn5 Acetyltransferase (SAGA) complex, Spt8p and Spt3p. Spt8Δ and spt3Δ rescue the cold-sensitivity of prp5-GAR allele, and prp5 mutants restore growth of spt8Δ and spt3Δ strains on 6-azauracil. By chromatin immunoprecipitation (ChIP), we find that prp5 alleles decrease recruitment of RNA polymerase II (Pol II) to an intron-containing gene, which is rescued by spt8Δ. Further ChIP-seq reveals that global effects on Pol II-binding are mutually rescued by prp5-GAR and spt8Δ. Inhibited splicing caused by prp5-GAR is also restored by spt8Δ. In vitro assays indicate that Prp5p directly interacts with Spt8p, but not Spt3p. We demonstrate that Prp5p's splicing proofreading is modulated by Spt8p and Spt3p. Therefore, this study reveals that interactions between the TBP-binding module of SAGA and the spliceosomal ATPase Prp5p mediate a balance between transcription initiation/elongation and pre-spliceosome assembly.


Assuntos
RNA Helicases DEAD-box/metabolismo , Splicing de RNA , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica , Alelos , Genes Fúngicos/genética , Genoma Fúngico/genética , Mutação , Fenótipo , Ligação Proteica , RNA Polimerase II/metabolismo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Proteínas de Saccharomyces cerevisiae/genética , Especificidade por Substrato , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética
5.
Acta Pharmacol Sin ; 41(3): 404-414, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31700088

RESUMO

Xanthatin is a natural sesquiterpene lactone purified from Xanthium strumarium L., which has shown prominent antitumor activity against a variety of cancer cells. In the current study, we investigated the effect of xanthatin on the growth of glioma cells in vitro and in vivo, and elucidated the underlying mechanisms. In both rat glioma C6 and human glioma U251 cell lines, xanthatin (1-15 µM) dose-dependently inhibited cell viability without apparent effect on the cell cycle. Furthermore, xanthatin treatment dose-dependently induced glioma cell apoptosis. In nude mice bearing C6 glioma tumor xenografts, administration of xanthatin (10, 20, 40 mg·kg-1·d-1, ip, for 2 weeks) dose-dependently inhibited the tumor growth, but did not affect the body weight. More importantly, xanthatin treatment markedly increased the expression levels of the endoplasmic reticulum (ER) stress-related markers in both the glioma cell lines as well as in C6 xenografts, including glucose-regulated protein 78, C/EBP-homologous protein (CHOP), activating factor 4, activating transcription factor 6, spliced X-box binding protein-1, phosphorylated protein kinase R-like endoplasmic reticulum kinase, and phosphorylated eukaryotic initiation factor 2a. Pretreatment of C6 glioma cells with the ER stress inhibitor 4-phenylbutyric acid (4-PBA, 7 mM) or knockdown of CHOP using small interfering RNA significantly attenuated xanthatin-induced cell apoptosis and increase of proapoptotic caspase-3. These results demonstrate that xanthatin induces glioma cell apoptosis and inhibits tumor growth via activating the ER stress-related unfolded protein response pathway involving CHOP induction. Xanthatin may serve as a promising agent in the treatment of human glioma.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias do Sistema Nervoso Central/tratamento farmacológico , Furanos/farmacologia , Glioma/tratamento farmacológico , Animais , Antineoplásicos Fitogênicos/química , Antineoplásicos Fitogênicos/isolamento & purificação , Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Neoplasias do Sistema Nervoso Central/metabolismo , Neoplasias do Sistema Nervoso Central/patologia , Relação Dose-Resposta a Droga , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Furanos/química , Furanos/isolamento & purificação , Glioma/metabolismo , Glioma/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Estrutura Molecular , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Ratos , Relação Estrutura-Atividade , Células Tumorais Cultivadas , Xanthium/química
6.
Neurochem Res ; 44(4): 959-967, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30694428

RESUMO

Iron overload is a common pathophysiological state underlying many diseases that has a detrimental influence on cells. The protective effects of Dexmedetomidine (Dex), a high selective alpha-2-adrenoceptor agonist, have been revealed through many experimental models, whereas no study reports its effects on an iron overload model. To elucidate these effects, we used FeCl2 with or without Dex to treat SH-SY5Y cells for 24 h and then detected indicators of oxidative stress, inflammation and apoptosis and investigated possible mechanisms further. After treatment with FeCl2 for 24 h, cell viability decreased in a dose dependent manner, and Dex promoted cell survival in FeCl2 incubation, also in a dose-dependent manner. Compared with the FeCl2 group, 20 µM Dex significantly attenuated ROS accumulation, reduced pro-inflammatory cytokine expression, and inhibited apoptosis. Furthermore, 20 µM concentration of Dex remarkably downregulated the expression of pro-apoptotic protein and activation of caspase 3 while increasing anti-apoptotic protein expression. Additionally, Dex also effectively suppressed the expression of NF-κB and its activation. In conclusion, Dex exerted anti-oxidative stress, anti-inflammation, and anti-apoptosis effects on FeCl2-treated SH-SY5Y cells, possibly by inhibiting NF-κB signaling pathway.


Assuntos
Agonistas de Receptores Adrenérgicos alfa 2/farmacologia , Cloretos/toxicidade , Dexmedetomidina/farmacologia , Compostos Férricos/toxicidade , Sobrecarga de Ferro/metabolismo , NF-kappa B/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Humanos , Sobrecarga de Ferro/prevenção & controle , NF-kappa B/antagonistas & inibidores , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
7.
Phytother Res ; 33(1): 149-158, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30346082

RESUMO

To investigate the suppressive effects of xanthatin on glioma growth in a nude mouse xenograft model and rat orthotopic implantation model using magnetic resonance imaging (MRI) to dynamically monitor the antitumour growth and antiangiogenesis effects of xanthatin. The nude mouse xenograft tumour model and rat orthotopic implantation model were established to observe the antitumour effects of xanthatin in vivo. In the rat orthotopic implanted tumour model, MRI scanning was used to dynamically monitor the antitumour growth effect and evaluate the antiangiogenesis effect of xanthatin. We found that xanthatin at a dose of 0.4 mg/10 g dramatically decreased the growth of xenograft tumours in nude mice. The antiangiogenesis effect of xanthatin C6 glioma was evaluated by dynamic contrast-enhanced (DCE) MRI via comparison of the volume transfer constant (Ktrans ) value, a parameter that reflects vessel permeability. We found that xanthatin at the doses of 8 and 16 mg/kg significantly decreased the Ktrans value, which suggests that xanthatin has antiangiogenesis effects. These data demonstrate the suppressive effects of xanthatin on C6 glioma occur via antiangiogenesis. Meanwhile, this study also provides evidence for the application of quantitative parameters of DCE-MRI for dynamically evaluating the growth and angiogenesis of intracranial tumours and for experimental and clinical research.


Assuntos
Antineoplásicos Fitogênicos/uso terapêutico , Neoplasias Encefálicas/tratamento farmacológico , Meios de Contraste/uso terapêutico , Furanos/uso terapêutico , Glioma/tratamento farmacológico , Imageamento por Ressonância Magnética/métodos , Animais , Antineoplásicos Fitogênicos/farmacologia , Neoplasias Encefálicas/patologia , Modelos Animais de Doenças , Furanos/química , Furanos/farmacologia , Glioma/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neovascularização Patológica , Ratos
8.
Int J Mol Sci ; 17(9)2016 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-27608005

RESUMO

As an endoplasmic reticulum (ER) stress-inducible protein, mesencephalic astrocyte-derived neurotrophic factor (MANF) has been proven to protect dopaminergic neurons and nondopaminergic cells. Our previous studies had shown that MANF protected against ischemia/reperfusion injury. Here, we developed a magnetic resonance imaging (MRI) technology to dynamically evaluate the therapeutic effects of MANF on ischemia/reperfusion injury. We established a rat focal ischemic model by using middle cerebral artery occlusion (MCAO). MRI was performed to investigate the dynamics of lesion formation. MANF protein was injected into the right lateral ventricle at 3 h after reperfusion following MCAO for 90 min, when the obvious lesion firstly appeared according to MRI investigation. T2-weighted imaging for evaluating the therapeutic effects of MANF protein was performed in ischemia/reperfusion injury rats on Days 1, 2, 3, 5, and 7 post-reperfusion combined with histology methods. The results indicated that the administration of MANF protein at the early stage after ischemia/reperfusion injury decreased the mortality, improved the neurological function, reduced the cerebral infarct volume, and alleviated the brain tissue injury. The findings collected from MRI are consistent with the morphological and pathological changes, which suggest that MRI is a useful technology for evaluating the therapeutic effects of drugs.


Assuntos
Infarto da Artéria Cerebral Média/tratamento farmacológico , Imageamento por Ressonância Magnética , Fatores de Crescimento Neural/uso terapêutico , Traumatismo por Reperfusão/tratamento farmacológico , Animais , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Humanos , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Masculino , Fatores de Crescimento Neural/administração & dosagem , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes , Traumatismo por Reperfusão/diagnóstico por imagem
9.
Mol Cell Biochem ; 385(1-2): 179-90, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24068329

RESUMO

Live ischemia-reperfusion injury is associated with endoplasmic reticulum (ER) stress-induced apoptosis. Activation of peroxisome proliferator-activated receptor-α (PPARα) may inhibit hepatocyte apoptosis induced by oxidative stress and protect against liver injury. This study aimed to investigate the effects of PPARα activation, through a specific agonist, on ER stress-induced apoptosis in human liver hepatocellular carcinoma (HepG2) cells. HepG2 cells were challenged with H2O2 and treated with WY14643, a selective PPARα agonist, in the presence or absence of the PPARα antagonist of MK886. Cell viable assay (MTT) and immunostaining were used to evaluate cell viability. The level of apoptotic cell death was quantified through Annexin V/PI staining. Alanine aminotransferase, asparatate aminotransferase, and malondialdehyde levels were measured to determine the presence of cellular injury and oxidative stress. RT-PCR and Western blot analysis were used to detect mRNA and protein expression of PPARα, BiP, and CHOP. Immunofluorescence was utilized to determine the intracellular localization of CHOP. H2O2 and MK886 both reduced the viability of HepG2 cells, increased oxidative stress and apoptosis, up-regulated the BiP and CHOP expression, and induced CHOP translocation from the cytoplasm to the nucleus. Compared with cells treated with H2O2 alone, pre-administration of WY14643 increased cell viability, attenuated apoptosis, improved cell function, down-regulated BiP and CHOP expression and inhibited CHOP translocation. The effects of WY14643 were completely abolished using the MK886 antagonist. PPARα activation protects against H2O2-induced HepG2 cell apoptosis. The underlying mechanisms may be associated with its activation to suppress excessive ER stress.


Assuntos
Apoptose , Citoproteção , Estresse do Retículo Endoplasmático , PPAR alfa/metabolismo , Apoptose/efeitos dos fármacos , Sobrevivência Celular , Citoproteção/efeitos dos fármacos , Chaperona BiP do Retículo Endoplasmático , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Células Hep G2 , Humanos , Peróxido de Hidrogênio/farmacologia , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Modelos Biológicos , Transporte Proteico/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator de Transcrição CHOP/genética , Fator de Transcrição CHOP/metabolismo
10.
Inflamm Res ; 63(5): 335-46, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24468888

RESUMO

OBJECTIVE: To explore the characteristic expression of endoplasmic reticulum (ER) stress protein in antigen-induced arthritis models and the role of ER stress in arthritis. METHODS: Effective animal models of rheumatoid arthritis in rabbits and rats were induced by methylated bovine serum albumin and Freund's complete adjuvant. Pathological changes were assessed by magnetic resonance imaging and histological analysis. The expression and localization of ER stress proteins in synovium and peritoneal macrophages (PMΦ) were analyzed by double immunofluorescence staining. RT-PCR was performed to detect mRNA expression of ER stress-related genes. Tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1ß) levels in synoviocytes were measured by RT-PCR and radioimmunoassay. RESULTS: We found that the ER stress marker BiP was highly up-regulated in arthritis synovium and extensively expressed in fibroblast-like synoviocytes (FLS) and macrophage-like synoviocytes (MLS). The expression of the pro-apoptotic factor CHOP/GADD153 was slightly elevated in inflammatory synovium and mainly localized in FLS, but insignificant in MLS. Unexpectedly, increased expression of CHOP was observed in PMΦ in arthritis rats. Likewise, cleaved caspase-3 was rarely expressed in MLS. In addition, induction of ER stress by tunicamycin resulted in significantly increased expression of pro-inflammatory molecules such as IL-1ß and TNF-α in cultured inflammatory FLS. CONCLUSION: Differential activation of the ER stress proteins in synovium MLS may contribute to the resistance of synoviocytes to ER stress-induced apoptosis. Furthermore, ER stress is a potential mediator of arthritis inflammation.


Assuntos
Apoptose , Artrite Experimental/patologia , Estresse do Retículo Endoplasmático , Macrófagos/fisiologia , Membrana Sinovial/citologia , Actinas/análise , Animais , Antígenos CD/análise , Antígenos de Diferenciação Mielomonocítica/análise , Caspase 3/metabolismo , Células Cultivadas , Feminino , Interleucina-1beta/genética , Ativação de Macrófagos , Imageamento por Ressonância Magnética , Masculino , Coelhos , Ratos , Ratos Sprague-Dawley , Fator de Transcrição CHOP/análise , Fator de Necrose Tumoral alfa/genética
11.
Nanomedicine (Lond) ; 17(11): 741-752, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35506304

RESUMO

Aim: To construct an edaravone-encapsulated liposomes (EDV-LIPs) formulation against acute ischemic stroke. Methods: EDV-LIPs were prepared by the film dispersion method. The biosafety was evaluated both in vitro and in vivo by flow cytometry and the histological staining method. Biodistribution and therapeutic effect of EDV-LIPs against acute ischemic stroke was investigated by fluorescent imaging, the behavior test, laser speckle imaging and triphenyltetrazolium chloride staining. Results: The nanoliposomes had a long circulation time and could accumulate in the brain lesion region in ischemic stroke rats. EDV-LIPs show good biosafety. EDV-LIPs could restore more cerebral blood flow, reduce infarct volume and decrease neuronal apoptosis. Conclusion: EDV-LIPs provide an effective alternative for drug-targeted delivery against acute ischemic stroke.


Assuntos
AVC Isquêmico , Acidente Vascular Cerebral , Animais , Encéfalo , Edaravone/farmacologia , Edaravone/uso terapêutico , Lipossomos/farmacologia , Ratos , Acidente Vascular Cerebral/tratamento farmacológico , Distribuição Tecidual
12.
Genes (Basel) ; 13(4)2022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-35456475

RESUMO

Many post-transcriptional mRNA processing steps play crucial roles in tumorigenesis and the progression of cancers, such as N6-methyladenosine (m6A) modification and alternative splicing. Upregulation of methyltransferase-like 3 (METTL3), the catalytic core of the m6A methyltransferase complex, increases m6A levels and results in significant effects on the progression of hepatocellular carcinoma (HCC). However, alternative splicing of METTL3 has not been fully investigated, and the functions of its splice variants remain unclear. Here, we analyzed both our and online transcriptomic data, obtaining 13 splice variants of METTL3 in addition to canonical full-length METTL3-A in HCC cell lines and tissues. Validated by RT-qPCR and Western blotting, we found that METTL3-D, one of the splice variants expressing a truncated METTL3 protein, exhibits higher levels than METTL3-A in normal human livers but lower levels than METTL3-A in HCC tumor tissues and cell lines. Further functional assays demonstrated that METTL3-D expression decreased cellular m6A modification, inhibited the proliferation, migration, and invasion of HCC cells, and was negatively associated with the malignancy of patient tumors, exhibiting functions opposite to those of full-length METTL3-A. This study demonstrates that the METTL3-D splice variant is a tumor suppressor that could potentially be used as a target for HCC therapy.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Adenosina/genética , Adenosina/metabolismo , Carcinoma Hepatocelular/patologia , Humanos , Neoplasias Hepáticas/patologia , Metiltransferases/genética , Metiltransferases/metabolismo , RNA Mensageiro/genética
13.
Biomed Pharmacother ; 150: 112943, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35405395

RESUMO

Acute lung injury (ALI) is an urgent respiratory disease without effective treatment. Mesencephalic astrocyte-derived neurotrophic factor (MANF)has been demonstrated to play a suppressive role in some inflammatory conditions. However, the effect of MANF on ALI has not yet been reported. In this study, we collected bronchoalveolar lavage fluid (BALF) from the patients with or without pulmonary inflammation, and used lipopolysaccharide (LPS) to induce mice ALI model. Mono-macrophage-specific MANF knockout (MKO) mice were constructed and recombinant human MANF protein was used to ALI mice. We found that the endogenous MANF protein in both human BALF and mice lung tissues was increased in inflammatory conditions. MANF level in the macrophages of inflammatory lung was higher than that in normal controls in both human and mice. MANF deficiency in macrophages induced lung inflammation and aggravated LPS-induced lung injury. MANF lowered LPS-induced lung injury, inhibited macrophage polarization to M1 functional type. Meanwhile, MANF inhibited-LPS induced activation of NF-κB signal pathway by down regulating phosphorylated p65in lung tissue and macrophages. These results indicate that MANF acts as a suppressor in ALI via negatively regulating NF-κB activation and macrophages polarization, which may be a novel potential target and shed light on ALI therapy.


Assuntos
Lesão Pulmonar Aguda , Lipopolissacarídeos , Macrófagos , Fatores de Crescimento Neural , Lesão Pulmonar Aguda/genética , Lesão Pulmonar Aguda/imunologia , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/patologia , Animais , Astrócitos/metabolismo , Astrócitos/patologia , Modelos Animais de Doenças , Humanos , Lipopolissacarídeos/farmacologia , Pulmão , Ativação de Macrófagos , Macrófagos/imunologia , Macrófagos/patologia , Camundongos , Camundongos Knockout , NF-kappa B/metabolismo , Fatores de Crescimento Neural/genética , Fatores de Crescimento Neural/imunologia , Fatores de Crescimento Neural/metabolismo
14.
Front Pharmacol ; 13: 975250, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36386180

RESUMO

Long noncoding RNAs (lncRNAs) are defined as transcripts of more than 200 nucleotides that have little or no coding potential. LncRNAs function as key regulators in diverse physiological and pathological processes. However, the roles of lncRNAs in lipopolysaccharide (LPS)-induced acute liver injury (ALI) are still elusive. In this study, we report the roles of lncRNA Gm26917 induced by LPS in modulating liver inflammation. As key components of the innate immune system, macrophages play critical roles in the initiation, progression and resolution of ALI. Our studies demonstrated that Gm26917 localized in the cytoplasm of hepatic macrophages and globally regulated the expression of inflammatory genes and the differentiation of macrophages. In vivo study showed that lentivirus-mediated gene silencing of Gm26917 attenuated liver inflammation and protected mice from LPS-induced ALI. Furthermore, mechanistic study showed that the 3'-truncation of Gm26917 interacted with the N-terminus of Annexin A1, a negative regulator of the NF-κB signaling pathway. We also found that Gm26917 knockdown suppressed NF-κB activity by decreasing the ubiquitination of Annexin A1 and its interaction with NEMO. In addition, expression of Gm26917 in inflammatory macrophages was regulated by the transcription factor forkhead box M1 (FOXM1). LPS treatment dramatically increased the binding of FOXM1 to the promoter region of Gm26917 in macrophages. In summary, our findings suggest that lncRNA Gm26917 silencing protects against LPS-induced liver injury by regulating the TLR4/NF-κB signaling pathway in macrophages.

15.
RSC Adv ; 10(9): 5294-5303, 2020 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-35498332

RESUMO

Multifunctional nanoclusters based on Fe3O4 nanoparticles for magnetic resonance imaging (MRI) and drug delivery are reported here. At first, oleic acid (OA)-coated Fe3O4 nanoparticles were prepared. Then block copolymer Pluronic F127 or folic acid (FA) conjugated-Pluronic F127 was used to modify the hydrophobic nanoparticles to become hydrophilic Fe3O4@F127 nanoclusters via facile ultrasonic treatment. During this process, drug molecules can also be introduced into the nanoclusters and therefore the targeted drug delivery system was formed. Next, we verified the feasibility of the nanoclusters as drug delivery vehicles and magnetic contrast agents. The nanoclusters have an average size of 200 nm and remained stable in water for long periods. Folic acid-modified nanoclusters showed an enhanced intracellular uptake into HepG2 cells by using both cellular iron amount analysis and flow cytometry analysis. Besides, Fe3O4@F127@FA nanoclusters showed good compatibility in the tested concentration range and good sensitivity in T 2-weighted MRI. The magnetic nanoclusters combined with drug delivery properties have greatly increased the significance in the diagnosis and therapy of diseases, which are suitable for systematical administration of hydrophobic drugs and simultaneously MRI diagnosis.

16.
Pathol Res Pract ; 215(9): 152523, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31300294

RESUMO

Mammary carcinoma (MC) is one of most common malignancy in women, and ring finger protein 2 (RNF2) possesses various roles in vast human tumors. In MC tissues as well as in cell lines RNF2 exhibited high expression, had significant association with tumor size, lymph node status, TNM stage, patients' poor survival, and promoted cell proliferation, colony formation, cell migration and invasion of MC cell lines which was mediated by downregulation of E-cadherin protein. These data reveal that RNF2 protein plays a vital role in the development of MC and may be a potential therapy target of MC.


Assuntos
Neoplasias da Mama/patologia , Carcinoma/patologia , Transição Epitelial-Mesenquimal/fisiologia , Complexo Repressor Polycomb 1/metabolismo , Adulto , Idoso , Biomarcadores Tumorais/análise , Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Carcinoma/metabolismo , Carcinoma/mortalidade , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Feminino , Humanos , Estimativa de Kaplan-Meier , Pessoa de Meia-Idade , Invasividade Neoplásica/patologia
17.
Eur J Pharmacol ; 843: 1-11, 2019 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-30389633

RESUMO

Hepatocellular carcinoma (HCC) has high incidence and mortality in patients with chronic liver diseases worldwide. However, there are limited chemotherapeutic agents for HCC in clinic. Xanthatin, a natural sesquiterpene lactone, has significant antitumor activity against a variety of cancers, but little is known about its effects on HCC and the underlying mechanism. Here, we evaluated the antitumor effects of xanthatin on human hepatoma cells. We found that xanthatin caused morphological changes and reduced cell viability in three HCC cell lines in concentration- and time-dependent manners. Xanthatin at 10 µM significantly arrested cell cycle at the G2/M checkpoint, and at 40 µM significantly arrested cell cycle at the S phase in hepatoma cells. Additionally, xanthatin induced apoptosis associated with activation of caspase-3 in hepatoma cells, but did not apparently induce apoptosis in human normal LO2 hepatocytes. We also demonstrated that the three primary signaling pathways of unfolded protein response (UPR) were activated by xanthatin to different extents. Notably, the PERK/eIF-2α/ATF4 axis was most significantly activated by xanthatin. More importantly, both xanthatin and tunicamycin, an endoplasmic reticulum stress (ERS) inducing compound, increased the levels of CHOP and cleaved-caspase-3 in HepG2 cells, but their effects were significantly abolished by siRNA-mediated knockdown of CHOP. Further experiments validated that xanthatin more potently activated ATF4 by promoting its nuclear translocation in hepatoma cells. Taken together, we discovered that xanthatin induced apoptosis in human hepatoma cells by activating ERS. Our current data revealed a novel mechanism for xanthatin as a promising anti-tumor candidate for HCC therapy.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Furanos/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Fator 4 Ativador da Transcrição/genética , Fator 4 Ativador da Transcrição/metabolismo , Apoptose/efeitos dos fármacos , Carcinoma Hepatocelular/metabolismo , Linhagem Celular , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Fator de Iniciação 2 em Eucariotos/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Humanos , Neoplasias Hepáticas/metabolismo , Fator de Transcrição CHOP/genética , Fator de Transcrição CHOP/metabolismo , eIF-2 Quinase/metabolismo
18.
Eur J Pharmacol ; 584(2-3): 246-52, 2008 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-18329639

RESUMO

Paeonol, a phenolic component from the root bark of Paeonia moutan, is traditionally used as a Chinese herbal medicine to activate the blood flow and remove blood stasis. Evidence shows that paeonol have anti-tumor, anti-inflammatory, and analgesic effects; however, the underlying mechanisms remain unknown. In this study, we investigated the molecular mechanisms by which paeonol exerts the anti-tumor effects by using a murine model of hepatoma established by in vivo injection of mouse HepA-hepatoma cells. Treatment of mice with 100, 200, or 400 mg/kg/day of paeonol significantly inhibited the growth of the HepA tumor in mice, induced HepA cell apoptosis as demonstrated by light microscopy and electron microscopy analyses, decreased the expression of Bcl-2 and increased the expression of Bax in HepA tumor tissues in a dose-related manner. Administration of paeonol in vivo also elevated serum levels of IL-2 and TNF-alpha in tumor-bearing mice. Moreover, splenocytes and macrophages isolated from paeonol-treated HepA tumor-bearing mice produced higher levels of IL-2 and TNF-alpha in response to concanavalin A and lipopolysaccharide stimulation, respectively, compared to these isolated from non-treated HepA tumor-bearing mice. In vitro treatment with paeonol was able to directly stimulate IL-2 and TNF-alpha production in splenocytes and macrophages from tumor-bearing mice, respectively. In conclusion, paeonol has the anti-tumor effect against hepatoma cells, which are likely mediated via induction of tumor cell apoptosis and stimulation of IL-2 and TNF-alpha production. Paeonol could be a promising drug to treat hepatocellular carcinoma.


Assuntos
Acetofenonas/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Interleucina-2/metabolismo , Neoplasias Hepáticas Experimentais/tratamento farmacológico , Fator de Necrose Tumoral alfa/metabolismo , Acetofenonas/uso terapêutico , Animais , Antineoplásicos Fitogênicos/uso terapêutico , Linhagem Celular Tumoral , Células Cultivadas , Relação Dose-Resposta a Droga , Interleucina-2/sangue , Neoplasias Hepáticas Experimentais/imunologia , Neoplasias Hepáticas Experimentais/patologia , Macrófagos Peritoneais/efeitos dos fármacos , Macrófagos Peritoneais/imunologia , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Baço/efeitos dos fármacos , Baço/imunologia , Fator de Necrose Tumoral alfa/sangue , Regulação para Cima , Proteína X Associada a bcl-2/metabolismo
19.
Chin Med J (Engl) ; 121(7): 602-7, 2008 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-18466679

RESUMO

BACKGROUND: Lumiracoxib is a highly selective cyclooxygenase-2 (COX-2) inhibitor with antiinflammatory, analgesic and antipyretic activities comparable with class specific drugs, but with much improved gastrointestinal safety. No studies have examined lumiracoxib for antitumorigenic activity on human nonsmall cell lung cancer cell lines in vitro or its possible molecular mechanisms. METHODS: The antiproliferative effect of lumiracoxib alone or combined with docetaxol on A549 and NCI-H460 lines was assessed by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Drug-drug interactions were analyzed using the coefficient of drug interaction (CDI) to characterize the interactions as synergism, additivity or antagonism. Morphological changes were observed by acridine orange fluorescent staining. Extent of apoptosis was determined by flow cytometry. RESULTS: Lumiracoxib (15 - 240 micromol/L) has an inhibitory effect on the proliferation of A549 and NCI-H460 cell lines in concentration- and time-dependent manners with the IC50 values of 2597 micromol/L and 833 micromol/L, respectively. The synergistic effect was prominent when lumiracoxib (15 - 240 micromol/L) was combined with docetaxol (0.2 - 2 micromol/L) (CDI < 1). Fluorescent staining showed that lumiracoxib could induce apoptosis in A549 and NCI-H460 cells. Lumiracoxib treatment also caused an increase of the sub-G1 fraction in each cell line and resulted in an increase of G0/G1-phase cells and a decrease of S-phase cells. CONCLUSIONS: Lumiracoxib had antiproliferative effect on the human nonsmall cell lung cancer cell lines A549 and NCI-H460 and had a significant synergy with docetaxol, which may be related to apoptotic induction and cell cycle arrest.


Assuntos
Apoptose/efeitos dos fármacos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Inibidores de Ciclo-Oxigenase 2/farmacologia , Diclofenaco/análogos & derivados , Neoplasias Pulmonares/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Diclofenaco/farmacologia , Docetaxel , Humanos , Neoplasias Pulmonares/patologia , Taxoides/farmacologia
20.
Zhonghua Bing Li Xue Za Zhi ; 37(2): 109-13, 2008 Feb.
Artigo em Zh | MEDLINE | ID: mdl-18681322

RESUMO

OBJECTIVE: To investigate the expression of a novel metastasis-inducing protein human anterior gradient-2 (AGR2) in breast cancer and its clinical and prognostic significance. METHODS: AGR2 expression was assessed in 160 cases of breast cancer and 20 cases of benign breast diseases by immunohistochemistry using tissue chip technology. In addition the expression of ERa, PR and c-erbB-2 in breast cancer was also evaluated. Follow-up information of 5-year duration was available in 127 patients with breast cancer. Kaplan-Meier analysis and COX regression model were used to analyze the correlation between AGR2 expression and the follow-up clinical data. RESULTS: The expression of AGR2 was significantly higher in breast cancers than that in benign diseases (68.3% vs. 25.0% , P < 0.01). There was a negative correlation between AGR2 expression and the histological grade of breast cancer (P <0.05) , whereas positive correlations was found between the expression of AGR2 and ERalpha (P <0.05), and between the expression of AGR2 and PR (P <0.01). In the subgroup of ERalpha-positive breast cancer, Logistic regression model demonstrated AGR2 and TNM stage were important factors affecting lymph node metastasis (both P < 0.01). Kaplan-Meier analysis demonstrated that a positive expression of AGR2 was associated with poor overall survival and relapse-free survival (both P <0.01). Moreover, COX regression model confirmed the expression of AGR2 as an independent prognostic factor among patients with ERa-positive breast cancer (P <0.01). CONCLUSIONS: The abnormal expression of AGR2 may play a role in the pathogenesis and progression of breast cancer. The metastasis-inducing capability of AGR2 may be partly regulated through the ER pathway. Therefore, AGR2 may be a useful molecular marker for prognostication for patient with hormone-responsive breast cancer.


Assuntos
Proteína BRCA2/metabolismo , Neoplasias da Mama/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Metástase Neoplásica/diagnóstico , Proteínas/metabolismo , Receptor ErbB-2/metabolismo , Antineoplásicos Hormonais/análise , Proteína BRCA2/genética , Biomarcadores Tumorais/análise , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Receptor alfa de Estrogênio/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Mucoproteínas , Estadiamento de Neoplasias , Proteínas Oncogênicas , Prognóstico , Proteínas/genética , Receptor ErbB-2/análise
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