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1.
J Gastroenterol Hepatol ; 37(10): 1946-1954, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35933582

RESUMO

BACKGROUND AND AIM: Hepatic stellate cells (HSCs), the main source of extracellular matrix in hepatic fibrogenesis, produce various cytokines, growth factors, and morphogenetic proteins. Among these, several factors are known to promote hepatocyte lipid accumulation, suggesting that HSCs can be efficient therapeutic targets for non-alcoholic steatohepatitis (NASH). This study aimed to investigate the effects of HSC depletion on the development of hepatic steatosis and fibrosis in a murine NASH model. METHODS: C57BL/6 mice were treated with gliotoxin (GTX), an apoptosis inducer of activated HSCs under the feeding of a choline-deficient l-amino acid-defined high-fat diet for 4 weeks. For in vitro study, Hc3716 cells, immortalized human hepatocytes, were treated with fatty acids in the presence or absence of LX2, immortalized HSCs. RESULTS: Choline-deficient l-amino acid-defined high-fat diet increased pronounced hepatic steatosis, which was attenuated by GTX treatment, together with a reduction in the number of activated HSCs. This change was associated with the downregulation of the peroxisome proliferator-activated receptor gamma (PPARγ) and its downstream genes, including adipocyte protein 2, cluster of differentiation 36 (CD36), and fatty acid transport protein 1, all of which increase the fatty acid uptake into hepatocytes. As expected, GTX treatment improved hepatic fibrosis. Co-culture of hepatocytes with HSCs enhanced intracellular lipid accumulation, together with the upregulation of PPARγ and CD36 protein expressions. CONCLUSIONS: In addition to the improvement in hepatic fibrogenesis, depletion of HSCs had a favorable effect on hepatic lipid metabolism in a mouse NASH model, suggesting that HSCs are potentially efficient targets for the treatment of NASH.


Assuntos
Gliotoxina , Hepatopatia Gordurosa não Alcoólica , Aminoácidos/metabolismo , Aminoácidos/farmacologia , Animais , Antígenos CD36/metabolismo , Colina/metabolismo , Colina/farmacologia , Citocinas/metabolismo , Modelos Animais de Doenças , Ácidos Graxos , Gliotoxina/metabolismo , Gliotoxina/farmacologia , Células Estreladas do Fígado/metabolismo , Hepatócitos/metabolismo , Humanos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Hepatopatia Gordurosa não Alcoólica/complicações , PPAR gama/metabolismo
2.
Clin Case Rep ; 10(3): e05416, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35261771

RESUMO

Here, we report a case of traumatic pulmonary pseudocysts (TPPs) coinciding with vertebral fracture. Traumatic pulmonary pseudocysts (TPPs) are rare complications of blunt chest trauma. These clinical images of CT, presenting here, seemed to be valuable because they show the process of pseudocyst formation.

4.
Intern Med ; 60(8): 1311-1315, 2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33191326

RESUMO

We herein report a case of aortitis induced by granulocyte colony-stimulating factor (G-CSF) that coincided with lung injury, splenomegaly, and cutaneous manifestations during treatment for recurrent extraosseous mucinous chondrosarcoma. Computed tomography revealed large-vessel vasculitis, splenomegaly, and pulmonary interstitial changes. Treatment with prednisolone was successful. Because sarcoma is a rare disease, this case is valuable for showing clinicians that G-CSF preparations could cause aortitis regardless of the patient's underlying diseases or therapeutic pharmacological backgrounds.


Assuntos
Aortite , Condrossarcoma , Exantema , Lesão Pulmonar , Aortite/induzido quimicamente , Aortite/diagnóstico por imagem , Aortite/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos , Humanos , Recidiva Local de Neoplasia , Esplenomegalia/induzido quimicamente , Esplenomegalia/tratamento farmacológico
5.
J Cancer Res Clin Oncol ; 146(12): 3255-3268, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32870388

RESUMO

PURPOSE: Deoxycholic acid (DCA), a secondary bile acid, is reportedly increased in the serum of patients with nonalcoholic steatohepatitis and animals with experimentally induced hepatocellular carcinoma (HCC), but its contribution to malignant behaviors of HCC has not been precisely clarified. This study aimed to examine the effect of DCA on hepatic stellate cells (HSCs), a major component of nonparenchymal cells in the liver, and its subsequent indirect effect on HCC cells. METHODS: LX2 cells, a human HSC line, were treated with DCA in vitro. Then, HuH7 cells, a human hepatoma cell line, were incubated in conditioned media of DCA-treated LX2 to investigate the subsequent effect focusing on malignant behaviors. RESULTS: DCA resulted in cellular senescence in LX2 with the decreased cell proliferation via cell cycle arrest at G0/1 phase, together with the induction of senescence-associated secretory phenotype (SASP) factors. To investigate the influence of SASP factors secreted by HSCs in response to DCA, HCC cells were treated with conditioned media that promoted cell migration and invasion via induction of epithelial mesenchymal transition. These changes were attenuated in the presence of neutralizing antibody against IL8 or TGFß. Pathological analysis of surgical specimens from HCC patients revealed that senescent HSCs were detected in the stroma surrounding HCC. CONCLUSION: Our data suggest an important role of HSC senescence caused by DCA for the malignant biological behaviors of HCC via induction of SASP factors, particularly IL8 and TGFß.


Assuntos
Carcinoma Hepatocelular/metabolismo , Ácido Desoxicólico/farmacologia , Células Estreladas do Fígado/efeitos dos fármacos , Neoplasias Hepáticas/metabolismo , Anticorpos Neutralizantes/farmacologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Células Estreladas do Fígado/metabolismo , Humanos , Interleucina-8/antagonistas & inibidores , Interleucina-8/imunologia , Fígado/efeitos dos fármacos , Fígado/patologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta/antagonistas & inibidores , Fator de Crescimento Transformador beta/imunologia
6.
Intern Med ; 59(20): 2623-2627, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32581157

RESUMO

We herein report on two male patients (age, 22 and 44 years) who were referred to our department with swelling of the upper right arm after attending other hospitals. Right subclavian vein thrombosis was demonstrated by ultrasonography and they were then further evaluated by contrast-enhanced computed tomography (CT). Successful treatment involved venous thrombectomy in one patient and anticoagulant therapy in the other. Paget-Schhroetter syndrome was confirmed using standard vascular ultrasonography. Despite the accuracy of this method for diagnosing Paget-Schroetter syndrome, some cases are difficult to confirm. We reviewed 29 previously published case reports of Paget-Schroetter syndrome and analyzed the patient baseline characteristics, time to diagnosis, and the diagnostic methods used.


Assuntos
Trombose Venosa Profunda de Membros Superiores/diagnóstico , Adulto , Anticoagulantes/uso terapêutico , Humanos , Masculino , Veia Subclávia/diagnóstico por imagem , Trombectomia/métodos , Ultrassonografia Doppler , Trombose Venosa Profunda de Membros Superiores/diagnóstico por imagem , Trombose Venosa Profunda de Membros Superiores/terapia , Adulto Jovem
7.
J Gastroenterol Hepatol ; 35(12): 2140-2150, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32365405

RESUMO

BACKGROUND AND AIM: Non-alcoholic steatohepatitis (NASH) is characterized by hepatic steatosis, inflammation, and hepatocellular injury with varying degrees of fibrosis. There are currently no established treatment approaches for NASH other than lifestyle interventions. Periostin, a matricellular protein required for tissue remodeling and fibrosis, plays an important role in hepatic steatosis and fibrosis and could be a potential target for NASH treatment. Advances in molecular biology and biochemical engineering have led to the development of antisense oligonucleotides (ASOs) that can inhibit target genes with no significant toxic effects. Herein, we investigated the therapeutic effects of periostin-targeting ASO (PNASO) in NASH. METHODS: C57BL/6J mice were fed a choline-deficient, l-amino acid-defined, high-fat diet (CDAHFD) to induce NASH with or without intraperitoneal injection of mouse PNASO. To explore the role of periostin in hepatocellular steatosis, Hc3716 cells, an immortalized human hepatocyte line, were treated with recombinant periostin in vitro. RESULTS: The induced periostin expression in the liver of CDAHFD-fed mice was significantly suppressed by PNASO. The deletion of hepatic periostin by PNASO significantly ameliorated hepatic steatosis while restoring the expression levels of peroxisome proliferator-activated receptor-alpha (PPAR-α) and its target genes. PNASO also inhibited hepatic fibrosis, reflected by the reduction of alpha-smooth muscle actin, collagen type I, and other fibrotic markers. In vitro experiments demonstrated that treatment with recombinant periostin increased cellular lipid accumulation in Hc3716 cells accompanied with the downregulation of PPAR-α. CONCLUSIONS: Periostin-targeting ASO is a potential therapeutic approach for the efficient treatment of hepatic steatosis and fibrosis in NASH.


Assuntos
Moléculas de Adesão Celular/fisiologia , Fígado/patologia , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Oligonucleotídeos Antissenso/uso terapêutico , Animais , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Fibrose/prevenção & controle , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Humanos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Terapia de Alvo Molecular , Hepatopatia Gordurosa não Alcoólica/patologia , Oligonucleotídeos Antissenso/farmacologia , PPAR alfa/genética , PPAR alfa/metabolismo
9.
J Hepatobiliary Pancreat Sci ; 26(12): 568-577, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31578786

RESUMO

BACKGROUND: Pancreaticobiliary maljunction and intrahepatic gallstones are at a high risk for biliary malignancy. Lysophosphatidylcholine (LPC) is increased in the bile of these patients, and we have previously reported that LPC-induced cytotoxicity causes senescence-associated secretory phenotype (SASP) in cholangiocytes. We aimed to determine the protective effect of phosphatidylcholine (PC) on LPC-induced cholangiocyte cytotoxicity. METHODS: MMNK-1, a human immortalized cholangiocyte cell line was treated with LPC with or without PC. To assess the biological effects of SASP components on cholangiocarcinoma, HuH28 and HuCCT1 (human cholangiocarcinoma cell lines) were cultured in the conditioned media where MMNK-1 cells treated with LPC. RESULTS: The presence of PC reduced reactive oxygen species generation and oxidative DNA damage in MMNK-1 treated with LPC. Moreover, SA-ß-gal activity was markedly downregulated by PC. The secretion of SASP components, including interleukin (IL)-8, IL-6, and C-C motif chemokine ligand 2 was also substantially reduced in the presence of PC. Cellular proliferation and migration were enhanced in HuCCT1 and HuH28 cells when cultured in the conditioned media, and these observations were suppressed by simultaneous addition of PC. CONCLUSION: PC protects cholangiocytes against LPC-induced cytotoxicity and cellular senescence, suggesting its potential as a target for inhibiting LPC-related carcinogenesis and its promotion.


Assuntos
Ductos Biliares/citologia , Senescência Celular/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Lisofosfatidilcolinas/efeitos adversos , Fosfatidilcolinas/farmacologia , Substâncias Protetoras/farmacologia , Ductos Biliares/patologia , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Senescência Celular/fisiologia , Colangiocarcinoma , Células Epiteliais/patologia , Células Epiteliais/fisiologia , Humanos , Lisofosfatidilcolinas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
10.
Intern Med ; 58(11): 1629-1634, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-30713307

RESUMO

Acute chest syndrome (ACS), characterized by fever, respiratory symptoms, and new pulmonary infiltration, is a serious complication of sickle cell disease (SCD). Regardless of the etiology, the conventional treatment options for ACS include empirical antibiotic therapy, the administration of analgesics, and red cell transfusion. The indications and methods of red cell transfusion are critical. We herein report the case of a 26-year-old African-American man with SCD who developed ACS and who was successfully treated with manual exchange transfusion. Despite increasing globalization, SCD remains extremely rare in Japan. Manual exchange transfusion can be performed easily anywhere and should be considered for treating SCD patients presenting with ACS.


Assuntos
Síndrome Torácica Aguda/terapia , Anemia Falciforme/complicações , Transfusão de Eritrócitos/métodos , Talassemia beta/complicações , Síndrome Torácica Aguda/diagnóstico por imagem , Síndrome Torácica Aguda/etiologia , Adulto , Humanos , Masculino , Radiografia Torácica , Tomografia Computadorizada por Raios X
11.
Intern Med ; 58(6): 871-875, 2019 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-30449779

RESUMO

A 78-year-old woman with fever of unknown origin that had persisted for 3 months, systemic edema, and cervical lymphadenopathy was admitted to our hospital. Skin purpura and jaw claudication were subsequently observed. Histopathological examinations of the lymph nodes, skin, and temporal artery revealed findings characteristic of eosinophilic granulomatosis with polyangiitis (EGPA). However, she had no past medical history of asthma with modest eosinophilia. Although EGPA is a systemic vasculitis characterized by asthma and eosinophilia, various limited forms have been described. This was therefore considered to be an atypical form of non-asthmatic EGPA complicating with temporal arteritis (TA) diagnosed by tissue biopsy.


Assuntos
Síndrome de Churg-Strauss/diagnóstico , Eosinofilia/diagnóstico , Granulomatose com Poliangiite/diagnóstico , Idoso , Asma/diagnóstico , Biópsia , Síndrome de Churg-Strauss/patologia , Eosinofilia/patologia , Feminino , Granulomatose com Poliangiite/patologia , Humanos , Linfonodos/patologia , Pele/patologia
12.
Clin Case Rep ; 7(12): 2534-2538, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31893095

RESUMO

Here, we describe a case of giant cell arteritis (GCA) simultaneously diagnosed with chronic subdural hematoma. In this case, head to chest computed tomography angiography was useful for the diagnosis and treatment of GCA.

13.
Clin Case Rep ; 6(9): 1905-1906, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30214793

RESUMO

Salicylate-induced acute respiratory syndrome (ARDS) is a well-known entity occurring in 35% of salicylate-intoxicated patient. Careful history taking, physical examination, arterial blood gas analysis, and measurement of serum salicylate concentration will lead to early recognition to initiate appropriate treatment.

14.
Intern Med ; 57(16): 2425-2429, 2018 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-29526930

RESUMO

Familial Mediterranean fever (FMF) is the most common genetic autoinflammatory disease, but it has been considered a rare disease in Japan. We herein describe five patients with FMF who were diagnosed both clinically and genetically at a single Japanese institute. A genetic investigation of Mediterranean fever (MEFV) detected heterozygosity for the compound mutations L110P/E148Q (n=2) and L110P/148Q/P369S/R406Q (n=1), and heterozygosity for M694I (n=1) and S503C (n=1). Colchicine prevented febrile attacks and accompanying symptoms in four patients. One patient with an S503C mutation showed resistance. Physicians should be aware of the characteristic symptoms, as well as the more unusual symptoms such as headache, when diagnosing FMF.


Assuntos
Colchicina/uso terapêutico , Proteínas do Citoesqueleto/genética , Febre Familiar do Mediterrâneo/tratamento farmacológico , Febre Familiar do Mediterrâneo/genética , Pirina/genética , Doenças Raras/genética , Adulto , Povo Asiático , Febre Familiar do Mediterrâneo/complicações , Febre Familiar do Mediterrâneo/diagnóstico , Feminino , Heterozigoto , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Mutação , Resultado do Tratamento
15.
Case Rep Med ; 2018: 5860815, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29560010

RESUMO

A 46-year-old man with severe back pain visited our hospital. Magnetic resonance imaging revealed extensive bone metastasis and rectal wall thickness. Colonoscopy revealed circumferential stenosis with edematous mucosa, suggesting colon cancer. However, histological findings of biopsy specimens revealed inflammatory cells but no malignant cells. The patient underwent endoscopic ultrasound, which demonstrated edematous wall thickness without destruction of the normal layer structure. After unsuccessful detection of neoplastic cells by boring biopsies, we performed endoscopic mucosal resection followed by boring biopsies that finally revealed signet ring cell carcinoma. Herein, we present a case and provide a review of the literature.

16.
Clin Case Rep ; 5(9): 1548-1549, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28878925

RESUMO

Venomous snake bites can be life threatening, occasionally requiring intensive care. For Mamushi bites, conservative treatment may be possible in mild cases but for severe cases or in cases where symptoms do not improve, a horse-derived antivenom is indicated.

17.
J Biol Chem ; 288(28): 20692-701, 2013 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-23720771

RESUMO

Pin1 and Par14 are parvulin-type peptidyl-prolyl cis/trans isomerases. Although numerous proteins have been identified as Pin1 substrates, the target proteins of Par14 remain largely unknown. Par14 expression levels are increased in the livers and embryonic fibroblasts of Pin1 KO mice, suggesting a compensatory relationship between the functions of Pin1 and Par14. In this study, the association of Par14 with insulin receptor substrate 1 (IRS-1) was demonstrated in HepG2 cells overexpressing both as well as endogenously in the mouse liver. The analysis using deletion-mutated Par14 and IRS-1 constructs revealed the N-terminal portion containing the basic domain of Par14 and the two relatively C-terminal portions of IRS-1 to be involved in these associations, in contrast to the WW domain of Pin1 and the SAIN domain of IRS-1. Par14 overexpression in HepG2 markedly enhanced insulin-induced IRS-1 phosphorylation and its downstream events, PI3K binding with IRS-1 and Akt phosphorylation. In contrast, treating HepG2 cells with Par14 siRNA suppressed these events. In addition, overexpression of Par14 in the insulin-resistant ob/ob mouse liver by adenoviral transfer significantly improved hyperglycemia with normalization of hepatic PEPCK and G6Pase mRNA levels, and gene suppression of Par14 using shRNA adenovirus significantly exacerbated the glucose intolerance in Pin1 KO mice. Therefore, although Pin1 and Par14 associate with different portions of IRS-1, the prolyl cis/trans isomerization in multiple sites of IRS-1 by these isomerases appears to be critical for efficient insulin receptor-induced IRS-1 phosphorylation. This process is likely to be one of the major mechanisms regulating insulin sensitivity and also constitutes a potential therapeutic target for novel insulin-sensitizing agents.


Assuntos
Proteínas Substratos do Receptor de Insulina/metabolismo , Insulina/farmacologia , Peptidilprolil Isomerase/metabolismo , Animais , Sítios de Ligação/genética , Intolerância à Glucose/genética , Células HEK293 , Células Hep G2 , Humanos , Hiperglicemia/genética , Hiperglicemia/terapia , Hipoglicemiantes/farmacologia , Immunoblotting , Proteínas Substratos do Receptor de Insulina/genética , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Obesos , Mutação , Peptidilprolil Isomerase de Interação com NIMA , Obesidade/sangue , Obesidade/genética , Peptidilprolil Isomerase/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Ligação Proteica , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA
18.
Biochem Biophys Res Commun ; 434(2): 197-202, 2013 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-23523797

RESUMO

The dynamic process of adipose differentiation involves stepwise expressions of transcription factors and proteins specific to the mature fat cell phenotype. In this study, it was revealed that expression levels of IntS6 and IntS11, subunits of the Integrator complex, were increased in 3T3-L1 cells in the period when the cells reached confluence and differentiated into adipocytes, while being reduced to basal levels after the completion of differentiation. Suppression of IntS6 or IntS11 expression using siRNAs in 3T3-L1 preadipocytes markedly inhibited differentiation into mature adipocytes, based on morphological findings as well as mRNA analysis of adipocyte-specific genes such as Glut4, perilipin and Fabp4. Although Pparγ2 protein expression was suppressed in IntS6 or IntS11-siRNA treated cells, adenoviral forced expression of Pparγ2 failed to restore the capacity for differentiation into mature adipocytes. Taken together, these findings demonstrate that increased expression of Integrator complex subunits is an indispensable event in adipose differentiation. Although further study is necessary to elucidate the underlying mechanism, the processing of U1, U2 small nuclear RNAs may be involved in cell differentiation steps.


Assuntos
Adipócitos/citologia , Adipogenia , RNA Helicases DEAD-box/metabolismo , Complexos Multiproteicos/metabolismo , Células 3T3-L1 , Adenoviridae/metabolismo , Adipócitos/metabolismo , Animais , Western Blotting , RNA Helicases DEAD-box/genética , Proteínas de Ligação a Ácido Graxo/genética , Proteínas de Ligação a Ácido Graxo/metabolismo , Fibroblastos/citologia , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Transportador de Glucose Tipo 4/genética , Transportador de Glucose Tipo 4/metabolismo , Camundongos , Complexos Multiproteicos/genética , PPAR gama/genética , PPAR gama/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas de Ligação a RNA , Fatores de Tempo , Transfecção , Proteínas Supressoras de Tumor
19.
J Biol Chem ; 287(53): 44526-35, 2012 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-23112047

RESUMO

Nonalcoholic steatohepatitis (NASH) is a disorder characterized by simultaneous fat accumulation and chronic inflammation in the liver. In this study, Pin1 expression was revealed to be markedly increased in the livers of mice with methionine choline-deficient (MCD) diet-induced NASH, a rodent model of NASH. In addition, Pin1 KO mice were highly resistant to MCD-induced NASH, based on a series of data showing simultaneous fat accumulation, chronic inflammation, and fibrosis in the liver. In terms of Pin1-induced fat accumulation, it was revealed that the expression levels of peroxisome proliferator-activated receptor α and its target genes were higher in the livers of Pin1 KO mice than in controls. Thus, resistance of Pin1 KO mice to hepatic steatosis is partially attributable to the lack of Pin1-induced down-regulation of peroxisome proliferator-activated receptor α, although multiple other mechanisms are apparently involved. Another mechanism involves the enhancing effect of hematopoietic Pin1 on the expressions of inflammatory cytokines such as tumor necrosis factor and monocyte chemoattractant protein 1 through NF-κB activation, eventually leading to hepatic fibrosis. Finally, to distinguish the roles of hematopoietic or nonhematopoietic Pin1 in NASH development, mice lacking Pin1 in either nonhematopoietic or hematopoietic cells were produced by bone marrow transplantation between wild-type and Pin1 KO mice. The mice having nonhematopoietic Pin1 exhibited fat accumulation without liver fibrosis on the MCD diet. Thus, hepatic Pin1 appears to be directly involved in the fat accumulation in hepatocytes, whereas Pin1 in hematopoietic cells contributes to inflammation and fibrosis. In summary, this is the first study to demonstrate that Pin1 plays critical roles in NASH development. This report also raises the possibility that hepatic Pin1 inhibition to the appropriate level might provide a novel therapeutic strategy for NASH.


Assuntos
Fígado Gorduroso/enzimologia , Peptidilprolil Isomerase/metabolismo , Animais , Modelos Animais de Doenças , Fígado Gorduroso/genética , Fígado Gorduroso/patologia , Feminino , Humanos , Fígado/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Peptidilprolil Isomerase de Interação com NIMA , Hepatopatia Gordurosa não Alcoólica , Peptidilprolil Isomerase/genética
20.
Am J Physiol Cell Physiol ; 300(5): C1047-54, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21270293

RESUMO

Glucose transporter 1 (GLUT1) is widely distributed throughout various tissues and contributes to insulin-independent basal glucose uptake. Using a split-ubiquitin membrane yeast two-hybrid system, we newly identified 4F2 heavy chain (4F2hc) as a membrane protein interacting with GLUT1. Though 4F2hc reportedly forms heterodimeric complexes between amino acid transporters, such as LAT1 and LAT2, and regulates amino acid uptake, we investigated the effects of 4F2hc on GLUT1 expression and the associated glucose uptake. First, FLAG-tagged 4F2hc and hemagglutinin-tagged GLUT1 were overexpressed in human embryonic kidney 293 cells and their association was confirmed by coimmunoprecipitation. The green fluorescent protein-tagged 4F2hc and DsRed-tagged GLUT1 showed significant, but incomplete, colocalization at the plasma membrane. In addition, an endogenous association between GLUT1 and 4F2hc was demonstrated using mouse brain tissue and HeLa cells. Interestingly, overexpression of 4F2hc increased the amount of GLUT1 protein in HeLa and HepG2 cells with increased glucose uptake. In contrast, small interfering RNA (siRNA)-mediated 4F2hc gene suppression markedly reduced GLUT1 protein in both cell types, with reduced glucose uptake. While GLUT1 mRNA levels were not affected by overexpression or gene silencing of 4F2hc, GLUT1 degradation after the addition of cycloheximide was significantly suppressed by 4F2hc overexpression and increased by 4F2hc siRNA treatment. Taken together, these observations indicate that 4F2hc is likely to be involved in GLUT1 stabilization and to contribute to the regulation of not only amino acid but also glucose metabolism.


Assuntos
Cadeia Pesada da Proteína-1 Reguladora de Fusão/metabolismo , Transportador de Glucose Tipo 1/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/fisiologia , Cicloeximida/farmacologia , Células HEK293 , Células HeLa , Humanos , Masculino , Camundongos , Inibidores da Síntese de Proteínas/farmacologia , RNA Interferente Pequeno/farmacologia , Técnicas do Sistema de Duplo-Híbrido
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