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1.
World J Gastroenterol ; 30(11): 1533-1544, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38617449

RESUMO

BACKGROUND: Patients with liver cancer complicated by portal hypertension present complex challenges in treatment. AIM: To evaluate the efficacy of radiofrequency ablation in combination with sorafenib for improving liver function and its impact on the prognosis of patients with this condition. METHODS: Data from 100 patients with liver cancer complicated with portal hypertension from May 2014 to March 2019 were analyzed and divided into a study group (n = 50) and a control group (n = 50) according to the treatment regimen. The research group received radiofrequency ablation (RFA) in combination with sorafenib, and the control group only received RFA. The short-term efficacy of both the research and control groups was observed. Liver function and portal hypertension were compared before and after treatment. Alpha-fetoprotein (AFP), glypican-3 (GPC-3), and AFP-L3 levels were compared between the two groups prior to and after treatment. The occurrence of adverse reactions in both groups was observed. The 3-year survival rate was compared between the two groups. Basic data were compared between the survival and non-surviving groups. To identify the independent risk factors for poor prognosis in patients with liver cancer complicated by portal hypertension, multivariate logistic regression analysis was employed. RESULTS: When comparing the two groups, the research group's total effective rate (82.00%) was significantly greater than that of the control group (56.00%; P < 0.05). Following treatment, alanine aminotransferase and aspartate aminotransferase levels increased, and portal vein pressure decreased in both groups. The degree of improvement for every index was substantially greater in the research group than in the control group (P < 0.05). Following treatment, the AFP, GPC-3, and AFP-L3 levels in both groups decreased, with the research group having significantly lower levels than the control group (P < 0.05). The incidence of diarrhea, rash, nausea and vomiting, and fatigue in the research group was significantly greater than that in the control group (P < 0.05). The 1-, 2-, and 3-year survival rates of the research group (94.00%, 84.00%, and 72.00%, respectively) were significantly greater than those of the control group (80.00%, 64.00%, and 40.00%, respectively; P < 0.05). Significant differences were observed between the survival group and the non-surviving group in terms of Child-Pugh grade, history of hepatitis, number of tumors, tumor size, use of sorafenib, stage of liver cancer, histological differentiation, history of splenectomy and other basic data (P < 0.05). Logistic regression analysis demonstrated that high Child-Pugh grade, tumor size (6-10 cm), history of hepatitis, no use of sorafenib, liver cancer stage IIIC, and previous splenectomy were independent risk factors for poor prognosis in patients with liver cancer complicated with portal hypertension (P < 0.05). CONCLUSION: Patients suffering from liver cancer complicated by portal hypertension benefit from the combination of RFA and sorafenib therapy because it effectively restores liver function and increases survival rates. The prognosis of patients suffering from liver cancer complicated by portal hypertension is strongly associated with factors such as high Child-Pugh grade, tumor size (6-10 cm), history of hepatitis, lack of sorafenib use, liver cancer at stage IIIC, and prior splenectomy.


Assuntos
Hepatite A , Hipertensão Portal , Neoplasias Hepáticas , Humanos , Prognóstico , Sorafenibe/uso terapêutico , alfa-Fetoproteínas , Neoplasias Hepáticas/complicações , Neoplasias Hepáticas/cirurgia , Hipertensão Portal/complicações
2.
Acta Pharmacol Sin ; 43(9): 2362-2372, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35105957

RESUMO

Bile acid (BA) homeostasis is regulated by the extensive cross-talk between liver and intestine. Many bile-acid-activated signaling pathways have become attractive therapeutic targets for the treatment of metabolic disorders. In this study we investigated the regulatory mechanisms of BA in the intestine. We showed that the BA levels in the gallbladder and faeces were significantly increased, whereas serum BA levels decreased in systemic Krüppel-like factor 9 (Klf9) deficiency (Klf9-/-) mice. These phenotypes were also observed in the intestine-specific Klf9-deleted (Klf9vil-/-) mice. In contrast, BA levels in the gallbladder and faeces were reduced, whereas BA levels in the serum were increased in intestinal Klf9 transgenic (Klf9Rosa26+/+) mice. By using a combination of biochemical, molecular and functional assays, we revealed that Klf9 promoted the expression of apical sodium-dependent bile acid transporter (Asbt) in the terminal ileum to enhance BA absorption in the intestine. Reabsorbed BA affected liver BA synthetic enzymes by regulating Fgf15 expression. This study has identified a previously neglected transcriptional pathway that regulates BA homeostasis.


Assuntos
Ácidos e Sais Biliares , Fatores de Transcrição Kruppel-Like/metabolismo , Simportadores , Animais , Ácidos e Sais Biliares/metabolismo , Circulação Êntero-Hepática , Intestinos , Fígado/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Transportadores de Ânions Orgânicos Dependentes de Sódio/genética , Transportadores de Ânions Orgânicos Dependentes de Sódio/metabolismo , Simportadores/metabolismo , Fatores de Transcrição/metabolismo
3.
Sheng Li Xue Bao ; 73(5): 772-780, 2021 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-34708234

RESUMO

The development of nonalcoholic fatty liver disease (NAFLD) is closely related to the fatty acid (FA) uptake. This study aimed to investigate the effect of Krüppel-like factor 9 (KLF9) on CD36 (typical fatty acid translocase), hepatocellular lipid metabolism as well as the development and progression of nonalcoholic fatty liver. High-fat diet-induced obese C57BL/6J mice and db/db mice were used to test the expression levels of Klf9 and Cd36 in the livers. The primary hepatocytes were isolated from C57BL/6J mice, treated with Ad-GFP, Ad-Klf9, Ad-shCtrl or Ad-shKlf9, and then incubated with oleic acid and palmitic acid for 24 h. Liver-specific knockout of Klf9 mice were established. The protein levels and relative mRNA levels were examined by Western blot and real-time PCR, respectively. Triglyceride content was determined by using an assay kit. Lipid content was determined by Oil Red O staining. The results showed that: (1) Klf9 expression levels were increased in the livers of high-fat diet-induced obese mice and db/db mice, compared to their respective control mice. (2) Adenovirus-mediated overexpression of Klf9 in primary hepatocytes increased Cd36 expression and cellular triglyceride contents. (3) In contrast, adenovirus-mediated knockdown of Klf9 expression in primary hepatocytes by Ad-shKlf9 decreased Cd36 expression and cellular triglyceride contents. (4) Finally, Klf9 deficiency decreased liver Cd36 expression and alleviated fatty liver phenotype of high-fat diet-induced obese mice. These results suggest that KLF9 can regulate hepatic lipid metabolism and development of NAFLD by promoting the expression of CD36.


Assuntos
Metabolismo dos Lipídeos , Hepatopatia Gordurosa não Alcoólica , Animais , Antígenos CD36/genética , Antígenos CD36/metabolismo , Dieta Hiperlipídica , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Fígado , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Hepatopatia Gordurosa não Alcoólica/metabolismo , Ácido Oleico/metabolismo
4.
Sheng Li Xue Bao ; 73(5): 821-827, 2021 Oct 25.
Artigo em Chinês | MEDLINE | ID: mdl-34708239

RESUMO

ß3-adrenergic agonists induce adaptive thermogenesis and promote beiging of white fat. However, it remains unclear which metabolites mediate the stimulatory effects of ß3-adrenergic agonists on thermogenesis of brown and beige fat. In this study, adipose tissue was isolated from 8-week-old C57/BL6J male mice by intraperitoneal administration of ß3-adrenergic agonist CL316,243 for RNA-Seq, which revealed that histidine decarboxylase, a key enzyme in histamine synthesis, was strongly induced in adipose by CL316,243. Therefore, we speculated that histamine might be involved in the process of thermogenesis in adipose tissue. We determined the physiological role and mechanism by which histamine promotes fat thermogenesis by intravenous administering histamine to C57BL/6J mice fed a normal or a high-fat diet. The results showed that intravenous injection of histamine into C57BL/6J mice fed a normal diet stimulated the expression of thermogenic genes, including peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) and uncoupling protein 1 (UCP1), in brown adipose tissue (BAT) and inguinal white adipose tissue (iWAT). H&E staining also suggested that histamine treatment decreased the size of lipid droplets in adipocytes. Moreover, histamine treatment also enhanced thermogenesis of fat in high-fat diet induced obese mice, and improved glucose intolerance and fatty liver phenotype. Finally, we demonstrated that the effects of histamine on the thermogenic program were cell autonomous. Our data suggest that histamine may mediate the effects of ß3-adrenergic agonists on thermogenesis of fat.


Assuntos
Tecido Adiposo Bege , Histamina , Tecido Adiposo Marrom , Animais , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Termogênese , Proteína Desacopladora 1/genética
5.
Chin Med Sci J ; 28(3): 140-6, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24074615

RESUMO

OBJECTIVES: To evaluate the expression profile of myoD microRNA-29 (miR-29) family in L6 myoblast differentiated to myotube of L6 myotube treated by glucose and insulin, and to further probe the molecular mechanism of myoD regulating the expression of miR-29 clusters. METHODS: The expression of myoD and miR-29 family was detected by using real-time PCR and Western blot analysis. The potential promoter and transcription factors binding sites of miR-29 clusters were predicted by Promoter scan and transcriptional factor search. The promoter sequence of miR-29b1-a and miR-29b2-c cluster was cloned into a luciferase reporter plasmid and the regulatory effect of myoD was analyzed by using dual luciferase reporter assay. Electrophoretic mobility shift assay was further conducted to indicate the binding of myoD on specific sequence. Moreover, overexpression of myoD was achieved by a recombinant adenovirus system (Ad-myoD). L6 cells were infected with Ad-myoD and real-time PCR was conducted to analyze the expression of miR-29b and miR-29c. RESULTS: The expression levels of myoD, miR-29a, miR-29b, and miR-29c were increased in L6 myoblast differentiated to myotube. The expression of myoD, miR-29b, and miR-29c was up-regulated in L6 myotube treated with glucose and insulin, but miR-29a depicted no significant change. Dual luciferase reporter gene assay showed that myoD functioned as a positive regulator of miR-29b2-c expression and myoD could bind to the specific sequence located at the promoter region of miR-29b2-c cluster. Enforced expression of myoD led to a marked increase of miR-29b and miR-29c levels in L6 cells. CONCLUSION: MyoD might act as a crucial regulator of myogenesis and glucose metabolism in muscle through regulating the expression of miR-29b2-c.


Assuntos
Diferenciação Celular/fisiologia , Regulação da Expressão Gênica/fisiologia , MicroRNAs/biossíntese , Família Multigênica/fisiologia , Fibras Musculares Esqueléticas/metabolismo , Proteína MyoD/metabolismo , Mioblastos/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/farmacologia , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Camundongos , MicroRNAs/genética , Fibras Musculares Esqueléticas/citologia , Proteína MyoD/genética , Mioblastos/citologia , Edulcorantes/farmacologia
6.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 33(6): 649-53, 2011 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-22509549

RESUMO

OBJECTIVE: To construct and identify a adenovirus vector of the expression of connective tissue growth factor (CTGF) and to explore the role of CTGF in the metabolism of glucose and lipid. METHODS: The over-expressed plasmid of CTGF was cloned, and then the CTGF sequences were cloned into pAdTrack-CMW vector. The reformed E. coli BJ5183-sensitive bacteria that contain pAdEasy-1 were transformed with lined vector cut by Pme I enzyme. The recombinant adenovirus vector was cut with Pac I enzyme and obtained, then transfected 293A cells to produce virus. Through three times of amplification, the adenovirus infected the primary hepatocytes to determine the infection efficiency and CTGF expression. The mice were starved for several time periods, and then the liver RNA was extracted for real-time PCR to detect the expressions of CTGF under different nutritional conditions. RESULTS: The adenovirus of CTGF was successfully produced with an infection efficiency of 90%. The expressions of the CTGF were different under different nutritional conditions and showed a coincidence with the expression of peroxisome proliferators-activated receptor gamma coactivator 1 alpha. After the mice were starved for 24h, the expression of CTGF increased by (2.38 +/- 0.51) folds; after the mice were starved for 48 h, the expression of CTGF increased by (2.95 +/- 0.57) folds (P < 0.05). CONCLUSION: CTGF is speculated to be involved in the metabolism of glucose and lipids.


Assuntos
Adenoviridae/genética , Fator de Crescimento do Tecido Conjuntivo/genética , Vetores Genéticos , Animais , Linhagem Celular , Escherichia coli/genética , Camundongos , Camundongos Endogâmicos C57BL , Plasmídeos , Transfecção
7.
Chin Med Sci J ; 25(2): 119-24, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20598236

RESUMO

Caveolin-2, a protein about 20 kD, is a major component of the inner surface of caveolae, small invaginations of the plasma membrane. Similar with caveolin-1 and caveolin-3, it serves as a protein marker of caveolae. Caveolin-1 and -2 are located next to each other at 7q31.1 on human chromosome, the proteins encoded are co-localized and form a stable hetero-oligomeric complex, distributing similarly in tissue and cultured cells. Caveolin-3 is located on different chromosomes but confirmed to interact with caveolin-2. Caveolin-2 is similar to caveolin-1 in many respects but differs from the latter in functional domains, especially in G-protein binding domain and caveolin scaffolding domain. The mRNAs of both caveolin-1 and caveolin-2 are most abundantly expressed in white adipose tissue and are induced during differentiation of 3T3-L1 cells to adipocytes. Caveolin-2-deficient mice demonstrate clear pulmonary defects, with little or no change in caveolin-1 expression and caveolae formation, suggesting that caveolin-2 plays a selective role in lung functions. Caveolin-2 is also involved in lipid metabolism and human cancers.


Assuntos
Biomarcadores/metabolismo , Cavéolas/metabolismo , Caveolina 2/metabolismo , Caveolina 2/genética , Cromossomos Humanos Par 7 , Humanos
8.
Am J Physiol Endocrinol Metab ; 298(6): E1210-8, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20215575

RESUMO

Peroxisome proliferator-activated receptor-gamma coactivator-1alpha (PGC-1alpha) is a key regulator of cellular energy metabolism and regulates processes such as adaptive thermogenesis, hepatic gluconeogenesis, fatty acid oxidation, and mitochondrial biogenesis by coactivating numerous nuclear receptors and transcription factors. Here, we demonstrate the presence of the ERRalpha binding site in the regulatory sequence of the glucokinase gene and that PGC-1alpha coactivates ERRalpha to stimulate the transcription of glucokinase. Simultaneous overexpression of PGC-1alpha and ERRalpha potently induced the glucokinase gene expression and its enzymatic activity in primary hepatocytes; however, expression of either PGC-1alpha or ERRalpha alone had no significant effect. Electrophoretic mobility shift and chromatin immunoprecipitation assays revealed the interaction of ERRalpha with the glucokinase promoter. Finally, the knockdown of endogenous ERRalpha with specific siRNA (siERRalpha) or pharmacological inhibition of ERRalpha with XCT790 attenuated insulin-induced glucokinase expression. Taken together, this research identifies glucokinase as a novel target of PGC-1alpha/ERRalpha and underscores the regulatory function of ERRalpha in insulin-dependent enzyme regulation.


Assuntos
Glucoquinase/biossíntese , Fígado/metabolismo , Proteínas de Ligação a RNA/metabolismo , Receptores de Estrogênio/metabolismo , Fatores de Transcrição/metabolismo , Animais , Western Blotting , Imunoprecipitação da Cromatina , Ensaio de Desvio de Mobilidade Eletroforética , Glucoquinase/genética , Glucose/metabolismo , Células Hep G2 , Hepatócitos/metabolismo , Insulina/metabolismo , Masculino , Mutagênese Sítio-Dirigida , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo , Regiões Promotoras Genéticas , RNA/química , RNA/genética , Interferência de RNA , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/genética , Ratos , Receptores de Estrogênio/antagonistas & inibidores , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Gênica
9.
Biochemistry (Mosc) ; 74(7): 703-8, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19747089

RESUMO

Sirtuins were originally defined as a family of oxidized nicotinamide adenine nucleotide (NAD+)-dependent enzymes that deacetylate lysine residues on various proteins. The sirtuins are remarkably conserved throughout evolution from archae to eukaryotes. They were named after their homology to the Saccharomyces cerevisiae gene silent information regulator 2 (Sir2). The mammalian sirtuins, SIRT1-7, are implicated in a variety of cellular functions ranging from gene silencing, control of the cell cycle and apoptosis, and energy homeostasis. As SIRT1 is a nuclear protein and is the mammalian homolog most highly related to Sir2, it has been the focus of a large number of recent studies. Here we review some of the current data related to SIRT1 and discuss its mode of action and biological role in cellular and organismal models.


Assuntos
Mamíferos/fisiologia , Sirtuínas/metabolismo , Animais , Humanos , Mamíferos/genética , Sirtuínas/genética
10.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 31(6): 773-7, 2009 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-20078951

RESUMO

Peroxisome proliferator-activated receptor gamma coactivator 1 (PGC1) family is highly expressed in tissues with high energy metabolism. They coactivate transcription factors in regulating genes engaged in processes such as gluconeogenesis, adipose beta-oxydation, lipoprotein synthesis and secretion, mitochondrial biogenesis, and oxidative metabolism. Protein conformation studies demonstrated that they lack DNA binding domains and act as coactivators through physical interaction with transcription factors. PGC1 activity is regulated at transcription level or by multiple covalent chemical modifications such as phosphorylation, methylation and acetylation/deacetylation. Abnormal expression of PGC1 coactivators usually is closely correlated with diseases such as diabetes, obesity, hyperglycemia, hyperlipemia, and arterial and brain neuron necrosis diseases.


Assuntos
Metabolismo Energético/fisiologia , Fatores de Transcrição/metabolismo , Animais , Humanos
11.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 31(6): 782-5, 2009 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-20078953

RESUMO

As the most homologic homologue of silent information regulator 2 of yeast, Sirt1 gene is extensively expressed in mature tissues, and is rich in early embryo and reproductive cells. It is involved in the regulation of gene transcription, energy metabolism and cell aging. It promotes fat mobilization in adipocytes and glucose production in liver and regulates insulin secretion in islet beta cell. Furthermore, Sirt1 gene is an essential endogenous apoptosis inhibitor. In future, it may be used as new drug targets or applied in other disease management modalities.


Assuntos
Sirtuína 1 , Animais , Humanos , Sirtuína 1/genética , Sirtuína 1/metabolismo , Sirtuína 1/fisiologia
12.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 31(6): 786-90, 2009 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-20078954

RESUMO

The disorders of DNA and histone methylation have a close relationship with the development and progression of tumors. Epigenetic regulation is critical in maintaining the stability and integrity of the expression profiles of different cell types by modifying DNA methylation and histone methylation. However, the abnormal changes of methylation often result in the development and progression of tumors. This review summarized the theory of tumor genomic and histone methylation, detection methods of methylation and their applications, and the clinical application of methylation as biological markers and drug targets.


Assuntos
Histonas/metabolismo , Metilação , Neoplasias/genética , Metilação de DNA , Humanos , Neoplasias/metabolismo
13.
Biomed Environ Sci ; 22(5): 359-68, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20163059

RESUMO

OBJECTIVE: To study the differential patterns of gene expression in skeletal muscle and adipose tissue between type 2 diabetes mellitus (T2DM) patients and healthy subjects using DNA microarray analysis. METHODS: T2DM patiens were divided into female group, young male group and old male group. DNA microarray analysis and quantitative real-time PCR were carried out to analyze the relation between gene expressions and T2DM. RESULTS: The mRNA expression of 298, 578, and 350 genes was changed in the skeletal muscle of diabetes mellitus patients compared with control subjects. The 1320, 1143, and 2847 genes were modified in adipose tissue of the three groups. Among the genes surveyed, the change of 25 and 39 gene transcripts in skeletal muscle and adipose tissue was > or = 2 folds. These differentially expressed genes were classified into 15 categories according to their functions. CONCLUSION: New genes are found and T2DM can be prevented or cured.


Assuntos
Tecido Adiposo/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Músculo Esquelético/metabolismo , Idoso , Povo Asiático , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos
14.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 29(5): 618-21, 2007 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-18051716

RESUMO

OBJECTIVE: To explore and identify the non-coding RNAs related to tumors. METHODS: We used RT-PCR and Northern blot to analyze non-coding RNAs in tumor tissues and cell lines. RESULTS: Two predicted non-coding RNAs were confirmed to be expressed in cancer tissues and cell lines by RT-PCR and DNA sequencing. We detected the expression of two non-coding RNA transcripts by Northern blot. The length of NC28 was about 1800 nt, and that of NC119 was about 1200nt. CONCLUSIONS: NC28 and NC119 have a tumor-associated expression pattern. The non-coding RNAs may play a role in the development of tumors.


Assuntos
Neoplasias/metabolismo , RNA não Traduzido/biossíntese , Linhagem Celular Tumoral , Humanos
16.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao ; 29(3): 430-5, 2007 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-17633477

RESUMO

Liver X receptors (LXRs) are members of the nuclear receptor superfamily and are activated by oxysterols and intermediates in the cholesterol synthetic pathway. The pivotal role of LXRs in the metabolic conversion of cholesterol to bile acids has been well established. Furthermore, insulin induces LXRa in hepatocytes, resulting in the suppression of key enzymes in gluconeogenesis, including phosphoenolpyruvate carboxykinase, glucose-6-phosphatase, and fructose-1, 6-bisphosphatase (FBPase). LXRs also play an important role in fatty acid metabolism by activating the sterol regulatory element-bing protein 1c gene (SREBP1c). This articles reviews the molecular mechanisms by which LXRs act to influence the lipid and carbohydrate metabolism.


Assuntos
Metabolismo dos Carboidratos , Metabolismo dos Lipídeos , Receptores Nucleares Órfãos/fisiologia , Animais , Humanos , Receptores X do Fígado
17.
J Mol Med (Berl) ; 85(8): 851-61, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17619838

RESUMO

Actin remodeling plays a crucial role in insulin-induced translocation of glucose transporter 4 (GLUT4) from the cytoplasm to the plasma membrane and subsequent glucose transport. Protein kinase C (PKC) zeta has been implicated in this translocation process, although the exact mechanism remains unknown. In this study, we investigated the effect of PKCzeta on actin cytoskeleton and translocation of GLUT4 in CHO-K1 cells expressing myc-tagged GLUT4. Insulin stimulated the phosphorylation of PKCzeta at Thr410 with no apparent effect on its protein expression. Moreover, insulin promoted colocalization of PKCzeta and actin that could be abolished by Latrunculin B. The overexpression of PKCzeta mimicked the insulin-induced change in actin cytoskeleton and translocation of GLUT4. These effects were also completely abrogated by Latrunculin B treatment. Using cell-permeable pseudosubstrate (PS) inhibitor of PKCzeta, the response to insulin could be alleviated. Our results strongly suggest that PKCzeta mediates the stimulatory effect of insulin on GLUT4 translocation through its interaction with actin cytoskeleton.


Assuntos
Actinas/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Proteína Quinase C/metabolismo , Animais , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Células CHO , Membrana Celular/metabolismo , Cricetinae , Cricetulus , Citoplasma/metabolismo , Citoesqueleto/metabolismo , Eletroforese em Gel de Poliacrilamida , Glucose/metabolismo , Transportador de Glucose Tipo 4/genética , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Immunoblotting , Insulina/farmacologia , Microscopia Confocal , Microscopia de Fluorescência , Fosforilação/efeitos dos fármacos , Proteína Quinase C/genética , Transporte Proteico/efeitos dos fármacos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Tiazolidinas/farmacologia , Treonina/metabolismo , Transfecção
18.
Biochemistry (Mosc) ; 71(7): 701-6, 2006 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16903823

RESUMO

Protein kinase Czeta (PKCzeta) is a member of the PKC family, serving downstream of insulin receptor and phosphatidylinositol (PI) 3-kinase. Many evidences suggest that PKCzeta plays a very important role in activating glucose transport response. Not only insulin but also glucose and exercise can activate PKCzeta through diverse pathways. PKCzeta activation and activity are impaired with insulin resistance in muscle and adipose tissues of type II diabetes individuals, but heightened in liver tissue, wherein it also increases lipid synthesis mediated by SREBP-1c (sterol-regulatory element-binding protein). Many studies have focused on linkage between PKCzeta and GLUT4 translocation and activation. Exploring the molecular mechanisms and pathways by which PKCzeta mediates glucose transport will highlight the insulin-signaling pathway.


Assuntos
Glucose/metabolismo , Proteína Quinase C/metabolismo , Transdução de Sinais , Animais , Transporte Biológico , Diabetes Mellitus Tipo 2/enzimologia , Diabetes Mellitus Tipo 2/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Humanos , Insulina/metabolismo , Modelos Genéticos , Proteína Quinase C/química
19.
Cell Signal ; 18(12): 2071-6, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16787739

RESUMO

Type 2 diabetes mellitus is a multigenic disease with evident genetic predisposition, and complex pathogenesis in which environmental and genetic factors interact. The disorder of body utilization glucose is a crucial reason for causing diabetes. Atypical PKCs, belonging to Ser/Thr protein kinase, have many important biological functions in vivo, and may be involved in the pathogenesis of diabetes mellitus. APKCs participate in glucose metabolism by regulating glucose transport and absorption, glycogen synthesis, and insulin secretion. The exact mechanism by which aPKCs participate in glucose metabolism remains unclear. So far, the clarification of which will be helpful for the prevention and cure of type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Glucose/metabolismo , Proteína Quinase C/metabolismo , Animais , Transporte Biológico/fisiologia , Diabetes Mellitus Tipo 2/enzimologia , Diabetes Mellitus Tipo 2/fisiopatologia , Humanos , Insulina/metabolismo , Insulina/fisiologia , Secreção de Insulina , Ilhotas Pancreáticas/metabolismo , Modelos Biológicos , Transdução de Sinais/fisiologia
20.
Biochemistry (Mosc) ; 71(5): 476-80, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16732724

RESUMO

Cytoskeleton plays an important role in glucose regulation, mainly in the following three aspects. First, cytoskeleton regulates insulin secretion by guiding intracellular transport of insulin-containing vesicles and regulating release of insulin. Second, cytoskeleton is involved in insulin action by regulating distribution of insulin receptor substrate, GLUT4 translocation, and internalization of insulin receptor. In addition, cytoskeleton directs the intracellular distribution of glucose metabolism related enzymes including glycogen synthase and many glycolysis enzymes.


Assuntos
Citoesqueleto/fisiologia , Glucose/metabolismo , Insulina/fisiologia , Animais , Transporte Biológico/efeitos dos fármacos , Citoesqueleto/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Humanos , Hipoglicemiantes/farmacologia , Insulina/farmacologia , Proteínas Substratos do Receptor de Insulina , Modelos Biológicos , Fosfoproteínas/metabolismo , Receptor de Insulina/metabolismo
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