RESUMO
Chronic hepatitis is a major cause of liver cancer, so earlier treatment of hepatitis might be reducing liver cancer incidence. Hepatitis can be induced in mice by treatment with Concanavalin A (Con A); the resulting liver injury causes significant CD4(+) T cell activation and infiltration. In these T cells, Roquin, a ring-type E3 ubiquitin ligase, is activated. To investigate the role of Roquin, we examined Con A-induced liver injury and T cell infiltration in transgenic (Tg) mice overexpressing Roquin specifically in T cells. In Roquin Tg mice, Con A treatment caused greater increases in both the levels of liver injury enzymes and liver tissue apoptosis, as revealed by TUNEL and H&E staining, than wild type (WT) mice. Further, Roquin Tg mice respond to Con A treatment with greater increases in the T cell population, particularly Th17 cells, though Treg cell counts are lower. Roquin overexpression also enhances increases in pro-inflammatory cytokines, including IFN-γ, TNF-α and IL-6, upon liver injury. Furthermore, Roquin regulates the immune response and apoptosis in Con A induced hepatitis via STATs, Bax and Bcl2. These findings suggest that over-expression of Roquin exacerbates T-cell mediated hepatitis.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/genética , Hepatócitos/metabolismo , Regiões Promotoras Genéticas , Células Th17/metabolismo , Ubiquitina-Proteína Ligases/genética , Animais , Apoptose , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/patologia , Concanavalina A , Feminino , Regulação da Expressão Gênica , Hepatócitos/patologia , Interferon gama/biossíntese , Interferon gama/metabolismo , Interleucina-6/biossíntese , Interleucina-6/metabolismo , Ativação Linfocitária , Contagem de Linfócitos , Camundongos , Camundongos Transgênicos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Fatores de Transcrição STAT/genética , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais , Linfócitos T Reguladores/metabolismo , Linfócitos T Reguladores/patologia , Células Th17/patologia , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/metabolismo , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Jazf1 is a 27 kDa nuclear protein containing three putative zinc finger motifs that is associated with diabetes mellitus and prostate cancer; however, little is known about the role that this gene plays in regulation of metabolism. Recent evidence indicates that Jazf1 transcription factors bind to the nuclear orphan receptor TR4. This receptor regulates PEPCK, the key enzyme involved in gluconeogenesis. To elucidate Jazf1's role in metabolism, we fed a 60% fat diet for up to 15 weeks. In Jazf1 overexpression mice, weight gain was found to be significantly decreased. The expression of Jazf1 in the liver also suppressed lipid accumulation and decreased droplet size. These results suggest that Jazf1 plays a critical role in the regulation of lipid homeostasis. Finally, Jazf1 may provide a new therapeutic target in the management of obesity and diabetes.
Assuntos
Proteínas de Transporte/genética , Dieta Hiperlipídica , Metabolismo dos Lipídeos/genética , Proteínas Nucleares/genética , Aumento de Peso/genética , Animais , Glicemia/análise , Proteínas Correpressoras , Proteínas de Ligação a DNA , Teste de Tolerância a Glucose , Homeostase , Insulina/fisiologia , Camundongos , Camundongos Transgênicos , Fosfoenolpiruvato Carboxiquinase (GTP)/antagonistas & inibidores , Fosfoenolpiruvato Carboxiquinase (GTP)/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Wnt/Wg genes play a critical role in the development of various organisms. For example, the Wnt/beta-catenin signal promotes heart formation and cardiomyocyte differentiation in mice. Previous studies have shown that RGS19 (regulator of G protein signaling 19), which has Galpha subunits with GTPase activity, inhibits the Wnt/beta-catenin signal through inactivation of Galpha(o). In the present study, the effects of RGS19 on mouse cardiac development were observed. In P19 teratocarcinoma cells with RGS19 overexpression, RGS19 inhibited cardiomyocyte differentiation by blocking the Wnt signal. Additionally, several genes targeted by Wnt were down-regulated. For the in vivo study, we generated RGS19-overexpressing transgenic (RGS19 TG) mice. In these transgenic mice, septal defects and thin-walled ventricles were observed during the embryonic phase of development, and the expression of cardiogenesis-related genes, BMP4 and Mef2C, was reduced significantly. RGS19 TG mice showed increased expression levels of brain natriuretic peptide and beta-MHC, which are markers of heart failure, increase of cell proliferation, and electrocardiogram analysis shows abnormal ventricle repolarization. These data provide in vitro and in vivo evidence that RGS19 influenced cardiac development and had negative effects on heart function.
Assuntos
Diferenciação Celular , Coração/embriologia , Miócitos Cardíacos/metabolismo , Proteínas RGS/metabolismo , Transdução de Sinais , Animais , Proteína Morfogenética Óssea 4/genética , Proteína Morfogenética Óssea 4/metabolismo , Linhagem Celular Tumoral , Subunidades alfa de Proteínas de Ligação ao GTP/genética , Subunidades alfa de Proteínas de Ligação ao GTP/metabolismo , Insuficiência Cardíaca/genética , Insuficiência Cardíaca/metabolismo , Defeitos dos Septos Cardíacos/genética , Defeitos dos Septos Cardíacos/metabolismo , Fatores de Transcrição MEF2 , Camundongos , Camundongos Transgênicos , Fatores de Regulação Miogênica/genética , Fatores de Regulação Miogênica/metabolismo , Cadeias Pesadas de Miosina/genética , Cadeias Pesadas de Miosina/metabolismo , Peptídeo Natriurético Encefálico/genética , Peptídeo Natriurético Encefálico/metabolismo , Proteínas RGS/genética , Proteínas Wnt/genética , Proteínas Wnt/metabolismoRESUMO
The major objective of this study was to improve the development rate of parthenogenetic porcine embryos. In this study, the anti-oxidative and anti-apoptotic effects of three antioxidants, ß-mercaptoethanol (ß-ME), α-tocopherol, and extracellular superoxide dismutase (EC-SOD), were examined on the development of parthenogenetic porcine embryos. The development rate of parthenogenetic porcine embryos to the blastocyst stage was 8.1% for control; 19.1%, 14.6%, and 5.0% for 1, 3, and 5 µM ß-ME; 17.2% and 17.5% for 50 and 100 µM α-tocopherol and 12.0% and 4.0% for EC-SOD transgenic mouse embryonic fibroblast (Tg-MEF) and EC-SOD non-transgenic mouse embryonic fibroblast (NTg-MEF) conditioned medium at day 3, respectively. Here, ß-ME, α-tocopherol, and EC-SOD Tg-MEF conditioned medium increased the development rate of parthenogenetic porcine embryos to the blastocyst stage (P < 0.05). The average number of total cells and apoptotic cells at the blastocyst was analyzed at the optimal conditions of the three antioxidants. The three antioxidants increased the average number of total cells at the blastocyst, and they decreased apoptotic cells at the blastocyst as compared to control without supplementation (P < 0.05). When the reactive oxygen species levels in two-cell embryos after 1 µM ß-ME and 100 µM α-tocopherol treatment were examined, those were lower than control group (P < 0.05). In conclusion, it was found that the three antioxidants, ß-mercaptoethanol, α-tocopherol, and EC-SOD Tg-MEF, conditioned medium can play a role as a strong stimulator in the development of parthenogenetic porcine embryos.