RESUMO
A sexual dimorphism in liver inflammation and repair was previously demonstrated. Its cellular dissection in the course of acute liver injury (ALI) was explored. BALB/c mice were treated with carbon tetrachloride (CCl4) by intraperitoneal injection and killed after 3, 5, and 8 days. Histological and hepatic cell population analyses were performed. The correlation between androgen receptor (AR) expression and liver recruited inflammatory cells was investigated by treatment with the AR antagonist flutamide. Additionally, patients with a diagnosis of drug induced liver injury (DILI) were included in the study, with a particular focus on gender dimorphism in circulating monocytes. A delayed resolution of necrotic damage and a higher expression of proinflammatory cytokines were apparent in male mice along with a slower recruitment of inflammatory monocytes. F4/80+CD11b+ macrophages and CD11bhighGr-1high monocytes expressed AR and were recruited later in male compared with female livers after CCl4 treatment. Moreover, CD11bhighAR+Gr-1high recruitment was negatively modulated by flutamide in males. Analysis of DILI patients showed overall a significant reduction in circulating mature monocytes compared with healthy subjects. More interestingly, male patients had higher numbers of immature monocytes compared with female patients.A stronger cytotoxic tissue response was correlated with an impaired recruitment of CD11bhighAR+Gr-1high cells and F4/80+CD11b+ macrophages in the early inflammatory phase under AR signaling. During DILI, a dimorphic immune response was apparent, characterized by a massive recruitment of monocytes to the liver both in males and females, but only in males was this recruitment sustained by a turnover of immature monocytes.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/imunologia , Modelos Animais de Doenças , Regeneração Hepática/imunologia , Macrófagos/imunologia , Monócitos/imunologia , Animais , Tetracloreto de Carbono/toxicidade , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Citocinas/genética , Citocinas/imunologia , Citocinas/metabolismo , Feminino , Expressão Gênica/imunologia , Hepatócitos/imunologia , Hepatócitos/metabolismo , Fígado/imunologia , Fígado/metabolismo , Macrófagos/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Monócitos/metabolismo , Fatores Sexuais , Fatores de TempoRESUMO
BACKGROUND: The human transcription factors (TFs) GATA4, NKX2.5 and TBX5 form part of the core network necessary to build a human heart and are involved in Congenital Heart Diseases (CHDs). The human natriuretic peptide precursor A (NPPA) and α-myosin heavy chain 6 (MYH6) genes are downstream effectors involved in cardiogenesis that have been demonstrated to be in vitro targets of such TFs. RESULTS: To study the interactions between these human TFs and their target enhancers in vivo, we overexpressed them in the whole Drosophila cardiac tube using the UAS/GAL4 system. We observed that all three TFs up-regulate their natural target enhancers in Drosophila and cause developmental defects when overexpressed in eyes and wings. CONCLUSIONS: A strong potential of the present model might be the development of combinatorial and mutational assays to study the interactions between human TFs and their natural target promoters, which are not easily undertaken in tissue culture cells because of the variability in transfection efficiency, especially when multiple constructs are used. Thus, this novel system could be used to determine in vivo the genetic nature of the human mutant forms of these TFs, setting up a powerful tool to unravel the molecular genetic mechanisms that lead to CHDs.
Assuntos
Drosophila melanogaster/genética , Elementos Facilitadores Genéticos/genética , Cardiopatias Congênitas/genética , Fatores de Transcrição/metabolismo , Ativação Transcricional , Animais , Animais Geneticamente Modificados , Drosophila melanogaster/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Coração/embriologia , Humanos , Organogênese/fisiologia , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Fatores de Transcrição/genéticaRESUMO
BACKGROUND: pituitary tumour transforming gene 1 (PTTG1) is over-expressed in a variety of endocrine-related tumours. We aimed at evaluating PTTG1 expression and function in human neoplastic parafollicular C-cells, represented by medullary thyroid carcinoma (MTC) and C-cell hyperplasia (CCH) samples and by the TT cell line. METHODS: TT cells and tissues derived from human CCH (8 samples) and MTC (12 samples) were analyzed by northern blot, furthermore TT cells were subjected to PTTG gene silencing and cells were analyzed for DNA synthesis. RESULTS: PTTG1 expression was significantly higher (p<0.01) in CCH (3-fold), in papillary thyroid cancer and in MTC (5-fold) than in normal thyroid, and in MTC lymph-node metastases as compared to primary lesions (approximately 2-fold; p<0.05). PTTG1 mRNA and protein correlated with tumour diameter and TNM status (p<0.05). In TT cells, PTTG1 silencing did not completely block DNA synthesis, but significantly reduced [3H]Thymidine incorporation (~50%; p<0.01) for up to 3 days. CONCLUSIONS: PTTG1 levels correlate with tumour aggressiveness. PTTG1 silencing causes reduced MTC cell proliferation, supporting the hypothesis that PTTG1 might have an important role in C-cell neoplastic proliferation.