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Thyroid dysfunctions are associated with liver diseases ranging, in severity, from insulin resistance (IR) to hepatocellular carcinoma. The pathogenic mechanisms appear complex and are not attributable, exclusively, to the impaired thyroid hormone (TH) signalling. Using a mouse model of human congenital hypothyroidism, young double heterozygote for both NK2 homeobox 1 (Nkx2-1)- and Paired box 8 (Pax8)-null mutations (DHTP) mice, and single heterozygous Pax8+/− and Nkx2-1+/− mice, we studied the liver pathways, the endocrine and metabolic factors affected in conditions of different dysthyroidisms. Young Nkx2-1+/− females displayed a slight hyperthyroidism and, in liver, increased TH signalling (i.e. increased expression of Dio1 and Trβ1) and lipogenic gene expression, with triglycerides accumulation. Hypothyroid DHTP and euthyroid Pax8+/− females shared liver and skeletal muscle IR and hepatic hypothyroidism (i.e. reduced expression of Mct8, Dio1 and TRβ1), activation of AKT and increased expression of glutathione peroxidase 4. Oxidative stress and reduced mitochondrial COX activity were observed in DHTP mice only. Pax8+/− females, but, unexpectedly, not DHTP ones, displayed transcriptional activation of the hepatic (and renal) gluconeogenic pathway, hypercortisolemia, fasting hyperglycaemia and hyperinsulinemia, reduced serum β-hydroxybutyrate, associated with hepatic AMPK activation. DHTP mice showed hypercholesterolemia and activation of mTOR. Collectively, the data indicate that heterozygote mutations of Pax8 and Nkx2-1 genes may produce multiple dysmetabolisms, even under systemic euthyroidism. Differential liver pathways and multiple hormonal axes are affected with implications for energy and nutrient homeostasis. The identified players may be specific target in the management of thyroid dysfunction-associated dysmetabolisms in terms of prevention/counteraction of IR, type 2 diabetes and related comorbidities.

Although the imbalance of circulating levels of Thyroid Hormones (THs) affects female fertility in vertebrates, its involvement in the promotion of Premature Ovarian Aging (POA) is debated. Therefore, altered synthesis of THs in both thyroid and ovary can be a trait of POA. We investigated the relationship between abnormal TH signaling, dysthyroidism, and POA in evolutionary distant vertebrates: from zebrafish to humans. Ovarian T3 signaling/metabolism was evaluated by measuring T3 levels, T3 responsive transcript, and protein levels along with transcripts governing T3 availability (deiodinases) and signaling (TH receptors) in distinct models of POA depending on genetic background and environmental exposures (e.g., diets, pesticides). Expression levels of well-known (Amh, Gdf9, and Inhibins) and novel (miR143/145 and Gas5) biomarkers of POA were assessed. Ovarian dysthyroidism was slightly influenced by genetics since very few differences were found between C57BL/6J and FVB/NJ females. However, diets exacerbated it in a strain-dependent manner. Similar findings were observed in zebrafish and mouse models of POA induced by developmental and long-life exposure to low-dose chlorpyrifos (CPF). Lastly, the T3 decrease in follicular fluids from women affected by diminished ovarian reserve, as well as of the transcripts modulating T3 signaling/availability in the cumulus cells, confirmed ovarian dysthyroidism as a common and evolutionary conserved trait of POA.

Background: The nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) transcription factor is a key regulator of cell survival, proliferation, and gene expression. Although activat...

The nuclear factor (NF)-κB signaling pathway controls a variety of important biological functions, including immune and inflammatory responses, differentiation, cell growth, tumorigenesis, and apoptosis. Two distinct pathways of NF-κB activation are known. The classical, canonical pathway is found virtually in all mammalian cells and NF-κB activation is mediated by the IKK complex, consisting of the IKK1/IKKα and IKK2/IKKβ catalytic kinase subunits and the NF-κB essential modulator (NEMO)/IKKγ protein. The NF-κB-driven transcriptional responses to many different stimuli have been widely characterized in the pathophysiology of the mammalian immune system, mainly because this transcription factor regulates the expression of cytokines, growth factors, and effector enzymes in response to ligation of cellular receptors involved in immunity and inflammation. However, an impressive literature produced in the last two decades shows that NF-κB signaling plays an important role also outside of the immune system, performing different roles and functions depending on the type of tissue and organ. In thyroid, NF-κB signaling is crucial for thyrocytes survival and expression of critical thyroid markers, including Nis, Ttf1, Pax8, Tpo, and thyroglobulin, making this transcription factor essential for maintenance of normal thyroid function.

The nuclear factor (NF)-κB signaling pathway controls a variety of important biological functions, including immune and inflammatory responses, differentiation, cell growth, tumorigenesis, and apoptosis. Two distinct pathways of NF-κB activation are known. The classical, canonical pathway is found virtually in all mammalian cells and NF-κB activation is mediated by the IKK complex, consisting of the IKK1/IKKα and IKK2/IKKβ catalytic kinase subunits and the NF-κB essential modulator (NEMO)/IKKγ protein. The NF-κB-driven transcriptional responses to many different stimuli have been widely characterized in the pathophysiology of the mammalian immune system, mainly because this transcription factor regulates the expression of cytokines, growth factors, and effector enzymes in response to ligation of cellular receptors involved in immunity and inflammation. However, an impressive literature produced in the last two decades shows that NF-κB signaling plays an important role also outside of the immune system, performing different roles and functions depending on the type of tissue and organ. In thyroid, NF-κB signaling is crucial for thyrocytes survival and expression of critical thyroid markers, including Nis, Ttf1, Pax8, Tpo, and thyroglobulin, making this transcription factor essential for maintenance of normal thyroid function.

Highlights • The complexes formed by BCL10, MALT1 and CARMA proteins are key regulators of NF-κB activation. • We report the functional characterization of tBCL10, a BCL10 isoform from the trout Oncorhynchus mykiss. • tBCL10 can functionally replace the human protein. • The rainbow trout Oncorhynchus mykiss can serve as a model organism to study this pathway., The complexes formed by BCL10, MALT1 and members of the family of CARMA proteins have recently been the focus of much attention because they represent a key mechanism for regulating activation of the transcription factor NF-κB. Here, we report the functional characterization of a novel isoform of BCL10 in the trout Oncorhynchus mykiss, which we named tBCL10. tBCL10 dimerizes, binds to components of the CBM complex and forms cytoplasmic filaments. Functionally, tBCL10 activates NF-κB transcription factor and is inhibited by the deubiquitinating enzyme A20. Finally, depletion experiments indicate that tBCL10 can functionally replace the human protein. This work demonstrates the evolutionary conservation of the mechanism of NF-κB activation through the CBM complex, and indicates that the rainbow trout O.mykiss can serve as a model organism to study this pathway.

Human BCL10 (hBCL10) protein is a signal transduction molecule originally identified because of its direct involvement in a subset of mucosa-associated lymphoid tissue (MALT) lymphomas, and later recognized as a crucial factor in regulating activation of NF-kB transcription factor following antigen receptor stimulation on lymphocytes. In this study, we characterized the NF-kB inducing activity of porcine BCL10 (pBCL10). pBCL10 oligimerizes, binds to components of the CARMA/ BCL10/MALT1 complex and forms cytoplasmic filaments. Functionally, in human cells pBCL10 is more effective in activating NF-kB compared to hBCL10, possibly due to the lack of carboxy-terminal inhibitory serine residues present in the human protein. Also, depletion experiments carried out through expression of short hairpin RNAs targeting hBCL10 indicate that pBcl10 can functionally replace the human protein and retains its higher NF-kB-inducing property in the absence of hBCL10. Our results contribute useful information on BCL10 protein in pigs, and may help the development of strategies based on the control of the immune response in pigs.

Genetic and environmental factors contribute to thyroid diseases. Although still debated, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is thought to induce thyroid dysfunction in humans and rodents. The data here reported point out the contribution of the exposure window and genetic background in mediating the low-dose TCDD effects on thyroid. Indeed, early (from E0.5 to PND30) and low-dose (0,001 μg/kg/day) TCDD exposure reduced the circulating fT4 and altered the expression of thyroid specific transcripts. The role of genetic components was estimated monitoring the same markers in Pax8+/− and Nkx2-1+/− mice, susceptible to thyroid dysfunction, exposed to 0, 1 μg/kg/day TCDD from E15.5 to PND60. Haploinsufficiency of either Pax8 or Nkx2-1 genes exacerbated the effects of the exposure impairing the thyroid enriched mRNAs in sex dependent manner. Such effect was mediated by mechanisms involving the Nkx2-1/p53/p65/IĸBα pathway in vitro and in vivo. Foetal exposure to TCDD impaired both thyroid function and genes expression while thyroid development and differentiation did not appear significantly affected. In mouse, stronger effects were related to earlier exposure or specific genetic background such as either Pax8 or Nkx2-1 haploinsufficiency, both associated to hypothyroidism in humans. Furthermore, our data underline that long exposure time are needed to model in vitro and in vivo results.

The atypical protein kinase C-interacting protein p62/sequestosome-1 (p62) has emerged as a crucial molecule in a variety of cellular functions due to its involvement in various signaling mechanisms. p62 has been implicated in the activation of NF-?B in TNF?-stimulated cells and has been shown to be activated in response to interleukin-1? (IL-1?). Here we demonstrate that p62 interacts with NEMO, the regulatory subunit of the complex responsible for activation of NF-?B transcription factor. Depletion of p62 obtained through a short interfering RNA targeting p62 mRNA abrogated TRAF6 capacity to promote NEMO ubiquitination and severely impairs NF-?B activation following IL-1? stimulation.Together, these results indicate that p62 is an important intermediary in the NF-?B activation pathways implemented through non-degradative ubiquitination events. Telethon Grant GGP08125B Scopus

Background: The CARMA-BCL10-MALT1 complex recruits signaling components leading to activation of NF-κB transcription factor. Results: The Rho guanine nucleotide exchange factor Net1 binds to BCL10, CARMA1, and CARMA3. Conclusion: Net1 modulates activation of NF-κB transcription factor. Significance: The results shown are important to understand events that control NF-κB activation and the mechanisms by which Net1 promotes cellular transformation., The molecular complexes containing CARMA proteins have been recently identified as a key components in the signal transduction pathways that regulate activation of nuclear factor κB (NF-κB) transcription factor. Here, we used immunoprecipitation coupled with mass spectrometry to identify cellular binding partners of CARMA proteins. Our data indicate that the Rho guanine nucleotide exchange factor Net1 binds to CARMA1 and CARMA3 in resting and activated cells. Net1 expression induces NF-κB activation and cooperates with BCL10 and CARMA proteins in inducing NF-κB activity. Conversely, shRNA-mediated abrogation of Net1 results in impaired NF-κB activation following stimuli that require correct CARMA-BCL10-MALT1 complex formation and functioning. Microarray expression data are consistent with a positive role for Net1 on NF-κB activation. Thus, this study identifies Net1 as a CARMA-interacting molecule and brings important information on the molecular mechanisms that control NF-κB transcriptional activity.

Objetivo: Avaliar o conhecimento de estudantes de Medicina sobre doação e transplantes de órgãos e o conceito de morte encefálica, além de identificar os possíveis fatores contrários à doação de órgãos e tecidos. Métodos: Trata-se de um estudo de corte transversal realizado com 266 estudantes de Medicina do primeiro ao quarto ano de graduação. A coleta de dados foi realizada entre agosto e outubro de 2010 através da aplicação de um questionário contendo dados demográficos e 13 perguntas de múltipla escolha sobre o tema. Resultados: Dentre os entrevistados, 61,3% tiveram atividades didáticas sobre transplantes de órgãos durante o curso. Sessenta por cento dos estudantes avaliaram o seu conhecimento, sobre o tema como regular. Oitenta e oito por cento dos estudantes acertaram o conceito de morte encefálica e 72% tinham noções de como realizar o diagnóstico. Em relação à quais transplantes poderiam ser realizados intervivos, 78,9% responderam corretamente. Já com relação aos transplantes realizados sem batimentos cardíacos, 45,4% acertaram a questão e 53,4% não souberam responder. Quando perguntados sobre a intenção de doar órgãos e tecidos, 78,6% eram doadores, sendo que a análise por semestre mostrou aumento progressivo na intenção de doar. Com relação aos cuidados que devem ser tomados para a manutenção do potencial doador de órgãos, 75,5% dos estudantes desconheciam as medidas de suporte necessárias. No que se refere à comunicação familiar da morte de um parente, 50,4% sabiam como era feita essa abordagem. Conclusão: Foi possível concluir que a maioria dos estudantes de Medicina da amostra estudada apresentou conhecimento sobre morte encefálica, e que durante o curso médico os estudantes adquirem maior conhecimento sobre transplante e doação de órgãos e tecidos. Esse conhecimento adquirido aumenta a intenção de doar, sugerindo que a educação seja imprescindível para melhorar as taxas de doação de órgãos. Dessa forma, é necessária inserção de matérias ou cursos específicos de doação de órgãos e tecidos para transplantes no currículo das faculdades de Medicina.

The molecular complexes containing BCL10, MALT1 and CARMA proteins (CBM complex) have been recently identified as a key component in the signal transduction pathways that regulate activation of Nuclear Factor kappaB (NF-κB) transcription factor. Herein we identified the DEP domain-containing protein DEPDC7 as cellular binding partners of CARMA2 and CARMA3 proteins. DEPDC7 displays a cytosolic distribution and its expression induces NF-κB activation. Conversely, shRNA-mediated abrogation of DEPDC7 results in impaired NF-κB activation following G protein-coupled receptors stimulation, or stimuli that require CARMA2 and CARMA3, but not CARMA1. Thus, this study identifies DEPDC7 as a CARMA interacting molecule, and provides evidence that DEPDC7 may be required to specifically convey on the CBM complex signals coming from activated G protein-coupled receptors.

Dicer is a type III ribonuclease required for the biogenesis of microRNAs (miRNAs), a class of small non-coding RNAs regulating gene expression at the post-transcriptional level. To explore the functional role of miRNAs in thyroid gland function, we generated a thyrocyte-specific Dicer conditional knockout mouse. Here we show that development and early differentiation of the thyroid gland are not affected by the absence of Dicer, while severe hypothyroidism gradually develops after birth, leading to reduced body weight and shortened life span. Histological and molecular characterization of knockout mice reveals a dramatic loss of the thyroid gland follicular architecture associated with functional aberrations and down-regulation of several differentiation markers. The data presented in this study show for the first time that an intact miRNAs processing machinery is essential for thyroid physiology, suggesting that deregulation of specific miRNAs could be also involved in human thyroid dysfunctions. © 2011 Frezzetti et al.