RESUMEN

Retinoic acid (RA) is a fundamental vitamin A metabolite involved in regulating immune responses through the nuclear RA receptor (RAR) and retinoid X receptor. While performing experiments using THP-1 cells as a model for Mycobacterium tuberculosis infection, we observed that serum-supplemented cultures displayed high levels of baseline RAR activation in the presence of live, but not heat-killed, bacteria, suggesting that M. tuberculosis robustly induces the endogenous RAR pathway. Using in vitro and in vivo models, we have further explored the role of endogenous RAR activity in M. tuberculosis infection through pharmacological inhibition of RARs. We found that M. tuberculosis induces classical RA response element genes such as CD38 and DHRS3 in both THP-1 cells and human primary CD14+ monocytes via a RAR-dependent pathway. M. tuberculosis-stimulated RAR activation was observed with conditioned media and required nonproteinaceous factor(s) present in FBS. Importantly, RAR blockade by (4-[(E)-2-[5,5-dimethyl-8-(2-phenylethynyl)-6H-naphthalen-2-yl]ethenyl]benzoic acid), a specific pan-RAR inverse agonist, in a low-dose murine model of tuberculosis significantly reduced SIGLEC-F+CD64+CD11c+high alveolar macrophages in the lungs, which correlated with 2× reduction in tissue mycobacterial burden. These results suggest that the endogenous RAR activation axis contributes to M. tuberculosis infection both in vitro and in vivo and reveal an opportunity for further investigation of new antituberculosis therapies.

Asunto(s)

Mycobacterium tuberculosis , Receptores de Ácido Retinoico , Ratones , Humanos , Animales , Receptores de Ácido Retinoico/metabolismo , Mycobacterium tuberculosis/metabolismo , Agonismo Inverso de Drogas , Tretinoina/farmacología , Receptores X Retinoide

RESUMEN

Infection with high-risk human papillomavirus (HR-HPV) is the main cause of cervical cancer (CC), but viral infection alone does not guarantee the development of this malignancy. Indeed, deficiencies of dietary micronutrients could favor cervical cancer development in individuals that harbor HR-HPV infections. The status of retinoid levels, natural and synthetic derivatives of vitamin A, is important in maintaining cellular differentiation of the cervical epithelium. Moreover, many studies show a link between deficient intake of retinoids or alteration of the retinoid receptors and CC development. In spite of this, the effect of vitamin A deficiency (VAD) in presence of HR-HPV oncoproteins on cervical carcinogenesis in vivo has not been reported. Transgenic mice expressing E6 or E7 oncoproteins (K14E6 or K14E7 mice, respectively) were used to evaluate the possible role of VAD in the development of malignant cervical lesions. The survival of the mice in VAD condition was studied, and histopathological analysis and immunohistochemical detection of molecular cancer markers such as the tumor suppressor retinoic acid receptor beta (RARß), proliferating cell nuclear antigen (PCNA), cleaved caspase 3, and the tumor suppressor protein p16INK4A (inhibitor of CDK4) were performed. Our results show that K14E6/VAD mice showed moderate cervical dysplasia; notably, K14E7/VAD mice developed severe cervical dysplasia and cervical in situ carcinoma at an early age. VAD synergizes with HPV16E7 oncoprotein expression favoring cervical carcinogenesis in vivo.

Asunto(s)

Proteínas E7 de Papillomavirus/genética , Infecciones por Papillomavirus/patología , Neoplasias del Cuello Uterino/patología , Deficiencia de Vitamina A/complicaciones , Animales , Cuello del Útero/metabolismo , Cuello del Útero/patología , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Progresión de la Enfermedad , Femenino , Humanos , Ratones , Ratones Transgénicos , Proteínas E7 de Papillomavirus/metabolismo , Infecciones por Papillomavirus/genética , Infecciones por Papillomavirus/metabolismo , Infecciones por Papillomavirus/virología , Antígeno Nuclear de Célula en Proliferación/genética , Antígeno Nuclear de Célula en Proliferación/metabolismo , Receptores de Ácido Retinoico/genética , Receptores de Ácido Retinoico/metabolismo , Neoplasias del Cuello Uterino/complicaciones , Neoplasias del Cuello Uterino/metabolismo , Neoplasias del Cuello Uterino/virología , Deficiencia de Vitamina A/genética , Deficiencia de Vitamina A/metabolismo , Deficiencia de Vitamina A/patología

RESUMEN

During mating, males provide not only the spermatozoa to fertilize the oocyte but also other stimuli that are essential for initiating and maintaining the reproductive programme in females. In the mammalian oviduct, mating regulates sperm storage, egg transport, fertilization, early embryonic development, and oestradiol metabolism. However, the main molecules underlying these processes are poorly understood. Using microarray analyses, we identified 58 genes that were either induced or repressed by mating in the endosalpinx at 3 h post-stimulus. RT-qPCR confirmed that mating downregulated the expression of the Oas1h and Prim1 genes and upregulated the expression of the Ceacam1, Chad, Chst10, Slc5a3 and Slc26a4 genes. The functional category 'cell-to-cell signalling and interaction' was over-represented in this gene list. Network modelling identified TNF and all-trans retinoic acid (RA) as upstream regulators of the mating-induced transcriptional response, which was confirmed by intraoviductal injection of TNF or RA in unmated rats. It partially mimicked the transcriptional effect of mating in the rat endosalpinx. Furthermore, mating decreased RA levels in oviductal fluid, and RA-receptor-gamma (RARG) exhibited a nuclear location in oviductal epithelium in both unmated and mated rats, indicating RA-RARG transcriptional activity. In conclusion, the early transcriptional response regulated by mating in the rat endosalpinx is mediated by TNF and RA. These signalling molecules regulate a cohort of genes involved in 'cell-to-cell signalling and interactions' and merit further studies to understand the specific processes activated in the endosalpinx to sustain the events that occur in the mammalian oviduct early after mating.

Asunto(s)

Oviductos/metabolismo , Conducta Sexual Animal/fisiología , Transcriptoma , Tretinoina/metabolismo , Factor de Necrosis Tumoral alfa/metabolismo , Animales , Femenino , Regulación de la Expresión Génica , Masculino , Membrana Mucosa/metabolismo , Ratas Sprague-Dawley , Receptores de Ácido Retinoico/metabolismo , Receptor de Ácido Retinoico gamma

RESUMEN

The peroxisome proliferator-activated receptor (PPAR) ß/δ has an important role in multiple inflammatory conditions, including obesity, hypertension, cancer, cardiovascular disease, diabetes mellitus, and autoimmune diseases. PPARß/δ forms a heterodimer with the retinoic acid receptor and binds to peroxisome proliferator response elements to initiate transcription of its target genes. PPARß/δ is also able to suppress the activities of several transcription factors, including nuclear factor κB, and activator protein 1, thus regulating anti-inflammatory cellular responses and playing a protective role in several diseases. Recent studies have shown that nutritional compounds, including nutrients and bioactive compounds, can regulate PPARß/δ expression. This review discusses key nutritional compounds that are known to modulate PPARß/δ and are likely to affect human health.

Asunto(s)

Dieta , Inflamación/metabolismo , PPAR delta/metabolismo , PPAR-beta/metabolismo , Animales , Curcumina/farmacología , Flavonoides/farmacología , Humanos , Inflamación/dietoterapia , FN-kappa B/metabolismo , PPAR delta/efectos de los fármacos , PPAR-beta/efectos de los fármacos , Fitoquímicos/farmacología , Polifenoles/farmacología , Receptores de Ácido Retinoico/metabolismo , Vitamina A/farmacología

RESUMEN

Cellular retinoic acid-binding protein 2 (CRABP2) delivers all-trans retinoic acid (atRA) to retinoic acid receptors (RARs), allowing for the activation of specific gene transcription. The structural similarities between free and atRA-bound CRABP2 raise the questions of how atRA binding occurs and how the atRA:CRABP2 complex is recognized by downstream binding partners. Thus, to gain insights into these questions, we conducted a detailed atRA-CRABP2 interaction study using nuclear magnetic resonance spectroscopy. The data showed that free CRABP2 displays widespread intermediate-time scale dynamics that is effectively suppressed upon atRA binding. This effect is mirrored by the fast-time scale dynamics of CRABP2. Unexpectedly, CRABP2 rigidification in response to atRA binding leads to the stabilization of a homodimerization interface, which encompasses residues located on helix α2 and the ßC-ßD loop as well as residues on strands ßI-ßA and the ßH-ßI loop. Critically, this rigidification also affects CRABP2's nuclear localization signal and RAR-binding motif, suggesting that the loss of conformational entropy upon atRA binding may be the key for the diverse cellular functions of CRABP2.

Asunto(s)

Multimerización de Proteína , Receptores de Ácido Retinoico/química , Receptores de Ácido Retinoico/metabolismo , Tretinoina/química , Tretinoina/metabolismo , Núcleo Celular/metabolismo , Cristalización , Entropía , Escherichia coli/genética , Escherichia coli/metabolismo , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Cinética , Ligandos , Espectroscopía de Resonancia Magnética , Unión Proteica , Estructura Secundaria de Proteína , Receptores de Ácido Retinoico/genética

RESUMEN

Retinoic acid receptors (RAR) and retinoid X receptors (RXR) are ligand-mediated transcription factors that synchronize intricate signaling networks in metazoans. Dimer formation between these two nuclear receptors mediates the recruitment of co-regulatory complexes coordinating the progression of signaling cascades during developmental and regenerative events. In the present study we identified and characterized the receptors for retinoic acid in the sea cucumber Holothuria glaberrima; a model system capable of regenerative organogenesis during adulthood. Molecular characterizations revealed the presence of three isoforms of RAR and two of RXR as a consequence of alternative splicing events. Various analyses including: primary structure sequencing, phylogenetic analysis, protein domain prediction, and multiple sequence alignment further confirmed their identity. Semiquantitative reverse transcription PCR analysis of each receptor isoform herein identified showed that the retinoid receptors are expressed in all tissues sampled: the mesenteries, respiratory trees, muscles, gonads, and the digestive tract. During regenerative organogenesis two of the receptors (RAR-L and RXR-T) showed differential expression in the posterior segment while RAR-S is differentially expressed in the anterior segment of the intestine. This work presents the first description of the components relaying the signaling for retinoic acid within this model system.

Asunto(s)

Perfilación de la Expresión Génica , Holothuria/fisiología , Intestinos/fisiología , Receptores de Ácido Retinoico/metabolismo , Empalme Alternativo , Animales , Biología Computacional , Mapeo Contig , ADN Complementario/metabolismo , Regulación de la Expresión Génica , Holothuria/genética , Sistemas de Lectura Abierta , Filogenia , Regeneración , Receptores X Retinoide/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Transducción de Señal

RESUMEN

Neuroblastoma (NB) is the most common extracranial solid childhood tumor accounting for around 15% of pediatric cancer deaths and most probably originates from a failure in the development of embryonic neural crest cells. Retinoids can inhibit the proliferation and stimulate differentiation of NB cells. In addition, epigenetic events involving changes in chromatin structure and DNA methylation can mediate the effects of retinoids; hence, the scope of this study is to investigate the use of retinoids and epigenetic drugs in NB cell lines. Here, we demonstrate that the combination of retinoid all trans-retinoic acid (ATRA) with inhibitors of either histone deacetylases (HDACs) or DNA methyltransferase is more effective in impairing the proliferation of human SH-SY5Y and SK-N-BE(2) NB cells than any drug given alone. Treatments also induced differential changes on the messenger RNA (mRNA) expression of retinoid receptor subtypes and reduced the protein content of c-Myc, the neuronal markers NeuN and ß-3 tubulin, and the oncoprotein Bmi1. These results suggest that the combination of retinoids with epigenetic modulators is more effective in reducing NB growth than treatment with single drugs.

Asunto(s)

Proliferación Celular/efectos de los fármacos , Epigénesis Genética/efectos de los fármacos , Neuroblastoma/metabolismo , Receptores de Ácido Retinoico/agonistas , Receptores de Ácido Retinoico/metabolismo , Línea Celular Tumoral , Proliferación Celular/fisiología , Epigénesis Genética/fisiología , Inhibidores de Histona Desacetilasas/administración & dosificación , Humanos , Esteroides/administración & dosificación , Tretinoina/administración & dosificación , Tretinoina/análogos & derivados

RESUMEN

The aim of this study was the characterization of transcriptional regulatory pathways mediated by retinoic acid (RA) in Senegalese sole larvae. For this purpose, pre-metamorphic larvae were treated with a low concentration of DEAB, an inhibitor of RALDH enzyme, until the end of metamorphosis. No differences in growth, eye migration or survival were observed. Nevertheless, gene expression analysis revealed a total of 20 transcripts differentially expressed during larval development and only six related with DEAB treatments directly involved in RA metabolism and actions (rdh10a, aldh1a2, crbp1, igf2r, rarg and cyp26a1) to adapt to a low-RA environment. In a second experiment, post-metamorphic larvae were exposed to the all-trans RA (atRA) observing an opposite regulation for those genes involved in RA synthesis and degradation (rdh10a, aldh1a2, crbp1 and cyp26a1) as well as other related with thyroid- (dio2) and IGF-axes (igfbp1, igf2r and igfbp5) to balance RA levels. In a third experiment, DEAB-pretreated post-metamorphic larvae were exposed to atRA and TTNPB (a specific RAR agonist). Both drugs down-regulated rdh10a and aldh1a2 and up-regulated cyp26a1 expression demonstrating their important role in RA homeostasis. Moreover, five retinoic receptors that mediate RA actions, the thyroid receptor thrb, and five IGF binding proteins changed differentially their expression. Overall, this study demonstrates that exogenous RA modulates the expression of some genes involved in the RA synthesis, degradation and cellular transport through RAR-mediated regulatory pathways establishing a negative feedback regulatory mechanism necessary to balance endogenous RA levels and gradients.

Asunto(s)

Peces Planos/genética , Peces Planos/metabolismo , Regulación de la Expresión Génica , Larva/genética , Larva/metabolismo , Tretinoina/metabolismo , Animales , Benzoatos/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Larva/crecimiento & desarrollo , Metamorfosis Biológica/efectos de los fármacos , Metamorfosis Biológica/genética , Receptores de Ácido Retinoico/agonistas , Receptores de Ácido Retinoico/genética , Receptores de Ácido Retinoico/metabolismo , Retinoides/farmacología , p-Aminoazobenceno/análogos & derivados , p-Aminoazobenceno/farmacología

RESUMEN

During development and through adulthood, differentiation of diverse cell types is controlled by specific genetic and molecular programs for which transcription factors are master regulators of gene expression. Here, we present an overview of the role of nuclear receptors and their selective pharmacological modulators in oligodendrocytes linage, their role in myelination and remyelination and their potential use as a therapeutic strategy for demyelinating diseases. We discuss several aspects of nuclear receptors including: (1) the biochemistry of nuclear receptors superfamily; (2) their role on stem cells physiology, focusing in differentiation and cell removal; (3) the role of nuclear receptor in the oligodendrocytes cell linage, from oligodendrocyte progenitors cells to mature myelinating cells; and (4) the therapeutics opportunities of nuclear receptors for specific demyelinating diseases.

Asunto(s)

Adrenoleucodistrofia/genética , Enfermedad de Alzheimer/genética , Oligodendroglía/metabolismo , Receptores de Ácido Retinoico/genética , Células Madre/metabolismo , Adrenoleucodistrofia/tratamiento farmacológico , Adrenoleucodistrofia/metabolismo , Adrenoleucodistrofia/patología , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Animales , Factores de Transcripción COUP/agonistas , Factores de Transcripción COUP/genética , Factores de Transcripción COUP/metabolismo , Diferenciación Celular , Linaje de la Célula , Drogas en Investigación/uso terapéutico , Regulación de la Expresión Génica , Humanos , Receptores X del Hígado/agonistas , Receptores X del Hígado/genética , Receptores X del Hígado/metabolismo , Fármacos Neuroprotectores/uso terapéutico , Oligodendroglía/efectos de los fármacos , Oligodendroglía/patología , Receptores Nucleares Huérfanos , Receptores Activados del Proliferador del Peroxisoma/agonistas , Receptores Activados del Proliferador del Peroxisoma/genética , Receptores Activados del Proliferador del Peroxisoma/metabolismo , Receptores Citoplasmáticos y Nucleares/agonistas , Receptores Citoplasmáticos y Nucleares/genética , Receptores Citoplasmáticos y Nucleares/metabolismo , Receptores de Ácido Retinoico/agonistas , Receptores de Ácido Retinoico/metabolismo , Células Madre/efectos de los fármacos , Células Madre/patología

RESUMEN

BACKGROUND: Transcription factors such as retinoic acid receptor alpha (RARα) and beta (RARß) and Yin Yang 1 (YY1) are associated with the progression of non-small cell lung cancer (NSCLC). In particular, a lack of RARß expression is associated with NSCLC development. The aim of this study was to analyze the expression of RARα, RARß and YY1 and their relationship with prognosis in patients with advanced NSCLC. METHODS: The expression of RARα, RARß and YY1 was assessed by immunohistochemistry and quantitative computerized image software. RESULTS: Eighty-five patients treated with platinum-based chemotherapy were included in the analysis. The mean and standard deviation of the nuclear expression of RARα, RARß and YY1 were 184.5 ± 124.4, 18 ± 27 and 16.6 ± 20.5, respectively. The nuclear expression of RARß was associated with the nuclear expression of YY1 (R 2 = 0.28; p value < 0.0001). Patients with high nuclear expression of YY1 were likely to be non-smokers (61.9 vs 40.5 %). Median progression-free survival (PFS) was 5.9 months (3.48-8.28). Low expression of RARα was independently associated with worse PFS following chemotherapy (10.3 vs 5.46 months p = 0.040). Median overall survival (OS) was 15.6 months (4.5-26.7), and lower nuclear expression of RARß was independently associated with shorter OS (27.5 vs 8.7 months; p = 0.037). CONCLUSION: Our study suggests that the loss of RARs is associated with a worse prognosis and these receptors could be a potential molecular target for NSCLC.

Asunto(s)

Carcinoma de Pulmón de Células no Pequeñas , Cisplatino/uso terapéutico , Neoplasias Pulmonares , Receptores de Ácido Retinoico , Receptor alfa de Ácido Retinoico , Factor de Transcripción YY1 , Adulto , Anciano , Antineoplásicos/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Diagnóstico por Computador , Supervivencia sin Enfermedad , Femenino , Regulación de la Expresión Génica , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Pronóstico , Receptores de Ácido Retinoico/genética , Receptores de Ácido Retinoico/metabolismo , Receptor alfa de Ácido Retinoico/genética , Receptor alfa de Ácido Retinoico/metabolismo , Factores de Transcripción , Factor de Transcripción YY1/genética , Factor de Transcripción YY1/metabolismo

RESUMEN

Breast cancer is the most common malignancy in women, with metastases being the cause of death in 98%. In previous works we have demonstrated that retinoic acid (RA), the main retinoic acid receptor (RAR) ligand, is involved in the metastatic process by inhibiting migration through a reduced expression of the specific migration-related proteins Moesin, c-Src, and FAK. At present, our hypothesis is that RA also acts for short periods in a non-genomic action to cooperate with motility reduction and morphology of breast cancer cells. Here we identify that the administration of 10(-6) M RA (10-20 min) induces the activation of the migration-related proteins Moesin, FAK, and Paxillin in T-47D breast cancer cells. The phosphorylation exerted by the selective agonists for RARα and RARß, on Moesin, FAK, and Paxillin was comparable to the activation exerted by RA. The RARγ agonist only led to a weak activation, suggesting the involvement of RARα and RARß in this pathway. We then treated the cells with different inhibitors that are involved in cell signaling to regulate the mechanisms of cell motility. RA failed to activate Moesin, FAK, and Paxillin in cells treated with Src inhibitor (PP2) and PI3K inhibitor (WM), suggesting the participation of Src-PI3K in this pathway. Treatment with 10(-6) M RA for 20 min significantly decreased cell adhesion. However, when cells were treated with 10(-6) M RA and FAK inhibitor, the RA did not significantly inhibit adhesion, suggesting a role of FAK in the adhesion inhibited by RA. By immunofluorescence and immunoblotting analysis we demonstrated that RA induced nuclear FAK translocation leading to a reduced cellular adhesion. These findings provide new information on the actions of RA for short periods. RA participates in cell adhesion and subsequent migration, modulating the relocation and activation of proteins involved in cell migration.

Asunto(s)

Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Núcleo Celular/metabolismo , Proteína-Tirosina Quinasas de Adhesión Focal/metabolismo , Proteínas de Microfilamentos/metabolismo , Paxillin/metabolismo , Tretinoina/farmacología , Adhesión Celular/efectos de los fármacos , Línea Celular Tumoral , Núcleo Celular/efectos de los fármacos , Femenino , Proteínas de Choque Térmico HSP27/metabolismo , Proteínas del Choque Térmico HSP72 , Humanos , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación , Transporte de Proteínas/efectos de los fármacos , Receptores de Ácido Retinoico/agonistas , Receptores de Ácido Retinoico/metabolismo , Receptor alfa de Ácido Retinoico/agonistas , Receptor alfa de Ácido Retinoico/metabolismo , Transducción de Señal/efectos de los fármacos , Proteína p53 Supresora de Tumor/metabolismo , Familia-src Quinasas/metabolismo

RESUMEN

The effects of lutein and conjugated linoleic acid (CLA) on growth performance and immune response of broiler chickens were evaluated in the presence and absence of Salmonella lipopolysaccharide (LPS) immune challenge. Cobb chicks (360; 1 to 22 d of age) were used in a 3 × 2 factorial arrangement of CLA (0, 1, and 2%) and lutein (0 and 50 mg/kg) dietary levels. At d 8 and 15, birds were injected with BSA to assess IgY production. At d 20, birds were injected with LPS. Samples of liver, spleen, and duodenum were collected at 3 and 16 h post-LPS challenge for RT-qPCR analysis of RXRα, RXRγ, PPARα, PPARγ, TLR-4, IL-1ß, IL-2, IL-10, and IL-12 gene expression. CLA decreased BW, BW gain (BWG), and G:F from d 1 to 20, but these effects were reversed when lutein was included in the 1% CLA diet (P < 0.001). The production of IgY anti-BSA increased following a 2% CLA supplementation (P < 0.01). LPS increased the liver:BW ratio at 3 h post-injection (P < 0.001) and decreased BWG at 3, 16, and 40 h (P < 0.001). Lutein decreased plasmatic nitric oxide levels (P < 0.01). LPS downregulated PPARα mRNA in the duodenum (P = 0.02) and liver (P = 0.04), and PPARγ (P = 0.01) and RXRα (P = 0.08) in the spleen; these effects were not reversed by CLA or lutein as initially hypothesized. Although LPS upregulated IL-1ß (P = 0.02) and IL-12 (P = 0.07) expression, lutein downregulated these pro-inflammatory cytokines in the liver (P = 0.03 and P = 0.07, respectively). Lutein decreased splenic (P = 0.09) but increased hepatic (P = 0.06) TLR-4 mRNA. A dietary CLA supplementation of 2% increased hepatic RXRα (P = 0.10). In conclusion, CLA decreased broiler chicken growth performance, but lutein could prevent this negative effect (depending on CLA dose). Lutein had an anti-inflammatory effect, and a 2% CLA supplementation improved the humoral immune response.

Asunto(s)

Proteínas Aviares/genética , Pollos/crecimiento & desarrollo , Pollos/inmunología , Dieta/veterinaria , Suplementos Dietéticos , Ácidos Linoleicos Conjugados , Luteína , Alimentación Animal/análisis , Animales , Proteínas Aviares/metabolismo , Suplementos Dietéticos/análisis , Femenino , Inmunidad Humoral , Lipopolisacáridos , Masculino , Estrés Oxidativo , Receptores Activados del Proliferador del Peroxisoma/genética , Receptores Activados del Proliferador del Peroxisoma/metabolismo , Receptores de Ácido Retinoico/genética , Receptores de Ácido Retinoico/metabolismo , Salmonella/fisiología

RESUMEN

All-trans retinoic acid (ATRA) has been used as an antineoplastic because of its ability to promote proliferation, inhibition, and differentiation, primarily in leukemia; however, in other types of cancer, such as lung cancer, treatment with ATRA is restricted because not all the patients experience the same results. The ERK signaling pathway is dysregulated in cancer cells, including lung cancer, and this dysregulation promotes proliferation and cell invasion. In this study, we demonstrate that treatment with ATRA can activate the ERK signaling pathway by a transcription-independent mechanism through a signaling cascade that involves RARα and PI3K, promoting growth, survival, and migration in lung cancer cells. Until now, this mechanism was unknown in lung cancer cells. The inhibition of the ERK signaling pathway restores the beneficial effects of ATRA, reduces proliferation, increases apoptosis, and blocks the cell migration process in lung cancer cells. In conclusion, our results suggest that the combination of ATRA with ERK inhibitor in clinical trials for lung cancer is warranted.

Asunto(s)

Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Neoplasias Pulmonares/tratamiento farmacológico , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Transcripción Genética/efectos de los fármacos , Tretinoina/farmacología , Antineoplásicos/farmacología , Apoptosis/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Línea Celular Tumoral , Humanos , Neoplasias Pulmonares/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Receptores de Ácido Retinoico/metabolismo , Receptor alfa de Ácido Retinoico

RESUMEN

Autism spectrum disorders (ASDs) are a range of complex neurodevelopmental conditions principally characterized by dysfunctions linked to mental development. Previous studies have shown that there are more than 1000 genes likely involved in ASD, expressed mainly in brain and highly interconnected among them. We applied whole exome sequencing in Colombian-South American trios. Two missense novel SNVs were found in the same child: ALDH1A3 (RefSeq NM_000693: c.1514T>C (p.I505T)) and FOXN1 (RefSeq NM_003593: c.146C>T (p.S49L)). Gene expression studies reveal that Aldh1a3 and Foxn1 are expressed in ~E13.5 mouse embryonic brain, as well as in adult piriform cortex (PC; ~P30). Conserved Retinoic Acid Response Elements (RAREs) upstream of human ALDH1A3 and FOXN1 and in mouse Aldh1a3 and Foxn1 genes were revealed using bioinformatic approximation. Chromatin immunoprecipitation (ChIP) assay using Retinoid Acid Receptor B (Rarb) as the immunoprecipitation target suggests RA regulation of Aldh1a3 and Foxn1 in mice. Our results frame a possible link of RA regulation in brain to ASD etiology, and a feasible non-additive effect of two apparently unrelated variants in ALDH1A3 and FOXN1 recognizing that every result given by next generation sequencing should be cautiously analyzed, as it might be an incidental finding.

Asunto(s)

Aldehído Oxidorreductasas/genética , Trastorno del Espectro Autista/genética , Exoma , Factores de Transcripción Forkhead/genética , Receptores de Ácido Retinoico/genética , Tretinoina/metabolismo , Adulto , Aldehído Oxidorreductasas/metabolismo , Animales , Trastorno del Espectro Autista/metabolismo , Trastorno del Espectro Autista/patología , Secuencia de Bases , Encéfalo/crecimiento & desarrollo , Encéfalo/metabolismo , Encéfalo/patología , Niño , Estudios de Cohortes , Colombia , Embrión de Mamíferos , Femenino , Factores de Transcripción Forkhead/metabolismo , Regulación del Desarrollo de la Expresión Génica , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Linaje , Pruebas Psicológicas , Receptores de Ácido Retinoico/metabolismo , Elementos de Respuesta , Transducción de Señal

RESUMEN

Acinus-S' is a corepressor for retinoic acid receptor (RAR)-dependent gene transcription and has been suggested to be involved in RNA processing. In this study, the role of Acinus isoforms in regulating pre-mRNA splicing was explored using in vivo splicing assays. Both Acinus-L and Acinus-S', with the activity of Acinus-L higher than that of Acinus-S', increase the splicing of a retinoic acid (RA)-responsive minigene containing a weak 5' splice site but not a RA-responsive minigene containing a strong 5' splice site. RA treatment further enhances the splicing of the weak 5' splice site by Acinus in a dose- and time-dependent manner, suggesting a RA-dependent activity in addition to a RA-independent activity of Acinus. The RA-independent effect of Acinus occurs to varying degrees using minigene constructs containing several different promoters, while the RA-dependent splicing activity of Acinus is specific for transcripts derived from the minigene driven by a RA response element (RARE)-containing promoter. This suggests that the ligand-dependent splicing activity of Acinus is related to the RA-activated RAR bound to the RARE. The RRM domain is necessary for the RA-dependent splicing activity of Acinus and the RA-independent splicing activity of Acinus is repressed by RNPS1. Importantly, measurement of the splicing of endogenous human RARß and Bcl-x in vivo demonstrates that Acinus stimulates the use of the weaker alternative 5' splice site of these two genes in a RA-dependent manner for RARß and a RA-independent manner for Bcl-x. Taken together, these studies demonstrate that Acinus functions in both RAR-dependent splicing and RAR-dependent transcription.

Asunto(s)

Proteínas Nucleares/metabolismo , Regiones Promotoras Genéticas/genética , Precursores del ARN/metabolismo , Empalme del ARN/fisiología , Receptores de Ácido Retinoico/metabolismo , Células Cultivadas , Expresión Génica/fisiología , Humanos , Empalme del ARN/genética , Factores de Transcripción/metabolismo

RESUMEN

It has been established that retinoids exert some of their effects on cell differentiation and malignant phenotype reversion through the interaction with different members of the protein kinase C (PKC) family. Till nowadays the nature and extension of this interaction is not well understood. Due to the cytostatic and differentiating effects of retinoids, in the present study we propose to evaluate whether the crosstalk between the retinoid system and the PKC pathway could become a possible target for breast cancer treatment. We could determine that ATRA (all-trans retinoic) treatment showed a significant growth inhibition due to (G1 or G2) cell cycle arrest both in LM3 and SKBR3, a murine and human mammary cell line respectively. ATRA also induced a remarkable increase in PKCα and PKCδ expression and activity. Interestingly, the pharmacological inhibition of these two PKC isoforms prevented the activation of retinoic acid receptors (RARs) by ATRA, indicating that both PKC isoforms are required for RARs activation. Moreover, PKCδ inhibition also impaired ATRA-induced RARα translocation to the nucleus. In vivo assays revealed that a combined treatment using ATRA and PKCα inhibitors prevented lung metastatic dissemination in an additive way. Our results clearly indicate that ATRA modulates the expression and activity of different PKCs. Besides inducing cell arrest, the activity of both PKC is necessary for the induction of the retinoic acid system. The combined ATRA and PKCα inhibitors could be an option for the hormone-independent breast cancer treatment.

Asunto(s)

Neoplasias de la Mama/metabolismo , Proteína Quinasa C-alfa/metabolismo , Proteína Quinasa C-delta/metabolismo , Receptores de Ácido Retinoico/metabolismo , Tretinoina/metabolismo , Animales , Neoplasias de la Mama/tratamiento farmacológico , Diferenciación Celular/efectos de los fármacos , Nucléolo Celular/efectos de los fármacos , Nucléolo Celular/metabolismo , Femenino , Puntos de Control de la Fase G1 del Ciclo Celular/efectos de los fármacos , Puntos de Control de la Fase G2 del Ciclo Celular/efectos de los fármacos , Humanos , Ratones , Ratones Endogámicos BALB C , Isoformas de Proteínas/antagonistas & inhibidores , Isoformas de Proteínas/metabolismo , Proteína Quinasa C-alfa/antagonistas & inhibidores , Proteína Quinasa C-delta/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Células Tumorales Cultivadas

RESUMEN

All-trans retinoic acid (ATRA) promotes the endogenous expression of both nerve growth factor (NGF) and retinoic acid receptor beta (RAR-ß). We have previously shown that the administration of ATRA partly reverts the damage induced by diabetic neuropathy (DN). In this investigation, we evaluated the effects of vitamin A, a commercial, inexpensive compound of retinoic acid, on the therapy of DN. A total of 70 rats were randomized into 4 groups. Group A was the control, and groups B, C, and D received a total dose of 60 mg/kg streptozotocin intraperitoneally. When signs of DN developed, groups C and D were treated either with vitamin A (20,000 IU) or with ATRA 25 mg/kg for 60 days. Plasma glucose, contents of NGF, thermal and nociceptive tests, and RAR-ß expression were evaluated. All diabetic rats developed neuropathy. The treatment with vitamin A and ATRA reverted similarly the sensorial disturbances, which was associated with increased contents of NGF and RAR-ß expression. Our results indicate that the administration of vitamin A has the same therapeutic effect as ATRA on peripheral neuropathy and suggest its potential therapeutic use in patients with diabetes.

Asunto(s)

Neuropatías Diabéticas/tratamiento farmacológico , Factor de Crecimiento Nervioso/metabolismo , Receptores de Ácido Retinoico/metabolismo , Vitamina A/farmacología , Animales , Neuropatías Diabéticas/metabolismo , Masculino , Ratas , Ratas Wistar , Nervio Ciático/metabolismo , Vitamina A/uso terapéutico

RESUMEN

Breast cancer is the most common malignancy in women and the appearance of distant metastases produces the death in 98% of cases. The retinoic acid receptor ß (RARß) is not expressed in 50% of invasive breast carcinoma compared with normal tissue and it has been associated with lymph node metastasis. Our hypothesis is that RARß protein participates in the metastatic process. T47D and MCF7 breast cancer cell lines were used to perform viability assay, immunobloting, migration assays, RNA interference and immunofluorescence. Administration of retinoic acid (RA) in breast cancer cells induced RARß gene expression that was greatest after 72 hrs with a concentration 1 µM. High concentrations of RA increased the expression of RARß causing an inhibition of the 60% in cell migration and significantly decreased the expression of migration-related proteins [moesin, c-Src and focal adhesion kinase (FAK)]. The treatment with RARα and RARγ agonists did not affect the cell migration. On the contrary, the addition of the selective retinoid RARß-agonist (BMS453) significantly reduced cell migration comparable to RA inhibition. When RARß gene silencing was performed, the RA failed to significantly inhibit migration and resulted ineffective to reduce moesin, c-Src and FAK expressions. RARß is necessary to inhibit migration induced by RA in breast cancer cells modulating the expression of proteins involved in cell migration.

Asunto(s)

Antineoplásicos/farmacología , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Movimiento Celular/efectos de los fármacos , Receptores de Ácido Retinoico/metabolismo , Tretinoina/farmacología , Citoesqueleto de Actina , Apoptosis/efectos de los fármacos , Western Blotting , Neoplasias de la Mama/metabolismo , Proteína Tirosina Quinasa CSK , Proliferación Celular/efectos de los fármacos , Femenino , Técnica del Anticuerpo Fluorescente , Quinasa 1 de Adhesión Focal/metabolismo , Humanos , Técnicas para Inmunoenzimas , Proteínas de Microfilamentos/metabolismo , ARN Interferente Pequeño/genética , Receptores de Ácido Retinoico/antagonistas & inhibidores , Receptores de Ácido Retinoico/genética , Retinoides/farmacología , Células Tumorales Cultivadas , Familia-src Quinasas/metabolismo

RESUMEN

We recently demonstrated better outcomes in helminth-infected multiple sclerosis (MS) patients, compared with uninfected ones. The present study evaluates the role of TLR2 and retinoic acid (RA) in parasite-driven protection in MS patients. RA serum levels were significantly higher in helminth-infected MS patients than in uninfected MS subjects or healthy controls. Genes involved in RA biosynthesis and metabolism, such as Adh1 and Raldh2, as well as RA receptors and IL-10, were induced in dendritic cells (DCs) via TLR2-dependent ERK signaling. This programmed DCs to induce FOXP3(+) T regulatory cells and suppressed production of proinflammatory cytokines (IL-6, IL-12, IL-23, and TNF-α) via induction of suppressor of cytokine signaling 3 (SOCS3), an effect mediated by soluble egg Ag (SEA) obtained from Schistosoma mansoni, and by RA. SEA-activated DCs also inhibited IL-17 and IFN-γ production through autoreactive T cells. These inhibitory effects were abrogated when SOCS3 gene expression was silenced, indicating that SEA-mediated signaling inhibited production of these cytokines by T cells, through a SOCS3-dependent pathway. Overall, helminth-related immunomodulation observed in MS patients was mediated by TLR2- and RA-dependent pathways, through two different mechanisms, as follows: 1) induction of IL-10 and FOXP3(+) T regulatory cells, and 2) suppression of proinflammatory cytokine production mediated by SOCS3.

Asunto(s)

Esclerosis Múltiple/inmunología , Esclerosis Múltiple/metabolismo , Enfermedades Parasitarias/inmunología , Enfermedades Parasitarias/metabolismo , Transducción de Señal , Tretinoina/metabolismo , Alcohol Deshidrogenasa/genética , Alcohol Deshidrogenasa/metabolismo , Familia de Aldehído Deshidrogenasa 1 , Antígenos Helmínticos/inmunología , Citocinas/biosíntesis , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Femenino , Factores de Transcripción Forkhead/metabolismo , Humanos , Mediadores de Inflamación/metabolismo , Masculino , Modelos Biológicos , Esclerosis Múltiple/complicaciones , Enfermedades Parasitarias/complicaciones , Receptores de Ácido Retinoico/genética , Receptores de Ácido Retinoico/metabolismo , Retinal-Deshidrogenasa/genética , Retinal-Deshidrogenasa/metabolismo , Proteína 3 Supresora de la Señalización de Citocinas , Proteínas Supresoras de la Señalización de Citocinas/genética , Proteínas Supresoras de la Señalización de Citocinas/metabolismo , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Tretinoina/sangre

RESUMEN

BACKGROUND: All-trans retinoic acid (ATRA) is currently being used in clinical trials for cancer treatment. The use of ATRA is limited because some cancers, such as lung cancer, show resistance to treatment. However, little is known about the molecular mechanisms that regulate resistance to ATRA treatment. Akt is a kinase that plays a key role in cell survival and cell invasion. Akt is often activated in lung cancer, suggesting its participation in resistance to chemotherapy. In this study, we explored the hypothesis that activation of the Akt pathway promotes resistance to ATRA treatment at the inhibition of cell survival and invasion in lung cancer. We aimed to provide guidelines for the proper use of ATRA in clinical trials and to elucidate basic biological mechanisms of resistance. RESULTS: We performed experiments using the A549 human lung adenocarcinoma cell line. We found that ATRA treatment promotes PI3k-Akt pathway activation through transcription-independent mechanisms. Interestingly, ATRA treatment induces the translocation of RARα to the plasma membrane, where it colocalizes with Akt. Immunoprecipitation assays showed that ATRA promotes Akt activation mediated by RARα-Akt interaction. Activation of the PI3k-Akt pathway by ATRA promotes invasion through Rac-GTPase, whereas pretreatment with 15e (PI3k inhibitor) or over-expression of the inactive form of Akt blocks ATRA-induced invasion. We also found that treatment with ATRA induces cell survival, which is inhibited by 15e or over-expression of an inactive form of Akt, through a subsequent increase in the levels of the active form of caspase-3. Finally, we showed that over-expression of the active form of Akt significantly decreases expression levels of the tumor suppressors RARß2 and p53. In contrast, over-expression of the inactive form of Akt restores RARß2 expression in cells treated with ATRA, indicating that activation of the PI3k-Akt pathway inhibits the expression of ATRA target genes. CONCLUSION: Our results demonstrate that rapid activation of Akt blocks transcription-dependent mechanism of ATRA, promotes invasion and cell survival and confers resistance to retinoic acid treatment in lung cancer cells. These findings provide an incentive for the design and clinical testing of treatment regimens that combine ATRA and PI3k inhibitors for lung cancer treatment.

Asunto(s)

Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Transducción de Señal/efectos de los fármacos , Transcripción Genética , Tretinoina/farmacología , Apoptosis/efectos de los fármacos , Caspasa 3/metabolismo , Línea Celular Tumoral , Membrana Celular/metabolismo , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Activación Enzimática/efectos de los fármacos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Neoplasias Pulmonares/patología , Invasividad Neoplásica , Fosfatidilinositol 3-Quinasas/metabolismo , Unión Proteica , Transporte de Proteínas/efectos de los fármacos , Receptores de Ácido Retinoico/metabolismo , Receptor alfa de Ácido Retinoico , Proteínas de Unión al GTP rac/metabolismo