RESUMO
Human Antigen Leukocyte-G (HLA-G) gene encodes an immune checkpoint molecule that has restricted tissue expression in physiological conditions; however, the gene may be induced in hypoxic conditions by the interaction with the hypoxia inducible factor-1 (HIF1). Hypoxia regulatory elements (HRE) located at the HLA-G promoter region and at exon 2 are the major HIF1 target sites. Since the G allele of the -964G > A transversion induces higher HLA-G expression when compared to the A allele in hypoxic conditions, here we analyzed HIF1-HRE complex interaction at the pair-atom level considering both -964G > A polymorphism alleles. Mouse HIF2 dimer crystal (Protein Data Bank ID: 4ZPK) was used as template to perform homology modelling of human HIF1 quaternary structure using MODELLER v9.14. Two 3D DNA structures were built from 5'GCRTG'3 HRE sequence containing the -964G/A alleles using x3DNA. Protein-DNA docking was performed using the HADDOCK v2.4 server, and non-covalent bonds were computed by DNAproDB server. Molecular dynamic simulation was carried out per 200 ns, using Gromacs v.2019. HIF1 binding in the HRE containing -964G allele results in more hydrogen bonds and van der Waals contact formation than HRE with -964A allele. Protein-DNA complex trajectory analysis revealed that HIF1-HRE-964G complex is more stable. In conclusion, HIF1 binds in a more stable and specific manner at the HRE with G allele.
Assuntos
Antígenos HLA-G/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Elementos de Resposta/genética , Alelos , Sítios de Ligação , Éxons , Antígenos HLA-G/química , Antígenos HLA-G/genética , Humanos , Ligação de Hidrogênio , Subunidade alfa do Fator 1 Induzível por Hipóxia/química , Simulação de Acoplamento Molecular , Regiões Promotoras Genéticas , Ligação Proteica , TermodinâmicaRESUMO
Retinoic acid (RA), an active metabolite of Vitamin A, and bone morphogenetic protein 4 (BMP-4) pathways control the transcription of pro-opiomelanocortin (Pomc), the precursor of ACTH. We describe a novel mechanism by which RA and BMP-4 act together in the context of pituitary corticotroph tumoral cells to regulate Pomc transcription. BMP-4 and RA exert a potentiated inhibition on Pomc gene expression. This potentiation of the inhibitory action on Pomc transcription was blocked by the inhibitory SMADs of the BMP-4 pathway (SMAD6 and SMAD7), a negative regulator of BMP-4 signaling (TOB1) and a blocker of RA pathway (COUP-TFI). AtT-20 corticotrophinoma cells express RA receptors (RARB, RXRA and RXRG) which associate with factors of BMP-4 (SMAD4 and SMAD1) signaling cascade in transcriptional complexes that block Pomc transcription. COUP-TFI and TOB1 disrupt these complexes. Deletions and mutations of the Pomc promoter and a specific DNA-binding assay show that the complexes bind to the RARE site in the Pomc promoter. The enhanced inhibitory interaction between RA and BMP-4 pathways occurs also in another relevant corticotroph gene promoter, the corticotropin-releasing hormone receptor 1 (Crh-r1). The understanding of the molecules that participate in the control of corticotroph gene expression contribute to define more precise targets for the treatment of corticotrophinomas.
Assuntos
Proteína Morfogenética Óssea 4/metabolismo , Corticotrofos/metabolismo , Regulação da Expressão Gênica , Pró-Opiomelanocortina/genética , Transdução de Sinais , Tretinoína/metabolismo , Animais , Sequência de Bases , Linhagem Celular , Pró-Opiomelanocortina/metabolismo , Regiões Promotoras Genéticas/genética , Ratos , Receptores de Hormônio Liberador da Corticotropina/genética , Elementos de Resposta/genética , Fatores de Transcrição/metabolismo , Transcrição GênicaRESUMO
Glucocorticoids are used during prostate cancer (PCa) treatment. However, they may also have the potential to drive castration resistant prostate cancer (CRPC) growth via the glucocorticoid receptor (GR). Given the association between inflammation and PCa, and the anti-inflammatory role of heme oxygenase 1 (HO-1), we aimed at identifying the molecular processes governed by the interaction between HO-1 and GR. PCa-derived cell lines were treated with Hemin, Dexamethasone (Dex), or both. We studied GR gene expression by RTqPCR, protein expression by Western Blot, transcriptional activity using reporter assays, and nuclear translocation by confocal microscopy. We also evaluated the expression of HO-1, FKBP51, and FKBP52 by Western Blot. Hemin pre-treatment reduced Dex-induced GR activity in PC3 cells. Protein levels of FKBP51, a cytoplasmic GR-binding immunophilin, were significantly increased in Hemin+Dex treated cells, possibly accounting for lower GR activity. We also evaluated these treatments in vivo using PC3 tumors growing as xenografts. We found non-significant differences in tumor growth among treatments. Immunohistochemistry analyses revealed strong nuclear GR staining in almost all groups. We did not observe HO-1 staining in tumor cells, but high HO-1 reactivity was detected in tumor infiltrating macrophages. Our results suggest an association and crossed modulation between HO-1 and GR pathways.
Assuntos
Heme Oxigenase-1/metabolismo , Neoplasias da Próstata/metabolismo , Receptores de Glucocorticoides/metabolismo , Animais , Linhagem Celular Tumoral , Dexametasona/farmacologia , Intervalo Livre de Doença , Heme Oxigenase-1/genética , Hemina/farmacologia , Humanos , Masculino , Camundongos , Regiões Promotoras Genéticas/genética , Elementos de Resposta/genética , Transdução de Sinais , Proteínas de Ligação a Tacrolimo/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Nrf2 (nuclear factor erythroid 2-related factor 2), a transcription factor that controls expression of several proteins that are related to cellular antioxidant capacity, such as the subunit xCT of the system xc-, is dysregulated in diabetes. Recently, it was described that system xc- is decreased in the retina after 3 weeks of diabetes. So, in the present work, the temporal relationship between xCT and Nrf2 in the retina of diabetic animals was investigated. Diabetes was induced in male Wistar rats (200 g) by a single injection of streptozotocin, and retinas were collected after 1, 2, and 6 months of diabetes induction. Expression of xCT, Nrf2 activity, and binding to antioxidant-responsive element (ARE) sequence were evaluated. Glutathione and reactive oxygen species (ROS) levels were also assessed. After 1 month of diabetes, Nrf2 activity, xCT expression, and glutathione levels were reduced whereas ROS were increased. Although glutathione and ROS levels remain unchanged until later stages, Nrf2 activity and xCT expression returned to normal levels after 2 months. However, they were decreased again at 6 months of diabetes. Accordingly, Nrf2 binding to xCT ARE sequence followed the same pattern of Nrf2 activity and xCT expression. These data showed that retinal xCT expression is regulated by Nrf2 in diabetic condition. The results also demonstrated a temporal relationship between Nrf2 and system xc- which could be implicated in the initiation of oxidative stress in retina in diabetes.
Assuntos
Sistemas de Transporte de Aminoácidos Acídicos/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Retina/metabolismo , Sistemas de Transporte de Aminoácidos Acídicos/genética , Animais , Antioxidantes/metabolismo , Glicemia/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Tipo 1/sangue , Glutationa/metabolismo , Masculino , Estresse Oxidativo , Regiões Promotoras Genéticas/genética , Ligação Proteica , Subunidades Proteicas/metabolismo , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Elementos de Resposta/genética , Fatores de TempoRESUMO
Paternal care is a complex social behavior common in primate species with socially monogamous mating systems and twin births. Evolutionary causes and consequences of such behavior are not well understood, nor are their neuroendocrine and genetic bases. However, the neuropeptide oxytocin (OXT) and its receptor (OXTR) are associated with parental care in mammalian lineages. Here we investigated the interspecific variation in the number of progesterone response elements (PREs) in the OXTR promoter region of 32 primate species, correlating genetic data with behavior, social systems, and ecological/life-history parameters, while controlling for phylogeny. We verified that PREs are only present in New World monkeys and that PRE number is significantly correlated with the presence of paternal care in this branch. We suggest that PRE number could be an essential part of the genetic repertoire that allowed the emergence of taxon-specific complex social behaviors, such as paternal care in marmosets and tamarins.
Assuntos
Comportamento Animal , Progesterona/genética , Regiões Promotoras Genéticas/genética , Receptores de Ocitocina/genética , Elementos de Resposta/genética , Animais , Teorema de Bayes , Genótipo , Humanos , Masculino , Fenótipo , Platirrinos , Característica Quantitativa Herdável , Reprodução , Alinhamento de SequênciaRESUMO
To get further insights on the estrogen regulation of the uteroglobin (UG) gene, the 5'-flanking region of the UG gene from the brown hare (Lepus capensis) (Lc) was cloned and compared with those from two phylogenetically related species: the rabbit (Orictolagus cuniculus) (Oc) and the volcano rabbit (Romerolagus diazi) (Rd). The Lc-UG gene is very similar to those from rabbits (94%) and volcano rabbits (95%), and shares a number of genetic elements, including an estrogen response element (ERE). The estrogen-regulated transcription of a series of progressive 5'-deletion mutants of the Lc-UG gene, identified a functional ERE in the promoter region exhibiting the same orientation and relative position than that previously described in rabbits. The Lc-ERE is identical to the Oc-ERE, but different from both the Rd-ERE and the consensus ERE (c-ERE) by one nucleotide. We also detected important species-specific differences in the estrogen-regulated transcription of the UG gene. A luciferase reporter driven by 333 base pairs (bp) of the Lc-UG promoter elicited a higher response to estradiol than its related counterparts when expressed in estrogen-sensitive MCF-7 cells. Several ERE-like motifs which failed to act as functional EREs were also identified; one of them exhibited two mismatches in its palindromic sequence, a characteristic exhibited in many other natural occurring EREs, including the Rd-ERE.
Assuntos
Estrogênios/farmacologia , Lebres/genética , Transcrição Gênica/efeitos dos fármacos , Uteroglobina/genética , Região 5'-Flanqueadora/genética , Animais , Sequência de Bases , Estradiol/farmacologia , Receptor alfa de Estrogênio/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Dados de Sequência Molecular , Motivos de Nucleotídeos/genética , Coelhos , Elementos de Resposta/genética , Homologia de Sequência do Ácido Nucleico , Especificidade da Espécie , Uteroglobina/metabolismoRESUMO
Os eventos regulatórios da puberdade dos teleósteos são semelhantes dentro da classe e mesmo em comparação com outros vertebrados, entretanto existem particularidades entre as espécies que tornam os estudos de reprodução de peixes espécie-específicos. Essa especificidade se estende à prática, em que os protocolos de manipulação da reprodução de peixes nem sempre têm o mesmo efeito nas diferentes espécies, acarretando, portanto, resultados finais diferentes. Ainda, na indústria de aquicultura, o manejo hormonal com finalidade de ganhos econômicos não se limita à reprodução artificial. A manipulação do sexo é uma técnica muito utilizada quando, em espécies de interesse econômico, determinado sexo apresenta superioridade zootécnica. Nesta palestra,serão apresentados os principais hormônios envolvidos na formação e na maturação gonadal de peixes, bem como suas atividades, funções e singularidades pertinentes, buscando estender dos conhecimentos fisiológicos aos tecnológicos, na intersecção entre biologia básica e aplicada. (AU)
Although the events regulating puberty in teleost are very similar inside the class, and even if compared with other vertebrates, there are particularities between the species that make studies in fish reproduction very species-specific. This specificity extends to the practical activities, where the protocols of artificial reproduction have different effects in different species. In the aquaculture industry, the administration of hormones for economic purposes goes beyond reproduction in captivity. Sex manipulation is a technique largely used in species where one gender is superior in production. In the current talk, the main hormones controlling gonadal development and maturation will be presented, as well as their activities, functions and singularities, aiming at extending the knowledge from physiology to technology, at the intersection between applied and basic science.(AU)
Assuntos
Animais , Endocrinologia/métodos , Comportamento Reprodutivo , Aquicultura/métodos , Biotecnologia/tendências , Elementos de Resposta/genéticaRESUMO
Os eventos regulatórios da puberdade dos teleósteos são semelhantes dentro da classe e mesmo em comparação com outros vertebrados, entretanto existem particularidades entre as espécies que tornam os estudos de reprodução de peixes espécie-específicos. Essa especificidade se estende à prática, em que os protocolos de manipulação da reprodução de peixes nem sempre têm o mesmo efeito nas diferentes espécies, acarretando, portanto, resultados finais diferentes. Ainda, na indústria de aquicultura, o manejo hormonal com finalidade de ganhos econômicos não se limita à reprodução artificial. A manipulação do sexo é uma técnica muito utilizada quando, em espécies de interesse econômico, determinado sexo apresenta superioridade zootécnica. Nesta palestra,serão apresentados os principais hormônios envolvidos na formação e na maturação gonadal de peixes, bem como suas atividades, funções e singularidades pertinentes, buscando estender dos conhecimentos fisiológicos aos tecnológicos, na intersecção entre biologia básica e aplicada.
Although the events regulating puberty in teleost are very similar inside the class, and even if compared with other vertebrates, there are particularities between the species that make studies in fish reproduction very species-specific. This specificity extends to the practical activities, where the protocols of artificial reproduction have different effects in different species. In the aquaculture industry, the administration of hormones for economic purposes goes beyond reproduction in captivity. Sex manipulation is a technique largely used in species where one gender is superior in production. In the current talk, the main hormones controlling gonadal development and maturation will be presented, as well as their activities, functions and singularities, aiming at extending the knowledge from physiology to technology, at the intersection between applied and basic science.
Assuntos
Animais , Aquicultura/métodos , Biotecnologia/tendências , Comportamento Reprodutivo , Endocrinologia/métodos , Elementos de Resposta/genéticaRESUMO
Transforming growth factor ß1 (TGF-ß1) is a pleiotropic cytokine that modulates cell homeostasis. In Leydig cells, TGF-ß1 exerts stimulatory and inhibitory effect depending on the type I receptor involved in the signaling pathway. The aim of the present work was to study the signaling mechanisms and the intermediates involved in the action of TGF-ß1 on TM3 Leydig cell proliferation in the presence or absence of progesterone. The MTT assay showed that the presence of progesterone in the culture media lead to a proliferative effect that was blocked by Ru 486, an inhibitor of progesterone receptor; and ALK-5 did not participate in this effect. TGF-ß1 (1 ng/ml) increased the expression of p15 (an inhibitor of cell cycle) in TM3 Leydig cells, and this effect was blocked by progesterone (1µM). The expression of PCNA presented a higher increase in the cell cultured with TGF-ß1 plus progesterone than in cells cultured only with TGF-ß1. Progesterone induced the gene expression of endoglin, a cofactor of TGF-ß1 receptor that leads to a stimulatory signaling pathway, despite of the absence of progesterone response element in endoglin gene. In addition, the presence of progesterone induced the gene expression of egr-1 and also KLF14, indicating that this steroid channels the signaling pathway into a non-canonical mechanism. In conclusion, these findings suggest that the proliferative action of TGF-ß1 involves endoglin. This co-receptor might be induced by KLF14 which is probably activated by progesterone.
Assuntos
Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Células Intersticiais do Testículo/citologia , Células Intersticiais do Testículo/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Receptores de Ativinas Tipo I/genética , Receptores de Ativinas Tipo I/metabolismo , Receptores de Activinas Tipo II , Animais , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p15/metabolismo , DNA Complementar/genética , Endoglina , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Progesterona/farmacologia , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptor do Fator de Crescimento Transformador beta Tipo I , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Elementos de Resposta/genética , Fatores de Transcrição/metabolismo , Fator de Crescimento Transformador beta1/genética , Fator de Crescimento Transformador beta1/farmacologiaRESUMO
BACKGROUND: In Virology Journal 2011, 8:535, Neto et al. described point mutations into Tax-responsive elements (TRE) of the LTR region of HTLV-1 isolates from asymptomatic carriers from Sao Paulo, Brazil, and hypothesized that the presence of the G232A mutation in the TRE-1 increase viral proliferation and consequently the proviral load (PvL), while the A184G mutation in the TRE-2 do not have such effect. FINDINGS: We performed the real-time PCR assay (pol) and sequenced LTR region of HTLV-1 isolates from 24 HIV/HTLV-1-coinfected patients without HTLV-1-associated diseases from the same geographic area. These sequences were classified as belonging to the transcontinental subgroup A of the Cosmopolitan subtype a. The frequency of G232A mutation (16/24, 66.7%) was high as much as 61.8% reported by Neto's in HTLV-1 asymptomatic carriers with high PvL. High frequency (13/24, 54.2%) of double mutations G232A and A184G was also detected in HIV/HTLV-1-coinfected patients. We did not quantify PvL, but comparative analyses of the cycle threshold (Ct) median values of the group of isolates presenting the mutated-types sequences (Ct 33.5, n = 16) versus the group of isolates with the wild-type sequences (Ct 32, n = 8) showed no statistical difference (p = 0.4220). CONCLUSION: The frequencies of mutated-type sequences in the TRE-1 and TRE-2 motifs were high in HIV/HTLV-1-coinfected patients from Sao Paulo, Brazil. If these LTR point mutations have predictive value for the development of HTLV-1-associated diseases or they correspond to the subtype of virus that circulate in this geographic area has to be determined.