RESUMO
The transcription factor Nrf2 plays a crucial role in the anti-oxidative stress response, protection of DNA from injury and DNA repair mechanisms. Nrf2 activity reduces cancer initiation, but how Nrf2 affects whole-genome alterations upon carcinogenic stimulus remains unexplored. Although recent genome-wide analysis using next-generation sequencing revealed landscapes of nucleotide mutations and copy number alterations in various human cancers, genomic changes in murine cancer models have not been thoroughly examined. We elucidated the relationship between Nrf2 expression levels and whole exon mutation patterns using an ethyl-carbamate (urethane)-induced lung carcinogenesis model employing Nrf2-deficient and Keap1-kd mice, the latter of which express high levels of Nrf2. Exome analysis demonstrated that single nucleotide and trinucleotide mutation patterns and the Kras mutational signature differed significantly and were dependent on the expression level of Nrf2. The Nrf2-deficient tumors exhibited fewer copy number alterations relative to the Nrf2-wt and Keap1-kd tumors. The observed trend in genomic alterations likely prevented the Nrf2-deficient tumors from progressing into malignancy. For the first time, we present whole-exome sequencing results for chemically-induced lung tumors in the Nrf2 gain or loss of function mouse models. Our results demonstrate that different Nrf2 expression levels lead to distinct gene mutation patterns that underly different oncogenic mechanisms in each tumor genotype.
Assuntos
Neoplasias Pulmonares , Fator 2 Relacionado a NF-E2 , Animais , Carcinogênese/induzido quimicamente , Carcinogênese/genética , Modelos Animais de Doenças , Genômica , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Camundongos , Mutação , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Nucleotídeos/efeitos adversos , Nucleotídeos/metabolismo , UretanaRESUMO
Double asymmetric hydrogenation of linear ß,ß-disubstituted α,ß-unsaturated ketones catalyzed by the DM-SEGPHOS/DMAPEN/RuII complex with t-C4 H9 OK afforded the γ-substituted secondary alcohols in high diastereo- and enantioselectivities. Some mechanistic experiments suggested that two different reactive species, typeâ (I) and (II), were reversibly formed in this catalytic system: Typeâ (I) with the diamine ligand DMAPEN enantioselectively hydrogenated the enones into the chiral allylic alcohols, and typeâ (II) without the diamine ligand diastereoselectively hydrogenated the allylic alcohols into the γ-substituted secondary alcohols. This dual catalysis protocol was successfully applied to the reaction of a variety of aliphatic- and aromatic-substituted enone substrates.
RESUMO
Mucinous gastric carcinoma (MGC) is a unique subtype of gastric cancer with a poor survival outcome. Comprehensive molecular profiles and putative therapeutic targets of MGC remain undetermined. We subjected 16 tumour-normal tissue pairs to whole-exome sequencing (WES) and an expanded set of 52 tumour-normal tissue pairs to subsequent targeted sequencing. The latter focused on 114 genes identified by WES. Twenty-two histologically differentiated MGCs (D-MGCs) and 46 undifferentiated MGCs (U-MGCs) were analysed. Chromatin modifier genes, including ARID1A (21%), MLL2 (19%), MLL3 (15%), and KDM6A (7%), were frequently mutated (47%) in MGC. We also identified mutations in potential therapeutic target genes, including MTOR (9%), BRCA2 (9%), BRCA1 (7%), and ERBB3 (6%). RHOA mutation was detected only in 4% of U-MGCs and in no D-MGCs. MYH9 was recurrently (13%) mutated in MGC, with all these being of the U-MGC subtype (p = 0.023). Three U-MGCs harboured MYH9 nonsense mutations. MYH9 knockdown enhanced cell migration and induced intracytoplasmic mucin and cellular elongation. BCOR mutation was associated with improved survival. In U-MGCs, the MLH1 expression status and combined mutation status (TP53/BCL11B or TP53/MLL2) were prognostic factors. A comparative analysis of driver genes revealed that the mutation profile of D-MGC was similar to that of intestinal-type gastric cancer, whereas U-MGC was a distinct entity, harbouring a different mutational profile to intestinal- and diffuse-type gastric cancers. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Assuntos
Adenocarcinoma Mucinoso/genética , Mutação , Neoplasias Gástricas/genética , Adenocarcinoma Mucinoso/patologia , Idoso , Idoso de 80 Anos ou mais , Análise Mutacional de DNA , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/patologiaRESUMO
Nuclear factor erythroid 2-related factor 2 (Nrf2) is a key regulator that activates many antioxidant enzymes. Oxidative stress, which accumulates in diseased lungs associated with pulmonary hypertension (PH), is thought to be responsible for the progression of cardiopulmonary changes. To test whether Nrf2 activation would exert therapeutic efficacy against cardiopulmonary changes in a hypoxia-induced PH model, wild-type (WT) and Nrf2-deficient mice as well as Kelch-like ECH associating protein 1 (Keap1) (negative regulator of Nrf2) knockdown mutant mice were exposed to hypobaric hypoxia for 3 weeks. This chronic hypoxia exacerbated right ventricular systolic pressure, right ventricular hypertrophy (RVH), and pulmonary vascular remodeling in the WT mice. These pathological changes were associated with aberrant accumulation of Tenascin-C, a disease-indicative extracellular glycoprotein. Simultaneous administration of oltipraz, a potent Nrf2 activator, significantly attenuated RVH and pulmonary vascular remodeling and concomitantly ameliorated Tenascin-C accumulation in the hypoxic mice. Hypoxia-exposed Nrf2-deficient mice developed more pronounced RVH than WT mice, whereas hypoxia-exposed Keap1-knockdown mice showed less RVH and pulmonary vascular remodeling than WT mice, underscoring the beneficial potency of Nrf2 activity against PH. We also demonstrated that expression of the Nrf2-regulated antioxidant enzymes was decreased in a patient with chronic obstructive pulmonary disease associated with PH. The decreased antioxidant enzymes may underlie the pathogenesis of cardiopulmonary changes in the patient with chronic obstructive pulmonary disease and PH. The pharmacologically or genetically induced Nrf2 activity clearly decreased RVH and pulmonary vascular remodeling in the hypoxic PH model. The efficacy of oltipraz highlights a promising therapeutic potency of Nrf2 activators for the prevention of PH in patients with hypoxemic lung disease.
Assuntos
Anticarcinógenos/farmacologia , Hipertensão Pulmonar/tratamento farmacológico , Hipertrofia Ventricular Direita/tratamento farmacológico , Hipóxia/tratamento farmacológico , Fator 2 Relacionado a NF-E2/metabolismo , Pirazinas/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Modelos Animais de Doenças , Humanos , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/genética , Hipertensão Pulmonar/metabolismo , Hipertensão Pulmonar/patologia , Hipertrofia Ventricular Direita/etiologia , Hipertrofia Ventricular Direita/genética , Hipertrofia Ventricular Direita/metabolismo , Hipertrofia Ventricular Direita/patologia , Hipóxia/complicações , Hipóxia/genética , Hipóxia/metabolismo , Hipóxia/patologia , Proteína 1 Associada a ECH Semelhante a Kelch , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Doença Pulmonar Obstrutiva Crônica/tratamento farmacológico , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/metabolismo , Doença Pulmonar Obstrutiva Crônica/patologia , Tenascina/metabolismo , Tionas , TiofenosRESUMO
A comprehensive immunohistochemistry with the isoform-distinguishable antibodies against prostaglandin (PG) F2α and PGE2 biosynthetic enzymes was undertaken to identify the cellular types and enzyme isoforms in rat ovary and uterus around parturition. In general ovarian and uterine cells showed positive immunoreactions for phospholipase A2 groups 4A and 6A, but not group 2A, and cyclooxygenase (COX)-1 rather than COX-2. Their immunoreactions for PGF2α synthase and PGE2 synthase were cell type-dependently variable. The putative PGF2α and PGE2 producing cell types included, as expected, ovarian luteal cells, uterine endometrial epithelium and myometrium, and cervical connective tissue and, unexpectedly, ovarian stromal cells and basal lamina of cervical endometrium. Obtained data indicate the generation of PGF2α and PGE2 by multiple sites, which are entirely the same as established sites of actions, in parturition processes and tissue-dependent differential usage of PG biosynthetic pathway.
Assuntos
Dinoprosta/biossíntese , Dinoprostona/biossíntese , Ovário/enzimologia , Ovário/fisiologia , Parto , Útero/enzimologia , Útero/fisiologia , Animais , Feminino , Imuno-Histoquímica , RatosRESUMO
OBJECTIVE: This observational retrospective cohort study investigates the effect of antihypertensive therapy with angiotensin II receptor blockers (ARBs) or dihydropyridine calcium channel blockers (dCCBs) monotherapy on renal function using longitudinal real-world health data of a drug-naive, hypertensive population without kidney disease. METHODS: Using propensity score matching, we selected untreated hypertensive participants ( n â=â10â151) and dCCB ( n â=â5078) or ARB ( n â=â5073) new-users based on annual health check-ups and claims between 2008 and 2020. Participants were divided by the first prescribed drug. RESULTS: The mean age was 51âyears, 79% were men and the mean estimated glomerular filtration rate (eGFR) was 78âml/min per 1.73âm 2 . Blood pressure rapidly decreased by approximately 10% in both treatment groups. At the 1-year visit, eGFR levels decreased in the ARB group by nearly 2% but increased in the dCCB group by less than 1%. However, no significant difference was apparent in the annual eGFR change after the 1-year visit. The risk for composite kidney outcome (new-onset proteinuria or eGFR decline ≥30%) was lowest in the ARB group owing to their robust effect on preventing proteinuria: hazard ratio (95% confidence interval) for proteinuria was 0.91 (0.78-1.05) for the dCCB group and 0.54 (0.44-0.65) for the ARB group, compared with that for the untreated group after ending follow-up at the last visit before changing antihypertensive treatment. CONCLUSION: From the present findings based on the real-world data, ARBs can be recommended for kidney protection even in a primary care setting. Meanwhile, dCCB treatment initially increases eGFR with no adverse effects on proteinuria.
Assuntos
Antagonistas de Receptores de Angiotensina , Hipertensão , Antagonistas de Receptores de Angiotensina/efeitos adversos , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/farmacologia , Anti-Hipertensivos/uso terapêutico , Bloqueadores dos Canais de Cálcio/uso terapêutico , Feminino , Humanos , Rim , Masculino , Pessoa de Meia-Idade , Proteinúria/tratamento farmacológico , Estudos RetrospectivosRESUMO
We determined a comprehensive immunohistochemistry of putative isoforms of enzymes for prostaglandin (PG) F2α and PGE2 biosynthesis and these PGs levels in placenta and fetal membrane of normal pregnant rats in vivo. Placenta and fetal membrane showed positive immunoreactions for phospholipase A2 group 4A, but not group 2A, and cyclooxygenase (COX)-1 rather than COX-2. They showed positive immunoreactions for at least one isoform of each of PGF synthase and PGE synthase with tissue-dependent variations. PGF2α and PGE2 levels in both tissues were highest on day 12 and declined and remained low thereafter. Obtained data would be the basic information on the primary PGs synthesis in rat placenta and fetal membrane in normal pregnancy.
Assuntos
Dinoprosta , Prostaglandinas F , Animais , Ciclo-Oxigenase 2 , Membranas Extraembrionárias , Feminino , Imuno-Histoquímica , Placenta , Gravidez , Prostaglandinas , RatosRESUMO
BACKGROUND: Miliary pulmonary metastasis characterized by tiny nodules is a rare metastatic pattern in advanced non-small cell lung cancer (NSCLC) and is usually seen in patients harboring an EGFR mutation, and amylase-producing lung cancer is highly uncommon and rarely reported in NSCLC patients who have an EGFR mutation. CASE: A 32-year-old Japanese female was found to have miliary pulmonary nodules throughout both lung fields on a chest x-ray examination during an annual health check-up. Further examination by computed tomography (CT) revealed diffuse, bilateral, miliary nodules. Blood tests showed no increased tumor marker levels, but there was a significantly increased serum amylase level. A diagnosis of ALK-rearranged adenocarcinoma was made based on the results of a mediastinal lymph node biopsy obtained by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Treatment with alectinib resulted in rapid regression of the CT shadows and a reduction in the patient's serum amylase level. CONCLUSION: We have reported a case of ALK-rearranged NSCLC with a miliary pulmonary metastasis pattern that was sensitive to alectinib and in which the serum amylase level decreased in response to treatment with alectinib. Young patients with miliary pulmonary metastasis should be checked for all driver mutations.
RESUMO
The Nrf2 transcription factor is crucial for regulating the cellular defense against various carcinogens. However, relationship between host Nrf2 and cancer metastasis remains unexplored. To address this issue, we examined susceptibility of Nrf2-deficient mice to pulmonary cancer metastasis following implantation of the mouse Lewis lung carcinoma (3LL) cell line. Nrf2-deficient mice reproducibly exhibited a higher number of pulmonary metastatic nodules than wild-type mice did. The lung and bone marrow (BM) of cancer-bearing Nrf2-deficient mice contained increased numbers of inflammatory cells, including myeloid-derived suppressor cells (MDSCs), a potent population of immunosuppressive cells. MDSCs can attenuate CD8(+) T-cell immunity through modification of the T-cell receptor complex exploiting reactive oxygen species (ROS). MDSCs of Nrf2-deficient mice retained elevated levels of ROS relative to wild-type mice. BM transplantation experiments revealed functional disturbance in the hematopoietic and immune systems of Nrf2-deficient mice. Wild-type recipient mice with Nrf2-deficient BM cells showed increased levels of lung metastasis after cancer cell inoculation. These mice exhibited high-level accumulation of ROS in MDSCs, which showed very good coincidence to the decrease of splenic CD8(+) T-cells. In contrast, Keap1-knockdown mutant mice harboring high-level Nrf2 expression displayed increased resistance against the cancer cell metastasis to the lung, accompanied by a decrease in ROS in the MDSCs fraction. Our results thus reveal a novel function for Nrf2 in the prevention of cancer metastasis, presumably by its ability to preserve the redox balance in the hematopoietic and immune systems.
Assuntos
Neoplasias Pulmonares/secundário , Fator 2 Relacionado a NF-E2/fisiologia , Animais , Linhagem Celular Tumoral , Proliferação de Células , Sistema Hematopoético/citologia , Sistema Hematopoético/metabolismo , Sistema Imunitário/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/deficiência , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismoRESUMO
There are many reports of olfactory impairment in patients with Parkinson's disease (PD) and the impairment can be observed before the appearance of typical PD symptom. Accordingly, olfactory screening tests may predict disease onset and indicates a need for early treatment before classic signs of the disease. Olfaction is dependent on inspiration, and activation of olfactory limbic areas are synchronized with the natural breathing cycle in animals and humans. Subconscious changes in respiratory pattern occur in response to odor stimulation. The use of olfactory stimuli to investigate respiratory pattern could be used to assess olfactory perception and serve as an index for olfactory limbic activation. In this study, we tested olfactory acuity in normal subjects and in patients with PD and recorded V(O2) and respiratory variables during pleasant and unpleasant odor presentation. All subjects were able to detect the odorants; however patients with PD were assigned to one of two groups, group that could recognize odors or the group with impaired odor recognition. Respiratory response toward unpleasant and pleasant odor recognition were weak in PD groups who could recognize odors than normal subject as well as emotional response to odor stimuli. PD group with impaired odor recognition showed no respiratory response toward odor stimuli. PD may experience difficulty in feeling positive emotions toward pleasant odors prior to the unpleasant odor because respiratory responses to pleasant odors may also be related to higher processes including intentional control of breathing pattern as a result of olfactory cortex processing and perceptions or emotions.
Assuntos
Transtornos do Olfato/complicações , Doença de Parkinson/fisiopatologia , Ventilação Pulmonar/fisiologia , Mecânica Respiratória/fisiologia , Olfato/fisiologia , Idoso , Análise de Variância , Estudos de Casos e Controles , Feminino , Humanos , Sistema Límbico/fisiologia , Sistema Límbico/fisiopatologia , Masculino , Pessoa de Meia-Idade , Odorantes , Transtornos do Olfato/diagnóstico , Doença de Parkinson/complicações , Reconhecimento Psicológico/fisiologia , Valores de Referência , Estatísticas não ParamétricasRESUMO
We report a case of syndrome of inappropriate secretion of anti-diuretic hormone (SIADH) associated with limbic encephalitis. A 79-year-old woman was admitted with a complaint of fever, disturbance of consciousness and generalized seizure. Her conscious level was E1V2M4 by Glasgow coma scale. Physical examination showed generalized seizure, neck stiffness, hyperreflexia and flaccid paralysis in her all extremities, and pathological reflexes. Blood analysis revealed hyponatremia, decrease of plasma osmolarity, spared secretion of urine sodium and increase of ADH, leading to the diagnosis of SIADH. Cerebrosponal fluid examination showed mild pleocytosis, elevated protein, and normal glucose level. Although herpes simplex virus (HSV) DNA was not detected by the polymerase chain reaction method, titers of anti-HSV IgG antibody elevated chronologically. Brain MRI revealed abnormal T2 and FLAIR high intensities in the cingulate gyrus and hippocampus bilaterally. An EEG revealed periodic synchronous discharges predominantly in the frontal areas. Based on the clinical course, laboratory data, MRI and EEG findings, we diagnosed as SIADH associated with acute limbic encephalitis caused by HSV infection. After the fluid restriction and sodium supply, plasma sodium was normalized. Administration of acyclovir and steroid was not so effective, however her condition improved gradually. Several cases of SIADH associated with limbic encephalitis have been reported; however, the pathophysiology is to be clarified. We thought that in the presented case, SIADH was caused by disturbance of the hormonal control at the hypothalamus on the pituitary gland due to the spreading of inflammation from limbic system to these areas.
Assuntos
Encefalite por Herpes Simples/complicações , Síndrome de Secreção Inadequada de HAD/etiologia , Encefalite Límbica/complicações , Doença Aguda , Idoso , Eletroencefalografia , Feminino , Humanos , Síndrome de Secreção Inadequada de HAD/diagnóstico , Síndrome de Secreção Inadequada de HAD/terapia , Encefalite Límbica/terapia , Imageamento por Ressonância Magnética , Resultado do TratamentoRESUMO
Though Fas/Fas ligand (FasL) system-dependent apoptosis is considered to be the primary form of cell death in regressing corpus luteum (CL), the cellular identity and regulation of expression of the ligand and receptor molecules are not fully understood. Here, we focused on immunohistochemical determination of Fas expression during natural regression with comparison of three different types of rat CLs. Detected Fas was in good spatial association with cleaved caspase-3 and FasL proteins and with macrophages and neutrophils. In CLs of the cycle and pseudopregnancy, Fas-positive cell types included large and small luteal (steroidogenic) cells and capillary endothelial cells mainly, and blood-derived immune cells occasionally. Fas signals were abundant at multiple focal inflammatory-like sites. In contrast, Fas signals in CL of pregnancy did not localize in steroidogenic cells, but almost exclusively in endothelial cells and granulocytes. The signals scattered evenly throughout the CL tissue as phagocytes also did. In all CLs types, the numbers of Fas-expressing cells increased transiently after functional inactivation and at the early phase of structural regression. This observation revealed spatio-temporally regulated expression of Fas that was highly associated with apoptotic and phagocytotic systems and type-dependent differences in Fas expression and phagocytes dynamics in naturally regressing CL of rats.
Assuntos
Corpo Lúteo/citologia , Proteína Ligante Fas/metabolismo , Luteólise/fisiologia , Fagócitos/citologia , Animais , Caspase 3/metabolismo , Corpo Lúteo/metabolismo , Proteína Ligante Fas/genética , Feminino , Regulação da Expressão Gênica , Macrófagos/metabolismo , Neutrófilos/metabolismo , Fagócitos/metabolismo , Gravidez , Pseudogravidez/veterinária , RatosRESUMO
Nrf2 activation promotes resistance to chemical carcinogenesis in animal models, but activating mutations in Nrf2 also confer malignant characters to human cells by activating antioxidative/detoxifying enzymes and metabolic reprogramming. In this study, we examined how these contradictory activities of Nrf2, cancer chemoprevention and cancer cell growth enhancement, can be reconciled in an established mouse model of urethane-induced lung carcinogenesis. Using Keap1-knockdown (kd) mice, which express high levels of Nrf2, we found that urethane was rapidly excreted into the urine, consistent with an upregulation in the expression of urethane detoxification genes. Consequently, urethane-induced tumors were significantly smaller and less frequent in Keap1-kd mice than in wild-type mice. In contrast, tumor cells derived from Keap1-kd mice and transplanted into nude mice exhibited higher tumorigenicity compared with cells derived from wild-type mice. To identify the factors contributing to the tumor growth phenotype in the transplantation model, we performed a microarray analysis and found that many antioxidative stress genes were upregulated in the Keap1-kd-derived tumors. Therefore, we suggest that Nrf2 activation in cancer cells enhances their tumorigenicity, but global Nrf2 activation, as in Keap1-kd mice, simultaneously enhances anticancer immunity, thereby suppressing the growth potential of Keap1-kd tumors. Our findings provide relevant insight into the dual role of Nrf2 in cancer and warrant further studies of Nrf2 function during different stages of carcinogenesis. Cancer Res; 76(10); 3088-96. ©2016 AACR.
Assuntos
Transformação Celular Neoplásica/patologia , Neoplasias Pulmonares/patologia , Mutação/genética , Fator 2 Relacionado a NF-E2/fisiologia , Microambiente Tumoral , Animais , Transformação Celular Neoplásica/efeitos dos fármacos , Transformação Celular Neoplásica/metabolismo , Perfilação da Expressão Gênica , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/genética , Masculino , Camundongos , Camundongos Endogâmicos ICR , Camundongos Knockout , Camundongos Nus , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas , Uretana/toxicidadeRESUMO
GATA1 is a key transcription factor for erythropoiesis. GATA1 gene expression is strictly regulated at the transcriptional level. While the regulatory mechanisms governing mouse Gata1 (mGata1) gene expression have been studied extensively, how expression of the human GATA1 (hGATA1) gene is regulated remains to be elucidated. To address this issue, we generated hGATA1 bacterial artificial chromosome (BAC) transgenic mouse lines harboring a 183-kb hGATA1 locus covering the hGATA1 exons and distal flanking sequences. Transgenic hGATA1 expression coincides with endogenous mGata1 expression and fully rescues hematopoietic deficiency in mGata1 knockdown mice. The transgene exhibited copy number-dependent and integration position-independent expression of hGATA1, indicating the presence of chromatin insulator activity within the transgene. We found a novel insulator element at 29 kb 5' to the hGATA1 gene and refer to this element as the 5' CCCTC-binding factor (CTCF) site. Substitution mutation of the 5' CTCF site in the hGATA1 BAC disrupted the chromatin architecture and led to a reduction of hGATA1 expression in splenic erythroblasts under conditions of stress erythropoiesis. Our results demonstrate that expression of the hGATA1 gene is regulated through the chromatin architecture organized by 5' CTCF site-mediated intrachromosomal interactions in the hGATA1 locus.
Assuntos
Cromossomos/genética , Eritroblastos/metabolismo , Fator de Transcrição GATA1/genética , Elementos Isolantes , Baço/citologia , Animais , Sítios de Ligação , Fator de Ligação a CCCTC , Células Cultivadas , Cromatina/fisiologia , Cromossomos Artificiais Bacterianos/genética , Fator de Transcrição GATA1/química , Fator de Transcrição GATA1/metabolismo , Vetores Genéticos/genética , Humanos , Células K562 , Camundongos , Camundongos Transgênicos , Proteínas Repressoras/metabolismo , Baço/metabolismoRESUMO
Oxidative stress accelerates the pathogenesis of a number of chronic diseases including cancer growth and its metastasis. Transcription factor NF-E2-related factor-2 (Nrf2), which regulates the cellular defense system against oxidative stress, elicits essential protection against chemical-induced carcinogenic insults. We recently demonstrate that the systemic deletion of Nrf2 leads to an increased susceptibility to cancer metastasis, which is associated with aberrant reactive oxygen species (ROS) accumulation in myeloid-derived suppressor cells (MDSC). However, it remains elusive whether cellular antioxidant defense system in the myeloid lineage cells plays indispensable roles for metastatic cancer progression. We herein found that myeloid lineage-specific Nrf2-deficient mice exhibited an increased susceptibility to pulmonary metastasis of the mouse Lewis lung carcinoma cells, and ROS level was more highly elevated in MDSCs of cancer-bearing Nrf2-deficient mice. Similarly, myeloid lineage-specific deletion of selenocysteine-tRNA gene (Trsp), which is essential for synthesis of antioxidant selenoenzymes, resulted in increased number of metastatic nodules along with ROS accumulation in MDSCs of cancer-bearing mice. These results thus indicate that the antioxidant systems directed by Nrf2 and selenoenzymes contribute to the clearance of ROS in MDSCs, efficiently preventing cancer cell metastasis. Consistent with this notion, a synthetic triterpenoid 1-[2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oyl] imidazole (CDDO-Im), a potent Nrf2 inducer, attenuated the ROS production in MDSCs, and thereafter reduced metastatic nodules. Taken together, this study provides compelling lines of evidence that Nrf2 inducer retains therapeutic efficacy against cancer cell metastasis.
Assuntos
Antioxidantes/metabolismo , Células Mieloides/citologia , Metástase Neoplásica , Neoplasias/metabolismo , Estresse Oxidativo , Animais , Linhagem Celular Tumoral , Linhagem da Célula , Deleção de Genes , Imidazóis/química , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Transplante de Neoplasias , Neoplasias/patologia , RNA de Transferência Aminoácido-Específico/genética , RNA de Transferência Aminoácido-Específico/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Although previous studies have shown that GATA1 is required for mast cell differentiation, the effects of the complete ablation of GATA1 in mast cells have not been examined. Using conditional Gata1 knockout mice (Gata1(-/y)), we demonstrate here that the complete ablation of GATA1 has a minimal effect on the number and distribution of peripheral tissue mast cells in adult mice. The Gata1(-/y) bone marrow cells were capable of differentiating into mast cells ex vivo. Microarray analyses showed that the repression of GATA1 in bone marrow mast cells (BMMCs) has a small impact on the mast cell-specific gene expression in most cases. Interestingly, however, the expression levels of mast cell tryptases in the mouse chromosome 17A3.3 were uniformly reduced in the GATA1 knockdown cells, and GATA1 was found to bind to a 500-bp region at the 5' end of this locus. Revealing a sharp contrast to that observed in the Gata1-null BMMCs, GATA2 deficiency resulted in a significant loss of the c-Kit(+) FcεRIα(+) mast cell fraction and a reduced expression of several mast cell-specific genes. Collectively, GATA2 plays a more important role than GATA1 in the regulation of most mast cell-specific genes, while GATA1 might play specific roles in mast cell functions.
Assuntos
Diferenciação Celular , Fator de Transcrição GATA1/fisiologia , Fator de Transcrição GATA2/fisiologia , Mastócitos/fisiologia , Animais , Sequência de Bases , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Células Cultivadas , Cromossomos de Mamíferos , Meios de Cultura , Regulação Enzimológica da Expressão Gênica , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Dados de Sequência Molecular , Transcriptoma , Triptases/genética , Triptases/metabolismoRESUMO
The transcription factor GATA2 plays pivotal roles in early renal development, but its distribution and physiological functions in adult kidney are largely unknown. We examined the GATA2 expression pattern in the adult kidney by tracing green fluorescent protein (GFP) fluorescence in Gata2(GFP/+) mice that recapitulate endogenous GATA2 expression and found a robust GFP expression specifically in the renal medulla. Upon purification of the GFP-positive cells, we found that collecting duct (CD)-specific markers, including aquaporin 2 (Aqp2), an important channel for water reabsorption from urine, were abundantly expressed. To address the physiological function of GATA2 in the CD cells, we generated renal tubular cell-specific Gata2-deficient mice (Gata2-CKO) by crossing Gata2 floxed mice with inducible Pax8-Cre mice. We found that the Gata2-CKO mice showed a significant decrease in Aqp2 expression. The Gata2-CKO mice exhibited high 24-h urine volume and low urine osmolality, two important signs of diabetes insipidus. We introduced biotin-tagged GATA2 into a mouse CD-derived cell line and conducted chromatin pulldown assays, which revealed direct GATA2 binding to conserved GATA motifs in the Aqp2 promoter region. A luciferase reporter assay using an Aqp2 promoter-reporter showed that GATA2 trans activates Aqp2 through the GATA motifs. These results demonstrate that GATA2 regulates the Aqp2 gene expression in CD cells and contributes to the maintenance of the body water homeostasis.
Assuntos
Aquaporina 2/genética , Água Corporal/metabolismo , Fator de Transcrição GATA2/fisiologia , Regulação da Expressão Gênica , Medula Renal/metabolismo , Túbulos Renais Coletores/metabolismo , Animais , Linhagem Celular , Fator de Transcrição GATA2/genética , Fator de Transcrição GATA3/metabolismo , Proteínas de Fluorescência Verde/biossíntese , Homeostase/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Concentração Osmolar , Regiões Promotoras Genéticas , Urina/fisiologiaRESUMO
Nrf2 (Nfe2l2) governs cellular defenses against oxidative and electrophilic stresses and protects against chemical carcinogenesis. However, many cancers have been found to accumulate NRF2 protein, raising questions of precisely how Nrf2 contributes to carcinogenesis. In this report, we explored such questions in an established urethane-induced multistep model of lung carcinogenesis. Consistent with earlier observations, Nrf2-deficient (Nrf2(-/-)) mice exhibited a relative increase in tumor foci by 8 weeks after urethane administration. However, after 16 weeks, we observed a relative reduction in the number of tumors with more malignant characteristics in Nrf2(-/-) mice. Furthermore, all Nrf2(+/+) tumors harbored activated mutations in Kras, whereas Nrf2(-/-) tumors were rarely associated with similar Kras mutations. Overall, our results established that Nrf2 has two roles during carcinogenesis, one of which is preventive during tumor initiation and the second that promotes malignant progression. These findings establish Nrf2 inhibitors as rational tools to prevent malignant progression in lung cancer, whereas Nrf2 activators are more suited for lung cancer prevention.
Assuntos
Adenocarcinoma/metabolismo , Transformação Celular Neoplásica/metabolismo , Neoplasias Pulmonares/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Adenocarcinoma/induzido quimicamente , Adenocarcinoma/imunologia , Adenocarcinoma/patologia , Animais , Sequência de Bases , Citocromo P-450 CYP2E1/genética , Citocromo P-450 CYP2E1/metabolismo , Análise Mutacional de DNA , Pulmão/enzimologia , Pulmão/patologia , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos ICR , Camundongos Knockout , Camundongos Nus , Mutação , Células Mieloides/imunologia , Fator 2 Relacionado a NF-E2/genética , Transplante de Neoplasias , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Proto-Oncogênicas p21(ras)/genética , Transdução de Sinais , Ativação Transcricional , Transcriptoma , Carga Tumoral , Evasão Tumoral , UretanaRESUMO
Enantioselective hydrogenation of alkynyl ketones catalyzed by Ru(OTf)(TsDPEN)(η(6)-p-cymene) (TsDPEN = N-(p-toluenesulfonyl)-1,2-diphenylethylenediamine) affords the propargylic alcohols in up to 97% ee. The alkynyl moieties are left intact in most cases. The reaction can be conducted with a substrate-to-catalyst molar ratio as high as 5000 under 10 atm of H2. The mode of enantioselection is elucidated with the transition state models directed by the CH/π attractive interaction between the substrate and the catalytic species.
RESUMO
NF-E2 is a heterodimeric transcription factor consisting of p45 and small Maf subunits. Since p45(-/-) mice display severe thrombocytopenia, p45 is recognized as a critical regulator of platelet production from megakaryocytes. To identify direct p45 target genes in megakaryocytes, we used chromatin immunoprecipitation (ChIP) sequencing to analyze the genome-wide chromatin occupancy of p45 in primary megakaryocytes. p45 target gene candidates obtained from the analysis are implicated in the production and function of platelets. Two of these genes, Selp and Myl9, were verified as direct p45 targets through multiple approaches. Since P-selectin, encoded by Selp, plays a critical role in platelet function during thrombogenesis, we tested whether p45 determines the intrinsic reactivity and potency of platelets generated from megakaryocytes. Mice expressing a hypomorphic p45 mutant instead of wild-type p45 in megakaryocytes (p45(-/-):ΔNTD-Tg mice) displayed platelet hypofunction accompanied by mild thrombocytopenia. Furthermore, lung metastasis of melanoma cells, which requires platelet activation, was repressed in p45(-/-):ΔNTD-Tg mice compared to control mice, validating the impaired function of platelets produced from p45(-/-):ΔNTD-Tg megakaryocytes. By activating genes in megakaryocytes that mediate platelet production and function, p45 determines the quantity and quality of platelets.