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1.
Anticancer Res ; 39(8): 4149-4164, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366500

RESUMO

BACKGROUND/AIM: Signaling regulation of myeloid zinc finger 1 (MZF1) has been implicated in the progression of many human malignancies; however, the mechanistic action of MZF1 in triple-negative breast cancer (TNBC) progression remains elusive. In this study, the aim was to investigate the molecular mechanisms of MZF1 and its functional role in TNBC cellular migration and invasion. MATERIALS AND METHODS: Hs578T and MDA-MB-231 cells were transfected to stably express the acidic domain of MZF1 (MZF160-72), or were transfected with MZF1-specific or ELK1-specific short hairpin RNA (shRNA). Changes in cell morphology and distributions of cellular proteins were observed and subsequently migration and invasion were measured by wound healing and transwell assays. Expression levels of epithelial-mesenchymal transition (EMT)-related genes were carried out using immunoblotting and quantitative reverse transcription-polymerase chain reaction (RT-PCR) assays. Data of transcriptional regulation were obtained from promoter-luciferase reporter and chromatin immunoprecipitation (ChIP) assays. RESULTS: Herein, we found that MZF1 in high-level MZF1-expressing TNBC cells is associated with cell migration, invasion, and mesenchymal phenotype. MZF1 interacted with the promoter region of insulin-like growth factor 1 receptor (IGF1R) to drive invasion and metastasis of high-level MZF1-expressing TNBC cells. Exogenous expression of the acidic domain of MZF1 repressed the binding of endogenous MZF1 to IGF1R promoter via blocking the interaction with ETS-like gene 1 (ELK1). This blockage not only caused MZF1 protein degradation, but also restrained ELK1 nuclear localization in high-level MZF1-expressing TNBC cells. MZF1, but not ELK1, was necessary for the retention of mesenchymal phenotype by repressing IGF1R promoter activity in TNBC cells expressing high levels of MZF1. Activation of the IGF1R-driven p38MAPK-ERα-slug-E-cadherin signaling axis mediated the conversion of mesenchymal cell to epithelial phenotype, caused by MZF1 destabilization. These results suggest that MZF1 is an oncogenic inducer. CONCLUSION: Blocking of the MZF1/ELK1 interaction to reduce MZF1 protein stability by saturating the endogenous MZF1/ELK1 binding domains might be a promising therapeutic strategy for the treatment of high-level MZF1-expressing TNBC.


Assuntos
Fatores de Transcrição Kruppel-Like/genética , Receptores de Somatomedina/genética , Neoplasias de Mama Triplo Negativas/genética , Proteínas Elk-1 do Domínio ets/genética , Caderinas/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proteínas de Ligação a DNA/genética , Transição Epitelial-Mesenquimal/genética , Receptor alfa de Estrogênio/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Regiões Promotoras Genéticas/genética , Domínios Proteicos/genética , Transdução de Sinais/genética , Neoplasias de Mama Triplo Negativas/patologia , Proteínas Quinases p38 Ativadas por Mitógeno/genética
2.
Life Sci ; 233: 116641, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31295469

RESUMO

Cardiomyocyte injury caused by excessive oxidative stress underlies the pathogenesis of myocardial infarction (MI), a devastating disease leading to heart failure and death. The Krüppel-like factor 9 (KLF9) is a transcriptional factor that has recently been reported to regulate oxidative stress, however, whether it is associated with cardiomyocyte injury and MI is unknown. We found that KLF9 was upregulated in the heart from a rat MI model. In addition, KLF9 was also upregulated in cardiomyocytes exposed to ischemia in vitro, suggesting that KLF9 responds to MI-relevant stimuli. Moreover, KLF9 knockdown protected cardiomyocytes against ischemic injury. Mechanistically, KLF9 knockdown reduced reactive oxygen species (ROS) generation in ischemic cardiomyocytes through upregulating the antioxidant thioredoxin reductase 2 (Txnrd2), and more important, Txnrd2 silencing abrogated KLF9 knockdown-mediated cardioprotection in ischemic cardiomyocytes. Altogether, these results suggest that KLF9 aggravates ischemic injury in cardiomyocytes through undermining Txnrd2-mediated ROS clearance, which might offer KLF9 as a possible target in alleviating MI.


Assuntos
Fatores de Transcrição Kruppel-Like/metabolismo , Traumatismo por Reperfusão Miocárdica/etiologia , Miócitos Cardíacos/patologia , Estresse Oxidativo , Tiorredoxina Redutase 2/metabolismo , Animais , Células Cultivadas , Fatores de Transcrição Kruppel-Like/genética , Masculino , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Tiorredoxina Redutase 2/genética , Regulação para Cima
3.
Toxicol Lett ; 314: 63-74, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31306741

RESUMO

This study aimed to verify the toxic effects of prenatal caffeine exposure (PCE) on the podocyte development in male offspring, and to explore the underlying intrauterine programming mechanisms. The pregnant rats were administered with caffeine (30 to 120 mg/kg⋅d) during gestational day (GD) 9 to 20. The male fetus on GD20 and the offspring at postnatal week (PW) 6 and PW28 were sacrificed. The results indicated that PCE caused ultrastructural abnormalities on podocyte, and inhibited the expression of podocyte marker genes such as Nephrin, Wilms tumor 1 (WT1), the histone 3 lysine 9 acetylation (H3K9ac) level in the Kruppel-like factor 4 (KLF4) promoter and its expression in the male offspring from GD20 to PW28. Meanwhile, the expression of glucocorticoid receptor (GR) and histone deacetylase 7 (HDAC7) in the fetus were increased by PCE. In vitro, corticosterone increased GR and HDAC7 whereas reduced the H3K9ac level of KLF4 and KLF4/Nephrin expression. KLF4 over-expression reversed the reduction of Nephrin expression, knockdown of HDAC7 and GR antagonist RU486 partially reversed the inhibitory effects of corticosterone on H3K9ac level and KLF4 expression. In conclusion, PCE caused podocyte developmental toxicity in male offspring, which was associated with corticosterone-induced low-functional programming of KLF4 through GR/HDAC7/H3K9ac pathway.


Assuntos
Cafeína/toxicidade , Estimulantes do Sistema Nervoso Central/toxicidade , Histonas/metabolismo , Nefropatias/induzido quimicamente , Fatores de Transcrição Kruppel-Like/metabolismo , Podócitos/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal , Acetilação , Animais , Células Cultivadas , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Idade Gestacional , Glucocorticoides/metabolismo , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Nefropatias/embriologia , Nefropatias/genética , Nefropatias/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Lisina , Masculino , Exposição Materna , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Fenótipo , Podócitos/metabolismo , Podócitos/ultraestrutura , Gravidez , Regiões Promotoras Genéticas , Ratos Wistar , Receptores de Glucocorticoides/genética , Receptores de Glucocorticoides/metabolismo , Transdução de Sinais/efeitos dos fármacos
4.
Biochimie ; 163: 152-162, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31199942

RESUMO

Extra-cellular signal regulated kinase-5 (Erk-5), a transcriptional activator and regulator of endothelial cells (ECs) homeostasis, has been implicated in shear stress-induced endothelial dysfunction (ED), however its role in oxidized low-density lipoprotein (oxLDL)- induced ED during metabolic stress is not known. Herein, regulation and function of Erk-5 in oxLDL-induced EC death, inflammation and dysfunction has been investigated. Primary Human Umbilical Vein Endothelial Cells (pHUVECs) were stimulated with oxLDL. MTT and Trypan blue exclusion assays to assess cell viability, RT-qPCR and Western blotting assays to determine expression of endothelial and inflammatory markers and ED mediators at mRNA and protein levels, respectively were performed. Monocyte adhesion assay was performed to examine monocytes adherence to oxLDL-stimulated pHUVECs. The exposure of oxLDL induced a dose- and time-dependent decrease in pHUVECs viability, which concurred with decreased Erk-5 expression. Further, oxLDL (100 µg/ml) decreased the expression of endothelial markers eNOS and vWF, and increased the expression of ICAM-1, at both mRNA and protein levels. SiRNA-mediated silencing of Erk-5 or its inhibition showed that changes in eNOS, vWF and ICAM-1 expression could be mediated through Erk-5. Furthermore, oxLDL decreased the levels of Erk-5's upstream regulator MEK5 and downstream regulators Mef2c and KLF2, which were similar to their expressions in Erk-5 silenced cells. Fisetin, a phytochemical and bioflavonoid, could reduce the effect of oxLDL in ECs by upregulating the expression of endothelial markers including Erk-5, and downregulating the expression of inflammation markers. These results suggest that Erk-5 could be a critical regulator of oxLDL-induced EC death, inflammation and dysfunction via downregulation of Erk-5/Mef2c-KLF2 signaling pathway, which can be ameliorated by a bioflavonoid, fisetin.


Assuntos
Flavonoides/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Lipoproteínas LDL/toxicidade , Proteína Quinase 7 Ativada por Mitógeno/metabolismo , Monócitos/fisiologia , Transdução de Sinais , Aterosclerose/induzido quimicamente , Aterosclerose/genética , Aterosclerose/metabolismo , Aterosclerose/prevenção & controle , Células Cultivadas , Regulação da Expressão Gênica , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Inflamação/induzido quimicamente , Inflamação/genética , Inflamação/metabolismo , Inflamação/prevenção & controle , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Lipoproteínas LDL/farmacologia , Fatores de Transcrição MEF2/genética , Fatores de Transcrição MEF2/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Substâncias Protetoras/farmacologia
5.
Nat Methods ; 16(7): 633-639, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31235883

RESUMO

Mammalian genomes are folded into tens of thousands of long-range looping interactions. The cause-and-effect relationship between looping and genome function is poorly understood, and the extent to which loops are dynamic on short time scales remains an unanswered question. Here, we engineer a new class of synthetic architectural proteins for directed rearrangement of the three-dimensional genome using blue light. We target our light-activated-dynamic-looping (LADL) system to two genomic anchors with CRISPR guide RNAs and induce their spatial colocalization via light-induced heterodimerization of cryptochrome 2 and a dCas9-CIBN fusion protein. We apply LADL to redirect a stretch enhancer (SE) away from its endogenous Klf4 target gene and to the Zfp462 promoter. Using single-molecule RNA-FISH, we demonstrate that de novo formation of the Zfp462-SE loop correlates with a modest increase in Zfp462 expression. LADL facilitates colocalization of genomic loci without exogenous chemical cofactors and will enable future efforts to engineer reversible and oscillatory loops on short time scales.


Assuntos
Regulação da Expressão Gênica , Engenharia de Proteínas , Animais , Proteínas de Transporte/genética , Células Cultivadas , Fatores de Transcrição Kruppel-Like/genética , Luz , Masculino , Camundongos , Proteínas do Tecido Nervoso/genética , Regiões Promotoras Genéticas , RNA Guia/genética
6.
BMC Genomics ; 20(1): 417, 2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31126231

RESUMO

BACKGROUND: Mutations in the transcription factor, KLF1, are common within certain populations of the world. Heterozygous missense mutations in KLF1 mostly lead to benign phenotypes, but a heterozygous mutation in a DNA-binding residue (E325K in human) results in severe Congenital Dyserythropoietic Anemia type IV (CDA IV); i.e. an autosomal-dominant disorder characterized by neonatal hemolysis. RESULTS: To investigate the biochemical and genetic mechanism of CDA IV, we generated murine erythroid cell lines that harbor tamoxifen-inducible (ER™) versions of wild type and mutant KLF1 on a Klf1-/- genetic background. Nuclear translocation of wild type KLF1 results in terminal erythroid differentiation, whereas mutant KLF1 results in hemolysis without differentiation. The E to K variant binds poorly to the canonical 9 bp recognition motif (NGG-GYG-KGG) genome-wide but binds at high affinity to a corrupted motif (NGG-GRG-KGG). We confirmed altered DNA-binding specificity by quantitative in vitro binding assays of recombinant zinc-finger domains. Our results are consistent with previously reported structural data of KLF-DNA interactions. We employed 4sU-RNA-seq to show that a corrupted transcriptome is a direct consequence of aberrant DNA binding. CONCLUSIONS: Since all KLF/SP family proteins bind DNA in an identical fashion, these results are likely to be generally applicable to mutations in all family members. Importantly, they explain how certain mutations in the DNA-binding domain of transcription factors can generate neomorphic functions that result in autosomal dominant disease.


Assuntos
Anemia Diseritropoética Congênita/genética , DNA/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Mutação Puntual , Animais , Linhagem Celular , DNA/química , Regulação da Expressão Gênica , Camundongos , Motivos de Nucleotídeos , Ligação Proteica , Transcrição Genética
7.
RNA ; 25(8): 905-920, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31088860

RESUMO

Altered splicing contributes to the pathogenesis of human blood disorders including myelodysplastic syndromes (MDS) and leukemias. Here we characterize the transcriptomic regulation of PRPF40B, which is a splicing factor mutated in a small fraction of MDS patients. We generated a full PRPF40B knockout (KO) in the K562 cell line by CRISPR/Cas9 technology and rescued its levels by transient overexpression of wild-type (WT), P383L or P540S MDS alleles. Using RNA sequencing, we identified hundreds of differentially expressed genes and alternative splicing (AS) events in the KO that are rescued by WT PRPF40B, with a majority also rescued by MDS alleles, pointing to mild effects of these mutations. Among the PRPF40B-regulated AS events, we found a net increase in exon inclusion in the KO, suggesting that this splicing factor primarily acts as a repressor. PRPF40B-regulated splicing events are likely cotranscriptional, affecting exons with A-rich downstream intronic motifs and weak splice sites especially for 5' splice sites, consistent with its PRP40 yeast ortholog being part of the U1 small nuclear ribonucleoprotein. Loss of PRPF40B in K562 induces a KLF1 transcriptional signature, with genes involved in iron metabolism and mainly hypoxia, including related pathways like cholesterol biosynthesis and Akt/MAPK signaling. A cancer database analysis revealed that PRPF40B is lowly expressed in acute myeloid leukemia, whereas its paralog PRPF40A expression is high as opposed to solid tumors. Furthermore, these factors negatively or positively correlated with hypoxia regulator HIF1A, respectively. Our data suggest a PRPF40B role in repressing hypoxia in myeloid cells, and that its low expression might contribute to leukemogenesis.


Assuntos
Processamento Alternativo , Proteínas de Transporte/genética , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes , Leucemia Mieloide Aguda/genética , Síndromes Mielodisplásicas/genética , Sistemas CRISPR-Cas , Hipóxia Celular , Regulação para Baixo , Regulação Neoplásica da Expressão Gênica , Técnicas de Inativação de Genes , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Células K562 , Fatores de Transcrição Kruppel-Like/genética , Mutação , Análise de Sequência de RNA/métodos
8.
Hum Genet ; 138(6): 649-659, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31041507

RESUMO

A linkage of dichorionic (DC) twin pregnancies with selective intrauterine growth restriction (IUGR) to alterations in placental gene expression is unclear. The aim of the study was to identify placental genes related to hypoxia, adipogenesis and human growth which may contribute to IUGR development. The study group (IUGR/AGA) comprised dichorionic (DC) twin pregnancies, where the weight of the twins differed by > 15%; in addition, one twin was small for gestational age (< 10th percentile-SGA) (IUGR) while the other was appropriate for gestational age (> 10th percentile-AGA). In the control group (AGA/AGA), both fetuses were AGA and their weights differed by < 15%. In the first step (selection), placental expression of 260 genes was analysed by commercial PCR profiler array or qPCR primer assay between six pairs of IUGR/AGA twins. In the second stage (verification), the expression of 20 genes with fold change (FC) > 1.5 selected from the first stage was investigated for 75 DC pregnancies: 23 IUGR/AGA vs. 52 AGA/AGA. The expression of Angiopoetin 2, Leptin and Kruppel-like factor 4 was significantly higher, and Glis Family Zinc Finger 3 was lower, in placentas of SGA fetuses (FC = 3.3; 4.4; 1.6; and - 1.8, respectively; p < 0.05). The dysregulation of gene expression related to angiogenesis and growth factors in placentas of twins born from IUGR/AGA pregnancies suggest that these alternations might represent biological fetal adaptation to the uteral condition. Moreover, DC twin pregnancies may be a good model to identify the differences in placental gene expression between SGA and AGA fetuses.


Assuntos
Retardo do Crescimento Fetal/genética , Perfilação da Expressão Gênica/métodos , Placenta/metabolismo , Gravidez de Gêmeos/genética , Feminino , Idade Gestacional , Humanos , Hipóxia , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Fatores de Transcrição Kruppel-Like/genética , Masculino , Gravidez , Fatores de Transcrição/genética
9.
J Mol Histol ; 50(3): 239-251, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31049798

RESUMO

Reduced expression of endothelial nitric oxide synthase (eNOS) is a hallmark of endothelial dysfunction in diabetes, which predisposes diabetic patients to numerous cardiovascular complications including blunted angiogenesis. The Krüppel-like factor (KLF) five has been implicated as a central regulator of cardiovascular remodeling, but its role in endothelial cells (ECs) remains poorly understood. We show here that expression of endothelial KLF5 was significantly increased in the ECs from mouse diabetes mellitus type 2 (T2DM) model, when compared to non-diabetic or T1DM mouse. KLF5 up-regulation by insulin was dependent on activation of multiple pathways, including mammalian target of rapamycin, oxidative stress and Protein kinase C pathways. Hyperinsulinemia-induced KLF5 inhibited endothelial function and migration, and thereby compromised in vitro and in vivo angiogenesis. Mechanistically, KLF5 acted in concert with the MTA1 coregulator to negatively regulate NOS3 transcription, thereby leading to the diminished eNOS levels in ECs. Conversely, potentiation of cGMP content (the essential downstream effector of eNOS signaling) by pharmacological approaches successfully rescued the endothelial proliferation and in vitro tube formation, in the HUVECs overexpressing the exogenous KLF5. Collectively, the available data suggest that the augmentation of endothelial KLF5 expression by hyperinsulinemia may represent a novel mechanism for negatively regulating eNOS expression, and may thus help to explain for the T2DM-related endothelial dysfunction at the transcriptional level.


Assuntos
Hiperinsulinismo/genética , Fatores de Transcrição Kruppel-Like/genética , Neovascularização Patológica/genética , Óxido Nítrico Sintase Tipo III/genética , Animais , Movimento Celular/genética , Proliferação de Células/genética , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patologia , Diabetes Mellitus Tipo 2/genética , Diabetes Mellitus Tipo 2/patologia , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Expressão Gênica/genética , Células Endoteliais da Veia Umbilical Humana , Humanos , Hiperinsulinismo/patologia , Masculino , Camundongos , Estresse Oxidativo/genética , Proteína Quinase C/genética , Transdução de Sinais/genética
10.
Nat Cell Biol ; 21(6): 731-742, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31086261

RESUMO

Deficiency in the deubiquitinating enzyme A20 causes severe inflammation in mice, and impaired A20 function is associated with human inflammatory diseases. A20 has been implicated in negatively regulating NF-κB signalling, cell death and inflammasome activation; however, the mechanisms by which A20 inhibits inflammation in vivo remain poorly understood. Genetic studies in mice revealed that its deubiquitinase activity is not essential for A20 anti-inflammatory function. Here we show that A20 prevents inflammasome-dependent arthritis by inhibiting macrophage necroptosis and that this function depends on its zinc finger 7 (ZnF7). We provide genetic evidence that RIPK1 kinase-dependent, RIPK3-MLKL-mediated necroptosis drives inflammasome activation in A20-deficient macrophages and causes inflammatory arthritis in mice. Single-cell imaging revealed that RIPK3-dependent death caused inflammasome-dependent IL-1ß release from lipopolysaccharide-stimulated A20-deficient macrophages. Importantly, mutation of the A20 ZnF7 ubiquitin binding domain caused arthritis in mice, arguing that ZnF7-dependent inhibition of necroptosis is critical for A20 anti-inflammatory function in vivo.


Assuntos
Artrite/genética , Inflamação/genética , Fatores de Transcrição Kruppel-Like/genética , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Animais , Artrite/induzido quimicamente , Artrite/patologia , Humanos , Inflamassomos/genética , Inflamassomos/metabolismo , Inflamação/induzido quimicamente , Inflamação/patologia , Interleucina-1beta/genética , Lipopolissacarídeos/toxicidade , Macrófagos/metabolismo , Macrófagos/patologia , Camundongos , Mutação , NF-kappa B/genética , Necrose/genética , Necrose/patologia , Ligação Proteica , Proteínas Quinases/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Ubiquitina/genética
11.
Neoplasma ; 66(4): 564-575, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-30943745

RESUMO

Long noncoding RNAs (lncRNAs) were reported to participate in the progression of gastric cancer (GC). However, litter is known about the biological functions of TTN antisense RNA 1 (TTN-AS1) in GC. Using qRT-PCR examination, we found that TTN-AS1 was expressed at a higher level in GC tissues and cell lines compared to the normal controls. Kaplan-Meier analysis of GC patients revealed the negative correlation between TTN-AS1 expression and the overall survival. To detect the biological function of TTN-AS1 in GC, we silenced TTN-AS1 to perform loss-of-function assays. The experimental results revealed that knockdown of TTN-AS1 obviously inhibited GC cell proliferation, induced cell apoptosis and impaired cell migration and invasion. In mechanism, TTN-AS1 was located in the cytoplasm of GC cells, indicating the post-transcriptional regulation of TTN-AS1 on gene expression. Bioinformatics analysis revealed the potential binding relation between TTN-AS1 and miR-376b-3p as well as between miR-376b-3p and KLF12. Mechanism experiments such as luciferase reporter assay and RNA pull-down assay demonstrated the interaction between TTN-AS1 and miR-376b-3p as well as between miR-376b-3p and KLF12 in GC cells. At last, rescue assays certified that miR-376b-3p and KLF12 involved in TTN-AS1-mediated GC progression. Similarly, the role of TTN-AS1-miR-376b-3p-KLF12 axis in GC progression was analyzed and validated. Taken together, we concluded that TTN-AS1 might function as a novel potential therapeutic target in the treatment of gastric cancer.


Assuntos
MicroRNAs/genética , RNA Longo não Codificante/genética , Neoplasias Gástricas/patologia , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Fatores de Transcrição Kruppel-Like/genética
12.
Nat Cell Biol ; 21(5): 560-567, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30988422

RESUMO

Haematopoietic stem cells (HSCs) are maintained by bone marrow niches in vivo1,2, but the ability of niche cells to maintain HSCs ex vivo is markedly diminished. Expression of niche factors by Nestin-GFP+ mesenchymal-derived stromal cells (MSCs) is downregulated upon culture, suggesting that transcriptional rewiring may contribute to this reduced HSC maintenance potential. Using an RNA sequencing screen, we identified five genes encoding transcription factors (Klf7, Ostf1, Xbp1, Irf3 and Irf7) that restored HSC niche function in cultured bone marrow-derived MSCs. These revitalized MSCs (rMSCs) exhibited enhanced synthesis of HSC niche factors while retaining their mesenchymal differentiation capacity. In contrast to HSCs co-cultured with control MSCs, HSCs expanded with rMSCs showed higher repopulation capacity and protected lethally irradiated recipient mice. Competitive reconstitution assays revealed an approximately sevenfold expansion of functional HSCs by rMSCs. rMSCs prevented the accumulation of DNA damage in cultured HSCs, a hallmark of ageing and replication stress. Analysis of the reprogramming mechanisms uncovered a role for myocyte enhancer factor 2c (Mef2c) in the revitalization of MSCs. These results provide insight into the transcriptional regulation of the niche with implications for stem cell-based therapies.


Assuntos
Diferenciação Celular/genética , Engenharia Celular/métodos , Células-Tronco Hematopoéticas/citologia , Nicho de Células-Tronco/genética , Animais , Células da Medula Óssea/metabolismo , Células da Medula Óssea/patologia , Regulação da Expressão Gênica/genética , Células-Tronco Hematopoéticas/metabolismo , Humanos , Fator Regulador 3 de Interferon/genética , Fatores de Transcrição Kruppel-Like/genética , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/patologia , Camundongos , Camundongos Transgênicos , Nestina/genética , Peptídeos/genética , Análise de Sequência de RNA/métodos , Proteína 1 de Ligação a X-Box/genética
13.
Artif Cells Nanomed Biotechnol ; 47(1): 1722-1729, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31032663

RESUMO

Mir-10b has been reported as a key regulator of metastasis in many human tumours. Moreover, it has also been regarded as a prognostic marker and therapeutic target of colorectal cancer (CRC). Whether miR-10b could affect the metastasis and proliferation of CRC is unclear. MiR-10b expression was detected by qPCR in human CRC tissues and cell line, Luciferase activity was employed for miR-10b binding to the 3`UTR of KLF4, Genes expression were examined by western blot, and mRNA by qPCR. PI and Annexin V staining were used to evaluate the cell cycle and apoptosis. Cell proliferation was detected with MTT, and cell migration and invasion were performed with Transwell assay. We found that miR-10b expression was up-regulated in metastatic CRC tissues and cell lines. Inhibition of miR-10b prevented cancer cell metastasis and growth by inducing cell-cycle arrest and apoptosis in vitro. Moreover, we found that KLF4 was a direct target of miR-10b. MiR-10b inhibitor led to the up-regulation of E-cadherin expression and the down-regulation of cyclin D1, which were partly abrogated after silencing KLF4.


Assuntos
Neoplasias Colorretais/patologia , Fatores de Transcrição Kruppel-Like/genética , MicroRNAs/genética , Apoptose/genética , Sequência de Bases , Pontos de Checagem do Ciclo Celular/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Invasividade Neoplásica , Metástase Neoplásica
14.
Biomed Res ; 40(2): 67-78, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30982802

RESUMO

T1R1 and T1R3 are receptors expressed in taste buds that detect L-amino acids. These receptors are also expressed throughout diverse organ systems, such as the digestive system and muscle tissue, and are thought to function as amino acid sensors. The mechanism of transcriptional regulation of the mouse T1R1 gene (Tas1r1) has not been determined; therefore, in this study, we examined the function of Tas1r1 promoter in the mouse myoblast cell line, C2C12. Luciferase reporter assays showed that a 148-bp region upstream of the ATG start codon of Tas1r1 had a promoter activity. The GT box in the Tas1r1 promoter was conserved in the dog, human, mouse, and pig. Site-directed mutagenesis of this GT box significantly reduced the promoter activation. The GT box in promoters is a recurring motif for Sp/KLF family members. RNAi-mediated depletion of Sp4 and Klf5 decreased Tas1r1 expression, while overexpression of Klf5, but not Sp4, significantly increased Tas1r1 expression. The ENCODE data of chromatin immunoprecipitation and sequencing (ChIP-seq) showed that Klf5 bound to the GT box during the myogenic differentiation. Furthermore, the Klf5 knockout cell lines led to a considerable decrease in the levels of Tas1r1 expression. Collectively, these results showed that Klf5 binds to the GT box in the Tas1r1 promoter and regulates Tas1r1 expression in C2C12 cells.


Assuntos
Fatores de Transcrição Kruppel-Like/genética , Mioblastos/metabolismo , Regiões Promotoras Genéticas , Receptores Acoplados a Proteínas-G/genética , Fator de Transcrição Sp4/genética , Sítio de Iniciação de Transcrição , Animais , Sequência de Bases , Sítios de Ligação , Diferenciação Celular , Linhagem Celular , Sequência Conservada , Cães , Regulação da Expressão Gênica , Genes Reporter , Humanos , Fatores de Transcrição Kruppel-Like/antagonistas & inibidores , Fatores de Transcrição Kruppel-Like/metabolismo , Luciferases/genética , Luciferases/metabolismo , Camundongos , Desenvolvimento Muscular/genética , Mioblastos/citologia , Ligação Proteica , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Receptores Acoplados a Proteínas-G/metabolismo , Transdução de Sinais , Fator de Transcrição Sp4/antagonistas & inibidores , Fator de Transcrição Sp4/metabolismo , Suínos
15.
Oncol Rep ; 41(6): 3393-3403, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31002352

RESUMO

Scientific evidence linking vitamin D with various cancer types is growing, but the effects of vitamin D on ovarian cancer stem cell­like cells (CSCs) are largely unknown. The present study aimed to examine whether vitamin D was able to restrain the stemness of ovarian cancer. A side population (SP) from malignant ovarian surface epithelial cells was identified as CSCs, in vitro and in vivo. Furthermore, 1α,25­dihydroxyvitamin D3 [1α,25(OH)2D3] treatment inhibited the self­renewal capacity of SP cells by decreasing the sphere formation rate and by suppressing the mRNA expression levels of cluster of differentiation CD44, NANOG, OCT4, SOX2, Krüppel­like factor 4 and adenosine triphosphate binding cassette subfamily G member 2. Additionally, 1α,25(OH)2D3 treatment decreased the expression of Cyclin D1, whereas it increased the expression of ß­catenin and vitamin D receptor (VDR). Notably, immunofluorescence staining verified that 1α,25(OH)2D3 promoted the expression of ß­catenin in the cytoplasm. Furthermore, vitamin D3 delayed the onset of tumor formation derived from injection of ovarian CSCs to nude mice, by reducing CD44 and enhancing ß­catenin expressions in vivo. In conclusion, 1α,25(OH)2D3 restrains the stem cell­like properties of ovarian cancer cells by enhancing the expression of VDR, by promoting the expression of ß­catenin in the cytoplasm, and by suppressing the expression of CD44. These findings provide a novel insight into the functions of vitamin D in diminishing the stemness of cancer CSCs.


Assuntos
Neoplasias Ovarianas/tratamento farmacológico , Receptores de Calcitriol/genética , Vitamina D/análogos & derivados , Vitamina D/genética , Autorrenovação Celular/efeitos dos fármacos , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Receptores de Hialuronatos/genética , Fatores de Transcrição Kruppel-Like/genética , Proteína Homeobox Nanog/genética , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/patologia , Fator 3 de Transcrição de Octâmero/genética , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/patologia , Fatores de Transcrição SOXB1/genética , Vitamina D/metabolismo , Vitamina D/farmacologia , beta Catenina/genética
16.
Phytomedicine ; 58: 152754, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31009837

RESUMO

BACKGROUND: Salvianolic acid B (Sal B), a water-soluble compound extracted from Salvia miltiorrhiza that has been widely used to treat cardiovascular diseases for hundreds of years in China, exerts cardiovascular protection by multiple mechanisms. miR-146a is involved in vascular smooth muscle cell (VSMC) phenotypic modulation and proliferation. However, it has yet to be investigated whether the cardiovascular protective effect of Sal B is mediated by miR-146a. PURPOSE: To determine the relationship among the cardiovascular protective effect of Sal B, miR-146a expression, and VSMC proliferation. METHODS: MTS assay and cell counting were performed to evaluate the effect of Ang II, Sal B and miR-146a on VSMC proliferation. The neointima hyperplasia was assessed by hematoxylin/eosin staining. qRT-PCR was used to detect the expression of miR-146a, KLF5, cyclin D1 and PCNA. Western blot analysis was used to detect the expressions of KLF5, cyclin D1 and PCNA after miR-20b-5p was knocked down or overexpressed in VSMC. RESULTS: Sal B suppressed intimal hyperplasia induced by carotid artery ligation and decreased Ang II-induced VSMC proliferation by down-regulating the positive cell-cycle regulators KLF5 and cyclin D1. Further experiments showed that VSMC proliferation and upregulation of KLF5 and cyclin D1 induced by Ang II were accompanied by elevated miR-146a level. Furthermore, overexpression of miR-146a promoted and knockdown of miR-146a reduced Ang II-induced VSMC proliferation and ameliorated intimal hyperplasia induced by carotid artery ligation. Sal B inhibited Ang II-induced VSMC proliferation by suppressing miR-146a expression. CONCLUSION: Sal B inhibited Ang II-induced VSMC proliferation in vitro and intimal hyperplasia in vivo by downregulating miR-146a expression.


Assuntos
Benzofuranos/farmacologia , Artérias Carótidas/patologia , MicroRNAs/genética , Músculo Liso Vascular/efeitos dos fármacos , Túnica Íntima/patologia , Angiotensina II/farmacologia , Animais , Artérias Carótidas/efeitos dos fármacos , Artérias Carótidas/cirurgia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Regulação para Baixo/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Hiperplasia/tratamento farmacológico , Hiperplasia/genética , Hiperplasia/patologia , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Miócitos de Músculo Liso/efeitos dos fármacos , Neointima/tratamento farmacológico , Neointima/genética , Neointima/patologia , Túnica Íntima/efeitos dos fármacos
17.
Chem Biol Interact ; 305: 105-111, 2019 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-30928399

RESUMO

Kruppel-like factor 2 (KLF2) regulates endothelial functions by modulating endothelial nitric oxide synthase (eNOS)/nitric oxide (NO) pathway. Tetrahydrobiopterin (BH4) and S-glutathionylation of eNOS play essential roles in eNOS uncoupling and activation. However, the influence of KLF2 on eNOS uncoupling and the mechanism of eNOS activation still remain unknown. A hypoxia and reoxygenation (H/R) model of human umbilical vein endothelial cells (HUVECs) was utilized in this study. Cell viability and the eNOS uncoupling-related oxidative stress index were measured. The Nrf2 inhibitor ML385 and HO-1 siRNA were used to elucidate the mechanism of activation. The results show that overexpression of KLF2 increased the cell viability, reduced the lactate dehydrogenase leakage rate, downregulated the generation of O2•- and ONOO-, and increased NO levels and eNOS activity. Overexpression of KLF2 also increased the BH4/BH2 ratio and the GSH/GSSG ratio, thus significantly improving eNOS uncoupling in the H/R model. KLF2 has no regulatory effect on the upstream-associated proteins in eNOS activation. However, when combined with the Nrf2 inhibitor or HO-1 siRNA, the regulatory effect of KLF2 on eNOS uncoupling was strongly reduced. These results suggest that KLF2 could improve eNOS uncoupling via Nrf2/HO-1 in H/R-induced endothelial injury.


Assuntos
Hipóxia Celular , Heme Oxigenase-1/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Oxigênio/química , Sobrevivência Celular/efeitos dos fármacos , Glutationa/metabolismo , Heme Oxigenase-1/antagonistas & inibidores , Heme Oxigenase-1/genética , Células Endoteliais da Veia Umbilical Humana , Humanos , Fatores de Transcrição Kruppel-Like/genética , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Óxido Nítrico/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Oxigênio/farmacologia , Interferência de RNA , RNA Interferente Pequeno/metabolismo
18.
PLoS Genet ; 15(4): e1008058, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30933982

RESUMO

In the skin and gill epidermis of fish, ionocytes develop alongside keratinocytes and maintain body fluid ionic homeostasis that is essential for adaptation to environmental fluctuations. It is known that ionocyte progenitors in zebrafish embryos are specified from p63+ epidermal stem cells through a patterning process involving DeltaC (Dlc)-Notch-mediated lateral inhibition, which selects scattered dlc+ cells into the ionocyte progenitor fate. However, mechanisms by which the ionocyte progenitor population is modulated remain unclear. Krüppel-like factor 4 (Klf4) transcription factor was previously implicated in the terminal differentiation of mammalian skin epidermis and is known for its bifunctional regulation of cell proliferation in a tissue context-dependent manner. Here, we report novel roles for zebrafish Klf4 in the ventral ectoderm during embryonic skin development. We found that Klf4 was expressed in p63+ epidermal stem cells of the ventral ectoderm from 90% epiboly onward. Knockdown or knockout of klf4 expression reduced the proliferation rate of p63+ stem cells, resulting in decreased numbers of p63+ stem cells, dlc-p63+ keratinocyte progenitors and dlc+ p63+ ionocyte progenitor cells. These reductions subsequently led to diminished keratinocyte and ionocyte densities and resulted from upregulation of the well-known cell cycle regulators, p53 and cdkn1a/p21. Moreover, mutation analyses of the KLF motif in the dlc promoter, combined with VP16-klf4 or engrailed-klf4 mRNA overexpression analyses, showed that Klf4 can bind the dlc promoter and modulate lateral inhibition by directly repressing dlc expression. This idea was further supported by observing the lateral inhibition outcomes in klf4-overexpressing or knockdown embryos. Overall, our experiments delineate novel roles for zebrafish Klf4 in regulating the ionocyte progenitor population throughout early stem cell stage to initiation of terminal differentiation, which is dependent on Dlc-Notch-mediated lateral inhibition.


Assuntos
Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Células Epidérmicas/citologia , Células Epidérmicas/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas de Peixe-Zebra/metabolismo , Peixe-Zebra/embriologia , Peixe-Zebra/metabolismo , Sequência de Aminoácidos , Animais , Animais Geneticamente Modificados , Padronização Corporal , Diferenciação Celular , Proliferação de Células , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Ectoderma/citologia , Ectoderma/embriologia , Ectoderma/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Brânquias/citologia , Brânquias/embriologia , Brânquias/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Transporte de Íons , Fatores de Transcrição Kruppel-Like/deficiência , Fatores de Transcrição Kruppel-Like/genética , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Regiões Promotoras Genéticas , Receptores Notch/genética , Receptores Notch/metabolismo , Transativadores/genética , Transativadores/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Peixe-Zebra/genética , Proteínas de Peixe-Zebra/deficiência , Proteínas de Peixe-Zebra/genética
19.
Fish Shellfish Immunol ; 89: 677-686, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30905839

RESUMO

Krϋppel-like factor 9 (KLF9) is a member of the SP/KL family, which are transcription factors implicated in several biological processes, including cell proliferation, differentiation, development and apoptosis. Studies have focused on the function of KLF9 in mammalian disease and the immune system, such as its regulatory role in the growth of tumors and its impact on interferon-related genes and inflammatory cytokines. In fish, little is known about the role of KLF9, especially its regulatory function in the innate antiviral immune response. In this study, we characterized the grouper KLF9 gene (EcKLF9) and investigated its role in viral infection. Amino acid alignment analysis showed that EcKLF9 was approximately 228 amino acids long and contained a typical three-tandem Krϋppel-like zinc fingers. Phylogenetic tree analysis revealed that EcKLF9 clustered with three fish species: Amphiprion ocellaris, Acanthochromis pollyacanthus and Stegastes partitus. Comparison analyses showed that the three Kruppel-like zinc finger domains of KLF9 were highly conserved in different fish species. Tissue expression analysis showed that EcKLF9 was constitutively expressed in all 12 tissues tested, in the healthy grouper, the highest expression being detected in the gonads. The relative expression levels of EcKLF9 in the head kidney, spleen and brain was significantly increased during red-spotted grouper nervous necrosis virus (RGNNV) and Singapore grouper iridovirus (SGIV) infections. Using fluorescence microscopy, EcKLF9 was primarily localized to the nucleus and cytoplasm. The in vitro ectopic expression of EcKLF9 significantly increased the severity of vacuoles induced by RGNNV and the cytopathic effect progression evoked by SGIV infection. Real-time PCR results showed that the transcription levels of viral genes, such as the Singapore grouper iridovirus infection genes, MCP (major capsid protein), LITAF (lipopolysaccharide induced TNF-α factor), VP19 (envelop protein) ICP-18 (infected cell protein-18) and the red-spotted grouper nervous necrosis virus genes, CP (coat protein), RdRp (RNA-dependent RNA polymerase), were all significantly increased in EcKLF9 overexpressing cells, when compared to control cells. Furthermore, western blotting analyses showed that protein levels of the RGNNV gene, CP and the SGIV gene, MCP were also increased in EcKLF9 overexpressing cells, suggesting EcKLF9 may promote viral activity against iridovirus and nodavirus, in vitro. Moreover, the overexpression of EcKLF9 significantly inhibited the expression of several interferon related cytokines and several inflammatory cytokines. Accordingly, we speculate that EcKLF9 may exert stimulatory effects on RGNNV and SGIV replication, through the negative regulation of host immune and inflammation responses.


Assuntos
Doenças dos Peixes/imunologia , Regulação da Expressão Gênica/imunologia , Imunidade Inata/genética , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/imunologia , Perciformes/genética , Perciformes/imunologia , Sequência de Aminoácidos , Animais , Infecções por Vírus de DNA/imunologia , Infecções por Vírus de DNA/veterinária , Proteínas de Peixes/química , Proteínas de Peixes/genética , Proteínas de Peixes/imunologia , Perfilação da Expressão Gênica/veterinária , Fatores de Transcrição Kruppel-Like/química , Nodaviridae/fisiologia , Filogenia , Infecções por Vírus de RNA/imunologia , Infecções por Vírus de RNA/veterinária , Ranavirus/fisiologia , Alinhamento de Sequência/veterinária , Especificidade da Espécie
20.
J Exp Clin Cancer Res ; 38(1): 126, 2019 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-30866999

RESUMO

BACKGROUND: Cancer stem cells (CSCs) play an important role in the development of pancreatic cancer. We previously showed that the microRNA miR-137 is downregulated in clinical samples of pancreatic cancer, and its expression negatively regulates the proliferation and invasiveness of pancreatic cancer cells. METHODS: The stemness features of pancreatic cancer cells was detected by flow cytometry, immunofluorescence and sphere formation assay. Xenograft mouse models were used to assess the role of miR-137 in stemness features of pancreatic cancer cells in vivo. Dual-luciferase reporter assays were used to determine how miR-137 regulates KLF12. Bioinformatics and Chromatin immunoprecipitation analysis of KLF12 recruitment to the DVL2 promoters. Involvement of the Wnt/ß-catenin pathways was investigated by western blot and Immunohistochemistry. RESULTS: miR-137 inhibits pancreatic cancer cell stemness in vitro and vivo. KLF12 as miR-137 target inhibits CSC phenotype in pancreatic cancer cells. Suppression of KLF12 by miR-137 inhibits Wnt/ß-catenin signalling. KLF12 expression correlates with DVL2 and canonical Wnt pathway in clinical pancreatic cancer. CONCLUSION: Our results suggest that miR-137 reduces stemness features of pancreatic cancer cells by Targeting KLF12-associated Wnt/ß-catenin pathways and may identify new diagnostic and therapeutic targets in pancreatic cancer.


Assuntos
Fatores de Transcrição Kruppel-Like/metabolismo , MicroRNAs/metabolismo , Células-Tronco Neoplásicas/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Animais , Carcinogênese/genética , Carcinogênese/metabolismo , Linhagem Celular Tumoral , Xenoenxertos , Humanos , Fatores de Transcrição Kruppel-Like/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Células-Tronco Neoplásicas/patologia , Neoplasias Pancreáticas/genética , Transfecção , Via de Sinalização Wnt
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