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The right and left mandibular processes derived from the first branchial arch grow toward the midline and fuse to create the rostral tip region of the mandible during mandibular development. Severe and mild cases of failure in this process results in rare median cleft of the lower lip and cleft chin, respectively. The detailed molecular mechanisms of mandibular tip formation are unknown. We hypothesize that the Msx1 gene is involved in mandibular tip development, because Msx1 has a central role in other craniofacial morphogenesis processes, such as teeth and the secondary palate development. Normal Msx1 expression was observed in the rostral end of the developing mandible; however, a reduced expression of Msx1 was observed in the soft tissue of the mandibular tip than in the lower incisor bud region. The rostral tip of the right and left mandibular processes was unfused in both control and Msx1-null (Msx1-/-) mice at embryonic day (E) 12.5; however, a complete fusion of these processes was observed at E13.5 in the control. The fused processes exhibited a conical shape in the control, whereas the same region remained bifurcated in Msx1-/-. This phenotype occurred with 100% penetrance and was not restored at subsequent stages of development. Furthermore, Meckel's cartilage in addition to the outline surface soft tissues was also unfused and bifurcated in Msx1-/- from E14.5 onward. The expression of phosho-Smad1/5, which is a mediator of bone morphogenetic protein (Bmp) signaling, was downregulated in the mandibular tip of Msx1-/- at E12.5 and E13.5, probably due to the downregulated Bmp4 expression in the neighboring lower incisor bud. Cell proliferation was significantly reduced in the midline region of the mandibular tip in Msx1-/- at the same developmental stages in which downregulation of pSmad was observed. Our results indicate that Msx1 is indispensable for proper mandibular tip development.
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Factor de Transcripción MSX1 , Diente , Ratones , Animales , Factor de Transcripción MSX1/genética , Factor de Transcripción MSX1/metabolismo , Mandíbula , Diente/metabolismo , Morfogénesis/genética , Transducción de SeñalRESUMEN
Hox transcription factors are conserved regulators of neuronal subtype specification on the anteroposterior axis in animals, with disruption of Hox gene expression leading to homeotic transformations of neuronal identities. We have taken advantage of an unusual mutation in the Caenorhabditis elegans Hox gene lin-39, lin-39(ccc16), which transforms neuronal fates in the C. elegans male ventral nerve cord in a manner that depends on a second Hox gene, mab-5. We have performed a genetic analysis centered around this homeotic allele of lin-39 in conjunction with reporters for neuronal target genes and protein interaction assays to explore how LIN-39 and MAB-5 exert both flexibility and specificity in target regulation. We identify cis-regulatory modules in neuronal reporters that are both region-specific and Hox-responsive. Using these reporters of neuronal subtype, we also find that the lin-39(ccc16) mutation disrupts neuronal fates specifically in the region where lin-39 and mab-5 are coexpressed, and that the protein encoded by lin-39(ccc16) is active only in the absence of mab-5. Moreover, the fates of neurons typical to the region of lin-39-mab-5 coexpression depend on both Hox genes. Our genetic analysis, along with evidence from Bimolecular Fluorescence Complementation protein interaction assays, supports a model in which LIN-39 and MAB-5 act at an array of cis-regulatory modules to cooperatively activate and to individually activate or repress neuronal gene expression, resulting in regionally specific neuronal fates.
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Proteínas de Caenorhabditis elegans , Caenorhabditis elegans , Proteínas de Homeodominio , Factores de Transcripción , Animales , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Regulación del Desarrollo de la Expresión Génica , Proteínas de Homeodominio/metabolismo , Masculino , Neuronas/metabolismo , Factores de Transcripción/metabolismoRESUMEN
General identity of the Caenorhabditis elegans AWC olfactory neuron pair is specified by the OTX/OTD transcription factor CEH-36 and the HMG-box transcription factor SOX-2, followed by asymmetrical differentiation of the pair into two distinct subtypes, default AWCOFF and induced AWCON, through a stochastic signaling event. The HMX/NKX transcription factor MLS-2 regulates the expression of ceh-36 to specify general AWC identity. However, general AWC identity is lost in only one of the two AWC cells in the majority of mls-2 null mutants displaying defective general AWC identity, suggesting that additional transcription factors have a partially overlapping role with MLS-2 in the specification of general AWC identity. Here, we identify a role of unc-62, encoding a homothorax/Meis/TALE homeodomain protein, in the specification of general AWC identity. As in mls-2 null mutants, unc-62 null mutants showed an incomplete penetrance in loss of general AWC identity. However, unc-62; mls-2 double mutants display a nearly complete penetrance of identity loss in both AWC cells. Thus, unc-62 and mls-2 have a partially overlapping function in the specification of general AWC identity. Furthermore, our genetic results suggest that mls-2 and unc-62 act cell autonomously in promoting the AWCON subtype. Together, our findings reveal the sequential roles of the unc-62 and mls-2 pair in AWC development, specification of general AWC identity in early embryogenesis, and asymmetric differentiation of AWC subtypes in late embryogenesis.
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Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Homeodominio/metabolismo , Neuronas Receptoras Olfatorias/metabolismo , Factores de Transcripción/metabolismo , Animales , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/genética , Proteínas de Homeodominio/genética , Factores de Transcripción/genéticaRESUMEN
BACKGROUND: PITX2 DNA methylation has been shown to predict outcomes in high-risk breast cancer patients after anthracycline-based chemotherapy. To determine its prognostic versus predictive value, the impact of PITX2 DNA methylation on outcomes was studied in an untreated cohort vs. an anthracycline-treated triple-negative breast cancer (TNBC) cohort. MATERIAL AND METHODS: The percent DNA methylation ratio (PMR) of paired-like homeodomain transcription factor 2 (PITX2) was determined by a validated methylation-specific real-time PCR test. Patient samples of routinely collected archived formalin-fixed paraffin-embedded (FFPE) tissue and clinical data from 144 TNBC patients of 2 independent cohorts (i.e., 66 untreated patients and 78 patients treated with anthracycline-based chemotherapy) were analyzed. RESULTS: The risk of 5- and 10-year overall survival (OS) increased continuously with rising PITX2 DNA methylation in the anthracycline-treated population, but it increased only slightly during 10-year follow-up time in the untreated patient population. PITX2 DNA methylation with a PMR cutoff of 2 did not show significance for poor vs. good outcomes (OS) in the untreated patient cohort (HR = 1.55; p = 0.259). In contrast, the PITX2 PMR cutoff of 2 identified patients with poor (PMR >2) vs. good (PMR ≤2) outcomes (OS) with statistical significance in the anthracycline-treated cohort (HR = 3.96; p = 0.011). The results in the subgroup of patients who did receive anthracyclines only (no taxanes) confirmed this finding (HR = 5.71; p = 0.014). CONCLUSION: In this hypothesis-generating study PITX2 DNA methylation demonstrated predominantly predictive value in anthracycline treatment in TNBC patients. The risk of poor outcome (OS) correlates with increasing PITX2 DNA methylation.
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BACKGROUND: Homeobox B13 (HOXB13) expression regulates normal prostate development and mutations are associated with prostate cancer (PCa) formation. OBJECTIVE: To assess the role of HOXB13 mRNA expression in PCa progression following radical prostatectomy. DESIGN, SETTING, AND PARTICIPANTS: Genome-wide expression profiles were queried from two retrospective prostatectomy cohorts with follow-up data (Mayo Clinic, n=780; Johns Hopkins Medical Institute [JHMI], n=355), and a prospective genomic registry (n=5239). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Multivariable Cox regressions were used to analyze metastasis-free survival (MFS). RESULTS AND LIMITATIONS: HOXB13 expression in primary PCa increased with increasing tumor grade and with high metastatic potential based on a genomic signature. The highest quartile of HOXB13 expression was associated with worse MFS compared with the lowest quartile (Mayo Clinic: adjusted hazard ratio [AHR] 1.46, 95% confidence interval [CI] 1.03-2.06, and JHMI: AHR 1.80, 95% CI 1.02-3.19). The combinations of high HOXB13 expression and low expression of its binding partner, MEIS1 (AHR 2.03, 95% CI 1.54-2.66) or MEIS2 (AHR 1.73, 95% CI 1.33-2.26), portended worse MFS. Additionally, high HOXB13 expression in combination with low MEIS1/2 expression correlated with high expression of androgen receptor-mediated genes. The retrospective nature of this study subjects the findings to a bias due to unmeasured variables. CONCLUSIONS: Primary PCa tumors with increased HOXB13 expression have an increased propensity for metastases following prostatectomy, particularly in the setting of low MEIS1/2 expression. High androgen receptor output may account for worse outcomes for these tumors and suggests heightened sensitivity to androgen suppression. PATIENT SUMMARY: Using genomic data from a large number of prostate cancer (PCa) tumors, we found that increased expression of homeobox B13 (HOXB13), a gene related to normal prostate development, was associated with worse outcomes following surgery for PCa. A biomarker signature suggests that these tumors would be more susceptible to androgen suppression, a common treatment for PCa. Take Home Messagece:: In multiple large cohorts, prostate cancer tumors with high homeobox B13 (HOXB13) expression and low expression of its binding partner MEIS1/2 were enriched with high androgen receptor output and had an increased propensity for metastases following surgery.
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Genes Homeobox , Neoplasias de la Próstata , Proteínas de Homeodominio/genética , Humanos , Masculino , Estudios Prospectivos , Próstata , Prostatectomía , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/cirugía , Estudios RetrospectivosRESUMEN
SUMMARY OBJECTIVES HOXB2 is a new prognostic indicator for lung cancer. But it is unclear whether HOXB2 holds an effect in glioblastoma (GBM) progression. The purpose of this article was to probe the influences of HOXB2 on GBM pathogenesis. METHODS HOXB2 expression level and prognostic power in GBM patients were analyzed. Then the mRNA and protein expression levels of HOXB2 in GBM cell lines were tested by qRT-PCR and western blotting. Cell proliferation, invasion, and migration were determined by CCK8 and transwell assay, severally. The protein levels of PI3K/AKT-pathway associated proteins were analyzed by western blotting. RESULTS The results indicated that HOXB2 was distinctly overexpressed in GBM patients and high expression of HOXB2 was related to a poor prognosis. Moreover, the expression of HOXB2 was higher in all GBM cell lines U251, U-87MG, GOS-3 than that in HEB cells (normal control). Meanwhile, decreased expression of p-PI3K and p-AKT were identified after HOXB2 knockdown. CONCLUSIONS These data demonstrated that HOXB2 had a vital role in GBM progression and could serve as a promising target for GBM treatment.
RESUMO OBJETIVOS A HOXB2 é um novo indicador prognóstico para o câncer de pulmão. Mas não está claro se a HOXB2 tem algum efeito na progressão do glioblastoma (GBM). O objetivo deste artigo foi sondar as influências da HOXB2 na patogênese do GBM. MÉTODOS Foram analisados o nível de expressão e o poder prognóstico da HOXB2 em pacientes com GBM. Em seguida, os níveis de expressão proteica e mRNA da HOXB2 em linhagens de células de GBM foram testados por qRT-PCR e western blotting. A proliferação, a invasão e migração celular foram determinadas por CCK8 e ensaios transwell, várias vezes. Os níveis proteicos das proteínas associadas à via PI3K/AKT foram analisados pelo método western blotting. RESULTADOS Os resultados indicaram que havia uma clara superrexpressão da HOXB2 em pacientes com GBM e que a alta expressão da HOXB2 estava relacionada a um prognóstico negativo. Além disso, a expressão da HOXB2 foi mais elevada em todas as linhagens de células do GBM U251, U-87MG, GOS-3 do que nas células HEB (controle normal). Entretanto, a diminuição da expressão de P-PI3K e p-AKT foi identificada após a redução da expressão da HOXB2. CONCLUSÕES Esses dados demonstram que a HOXB2 desempenha um papel vital na progressão do GBM, podendo ser um alvo promissor para o tratamento do GBM.
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Humanos , Neoplasias Encefálicas/diagnóstico , Genes Homeobox/fisiología , Glioblastoma/diagnóstico , Pronóstico , Biomarcadores , Regulación Neoplásica de la Expresión Génica , Fosfatidilinositol 3-Quinasas , Línea Celular Tumoral , Proliferación CelularRESUMEN
Angiogenesis depends on a delicate balance between the different transcription factors, and their control should be considered necessary for preventing or treating diseases. Pre-B-cell leukemia transcription factor regulating protein 1 (Prep1) is a homeodomain transcription factor that plays a primary role in organogenesis and metabolism. Observations performed in a Prep1 hypomorphic mouse model, expressing 3-5% of the protein, show an increase of embryonic lethality due, in part, to defects in angiogenesis. In this study, we provide evidence that overexpression of Prep1 in mouse aortic endothelial cells (MAECs) stimulates migration, proliferation, and tube formation. These effects are paralleled by an increase of several proangiogenic factors and by a decrease of the antiangiogenic gene neurogenic locus notch homolog protein 1 (Notch1). Prep1-mediated angiogenesis involves the activation of the p160 Myb-binding protein (p160)/peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) pathway. Indeed, Prep1 overexpression increases its binding with p160 and induces a 4-fold increase of p160 and 70% reduction of PGC-1α compared with control cells. Incubation of MAECs with a synthetic Prep1(54-72) peptide, mimicking the Prep1 region involved in the interaction with p160, reverts the proangiogenic effects mediated by Prep1. In addition, Prep1 levels increase by 3.2-fold during the fibroblast growth factor ß (bFGF)-mediated endothelial colony-forming cells' activation, whereas Prep1(54-72) peptide reduces the capability of these cells to generate tubular-like structures in response to bFGF, suggesting a possible role of Prep1 both in angiogenesis from preexisting vessels and in postnatal vasculogenesis. Finally, Prep1 hypomorphic heterozygous mice, expressing low levels of Prep1, show attenuated placental angiogenesis and vessel formation within Matrigel plugs. All of these observations indicate that Prep1, complexing with p160, decreases PGC-1α and stimulates angiogenesis.-Cimmino, I., Margheri, F., Prisco, F., Perruolo, G., D'Esposito, V., Laurenzana, A., Fibbi, G., Paciello, O., Doti, N., Ruvo, M., Miele, C., Beguinot, F., Formisano, P., Oriente, F. Prep1 regulates angiogenesis through a PGC-1α-mediated mechanism.
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Células Endoteliales/metabolismo , Proteínas de Homeodominio/metabolismo , Neovascularización Patológica/metabolismo , Coactivador 1-alfa del Receptor Activado por Proliferadores de Peroxisomas gamma/metabolismo , Animales , Movimiento Celular/fisiología , Proliferación Celular/fisiología , Células Cultivadas , Regulación de la Expresión Génica/fisiología , RatonesRESUMEN
Objective To analyze the relationship between the expression of homeobox A13 (HOXA13),epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) gene in prepuce tissue of children with congenital hypospadias,discuss the relationship and significance of HOXA13,EGF and EGFR genes in congenital hypospadias and to understand their role in the pathogenesis of hypospadias.Methods 65 cases of hypospadias were selected as the experimental group and 42 cases of phimosis as the control group.Hematoxylin-eosin (HE) staining was used to observe the pathological characteristics of prepuce tissues in the two groups.Immunohistochemistry,real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) and Western blot were used to detect the expression of HOXA13,EGF and EGFR in the two groups.Results (1) HE staining showed that the epidermis of hypospadias was composed of keratinized stratified flat epithelium and epidermis of penile skin.The prepuce of phimosis children showed only infiltration of inflammatory cells in the superficial layer of the inner prepuce,blood vessel congestion,no obvious appendage structure,mostly fibroblasts.(2) Immunohistochemistry:The positive expressions of HOXA13,EGF and EGFR in the control group were significantly higher than those in the experimental group (P ＜ 0.01).(3) qRT-PCR:The expression levels of HOXA13,EGF and EGFR in the control group were 53.447 ±33.471,80.012 ±20.430,75.012 ± 14.339,and the expression levels of HOXA13,EGF and EGFR in the experimental group were 9.128 ± 5.996,45.521 ± 18.242,32.043 ± 10.215,respectively.The expression of HOXA13,EGF and EGFR in the control group was significantly higher than that in the experimental group (P ＜0.01).(4) Western blot:The expression levels of HOXA13,EGF and EGFR in the experimental group were lower than those in the control group.Conclusions The expression of HOXA13,EGF and EGFR in prepuce tissue of children with hypospadias is low,which may be related to hypospadias.
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Objective@#To analyze the relationship between the expression of homeobox A13 (HOXA13), epidermal growth factor (EGF) and epidermal growth factor receptor (EGFR) gene in prepuce tissue of children with congenital hypospadias, discuss the relationship and significance of HOXA13, EGF and EGFR genes in congenital hypospadias and to understand their role in the pathogenesis of hypospadias.@*Methods@#65 cases of hypospadias were selected as the experimental group and 42 cases of phimosis as the control group. Hematoxylin-eosin (HE) staining was used to observe the pathological characteristics of prepuce tissues in the two groups. Immunohistochemistry, real-time fluorescence quantitative polymerase chain reaction (qRT-PCR) and Western blot were used to detect the expression of HOXA13, EGF and EGFR in the two groups.@*Results@#⑴ HE staining showed that the epidermis of hypospadias was composed of keratinized stratified flat epithelium and epidermis of penile skin. The prepuce of phimosis children showed only infiltration of inflammatory cells in the superficial layer of the inner prepuce, blood vessel congestion, no obvious appendage structure, mostly fibroblasts. ⑵ Immunohistochemistry: The positive expressions of HOXA13, EGF and EGFR in the control group were significantly higher than those in the experimental group (P<0.01). ⑶ qRT-PCR: The expression levels of HOXA13, EGF and EGFR in the control group were 53.447±33.471, 80.012±20.430, 75.012±14.339, and the expression levels of HOXA13, EGF and EGFR in the experimental group were 9.128±5.996, 45.521±18.242, 32.043±10.215, respectively. The expression of HOXA13, EGF and EGFR in the control group was significantly higher than that in the experimental group (P<0.01). ⑷ Western blot: The expression levels of HOXA13, EGF and EGFR in the experimental group were lower than those in the control group.@*Conclusions@#The expression of HO-XA13, EGF and EGFR in prepuce tissue of children with hypospadias is low, which may be related to hypospadias.
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The ancient mechanisms that caused developmental gene regulatory networks to diversify among distantly related taxa are not well understood. Here we use ancestral protein reconstruction, biochemical experiments, and developmental assays of transgenic animals carrying reconstructed ancestral genes to investigate how the transcription factor Bicoid (Bcd) evolved its central role in anterior-posterior patterning in flies. We show that most of Bcd's derived functions are attributable to evolutionary changes within its homeodomain (HD) during a phylogenetic interval >140 million years ago. A single substitution from this period (Q50K) accounts almost entirely for the evolution of Bcd's derived DNA specificity in vitro. In transgenic embryos expressing the reconstructed ancestral HD, however, Q50K confers activation of only a few of Bcd's transcriptional targets and yields a very partial rescue of anterior development. Adding a second historical substitution (M54R) confers regulation of additional Bcd targets and further rescues anterior development. These results indicate that two epistatically interacting mutations played a major role in the evolution of Bcd's controlling regulatory role in early development. They also show how ancestral sequence reconstruction can be combined with in vivo characterization of transgenic animals to illuminate the historical mechanisms of developmental evolution.
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Animales Modificados Genéticamente/genética , Drosophila melanogaster/genética , Evolución Molecular , Proteínas de Homeodominio/genética , Transactivadores/genética , Animales , Tipificación del Cuerpo/genética , Proteínas de Drosophila , Drosophila melanogaster/crecimiento & desarrollo , Regulación del Desarrollo de la Expresión Génica/genética , Redes Reguladoras de Genes/genética , Mutación , FilogeniaRESUMEN
Ataxia-telangiectasia mutated (ATM) is a serine/threonine kinase that coordinates the response to DNA double-strand breaks and oxidative stress. NKX3.1, a prostate-specific transcription factor, was recently shown to directly stimulate ATM kinase activity through its highly conserved homeodomain. Here, we show that other members of the homeodomain family can also regulate ATM kinase activity. We found that six representative homeodomain proteins (NKX3.1, NKX2.2, TTF1, NKX2.5, HOXB7, and CDX2) physically and functionally interact with ATM and with the Mre11-Rad50-Nbs1 (MRN) complex that activates ATM in combination with DNA double-strand breaks. The binding between homeodomain proteins and ATM stimulates oxidation-induced ATM activation in vitro but inhibits ATM kinase activity in the presence of MRN and DNA and in human cells. These findings suggest that many tissue-specific homeodomain proteins may regulate ATM activity during development and differentiation and that this is a unique mechanism for the control of the DNA damage response.
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Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Proteínas de Homeodominio/metabolismo , Proteína Homeobox Nkx-2.2 , Humanos , Proteínas Nucleares , Factores de Transcripción , TransfecciónRESUMEN
Tooth enamel is manufactured by the inner enamel epithelium of the multilayered enamel organ. Msx2 loss-of-function mutation in a mouse model causes an abnormal accumulation of epithelial cells in the enamel organ, but the underlying mechanism by which Msx2 regulates amelogenesis is poorly understood. We therefore performed detailed histological and molecular analyses of Msx2 null mice. Msx2 null ameloblasts and stratum intermedium (SI) cells differentiated normally in the early stages of amelogenesis. However, during subsequent developmental stages, the outer enamel epithelium (OEE) became highly proliferative and transformed into a keratinized stratified squamous epithelium that ectopically expressed stratified squamous epithelium markers, including Heat shock protein 25, Loricrin, and Keratin 10. Moreover, expression of hair follicle-specific keratin genes such as Keratin 26 and Keratin 73 was upregulated in the enamel organ of Msx2 mutants. With the accumulation of keratin in the stellate reticulum (SR) region and subsequent odontogenic cyst formation, SI cells gradually lost the ability to differentiate, and the expression of Sox2 and Notch1 was downregulated, leading to ameloblast depolarization. As a consequence, the organization of the Msx2 mutant enamel organ became disturbed and enamel failed to form in the normal location. Instead, there was ectopic mineralization that likely occurred within the SR. In summary, we show that during amelogenesis, Msx2 executes a bipartite function, repressing the transformation of OEE into a keratinized stratified squamous epithelium while simultaneously promoting the development of a properly differentiated enamel organ competent for enamel formation.
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Órgano del Esmalte/metabolismo , Epitelio/metabolismo , Proteínas de Homeodominio/metabolismo , Ameloblastos/metabolismo , Animales , Diferenciación Celular , Proliferación Celular , Quistes/embriología , Quistes/metabolismo , Microanálisis por Sonda Electrónica , Órgano del Esmalte/embriología , Epitelio/embriología , Genotipo , Hibridación in Situ , Etiquetado Corte-Fin in Situ , Ratones , Ratones Noqueados , Microscopía Electrónica de Transmisión , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Microtomografía por Rayos XRESUMEN
Objective: To investigate the possibility of the visual system homeobox 1 (VSX1) gene as a candidate susceptibility gene for Chinese patients with sporadic keratoconus, and to identify sequence variants of the VSX1 gene in such patients. Methods: Cross-sectional study. Genomic DNA was extracted from the leukocytes in the peripheral venous blood of 50 patients with sporadic keratoconus and 50 control subjects without this ocular disorder. Five exons and the intron-exon splicing of the VSX1 gene were amplified by polymerase chain reaction (PCR). The PCR products were directly sequenced and compared to the GeneBank database to find mutations. Bioinformatics analysis was done to predict the influence of these mutations on proteins. Results: One novel missense heterozygous mutation (p.R131P) was found in exon 1 of the VSX1 gene in one keratoconus patient. Another heterozygous mutation (p.G160V) in exon 2 was found in two keratoconus patients. These mutations were not detected in the control subjects. Bioinformatics analysis predicted that the p.R131P mutation may not cause a pathogenic change, but the p.G160V mutation might be functionally deleterious. In intron 3 of the VSX1 gene, the nucleotide substitution of g.8326G>A was detected to be heterozygous in 3 cases of sporadic keratoconus and 4 cases of control and homozygous in 2 cases of sporadic keratoconus and 1 case of control. The variation of g.8326G>A belonged to a single polymorphism change of the VSX1 gene. Conclusions: The p.R131P detected in this study is a novel mutation of the VSX1 gene. Sequence variants of the VSX1 gene were identified for the first time in Chinese patients with sporadic keratoconus, but their precise role in disease causation requires further investigations. (Chin J Ophthalmol, 2018, 54: 212-217).
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Proteínas del Ojo , Proteínas de Homeodominio , Queratocono , Estudios de Casos y Controles , China , Estudios Transversales , Proteínas del Ojo/genética , Proteínas de Homeodominio/genética , Humanos , Queratocono/genética , MutaciónRESUMEN
Human cleft lip with or without cleft palate (CL/P) is a common craniofacial abnormality caused by impaired fusion of the facial prominences. We have previously reported that, in the mouse embryo, epithelial apoptosis mediates fusion at the seam where the prominences coalesce. Here, we show that apoptosis alone is not sufficient to remove the epithelial layers. We observed morphological changes in the seam epithelia, intermingling of cells of epithelial descent into the mesenchyme and molecular signatures of epithelial-mesenchymal transition (EMT). Utilizing mouse lines with cephalic epithelium-specific Pbx loss exhibiting CL/P, we demonstrate that these cellular behaviors are Pbx dependent, as is the transcriptional regulation of the EMT driver Snail1. Furthermore, in the embryo, the majority of epithelial cells expressing high levels of Snail1 do not undergo apoptosis. Pbx1 loss- and gain-of-function in a tractable epithelial culture system revealed that Pbx1 is both necessary and sufficient for EMT induction. This study establishes that Pbx-dependent EMT programs mediate murine upper lip/primary palate morphogenesis and fusion via regulation of Snail1. Of note, the EMT signatures observed in the embryo are mirrored in the epithelial culture system.
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Tipificación del Cuerpo/genética , Transición Epitelial-Mesenquimal/genética , Cara/embriología , Morfogénesis/genética , Nariz/embriología , Factor de Transcripción 1 de la Leucemia de Células Pre-B/fisiología , Factores de Transcripción de la Familia Snail/genética , Animales , Apoptosis/genética , Células Cultivadas , Labio Leporino/embriología , Labio Leporino/genética , Fisura del Paladar/embriología , Fisura del Paladar/genética , Embrión de Mamíferos , Cara/anomalías , Regulación del Desarrollo de la Expresión Génica , Labio/embriología , Ratones , Ratones Transgénicos , Hueso Paladar/embriología , Factor de Transcripción 1 de la Leucemia de Células Pre-B/genéticaRESUMEN
Objective To investigate the expression of HOXB7 in colorectal cancer and its relationship with clinicopathological factors and prognosis.Methods Eighty-seven patients with colorectal cancer were retrospectively analyzed.The expression of HOXB7 mRNA and protein in colorectal cancer tissues was detected by RT-PCR and immunohistochemical methods.Their correlation with clinicopathological parameters and prognosis was analyzed.Results The relative expression level of HOXB7 mRNA in colorectal cancer tissue was(42.4 ± 16.3),which was significantly higher than(19.4 ± 7.6) in the paracancerous normal tissue(P＜0.05).The positive expression rate of HOXB7 protein in colorectal cancer tissues was 73.9％,which was obviously higher than 10.3 ％ in the paracancerous normal tissue (P＜ 0.05);expression of HOXB7 protein was significantly correlated with the TNM stage,lymph node metastasis and distant metastasis(P＜0.05),moreover the patients with HOXB7 positive expression had poorer prognosis.Conclusion HOXB7 protein expression is up-regulated in colorectal cancer tissue,and its high expression is correlated with the clinicopathological factors and prognosis in the patients with colorectal cancer.
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The regulation of innate immunity and plant growth, along with the trade-off between them, affects the defense and recovery mechanisms of the plant after it is attacked by pathogens. Although it is known that hormonal crosstalk plays a major role in regulating interaction of plant growth and PAMP-triggered immunity, the relationship between plant growth and effector-triggered immunity (ETI) remains unclear. In a large-scale yeast two-hybrid screening for Pik-H4-interacting proteins, a homeodomain transcription factor OsBIHD1 was identified, which is previously known to function in biotic and abiotic stress responses. The knockout of OsBIHD1 in rice lines carrying Pik-H4 largely compromised the resistance of the rice lines to Magnaporthe oryzae, the fungus that causes rice blast. While overexpression of OsBIHD1 resulted in enhanced expression of the pathogenesis-related (PR) and ethylene (ET) synthesis genes. Moreover, OsBIHD1 was also found to directly bind to the promoter region of ethylene-synthesis enzyme OsACO3. In addition, OsBIHD1 overexpression or deficiency provoked dwarfism and reduced brassinosteroid (BR) insensitivity through repressing the expression of several critical genes involved in BR biosynthesis and BR signaling. During M. oryzae infection, transcript levels of the crucial BR catabolic genes (CYP734A2, CYP734A4, and CYP734A6) were significantly up-regulated in OsBIHD1-OX plants. Furthermore, OsBIHD1 was found to be capable of binding to the sequence-specific cis-elements on the promoters of CYP734A2 to suppress the plant growth under fungal invasion. Our results collectively suggest a model that OsBIHD1 is required for Pik-H4-mediated blast resistance through modulating the trade-off between resistance and growth by coordinating brassinosteroid-ethylene pathway.
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BACKGROUND: The NAC family of transcription factors is one of the largest gene families of transcription factors in plants and the conifer NAC gene family is at least as large, or possibly larger, as in Arabidopsis. These transcription factors control both developmental and stress induced processes in plants. Yet, conifer NACs controlling stress induced processes has received relatively little attention. This study investigates NAC family transcription factors involved in the responses to the pathogen Heterobasidion annosum (Fr.) Bref. sensu lato. RESULTS: The phylogeny and domain structure in the NAC proteins can be used to organize functional specificities, several well characterized stress-related NAC proteins are found in III-3 in Arabidopsis (Jensen et al. Biochem J 426:183-196, 2010). The Norway spruce genome contain seven genes with similarity to subgroup III-3 NACs. Based on the expression pattern PaNAC03 was selected for detailed analyses. Norway spruce lines overexpressing PaNAC03 exhibited aberrant embryo development in response to maturation initiation and 482 misregulated genes were identified in proliferating cultures. Three key genes in the flavonoid biosynthesis pathway: a CHS, a F3'H and PaLAR3 were consistently down regulated in the overexpression lines. In accordance, the overexpression lines showed reduced levels of specific flavonoids, suggesting that PaNAC03 act as a repressor of this pathway, possibly by directly interacting with the promoter of the repressed genes. However, transactivation studies of PaNAC03 and PaLAR3 in Nicotiana benthamiana showed that PaNAC03 activated PaLAR3A, suggesting that PaNAC03 does not act as an independent negative regulator of flavan-3-ol production through direct interaction with the target flavonoid biosynthetic genes. CONCLUSIONS: PaNAC03 and its orthologs form a sister group to well characterized stress-related angiosperm NAC genes and at least PaNAC03 is responsive to biotic stress and appear to act in the control of defence associated secondary metabolite production.
Asunto(s)
Flavonoides/biosíntesis , Picea/embriología , Proteínas de Plantas/metabolismo , Regulación de la Expresión Génica de las Plantas , Familia de Multigenes , Noruega , Filogenia , Picea/clasificación , Picea/genética , Picea/metabolismo , Proteínas de Plantas/genética , Factores de Transcripción/genética , Factores de Transcripción/metabolismoRESUMEN
Gonadotrope cell identity genes emerge in a stepwise process during mouse pituitary development. Cga, encoding for the α-subunit of TSH, LH, and FSH, is initially detected at E11.5 followed by Gnrhr and steroidogenic factor Sf1 at E13.5, specifying cells engaged in a gonadotrope cell fate. Lhb and Fshb appear at E16.5 and 17.5, respectively, typifying differentiated gonadotrope cells. Using the αT1-1, αT3-1 and LßT2 cell lines recapitulating these stages of gonadotrope differentiation, DNA methylation at Gnrhr and Sf1 was investigated. Regulatory regions were found hypermethylated in progenitor αT1-1 cells and hypomethylated in differentiated LßT2 cells. Abundance of RNA polymerase II together with active histone modifications including H3K4me1, H3K4me3, and H3K27ac were strictly correlated with DNA hypomethylation. Analyses of epigenomic modifications and chromatin accessibility were further extended to Isl1, Lhx3, Gata2, and Pitx2, highlighting alternative usages of specific regulatory gene domains in progenitor αT1-1, immature αT3-1, and mature LßT2 gonadotrope cells.
Asunto(s)
Metilación de ADN , Elementos de Facilitación Genéticos , Gonadotrofos/citología , Regiones Promotoras Genéticas , Animales , Diferenciación Celular , Línea Celular , Epigénesis Genética , Epigenómica/métodos , Regulación del Desarrollo de la Expresión Génica , Hormonas Glicoproteicas de Subunidad alfa/genética , Gonadotrofos/metabolismo , Ratones , Factores de Empalme de ARN/genética , Receptores LHRH/genéticaRESUMEN
Transcription-regulating long non-coding RNAs (lncRNAs) have the potential to control the site-specific expression of thousands of target genes. Previously, we showed that Evf2, the first described ultraconserved lncRNA, increases the association of transcriptional activators (DLX homeodomain proteins) with key DNA enhancers but represses gene expression. In this report, mass spectrometry shows that the Evf2-DLX1 ribonucleoprotein (RNP) contains the SWI/SNF-related chromatin remodelers Brahma-related gene 1 (BRG1, SMARCA4) and Brahma-associated factor (BAF170, SMARCC2) in the developing mouse forebrain. Evf2 RNA colocalizes with BRG1 in nuclear clouds and increases BRG1 association with key DNA regulatory enhancers in the developing forebrain. While BRG1 directly interacts with DLX1 and Evf2 through distinct binding sites, Evf2 directly inhibits BRG1 ATPase and chromatin remodeling activities. In vitro studies show that both RNA-BRG1 binding and RNA inhibition of BRG1 ATPase/remodeling activity are promiscuous, suggesting that context is a crucial factor in RNA-dependent chromatin remodeling inhibition. Together, these experiments support a model in which RNAs convert an active enhancer to a repressed enhancer by directly inhibiting chromatin remodeling activity, and address the apparent paradox of RNA-mediated stabilization of transcriptional activators at enhancers with a repressive outcome. The importance of BRG1/RNA and BRG1/homeodomain interactions in neurodevelopmental disorders is underscored by the finding that mutations in Coffin-Siris syndrome, a human intellectual disability disorder, localize to the BRG1 RNA-binding and DLX1-binding domains.
Asunto(s)
Ensamble y Desensamble de Cromatina/fisiología , ADN Helicasas/metabolismo , Regulación de la Expresión Génica/genética , Proteínas de Homeodominio/metabolismo , Proteínas Nucleares/metabolismo , Prosencéfalo/embriología , ARN Largo no Codificante/metabolismo , Ribonucleoproteínas/metabolismo , Factores de Transcripción/metabolismo , Anomalías Múltiples/genética , Animales , Secuencia de Bases , Ensamble y Desensamble de Cromatina/genética , Inmunoprecipitación de Cromatina , ADN Helicasas/genética , Cartilla de ADN/genética , Cara/anomalías , Deformidades Congénitas de la Mano/genética , Humanos , Inmunohistoquímica , Hibridación Fluorescente in Situ , Discapacidad Intelectual/genética , Espectrometría de Masas , Ratones , Micrognatismo/genética , Datos de Secuencia Molecular , Cuello/anomalías , Proteínas Nucleares/genética , ARN Largo no Codificante/genética , Análisis de Secuencia de ARN , Factores de Transcripción/genéticaRESUMEN
Meis homeodomain transcription factors control cell proliferation, cell fate specification and differentiation in development and disease. Previous studies have largely focused on Meis contribution to the development of non-neuronal tissues. By contrast, Meis function in the brain is not well understood. Here, we provide evidence for a dual role of the Meis family protein Meis2 in adult olfactory bulb (OB) neurogenesis. Meis2 is strongly expressed in neuroblasts of the subventricular zone (SVZ) and rostral migratory stream (RMS) and in some of the OB interneurons that are continuously replaced during adult life. Targeted manipulations with retroviral vectors expressing function-blocking forms or with small interfering RNAs demonstrated that Meis activity is cell-autonomously required for the acquisition of a general neuronal fate by SVZ-derived progenitors in vivo and in vitro. Additionally, Meis2 activity in the RMS is important for the generation of dopaminergic periglomerular neurons in the OB. Chromatin immunoprecipitation identified doublecortin and tyrosine hydroxylase as direct Meis targets in newly generated neurons and the OB, respectively. Furthermore, biochemical analyses revealed a previously unrecognized complex of Meis2 with Pax6 and Dlx2, two transcription factors involved in OB neurogenesis. The full pro-neurogenic activity of Pax6 in SVZ derived neural stem and progenitor cells requires the presence of Meis. Collectively, these results show that Meis2 cooperates with Pax6 in generic neurogenesis and dopaminergic fate specification in the adult SVZ-OB system.