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1.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(6): 616-619, 2019 Jun 10.
Artigo em Chinês | MEDLINE | ID: mdl-31055820

RESUMO

OBJECTIVE: To identify mutation of the PAX6 gene in a patient with congenital aniridia. METHODS: DNA was extracted from peripheral blood sample of the patient and analyzed by direct PCR-Sanger sequencing. RESULTS: The proband was found to harbor a heterozygous c.239T>A (p.Ile80Asn) mutation of the PAX6 gene. The same mutation was not found in his parents and 150 healthy controls. CONCLUSION: A novel mutation of the PAX6 gene has been identified in a sporadic case with congenital aniridia.


Assuntos
Aniridia , Fator de Transcrição PAX6/genética , Aniridia/genética , Sequência de Bases , Humanos , Mutação , Linhagem
2.
Gene ; 705: 177-180, 2019 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-30986449

RESUMO

Congenital nystagmus (CN) is a heterogeneous disease that shows variable clinical features. There are a few mutations that are known to cause CN. Among them, a PAX6 mutation is known to cause CN with an extremely high frequency of aniridia. Here, we report on a family with an autosomal dominant PAX6 mutation, c.214G > A (p.Gly72Ser.), who presented with CN in the absence of aniridia. This study describes detailed clinical findings, including videonystagmography and fundus photography findings and emphasizes the importance of screening for the PAX6 gene in patients who present with CN in the absence of aniridia, as this will further elucidate the known phenotypes of PAX6-related diseases.


Assuntos
Coloboma/patologia , Nistagmo Congênito/patologia , Nervo Óptico/anormalidades , Fator de Transcrição PAX6/genética , Mutação Puntual , Sequenciamento Completo do Exoma/métodos , Pré-Escolar , Coloboma/genética , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Nistagmo Congênito/genética , Disco Óptico/patologia , Nervo Óptico/patologia , Linhagem , Fenótipo , Gravação em Vídeo
3.
Proc Natl Acad Sci U S A ; 116(14): 7089-7094, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30894491

RESUMO

The primate cerebrum is characterized by a large expansion of cortical surface area, the formation of convolutions, and extraordinarily voluminous subcortical white matter. It was recently proposed that this expansion is primarily driven by increased production of superficial neurons in the dramatically enlarged outer subventricular zone (oSVZ). Here, we examined the development of the parietal cerebrum in macaque monkey and found that, indeed, the oSVZ initially adds neurons to the superficial layers II and III, increasing their thickness. However, as the oSVZ grows in size, its output changes to production of astrocytes and oligodendrocytes, which in primates outnumber cerebral neurons by a factor of three. After the completion of neurogenesis around embryonic day (E) 90, when the cerebrum is still lissencephalic, the oSVZ enlarges and contains Pax6+/Hopx+ outer (basal) radial glial cells producing astrocytes and oligodendrocytes until after E125. Our data indicate that oSVZ gliogenesis, rather than neurogenesis, correlates with rapid enlargement of the cerebrum and development of convolutions, which occur concomitantly with the formation of cortical connections via the underlying white matter, in addition to neuronal growth, elaboration of dendrites, and amplification of neuropil in the cortex, which are primary factors in the formation of cerebral convolutions in primates.


Assuntos
Cérebro/crescimento & desenvolvimento , Cérebro/metabolismo , Ventrículos Laterais/crescimento & desenvolvimento , Ventrículos Laterais/metabolismo , Neurogênese/fisiologia , Neurônios/metabolismo , Animais , Astrócitos/metabolismo , Cérebro/citologia , Cérebro/embriologia , Embrião de Mamíferos , Proteínas de Homeodomínio/metabolismo , Ventrículos Laterais/citologia , Ventrículos Laterais/embriologia , Macaca , Oligodendroglia/citologia , Oligodendroglia/metabolismo , Fator de Transcrição PAX6/metabolismo , Primatas , Proteínas Supressoras de Tumor/metabolismo
4.
Int J Oncol ; 54(5): 1884-1896, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30896829

RESUMO

The abnormal expression of microRNAs (miRNAs or miRs) with oncogenic or tumor­suppressive roles in pancreatic ductal adenocarcinoma (PDAC) has been widely reported in recent years, and these dysregulated miRNAs are implicated in the formation and progression of PDAC. Therefore, an investigation into the functional roles of miRNAs in PDAC may facilitate the identification of effective therapeutic targets. miRNA­664 (miR­664) has been found to be aberrantly expressed and to play crucial roles in several human cancer types. However, the expression pattern and functional roles of miR­664 in the malignant capacity of PDAC have yet to be elucidated. In this study, the results revealed that miR­664 was clearly downregulated in PDAC tissues and cell lines. The low miR­664 expression was strongly associated with pathological T stage and lymph node metastasis of the patients with PDAC. Patients with PDAC with a low miR­664 expression had a poorer overall survival and a worse disease­free survival than those patients with a high miR­664 level. Functional experiments suggested that exogenous miR­664 expression suppressed the growth and metastasis of PDAC cells in vitro, whereas miR­664 downregulation exerted the opposite effects. In addition, miR­664 suppressed the tumor growth of PDAC cells in vivo. Mechanistically, paired box protein 6 (PAX6) was identified as a direct target gene of miR­664 in PDAC cells. Furthermore, PAX6 was upregulated in PDAC tissues, and its upregulation inversely correlated with miR­664 levels. Moreover, the silencing of PAX6 mimicked the effects of miR­664 upregulation in PDAC cells, and the recovered expression of PAX6 eliminated the effects of miR­664 on PDAC cells. Notably, miR­664 could inhibit the activation of PI3K/Akt pathway in PDAC cells in vitro and in vivo. Cumulatively, these results indicate an important role of the miR­664/PAX6 pathway in suppressing the aggressiveness of PDAC cells, suggesting that miR­664 may be an attractive therapeutic target for the treatment of patients with this fatal disease.


Assuntos
Carcinoma Ductal Pancreático/patologia , MicroRNAs/genética , Fator de Transcrição PAX6/genética , Neoplasias Pancreáticas/patologia , Animais , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Metástase Neoplásica , Estadiamento de Neoplasias , Fator de Transcrição PAX6/metabolismo , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Prognóstico
5.
Invest Ophthalmol Vis Sci ; 60(2): 570-579, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30721274

RESUMO

Purpose: The adult mammalian retina is typically incapable of regeneration when damaged by disease or trauma. Restoration of function would require generation of new adult neurons, something that until recently, mammals were thought to be incapable of doing. However, previous studies from this laboratory have shown that the α7 nicotinic acetylcholine receptor (α7 nAChR) agonist, PNU-282987, induces cell cycle reentry of Müller glia and generation of mature retinal neurons in adult rats, in the absence of detectible injury. This study analyzes how PNU-282987 treatment in RPE leads to robust BrdU incorporation in Müller glia in adult mice and leads to generation of Müller-derived retinal progenitors and neuronal differentiation. Methods: Retinal BrdU incorporation was examined after eye drop application of PNU-282987 in adult wild-type and transgenic mice that contain tamoxifen-inducible tdTomato Müller glia, or after intraocular injection of conditioned medium from PNU-282987-treated cultured RPE cells. Results: PNU-282987 induced robust incorporation of BrdU in all layers of the adult mouse retina. The α7 nAChR agonist was found to stimulate cell cycle reentry of Müller glia and their generation of new retinal progenitors indirectly, via the RPE, in an α7 nAChR-dependent fashion. Conclusions: The results from this study point to RPE as a contributor to Müller glial neurogenic responses. The manipulation of the RPE to stimulate retinal neurogenesis offers a new direction for developing novel and potentially transformative treatments to reverse the loss of neurons associated with neurodegenerative disease, traumatic injury, or aging.


Assuntos
Benzamidas/farmacologia , Compostos Bicíclicos com Pontes/farmacologia , Células Ependimogliais/fisiologia , Neurogênese/fisiologia , Neuroglia/fisiologia , Agonistas Nicotínicos/farmacologia , Epitélio Pigmentado da Retina/efeitos dos fármacos , Receptor Nicotínico de Acetilcolina alfa7/agonistas , Animais , Bromodesoxiuridina/metabolismo , Ciclo Celular/fisiologia , Células Cultivadas , Células Ependimogliais/citologia , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Fator de Transcrição PAX6/metabolismo , Ratos , Epitélio Pigmentado da Retina/citologia , Epitélio Pigmentado da Retina/metabolismo , Células-Tronco/fisiologia
6.
BMC Ophthalmol ; 19(1): 10, 2019 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-30621664

RESUMO

BACKGROUND: This study aims to investigate the clinical characterization and causative genetic defect of a four-generation Chinese family with autosomal dominant aniridia. METHODS: The recruited family members underwent comprehensive routine and ophthalmic examinations, and Sanger sequencing was performed to screen the mutation in PAX6. RESULTS: A novel heterozygous PAX6 deletion c.435_445delTAGCGAAAAGC (p.Ser146ThrfsX9) in exon 7 was identified in all affected individuals, but this was absent in any of the unaffected family members and in the 200 unrelated controls. CONCLUSION: A novel deletion in the PAX6 gene was identified in a Chinese family associated with aniridia, which expands the spectrum of the PAX6 mutation and its associated phenotype.


Assuntos
Aniridia/genética , Grupo com Ancestrais do Continente Asiático/genética , Proteínas do Olho/genética , Predisposição Genética para Doença/genética , Fator de Transcrição PAX6/genética , Deleção de Sequência , Adulto , Pré-Escolar , China , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
7.
Diabetes Res Clin Pract ; 148: 64-71, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30572005

RESUMO

AIMS: Analyze cosegregation of aniridia and diabetes to identify genetic criteria for detection and early treatment of diabetes-susceptible aniridia patients. METHODS: We assessed a two-generation family: three individuals with aniridia, two previously diagnosed as type 2 diabetes. One individual with aniridia, with unknown diabetes status, was evaluated by oral glucose tolerance test. Genetic analysis of aniridia-associated genes was performed on all available family members. Candidate genes were functionally tested by gene silencing in MIN6 pancreatic ß-cells. RESULTS: A 25 year old male with aniridia had a diabetic oral glucose tolerance test despite a normal fasting blood glucose. A 484-630 kb deletion ∼120 kb distal to PAIRED BOX 6 (PAX6) showed dominant cosegregation with aniridia and diabetes in all affected family members. The deleted region contains regulatory elements for PAX6 expression and four additional coding regions. Knockdown of two of the deleted genes (Dnajc24 or Immp1l) with Pax6 impaired glucose-stimulated insulin secretion. CONCLUSIONS: We demonstrate dominant cosegregation of diabetes and aniridia with a deletion distal to PAX6, which is clinically distinct from the mild glucose intolerance previously reported with PAX6 coding mutations. Asymptomatic aniridia individuals appear at risk of diabetes (and its complications) and could benefit from earlier diagnosis and treatment.


Assuntos
Aniridia/complicações , Aniridia/genética , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/genética , Fator de Transcrição PAX6/genética , Deleção de Sequência , Adulto , Família , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Fases de Leitura Aberta/genética , Linhagem , Regiões não Traduzidas/genética
8.
Mol Med Rep ; 19(2): 1403-1409, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30569166

RESUMO

MicroRNAs (miRNAs/miRs) negatively regulate the expression of numerous genes and therefore contribute to the occurrence and development of papillary thyroid carcinoma (PTC). Hence, further investigation into the specific roles of miRNAs in PTC is valuable for developing effective therapeutic methods for patients with this disease. MiRNA­509 is dysregulated and serves pivotal roles in several types of human cancer; however, the expression and roles of miR­509 in PTC and its underlying mechanism require further investigation. In the present study, the expression of miR­509 in PTC tissues and cell lines was detected and the specific functions of miR­509 in the progression of PTC were investigated. Additionally, the molecular mechanisms underlying the action of miR­509 in PTC were determined. The present study demonstrated that miR­509 was significantly downregulated in PTC tissues and cell lines. MiR­509 upregulation inhibited the PTC cell proliferation and invasion. Mechanistically, paired box 6 (PAX6) was identified as a novel target of miR­509 in PTC cells. In clinical PTC samples, miR­509 was significantly overexpressed and inversely correlated with PAX6 expression. PAX6 restoration effectively reversed the inhibitory effects of miR­509 overexpression on PTC cell proliferation and invasion. These results demonstrated that miR­509 may act as a tumor suppressor in PTC by directly targeting PAX6. Thus, miR­509 may be a potential therapeutic target for the treatment of patients with PTC.


Assuntos
Carcinoma Papilar/genética , Proliferação de Células/genética , MicroRNAs/genética , Invasividade Neoplásica/genética , Fator de Transcrição PAX6/genética , Câncer Papilífero da Tireoide/genética , Neoplasias da Glândula Tireoide/genética , Adulto , Carcinoma Papilar/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Regulação para Baixo/genética , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/patologia , Câncer Papilífero da Tireoide/patologia , Neoplasias da Glândula Tireoide/patologia , Regulação para Cima/genética
9.
Exp Eye Res ; 180: 208-225, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30590023

RESUMO

Ocular surface disease is one major type of eye diseases. Different etiologies trigger distinct pathological responses of the ocular surface. We previously reported that genetically engineered mice with ablation of Prickle 1 manifested precocious eyelid opening with ensuing cornea dysplasia. The current study aimed to characterize the molecular traits and the direct cause of ocular pathology associated with precocious eyelid opening in the Prickle 1 mutant mouse. Prickle 1 mutant mice exhibited a slew of ocular surface pathology including cell proliferation, cell fate transformation and inflammatory infiltration coinciding with the timing of the precocious eyelid opening. Forced eyelid opening in wild type mice did not induce cornea pathology comparable to that of the Prickle 1 mutants. Necrotic tissue debris was found associated with the lesioned cornea. RNAseq analysis of the mutant cornea revealed an expression profile shared by a range of dermatological diseases involving immune responses and cancer. Taken together, the data suggest that the necrotic eyelid debris plays an important role in ocular pathogenesis of the Prickle 1 mutant mouse, which may represent a type of non-infectious keratoconjunctivitis caused by damaged autologous tissues. Additionally, Prickle 1 mutant cornea pathogenesis may offer molecular insights into other types of epithelial pathogenesis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Córnea/patologia , Pálpebras/fisiologia , Ceratoconjuntivite/genética , Proteínas com Domínio LIM/genética , Animais , Animais Recém-Nascidos , Túnica Conjuntiva/patologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/fisiologia , Células Caliciformes/patologia , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Ceratoconjuntivite/fisiopatologia , Metaplasia , Camundongos , Camundongos Endogâmicos C57BL , Necrose/patologia , Fator de Transcrição PAX6/genética , Reação em Cadeia da Polimerase em Tempo Real
10.
Respir Res ; 19(1): 262, 2018 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-30594196

RESUMO

BACKGROUND: This study investigated the function of SMAD3 (SMAD family member 3) in regulating PAX6 (paired box 6) in non-small cell lung cancer. METHODS: First, qRT-PCR was employed to detect SMAD3 expression in cancer tissues along with normal tissues and four cell lines, including BEAS-2B, H125, HCC827 and A549 cells. SMAD3 was knocked down by small interference RNA (siRNA), and then its expression was determined via qRT-PCR and Western blot analysis. The correlation between SMAD3 and PAX6 was determined by double luciferase reporter experiments and chromatin immunoprecipitation (ChIP) assay. Cell viability was evaluated by CCK-8 and colony forming assays, while cell migration and invasion were detected by Transwell analysis. RESULTS: SMAD3 and PAX6 were upregulated in lung cancer tissues and cancer cells. Knocking down SMAD3 and PAX6 by transfection with siRNAs specifically suppressed the expression of SMAD3 and PAX6 mRNA and protein levels. SMAD3 could promote PAX6 transcriptional activity by binding to its promoter. Reduced expression of SMAD3 led to the downregulation of PAX6 mRNA and protein levels along with decreased cell migration, invasion, proliferation and viability in A549 and HCC827 cells. PAX6 overexpression altered the si-SMAD3-induced inhibition of cell migration, invasion, proliferation and viability in A549 and HCC827 cells. Additionally, PAX6 knockdown alone also repressed the cell migration, invasion, proliferation and viability of the cell lines. CONCLUSIONS: SMAD3 promotes the progression of non-small cell lung cancer by upregulating PAX6 expression.


Assuntos
Biomarcadores Tumorais/biossíntese , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Neoplasias Pulmonares/metabolismo , Fator de Transcrição PAX6/biossíntese , Proteína Smad3/biossíntese , Transcrição Genética/fisiologia , Células A549 , Biomarcadores Tumorais/genética , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/patologia , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Fator de Transcrição PAX6/genética , Proteína Smad3/genética
11.
Hum Genet ; 137(10): 831-846, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30291432

RESUMO

There is an increasing implication of non-coding regions in pathological processes of genetic origin. This is partly due to the emergence of sophisticated techniques that have transformed research into gene expression by allowing a more global understanding of the genome, both at the genomic, epigenomic and chromatin levels. Here, we implemented the analysis of PAX6, whose coding loss-of-function variants are mainly implied in aniridia, by studying its non-coding regions (untranslated regions, introns and cis-regulatory sequences). In particular, we have taken advantage of the development of high-throughput approaches to screen the upstream and downstream regulatory regions of PAX6 in 47 aniridia patients without identified mutation in the coding sequence. This was made possible through the use of custom targeted resequencing and/or CGH array to analyze the entire PAX6 locus on 11p13. We found candidate variants in 30 of the 47 patients. 9/30 correspond to the well-known described 3' deletions encompassing SIMO and other enhancer elements. In addition, we identified numerous different variants in various non-coding regions, in particular untranslated regions. Among these latter, most of them demonstrated an in vitro functional effect using a minigene strategy, and 12/21 are thus considered as causative mutations or very likely to explain the phenotypes. This new analysis strategy brings molecular diagnosis to more than 90% of our aniridia patients. This study revealed an outstanding mutation pattern in non-coding PAX6 regions confirming that PAX6 remains the major gene for aniridia.


Assuntos
Regiões 3' não Traduzidas , Aniridia/genética , Elementos Facilitadores Genéticos , Loci Gênicos , Mutação , Fator de Transcrição PAX6/genética , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
12.
Graefes Arch Clin Exp Ophthalmol ; 256(11): 2157-2164, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30167917

RESUMO

PURPOSE: Aniridia is a rare panocular disorder caused by mutations in the PAX6 gene and characterized mainly by iris hypoplasia. Here, we present six families with a history of low vision/blindness with a previously undiagnosed mild aniridia phenotype with minimal iris changes. METHODS: Retrospective case series of patients diagnosed with a subtle aniridia phenotype characterized by minimal iris abnormalities, foveal hypoplasia, and an identified mutation in PAX6. Data collection from patient's charts included ocular examination findings, visual acuity, refraction, and clinical pictures when available. Genetic analysis was performed by isolation of genomic DNA from peripheral blood. The main outcome was the identification of patients with mild aniridia harboring a PAX6 mutation. RESULTS: In all six families, the phenotype included minimal corectopia and foveal hypoplasia; nystagmus was present in 10 out of 11 patients. A PAX6 mutation was identified in all six families; three of these mutations were identified previously, and three are novel mutations. All the mutations are located within the conventional 128-residue paired domain of PAX6. CONCLUSIONS: A mild form of aniridia should be considered in the differential diagnosis of patients with low vision associated with mild iris abnormalities, nystagmus, and foveal hypoplasia. To ensure an accurate diagnosis of aniridia, minimal pupillary changes and/or incipient keratopathy should be examined. The broad phenotypic heterogeneity among aniridia leads to the fact that eye care clinicians must have a high index of suspicion for the disease when seeing undiagnosed low vision patients, because proper diagnosis can improve management as well as facilitate genetic testing and counselling.


Assuntos
Aniridia/diagnóstico , Cegueira/diagnóstico , Oftalmopatias Hereditárias/diagnóstico , Mutação de Sentido Incorreto , Baixa Visão/diagnóstico , Adulto , Idoso , Aniridia/genética , Aniridia/fisiopatologia , Cegueira/genética , Cegueira/fisiopatologia , Criança , Pré-Escolar , Oftalmopatias Hereditárias/genética , Oftalmopatias Hereditárias/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fator de Transcrição PAX6/genética , Linhagem , Fenótipo , Refração Ocular/fisiologia , Estudos Retrospectivos , Baixa Visão/genética , Baixa Visão/fisiopatologia , Acuidade Visual/fisiologia , Adulto Jovem
13.
Mol Vis ; 24: 536-545, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30090016

RESUMO

Purpose: In mice, retinal development continues throughout the postnatal stage accompanied by the proliferation of retinal precursor cells. Previous reports showed that during the postnatal stage microglia increase from postnatal day 0 (P0) to P7. However, how microglia are associated with retinal development remains unknown. Methods: The involvement of microglia in retinal development was investigated by two approaches, microglial activation and loss, using lipopolysaccharide (LPS) and PLX3397 (pexidartinib), respectively. Results: LPS injection at 1 mg/kg, intraperitoneally (i.p.) in the neonatal mice increased the number of retinal microglia at P7. 5-Bromo-2´-deoxyuridine (BrdU)-positive proliferative cells were increased by LPS treatment compared to the control group. The proliferative cells were mainly colocalized with paired box 6 (Pax6), a marker of retinal precursor cells. However, the depletion of microglia by treatment with PLX3397 decreased the BrdU-positive proliferative cells. Moreover, progranulin deficiency decreased the number of microglia and retinal precursor cells. Conclusions: These findings indicated that microglia regulate the proliferation of immature retinal cells.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Peptídeos e Proteínas de Sinalização Intercelular/genética , Microglia/citologia , Fator de Transcrição PAX6/genética , Retina/citologia , Células-Tronco/citologia , Aminopiridinas/farmacologia , Animais , Animais Recém-Nascidos , Bromodesoxiuridina , Calbindinas/genética , Calbindinas/metabolismo , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Comunicação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Injeções Intraperitoneais , Peptídeos e Proteínas de Sinalização Intercelular/deficiência , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Microglia/efeitos dos fármacos , Microglia/metabolismo , Nestina/genética , Nestina/metabolismo , Organogênese/efeitos dos fármacos , Organogênese/genética , Fator de Transcrição PAX6/metabolismo , Pirróis/farmacologia , Retina/efeitos dos fármacos , Retina/metabolismo , Rodopsina/genética , Rodopsina/metabolismo , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo
14.
Development ; 145(15)2018 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-29986868

RESUMO

The synchronized differentiation of neuronal and vascular tissues is crucial for normal organ development and function, although there is limited information about the mechanisms regulating the coordinated development of these tissues. The choroid vasculature of the eye serves as the main blood supply to the metabolically active photoreceptors, and develops together with the retinal pigmented epithelium (RPE). Here, we describe a novel regulatory relationship between the RPE transcription factors Pax6 and Sox9 that controls the timing of RPE differentiation and the adjacent choroid maturation. We used a novel machine learning algorithm tool to analyze high resolution imaging of the choroid in Pax6 and Sox9 conditional mutant mice. Additional unbiased transcriptomic analyses in mutant mice and RPE cells generated from human embryonic stem cells, as well as chromatin immunoprecipitation and high-throughput analyses, revealed secreted factors that are regulated by Pax6 and Sox9. These factors might be involved in choroid development and in the pathogenesis of the common blinding disease: age-related macular degeneration (AMD).


Assuntos
Diferenciação Celular , Corioide/irrigação sanguínea , Corioide/metabolismo , Neovascularização Fisiológica , Fator de Transcrição PAX6/metabolismo , Epitélio Pigmentado da Retina/citologia , Epitélio Pigmentado da Retina/metabolismo , Fatores de Transcrição SOX9/metabolismo , Algoritmos , Animais , Sequência de Bases , Regulação da Expressão Gênica no Desenvolvimento , Aprendizado de Máquina , Degeneração Macular/genética , Degeneração Macular/patologia , Camundongos Endogâmicos C57BL , Modelos Biológicos , Fatores de Transcrição SOX9/genética , Fatores de Tempo , Regulação para Cima/genética
15.
Oncol Rep ; 40(3): 1777-1786, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30015924

RESUMO

Accumulated studies have highlighted that the dysregulation of microRNAs (miRNAs) in retinoblastoma (RB) is a leading cause for tumourigenesis and tumour development. Therefore, the elucidation of the expression, functional roles and underlying mechanisms of miRNAs in RB will help the development of promising therapeutic methods to improve the prognosis of RB patients. The aim of this study was to detect miRNA­758 (miR­758) expression in RB tissues and cell lines, and to determine the effects and underlying mechanisms of miR­758 on RB progression. The results demonstrated that miR­758 was downregulated in both RB tissues and cell lines. In vitro functional experiments revealed that upregulation of miR­758 inhibited cell proliferation, migration and invasion, and induced apoptosis in RB. In addition, paired box protein 6 (PAX6) was a direct target gene of miR­758 in RB. Furthermore, PAX6 was upregulated in RB tissues, and this upregulation was inversely associated with the expression level of miR­758. In addition, PAX6 reintroduction abrogated the tumour­suppressive effects of miR­758 overexpression on RB cell proliferation, migration, invasion and apoptosis. Furthermore, miR­758 overexpression inactivated the PI3K/Akt pathway in RB cells by inhibiting PAX6. In conclusion, our current study provided sufficient evidence to demonstrate that miR­758 inhibits the progression of RB by directly targeting PAX6 and regulating the PI3K/Akt pathway, thereby suggesting that this miRNA may be developed as a therapeutic target for treating patients with RB.


Assuntos
Biomarcadores Tumorais/metabolismo , Movimento Celular , Regulação Neoplásica da Expressão Gênica , MicroRNAs/genética , Fator de Transcrição PAX6/metabolismo , Retinoblastoma/patologia , Adolescente , Adulto , Apoptose , Biomarcadores Tumorais/genética , Estudos de Casos e Controles , Proliferação de Células , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Fator de Transcrição PAX6/genética , Prognóstico , Retinoblastoma/genética , Retinoblastoma/metabolismo , Células Tumorais Cultivadas , Adulto Jovem
16.
Development ; 145(15)2018 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-29980566

RESUMO

The transcription factor Pax6 is considered the master control gene for eye formation because (1) it is present within the genomes and retina/lens of all animals with a visual system; (2) severe retinal defects accompany its loss; (3) Pax6 genes have the ability to substitute for one another across the animal kingdom; and (4) Pax6 genes are capable of inducing ectopic eye/lens in flies and mammals. Many roles of Pax6 were first elucidated in Drosophila through studies of the gene eyeless (ey), which controls both growth of the entire eye-antennal imaginal disc and fate specification of the eye. We show that Ey also plays a surprising role within cells of the peripodial epithelium to control pattern formation. It regulates the expression of decapentaplegic (dpp), which is required for initiation of the morphogenetic furrow in the eye itself. Loss of Ey within the peripodial epithelium leads to the loss of dpp expression within the eye, failure of the furrow to initiate, and abrogation of retinal development. These findings reveal an unexpected mechanism for how Pax6 controls eye development in Drosophila.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Proteínas de Drosophila/fisiologia , Epitélio/embriologia , Olho/embriologia , Morfogênese/genética , Fator de Transcrição PAX6/fisiologia , Animais , Animais Geneticamente Modificados , Padronização Corporal/genética , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila/genética , Drosophila melanogaster , Embrião não Mamífero , Epitélio/metabolismo , Olho/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Discos Imaginais/embriologia , Discos Imaginais/metabolismo , Fator de Transcrição PAX6/genética
17.
J Trace Elem Med Biol ; 49: 51-59, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29895372

RESUMO

Zinc is integral for the normal function of pancreatic ß-cells in glycaemic control. Large amounts of zinc are secreted from ß-cells following insulin exocytosis and regulated replenishment is required, which is thought to be mediated by the ZIP family of zinc importer proteins. Within Type 2 Diabetic patients, ß-cells are stressed through prolonged stimulation by hyperglycaemia and this is thought to be a major factor contributing to loss of ß-cell identity and mass. However, the consequences for the ß-cell zinc status remain largely unexplored. We used inductively coupled plasma mass spectrometry (ICP-MS) to show that 24 h treatment of MIN6 cells with potassium chloride, mimicking hyperglycaemic stimulation, reduces the total cellular zinc content 2.8-fold, and qPCR to show an increase in mRNA expression for metallothioneins (Mt1 and Mt2) following 4 and 24 h of stimulation, suggestive of an early rise in cytosolic zinc. To determine which ZIP paralogues may be responsible for zinc replenishment, we used immunocytochemistry, Western blot and qPCR to demonstrate initial ZIP1 protein upregulation proceeded by downregulation of mRNA coding for ZIP1, ZIP6, ZIP7 and ZIP14. To assign a biological significance to the decreased total cellular zinc content, we assessed expression of key ß-cell markers to show downregulation of mRNA for MafA, Mnx-1, Nkx2.2 and Pax6. Our data suggest hyperglycaemia-induced zinc depletion may contribute to loss of ß-cell markers and promote ß-cell dedifferentiation through disrupting expression of key transcription factors.


Assuntos
Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Zinco/metabolismo , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Proteínas de Transporte de Cátions/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proteínas de Homeodomínio/metabolismo , Hiperglicemia/metabolismo , Imuno-Histoquímica , Fatores de Transcrição Maf Maior/metabolismo , Camundongos , Fator de Transcrição PAX6/metabolismo , Cloreto de Potássio/farmacologia , Fatores de Transcrição/metabolismo , Transportador 8 de Zinco/metabolismo
18.
Mol Vis ; 24: 407-413, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29930474

RESUMO

Purpose: To report on a clinical and genetic investigation of a large, multigenerational South African family of mixed ancestry with autosomal dominant congenital cataracts, coloboma, and nystagmus. Methods: Ophthalmic examination was performed in 27 individuals from the same admixed South African family. DNA was sampled from either peripheral blood or buccal swabs in all 27 individuals, and whole genome sequencing was performed in six individuals. Sanger sequencing was used to validate the probable mutation in the remaining family members. Results: Twenty-seven family members with 19 affected individuals were included in the study. The predominant phenotype, with highly variable expression, was congenital cataract (14 individuals), posterior segment coloboma (17 individuals), and nystagmus (18 individuals). Other features present included high myopia, microcornea, and strabismus. An R208W mutation in PAX6 (dbSNP rs757259413; HGMD CM930572; NM_000280.3:c.622G>A; NP_000271.1:p.Arg208Trp) was identified as being the most probable pathogenic mutation. Cosegregation of the mutation with the phenotype was confirmed in all 27 family members. Conclusions: PAX6 is a highly conserved gene crucial for normal oculogenesis, and although mutations within the gene may cause an array of ocular developmental abnormalities, most are associated with aniridia and aniridia-related ocular defects. The observation that PAX6 aniridia phenotypes are largely associated with nonsense mutations and milder non-aniridia phenotypes with missense mutations suggested that there may be specific genotype-phenotype correlations for the gene. The R208W mutation in PAX6 identified in this family challenges this theory as it has previously been reported in three unrelated families and is associated with aniridia and non-aniridia phenotypes across the four families. PAX6 with its wide phenotypic associations and highly variable expression should be considered a candidate gene in the diagnostic screen for any ocular developmental abnormality.


Assuntos
Catarata/genética , Coloboma/genética , Mutação , Nistagmo Patológico/genética , Fator de Transcrição PAX6/genética , Adulto , Catarata/congênito , Catarata/patologia , Criança , Coloboma/patologia , Família , Feminino , Expressão Gênica , Humanos , Masculino , Nistagmo Patológico/congênito , Nistagmo Patológico/patologia , Linhagem , Fenótipo , África do Sul , Sequenciamento Completo do Genoma
19.
Mol Med Rep ; 18(2): 1623-1627, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29901133

RESUMO

The present study investigated the clinical and mutational spectrum of aniridia in a cohort of 17 affected individuals from six families from Cyprus. Each proband was initially evaluated for copy number variants at the PAX6 locus and subsequently underwent PAX6 mutation screening. Sequence analysis of FOXC1 and PITX2 was performed in patients who did not carry a PAX6 mutation. The most common clinical features in the group of aniridia patients associated with aniridia were nystagmus, cataracts and glaucoma. PAX6 pathogenic mutations were identified in five out of six families (a diagnostic yield of 84%). Previously reported pathogenic mutations in PAX6 were identified in four families, which comprise p.R203*, p.R240* and p.R317*. In addition, a novel pathogenic variant (p.E220Gfs*23) was identified in a single family. No pathogenic mutations were detected in PAX6, FOXC1 or PITX2 in the only patient with a sporadic form of aniridia­like phenotype, confirming the genetic heterogeneity associated with this disease. To the best of our knowledge this is the first report on the mutational spectrum of PAX6 in aniridia patients of Cypriot ancestry. Mutational screening of PAX6 serves a crucial role in distinguishing isolated from syndromic forms of aniridia, and it may therefore eliminate the need for renal ultrasound scan surveillance, delineate the phenotype and improve genetic counseling.


Assuntos
Aniridia/genética , Catarata/genética , Glaucoma/genética , Mutação , Nistagmo Congênito/genética , Fator de Transcrição PAX6/genética , Aniridia/complicações , Aniridia/patologia , Sequência de Bases , Catarata/complicações , Catarata/patologia , Hibridização Genômica Comparativa , Chipre , Análise Mutacional de DNA , Éxons , Feminino , Fatores de Transcrição Forkhead/genética , Expressão Gênica , Heterogeneidade Genética , Predisposição Genética para Doença , Glaucoma/complicações , Glaucoma/patologia , Proteínas de Homeodomínio/genética , Humanos , Masculino , Nistagmo Congênito/complicações , Nistagmo Congênito/patologia , Linhagem , Fatores de Transcrição/genética
20.
J Genet ; 97(2): 555-562, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29932076

RESUMO

Aniridia is a rare congenital ocular malformation that follows an autosomal dominant mode of inheritance. Most patients carry pathogenic point mutations in the paired box 6 gene (PAX6), but some carry deletions involving the 11p13 region, encompassing partly or completely PAX6 or the region downstream. We identified a novel deletion, ~564 kb in size located about 46.5 kb downstream of PAX6 in a family with bilateral aniridia and foveal hypoplasia using array-CGH and multiplex ligation-dependent probe amplification. We also reviewall of the reported deletions downstream of PAX6 in patients with aniridia and/or other congenital malformations and define the overlapping region that leads to aniridia when deleted.


Assuntos
Aniridia/genética , Elementos Facilitadores Genéticos/genética , Fator de Transcrição PAX6/genética , Deleção de Sequência , Adolescente , Adulto , Aniridia/patologia , Análise Mutacional de DNA , Saúde da Família , Feminino , Humanos , Masculino , Linhagem
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