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1.
Phys Rev Lett ; 128(18): 187402, 2022 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-35594087

RESUMO

The fate of a Mott insulator under strong low frequency optical driving conditions is a fundamental problem in quantum many-body dynamics. Using ultrafast broadband optical spectroscopy, we measured the transient electronic structure and charge dynamics of an off-resonantly pumped Mott insulator Ca_{2}RuO_{4}. We observe coherent bandwidth renormalization and nonlinear doublon-holon pair production occurring in rapid succession within a sub-100-fs pump pulse duration. By sweeping the electric field amplitude, we demonstrate continuous bandwidth tuning and a Keldysh crossover from a multiphoton absorption to quantum tunneling dominated pair production regime. Our results provide a procedure to control coherent and nonlinear heating processes in Mott insulators, facilitating the discovery of novel out-of-equilibrium phenomena in strongly correlated systems.

2.
Phys Rev Lett ; 124(2): 027601, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-32004043

RESUMO

The transition metal thiophosphates MPS_{3} (M=Mn, Fe, Ni) are a class of van der Waals stacked insulating antiferromagnets that can be exfoliated down to the ultrathin limit. MnPS_{3} is particularly interesting because its Néel ordered state breaks both spatial-inversion and time-reversal symmetries, allowing for a linear magnetoelectric phase that is rare among van der Waals materials. However, it is unknown whether this unique magnetic structure of bulk MnPS_{3} remains stable in the ultrathin limit. Using optical second harmonic generation rotational anisotropy, we show that long-range linear magnetoelectric type Néel order in MnPS_{3} persists down to at least 5.3 nm thickness. However an unusual mirror symmetry breaking develops in ultrathin samples on SiO_{2} substrates that is absent in bulk materials, which is likely related to substrate induced strain.

3.
J Cell Biochem ; 120(1): 533-543, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30191601

RESUMO

Glioblastoma (GBM) is the most common malignant brain tumor and is associated with a poor prognosis, with most patients living less than a year after diagnosis. Given that GBM nearly always recurs after conventional treatments, there is an urgent need to identify novel molecular targets. Hairless (HR) is a nuclear factor enriched in the skin and has been previously implicated in hair cycling. HR is also highly expressed in the brain, but its significance is unknown. We found that human hairless gene (HR) expression is significantly decreased in all GBM subtypes compared with normal brain tissue and is predictive of prognosis, which suggests that loss of HR expression can contribute to GBM pathogenesis. HR was recently discovered to bind to and regulate p53 responsive elements, and thus we hypothesized that HR may have a tumor suppressive function in GBM by modulating p53 target gene expression. We found that HR indeed regulates p53 target genes, including those implicated in cell cycle progression and apoptosis in the GBM-derived U87 cell line, and restoring HR expression triggered G2/M arrest and apoptosis. An analysis of sequenced genomes from patients with GBM revealed 10 HR somatic mutations in patients with glioma, two of which are located in the histone demethylase domain of HR. These two mutations, P996S and K1004N, were reconstructed and found to have impaired p53 transactivating properties. Collectively, the results of our study suggest that HR has tumor suppressive functions in GBM, which may be clinically relevant and a potential avenue for therapeutic intervention.


Assuntos
Neoplasias Encefálicas/genética , Glioblastoma/genética , Fatores de Transcrição/genética , Proteína Supressora de Tumor p53/genética , Apoptose/genética , Linhagem Celular Tumoral , Sobrevivência Celular/genética , Pontos de Checagem da Fase G2 do Ciclo Celular/genética , Regulação Neoplásica da Expressão Gênica , Células HEK293 , Histona Desmetilases/genética , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/genética , Mutação , Prognóstico , Domínios Proteicos/genética , Transfecção , Sequenciamento Completo do Genoma
4.
J Clin Microbiol ; 57(4)2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30728196

RESUMO

Voxilaprevir is a direct-acting antiviral agent (DAA) that targets the NS3/4A protease of hepatitis C virus (HCV). High sequence diversity of HCV and inadequate drug exposure during unsuccessful treatment may lead to the accumulation of variants with reduced susceptibility to DAAs, including NS3/4A protease inhibitors such as voxilaprevir. The voxilaprevir susceptibility of clinical and laboratory strains of HCV was assessed. The NS3 protease regions of viruses belonging to 6 genotypes and 29 subtypes from 345 DAA-naive or -experienced (including protease inhibitor) patients and 344 genotype 1 to 6 replicons bearing engineered NS3 resistance-associated substitutions (RASs) were tested in transient-transfection assays. The median voxilaprevir 50% effective concentration against NS3 from protease inhibitor-naive patient samples ranged from 0.38 nM for genotype 1 to 5.8 nM for genotype 3. Voxilaprevir susceptibilities of HCV replicons with NS3 RASs were dependent on subtype background and the type and number of substitutions introduced. The majority of RASs known to confer resistance to other protease inhibitors had little to no impact on voxilaprevir susceptibility, except A156L, T, or V in genotype 1 to 4 which conferred >100-fold reductions but exhibited low replication capacity in most genotypes. These data support the use of voxilaprevir in combination with other DAAs in DAA-naive and DAA-experienced patients infected with any subtype of HCV.


Assuntos
Antivirais/farmacologia , Hepacivirus/efeitos dos fármacos , Compostos Macrocíclicos/farmacologia , Inibidores de Proteases/farmacologia , Sulfonamidas/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Substituição de Aminoácidos , Ácidos Aminoisobutíricos , Ciclopropanos , Farmacorresistência Viral/genética , Genótipo , Hepacivirus/genética , Hepatite C Crônica/virologia , Humanos , Lactamas Macrocíclicas , Leucina/análogos & derivados , Prolina/análogos & derivados , Quinoxalinas
5.
Aust N Z J Obstet Gynaecol ; 59(5): 677-683, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30734276

RESUMO

BACKGROUND: Vaginal instrumental delivery is a common obstetrical intervention, but its effect on children's later development is not well known. AIMS: To determine if vaginal instrumental delivery is associated with adverse neurodevelopment as measured by school achievement. MATERIAL AND METHODS: We performed a whole-of-population study involving linkage of routinely collected perinatal data with school assessments among children born in South Australia from 1999 to 2008. Participants were singleton children born by forceps (n = 5494), ventouse (n = 6988), or normal delivery (n = 80 803). School achievement was measured through performance on the National Assessment Program in Literacy and Numeracy (NAPLAN), at around eight years of age. This assessment involved five domains and scores were categorised according to performing at or above National Minimum Standards (NMS). Effects of instrumental versus normal vaginal delivery were analysed via augmented inverse probability weighting (AIPW), taking into account a variety of maternal, perinatal and sociodemographic characteristics. RESULTS: In unadjusted analyses, instrumental delivery was not associated with poor NAPLAN scores. AIPW analyses also suggested that instrumental delivery had minimal adverse effect on NAPLAN scores, with the largest difference being lower spelling scores among forceps-delivered children (-0.022 (95% CI -0.0053-0.009)) compared with spontaneous vaginal births. The findings were consistent among exploratory subgroup analyses involving births in the absence of prolonged labour, with APGAR ≥ 9, and among normotensive and non-diabetic mothers. CONCLUSION: In singleton children born at term, instrumental delivery does not have an adverse effect on neurodevelopment as measured by NAPLAN performance at age eight.


Assuntos
Traumatismos do Nascimento/epidemiologia , Parto Obstétrico/efeitos adversos , Adulto , Traumatismos do Nascimento/etiologia , Criança , Desenvolvimento Infantil , Bases de Dados Factuais , Demografia , Escolaridade , Extração Obstétrica/efeitos adversos , Feminino , Humanos , Recém-Nascido , Gravidez , Fatores Socioeconômicos , Austrália do Sul/epidemiologia
6.
J Cell Biochem ; 119(1): 69-80, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-28543886

RESUMO

The mammalian hairless protein (HR) is a 130 kDa nuclear transcription factor that is essential for proper skin and hair follicle function. Previous studies have focused on the role of HR in skin maintenance and hair cycling. However, the hairless gene (HR) is also expressed in brain and other tissues, where its role remains poorly understood. HR has been reported to contain functional domains that potentially serve in DNA binding, histone demethylation, nuclear translocation and protein-protein interactions. Indeed, HR has been shown to interact with and repress the action of the nuclear receptors for vitamin D and thyroid hormone as well as RAR-related orphan receptor alpha, possibly via recruitment of histone deacetylases. HR may also have important functions in non-skin tissues given that nearly 200 HR mutations have been identified in patients with various cancers, including prostate, breast, lung, melanoma, uterine, and glioma. This suggests that HR and/or mutants thereof have relevance to the growth and survival of cancer cells. For example, the reported intrinsic histone H3K9 demethylase activity of HR may activate dormant genes to contribute to carcinogenesis. Alternatively, the demonstrated ability of HR to interact with p53 and/or the p53 DNA response element to influence p53-regulated pathways may explain, at least in part, why many cancers express mutated HR proteins. In this review, we summarize the current knowledge of HR bioactions, how HR mutations may be contributing to alopecia as well as to cancer, and, finally, outline future directions in the study of this largely enigmatic nuclear protein. J. Cell. Biochem. 119: 69-80, 2018. © 2017 Wiley Periodicals, Inc.


Assuntos
Neoplasias/genética , Fatores de Transcrição/genética , Fatores de Transcrição/fisiologia , Alopecia/genética , Neoplasias Encefálicas/genética , Proteínas Correpressoras/metabolismo , Regulação da Expressão Gênica , Doenças do Cabelo/genética , Folículo Piloso/anormalidades , Humanos , Dermatopatias Vesiculobolhosas/genética , Fatores de Transcrição/química , Fatores de Transcrição/metabolismo
7.
J Cell Biochem ; 118(2): 341-350, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27355563

RESUMO

The mammalian hairless (Hr) protein plays critical roles in skin and brain tissues, but how it interacts with DNA and partner protein is only now being defined. Our initial tests of four consensus response elements, revealed that rat Hr can specifically bind to a consensus p53 response element (p53RE), 5'-AGACATGCCTAGACATGCCT-3', but not to response elements for NF-κB, TCF4 or Sp1. We then employed ChIP assays which verified that human HR binds to a p53RE of the GADD45A gene in both HEK293 (embryonic kidney) and U87 (glioblastoma) cells. Further, HR was shown to interact directly with the p53 protein in a co-immunoprecipitation assay. Cotransfections with p53RE reporter gene constructs revealed that rat Hr can boost p53-mediated transactivation of a reporter gene linked to the GADD45A p53RE, but blunts p53-mediated transactivation when the reporter gene is linked to a p21 promoter fragment containing a p53RE, with implications for the regulation of these two cell cycle control genes. Finally, our investigations of HR phosphorylation revealed that rat Hr is a substrate for PKC, but not PKA, and that human HR is phosphorylated in intact U87 cells at Ser-416, located in a highly conserved region which partially fulfills the criteria of a PKC site. We propose that mammalian Hr is a phosphoprotein which can exert cross-talk with the p53 pathway with important implications for the regulation of cell proliferation and differentiation in tissues such as skin and brain where Hr is highly expressed. J. Cell. Biochem. 118: 341-350, 2017. © 2016 Wiley Periodicals, Inc.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Fosfoproteínas/metabolismo , Fatores de Transcrição/metabolismo , Encéfalo/metabolismo , Proteínas de Ciclo Celular/biossíntese , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Inibidor de Quinase Dependente de Ciclina p21/biossíntese , Inibidor de Quinase Dependente de Ciclina p21/genética , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica , Células HEK293 , Humanos , Proteínas Nucleares/biossíntese , Proteínas Nucleares/genética , Especificidade de Órgãos , Fosfoproteínas/genética , Fosforilação/genética , Elementos de Resposta , Pele/metabolismo , Fatores de Transcrição/genética , Proteína Supressora de Tumor p53/biossíntese , Proteína Supressora de Tumor p53/genética
8.
Am J Med Genet A ; 173(6): 1625-1630, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28462982

RESUMO

Early infantile epileptic encephalopathy-9 (EIEE9) linked to mutations of the PCDH19 gene on the X chromosome was once thought to only affect females. Clinical features of the mutation include early onset of variable types and frequency of recurrent cluster of seizures, mild to profound intellectual disability, autistic traits, psychiatric features, and behavioral disturbances. PCDH19 pathogenic variants usually occur via an unusual X-linked pattern where heterozygous females are affected, but hemizygous males are asymptomatic. Somatic mosaic males for PCDH19 mutations are affected with EIEE9; since this discovery, four somatic mosaic males have been reported. We report the fifth confirmed male with somatic mosaicism of a novel pathogenic variant c.2147+2 T>C located in the splice site of Intron 1 of the PCDH19 gene, which continues to support that cellular interference is responsible for the pathogenic mechanism. The importance of our report is to provide significant knowledge about this rare cause of epilepsy in males, guide subsequent functional studies on males portraying an EIEE9 phenotype that have been potentially misdiagnosed, targeted therapeutic approaches, and further elucidation of this complex and interesting genetic disorder.


Assuntos
Caderinas/genética , Deficiência Intelectual/genética , Mosaicismo , Espasmos Infantis/genética , Genes Ligados ao Cromossomo X , Humanos , Deficiência Intelectual/fisiopatologia , Masculino , Mutação , Fenótipo , Protocaderinas , Sítios de Splice de RNA/genética , Espasmos Infantis/fisiopatologia
9.
Am J Med Genet A ; 170(7): 1780-5, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27112432

RESUMO

Troyer syndrome is a complex hereditary spastic paraplegia (HSP) due to a mutation in SPG20 first reported in the Old Amish population. A genetic mutation in SPG20 is responsible for a loss of function of the protein spartin in this disease. Since its initial report, this syndrome has also been reported in Turkish and Omani families. Here we report the case of three patients of Filipino descent with Troyer syndrome. Whole exome sequencing (WES) identified a homozygous mutation c.364_365delAT which predicts p.Met122Valfs*2 in SPG20. This is the same mutation identified in affected patients from the Omani and Turkish families, and is the first report of this syndrome in the Filipino population. Although Troyer syndrome has characteristic phenotypic manifestations it is likely underdiagnosed due to its rarity and we expect that WES will lead to identifying this disease in other individuals. © 2016 Wiley Periodicals, Inc.


Assuntos
Proteínas/genética , Paraplegia Espástica Hereditária/genética , Proteínas de Ciclo Celular , Criança , Exoma/genética , Feminino , Humanos , Masculino , Mutação , Paraplegia Espástica Hereditária/epidemiologia , Paraplegia Espástica Hereditária/fisiopatologia
10.
J Cell Mol Med ; 19(10): 2385-96, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26218750

RESUMO

Malignant pleural mesothelioma (mesothelioma) is a highly aggressive cancer without an effective treatment. Cul4A, a scaffold protein that recruits substrates for degradation, is amplified in several human cancers, including mesothelioma. We have recently shown that Cul4A plays an oncogenic role in vitro and in a mouse model. In this study, we analysed clinical mesothelioma tumours and found moderate to strong expression of Cul4A in 70.9% (51/72) of these tumours, as shown by immunohistochemistry. In 72.2% mesothelioma tumours with increased Cul4A copy number identified by fluorescence in situ hybridization analysis, Cul4A protein expression was moderate to strong. Similarly, Cul4A was overexpressed and Cul4A copy number was increased in human mesothelioma cell lines. Because Gli1 is highly expressed in human mesothelioma cells, we compared Cul4A and Gli1 expression in mesothelioma tumours and found their expression associated (P < 0.05, chi-square). In mesothelioma cell lines, inhibiting Cul4A by siRNA decreased Gli1 expression, suggesting that Gli1 expression is, at least in part, regulated by Cul4A in mesothelioma cells. Our results suggest a linkage between Cul4A and Gli1 expression in human mesothelioma.


Assuntos
Proteínas Culina/metabolismo , Neoplasias Pulmonares/metabolismo , Mesotelioma/metabolismo , Fatores de Transcrição/metabolismo , Estudos de Casos e Controles , Linhagem Celular Tumoral , Distribuição de Qui-Quadrado , Proteínas Culina/genética , Dosagem de Genes , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Mesotelioma/genética , Mesotelioma/patologia , Mesotelioma Maligno , Neoplasias Pleurais/metabolismo , Neoplasias Pleurais/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Transcrição/genética , Proteína GLI1 em Dedos de Zinco
12.
Am J Med Genet A ; 167A(4): 826-30, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25758335

RESUMO

Vanishing White Matter disease (VWM) is an inherited progressive leukoencephalopathy caused by mutations in the genes EIF2B1-5, which encode for the 5 subunits of the eukaryotic initiation factor 2B (eIF2B), a regulator of protein synthesis. VWM typically presents with acute neurological decline following febrile infections or minor head trauma, and subsequent progressive neurological and cognitive regression. There is a varied clinical spectrum of VWM, with earlier onset associated with more severe phenotypes. Brain magnetic resonance imaging is usually diagnostic with diffusely abnormal white matter, progressing over time to cystic degeneration. We are reporting on a patient with infantile onset VWM associated with three heterozygous missense variants in EIF2B5, including a novel missense variant on exon 6 of EIF2B5 (D262N), as well as an interstitial duplication at 7q21.12. In addition, our case is unusual because of a severe epilepsy course, a novel clinical finding of hypopituitarism manifested by hypothyroidism and adrenal insufficiency, and a prolonged life span with current age of survival of 4 years and 11 months.


Assuntos
Anormalidades Múltiplas/diagnóstico , Epilepsia/diagnóstico , Fator de Iniciação 2B em Eucariotos/genética , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/diagnóstico , Hipopituitarismo/diagnóstico , Anormalidades Múltiplas/genética , Pré-Escolar , Epilepsia/genética , Estudos de Associação Genética , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , Humanos , Hipopituitarismo/genética , Expectativa de Vida , Masculino
13.
J Pathol ; 233(2): 113-23, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24648314

RESUMO

Cullin4A (Cul4A) is a scaffold protein that assembles cullin-RING ubiquitin ligase (E3) complexes and regulates many cellular events, including cell survival, development, growth and cell cycle control. Our previous study suggested that Cul4A is oncogenic in vitro, but its oncogenic role in vivo has not been studied. Here, we used a Cul4A transgenic mouse model to study the potential oncogenic role of Cul4A in lung tumour development. After Cul4A over-expression was induced in the lungs for 32 weeks, atypical epithelial cells were observed. After 40 weeks, lung tumours were visible and were characterized as grade I or II adenocarcinomas. Immunohistochemistry (IHC) revealed decreased levels of Cul4A-associated proteins p21(CIP1) and tumour suppressor p19(ARF) in the lung tumours, suggesting that Cul4A regulated their expression in these tumours. Increased levels of p27(KIP1) and p16(INK4a) were also detected in these tumours. Moreover, the protein level of DNA replication licensing factor CDT1 was decreased. Genomic instability in the lung tumours was further analysed by the results from pericentrin protein expression and array comparative genomic hybridization analysis. Furthermore, knocking down Cul4A expression in lung cancer H2170 cells increased their sensitivity to the chemotherapy drug cisplatin in vitro, suggesting that Cul4A over-expression is associated with cisplatin resistance in the cancer cells. Our findings indicate that Cul4A is oncogenic in vivo, and this Cul4A mouse model is a tool in understanding the mechanisms of Cul4A in human cancers and for testing experimental therapies targeting Cul4A.


Assuntos
Adenocarcinoma/metabolismo , Transformação Celular Neoplásica/metabolismo , Proteínas Culina/metabolismo , Neoplasias Pulmonares/metabolismo , Pulmão/metabolismo , Adenocarcinoma/genética , Adenocarcinoma/patologia , Adenocarcinoma de Pulmão , Animais , Antineoplásicos/farmacologia , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/patologia , Cisplatino/farmacologia , Proteínas Culina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Inibidor de Quinase Dependente de Ciclina p19/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Proteínas de Ligação a DNA/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Instabilidade Genômica , Humanos , Pulmão/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Transgênicos , Gradação de Tumores , Antígeno Nuclear de Célula em Proliferação/metabolismo , Interferência de RNA , Fatores de Tempo , Transfecção , Regulação para Cima
15.
J Cell Mol Med ; 17(7): 854-62, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23651443

RESUMO

Protein kinase CK2 is frequently elevated in a variety of human cancers. The Notch1 signalling pathway has been implicated in stem cell maintenance and its aberrant activation has been shown in several types of cancer including lung cancer. Here, we show, for the first time, that CK2α is a positive regulator of Notch1 signalling in lung cancer cell lines A549 and H1299. We found that Notch1 protein level was reduced after CK2α silencing. Down-regulation of Notch1 transcriptional activity was demonstrated after the silencing of CK2α in lung cancer cells. Furthermore, small-molecule CK2α inhibitor CX-4945 led to a dose-dependent inhibition of Notch1 transcriptional activity. Conversely, forced overexpression of CK2α resulted in an increase in Notch1 transcriptional activity. Finally, the inhibition of CK2α led to a reduced proportion of stem-like CD44 + /CD24- cell population. Thus, we report that the inhibition of CK2α down-regulates Notch1 signalling and subsequently reduces a cancer stem-like cell population in human lung cancer cells. Our data suggest that CK2α inhibitors may be beneficial to the lung cancer patients with activated Notch1 signalling.


Assuntos
Caseína Quinase II/antagonistas & inibidores , Regulação Neoplásica da Expressão Gênica , Neoplasias Pulmonares/metabolismo , Receptor Notch1/metabolismo , Transdução de Sinais , Antígeno CD24/metabolismo , Caseína Quinase II/metabolismo , Linhagem Celular Tumoral , DNA/metabolismo , Relação Dose-Resposta a Droga , Regulação para Baixo , Citometria de Fluxo , Humanos , Receptores de Hialuronatos/metabolismo , Imuno-Histoquímica , Naftiridinas/farmacologia , Células-Tronco Neoplásicas/citologia , Fenazinas , Fenótipo , RNA Interferente Pequeno/metabolismo , Transcrição Gênica
16.
Calcif Tissue Int ; 92(2): 77-98, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22782502

RESUMO

The hormonal metabolite of vitamin D, 1α,25-dihydroxyvitamin D(3) (1,25D), initiates biological responses via binding to the vitamin D receptor (VDR). When occupied by 1,25D, VDR interacts with the retinoid X receptor (RXR) to form a heterodimer that binds to vitamin D responsive elements in the region of genes directly controlled by 1,25D. By recruiting complexes of either coactivators or corepressors, ligand-activated VDR-RXR modulates the transcription of genes encoding proteins that promulgate the traditional functions of vitamin D, including signaling intestinal calcium and phosphate absorption to effect skeletal and calcium homeostasis. Thus, vitamin D action in a particular cell depends upon the metabolic production or delivery of sufficient concentrations of the 1,25D ligand, expression of adequate VDR and RXR coreceptor proteins, and cell-specific programming of transcriptional responses to regulate select genes that encode proteins that function in mediating the effects of vitamin D. For example, 1,25D induces RANKL, SPP1 (osteopontin), and BGP (osteocalcin) to govern bone mineral remodeling; TRPV6, CaBP(9k), and claudin 2 to promote intestinal calcium absorption; and TRPV5, klotho, and Npt2c to regulate renal calcium and phosphate reabsorption. VDR appears to function unliganded by 1,25D in keratinocytes to drive mammalian hair cycling via regulation of genes such as CASP14, S100A8, SOSTDC1, and others affecting Wnt signaling. Finally, alternative, low-affinity, non-vitamin D VDR ligands, e.g., lithocholic acid, docosahexaenoic acid, and curcumin, have been reported. Combined alternative VDR ligand(s) and 1,25D/VDR control of gene expression may delay chronic disorders of aging such as osteoporosis, type 2 diabetes, cardiovascular disease, and cancer.


Assuntos
Regulação da Expressão Gênica/fisiologia , Transdução de Sinais/fisiologia , Vitamina D/fisiologia , Animais , Humanos , Receptores de Calcitriol/biossíntese
17.
Nat Commun ; 14(1): 8258, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38086872

RESUMO

Ultrafast laser excitation provides a means to transiently realize long-range ordered electronic states of matter that are hidden in thermal equilibrium. Recently, this approach has unveiled a variety of thermally inaccessible ordered states in strongly correlated materials, including charge density wave, ferroelectric, magnetic, and intertwined charge-orbital ordered states. However, more exotic hidden states exhibiting higher multipolar ordering remain elusive owing to the challenge of directly manipulating and detecting them with light. Here we demonstrate a method to induce a dynamical transition from a thermally allowed to a thermally forbidden spin-orbit entangled quadrupolar ordered state in Ca2RuO4 by coherently exciting a phonon that is strongly coupled to the order parameter. Combining probe photon energy-resolved coherent phonon spectroscopy measurements with model Hamiltonian calculations, we show that the dynamical transition is manifested through anomalies in the temperature, pump excitation fluence, and probe photon energy dependence of the strongly coupled phonon. With this procedure, we introduce a general pathway to uncover hidden multipolar ordered states and to control their re-orientation on ultrashort timescales.

18.
BMC Biol ; 9: 83, 2011 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-22128911

RESUMO

BACKGROUND: Hepatocellular carcinoma (HCC) is a common, highly invasive malignant tumor associated with a high mortality rate. We previously reported that the aberrant expression of Snail via activation of reactive oxygen species contributes to the invasive property of HCC, in part by downregulation of E-cadherin through both transcriptional repression and epigenetic modification of the E-cadherin promoter. Having demonstrated the ability of Snail to bind and recruit histone deacetylase 1 and DNA methyltransferase 1 in this context, we set out to look for other interactions that could affect its ability to promote oncogenic transformation and cancer cell invasion. RESULTS: Using cells that stably expressed Snail, we characterized Snail protein interactors by tandem affinity purification and mass spectrometry. Immunoprecipitation and subcellular colocalization studies were performed to confirm our identification of the Notch1 intracellular domain (NICD) as a novel Snail-binding partner. NICD interaction with Snail was found to induce ubiquitination and MDM2-dependent degradation of Snail. Interestingly, NICD inhibited Snail-dependent invasive properties in both HCC cells and mouse embryonic fibroblasts. CONCLUSIONS: Our study demonstrates that NICD can oppose Snail-dependent HCC cell invasion by binding and inducing proteolytic degradation of Snail. Although Notch signaling and Snail are both widely considered tumor-promoting factors, our findings indicate that the individual oncogenic contribution of Notch1 and Snail in malignant systems should be interpreted carefully, particularly when they are conjointly expressed.


Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Receptor Notch1/metabolismo , Fatores de Transcrição/metabolismo , Animais , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Humanos , Neoplasias Hepáticas/patologia , Camundongos , Invasividade Neoplásica , Ligação Proteica , Estrutura Terciária de Proteína , Receptor Notch1/análise , Fatores de Transcrição da Família Snail , Fatores de Transcrição/química , Ubiquitinação , Dedos de Zinco
19.
Plants (Basel) ; 11(3)2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35161261

RESUMO

The recovery of physiologically bioactive ingredients from agricultural wastes as an abundant and low-cost source for the production of high value-added mutraceuticlas has been recognized and supported for the commercial interests and sustainable managements. In the extraction of geniposide for the development of natural food colorants from the dried fruits of Gardenia jasminoides Rubiaceae, the gardenia fruit waste (GFW) still remaining 0.86% (w/w) of crocins has always been discarded without any further treatments Until now, there was no simple and effective protocol for high-purity trans-crocein (TC) preparation without the coexistence of non-biologically active cis-crocein from GFW. We proposed an effective process to obtain the compound as follows. Crocins were extracted firstly by 50% of ethanol in the highest yield of 8.61 mg/g (w/w) from GFW. After the HPD-100 column fractionation in the collecting of crocins, the conversion ratio of 75% of crocins to crocetins can be obtained from the commercial available enzyme- Celluclast® 1.5 L. The crocins hydrolyzed products, were then separated through the HPD-100 resin adsorption and finally purified with the centrifugal partition chromatography (CPC) in single-step to obtain TC in a purity of 96.76 ± 0.17%. Conclusively, the effective enzyme transformation and purification co-operated with CPC technologies on crocins resulted in a high purity product of TC may be highly application in the commercial production.

20.
J Cell Physiol ; 226(4): 1118-27, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20857406

RESUMO

A population of tumorigenic, chemoresistant, and radioresistant cancer stem cells is postulated to contribute to the aggressive and fatal clinical course of glioblastomas. Activation of the Hedgehog (HH) pathway and increased expression of its downstream effector GLI1 are driving factors of glioma tumorigenicity and glioma stem cell (GSC) biology. In this study, we describe a dependence of insulin-like growth factor (IGF) signaling on active HH/GLI1 in GSCs. Insulin receptor substrate 1 (IRS1) was identified as a target of the GLI1 transcription factor and inhibition of GLI1 was sufficient to obstruct IRS1 protein expression and IGF-I induced mitogen-activated protein kinase (MAPK) activation. Suppression of GLI1 activity decreased the responsiveness of GSCs to IGF-I stimulation and constrained IGF-I dependent GSC proliferation, clonogenicity, invasion, and angiogenesis. In addition, blockade of the HH/GLI1 and IGF pathways countered the intrinsic and acquired resistance of GSCs to temozolomide. These results provide further insight into the oncogenic mechanisms of the HH pathway in glioblastoma and demonstrate a cooperative signaling axis between the HH/GLI1 and IGF pathways to propagate malignant GSC phenotypes.


Assuntos
Glioma/patologia , Proteínas Hedgehog/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Células-Tronco Neoplásicas/patologia , Fatores de Transcrição/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Dacarbazina/análogos & derivados , Dacarbazina/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Inativação Gênica/efeitos dos fármacos , Glioma/enzimologia , Glioma/genética , Humanos , Proteínas Substratos do Receptor de Insulina/genética , Proteínas Substratos do Receptor de Insulina/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Células-Tronco Neoplásicas/enzimologia , RNA Interferente Pequeno/metabolismo , Tolerância a Radiação/efeitos dos fármacos , Temozolomida , Transcrição Gênica/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Proteína GLI1 em Dedos de Zinco
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