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1.
Sci Transl Med ; 15(698): eabo3189, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-37256937

RESUMO

A critical step in preserving protein homeostasis is the recognition, binding, unfolding, and translocation of protein substrates by six AAA-ATPase proteasome subunits (ATPase-associated with various cellular activities) termed PSMC1-6, which are required for degradation of proteins by 26S proteasomes. Here, we identified 15 de novo missense variants in the PSMC3 gene encoding the AAA-ATPase proteasome subunit PSMC3/Rpt5 in 23 unrelated heterozygous patients with an autosomal dominant form of neurodevelopmental delay and intellectual disability. Expression of PSMC3 variants in mouse neuronal cultures led to altered dendrite development, and deletion of the PSMC3 fly ortholog Rpt5 impaired reversal learning capabilities in fruit flies. Structural modeling as well as proteomic and transcriptomic analyses of T cells derived from patients with PSMC3 variants implicated the PSMC3 variants in proteasome dysfunction through disruption of substrate translocation, induction of proteotoxic stress, and alterations in proteins controlling developmental and innate immune programs. The proteostatic perturbations in T cells from patients with PSMC3 variants correlated with a dysregulation in type I interferon (IFN) signaling in these T cells, which could be blocked by inhibition of the intracellular stress sensor protein kinase R (PKR). These results suggest that proteotoxic stress activated PKR in patient-derived T cells, resulting in a type I IFN response. The potential relationship among proteosome dysfunction, type I IFN production, and neurodevelopment suggests new directions in our understanding of pathogenesis in some neurodevelopmental disorders.


Assuntos
Interferon Tipo I , Complexo de Endopeptidases do Proteassoma , Animais , Humanos , Camundongos , Adenosina Trifosfatases/genética , Drosophila melanogaster , Expressão Gênica , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteômica
2.
Front Microbiol ; 11: 1571, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32765452

RESUMO

In contrast to Eurasia and North America, powdery mildews (Ascomycota, Erysiphales) are understudied in Australia. There are over 900 species known globally, with fewer than currently 60 recorded from Australia. Some of the Australian records are doubtful as the identifications were presumptive, being based on host plant-pathogen lists from overseas. The goal of this study was to provide the first comprehensive catalog of all powdery mildew species present in Australia. The project resulted in (i) an up-to-date list of all the taxa that have been identified in Australia based on published DNA barcode sequences prior to this study; (ii) the precise identification of 117 specimens freshly collected from across the country; and (iii) the precise identification of 30 herbarium specimens collected between 1975 and 2013. This study confirmed 42 species representing 10 genera, including two genera and 13 species recorded for the first time in Australia. In Eurasia and North America, the number of powdery mildew species is much higher. Phylogenetic analyses of powdery mildews collected from Acalypha spp. resulted in the transfer of Erysiphe acalyphae to Salmonomyces, a resurrected genus. Salmonomyces acalyphae comb. nov. represents a newly discovered lineage of the Erysiphales. Another taxonomic change is the transfer of Oidium ixodiae to Golovinomyces. Powdery mildew infections have been confirmed on 13 native Australian plant species in the genera Acacia, Acalypha, Cephalotus, Convolvulus, Eucalyptus, Hardenbergia, Ixodia, Jagera, Senecio, and Trema. Most of the causal agents were polyphagous species that infect many other host plants both overseas and in Australia. All powdery mildews infecting native plants in Australia were phylogenetically closely related to species known overseas. The data indicate that Australia is a continent without native powdery mildews, and most, if not all, species have been introduced since the European colonization of the continent.

4.
Horm Cancer ; 6(2-3): 87-99, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25800363

RESUMO

Thyroid cancer incidence has been increasing over time, and it is estimated that ∼1950 advanced thyroid cancer patients will die of their disease in 2015. To combat this disease, an enhanced understanding of thyroid cancer development and progression as well as the development of efficacious, targeted therapies are needed. In vitro and in vivo studies utilizing thyroid cancer cell lines and animal models are critically important to these research efforts. In this report, we detail our studies with a panel of authenticated human anaplastic and papillary thyroid cancer (ATC and PTC) cell lines engineered to express firefly luciferase in two in vivo murine cancer models-an orthotopic thyroid cancer model as well as an intracardiac injection metastasis model. In these models, primary tumor growth in the orthotopic model and the establishment and growth of metastases in the intracardiac injection model are followed in vivo using an IVIS imaging system. In the orthotopic model, the ATC cell lines 8505C and T238 and the PTC cell lines K1/GLAG-66 and BCPAP had take rates >90 % with final tumor volumes ranging 84-214 mm(3) over 4-5 weeks. In the intracardiac model, metastasis establishment was successful in the ATC cell lines HTh74, HTh7, 8505C, THJ-16T, and Cal62 with take rates ≥70 %. Only one of the PTC cell lines tested (BCPAP) was successful in the intracardiac model with a take rate of 30 %. These data will be beneficial to inform the choice of cell line and model system for the design of future thyroid cancer studies.


Assuntos
Modelos Animais de Doenças , Metástase Neoplásica/patologia , Transplante de Neoplasias/métodos , Neoplasias da Glândula Tireoide/patologia , Animais , Linhagem Celular Tumoral , Neoplasias Cardíacas/secundário , Xenoenxertos , Humanos , Camundongos , Camundongos Nus
5.
Mol Cancer ; 13: 62, 2014 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-24645981

RESUMO

BACKGROUND: Thyroid cancer is the most common endocrine malignancy, and many patients with metastatic differentiated thyroid cancer (DTC), poorly differentiated thyroid cancer (PDTC), and anaplastic thyroid cancer (ATC) fail to respond to conventional therapies, resulting in morbidity and mortality. Additional therapeutic targets and treatment options are needed for these patients. We recently reported that peroxisome proliferator-activated receptor gamma (PPARγ) is highly expressed in ATC and confers an aggressive phenotype when overexpressed in DTC cells. METHODS: Microarray analysis was used to identify downstream targets of PPARγ in ATC cells. Western blot analysis and immunohistochemistry (IHC) were used to assess thioredoxin interacting protein (TXNIP) expression in thyroid cancer cell lines and primary tumor specimens. Retroviral transduction was used to generate ATC cell lines that overexpress TXNIP, and assays that assess glucose uptake, viable cell proliferation, and invasion were used to characterize the in vitro properties of these cells. An orthotopic thyroid cancer mouse model was used to assess the effect of TXNIP overexpression in ATC cell lines in vivo. RESULTS: Using microarray analysis, we show that TXNIP is highly upregulated when PPARγ is depleted from ATC cells. Using Western blot analysis and IHC, we show that DTC and ATC cells exhibit differential TXNIP expression patterns. DTC cell lines and patient tumors have high TXNIP expression in contrast to low or absent expression in ATC cell lines and tumors. Overexpression of TXNIP decreases the growth of HTh74 cells compared to vector controls and inhibits glucose uptake in the ATC cell lines HTh74 and T238. Importantly, TXNIP overexpression in T238 cells results in attenuated tumor growth and decreased metastasis in an orthotopic thyroid cancer mouse model. CONCLUSIONS: Our findings indicate that TXNIP functions as a tumor suppressor in thyroid cells, and its downregulation is likely important in the transition from differentiated to advanced thyroid cancer. These studies underscore the potential of TXNIP as a novel therapeutic target and prognostic indicator in advanced thyroid cancer.


Assuntos
Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Genes Supressores de Tumor/fisiologia , Neoplasias da Glândula Tireoide/genética , Neoplasias da Glândula Tireoide/metabolismo , Animais , Western Blotting , Linhagem Celular Tumoral , Xenoenxertos , Humanos , Imuno-Histoquímica , Camundongos , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução Genética
6.
J Virol ; 79(4): 2375-82, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15681438

RESUMO

Epstein-Barr virus (EBV) latent membrane protein 2A (LMP2A) is important for maintenance of latency in infected B lymphocytes. Through its immunoreceptor tyrosine-based activation motif (ITAM) and PY motifs, LMP2A is able to block B-cell receptor (BCR) signaling, bind BCR-associated kinases, and manipulate the turnover of itself and these kinases via a PY-mediated interaction with the Nedd4 family of ubiquitin ligases. In epithelial cells, LMP2A has been shown to activate the phosphatidylinositol 3'-OH kinase/Akt and beta-catenin signaling pathways. In the present study, the biological consequences of LMP2A expression in the normal human foreskin keratinocyte (HFK) cell line were investigated and the importance of the ITAM and PY motifs for LMP2A signaling effects in HFK cells was ascertained. The ITAM was essential for the activation of Akt by LMP2A in HFK cells, while both the ITAM and PY motifs contributed to LMP2A-mediated accumulation and nuclear translocation of the oncoprotein beta-catenin. LMP2A inhibited induction of differentiation in an assay conducted with semisolid methylcellulose medium, and the PY motifs were critical for this inhibition. LMP2A is expressed in the EBV-associated epithelial malignancies nasopharyngeal carcinoma and gastric carcinoma, and these data indicate that LMP2A affects cellular processes that likely contribute to carcinogenesis.


Assuntos
Motivos de Aminoácidos/fisiologia , Proteínas do Citoesqueleto/metabolismo , Células Epiteliais/efeitos dos fármacos , Herpesvirus Humano 4/química , Transativadores/metabolismo , Proteínas da Matriz Viral/farmacologia , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Linhagem Celular Transformada , Células Epiteliais/citologia , Células Epiteliais/virologia , Humanos , Transdução de Sinais/efeitos dos fármacos , Proteínas da Matriz Viral/química , beta Catenina
7.
Cancer Res ; 64(15): 5251-60, 2004 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-15289331

RESUMO

EBV is associated with the epithelial cancer, nasopharyngeal carcinoma (NPC), and the lymphoid malignancy, Hodgkin lymphoma (HL). The EBV latent membrane proteins 1 and 2A are expressed in these tumors. These proteins activate the phosphatidylinositol 3'-OH kinase (PI3K)/Akt pathway, which is commonly activated inappropriately in malignancy. In this study, the status of Akt activation and its targets, glycogen synthase kinase-3beta (GSK-3beta) and beta-catenin, was investigated in NPC and HL clinical specimens. In the majority of HL and NPC specimens, Akt was activated, indicating an important role for this kinase in the development and/or progression of these tumors. Akt phosphorylates and inactivates GSK-3beta, a negative regulator of the proto-oncoprotein beta-catenin that is aberrantly activated in many cancers. GSK-3beta was phosphorylated and inactivated with concomitant nuclear beta-catenin accumulation in the majority of NPC specimens. The malignant cells of the majority of HL cases, however, did not have inactivated GSK-3beta and lacked nuclear beta-catenin expression. These data indicate that this signaling arm of PI3K/Akt is universal and important in NPC pathogenesis but is apparently not affected in HL. These findings point to a divergence in pathways activated by EBV in different cellular contexts.


Assuntos
Infecções por Vírus Epstein-Barr/metabolismo , Herpesvirus Humano 4/patogenicidade , Doença de Hodgkin/metabolismo , Neoplasias Nasofaríngeas/metabolismo , Transdução de Sinais , Animais , Proteínas do Citoesqueleto/metabolismo , Infecções por Vírus Epstein-Barr/virologia , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Doença de Hodgkin/patologia , Doença de Hodgkin/virologia , Humanos , Camundongos , Neoplasias Nasofaríngeas/patologia , Neoplasias Nasofaríngeas/virologia , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt , Transativadores/metabolismo , Transplante Heterólogo , Células Tumorais Cultivadas , Proteínas da Matriz Viral/genética , Proteínas da Matriz Viral/fisiologia , beta Catenina
8.
Fetal Diagn Ther ; 18(5): 360-9, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12913349

RESUMO

Both insulin and estrogen are well recognized as growth-promoting substances at physiological concentrations, but they function as teratogens at high doses. Both agents can affect alterations in fetal and maternal serum human alpha-fetoprotein (HAFP) levels during pregnancy. In the present study, we have employed animal models of both insulin and estrogen fetotoxicity and teratogenicity in order to study the growth-regulatory properties of HAFP and its derived peptides (HAFP/PEP). We report here the effects of HAFP/PEP on fetotoxicity, congenital malformations, and growth retardation in developing chick and murine fetuses. In the insulin model, HAFP/PEP were effective in reducing both fetal mortality and anatomic anomalies, with the result that growth-retarded fetuses were produced. With HAFP/PEP treatment, fetal demise was reduced by as much as 73 and 63% in murine and chick fetuses, respectively, while fetal anomalies were diminished by 50% during chick development. Genebank searches of identity/similarity in a HAFP/PEP fragment identified matches with a number of proteins associated with glucose, pH, ionic, osmotic, and oxidative stresses, and with heat shock, in addition to stress proteins related to protein folding/unfolding processes. It was proposed that the peptide segment on HAFP may represent a topographic 'hotspot', sensitive to stress/shock conditions, which exhibits a propensity for conformational alteration in the tertiary structure of the fetal protein.


Assuntos
Estrogênios/toxicidade , Retardo do Crescimento Fetal/fisiopatologia , Hipoglicemiantes/toxicidade , Insulina/toxicidade , Teratogênicos/toxicidade , alfa-Fetoproteínas/farmacologia , Albuminas/genética , Sequência de Aminoácidos , Animais , Embrião de Galinha , Galinhas , Feminino , Retardo do Crescimento Fetal/induzido quimicamente , Retardo do Crescimento Fetal/tratamento farmacológico , Proteínas de Choque Térmico/genética , Camundongos , Dados de Sequência Molecular , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/farmacologia , Gravidez , alfa-Fetoproteínas/genética
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