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1.
Exp Hematol Oncol ; 13(1): 49, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38730491

RESUMO

BACKGROUND: Leukemias driven by activated, chimeric FGFR1 kinases typically progress to AML which have poor prognosis. Mouse models of this syndrome allow detailed analysis of cellular and molecular changes occurring during leukemogenesis. We have used these models to determine the effects of leukemia development on the immune cell composition in the leukemia microenvironment during leukemia development and progression. METHODS: Single cell RNA sequencing (scRNA-Seq) was used to characterize leukemia associated neutrophils and define gene expression changes in these cells during leukemia progression. RESULTS: scRNA-Seq revealed six distinct subgroups of neutrophils based on their specific differential gene expression. In response to leukemia development, there is a dramatic increase in only two of the neutrophil subgroups. These two subgroups show specific gene expression signatures consistent with neutrophil precursors which give rise to immature polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs). Analysis of gene expression in these precursor cells identified pathways that were specifically upregulated, the most pronounced of which involved matrix metalloproteinases Mmp8 and Mmp9, during leukemia progression. Pharmacological inhibition of MMPs using Ilomastat preferentially restricted in vitro migration of neutrophils from leukemic mice and led to a significantly improved survival in vivo, accompanied by impaired PMN-MDSC recruitment. As a result, levels of T-cells were proportionally increased. In clinically annotated TCGA databases, MMP8 was shown to act as an independent indicator for poor prognosis and correlated with higher neutrophil infiltration and poor pan-cancer prognosis. CONCLUSION: We have defined specific leukemia responsive neutrophil subgroups based on their unique gene expression profile, which appear to be the precursors of neutrophils specifically associated with leukemia progression. An important event during development of these neutrophils is upregulation MMP genes which facilitated mobilization of these precursors from the BM in response to cancer progression, suggesting a possible therapeutic approach to suppress the development of immune tolerance.

2.
Haematologica ; 108(1): 122-134, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-35833297

RESUMO

The Philadelphia 9;22 chromosome translocation has two common isoforms that are preferentially associated with distinct subtypes of leukemia. The p210 variant is the hallmark of chronic myeloid leukemia (CML) whereas p190 is frequently associated with B-cell acute lymphoblastic leukemia. The only sequence difference between the two isoforms is the guanidine exchange factor domain. This guanidine exchange factor is reported to activate RHO family GTPases in response to diverse extracellular stimuli. It is not clear whether and, if so, how RHOA contributes to progression of p210 CML. Here we show that knockout of RHOA in the K562 and KU812, p210-expressing cell lines leads to suppression of leukemogenesis in animal models in vivo. RNA-sequencing analysis of the mock control and null cells demonstrated a distinct change in the gene expression profile as a result of RHOA deletion, with significant downregulation of genes involved in cell activation and cell adhesion. Cellular analysis revealed that RHOA knockout leads to impaired cell adhesion and migration and, most importantly, the homing ability of leukemia cells to the bone marrow, which may be responsible for the attenuated leukemia progression. We also identified IGFBP2 as an important downstream target of RHOA. Further mechanistic investigation showed that RHOA activation leads to relocation of the serum response factor (SRF) into the nucleus, where it directly activates IGFBP2. Knockout of IGFBP2 in CML cells suppressed cell adhesion/invasion, as well as leukemogenesis in vivo. This elevated IGFBP2 expression was confirmed in primary CML samples. Thus, we demonstrate one mechanism whereby the RHOA-SRF-IGFBP2 signaling axis contributes to the development of leukemia in cells expressing the p210 BCR-ABL1 fusion kinase.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Animais , Proteínas de Fusão bcr-abl/genética , Proteínas de Fusão bcr-abl/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Transdução de Sinais , Fatores de Troca do Nucleotídeo Guanina , Isoformas de Proteínas
3.
Mol Cancer ; 21(1): 156, 2022 07 29.
Artigo em Inglês | MEDLINE | ID: mdl-35906694

RESUMO

BACKGROUND: Myeloid and lymphoid malignancies associated with chimeric FGFR1 kinases are the hallmark of stem cell leukemia and lymphoma syndrome (SCLL). In all cases, FGFR1 kinase is constitutively phosphoactivated as a result of chromosome translocations, which lead to acquisition of dimerization motifs in the chimeric proteins. Recently, we demonstrated that these chimeric kinases could be cleaved by granzyme B to generate a truncated derivative, tnFGFR1, which localized exclusively into the nucleus and was not phosphorylated. METHODS: Stem cell transduction and transplantation in syngeneic mice was used to assess the transforming ability of tnFGFR1 in bone marrow stem cells, and RPPA and RNA-Seq was used to examine the related signaling pathways and regulated target genes. RESULTS: For the first time, we show that this non-classical truncated form of FGFR1 can independently lead to oncogenic transformation of hematopoietic stem cells in an animal model in vivo. These leukemia cells show a mixed immunophenotype with a B-cell B220 + Igm- profile in the majority of cells and Kit+ in virtually all cells, suggesting a stem cell disease. tnFGFR1, however, does not activate classic FGFR1 downstream signaling pathways but induces a distinct profile of altered gene expression with significant upregulation of transmembrane signaling receptors including FLT3 and KIT. We further show that de novo human AML also express tnFGFR1 which correlates with upregulation of FLT3 and KIT as in mouse leukemia cells. ChIP analysis demonstrates tnFGFR1 occupancy at the Flt3 and Kit promoters, suggesting a direct transcriptional regulation. Cells transformed with tnFGFR1 are insensitive to FGFR1 inhibitors but treatment of these cells with the Quizartinib (AC220) FLT3 inhibitor, suppresses in vitro growth and development of leukemia in vivo. Combined treatment with FGFR1 and FLT3 inhibitors provides increased survival compared to FGFR1 inhibition alone. CONCLUSIONS: This study demonstrates a novel model for transformation of hematopoietic stem cells by chimeric FGFR1 kinases with the combined effects of direct protein activation by the full-length kinases and transcriptional regulation by the truncated nuclear tnFGFR1 derivative, which is associated with GZMB expression levels. Genes significantly upregulated by tnFGFR1 include Flt3 and Kit which promote a leukemia stem cell phenotype. In human AML, tnFGFR1 activation leads to increased FLT3 and KIT expression, and higher FLT3 and GZMB expression levels are associated with an inferior prognosis. These observations provide insights into the relative therapeutic value of targeting FGFR1 and FLT3 in treating AML with this characteristic gene expression profile.


Assuntos
Células-Tronco Hematopoéticas , Leucemia Mieloide Aguda , Animais , Transformação Celular Neoplásica/genética , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/patologia , Humanos , Leucemia Mieloide Aguda/metabolismo , Camundongos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-kit , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Translocação Genética , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/metabolismo
4.
Mol Cell Neurosci ; 120: 103707, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35231567

RESUMO

The neuronal microtubule-associated protein tau undergoes multiple post-translational modifications, which dynamically modulate its molecular functions and biochemical features in space and time. Among them, we have recently reported that a conserved lysine residue mapping to the microtubule-binding domain of the protein (K306 in mouse and K317 in human) is differentially methylated in a model of chronic autoimmune demyelination. In contrast with other well-studied tau post-translational modifications such as phosphorylation, lysine methylation is far less investigated and its specific impact on tau biology is not fully understood. Here we performed a comprehensive analysis of the effects of K317 methylation on key tau features. By combining in silico simulations with in vitro biochemical assays and live-cell imaging, we show that methylated tau is more prone to self-assembly into insoluble structures. Moreover, we demonstrate that K317 methylation affects the stabilization activity of tau on microtubule dynamics. Lastly, we highlight a role for K317 methylation in regulating both neuronal differentiation and cell proliferation. Altogether, these findings shed light on the biology of an overlooked tau post-translational modification as well as on the fine tuning of tau functionality in health and disease.


Assuntos
Lisina , Proteínas tau , Animais , Lisina/metabolismo , Metilação , Camundongos , Neurônios/metabolismo , Fosforilação , Processamento de Proteína Pós-Traducional , Proteínas tau/metabolismo
5.
Arch Biochem Biophys ; 719: 109156, 2022 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-35218721

RESUMO

The human leukocyte antigen (HLA) locus encodes a large group of proteins governing adaptive and innate immune responses. Among them, HLA class II proteins form α/ß heterodimers on the membrane of professional antigen-presenting cells (APCs), where they display both, self and pathogen-derived exogenous antigens to CD4+ T lymphocytes. We have previously shown that a shorter HLA-DRA isoform (sHLA-DRA) lacking 25 amino acids can be presented onto the cell membrane via binding to canonical HLA-DR2 heterodimers. Here, we employed atomistic molecular dynamics simulations to decipher the binding position of sHLA-DRA and its structural impact on functional regions of the HLA-DR2 molecule. We show that a loop region exposed only in the short isoform (residues R69 to G83) is responsible for binding to the outer domain of the HLA-DR2 peptide-binding site, and experimentally validated the critical role of F76 in mediating such interaction. Additionally, sHLA-DRA allosterically modifies the peptide-binding pocket conformation. In summary, this study unravels key molecular mechanisms underlying sHLA-DRA function, providing important insights into the role of full-length proteins in structural modulation of HLA class II receptors.


Assuntos
Antígeno HLA-DR2 , Peptídeos , Sítios de Ligação , Cadeias alfa de HLA-DR , Antígeno HLA-DR2/química , Antígeno HLA-DR2/metabolismo , Humanos , Isoformas de Proteínas/metabolismo
6.
Mol Cancer ; 20(1): 165, 2021 12 14.
Artigo em Inglês | MEDLINE | ID: mdl-34906138

RESUMO

BACKGROUND: Stem Cell leukemia/lymphoma syndrome (SCLL) presents as a myeloproliferative disease which can progress to acute myeloid leukemia and is associated with the coincident development of B-cell and T-cell lymphomas. SCLL is driven by the constitutive activation of fibroblast growth factor receptor-1 (FGFR1) as a result of chromosome translocations with poor outcome. Mouse models have been developed which faithfully recapitulate the human disease and have been used to characterize the molecular genetic events that are associated with development and progression of the disease. METHODS: CRISPR/Cas9 approaches were used to generate SCLL cells null for Interleukin receptor associated kinase 1 (IRAK1) and interferon gamma (IFNG) which were introduced into syngeneic hosts through tail vein injection. Development of the disease and changes in immune cell composition and activity were monitored using flow cytometry. Bead-based immunoassays were used to compare the cytokine and chemokine profiles of control and knock out (KO) cells. Antibody mediated, targeted depletion of T cell and MDSCs were performed to evaluate their role in antitumor immune responses. RESULTS: In SCLL, FGFR1 activation silences miR-146b-5p through DNMT1-mediated promoter methylation, which derepresses the downstream target IRAK1. IRAK1 KO SCLL cells were xenografted into immunocompetent syngeneic mice where the typical rapid progression of disease was lost and the mice remained disease free. IRAK1 in this system has no effect on cell cycle progression or apoptosis and robust growth of the KO cells in immunodeficient mice suggested an effect on immune surveillance. Depletion of T-cells in immunocompetent mice restored leukemogenesis of the KO cells, and tumor killing assays confirmed the role of T cells in tumor clearance. Analysis of the immune cell profile in mice transplanted with the IRAK1 expressing mock control (MC) cells shows that there is an increase in levels of myeloid-derived suppressor cells (MDSCs) with a concomitant decrease in CD4+/CD8+ T-cell levels. MDSC suppression assays and depletion experiments showed that these MDSCs were responsible for suppression of the T cell mediated leukemia cell elimination. Immuno-profiling of a panel of secreted cytokines and chemokines showed that activation of IFN-γ is specifically impaired in the KO cells. In vitro and in vivo expression assays and engraftment with interferon gamma receptor-1 (IFNGR1) null mice and IFNG KO SCLL cells, showed the leukemia cells produced IFN-γ directly participating in the induction of MDSCs to establish immune evasion. Inhibition of IRAK1 using pacritinib suppresses leukemogenesis with impaired induction of MDSCs and attenuated suppression of CD4+/CD8+ T-cells. CONCLUSIONS: IRAK1 orchestrates a previously unknown FGFR1-directed immune escape mechanism in SCLL, through induction of MDSCs via regulation of IFN-γ signaling from leukemia cells, and targeting IRAK1 may provide a means of suppressing tumor growth in this syndrome by restoring immune surveillance.


Assuntos
Neoplasias Hematológicas/etiologia , Neoplasias Hematológicas/metabolismo , Evasão da Resposta Imune , Interferon gama/metabolismo , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Células Supressoras Mieloides/imunologia , Células Supressoras Mieloides/metabolismo , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/genética , Biomarcadores , Suscetibilidade a Doenças , Regulação Neoplásica da Expressão Gênica , Neoplasias Hematológicas/patologia , Humanos , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais
7.
Immunology ; 162(2): 194-207, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-32986852

RESUMO

Class II human leucocyte antigen (HLA) proteins are involved in the immune response by presenting pathogen-derived peptides to CD4+ T lymphocytes. At the molecular level, they are constituted by α/ß-heterodimers on the surface of professional antigen-presenting cells. Here, we report that the acceptor variant (rs8084) in the HLA-DRA gene mediates the transcription of an alternative version of the α-chain lacking 25 amino acids in its extracellular domain. Molecular dynamics simulations suggest this isoform undergoes structural refolding which in turn affects its stability and cellular trafficking. The short HLA-DRA isoform cannot reach the cell surface, although it is still able to bind the corresponding ß-chain. Conversely, it remains entrapped within the endoplasmic reticulum where it is targeted for degradation. Furthermore, we demonstrate that the short isoform can be transported to the cell membrane via interactions with the peptide-binding site of canonical HLA heterodimers. Altogether, our findings indicate that short HLA-DRA functions as a novel intact antigen for class II HLA molecules.


Assuntos
Cadeias alfa de HLA-DR/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Isoformas de Proteínas/imunologia , Adulto , Idoso , Aminoácidos/imunologia , Células Apresentadoras de Antígenos/imunologia , Sítios de Ligação/imunologia , Linhagem Celular , Linhagem Celular Tumoral , Membrana Celular/imunologia , Retículo Endoplasmático/imunologia , Feminino , Células HEK293 , Células HeLa , Humanos , Leucócitos Mononucleares/imunologia , Masculino , Pessoa de Meia-Idade , Peptídeos/imunologia , T-Linfocitopenia Idiopática CD4-Positiva/imunologia
8.
Database (Oxford) ; 20202020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33206961

RESUMO

Animal models are widely employed in basic research to test mechanistic hypotheses in a complex biological environment as well as to evaluate the therapeutic potential of candidate compounds in preclinical settings. Rodents, and in particular mice, represent the most common in vivo models for their small size, short lifespan and possibility to manipulate their genome. Over time, a typical laboratory will develop a substantial number of inbred strains and transgenic mouse lines, requiring a substantial effort, in both logistic and economic terms, to maintain an animal colony for research purposes and to safeguard the integrity of results. To meet this need, here we present TopoDB, a robust and extensible web-based platform for the rational management of laboratory animals. TopoDB allows an easy tracking of individual animals within the colony and breeding protocols as well as the convenient storage of both genetic and phenotypic data generated in the different experiments. Altogether, these features facilitate and enhance the design of in vivo research, thus reducing the number of necessary animals and the housing costs. In summary, TopoDB represents a novel valuable tool in modern biomedical research. Database URL: https://github.com/UCSF-MS-DCC/TopoDB.


Assuntos
Animais de Laboratório , Pesquisa Biomédica , Animais , Genoma , Camundongos
9.
J Neuroinflammation ; 17(1): 297, 2020 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-33046105

RESUMO

BACKGROUND: MicroRNAs (miRNAs) belong to a class of evolutionary conserved, non-coding small RNAs with regulatory functions on gene expression. They negatively affect the expression of target genes by promoting either RNA degradation or translational inhibition. In recent years, converging studies have identified miRNAs as key regulators of oligodendrocyte (OL) functions. OLs are the cells responsible for the formation and maintenance of myelin in the central nervous system (CNS) and represent a principal target of the autoimmune injury in multiple sclerosis (MS). METHODS: MiRAP is a novel cell-specific miRNA affinity-purification technique which relies on genetically tagging Argonaut 2 (AGO2), an enzyme involved in miRNA processing. Here, we exploited miRAP potentiality to characterize OL-specific miRNA dynamics in the MS model experimental autoimmune encephalomyelitis (EAE). RESULTS: We show that 20 miRNAs are differentially regulated in OLs upon transition from pre-symptomatic EAE stages to disease peak. Subsequent in vitro differentiation experiments demonstrated that a sub-group of them affects the OL maturation process, mediating either protective or detrimental signals. Lastly, transcriptome profiling highlighted the endocytosis, ferroptosis, and FoxO cascades as the pathways associated with miRNAs mediating or inhibiting OL maturation. CONCLUSIONS: Altogether, our work supports a dual role for miRNAs in autoimmune demyelination. In particular, the enrichment in miRNAs mediating pro-myelinating signals suggests an active involvement of these non-coding RNAs in the homeostatic response toward neuroinflammatory injury.


Assuntos
Proteínas Argonautas/biossíntese , Encefalomielite Autoimune Experimental/metabolismo , Perfilação da Expressão Gênica/métodos , MicroRNAs/biossíntese , Oligodendroglia/metabolismo , Animais , Proteínas Argonautas/genética , Células Cultivadas , Encefalomielite Autoimune Experimental/genética , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , MicroRNAs/genética
10.
Proc Natl Acad Sci U S A ; 117(38): 23742-23750, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32878998

RESUMO

Ataxin-1 (ATXN1) is a ubiquitous polyglutamine protein expressed primarily in the nucleus where it binds chromatin and functions as a transcriptional repressor. Mutant forms of ataxin-1 containing expanded glutamine stretches cause the movement disorder spinocerebellar ataxia type 1 (SCA1) through a toxic gain-of-function mechanism in the cerebellum. Conversely, ATXN1 loss-of-function is implicated in cancer development and Alzheimer's disease (AD) pathogenesis. ATXN1 was recently nominated as a susceptibility locus for multiple sclerosis (MS). Here, we show that Atxn1-null mice develop a more severe experimental autoimmune encephalomyelitis (EAE) course compared to wildtype mice. The aggravated phenotype is mediated by increased T helper type 1 (Th1) cell polarization, which in turn results from the dysregulation of B cell activity. Ataxin-1 ablation in B cells leads to aberrant expression of key costimulatory molecules involved in proinflammatory T cell differentiation, including cluster of differentiation (CD)44 and CD80. In addition, comprehensive phosphoflow cytometry and transcriptional profiling link the exaggerated proliferation of ataxin-1 deficient B cells to the activation of extracellular signal-regulated kinase (ERK) and signal transducer and activator of transcription (STAT) pathways. Lastly, selective deletion of the physiological binding partner capicua (CIC) demonstrates the importance of ATXN1 native interactions for correct B cell functioning. Altogether, we report a immunomodulatory role for ataxin-1 and provide a functional description of the ATXN1 locus genetic association with MS risk.


Assuntos
Ataxina-1/metabolismo , Linfócitos B/metabolismo , Encefalomielite Autoimune Experimental/metabolismo , Animais , Apresentação de Antígeno , Proliferação de Células , Encefalomielite Autoimune Experimental/fisiopatologia , Camundongos , Camundongos Knockout , Esclerose Múltipla , Transdução de Sinais
11.
PLoS One ; 10(5): e0128189, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26010099

RESUMO

Kawasaki disease (KD), an acute vasculitis that preferentially affects coronary arteries, is still the leading cause of acquired heart disease in children. Although the involvement of immune system malfunction in the onset of KD is suggested, its etiology still remains to be clarified. We investigated autoantibodies in KD patients, which are frequently found in sera from patients with autoimmune diseases, vasculitides and arteritides. We performed two-dimensional western blotting and LC-MS/MS to analyze the antigens of autoantibodies, detected two protein spots with 4 out of 24 sera from KD patients but not with 6 control sera, and identified the antigens as 4-trimethylaminobutyraldehyde dehydrogenase (TMABA-DH). A slot blot analysis with TMABA-DH as an antigen also revealed higher reactivities of patients' sera than control sera (positive rates: 18/43 vs 3/41). Using an enzyme-linked immunosorbent assay (ELISA), we found that the reactivity of anti-TMABA-DH antibodies in sera from KD patients was significantly higher than that in sera from age-matched controls. The optimal cut-off value of 0.043 had a sensitivity of 83.7% and a specificity of 80.0% in detecting KD patients (positive rates: 37/43 for KD patients, 9/41 for controls). Immunohistochemistry performed on thin sections of rat heart revealed that TMABA-DH colocalized with myosin light chains in cardiac myocytes. Patient sera with high reactivity gave similar immunostaining pattern. These results suggest that the detection of anti-TMABA-DH autoantibody could be a potential strategy for a diagnosis of KD.


Assuntos
Aldeído Oxirredutases/imunologia , Autoanticorpos/imunologia , Autoantígenos/imunologia , Síndrome de Linfonodos Mucocutâneos/imunologia , Miócitos Cardíacos/imunologia , Aldeído Oxirredutases/sangue , Animais , Autoanticorpos/sangue , Autoantígenos/sangue , Criança , Pré-Escolar , Feminino , Células HEK293 , Células Endoteliais da Veia Umbilical Humana , Humanos , Lactente , Masculino , Síndrome de Linfonodos Mucocutâneos/sangue , Síndrome de Linfonodos Mucocutâneos/diagnóstico , Miócitos Cardíacos/metabolismo , Cadeias Leves de Miosina/imunologia , Cadeias Leves de Miosina/metabolismo , Ratos
12.
Genome Res ; 24(8): 1396-410, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24904046

RESUMO

Underlying the complexity of the mammalian brain is its network of neuronal connections, but also the molecular networks of signaling pathways, protein interactions, and regulated gene expression within each individual neuron. The diversity and complexity of the spatially intermingled neurons pose a serious challenge to the identification and quantification of single neuron components. To address this challenge, we present a novel approach for the study of the ribosome-associated transcriptome-the translatome-from selected subcellular domains of specific neurons, and apply it to the Purkinje cells (PCs) in the rat cerebellum. We combined microdissection, translating ribosome affinity purification (TRAP) in nontransgenic animals, and quantitative nanoCAGE sequencing to obtain a snapshot of RNAs bound to cytoplasmic or rough endoplasmic reticulum (rER)-associated ribosomes in the PC and its dendrites. This allowed us to discover novel markers of PCs, to determine structural aspects of genes, to find hitherto uncharacterized transcripts, and to quantify biophysically relevant genes of membrane proteins controlling ion homeostasis and neuronal electrical activities.


Assuntos
Perfilação da Expressão Gênica , Células de Purkinje/metabolismo , Animais , Sítios de Ligação , Mapeamento Cromossômico , Análise por Conglomerados , Citoplasma/metabolismo , Dendritos/metabolismo , Retículo Endoplasmático Rugoso/metabolismo , Família Multigênica , Regiões Promotoras Genéticas , Biossíntese de Proteínas , RNA não Traduzido/genética , RNA não Traduzido/metabolismo , Ratos , Ribossomos/fisiologia , Transcriptoma
13.
Kidney Int ; 86(3): 548-57, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24694988

RESUMO

Mesangial cell migration, regulated by several growth factors, is crucial after glomerulopathy and during glomerular development. Directional migration requires the establishment of a polarized cytoskeletal arrangement, a process regulated by coordinated actin dynamics and focal adhesion turnover at the peripheral ruffles in migrating cells. Here we found high expression of the actin cross-linking protein EPLIN (epithelial protein lost in neoplasm) in mesangial cells. EPLIN was localized in mesangial angles, which consist of actin-containing microfilaments extending underneath the capillary endothelium, where they attach to the glomerular basement membrane. In cultured mesangial cells, EPLIN was localized in peripheral actin bundles at focal adhesions and formed a protein complex with paxillin. The MEK-ERK (extracellular signal-regulated kinase) cascade regulated EPLIN-paxillin interaction and induced translocalization of EPLIN from focal adhesion sites to peripheral ruffles. Knockdown of EPLIN in mesangial cells enhanced platelet-derived growth factor-induced focal adhesion disassembly and cell migration. Furthermore, EPLIN expression was decreased in mesangial proliferative nephritis in rodents and humans in vivo. These results shed light on the coordinated actin remodeling in mesangial cells during restorative remodeling. Thus, changes in expression and localization of cytoskeletal regulators underlie phenotypic changes in mesangial cells in glomerulonephritis.


Assuntos
Adesão Celular , Movimento Celular , Proteínas do Citoesqueleto/metabolismo , Glomerulonefrite Membranoproliferativa/metabolismo , Células Mesangiais/fisiologia , Proteínas dos Microfilamentos/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismo , Actinas/metabolismo , Adolescente , Animais , Células Cultivadas , Criança , Proteínas do Citoesqueleto/genética , Expressão Gênica , Glomerulonefrite por IGA/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases , Proteínas dos Microfilamentos/genética , Paxilina/metabolismo , RNA Mensageiro/metabolismo , Ratos , Antígenos Thy-1/metabolismo
14.
J Cell Biol ; 205(2): 233-49, 2014 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-24751537

RESUMO

Voltage-gated calcium channels (VGCCs) are key regulators of cell signaling and Ca(2+)-dependent release of neurotransmitters and hormones. Understanding the mechanisms that inactivate VGCCs to prevent intracellular Ca(2+) overload and govern their specific subcellular localization is of critical importance. We report the identification and functional characterization of VGCC ß-anchoring and -regulatory protein (BARP), a previously uncharacterized integral membrane glycoprotein expressed in neuroendocrine cells and neurons. BARP interacts via two cytosolic domains (I and II) with all Cavß subunit isoforms, affecting their subcellular localization and suppressing VGCC activity. Domain I interacts at the α1 interaction domain-binding pocket in Cavß and interferes with the association between Cavß and Cavα1. In the absence of domain I binding, BARP can form a ternary complex with Cavα1 and Cavß via domain II. BARP does not affect cell surface expression of Cavα1 but inhibits Ca(2+) channel activity at the plasma membrane, resulting in the inhibition of Ca(2+)-evoked exocytosis. Thus, BARP can modulate the localization of Cavß and its association with the Cavα1 subunit to negatively regulate VGCC activity.


Assuntos
Canais de Cálcio Tipo L/metabolismo , Cálcio/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Células Neuroendócrinas/metabolismo , Neurônios/metabolismo , Animais , Sítios de Ligação , Células COS , Canais de Cálcio Tipo L/genética , Chlorocebus aethiops , Cricetinae , Humanos , Glicoproteínas de Membrana/genética , Camundongos , Proteínas do Tecido Nervoso/genética , Células Neuroendócrinas/citologia , Neurônios/citologia , Células PC12 , Ligação Proteica , Estrutura Terciária de Proteína , Ratos
15.
FEBS J ; 279(17): 3010-21, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22747997

RESUMO

The slit diaphragm (SD) is an intercellular junction between renal glomerular epithelial cells (podocytes) that is essential for permselectivity in glomerular ultrafiltration. The SD components, nephrin and Neph1, assemble a signaling complex in a tyrosine phosphorylation dependent manner, and regulate the unique actin cytoskeleton of podocytes. Mutations in the NPHS1 gene that encodes nephrin cause congenital nephrotic syndrome (CNS), which is characterized by the loss of the SD and massive proteinuria. Recently, we have identified the expression of the transmembrane glycoprotein signal regulatory protein α (SIRPα) at the SD. In the present study, we analyzed the expression of SIRPα in developing kidneys, in kidneys from CNS patients and in proteinuric rat models. The possibility that SIRPα interacts with known SD proteins was also investigated. SIRPα was concentrated at the SD junction during the maturation of intercellular junctions. In the glomeruli of CNS patients carrying mutations in NPHS1, where SD formation is disrupted, the expression of SIRPα as well as Neph1 and nephrin was significantly decreased, indicating that SIRPα is closely associated with the nephrin complex. Indeed, SIRPα formed hetero-oligomers with nephrin in cultured cells and in glomeruli. Furthermore, the cytoplasmic domain of SIRPα was highly phosphorylated in normal glomeruli, and its phosphorylation was dramatically decreased upon podocyte injury in vivo. Thus, SIRPα interacts with nephrin at the SD, and its phosphorylation is dynamically regulated in proteinuric states. Our data provide new molecular insights into the phosphorylation events triggered by podocyte injury.


Assuntos
Antígenos de Diferenciação/metabolismo , Proteínas de Membrana/metabolismo , Síndrome Nefrótica/metabolismo , Podócitos/metabolismo , Receptores Imunológicos/metabolismo , Animais , Modelos Animais de Doenças , Humanos , Glomérulos Renais/metabolismo , Glomérulos Renais/patologia , Proteínas de Membrana/genética , Mutação , Fosforilação , Ligação Proteica , Proteinúria/metabolismo , Ratos , Tirosina/metabolismo
16.
Mol Cancer Ther ; 8(1): 171-7, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19139126

RESUMO

Telomerase-specific replication-competent adenovirus, Telomelysin (OBP-301), has a human telomerase reverse transcriptase promoter that regulates viral replication and efficiently kills human cancer cells. The objectives of this study are to examine the effects of OBP-301 in squamous cell carcinoma of the head and neck cells in vitro and in xenografted animals in vivo. OBP-301 was found to be cytotoxic to the YCUT892, KCCT873, KCCT891, KCCL871, YCUM862, HN12, and KCCOR891 cell lines in vitro. However, the level of cytotoxicity is not correlated with the expression levels of adenoviral receptors, which may be required for adenoviral infection in squamous cell carcinoma of the head and neck cells. OBP-301 shows remarkable antitumor activity against established s.c. KCCT873 tumors in immunodeficient animals in a dose-dependent manner. In addition, no significant toxicity was observed in animals receiving treatment. These results suggest that OBP-301 is a novel therapeutic agent with promise for the treatment of human head and neck cancers.


Assuntos
Neoplasias de Cabeça e Pescoço/enzimologia , Neoplasias de Cabeça e Pescoço/terapia , Terapia Viral Oncolítica , Telomerase/metabolismo , Adenoviridae/genética , Animais , Linhagem Celular Tumoral , Proteína de Membrana Semelhante a Receptor de Coxsackie e Adenovirus , Modelos Animais de Doenças , Feminino , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/virologia , Humanos , Camundongos , Camundongos Nus , Receptores Virais/genética , Receptores Virais/metabolismo , Telomerase/genética , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Gan To Kagaku Ryoho ; 36 Suppl 1: 110-2, 2009 Dec.
Artigo em Japonês | MEDLINE | ID: mdl-20443419

RESUMO

A breakdown of 28 patients on domiciliary NPPV from September. 3, 2007 through July 31, 2009 includes 11 patients with chronic obstructive pulmonary disease, 7 patients with neuro-muscular disease, 4 patients with pulmonary tuberculosis sequela, 4 patients with conjestive heart failure, a patient with bronchiectasis and a patient with pulmonary interstitial pneumonia. Sixteen patients of them started NPPV at home. All of domiciliary NPPV patients had very severe conditions and frequent exacerbations. An avoidance of exacerbation led to improve a prognosis. Actually, a domiciliary pulmonary care team should do a pulmonary rehabilitation for them. It needs a special knowledge and artistic skills for their stable and high quality of life at home. Not only all of the team members should be an expert, but also the patient and family members who belong to the team should be an expert as well. We should educate them how to assess their symptoms and act patho-physiologically.


Assuntos
Serviços de Assistência Domiciliar , Equipe de Assistência ao Paciente , Respiração com Pressão Positiva , Feminino , Humanos , Pessoa de Meia-Idade
18.
J Vet Med Sci ; 65(10): 1107-9, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-14600349

RESUMO

Complement-mediated cytotoxicity for porcine islet cells (PICs) was evaluated using sera of six animal species. Then soluble complement receptor type-1 (sCR1) as an anti-complement agent was added to those sera, and the changes in 50% hemolytic unit of complement serum (CH50) and cytotoxic effect of those sera on PICs were examined. All the sera except for that of pig showed cytotoxicity. However, the extent of toxicity was considerably different between species. In the rat and human serum, sCR1 significantly reduced CH50 and cytotoxicity, however in the dog serum, sCR1 had no suppressive effects. These results may suggest that complement contribute to humoral cytotoxicity for PICs as a main factor, and the compatibility of complement with PICs differs between animal species.


Assuntos
Proteínas do Sistema Complemento/toxicidade , Ilhotas Pancreáticas/patologia , Animais , Sobrevivência Celular/efeitos dos fármacos , Cães , Cobaias , Humanos , Ilhotas Pancreáticas/efeitos dos fármacos , Ratos , Especificidade da Espécie , Suínos
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