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1.
Nat Commun ; 11(1): 4946, 2020 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009409

RESUMO

Immune-related adverse events (irAEs), caused by anti-PD-1/PD-L1 antibodies, can lead to fulminant and even fatal consequences and thus require early detection and aggressive management. However, a comprehensive approach to identify biomarkers of irAE is lacking. Here, we utilize a strategy that combines pharmacovigilance data and omics data, and evaluate associations between multi-omics factors and irAE reporting odds ratio across different cancer types. We identify a bivariate regression model of LCP1 and ADPGK that can accurately predict irAE. We further validate LCP1 and ADPGK as biomarkers in an independent patient-level cohort. Our approach provides a method for identifying potential biomarkers of irAE in cancer immunotherapy using both pharmacovigilance data and multi-omics data.


Assuntos
Genômica , Imunoterapia/efeitos adversos , Neoplasias/imunologia , Neoplasias/terapia , Biomarcadores Tumorais/metabolismo , Estudos de Coortes , Análise Fatorial , Humanos , Proteínas dos Microfilamentos/metabolismo , Reprodutibilidade dos Testes
2.
Nat Commun ; 11(1): 4818, 2020 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-32968060

RESUMO

Migrating cells move across diverse assemblies of extracellular matrix (ECM) that can be separated by micron-scale gaps. For membranes to protrude and reattach across a gap, actin filaments, which are relatively weak as single filaments, must polymerize outward from adhesion sites to push membranes towards distant sites of new adhesion. Here, using micropatterned ECMs, we identify T-Plastin, one of the most ancient actin bundling proteins, as an actin stabilizer that promotes membrane protrusions and enables bridging of ECM gaps. We show that T-Plastin widens and lengthens protrusions and is specifically enriched in active protrusions where F-actin is devoid of non-muscle myosin II activity. Together, our study uncovers critical roles of the actin bundler T-Plastin to promote protrusions and migration when adhesion is spatially-gapped.


Assuntos
Movimento Celular/fisiologia , Extensões da Superfície Celular/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas dos Microfilamentos/metabolismo , Citoesqueleto de Actina/metabolismo , Actinas/metabolismo , Sistemas CRISPR-Cas , Adesão Celular , Linhagem Celular , Citoesqueleto/metabolismo , Matriz Extracelular/metabolismo , Técnicas de Inativação de Genes , Humanos , Cinética , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/ultraestrutura , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/ultraestrutura , Miosinas/metabolismo , Pseudópodes/metabolismo , Receptor EphB2
3.
PLoS Pathog ; 16(9): e1008879, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32997728

RESUMO

The Human T-cell leukemia virus type 1 (HTLV-1) orf I-encoded accessory protein p8 is cleaved from its precursor p12, and both proteins contribute to viral persistence. p8 induces cellular protrusions, which are thought to facilitate transfer of p8 to target cells and virus transmission. Host factors interacting with p8 and mediating p8 transfer are unknown. Here, we report that vasodilator-stimulated phosphoprotein (VASP), which promotes actin filament elongation, is a novel interaction partner of p8 and important for p8 and HTLV-1 Gag cell-to-cell transfer. VASP contains an Ena/VASP homology 1 (EVH1) domain that targets the protein to focal adhesions. Bioinformatics identified a short stretch in p8 (amino acids (aa) 24-45) which may mediate interactions with the EVH1 domain of VASP. Co-immunoprecipitations confirmed interactions of VASP:p8 in 293T, Jurkat and HTLV-1-infected MT-2 cells. Co-precipitation of VASP:p8 could be significantly blocked by peptides mimicking aa 26-37 of p8. Mutational studies revealed that the EVH1-domain of VASP is necessary, but not sufficient for the interaction with p8. Further, deletion of the VASP G- and F-actin binding domains significantly diminished co-precipitation of p8. Imaging identified areas of partial co-localization of VASP with p8 at the plasma membrane and in protrusive structures, which was confirmed by proximity ligation assays. Co-culture experiments revealed that p8 is transferred between Jurkat T-cells via VASP-containing conduits. Imaging and flow cytometry revealed that repression of both endogenous and overexpressed VASP by RNA interference or by CRISPR/Cas9 reduced p8 transfer to the cell surface and to target Jurkat T-cells. Stable repression of VASP by RNA interference in chronically infected MT-2 cells impaired both p8 and HTLV-1 Gag transfer to target Jurkat T-cells, while virus release was unaffected. Thus, we identified VASP as a novel interaction partner of p8, which is important for transfer of HTLV-1 p8 and Gag to target T-cells.


Assuntos
Moléculas de Adesão Celular , Adesões Focais , Produtos do Gene gag , Vírus Linfotrópico T Tipo 1 Humano , Proteínas dos Microfilamentos , Fosfoproteínas , Linfócitos T , Moléculas de Adesão Celular/química , Moléculas de Adesão Celular/genética , Moléculas de Adesão Celular/metabolismo , Adesões Focais/química , Adesões Focais/genética , Adesões Focais/metabolismo , Adesões Focais/virologia , Produtos do Gene gag/química , Produtos do Gene gag/genética , Produtos do Gene gag/metabolismo , Vírus Linfotrópico T Tipo 1 Humano/química , Vírus Linfotrópico T Tipo 1 Humano/genética , Vírus Linfotrópico T Tipo 1 Humano/metabolismo , Humanos , Células Jurkat , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Fosfoproteínas/química , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Domínios Proteicos , Linfócitos T/química , Linfócitos T/metabolismo , Linfócitos T/virologia
4.
PLoS Comput Biol ; 16(9): e1007815, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32925900

RESUMO

Protein-protein interactions are involved in a wide range of cellular processes. These interactions often involve intrinsically disordered proteins (IDPs) and protein binding domains. However, the details of IDP binding pathways are hard to characterize using experimental approaches, which can rarely capture intermediate states present at low populations. SH3 domains are common protein interaction domains that typically bind proline-rich disordered segments and are involved in cell signaling, regulation, and assembly. We hypothesized, given the flexibility of SH3 binding peptides, that their binding pathways include multiple steps important for function. Molecular dynamics simulations were used to characterize the steps of binding between the yeast Abp1p SH3 domain (AbpSH3) and a proline-rich IDP, ArkA. Before binding, the N-terminal segment 1 of ArkA is pre-structured and adopts a polyproline II helix, while segment 2 of ArkA (C-terminal) adopts a 310 helix, but is far less structured than segment 1. As segment 2 interacts with AbpSH3, it becomes more structured, but retains flexibility even in the fully engaged state. Binding simulations reveal that ArkA enters a flexible encounter complex before forming the fully engaged bound complex. In the encounter complex, transient nonspecific hydrophobic and long-range electrostatic contacts form between ArkA and the binding surface of SH3. The encounter complex ensemble includes conformations with segment 1 in both the forward and reverse orientation, suggesting that segment 2 may play a role in stabilizing the correct binding orientation. While the encounter complex forms quickly, the slow step of binding is the transition from the disordered encounter ensemble to the fully engaged state. In this transition, ArkA makes specific contacts with AbpSH3 and buries more hydrophobic surface. Simulating the binding between ApbSH3 and ArkA provides insight into the role of encounter complex intermediates and nonnative hydrophobic interactions for other SH3 domains and IDPs in general.


Assuntos
Proteínas Intrinsicamente Desordenadas , Proteínas dos Microfilamentos , Proteínas de Saccharomyces cerevisiae , Domínios de Homologia de src , Proteínas Intrinsicamente Desordenadas/química , Proteínas Intrinsicamente Desordenadas/genética , Proteínas Intrinsicamente Desordenadas/metabolismo , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Domínios de Homologia de src/genética , Domínios de Homologia de src/fisiologia
5.
Nat Commun ; 11(1): 4187, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826901

RESUMO

EHBP1 is an adaptor protein that regulates vesicular trafficking by recruiting Rab8 family members and Eps15-homology domain-containing proteins 1/2 (EHD1/2). It also links endosomes to the actin cytoskeleton. However, the underlying molecular mechanism of activation of EHBP1 actin-binding activity is unclear. Here, we show that both termini of EHBP1 have membrane targeting potential. EHBP1 associates with PI(3)P, PI(5)P, and phosphatidylserine via its N-terminal C2 domain. We show that in the absence of Rab8 family members, the C-terminal bivalent Mical/EHBP Rab binding (bMERB) domain forms an intramolecular complex with its central calponin homology (CH) domain and auto-inhibits actin binding. Rab8 binding to the bMERB domain relieves this inhibition. We have analyzed the CH:bMERB auto-inhibited complex and the active bMERB:Rab8 complex biochemically and structurally. Together with structure-based mutational studies, this explains how binding of Rab8 frees the CH domain and allows it to interact with the actin cytoskeleton, leading to membrane tubulation.


Assuntos
Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/metabolismo , Proteínas rab de Ligação ao GTP/química , Proteínas rab de Ligação ao GTP/metabolismo , Citoesqueleto de Actina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/química , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Transporte/genética , Proteínas dos Microfilamentos/genética , Modelos Moleculares , Fosfatos de Fosfatidilinositol/metabolismo , Ligação Proteica , Conformação Proteica , Domínios Proteicos , Domínios e Motivos de Interação entre Proteínas , Transporte Proteico/fisiologia , Alinhamento de Sequência , Proteínas de Transporte Vesicular , Proteínas rab de Ligação ao GTP/genética
6.
Proc Natl Acad Sci U S A ; 117(32): 19388-19398, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32727906

RESUMO

CD8+ T cells play pivotal roles in eradicating pathogens and tumor cells. T cell receptor (TCR) signaling is vital for the optimal activation of CD8+ T cells. Upon TCR engagement, the transmembrane adapter protein LAT (linker for activation of T cells) recruits other key signaling molecules and forms the "LAT signalosome" for downstream signal transduction. However, little is known about which functional partners could restrain the formation of the LAT signalosome and inhibit CD8+ cytotoxic T lymphocyte (CTL)-mediated cytotoxicity. Here we have demonstrated that LRCH1 (leucine-rich repeats and calponin homology domain containing 1) directly binds LAT, reduces LAT phosphorylation and interaction with GRB2, and also promotes the endocytosis of LAT. Lrch1 -/- mice display better protection against influenza virus and Listeria infection, with enhanced CD8+ T cell proliferation and cytotoxicity. Adoptive transfer of Lrch1 -/- CD8+ CTLs leads to increased B16-MO5 tumor clearance in vivo. Furthermore, knockout of LRCH1 in human chimeric antigen receptor (CAR) T cells that recognize the liver tumor-associated antigen glypican-3 could improve CAR T cell migration and proliferation in vitro. These findings suggest LRCH1 as a potential translational target to improve T cell immunotherapy against infection and tumors.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Linfócitos T CD8-Positivos/imunologia , Proteínas de Membrana/metabolismo , Proteínas dos Microfilamentos/deficiência , Transdução de Sinais , Animais , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/transplante , Movimento Celular , Células Cultivadas , Citotoxicidade Imunológica , Endocitose , Proteína Adaptadora GRB2/metabolismo , Humanos , Imunoterapia Adotiva , Infecções/imunologia , Infecções/microbiologia , Infecções/virologia , Interferon gama/metabolismo , Neoplasias Pulmonares/terapia , Ativação Linfocitária , Camundongos , Camundongos Knockout , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Fosforilação , Ligação Proteica , Receptores de Antígenos de Linfócitos T/metabolismo , Receptores de Antígenos Quiméricos/metabolismo
7.
Nat Commun ; 11(1): 3457, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32651364

RESUMO

Glioblastoma is a deadly cancer, with no effective therapies. Better understanding and identification of selective targets are urgently needed. We found that advillin (AVIL) is overexpressed in all the glioblastomas we tested including glioblastoma stem/initiating cells, but hardly detectable in non-neoplastic astrocytes, neural stem cells or normal brain. Glioma patients with increased AVIL expression have a worse prognosis. Silencing AVIL nearly eradicated glioblastoma cells in culture, and dramatically inhibited in vivo xenografts in mice, but had no effect on normal control cells. Conversely, overexpressing AVIL promoted cell proliferation and migration, enabled fibroblasts to escape contact inhibition, and transformed immortalized astrocytes, supporting AVIL being a bona fide oncogene. We provide evidence that the tumorigenic effect of AVIL is partly mediated by FOXM1, which regulates LIN28B, whose expression also correlates with clinical prognosis. AVIL regulates the cytoskeleton through modulating F-actin, while mutants disrupting F-actin binding are defective in its tumorigenic capabilities.


Assuntos
Glioblastoma/metabolismo , Glioblastoma/patologia , Proteínas dos Microfilamentos/metabolismo , Animais , Western Blotting , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Movimento Celular/fisiologia , Proliferação de Células/genética , Proliferação de Células/fisiologia , Citoesqueleto/metabolismo , Imunofluorescência , Glioblastoma/genética , Humanos , Imuno-Histoquímica , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Proteínas dos Microfilamentos/genética , Microscopia Confocal , Reação em Cadeia da Polimerase em Tempo Real
8.
Life Sci ; 258: 118085, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32663578

RESUMO

BACKGROUND: An integral intestinal barrier is essential for intestinal homeostasis. Yet, as a side effect of cancer treatment, chemotherapeutic drugs have been reported to cause mucositis. In a recent study, we found that alginate oligosaccharides (AOS) prevent busulfan induced intestinal mucositis. However, it is not known if AOS improves small intestine epithelial cell integrity and migration, which are two essential processes for maintaining the mechanical barrier function of the small intestine. In the current investigation, we aimed to explore the effects of AOS on the integrity and migration of small intestine cells using swine intestinal epithelial IPEC-J2 cells. METHODS: Cell integrity was determined using the TEER assay. Cell migration capability was detected using a wound healing experiment. Small interfering RNA (siRNA) was used to inhibit mannose receptor (MR) expression. Western blotting and immunofluorescence staining were used to determine protein expression. RESULTS: Increasing levels of AOS improved cell integrity as measure by TEER. At the same time, AOS improved IPEC-J2 cell migration capacity as shown in the wound closure assay. It is interesting to note that AOS increased the expression of intestinal microvillus proteins and junction proteins to benefit cell integrity. MR siRNA blocked the action of AOS on cell integrity and cell migration and inhibited the expression of microvillus and cell junction proteins. CONCLUSION: We identified the underlying mechanisms by which AOS improved small intestinal mucositis. As a novel, natural food additive, AOS may be administered to prevent intestinal mucositis induced by chemotherapy or other issues.


Assuntos
Alginatos/farmacologia , Movimento Celular/efeitos dos fármacos , Intestino Delgado/citologia , Oligossacarídeos/farmacologia , Animais , Linhagem Celular , Lectinas Tipo C/metabolismo , Lectinas de Ligação a Manose/metabolismo , Proteínas dos Microfilamentos/metabolismo , Microvilosidades/efeitos dos fármacos , Microvilosidades/metabolismo , Miosinas/metabolismo , RNA Interferente Pequeno/metabolismo , Receptores de Superfície Celular/metabolismo , Suínos , Proteínas de Junções Íntimas/metabolismo , Cicatrização/efeitos dos fármacos
9.
Mol Cell Biol ; 40(17)2020 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-32601107

RESUMO

Fodrin and its erythroid cell-specific isoform spectrin are actin-associated fibrous proteins that play crucial roles in the maintenance of structural integrity in mammalian cells, which is necessary for proper cell function. Normal cell morphology is altered in diseases such as various cancers and certain neuronal disorders. Fodrin and spectrin are two-chain (αß) molecules that are encoded by paralogous genes and share many features but also demonstrate certain differences. Fodrin (in humans, typically a heterodimer of the products of the SPTAN1 and SPTBN1 genes) is expressed in nearly all cell types and is especially abundant in neuronal tissues, whereas spectrin (in humans, a heterodimer of the products of the SPTA1 and SPTB1 genes) is expressed almost exclusively in erythrocytes. To fulfill a role in such a variety of different cell types, it was anticipated that fodrin would need to be a more versatile scaffold than spectrin. Indeed, as summarized here, domains unique to fodrin and its regulation by Ca2+, calmodulin, and a variety of posttranslational modifications (PTMs) endow fodrin with additional specific functions. However, how fodrin structural variations and misregulated PTMs may contribute to the etiology of various cancers and neurodegenerative diseases needs to be further investigated.


Assuntos
Proteínas de Transporte/química , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas dos Microfilamentos/química , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Actinas/metabolismo , Animais , Cálcio/metabolismo , Calmodulina/metabolismo , Células Eritroides/metabolismo , Humanos , Neurônios/metabolismo , Espectrina/metabolismo , Espectrina/fisiologia , Relação Estrutura-Atividade
10.
Am J Physiol Heart Circ Physiol ; 319(2): H306-H319, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32618513

RESUMO

Dilated cardiomyopathy (DCM) is clinically characterized by dilated ventricular cavities and reduced ejection fraction, leading to heart failure and increased thromboembolic risk. Mutations in thin-filament regulatory proteins can cause DCM and have been shown in vitro to reduce contractility and myofilament Ca2+-affinity. In this work we have studied the functional consequences of mutations in cardiac troponin T (R131W), cardiac troponin I (K36Q) and α-tropomyosin (E40K) using adenovirally transduced isolated guinea pig left ventricular cardiomyocytes. We find significantly reduced fractional shortening with reduced systolic Ca2+. Contraction and Ca2+ reuptake times were slowed, which contrast with some findings in murine models of myofilament Ca2+ desensitization. We also observe increased sarcoplasmic reticulum (SR) Ca2+ load and smaller fractional SR Ca2+ release. This corresponds to a reduction in SR Ca2+-ATPase activity and increase in sodium-calcium exchanger activity. We also observe dephosphorylation and nuclear translocation of the nuclear factor of activated T cells (NFAT), with concordant RAC-α-serine/threonine protein kinase (Akt) phosphorylation but no change to extracellular signal-regulated kinase activation in chronically paced cardiomyocytes expressing DCM mutations. These changes in Ca2+ handling and signaling are common to all three mutations, indicating an analogous pathway of disease pathogenesis in thin-filament sarcomeric DCM. Previous work has shown that changes to myofilament Ca2+ sensitivity caused by DCM mutations are qualitatively opposite from hypertrophic cardiomyopathy (HCM) mutations in the same genes. However, we find several common pathways such as increased relaxation times and NFAT activation that are also hallmarks of HCM. This suggests more complex intracellular signaling underpinning DCM, driven by the primary mutation.NEW & NOTEWORTHY Dilated cardiomyopathy (DCM) is a frequently occurring cardiac disorder with a degree of genetic inheritance. We have found that DCM mutations in proteins that regulate the contractile machinery cause alterations to contraction, calcium-handling, and some new signaling pathways that provide stimuli for disease development. We have used guinea pig cells that recapitulate human calcium-handling and introduced the mutations using adenovirus gene transduction to look at the initial triggers of disease before remodeling.


Assuntos
Sinalização do Cálcio , Cardiomiopatia Dilatada/genética , Proteínas dos Microfilamentos/genética , Mutação , Contração Miocárdica , Miócitos Cardíacos/enzimologia , Fatores de Transcrição NFATC/metabolismo , Proteína Oncogênica v-akt/metabolismo , Função Ventricular Esquerda , Animais , Cardiomiopatia Dilatada/metabolismo , Cardiomiopatia Dilatada/fisiopatologia , Cardiomiopatia Hipertrófica/genética , Cardiomiopatia Hipertrófica/metabolismo , Cardiomiopatia Hipertrófica/fisiopatologia , Células Cultivadas , Predisposição Genética para Doença , Cobaias , Masculino , Proteínas dos Microfilamentos/metabolismo , Fenótipo , Retículo Sarcoplasmático/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Trocador de Sódio e Cálcio/metabolismo , Tropomiosina/genética , Tropomiosina/metabolismo , Troponina I/genética , Troponina I/metabolismo , Troponina T/genética , Troponina T/metabolismo
11.
PLoS Pathog ; 16(5): e1008503, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32365138

RESUMO

Salmonella enterica serovar Typhimurium (S.Tm) infections of cultured cell lines have given rise to the ruffle model for epithelial cell invasion. According to this model, the Type-Three-Secretion-System-1 (TTSS-1) effectors SopB, SopE and SopE2 drive an explosive actin nucleation cascade, resulting in large lamellipodia- and filopodia-containing ruffles and cooperative S.Tm uptake. However, cell line experiments poorly recapitulate many of the cell and tissue features encountered in the host's gut mucosa. Here, we employed bacterial genetics and multiple imaging modalities to compare S.Tm invasion of cultured epithelial cell lines and the gut absorptive epithelium in vivo in mice. In contrast to the prevailing ruffle-model, we find that absorptive epithelial cell entry in the mouse gut occurs through "discreet-invasion". This distinct entry mode requires the conserved TTSS-1 effector SipA, involves modest elongation of local microvilli in the absence of expansive ruffles, and does not favor cooperative invasion. Discreet-invasion preferentially targets apicolateral hot spots at cell-cell junctions and shows strong dependence on local cell neighborhood. This proof-of-principle evidence challenges the current model for how S.Tm can enter gut absorptive epithelial cells in their intact in vivo context.


Assuntos
Aderência Bacteriana , Mucosa Intestinal/microbiologia , Infecções por Salmonella , Salmonella typhimurium , Sistemas de Secreção Tipo I/metabolismo , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cães , Fatores de Troca do Nucleotídeo Guanina/genética , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Células HeLa , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Células Madin Darby de Rim Canino , Camundongos , Camundongos Knockout , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Infecções por Salmonella/genética , Infecções por Salmonella/metabolismo , Infecções por Salmonella/microbiologia , Infecções por Salmonella/patologia , Salmonella typhimurium/genética , Salmonella typhimurium/metabolismo , Salmonella typhimurium/patogenicidade , Sistemas de Secreção Tipo I/genética
12.
PLoS One ; 15(4): e0232025, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32353019

RESUMO

The actin cytoskeleton plays a central role in establishing cell polarity and shape during embryonic morphogenesis. Daam1, a member of the Formin family of actin cytoskeleton regulators, is a Dvl2-binding protein that functions in the Wnt/Planar Cell Polarity (PCP) pathway. To examine the role of the Daam proteins in mammalian development, we generated Daam-deficient mice by gene targeting and found that Daam1, but not Daam2, is necessary for fetal survival. Embryonic development of Daam1 mutants was delayed most likely due to functional defects in the labyrinthine layer of the placenta. Examination of Daam2 and Daam1/2 double mutants revealed that Daam1 and Daam2 are functionally redundant during placental development. Of note, neural tube closure defects (NTD), which are observed in several mammalian PCP mutants, are not observed in Wnt5a or Daam1 single mutants, but arise in Daam1;Wnt5a double mutants. These findings demonstrate a unique function for Daam genes in placental development and are consistent with a role for Daam1 in the Wnt/PCP pathway in mammals.


Assuntos
Proteínas dos Microfilamentos/genética , Placentação/genética , Proteínas rho de Ligação ao GTP/genética , Citoesqueleto de Actina/genética , Citoesqueleto de Actina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Proteínas de Transporte/metabolismo , Polaridade Celular , Citoesqueleto/metabolismo , Desenvolvimento Embrionário , Feminino , Forminas/genética , Forminas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Masculino , Camundongos/embriologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas dos Microfilamentos/metabolismo , Placenta/embriologia , Gravidez , Via de Sinalização Wnt , Proteínas rho de Ligação ao GTP/metabolismo
13.
Mol Biol (Mosk) ; 54(2): 285-292, 2020.
Artigo em Russo | MEDLINE | ID: mdl-32392198

RESUMO

The actin-binding proteins profilin, fascin, and ezrin were tested for involvement in metastasis of non-small cell lung cancer (NSCLC). The levels of the PFN1, FSCN1, and EZR mRNAs and respective proteins were determined by real-time PCR and Western blotting; tumor and adjacent normal lung tissue samples were obtained from 46 NSCLC patients. Patients with lymphatic metastasis had higher expression levels of the profilin, fascin, and ezrin mRNAs and the profilin and fascin proteins. Both mRNA and protein expression levels increased in patients with distant metastasis. The molecules may serve as predictors to evaluate the prognosis in NSCLC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas de Transporte/metabolismo , Proteínas do Citoesqueleto/metabolismo , Neoplasias Pulmonares/patologia , Proteínas dos Microfilamentos/metabolismo , Profilinas/metabolismo , Linhagem Celular Tumoral , Humanos , Metástase Neoplásica , RNA Mensageiro
14.
PLoS One ; 15(5): e0233152, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32453755

RESUMO

Obesity is associated with significantly higher mortality rates, and excess adipose tissue is involved in respective pathologies. Here we established a human adipose tissue slice cultures (HATSC) model ex vivo. HATSC match the in vivo cell composition of human adipose tissue with, among others, mature adipocytes, mesenchymal stem cells as well as stroma tissue and immune cells. This is a new method, optimized for live imaging, to study adipose tissue and cell-based mechanisms of obesity in particular. HATSC survival was tested by means of conventional and immunofluorescence histological techniques, functional analyses and live imaging. Surgery-derived tissue was cut with a tissue chopper in 500 µm sections and transferred onto membranes building an air-liquid interface. HATSC were cultured in six-well plates filled with Dulbecco's Modified Eagle's Medium (DMEM), insulin, transferrin, and selenium, both with and without serum. After 0, 1, 7 and 14 days in vitro, slices were fixated and analyzed by morphology and Perilipin A for tissue viability. Immunofluorescent staining against IBA1, CD68 and Ki67 was performed to determine macrophage survival and proliferation. These experiments showed preservation of adipose tissue as well as survival and proliferation of monocytes and stroma tissue for at least 14 days in vitro even in the absence of serum. The physiological capabilities of adipocytes were functionally tested by insulin stimulation and measurement of Phospho-Akt on day 7 and 14 in vitro. Viability was further confirmed by live imaging using Calcein-AM (viable cells) and propidium iodide (apoptosis/necrosis). In conclusion, HATSC have been successfully established by preserving the monovacuolar form of adipocytes and surrounding macrophages and connective tissue. This model allows further analysis of mature human adipose tissue biology ex vivo.


Assuntos
Adipócitos , Tecido Adiposo , Modelos Biológicos , Obesidade , Técnicas de Cultura de Tecidos , Adipócitos/metabolismo , Adipócitos/patologia , Tecido Adiposo/metabolismo , Tecido Adiposo/patologia , Adolescente , Adulto , Idoso , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Sobrevivência Celular , Feminino , Humanos , Antígeno Ki-67/metabolismo , Masculino , Proteínas dos Microfilamentos/metabolismo , Pessoa de Meia-Idade , Obesidade/metabolismo , Obesidade/patologia
15.
PLoS Genet ; 16(5): e1008754, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32365093

RESUMO

FSHD is characterized by the misexpression of DUX4 in skeletal muscle. Although DUX4 upregulation is thought to be the pathogenic cause of FSHD, DUX4 is lowly expressed in patient samples, and analysis of the consequences of DUX4 expression has largely relied on artificial overexpression. To better understand the native expression profile of DUX4 and its targets, we performed bulk RNA-seq on a 6-day differentiation time-course in primary FSHD2 patient myoblasts. We identify a set of 54 genes upregulated in FSHD2 cells, termed FSHD-induced genes. Using single-cell and single-nucleus RNA-seq on myoblasts and differentiated myotubes, respectively, we captured, for the first time, DUX4 expressed at the single-nucleus level in a native state. We identified two populations of FSHD myotube nuclei based on low or high enrichment of DUX4 and FSHD-induced genes ("FSHD-Lo" and "FSHD Hi", respectively). FSHD-Hi myotube nuclei coexpress multiple DUX4 target genes including DUXA, LEUTX and ZSCAN4, and also upregulate cell cycle-related genes with significant enrichment of E2F target genes and p53 signaling activation. We found more FSHD-Hi nuclei than DUX4-positive nuclei, and confirmed with in situ RNA/protein detection that DUX4 transcribed in only one or two nuclei is sufficient for DUX4 protein to activate target genes across multiple nuclei within the same myotube. DUXA (the DUX4 paralog) is more widely expressed than DUX4, and depletion of DUXA suppressed the expression of LEUTX and ZSCAN4 in late, but not early, differentiation. The results suggest that the DUXA can take over the role of DUX4 to maintain target gene expression. These results provide a possible explanation as to why it is easier to detect DUX4 target genes than DUX4 itself in patient cells and raise the possibility of a self-sustaining network of gene dysregulation triggered by the limited DUX4 expression.


Assuntos
Núcleo Celular/metabolismo , Fibras Musculares Esqueléticas/metabolismo , Distrofia Muscular Facioescapuloumeral , RNA-Seq/métodos , Análise de Célula Única/métodos , Estudos de Casos e Controles , Diferenciação Celular , Núcleo Celular/química , Núcleo Celular/classificação , Núcleo Celular/patologia , Células Cultivadas , Regulação da Expressão Gênica , Células HEK293 , Humanos , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Fibras Musculares Esqueléticas/patologia , Fibras Musculares Esqueléticas/fisiologia , Fibras Musculares Esqueléticas/ultraestrutura , Distrofia Muscular Facioescapuloumeral/genética , Distrofia Muscular Facioescapuloumeral/metabolismo , Distrofia Muscular Facioescapuloumeral/patologia , Mioblastos/metabolismo , Mioblastos/fisiologia , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Sequenciamento Completo do Exoma
16.
Nanotoxicology ; 14(6): 774-787, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32401088

RESUMO

Gastric carcinoma is one of the most lethal malignant tumors. As part of our long-term efforts on seeking effective diagnosis and therapeutic strategies of gastric cancer, we present herein novel ternary copper-based chalcogenide nanoplatform CuS-NiS2 nanomaterials with outstanding photothermal (PT)/photodynamic (PD) property that could effectively suppress human gastric cancer in vitro and in vivo without obvious side effects. We revealed that CuS-NiS2 induced reactive oxygen species (ROS) generation, leading to apoptosis through Bcl-2/Bax pathway of human gastric cancer cells under 808 nm near-infrared (NIR) irradiation. In addition, we also confirmed that the combination of CuS-NiS2 and 808 nm NIR laser treatment triggered necroptosis by regulating the novel pathway MLKL/CAPG of human gastric cancer cells. Moreover, the CuS-NiS2 exhibited excellent contrast enhancement according to magnetic resonance imaging (MRI). Taken together, we reported new ternary copper-based chalcogenide nanomaterials CuS-NiS2, which could be successfully applied for MRI-guided PT/PD therapy of gastric carcinoma through mitochondria-mediated apoptosis and MLKL/CAPG-mediated necroptosis.


Assuntos
Apoptose/efeitos dos fármacos , Cobre/uso terapêutico , Proteínas dos Microfilamentos/metabolismo , Mitocôndrias/efeitos dos fármacos , Nanoestruturas/uso terapêutico , Necroptose/efeitos dos fármacos , Níquel/uso terapêutico , Proteínas Nucleares/metabolismo , Fototerapia/métodos , Proteínas Quinases/metabolismo , Neoplasias Gástricas/terapia , Animais , Linhagem Celular Tumoral , Cobre/administração & dosagem , Humanos , Imagem por Ressonância Magnética , Masculino , Camundongos Nus , Mitocôndrias/metabolismo , Nanoestruturas/administração & dosagem , Níquel/administração & dosagem , Neoplasias Gástricas/diagnóstico por imagem , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Proc Natl Acad Sci U S A ; 117(22): 12324-12331, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32409605

RESUMO

Glioblastoma multiforme (GBM) is an aggressive cancer without currently effective therapies. Radiation and temozolomide (radio/TMZ) resistance are major contributors to cancer recurrence and failed GBM therapy. Heat shock proteins (HSPs), through regulation of extracellular matrix (ECM) remodeling and epithelial mesenchymal transition (EMT), provide mechanistic pathways contributing to the development of GBM and radio/TMZ-resistant GBM. The Friend leukemia integration 1 (Fli-1) signaling network has been implicated in oncogenesis in GBM, making it an appealing target for advancing novel therapeutics. Fli-1 is linked to oncogenic transformation with up-regulation in radio/TMZ-resistant GBM, transcriptionally regulating HSPB1. This link led us to search for targeted molecules that inhibit Fli-1. Expression screening for Fli-1 inhibitors identified lumefantrine, an antimalarial drug, as a probable Fli-1 inhibitor. Docking and isothermal calorimetry titration confirmed interaction between lumefantrine and Fli-1. Lumefantrine promoted growth suppression and apoptosis in vitro in parental and radio/TMZ-resistant GBM and inhibited tumor growth without toxicity in vivo in U87MG GBM and radio/TMZ-resistant GBM orthotopic tumor models. These data reveal that lumefantrine, an FDA-approved drug, represents a potential GBM therapeutic that functions through inhibition of the Fli-1/HSPB1/EMT/ECM remodeling protein networks.


Assuntos
Antimaláricos/administração & dosagem , Antineoplásicos Alquilantes/administração & dosagem , Neoplasias Encefálicas/tratamento farmacológico , Glioblastoma/tratamento farmacológico , Lumefantrina/administração & dosagem , Temozolomida/administração & dosagem , Neoplasias Encefálicas/radioterapia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/radioterapia , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Humanos , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Transativadores/genética , Transativadores/metabolismo
18.
Proc Natl Acad Sci U S A ; 117(21): 11648-11657, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32398370

RESUMO

The intestinal mucosa exists in dynamic balance with trillions of luminal microbes. Disruption of the intestinal epithelial barrier, commonly observed in mucosal inflammation and diseases such as inflammatory bowel diseases (IBDs), is often associated with dysbiosis, particularly decreases in species producing short-chain fatty acids (SCFAs), such as butyrate. It remains unclear to what extent microbiota-derived factors contribute to the overall maintenance of intestinal homeostasis. Initial studies revealed that butyrate selectively promotes epithelial barrier function and wound healing. We aimed to define the specific mechanism(s) through which butyrate contributes to these epithelial responses. Guided by an unbiased profiling approach, we identified the dominant regulation of the actin-binding protein synaptopodin (SYNPO). Extensions of this work revealed a role for SYNPO in intestinal epithelial barrier function and wound healing. SYNPO was localized to the intestinal epithelial tight junction and within F-actin stress fibers where it is critical for barrier integrity and cell motility. Butyrate, but not other SCFAs, induced SYNPO in epithelial cell lines and murine colonic enteroids through mechanisms possibly involving histone deacetylase inhibition. Moreover, depletion of the microbiota abrogated expression of SYNPO in the mouse colon, which was rescued with butyrate repletion. Studies in Synpo-deficient mice demonstrated exacerbated disease susceptibility and increased intestinal permeability in a dextran sulfate sodium colitis model. These findings establish a critical role for the microbiota and their products, specifically butyrate, in the regulated expression of SYNPO for intestinal homeostasis and reveal a direct mechanistic link between microbiota-derived butyrate and barrier restoration.


Assuntos
Butiratos/metabolismo , Microbioma Gastrointestinal/fisiologia , Mucosa Intestinal/metabolismo , Proteínas dos Microfilamentos , Animais , Linhagem Celular , Homeostase/fisiologia , Humanos , Camundongos Knockout , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Junções Íntimas/metabolismo
19.
Mutat Res ; 852: 503167, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32265040

RESUMO

Chronic kidney disease (CKD) is a multifactorial disorder with an important genetic component, and several studies have demonstrated potential associations with allelic variants. In addition, CKD patients are also characterized by high levels of genomic damage. Nevertheless, no studies have established relationships between DNA damage, or genomic instability present in CKD patients, and gene polymorphisms. To fill in this gap, the potential role of polymorphisms in genes involved in base excision repair (OGG1, rs1052133; MUTYH, rs3219489; XRCC1, rs25487), nucleotide excision repair (ERCC2/XPD, rs1799793, rs171140, rs13181; ERCC4, rs3136166); phase II metabolism (GSTP1, rs749174; GSTO1, rs2164624; GSTO2, rs156697), and antioxidant enzymes (SOD1, rs17880135, rs1041740, rs202446; SOD2, rs4880; CAT, rs1001179; GPX1, rs17080528; GPX3, rs870406: GPX4, rs713041) were inquired. In addition, some genes involved in CKD (AGT, rs5050; GLO1, rs386572987; SHROOM3, rs17319721) were also evaluated. The genomic damage, the genomic instability, and oxidative damage were evaluated by using the micronucleus and the comet assay in 589 donors (415 CKD patients and 174 controls). Our results showed significant associations between genomic damage and genes directly involved in DNA repair pathways (XRCC1, and ERCC2), and with genes encoding for antioxidant enzymes (SOD1 and GPX1). GSTO2, as a gene involved in phase II metabolism, and MUTYH showed also an association with genomic instability. Interestingly, the three genes associated with CKD (AGT, GLO1, and SHROOM3) showed associations with both the high levels of oxidatively damaged DNA and genomic instability. These results support our view that genomic instability can be considered a biomarker of the CKD status.


Assuntos
Angiotensinogênio/genética , Reparo do DNA , Instabilidade Genômica , Lactoilglutationa Liase/genética , Proteínas dos Microfilamentos/genética , Insuficiência Renal Crônica/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Angiotensinogênio/metabolismo , Estudos de Casos e Controles , Ensaio Cometa , Dano ao DNA , DNA Glicosilases/genética , DNA Glicosilases/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Predisposição Genética para Doença , Genoma Humano , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Glutationa Transferase/genética , Glutationa Transferase/metabolismo , Humanos , Lactoilglutationa Liase/metabolismo , Masculino , Proteínas dos Microfilamentos/metabolismo , Testes para Micronúcleos , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/fisiopatologia , Superóxido Dismutase-1/genética , Superóxido Dismutase-1/metabolismo , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/genética , Proteína 1 Complementadora Cruzada de Reparo de Raio-X/metabolismo , Proteína Grupo D do Xeroderma Pigmentoso/genética , Proteína Grupo D do Xeroderma Pigmentoso/metabolismo
20.
PLoS One ; 15(4): e0231597, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32287325

RESUMO

Resident microglia of the central nervous system are being increasingly recognized as key players in diseases such as neuropathic pain. Biochemical and behavioral studies in neuropathic pain rodent models have documented compelling evidence of the critical role of ATP mediated-P2X4R-brain-derived neurotrophic factor (BDNF) signaling pathway in the initiation and maintenance of pain hypersensitivity, a feature driving neuropathic pain-related behavior. The goal of this study was to develop and characterize an in vitro cell line model of activated microglia that can be subsequently utilized for screening neuropathic pain therapeutics. In the present study, we characterized the SIM-A9 microglia cell line for key molecules in the P2X4R-BDNF signaling axis using a combination of biochemical techniques and developed an ATP-activated SIM-A9 microglia model. We present three novel findings: first, SIM-A9 cells expressed P2X4R and BDNF proteins, second, ATP, but not LPS, was cytocompatible with SIM-A9 cells and third, exposure of cells to optimized ATP concentrations for defined periods increased intracellular expression of Iba1 and BDNF proteins. Increased Iba1 levels confirmed microglia activation and increased BDNF expression confirmed ATP-mediated stimulation of the P2X4R signaling pathway. We propose that this ATP-activated SIM-A9 cell line model system can be utilized for screening both small- as well as macro-molecular neuropathic pain therapeutics targeting BDNF and/or P2X4R knockdown.


Assuntos
Microglia/metabolismo , Neuralgia/metabolismo , Transdução de Sinais , Trifosfato de Adenosina/farmacologia , Animais , Fator Neurotrófico Derivado do Encéfalo/genética , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Técnicas de Cultura de Células/métodos , Lipopolissacarídeos/farmacologia , Camundongos , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Microglia/citologia , Microglia/efeitos dos fármacos , Neuralgia/patologia , Receptores Purinérgicos P2X4/genética , Receptores Purinérgicos P2X4/metabolismo
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