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1.
PLoS Pathog ; 16(9): e1008854, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32956405

RESUMO

Aspergillus fumigatus is an opportunistic fungal pathogen of immunocompromised patient populations. Mortality is thought to be context-specific and occurs via both enhanced fungal growth and immunopathogenesis. NLRX1 is a negative regulator of immune signaling and metabolic pathways implicated in host responses to microbes, cancers, and autoimmune diseases. Our study indicates loss of Nlrx1 results in enhanced fungal burden, pulmonary inflammation, immune cell recruitment, and mortality across immuno-suppressed and immuno-competent models of IPA using two clinically derived isolates (AF293, CEA10). We observed that the heightened mortality is due to enhanced recruitment of CD103+ dendritic cells (DCs) that produce elevated amounts of IL-4 resulting in a detrimental Th2-mediated immune response. Adoptive transfer of Nlrx1-/- CD103+ DCs in neutropenic NRG mice results in enhanced mortality that can be ablated using IL-4 neutralizing antibodies. In vitro analysis of CD103+ DCs indicates loss of Nlrx1 results in enhanced IL-4 production via elevated activation of the JNK/JunB pathways. Interestingly, loss of Nlrx1 also results in enhanced recruitment of monocytes and neutrophils. Chimeras of irradiated Nlrx1-/- mice reconstituted with wild type bone marrow have enhanced neutrophil recruitment and survival during models of IPA. This enhanced immune cell recruitment in the absence of Nlrx1 is mediated by excessive production of CXCL8/IL-8 family of chemokines and IL-6 via early and enhanced activation of P38 in response to A. fumigatus conidia as shown in BEAS-2B airway epithelial cells. In summary, our results point strongly towards the cell-specific and contextual function of Nlrx1 during invasive pulmonary aspergillosis and may lead to novel therapeutics to reduce Th2 responses by CD103+ DCs or heightened recruitment of neutrophils.


Assuntos
Aspergillus fumigatus/imunologia , Células Dendríticas/imunologia , Sistema de Sinalização das MAP Quinases/imunologia , Proteínas Mitocondriais/imunologia , Aspergilose Pulmonar/imunologia , Células Th2/imunologia , Animais , Linhagem Celular , Citocinas/genética , Citocinas/imunologia , MAP Quinase Quinase 4/genética , MAP Quinase Quinase 4/imunologia , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Camundongos Knockout , Proteínas Mitocondriais/genética , Neutrófilos/imunologia , Neutrófilos/patologia , Aspergilose Pulmonar/genética , Aspergilose Pulmonar/patologia , Células Th2/patologia , Fatores de Transcrição/genética , Fatores de Transcrição/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/imunologia
2.
Clin Dermatol ; 38(4): 455-461, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32972603

RESUMO

RASopathies are a group of disorders characterized by mutations in the RAS-MAPK pathway. RAS-MAP signaling plays a critical role in cell differentiation, proliferation, and survival. Germline mutations can result in distinctive syndromes, including Noonan syndrome, Costello syndrome, and neurofibromatosis type 1. Mosaic RASopathies can present as localized cutaneous lesions like epidermal nevi and nevus sebaceous, or more extensive conditions such as encephalocraniocutaneous lipomatosis. We review the heterogenous presentation of RAS mutations, discuss new targeted therapies, and highlight areas of uncertainty, including carcinogenesis risk and appropriate screening.


Assuntos
Síndrome de Costello/genética , Oftalmopatias/genética , Mutação em Linhagem Germinativa , Lipomatose/genética , Sistema de Sinalização das MAP Quinases/genética , Proteínas Monoméricas de Ligação ao GTP/genética , Síndromes Neurocutâneas/genética , Neurofibromatose 1/genética , Síndrome de Noonan/genética , Síndrome de Costello/diagnóstico , Síndrome de Costello/terapia , Oftalmopatias/diagnóstico por imagem , Oftalmopatias/terapia , Humanos , Lipomatose/diagnóstico por imagem , Lipomatose/terapia , Terapia de Alvo Molecular , Mutação , Síndromes Neurocutâneas/diagnóstico por imagem , Síndromes Neurocutâneas/terapia , Neurofibromatose 1/diagnóstico , Neurofibromatose 1/terapia , Síndrome de Noonan/diagnóstico , Síndrome de Noonan/terapia , Risco
3.
Nat Commun ; 11(1): 4673, 2020 09 16.
Artigo em Inglês | MEDLINE | ID: mdl-32938917

RESUMO

RAS-MAPK signaling mediates processes critical to normal development including cell proliferation, survival, and differentiation. Germline mutation of RAS-MAPK genes lead to the Noonan-spectrum of syndromes. Here, we present a patient affected by a 6p-interstitial microdeletion with unknown underlying molecular etiology. Examination of 6p-interstitial microdeletion cases reveals shared clinical features consistent with Noonan-spectrum disorders including short stature, facial dysmorphia and cardiovascular abnormalities. We find the RAS-responsive element binding protein-1 (RREB1) is the common deleted gene in multiple 6p-interstitial microdeletion cases. Rreb1 hemizygous mice display orbital hypertelorism and cardiac hypertrophy phenocopying the human syndrome. Rreb1 haploinsufficiency leads to sensitization of MAPK signaling. Rreb1 recruits Sin3a and Kdm1a to control H3K4 methylation at MAPK pathway gene promoters. Haploinsufficiency of SIN3A and mutations in KDM1A cause syndromes similar to RREB1 haploinsufficiency suggesting genetic perturbation of the RREB1-SIN3A-KDM1A complex represents a new category of RASopathy-like syndromes arising through epigenetic reprogramming of MAPK pathway genes.


Assuntos
Proteínas de Ligação a DNA/genética , Haploinsuficiência , Sistema de Sinalização das MAP Quinases/genética , Síndrome de Noonan/etiologia , Fatores de Transcrição/genética , Proteínas ras/metabolismo , Anormalidades Múltiplas/genética , Animais , Deleção Cromossômica , Cromossomos Humanos Par 6 , Proteínas de Ligação a DNA/metabolismo , Epigênese Genética , Feminino , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Histona Desmetilases/genética , Histona Desmetilases/metabolismo , Histonas/metabolismo , Humanos , Masculino , Metilação , Camundongos Endogâmicos C57BL , Camundongos Knockout , Complexo Correpressor Histona Desacetilase e Sin3/genética , Complexo Correpressor Histona Desacetilase e Sin3/metabolismo , Fatores de Transcrição/metabolismo , Proteínas ras/genética
4.
Nat Commun ; 11(1): 4370, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32873792

RESUMO

BRAF kinase, a critical effector of the ERK signaling pathway, is hyperactivated in many cancers. Oncogenic BRAFV600E signals as an active monomer in the absence of active RAS, however, in many tumors BRAF dimers mediate ERK signaling. FDA-approved RAF inhibitors poorly inhibit BRAF dimers, which leads to tumor resistance. We found that Ponatinib, an FDA-approved drug, is an effective inhibitor of BRAF monomers and dimers. Ponatinib binds the BRAF dimer and stabilizes a distinct αC-helix conformation through interaction with a previously unrevealed allosteric site. Using these structural insights, we developed PHI1, a BRAF inhibitor that fully uncovers the allosteric site. PHI1 exhibits discrete cellular selectivity for BRAF dimers, with enhanced inhibition of the second protomer when the first protomer is occupied, comprising a novel class of dimer selective inhibitors. This work shows that Ponatinib and BRAF dimer selective inhibitors will be useful in treating BRAF-dependent tumors.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Sítio Alostérico/efeitos dos fármacos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linhagem Celular Tumoral , Cristalografia por Raios X , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Imidazóis/farmacologia , Imidazóis/uso terapêutico , Sistema de Sinalização das MAP Quinases/genética , Simulação de Acoplamento Molecular , Mutação , Neoplasias/genética , Neoplasias/patologia , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/uso terapêutico , Multimerização Proteica/efeitos dos fármacos , Subunidades Proteicas/antagonistas & inibidores , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas B-raf/ultraestrutura , Piridazinas/farmacologia , Piridazinas/uso terapêutico , Bibliotecas de Moléculas Pequenas , Relação Estrutura-Atividade
5.
Am J Hum Genet ; 107(3): 499-513, 2020 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-32721402

RESUMO

Signal transduction through the RAF-MEK-ERK pathway, the first described mitogen-associated protein kinase (MAPK) cascade, mediates multiple cellular processes and participates in early and late developmental programs. Aberrant signaling through this cascade contributes to oncogenesis and underlies the RASopathies, a family of cancer-prone disorders. Here, we report that de novo missense variants in MAPK1, encoding the mitogen-activated protein kinase 1 (i.e., extracellular signal-regulated protein kinase 2, ERK2), cause a neurodevelopmental disease within the RASopathy phenotypic spectrum, reminiscent of Noonan syndrome in some subjects. Pathogenic variants promote increased phosphorylation of the kinase, which enhances translocation to the nucleus and boosts MAPK signaling in vitro and in vivo. Two variant classes are identified, one of which directly disrupts binding to MKP3, a dual-specificity protein phosphatase negatively regulating ERK function. Importantly, signal dysregulation driven by pathogenic MAPK1 variants is stimulus reliant and retains dependence on MEK activity. Our data support a model in which the identified pathogenic variants operate with counteracting effects on MAPK1 function by differentially impacting the ability of the kinase to interact with regulators and substrates, which likely explains the minor role of these variants as driver events contributing to oncogenesis. After nearly 20 years from the discovery of the first gene implicated in Noonan syndrome, PTPN11, the last tier of the MAPK cascade joins the group of genes mutated in RASopathies.


Assuntos
Carcinogênese/genética , Proteína Quinase 1 Ativada por Mitógeno/genética , Transtornos do Neurodesenvolvimento/genética , Síndrome de Noonan/genética , Pré-Escolar , Feminino , Humanos , Sistema de Sinalização das MAP Quinases/genética , Masculino , Mutação de Sentido Incorreto/genética , Transtornos do Neurodesenvolvimento/patologia , Síndrome de Noonan/fisiopatologia , Fenótipo , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Transdução de Sinais , Sequenciamento Completo do Exoma , Proteínas ras/genética
6.
Am J Physiol Cell Physiol ; 319(2): C441-C454, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32639872

RESUMO

Skeletal muscle atrophy is caused by a decrease in muscle size and strength and results from a range of physiological conditions, including denervation, immobilization, corticosteroid exposure and aging. Newly named dual-specificity phosphatase 29 (Dusp29) has been identified as a novel neurogenic atrophy-induced gene in skeletal muscle. Quantitative PCR analysis revealed that Dusp29 expression is significantly higher in differentiated myotubes compared with proliferating myoblasts. To determine how Dusp29 is transcriptionally regulated in skeletal muscle, fragments of the promoter region of Dusp29 were cloned, fused to a reporter gene, and found to be highly inducible in response to ectopic expression of the myogenic regulatory factors (MRF), MyoD and myogenin. Furthermore, site-directed mutagenesis of conserved E-box elements within the proximal promoter of Dusp29 rendered a Dusp29 reporter gene unresponsive to MRF overexpression. Dusp29, an atypical Dusp also known as Dupd1/Dusp27, was found to attenuate the ERK1/2 branch of the MAP kinase signaling pathway in muscle cells and inhibit muscle cell differentiation when ectopically expressed in proliferating myoblasts. Interestingly, Dusp29 was also found to destabilize AMPK protein while simultaneously enriching the phosphorylated pool of AMPK in muscle cells. Additionally, Dusp29 overexpression resulted in a significant increase in the glucocorticoid receptor (GR) protein and elevation in GR phosphorylation. Finally, Dusp29 was found to significantly impair the ability of the glucocorticoid receptor to function as a transcriptional activator in muscle cells treated with dexamethasone. Identifying and characterizing the function of Dusp29 in muscle provides novel insights into the molecular and cellular mechanisms for skeletal muscle atrophy.


Assuntos
Fosfatases de Especificidade Dupla/genética , Atrofia Muscular/genética , Proteína MyoD/genética , Miogenina/genética , Animais , Diferenciação Celular/genética , Linhagem Celular , Proliferação de Células/genética , Regulação da Expressão Gênica/genética , Humanos , Sistema de Sinalização das MAP Quinases/genética , Células Musculares/metabolismo , Células Musculares/patologia , Atrofia Muscular/patologia , Mioblastos/metabolismo , Fosforilação/genética , Receptores de Glucocorticoides/genética , Transdução de Sinais , Ativação Transcricional/genética
7.
Nat Commun ; 11(1): 3494, 2020 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-32661402

RESUMO

Cellular processes are inherently noisy, and the selection for accurate responses in presence of noise has likely shaped signalling networks. Here, we investigate the trade-off between accuracy of information transmission and its energetic cost for a mitogen-activated protein kinase (MAPK) signalling cascade. Our analysis of the pheromone response pathway of budding yeast suggests that dose-dependent induction of the negative transcriptional feedbacks in this network maximizes the information per unit energetic cost, rather than the information transmission capacity itself. We further demonstrate that futile cycling of MAPK phosphorylation and dephosphorylation has a measurable effect on growth fitness, with energy dissipation within the signalling cascade thus likely being subject to evolutionary selection. Considering optimization of accuracy versus the energetic cost of information processing, a concept well established in physics and engineering, may thus offer a general framework to understand the regulatory design of cellular signalling systems.


Assuntos
Sistema de Sinalização das MAP Quinases/fisiologia , Animais , Proteínas Ativadoras de GTPase/metabolismo , Humanos , Sistema de Sinalização das MAP Quinases/genética , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fosforilação , Proteínas Tirosina Fosfatases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomycetales/genética , Saccharomycetales/metabolismo , Transdução de Sinais/genética , Transdução de Sinais/fisiologia
8.
PLoS Genet ; 16(6): e1008863, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32559195

RESUMO

Inactivation of the Rb tumor suppressor causes context-dependent increases in cell proliferation or cell death. In a genetic screen for factors that promoted Rb mutant cell death in Drosophila, we identified Psid, a regulatory subunit of N-terminal acetyltransferase B (NatB). We showed that NatB subunits were required for elevated EGFR/MAPK signaling and Rb mutant cell survival. We showed that NatB regulates the posttranscriptional levels of the highly conserved pathway components Grb2/Drk, MAPK, and PP2AC but not that of the less conserved Sprouty. Interestingly, NatB increased the levels of positive pathway components Grb2/Drk and MAPK while decreased the levels of negative pathway component PP2AC, which were mediated by the distinct N-end rule branch E3 ubiquitin ligases Ubr4 and Cnot4, respectively. These results suggest a novel mechanism by which NatB and N-end rule pathways modulate EGFR/MAPK signaling by inversely regulating the levels of multiple conserved positive and negative pathway components. As inactivation of Psid blocked EGFR signaling-dependent tumor growth, this study raises the possibility that NatB is potentially a novel therapeutic target for cancers dependent on deregulated EGFR/Ras signaling.


Assuntos
Proteínas Sanguíneas/metabolismo , Proteínas de Drosophila/metabolismo , Receptores ErbB/metabolismo , Sistema de Sinalização das MAP Quinases/genética , Acetiltransferase N-Terminal B/metabolismo , Neoplasias/genética , Receptores de Peptídeos de Invertebrados/metabolismo , Acetilcoenzima A/metabolismo , Acetilação , Alelos , Animais , Animais Geneticamente Modificados , Apoptose/genética , Proteínas Sanguíneas/genética , Proliferação de Células/genética , Sobrevivência Celular/genética , Modelos Animais de Doenças , Proteínas de Drosophila/genética , Regulação Neoplásica da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Masculino , Acetiltransferase N-Terminal B/genética , Neoplasias/patologia , Proteína do Retinoblastoma/genética , Mutações Sintéticas Letais , Fatores de Transcrição/genética
9.
PLoS One ; 15(5): e0232985, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32413049

RESUMO

Receptor tyrosine kinases, such as VEGFR, PDGFR and EGFR, play important roles in renal cancer. In this study, we investigated EGFR knockout as a therapeutic approach in renal cell carcinoma (RCC). We showed that a renal cell carcinoma cell line (RC21) has higher expression of EGFR as compared to other frequently used cell lines such as HEK293, A549, Hela and DLD1. Ablation of EGFR by CRISPR/Cas9 significantly restrained tumor cell growth and activated the MAPK (pERK1/2) pathway. The VEGFR and PDGFR inhibitor, sunitinib, attenuated the expression of MAPK (pERK1/2) and pAKT induced by EGFR loss and further inhibited EGFR-/- cell proliferation. We showed that loss of EGFR eventually leads to resistance to SAHA and cisplatin. Furthermore, EGFR loss induced G2/M phase arrest and resulted in an increased resistance to TNF-related apoptosis-inducing ligand (TRAIL) in renal cell carcinoma. Thus, ablation of overexpressed EGFR by CRISPR/Cas9 alone or in combination with sunitinib may be a new treatment option for renal cell carcinoma.


Assuntos
Sistemas CRISPR-Cas , Carcinoma de Células Renais/terapia , Técnicas de Inativação de Genes/métodos , Neoplasias Renais/terapia , Sunitinibe/uso terapêutico , Células A549 , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Apoptose/genética , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Cisplatino/farmacologia , Terapia Combinada , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Genes erbB-1 , Células HEK293 , Células HeLa , Humanos , Neoplasias Renais/genética , Neoplasias Renais/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Modelos Biológicos , Inibidores de Proteínas Quinases/uso terapêutico
10.
PLoS One ; 15(5): e0232756, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32407323

RESUMO

Mitogen-activated protein kinase (MAPK) is a form of serine/threonine protein kinase that activated by extracellular stimulation acting through the MAPK cascade (MAPKKK-MAPKK-MAPK). The MAPK cascade gene family, an important family of protein kinases, plays a vital role in responding to various stresses and hormone signal transduction processes in plants. In this study, we identified 14 CmMAPKs, 6 CmMAPKKs and 64 CmMAPKKKs in melon genome. Based on structural characteristics and a comparison of phylogenetic relationships of MAPK gene families from Arabidopsis, cucumber and watermelon, CmMAPKs and CmMAPKKs were categorized into 4 groups, and CmMAPKKKs were categorized into 3 groups. Furthermore, chromosome location revealed an unevenly distribution on chromosomes of MAPK cascade genes in melon, respectively. Eventually, qRT-PCR analysis showed that all 14 CmMAPKs had different expression patterns under drought, salt, salicylic acid (SA), methyl jasmonate (MeJA), red light (RL), and Podosphaera xanthii (P. xanthii) treatments. Overall, the expression levels of CmMAPK3 and CmMAPK7 under different treatments were higher than those in control. Our study provides an important basis for future functional verification of MAPK genes in regulating responses to stress and signal substance in melon.


Assuntos
Cucumis melo/enzimologia , Cucumis melo/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Sistema de Sinalização das MAP Quinases/genética , Acetatos/farmacologia , Motivos de Aminoácidos , Sequência de Aminoácidos , Cromossomos de Plantas/genética , Cucumis melo/efeitos dos fármacos , Ciclopentanos/farmacologia , Secas , Éxons/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas , Íntrons/genética , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/química , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Oxilipinas/farmacologia , Filogenia , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/genética , Domínios Proteicos , Ácido Salicílico/farmacologia , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/genética , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética
11.
Nat Commun ; 11(1): 2487, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32427938

RESUMO

Cancer stem-like cells (CSCs) are the tumorigenic cell subpopulation and contribute to cancer recurrence and metastasis. However, the understanding of CSC regulatory mechanisms remains incomplete. By transcriptomic analysis, we identify a scaffold protein SH3RF3 (also named POSH2) that is upregulated in CSCs of breast cancer clinical tumors and cancer cell lines, and enhances the CSC properties of breast cancer cells. Mechanically, SH3RF3 interacts with the c-Jun N-terminal kinase (JNK) in a JNK-interacting protein (JIP)-dependent manner, leading to enhanced phosphorylation of JNK and activation of the JNK-JUN pathway. Further the JNK-JUN signaling expands CSC subpopulation by transcriptionally activating the expression of Pentraxin 3 (PTX3). The functional role of SH3RF3 in CSCs is validated with patient-derived organoid culture, and supported by clinical cohort analyses. In conclusion, our work elucidates the role and molecular mechanism of SH3RF3 in CSCs of breast cancer, and might provide opportunities for CSC-targeting therapy.


Assuntos
Neoplasias da Mama/genética , Proteína C-Reativa/genética , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Células-Tronco Neoplásicas/metabolismo , Componente Amiloide P Sérico/genética , Ubiquitina-Proteína Ligases/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proteína C-Reativa/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Ativação Enzimática , Feminino , Perfilação da Expressão Gênica/métodos , Regulação Neoplásica da Expressão Gênica , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Sistema de Sinalização das MAP Quinases/genética , Fosforilação , Componente Amiloide P Sérico/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Regulação para Cima
12.
PLoS Pathog ; 16(5): e1008576, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32392230

RESUMO

Yersinia suppress neutrophil responses by using a type 3 secretion system (T3SS) to inject 6-7 Yersinia effector proteins (Yops) effectors into their cytoplasm. YopH is a tyrosine phosphatase that causes dephosphorylation of the adaptor protein SKAP2, among other targets in neutrophils. SKAP2 functions in reactive oxygen species (ROS) production, phagocytosis, and integrin-mediated migration by neutrophils. Here we identify essential neutrophil functions targeted by YopH, and investigate how the interaction between YopH and SKAP2 influence Yersinia pseudotuberculosis (Yptb) survival in tissues. The growth defect of a ΔyopH mutant was restored in mice defective in the NADPH oxidase complex, demonstrating that YopH is critical for protecting Yptb from ROS during infection. The growth of a ΔyopH mutant was partially restored in Skap2-deficient (Skap2KO) mice compared to wild-type (WT) mice, while induction of neutropenia further enhanced the growth of the ΔyopH mutant in both WT and Skap2KO mice. YopH inhibited both ROS production and degranulation triggered via integrin receptor, G-protein coupled receptor (GPCR), and Fcγ receptor (FcγR) stimulation. SKAP2 was required for integrin receptor and GPCR-mediated ROS production, but dispensable for degranulation under all conditions tested. YopH blocked SKAP2-independent FcγR-stimulated phosphorylation of the proximal signaling proteins Syk, SLP-76, and PLCγ2, and the more distal signaling protein ERK1/2, while only ERK1/2 phosphorylation was dependent on SKAP2 following integrin receptor activation. These findings reveal that YopH prevents activation of both SKAP2-dependent and -independent neutrophilic defenses, uncouple integrin- and GPCR-dependent ROS production from FcγR responses based on their SKAP2 dependency, and show that SKAP2 is not required for degranulation.


Assuntos
Proteínas da Membrana Bacteriana Externa/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/imunologia , Neutrófilos/imunologia , Proteínas Tirosina Fosfatases/imunologia , Transdução de Sinais/imunologia , Infecções por Yersinia pseudotuberculosis/imunologia , Yersinia pseudotuberculosis/imunologia , Animais , Peptídeos e Proteínas de Sinalização Intracelular/genética , Sistema de Sinalização das MAP Quinases/genética , Sistema de Sinalização das MAP Quinases/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Neutrófilos/patologia , Espécies Reativas de Oxigênio/imunologia , Transdução de Sinais/genética , Yersinia pseudotuberculosis/patogenicidade , Infecções por Yersinia pseudotuberculosis/genética , Infecções por Yersinia pseudotuberculosis/patologia
13.
PLoS Pathog ; 16(5): e1008572, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32413093

RESUMO

The apicomplexan Toxoplasma gondii induces strong protective immunity dependent upon recognition by Toll-like receptors (TLR)11 and 12 operating in conjunction with MyD88 in the murine host. However, TLR11 and 12 proteins are not present in humans, inspiring us to investigate MyD88-independent pathways of resistance. Using bicistronic IL-12-YFP reporter mice on MyD88+/+ and MyD88-/- genetic backgrounds, we show that CD11c+MHCII+F4/80- dendritic cells, F4/80+ macrophages, and Ly6G+ neutrophils were the dominant cellular sources of IL-12 in both wild type and MyD88 deficient mice after parasite challenge. Parasite dense granule protein GRA24 induces p38 MAPK activation and subsequent IL-12 production in host macrophages. We show that Toxoplasma triggers an early and late p38 MAPK phosphorylation response in MyD88+/+ and MyD88-/- bone marrow-derived macrophages. Using the uracil auxotrophic Type I T. gondii strain cps1-1, we demonstrate that the late response does not require active parasite proliferation, but strictly depends upon GRA24. By i. p. inoculation with cps1-1 and cps1-1:Δgra24, we identified unique subsets of chemokines and cytokines that were up and downregulated by GRA24. Finally, we demonstrate that cps1-1 triggers a strong host-protective GRA24-dependent Th1 response in the absence of MyD88. Our data identify GRA24 as a major mediator of p38 MAPK activation, IL-12 induction and protective immunity that operates independently of the TLR/MyD88 cascade.


Assuntos
Interleucina-12/imunologia , Sistema de Sinalização das MAP Quinases/imunologia , Macrófagos/imunologia , Fator 88 de Diferenciação Mieloide/imunologia , Proteínas de Protozoários/imunologia , Toxoplasma/imunologia , Toxoplasmose/imunologia , Proteínas Quinases p38 Ativadas por Mitógeno/imunologia , Animais , Ativação Enzimática/genética , Ativação Enzimática/imunologia , Interleucina-12/genética , Sistema de Sinalização das MAP Quinases/genética , Macrófagos/parasitologia , Macrófagos/patologia , Camundongos , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Proteínas de Protozoários/genética , Toxoplasma/genética , Toxoplasmose/genética , Toxoplasmose/patologia , Proteínas Quinases p38 Ativadas por Mitógeno/genética
14.
J Endocrinol ; 244(2): 415-429, 2020 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-32395971

RESUMO

Among all the hormone-secreting pituitary tumours, prolactinomas are the most frequently found in the clinic. Since dopamine is the primary inhibitor of lactotroph function, dopamine agonists represent the first-line therapy. However, a subset of patients exhibits resistance to these drugs, and therefore, alternative treatments are desired. As activins inhibit prolactin gene expression through the inhibition of Pit-1 involving the p38MAPK pathway, in the present work, we studied the local activin system as an alternative inhibitory system for lactotroph hyperplasia treatment. We used two different mouse models of prolactinoma: transgenic mice with overexpression of the human chorionic gonadotropin ß-subunit (hCGß) and mice lacking dopamine receptor type 2. In both models, females, but not males, develop lactotroph hyperplasia from the fourth month of life. We found reduced expression of pituitary activin subunits and activin receptors in hyperplastic pituitaries from both models compared with wild-type counterparts. Consequently, hyperplastic pituitaries presented a reduced activin-inhibitory action on prolactin secretion. Additionally, while female wild-type lactotrophs presented high levels of phospho-p38MAPK, it was lost in prolactinomas, concomitant with decreased activin expression, increased Pit-1 expression and tumour development. In contrast, male pituitaries express higher mRNA levels of activin subunits ßA and ßB, which would suggest a stronger activin inhibitory function on lactotrophs, protecting this sex from tumour development, despite genotype. The present results highlight the importance of the activin inhibitory action on lactotroph function and place the local activin system as a new target for the treatment of dopamine agonist-resistant prolactinomas.


Assuntos
Ativinas/metabolismo , Lactotrofos/metabolismo , Neoplasias Hipofisárias/genética , Prolactinoma/genética , Animais , Agonistas de Dopamina/farmacologia , Resistencia a Medicamentos Antineoplásicos/genética , Feminino , Genótipo , Sistema de Sinalização das MAP Quinases/genética , Masculino , Camundongos , Camundongos Transgênicos , Hipófise/metabolismo , Neoplasias Hipofisárias/complicações , Neoplasias Hipofisárias/tratamento farmacológico , Prolactinoma/complicações , Prolactinoma/tratamento farmacológico , RNA Mensageiro/metabolismo , Fatores Sexuais , Fator de Transcrição Pit-1/metabolismo
15.
Nat Commun ; 11(1): 2228, 2020 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-32376880

RESUMO

Cell competition is an emerging principle that eliminates suboptimal or potentially dangerous cells. For 'unfit' cells to be detected, their competitive status needs to be compared to the collective fitness of cells within a tissue. Here we report that the NMDA receptor controls cell competition of epithelial cells and Myc supercompetitors in the Drosophila wing disc. While clonal depletion of the NMDA receptor subunit NR2 results in their rapid elimination via the TNF/Eiger>JNK signalling pathway, local over-expression of NR2 causes NR2 cells to acquire supercompetitor-like behaviour that enables them to overtake the tissue through clonal expansion that causes, but also relies on, the killing of surrounding cells. Consistently, NR2 is utilised by Myc clones to provide them with supercompetitor status. Mechanistically, we find that the JNK>PDK signalling axis in 'loser' cells reprograms their metabolism, driving them to produce and transfer lactate to winners. Preventing lactate transfer from losers to winners abrogates NMDAR-mediated cell competition. Our findings demonstrate a functional repurposing of NMDAR in the surveillance of tissue fitness.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila/metabolismo , Células Epiteliais/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Fatores de Transcrição/metabolismo , Asas de Animais/metabolismo , Animais , Apoptose/genética , Drosophila/genética , Proteínas de Drosophila/genética , Ácido Láctico/metabolismo , Sistema de Sinalização das MAP Quinases/genética , Mitocôndrias/metabolismo , Receptores de N-Metil-D-Aspartato/genética , Transdução de Sinais/genética , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Asas de Animais/crescimento & desenvolvimento
16.
Environ Toxicol ; 35(9): 1007-1014, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32441858

RESUMO

Arecoline, a component of betel nuts, is a known carcinogen that causes oral cancers among those who chew betel nuts. Betel nut chewing is also associated with an increased risk of chronic kidney disease (CKD), but the role of arecoline in this association is unclear. This in vitro study investigates the effects of arecoline on cultured human kidney (HK2) cells. We observed that arecoline had no effect on cell viability but increased cell migration in a dose-dependent manner. Western blot analysis showed that arecoline treatment caused a dose-dependent decrease in E-cadherin expression and dose-dependent increases in N-cadherin, vimentin, α-SMA, and collagen expression; reverse transcriptase-polymerase chain reaction analysis revealed dose-dependent increases in α-SMA and collagen mRNA. Arecoline treatment upregulated the expression of phosphorylated extracellular signal-regulated kinase through epithelial mesenchymal transition and renal fibrosis in HK2 cells. These findings demonstrate that arecoline plays a role in inducing the epithelial mesenchymal transition and fibrogenesis in renal tubule cells and suggest that arecoline promotes the progression of CKD.


Assuntos
Areca/toxicidade , Arecolina/toxicidade , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Túbulos Renais/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Actinas/genética , Actinas/metabolismo , Antígenos CD/genética , Antígenos CD/metabolismo , Areca/química , Caderinas/genética , Caderinas/metabolismo , Ciclo Celular/efeitos dos fármacos , Linhagem Celular , Movimento Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Transição Epitelial-Mesenquimal/genética , Fibrose , Humanos , Túbulos Renais/metabolismo , Túbulos Renais/patologia , Sistema de Sinalização das MAP Quinases/genética , Fosforilação , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/patologia , Regulação para Cima
17.
Am J Chin Med ; 48(4): 1021-1034, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32471314

RESUMO

Codonopsis lanceolata roots have been widely used in Korean cuisine and traditional medicine. This study aimed to investigate the antimetastatic effects of lancemaside A, a major triterpenoid saponin, isolated from the roots of C. lanceolata, in human ovarian cancer cells. Lancemaside A significantly suppressed the migration and invasion and the expression of matrix metalloproteinases (MMPs)-2 and -9 in ovarian cancer A2780 and SKOV3 cells. Treatment with lancemaside A generated reactive oxygen species (ROS) in ovarian cancer cells. However, treatment with anti-oxidant N-acetyl-L-cysteine (NAC) significantly negated the anti-invasive activity of lancemaside A. Additionally, lancemaside A activated p38 MAP kinase, which is mediated by ROS generation. This is the first study, to our knowledge, to reveal that lancemaside A isolated from the roots of C. lanceolata exerts antimetastatic activity through inhibition of MMP expression and cancer cell invasion via activation of the ROS-mediated p38 pathway.


Assuntos
Codonopsis/química , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Invasividade Neoplásica/genética , Invasividade Neoplásica/patologia , Neoplasias Ovarianas/patologia , Raízes de Plantas/química , Espécies Reativas de Oxigênio/metabolismo , Saponinas/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Antineoplásicos Fitogênicos , Linhagem Celular Tumoral , Feminino , Expressão Gênica , Humanos , Saponinas/isolamento & purificação , Proteínas Quinases p38 Ativadas por Mitógeno/genética
18.
Anticancer Res ; 40(4): 1817-1831, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32234870

RESUMO

Almost all individuals with neurofibromatosis type 1 (NF1) develop peripheral nerve sheath tumors (PNSTs), mainly benign neurofibromas, however about 10% of PNSTs will undergo transformation to malignant peripheral nerve sheath tumors (MPNSTs). Surgical treatment of PNSTs has traditionally been regarded as a standard approach. The availability of new agents that target specific molecular pathways involved in the pathogenesis of PNST has led to a number of clinical trials, which resulted in increased chances for better survival and quality of life. This review presents the latest evidence and clinical implications for new therapies of PNSTs in patients with NF1 emphasizing the potential benefit from the use of Ras/MAPK pathway inhibitors, immunotherapy, chemotherapy or radiation therapy. We present evaluation of current knowledge on available treatment modalities.


Assuntos
Neoplasias/tratamento farmacológico , Neoplasias da Bainha Neural/tratamento farmacológico , Neurofibromatose 1/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Neoplasias/complicações , Neoplasias/genética , Neoplasias/patologia , Neoplasias da Bainha Neural/complicações , Neoplasias da Bainha Neural/genética , Neoplasias da Bainha Neural/patologia , Neurofibromatose 1/complicações , Neurofibromatose 1/genética , Neurofibromatose 1/patologia , Transdução de Sinais/efeitos dos fármacos , Tomografia Computadorizada por Raios X , Proteínas ras/antagonistas & inibidores , Proteínas ras/genética
19.
Metabolism ; 107: 154241, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32304754

RESUMO

BACKGROUND: Hyperandrogenism is one of the major characteristics of polycystic ovary syndrome (PCOS). Abnormal miR-125b-5p expression has been documented in multiple diseases, but whether miR-125b-5p is associated with aberrant steroidogenesis in preantral follicles remains unknown. METHODS: Steriod hormone concentrations and miR-125b-5p expression were measured in clinical serum samples from PCOS patients. Using a mouse preantral follicle culture model and a letrozole-induced PCOS mouse model, we investigated the mechanism underlying miR-125b-5p regulation of androgen and oestrogen secretion. RESULTS: The decreased miR-125b-5p expression was observed in the sera from hyperandrogenic PCOS (HA-PCOS) patients. In mouse preantral follicles, inhibiting miR-125b-5p increased the expression of androgen synthesis-related genes and stimulated the secretion of testosterone, while simultaneously downregulating oestrogen synthesis-related genes and decreasing oestradiol release. Ectopically expressed miR-125b-5p reversed the effects on steroidogenesis-related gene expression and hormone release. Mechanistic studies identified Pak3 as a direct target of miR-125b-5p. Furthermore, inhibiting miR-125b-5p facilitated the activation of ERK1/2 in mouse preantral follicles, while inhibiting Pak3 abrogated this activating effect. These results were recapitulated in letrozole-induced PCOS mouse ovaries. Of note, inhibiting PAK3 antagonised the positive effect of miR-125b-5p siRNA on the expressions of androgen synthesis-related enzymes and testosterone secretion. Luteinizing hormone (LH) inhibited miR-125b-5p expression, and stimulated Pak3 expression. CONCLUSION: High serum LH concentrations in PCOS patients repress miR-125b-5p expression, which further increases Pak3 expression, leading to activation of ERK1/2 signalling, thus stimulating the expression of androgen synthesis-related enzymes and testosterone secretion in HA-PCOS.


Assuntos
MicroRNAs/genética , Folículo Ovariano/metabolismo , Esteroides/biossíntese , Androgênios/biossíntese , Androgênios/genética , Animais , Estradiol/metabolismo , Estrogênios/biossíntese , Estrogênios/genética , Feminino , Regulação da Expressão Gênica/genética , Hiperandrogenismo/induzido quimicamente , Hiperandrogenismo/metabolismo , Letrozol , Hormônio Luteinizante/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/genética , Camundongos , Camundongos Endogâmicos C57BL , Síndrome do Ovário Policístico/induzido quimicamente , Síndrome do Ovário Policístico/genética , Síndrome do Ovário Policístico/metabolismo , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo
20.
Biochim Biophys Acta Rev Cancer ; 1873(2): 188364, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32275934

RESUMO

Hyperactivation of the Mitogen Activated Protein Kinase (MAPK) pathway is prevalent in melanoma, principally due to mutations in the BRAF and NRAS genes. MAPK inhibitors are effective only short-term, and recurrence occurs due to functional redundancies or intertwined pathways. The remodeling of Ca2+ signaling is also common in melanoma cells, partly through the increased expression of T-type channels (TTCCs). Here we summarize current knowledge about the prognostic value and molecular targeting of TTCCs. Furthermore, we discuss recent evidence pointing to TTCCs as molecular switches for melanoma chemoresistance, which set the grounds for novel combined therapies against the advanced disease.


Assuntos
Antineoplásicos/uso terapêutico , Canais de Cálcio Tipo T/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Melanoma/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Antineoplásicos/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Bloqueadores dos Canais de Cálcio/uso terapêutico , Linhagem Celular Tumoral , Progressão da Doença , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , GTP Fosfo-Hidrolases/antagonistas & inibidores , GTP Fosfo-Hidrolases/genética , Humanos , Estimativa de Kaplan-Meier , Sistema de Sinalização das MAP Quinases/genética , Melanoma/genética , Melanoma/mortalidade , Melanoma/patologia , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/genética , Mutação , Prognóstico , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/patologia , Resultado do Tratamento
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