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1.
PLoS One ; 14(6): e0217880, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31194769

RESUMO

Protein tyrosine phosphatase receptor type Z (PTPRZ) is preferentially expressed in the central nervous system as two transmembrane receptor isoforms PTPRZ-A/B and one secretory isoform PTPRZ-S. Ptprz-knockout mice lacking the expression of all three isoforms show behavioral, learning, and neurological abnormalities, including increased exploratory activities to novelty, deficits in spatial and contextual learning, and reduced responses to methamphetamine, relative to wild-type mice. To investigate whether PTPRZ isoforms play distinct physiological roles, we herein performed behavioral studies on two knock-in mouse lines: One expresses the catalytically inactive Cys-1930 to Ser (CS) mutants of PTPRZ-A/B, while the other generated in the present study expresses catalytically active mutants of PTPRZ-A/B lacking the negative regulatory PTP-D2 domain and C-terminal PDZ-binding motif (ΔD2) instead of wild-type PTPRZ-A/-B. In contrast to Ptprz-knockout mice, neither increased responses to novelty in the open field nor memory impairments in the inhibitory-avoidance task were observed in Ptprz-CS or Ptprz-ΔD2 mice. However, the effects of methamphetamine on locomotor activity were significantly weaker in Ptprz-KO mice and CS mutant mice than in wild-type mice, but were normal in ΔD2 mutant mice. Furthermore, microdialysis experiments revealed that methamphetamine-evoked dopamine release in the nucleus accumbens was reduced in Ptprz-KO mice and CS mutant mice. These results suggest that the extracellular region of PTPRZ, including the secretory isoform, is crucial for behavioral responses to novelty and the formation of aversive memories, whereas the PTPase activities of PTPRZ receptor isoforms are involved in regulating the dopaminergic system.


Assuntos
Comportamento Animal , Mutação com Perda de Função , Núcleo Accumbens/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/genética , Substituição de Aminoácidos , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Catálise , Dopamina/metabolismo , Comportamento Exploratório/efeitos dos fármacos , Feminino , Técnicas de Introdução de Genes , Locomoção/efeitos dos fármacos , Masculino , Metanfetamina/farmacologia , Camundongos , Camundongos Knockout , Núcleo Accumbens/efeitos dos fármacos , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/química , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo
2.
Nat Chem Biol ; 15(7): 699-709, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31061498

RESUMO

Chondroitin sulfate (CS) and heparan sulfate (HS) are glycosaminoglycans that both bind the receptor-type protein tyrosine phosphatase PTPRσ, affecting axonal regeneration. CS inhibits axonal growth, while HS promotes it. Here, we have prepared a library of HS octasaccharides and, together with synthetic CS oligomers, we found that PTPRσ preferentially interacts with CS-E-a rare sulfation pattern in natural CS-and most HS oligomers bearing sulfate and sulfamate groups. Consequently, short and long stretches of natural CS and HS, respectively, bind to PTPRσ. CS activates PTPRσ, which dephosphorylates cortactin-herein identified as a new PTPRσ substrate-and disrupts autophagy flux at the autophagosome-lysosome fusion step. Such disruption is required and sufficient for dystrophic endball formation and inhibition of axonal regeneration. Therefore, sulfation patterns determine the length of the glycosaminoglycan segment that bind to PTPRσ and define the fate of axonal regeneration through a mechanism involving PTPRσ, cortactin and autophagy.


Assuntos
Autofagia/efeitos dos fármacos , Sulfatos de Condroitina/farmacologia , Cortactina/metabolismo , Heparitina Sulfato/farmacologia , Regeneração Nervosa/efeitos dos fármacos , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Animais , Sulfatos de Condroitina/química , Heparitina Sulfato/química , Humanos , Camundongos
3.
Cell Prolif ; 52(3): e12610, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31012177

RESUMO

OBJECTIVES: Circular RNA, a type of RNA formed by a covalently closed loop, possesses sophisticated abilities of gene regulation in tumorigenesis and metastasis. However, the role of circRNAs on lung adenocarcinoma (LUAD) remains largely unknown. MATERIALS AND METHODS: The role of cMras was examined both in vitro and in vivo. cMras expression in LUAD tissues was determined by quantitative real-time PCR (qRT-PCR). Downstream targets of cMras were predicted by bioinformatics tools and confirmed by RNA immunoprecipitation assay and luciferase assay. qRT-PCR and western blot assay were used to detect the expression of specific targets. RESULTS: Thirty-six paired LUAD and healthy tissues were collected and cMras resulted significantly downregulated in cancerous tissues. Its expression was negatively associated with tumour stages. cMras overexpression suppressed LUAD growth and metastasis, while endogenous cMras silencing resulted in the opposite effects. Bioinformatics analysis and experimental evidence confirmed that cMras was a sponge of miRNA-567 and released its direct target, PTPRG. cMras overexpression decreased miR-567 expression and subsequently increased PTPRG expression, while increased miRNA-567 expression blocked the effects induced by cMras. Moreover, PTPRG was downregulated in LUAD and patients with low PTPRG expression exhibited significantly poor prognosis. These results suggested that cMras/miR-567/PTPRG regulatory pathway might be associated to LUAD tumorigenesis and development. CONCLUSIONS: A novel circular RNA cMras and its functions were identified, discovering a cMras/miR-567/PTPRG regulatory pathway in LUAD tumorigenesis and development.


Assuntos
Adenocarcinoma de Pulmão/genética , Neoplasias Pulmonares/genética , MicroRNAs/genética , RNA/genética , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/genética , Células A549 , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/patologia , Animais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Carcinogênese/genética , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células/genética , Progressão da Doença , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica , Xenoenxertos , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Camundongos , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Modelos Biológicos , Invasividade Neoplásica/genética , RNA/metabolismo , RNA Interferente Pequeno/genética , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo
4.
Glia ; 67(5): 967-984, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30667096

RESUMO

Protein tyrosine phosphatase receptor type Z (PTPRZ) maintains oligodendrocyte precursor cells (OPCs) in an undifferentiated state. The inhibition of PTPase by its ligand pleiotrophin (PTN) promotes OPC differentiation; however, the substrate molecules of PTPRZ involved in the differentiation have not yet been elucidated in detail. We herein demonstrated that the tyrosine phosphorylation of AFAP1L2, paxillin, ERBB4, GIT1, p190RhoGAP, and NYAP2 was enhanced in OPC-like OL1 cells by a treatment with PTN. AFAP1L2, an adaptor protein involved in the PI3K-AKT pathway, exhibited the strongest response to PTN. PTPRZ dephosphorylated AFAP1L2 at tyrosine residues in vitro and in HEK293T cells. In OL1 cells, the knockdown of AFAP1L2 or application of a PI3K inhibitor suppressed cell differentiation as well as the PTN-induced phosphorylation of AKT and mTOR. We generated a knock-in mouse harboring a catalytically inactive Cys to Ser (CS) mutation in the PTPase domain. The phosphorylation levels of AFAP1L2, AKT, and mTOR were higher, and the expression of oligodendrocyte markers, including myelin basic protein (MBP) and myelin regulatory factor (MYRF), was stronger in CS knock-in brains than in wild-type brains on postnatal day 10; however, these differences mostly disappeared in the adult stage. Adult CS knock-in mice exhibited earlier remyelination after cuprizone-induced demyelination through the accelerated differentiation of OPCs. These phenotypes in CS knock-in mice were similar to those in Ptprz-deficient mice. Therefore, we conclude that the PTN-PTPRZ signal stimulates OPC differentiation partly by enhancing the tyrosine phosphorylation of AFAP1L2 in order to activate the PI3K-AKT pathway.


Assuntos
Proteínas de Transporte/metabolismo , Diferenciação Celular/fisiologia , Citocinas/metabolismo , Oligodendroglia/fisiologia , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Transdução de Sinais/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Diferenciação Celular/efeitos dos fármacos , Cuprizona/toxicidade , Doenças Desmielinizantes/induzido quimicamente , Doenças Desmielinizantes/diagnóstico por imagem , Modelos Animais de Doenças , Células HEK293 , Humanos , Imunoprecipitação , Marcação In Situ das Extremidades Cortadas , Proteínas Luminescentes/genética , Proteínas Luminescentes/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas dos Microfilamentos/metabolismo , Proteínas da Mielina/metabolismo , Proteínas Proto-Oncogênicas c-akt , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/genética , Detecção de Sinal Psicológico/efeitos dos fármacos , Detecção de Sinal Psicológico/fisiologia , Transfecção , Microtomografia por Raio-X
5.
Acta Pharmacol Sin ; 40(6): 724-736, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30315251

RESUMO

Increasing evidence suggests that Ras-related in brain 7 (Rab7), an endosome-localized small GTPase contributes to cerebral ischemic brain injury. In the present study, we investigated the role of Rab7 in ischemic stroke-induced formation of astrogliosis and glial scar. Rats were subjected to transient middle cerebral artery occlusion (tMCAO); the rats were injected with the Rab7 receptor antagonist CID1067700 (CID). Primary astrocytes were subjected to an oxygen and glucose deprivation and reoxygenation (OGD/Re) procedure; CID was added to the cell culture media. We found that Rab7 was significantly elevated over time in both the in vivo and in vitro astrocytic injury models, and administration of CID significantly down-regulated the glial scar markers such as glial fibillary acidic protein (GFAP), neurocan and phosphacan. Moreover, administration of CID significantly attenuated the brain atrophy and improved neurologic deficits in tMCAO rats, and protected astrocytes against OGD/Re-induced injury. Further, CID downregulated the protein levels of Lamp1 and active cathepsin B in astrocytes after OGD/Re or tMCAO injury; CID inhibited the co-localization of cathepsin B and Rab7, Lamp1 and Rab7; CID decreased OGD/Re-induced increase in lysosomal membrane permeability and blocked OGD/Re-induced release of cathepsin B from the lysosome into the cytoplasm in astrocytes. Taken together, these results suggest that Rab7 is involved in ischemic stroke-induced formation of astrogliosis and glial scar. CID administration attenuates brain atrophy and improves neurologic deficits and inhibits astrogliosis and glial scar formation after ischemic stroke via reducing the activation and release of cathepsin B from the lysosome into the cytoplasm.


Assuntos
Atrofia/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Gliose/tratamento farmacológico , Compostos Heterocíclicos com 2 Anéis/uso terapêutico , Infarto da Artéria Cerebral Média/tratamento farmacológico , Fármacos Neuroprotetores/uso terapêutico , Tioureia/análogos & derivados , Proteínas rab de Ligação ao GTP/antagonistas & inibidores , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Encéfalo/patologia , Catepsina B/metabolismo , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Proteína Glial Fibrilar Ácida/metabolismo , Glicoproteínas de Membrana Associadas ao Lisossomo/metabolismo , Lisossomos/metabolismo , Masculino , Ratos Sprague-Dawley , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Tioureia/uso terapêutico , Proteínas rab de Ligação ao GTP/metabolismo
6.
Cell Commun Signal ; 16(1): 92, 2018 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-30497491

RESUMO

BACKGROUND: Chemotherapy is the primary established systemic treatment for patients with breast cancer, especially those with the triple-negative subtype. Simultaneously, the resistance of triple-negative breast cancer (TNBC) to chemotherapy remains a major clinical problem. Our previous study demonstrated that the expression levels of PTN and its receptor PTPRZ1 were upregulated in recurrent TNBC tissue after chemotherapy, and this increase was closely related to poor prognosis in those patients. However, the mechanism and function of chemotherapy-driven increases in PTN/PTPRZ1 expression are still unclear. METHODS: We compared the expression of PTN and PTPRZ1 between normal breast and cancer tissues as well as before and after chemotherapy in cancer tissue using the microarray analysis data from the GEPIA database and GEO database. The role of chemotherapy-driven increases in PTN/PTPRZ1 expression was examined with a CCK-8 assay, colony formation efficiency assay and apoptosis analysis with TNBC cells. The potential upstream pathways involved in the chemotherapy-driven increases in PTN/PTPRZ1 expression in TNBC cells were explored using microarray analysis, and the downstream mechanism was dissected with siRNA. RESULTS: We demonstrated that the expression of PTN and PTPRZ1 was upregulated by chemotherapy, and this change in expression decreased chemosensitivity by promoting tumour proliferation and inhibiting apoptosis. CDKN1A was the critical switch that regulated the expression of PTN/PTPRZ1 in TNBC cells receiving chemotherapy. We further demonstrated that the mechanism of chemoresistance by chemotherapy-driven increases in the CDKN1A/PTN/PTPRZ1 axis depended on the NF-κB pathway. CONCLUSIONS: Our studies indicated that chemotherapy-driven increases in the CDKN1A/PTN/PTPRZ1 axis play a critical role in chemoresistance, which suggests a novel strategy to enhance chemosensitivity in breast cancer cells, especially in those of the triple-negative subtype.


Assuntos
Proteínas de Transporte/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Citocinas/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , NF-kappa B/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Transdução de Sinais/efeitos dos fármacos , Neoplasias de Mama Triplo Negativas/patologia , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Retroalimentação Fisiológica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos
7.
Int J Oncol ; 53(5): 1847-1856, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30226583

RESUMO

Preeclampsia (PE) in pregnancy is associated with vitrified-thawed embryo transfer. Pleiotrophin (PTN) is important in inflammation via its receptors. The aim of the present study was to determine the effect of PTN on the risk of PE following embryo transfer. An enzyme-linked immunosorbent assay was performed to determine the levels of tumor necrosis factor (TNF)-α and PTN in serum. The knockdown of PTN was conditionally induced by tamoxifen (tax) treatment. The tail-cuff method and Bradford assay were used to monitor blood pressure and the level of urine protein, respectively. The expression patterns of PTN, receptor protein tyrosine phosphatase ß/ζ, (RPTPß/ζ), syndecan-1 (SDC1), syndecan-3 (SDC3) and anaplastic lymphoma kinase (ALK) were determined by immunohistochemistry (IHC). Western blot analysis was performed to evaluate the expression level of PTN and its receptors. The risk of PE was elevated following embryo transfer in clinical and in the tax/PTN-/- group. It was found that the level of PTN increased when pregnancy progressed in normal conditions, however, the level of PTN was reduced in the PE mice. In addition, increases in TNF-α, blood pressure and urine protein were more marked in the PE mice that lacked PTN, compared with those in other PE mice. In addition, overlapping expression of PTN and its receptors in villous mesenchyme and fetal macrophages were identified using an IHC assay. However, the positive staining of PTN and its receptors was weaker or even absent in the PE mice. The protein level of RPTPß/ζ was lower in the PE mice that lacked PTN than that in the other PE mice. The knockdown of PTN increased the risk of PE following vitrified-thawed embryo transfer, in which its receptors, particularly RPTPß/ζ, may be involved.


Assuntos
Proteínas de Transporte/genética , Criopreservação/métodos , Citocinas/genética , Transferência Embrionária/efeitos adversos , Pré-Eclâmpsia/etiologia , Resultado da Gravidez , Adulto , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Blastocisto , Proteínas de Transporte/sangue , Proteínas de Transporte/metabolismo , Citocinas/sangue , Citocinas/metabolismo , Transferência Embrionária/métodos , Feminino , Fertilização In Vitro/efeitos adversos , Fertilização In Vitro/métodos , Técnicas de Silenciamento de Genes , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pré-Eclâmpsia/sangue , Gravidez , Prognóstico , Proteínas Tirosina Fosfatases Classe 3 Semelhantes a Receptores , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Transdução de Sinais , Adulto Jovem
8.
Cell Syst ; 7(3): 295-309.e11, 2018 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-30145116

RESUMO

The proto-oncogenic epidermal growth factor receptor (EGFR) is a tyrosine kinase whose sensitivity to growth factors and signal duration determines cellular behavior. We resolve how EGFR's response to epidermal growth factor (EGF) originates from dynamically established recursive interactions with spatially organized protein tyrosine phosphatases (PTPs). Reciprocal genetic PTP perturbations enabled identification of receptor-like PTPRG/J at the plasma membrane and ER-associated PTPN2 as the major EGFR dephosphorylating activities. Imaging spatial-temporal PTP reactivity revealed that vesicular trafficking establishes a spatially distributed negative feedback with PTPN2 that determines signal duration. On the other hand, single-cell dose-response analysis uncovered a reactive oxygen species-mediated toggle switch between autocatalytically activated monomeric EGFR and the tumor suppressor PTPRG that governs EGFR's sensitivity to EGF. Vesicular recycling of monomeric EGFR unifies the interactions with these PTPs on distinct membrane systems, dynamically generating a network architecture that can sense and respond to time-varying growth factor signals.


Assuntos
Membrana Celular/metabolismo , Vesículas Citoplasmáticas/metabolismo , Retículo Endoplasmático/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 2/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Biologia Computacional , Fator de Crescimento Epidérmico/metabolismo , Receptores ErbB/metabolismo , Retroalimentação Fisiológica , Humanos , Células MCF-7 , Microscopia Confocal , Modelos Teóricos , Fosforilação , Mapas de Interação de Proteínas , Transporte Proteico , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/genética , Transdução de Sinais , Análise de Célula Única
9.
EMBO Rep ; 19(8)2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29907679

RESUMO

In ovarian cancer, the prometastatic RTK AXL promotes motility, invasion and poor prognosis. Here, we show that reduced survival caused by AXL overexpression can be mitigated by the expression of the GPI-anchored tumour suppressor OPCML Further, we demonstrate that AXL directly interacts with OPCML, preferentially so when AXL is activated by its ligand Gas6. As a consequence, AXL accumulates in cholesterol-rich lipid domains, where OPCML resides. Here, phospho-AXL is brought in proximity to the lipid domain-restricted phosphatase PTPRG, which de-phosphorylates the RTK/ligand complex. This prevents AXL-mediated transactivation of other RTKs (cMET and EGFR), thereby inhibiting sustained phospho-ERK signalling, induction of the EMT transcription factor Slug, cell migration and invasion. From a translational perspective, we show that OPCML enhances the effect of the phase II AXL inhibitor R428 in vitro and in vivo We therefore identify a novel mechanism by which two spatially restricted tumour suppressors, OPCML and PTPRG, coordinate to repress AXL-dependent oncogenic signalling.


Assuntos
Moléculas de Adesão Celular/metabolismo , Neoplasias Ovarianas/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Receptores Proteína Tirosina Quinases/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Animais , Benzocicloeptenos/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Galinhas , Colesterol/metabolismo , Ativação Enzimática/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Tubas Uterinas/patologia , Feminino , Proteínas Ligadas por GPI/metabolismo , Inativação Gênica/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Microdomínios da Membrana/metabolismo , Invasividade Neoplásica , Neoplasias Ovarianas/patologia , Fosforilação/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Resultado do Tratamento , Triazóis/farmacologia
10.
Int Heart J ; 59(4): 829-836, 2018 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-29877301

RESUMO

MicroRNAs, a class of small and non-encoding RNAs that transcriptionally or post-transcriptionally modulate the expression of their target genes, have been implicated as critical regulatory molecules in ischemia-/reperfusion-induced cardiac injury. In the present study, we report on the role of miR-208a in myocardial I/R injury and the underlying cardio-protective mechanism. The gain-of-function and loss-of-function were used to explore the effects of miR-208a on cardiac injury induced by H2O2 in cardiomyocytes. As predicted, knockdown of endogenous miR-208a significantly decreased the level of cellular reactive oxygen species (ROS) and reduced cardiomyocyte apoptosis. In addition, miR-208a overexpression increased the ROS level and attenuated cell apoptosis in cardiomyocytes. Furthermore, protein tyrosine phosphatase receptor type G (PTPRG) and protein tyrosine phosphatase, non-receptor type 4 (PTPN4), which participate in regulating the level of cellular protein tyrosine phosphorylation balance, were predicted and verified as potential miR-208a targets using bioinformatics and luciferase assay. In summary, this study demonstrated that miR-208a plays a critical protective role in ROS-induced cardiac apoptosis.


Assuntos
MicroRNAs/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miócitos Cardíacos , Proteína Tirosina Fosfatase não Receptora Tipo 4/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Animais , Apoptose , Técnicas de Silenciamento de Genes , Peróxido de Hidrogênio/metabolismo , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/metabolismo , Estresse Oxidativo , Proteínas Tirosina Quinases/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismo
11.
Neuropharmacology ; 137: 86-95, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29753117

RESUMO

Pleiotrophin (PTN) and Midkine (MK) are neurotrophic factors that are upregulated in the prefrontal cortex after alcohol administration and have been shown to reduce ethanol drinking and reward. PTN and MK are the endogenous inhibitors of Receptor Protein Tyrosine Phosphatase (RPTP) ß/ζ (a.k.a. PTPRZ1, RPTPß, PTPζ), suggesting a potential role for this phosphatase in the regulation of alcohol effects. To determine if RPTPß/ζ regulates ethanol consumption, we treated mice with recently developed small-molecule inhibitors of RPTPß/ζ (MY10, MY33-3) before testing them for binge-like drinking using the drinking in the dark protocol. Mice treated with RPTPß/ζ inhibitors, particularly with MY10, drank less ethanol than controls. MY10 treatment blocked ethanol conditioned place preference, showed limited effects on ethanol-induced ataxia, and potentiated the sedative effects of ethanol. We also tested whether RPTPß/ζ is involved in ethanol signaling pathways. We found that ethanol treatment of neuroblastoma cells increased phosphorylation of anaplastic lymphoma kinase (ALK) and TrkA, known substrates of RPTPß/ζ. Treatment of neuroblastoma cells with MY10 or MY33-3 also increased levels of phosphorylated ALK and TrkA. However, concomitant treatment of neuroblastoma cells with ethanol and MY10 or MY33-3 prevented the increase in pTrkA and pALK. These results demonstrate for the first time that ethanol engages TrkA signaling and that RPTPß/ζ modulates signaling pathways activated by alcohol and behavioral responses to this drug. The data support the hypothesis that RPTPß/ζ might be a novel target of pharmacotherapy for reducing excessive alcohol consumption.


Assuntos
Bebedeira/enzimologia , Depressores do Sistema Nervoso Central/farmacologia , Etanol/farmacologia , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/antagonistas & inibidores , Dissuasores de Álcool/síntese química , Dissuasores de Álcool/química , Dissuasores de Álcool/farmacologia , Quinase do Linfoma Anaplásico/metabolismo , Animais , Bebedeira/tratamento farmacológico , Linhagem Celular Tumoral , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Masculino , Camundongos Endogâmicos C57BL , Receptor trkA/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo
12.
Sci Rep ; 8(1): 5893, 2018 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-29651006

RESUMO

Pleiotrophin (PTN) stimulates endothelial cell migration through binding to receptor protein tyrosine phosphatase beta/zeta (RPTPß/ζ) and ανß3 integrin. Screening for proteins that interact with RPTPß/ζ and potentially regulate PTN signaling, through mass spectrometry analysis, identified cyclin-dependent kinase 5 (CDK5) activator p35 among the proteins displaying high sequence coverage. Interaction of p35 with the serine/threonine kinase CDK5 leads to CDK5 activation, known to be implicated in cell migration. Protein immunoprecipitation and proximity ligation assays verified p35-RPTPß/ζ interaction and revealed the molecular association of CDK5 and RPTPß/ζ. In endothelial cells, PTN activates CDK5 in an RPTPß/ζ- and phosphoinositide 3-kinase (PI3K)-dependent manner. On the other hand, c-Src, ανß3 and ERK1/2 do not mediate the PTN-induced CDK5 activation. Pharmacological and genetic inhibition of CDK5 abolished PTN-induced endothelial cell migration, suggesting that CDK5 mediates PTN stimulatory effect. A new pyrrolo[2,3-α]carbazole derivative previously identified as a CDK1 inhibitor, was found to suppress CDK5 activity and eliminate PTN stimulatory effect on cell migration, warranting its further evaluation as a new CDK5 inhibitor. Collectively, our data reveal that CDK5 is activated by PTN, in an RPTPß/ζ-dependent manner, regulates PTN-induced cell migration and is an attractive target for the inhibition of PTN pro-angiogenic properties.


Assuntos
Proteínas de Transporte/farmacologia , Movimento Celular/efeitos dos fármacos , Quinase 5 Dependente de Ciclina/genética , Citocinas/farmacologia , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Sequência de Aminoácidos , Animais , Carbazóis/farmacologia , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Quinase 5 Dependente de Ciclina/antagonistas & inibidores , Quinase 5 Dependente de Ciclina/metabolismo , Citocinas/genética , Citocinas/metabolismo , Regulação da Expressão Gênica , Guanina/análogos & derivados , Guanina/farmacologia , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Integrina alfaVbeta3/genética , Integrina alfaVbeta3/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Isoenzimas/farmacologia , Neuroglia/efeitos dos fármacos , Neuroglia/metabolismo , Neuroglia/patologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Ligação Proteica/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Ratos , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Roscovitina/farmacologia , Transdução de Sinais
13.
Mol Cell Proteomics ; 17(5): 850-870, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29371290

RESUMO

Recently, FGFR1 was found to be overexpressed in osteosarcoma and represents an important target for precision medicine. However, because targeted cancer therapy based on FGFR inhibitors has so far been less efficient than expected, a detailed understanding of the target is important. We have here applied proximity-dependent biotin labeling combined with label-free quantitative mass spectrometry to identify determinants of FGFR1 activity in an osteosarcoma cell line. Many known FGFR interactors were identified (e.g. FRS2, PLCG1, RSK2, SRC), but the data also suggested novel determinants. A strong hit in our screen was the tyrosine phosphatase PTPRG. We show that PTPRG and FGFR1 interact and colocalize at the plasma membrane where PTPRG directly dephosphorylates activated FGFR1. We further show that osteosarcoma cell lines depleted for PTPRG display increased FGFR activity and are hypersensitive to stimulation by FGF1. In addition, PTPRG depletion elevated cell growth and negatively affected the efficacy of FGFR kinase inhibitors. Thus, PTPRG may have future clinical relevance by being a predictor of outcome after FGFR inhibitor treatment.


Assuntos
Inibidores de Proteínas Quinases/farmacologia , Receptor Tipo 1 de Fator de Crescimento de Fibroblastos/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Linhagem Celular Tumoral , Regulação para Baixo , Fatores de Crescimento de Fibroblastos/farmacologia , Técnicas de Silenciamento de Genes , Humanos , Osteossarcoma/metabolismo , Fosforilação/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Proteômica , Reprodutibilidade dos Testes
14.
Eur J Med Chem ; 144: 318-329, 2018 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-29275231

RESUMO

A new series of blood-brain barrier permeable molecules designed to mimic the activity of Pleiotrophin in the CNS has been designed and synthesized. These compounds exert their action by interacting with the intracellular domain PD1 of the Protein Tyrosine-Phosphatase Receptor Z1 (PTPRZ1), and inhibiting its tyrosine phosphatase activity. The most potent compounds 10a and 12b (IC50 = 0,1 µM) significantly increase the phosphorylation of key tyrosine residues of PTPRZ1 substrates involved in neuronal survival and differentiation, and display protective effects against amphetamine-induced toxicity. Docking and molecular dynamics experiments have been used to analyze the binding mode and to explain the observed selectivity against PTP1B. An In vivo experiment has demonstrated that 10a can cross the BBB, thus promoting the possibility of moving forward these candidates for the development of drugs for the treatment of CNS disorders, such as drug addiction and neurodegenerative diseases.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Proteínas de Transporte/farmacologia , Doenças do Sistema Nervoso Central/tratamento farmacológico , Citocinas/farmacologia , Inibidores Enzimáticos/farmacologia , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/antagonistas & inibidores , Animais , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/metabolismo , Proteínas de Transporte/síntese química , Proteínas de Transporte/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Doenças do Sistema Nervoso Central/metabolismo , Citocinas/síntese química , Citocinas/química , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Camundongos , Modelos Moleculares , Estrutura Molecular , Ratos , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Relação Estrutura-Atividade
15.
J Biochem ; 162(5): 381-390, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28992190

RESUMO

Protein tyrosine phosphatase receptor type Z (PTPRZ, also known as PTPζ or RPTPß) is preferentially expressed in the central nervous system (CNS). PTPRZ plays important roles during development and adulthood in CNS myelination, learning and memory. Three splicing isoforms for PTPRZ have been identified to date: two receptor type isoforms, PTPRZ-A and PTPRZ-B, and one secretory isoform, PTPRZ-S. We herein identified novel PTPRZ receptor sub-isoforms without a seven-amino acid sequence encoded by exon 16. This sequence forms a part of the helix-turn-helix segment called the 'wedge' structure, which is located at the N-terminal region in the membrane-proximal protein tyrosine phosphatase domain. In contrast to conventional receptor isoforms with uniform expression, the deleted isoforms were expressed in the brain, but not in the retina, indicating the tissue-specific splicing of exon 16. Biochemical analyses of PTPRZ intracellular regions revealed differences in the characteristics of the deleted form, namely, stronger binding activity to postsynaptic density protein 95 (PSD95) and greater enrichment in the postsynaptic density fraction than the full-length form. Furthermore, the exon 16-deleted form exhibited higher catalytic efficiency in vitro. These results suggest that sub-isoforms of PTPRZ have different functions because of variations in the wedge structure.


Assuntos
Regulação Enzimológica da Expressão Gênica/fisiologia , Isoformas de Proteínas/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Animais , Proteína 4 Homóloga a Disks-Large/genética , Proteína 4 Homóloga a Disks-Large/metabolismo , Variação Genética , Células HEK293 , Humanos , Camundongos , Camundongos Knockout , Conformação Proteica , Isoformas de Proteínas/genética , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/genética
16.
Shanghai Kou Qiang Yi Xue ; 26(2): 198-203, 2017 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-28815252

RESUMO

PURPOSE: This study was aimed to detect the expression of PTPRZ1 in oral squamous cell carcinoma (OSCC) originated from oral submucous fibrosis (OSF), and discuss its role in the development and progression of OSCC originating from OSF as well as its clinical significance. METHODS: Immunohistochemisty (IHC) and Western blot (WB) for the expression and distribution of PTPRZ1 were carried out in 36 cases of OSF transforming into OSCC, 23 cases of OSCC and 21 cases of healthy controls. The data were analyzed by Chi-square test using SPSS 21.0 software package. RESULTS: IHC results demonstrated that the expression of PTPRZ1 in OSCC originated from the OSF was strongly positive and the rate of positive expression was 72.22%; expression of PTPRZ1 in OSCC was weakly positive, the positive rate was 43.47%; and the expression of PTPRZ1 in healthy controls was negative. The rate of PTPRZ1 positive expression was significantly higher in OSCC originated from OSF and OSCC with non-OSF than that of the healthy controls (P<0.01). The positive expression rate of OSCC originated from OSF was significantly higher than that of OSCC with non-OSF (P<0.05).WB results showed the expression of PTPRZ1 was weak in the healthy controls and in OSCC with non-OSF, but strong in OSCC originated from OSF. Correlation analysis between PTPRZ1 and clinical data showed PTPRZ1 was correlated with recurrence and metastasis positively (rk=0.642, P<0.05; rk=0.656, P<0.05). CONCLUSIONS: Differential expression of PTPRZ1 in OSCC originating from OSF and OSCC with non-OSF was significant. PTPRZ1, which plays an important role in the processes of development, invasion and metastasis of OSCC originated from OSF, can be used as a molecular marker for early diagnosis and targeted gene for treatment of OSCC originating from OSF.


Assuntos
Carcinoma de Células Escamosas/metabolismo , Neoplasias Bucais/metabolismo , Fibrose Oral Submucosa/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Western Blotting , Distribuição de Qui-Quadrado , Humanos , Recidiva Local de Neoplasia
17.
Sci Rep ; 7(1): 5609, 2017 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-28717188

RESUMO

The R5 subfamily of receptor-type protein tyrosine phosphatases (RPTPs) comprises PTPRZ and PTPRG. A recent study on primary human glioblastomas suggested a close association between PTPRZ1 (human PTPRZ) expression and cancer stemness. However, the functional roles of PTPRZ activity in glioma stem cells have remained unclear. In the present study, we found that sphere-forming cells from the rat C6 and human U251 glioblastoma cell lines showed high expression levels of PTPRZ-B, the short receptor isoform of PTPRZ. Stable PTPRZ knockdown altered the expression levels of stem cell transcription factors such as SOX2, OLIG2, and POU3F2 and decreased the sphere-forming abilities of these cells. Suppressive effects on the cancer stem-like properties of the cells were also observed following the knockdown of PTPRG. Here, we identified NAZ2329, a cell-permeable small molecule that allosterically inhibits both PTPRZ and PTPRG. NAZ2329 reduced the expression of SOX2 in C6 and U251 cells and abrogated the sphere-forming abilities of these cells. Tumor growth in the C6 xenograft mouse model was significantly slower with the co-treatment of NAZ2329 with temozolomide, an alkylating agent, than with the individual treatments. These results indicate that pharmacological inhibition of R5 RPTPs is a promising strategy for the treatment of malignant gliomas.


Assuntos
Carcinogênese/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Glioblastoma/prevenção & controle , Células-Tronco Neoplásicas/efeitos dos fármacos , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/antagonistas & inibidores , Bibliotecas de Moléculas Pequenas/farmacologia , Temozolomida/farmacologia , Animais , Antineoplásicos Alquilantes/farmacologia , Carcinogênese/metabolismo , Carcinogênese/patologia , Feminino , Glioblastoma/enzimologia , Glioblastoma/patologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Células-Tronco Neoplásicas/enzimologia , Células-Tronco Neoplásicas/patologia , Ratos , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
18.
Nat Commun ; 8: 15080, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28569747

RESUMO

Intense infiltration of tumour-associated macrophages (TAMs) facilitates malignant growth of glioblastoma (GBM), but the underlying mechanisms remain undefined. Herein, we report that TAMs secrete abundant pleiotrophin (PTN) to stimulate glioma stem cells (GSCs) through its receptor PTPRZ1 thus promoting GBM malignant growth through PTN-PTPRZ1 paracrine signalling. PTN expression correlates with infiltration of CD11b+/CD163+ TAMs and poor prognosis of GBM patients. Co-implantation of M2-like macrophages (MLCs) promoted GSC-driven tumour growth, but silencing PTN expression in MLCs mitigated their pro-tumorigenic activity. The PTN receptor PTPRZ1 is preferentially expressed in GSCs and also predicts GBM poor prognosis. Disrupting PTPRZ1 abrogated GSC maintenance and tumorigenic potential. Moreover, blocking the PTN-PTPRZ1 signalling by shRNA or anti-PTPRZ1 antibody potently suppressed GBM tumour growth and prolonged animal survival. Our study uncovered a critical molecular crosstalk between TAMs and GSCs through the PTN-PTPRZ1 paracrine signalling to support GBM malignant growth, indicating that targeting this signalling axis may have therapeutic potential.


Assuntos
Proteínas de Transporte/metabolismo , Citocinas/metabolismo , Glioblastoma/imunologia , Macrófagos/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Animais , Células Cultivadas , Glioblastoma/metabolismo , Humanos , Camundongos , Transplante de Neoplasias , Comunicação Parácrina , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Proto-Oncogênicas c-fyn/metabolismo
19.
Oncogene ; 36(38): 5369-5381, 2017 09 21.
Artigo em Inglês | MEDLINE | ID: mdl-28504721

RESUMO

Exosomes are carriers of pro-tumorigenic factors that participate in glioblastoma (GBM) progression, and many fusion genes are strong driver mutations in neoplasia and are involved in tumorigenesis. However, the ability of fusion genes to be transduced by exosomes is unknown. We characterized exosomes from GBM cells harbouring and not harbouring PTPRZ1-MET fusion (ZM fusion). We also determined the effect of the exosomes from ZM fusion cells (ZM exosomes) on pro-oncogenic secretions and showed that ZM exosomes are internalized by the recipient cells. In addition, we studied the effect of ZM exosome-mediated intercellular communication in the GBM microenvironment. MET proto-oncogene expression was higher in ZM exosomes. Moreover, phosphorylated MET was detected only in ZM exosomes and not in exosomes released by non-ZM fusion GBM cells. ZM exosomes transferred to non-ZM fusion GBM cells and normal human astrocytes altered gene expression and induced epithelial-mesenchymal transition. The uptake of ZM exosomes also induced an exosome-dependent phenotype defined by GBM cell migration and invasion, neurosphere growth and angiogenesis. In addition, ZM exosomes conferred temozolomide resistance to the GBM cells, and exosome-derived ZM fusion network proteins targeted multiple pro-oncogenic effectors in recipient cells within the GBM microenvironment. Our findings show that exosomes mediate the aggressive character of GBM and demonstrate the role of ZM fusion in the exacerbation of this effect. These findings have possible implications for the foundation of gene fusion-based therapy for managing GBM.


Assuntos
Antineoplásicos Alquilantes/farmacologia , Dacarbazina/análogos & derivados , Exossomos/metabolismo , Glioblastoma/tratamento farmacológico , Proteínas de Fusão Oncogênica/metabolismo , Proteínas Proto-Oncogênicas c-met/metabolismo , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Animais , Comunicação Celular , Linhagem Celular Tumoral , Dacarbazina/farmacologia , Resistencia a Medicamentos Antineoplásicos , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Proteínas de Fusão Oncogênica/genética , Fenótipo , Fosforilação , Proteínas Proto-Oncogênicas c-met/genética , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/genética , Temozolomida
20.
Sci Rep ; 7: 43470, 2017 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-28262779

RESUMO

Retinal ischemia occurs in a variety of eye diseases. Restrained blood flow induces retinal damage, which leads to progressive optic nerve degeneration and vision loss. Previous studies indicate that extracellular matrix (ECM) constituents play an important role in complex tissues, such as retina and optic nerve. They have great impact on de- and regeneration processes and represent major candidates of central nervous system glial scar formation. Nevertheless, the importance of the ECM during ischemic retina and optic nerve neurodegeneration is not fully understood yet. In this study, we analyzed remodeling of the extracellular glycoproteins fibronectin, laminin, tenascin-C and tenascin-R and the chondroitin sulfate proteoglycans (CSPGs) aggrecan, brevican and phosphacan/RPTPß/ζ in retinae and optic nerves of an ischemia/reperfusion rat model via quantitative real-time PCR, immunohistochemistry and Western blot. A variety of ECM constituents were dysregulated in the retina and optic nerve after ischemia. Regarding fibronectin, significantly elevated mRNA and protein levels were observed in the retina following ischemia, while laminin and tenascin-C showed enhanced immunoreactivity in the optic nerve after ischemia. Interestingly, CSPGs displayed significantly increased expression levels in the optic nerve. Our study demonstrates a dynamic expression of ECM molecules following retinal ischemia, which strengthens their regulatory role during neurodegeneration.


Assuntos
Regulação da Expressão Gênica , Nervo Óptico/metabolismo , Traumatismo por Reperfusão/genética , Retina/metabolismo , Degeneração Retiniana/genética , Agrecanas/genética , Agrecanas/metabolismo , Animais , Brevicam/genética , Brevicam/metabolismo , Modelos Animais de Doenças , Fibronectinas/genética , Fibronectinas/metabolismo , Laminina/genética , Laminina/metabolismo , Masculino , Nervo Óptico/irrigação sanguínea , Nervo Óptico/patologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/genética , Proteínas Tirosina Fosfatases Classe 5 Semelhantes a Receptores/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Retina/patologia , Degeneração Retiniana/metabolismo , Degeneração Retiniana/patologia , Transdução de Sinais , Tenascina/genética , Tenascina/metabolismo
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