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1.
Int J Mol Sci ; 20(19)2019 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-31547056

RESUMO

Treatment of high grade gliomas (HGGs) has remained elusive due to their high heterogeneity and aggressiveness. Surgery followed by radiotherapy represents the mainstay of treatment for HGG. However, the unfavorable location of the tumor that usually limits total resection and the resistance to radiation therapy are the major therapeutic problems. Chemotherapy with DNA alkylating agent temozolomide is also used to treat HGG, despite modest effects on survival. Disregulation of several growth factor receptors (GFRs) were detected in HGG and receptor amplification in glioblastoma has been suggested to be responsible for heterogeneity propagation through clonal evolution. Molecularly targeted agents inhibiting these membrane proteins have demonstrated significant cytotoxicity in several types of cancer cells when tested in preclinical models. Platelet-derived growth factor receptors (PDGFRs) and associated signaling were found to be implicated in gliomagenesis, moreover, HGG commonly display a Platelet-derived growth factor (PDGF) autocrine pathway that is not present in normal brain tissues. We have previously shown that both the susceptibility towards PDGFR and the impact of the PDGFR inactivation on the radiation response were different in different HGG cell lines. Therefore, we decided to extend our investigation, using two other HGG cell lines that express PDGFR at the cell surface. Here, we investigated the effect of PDGFR inhibition alone or in combination with gamma radiation in 11 and 15 HGG cell lines. Our results showed that while targeting the PDGFR represents a good means of treatment in HGG, the combination of receptor inhibition with gamma radiation did not result in any discernable difference compared to the single treatment. The PI3K/PTEN/Akt/mTOR and Ras/Raf/MEK/ERK pathways are the major signaling pathways emerging from the GFRs, including PDGFR. Decreased sensitivity to radiation-induced cell death are often associated with redundancy in these pro-survival signaling pathways. Here we found that Phosphoinositide 3-kinases (PI3K), Extracellular-signal-regulated kinase 1/2 (ERK1/2), or c-Jun N-terminal kinase 1/2 (JNK1/2) inactivation induced radiosensitivity in HGG cells.


Assuntos
Comunicação Autócrina/efeitos da radiação , Glioma , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Proteínas de Neoplasias/metabolismo , Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptores do Fator de Crescimento Derivado de Plaquetas/metabolismo , Linhagem Celular Tumoral , Raios gama , Glioma/metabolismo , Glioma/patologia , Glioma/radioterapia , Humanos
2.
BMC Cancer ; 19(1): 889, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488097

RESUMO

BACKGROUND: Capacitive-resistive electric transfer (CRET) is a non-invasive therapeutic strategy that applies radiofrequency electric currents within the 400-600 kHz range to tissue repair and regeneration. Previous studies by our group have shown that 48 h of intermittent exposure to a 570 kHz CRET signal at a subthermal density of 50 µA/mm2 causes significant changes in the expression and activation of cell cycle control proteins, leading to cycle arrest in human cancer cell cultures. The present study investigates the relevance of the signal frequency in the response of the human neuroblastoma cell line NB69 to subthermal electric treatment with four different signal frequency currents within the 350-650 kHz range. METHODS: Trypan blue assay, flow cytometry, immunofluorescence and immunoblot were used to study the effects of subthermal CRET currents on cell viability, cell cycle progression and the expression of several marker proteins involved in NB69 cell death and proliferation. RESULTS: The results reveal that among the frequencies tested, only a 448 kHz signal elicited both proapoptotic and antiproliferative, statistically significant responses. The apoptotic effect would be due, at least in part, to significant changes induced by the 448 kHz signal in the expression of p53, Bax and caspase-3. The cytostatic response was preceded by alterations in the kinetics of the cell cycle and in the expression of proteins p-ERK1/2, cyclin D1 and p27, which is consistent with a potential involvement of the EGF receptor in electrically induced changes in the ERK1/2 pathway. This receives additional support from results indicating that the proapototic and antiproliferative responses to CRET can be transiently blocked when the electric stimulus is applied in the presence of PD98059, a chemical inhibitor of the ERK1/2 pathway. CONCLUSION: The understanding of the mechanisms underlying the ability of slowing down cancer cell growth through electrically-induced changes in the expression of proteins involved in the control of cell proliferation and apoptosis might afford new insights in the field of oncology.


Assuntos
Crista Neural/efeitos da radiação , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Tratamento por Radiofrequência Pulsada/métodos , Apoptose/efeitos da radiação , Caspase 3/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos da radiação , Linhagem Celular Tumoral , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Ciclina D1/metabolismo , Inibidor de Quinase Dependente de Ciclina p27/metabolismo , Receptores ErbB/metabolismo , Flavonoides/farmacologia , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Neuroblastoma/radioterapia , Transdução de Sinais/efeitos da radiação , Proteína Supressora de Tumor p53/metabolismo , Proteína X Associada a bcl-2/metabolismo
3.
Radiat Res ; 192(4): 410-421, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31390312

RESUMO

Radiation-induced acute skin injury and consequent fibrosis are common complications of cancer radiotherapy and radiation accidents. Stromal cell-derived factor-1α (SDF-1α) and its receptor, CXC chemokine receptor 4 (CXCR4) have been shown to be involved in multiple cellular events. However, the role of SDF-1α/CXCR4 axis in radiation-induced acute injury and fibrosis of skin has not been reported. In this study, we found that the expression of SDF-1α and CXCR4 was significantly increased in irradiated skin tissues of humans, monkeys and rats, compared to their nonirradiated counterparts. Mice with keratinocyte-specific ablation of CXCR4 showed less severe skin damage than wild-type mice after receiving a 35 Gy dose of radiation. Consistently, subcutaneous injection of AMD3100, an FDA approved SDF-1α/CXCR4 inhibitor, attenuated skin injury and fibrosis induced by exposure to radiation in a rat model. Mechanically, the SDF-1α/CXCR4 axis promotes pro-fibrotic TGF-b/Smad signaling through the PI3K-MAPK signaling cascade in human keratinocyte HaCaT cells and skin fibroblast WS1 cells. AMD3100 inhibited Smad2 nuclear translocation and transcriptional activity of Smad2/3 induced by radiation, which suppressed the pro-fibrotic TGF-b/Smad signaling pathway activated by exposure. Taken together, these findings demonstrate the involvement of SDF-1α/CXCR4 axis in radiation-induced acute injury and fibrosis of skin, and indicate that AMD3100 would be an effective countermeasure against these diseases.


Assuntos
Quimiocina CXCL12/metabolismo , Lesões por Radiação/metabolismo , Receptores CXCR4/metabolismo , Pele/patologia , Pele/efeitos da radiação , Animais , Fibrose , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos da radiação , Técnicas de Inativação de Genes , Compostos Heterocíclicos/farmacologia , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Queratinócitos/efeitos da radiação , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Lesões por Radiação/patologia , Ratos , Receptores CXCR4/deficiência , Receptores CXCR4/genética , Pele/lesões , Pele/metabolismo , Proteína Smad2/metabolismo , Fator de Crescimento Transformador beta/metabolismo
4.
Technol Cancer Res Treat ; 18: 1533033819868225, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31401938

RESUMO

OBJECTIVE: Tumor-treating fields are currently used to successfully treat various cancers; however, the specific pathways associated with its efficacy remain unknown in the immune responses. Here, we evaluated tumor-treating fields-mediated initiation of the macrophage-specific immune response. MATERIALS AND METHODS: We subjected RAW 264.7 mouse macrophages to clinically relevant levels of tumor-treating fields (0.9 V/cm, 150 kHz) and evaluated alterations in cytokine expression and release, as well as cell viability. Additionally, we investigated the status of immunomodulatory pathways to determine their roles in tumor-treating fields-mediated immune activation. RESULTS AND DISCUSSION: Our results indicated that tumor-treating fields treatment at 0.9 V/cm decreased cell viability and increased cytokine messenger RNA/protein levels, as well as levels of nitric oxide and reactive oxygen species, relative to controls. The levels of tumor necrosis factor α, interleukin 1ß, and interleukin 6 were markedly increased in tumor-treating fields-treated RAW 264.7 cells cocultured with 4T1 murine mammary carcinoma cells compared with those in 4T1 or RAW 264.7 cells with or without tumor-treating fields treatment. Moreover, the viability of 4T1 cells treated with the conditioned medium of tumor-treating fields-stimulated RAW 264.7 cells decreased, indicating that macrophage activation by tumor-treating fields effectively killed the tumor cells. Moreover, tumor-treating fields treatment activated the nuclear factor κB and mitogen-activated protein kinase pathways involved in immunomodulatory signaling. CONCLUSION: These results provide critical insights into the mechanisms through which tumor-treating fields affect macrophage-specific immune responses and the efficacy of this method for cancer treatment.


Assuntos
Antígenos de Histocompatibilidade Classe II/imunologia , Ativação de Macrófagos/imunologia , Terapia de Campo Magnético , Neoplasias/radioterapia , Animais , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/efeitos da radiação , Humanos , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Ativação de Macrófagos/genética , Ativação de Macrófagos/efeitos da radiação , Macrófagos/imunologia , Macrófagos/efeitos da radiação , Camundongos , NF-kappa B/genética , Neoplasias/imunologia , Neoplasias/patologia , Células RAW 264.7 , Transdução de Sinais/imunologia , Transdução de Sinais/efeitos da radiação
5.
Lipids Health Dis ; 18(1): 135, 2019 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-31174532

RESUMO

BACKGROUND: Heat induced by infrared (IR) radiation from sun exposure increases skin temperature and can lead to thermal and photo-aging. However, little is known about the relationship between heat induced by IR radiation and lipid biosynthesis in human sebocytes. This study investigated the expression of factors involved in lipid biosynthesis in human sebocytes exposed to heat. The effect of Cassia tora extract and chrysophanol, which is widely used as anti-inflammatory agent, on the heat shock effect in sebocytes was then examined. METHODS: For the treatment, cells were maintained in culture medium without FBS (i.e., serum starved) for 6 h and then moved for 30 min to incubators at 37 °C (control), 41 °C, or 44 °C (heat shock). Culture media were replaced with fresh media without FBS. To investigate expression of gene and signaling pathway, we performed western blotting. Lipid levels were assessed by Nile red staining. The cytokine levels were measured by cytokine array and ELISA kit. RESULTS: We found that peroxisome proliferator-activated receptor (PPAR)γ and fatty acid synthase (FAS) were upregulated and the c-Jun N-terminal kinase (JNK)/p38 signaling pathways were activated in human sebocytes following heat exposure. Treatment with Cassia tora seed extract and chrysophanol suppressed this up-regulation of PPARγ and FAS and also suppressed the increase in IL-1ß levels. CONCLUSION: These findings provide evidence that IR radiation can stimulate sebum production; Cassia tora seed extract and chrysophanol can reverse lipid stimulated inflammatory mediation, and may therefore be useful for treating skin disorders such as acne vulgaris.


Assuntos
Antraquinonas/farmacologia , Cassia/química , Lipogênese/efeitos dos fármacos , Extratos Vegetais/farmacologia , Antraquinonas/química , Células Epiteliais/química , Ácido Graxo Sintases/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Temperatura Alta/efeitos adversos , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Lipogênese/genética , Lipogênese/efeitos da radiação , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos da radiação , PPAR gama/genética , Extratos Vegetais/química , Radiação , Transdução de Sinais/efeitos dos fármacos , Temperatura Cutânea/efeitos da radiação , Proteínas Quinases p38 Ativadas por Mitógeno/genética
6.
Biochem J ; 476(10): 1387-1400, 2019 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-31036716

RESUMO

Ultraviolet-B exposure causes an inflammatory response, photoaged skin, and degradation of extracellular matrix proteins including collagen and elastin. The regulation of these genes was suggested as an important mechanism to attenuate skin aging. Glycolic acid (GA) is commonly present in fruits and recently used to treat dermatological diseases. We reported that GA slows down cell inflammation and aging caused by UVB. Little is known about GA retarding the skin premature senescence or how to impede these events. To investigate the potential of GA to regulate the expression of MMPs and collagen, GA was topically applied onto human keratinocytes and the C57BL/6J mice dorsal skin. In the present study, we demonstrated that GA reduced UVB-induced type-I procollagen expression and secretory collagen levels. GA reverted and dose-dependently increased the level of aquaporin-3 (AQP3), the expression of which was down-regulated by UVB. The UV-induced MMP-9 level and activity were reduced by GA pre-treatment. Concomitantly, GA reverted mitogen-activated protein kinase (MMP-9) activation and inhibited the extracellular signal-regulated kinase activation (p38, pERK) triggered by UVB. The animal model also presented that GA attenuated the wrinkles caused by UVB on the mouse dorsal skin. Finally, GA triggers the transient receptor potential vanilloid-1 (TRPV-1) channel to initiate the anti-photoaging mechanism in keratinocytes. These findings clearly indicated that the mechanisms of GA promote skin protection against UVB-induced photoaging and wrinkle formation. GA might be an important reagent and more widely used to prevent UVB-induced skin aging.


Assuntos
Aquaporina 3/biossíntese , Colágeno/metabolismo , Regulação da Expressão Gênica , Glicolatos/farmacologia , Queratinócitos , Metaloproteinase 9 da Matriz/química , Envelhecimento da Pele , Pele , Raios Ultravioleta , Administração Tópica , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos da radiação , Queratinócitos/metabolismo , Queratinócitos/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Camundongos , Pele/metabolismo , Pele/patologia , Envelhecimento da Pele/efeitos dos fármacos , Envelhecimento da Pele/patologia , Envelhecimento da Pele/efeitos da radiação , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
7.
Int J Mol Sci ; 20(6)2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30934595

RESUMO

Horse oil products have been used in skin care for a long time in traditional medicine, but the biological effects of horse oil on the skin remain unclear. This study was conducted to evaluate the protective effect of horse oil on ultraviolet B (UVB)-induced oxidative stress in human HaCaT keratinocytes. Horse oil significantly reduced UVB-induced intracellular reactive oxygen species and intracellular oxidative damage to lipids, proteins, and DNA. Horse oil absorbed light in the UVB range of the electromagnetic spectrum and suppressed the generation of cyclobutane pyrimidine dimers, a photoproduct of UVB irradiation. Western blotting showed that horse oil increased the UVB-induced Bcl-2/Bax ratio, inhibited mitochondria-mediated apoptosis and matrix metalloproteinase expression, and altered mitogen-activated protein kinase signaling-related proteins. These effects were conferred by increased phosphorylation of extracellular signal-regulated kinase 1/2 and decreased phosphorylation of p38 and c-Jun N-terminal kinase 1/2. Additionally, horse oil reduced UVB-induced binding of activator protein 1 to the matrix metalloproteinase-1 promoter site. These results indicate that horse oil protects human HaCaT keratinocytes from UVB-induced oxidative stress by absorbing UVB radiation and removing reactive oxygen species, thereby protecting cells from structural damage and preventing cell death and aging. In conclusion, horse oil is a potential skin protectant against skin damage involving oxidative stress.


Assuntos
Queratinócitos/patologia , Queratinócitos/efeitos da radiação , Óleos/farmacologia , Estresse Oxidativo/efeitos da radiação , Raios Ultravioleta , Absorção de Radiação , Animais , Apoptose/efeitos da radiação , Linhagem Celular , Ativação Enzimática/efeitos da radiação , Cavalos , Humanos , Queratinócitos/enzimologia , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Metaloproteinases da Matriz/metabolismo , Espécies Reativas de Oxigênio/metabolismo
8.
J Photochem Photobiol B ; 194: 46-55, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30925276

RESUMO

Human papillomavirus (HPV) infection is linked to several diseases, the most prominent of which are cervical cancer and genital condyloma acuminatum. Previous studies have suggested an effective role for 5-aminolevulinic acid photodynamic therapy (ALA-PDT) against various cancers by the induction of autophagy and apoptosis. However, few reports have focused on the effectiveness of ALA-PDT on HPV related disorders. To identify the role of ALA-PDT in the context of HPV infection, we initially investigated 111 patients suffering from genital condyloma acuminatum. HPV viral load detected before and after ALA-PDT treatment was compared during this procedure; a significant difference was noted. HeLa (HPV18) cells were exposed to ALA-PDT in vitro to further explore the underlying mechanisms. Western blot analysis showed that ALA-PDT induces LC3II and p62 expression, along with the up regulation of caspase-3 and cleaved caspase-3. Our study also demonstrated that ALA-PDT treatment inhibits the proliferation of HeLa cells in a dose dependent manner and effectively reduces HPV viral load via autophagy and apoptosis by regulating the Ras/Raf/MEK/ERK and PI3K/AKT/mTOR pathways. Hydroxychloroquine (HCQ), although it inhibited autophagy degradation, functioned to activate reactive oxygen species (ROS) levels of ALA-PDT to enhance the observed effect. These findings suggest strategies for the improvement of PDT efficacy in patients.


Assuntos
Morte Celular/efeitos dos fármacos , Morte Celular/efeitos da radiação , Ácidos Levulínicos/farmacologia , Papillomaviridae/fisiologia , Fotoquimioterapia , Carga Viral/efeitos dos fármacos , Carga Viral/efeitos da radiação , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Autofagia/efeitos dos fármacos , Autofagia/efeitos da radiação , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Relação Dose-Resposta a Droga , Relação Dose-Resposta à Radiação , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Células HeLa , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Papillomaviridae/efeitos dos fármacos , Papillomaviridae/efeitos da radiação , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Quinases raf/metabolismo , Proteínas ras/metabolismo
9.
Photodermatol Photoimmunol Photomed ; 35(4): 221-231, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30739336

RESUMO

BACKGROUND: People living in Mediterranean countries are mostly exposed to solar ultraviolet (UV) radiation that damages skin and results in photoaging which involves activation of epidermal growth factor receptor (EGFR) and downstream signal transduction through mitogen-activated protein kinases (MAPKs) in fibroblasts. Generation of reactive oxygen/nitrogen species by UV radiation is also critical for EGFR and MAPKs activation. MAPKs are responsible for activation of AP-1 subunits in the nucleus which induce matrix metalloproteinases. Melatonin, along with its metabolites, are known to be the most effective free radical scavenger and protective agent due to its ability to react with various radicals, lipophilic/hydrophilic structures. OBJECTIVES: In this study, we investigated the effects of melatonin on UVA-irradiated primary human dermal fibroblasts (HDFs) by following the alteration of molecules from cell membrane to the nucleus and oxidative/nitrosative damage status of the cells in a time-dependent manner which have not been clearly elucidated yet. METHODS: To mimic UVA dosage in Mediterranean countries, HDFs were exposed to UVA with sub-cytotoxic dosage (20 J/cm2 ) after pretreatment with melatonin (1 µmol/L) for 1 hour. Changes in the activation of the molecules and oxidative/nitrosative stress damage were analyzed at different time points. RESULTS: Our results clearly show that melatonin decreases UVA-induced oxidative/nitrosative stress damage in HDFs. It also suppresses phosphorylation of EGFR, activation of MAPK/AP-1 signal transduction pathway and production of matrix metalloproteinases in a time-dependent manner. CONCLUSION: Melatonin can be used as a protective agent for skin damage against intracellular detrimental effects of relatively high dosage of UVA irradiation.


Assuntos
Derme/metabolismo , Fibroblastos/metabolismo , Melatonina/farmacologia , Fator de Transcrição AP-1/metabolismo , Raios Ultravioleta/efeitos adversos , Adulto , Células Cultivadas , Derme/patologia , Feminino , Fibroblastos/patologia , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Masculino , Oxirredução/efeitos dos fármacos , Oxirredução/efeitos da radiação , Protetores Solares/farmacologia
10.
Nat Commun ; 10(1): 542, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30710088

RESUMO

The suprachiasmatic nucleus (SCN) co-ordinates circadian behaviour and physiology in mammals. Its cell-autonomous circadian oscillations pivot around a well characterised transcriptional/translational feedback loop (TTFL), whilst the SCN circuit as a whole is synchronised to solar time by its retinorecipient cells that express and release vasoactive intestinal peptide (VIP). The cell-autonomous and circuit-level mechanisms whereby VIP synchronises the SCN are poorly understood. We show that SCN slices in organotypic culture demonstrate rapid and sustained circuit-level circadian responses to VIP that are mediated at a cell-autonomous level. This is accompanied by changes across a broad transcriptional network and by significant VIP-directed plasticity in the internal phasing of the cell-autonomous TTFL. Signalling via ERK1/2 and tuning by its negative regulator DUSP4 are critical elements of the VIP-directed circadian re-programming. In summary, we provide detailed mechanistic insight into VIP signal transduction in the SCN at the level of genes, cells and neural circuit.


Assuntos
Relógios Circadianos/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas Tirosina Fosfatases/metabolismo , Núcleo Supraquiasmático/fisiologia , Peptídeo Intestinal Vasoativo/farmacologia , Animais , Sistemas CRISPR-Cas , Relógios Circadianos/genética , Relógios Circadianos/efeitos da radiação , AMP Cíclico/metabolismo , Retroalimentação Fisiológica/efeitos dos fármacos , Retroalimentação Fisiológica/efeitos da radiação , Redes Reguladoras de Genes/efeitos dos fármacos , Redes Reguladoras de Genes/efeitos da radiação , Luz , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Camundongos Knockout , Biossíntese de Proteínas/efeitos dos fármacos , Biossíntese de Proteínas/efeitos da radiação , Elementos de Resposta/genética , Núcleo Supraquiasmático/citologia , Núcleo Supraquiasmático/efeitos dos fármacos , Núcleo Supraquiasmático/efeitos da radiação , Transcrição Genética/efeitos dos fármacos , Transcrição Genética/efeitos da radiação
11.
Oxid Med Cell Longev ; 2019: 2419096, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30800206

RESUMO

Chronic UVB exposure promotes oxidative stress, directly causes molecular damage, and induces aging-related signal transduction, leading to skin photoaging. Dihydrocaffeic acid (DHCA) is a phenolic compound with potential antioxidant capacity and is thus a promising compound for the prevention of UVB-induced skin photodamage. The aim of this study was to evaluate the antioxidant and protective effect of DHCA against oxidative stress, apoptosis, and matrix metalloproteinase (MMP) expression via the mitogen-activated protein kinase (MAPK) signaling pathway on L929 fibroblasts irradiated with UVB. DHCA exhibited high antioxidant capacity on 2,2-diphenyl-1-picrylhydrazyl (DPPH•), 2,2-azinobis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS•+), and xanthine/luminol/xanthine oxidase (XOD) assays and reduced UVB-induced cell death in the neutral red assay. DHCA also modulated oxidative stress by decreasing intracellular reactive oxygen species (ROS) and extracellular hydrogen peroxide (H2O2) production, enhancing catalase (CAT) and superoxide dismutase (SOD) activities and reduced glutathione (GSH) levels. Hence, cellular damage was attenuated by DHCA, including lipid peroxidation, apoptosis/necrosis and its markers (loss of mitochondria membrane potential, DNA condensation, and cleaved caspase 9 expression), and MMP-1 expression. Furthermore, DHCA reduced the phosphorylation of MAPK p38. These findings suggest that DHCA can be used in the development of skin care products to prevent UVB-induced skin damage.


Assuntos
Apoptose/efeitos dos fármacos , Ácidos Cafeicos/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Metaloproteinase 1 da Matriz/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Raios Ultravioleta , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Antioxidantes/farmacologia , Apoptose/efeitos da radiação , Ácidos Cafeicos/química , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Citoproteção/efeitos dos fármacos , Citoproteção/efeitos da radiação , Peroxidação de Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos da radiação , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos da radiação , Camundongos , Estresse Oxidativo/efeitos da radiação , Fosforilação/efeitos dos fármacos , Fosforilação/efeitos da radiação , Espécies Reativas de Oxigênio/metabolismo
12.
Lasers Med Sci ; 34(5): 963-971, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30448939

RESUMO

The 1064-nm Q-switched neodymium-doped yttrium aluminum garnet (Nd:YAG) laser is widely used in clinical practice. However, the effects of 1064-nm Q-switched Nd:YAG laser on skin collagen generation have not been fully elucidated. The objectives of the present study were to investigate whether the 1064-nm Q-switched Nd:YAG laser can be used for non-ablative rejuvenation and to explore the possible mechanism underlying the effects. Six-week-old SKH-1 hairless mice were irradiated by the 1064-nm Nd:YAG laser at fluences of 0, 0.5, 1, 1.5, and 2 J/cm2, respectively. The contents of hydroxyproline and hydration were detected after laser irradiation. Moreover, hematoxylin-eosin (HE) staining was preformed to evaluate the dermal thickness. Immunofluorescence was used to detect the expressions of MMP-2 and TIMP-1 in the skin after laser irradiation. Furthermore, qRT-PCR was performed to determine the expressions of TGF-ß1 and Smad3. In addition, the expressions of ERK1/2, p-ERK1/2, p38, p-p38, JNK, ERK5, and collagen were evaluated by Western blotting. The results indicated that the levels of hydroxyproline, hydration, and collagen were markedly increased; both the thickness of dermal was enhanced after low dose of laser treatment. Moreover, the expression of TIMP-1 was significantly increased, whereas the expression of MMP-2 was remarkably decreased after laser irradiation. Meanwhile, TGF-ß1, Smad3, p-ERK1/2, p-P38, and JNK productions were significantly enhanced in irradiated group compared with the ones non-irradiated. Nevertheless, no significant changes were observed in the expression of ERK5 after irradiation. In summary, our study demonstrated that Q-switched 1064-nm Nd:YAG laser can induce collagen generation, at least in part, through activating TGF-ß1/Smad3/MAPK signaling pathway.


Assuntos
Colágeno/biossíntese , Lasers de Estado Sólido/uso terapêutico , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Pele/enzimologia , Pele/efeitos da radiação , Animais , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Camundongos Pelados , Pele/patologia , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Cicatrização/efeitos da radiação
13.
Braz J Med Biol Res ; 51(12): e7862, 2018 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-30365726

RESUMO

Although the effects of low-intensity pulsed ultrasound (LIPUS) on diverse cell types have been fully studied, the functional role of LIPUS in keratinocytes remains poorly understood. This study aimed to investigate the effects of LIPUS on proliferation and migration of HaCaT cells as well as the regulatory mechanisms associated with signaling pathways. Human HaCaT cells were exposed or not to LIPUS, and cell proliferation and migration were measured by BrdU incorporation assay and Transwell assay, respectively. Expression of proteins associated with proliferation and migration was evaluated by western blot analysis. Expression of key kinases in the PI3K/AKT and JNK pathways was also evaluated by western blot analysis. Effects of LIPUS on the PI3K/AKT and JNK pathways, and whether LIPUS affected HaCaT cells via these two pathways were finally explored. When the parameter of LIPUS (number of cycles) was set at 300, cell viability was the highest after LIPUS stimulation. We then found that the percentage of BrdU positive cells was enhanced by LIPUS, along with up-regulation of cyclinD1, CDK6, CDK4, and VEGF. LIPUS promoted migration, as well as up-regulation of MMP-2 and MMP-9. Phosphorylation levels of key kinases in the PI3K/AKT and JNK pathways were increased by LIPUS. Inhibition of either PI3K/AKT pathway or JNK pathway attenuated effects of LIPUS on HaCaT cells, and co-inhibition of these two pathways showed augmented effects. LIPUS promoted proliferation and migration of HaCaT cells through activating the PI3K/AKT and JNK pathways.


Assuntos
Movimento Celular/efeitos da radiação , Proliferação de Células/efeitos da radiação , Queratinócitos/efeitos da radiação , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Fosfatidilinositol 3-Quinases/efeitos da radiação , Proteínas Proto-Oncogênicas c-akt/efeitos da radiação , Ondas Ultrassônicas , Análise de Variância , Western Blotting , Bromodesoxiuridina , Linhagem Celular Transformada , Sobrevivência Celular/efeitos da radiação , Humanos , Queratinócitos/metabolismo , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Reprodutibilidade dos Testes , Transdução de Sinais/efeitos da radiação , Regulação para Cima
14.
PLoS One ; 13(10): e0205666, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30359388

RESUMO

BACKGROUND: Activation of Ras oncogene in human tumors is associated with radiation-associated metastatic potential. Although ionizing radiation is one important method of cancer treatments, it has been shown to enhance matrix metalloproteinases (MMPs) activity and facilitates a more aggressive cancer phenotype. Our previous studies showed that andrographolide with lower dose rates of radiation could inhibit RAS-transformed cancer metastasis in vivo; however, the molecular mechanisms are not yet clear. In this study, we aimed to explore the anti-metastatic effect of andrographolide combined with radiation on Ras-transformed cells. METHODS: RAS-transformed cells were treated with andrographolide in the presence or absence of irradiation (2-4 Gy) or angiotensin II to examine cell invasion. In vivo tumorigenesis assays were also performed. The MMP-2 activity was detected by using Gelatin zymography. Signal transduction of NF-κB subunit, p65 and phosphor-ERK 1/2, were examined by using Western blotting analysis. RESULTS: Treatment with andrographolide inhibited migration of Ras-transformed cells. Andrographolide treatment with radiation significantly inhibited cancer metastasis in vivo. We found that andrographolide exhibited anti-migration and anti-invasive ability against cancer metastasis via inhibition of MMP2 activity rather than affected MMP-9 and EMT. In addition, combined andrographolide with radiation appeared to be more effective in reducing MMP-2 expression, and this effect was accompanied by suppression of ERK activation that inhibits cancer cell migration and invasion. CONCLUSIONS: These findings suggest that andrographolide enhances the anti-metastatic effect of radiation in Ras-transformed cells via suppression of ERK-mediated MMP-2 activity.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Diterpenos/farmacologia , Metaloproteinase 2 da Matriz/metabolismo , Neoplasias/terapia , Animais , Antineoplásicos Fitogênicos/uso terapêutico , Linhagem Celular Transformada/transplante , Movimento Celular/efeitos dos fármacos , Movimento Celular/efeitos da radiação , Transformação Celular Viral , Quimiorradioterapia/métodos , Modelos Animais de Doenças , Diterpenos/uso terapêutico , Ensaios de Seleção de Medicamentos Antitumorais , Transição Epitelial-Mesenquimal , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Masculino , Metaloproteinase 9 da Matriz/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica/prevenção & controle , Neoplasias/patologia , Proteína Oncogênica p21(ras)/genética , Proteína Oncogênica p21(ras)/metabolismo , Ratos , Retroviridae/genética , Retroviridae/metabolismo
15.
J Environ Pathol Toxicol Oncol ; 37(3): 261-272, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30317975

RESUMO

Ultraviolet B radiation (UVB) activates mitogen-activated protein kinases (MAPK): p38, extracellular signal regulated (ERK), and c-Jun N-terminal (JNK) kinases in human skin cells. Human keratinocytes (KC) exposed to UVB secrete several cytokines (CK), among which the growth differentiation factor-15 (GDF-15) is augmented in inflammatory and aging processes and the granulocyte macrophage-colony stimulating factor (GM-CSF) is involved in cell proliferation, differentiation, and survival, and both CK have implications in skin carcinogenesis. We assessed p38, ERK, JNK, GDF-15, and GM-CSF in UVB-exposed skin cells and a red grape (Vitis vinifera) seed extract's (GSE) capacities to regulate these pathways in UVB-exposed KC. Two concentrations of the GSE extract were selected: GSE1 (37.5 µgEqGA/mL) and GSE2 (75 µgEqGA/mL) and a UVB dose (100 mJ/cm2) within the physiological range. Molecules were assessed with ELISA, semiquantitative results being confirmed by Western blot. UVB triggered the signaling molecules' phosphorylation and the concentrations of CK. All molecules but GM-CSF increased early, at 2 h, from UVB exposure while GM-CSF increased later (at 8 h). MAPK and GDF-15 were regulated by GSE1; GM-CSF, by the higher concentration, GSE2. The amplitude and kinetics of the responses were diverse according to time point, molecules, and the extract's concentration. GSE exerted beneficial effects on MAPK and CK triggered by UVB in human skin cells: reduction of phosphorylation of the assessed signaling molecules and anti-inflammatory effects. Targeting MAPK and specific inflammatory mediators such as GDF-15 and GM-CSF with GSE in UVB-induced skin cells represents a novel and a promising starting point for future photoprotection strategies.


Assuntos
Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Fator 15 de Diferenciação de Crescimento/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Extratos Vegetais/farmacologia , Pele/efeitos dos fármacos , Pele/metabolismo , Vitis/química , Linhagem Celular Transformada , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos da radiação , MAP Quinase Quinase 4/metabolismo , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Fosforilação/efeitos dos fármacos , Fosforilação/efeitos da radiação , Sementes/química , Pele/citologia , Pele/efeitos da radiação , Raios Ultravioleta , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
16.
Cancer Med ; 7(10): 5187-5193, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30239172

RESUMO

Laryngeal cancer is a common cancer occurred in the head and neck. Irradiation sensitivity is a problem affecting the treatment of laryngeal cancer. Tanshinone IIA has been reported to play an important role in treating multiple diseases; yet, whether Tanshinone IIA can be an irradiation sensitizer has not been reported. Clonogenic assay, annexin-V/propidium iodide double-staining assay, and Cell Counting Kit-8 assay were performed to detect cell survival, proliferation, apoptosis, and viability. Mouse laryngeal cancer xenograft model was established and subjected to tumor size analysis. Tanshinone IIA treatment increased the irradiation sensitivity of laryngeal cancer cells by reducing cell survival, viability and proliferation, and increasing cell apoptosis. Tanshinone IIA treatment increased the survival period of mice in the in vivo laryngeal cancer model, evidenced by decreased growth and weight of tumors, which was possibly mediated through the JNK pathway. Tanshinone IIA increases the sensitivity to irradiation in laryngeal cancer cells and in vivo laryngeal cancer model, suggesting that Tanshinone IIA can be a therapeutic antitumor agent for treating laryngeal cancer.


Assuntos
/administração & dosagem , Antineoplásicos Fitogênicos/administração & dosagem , Neoplasias Laríngeas/terapia , Radiossensibilizantes/administração & dosagem , /farmacologia , Animais , Antineoplásicos Fitogênicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Células Hep G2 , Humanos , Neoplasias Laríngeas/metabolismo , Neoplasias Laríngeas/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Camundongos , Radiossensibilizantes/farmacologia , Carga Tumoral/efeitos dos fármacos , Carga Tumoral/efeitos da radiação , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Cell Rep ; 24(10): 2658-2668, 2018 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-30184500

RESUMO

The stress-activated protein kinases c-Jun N-terminal kinase (JNK) and p38 are important players in cell-fate decisions in response to environmental stress signals. Crosstalk signaling between JNK and p38 is emerging as an important regulatory mechanism in inflammatory and stress responses. However, it is unknown how this crosstalk affects signaling dynamics, cell-to-cell variation, and cellular responses at the single-cell level. We established a multiplexed live-cell imaging system based on kinase translocation reporters to simultaneously monitor JNK and p38 activities with high specificity and sensitivity at single-cell resolution. Various stresses activated JNK and p38 with various dynamics. In all cases, p38 suppressed JNK activity in a cross-inhibitory manner. We demonstrate that p38 antagonizes JNK through both transcriptional and post-translational mechanisms. This cross-inhibition generates cellular heterogeneity in JNK activity after stress exposure. Our data indicate that this heterogeneity in JNK activity plays a role in fractional killing in response to UV stress.


Assuntos
Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Apoptose/efeitos da radiação , Morte Celular/fisiologia , Morte Celular/efeitos da radiação , Fosfatase 1 de Especificidade Dupla/genética , Fosfatase 1 de Especificidade Dupla/metabolismo , Humanos , Proteínas Quinases JNK Ativadas por Mitógeno/genética , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Proteínas Quinases Ativadas por Mitógeno/genética , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Imagem Óptica , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Raios Ultravioleta , Proteínas Quinases p38 Ativadas por Mitógeno/genética
18.
Int J Oncol ; 53(4): 1691-1702, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30066913

RESUMO

MicroRNAs (miRNAs or miRs) play important roles in numerous cellular processes, including development, proliferation, tumorigenesis and apoptosis. It has been reported that miRNA expression is induced by ionizing radiation (IR) in cancer cells. However, the underlying molecular mechanisms are not yet fully understood. In this study, endogenous miR­320a and its primary precursor (pri­miR­320a) were assayed by reverse transcription­quantitative PCR (RT­qPCR). Luciferase activities were measured using a dual­luciferase reporter assay system. Western blot analysis was used to determine the protein expressions of upstream and downstream genes of miR­320a. Cell apoptosis was evaluated by Annexin V apoptosis assay and cell proliferation was measured using the trypan blue exclusion method. The results revealed that miR­320a expression increased linearly with the IR dose and treatment duration. Three transcription factors, activating transcription factor 2 (ATF2), ETS transcription factor (ELK1) and YY1 transcription factor (YY1), were activated by p38 mitogen­activated protein kinase (MAPK) and mitogen­activated protein kinase 8 (JNK) and by upregulated miR­320a expression under IR conditions. In addition, it was identified that X­linked inhibitor of apoptosis (XIAP) was an miR­320a target gene during the IR response. By targeting XIAP, miR­320a induced apoptosis and inhibited the proliferation of the cancer cells. On the whole, the results of this study demonstrated that miRNA­320a, regulated by the p38 MAPK/JNK pathway, enhanced the radiosensitivity of cancer cells by inhibiting XIAP and this may thus prove to be a potential therapeutic approach with which to overcome radioresistance in cancer treatment.


Assuntos
Apoptose/efeitos da radiação , Sistema de Sinalização das MAP Quinases/efeitos da radiação , MicroRNAs/genética , Neoplasias/radioterapia , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/genética , Fator 2 Ativador da Transcrição/genética , Fator 2 Ativador da Transcrição/metabolismo , Apoptose/genética , Linhagem Celular Tumoral , Proliferação de Células/genética , Proliferação de Células/efeitos da radiação , Relação Dose-Resposta à Radiação , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Humanos , Sistema de Sinalização das MAP Quinases/genética , MicroRNAs/metabolismo , Neoplasias/genética , Regiões Promotoras Genéticas , RNA Interferente Pequeno/metabolismo , Tolerância a Radiação/genética , Radiação Ionizante , Resultado do Tratamento , Regulação para Cima/efeitos da radiação , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , Fator de Transcrição YY1/genética , Fator de Transcrição YY1/metabolismo , Proteínas Elk-1 do Domínio ets/genética , Proteínas Elk-1 do Domínio ets/metabolismo
19.
PLoS One ; 13(8): e0202323, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30118525

RESUMO

Exposure to ultraviolet (UV) radiation is a major contributing factor to premature aging (photoaging) and skin cancer. In vitro models of cellular senescence have proven to be very useful for the study of slow and progressive accumulation of damage resulting in the growth arrest of aging skin cells. In this study, we compared UVA-induced cellular responses in non-senescent (NS) vs. senescent (S) human dermal fibroblasts (HDFs). HDFs were irradiated with a single dose of UVA (7.5 J/cm2) and QuantSeq 3' mRNA sequencing was performed to assess differential gene expression. Both NS and S HDFs expressed similar numbers of differentially expressed genes, although distinct sets of genes were differentially expressed between the two groups. Higher expression of matrix metalloproteinases (MMPs) and Toll-like receptor (TLR) pathway genes, such as TLR4, MyD88, and CXCL-8, was detected in S HDFs as compared with NS HDFs, and UVA exposure led to a downregulation of collagen genes, such as COL8A2 and COL5A3. Consistent with gene expression profiling, enhanced IL-6 and IL-8 secretion was observed in S HDFs compared with NS HDFs, in response to UVA. Furthermore, we show that TLR4-mediated ERK pathway is responsible for the UVA-mediated mitochondrial dysfunction as well as increased secretion of MMP-1 and IL-8 in S HDFs. Taken together, our results demonstrate the UVA-induced common and distinct molecular patterns of cellular responses between NS and S HDFs and suggest TLR4/ERK pathways as candidate targets to reduce senescent phenotypes.


Assuntos
Senescência Celular/efeitos da radiação , Derme/efeitos da radiação , Fibroblastos/efeitos da radiação , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Receptor 4 Toll-Like/metabolismo , Raios Ultravioleta/efeitos adversos , Células Cultivadas , Senescência Celular/fisiologia , Citocinas/metabolismo , Derme/metabolismo , Fibroblastos/metabolismo , Regulação da Expressão Gênica/efeitos da radiação , Humanos , Sistema de Sinalização das MAP Quinases/fisiologia , Metaloproteinases da Matriz/metabolismo , Envelhecimento da Pele/fisiologia , Envelhecimento da Pele/efeitos da radiação , Transcriptoma
20.
Cell Death Dis ; 9(7): 730, 2018 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-29955047

RESUMO

UVB exposure can contribute to the development of skin cancer by modulating protein tyrosine kinase (PTK) signaling. It has been suggested that UVB radiation increases the ligand-dependent activation of PTKs and induces PTP inactivation. Our recent studies have shown that T-cell protein tyrosine phosphatase (TC-PTP) attenuates skin carcinogenesis induced by chemical regimens, which indicates its critical role in the prevention of skin cancer. In the current work, we report that TC-PTP increases keratinocyte susceptibility to UVB-induced apoptosis via the downregulation of Flk-1/JNK signaling. We showed that loss of TC-PTP led to resistance to UVB-induced apoptosis in vivo epidermis. We established immortalized primary keratinocytes (IPKs) from epidermal-specific TC-PTP-deficient (K14Cre.Ptpn2fl/fl) mice. Immortalized TC-PTP-deficient keratinocytes (TC-PTP/KO IPKs) showed increased cell survival against UVB-induced apoptosis which was concomitant with a UVB-mediated increase in Flk-1 phosphorylation, especially on tyrosine residue 1173. Inhibition of Flk-1 by either its specific inhibitors or siRNA in TC-PTP/KO IPKs reversed this effect and significantly increased cell death after UVB irradiation in comparison with untreated TC-PTP/KO IPKs. Immunoprecipitation analysis using the TC-PTP substrate-trapping mutant TCPTP-D182A indicated that TC-PTP directly interacts with Flk-1 to dephosphorylate it and their interaction was stimulated by UVB. Following UVB-mediated Flk-1 activation, the level of JNK phosphorylation was also significantly increased in TC-PTP/KO IPKs compared to control IPKs. Similar to our results with Flk-1, treatment of TC-PTP/KO IPKs with the JNK inhibitor SP600125 significantly increased apoptosis after UVB irradiation, confirming that the effect of TC-PTP on UVB-mediated apoptosis is regulated by Flk-1/JNK signaling. Western blot analysis showed that both phosphorylated Flk-1 and phosphorylated JNK were significantly increased in the epidermis of TC-PTP-deficient mice compared to control mice following UVB. Our results suggest that TC-PTP plays a protective role against UVB-induced keratinocyte cell damage by promoting apoptosis via negative regulation of Flk-1/JNK survival signaling.


Assuntos
Células Epidérmicas/efeitos da radiação , Epiderme/metabolismo , Deleção de Genes , Sistema de Sinalização das MAP Quinases , Proteína Tirosina Fosfatase não Receptora Tipo 2/genética , Raios Ultravioleta , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Apoptose/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Células Cultivadas , Queratinócitos/metabolismo , Queratinócitos/efeitos da radiação , Sistema de Sinalização das MAP Quinases/efeitos da radiação , Camundongos , Camundongos Knockout , Especificidade de Órgãos , Fosforilação , Proteína Tirosina Fosfatase não Receptora Tipo 2/metabolismo , Tirosina/metabolismo
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