RESUMO
Lung cancer is often diagnosed at an advanced stage and has a poor prognosis. Conventional treatments are not effective for metastatic lung cancer therapy. Although some of molecular targets have been identified with favorable response, those targets cannot be exploited due to the lack of suitable drug carriers. Lung cancer cell-derived exosomes (LCCDEs) receive recent interest in its role in carcinogenesis, diagnosis, therapy, and prognosis of lung cancer due to its biological functions and natural ability to carry donor cell biomolecules. LCCDEs can promote cell proliferation and metastasis, affect angiogenesis, modulate antitumor immune responses during lung cancer carcinogenesis, regulate drug resistance in lung cancer therapy, and be now considered an important component in liquid biopsy assessments for detecting lung cancer. Therapeutic deliverable exosomes are emerging as promising drug delivery agents specifically to tumor high precision medicine because of their natural intercellular communication role, excellent biocompatibility, low immunogenicity, low toxicity, long blood circulation ability, biodegradable characteristics, and their ability to cross various biological barriers. Several studies are currently underway to develop novel diagnostic and prognostic modalities using LCCDEs, and to develop methods of exploiting exosomes for use as efficient drug delivery vehicles. Current status of lung cancer and extensive applicability of LCCDEs are illustrated in this review. The promising data and technologies indicate that the approach on LCCDEs implies the potential application of LCCDEs to clinical management of lung cancer patients.
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Transformação Celular Neoplásica/metabolismo , Suscetibilidade a Doenças , Exossomos/metabolismo , Neoplasias Pulmonares/etiologia , Neoplasias Pulmonares/metabolismo , Animais , Biomarcadores Tumorais , Gerenciamento Clínico , Progressão da Doença , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Técnicas de Diagnóstico Molecular , Metástase Neoplásica , PrognósticoRESUMO
BACKGROUND: Translationally controlled tumor protein (TCTP) is linked to lung cancer. However, upon lung cancer carcinogens stimulation, there were no reports on the relationship between TCTP and lung cell carcinogenic epithelial-mesenchymal transition (EMT). This study was designed to investigate the molecular mechanism of regulation of TCTP expression and its role in lung carcinogens-induced EMT. METHODS: To study the role of TCTP in lung carcinogens [particulate matter 2.5 (PM2.5) or 4-methylnitrosamino-l-3-pyridyl-butanone (NNK)]-induced EMT, PM2.5/NNK-treated lung epithelial and non-small cell lung cancer (NSCLC) cells were tested. Cell derived xenografts, human lung cancer samples and online survival analysis were used to confirm the results. MassArray assay, Real-time PCR and Reporter assays were performed to elucidate the mechanism of regulation of TCTP expression. All statistical analyses were performed using GraphPad Prism version 6.0 or SPSS version 20.0. RESULTS: Translationally controlled tumor protein and vimentin expression were up-regulated in PM2.5/NNK-treated lung cells and orthotopic implantation tumors. TCTP expression was positively correlated with vimentin in human NSCLC samples. Patients with high expression of TCTP displayed reduced overall and disease-free survival. TCTP overexpression could increase vimentin expression and promote cell metastasis. Furthermore, PM2.5/NNK stimulation brought a synergistic effect on EMT in TCTP-transfected cells. TCTP knockdown blocked PM2.5/NNK carcinogenic effect. Mechanically, PM2.5/NNK-induced TCTP expression was regulated by one microRNA, namely miR-125a-3p, but not by methylation on TCTP gene promoter. The level of TCTP was regulated by its specific microRNA during the process of PM2.5/NNK stimulation, which in turn enhanced vimentin expression and played a permissive role in carcinogenic EMT. CONCLUSIONS: Our results provided new insights into the mechanisms of TCTP regulatory expression in lung carcinogens-induced EMT. TCTP and miR-125a-3p might act as potential prognostic biomarkers and therapeutic targets for NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular Tumoral , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Humanos , Pulmão , Neoplasias Pulmonares/genética , Material Particulado/toxicidade , Proteína Tumoral 1 Controlada por TraduçãoRESUMO
BACKGROUND: The role of cancer cell FOXP3 in tumorigenesis is conflicting. We aimed to study FOXP3 expression and regulation, function and clinical implication in human non-small cell lung cancer (NSCLC). METHODS: One hundred and six patients with histologically-confirmed NSCLC who underwent surgery were recruited for the study. Tumor samples and NSCLC cell lines were used to examine FOXP3 and its related molecules. Various cell functions related to tumorigenesis were performed. In vivo mouse tumor xenograft was used to confirm the in vitro results. RESULTS: NSCLC patients with the high level of FOXP3 had a significant decrease in overall survival and recurrence-free survival. FOXP3 overexpression significantly induced cell proliferation, migration, and invasion, whereas its inhibition impaired its oncogenic function. In vivo studies confirmed that FOXP3 promoted tumor growth and metastasis. The ectopic expression of FOXP3 induced epithelial-mesenchymal transition (EMT) with downregulation of E-cadherin and upregulation of N-cadherin, vimentin, snail, slug, and MMP9. The oncogenic effects by FOXP3 could be attributed to FOX3-mediated activation of Wnt/ß-catenin signaling, as FOXP3 increased luciferase activity of Topflash reporter and upregulated Wnt signaling target genes including c-Myc and Cyclin D1 in NSCLC cells. Co-immunoprecipitation results further indicated that FOXP3 could physically interacted with ß-catenin and TCF4 to enhance the functions of ß-catenin and TCF4, inducing transcription of Wnt target genes to promote cell proliferation, invasion and EMT induction. CONCLUSIONS: FOXP3 can act as a co-activator to facilitate the Wnt-b-catenin signaling pathway, inducing EMT and tumor growth and metastasis in NSCLC.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Transição Epitelial-Mesenquimal , Fatores de Transcrição Forkhead/metabolismo , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Via de Sinalização Wnt , Animais , Carcinogênese/patologia , Linhagem Celular Tumoral , Proliferação de Células , Células HEK293 , Humanos , Camundongos Nus , Metástase Neoplásica , PrognósticoRESUMO
Obesity/overweight and lipid metabolism disorders have become increased risk factors for lung cancer. Fatty acid translocase CD36 promotes cellular uptake of fatty acids. Whether and how CD36 facilitates lung adenocarcinoma (LUAD) growth in high-fat environment is unknown. Here, we demonstrated that palmitic acid (PA) or high-fat diet (HFD) promoted LUAD cell proliferation and metastasis in a CD36-dependent manner. Mechanistically, CD36 translocated from cytoplasm to cell membrane and interacted with Src kinase upon PA stimulation in human LUAD cells. Akt and ERK, downstream of Src, were then activated to mediate LUAD cell proliferation and metastasis. Furthermore, PA treatment promoted CD36 sarcolemmal translocation, where it activated Rac1 and upregulated MMP-9 through Src-Akt/ERK pathway, resulting in redistribution of cortactin, N-WASP and Arp2/3, and finally led to occurrence of finger-like protrusions of actin on cell surface to enhance cell metastasis. Compared with normal-chew diet (NCD) mice, the HFD group exhibited higher level of blood free fatty acid (FFA) and cholesterol (TC), developed larger xenograft LUAD tumors and enhanced tumor cell metastatic potential, which were accompanied by obvious sarcolemmal actin remodeling and were blocked by simultaneous CD36 knockdown in LUAD cells. Consistently, xenografted and tail vein-injected scramble-RNA-A549 cells but not CD36-shRNA-A549 in HFD mice formed metastatic LUAD tumors on the lung. CD36 inhibitor SSO significantly inhibited LUAD cell metastasis to the lung. Collectively, CD36 initiates Src signaling to promote LUAD cell proliferation and actin remodeling-involved metastasis under high-fat environment. Our study provides the new insights that CD36 is a valid target for LUAD therapy.
Assuntos
Adenocarcinoma de Pulmão , Neoplasias Pulmonares , Animais , Humanos , Camundongos , Actinas , Adenocarcinoma de Pulmão/genética , Antígenos CD36/genética , Proliferação de Células , Neoplasias Pulmonares/genética , Proteínas Proto-Oncogênicas c-akt , Proteínas Proto-Oncogênicas pp60(c-src)/metabolismoRESUMO
Pancreatic ß-cell apoptosis is a key feature of diabetes and can be induced by chronic exposure to saturated fatty acids (FAs). However, the underlying mechanisms remain poorly understood. We presently evaluated the role of Mcl-1 and mTOR in mice fed with high-fat-diet (HFD) and ß-cells exposed to the overloaded palmitic acid (PA). Compared with normal-chow-diet (NCD)-fed mice, HFD group showed impaired glucose tolerance after two months. Along with the diabetes progression, pancreatic islets first became hypertrophic and then atrophic, the ratio of ß-cell:α-cell increased in the islets of four months HFD-fed mice while decreased after six months. This process was accompanied by significantly increased ß-cell apoptosis and AMPK activity, and decreased Mcl-1 expression and mTOR activity. Consistently, glucose-induced insulin secretion dropped. In terms of mechanism, PA with lipotoxic dose could activate AMPK, which in turn inhibited ERK-stimulated Mcl-1Thr163 phosphorylation. Meanwhile, AMPK blocked Akt activity to release Akt inhibition on GSK3ß, followed by GSK3ß-initiated Mcl-1Ser159 phosphorylation. The context of Mcl-1 phosphorylation finally led to its degradation by ubiquitination. Also, AMPK inhibited the activity of mTORC1, resulting in a lower level of Mcl-1. Suppression of mTORC1 activity and Mcl-1 expression positively related to ß-cell failure. Alteration of Mcl-1 or mTOR expression rendered different tolerance of ß-cell to different dose of PA. In conclusion, lipid oversupply-induced dual modulation of mTORC1 and Mcl-1 finally led to ß-cell apoptosis and impaired insulin secretion. The study may help further understand the pathogenesis of ß-cell dysfunction in case of dyslipidemia, and provide promising therapeutic targets for diabetes.
Assuntos
Insulina , Proteínas Proto-Oncogênicas c-akt , Camundongos , Animais , Insulina/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Regulação para Baixo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Ácido Palmítico/farmacologia , ApoptoseRESUMO
Smoking carcinogen nicotine-derived nitrosamine ketone (NNK) is the most potent contributor to lung adenocarcinoma (LUAD) development, but the mechanism has not been fully elucidated. Here, we reported that fatty acid translocase CD36 was significantly overexpressed in both human LUAD tissues and NNK-induced A/J mice LUAD tumors. The overexpressed CD36 was positively correlated with Src kinase activation, smoking status, metastasis, and worse overall survival of patients with smoking history. Upon NNK binding with α7 nicotinic acetylcholine receptor (α7nAChR), sarcolemmal CD36 was increased and it interacted with surface α7nAChR and cytosol Src simultaneously, which in turn activated Src and downstream pro-carcinogenic kinase ERK1/2 and Akt, and finally caused LUAD cells to form subcutaneous and pulmonary metastatic tumors. This process could be blocked by CD36 knockdown and CD36 irreversible inhibitor SSO. Furthermore, the effect of NNK was inhibited obviously in CD36-/- A/J mice. Thus, targeting CD36 may provide a breakthrough therapy of LUAD.
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Gene therapy provides a promising approach to curing diabetes. However, an effective route for islet-specific targeting has yet to be established. Toward this end, the pancreatic blood circulation system in Balb/c mice was determined by the injection of rhodamine-containing beads. The efficiency of islet targeting was then measured by the injection of adenoviral vectors carrying a green fluorescence gene via the celiac trunk (C.T.). The results showed that >95% of islets and about 60% of ß cells within the pancreatic body and tail could be labeled 3 days after surgery. α-Cell labeling was not as efficient, whereas labeling of nonendocrine tissues was barely detectable. For proof of principle, adenoviral vectors carrying a Sirtuin transgene were injected similarly to test the islet protection effect in the streptozotocin (STZ)-induced type 1 diabetic model. The results demonstrated that overexpression of Sirtuin in STZ-treated mice reduced the level of ß-cell death and extent of glucose intolerance. This study reports on efficient islet-specific targeting by using adenoviral injection. This procedure could be invaluable to the treatment of diabetes and the study of islet biology.
Assuntos
Apoptose/efeitos dos fármacos , Diabetes Mellitus Experimental/terapia , Terapia Genética/métodos , Células Secretoras de Insulina/efeitos dos fármacos , Sirtuína 1/biossíntese , Estreptozocina/farmacologia , Adenoviridae/genética , Animais , Glicemia/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patologia , Vetores Genéticos/administração & dosagem , Vetores Genéticos/genética , Intolerância à Glucose/terapia , Proteínas de Fluorescência Verde/genética , Injeções Intra-Arteriais , Células Secretoras de Insulina/metabolismo , Células Secretoras de Insulina/patologia , Camundongos , Camundongos Endogâmicos BALB C , Terapia de Alvo Molecular/métodos , Pâncreas/irrigação sanguínea , Pâncreas/efeitos dos fármacos , Pâncreas/metabolismo , Rodaminas , Sirtuína 1/genética , TransgenesRESUMO
To investigate the characteristics and source apportionment of atmospheric volatile organic compounds (VOCs) in Dalian, the concentration level, composition characteristics, reaction activity, and source apportionment of atmospheric VOCs in Dalian were analyzed based on high-resolution online observation VOCs data from June to August 2020. The results showed that the average φ(VOCs) was (10.21±5.71)×10-9, in which alkanes accounted for 66.35%, alkenes for 11.89%, alkynes for 7.75%, and aromatics for 14.01%. VOCs and NOx were high at night and low during the day, whereas the change trend of O3 was opposite. Considering the species activity, it was determined that toluene, ethylene, m/p-xylene, 1-hexene, n-butane, isopentane, n-pentane, and isoprene were the key species affecting atmospheric VOCs in Dalian. Priority control of olefin and aromatic hydrocarbon emissions is the key to improve O3 pollution in summer in Dalian. By applying the positive matrix factorization (PMF) model, six major VOCs sources were extracted, namely traffic sources (26.38%), combustion sources (22.75%), industrial emission sources (17.09%), solvent usage sources (14.59%), natural sources (11.72%), and others (7.47%). The emissions of traffic sources and combustion sources are the key pollution sources for O3 prevention and control in Dalian in summer.
Assuntos
Poluentes Atmosféricos , Ozônio , Compostos Orgânicos Voláteis , Poluentes Atmosféricos/análise , China , Monitoramento Ambiental , Ozônio/análise , Estações do Ano , Emissões de Veículos/análise , Compostos Orgânicos Voláteis/análiseRESUMO
BACKGROUND: Human insulin-like growth factor-I (hIGF-I) is a growth factor which is highly resemble to insulin. It is essential for cell proliferation and has been proposed for treatment of various endocrine-associated diseases including growth hormone insensitivity syndrome and diabetes mellitus. In the present study, an efficient plant expression system was developed to produce biologically active recombinant hIGF-I (rhIGF-I) in transgenic rice grains. RESULTS: The plant-codon-optimized hIGF-I was introduced into rice via Agrobacterium-mediated transformation. To enhance the stability and yield of rhIGF-I, the endoplasmic reticulum-retention signal and glutelin signal peptide were used to deliver rhIGF-I to endoplasmic reticulum for stable accumulation. We found that only glutelin signal peptide could lead to successful expression of hIGF-I and one gram of hIGF-I rice grain possessed the maximum activity level equivalent to 3.2 micro molar of commercial rhIGF-I. In vitro functional analysis showed that the rice-derived rhIGF-I was effective in inducing membrane ruffling and glucose uptake on rat skeletal muscle cells. Oral meal test with rice-containing rhIGF-I acutely reduced blood glucose levels in streptozotocin-induced and Zucker diabetic rats, whereas it had no effect in normal rats. CONCLUSION: Our findings provided an alternative expression system to produce large quantities of biologically active rhIGF-I. The provision of large quantity of recombinant proteins will promote further research on the therapeutic potential of rhIGF-I.
Assuntos
Glicemia/metabolismo , Fator de Crescimento Insulin-Like I/biossíntese , Fator de Crescimento Insulin-Like I/farmacologia , Oryza/genética , Extratos Vegetais/farmacologia , Animais , Animais Geneticamente Modificados , Transporte Biológico , Células Cultivadas , DNA Complementar/metabolismo , Diabetes Mellitus Experimental , Modelos Animais de Doenças , Regulação da Expressão Gênica de Plantas , Glutens/genética , Humanos , Fator de Crescimento Insulin-Like I/administração & dosagem , Fator de Crescimento Insulin-Like I/genética , Músculo Esquelético/citologia , Músculo Esquelético/metabolismo , Oligopeptídeos , Oryza/química , Extratos Vegetais/química , Plantas Geneticamente Modificadas/química , Plantas Geneticamente Modificadas/genética , Regiões Promotoras Genéticas/genética , Sinais Direcionadores de Proteínas , Ratos , Ratos Zucker , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/farmacologia , Sementes/química , Sementes/genética , Amido/análise , Transformação GenéticaRESUMO
Eleven new cyclohexane-type meroterpenoids (1, 3-5, 7, 8, 11-15) and four known similar meroterpenoids (2, 6, 9, and 10) were isolated from Ganoderma cochlear. Their structures and absolute configurations at stereogenic centers were elucidated by using HRESIMS, NMR spectroscopy and computational methods. In addition, the structure of the known meroterpenoid, cochlearol G (2), was revised, and the absolute configurations at the stereogenic centers of known meroterpenoids 9 and 10 were determined. All the isolated meroterpenoids were evaluated for their activities against renal fibrosis and triple negative breast cancer, and their insulin resistance. The results of the renal fibrosis study showed that meroterpenoid 11 inhibits over-expression of fibronectin, collagen I and α-SMA. Results of the wound healing study revealed that 4, 6 and 8 significantly inhibit migration of BT549 cells. Observations made in Western blotting experiments showed that 6 decreases the levels of TWIST1 and ZEB1, and increases the level of E-cadherin. Finally, meroterpenoids 7, 9, 11, and 15 significantly up-regulate p-AMPK protein expression in normal L6 myotubes cells.
RESUMO
Lipid oversupply may induce CD36 sarcolemmal translocation to facilitate fatty acid transport, which in turn causes dyslipidemia and type 2 diabetes. However, the underlying mechanisms of CD36 redistribution are still yet to be unraveled. Methods: High fat diet fed mice and palmitate/oleic acid-treated L6 cells were used to investigate the initial events of subcellular CD36 recycling prior to insulin resistance. The regulation of CD36 sarcolemmal translocation by lipid oversupply was assessed by insulin tolerance test (ITT), oral glucose tolerance test (OGTT), glucose/fatty acid uptake assay, surface CD36 and GLUT4 detection, and ELISA assays. To elucidate the underlying mechanisms, specific gene knockout, gene overexpression and/or gene inhibition were employed, followed by Western blot, co-immunoprecipitation, immunostaining, and kinase activity assay. Results: Upon lipid/fatty acid overload, PKCζ activity and TBC1D1 phosphorylation were enhanced along with increased sarcolemmal CD36. The inhibition of PKCζ or TBC1D1 was shown to block fatty acid-induced CD36 translocation and was synergistic in impairing CD36 redistribution. Mechanically, we revealed that AMPK was located upstream of PKCζ to control its activity whereas Rac1 facilitated PKCζ translocation to the dorsal surface of the cell to cause actin remodeling. Furthermore, AMPK phosphorylated TBC1D1 to release retained cytosolic CD36. The activated PKCζ and phosphorylated TBC1D1 resulted in a positive feedback regulation of CD36 sarcolemmal translocation. Conclusion: Collectively, our study demonstrated exclusively that lipid oversupply induced CD36 sarcolemmal translocation via dual modulation of PKCζ and TBC1D1, which was as an early event prior to insulin resistance. The acquired data may provide potential therapy targets to prevent lipid oversupply-induced insulin resistance.
Assuntos
Antígenos CD36/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Ácidos Graxos/administração & dosagem , Resistência à Insulina , Sarcolema/metabolismo , Animais , Linhagem Celular , Dieta Hiperlipídica , Proteínas Ativadoras de GTPase/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células Musculares , Proteína Quinase C-theta/metabolismo , Transporte Proteico , RatosRESUMO
Protein kinase C (PKC) zeta has been implicated in insulin-induced glucose uptake in skeletal muscle cell, although the underlying mechanism remains unknown. In this study, we investigated the effect of PKCzeta on actin remodeling and glucose transport in differentiated rat L6 muscle cells expressing myc-tagged glucose transporter 4 (GLUT4). On insulin stimulation, PKCzeta translocated from low-density microsomes to plasma membrane accompanied by increase in GLUT4 translocation and glucose uptake. Z-scan confocal microscopy revealed a spatial colocalization of relocated PKCzeta with the small GTPase Rac-1, actin, and GLUT4 after insulin stimulation. The insulin-mediated colocalization, PKCzeta distribution, GLUT4 translocation, and glucose uptake were inhibited by wortmannin and cell-permeable PKCzeta pseudosubstrate peptide. In stable transfected cells, overexpression of PKCzeta caused an insulin-like effect on actin remodeling accompanied by a 2.1-fold increase in GLUT4 translocation and 1.7-fold increase in glucose uptake in the absence of insulin. The effects of PKCzeta overexpression were abolished by cell-permeable PKCzeta pseudosubstrate peptide, but not wortmannin. Transient transfection of constitutively active Rac-1 recruited PKCzeta to new structures resembling actin remodeling, whereas dominant negative Rac-1 prevented the insulin-mediated PKCzeta translocation. Together, these results suggest that PKCzeta mediates insulin effect on glucose transport through actin remodeling in muscle cells.
Assuntos
Actinas/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Glucose/metabolismo , Insulina/farmacologia , Células Musculares/metabolismo , Proteína Quinase C/metabolismo , Actinas/análise , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Membrana Celular/química , Membrana Celular/metabolismo , Células Cultivadas , Transportador de Glucose Tipo 4/análise , Transportador de Glucose Tipo 4/genética , Proteínas Monoméricas de Ligação ao GTP/análise , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Células Musculares/química , Células Musculares/efeitos dos fármacos , Fosforilação , Proteína Quinase C/análise , Proteína Quinase C/genética , Transporte Proteico , Ratos , Proteínas rac1 de Ligação ao GTP/análise , Proteínas rac1 de Ligação ao GTP/metabolismoRESUMO
In order to study the pollution characteristics and sources of fine particulate matter in the Guanzhong area of China, PM2.5 samples were collected and observed by hand from September 4, 2017 to January 19, 2018 at five sites (XA, WN, TCH, BJ and XY). The carbonaceous component of these samples was analyzed by thermal-optical transmission, which showed that the average concentrations of OC and EC in the fine particulate matter were (14.48±7.86) µg·m-3 and (2.27±0.95) µg·m-3, respectively, Percentages of OC and EC were 18.04% and 2.99%, respectively. Compared with other cities, the measured levels of pollution in the Guanzhong areas were more severe. The spatial distribution of percentage of carbon component in PM2.5 was XY > WN > XA > BJ > TCH, and the concentrations in winter were higher than in autumn. The correlation between OC and EC was significant (R2=0.79), which indicates a common source. The highest proportion of OC1 was 23.44%. The concentration of the carbonaceous component from high to low was OC1 > EC2 > EC3 > OC4 > EC1 > OC2 > OC3 > EC4 > EC6 > EC5. The results of PMF modeling show that the four main contributing sources of carbon components in pollution in this area are biomass combustion and coal-burning, gasoline vehicle exhaust emissions, diesel vehicle exhaust emissions, and road dust, contribution 48.63%, 23.07%, 18.82%, and 9.47%, respectively. Furthermore, there were clear differences in the pollution structure at each study site.
RESUMO
BACKGROUND: Epidemiological observations have demonstrated that ambient fine particulate matter with dp < 2.5 µm (PM2.5) as the major factor responsible for the increasing incidence of lung cancer in never-smokers. However, there are very limited experimental data to support the association of PM2.5 with lung carcinogenesis and to compare PM2.5 with smoking carcinogens. METHODS: To study whether PM2.5 can contribute to lung tumorigenesis in a way similar to smoking carcinogen 4-methylnitrosamino-l-3-pyridyl-butanone (NNK) via 15-lipoxygenases (15-LOXs) reduction, normal lung epithelial cells and cancer cells were treated with NNK or PM2.5 and then epigenetically and post-translationally examined the cellular and molecular profiles of the cells. The data were verified in lung cancer samples and a mouse lung tumor model. RESULTS: We found that similar to smoking carcinogen NNK, PM2.5 significantly enhanced cell proliferation, migration and invasion, but reduced the levels of 15-lipoxygenases-1 (15-LOX1) and 15-lipoxygenases-2 (15-LOX2), both of which were also obviously decreased in lung cancer tissues. 15-LOX1/15-LOX2 overexpression inhibited the oncogenic cell functions induced by PM2.5/NNK. The tumor formation and growth were significantly higher/faster in mice implanted with PM2.5- or NNK-treated NCI-H23 cells, accompanied with a reduction of 15-LOX1/15-LOX2. Moreover, 15-LOX1 expression was epigenetically regulated at methylation level by PM2.5/NNK, while both 15-LOX1 and 15-LOX2 could be significantly inhibited by a set of PM2.5/NNK-mediated microRNAs. CONCLUSION: Collectively, PM2.5 can function as the smoking carcinogen NNK to induce lung tumorigenesis by inhibiting 15-LOX1/15-LOX2.
Assuntos
Araquidonato 15-Lipoxigenase/química , Carcinogênese/patologia , Neoplasias Pulmonares/patologia , Material Particulado/efeitos adversos , Animais , Apoptose , Biomarcadores Tumorais/metabolismo , Carcinogênese/induzido quimicamente , Carcinogênese/metabolismo , Estudos de Casos e Controles , Movimento Celular , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Inibidores de Lipoxigenase/efeitos adversos , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/etiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Nitrosaminas/toxicidade , Prognóstico , Fumar/efeitos adversos , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
There are many herbal teas that are found in nature that may be effective at treating the symptoms and also shortening the duration of viral infections. When combating viral infections, T lymphocytes are an indispensable part of human acquired immunity. However, studies on the use of natural products in stimulating lymphocyte-mediated interferon-gamma (IFN-γ) production are very limited. In this study, we found that acteoside, a natural phenylpropanoid glycoside from Kuding Tea, enhanced IFN-γ production in mouse lymphocytes in a dose-dependent manner, particularly in the CD4+ and CD8+ subsets of T lymphocytes. To this end, we suggest that the antiviral activity of acteoside was highly correlated to its inducing ability of IFN-γ production. Mechanistically, the activation of T-bet enhanced the promoter of IFN-γ and subsequently resulted in an increased IFN-γ production in T cells. Collectively, we have found a natural product with the capacity to selectively enhance mouse T cell IFN-γ production. Given the role of IFN-γ in the immune system, further studies to clarify the role of acteoside in inducing IFN-γ and prevention of viral infection are needed.
Assuntos
Antivirais/farmacologia , Produtos Biológicos/farmacologia , Glucosídeos/farmacologia , Interferon gama/metabolismo , Fenóis/farmacologia , Animais , Apoptose/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Relação Dose-Resposta Imunológica , Glicosídeos/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Regiões Promotoras Genéticas , Células RAW 264.7 , Proteínas com Domínio T/metabolismo , Linfócitos T/efeitos dos fármacos , Linfócitos T/metabolismo , Chás de Ervas/análiseRESUMO
UNLABELLED: Smoking carcinogen N-nitrosamines such as 4-methylnitrosamino-l-3-pyridyl-butanone (NNK) require metabolic activation to exert their genotoxicity. The first activation step is mainly catalyzed by cytochrome P450 (CYP) family. Estrogen receptor α (ERα) plays a role in lung pathology. The association between them is unknown. In this study, we explored the relationship and function of CYP1B1 and ERα in NNK-induced lung tumorigenesis. CYP1B1 and ERα expression was analyzed in human lung cancer tissues and NNK-induced lung tumor of A/J mice. Cell lines NCI-H23 and NCI-H460 were employed to further study the responsible mechanisms using various cellular and molecular approaches. Our in vivo experiments demonstrated that CYP1B1 and ERα were over-expressed at the early stage of NNK-induced lung tumorigenesis. Microarray analysis found that ERα was involved in the extracellular-signal-regulated kinase (ERK)/MAPK pathway. NNK activated RAS/ERK/AP1 as it remarkably increased the levels of p-ERK, c-Fos, and c-Jun but inhibited multiple negative regulators of Ras/ERK/AP1, Pdcd4, Spry1, Spry2, and Btg2 through up-regulating miR-21. Both CYP1B1 siRNA and ERK-specific inhibitor U0126 suppressed NNK-mediated ERα up-regulation, suggesting that ERα was downstream of CYP1B1 and ERK. ERK inactivation led to the accumulation of CYP1B1, indicating that CYP1B1 was upstream of ERK activation. Inhibition of ERK or ERα decreased NNK-induced cell proliferation. Blockage of CYP1B1 or ERα induced apoptosis of lung cancer cells. Collectively, NNK-mediated ERα induction is via CYP1B1 and ERK and contributes to the lung carcinogenesis. The inhibition of CYP1B1, ERK, or ERα may arrest the lung cancer cell growth, implicating a pivotal strategy for the treatment of lung cancer. KEY MESSAGES: Smoking carcinogen NNK requires metabolic activation to exert their genotoxicity. CYP1B1 is the enzyme to catalyze NNK. NNK activates CYP1B1 and ERK to induce ERα. Inhibition of CYP1B1, ERK, or ERα arrests the lung cancer cell growth.
Assuntos
Sistema Enzimático do Citocromo P-450/metabolismo , Receptor alfa de Estrogênio/metabolismo , Neoplasias Pulmonares/patologia , Sistema de Sinalização das MAP Quinases , Animais , Linhagem Celular , Humanos , Neoplasias Pulmonares/etiologia , Neoplasias Pulmonares/fisiopatologia , Neoplasias Pulmonares/terapia , Camundongos , Nitrosaminas/farmacologiaRESUMO
OBJECTIVE: To evaluate the efficacy of the modified Epley maneuver Versus modified Semont maneuver for posterior canal benign paroxysmal positional vertigo. METHODS: The randomized controlled trials (RCT) about modified Epley maneuver Versus modified Semont maneuver for posterior canal benign paroxysmal positional vertigo from January 1985 to July 2013 were searched in CNKI,OVID, PubMed, CBM, EMBASE, WanFang Data, and Cochrane Library. Two reviewers independently screened the literatures, extracted the data, and evaluated the methodological quality. Then meta-analyses were conducted by using RevMan 5.1 software. RESULTS: A total of six RCTs were included. Among the 453 patients involved, 232 patients were in the modified Epley maneuver group, while the other 221 patients were in the modified Semont maneuver group. The results of meta-analyses showed that the efficacy of the modified Epley maneuve group was superior to that of the modified Semont maneuver group in one-week cure rate[OR = 3.25, 95%CI (2.08, 5.10) , P < 0.01], one-week efficient [OR = 4.72, 95%CI (1.16, 19.15) , P = 0.03], with significant differences. There was no significant difference between the two groups in three-months cure rate [OR = 2.10, 95%CI (0.57, 7.75) , P = 0.27], incidence of adverse reactions [OR = 0.82, 95%CI(0.44, 1.52), P = 0.53] and relapse rate [OR = 0.56, 95%CI (0.20, 1.57) , P = 0.27]. CONCLUSIONS: Based on the current studies, modified Epley maneuver is superior to modified Semont maneuver in quicking relief posterior canal benign paroxysmal positional vertigo symptoms, but the long-term efficacy, recurrence rate and incidence of adverse reactions had no significant difference. For the quality restrictions and possible publication bias of the included studies, more double blind RCTs with high quality are required to further assess the effects.
Assuntos
Vertigem Posicional Paroxística Benigna/terapia , Técnicas de Exercício e de Movimento/métodos , Método Duplo-Cego , Humanos , Recidiva , VertigemRESUMO
Both microtubule and actin are required for insulin-induced glucose uptake. However, the roles of these two cytoskeletons and their relationship in insulin action still remain unclear. In this work, we examined the morphological change of microtubule/actin and their involvement in insulin signal transduction using rat skeletal muscle cells. Insulin rapidly led to microtubule clustering from ventral to dorsal surface of the cell. Microtubule filaments were rearranged to create space where new actin structures formed. Disruption of microtubule prevented insulin-induced actin remodeling and distal insulin signal transduction, with reduction in surface glucose transporter isoform 4 (GLUT4) and glucose uptake. Though microtubule mediated actin remodeling through PKCζ, reorganization of microtubule depended on tyrosine phosphorylation of insulin receptor, the mechanism is different from insulin-induced actin remodeling, which relied on the activity of PI3-kinase and PKCζ. We propose that microtubule network is required for insulin-induced signal transduction and actin remodeling in skeletal muscle cells.
Assuntos
Citoesqueleto de Actina/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Insulina/metabolismo , Microtúbulos/metabolismo , Mioblastos Esqueléticos/metabolismo , Receptor de Insulina/metabolismo , Transdução de Sinais , Animais , Transporte Biológico , Linhagem Celular , Membrana Celular/metabolismo , Polaridade Celular , Glucose/metabolismo , Cinética , Mioblastos Esqueléticos/citologia , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Proteína Quinase C/metabolismo , Processamento de Proteína Pós-Traducional , Transporte Proteico , RatosRESUMO
Diabetes and obesity are complex diseases associated with insulin resistance and fatty liver. The latter is characterized by dysregulation of the Akt, AMP-activated protein kinase (AMPK), and IGF-I pathways and expression of microRNAs (miRNAs). In China, multicomponent traditional Chinese medicine (TCM) has been used to treat diabetes for centuries. In this study, we used a three-herb, berberine-containing TCM to treat male Zucker diabetic fatty rats. TCM showed sustained glucose-lowering effects for 1 week after a single-dose treatment. Two-week treatment attenuated insulin resistance and fatty degeneration, with hepatocyte regeneration lasting for 1 month posttreatment. These beneficial effects persisted for 1 year after 1-month treatment. Two-week treatment with TCM was associated with activation of AMPK, Akt, and insulin-like growth factor-binding protein (IGFBP)1 pathways, with downregulation of miR29-b and expression of a gene network implicated in cell cycle, intermediary, and NADPH metabolism with normalization of CYP7a1 and IGFBP1 expression. These concerted changes in mRNA, miRNA, and proteins may explain the sustained effects of TCM in favor of cell survival, increased glucose uptake, and lipid oxidation/catabolism with improved insulin sensitivity and liver regeneration. These novel findings suggest that multicomponent TCM may be a useful tool to unravel genome regulation and expression in complex diseases.