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1.
J Agric Food Chem ; 68(1): 193-205, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31826610

RESUMO

Gynostemma pentaphyllum possesses neuroprotective bioactivity. However, the effect of gypenosides on hypoxia-induced neural damage remains obscure. In this study, Gyp, the active fraction extracted from G. pentaphyllum and its bioactive compounds as well as the underlying molecular mechanisms were investigated. Eighteen dammarane-type saponins were isolated from Gyp. The absolute configurations of six unreported compounds (13-18) were assessed via electron capture detection (ECD) analyses. The results of cell viability assay showed that Gyp and its bioactive compounds (13-16 and 18) effectively protected PC12 cells from hypoxia injury. Gyp pretreatment also improved mice spatial memory impairment caused by hypoxia exposure. At the molecular level, Gyp and its bioactive compounds could activate the signaling pathways of ERK, Akt, and CREB in vitro and in vivo. In summary, Gyp and its bioactive compounds could prevent hypoxia-induced injury via ERK, Akt, and CREB signaling pathways.


Assuntos
Proteína de Ligação a CREB/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Gynostemma/química , Hipóxia/tratamento farmacológico , Neurônios/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Proteínas Proto-Oncogênicas c-akt/metabolismo , Animais , Proteína de Ligação a CREB/genética , Sobrevivência Celular , MAP Quinases Reguladas por Sinal Extracelular/genética , Humanos , Hipóxia/genética , Hipóxia/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/metabolismo , Células PC12 , Extratos Vegetais/administração & dosagem , Proteínas Proto-Oncogênicas c-akt/genética , Ratos , Saponinas/administração & dosagem
2.
Food Chem Toxicol ; 135: 110968, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31738984

RESUMO

This October, the Nobel Prize in Physiology or Medicine 2019 was jointly awarded to William G. Kaelin Jr., Sir Peter J. Ratcliffe, and Gregg L. Semenza for their discoveries of "how cells sense and adapt to oxygen availability." Importantly, the protein named hypoxia-inducible factors (HIF) were revealed in the molecular machinery that how cells regulate the activity of genes in response to hypoxia. Hypoxia has a close relationship with oxidative stress and its related diseases including cancer. Actually, accumulating evidence and recent advances show that mycotoxins, including ochratoxin A, trichothecene mycotoxins T-2 toxin, deoxynivalenol, and diacetoxyscirpenol have the potential of triggering hypoxia in cells. Moreover, HIF-1α activation is involved in the mycotoxin-induced oxidative stress response. As is known, oxidative stress is considered to be a common mechanism of various toxicities of mycotoxins; however, an in-depth molecular mechanism, especially the molecular target in this context is not fully understood. Therefore, in this work, we have discussed the underlying mechanism(s) of hypoxia and HIF-1α in the mycotoxin-induced oxidative stress effect. We believe that the explanation of hypoxia and HIF-1α would open up new avenues for early diagnosis and treatment of mycotoxicosis. More importantly, under these circumstances, we compile a special issue, "Mycotoxins in Food: New Determination Methods, Toxic Mechanisms, and Control Strategies" for Food and Chemical Toxicology. Researchers are encouraged to submit their newest research articles and excellent work within this topic for the readers of Food and Chemical Toxicology.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Hipóxia/metabolismo , Micotoxinas/efeitos adversos , Estresse Oxidativo/efeitos dos fármacos , Animais , Humanos , Estresse Oxidativo/fisiologia
3.
Biomed Khim ; 65(6): 485-497, 2019 Oct.
Artigo em Russo | MEDLINE | ID: mdl-31876519

RESUMO

In socially isolated male outbred albino mice, the changes of monoaminergic systems under acute hypoxia with hypercapnia were studied. In cerebral cortex, hippocampus and striatum of the right and left sides of the brain, the concentrations of norepinephrine, dopamine, serotonin and their metabolites - dihydroxyphenylacetic, homovanillic and 5-hydroxyindoleacetic acids were investigated using the HPLC method. In isolated mice, which were not subjected to hypoxia with hypercapnia, higher levels of dopamine and serotonin in the left cortex were found. There was no asymmetry in monoamines and their metabolites in other studied brain structures. 10 min after the onset of exposure, acute hypoxia with hypercapnia resulted in a right-sided increase in norepinephrine levels and a decrease in dopamine levels in the striatum and serotonin levels in the hippocampus. In the cerebral cortex, 10 min after of hypoxic exposure beginning, there was a left-sided decrease in the dopamine content, while the original asymmetry found in the cortex of intact animals disappeared. In isolated mice perished of hypoxia with hypercapnia, almost all parameters returned to the control level. The exception was the ratio of serotonin metabolite level to the neurotransmitter, which in the right cortex became lower than in control animals. In white outbred mice, the brain monoaminergic systems are suggested to be relatively resistant to the negative consequences of hypoxia and hypercapnia, and corresponding shifts resulting in the reflex brain response to changes in the gas composition of the respiratory air.


Assuntos
Química Encefálica , Dopamina/química , Hipercapnia/metabolismo , Hipóxia/metabolismo , Norepinefrina/química , Serotonina/química , Animais , Encéfalo , Ácido Homovanílico , Masculino , Camundongos
4.
Int Heart J ; 60(6): 1430-1434, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31735783

RESUMO

Pulmonary arterial hypertension is a fatal disease caused by pulmonary arterial vasoconstriction and organic stenosis due to the proliferation of pulmonary smooth muscle cells and endothelial cells. Endothelial dysfunction, including impaired nitric oxide (NO) bioavailability, plays a crucial role in the pathogenesis of pulmonary hypertension, and endothelial nitric oxide synthase (eNOS) is an important modulator of pulmonary vasodilatation. Although senescence marker protein (SMP) 30 is known as an anti-aging protein, the role of SMP30 in pulmonary vessels is still unclear. In this study, we examined the role of SMP30 in pulmonary vasculature using SMP30-deficient mice.We used female SMP30-deficient mice and wild-type littermate (WT) mice at the age of 12 to 18 weeks. The WT and SMP30-deficient mice were exposed to normoxia or hypoxia (10% oxygen for 4 weeks). In normoxia, the right ventricular systolic pressure (RVSP) was not different between the WT and SMP30-deficient mice, but in hypoxia, the RVSP was significantly higher in the SMP30-deficient mice compared to the WT mice (P < 0.05). The hypoxia-induced increases in right ventricular hypertrophy and medial smooth muscle area of the pulmonary artery were comparable between the WT and the SMP30-deficient mice. Western blotting showed that eNOS phosphorylation in lung tissue was reduced in the SMP30-deficient mice compared to the WT mice in normoxia. However, in hypoxic conditions, eNOS phosphorylation was reduced in both the WT and SMP30-deficient mice with no differences in Akt phosphorylation.Our study demonstrated that SMP30 is involved in the development of hypoxia-induced pulmonary hypertension by impairment of eNOS activity.


Assuntos
Proteínas de Ligação ao Cálcio/fisiologia , Hipertensão Pulmonar/etiologia , Hipóxia/complicações , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Animais , Modelos Animais de Doenças , Feminino , Hipertensão Pulmonar/metabolismo , Hipóxia/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Óxido Nítrico Sintase Tipo III/metabolismo
5.
Analyst ; 144(22): 6609-6616, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31616873

RESUMO

Maintaining the redox balance of biological systems is a key point to maintain a healthy physiological environment. Excessive iron ions (Fe3+) can cause apoptosis, tissue damage and death. Fortunately, ascorbic acid (AA) as a reducing agent has been evaluated for the reduction of Fe3+. Moreover, AA plays an important role in relieving hypoxia-induced oxidative stress. Therefore, the real-time imaging of the Fe3+ and AA fluctuations is important for understanding their biofunctions in cells and in vivo. In this work, we developed a fluorescent nanoprobe carbon dot-desferrioxamine B (CD-DB) by the conjugate connection of CDs and desferrioxamine B (a complexing agent for Fe3+) for the associated detection of Fe3+ and AA. CD-DB exhibited excellent sensitivity and selectivity for the detection of Fe3+ and AA. The nanoprobe CDs-DB@Fe obtained by the reaction of CD-DB and Fe3+ was suitable for tracing the dynamic changes of AA in cells and in vivo. Therefore, CDs-DB@Fe was used for monitoring the fluctuation of AA in hypoxic cell models, hypoxic zebrafish models and liver ischemia mice models. These results exhibited the decrease in AA under hypoxic conditions because AA was consumed to neutralize free radicals and relieve hypoxia-induced oxidative stress damage. The ideal biocompatibility and low toxicity make our nanoprobe a potential candidate for the research of the physiological effects of AA in vivo.


Assuntos
Ácido Ascórbico/análise , Corantes Fluorescentes/química , Hipóxia/metabolismo , Ferro/análise , Pontos Quânticos/química , Animais , Carbono/química , Hipóxia Celular , Desferroxamina/química , Corantes Fluorescentes/síntese química , Células Hep G2 , Humanos , Isquemia/metabolismo , Limite de Detecção , Fígado/irrigação sanguínea , Fígado/metabolismo , Camundongos Endogâmicos BALB C , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Estresse Oxidativo , Peixe-Zebra
6.
Nature ; 574(7779): 575-580, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31645732

RESUMO

The Warburg effect, which originally described increased production of lactate in cancer, is associated with diverse cellular processes such as angiogenesis, hypoxia, polarization of macrophages and activation of T cells. This phenomenon is intimately linked to several diseases including neoplasia, sepsis and autoimmune diseases1,2. Lactate, which is converted from pyruvate in tumour cells, is widely known as an energy source and metabolic by-product. However, its non-metabolic functions in physiology and disease remain unknown. Here we show that lactate-derived lactylation of histone lysine residues serves as an epigenetic modification that directly stimulates gene transcription from chromatin. We identify 28 lactylation sites on core histones in human and mouse cells. Hypoxia and bacterial challenges induce the production of lactate by glycolysis, and this acts as a precursor that stimulates histone lactylation. Using M1 macrophages that have been exposed to bacteria as a model system, we show that histone lactylation has different temporal dynamics from acetylation. In the late phase of M1 macrophage polarization, increased histone lactylation induces homeostatic genes that are involved in wound healing, including Arg1. Collectively, our results suggest that an endogenous 'lactate clock' in bacterially challenged M1 macrophages turns on gene expression to promote homeostasis. Histone lactylation thus represents an opportunity to improve our understanding of the functions of lactate and its role in diverse pathophysiological conditions, including infection and cancer.


Assuntos
Epigênese Genética , Glicólise/genética , Histonas/química , Histonas/metabolismo , Ácido Láctico/metabolismo , Acetilação , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Cromatina/química , Cromatina/genética , Cromatina/metabolismo , Homeostase , Humanos , Hipóxia/metabolismo , Lisina/química , Lisina/metabolismo , Macrófagos/metabolismo , Macrófagos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reprodutibilidade dos Testes , Transcrição Genética
8.
Life Sci ; 238: 116876, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31655194

RESUMO

AIMS: Adiponectin (APN) is a protein hormone secreted mainly by adipose tissue that exhibits biological functions such as anti-inflammatory, anti-atherosclerotic, anti-apoptotic, hearing-protective and microcirculation-regulating functions. In this study, we explored whether APN could attenuate damage caused by CoCl2-induced hypoxic conditions in smooth muscle cells (SMCs) of the spiral modiolar artery (SMA). MAIN METHODS: We first cultured and identified primary SMCs of the SMA. Afterward, the SMCs were pre-treated with APN and then stimulated with CoCl2. KEY FINDINGS: Compared with the control group, the group treated with CoCl2 for 24 h exhibited significantly decreased cell viability, significantly increased apoptosis rates and Malondialdehyde (MDA) levels, and decreased Superoxide Dismutase (SOD) activity. In addition, the expression levels of Bax and cleaved caspase-3 were upregulated, while those of Bcl2 were downregulated evidently. Compared with the CoCl2 group, the group pre-treated with APN before receiving CoCl2 treatment had increased cell viability and SOD activity but decreased MDA levels and apoptosis rates. The expression levels of Bcl2, p-AMPKα and Cx43 were evidently increased, while those of Bax and cleaved caspase-3 were decreased, in the group pre-treated with APN compared to the CoCl2 group. The protective effect of APN was blocked by the AMPK inhibitor Compound C and the Cx43 inhibitor Gap19. SIGNIFICANCE: Our study demonstrated that APN protected SMCs against CoCl2-induced hypoxic injury via the AMPK signalling pathway and regulated the expression of Cx43 in cells. Therefore, APN might be a promising treatment for diseases related to circulation disturbances of the inner ear.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Adiponectina/farmacologia , Apoptose/efeitos dos fármacos , Artérias/efeitos dos fármacos , Cóclea/irrigação sanguínea , Conexina 43/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , Animais , Antimutagênicos/toxicidade , Artérias/metabolismo , Artérias/patologia , Cobalto/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Cobaias , Hipóxia/induzido quimicamente , Hipóxia/tratamento farmacológico , Hipóxia/metabolismo , Hipóxia/patologia , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Espécies Reativas de Oxigênio
9.
Acta Cir Bras ; 34(8): e201900802, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31618402

RESUMO

PURPOSE: To reveal the function of miR-134 in myocardial ischemia. METHODS: Real-time PCR and western blotting were performed to measure the expression of miR-134, nitric oxide synthase 3 (NOS3) and apoptotic-associated proteins. Lactic dehydrogenase (LDH) assay, cell counting kit-8 (CCK-8), Hoechst 33342/PI double staining and flow cytometry assay were implemented in H9c2 cells, respectively. MiR-134 mimic/inhibitor was used to regulate miR-134 expression. Bioinformatic analysis and luciferase reporter assay were utilized to identify the interrelation between miR-134 and NOS3. Rescue experiments exhibited the role of NOS3. The involvement of PI3K/AKT was assessed by western blot analysis. RESULTS: MiR-134 was high regulated in the myocardial ischemia model, and miR-134 mimic/inhibitor transfection accelerated/impaired the speed of cell apoptosis and attenuated/exerted the cell proliferative prosperity induced by H/R regulating active status of PI3K/AKT signaling. LDH activity was also changed due to the different treatments. Moreover, miR-134 could target NOS3 directly and simultaneously attenuated the expression of NOS3. Co-transfection miR-134 inhibitor and pcDNA3.1-NOS3 highlighted the inhibitory effects of miR-134 on myocardial H/R injury. CONCLUSION: This present work puts insights into the crucial effects of the miR-134/NOS3 axis in myocardial H/R injury, delivering a potential therapeutic technology in future.


Assuntos
Hipóxia/metabolismo , MicroRNAs/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Proliferação de Células/efeitos dos fármacos , MicroRNAs/genética , MicroRNAs/uso terapêutico , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/patologia , Óxido Nítrico Sintase Tipo III/genética , Óxido Nítrico Sintase Tipo III/uso terapêutico , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Transdução de Sinais/efeitos dos fármacos
10.
Anticancer Res ; 39(9): 4865-4876, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31519589

RESUMO

BACKGROUND/AIM: Hypoxia promotes tumor proliferation and metastasis in colorectal cancer (CRC). Since the tumor microenvironment is generally characterized by hypoxia, its understanding is important for cancer therapy. We hypothesized that hypoxia promotes the mitochondrial function, mobility, and proliferation of CRC by up-regulating peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). MATERIALS AND METHODS: To assess the effects of PGC-1α under hypoxia, we investigated the mitochondrial function, cell motility, and sphere formation as well as proliferation and apoptosis of CRC. RESULTS: Under hypoxia, we confirmed the increased expression of PGC-1α and reduced production of reactive oxygen species (ROS) by activating anti-oxidant enzymes. Also, up-regulation of PGC-1α enhanced the motility, sphere formation, and proliferation of CRC. Under the presence of the anti-cancer drug 5-fluorouracil (5FU), up-regulation of PGC-1α under hypoxia promoted resistance of CRC against 5FU-induced apoptosis. CONCLUSION: Targeting PGC-1α could to be a powerful strategy for CRC therapy.


Assuntos
Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Hipóxia/metabolismo , Mitocôndrias/genética , Mitocôndrias/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Apoptose , Catalase/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Neoplasias Colorretais/patologia , Resistencia a Medicamentos Antineoplásicos , Complexo I de Transporte de Elétrons/metabolismo , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Modelos Biológicos , Fosforilação Oxidativa , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
11.
Nat Commun ; 10(1): 4108, 2019 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-31511525

RESUMO

Recent advance in cancer research sheds light on the contribution of mitochondrial respiration in tumorigenesis, as they efficiently produce ATP and oncogenic metabolites that will facilitate cancer cell growth. Here we show that a stabilizing factor for mitochondrial supercomplex assembly, COX7RP/COX7A2L/SCAF1, is abundantly expressed in clinical breast and endometrial cancers. Moreover, COX7RP overexpression associates with prognosis of breast cancer patients. We demonstrate that COX7RP overexpression in breast and endometrial cancer cells promotes in vitro and in vivo growth, stabilizes mitochondrial supercomplex assembly even in hypoxic states, and increases hypoxia tolerance. Metabolomic analyses reveal that COX7RP overexpression modulates the metabolic profile of cancer cells, particularly the steady-state levels of tricarboxylic acid cycle intermediates. Notably, silencing of each subunit of the 2-oxoglutarate dehydrogenase complex decreases the COX7RP-stimulated cancer cell growth. Our results indicate that COX7RP is a growth-regulatory factor for breast and endometrial cancer cells by regulating metabolic pathways and energy production.


Assuntos
Neoplasias da Mama/patologia , Carcinogênese/patologia , Neoplasias do Endométrio/metabolismo , Hipóxia/patologia , Mitocôndrias/metabolismo , Neoplasias da Mama/genética , Carcinogênese/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Neoplasias do Endométrio/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Hipóxia/metabolismo , Complexo Cetoglutarato Desidrogenase/metabolismo , Consumo de Oxigênio , Espécies Reativas de Oxigênio/metabolismo
12.
Invest Ophthalmol Vis Sci ; 60(12): 3854-3862, 2019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31529118

RESUMO

Purpose: Subconjunctival injection of antagomir-21 attenuates the progression of corneal neovascularization. We examined the underlying mechanism by investigating the regulation of microRNA (miR)-21 expression and the involvement of miR-21 in the homeostasis of corneal epithelial cells. Methods: Corneal epithelial cells were cultured with TGF-ß1 and/or under hypoxia conditions. miR-21 expression was measured by quantitative PCR. The direct targets of miR-21 were validated by the 3'-UTR luciferase reporter assay. Alterations of proangiogenic signaling and the epithelial-mesenchymal transition (EMT) phenotype after miR-21/Sprouty2 (SPRY2) knockdown were examined by Western blotting. The effect of conditioned medium on angiogenesis was assessed using the tube formation assay. Wound healing was evaluated by the migration and scratch assays. Results: TGF-ß1 or hypoxia upregulated miR-21, and miR-21 silencing abolished TGF-ß1/hypoxia-induced hypoxia inducible factor (HIF)-1α and VEGF expression. miR-21 inhibited SPRY2 by directly targeting its 3'-UTR. Simultaneous silencing of miR-21 and SPRY2 significantly upregulated p-ERK, HIF-1α, and VEGF and promoted angiogenesis. Induction of miR-21 or inhibition of SPRY2 reduced the levels of cytokeratin (CK)-3 and CK-12 and promoted EMT. Transwell and wound healing assays indicated that miR-21 promoted cell migration. Conclusions: TGF-ß1 or hypoxia induced miR-21 and inhibited SPRY2, thereby enhancing proangiogenic signaling, suppressing the epithelial phenotype, and promoting wound healing in corneal epithelial cells.


Assuntos
Epitélio Anterior/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Proteínas de Membrana/fisiologia , MicroRNAs/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Fator A de Crescimento do Endotélio Vascular/metabolismo , Cicatrização/fisiologia , Animais , Western Blotting , Movimento Celular/fisiologia , Células Epiteliais/citologia , Transição Epitelial-Mesenquimal , Epitélio Anterior/efeitos dos fármacos , Hipóxia/metabolismo , Queratina-12/metabolismo , Queratina-3/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Fenótipo , Reação em Cadeia da Polimerase em Tempo Real , Transfecção , Fator de Crescimento Transformador beta1/farmacologia
13.
J Exp Clin Cancer Res ; 38(1): 388, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488193

RESUMO

BACKGROUND: Hypoxia is a key feature of breast cancer, which affects cancer development, metastasis and metabolism. Previous studies suggested that circular RNAs (circRNAs) could participate in cancer progression and hypoxia regulation. This study aimed to investigate the role of circRNA differentially expressed in normal cells and neoplasia domain containing 4C (circDENND4C) in breast cancer progression under hypoxia. METHODS: Forty-three patients with breast cancer were involved in this study. Breast cancer cell lines MDA-MB-453 and SK-BR-3 were cultured under hypoxia (1% O2) for experiments in vitro. The expression levels of circDENND4C, microRNA-200b (miR-200b) and miR-200c were measured by quantitative real-time polymerase chain reaction. Glycolysis was investigated by glucose consumption, lactate production and hexokinase II (HK2) protein level. Migration and invasion were evaluated via trans-well assay and protein levels of matrix metallopeptidase 9 (MMP9) and MMP2. The interaction between circDENND4C and miR-200b or miR-200c was explored by bioinformatics analysis, luciferase assay and RNA immunoprecipitation. Murine xenograft model was established to investigate the anti-cancer role of circDENND4C in vivo. RESULTS: circDENND4C highly expressed in breast cancer was up-regulated in response to hypoxia. Knockdown of circDENND4C decreased glycolysis, migration and invasion in breast cancer cells under hypoxia. circDENND4C was validated as a sponge of miR-200b and miR-200c. Deficiency of miR-200b or miR-200c reversed the suppressive effect of circDENND4C knockdown on breast cancer progression. Moreover, silence of circDENND4C reduced xenograft tumor growth by increasing miR-200b and miR-200c. CONCLUSION: circDENND4C silence suppresses glycolysis, migration and invasion in breast cancer cells under hypoxia by increasing miR-200b and miR-200c.


Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Fatores de Troca do Nucleotídeo Guanina/genética , Hipóxia/genética , MicroRNAs/genética , /genética , Adulto , Idoso , Animais , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Modelos Animais de Doenças , Feminino , Glicólise , Humanos , Hipóxia/metabolismo , Camundongos , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias
14.
J Exp Clin Cancer Res ; 38(1): 389, 2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31488217

RESUMO

BACKGROUND: In cancer progression, hypoxia, or low oxygen tension, is a major regulator of tumor aggressiveness and metastasis. However, how cancer cells adapt to the hypoxia and communicate with other mesenchymal cells in microenvironment during tumor development remains to be elucidated. Here, we investigated the involvement of exosomes in modulating angiogenesis and enhancing metastasis in esophageal squamous cell carcinoma (ESCC). METHODS: Differential centrifugation, transmission electron microscopy and nanoparticle tracking analysis were used to isolate and characterize exosomes. Colony formation and transwell assay were performed to assess the proliferation, migration and invasion of human umbilical vein endothelial cells (HUVECs). The tube formation assay and matrigel plug assay were used to evaluate the vascular formation ability of HUVECs in vitro and in vivo respectively. An in vivo nude mice model was established to detect the regulatory role of exosomes in ESCC progression. Microarray analysis was performed to analyze the transcriptome profiles in HUVECs. RESULTS: Exosomes derived from ESCC cells cultured under hypoxia played a better role in promoting proliferation, migration, invasion and tube formation of HUVECs in vitro and in vivo than exosomes from ESCC cells cultured under normoxia. Moreover, hypoxic exosomes significantly enhanced the tumor growth and lung metastasis compared with normoxic exosomes in nude mice models. Interestingly, endothelial cells were programmed by hypoxic and normoxic exosomes from ESCC cells which altered the transcriptome profile of HUVECs. CONCLUSIONS: Taken together, our data identified an angiogenic role of exosomes from ESCC cells which shed light on the further application of exosomes as valuable therapeutic target for ESCC.


Assuntos
Carcinoma de Células Escamosas do Esôfago/genética , Carcinoma de Células Escamosas do Esôfago/metabolismo , Exossomos/metabolismo , Hipóxia/genética , Hipóxia/metabolismo , Neovascularização Patológica/genética , Neovascularização Patológica/metabolismo , Transcriptoma , Animais , Ciclo Celular , Linhagem Celular Tumoral , Biologia Computacional/métodos , Modelos Animais de Doenças , Progressão da Doença , Células Endoteliais , Carcinoma de Células Escamosas do Esôfago/patologia , Perfilação da Expressão Gênica , Humanos , Camundongos , Anotação de Sequência Molecular , Metástase Neoplásica , Estadiamento de Neoplasias , Fenótipo
15.
Int J Mol Sci ; 20(18)2019 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-31491980

RESUMO

5-Fluorouracil (5-FU) is an important chemotherapeutic agent for the systemic treatment of colorectal cancer (CRC), but its effectiveness against CRC is limited by increased 5-FU resistance caused by the hypoxic tumor microenvironment. The purpose of our study was to assess the feasibility of using quinacrine (QC) to increase the efficacy of 5-FU against CRC cells under hypoxic conditions. QC reversed the resistance to 5-FU induced by hypoxia in CRC cell lines, as determined using ATP-Glo cell viability assays and clonogenic survival assays. Treatment of cells with 5-FU under hypoxic conditions had no effect on the expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a regulator of cellular resistance to oxidative stress, whereas treatment with QC alone or in combination with 5-FU reduced Nrf2 expression in all CRC cell lines tested. Overexpression of Nrf2 effectively prevented the increase in the number of DNA double-strand breaks induced by QC alone or in combination with 5-FU. siRNA-mediated c-Jun N-terminal kinase-1 (JNK1) knockdown inhibited the QC-mediated Nrf2 degradation in CRC cells under hypoxic conditions. The treatment of CRC xenografts in mice with the combination of QC and 5-FU was more effective in suppressing tumor growth than QC or 5-FU alone. QC increases the susceptibility of CRC cells to 5-FU under hypoxic conditions by enhancing JNK1-dependent Nrf2 degradation.


Assuntos
Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Fluoruracila/farmacologia , Hipóxia/genética , Hipóxia/metabolismo , Fator 2 Relacionado a NF-E2/genética , Quinacrina/farmacologia , Animais , Linhagem Celular Tumoral , Neoplasias Colorretais/tratamento farmacológico , Modelos Animais de Doenças , Fluoruracila/uso terapêutico , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Modelos Biológicos , Fator 2 Relacionado a NF-E2/metabolismo , Estadiamento de Neoplasias , Proteólise , Ensaios Antitumorais Modelo de Xenoenxerto
16.
Life Sci ; 235: 116842, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31494170

RESUMO

MicroRNAs plays important role in the development of myocardial infarction (MI). The aim of this study was to analyze whether miR-429 has effect on the process of autophagy in myocardial anoxia/reoxygenation (AR) or ischemia/reperfusion (IR) injury and explore the underlying mechanism. The results showed that miR-429 was significantly decreased in MI mouse hearts and AR treated cardiomyocytes. Dual luciferase activity assay proved that MO25 was the direct target of miR-429. MO25 was dramatically decreased in AR treated cardiomyocytes. Overexpression of miR-429 dramatically decreased the expression of MO25, whereas inhibition of miR-429 noticeably increased the expression of MO25. In addition, overexpression of miR-429 reduced GFP-LC3B labelled cells, decreased the number of vesicle and autophagosome in each cardiomyocyte, and induced cell apoptosis in AR treated cardiomyocytes. In contrast, inhibition of miR-429 had the opposite effect. The further in vivo study showed that when mouse in IR group were injected with antagomiR-429, the weight of left ventricular was increased and infarct size was significantly decreased. Finally, both the in vitro and in vivo study showed that the expression of MO25, LKB1, pAMPKa, ATG13, p62 and LC3BI/II was noticeably increased by antagomiR-429. In conclusion, our results suggested that antagonism of miR-429 ameliorates anoxia/reoxygenation injury in cardiomyocytes by enhancing MO25/LKB1/AMPK mediated autophagy.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia/efeitos dos fármacos , Proteínas de Ligação ao Cálcio/metabolismo , Hipóxia/metabolismo , MicroRNAs/antagonistas & inibidores , Miócitos Cardíacos/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Animais , Antagomirs/farmacologia , Antagomirs/uso terapêutico , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Autofagossomos/efeitos dos fármacos , Contagem de Células , Vesículas Citoplasmáticas/efeitos dos fármacos , Glicoproteínas de Membrana/metabolismo , Camundongos , MicroRNAs/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Traumatismo por Reperfusão Miocárdica , Miocárdio/metabolismo , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo
17.
Int J Mol Sci ; 20(15)2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31370155

RESUMO

Despite the significant recent advances in clinical practice, gastric cancer (GC) represents a leading cause of cancer-related deaths in the world. In fact, occurrence of chemo-resistance still remains a daunting hindrance to effectiveness of the current approach to GC therapy. There is accumulating evidence that a plethora of cellular and molecular factors is implicated in drug-induced phenotypical switching of GC cells. Among them, epithelial-mesenchymal transition (EMT), autophagy, drug detoxification, DNA damage response and drug target alterations, have been reported as major determinants. Intriguingly, resistant GC phenotype may be the result of GC cell-induced tumor microenvironment (TME) remodeling, which is currently emerging as a key player in promoting drug resistance and overcoming cytotoxic effects of drugs. In this review, we discuss the possible mechanisms of drug resistance and their involvement in determining current GC therapies failure.


Assuntos
Autofagia/genética , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Neovascularização Patológica/genética , Neoplasias Gástricas/genética , Microambiente Tumoral/genética , Transportadores de Cassetes de Ligação de ATP/genética , Transportadores de Cassetes de Ligação de ATP/metabolismo , Antineoplásicos/uso terapêutico , Autofagia/efeitos dos fármacos , Proteínas Relacionadas à Autofagia/genética , Proteínas Relacionadas à Autofagia/metabolismo , Sobrevivência Celular/genética , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Transição Epitelial-Mesenquimal/genética , Infecções por Helicobacter/tratamento farmacológico , Infecções por Helicobacter/genética , Infecções por Helicobacter/metabolismo , Infecções por Helicobacter/patologia , Helicobacter pylori/crescimento & desenvolvimento , Helicobacter pylori/patogenicidade , Humanos , Hipóxia/tratamento farmacológico , Hipóxia/genética , Hipóxia/metabolismo , Hipóxia/patologia , Inativação Metabólica/genética , MicroRNAs/genética , MicroRNAs/metabolismo , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neovascularização Patológica/tratamento farmacológico , Neovascularização Patológica/metabolismo , Neovascularização Patológica/patologia , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Microambiente Tumoral/efeitos dos fármacos
18.
Cell Biochem Funct ; 37(7): 545-552, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31429100

RESUMO

Ras-GTPases regulate many central signalling pathways in the cell. Hypoxia induces nitrosative/oxidative stress and dysregulates Ras-dependent downstream processes. H-Ras possesses two cysteine residues (C181 and C184) in the C-termini, which are palmitoylated once or twice. Palmitoylation is sufficient for promoting stable plasma membrane localization. We hypothesized that high concentrations of hypoxia-formed nitric oxide could induce terminal cysteine S-nitrosylation, followed by depalmitoylation and H-Ras mislocalization. We investigated the action of a 100-µM nitric oxide-donor (sodium nitroprusside [SNP]) and a 100-µM palmitoylation inhibitor (2-bromopalmitate) on the distribution of membrane-bound S-nitrosylated and palmitoylated H-Ras under hypoxic/normoxic conditions in undifferentiated/differentiated pheochromocytoma (PC12) cells. We found that under normoxic conditions, SNP increases membrane-bound H-Ras nitrosylation only in differentiated cells, whereas under hypoxic conditions, SNP stimulates H-Ras nitrosylation in both differentiated and undifferentiated cells. SNP greatly decreases the palmitoylation of H-Ras under hypoxic conditions in both undifferentiated and differentiated cells, while under normoxic conditions, the effect of SNP is more negligible. Furthermore, Western blot analyses have shown that SNP decreases ERK phosphorylation under hypoxic conditions, in parallel with an elevation in hypoxia-induced factor activity and intracellular succinate concentration. We propose that high concentrations of hypoxia-formed nitric oxide can nitrosylate H-Ras terminal cysteines, which induce H-Ras activity dysregulation and alter the cellular response to hypoxia. SIGNIFICANCE OF THE STUDY: To our knowledge, these observations may be important for cancer prevention and therapy because cancer is one of the most prevalent disorders caused by the misregulation of Ras activity by a redox agent. Oncogenic activation of the H-Ras gene has been found in a wide variety of neoplastic transformations, and thus, investigation of the redox regulation of H-Ras activity is significant for cancer research as well.


Assuntos
Diferenciação Celular , Hipóxia/tratamento farmacológico , Nitroprussiato/farmacologia , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Animais , Diferenciação Celular/efeitos dos fármacos , Hipóxia/metabolismo , Células PC12 , Proteínas Proto-Oncogênicas p21(ras)/análise , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Ratos
19.
Artigo em Inglês | MEDLINE | ID: mdl-31465877

RESUMO

Hypoxia-tolerant animals use metabolic suppression as an essential strategy to survive low oxygen. Ectotherms can alter membrane lipid composition in response to changes in environmental temperature, but it is currently unknown whether chronic hypoxia can also elicit membrane restructuring. The goal of this study was to investigate a possible physiological link between membrane remodelling and metabolic suppression in goldfish exposed to prolonged hypoxia (4 weeks at 10% air saturation). We have tested the hypothesis that chronic hypoxia would modulate membrane lipid composition in ways that are consistent with known mechanisms of ion pump inhibition. Because homeoviscous membrane restructuring could interfere with the response to hypoxia, measurements were made at 2 temperatures. Results show that hypoxic goldfish suppress metabolic rate by 74% (at 13 °C) and 63% (at 20 °C). This study is the first to reveal that cold-acclimated animals undergo extensive, tissue-specific restructuring of membrane lipids as they reach minimal metabolic rates. However, hypoxia does not affect membrane composition in fish acclimated to 20 °C. The strong membrane response of cold-acclimated fish involves increases in cholesterol abundance (in white muscle and gills) and in fatty acid saturation, mainly caused by a reduction in %22:6 (docosahexaenoic acid in gills and liver). Major ion pumps like Na+/K+-ATPase are known to be inhibited by cholesterol and activated by 22:6. Because ion pumping by membrane-bound ATPases accounts for a large fraction of basal cellular energy use, we propose that the membrane responses reported here could be a novel mechanism to promote metabolic suppression in cold-acclimated animals.


Assuntos
Ácidos Graxos/metabolismo , Hipóxia/metabolismo , Animais , Colesterol/metabolismo , Carpa Dourada , Temperatura Ambiente
20.
Int J Mol Sci ; 20(16)2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31443163

RESUMO

Retinal neurodegeneration, an early characteristic of several blinding diseases, triggers glial activation, resulting in inflammation, secondary damage and visual impairment. Treatments that aim only at neuroprotection have failed clinically. Here, we examine the impact of modulating thioredoxin interacting protein (TXNIP) to the inflammatory secondary damage and visual impairment in a model of ischemia/reperfusion (IR). Wild type (WT) and TXNIP knockout (TKO) mice underwent IR injury by increasing intraocular pressure for 40 min, followed by reperfusion. An additional group of WT mice received intravitreal TXNIP-antisense oligomers (ASO, 100 µg/2 µL) 2 days post IR injury. Activation of Müller glial cells, apoptosis and expression of inflammasome markers and visual function were assessed. IR injury triggered early TXNIP mRNA expression that persisted for 14 days and was localized within activated Müller cells in WT-IR, compared to sham controls. Exposure of Müller cells to hypoxia-reoxygenation injury triggered endoplasmic reticulum (ER) stress markers and inflammasome activation in WT cells, but not from TKO cells. Secondary damage was evident by the significant increase in the number of occluded acellular capillaries and visual impairment in IR-WT mice but not in IR-TKO. Intervention with TXNIP-ASO prevented ischemia-induced glial activation and neuro-vascular degeneration, and improved visual function compared to untreated WT. Targeting TXNIP expression may offer an effective approach in the prevention of secondary damage associated with retinal neurodegenerative diseases.


Assuntos
Proteínas de Transporte/metabolismo , Traumatismo por Reperfusão/metabolismo , Tiorredoxinas/metabolismo , Animais , Proteínas de Transporte/genética , Modelos Animais de Doenças , Estresse do Retículo Endoplasmático/genética , Estresse do Retículo Endoplasmático/fisiologia , Gliose/metabolismo , Hipóxia/metabolismo , Inflamassomos/metabolismo , Camundongos , Camundongos Knockout , RNA Mensageiro/metabolismo , Traumatismo por Reperfusão/genética , Tiorredoxinas/genética
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