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1.
Clin Sci (Lond) ; 137(1): 17-30, 2023 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-36416117

RESUMO

Oxidative stress is vital for pathophysiology of atherosclerosis and non-alcoholic fatty liver disease (NAFLD). Monoamine oxidase (MAO) is an important source of oxidative stress in the vascular system and liver. However, the effect of MAO inhibition on atherosclerosis and NAFLD has not been explored. In the present study, MAO A and B expressions were increased in atherosclerotic plaques in human and apolipoprotein E (ApoE)-deficient mice. Inhibition of MAO B (by deprenyl), but not MAO A (by clorgyline), reduced the atheroma area in the thoracic aorta and aortic sinus in ApoE-deficient mice fed the cholesterol-enriched diet for 15 weeks. MAO B inhibition attenuated oxidative stress, expression of adhesion molecules, production of inflammatory cytokines, and macrophage infiltration in atherosclerotic plaques and decreased plasma triglyceride and low-density lipoprotein (LDL) cholesterol concentrations. MAO B inhibition had no therapeutic effect on restenosis in the femoral artery wire-induced injury model in C57BL/6 mice. In the NAFLD mouse model, MAO B inhibition reduced lipid droplet deposition in the liver and hepatic total cholesterol and triglyceride levels in C57BL/6 mice fed high-fat diets for 10 weeks. Key enzymes for triglyceride and cholesterol biosynthesis (fatty acid synthase and 3-hydroxy-3-methylglutaryl-CoA reductase, HMGCR) and inflammatory markers were inhibited, and cholesterol clearance was up-regulated (increased LDL receptor expression and reduced proprotein convertase subtilisin/kexin type 9, PCSK9, expression) by MAO B inhibition in the liver. These results were also demonstrated in the HepG2 liver cell model. Our data suggest that MAO B inhibition is a potential and novel treatment for atherosclerosis and NAFLD.


Assuntos
Aterosclerose , Hipercolesterolemia , Hepatopatia Gordurosa não Alcoólica , Placa Aterosclerótica , Camundongos , Humanos , Animais , Placa Aterosclerótica/metabolismo , Pró-Proteína Convertase 9/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/metabolismo , Monoaminoxidase/metabolismo , Camundongos Endogâmicos C57BL , Aterosclerose/tratamento farmacológico , Aterosclerose/prevenção & controle , Colesterol/metabolismo , Fígado/metabolismo , Triglicerídeos/metabolismo , Hipercolesterolemia/metabolismo , Apolipoproteínas E
2.
FASEB J ; 34(2): 2958-2967, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31908014

RESUMO

Fibrinogen-like-protein 1 (FGL1) is a novel hepatokine that plays an important role in hepatic steatosis and insulin resistance. Although FGL1 expression can be detected in adipose tissues, the functions of FGL1 in adipose tissues are still unknown. In this study, 356 participants with (body mass index (BMI) ≥25 kg/m2 ; n = 134) or without obesity (BMI <25 kg/m2 ; n = 222) were recruited, and we found that the plasma FGL1 concentrations were significantly higher in obese group than those of in the normal weight group, and were positively correlated with age, BMI, waist circumference, fat content, plasma glucose at 2 hours during an oral glucose tolerance test, and the insulin sensitivity index. In univariate analyses, BMI, waist circumference, total fat, visceral fat, and subcutaneous fat areas were positively correlated with FGL1 levels. After adjusting for age and gender, obesity indices, including the BMI and different fat areas, remained significantly associated with FGL1 levels. In order to investigate the causal relationship between FGL1 and obesity, animal and cell models were used. Overexpression of FGL1 in epididymal adipose tissue by lentiviral vector encoding FGL1 increased the fat pad size, whereas FGL1-knockdown by lentiviral vector encoding short-hairpin RNA targeted to FGL1 decreased high-fat diet-induced adiposity. In addition, 3T3-L1 adipocytes were used to clarify the possible mechanism of FGL1-induced adipogenesis. FGL1 induced adipogenesis through an ERK1/2-C/EBPß-dependent pathway in 3T3-L1 adipocytes. These findings highlight the pathophysiological role of FGL1 in obesity, and FGL1 might be a novel therapeutic target to combat obesity.


Assuntos
Adipócitos/metabolismo , Adipogenia , Tecido Adiposo/metabolismo , Fibrinogênio/metabolismo , Sistema de Sinalização das MAP Quinases , Obesidade/metabolismo , Células 3T3-L1 , Tecido Adiposo/patologia , Animais , Glicemia/genética , Glicemia/metabolismo , Gorduras na Dieta/efeitos adversos , Gorduras na Dieta/farmacologia , Feminino , Fibrinogênio/antagonistas & inibidores , Fibrinogênio/genética , Humanos , Masculino , Camundongos , Obesidade/induzido quimicamente , Obesidade/genética , Obesidade/terapia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/farmacologia
3.
Pharmacol Res ; 164: 105291, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33253817

RESUMO

Brown adipose tissue (BAT) activation or beige adipocytes in white adipocytes (WAT) (browning) is a novel strategy against obesity. Corylin, a flavonoid compound extract from Psoralea corylifolia L., has been shown to exert anti-inflammatory, anticancer, and anti-atherosclerotic effects and ameliorate hyperlipidemia and insulin resistance. However, the therapeutic effect of corylin on obesity remains unknown. The objective of this study was to evaluate the effect of corylin on browning or obesity. Here, we report that corylin induced browning by elevating the expression levels of beige- or browning-specific marker genes, including cited1, hoxc9, pgc1α, prdm16, and ucp1, in 3T3-L1 adipocytes, WAT and BAT. Moreover, corylin also strikingly reduced body weight and fat accumulation and increased insulin sensitivity, mitochondrial biogenesis, and ß-oxidation in HFD- and DIO-treated mice. The browning and lipolysis effects of corylin were abolished by sirtuin 1 (SIRT1) inhibitor (EX527) and ß3-adrenergic receptor (ß3-AR) antagonist (L-748,337) treatment. The possible molecular mechanism of corylin on the browning and lipolysis of adipocytes is through SIRT1- or ß3-AR-dependent pathways. The study suggested that corylin exerts anti-obesity effects through the browning of white adipocytes, activating of BAT and promoting of lipid metabolism. Therefore, corylin may be a helpful therapeutic candidate for treating obesity.


Assuntos
Fármacos Antiobesidade/uso terapêutico , Flavonoides/uso terapêutico , Obesidade/tratamento farmacológico , Receptores Adrenérgicos beta 3/metabolismo , Sirtuína 1/metabolismo , Células 3T3-L1 , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Tecido Adiposo Marrom/efeitos dos fármacos , Tecido Adiposo Branco/efeitos dos fármacos , Animais , Fármacos Antiobesidade/farmacologia , Dieta Hiperlipídica , Flavonoides/farmacologia , Resistência à Insulina , Lipólise/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/metabolismo
4.
Hum Mol Genet ; 26(14): 2768-2780, 2017 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-28460014

RESUMO

Spinal muscular atrophy (SMA) is a neuromuscular disease caused by reduced expression of survival of motor neuron (SMN), a protein expressed in humans by two paralogous genes, SMN1 and SMN2. These genes are nearly identical, except for 10 single-nucleotide differences and a 5-nucleotide insertion in SMN2. SMA is subdivided into four main types, with type I being the most severe. SMN2 copy number is a key positive modifier of the disease, but it is not always inversely correlated with clinical severity. We previously reported the c.859G > C variant in SMN2 exon 7 as a positive modifier in several patients. We have now identified A-44G as an additional positive disease modifier, present in a group of patients carrying 3 SMN2 copies but displaying milder clinical phenotypes than other patients with the same SMN2 copy number. One of the three SMN2 copies appears to have been converted from SMN1, but except for the C6T transition, no other changes were detected. Analyzed with minigenes, SMN1C6T displayed a ∼20% increase in exon 7 inclusion, compared to SMN2. Through systematic mutagenesis, we found that the improvement in exon 7 splicing is mainly attributable to the A-44G transition in intron 6. Using RNA-affinity chromatography and mass spectrometry, we further uncovered binding of the RNA-binding protein HuR to the -44 region, where it acts as a splicing repressor. The A-44G change markedly decreases the binding affinity of HuR, resulting in a moderate increase in exon 7 inclusion.


Assuntos
Atrofia Muscular Espinal/genética , Animais , Células COS , Chlorocebus aethiops , Proteína Semelhante a ELAV 1/metabolismo , Éxons , Células HEK293 , Células HeLa , Humanos , Íntrons , Atrofia Muscular Espinal/metabolismo , Ligação Proteica , RNA/genética , Motivo de Reconhecimento de RNA , Splicing de RNA , Proteína 1 de Sobrevivência do Neurônio Motor/genética , Proteína 1 de Sobrevivência do Neurônio Motor/metabolismo , Proteína 2 de Sobrevivência do Neurônio Motor/genética , Proteína 2 de Sobrevivência do Neurônio Motor/metabolismo
5.
Int J Obes (Lond) ; 43(3): 512-522, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30022055

RESUMO

BACKGROUND/OBJECTIVES: Vascular adhesion protein-1 (VAP-1) can enhance tissue glucose uptake in cell studies and normalize hyperglycemia in animal studies. However, serum VAP-1 concentration (sVAP-1) is higher in subjects with diabetes in cross-sectional studies. In this cohort study, we test our hypothesis that sVAP-1 is increased in prediabetes to counteract hyperglycemia and is associated with incident diabetes negatively. SUBJECTS/METHODS: From 2006 to 2012, 600 subjects without diabetes from Taiwan Lifestyle Study were included and followed regularly. Diabetes was diagnosed if FPG ≥ 126 mg/dL (7 mmol/L), 2-h plasma glucose (2hPG) during an oral glucose tolerance test (OGTT) ≥ 200 mg/dL (11.1 mmol/L), or hemoglobin A1c (HbA1c) ≥ 6.5%, or if the subject received anti-diabetic medications. Abdominal fat areas were measured by abdominal computed tomography and sVAP-1 was analyzed by ELISA. RESULTS: sVAP-1 was higher in subjects with prediabetes (p < 0.05) and increased during an OGTT (p < 0.001). Fasting sVAP-1 was associated with the response of sVAP-1 during an OGTT (p < 0.001). Besides, sVAP-1 was associated negatively with body mass index (BMI, r = -0.1449, p = 0.003), waist circumference (r = -0.1425, p = 0.004), abdominal visceral (r = -0.1457, p = 0.003), and subcutaneous (r = -0.1025, p = 0.035) fat areas, and serum high-sensitivity C-reactive protein (hsCRP) concentration (r = -0.2035, p < 0.0001), and positively with plasma adiponectin concentration (r = 0.2086, p < 0.0001), adjusted for age and gender. After 4.7 ± 2.6 years, 73 subjects (12.2%) developed incident diabetes. High sVAP-1 predicted a lower incidence of diabetes, adjusted for age, gender, BMI, family history of diabetes, HbA1c, HOMA2-%B and HOMA2-IR (HR = 0.66, 95% CI = 0.50-0.88, p < 0.01). CONCLUSIONS: sVAP-1 is increased in response to hyperglycemia. It is associated with obesity and serum hsCRP concentration negatively, and plasma adiponectin concentration positively. Besides, a high sVAP-1 is associated with a lower incidence of diabetes in human.


Assuntos
Amina Oxidase (contendo Cobre)/sangue , Moléculas de Adesão Celular/sangue , Hiperglicemia , Estado Pré-Diabético , Adiponectina/sangue , Adulto , Proteína C-Reativa/análise , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/metabolismo , Feminino , Humanos , Hiperglicemia/sangue , Hiperglicemia/epidemiologia , Hiperglicemia/metabolismo , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Obesidade , Estado Pré-Diabético/sangue , Estado Pré-Diabético/epidemiologia , Estado Pré-Diabético/metabolismo , Taiwan , Regulação para Cima
6.
Part Fibre Toxicol ; 15(1): 4, 2018 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-29329563

RESUMO

BACKGROUND: Epidemiological studies have shown that ambient air pollution is closely associated with increased respiratory inflammation and decreased lung function. Particulate matters (PMs) are major components of air pollution that damages lung cells. However, the mechanisms remain to be elucidated. This study examines the effects of PMs on intercellular adhesion molecule-1 (ICAM-1) expression and the related mechanisms in vitro and in vivo. RESULT: The cytotoxicity, reactive oxygen species (ROS) generation, and monocyte adherence to A549 cells were more severely affected by treatment with O-PMs (organic solvent-extractable fraction of SRM1649b) than with W-PMs (water-soluble fraction of SRM1649b). We observed a significant increase in ICAM-1 expression by O-PMs, but not W-PMs. O-PMs also induced the phosphorylation of AKT, p65, and STAT3. Pretreating A549 cells with N-acetyl cysteine (NAC), an antioxidant, attenuated O-PMs-induced ROS generation, the phosphorylation of the mentioned kinases, and the expression of ICAM-1. Furthermore, an AKT inhibitor (LY294002), NF-κB inhibitor (BAY11-7082), and STAT3 inhibitor (Stattic) significantly down-regulated O-PMs-induced ICAM-1 expression as well as the adhesion of U937 cells to epithelial cells. Interleukin-6 (IL-6) was the most significantly changed cytokine in O-PMs-treated A549 cells according to the analysis of the cytokine antibody array. The IL-6 receptor inhibitor tocilizumab (TCZ) and small interfering RNA for IL-6 significantly reduced ICAM-1 secretion and expression as well as the reduction of the AKT, p65, and STAT3 phosphorylation in O-PMs-treated A549 cells. In addition, the intratracheal instillation of PMs significantly increased the levels of the ICAM-1 and IL-6 in lung tissues and plasma in WT mice, but not in IL-6 knockout mice. Pre-administration of NAC attenuated those PMs-induced adverse effects in WT mice. Furthermore, patients with chronic obstructive pulmonary disease (COPD) had higher plasma levels of ICAM-1 and IL-6 compared to healthy subjects. CONCLUSION: These results suggest that PMs increase ICAM-1 expression in pulmonary epithelial cells in vitro and in vivo through the IL-6/AKT/STAT3/NF-κB signaling pathway.


Assuntos
Poluentes Atmosféricos/toxicidade , Molécula 1 de Adesão Intercelular/genética , Pulmão/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Material Particulado/toxicidade , Doença Pulmonar Obstrutiva Crônica/sangue , Transdução de Sinais , Células A549 , Poluentes Atmosféricos/química , Animais , Sobrevivência Celular/efeitos dos fármacos , Humanos , Exposição por Inalação , Molécula 1 de Adesão Intercelular/sangue , Interleucina-6/sangue , Interleucina-6/metabolismo , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , NF-kappa B/metabolismo , Estresse Oxidativo/genética , Material Particulado/química , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator de Transcrição STAT3/metabolismo , Solubilidade
7.
Int J Mol Sci ; 19(2)2018 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-29382035

RESUMO

Corylin is a flavonoid extracted from the nuts of Psoralea corylifolia L. (Fabaceae), which is a widely used anti-inflammatory and anticancer herb in China. Recent studies revealed antioxidant, anti-inflammatory, and bone differentiation-promoting effects of corylin. However, there are no studies examining the anticancer activity of corylin. In this study, we used cells and animal models to examine the antitumor effects of corylin on hepatocellular carcinoma (HCC) and then studied its downstream regulatory mechanisms. The results showed that corylin significantly inhibited the proliferation, migration, and invasiveness of HCC cells and suppressed epithelial-mesenchymal transition. We found that the anti-HCC mechanism of corylin's action lies in the upregulation of tumor suppressor long noncoding RNA growth arrest-specific transcript 5 (GAS5) and the activation of its downstream anticancer pathways. In animal experiments, we also found that corylin can significantly inhibit tumor growth without significant physiological toxicity. The above results suggest that corylin has anti-HCC effects and good potential as a clinical treatment.


Assuntos
Antineoplásicos/farmacologia , Carcinoma Hepatocelular/tratamento farmacológico , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Flavonoides/farmacologia , Neoplasias Hepáticas/tratamento farmacológico , Animais , Antineoplásicos/uso terapêutico , Transição Epitelial-Mesenquimal/genética , Flavonoides/uso terapêutico , Células Hep G2 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , RNA Nucleolar Pequeno/genética
8.
Int J Mol Sci ; 18(12)2017 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-29215575

RESUMO

Effective DNA repair enables cancer cells to survive DNA damage induced by chemotherapeutic or radiotherapeutic treatments. Therefore, inhibiting DNA repair pathways is a promising therapeutic strategy for increasing the efficacy of such treatments. In this study, we found that dihydrocoumarin (DHC), a flavoring agent, causes deficiencies in double-stand break (DSB) repair and prolonged DNA damage checkpoint recovery in yeast. Following DNA damage, Rad52 recombinase was revealed to be inhibited by DHC, which results in deficiencies in DSB repair and prolonged DNA damage checkpoint recovery. The deletion of RPD3, a class I histone deacetylase (HDAC), was found to mimic DHC-induced suppression of Rad52 expression, suggesting that the HDAC inhibitor activity of DHC is critical to DSB repair and DNA damage sensitivity. Overall, our findings delineate the regulatory mechanisms of DHC in DSB repair and suggest that it might potentially be used as an inhibitor of the DNA repair pathway in human cells.


Assuntos
Cumarínicos/toxicidade , Dano ao DNA , Aromatizantes/toxicidade , Inibidores de Histona Desacetilases/toxicidade , Proteína Rad52 de Recombinação e Reparo de DNA/antagonistas & inibidores , Proteínas de Saccharomyces cerevisiae/antagonistas & inibidores , Cumarínicos/farmacologia , Aromatizantes/farmacologia , Inibidores de Histona Desacetilases/farmacologia , Reparo de DNA por Recombinação , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
9.
Arch Toxicol ; 90(11): 2779-2792, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26659566

RESUMO

Uremic toxins are considered a risk factor for cardiovascular disorders in kidney diseases, but it is not known whether, under inflammatory conditions, they affect adhesion molecule expression on endothelial cells, which may play a critical role in acute kidney injury (AKI). In the present study, in cardiovascular surgery-related AKI patients, who are known to have high plasma levels of the uremic toxin indoxyl sulfate (IS), plasma levels of IL-1ß were found to be positively correlated with plasma levels of the adhesion molecule E-selectin. In addition, high E-selectin and IL-1ß expression were seen in the kidney of ischemia/reperfusion mice in vivo. We also examined the effects of IS on E-selectin expression by IL-1ß-treated human umbilical vein endothelial cells (HUVECs) and the underlying mechanism. IS pretreatment of HUVECs significantly increased IL-1ß-induced E-selectin expression, monocyte adhesion, and the phosphorylation of mitogen-activated protein kinases (ERK, p38, and JNK) and transcription factors (NF-κB and AP-1), and phosphorylation was decreased by pretreatment with inhibitors of ERK1/2 (PD98059), p38 MAPK (SB202190), and JNK (SP600125). Furthermore, IS increased IL-1ß-induced reactive oxygen species (ROS) production and this effect was inhibited by pretreatment with N-acetylcysteine (a ROS scavenger) or apocynin (a NADPH oxidase inhibitor). Gel shift assays and ChIP-PCR demonstrated that IS enhanced E-selectin expression in IL-1-treated HUVECs by increasing NF-κB and AP-1 DNA-binding activities. Moreover, IS-enhanced E-selectin expression in IL-1ß-treated HUVECs was inhibited by Bay11-7082, a NF-κB inhibitor. Thus, IS may play an important role in the development of cardiovascular disorders in kidney diseases during inflammation by increasing endothelial expression of E-selectin.


Assuntos
Selectina E/metabolismo , Endotélio Vascular/efeitos dos fármacos , Indicã/toxicidade , Interleucina-1beta/agonistas , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Venenos/toxicidade , Regulação para Cima/efeitos dos fármacos , Injúria Renal Aguda/sangue , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Injúria Renal Aguda/fisiopatologia , Idoso , Animais , Biomarcadores/sangue , Biomarcadores/metabolismo , Células Cultivadas , Modelos Animais de Doenças , Selectina E/química , Selectina E/genética , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Endotélio Vascular/fisiopatologia , Feminino , Células Endoteliais da Veia Umbilical Humana , Humanos , Indicã/sangue , Interleucina-1beta/metabolismo , Rim/irrigação sanguínea , Rim/metabolismo , Rim/patologia , Rim/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Estresse Oxidativo/efeitos dos fármacos , Venenos/sangue , Traumatismo por Reperfusão/sangue , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia , Uremia/etiologia
10.
Proc Natl Acad Sci U S A ; 110(13): 5058-63, 2013 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-23479629

RESUMO

The acquisition of flight contributed to the success of insects and winged forms are present in most orders. Key to understanding the origin of wings will be knowledge of the earliest postembryonic events promoting wing outgrowth. The Drosophila melanogaster wing is intensely studied as a model appendage, and yet little is known about the beginning of wing outgrowth. Vein (Vn) is a neuregulin-like ligand for the EGF receptor (Egfr), which is necessary for global development of the early Drosophila wing disc. vn is not expressed in the embryonic wing primordium and thus has to be induced de novo in the nascent larval wing disc. We find that Decapentaplegic (Dpp), a Bone Morphogenetic Protein (BMP) family member, provides the instructive signal for initiating vn expression. The signaling involves paracrine communication between two epithelia in the early disc. Once initiated, vn expression is amplified and maintained by autocrine signaling mediated by the E-twenty six (ETS)-factor PointedP2 (PntP2). This interplay of paracrine and autocrine signaling underlies the spatial and temporal pattern of induction of Vn/Egfr target genes and explains both body wall development and wing outgrowth. It is possible this gene regulatory network governing expression of an EGF ligand is conserved and reflects a common origin of insect wings.


Assuntos
Proteínas de Drosophila/metabolismo , Receptores ErbB/metabolismo , Regulação da Expressão Gênica/fisiologia , Receptores de Peptídeos de Invertebrados/metabolismo , Transdução de Sinais/fisiologia , Asas de Animais/crescimento & desenvolvimento , Animais , Proteínas de Drosophila/biossíntese , Proteínas de Drosophila/genética , Drosophila melanogaster , Receptores ErbB/genética , Neurregulinas/biossíntese , Neurregulinas/genética , Receptores de Peptídeos de Invertebrados/genética
11.
Nature ; 462(7275): 930-4, 2009 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-20016602

RESUMO

In the established model of mammalian cell cycle control, the retinoblastoma protein (Rb) functions to restrict cells from entering S phase by binding and sequestering E2f activators (E2f1, E2f2 and E2f3), which are invariably portrayed as the ultimate effectors of a transcriptional program that commit cells to enter and progress through S phase. Using a panel of tissue-specific cre-transgenic mice and conditional E2f alleles we examined the effects of E2f1, E2f2 and E2f3 triple deficiency in murine embryonic stem cells, embryos and small intestines. We show that in normal dividing progenitor cells E2f1-3 function as transcriptional activators, but contrary to the current view, are dispensable for cell division and instead are necessary for cell survival. In differentiating cells E2f1-3 function in a complex with Rb as repressors to silence E2f targets and facilitate exit from the cell cycle. The inactivation of Rb in differentiating cells resulted in a switch of E2f1-3 from repressors to activators, leading to the superactivation of E2f responsive targets and ectopic cell divisions. Loss of E2f1-3 completely suppressed these phenotypes caused by Rb deficiency. This work contextualizes the activator versus repressor functions of E2f1-3 in vivo, revealing distinct roles in dividing versus differentiating cells and in normal versus cancer-like cell cycles.


Assuntos
Diferenciação Celular , Fatores de Transcrição E2F/metabolismo , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Regulação da Expressão Gênica , Proteínas Repressoras/metabolismo , Alelos , Animais , Apoptose , Ciclo Celular/genética , Ciclo Celular/fisiologia , Proliferação de Células , Fatores de Transcrição E2F/deficiência , Fatores de Transcrição E2F/genética , Fator de Transcrição E2F1/deficiência , Fator de Transcrição E2F1/genética , Fator de Transcrição E2F1/metabolismo , Fator de Transcrição E2F2/deficiência , Fator de Transcrição E2F2/genética , Fator de Transcrição E2F2/metabolismo , Fator de Transcrição E2F3/deficiência , Fator de Transcrição E2F3/genética , Fator de Transcrição E2F3/metabolismo , Embrião de Mamíferos/citologia , Embrião de Mamíferos/metabolismo , Feminino , Intestino Delgado/citologia , Intestino Delgado/metabolismo , Camundongos , Camundongos Transgênicos , Proteínas Repressoras/deficiência , Proteínas Repressoras/genética , Proteína do Retinoblastoma/deficiência , Proteína do Retinoblastoma/metabolismo
12.
Biochim Biophys Acta Mol Basis Dis ; 1870(4): 167099, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38428686

RESUMO

The abnormal proliferation, migration, and inflammation of vascular smooth muscle cells (VSMCs) play crucial roles in the development of neointimal hyperplasia and restenosis. Exposure to inflammatory cytokines such as platelet-derived growth factor (PDGF)-BB and tumour necrosis factor-alpha (TNF-α) induces the transformation of contractile VSMCs into abnormal synthetic VSMCs. Isoxanthohumol (IXN) has significant anti-inflammatory, antiproliferative, and antimigratory effects. This study aimed to explore the therapeutic impact and regulatory mechanism of IXN in treating neointimal hyperplasia. The present findings indicate that IXN effectively hinders the abnormal proliferation, migration, and inflammation of VSMCs triggered by PDGF or TNF-α. This inhibition is primarily achieved through the modulation of the apelin/AKT or AKT pathway, respectively. In an in vivo model, IXN effectively reduced neointimal hyperplasia in denuded femoral arteries. These results suggest that IXN holds promise as a potential and innovative therapeutic candidate for the treatment of restenosis.


Assuntos
Proteínas Proto-Oncogênicas c-akt , Fator de Necrose Tumoral alfa , Xantonas , Humanos , Hiperplasia/tratamento farmacológico , Proliferação de Células , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Apelina , Movimento Celular , Becaplermina/farmacologia , Neointima/tratamento farmacológico , Neointima/metabolismo , Inflamação
13.
Biofactors ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38760159

RESUMO

Angiopoietin-like protein 4 (ANGPTL4) is a secretory glycoprotein involved in regulating glucose homeostasis in non-pregnant subjects. However, its role in glucose metabolism during pregnancy and the pathophysiology of gestational diabetes mellitus (GDM) remains elusive. Thus, this study aimed to clarify the relationship between ANGPTL4 and GDM and investigate the pathophysiology of placental ANGPTL4 in glucose metabolism. We investigated this issue using blood and placenta samples in 957 pregnant women, the human 3A-sub-E trophoblast cell line, and the L6 skeletal muscle cell line. We found that ANGPTL4 expression in the placenta was higher in obese pregnant women than in lean controls. Palmitic acid significantly induced ANGPTL4 expression in trophoblast cells in a dose-response manner. ANGPTL4 overexpression in trophoblast cells resulted in endoplasmic reticulum (ER) stress, which stimulated the expression and secretion of growth hormone-variant (GH2) but not human placental lactogen. In L6 skeletal muscle cells, soluble ANGPTL4 suppressed insulin-mediated glucose uptake through the epidermal growth factor receptor (EGFR)/extracellular signal-regulated kinases 1/2 (ERK 1/2) pathways. In pregnant women, plasma ANGPTL4 concentrations in the first trimester predicted the incidence of GDM and were positively associated with BMI, plasma triglyceride, and plasma GH2 in the first trimester. However, they were negatively associated with insulin sensitivity index ISI0,120 in the second trimester. Overall, placental ANGPTL4 is induced by obesity and is involved in the pathophysiology of GDM via the induction of ER stress and GH2 secretion. Soluble ANGPTL4 can lead to insulin resistance in skeletal muscle cells and is an early biomarker for predicting GDM.

14.
Bioorg Med Chem Lett ; 23(3): 687-92, 2013 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-23265893

RESUMO

Receptor targeting ligands for imaging and/or therapy of cancer are limited by heterogeneity of receptor expression by tumor cells, both inter-patient and intra-patient. It is often more important for imaging agents to identify local and distant spread of disease than it is to identify a specific receptor presence. Two natural hormone peptide receptors, GRPR and Y1, are specifically interesting because expression of GRPR, Y1 or both is up-regulated in most breast cancers. We describe here the design and development of a new heterobivalent peptide ligand, truncated bombesin (t-BBN)/BVD15-DO3A, for dual-targeting of GRPR and Y1, and validation of its dual binding capability. Such a probe should be useful in imaging cells, tissues and tumors that are GRPR and/or Y1 positive and should target radioisotopes, for example, (68)Ga and/or (177)Lu, to more tumors cells than single GRPR or Y1 targeted probes. A GRP targeting ligand, J-G-Abz4-QWAVGHLM-NH(2) (J-G-Abz4-t-BBN), and an Y1 targeting ligand, INP-K[ε-J-(α-DO3A-ε-DGa)-K]-YRLRY-NH(2)([ε-J-(α-DO3A-ε-DGa)-K]-BVD-15), were synthesized and coupled to produce the heterobivalent ligand, t-BBN/BVD15-DO3A. Competitive displacement binding assays using t-BBN/BVD15-DO3A against (125)I-Tyr(4)-BBN yielded an IC(50) value of 18 ± 0.7 nM for GRPR in T-47D cells, a human breast cancer cell line. A similar assay using t-BBN/BVD15-DO3A against porcine (125)I-NPY showed IC(50) values of 80 ± 11 nM for Y1 receptor in MCF7 cells, another human breast cancer cell line. In conclusion, it is possible to construct a single DO3A chelate containing probe that can target both GRPR and Y1 on human tumor cells.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Sistemas de Liberação de Medicamentos , Ligantes , Peptídeos/metabolismo , Receptores da Bombesina/metabolismo , Receptores de Neuropeptídeo Y/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular Tumoral , Técnicas de Química Sintética , Feminino , Humanos , Concentração Inibidora 50 , Dados de Sequência Molecular , Peptídeos/genética , Ligação Proteica , Receptores da Bombesina/genética , Receptores de Neuropeptídeo Y/genética , Suínos
15.
J Cell Physiol ; 227(8): 3063-71, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22021110

RESUMO

Ganoderma lucidum is used in traditional Chinese medicine to prevent or treat a variety of diseases, including cardiovascular disorders. We previously demonstrated that a glucan-containing extract of Reishi polysaccharides (EORP) has the potent anti-inflammatory action of reducing ICAM-1 expression in lipopolysaccharide (LPS)-treated human aortic smooth muscle cells (HASMCs) and LPS-treated mice. In the present study, we examined whether EORP inhibited platelet-derived growth factor-BB (PDGF)-stimulated HASMC proliferation and the mechanism involved. EORP dose-dependently reduced cell numbers and DNA synthesis of PDGF-treated HASMCs in vitro. EORP also arrested cell cycle progression in the G0/G1 phase, and this was associated with decreased expression of cyclin D1, cyclin E, CDK2, CDK4, and p21(Cip1) and upregulation of the cyclin-dependent kinase inhibitor p27(Kip1). The anti-proliferative effect of EORP was partly mediated by downregulation of PDGF-induced JNK phosphorylation. In in vivo studies, the femoral artery of C57BL/6 mice was endothelial-denuded and the mice were fed a diet containing 100 mg/kg/day of EORP. On day 14, both cell proliferation (proliferating cell nuclear antigen-positive cells) in the neointima and the neointima/media area ratio (0.67 ± 0.03 vs. 1.46 ± 0.30) were significantly reduced. Our data show that EORP interferes with the mitogenic activation of JNK, preventing entry of HASMCs into the cell cycle in vitro and reducing cell proliferation in the neointima and decreasing the neointimal area in vivo. Thus, EORP may represent a safe and effective novel approach to the prevention and treatment of vascular proliferative diseases.


Assuntos
Proliferação de Células/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Miócitos de Músculo Liso , Neointima , Polissacarídeos/farmacologia , Reishi , Animais , Aorta/citologia , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Medicamentos de Ervas Chinesas/química , Técnicas de Silenciamento de Genes , Humanos , Lipopolissacarídeos/farmacologia , MAP Quinase Quinase 4/genética , MAP Quinase Quinase 4/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/patologia , Fosforilação/efeitos dos fármacos , Fator de Crescimento Derivado de Plaquetas/farmacologia
16.
J Biomed Biotechnol ; 2012: 871272, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22685380

RESUMO

Pigment epithelium-derived factor (PEDF) was first identified in retinal pigment epithelium cells. It is an endogenously produced protein that is widely expressed throughout the human body such as in the eyes, liver, heart, and adipose tissue; it exhibits multiple and varied biological activities. PEDF is a multifunctional protein with antiangiogenic, antitumorigenic, antioxidant, anti-inflammatory, antithrombotic, neurotrophic, and neuroprotective properties. More recently, PEDF has been shown to be the most potent inhibitor of stem/progenitor cell-associated neovascularization. Neovascularization is a complex process regulated by a large, interacting network of molecules from stem/progenitor cells. PEDF is also involved in the pathogenesis of angiogenic eye disease, tumor growth, and cardiovascular disease. Novel antiangiogenic agents with tolerable side effects are desired for the treatment of patients with various diseases. Here, we review the value of PEDF as an important endogenous antiangiogenic molecule; we focus on the recently identified role of PEDF as a possible new target molecule to influence stem/progenitor cell-related neovascularization.


Assuntos
Proteínas do Olho/fisiologia , Neovascularização Fisiológica/fisiologia , Fatores de Crescimento Neural/fisiologia , Serpinas/fisiologia , Células-Tronco/fisiologia , Animais , Humanos , Células-Tronco/citologia
17.
Cell Biol Int ; 36(9): 833-41, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22582758

RESUMO

LPA (lysophosphatidic acid) is a natural phospholipid that plays important roles in promoting cancer cell proliferation, invasion and metastases. We previously reported that LPA induces ovarian cancer cell dispersal and disruption of AJ (adherens junction) through the activation of SFK (Src family kinases). In this study, we have investigated the regulatory mechanisms during the early phase of LPA-induced cell dispersal. An in vitro model of the ovarian cancer cell line SKOV3 for cell dispersal was used. LPA induces rapid AJ disruption by increasing the internalization of N-cadherin-ß-catenin. By using immunoprecipitations, LPA was shown to induce increased tyrosine phosphorylation of ß-catenin and alter the balance of ß-catenin-bound SFK and PTP1B (phosphotyrosine phosphatase 1B). The altered balance of tyrosine kinase/phosphatase correlated with a concomitant disintegration of the ß-catenin-α-catenin, but not the ß-catenin-N-cadherin complex. This disintegration of ß-catenin from α-catenin and the cell dispersal caused by LPA can be rescued by blocking SFK activity with the chemical inhibitor, PP2. More importantly, PP2 also restores the level of PTP1B bound to ß-catenin. We propose that LPA signalling alters AJ stability by changing the dynamics of tyrosine kinase/phosphatase bound to AJ proteins. This work provides further understanding of the early signalling events regulating ovarian cancer cell dispersal and AJ disruption induced by LPA.


Assuntos
Junções Aderentes/metabolismo , Caderinas/metabolismo , Cateninas/metabolismo , Lisofosfolipídeos/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 1/metabolismo , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Complexos Multiproteicos/metabolismo , Invasividade Neoplásica , Metástase Neoplásica , Neoplasias Ovarianas , Fosforilação , Proteínas Proto-Oncogênicas c-fyn/genética , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Interferência de RNA , RNA Interferente Pequeno , Transdução de Sinais , Quinases da Família src/antagonistas & inibidores , Quinases da Família src/metabolismo
18.
Nat Commun ; 13(1): 1238, 2022 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-35264584

RESUMO

In the long history of traditional Chinese medicine, single herbs and complex formulas have been suggested to increase lifespan. However, the identification of single molecules responsible for lifespan extension has been challenging. Here, we collected a list of traditional Chinese medicines with potential longevity properties from pharmacopeias. By utilizing the mother enrichment program, we systematically screened these traditional Chinese medicines and identified a single herb, Psoralea corylifolia, that increases lifespan in Saccharomyces cerevisiae. Next, twenty-two pure compounds were isolated from Psoralea corylifolia. One of the compounds, corylin, was found to extend the replicative lifespan in yeast by targeting the Gtr1 protein. In human umbilical vein endothelial cells, RNA sequencing data showed that corylin ameliorates cellular senescence. We also examined an in vivo mammalian model, and found that corylin extends lifespan in mice fed a high-fat diet. Taken together, these findings suggest that corylin may promote longevity.


Assuntos
Células Endoteliais , Longevidade , Animais , Flavonoides/farmacologia , Mamíferos , Medicina Tradicional Chinesa , Camundongos
19.
Br J Haematol ; 153(5): 623-33, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21470196

RESUMO

Drug resistance and associated immune deregulation limit use of current therapies in chronic lymphocytic leukaemia (CLL), thus warranting alternative therapy development. Herein we demonstrate that OSU-DY7, a novel D-tyrosinol derivative targeting p38 mitogen-activated protein kinase (MAPK), mediates cytotoxicity in lymphocytic cell lines representing CLL (MEC-1), acute lymphoblastic leukaemia (697 cells), Burkitt lymphoma (Raji and Ramos) and primary B cells from CLL patients in a dose- and time-dependent manner. The OSU-DY7-induced cytotoxicity is dependent on caspase activation, as evidenced by induction of caspase-3 activation and poly (ADP-ribose) polymerase (PARP) cleavage and rescue of cytotoxicity by Z-VAD-FMK. Interestingly, OSU-DY7-induced cytotoxicity is mediated through activation of p38 MAPK, as evidenced by increased phosphorylation of p38 MAPK and downstream target protein MAPKAPK2. Pretreatment of B-CLL cells with SB202190, a specific p38 MAPK inhibitor, results in decreased MAPKAPK2 protein level with concomitant rescue of the cells from OSU-DY7-mediated cytotoxicity. Furthermore, OSU-DY7-induced cytotoxicity is associated with down regulation of p38 MAPK target BIRC5, that is rescued at protein and mRNA levels by SB202190. This study provides evidence for a role of OSU-DY7 in p38 MAPK activation and BIRC5 down regulation associated with apoptosis in B lymphocytic cells, thus warranting development of this alternative therapy for lymphoid malignancies.


Assuntos
Antineoplásicos/farmacologia , Linfoma de Burkitt/patologia , Leucemia Linfocítica Crônica de Células B/patologia , Tirosina/análogos & derivados , Proteínas Quinases p38 Ativadas por Mitógeno/fisiologia , Antineoplásicos/administração & dosagem , Apoptose/efeitos dos fármacos , Linfócitos B/efeitos dos fármacos , Linfoma de Burkitt/enzimologia , Caspase 3/metabolismo , Morte Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos/métodos , Ativação Enzimática/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Proteínas Inibidoras de Apoptose/biossíntese , Proteínas Inibidoras de Apoptose/genética , Leucemia Linfocítica Crônica de Células B/enzimologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Fosforilação/efeitos dos fármacos , Poli(ADP-Ribose) Polimerases/metabolismo , Survivina , Células Tumorais Cultivadas , Tirosina/administração & dosagem , Tirosina/farmacologia
20.
Nutrients ; 13(11)2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34836239

RESUMO

Obesity is associated with the risk of cardiovascular disease, and non-nutritive sweetener, such as acesulfame potassium (AceK) has been used to combat obesity. However, the effects of AceK on cardiovascular disease are still unclear. In this study, high cholesterol diet (HCD)-fed ApoE-/- mice had dysregulated plasma lipid profile, and developed atherosclerosis, determined by atherosclerotic plaque in the aorta. Supplement of AceK in HCD worsened the dyslipidemia and increased atherosclerotic plaque, as compared with HCD-fed ApoE-/- mice. Since treatment of AceK in RAW264.7 macrophages showed no significant effects on inflammatory cytokine expressions, we then investigated the impacts of AceK on lipid metabolism. We found that AceK consumption enhanced hepatic lipogenesis and decreased ß-oxidation in ApoE-/- mice. In addition, AceK directly increased lipogenesis and decreased ß-oxidation in HepG2 cells. Taken together, a concurrent consumption of AceK exacerbated HCD-induced dyslipidemia and atherosclerotic lesion in ApoE-/- mice, and AceK might increase the risk of atherosclerosis under HCD.


Assuntos
Apolipoproteínas E/deficiência , Aterosclerose/metabolismo , Aterosclerose/patologia , Progressão da Doença , Metabolismo dos Lipídeos , Adoçantes não Calóricos/efeitos adversos , Tiazinas/efeitos adversos , Animais , Apolipoproteínas E/metabolismo , Aterosclerose/complicações , Aterosclerose/genética , Citocinas/metabolismo , Dieta Hiperlipídica , Dislipidemias/complicações , Regulação da Expressão Gênica , Células Hep G2 , Homeostase , Humanos , Mediadores da Inflamação/metabolismo , Metabolismo dos Lipídeos/genética , Masculino , Camundongos , Camundongos Knockout , Células RAW 264.7 , Tiazinas/administração & dosagem
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