RESUMO
Background: Hepatocellular carcinoma (HCC) is the most common form of liver cancer. Circular RNAs (circRNAs) play a vital role in cancer development and progression. This study investigated the role and potential mechanism of circRNA filamin binding LIM protein 1 (circFBLIM1) in HCC. Methods: Exosomes were identified by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and Western blot assay. The levels of circFBLIM1, miR-338, and low-density lipoprotein receptor-related protein 6 (LRP6) were measured by quantitative real-time polymerase chain reaction or Western blot. Glycolysis was analyzed by detecting glucose consumption, lactate production, ATP level, extracellular acidification rate (ECAR), and oxygen consumption rate (OCR). Cell viability was evaluated by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay. Cell apoptosis was detected by flow cytometry. Xenograft assay was performed to analyze tumor growth in vivo. The interaction among circFBLIM1, miR-338, and LRP6 was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. This study was approved by the Institutional Review Board of the First Affiliated Hospital of Guizhou University of Traditional Chinese Medicine. Results: CircFBLIM1 was highly expressed in HCC serum exosomes and HCC cells. Inhibition of circFBLIM1 confined HCC glycolysis and progression. CircFBLIM1 knockdown blocked tumorigenesis in vivo. CircFBLIM1 was a sponge of miR-338 and promoted HCC progression and glycolysis by regulating miR-338. Moreover, miR-338 suppressed HCC progression and glycolysis via targeting LRP6. Mechanistically, circFBLIM1 functioned as an miR-338 sponge to upregulate LRP6. Conclusion: CircFBLIM1 facilitated HCC progression and glycolysis via modulating the miR-338/LRP6 axis, which may provide promising therapeutic targets for HCC.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Humanos , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Apoptose , MicroRNAs/genética , Proliferação de Células , Linhagem Celular Tumoral , GlicóliseRESUMO
Our study is to explore the key molecular of Low-density lipoprotein receptor-related protein 6 (LRP6) and the related Wnt/ß-catenin pathway regulated by LRP6 during the intestinal barrier dysfunction. Colorectal protein profile analysis showed that LRP6 expression was decreased in dextran sulfate sodium (DSS)-induced colitis mice, and mice received fecal bacteria transplantation from stroke patients. Mice with intestinal hypoxia and intestinal epithelial cells cultured in hypoxia showed decreased expression of LRP6. Overexpression of LPR6 or its N-terminus rescued the Wnt/ß-catenin signaling pathway which was inhibited by hypoxia and endoplasmic reticulum stress. In mice overexpressing of LRP6, the expression of ß-catenin and DKK1 increased, Bcl2 decreased, and Bax increased. Mice with LRP6 knockout showed an opposite trend, and the expression of Claudin2, Occludin and ZO-1 decreased. Two drugs, curcumin and auranofin could alleviate intestinal barrier damage in DSS-induced colitis mice by targeting LRP-6. Therefore, gut microbiota dysbiosis and hypoxia can inhibit the LRP6 and Wnt/ß-catenin pathway, and drugs targeting LRP6 can protect the intestinal barrier.
Assuntos
Colite , Microbioma Gastrointestinal , Via de Sinalização Wnt , Animais , Colite/induzido quimicamente , Colite/tratamento farmacológico , Hipóxia , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Camundongos , beta Catenina/genética , beta Catenina/metabolismoRESUMO
BACKGROUND: Gigantol is a bibenzyl compound derived from several medicinal orchids. This biologically active compound has been shown to have promising therapeutic potential against cancer cells, but its mechanism of action remains unclear. METHODS: The inhibitory effect of gigantol on Wnt/ß-catenin signaling was evaluated with the SuperTOPFlash reporter system. The levels of phosphorylated low-density lipoprotein receptor related protein 6 (LRP6), total LRP6 and cytosolic ß-catenin were determined by Western blot analysis. The expression of Wnt target genes was analyzed using real-time PCR. Cell viability was measured with a MTT assay. The effect of gigantol on cell migration was examined using scratch wound-healing and transwell migration assays. RESULTS: Gigantol decreased the level of phosphorylated LRP6 and cytosolic ß-catenin in HEK293 cells. In breast cancer MDA-MB-231 and MDA-MB-468 cells, treatment with gigantol reduced the level of phosphorylated LRP6, total LRP6 and cytosolic ß-catenin in a dose-dependent manner, resulting in a decrease in the expression of Wnt target genes Axin2 and Survivin. We further demonstrated that gigantol suppressed the viability and migratory capacity of breast cancer cells. CONCLUSION: Gigantol is a novel inhibitor of the Wnt/ß-catenin pathway. It inhibits Wnt/ß-catenin signaling through downregulation of phosphorylated LRP6 and cytosolic ß-catenin in breast cancer cells.
Assuntos
Antineoplásicos/farmacologia , Bibenzilas/farmacologia , Neoplasias da Mama/metabolismo , Guaiacol/análogos & derivados , Orchidaceae/química , Extratos Vegetais/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/genética , Neoplasias da Mama/fisiopatologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Guaiacol/farmacologia , Humanos , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Fosforilação/efeitos dos fármacos , Via de Sinalização Wnt/efeitos dos fármacos , beta Catenina/genética , beta Catenina/metabolismoRESUMO
The composition of Morinda citrifolia (M. citrifolia) was determined using high-performance liquid chromatography (HPLC), and the anticancer effects of M. citrifolia extract evaluated in HepG2, Huh7, and MDA-MB-231 cancer cells. M. citrifolia fruit extracts were obtained by using five different organic solvents, including hexane (Hex), methanol (MeOH), ethyl acetate (EtOAc), chloroform (CHCl3), and ethanol (EtOH). The water-EtOAc extracts from M. citrifolia fruits was found to have the highest anticancer activity. HPLC data revealed the predominance of chrysin in water-EtOAc extracts of M. citrifolia fruit. Furthermore, the combined effects of cotreatment with apigenin and chrysin on liver and breast cancer were investigated. Treatment with apigenin plus chrysin for 72-96 h reduced HepG2 and MDA-MB-231 cell viability and induced apoptosis through down-regulation of S-phase kinase-associated protein-2 (Skp2) and low-density lipoprotein receptor-related protein 6 (LRP6) expression. However, the combination treatment for 36 h synergistically decreased MDA-MB-231 cell motility but not cell viability through down-regulation of MMP2, MMP9, fibronectin, and snail in MDA-MB-231 cells. Additionally, chrysin combined with apigenin also suppressed tumor growth in human MDA-MB-231 breast cancer cells xenograft through down-regulation of ki-67 and Skp2 protein. The experimental results showed that chrysin combined with apigenin can reduce HepG2 and MDA-MB-231 proliferation and cell motility and induce apoptosis. It also offers opportunities for exploring new drug targets, and further investigations are underway in this regard.
Assuntos
Apigenina/administração & dosagem , Apoptose/efeitos dos fármacos , Neoplasias da Mama/tratamento farmacológico , Flavonoides/administração & dosagem , Neoplasias Hepáticas/tratamento farmacológico , Morinda/química , Extratos Vegetais/administração & dosagem , Animais , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/fisiopatologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células , Sinergismo Farmacológico , Feminino , Flavonoides/isolamento & purificação , Frutas/química , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/fisiopatologia , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Extratos Vegetais/isolamento & purificação , Proteínas Quinases Associadas a Fase S/genética , Proteínas Quinases Associadas a Fase S/metabolismoRESUMO
Low-density lipoprotein receptor-related protein 6 (LRP6) is a member of the low-density lipoprotein receptor family and has a unique structure, which facilitates its multiple functions as a co-receptor for Wnt/ß-catenin signaling and as a ligand receptor for endocytosis. The role LRP6 plays in metabolic regulation, specifically in the nutrient-sensing pathway, has recently garnered considerable interest. Patients carrying an LRP6 mutation exhibit elevated levels of LDL cholesterol, triglycerides, and fasting glucose, which cooperatively constitute the risk factors of metabolic syndrome and atherosclerosis. Since the discovery of this mutation, the general role of LRP6 in lipid homeostasis, glucose metabolism, and atherosclerosis has been thoroughly researched. These studies have demonstrated that LRP6 plays a role in LDL receptor-mediated LDL uptake. In addition, when the LRP6 mutant impaired Wnt-LRP6 signaling, hyperlipidemia, non-alcoholic fatty liver disease, and atherosclerosis developed. LRP6 regulates lipid homeostasis and body fat mass via the nutrient-sensing mechanistic target of the rapamycin (mTOR) pathway. Furthermore, the mutant LRP6 triggers atherosclerosis by activating platelet-derived growth factor (PDGF)-dependent vascular smooth muscle cell differentiation. This review highlights the exceptional opportunities to study the pathophysiologic contributions of LRP6 to metabolic syndrome and cardiovascular diseases, which implicate LRP6 as a latent regulator of lipid metabolism and a novel therapeutic target for nutritional intervention.
Assuntos
Aterosclerose/genética , Marcação de Genes/métodos , Hiperlipidemias/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Hepatopatia Gordurosa não Alcoólica/genética , Animais , Aterosclerose/dietoterapia , LDL-Colesterol/sangue , Modelos Animais de Doenças , Homeostase , Humanos , Hiperlipidemias/dietoterapia , Metabolismo dos Lipídeos/genética , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Hepatopatia Gordurosa não Alcoólica/dietoterapia , Receptores de LDL/genética , Receptores de LDL/metabolismo , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Triglicerídeos/sangue , Via de Sinalização Wnt , beta Catenina/genética , beta Catenina/metabolismoRESUMO
In diabetes mellitus (DM), podocyte apoptosis leads to albuminuria and nephropathy progression. Low-density lipoprotein receptor-related protein 6 (LRP6) is WNT pathway receptor that is involved in podocyte death, adhesion and motility. Glycogen synthase kinase 3 (GSK3) interaction with p53 (GSK3-p53) promotes apoptosis in carcinoma cells. It is unknown if GSK3-p53 contributes to podocyte apoptosis in DM. In experimental DM, green tea (GT) reduces albuminuria by an unknown mechanism. In the present study, we assessed the role of the GSK3ß-p53 in podocyte apoptosis and the effects of GT on these abnormalities. In diabetic spontaneously hypertensive rats (SHRs), GT prevents podocyte's p-LRP6 expression reduction, increased GSK3ß-p53 and high p53 levels. In diabetic SHR rats, GT reduces podocyte apoptosis, foot process effacement and albuminuria. In immortalized mouse podocytes (iMPs), high glucose (HG), silencing RNA (siRNA) or blocking LRP6 (DKK-1) reduced p-LRP6 expression, leading to high GSK3ß-p53, p53 expression, apoptosis and increased albumin influx. GSK3ß blockade by BIO reduced GSK3ß-p53 and podocyte apoptosis. In iMPs under HG, GT reduced apoptosis and the albumin influx by blocking GSK3ß-p53 following the rise in p-LRP6 expression. These effects of GT were prevented by LRP6 siRNA or DKK-1. In conclusion, in DM, WNT inhibition, via LRP6, increases GSK3ß-p53 and podocyte apoptosis. Maneuvers that inactivate GSK3ß-p53, such as GT, may be renoprotective in DM.
Assuntos
Apoptose , Diabetes Mellitus Experimental/prevenção & controle , Quinase 3 da Glicogênio Sintase/metabolismo , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Podócitos/citologia , Chá , Proteína Supressora de Tumor p53/metabolismo , Albuminúria/prevenção & controle , Animais , Biópsia , Caspase 3/genética , Caspase 3/metabolismo , Nefropatias Diabéticas/patologia , Nefropatias Diabéticas/terapia , Regulação para Baixo , Quinase 3 da Glicogênio Sintase/genética , Glicogênio Sintase Quinase 3 beta , Humanos , Marcação In Situ das Extremidades Cortadas , Rim/metabolismo , Rim/patologia , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Masculino , Camundongos , Microscopia Eletrônica de Transmissão , Ratos , Ratos Endogâmicos SHR , Proteína Supressora de Tumor p53/genética , Via de Sinalização WntRESUMO
BACKGROUND: Neural tube closure defects (NTDs) are among the most common congenital malformation in human, typically presenting in liveborns as spina bifida. At least 240 gene mutations in mouse are known to increase the risk of NTD. There is a growing appreciation that environmental factors significantly contribute to NTD expression, and that NTDs likely arise from complex gene-environment interactions. Because maternal folic acid supplementation reduces human NTD risk in some populations by 60 to 70%, it is likely that NTD predisposition is often associated with a defect in folate-dependent one-carbon metabolism. A comprehensive, untargeted metabolic survey of NTD-associated changes in embryo metabolism would provide a valuable test of this assumption. We sought to establish a metabolic profiling platform that is capable of broadly assessing metabolic aberrations associated with NTD-promoting gene mutations in early-stage mouse embryos. METHODS: A liquid chromatography/mass spectrometry-based untargeted metabolite profiling platform was used to broadly identify significant differences in small molecule levels (50-1000 Da) in NTD-affected embryonic day (E) 9.5 mouse embryos (Lrp6(-) (/) (-) ) versus unaffected (Lrp6(+/+) ) control embryos. RESULTS: Results provide proof-of-principal feasibility for the broad survey of the metabolome of individual E9.5 mouse embryos and identification of metabolic changes associated with NTDs and gene mutations. Levels of 30 different metabolites were altered in association with Lrp6 gene deletion. Some metabolites link to folate-dependent one-carbon transfer reactions, as anticipated, while others await structure elucidation and pathway integration. CONCLUSION: Whole-embryo metabolomics offers the potential to identify metabolic changes in genetically determined NTD-prone embryos.
Assuntos
Ácido Fólico/metabolismo , Proteína-6 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Defeitos do Tubo Neural/embriologia , Tubo Neural/embriologia , Disrafismo Espinal/embriologia , Animais , Modelos Animais de Doenças , Glutationa/metabolismo , Metaboloma/genética , Camundongos , Camundongos Knockout , Tubo Neural/metabolismo , Defeitos do Tubo Neural/genética , Defeitos do Tubo Neural/metabolismo , Oxirredução , Estresse Oxidativo/genética , Disrafismo Espinal/genéticaRESUMO
We hypothesized that the effect of hyperbaric oxygen (HBO) on bone formation is increased via osteogenic differentiation of bone marrow stromal cells (BMSCs), which is regulated by Wnt3a/ß-catenin signaling. Our in vitro data showed that HBO increased cell proliferation, Wnt3a production, LRP6 phosphorylation, and cyclin D1 expression in osteogenically differentiated BMSCs. The mRNA and protein levels of Wnt3a, ß-catenin, and Runx2 were upregulated while those of GSK-3ß were downregulated after HBO treatment. The relative density ratio (phospho-protein/protein) of Akt and GSK-3ß was both up-regulated while that of ß-catenin was down-regulated after HBO treatment. We next investigated whether HBO affects the accumulation of ß-catenin. Our Western blot analysis showed increased levels of translocated ß-catenin that stimulated the expression of target genes after HBO treatment. HBO increased TCF-dependent transcription, Runx2 promoter/Luc gene activity, and the expression of osteogenic markers of BMSCs, such as alkaline phosphatase activity, type I collagen, osteocalcin, calcium, and the intensity of Alizarin Red staining. HBO dose dependently increased the bone morphogenetic protein (BMP2) and osterix production. We further demonstrated that HBO increased the expression of vacuolar-ATPases, which stimulated Wnt3a secretion from BMSCs. Finally, we showed that the beneficial effects of HBO on bone formation were related to Wnt3a/ß-catenin signaling in a rabbit model by histology, mechanical testing, and immunohistochemical assays. Accordingly, we concluded that HBO increased the osteogenic differentiation of BMSCs by regulating Wnt3a secretion and signaling.