RESUMO
Metformin, a traditional first-line pharmacological treatment for type 2 diabetes, has recently been shown to have anti-cancer effects on hepatocellular carcinoma (HCC). However, the molecular mechanism underlying the anti-tumor activity of metformin remains unclear. The Sonic hedgehog (Shh) signaling pathway is closely associated with the initiation and progression of HCC. Therefore, the aim of the current study was to investigate the effects of metformin on the biological behavior of HCC and the underlying functional mechanism of metformin in the Shh pathway. HCC was induced in HepG2 cells using recombinant human Shh (rhShh). The effects of metformin on proliferation and metastasis were evaluated using in vitro proliferation, wound healing, and invasion assays. The mRNA and protein expression levels of proteins related to the Shh pathway were measured using western blotting, quantitative PCR, and immunofluorescence staining. Metformin inhibited rhShh-induced proliferation and metastasis. Furthermore, metformin decreased the mRNA and protein expression of Shh pathway components, including Shh, Ptch, Smo, and Gli-1. Silencing of AMPK in the presence of metformin revealed that metformin exerted its inhibitory effects via AMPK. Our findings demonstrate that metformin suppresses the migration and invasion of HepG2 cells via AMPK-mediated inhibition of the Shh pathway.
Assuntos
Carcinoma Hepatocelular , Diabetes Mellitus Tipo 2 , Neoplasias Hepáticas , Metformina , Proteínas Quinases Ativadas por AMP/metabolismo , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Células Hep G2 , Humanos , Neoplasias Hepáticas/metabolismo , Metformina/farmacologia , Transdução de Sinais , Proteína GLI1 em Dedos de Zinco/genética , Proteína GLI1 em Dedos de Zinco/metabolismo , Proteína GLI1 em Dedos de Zinco/farmacologiaRESUMO
Aberrant activation of Wnt/ß-catenin induces renal dysfunction by initiating pro-apoptotic cascades, fibrosis, oxidative and inflammatory burden. This study tested the therapeutic effects of Wnt/ß-catenin inhibitor pyrvinium against cisplatin-induced acute kidney injury (AKI) in rats. Cisplatin was administered at a single dose of 5 mg/kg (i.p.) and renal cisplatin accumulation and uptake in cortical slices were determined after the fifth day by atomic absorption spectroscopy. Levels of pro-inflammatory cytokines were checked by ELISA, and organic cation transporter-2 (OCT-2) transcription and expression in renal tissue were evaluated by RT-PCR and immunohistochemical technique. Cisplatin administration produced renal dysfunction manifested as increase in serum creatinine, blood urea nitrogen, proteinuria, reduced clearance and electrolyte imbalance. Oxidative stress indices, pro-inflammatory cytokines, fibronectin, and caspase-3 activity were elevated in cisplatin-challenged rats. Moreover, increased renal OCT-2 transcription and immunostaining were detected in cisplatin kidneys which resulted in platinum accumulation. Additional docking studies depicted strong interaction between the ß-catenin and OCT-2 protein. These manifestations induced mitochondrial dysfunction, histological damage and fibrosis. Notably, Wnt/ß-catenin inhibitor pyrvinium (60 µg/kg; p.o.) treatment reduced the renal OCT-2 gene transcription causing a decline in platinum levels. Thus, the present study concludes that Wnt/ß-catenin inhibition attenuates cisplatin-induced AKI in rats, partly by down-regulating OCT-2 expression.
Assuntos
Injúria Renal Aguda , Cisplatino , Animais , Ratos , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/prevenção & controle , beta Catenina/metabolismo , Cátions/metabolismo , Cátions/farmacologia , Cátions/uso terapêutico , Cisplatino/toxicidade , Citocinas/metabolismo , Fibrose , Rim/metabolismo , Platina/metabolismo , Platina/farmacologia , Platina/uso terapêutico , Via de Sinalização Wnt , Proteínas Wnt/antagonistas & inibidoresRESUMO
Paeonol is the bioactive component in Paeonia lactiflora Pall., Cynanchum paniculatum and Paeonia × suffruticosa Andr. Paeonol has been previously demonstrated to inhibit the release of tumor necrosis factor α (TNF-α) and interluekin 6 (IL-6) in chondrocytes. Sirtuin 1 (SIRT1) is downregulated in degraded cartilage and paeonol could induce nuclear accumulation of SIRT1. Therefore, the present study aims to investigate the possible role of paeonol in chondrocyte inflammation and cartilage protection in osteoarthritis (OA) as well as its regulation of SIRT1. Primary chondrocytes from rat knee joints were transfected with short hairpin (sh) - SIRT1 and (or) paeonol prior to IL-1ß exposure, and then inflammatory response, apoptosis, and extracellular matrix (ECM) degradation in the cells were evaluated concurrent with the activation of the nuclear factor κß (NF-κß) signaling pathway. Increased levels of TNF-α, IL-17, IL-6, matrix metalloproteinase 1 (MMP-1), MMP-3, and MMP-13 along with decreased tissue inhibitor of metalloproteinases 1 and type II collagen levels were found in IL-1ß-stimulated chondrocytes. Chondrocyte apoptosis was elevated and the NF-κß signaling pathway was activated in response to IL-1ß treatment. Paeonol enhanced SIRT1 expression to inactivate the NF-κß signaling pathway, thereby ameliorating inflammatory cytokine secretion, ECM degradation, and chondrocyte apoptosis. In conclusion, the results of the present study confirm the potential of paeonol as a candidate OA drug.
Assuntos
Condrócitos , Osteoartrite , Acetofenonas/metabolismo , Acetofenonas/farmacologia , Acetofenonas/uso terapêutico , Animais , Células Cultivadas , Condrócitos/metabolismo , Interleucina-1beta/metabolismo , NF-kappa B/metabolismo , Osteoartrite/tratamento farmacológico , Osteoartrite/patologia , Ratos , Sirtuína 1/metabolismoRESUMO
Autophagy plays a key role in the metabolism of macromolecules via the degradative abilities of the lysosome. Transcription factor EB (TFEB) regulates autophagosome biogenesis and lysosome function, and promoting TFEB activity has emerged as a potential strategy for the treatment of metabolic disorders. Herein, we report that cetrimonium bromide (CTAB; a quaternary ammonium compound) promotes autophagy and lysosomal biogenesis by inducing the nuclear translocation of TFEB in hepatic cells. Knockdown of TFEB mediated by short hairpin RNA inhibits CTAB-induced autophagy and lysosomal biogenesis. Mechanistically, CTAB treatment inhibits the Akt-mTORC1 signaling pathway. Moreover, CTAB treatment significantly increases lipid metabolism in both palmitate- and oleate-treated HepG2 cells, and this increase was attenuated by knockdown of TFEB. Collectively, our results indicate that CTAB activates the autophagosome-lysosome pathway via inducing the nuclear translocation of TFEB by inhibiting the mTORC1 signaling pathway. These results add to the collective understanding of TFEB function and provide new insights into CTAB-mediated lipid metabolism.
Assuntos
Autofagossomos/metabolismo , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Cetrimônio/farmacologia , Hepatócitos/metabolismo , Lisossomos/metabolismo , Autofagossomos/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/antagonistas & inibidores , Células Cultivadas , Cetrimônio/antagonistas & inibidores , Hepatócitos/efeitos dos fármacos , Humanos , Metabolismo dos Lipídeos/efeitos dos fármacos , Lisossomos/efeitos dos fármacos , RNA Interferente Pequeno/farmacologiaRESUMO
Chemo-resistance and metastasis are the most common causes of breast cancer recurrence and death. Thidiazuron (TDZ) is a plant growth regulator (phytohormone) whose biological effects on humans and animals has not yet been determined. In this study, we investigated the anticancer activity of this phytohormone on the drug resistant-triple negative breast cancer cell line MDA-MB-231. Treatment of the breast cancer cells with TDZ (1-50 µmol/L) caused more stressful environment and induced a significant increase in active caspase-positive cells. In addition, TDZ treatment (5 and 10 µmol/L) significantly attenuated the migration and the invasiveness of these highly metastatic cancer cells. Mechanistically, TDZ reduces cancer progression and invasiveness by targeting miR-202-5p, which stimulates the expression of phosphatase and tensin homolog (PTEN), the tumor suppressor that downregulates the PI3K-Akt signaling pathway. Treatment with TDZ significantly upregulates miRNA-132, the suppressor of breast cancer proliferation, which is also implicated in dysregulation of the TEN-Akt-NFκB signaling pathway. Interestingly, our molecular docking analysis revealed a potential non-covalent interaction between TDZ and Akt, PTEN, and PI3K. These findings suggest that TDZ suppresses breast cancer metastasis by targeting miRNA-132, the miR-202-5p-PTEN axis, and the PI3K-Akt signaling pathway downstream.
Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , MicroRNAs/genética , PTEN Fosfo-Hidrolase/metabolismo , Compostos de Fenilureia/farmacologia , Tiadiazóis/farmacologia , Apoptose , Biomarcadores Tumorais/genética , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Proliferação de Células , Feminino , Humanos , Invasividade Neoplásica , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células Tumorais CultivadasRESUMO
This study explored the molecular mechanism behind the protective effects from low-dose lipopolysaccharide (LPS) on an in-vitro model of spinal cord injury (SCI). For this, PC12 cells were treated with different concentrations of LPS and the cell counting kit-8 assay was used to measure the toxicity of LPS to the cells. Next, we used immunofluorescence to measure nuclear translocation of Nrf2 in PC12 cells. PC12 cells were then treated with IGF-1 (PI3K agonist) and LY294002 (PI3K inhibitor). An in-vitro model of SCI was then established via oxygen-glucose deprivation/reoxygenation. Rates of apoptosis were measured using flow cytometry and the TUNEL assay. Low-dose LPS increased the expression levels of Nrf2, p-PI3K/PI3K, and p-AKT/AKT, and facilitated nuclear translocation of Nrf2. The activation of PI3K-AKT signaling by IGF-1 significantly increased the expression of Nrf2, whereas inhibition of PI3K-AKT signaling significantly decreased the expression of Nrf2. Low-dose LPS reduced the apoptotic ratio of PC12 cells, decreased the expression levels of caspase 3 and caspase 9, and increased the expression levels of HO-1, NQO1, and γ-GCS. Low-dose LPS also reduced the rate of apoptosis and oxidative stress by activating the PI3K-AKT-Nrf2 signaling pathway. Collectively, the results indicate that PI3K-AKT-Nrf2 signaling participates in the protective effects from low-dose LPS in an in-vitro PC12 cell model of SCI.
Assuntos
Lipopolissacarídeos/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Neurônios/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Substâncias Protetoras/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Traumatismos da Medula Espinal/tratamento farmacológico , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Fator 2 Relacionado a NF-E2/genética , Neurônios/metabolismo , Células PC12 , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Ratos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Traumatismos da Medula Espinal/metabolismo , Traumatismos da Medula Espinal/patologiaRESUMO
The discovery of new pharmacological agents is needed to control the progression of osteoarthritis (OA), characterized by joint cartilage damage. Human OA chondrocyte (OAC) cultures were either applied to S-allylcysteine (SAC), a sulfur-containing amino acid derivative, or colchicine, an ancient anti-inflammatory therapeutic, for 24 h. SAC or colchicine did not change viability at 1 nM-10 µM but inhibited p-JNK/pan-JNK. While SAC seems to be more effective, both agents inhibited reactive oxygen species (ROS), 3-nitrotyrosine (3-NT), lipid hydroperoxides (LPO), advanced lipoxidation end-products (ALEs as 4-hydroxy-2-nonenal, HNE), advanced glycation end-products (AGEs), and increased glutathione peroxidase (GPx) and type-II-collagen (COL2). IL-1ß, IL-6, and osteopontin (OPN) were more strongly inhibited by SAC than by colchicine. In contrast, TNF-α was inhibited only by SAC, and COX2 was only inhibited by colchicine. Casp-1/ICE, GM-CSF, receptor for advanced glycation end-products (RAGE), and toll-like receptors (TLR4) were inhibited by both agents, but bone morphogenetic protein 7 (BMP7) was partially inhibited by SAC and induced by colchicine. Nuclear factor erythroid 2-related factor 2 (Nrf2) was induced by SAC; in contrast, it was inhibited by colchicine. Although they exert opposite effects on TNF-α, COX2, BMP7, and Nrf2, SAC and colchicine exhibit anti-osteoarthritic properties in OAC by modulating redox-sensitive inflammatory signaling.
Assuntos
Condrócitos/efeitos dos fármacos , Cisteína/análogos & derivados , Inflamação/tratamento farmacológico , Osteoartrite/tratamento farmacológico , Idoso , Antígenos de Neoplasias/metabolismo , Condrócitos/metabolismo , Cisteína/farmacologia , Feminino , Humanos , Inflamação/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Masculino , Pessoa de Meia-Idade , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fator 2 Relacionado a NF-E2/antagonistas & inibidores , Fator 2 Relacionado a NF-E2/metabolismo , Osteoartrite/metabolismo , Transdução de Sinais/efeitos dos fármacos , Receptor 4 Toll-Like/antagonistas & inibidores , Receptor 4 Toll-Like/metabolismoRESUMO
Ribavirin is a guanosine analog with broad-spectrum antiviral activity against RNA viruses. Based on this, we aimed to show the anti-SARS-CoV-2 activity of this drug molecule via in vitro, in silico, and molecular techniques. Ribavirin showed antiviral activity in Vero E6 cells following SARS-CoV-2 infection, whereas the drug itself did not show any toxic effect over the concentration range tested. In silico analysis suggested that ribavirin has a broad-spectrum impact on SARS-CoV-2, acting at different viral proteins. According to the detailed molecular techniques, ribavirin was shown to decrease the expression of TMPRSS2 at both mRNA and protein levels 48 h after treatment. The suppressive effect of ribavirin in ACE2 protein expression was shown to be dependent on cell types. Finally, proteolytic activity assays showed that ribavirin also showed an inhibitory effect on the TMPRSS2 enzyme. Based on these results, we hypothesized that ribavirin may inhibit the expression of TMPRSS2 by modulating the formation of inhibitory G-quadruplex structures at the TMPRSS2 promoter. As a conclusion, ribavirin is a potential antiviral drug for the treatment against SARS-CoV-2, and it interferes with the effects of TMPRSS2 and ACE2 expression.
Assuntos
Enzima de Conversão de Angiotensina 2/metabolismo , Antivirais/farmacologia , Regulação para Baixo/efeitos dos fármacos , Ribavirina/farmacologia , SARS-CoV-2/efeitos dos fármacos , Serina Endopeptidases/metabolismo , Animais , Células CACO-2 , Chlorocebus aethiops , Quadruplex G/efeitos dos fármacos , Humanos , Regiões Promotoras Genéticas/genética , SARS-CoV-2/fisiologia , Serina Endopeptidases/genética , Células VeroRESUMO
The Hippo/YAP (yes-associated protein) pathway is an important signaling pathway to control organ development and tissue homeostasis. YAP is a downstream effector of the Hippo pathway and a critical mediator of mechanic stress. Hypertensive nephropathy is characterized with glomerular sclerosis stiffness and renal fibrosis. The present study investigated the role of YAP pathway in angiotensin (Ang) II hypertensive renal injury by using YAP activation inhibitor verteporfin. Ang II increased the protein expression of YAP in renal nucleus fraction, decreased phospho-YAP, and phospho-LATS1/2 (large tumor suppressors 1 and 2) expressions in renal cytoplasmic fraction, suggesting Ang II activation of renal YAP. Ang II significantly increased systolic blood pressure (SBP), proteinuria, glomerular sclerosis, and fibrosis; treatment with verteporfin attenuated Ang II-induced proteinuria and renal injury with a mild reduction in SBP. Moreover, Ang II increased the protein expressions of inflammatory factors including tumor necrosis factor α, interleukin 1ß, and monocyte chemoattractant protein-1, and profibrotic factors including transforming growth factor ß, phospho-Smad3 and fibronectin. Verteporfin reversed abovementioned Ang II-induced molecule expressions. Our results for the first time demonstrate that the activation of the YAP pathway promotes hypertensive renal inflammation and fibrosis, which may promote hypertensive renal injury. YAP may be a new target for prevention and treatment of hypertensive renal diseases.
Assuntos
Injúria Renal Aguda/tratamento farmacológico , Angiotensina II/toxicidade , Hipertensão Renal/tratamento farmacológico , Hipertensão/metabolismo , Nefrite/tratamento farmacológico , Verteporfina/farmacologia , Proteínas de Sinalização YAP/antagonistas & inibidores , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Animais , Pressão Sanguínea , Quimiocina CCL2/genética , Quimiocina CCL2/metabolismo , Fibrose , Hipertensão/induzido quimicamente , Hipertensão/patologia , Hipertensão Renal/etiologia , Hipertensão Renal/metabolismo , Hipertensão Renal/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Nefrite/etiologia , Nefrite/metabolismo , Nefrite/patologia , Fármacos Fotossensibilizantes/farmacologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Vasoconstritores/toxicidadeRESUMO
The present study aims to explore the role of microRNA 145-5p (miR-145-5p) in hyperlipidemia. Using bioinformatics tools and a wide range of function and mechanism assays, we attempted to understand the specific function and potential mechanism of miR-145-5p in hyperlipidemia. A cholesterol-enriched diet induced an increase of serum cholesterol and triacylglycerol but a decrease of serum high-density lipoprotein. MiR-145-5p level was decreased in hyperlipidemia rat models. MiR-145-5p regulated lipid metabolism by antagonizing the alteration of high-density lipoprotein, cholesterol, and triacylglycerol in serum mediated by a cholesterol-enriched diet. In mechanism, miR-145-5p directly bound with p21 protein (RAC1)-activated kinase 7 (PAK7) and negatively regulated mRNA and protein levels of PAK7 in THP-1 cells. Furthermore, miR-145-5p level was negatively associated with PAK7 level in rat cardiac tissues. Finally, overexpression of PAK7 reversed the effects of miR-145-5p on ß-catenin activation and M2 macrophages polarization in THP-1 cells. In conclusion, MiR-145-5p modulated lipid metabolism and M2 macrophage polarization by targeting PAK7 and regulating ß-catenin signaling in hyperlipidemia, which may provide a potential biomarker for the treatment of hyperlipidemia-induced cardiovascular diseases.
Assuntos
Hiperlipidemias/etiologia , Metabolismo dos Lipídeos , Macrófagos/fisiologia , MicroRNAs/fisiologia , beta Catenina/fisiologia , Quinases Ativadas por p21/genética , Animais , Polaridade Celular , Células Cultivadas , Humanos , Hiperlipidemias/metabolismo , Masculino , Ratos , Ratos Wistar , Transdução de Sinais/fisiologiaRESUMO
The aim of the present study was to investigate the protective effect of S-ketamine (S-KET) against carbon tetrachloride (CCl4) - induced liver damage and oxidative stress, as well as to elucidate the related underlying mechanisms. Blood was collected to measure biochemical parameters (alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), total bilirubin (TB) and γ-glutamyltransferase (γ-GT)) and the liver was harvested for histopathological analysis of enzymes related to the antioxidant response (malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH), and glutathione peroxidase (GSH-PX)). Liver cell apoptosis was evaluated using the TUNEL assay. In addition, the expression levels of apoptosis-related proteins and the nuclear factor erythroid 2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) signaling pathway were detected by Western blot analysis to explore potential mechanisms. S-KET protected the liver from CCl4-induced damage. The changes to the liver biochemical parameters (increased ALT, AST, ALP, TB, and γ-GT) and oxidative stress-related indicators (increased MDA; depleted SOD, GSH, and GSH-PX) induced by CCl4 were inhibited by S-KET. S-Ket also inhibited CCl4-induced cell apoptosis, the changes in expression of related proteins, and blocked CCl4-induced liver injury and oxidative stress via activation of the Nrf2/HO-1 signaling pathway. S-KET effectively protected the liver by inhibition of CCl4-induced damage via upregulation the Nrf2/HO-1 signaling pathway.
Assuntos
Tetracloreto de Carbono/efeitos adversos , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/genética , Heme Oxigenase (Desciclizante)/metabolismo , Ketamina/farmacologia , Ketamina/uso terapêutico , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Animais , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Masculino , Ratos Sprague-DawleyRESUMO
We earlier showed that angiotensin (Ang) II-induced overexpression of Giα proteins contributes to the hyperproliferation of vascular smooth muscle cells (VSMC). In addition, the implication of the JAK2/STAT3 pathway in Ang II-induced hyperproliferation of VSMC has also been reported. However, the role of the JAK2/STAT3 pathway in Ang II-induced overexpression of Giα proteins and hyperproliferation of VSMC remains unexplored. In the present study, we show that inhibition or knockdown of the JAK2/STAT3 pathway by a specific inhibitor "cucurbitacin I" (CuI) or siRNAs attenuated Ang II-induced overexpression of Giα proteins and hyperproliferation of VSMC. In addition, the enhanced expression of cell cycle proteins induced by Ang II was also attenuated by CuI. Furthermore, Ang II-induced enhanced production of the superoxide anion (O2 -), H2O2, and NADPH oxidase activity, as well as the enhanced expression of NADPH oxidase subunits implicated in enhanced expression of Giα proteins and hyperproliferation, were also attenuated by inhibition of the JAK2/STAT3 pathway. On the other hand, Ang II-induced inhibition and augmentation of the levels of nitric oxide and peroxynitrite, respectively, in VSMC were restored to control levels by CuI. In summary, our results demonstrate that Ang II through the JAK2/STAT3 pathway increases nitroxidative stress, which contributes to the overexpression of Giα proteins and cell cycle proteins and the hyperproliferation of VSMC.
Assuntos
Angiotensina II/farmacologia , Aorta/patologia , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Janus Quinase 2/metabolismo , Músculo Liso Vascular/patologia , Fator de Transcrição STAT3/metabolismo , Animais , Aorta/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Músculo Liso Vascular/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Ratos , Ratos Endogâmicos SHR , Transdução de Sinais/efeitos dos fármacosRESUMO
Physical exercise is essential for the amelioration of insulin resistance (IR). The mechanisms in charge of improved IR, regulated by exercise, are insufficiently studied. Previous research revealed that Sirtuin 6 (SIRT6) - mediated insulin signaling acts a crucial element in hepatic IR. The objective of our research was to determine the effects of exercise on SIRT6-mediated insulin signaling in liver of IR rats. Forty male Sprague Dawley rats were randomly assigned to four groups (n = 10 rats each): control rats fed with standard chow (Lean group); sedentary rats fed with a high-fat diet (HFD-SED); rats fed with HFD and submitted to 8 week chronic swimming exercise training (HFD-CE); and rats fed HFD and submitted to one acute swimming exercise training (HFD-AE). HFD feeding lead to increased body weight, accumulation of hepatic triglyceride and serum free fatty acids, and enhanced gluconeogenesis. Besides, HFD feeding decreased body insulin sensitivity. Hepatic USP10 and SIRT6 protein levels decreased under obese status. Both chronic and acute exercise intervention alleviated physiological and metabolic status, increased hepatic USP10 and SIRT6 levels, improved insulin signaling transduction, and inhibited gluconeogenesis. These results showed that exercise intervention regulated SIRT6-mediated insulin signaling, which contributes to our understanding of the molecular mechanisms behind IR, in that a regular exercise can mitigate the effects of IR.
Assuntos
Resistência à Insulina , Obesidade , Animais , Masculino , RatosRESUMO
The Wnt/ß-catenin pathway, which interferes with cell proliferation, differentiation, and autophagy, is commonly dysregulated in colorectal cancer (CRC). Mutation of the RAS oncogene is the most prevalent genetic alteration in CRC and has been linked to activation of protein kinase B (AKT) signaling. Phosphorylation of ß-catenin at Ser 552 by AKT contributes to ß-catenin stability, transcriptional activity, and increase of cell proliferation. Casein kinase 1 alpha (CK1α) is an enzyme that simultaneously regulates Wnt/ß-catenin and AKT. The link of the AKT and Wnt pathway to autophagy in RAS-mutated CRC cells has not well identified. Therefore, we investigated how pharmacological CK1α inhibition (D4476) is involved in regulation of autophagy, Wnt/ß-catenin, and AKT pathways in RAS-mutated CRC cell lines. qRT-PCR and immunoblotting experiments revealed that phospho-AKT (S473) and phospho-ß-catenin (S552) are constitutively increased in RAS-mutated CRC cell lines, in parallel with augmented CK1α expression. The results also showed that D4476 significantly reduced the AKT/phospho-ß-catenin (S552) axis concomitantly with autophagy flux inhibition in RAS-mutated CRC cells. Furthermore, D4476 significantly induced apoptosis in RAS-mutated CRC cells. In conclusion, our results indicate that CK1α inhibition reduces autophagy flux and promotes apoptosis by interfering with the AKT/phospho-ß-catenin (S552) axis in RAS-mutated CRC cells.
Assuntos
Autofagia/efeitos dos fármacos , Neoplasias Colorretais/genética , Genes ras/genética , Proteína Oncogênica v-akt/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , beta Catenina/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Inibidores Enzimáticos/farmacologia , Células HCT116 , Humanos , Mutação , Fosforilação , beta Catenina/antagonistas & inibidoresRESUMO
The effects of long non-coding RNAs (lncRNAs) on the proliferation of hypertrophic scars have been described, however, the underlying mechanisms are not well characterized. The present study aimed to investigate the mechanisms of lncRNA H19 in hypertrophic scars. The effects of the lncRNA H19 on the proliferation and apoptosis of hypertrophic scar fibroblasts (HSFs) were analyzed using 5'-ethynyl-2'-deoxyuridine staining, flow cytometry, and 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT). The results revealed H19 promoted the proliferation and inhibited the apoptosis in HSF. In addition, the binding associations between H19 and microRNA-194 (miR-194), and miR-194 and insulin-like growth factor I receptor (IGF1R) were identified using bioinformatics screening and verified using dual-luciferase assays. Furthermore, the effects of the IGF1R knockdown on H19-induced HSF phenotypes and regulation over the p38 MAPK pathway were determined. Mechanistically, miR-194 was identified as the downstream effector of the H19-mediated phenotypes of HSFs through its ability to directly target IGF1R, thus modulating the p38 MAPK signaling pathway. In conclusion, the findings suggested that H19 may inhibit the apoptosis and promote the proliferation of HSFs through the miR-194/IGF1R/p38 MAPK signaling axis, thereby contributing to the progression of hypertrophic scars. These findings may provide novel targets for the treatment of hypertrophic scars.
Assuntos
Apoptose/genética , Proliferação de Células/genética , Cicatriz Hipertrófica/genética , Cicatriz Hipertrófica/patologia , Fibroblastos/patologia , MicroRNAs/metabolismo , RNA Longo não Codificante/genética , RNA Longo não Codificante/fisiologia , Linhagem Celular , Humanos , Sistema de Sinalização das MAP Quinases , Receptor IGF Tipo 1 , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Both the Notch1 and Keap1-Nrf2 signaling pathways have cardioprotective effects, but the role of Notch1-Nrf2 crosstalk in myocardial ischemia-reperfusion injury is unclear. In this study, we established hypoxia-reoxygenation in neonate rat myocardial cells and employed γ-secretase inhibitor and curcumin to inhibit and activate the Notch1 and Keap1-Nrf2 signaling pathways, respectively. We found that the combined action of the Notch1 and Keap1-Nrf2 signaling pathways significantly increased cardiomyocyte viability, inhibited cardiomyocyte apoptosis, reduced the formation of reactive oxygen species, and increased antioxidant activities. In conclusion, these findings suggest that Notch1-Nrf2 crosstalk exerts myocardial protection by reducing the formation of reactive oxygen species.
Assuntos
Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Isquemia Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptor Notch1/metabolismo , Animais , Animais Recém-Nascidos , Antioxidantes/metabolismo , Apoptose , Hipóxia Celular , Núcleo Celular/metabolismo , Proliferação de Células , Sobrevivência Celular , Citoplasma/metabolismo , Regulação Neoplásica da Expressão Gênica , Hipóxia , Miocárdio/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ratos , Transdução de SinaisRESUMO
Apolipoprotein E2 (ApoE2) is reportedly critical for cell proliferation and survival, and has been identified as a potential tumour-associated marker in many kinds of cancer. However, studies of the function and mechanisms of ApoE2 in pancreatic cancer proliferation and development are rare. In this study, we performed an analysis to determine the modulatory effects of ApoE2-LRP8 (lipoprotein receptor-related protein 8) pathway on cell cycle and cell proliferation, and explored its mechanisms in pancreatic cancer. High expression levels of ApoE2-LRP8/c-Myc were detected in tumour tissues and cell lines by immunohistochemistry and Western blotting. It was also shown that ApoE2-LRP8 induced phosphorylation of ERK1/2 to activate c-Myc and contribute to cell-cycle-related protein expression. ApoE2 conditions induced c-Myc binding to target gene sequences in the p21Waf1 promoter, resulting in decreased transcription. ERK/c-Myc contributes to the promotion of the expression levels of cyclin D1, cdc2, and cyclin B1, and reduces p21Waf1 activity, thereby promoting cell cycle distribution. We demonstrated the function of ApoE2-LRP8 in the activation of the ERK-c-Myc-p21Waf1 signalling cascade and the modulation of G1/S and G2/M transition, indicating ApoE2-LRP8's important role in the cancer cell proliferation. ApoE2 could serve as a diagnostic marker and chemotherapeutic target in pancreatic cancer.
Assuntos
Apolipoproteína E2/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Proteínas Relacionadas a Receptor de LDL/metabolismo , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Transporte Ativo do Núcleo Celular , Biomarcadores Tumorais , Ciclo Celular , Linhagem Celular Tumoral , Proliferação de Células , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Humanos , Imuno-Histoquímica , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Interferência de RNA , Reação em Cadeia da Polimerase em Tempo Real , Transdução de SinaisRESUMO
Osteoarthritis (OA) is a common joint degenerative disease. Vitamin D (VD) is essential for bone health. We hypothesized that active VD could be used as a therapeutic treatment for OA. Low serum levels of 25-hydroxyvitamin D [25(OH)D] have been found in patients with OA, and thus the serum level of VD could be diagnostic of OA. To test this, we established a mouse model of OA. The results from staining with hematoxylin-eosin and Safranin O - Fast Green indicated that active VD reduced the symptoms of OA in mice. The results from Western blotting indicated that treatment with VD increased the activity of the p-AMPK-AMPK signaling pathway and decreased the p-mTOR-mTOR pathway; it also increased the ratio of LC3II:LC3I antibodies and the protein expression levels of Beclin-1, but decreased the level of p62. Further, treatment with VD reduced the levels of tumor necrosis factor-α and interleukin-6 both in cartilage tissues and in chondrocytes. Administration of the AMPK inhibitor compound C and autophagy inhibitor 3-methyladenine (3-MA) reversed these changes following VD treatment. In addition, the results from transfection with mRFP-GFP-LC3 indicated that active VD led to autophagosome aggregation in OA chondrocytes. 3-MA inhibited cell autophagy and promoted inflammation in OA. This study provides evidence that active VD activate chondrocyte autophagy to reduce OA inflammation via activating the AMPK-mTOR signaling pathway. Treatment with active VD could be a novel therapeutic option for OA.
Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia , Condrócitos/citologia , Osteoartrite/tratamento farmacológico , Serina-Treonina Quinases TOR/metabolismo , Vitamina D/análogos & derivados , Animais , Osso e Ossos/metabolismo , Sobrevivência Celular , Células Cultivadas , Condrócitos/metabolismo , Modelos Animais de Doenças , Feminino , Proteínas de Fluorescência Verde/metabolismo , Humanos , Inflamação , Masculino , Camundongos , Pessoa de Meia-Idade , Transdução de Sinais , Vitamina D/sangue , Vitamina D/farmacologiaRESUMO
The study investigated the expression of long noncoding RNA (lncRNA) MALAT1 in high glucose (HG)-induced human vascular endothelial cells (HUVECs) and the role of MALAT1 in the apoptosis of HG-induced HUVECs. The HUVECs were cultured and induced with 25 mmol/L HG. After that, the HUVECs were transfected with MALAT1 siRNA. The expression levels of MALAT1 were detected with qPCR, whereas the expression levels of Bax, Bcl-2, cleaved-caspase-3, cleaved-caspase-9, p-65, and p-p65 were detected using Western blot. The roles of MALAT1 in cell activities, including apoptosis, were evaluated using the CCK-8 assay, TUNEL staining, and flow cytometry. The expression levels of inflammatory factors (TNF-α and IL-6) were measured using ELISA. The expression levels of MALAT1, TNF-α, and IL-6 in HUVECs were increased in the HG environment; however, when MALAT1 was silenced in the HUVECs, cell proliferation increased significantly, the expression levels of TNF-α, IL-6, Bax, cleaved-caspase-3, and cleaved-caspase-9 decreased, and the rate of apoptosis also decreased. Silencing MALAT1 inhibited the expression of p-p65 in HG-induced HUVECs. In conclusion, our study demonstrated that MALAT1 is upregulated in HG-induced HUVECs, and inhibition of MALAT1 inhibits HG-induced apoptosis and inflammation in HUVECs by suppression of the NF-κB signaling pathway.
Assuntos
Apoptose/efeitos dos fármacos , Glucose/farmacologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , RNA Longo não Codificante/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Transcrição RelA/metabolismo , Humanos , Inflamação/induzido quimicamente , Inflamação/metabolismoRESUMO
In this study we investigated the regulatory role of cell-migration-inducing and hyaluronan-binding protein (CEMIP) in the proliferation and migration of vascular smooth muscle cells (VSMCs). The mRNA and protein levels of CEMIP were upregulated in the plasma samples from patients with atherosclerosis, and in VSMCs stimulated with platelet-derived growth factor-BB (PDGF-BB), compared with plasma from healthy subjects and untreated VSMCs. Silencing CEMIP suppressed PDGF-BB-induced cell migration and proliferation in VSMCs, as determined using a Cell Counting Kit-8 assays, 5-ethynyl-2'-deocyuridine (EDU) assays, flow cytometry, wound healing assays, and Transwell assays. Overexpression of CEMIP promoted the proliferation and migration of VSMCs via activation of the Wnt-ß-catenin signaling pathway and the upregulation of its target genes, including matrix metalloproteinase-2, matrix metalloproteinase-7, cyclin D1, and c-myc, whereas CEMIP deficiency showed the opposite effects. The knockdown of CEMIP in ApoE-/- mice by intravenous injection of lentiviral vector expressing si-CEMIP protected against high-fat-diet-induced atherosclerosis, as shown by the reduced aortic lesion areas, aortic sinus lesion areas, and the concentration of blood lipids compared with mice normally expressing CEMIP. These results demonstrated that CEMIP regulates the proliferation and migration of VSMCs in atherosclerosis by activating the WNT-ß-catenin signaling pathway, which suggests the therapeutic potential of CEMIP for the management of atherosclerosis.