RESUMO
Liver fibrosis is a common pathological process for chronic liver injury caused by multiple etiological factors and an inevitable phase leading to liver cirrhosis. According to the previous studies, hesperidin (HDN) shows a very good protective effect on CCl4-induced chemical hepatic fibrosis in rats. In this experiment, based on the findings of the previous studies, a platelet-derived growth factor (PDGF)-induced HSC-T6 model was established to observe the inhibitory effect of HDN on HSC-T6 proliferation. The ELISA method was adopted to detect the content of collagen I in HSC-T6 supernatant. Transforming growth factor (TGF)-beta1, Smad2, Smad3, Smad7 and connective tissue growth factor (CTGF) mRNA expressions were measured by RT-PCR; TGF-beta1 and CT-GF protein expressions in HSC-T6 were determined by Western blot, in order to study HDN's effect on TGF-beta1 signaling pathway in HSC and its potential action mechanism. The results demonstrated that HDN could notably improve HSC-T6 proliferation, Collagen I growth and TGF-beta1, Smad2, Smad3 and CTGF mRNA.expressions. After being intervened with HDN, it could notably inhibit HSC-T6 proliferation and Collagen I growth, reduce TGF-beta1, Smad2, Smad3 and CTGF mRNA and TGF-beta1, CTGF protein expressions and increase Smad7 mRNA expression. HDN's antihepatic fibrosis effect may be related to the inhibition of HSC proliferation and activation by modulating TGF-beta/Smad signaling pathway.
Assuntos
Hesperidina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Proteínas Smad/fisiologia , Fator de Crescimento Transformador beta1/fisiologia , Animais , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Fator de Crescimento do Tecido Conjuntivo/fisiologia , Fator de Crescimento Derivado de Plaquetas/farmacologia , RatosRESUMO
Previously we found carbon tetrachloride (CCl4) induced cirrhosis associated cardiac hypertrophy and apoptosis. The purpose of this study is to determine whether further CCl4 treatment would induce cardiac cell fibrosis. The cardiac tissues were analyzed by H&E. histological staining, Trichrome Masson staining and Western blotting. The results showed that the CCl4-treated-only group exhibits more trichrome staining, meaning that more fibrosis is present. Moreover, CCl4 could further induce cardiac-fibrosis via TGF-ß-p-Smad2/3-CTGF pathway. However, our data showed that the CCl4- indcued cardiac abnormalities were attenuated by Ocimum gratissimum extract (OGE) and silymarin co- treatments. In conclusion, our results indicated that the OGE and silymarin may be a potential traditional herb for the protection of cardiac tissues from the CCl4 induced cirrhosis associated cardiac fibrosis through modulating the TGF-ß signaling pathway.
Assuntos
Cirrose Hepática Experimental/tratamento farmacológico , Miocárdio/patologia , Ocimum , Extratos Vegetais/uso terapêutico , Silimarina/uso terapêutico , Animais , Tetracloreto de Carbono/toxicidade , Fator de Crescimento do Tecido Conjuntivo/fisiologia , Fibrose , Cirrose Hepática Experimental/induzido quimicamente , Cirrose Hepática Experimental/patologia , Masculino , Ratos , Ratos Wistar , Fator de Crescimento Transformador beta1/fisiologiaRESUMO
AIMS: In this study, we investigated whether pre-conditioning (PC) by electrical stimulation (EleS) induces cytoprotective effect on cardiac stem cells (CSCs) and determined its underlying molecular mechanisms. METHODS AND RESULTS: Sca-1(+) CSCs were isolated from male C57BL6 mice (12 weeks) hearts. PC of CSCs with EleS ((EleS)CSCs) was carried out for 3 h at 1.5 V followed by exposure to 300 µM H2O2 for 5 h. Cytoprotective effects and cell adhesion ability were significantly increased by EleS as evaluated by transferase-mediated dUTP nick-end labelling (TUNEL), lactate dehydrogenase (LDH) release assay, and adhesion assay. EleS increased phosphorylation of AKT, focal adhesion kinase (FAK), and glycogen synthase kinase (GSK3ß), as well as decreased caspase-3 cleavage. Interestingly, inhibition of AKT or FAK abolished the pro-survival effects of EleS. We found that connective tissue growth factor (Ctgf) was responsible for EleS-induced CSC survival and adhesion.The survival rate of (EleS)CSCs after transplantation in the infarcted myocardium was significantly increased together with improvement in cardiac function. Importantly, knockdown of Ctgf abolished EleS-induced cytoprotective effects and recovery of cardiac function. Furthermore, we identified miR-378 as a potential Ctgf regulator in (EleS)CSCs. CONCLUSION: EleS enhanced CSC survival in vitro and in vivo as well as functional recovery of the ischaemic heart through an AKT/FAK/CTGF signalling pathway. It is suggested that Ctgf and miR-378 are novel therapeutic targets for stem cell-based therapy.
Assuntos
Fator de Crescimento do Tecido Conjuntivo/fisiologia , Terapia por Estimulação Elétrica , MicroRNAs/fisiologia , Isquemia Miocárdica/terapia , Miócitos Cardíacos/fisiologia , Transplante de Células-Tronco , Animais , Antígenos Ly/análise , Adesão Celular , Sobrevivência Celular , Citoproteção , Proteína-Tirosina Quinases de Adesão Focal/fisiologia , Proteínas de Membrana/análise , Camundongos , Camundongos Endogâmicos C57BL , Isquemia Miocárdica/fisiopatologia , Estresse Oxidativo , Proteínas Proto-Oncogênicas c-akt/fisiologia , Células-Tronco/fisiologiaRESUMO
BACKGROUND: Malignant melanoma cells are known to have altered expression of growth factors compared with normal human melanocytes. These changes most likely favour tumour growth and progression, and influence tumour environment. The induction of transforming growth factor beta1, 2 and 3 as well as BMP4 and BMP7 expression in malignant melanoma has been reported before, whereas the expression of an important modulator of these molecules, connective tissue growth factor (CTGF), has not been investigated in melanomas until now. METHODS: Expression of CTGF was analysed in melanoma cell lines and tissue samples by qRT-PCR and immunohistochemistry. To determine the regulation of CTGF expression in malignant melanoma, specific siRNA was used. Additionally, migration, invasion and attachment assays were carried out. RESULTS: We were able to demonstrate that CTGF expression is upregulated in nine melanoma cell lines and in primary and metastatic melanoma in situ. The transcription factor HIF-1α was revealed as a positive regulator for CTGF expression. Melanoma cells, in which CTGF expression is diminished, show a strong reduction of migratory and invasive properties when compared with controls. Further, treatment of normal human epidermal melanocytes with recombinant CTGF leads to an increase of migratory and invasive behaviour of these cells. CONCLUSION: These results suggest that CTGF promotes melanoma cell invasion and migration and, therefore, has an important role in the progression of malignant melanoma.
Assuntos
Movimento Celular/genética , Fator de Crescimento do Tecido Conjuntivo/genética , Fator de Crescimento do Tecido Conjuntivo/fisiologia , Melanoma/genética , Melanoma/patologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologia , Proteína Morfogenética Óssea 7/genética , Proteína Morfogenética Óssea 7/metabolismo , Linhagem Celular Tumoral , Células Cultivadas , Fator de Crescimento do Tecido Conjuntivo/antagonistas & inibidores , Fator de Crescimento do Tecido Conjuntivo/farmacologia , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/fisiologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/fisiologia , Melanócitos/efeitos dos fármacos , Melanócitos/metabolismo , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Invasividade Neoplásica , RNA Interferente Pequeno/farmacologia , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genéticaRESUMO
BACKGROUND: Diabetic nephropathy (DN) is the most common cause of end-stage renal failure. Grape seed proanthocyanidin extracts (GSPE) are powerful antioxidants. However, the role of GSPE on advanced glycation end products (AGEs), receptor for advanced glycation end products (RAGE) and expression of connective tissue growth factor (CTGF) in DN has not been elucidated. Using streptozotocin-induced diabetic rats, we evaluated the effects of GSPE in DN. METHODS: Wistar rats were induced into diabetes using streptozotocin injections and diabetic rats were treated with GSPE (dosage: 500 mg x kg(-1) x day(-1)) for 24 weeks. The renal pathological changes were examined with PAS staining and electron microscope. The mRNA and protein expression of RAGE and CTGF in kidney were detected by RT-PCR, Western blot and immunohistochemical staining. RESULTS: Treated animals showed reduction in serum AGEs (p < 0.01), proteinuria (p < 0.01) and systolic blood pressure (p < 0.01). GSPE reduced the expression of RAGE (p < 0.01) and CTGF (p < 0.01) in the kidney, which were contributing to reversal of extracellular matrix accumulation in DN. CONCLUSION: Our results suggest that GSPE hold substantial promise for the treatment of DN. GSPE can decrease proteinuria, attenuating the progression of nephropathy in diabetic rats. Renoprotective effects of GSPE are correlated with suppression on AGEs/RAGE axis, downregulating expression of CTGF.