RESUMO
We previously reported that daucosterol (a sterolin) up-regulates the expression of insulin-like growth factor I (IGF1)(1) protein in neural stem cells. In this study, we investigated the effects of daucosterol on the survival of cultured cortical neurons after neurons were subjected to oxygen and glucose deprivation and simulated reperfusion (OGD/R)(2), and determined the corresponding molecular mechanism. The results showed that post-treatment of daucosterol significantly reduced neuronal loss, as well as apoptotic rate and caspase-3 activity, displaying the neuroprotective activity. We also found that daucosterol increased the expression level of IGF1 protein, diminished the down-regulation of p-AKT(3) and p-GSK-3ß(4), thus activating the AKT(5) signal pathway. Additionally, it diminished the down-regulation of the anti-apoptotic proteins Mcl-1(6) and Bcl-2(7), and decreased the expression level of the pro-apoptotic protein Bax(8), thus raising the ratio of Bcl-2/Bax. The neuroprotective effect of daucosterol was inhibited in the presence of picropodophyllin (PPP)(9), the inhibitor of insulin-like growth factor I receptors (IGF1R)(10). Our study provided information about daucosterol as an efficient and inexpensive neuroprotectants, to which the IGF1-like activity of daucosterol contributes. Daucosterol could be potentially developed as a medicine for ischemic stroke treatment.
Assuntos
Apoptose/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/metabolismo , Fármacos Neuroprotetores/farmacologia , Traumatismo por Reperfusão/tratamento farmacológico , Sitosteroides/farmacologia , Animais , Encéfalo/citologia , Caspase 3/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Glucose/metabolismo , Quinase 3 da Glicogênio Sintase/biossíntese , Glicogênio Sintase Quinase 3 beta , Fator de Crescimento Insulin-Like I/biossíntese , Proteína de Sequência 1 de Leucemia de Células Mieloides/biossíntese , Oxigênio/metabolismo , Podofilotoxina/análogos & derivados , Podofilotoxina/farmacologia , Proteínas Proto-Oncogênicas c-akt/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Ratos , Ratos Sprague-Dawley , Receptores de Somatomedina/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Proteína X Associada a bcl-2/biossínteseRESUMO
OBJECTIVE: To investigate the effect of RNA interference mediated angiopoietin-2 (ANG-2) gene silencing on human endometrial carcinoma cell line Ishikawa. METHODS: Short hairpin RNA (shRNA) targeting ANG-2 gene was designed and transfected into Ishikawa cells with Lipofectamine 2000. The mRNA and protein expression level of ANG-2, proliferation, morphological changes, apoptosis, cell cycle and invasive ability of the cells after transfection were analyzed. RESULTS: The shRNA targeting the human ANG-2 gene effectively decreased the expression of ANG-2 on both mRNA and protein level, the proliferation inhibition rate of the Ishikawa cells was 63.11%, cell apoptosis was induced, and the cell cycle was arrested in G1 phase. The apoptotic rate of the Ishikawa cells in the transfected group was significantly higher, and the invasive ability was decreased markedly, than that of control groups. CONCLUSION: The shRNA targeting human ANG-2 gene could reduce ANG-2 expression, inhibit cellular growth and invasion in Ishikawa cells in vitro.