RESUMEN
Preeclampsia is a pregnancy disorder associated with shallow placentation, forcing placental cells to live in hypoxic conditions. This activates the transcription factor kappa B (NFκB) in maternal and placental cells. Although the role of NFκB in preeclampsia is well documented, its mechanism of activation in trophoblastic cells has been never studied. This study investigates the mechanism of NFκB activation in a first trimester trophoblastic cell line (HTR8/SVneo) stimulated by a medium containing serum from preeclamptic (PE) or normotensive (C) women in hypoxic (2% O2) or normoxic (8% O2) conditions. The results indicate that in HTR8/SVneo cells, the most widely studied NFκB pathways, i.e., canonical, non-canonical and atypical, are downregulated in environment PE 2% O2 in comparison to C 8% O2. Therefore, other pathways may be responsible for NFκB activation. One such pathway depends on the activation of NFκB by the p53/RSK1 complex through its phosphorylation at Serine 536 (pNFκB Ser536). The data generated by our study show that inhibition of the p53/RSK1 pathway by p53-targeted siRNA results in a depletion of pNFκB Ser536 in the nucleus, but only in cells incubated with PE serum at 2% O2. Thus, the p53/RSK1 complex might play a critical role in the activation of NFκB in trophoblastic cells and preeclamptic placentas.
Asunto(s)
FN-kappa B/metabolismo , Preeclampsia/patología , Proteínas Quinasas S6 Ribosómicas 90-kDa/metabolismo , Trofoblastos/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Hipoxia de la Célula/fisiología , Línea Celular , Activación Enzimática/genética , Femenino , Humanos , Placenta/patología , Embarazo , Interferencia de ARN , ARN Interferente Pequeño/genética , Especies Reactivas de Oxígeno/metabolismo , Proteína p53 Supresora de Tumor/genéticaRESUMEN
Although higher nuclear factor κB (NFκB) expression and activity is observed in preeclamptic placentas, its mechanism of activation is unknown. This is the first study to investigate whether the canonical, non-canonical, or atypical NFκB activation pathways may be responsible for the higher activation of NFκB observed in preeclamptic placentas. The study included 268 cases (130 preeclamptic women and 138 controls). We studied the expression of the genes coding for NFκB activators (NIK, IKKα, IKKß, and CK2α) and inhibitors (IκBα and IκBß) using RT-PCR in real time. The RT-PCR results were verified on the protein level using ELISA and Western blot. To determine the efficiency of the pathways, the ratios of activator(s) to one of the inhibitors (IκBα or IκBß) were calculated for each studied pathway. The preeclamptic placentas demonstrated significantly lower IKKα and CK2α but higher IκBα and IκBß protein levels. In addition, the calculated activator(s) to inhibitor (IκBα or IκBß) ratios suggested that all studied pathways might be downregulated in preeclamptic placentas. Our results indicate that preeclamptic placentas may demonstrate mechanisms of NFκB activation other than the canonical, non-canonical, and atypical forms. In these mechanisms, inhibitors of NFκB may play a key role. These observations broaden the existing knowledge regarding the molecular background of preeclampsia development.
Asunto(s)
Quinasa I-kappa B/genética , Preeclampsia/genética , Proteínas Serina-Treonina Quinasas/genética , Adulto , Núcleo Celular/genética , Femenino , Regulación de la Expresión Génica/genética , Humanos , FN-kappa B/genética , Placenta/metabolismo , Placenta/patología , Preeclampsia/patología , Embarazo , Transducción de Señal/genética , Quinasa de Factor Nuclear kappa BRESUMEN
This study was undertaken to verify whether simvastatin modulates Cav-1/eNOS expression, and if this modulation is associated with changes in pro- and anti-inflammatory cytokine and Toll-like receptor 4 (TLR4) level in abdominal aortic aneurysm (AAA). It is a 1:2 case-control study of non-statin (n=12) and simvastatin-treated patients (n=24) who underwent open AAA repair. Simvastatin treatment decreased Cav-1 (p<0.05) and increased eNOS expression (p<0.01) in the AAA wall. These changes might be dose dependent. The changes in Cav-1 and eNOS were associated with a trend towards decreased IL-6 and IL-17 concentration (p>0.05) and increased IL-10 concentration (p=0.055); however, TLR4 expression was unaffected, suggesting that simvastatin influences Cav-1 and eNOS in the AAA wall by other mechanisms. Simvastatin may modulate Cav-1 and eNOS expression in the aneurysmal wall, indicating a potentially beneficial role for statins in AAA patients.