RESUMEN
The oxidative damage initiated by reactive oxygen species (ROS) is a major contributor to the functional decline and disability that characterizes aging. The anti-oxidant flavonoid, quercetin, is a plant polyphenol that may be beneficial for retarding the aging process. We examined the restoring properties of quercetin on human dermal fibroblasts (HDFs). Quercetin directly reduced either intracellular or extracellular ROS levels in aged HDFs. To find the aging-related target genes by quercetin, microarray analysis was performed and two up-regulated genes LPL and KCNE2 were identified. Silencing LPL increased the expression levels of senescence proteins such as p16INK4A and p53 and silencing KCNE2 reversed gene expressions of EGR1 and p-ERK in quercetin-treated aged HDFs. Silencing of LPL and KCNE2 decreased the expression levels of anti-oxidant enzymes such as superoxide dismutase and catalase. Also, the mitochondrial dysfunction in aged HDFs was ameliorated by quercetin treatment. Taken together, these results suggest that quercetin has restoring effect on the cellular senescence by down-regulation of senescence activities and up-regulation of the gene expressions of anti-oxidant enzymes in aged HDFs.
Asunto(s)
Antioxidantes/farmacología , Senescencia Celular/efectos de los fármacos , Senescencia Celular/genética , Fibroblastos/metabolismo , Fibroblastos/fisiología , Quercetina/farmacología , Catalasa/metabolismo , Células Cultivadas , Inhibidor p16 de la Quinasa Dependiente de Ciclina/genética , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Proteína 1 de la Respuesta de Crecimiento Precoz/genética , Proteína 1 de la Respuesta de Crecimiento Precoz/metabolismo , Expresión Génica/efectos de los fármacos , Silenciador del Gen , Lipoproteína Lipasa/genética , Lipoproteína Lipasa/metabolismo , Canales de Potasio con Entrada de Voltaje/genética , Canales de Potasio con Entrada de Voltaje/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Piel/citología , Superóxido Dismutasa/metabolismo , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/metabolismo , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Nuclear factor-[Formula: see text]B (NF-[Formula: see text]B)/Rel transcription factors are best known for their central roles in promoting cell survival in cancer. NF-[Formula: see text]B antagonizes tumor necrosis factor (TNF)-[Formula: see text]-induced apoptosis through a process involving attenuation of the c-Jun-N-terminal kinase (JNK). However, the role of JNK activation in apoptosis induced by negative regulation of NF-[Formula: see text]B is not completely understood. We found that allergen-removed Rhus verniciflua Stokes (aRVS) extract-mediated NF-[Formula: see text]B inhibition induces apoptosis in SKOV-3 ovarian cancer cells via the serial activation of caspases and SKOV-3 cells are most specifically suppressed by aRVS. Here, we show that in addition to activating caspases, aRVS extract negatively modulates the TNF-[Formula: see text]-mediated I[Formula: see text]B/NF-[Formula: see text]B pathway to promote JNK activation, which results in apoptosis. When the cytokine TNF-[Formula: see text] binds to the TNF receptor, I[Formula: see text]B dissociates from NF-[Formula: see text]B. As a result, the active NF-[Formula: see text]B translocates to the nucleus. aRVS extract (0.5[Formula: see text]mg/ml) clearly prevented NF-[Formula: see text]B from mobilizing to the nucleus, resulting in the upregulation of JNK phosphorylation. This subsequently increased Bax activation, leading to marked aRVS-induced apoptosis, whereas the JNK inhibitor SP600125 in aRVS extract treated SKOV-3 cells strongly inhibited Bax. Bax subfamily proteins induced apoptosis through caspase-3. Thus, these results indicate that aRVS extract contains components that inhibit NF-[Formula: see text]B signaling to upregulate JNK activation in ovarian cancer cells and support the potential of aRVS as a therapeutic agent for ovarian cancer.