RESUMO
Apoptosis, as a programmed cell death process, is essential for the maintenance of tissue function in organisms. Alteration of this process is linked to many diseases. Over-expression of clusterin (Clu) can antagonize apoptosis in various cells. Selenium (Se) is an essential trace element for human health. Its biological function is also associated with cell apoptosis. To explore the function of Clu and the impact of Se in the process of apoptosis, several short-hairpin RNAs (shRNA) were designed for the construction of two sets of recombinant plasmids: one set for plasmid-transfection of mouse neuroblastoma N2a cells (N2a cells); and the other set for lentiviral infection of human neuroblastoma SH-SY5Y cells (SH-SY5Y cells). These shRNAs specifically and efficiently interfered with the intracellular expression of Clu at both the mRNA and protein levels. The Clu-knockdown cells showed apoptosis-related features, including down-regulation of antioxidative capacity and the Bcl-2/Bax ratio and up-regulation of caspase-8 activity. Se-methylselenocysteine (MSC) at an optimum concentration of 1 µM could reverse the alteration in antioxidative capacity, Bcl2/Bax ratio and caspase-8 activity caused by Clu-knockdown, thus inhibiting apoptosis and maintaining cell viability. The results hereby imply the potentiality of Clu and Se in neuroprotection.
Assuntos
Apoptose/efeitos dos fármacos , Clusterina/genética , Neuroblastoma/tratamento farmacológico , Selenocisteína/análogos & derivados , Animais , Apoptose/genética , Caspase 8/genética , Caspase 8/metabolismo , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Humanos , Camundongos , Neuroblastoma/genética , Neuroblastoma/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Interferente Pequeno/genética , Selênio/metabolismo , Selenocisteína/farmacologia , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
Vaccine development by the use of calpain of Schistosoma japonicum has been tried in our laboratory. We cloned cDNA encoding the heavy chain of S. japonicum calpain, and prepared recombinant molecule of a possible vaccine region of the heavy chain. When BALB/c mice were immunized with our recombinant calpain of S. japonicum with Freund's complete adjuvant, we observed significant reduction in worm burden (41.2% reduction, P<0.05), and also significant anti-fecundity effects. In this sense, calpain of S. japonicum seems to have infection control as well as anti-disease effects. Mechanisms of vaccine effects of calpain remain to be clarified, however, several effector mechanisms are suspected. In immunized mice, raised level of iNos expression was observed, while adhesion of peritoneal exudates cells were also observed in the presence of calpain-immunized sera, suggesting the possibilities of both cellular and humoral protective mechanisms. We examined tissue distribution of calpain in various developmental stages of S. japonicum. Strong signal was observed around excretory grand of cercariae, and they secreted calpain during their migratory movement tested in vitro. Together with the findings, calpain seems to induce larvicidal effects in the immunized mice. We observed time-course kinetics of antibody production against vaccine candidates in experimental S. japonicum infection in pigs. Although significant levels of antibody production were observed for paramyosin and GST, no significant antibody production was observed for calpain. This suggests that calpain is less immunogenic, and route of immunization and/or choice of adjuvant are important in future trials of calpain vaccine.
Assuntos
Calpaína/imunologia , Schistosoma japonicum/imunologia , Esquistossomose Japônica/prevenção & controle , Vacinas , Animais , Calpaína/genética , Camundongos , Camundongos Endogâmicos BALB C , Schistosoma japonicum/enzimologia , Esquistossomose Japônica/parasitologia , Vacinação , Vacinas/administração & dosagem , Vacinas/imunologiaRESUMO
AIM:To study the thermotherapeutic effects of implanted ferromagnetic thermoseeds in high frequency electromagnetic field in hepatic tumors.METHODS:The ferromagnetic thermoseeds made of nickel-copper alloy, which has a lower Curie temperature, were implanted into hepatic tumors of mice. The high frequency electromagnetic field was then applied in vitro to make the ferromagnetic thermoseeds produce the hyperthermia. Before and after thermotherapy, the tumor size, pathologic alteration and animal survival period were assessed.RESULTS:The temperature at the central area of the tumor could be heated up to 50°. Most of tumors in mice disappeared with a large amount of tumor necrosis. The survival period of mice was prolonged.CONCLUSION:This thermotherapy is beneficial to directional selection and temperature control for treatment of hepatic tumors.