Prenatal Exposure of Rats to Staphylococcal Enterotoxin B Alters the Expression of Th1 and Th2 Cytokines via Decreased Methylation in the Spleen of Adult but not Neonatal Offspring.

BACKGROUND: The methylation of IFN-γ and IL-4 genes is regarded as an epigenetic regulation that maintains the Th1 or Th2 phenotype. OBJECTIVE: To explore the influence of prenatal administration of the staphylococcal enterotoxin B (SEB) in pregnant rats, on the IFN-γ or IL-4 expression in the offspring spleen. METHODS: The SEB or PBS was administered intravenously to pregnant rats on the embryo-day 16. After normal delivery, the spleens from the fifth-day neonates and adult offspring were isolated under anesthesia. Quantitative PCR, western blot, ELISA and MeDIP-qPCR were applied to determine the levels of the splenic IFN-γ or IL-4 mRNAs, their protein levels, and methylation status, respectively. RESULTS: Prenatal administration of the SEB in pregnant rats decreased the levels of the splenic IFN-γ and IL-4 proteins in neonates, but increased their mRNA levels. However, prenatal administration of the SEB significantly augmented both mRNA and protein levels of the IFN-γ and IL-4 in the adult spleen. In addition, the prenatal SEB administration decreased the methylation of the splenic IFN-γ and IL-4 in adult but not neonatal offspring. CONCLUSION: The prenatal administration of SEB in pregnant rats can cause a mixed Th1 and Th2 cytokines response in the offspring spleen, and alter the cytokine expression of the Th1 and Th2 via decreasing the methylation in adult but, not neonatal offspring spleen.

Exposure of pregnant rats to staphylococcal enterotoxin B attenuates the response of increased Tregs to re-exposure to SEB in the thymus of adult offspring.

Regulatory T cells (Tregs) play an essential role during homeostasis and tolerance of the immune system. Based on our previous study that exposure of pregnant rats to staphylococcal enterotoxin B (SEB) can alter the percentage of CD4/CD8 subsets in the thymus of the offspring, in this study, we focus on the influence of exposure of pregnant rats to SEB on number, function and response of Tregs in the thymus of the offspring. Pregnant rats at gestational day of 16 were intravenously injected with 15 µg SEB and the thymuses of the neonatal and adult offspring were harvested for this study. We found that exposure of pregnant rats to SEB could significantly increase the absolute number of Tregs and the FoxP3 expression level in the thymus of not only neonatal but also adult offspring. Re-exposure of adult offspring to SEB remarkably reduced the suppressive capacity of Tregs to CD4+ T cells and the expression levels of TGF-ß and IL-10 in the thymus, but had no effect on production of IL-4 and IFN-γ. Furthermore, it also notedly decreased the absolute number of Tregs and the FoxP3 expression level. These data suggest that prenatal exposure of pregnant rats to SEB attenuates the response of increased Tregs to re-exposure to SEB in the thymus of adult offspring.

Prenatal exposure of staphylococcal enterotoxin B attenuates the development and function of blood regulatory T cells to repeated staphylococcal enterotoxin B exposure in adult offspring rats.

Introduction. Staphylococcal enterotoxin B (SEB) is an extensively studied super-antigen. A previous study by us suggested that SEB exposure during pregnancy could alter the percentage of CD4+ and CD8+ T cells in the peripheral blood of neonatal offspring rats.Aim. It is unknown whether SEB exposure during pregnancy can influence the development of regulatory T cells (Tregs) in the peripheral blood of neonatal offspring rats.Methodology. Pregnant rats at gestational day 16 were intravenously injected with 15 µg SEB. Peripheral blood was acquired from neonatal offspring rats on days 1, 3 and 5 after delivery and from adult offspring rats for determination of Treg number by cytometry, cytokines by ELISA, and FoxP3 expression by real-time PCR and western blot.Results. SEB given to pregnant rats significantly increased the absolute number of Tregs and the expression levels of FoxP3, IL-10 and TGF-ß (P<0.05, P<0.01) in the peripheral blood of not only neonatal but also adult offspring rats. Furthermore, repeated SEB exposure in adult offspring rats significantly decreased the absolute number of Tregs (P<0.01), and the expression levels of FoxP3, IL-10 and TGF-ß (P<0.05, P<0.01) in their peripheral blood.Conclusion. Prenatal SEB exposure attenuates the development and function of Tregs to repeated SEB exposure in the peripheral blood of adult offspring rats.

[Effects of Targeting lncRNA HOTAIR on the Invasion and Nude Mouse Tumorigenicity of Epithelial Ovarian Cancer Cells].

OBJECTIVE: To explore the effects of shRNA-mediated downregulating lncRNA HOTAIR on the invasion,nude mouse tumorigenicity and snail expression of epithelial ovarian cancer SKOV3 cells. METHODS: The expression of lncRNA HOTAIR was detected by RT-PCR in SKOV3 cells. The shRNA targeting the lncRNA HOTAIR gene was cloned into RNA interference plasmid. The construction shHOTAIR vector was transfected into ovarian cancer SKOV3 cells by lipofectamine 2000,and the stably transfected cells were isolated by G418 and single clone selection. The downregulating expression of lncRNA HOTAIR was detected by quantitative real time PCR(qRT-PCR). The characteristics of shHOTAIR transfected SKOV3 cells were analyzed from the assays of invasion and nude mouse tumorigenicity,as well as the expression of snail and E-cadherin mRNA detected by qRT-PCR,and snail detected by immunohistochemistry and Western blot methods in xenograft tumor,respectively. RESULTS: The lncRNA HOTAIR expression was proved by RT-PCR in SKOV3 cells. The lncRNA HOTAIR expression in shHOTAIR transfected SKOV3 cells was significantly lower than the scramble control (P<0.01). The shHOTAIR transfected SKOV3 cells show that the invasion ability was significantly decreased compared with the scramble control (P<0.01). The nude mouse tumorigenicity,including tumorigenicity mouse number and tumor volume,was significantly decreased compared with the control group (P<0.01). The snail protein expression detected by IHC and Western blot in shHOTAIR-SKOV3 xenograft tumor was significantly decreased compared with the control scramble- SKOV3 group (P<0.05). The lncRNA HOTAIR low expression resulted in increasing E-cadherin and decreasing snail expression detected by qRT-PCR in the shHOTAIR transfected SKOV3 cells of xenograft tumor,compared with the scramble control (P<0.05). CONCLUSION: Targeting lncRNA HOTAIR expression in SKOV3 cells with RNA interference can decrease snail,increase E-cadherin and significantly reduce the invasion and tumorigenicity of epithelial ovarian cancer SKOV3 cells. These results suggest that the lncRNA HOTAIR could be an effective therapeutic target for human epithelial ovarian caner treatment.

[Effect of cordycepin on apoptosis and autophagy of tongue cancer cells in vitro and the molecular mechanism].

OBJECTIVE: To study the effect of cordycepin on cell cycle, apoptosis and autophagy of human tongue cancer TCA-8113 cells and explore the mechanism of cordycepin for inhibiting the occurrence of tongue cancer. METHODS: CCK-8 method was used to assess the inhibitory effect of cordycepin on TCA-8113 cell proliferation in vitro. The cell cycle and cell apoptosis of TCA-8113 cells treated with different concentrations of cordycepin were analyzed using flow cytometry. The expressions of apoptosis-related genes caspase-3, caspase-9, Bcl-2, and Bax were examined using quantitative real-time PCR and Western blotting, and immunohistochemistry was used to detect the expressions of autophagy-related proteins LC-3ß, P62, p-mTOR, and AMPK. RESULTS: CCK-8 assay showed that cordycepin significantly inhibited the proliferation of TCA-8113 cells in a concentration-dependent manner with an IC50 of 3.548 mg/mL at 24 h and an IC50 of 1.185 mg/mL at 48 h. Flow cytometric analysis showed that cordycepin caused cell cycle arrest at S phase and dose-dependently increased the apoptotic rate of TCA-8113 cells. Treatment of the cells with cordycepin enhanced the expressions of Bax, caspase-3 and caspase-9 at both the mRNA and protein levels and inhibited the expression of the antiapoptotic gene Bcl-2. Immunohistochemistry demonstrated that cordycepin promoted the expression of LC-3ß and AMPK and inhibited the expression of P62 and p-mTOR. CONCLUSION: Cordycepin inhibits the proliferation and induces apoptosis of HCT-116 cells through the mitochondrial pathway and induces autophagy via the AMPK/mTOR pathway.

Staphylococcal enterotoxin B administration in pregnant rats alters the splenic lymphocyte response in adult offspring rats.

BACKGROUND: Our previous study suggested that SEB exposure in pregnant rats could lead to the change of T cells subpopulation in both peripheral blood and thymus of the offspring rats. However, rarely is known about the influence of SEB exposure in pregnant rats on T cell subpopulation in the spleens of offspring rats. RESULTS: SEB was intravenously administered to the pregnant rats at gestational day 16 in this study. The percentages, in vivo and in vitro responses of CD4 and CD8 T cells were investigated with flow cytometry. The prenatal SEB exposure obviously increased splenic CD4 T cell percentages of both neonates and adult offspring rats, and obviously reduced splenic CD8 T cell percentages of both the fifth day neonates and adult offspring rats. After spleens in the adult offspring rats were re-stimulated with SEB in vivo or in vitro, in vivo SEB stimulation could lead to the marked decrease of splenic CD4 T cell percentage and the marked increase of splenic CD8 T cell percentage. While in vitro SEB stimulation to the cultured splenocytes markedly decreased the proliferation of the splenic lymphocytes and the CD4 T cell percentage, and had no influence on CD8 T cell percentage. CONCLUSION: The prenatal SEB exposure could alter the percentages of CD4/CD8 T cell subpopulation and the response of CD4 and CD8 T cells to the in vivo and in vitro secondary SEB stimulation in the splenocytes of adult offspring rats.