Expression of NF-κB in hRPE Cells Stimulated by PDTC and IL-1β

The constitutive expression of nuclear-factor-κB (NF-κB) in human pigment epithelial (hRPE) cells cultivated in vitro and the possible changes when incubated with PDTC and IL-I were investigated. The synchronized hRPE cells in vitro were divided into two groups. In nonPDTC group, hRPE cells were exposed respectively to IL-1β and NS (for detecting the constitutive expressions of NF-κB in hRPE cells) ; In PDTC group, PDTC-pretreated hRPE cells were exposed respectively to IL-1β?Aand NS. (for detecting the constitutive expression of NF-κB in PDTC-pretreated hRPE cells). The expression of NF-κB in hRPE cells in two groups was detected by immunofluorescence stain and flow cytometry. The results showed that the constitutive expression of NF-κB in hRPE cells in vitro was 8.05 %, and increased to 30.26 % by IL-1β. After PDTC pretreatment, the constitutive expression of NF-κB in hRPE cells was decreased to 3.74%, and 3.66 % by IL-l,respectively. It was concluded that the expressions of NF-κB in hRPE cells could be increased significantly by IL-1βand depressed effectively by PDTC. Also, PDTC could significantly inhibit the activation of NF-κB induced by IL-1β.     

Role of liver X receptors alpha agonist on expressions of LPS-induced inflammatory response associated factor IRAK-4 and NF-kappaB in Kupffer cells

Objective： To explore the role of activated liver X receptor α （LXRα） on the expressions of interleukin-1 receptor associated kinase-4 （IRAK-4） and NF-kappaB （NF-κB） in the inflammatory response which induced by LPS in the Kupffer cells and to investigate the possible mechanisms of LXRα negative regulation of inflammatory response. Methods： The Kupffer cells were isolated from male Kunming mice by collagen perfusion in situ. And these cells were divided into 4 groups： normal control group, LPS treatment group, LXRct agonist T0901317 treatment group, LPS and T0901317 combined treatment group. The LPS treatment group were treated with a final concentration of 1 μg/ml LPS in RPMI 1640 and cultured for 6 h, the T0901317 treatment group were treated with a final concentration of 5 μg/ml in RPMI 1640 and cultured for 24 h, and the combined treatment group received pre-culture for 24 h with a final concentration of 1μg/ml T0901317 in RPMI 1640 and then cultured for 6 h with a final concentration of 5 μg/ml LPS in RPMI 1640. All groups were cultured for 30 h. The expression of LXRα, IRAK-4 and NF-κB at mRNA and protein levels were detected by real-time PCR and Western blotting, and the TNF-α and IL-1β levels were detected by ELISA. Results： The levels of LXRα mRNA and protein were highest in T0901317 group, and lowest in LPS group （P〈0.05）. The level of IRAK4 and NF-κB mRNAs and proteins were evidently lower in the Combined-treated group than in LPS group （P〈0.05）. And the level of TNF-α and IL-1 were observed highest in LPS group （P〈0.05）, but no difference among the Control group, T0901317 group and Combined-treated group （P〉0.05）. Conclusion： These date suggest that the LXR agonists can effectively up-regulate the expressions of LXRα mRNA and protein and inhibit the inflammatory response. This may be via down-regulating the expressions of IRAK4 and NF-κB at mRNA and protein levels.     

Effect of Lipoxin A4 on IL-1β Production of Monocytes and Its Possible Mechanism in Severe Preeclampsia

This study examined in vitro effect of lipoxin A 4 (LXA 4) on interleukin-1β (IL-1β) production of monocytes and its possible mechanism in severe preeclampsia (PE).Peripheral venous blood was drawn from 15 patients with severe preeclampsia (PE group) and 20 normal pregnant women (control group) to prepare monocytes which were then treated with LXA 4 at different concentrations of 0,10,100 nmol/L respectively.IL-1β level in the supernatant of monocytes was detected by enzyme linked immunoassay.The [Ca 2+ ] i of monocytes was measured by laser scanning confocal microscopy.The results showed that the IL-1β level and the [Ca 2+ ] i of monocytes in the PE group were significantly higher than those in the control group.LXA 4 significantly decreased the generation of IL-1β in a dose-dependent manner in the PE group.After treatment with 100-nmol/L LXA 4,in the PE group,the [Ca 2+ ] i concentration of monocytes was significantly reduced.It was concluded that LXA 4 may inhibit the IL-1β production of monocytes from severe preeclampsia women by inhibiting extracellular calcium influx.     

Effects of emodin on the proliferation of the glomerular mesangial cell and correlative cytokines in rats

Objective：To investigate the effects of emodin（EMD） on cell proliferation and correlative cytokines secretion of glomerular mesangial in rats. Methods：The effects of EMD on cell proliferation and IL-6, TGF-β1 secretion of glomerular mesangial in rats were observed. Cell proliferation was measured by MTT method. IL-6 and TGF-β1 secretion was detected with ELISA. Results：EMD was able to inhibit the cell proliferation and down-regulate the IL-6 and TGF-β 1 secretion of glomerular mesangial, as compared to the model group in rats （P 〈 0.05）. Conclusion：EMD could significantly inhibit the cell proliferation, and reduce the creation of extracellular matrix（ECM）, this indicated that it could play an important role in alleviation and prevention of glomerular sclerosis. The mechanism may be that EMD can reduce the IL-6 and TGF-β1 secretion ofglomerular mesangial cell in rats.     

Expression and Significance of NF-κB, IL-1β and COX-2 in the Murine Model of Estrogen-dependent Experimental Vulvovaginal Candidiasis

Objective To investigate the possible role of estrogen in the pathogenesis of vulvovaginal candidiasis(VVC). Methods Estrogen-dependent experimental murine model of C. albicans vaginal infection was established by injecting subcutaneously with estradiol benzoate and then 5×106 stationary-phase C. albicans blastoconidia was inoculated intravaginally to mice (group EI), and other 3 groups were set up: estrogen-treated but not infected (group E); estrogen-untreated but infected (group I); normal control (group C). The dynamic change of colony-forming unit (CFU) of cervivovaginal lavage fluid was observed. Vaginal tissues at different time points (d 2, d 4, d 7 and d 14) after inoculation of C. albicans were obtained. In situ hybridization staining was used to detect expression of cyclooxygenase-2 (COX-2) mRNA and expression of nuclear factor-κB (NF-κB) was examined by immuohistochemistry. ELISA was applied to determine the interlenkin-1β (IL-1β) level. Results The constitutional high level expression of COX-2 mRNA in the vaginal tissue of group E was significantly higher than that in group C on d 4 and d 7 (P<0.01), and the optical density (OD) in group EI was higher than that in the other 3 groups (P<0.05). There were higher IL-1a levels in vaginal tissues from d 4 to d 7 postin- oculation in group EI and group I than group C (P<0.01). Furthermore, IL-1β in group EI was markedly elevated on d 4 and d 7 compared with group I (P<0.01). Compared with group C, the expression of NF-κB in group E was increased obviously on d 4 (P<0.01), and there was significant difference between group EI and group Ion d 4 and d 7 (P<0.01). Conclusions In the murine model of estrogen-dependent experimental VVC, estrogen promotes the infection establishment by up-regulating expression of COX-2 via activating NF-κB signal pathway, and the high expression of COX-2 promoted by the interaction of IL-1β and NF-êB after infection formation was involved in persistence of infection.     

Inhibition of NF-κB by mutant IκBα enhances TNF-α-induced apoptosis in HL-60 cells by controlling bcl-xL expression

Backgound The aim of this study was to explore whether the inhibition of nuclear factor-κB (NF-κB)activation by mutant IκBα (S32,36→A) can enhance TNF-α-induced apoptosis of leukemia cells and to investigate the possible mechanism. Methods The mutant IκBα gene was transfected into HL-60 cells by liposome-mediated techniques. G418 resistant clones stably expressing mutant IκBα were obtained by the limiting dilution method. TNF-α-induced NF-κB activation was measured by electrophoretic mobility shift assay (EMSA). The expression of bcl-xL was detected by RT-PCR and Western blot after 4 hours exposure of parental HL-60 and transfected HL-60 cells to a variety of concentrations of TNF-α. The percentage of apoptotic leukemia cells was evaluated by flow cytometry (FCM). Results Mutant IκBα protein was confirmed to exist by Western blot. The results of EMSA showed that NF-κB activation by TNF-α in HL-60 cells was induced in a dose-dependent manner, but was almost completely inhibited by mutant IκBα repressor in transfected cells. The levels of bcl-xL mRNA and protein in HL-60 cells increased after exposure to TNF-α, but changed very little in transfected HL-60 cells. The inhibition of NF-κB activation by mutant IκBα enhanced TNF-α-induced apoptosis. Thecytotoxic effects of TNF-α were amplified in a time- and dose-dependent manner. Conclusions NF-κB activation plays an important role in the resistance to TNF-α-induced apoptosis. The inhibition of NF-κB by mutant IκBα could provide a new approach that may enhance the antileukemia effects of TNF-α or even of other cytotoxic agents.