Mechanism of n-butanol alcohol extract of Baitouweng Decoction in treatment of vulvovaginal candidiasis based on negative regulation of NLRP3 inflammasome via PKCδ/NLRC4/IL-1Ra axis / 中国中药杂志

This study aimed to explore the mechanism of n-butanol alcohol extract of Baitouweng Decoction(BAEB) in the treatment of vulvovaginal candidiasis(VVC) in mice based on the negative regulation of NLRP3 inflammasome via PKCδ/NLRC4/IL-1Ra axis. In the experiment, female C57BL/6 mice were divided randomly into the following six groups: a blank control group, a VVC model group, high-, medium-, and low-dose BAEB groups(80, 40, and 20 mg·kg~(-1)), and a fluconazole group(20 mg·kg~(-1)). The VVC model was induced in mice except for those in the blank control group by the estrogen dependence method. After modeling, no treatment was carried out in the blank control group. The mice in the high-, medium-, and low-dose BAEB groups were treated with BAEB at 80, 40, and 20 mg·kg~(-1), respectively, and those in the fluconazole group were treated with fluconazole at 20 mg·kg~(-1). The mice in the VVC model group received the same volume of normal saline. The general state and body weight of mice in each group were observed every day, and the morphological changes of Candida albicans in the vaginal lavage of mice were examined by Gram staining. The fungal load in the vaginal lavage of mice was detected by microdilution assay. After the mice were killed, the degree of neutrophil infiltration in the vaginal lavage was detected by Papanicolaou staining. The content of inflammatory cytokines interleukin(IL)-1β, IL-18, and lactate dehydrogenase(LDH) in the vaginal lavage was tested by enzyme-linked immunosorbent assay(ELISA), and vaginal histopathology was analyzed by hematoxylin-eosin(HE) staining. The expression and distribution of NLRP3, PKCδ, pNLRC4, and IL-1Ra in vaginal tissues were measured by immunohistochemistry(IHC), and the expression and distribution of pNLRC4 and IL-1Ra in vaginal tissues were detected by immunofluorescence(IF). The protein expression of NLRP3, PKCδ, pNLRC4, and IL-1Ra was detected by Western blot(WB), and the mRNA expression of NLRP3, PKCδ, pNLRC4, and IL-1Ra was detected by qRT-PCR. The results showed that compared with the blank control group, the VVC model group showed redness, edema, and white secretions in the vagina. Compared with the VVC model group, the BAEB groups showed improved general state of VVC mice. As revealed by Gram staining, Papanicolaou staining, microdilution assay, and HE staining, compared with the blank control group, the VVC model group showed a large number of hyphae, neutrophils infiltration, and increased fungal load in the vaginal lavage, destroyed vaginal mucosa, and infiltration of a large number of inflammatory cells. BAEB could reduce the transformation of C. albicans from yeast to hyphae. High-dose BAEB could significantly reduce neutrophil infiltration and fungal load. Low-and medium-dose BAEB could reduce the da-mage to the vaginal tissue, while high-dose BAEB could restore the damaged vaginal tissues to normal levels. ELISA results showed that the content of inflammatory cytokines IL-1β, IL-18, and LDH in the VVC model group significantly increased compared with that in the blank control group, and the content of IL-1β, IL-18 and LDH in the medium-and high-dose BAEB groups was significantly reduced compared with that in the VVC model group. WB and qRT-PCR results showed that compared with the blank control group, the VVC model group showed reduced protein and mRNA expression of PKCδ, pNLRC4, and IL-1Ra in vaginal tissues of mice and increased protein and mRNA expression of NLRP3. Compared with the VVC model group, the medium-and high-dose BAEB groups showed up-regulated protein and mRNA expression of PKCδ, pNLRC4, and IL-1Ra in vaginal tissues and inhibited protein and mRNA expression of NLRP3 in vaginal tissues. This study indicated that the therapeutic effect of BAEB on VVC mice was presumably related to the negative regulation of NLRP3 inflammasome by promoting PKCδ/NLRC4/IL-1Ra axis.

Impact of TLR5 and NLRC4 activation on proliferation of different breast cancer cell lines / 中国免疫学杂志

Objective:To explore the impact of TLR5 and NLRC4 activation on the proliferation of different breast cancer cell lines,MCF-7 and MDA-MB-23 i.Methods:Induction,expression,purification and identification of recombiant flagellin,including FliC (activating both TLR5 and NLRC4),FliC△90-97 (unable to activate TLR5),FliC-L3A (unable to activate NLRC4),FliC△90-97:L3A (unable to activate both TLR5 and NLRC4).Using different concentration of recombinant flagellin to stimulate MCF-7 and MDA-MB-231 cell lines,72 h later,the proliferation of tumor cells were detected with CCK8.We also used soft AGAR forming experiments to detect the inhibition ratio of recombinant flagellin on breast cancer cell lines.Briefly,1 000 cells were plated in the 6-well plate,then stimulated with 1 μg/ml recombinant flagellin,14 days later,the number of cloning were counted after crystal violet staining.Results:After stimulation with four recombinant flagellins at the concentration of 0.1 μ,g/ml,the inhibition ratio on MCF-7 reached 30％,and FliC△90-97 were dose-dependent on the inhibition of MCF-7 proliferation.At the concentration of 1 μg/ml,FliC-L3A which only activated TLR5 showed stronger inhibition ratio than FliC.FliC△90-97:L3A which did not activate both TLR5 and NLRC4 also inhibited the proliferation of MCF-7.After adding transfection reagent,four recombinant flagellins showed inhibition effect on MDA-MB-231.Conclusion:Flagellin can inhibit the proliferation of MCF-7 and MDA-MB-231,and the mechanism of inhibition on the proliferation were not TLR5 and NLRC4 pathway dependent.There might exist new mechanisms to explain this phenomenon.

Impact of TLR5 and NLRC4 activation on innate immune cells in mice / 中国免疫学杂志

Objective:To investigate the impact of recombinant flagellin targeting TLR5 and NLRC4 simultaneously or respectively on innate immune cells in mice. Methods: Induction,expression,purification and identification of recombiant FliC,which were FliC(activating both TLR5 and NLRC4);FliCΔ90-97(unable to activate TLR5),FliC-L3A(unable to activate NLRC4),FliCΔ90-97:L3A(unable to activate both TLR5 and NLRC4). The mice were divided into five groups,namely group FliC,FliC-L3A,FliCΔ90-97,FliCΔ90-97:L3A and PBS,which were injected with 100μl PBS or 10μg recombinant flagellin intraperitoneally,three mice in each group. 12 h later,the mice were executed using dislocation of cervical vertebra and the splenic and peritoneal cells were isolated. The spleen was grinded into single-cell suspension. The proportion of neutrophils,NK cells,DCs and the expression level of CD80 and CD86 on DCs were evaluated with flow cytometry. Results:Group FliC,group FliC-L3A and group FliCΔ90-97 shared the similar proportion of neutrophils in peritoneal cavity ( P>0. 05 ) , and all of which were significantly higher than group PBS and group FliCΔ90-97 ( P<0. 01),and NK cells also showed the similar trend. Compared with group FliCΔ90-97 and FliCΔ90-97:L3A,the mean fluorescence intensities(MFIs) of CD80 and CD86 in group FliC and FliC-L3A increased significantly(P<0. 01). The proportion of Treg in spleen was highest among all groups. Conclusion:Activation of TLR5 and NLRC4 had similar chemotaxis of neutrophils and NK cells. The ex-pression of CD80 and CD86 on DCs were upregulated after stimulation by flagellin and TLR5-dependent. Activation of TLR5,but not NLRC4,increased the proportion of Treg in spleen.

Expression and location of TLR5 and NLRC4 in different breast cancer cell lines / 中国免疫学杂志

Objective:To explore the expression and location of TLR5 and NLRC4 on different breast cancer cell lines MDA-MB-231,MCF-7 and MDA-MB-435 and TLR5 activation in breast cancer cell line by recombinant flagellin . Methods:The mRNA level of TLR5 and NLRC4 in MDA-MB-231, MCF-7 and MDA-MB-435 cell were detected with quantitative Real-time PCR and TLR5 expression and location in MDA-MB-231 and MCF-7 cell were detected with Flow cytometry. Induction,expression,purification and i-dentification of recombiant flagellin,including FliC (activating both TLR5 and NLRC4),FliC△90-97(unable to activate TLR5),FliC-L3A (unable to activate NLRC4),FliC△90-97:L3A (unable to activate both TLR5 and NLRC4). 1 μg/ml recombinant flagellin were used to stimulate MCF-7 cell lines,12 h later,the supernate were collected,and ELISA was performed to assess the secretion of IL-8. Results:The mRNA level of TLR5 in MCF-7 cell was 1 700 folds higher than that of MDA-MB-435. TLR5 was expressed in MCF-7 cell surface and ctyosol,while expressed only in cytosol in MDA-MB-231 cell. FliC and FliC-L3A,which were able to activate TLR5 pathway,stimualted MCF-7 cell line to secret IL-8,but FliC△90-97 and FliC△90-97:L3A did not. Conclusion:TLR5 and NLRC4 have been expressed in different breast cancer lines,but there exists difference on the expression level and location of TLR5. Expression level of TLR5 and NLRC4 in MCF-7 cell were higher than other breast cancer lines. TLR5 receptor which is expressed on the surface of breast cancer cell can be activated by flagellin,and these work also provide us experimental basis to further understand the impact of TLR5 activation on breast cancer cell proliferation.