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ObjectiveTo investigate the effect of Ziziphi Spinosae Semen-Albiziae Flos on the nucleotide-binding oligomerization domain，NOD-like receptor thermal protein domain associated protein 1 （NLRP1）/chemokine ligand 1 （CXCL1）/chemokine receptor 2 （CXCR2） pathway in the hippocampus of the rat model of chronic unpredictable mild stress （CUMS）-induced depression. MethodA total of 120 male SD rats were randomized into blank，CUMS，CUMS + low-，medium-，and high-dose （4，8，16 g·kg-1） Ziziphi Spinosae Semen-Albiziae Flos，and CUMS + venlafaxine hydrochloride （0.008 g·kg-1） groups，with 20 rats in each group.The rat model of depression was established by solitary feeding combined with CUMS.The behaviors and spatial learning and memory abilities of rats were examined by sugar water consumption test，tail suspension test，forced swimming test，and Morris water maze test.Quantitative real-time PCR （Real-time PCR） and Western blot were employed to determine the expression of factors associated with the NLRP1/CXCL1/CXCR2 pathway in the hippocampus.Enzyme-linked immunosorbent assay was employed to determine the levels of tumor necrosis factor-α （TNF-α），interleukin （IL）-18，IL-1β，and IL-6 in the hippocampus.The immunofluorescence assay was used to measure the levels of reactive oxygen species （ROS） in the hippocampus. ResultCompared with the blank group，the CUMS group showed decreased preference to sugar water and times of crossing the platform （P<0.01），and increased immobility time of tail suspension，forced swimming floating time，and escape latency （P<0.01）.Compared with the CUMS group，the administration of Ziziphi Spinosae Semen-Albiziae Flos and venlafaxine hydrochloride alleviated the effects of CUMS on the above-mentioned behaviors and spatial learning and memory abilities of the rats （P<0.05，P<0.01）.Compared with the blank group，the CUMS group showed up-regulated protein levels of NLRP1，CXCL1，and CXCR2 （P<0.01） and elevated levels of IL-18，IL-1β，TNF-α，and IL-6 （P<0.01） in the hippocampus.The treatment with Ziziphi Spinosae Semen-Albiziae Flos and venlafaxine hydrochloride attenuated the activation of NLRP1/CXCL1/CXCR2 signaling pathway and lowered the levels of inflammatory cytokines in the hippocampus of CUMS rats （P<0.05，P<0.01）.In addition，Ziziphi Spinosae Semen-Albiziae Flos lowered the level of ROS in the hippocampus （P<0.05，P<0.01）. ConclusionZiziphi Spinosae Semen-Albiziae Flos can mitigate the depressive behaviors of the rat model of CUMS-induced depression by inhibiting the activation of NLRP1/CXCL1/CXCR2 signaling pathway.
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BACKGROUND:Little data have been available concerning the mechanism of drag resistance and anti-apoptosis in leukemic cells of leukemia children.The majority of studies focus on normal bone marrow mesenchymal stem cells (MSCs) and established stroma cells,but not interaction of MSCs and leukemic cells in leukemia children.OBJECTIVE:To explore the effect of MSCs in leukemia children on the proliferation and apoptosis of leukemic cell strain K562/AO_2.DESIGN,TIME AND SETTING:In vitro cytology experiment was performed at the laboratory of Department of Pediatrics,First Affiliated Hospital of Guangzhou Medical College from December 2007 to August 2008.MATERIALS:MSCs were provided by 30 leukemia children admitted to First Affiliated Hospital of Guangzhou Medical College,including 22 acute lymphoblastic leukemia and 8 acute myeloblastic leukemia.Written informed content was obtained from all families.K562/AO_2 was provided by Tianjin Institute of Hematopathy.METHODS:MSCs were isolated and cultured by Ficoll density gradient method.They were cultured in two conditions:the co-culture of MSCs and K562/AO_2 and K562/AO_2 suspension alone.In co-culture group,1×10~8 /L K562/AO_2 cells at log phase were added to confluent MSCs,and free floating K562/AO_2 cells were discarded after 24 hours.MAIN OUTCOME MEASURES:Effect of MSCs on the growth of K562/AO_2 cells was observed;effect of addamycln on K562/AO_2 cell apoptosis was detected by AnnexinV-FITC method.Cell cycle was determined by flow cytomtry,mdrl gene of K562/AO_2 cell was detected by Taqman-MGB probe real-time PCR.RESULTS:Compared with K562/AO_2 alone,the K562/AO_2 cell co-cultured with MSCs grew slower and the log phase of growth was not significant;the rate of apoptosis in earlier period was significantly decreased (P ＜ 0.05);co-cultured K562/AO_2 G_0-G_1 phase increased,but S phase decreased.No changes in mdr1 gene in cells were found between two culture conditions (P ＞ 0.05).CONCLUSION:In vitro cytology has demonstrated that leukemia children MSCs induce drug resistance of K562/AO_2 cells by changing K562/AO2 cell cycle through adhesion to avoid pro-apoptotic effect of drugs but not related with mdr1 gene.