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Objective: To screen the anti-atherosclerosis (AS) activity of the compounds by using THP-1-HIF-1α-HER-Luciferase high-throughput model, and to verify the anti-AS function of the effective compounds. Methods: THP-1-HIF-1α-HER-Luciferase cells were pretreated with different concentrations of compounds (1, 10, and 100 μg/mL) for 2 h, then cultured under hypoxia for 24 h. Luciferase activity of cells was detected and compounds with anti-AS activity were screened by luciferase activity evaluation. THP-1 and U937 cells were pretreated with effective compounds, and then induced for 24 h by oxidized low density lipoprotein (OX-LDL). The formation of foam cells was observed by oil red staining. The mRNA level of hypoxia-inducible factor 1α (HIF-1α) was detected by real-time quantitative PCR (qPCR). HIF-1α protein expression was detected by Western blotting. Anti-AS activity of effective compounds were evaluated. Results: Among the 200 compounds, 11 compounds could significantly inhibit the increase of luciferase activity in THP-1-HIF-1α-HER-Luciferase cells induced by hypoxia (all P<0.05), and compound numbered 14 (C14) had the most significant inhibitory effect. THP-1 and U937 cells formed foam cells induced for 24 h by OX-LDL. However, cells were pretreated with C14 for 2 h, which could significantly inhibit the formation of foam cells induced by OX-LDL. Cells were induced for 24 h by OX-LDL, which could significantly increase the expression of HIF-1α mRNA and protein (all P<0.05), while cells pretreated with C14 could significantly inhibit the increase of HIF-1α mRNA and protein expression in a gradient-dependent manner (all P<0.05). Conclusion: THP-1-HIF-1α-HER-Luciferase high-throughput model can be reliability used in screening of compounds with anti-AS activity. C14 has the good anti-AS activity characteristics.
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OBJECTIVE@#To investigate the effect of phorbol 12-myristate 13-acetate (PMA) and formyl-methionyl-leucyl-phenylalanine (FMLP) on oxygen consumption of differentiated and non-differentiated immune cell lines by retinoic acid and calcitriol treatment which might be useful in subsequent elicitation of immunological action during immunosuppressive states.@*METHODS@#PMA and FMLP were used to artificially stimulate reactive oxygen production in cultured promonocytic U937 cell line. Paralleled samples of the cultured cells were separately prepared with calcitriol (1, 25- dihydroxyvitamin D3) and retinoic acid followed by a 72-hour incubation period. The rate of respiratory burst was measured using the Clark oxygen electrode.@*RESULTS@#The average increase in cell concentrations per mL observed was significantly higher in retinoic acid-treated cells (9×10(6) cells/mL) when compared with calcitriol-treated samples (4×10(6) cells/mL). There was a marked increase in oxygen consumption of the calcitriol-treated cell lines against the retinoic acid-treated ones. Exposure of differentiated U937 cells to PMA and FMLP increased significantly (P<0.05) in their oxygen consumption when compared with the control. PMA calcitriol-treated cells resulted in 55% oxygen consumption more than the control while FMLP oxygen consumption increased 78% by comparison with the control.@*CONCLUSIONS@#The result demonstrated that calcitriol may serve as a physiological promoter of normal differentiation of precursor cells which may exert an immunological action. This effect could elicit a marker potential and increase immune cell activity of the host especially in immunosuppressed diseased states.
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Objective: To investigate the effect of phorbol 12-myristate 13-acetate (PMA) and formyl-methionyl-leucyl-phenylalanine (FMLP) on oxygen consumption of differentiated and non-differentiated immune cell lines by retinoic acid and calcitriol treatment which might be useful in subsequent elicitation of immunological action during immunosuppressive states. Methods: PMA and FMLP were used to artificially stimulate reactive oxygen production in cultured promonocytic U937 cell line. Paralleled samples of the cultured cells were separately prepared with calcitriol (1, 25- dihydroxyvitamin D
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[Objective] To investigate the anti-proliferative and apoptosis effect induced by Honokiol (HNK) on human myeloid leukemia cell line U937 cells in vitro.[Methods] After treated with different concentration of HNK,Hoechst33342 fluorescent staining was used to detect cell apoptosis;the growth inhibition ration of U937 cells and PBMCs were analyzed by MTT assay;the apoptosis ration was detected by flow cytometry;mitochondrial membrane potential was explored by rhodamine 123 stain;Caspase3/7 protein activity kit was used to test the Caspase3/7 activity;the Caspase-3 and Caspase-7 mRNA levels were detected by real-time fluorescent relative-quantification reverse transcriptional PCR (FQ-PCR).[Results] Honokiol could significantly inhibit the proliferation of U937 cells in terms of the indexes of IC50/U937 11.8 μg/mL and IC50/PBMCs 40.3 μg/mL,and the anti-proliferative effect was in a time and concentration dependent manner;Flow cytometry analysis manifested that Honokiol could induce U937cells apoptosis by Annexin V/PI double Annexin V/PI fluorescein stain;Honokiol significantly inhibited the mitochondrial membrane potential of U937 cells and enhanced the ability of Caspase3/7 and the mRNA expression levels,but not the PBMCs.[Conclusion] HNK can inhibit U937 cells proliferation and induce cells apoptosis via activating Caspase 3/7.
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Objective To investigate the effects of different dialysates on expression of protein kinase C-δ (PKCδ) and apoptosis of U937 cell line. Methods Different dialysates were added into culture fluid with U937 cell line at exponential phase of growth, and groups were divided: fluid A+fluid B group (dialysate A+dialysate B), fluid A+fluid B+rottlerin (PKCδ specific inhibitor)group, fluid A+powder B group (dialysate A+powder B) and fluid A+powder B + rottlerin group. Besides, blank control group and normal control group were established. Cells were harvested 24 h and 48 h after treatment, morphological changes were observed by Hoechst33258 fluorescence staining, cell apoptosis was measured by Annexin-V-FITC/PI double staining, and expression of PKCδ mRNA and protein was detected by RT-PCR and Western blotting, respectively. Results Cell apoptosis significantly increased in fluid A+powder B group, with typical morphology of apoptosis. After treatment for 24 h and 48 h, cell apoptosis rates in fluid A+powder B group were significantly higher than those at corresponding time points in blank control group , normal control group and fluid A+powder B+rottlerin group (P<0.05). Compared with normal control group, blank control group and fluid A+powder B+rottlerin group, the expression of PKCδ mRNA and protein of U937 cells in fluid A+powder B group were significantly increased (P<0.05). There was no significant difference in cell apoptosis rates and expression of PKCδ mRNA and protein between fluid A+fluid B group and blank control group, normal control group and fluid A+fluid B+rottlerin group (P＞0.05). Conclusion Fluid A+powder B can significantly increase apoptosis of U937 cell line, the mechanism of which may be associated with the up-regulation of expression of PKCδ. Compared with fluid A+powder B, fluid A+fluid B is superior in reducing apoptosis of peripheral blood monouclear cells.
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This study is to investigate the protein and mRNA expressions of pro-inflammatory and anti-inflammatory cytokines in U937 foam cells and effects of Ginkgo biloba extract (GbE) on the cytokines.U937 cells were cultured with different concentrations of GbE (0.1,1,and 10 μg·L-1),and stimulated by 100 mg·L-1 oxidized low density lipoprotein (ox-LDL) for 24 h.The expressions of interleukin-1β (IL-1β),tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10) in culture solution were detected by enzyme-linked immunosorbant assay (ELISA) and reverse transcriptase polymerase chain reaction (RT-PCR).The results showed that incubated with 100 mg·L-1 ox-LDL for 24 h,the U937 cells became foam cells,the protein or mRNA expressions of IL-1β,TNF-α,IL-10,and its receptor IL-10R in U937 foam cells were higher markedly than those in normal U937 cells.When the cells were pretreated with GbE (0.1,1,and 10 μg·L-1),the increases of IL-1β and TNF-α in U937 foam cells were remarkably inhibited,but IL-10 expression increased greatly.Especially when cells were pretreated with 10 μg·L-1 GbE,the protein and mRNA expressions of IL-1β and TNF-α were markedly lower than those in U937 foam cells.The protein expression of IL-10 and mRNA expressions of IL-10 and its receptor IL-10R were markedly higher than those in U937 foam cells.GbE inhibited production of pro-inflammatory cytokines IL-1β and TNF-α,but up-regulated the production of anti-inflammatory cytokine IL-10 and its receptor IL-10R in U937 foam cells,which might be related with its anti-atherosclerotic actions.
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Objective To investigate the effects of different dialysates on expression of protein kinase C-? (PKC?) and apoptosis of U937 cell line. Methods Different dialysates were added into culture fluid with U937 cell line at exponential phase of growth, and groups were divided: fluid A+fluid B group (dialysate A+dialysate B), fluid A+fluid B+rottlerin (PKC? specific inhibitor)group, fluid A+powder B group (dialysate A+powder B) and fluid A+powder B + rottlerin group. Besides, blank control group and normal control group were established. Cells were harvested 24 h and 48 h after treatment, morphological changes were observed by Hoechst33258 fluorescence staining, cell apoptosis was measured by Annexin-V-FITC/PI double staining, and expression of PKC? mRNA and protein was detected by RT-PCR and Western blotting, respectively. Results Cell apoptosis significantly increased in fluid A+powder B group, with typical morphology of apoptosis. After treatment for 24 h and 48 h, cell apoptosis rates in fluid A+powder B group were significantly higher than those at corresponding time points in blank control group, normal control group and fluid A+powder B+rottlerin group (P0.05). Conclusion Fluid A+powder B can significantly increase apoptosis of U937 cell line, the mechanism of which may be associated with the up-regulation of expression of PKC?. Compared with fluid A+powder B, fluid A+fluid B is superior in reducing apoptosis of peripheral blood monouclear cells.
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Aim To study IL-8 expression of U937 cells directly induced by Pseudomonas aeruginosa(PA)and its mechanism through the mitogen-activated protein kinase pathways.Methods The expressions of IL-8 mRNA in human monocytic leukemia cell lines(U937 cells)infected by Pseudomonas aeruginosa which were in differently differentiated and its protein secretion in the supernatant of culture medium were examined by the methods of RT-PCR and ELISA respectively.And these were then to be compared with those inhibited by MAPK inhibitors.Results Pseudomonas aeruginosa was able to induce IL-8 mRNA expression and their protein secretion both in U937 cells and in PMA differentiated U937 cells and had marked time and concentration dependent relations.Pretreament of U937 cells with specific inhibitors of ERK1/2(PD98059),the kinase that activated ERK1/2,p38(SB203580)could significantly diminished the PA-induced IL-8 production(P
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AIM: To investigate the influence of matrine on cyclin E and cyclin A in U937 cell strain. METHODS: The inhibitory effect of matrine on proliferation in U937 cell strain was observed by MTT.The distribution of cell cycle was measured by flow cytometry.Immunocytochemical method and Western blot were used to detect the protein expression of cyclin E and cyclin A. RESULTS: After being treated with matrine,the proliferation of U937 cell strain was inhibited significantly,the inhibiting effect conformed to time and dose-dependence,cells were arrested in S-phase.The expression of cyclin E and cyclin A was down-regulated significantly in a dose-dependence manner. CONCLUSION: Matrine could reduce the expression of cyclin E and cyclin A and inhibit the proliferation in U937 cell strain.
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Aim To study the mechanisms of oridonin-enhanced phagocytosis of apoptotic bodies by macrophage-like U937 cells.Methods Photomicroscopical observation,PKC activity assay,acridine orange staining,Hoechst 33258 staining,and Western blot analysis were used.Results Oridonin-augmented phagocytosis was suppressed by either protein tyrosine kinase(PTK) inhibitor genistein or protein kinase C(PKC) inhibitor stauroporine.Exposure of U937 cells to 2.7 ?mol?L~(-1) oridonin caused an increase in PKC activity time dependently.In addition,ERK inhibitor PD98059 blocked phagocytic stimulation as well as the increased expression of phsophorylated ERK in response to oridonin.Conclusion Oridonin enhanced macrophage-like U937 cells to ingest apoptotic bodies by upregulation of PTK activity and thus PKC activation,resulting in phosphorylation of the downstream mediator,ERK.
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Aim To observe the effects of 2,3,4′,5-tetrahydroxystilbene-2-0-?-D glucoside on expression of ICAM-1、VCAM-1 and VEGF excited by ox-LDL in U937 cell.Methods Differentiated U937 cells were cultured in vitro,excited by ox-LDL and intervened by different concentrations of TSG,then the level of SOD and MDA were determined.ICAM-1、VCAM-1 and VEGF protein were determined by Western blot and ICAM-1 mRNA and VCAM-1 mRNA were measured by reverse transcriptase-polymerase chain reaction(RT-PCR).Results In comparison with those of the control,the level of SOD remarkably decreased and the level of MDA remarkably increased in model group;the level of SOD increased markedly and the level of MDA decreased markedly in Simvastatin group and TSG 120 mg?L-1 group(P
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In this study, several physiological factors were studied for their effects on the growth and differentiation of U937 cells in vitro .The results showed that (1)rhTNF-?,PHA-LCM and c-RA exerted a dose and time-dependent suppression of proliferation of U937 cells; (2) the synergistic effect oc-cured when rhTNF-? was combined with c-RA in the cell culture; and (3)rhIL-1-? augmented the differentiation of U937 cells induced by c-RA though it had no effect on the cell line by itself. According to the [3H]-TdR incorporation, it can be concluded that the reduction of DNA synthesis of U917 cells by rhTNF-? ,PHA-LCM,and c-RA is attributed to the inhibition of the growth. The results might have clinical significance in the induction of differentiation of leukemia cells.