Effect of ex vivo short time expansion with SCF and IL-6 on the adhesion and transmigration activities of hematopoietic stem/progenitor cells

AIM:To investigate the expression and function of homing related molecules and transmigration ability of human cord blood CD34+ hematopoietic stem/progenitor cells after short time stimulation with cytokine SCF and IL-6.METHODS:CD34+ cells were separated by Ficoll density gradient centrifugation and stimulated by SCF and IL-6 cytokines for 48 h. The changes of CD49d (VLA-4), CD11a (LFA-1), CD62L (L-selectin) and CD184 (CXCR4) were analyzed by flow cytometry. The adherent and migration activities of CD34+ cells were evaluated in human fibronectin (FN) coated microplates (96 wells) and transwell system.RESULTS:The numbers of CD34+ cell expanded to 3 folds and the percentages of CD34+ cells that were positive expressions for CD49d, CD11a, CD62L or CD184 increased 1 to 2 folds after the cytokine stimulation. The spontaneous adhesion between CD34+, FN and SDF-1 induced migration increased after SCF+IL-6 stimulated.CONCLUSION:SCF+IL-6 can improve the most of the homing related characteristics and activities in the short time expansion of CD34+ hematopoietic stem/progenitor cells, which may be partly related to the increased intrinsic homing potential.     

Effect of decitabine on proliferation and differentiation of K562 cells

AIM: To investigate the effect of decitabine (Dacogen, DAC) on the proliferation and differentiation of K562 cells. METHODS: The K562 cells were treated with different concentrations of DAC. The colony formation ability of the cells was detected by the colony formation assay with semi-solid culture. The cell viability was detected with MTT assay. The morphologic features were observed under inverted microscope with Wright's staining. The changes of the cell cycle distribution and the expression of CD11b and CD42b were analyzed with flow cytometry. The protein expression of CDK2, cyclin E1, P27, GATA-1 and PU.1 in the K562 cells was determined by Western blot. RESULTS: DAC significantly decreased the colony number of the cells and cell viability in a dose-dependent manner. The morphological changes of the cells displayed partial differentiation. After treated the K562 cells with DAC for 72 h, the cell proportion in S phase was obviously decreased, while the cell proportion in G₂/M phase was obviously increased in a dose-dependent manner. After treated the K562 cells with DAC for 7 d, the percentage of CD11b and CD14 positive cells was further elevated, and the protein expression of P27, GATA-1 and PU.1 was increased. However, the protein expression of CDK2 and cyclin E1 was decreased. CONCLUSION: DAC inhibits the proliferation and induces differentiation of the K562 cells via regulation of cell cycle.     

Supportive and expansive effects of aorta-gonad-mesonephros (AGM)-derived stromal cells on hematopoietic stem in vitro

AIM: To explore the supportive and expansive effects of aorta-gonad-mesonephros(AGM) region derived stromal cells on hematopoietic stem cells (HSC) in vitro.METHODS: The murine stromal cells were separated and cultured from AGM region of a 11 day postcoitum (dpc) mouse embryo and 6 week mouse. After identification by Wrights staining and flow cytometry, the stromal cells were co-cultured with the embryonic stem cell(ESC)-derived, cytokine-induced HSCs, and the maintenance and expansion of HSCs were evaluated by detecting CD34+，CD34+Sca-1+cells with flow cytometry.Blast colony-forming cell (BL-CFC) and high proliferative potential colony-forming cells(HPP-CFC) were determined by semi-solid medium clonal culture.RESULTS: AGM-derived and bone marrow(BM)-derived stromal cells were similar in morphology and phenotype, and had common character of stromal cells. Supported by AGM stromal cells or by BM stromal cells, more primitive progenitor cells HPP-CFC were expanded, but BL-CFC expansion was only detected in AGM-derived stromal cells. In the supporting of BM stromal cells CD34+ hematopoietic stem/progenitor cells were expanded 3-4 times, but no significant expansion in CD34+Sca-1+ cells was observed. While in the supporting of AGM stromal cells, both CD34+ hematopoietic stem/progenitor cells and CD34+Sca-1+ cells were expanded significantly from 4 to 5 times, respectively (P<0.05).CONCLUSION: AGM-derived stromal cells significantly support the expansion of HSC, and also maintain the self-renewal activity and multi-lineage differentiation of HSC in vitro.     

Effect of uric acid on the maturation and the biological function of BMDCs

AIM: To investigate the effect of uric acid on the maturation and the biological function of murine bone-marrow derived dendritic cells (BMDCs) in vitro.METHODS: BMDCs were cultured with GM-CSF, IL-4, LPS and uric acid. Cell phenotypes were analyzed by flow cytometry. MTT was used to detect the effect of uric acid on the function of BMDCs in stimulating the proliferation of T cells. IL-12 released by BMDCs was also detected. RESULTS: BMDCs were cultured and identified. Uric acid at concentrations of 200 mg/L and 400 mg/L increased the expression of the molecules (CD11c, CD83, CD86, IA/IE) on BMDCs surface and the IL-12 level in the culture supernatants (P<0.05), promoted the proliferation of T cells at the T: DC rate 5∶1, 10∶1, 20∶1 (P<0.05). However, uric acid at concentration of 70 mg/L had no effect on above molecule expression (P>0.05), no effect on T cell proliferation with BMDCs (P>0.05) was observed. CONCLUSION: Uric acid promotes the differentiation, maturation, the expression of co-stimulatory molecules, the IL-12 production in BMDCs and enhances the ability of BMDCs to stimulate the proliferation of T cell in a specical dose range.     

Role of Gab2 in mouse myeloid abnormal proliferation induced by SHP-2D61G/+ mutation

AIM: To investigate whether Gab2, the key adapter protein in the SHP-2 signaling pathway, is involved in mouse myeloid abnormal proliferation induced by SHP-2D61G/+ mutation.METHODS: Four kinds of mouse model genotyped as SHP-2+/+, Gab2-/-, SHP-2D61G/+ and SHP-2D61G/+/Gab2-/- were generated from crossbreeding of Gab2-/- mice and SHP-2D61G/+ mice. The mouse spleen size was analyzed. The number of peripheral blood leukocytes was counted by cell counting and the percentage of Mac-1 or Gr-1 positive myeloid cells in the bone marrow was detected by flow cytometry. The proliferation ability of bone marrow hematopoietic stem/progenitor cells in response to cytokines was assayed by colony formation. The expression of p-ERK and p-Akt and the binding capacity of SHP-2 with Gab2 in the bone marrow-derived mast cells stimulated with IL-3 were detected by Western blotting and immunoprecipitation.RESULTS: The phenotype of myeloproliferative disorder, such as enlarged spleen size, increased leukocyte number and high percentage of myeloid cells, in SHP-2D61G/+ mutant mice was found, and was dramatically improved in SHP-2D61G/+/Gab2-/- double mutation mice. Furthermore, compared with SHP-2D61G/+ mutation mice, significantly decreased colony formation ability of the bone marrow cells with IL-3 stimulation was observed in SHP-2D61G/+/Gab2-/- double mutation mice. A reduced phosphorylation level of ERK/Akt, and SHP-2 without binding of Gab2 were found in SHP-2D61G/+/Gab2-/- bone marrow-derived mast cells with IL-3 stimulation.CONCLUSION: Gab2 knockout significantly reduces mouse myeloid abnormal proliferation induced by SHP-2D61G/+ mutation. The molecular mechanism may be associated with reduced binding of SHP-2D61G/+ under Gab2 knockout, and further weakened the activation of downstream signaling pathways of ERK and Akt.     

Differentiation of CD34+ cells in human umbilical blood to eosinophils under the condition of cell culture in vitro

AIM: To investigate differentiation of CD34+ cells in human umbilical blood into eosinophils under the condition of cell culture in vitro. METHODS: CD34+ cells were separated and purified from human umbilical blood. The cells were divided into negative group, IL-5 group and allergic rhinitis serum group. The differentiation ability of the cells was measured by flow cytometry, HE staining and electron microscope at the first day, second day, 7th day, 14th day and 28th day culture. RESULTS: The proportion of CD34+ cells in IL-5 group and allergic rhinitis serum group were decreased at the second day. The proportion in allergic rhinitis serum group was lower than that in IL-5 group significantly. The typical structure of eosinophils was observed at the second day. CONCLUSION: The allergic patient serum and IL-5 induce differentiation of CD34+ cells in human umbilical blood to eosinophils.     

Effects of aplastic anemia patient serum on the expression of the crucial cyclin D isoform in cord blood CD34+ cells

AIM:To explore the pathogenesis of aplastic anemia (AA), we identified the crucial isoform of cyclin D that determine the proliferation of the cord blood CD34+ cells and observed effects of AA serum on the expression of crucial cyclin D isoform in umbilical cord blood CD34+ cells. METHODS:The CD34+ cells were isolated with MIDI-MACS system. The isoforms of cyclin D were detected by RT-PCR and Western blotting. Methylcellulose culture system was used to measure the formation of CFU-GM. The expression level of crucial cyclin D isoform was assayed by RT-PCR and Western blotting after the CD34+ cells were incubated in AA serum. RESULTS:The crucial cyclin D isoform in CD34+ cells was cyclin D3. The AA serum inhibited the formation of CFU-GM and down-regulated expression level of the cyclin D3 from the mRNA to protein level, respectively. CONCLUSION:The AA serum inhibits the proliferation of CD34+ cells and down-regulates level of cyclin D3, this may be one of hematopoiesis inhibition mechanisms in AA.     

In vitro hematopoietic stem cells from embryonic stem cells reconstruct hematopoiesis in mice

AIM: To investigate the potential of hematopoietic stem cells (HSCs) derived from mouse embryonic stem cells (ESCs) to reconstruct hematopoiesis in vivo. METHODS: Using a three-step method, a mice embryonic stem cell line, E14.1 was induced into hematopoietic stem cells. The cell markers with CD34+/ Sca-1+ were identified by flow cytometry analysis, then HSCs (1×109 cells/L) from third-step were injected into SCID mice for observing teratoma formation. To validate function of HSCs, colonogenic cell assay was conducted and the hematopoiesis in lethally irradiated mice was reconstituted. RESULTS: The method of three-step differentiation, combined to use more hematopoietic stimulating factor promoted the E14.1 cell differentiation into HSCs with highest percent of CD34+/Sca-1+ cells (as high as 58.64%±4.20%) with more CFU-E, CFU-GM and CFU-GEMM populations. The cells showed the character of hematopoietic progenitors by Wright-Giemsa staining. Positive selected CD34+/Sca-1+ cells by magnetic sorting from third-step differentiation were transplanted into 7 lethally irradiated female mice while predominant hematopoietic reconstitution were observed in 10 d after transplantation, with 71.4% (5/7) successful engraftment rate. Three recipients showed that the cell population of the peripheral blood leukocytes, red blood cells and hemoglobin approached to normal index at 40 d after transplantation, but followed relative slow renew in platelet count. Survival rate in transplant group was 43%, compared to 100% mortality in control mice. Karyotyping assays confirmed the female mice with XY. CONCLUSION: The three-step differentiation and the culture conditions described here support the differentiation of mouse ESCs into HSCs. HSCs derived from mouse ESCs can reconstruct hematopoiesis.     

IL-1β promotes differentiation of naïve T cells into Th22 cells and its expression in non-small cell lung cancer

AIM:To investigate the mechanism of interleukin-1β (IL-1β) promoting the transformation of naïve T cells into Th22 cells and the correlation of its peripheral blood expression in non-small cell lung cancer patients. METHODS:CD4⁺ naïve T cell magnetic bead sorting kit was used to isolate the peripheral blood mononuclear T cells from healthy people. Transforming growth factor-β (TGF-β) and IL-2 were added to promote differentiation and proliferation. IL-1β was used to induce differentiation into Th22 cells. The proportion of CD4⁺ IL-22⁺ T cells was analyzed by flow cytometry, and the expression of IL-22 was detected by ELISA. We selected 60 cases of non-small cell lung cancer patients in our hospital, including 18 in I phase, 20 in Ⅱ phase, 13 in Ⅲ phase and 9 in IV phase, as well as 25 healthy persons. The proportion of Th22 (CD4⁺ IL-22⁺) cells in peripheral blood was detected by flow cytometry, and the serum levels of IL-1β and IL-22 were measured by ELISA. RESULTS:IL-1β induced the transformation of naïve T cells into Th22 cells and promoted the secretion of IL-22 (P<0.05). The proportion of Th22 cells and the IL-22 and IL-1β levels in peripheral blood of the patients with non-small cell lung cancer were higher than those in healthy subjects, and correlated with the clinical stage. CONCLUSION:IL-1β induces the differentiation of Th22 cells and the expression of IL-22. The levels of IL-1β and IL-22 are related to the progression of non-small cell lung cancer, which may be involved in immunosuppression and promote the occurrence of non-small cell lung cancer.     

Effects of basic fibroblast growth factor on proliferation and collagen production in human umbilical cord mesenchymal stem cells

AIM：To observe the growth pattern and surface markers of human umbilical cord mesenchymal stem cells(hUCMSCs) and to explore the influence of basic fibroblast growth factor (bFGF) on the proliferation and collagen production in hUCMSCs cultured in vitro. METHODS：hUCMSCs were isolated by enzyme digestion method and adherent culture. The surface markers CD45, CD34, CD105, CD29 and HLA-DR of the cells were analyzed by flow cytometry. The osteogenic ability and adipogenic differentiation were confirmed with oil red O and alizarin red staining. The optimal concentration of bFGF to promote the proliferation of hUCMSCs was 20 μg/L. The cells in control group were cultured in the growth medium consisting of DMEM/F12 and 10% volume fraction of fetal bovine serum. The cells in experiment group were cultured under the same condition of control group but plus 20 μg/L bFGF. The proliferation of hUCMSCs was analyzed by MTT assay. The expression of type I and III collagens at mRNA and protein levels was determined by RT-PCR and Western blotting. RESULTS：The growth curves indicated that bFGF promoted the proliferation of hUCMSCs. The hUCMSCs expressed CD29, but did not express CD34, CD45 or HLA-DR in the presence or absence of bFGF unanimously. The cells were alizarin red staining-positive and oil red O staining-positive. Compared with control group, the expression of type I and III collagens significantly decreased at mRNA and protein levels in experiment group. CONCLUSION：bFGF promotes the proliferation of hUCMSCs and does not change the expression of the surface markers. bFGF inhibits the expression of type I and III collagens at mRNA and protein levels, indicating that bFGF enhances the healing of wound without inducing scar hyperplasia.     

Generation of thalassemia-specific integration-free induced pluripotent stem cells and determination of their differentiation ability

AIM: To generate thalassemia-specific integration-free induced pluripotent stem cells(iPSC) and to detect their ability of differentiation into hematopoietic precursors.METHODS: The plasmids pEB-C5 and pEB-Tg were transfected into the fibroblast cells from hemoglobin Bart's hydrops fetalis's skin by the method of nuclear transfection to reprogramm the cells into iPSC. The ability of the iPSC to differentiate into 3-germ layer cells was determined. The iPSC were cocultured with mouse OP9 cells to differentiate into hematopoietic precursors and the hematopoietic precursor specific antigens were detected. RESULTS: The integration-free iPSC from hemoglobin Bart's hydrops fetalis's skin fibroblasts were successfully derived, and had the ability to differentiate into 3 germ layers. When cocultured with OP9 cells for 9 d, the positive rate of hematopoietic progenitor cell marker CD34 was 18.7%, and the CD34 and CD45 double positive rate was 12.2%. CONCLUSION: Hemoglobin Bart's hydrops fetalis's skin fibroblasts can be successfully induced into "integration-free" iPSC. This cell line has the ability to differentiate into 3 germ layers, and can be differentiated into hematopoietic precursors when cocultured with OP9 cells.     

Osteogenic and neurogenic differentiation of human yolk sac mesenchymal stem cells

AIM: To purify human yolk sac mesenchymal stem cells (hYS-MSC) and investigate its osteogenic and neurogenic differentiation potentials. METHODS: hYS-MSC were separated from yolk sac and purified via passage culture. The karyotype of hYS-MSCs was analyzed via G-banded characteristics. Flow cytometric analysis was used to determine the cell cycle and phenotype of hYS-MSC. The AKP expression of hYS-MSC was also tested. Osteogenic differentiation of hYS-MSCs was induced by 10-8mol/L dexamethasone, 10 mmol/L β-glycerophosphate and 50 mg/L vitamin C. Alizarin red S stain was used for identification of mineralization. β-mecaptoethanol or salviae miltiorrhizae were used to induce neurogenic differentiation of hYS-MSCs. The expressions of NSE, NF and GFAP were identified by immunohistochemical method. RESULTS: hYS-MSCs could be purified at passages 2 or 3. The cell cycle analysis suggested that hYS-MSCs showed strong proliferational potentials by which the cells kept normal diploid karyotype during the in vitro culture. Flow cytometry showed the phenotype of purified hYS-MSCs was uniformly positive for CD29, CD44, CD105, and CD166, and negative for reactivity to antigens CD34, CD45, or CD86. hYS-MSCs were weakly but clearly positive in AKP. Osteogenic differentiation was appeared after induction of osteogenic differentiation. hYS-MSCs, which were of spindle shape, uniform in size, were induced to pleomorphism osteoblast-like cells which expressed high level of AKP. Aggregates or nodules were formed at day 7 and calcium accumulation was detected by alizarin red S staining on day 10 or day 14. Neurogenic differentiation of hYS-MSCs was induced by β-mecaptoethanol or salviae miltiorrhizae. NSE, NF or GFAP positive cells were detected by immunohistochemical staining. CONCLUSIONS: hYS-MSCs have strong proliferation potential and the normal diploid karyotype is kept during the in vitro culture. The phenotype of hYS-MSCs is coincident with adult hMSCs. hYS-MSCs could be induced to differentiate into osteogenic or neurogenic cells.     

Aged bone marrow stem cells can be rejuvenated by cell fusion with young bone marrow stem cells

AIM: To investigate the function of aged bone marrow mesenchymal stem cells (BMSCs) fused with young BMSCs in mice. METHODS: The cell fusion model, which was made by C57BL/6 mouse BMSCs labeled with PKH26 membrane red fluorescence (young cells, age of 2-3 months, Y) and (old cells, age of 18-24 months, O), and young and old BMSCs of green fluorescent protein (GFP) transgenic C57BL/6 mouse, was established by the induction of polyethylene glycol 1500 (PEG 1500). The cell fusion rate and cell surface markers were detected by flow cytometry. The morphology and nuclear characteristics of the fused cells were observed under fluorescence microscopy. In this study, the age dependent changes in BMSCs proliferation and differentiation potential in Y group, O group, and another three fusion groups (Y-Y group, Y-O group, O-O group) were examined. The proliferation potentials in 5 groups were compared by counting cell numbers at days 2, 4, 6, and 8. The osteogenic and adipogenic differentiation potentials of the cells in 5 groups were determined by using standard differentiation procedures. RESULTS: The fusion rate of 30.45%±4.13% was obtained by PEG 1500 induction. No significant difference of the fusion rates in Y-Y, Y-O and O-O groups was observed. Fused BMSCs coincided with the common BMSCs were reactive to the BMSCs lineage-specific CD44, Sca-1 surface markers and negative for the hematopoietic stem cells (HSCs) lineage-specific surface markers such as CD34, CD117, CD31, and CD45. The percentage of increasing cell numbers in Y-O group was significantly higher than that in O-O group at days 2, 4, 6, and 8. The positive rate of the area stained with Alizarin red, which represents osteogenic differentiation potential of BMSCs, was significantly higher in Y-O group than that in O-O group ［(25.46%±1.52%) vs (13.85%±1.69%), P<0.01］. In Y-O group, the higher rate of the positive area stained with oil red O, which represents adipogenic differentiation potential of BMSCs, was observed as compared to that in O-O group ［(12.99%±2.61%) vs (6.03%±1.71%), P<0.05］. CONCLUSION: Aged bone marrow stem cells can be rejuvenated by cell fusion with young bone marrow stem cells, particularly the proliferation and differentiation potentials.     

Inhibitory role of epigallocatechin-3-gallate in proliferation of human nasopharyngeal carcinoma cells by targeting P53/miR-34a

AIM: To study the effect of epigallocatechin-3-gallate(EGCG) on the proliferation of human nasopharyngeal carcinoma(NPC) cells, and to explore its mechanism by targeting miR-34a.METHODS: Nasopharyngeal carcinoma CNE-2Z cells were treated with various concentrations of EGCG. The ability of cell proliferation was detected by CCK-8 assay, 5-ethynyl-2-deoxyuridine(EdU) incorporation assay and colony-forming assay. The cell cycle distributions were analyzed by flow cytometry. The protein levels of P53 and Notch1 were detected by Western blot. The expression of miR-34a and Notch1 mRNA was measured by real-time PCR.RESULTS: EGCG effectively inhibited the proliferation and colony formation of CNE-2Z cells in a dose-dependent manner, which was related to its induction of cell cycle arrest at G₀/G₁ phase. The expression of P53 and miR-34a in CNE-2Z cells was significantly increased after treated with EGCG, while the expression of Notch1 at mRNA and protein levels was markedly suppressed.CONCLUSION: EGCG induces cell cycle arrest and suppresses cell proliferation by regulating the P53/miR-34a/Notch1 pathway in NPC cells.     

Influence of Jiaomu oil A2 on eosinophil manifold and CD34+ with marrow granule system mobilization in bronchia asthma mice

AIM: To observe the influence of Jiaomu oil A2 on eosinophil manifold and CD34+ with marrow granule system mobilization in bronchial asthma mice. METHODS: The asthmatic mouse model was established by sensitization and challenge of the animals with 20% Al(OH)3+10% ovalbumen (OVA). After the mice were excitated for 10 d and giving medical therapy at the same time, the mice were executed, the bronchial-alveolar lavage inflammatory cells and the hemocytopoiesis cells were examined using Wrish-Giemsa staining. The expressions of interleukin-5 (IL-5) and eotaxin (EON) in lung tissue and marrow were examined by in situ hybridization. The expression of IL-5 and EON albumen in lung tissue and marrow were detected by immunohistochemistry. The inflammatory cell infiltration and CD34+ cells in lung tissue were also observed by HE and immunofluorescence staining. RESULTS: Both Jiaomu oil A2 and prednisone significantly attenuated the pathological process degree of bronchial inflammatory reaction such as tissue swelling, reconstruction, hyperplasia, and epithelial cell shedding, and inhibited eosinophil count and infiltration caused by stimulation of allergic effect. Moreover, the two drugs markedly lessen the eosinophil density in tracheal surrounding tissue and marrow in asthma mice and depressed the differentiation of marrow myelocyte to eosinophil. Finally, the apparent decrement of CD34+IL-5, CD34+IL-5R, CD34+CCR-3 cells in bronchial tissue and marrow showed some relationship with the downregulation of IL-5, IL-4, GM-CSF in lung tissue. CONCLUSION: The effect of Jiaomu oil on airway inflammation in asthma mice is associated with inhibiting the mobilization of eosinophil and marrow granule system.     

Effect of G-CSF on dendritic cell subsets in donors mobilized peripheral blood cells

AIM: To explore the effect of granulocyte colony stimulating factor (G-CSF) on donor’s dendritic cell （DC）subsets in peripheral blood cells (PBC). METHODS: The subsets of dendritic cells in PBC were analyzed by CD34^-Lin^- HLA-DR⁺ cells and the levels of IL-12p40, IL-10, IFN-γ, IL-4 in the serum were tested by ELISA before (25 cases) or after G-CSF mobiling. The relationship between the ratio of DC₁/DC₂ (CD11c⁺CD123^-/CD11c^-CD123⁺) and CD34⁺/MNC was explored. RESULTS: CD34⁺/MNC in PBC harvests was above 0.4% in 23 cases, and the ratio of DC₁/DC₂ was lower, the HLA-DR expression of DC₂ was enhanced after G-CSF mobiling than before, but the levels of IL-12p40, IL-10, IFN-γ, IL-4 in donors serum and CD83 expression of DC₂ were not changed by G-CSF. CONCLUSION: DC₂ increased accompanied by the increase in CD34⁺ cells in the PBC harvests. Although the expression of HLA-DR in DC₂ was up-regulated by G-CSF, these DC₂ did not regulate Th2 cells to excrete inhibitor cell factors and kept on the precursor characters.     

Unfractionated heparin ameliorates lipopolysaccharide-induced expression of interleukin-8 in human endothelial cells through Toll-like receptor 4 signaling

AIM:To determine the effect of unfractionated heparin(UFH) on lipopolysaccharide(LPS)-induced expression of interleukin-8(IL-8) and the role of Toll-like receptor 4(TLR4) signaling. METHODS:Human pulmonary microvascular endothelial cells(HPMECs) were either exposed to LPS alone(10 mg/L) or in combination with 100 U/L or 10³ U/L UFH. UFH was added to the cells 15 min prior to stimulation with LPS. Those samples not receiving LPS or UFH received an equal volume of phosphate-buffered saline. The concentrations of IL-8 in the cell culture supernatants were detected by ELISA at 2, 6 and 12 h. The mRNA expression of IL-8, CD14 and TLR4 in HPMECs was detected by real-time fluorescence quantitative polymerase chain reaction at 2, 6 and 12 h. RESULTS:Compared with normal control group, the mRNA expression of IL-8 in LPS group was increased, and reached the peak at 6 h. The protein level of IL-8 reached the peak at 12 h. The mRNA expression of TLR4 in LPS group reached the peak at 6 h. They were down-regulated in UFH group. The mRNA expression of CD14 was not detected. CONCLUSION:The expression of IL-8 is obviously increased in LPS-treated HPMECs. UFH might exert its therapeutic effect through TLR4 signaling.