This study was aimed to investigate the effect of hypoxia on lipopolysaccharide (LPS)-induced CXC-chemokine ligand-10 (CXCL10) expression and the underlying mechanism. C57BL/6J mice were randomly divided into control, hypoxia, LPS, and hypoxia combined with LPS groups. The LPS group was intraperitoneally injected with 0.5 mg/kg LPS, and the hypoxia group was placed in a hypobaric hypoxia chamber (simulated altitude of 6 000 m). The serum and hippocampal tissue samples were collected after 6 h of the treatment. The levels of CXCL10 in the serum and hippocampal tissue of mice were detected by ELISA. The microglia cell line BV2 and primary microglia were stimulated with hypoxia (1% O₂) and/or LPS (100 ng/mL) for 6 h. The mRNA expression level of CXCL10 and its content in culture supernatant were detected by real-time quantitative PCR and ELISA, respectively. The phosphorylation levels of nuclear factor κB (NF-κB) signaling pathway-related proteins, p65 and IκBα, were detected by Western blot. Moreover, after NF-κB signaling pathway being blocked with a small molecular compound, PDTC, CXCL10 mRNA expression level was detected in the BV2 cells. The results showed that in the LPS-induced mouse inflammatory model, hypoxia treatment could promote LPS-induced up-regulation of CXCL10 in both serum and hippocampus. Compared with the cells treated with LPS alone, the expression of CXCL10 mRNA and the content of CXCL10 in the culture supernatant of BV2 cells treated with hypoxia combined with LPS were significantly increased. The CXCL10 mRNA level of primary microglial cells treated with hypoxia combined with LPS was significantly up-regulated. Compared with the cells treated with hypoxia or LPS alone, the phosphorylation levels of p65 and IκBα in the BV2 cells treated with hypoxia combined with LPS were significantly increased. PDTC blocked the induction of CXCL10 gene expression by LPS in the BV2 cells. These results suggest that hypoxia promotes LPS-induced expression of CXCL10 in both animal and cell models, and NF-κB signaling pathway plays an important role in this process.
Animals ; Mice ; Chemokines, CXC/pharmacology* ; Hypoxia ; Ligands ; Lipopolysaccharides/pharmacology* ; Mice, Inbred C57BL ; Microglia/metabolism* ; NF-kappa B/metabolism* ; NF-KappaB Inhibitor alpha/pharmacology* ; RNA, Messenger/metabolism*

This study was aimed to investigate the importance of chemokine SDF-1 in maintaining proliferation ability of acute myelocytic leukemia cell line HL-60 when the effects of SDF-1 on HL-60 cell proliferation were inhibited. Marrow stromal cells were cultured and co-cultured with HL-60 cells, and SDF-1 activity was blocked with anti-CXCR4 McAb. HL-60 cell activity was detected by MTT while cell cycle and the expression of CXCR4 on HL-60 cell membrane were observed by flow cytometry meanwhile. The internal calcium ionic concentration in HL-60 cell was detected as well before and after treated with 12G5. The results showed that 12G5 down-regulated the expression of CXCR4 on HL-60 cell membrane; HL-60 cells at G(0)/G(1) phase increased, but decreased at S phase; survive rate of leukemia cells reduced; the intercellular calcium ionic concentration of HL-60 cell decreased after treated with 12G5. It was concluded that brockage of the SDF-1 activity may inhibit proliferation of leukemia cell at certain level.
Antibodies, Monoclonal ; pharmacology ; Calcium ; metabolism ; Cell Cycle ; Cell Division ; Cell Survival ; Chemokine CXCL12 ; Chemokines, CXC ; antagonists & inhibitors ; physiology ; HL-60 Cells ; cytology ; Humans ; Receptors, CXCR4 ; analysis

To investigate the effects of stromal cell-derived factor 1 (SDF-1) and platelet factor 4 (PF4) on the homing-related function of expanded ex vivo umbilical cord blood CD34(+) cells, purified cord blood CD34(+) cells were cultured in serum-free medium containing a HGF combination of FL + SCF + TPO (FST) with either 100 ng/ml SDF-1 alone, 100 ng/ml PF4 alone, or both of these 2 cytokines. The expansion rate of CD34(+) cells, colony formation, homing-related functions including expression of homing-related adhesion molecules of expanded CD34(+) cell, adhesion activity and chemotactic function of the re-selected expanded CD34(+) cells were evaluated at different time points. The results showed that expansion rate of CD34(+) cells and expansion multiple of CFU in SDF-1 groups were higher than those in control. The expression of CD49e on the expanded CD34(+) cells was remarkable up-regulated, in contrast, expression of CXCR-4 on the expanded CD34(+) cells was remarkable down-regulated in SDF-1 groups. The expression of CD49e, CD54 and CXCR-4 on the expanded CD34(+) cells were remarkably up-regulated in the PF4 groups. In all the SDF-1 group, PF4 group and SDF-1 plus PF4 group, the ability of expanded CD34(+) cells adhering to fibronectin layer were higher than those in the control on day 10. Spontaneous migration rate of expanded CD34(+) cells in SDF-1 groups were higher than those in control, while SDF-1-induced migration rate were lower than those in control on day 10. SDF-1-induced migration rate in PF4 groups were higher than those in control on day 10. Spontaneous and SDF-1-induced migration rate of expanded CD34(+) cells in the SDF-1 plus PF4 groups were higher than those in control on day 10. It is concluded that, SDF-1 and PF4 can up-regulate expression of adhesion molecules on expanded CD34(+) cells, and retain the adherent and migration ability of expanded CD34(+) cells, which is helpful for the homing of expanded CD34(+) cells. In short, SDF-1 and PF4 are helpful for the homing-related function of the expanded UCB HSPC.
Antigens, CD34 ; blood ; immunology ; Cell Adhesion ; drug effects ; Cells, Cultured ; Chemokine CXCL12 ; Chemokines, CXC ; pharmacology ; Chemotaxis ; immunology ; physiology ; Culture Media, Serum-Free ; Fetal Blood ; cytology ; immunology ; Hematopoietic Stem Cells ; cytology ; drug effects ; Humans ; Platelet Factor 4 ; pharmacology

OBJECTIVETo study the effects on adherence of hematopoietic stem/progenitor cells, PF4 was assessed alone or in combination with IL-3 for effects on the total adherence and various kinds of adhesion molecules of KG1a cells as well as actin polymerization in KG1a cells.

METHODSThe total adherence was assayed by crystal violet dye staining. The adhesion molecule expression was determined by FACS analysis. These adhesion molecule monoclonal antibodies individually blocked total adherence by MTT. F-actin content was monitored by fluorospectrophotometry.

RESULTS100 ng/ml PF4 could increase the total adherence of KG1a cells by 80%. 20 ng/ml IL-3 could increase the total adherence of KG1a cells by 96%. When PF4 and IL-3 were combined, the total adherence could be promoted by 97%. Exposure of 1 x 10(6) cells/ml of KG1a cells to 100 ng/ml PF4 the increased total adherence of KG1a cells was mediated by PECAM-1 (CD31), CD44, LFA-1 (CD11a) and Mac-1 (CD11b) but not by P-selectin (CD62P) and E-selectin (CD62E). These adhesion molecule monoclonal antibodies could individually block total adherence for 34%-43%. Similar phenomenon was observed when IL-3 was added onto KG1a cells. Further study found that PF4 induced actin polymerization of KG1a cells.

CONCLUSIONSOur study indicated that PF4 promoted total adherence, as well as several adhesion molecule expression and actin polymerization of KG1a cells. The results suggest that PF4 may have therapeutic utility along with other cytokines by enhancing the total adhesion of hematopoietic stem/progenitor cells to promote the homing.

Actins ; metabolism ; Cell Adhesion ; Cell Adhesion Molecules ; metabolism ; Chemokines, CXC ; metabolism ; Endothelium, Vascular ; metabolism ; Hematopoietic Stem Cells ; metabolism ; Humans ; Hyaluronan Receptors ; metabolism ; Intercellular Adhesion Molecule-1 ; metabolism ; Interleukin-3 ; pharmacology ; Platelet Factor 4 ; pharmacology ; Polymers

OBJECTIVETo investigate the effects of nitric oxide (NO) on reperfusion injury following pancreaticoduodenal transplantation in rats.

METHODSThe homologous male Wistar rat model of heterotopic total pancreaticoduodenal transplantation was used. The L-arginine (L-Arg) group received intravenous injection of L-Arg 5 minutes before and after reperfusion at a dose of 200 mg/kg while the N-Nitro-L-Arginine methyl ester (L-NAME) group received intravenous injection of L-NAME at a dose of 10 mg/kg, and control group received saline. The amount of NO in the pancreas graft was measured. Serum concentration of cytokine-induced neutrophil chemoattractant (CINC) determined by enzyme-linked immunosorbant assay, expression of CINC mRNA detected by Northern blot assay, and myeloperoxidase (MPO) activity in the pancreas graft were measured. Histological observation was performed.

RESULTSThe amount of NO in the L-Arg group was higher than in the control group, while in the L-NAME group was lower than in the control group (P < 0.05). The peak of serum CINC concentration occurred 3 hours after reperfusion with significant difference among groups. Expression peak of CINC mRNA in the pancreas graft occurred 3 hours after reperfusion. The expression level in the L-Arg group was lower than in the control group, the L-NAME group was higher than control group (P < 0.05). MPO activity in the L-Arg group obviously decreasd compared with other groups. The pancreas inflammation was ameliorated in L-Arg group, and pancreas damage was aggravated in L-NAME group.

CONCLUSIONSL-Arg can increase the amount of NO and inhibit the elevation of CINC, CINC mRNA expression, and early neutrophil accumulation in the transplanted pancreas. NO has protective effects on the ischemia/reperfusion injury of pancreaticoduodenal transplantation.

Animals ; Arginine ; pharmacology ; Chemokines, CXC ; biosynthesis ; genetics ; Duodenum ; transplantation ; Male ; NG-Nitroarginine Methyl Ester ; pharmacology ; Nitric Oxide ; metabolism ; Pancreas Transplantation ; Peroxidase ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Reperfusion Injury ; metabolism

To study the importance of chemokine SDF-1 in surviving of acute myelocytic leukemia cells HL-60, the adhesion ability of HL-60 and expression of Bcl-2, Fas protein when SDF-1 activity was blocked by anti-CXCR4 monoclonal antibody (12G5) were compared with those detected before MAb incubation, in this experiment, HL-60 cell were cultured and co-cultured with normal marrow stromal cell. The adhesion rate was detected while the expression of Bcl-2 and Fas proteins were assayed by immunohistochemical technique when SDF-1 activity was inhibited. The results showed that cell adhesion rate of HL-60 decreased while the expression Bcl-2 decreased and Fas increased. It is concluded that inhibition of SDF-1 activity increases cell apoptosis and thus reduces life-span of leukemia cell at certain level.
Antibodies, Monoclonal ; pharmacology ; Apoptosis ; Cell Adhesion ; Chemokine CXCL12 ; Chemokines, CXC ; physiology ; HL-60 Cells ; chemistry ; cytology ; Humans ; Proto-Oncogene Proteins c-bcl-2 ; analysis ; Receptors, CXCR4 ; physiology ; fas Receptor ; analysis

BACKGROUNDMutation or deletion in the phosphatase and tensin homologue deleted on chromosome ten (PTEN) gene has been identified as an important cause of endometrial carcinoma; stromal cell derived factor-1alpha (SDF-1alpha) exerts growth-promoting effects on endometrial cancer cells through activation of the PI-3 kinase/Akt pathway and downstream effectors such as extracellular-responsive kinase (ERK). In this study, a plasmid containing the PTEN gene was transfected into Ishikawa cells to investigate the difference in growth and signal transduction between Ishikawa-PTEN and Ishikawa cells after SDF-1alpha stimulation, and to study mechanisms of the involvement of PTEN protein in endometrial carcinoma development.

METHODSIshikawa cells were transfected with a plasmid (pLXSN-PTEN) containing the PTEN gene and a plasmid (pLXSN-EGFP) with enhanced green fluorescent protein (EGFP). Cells were then screened to obtain Ishikawa-PTEN cells and Ishikawa-neo cells that can both stably express PTEN protein and EGFP. Expression of PTEN protein, phosphorylation levels of AKT and ERK (pAKT and pERK) and growth differences in Ishikawa-PTEN, Ishikawa-neo and Ishikawa cells before and after SDF-1alpha stimulation were then determined by Western blots and MTT assays.

RESULTSWestern blot analysis showed that Ishikawa cells produced PTEN after transfection with the PTEN gene. At 15 minutes after SDF-1alpha stimulation, the pAKT level of Ishikawa-PTEN cells was lower than that of Ishikawa-neo cells and Ishikawa cells. There was no significant difference in pERK levels among the three cell lines. The positive effect of SDF-1alpha on Ishikawa-PTEN cells growth was markedly less than the effect on Ishikawa-neo and Ishikawa cells. However, in the absence of SDF-1alpha stimulation (baseline), the pAKT level in Ishikawa-PTEN cells was less than that in Ishikawa cells. There was a significant difference in growth between the Ishikawa-PTEN cells and the Ishikawa-neo cells.

CONCLUSIONSPTEN gene transfection can regulate the level of pAKT but not pERK in Ishikawa-PTEN cells. PTEN protein may suppress the growth-promoting effect of SDF-1alpha on endometrial carcinoma by inhibiting the PI-3K/AKT signal transduction pathway.

Cell Line, Tumor ; Cell Proliferation ; drug effects ; Chemokine CXCL12 ; Chemokines, CXC ; pharmacology ; Endometrial Neoplasms ; pathology ; Female ; Humans ; PTEN Phosphohydrolase ; physiology ; Phosphatidylinositol 3-Kinases ; physiology ; Proto-Oncogene Proteins c-akt ; physiology ; Signal Transduction

Animals ; Chemokines, CXC ; genetics ; Enzyme Activation ; Intercellular Signaling Peptides and Proteins ; genetics ; Lipopolysaccharides ; pharmacology ; Lung ; enzymology ; Male ; Mitogen-Activated Protein Kinases ; metabolism ; Rats ; Rats, Sprague-Dawley ; Respiration, Artificial ; Tidal Volume ; Tumor Necrosis Factor-alpha ; genetics

His-Phe-Tyr-Leu-Pro-Met (HFYLPM) is a synthetic peptide that stimulates Jurkat T cells resulting in intracellular calcium ([Ca2+]i) increase in a pertussis toxin (PTX)-sensitive manner. We have examined the physiological role of the peptide in T cell activity by comparative investigation of intracellular signaling pathways accompanied with HFYLPM-induced T cell chemotaxis with a well-known chemokine, stromal cell-derived factor-1 (SDF-1)-induced signalings. Wortmannin and genistein inhibited both of HFYLPM- and SDF-1-induced Jurkat T cell chemotaxis indicating that phosphoinositide-3-kinase and tyrosine kinase activity were required for the processes. However, U-73122 and BAPTA/AM preferentially blocked HFYLPM- but not SDF-1-induced T cell chemotaxis. It indicates that phospholipase C/calcium signaling is necessary for only chemotaxis by HFYLPM. One of the well-known cellular molecules involving chemotaxis, extracellular signal-regulated protein kinase (ERK), was activated by SDF-1 but not by HFYLPM ruling out a possible role of ERK on the peptide-mediated chemotaxis. These results indicate that the synthetic peptide, HFYLPM, stimulates T cell chemotaxis showing unique signaling and provide a useful tool for the study of T cell activation mechanism.
1-Phosphatidylinositol 3-Kinase/metabolism ; Androstadienes/pharmacology ; Calcium/metabolism ; Cell Line ; Chemokines, CXC/*pharmacology ; Chemotaxis, Leukocyte/drug effects/*physiology ; Dose-Response Relationship, Drug ; Genistein/pharmacology ; Human ; Jurkat Cells ; Oligopeptides ; Peptide Fragments/chemical synthesis/metabolism/*physiology ; Pertussis Toxin ; Phospholipase C/metabolism ; Protein-Tyrosine Kinase/metabolism ; Signal Transduction/drug effects ; T-Lymphocytes/*drug effects ; Virulence Factors, Bordetella/pharmacology

His-Phe-Tyr-Leu-Pro-Met (HFYLPM) is a synthetic peptide that stimulates Jurkat T cells resulting in intracellular calcium ([Ca2+]i) increase in a pertussis toxin (PTX)-sensitive manner. We have examined the physiological role of the peptide in T cell activity by comparative investigation of intracellular signaling pathways accompanied with HFYLPM-induced T cell chemotaxis with a well-known chemokine, stromal cell-derived factor-1 (SDF-1)-induced signalings. Wortmannin and genistein inhibited both of HFYLPM- and SDF-1-induced Jurkat T cell chemotaxis indicating that phosphoinositide-3-kinase and tyrosine kinase activity were required for the processes. However, U-73122 and BAPTA/AM preferentially blocked HFYLPM- but not SDF-1-induced T cell chemotaxis. It indicates that phospholipase C/calcium signaling is necessary for only chemotaxis by HFYLPM. One of the well-known cellular molecules involving chemotaxis, extracellular signal-regulated protein kinase (ERK), was activated by SDF-1 but not by HFYLPM ruling out a possible role of ERK on the peptide-mediated chemotaxis. These results indicate that the synthetic peptide, HFYLPM, stimulates T cell chemotaxis showing unique signaling and provide a useful tool for the study of T cell activation mechanism.
1-Phosphatidylinositol 3-Kinase/metabolism ; Androstadienes/pharmacology ; Calcium/metabolism ; Cell Line ; Chemokines, CXC/*pharmacology ; Chemotaxis, Leukocyte/drug effects/*physiology ; Dose-Response Relationship, Drug ; Genistein/pharmacology ; Human ; Jurkat Cells ; Oligopeptides ; Peptide Fragments/chemical synthesis/metabolism/*physiology ; Pertussis Toxin ; Phospholipase C/metabolism ; Protein-Tyrosine Kinase/metabolism ; Signal Transduction/drug effects ; T-Lymphocytes/*drug effects ; Virulence Factors, Bordetella/pharmacology