This study was conducted to elucidate the effects of different fluid shear stress on the expression of IL-8 receptors CXCR1 in endothelial cells. The HUVEC cell lines, EA. Hy926 cells, were cultured in vitro, exposed to 5.56, 10.02, and 15.27 dyn/cm2 laminar shear stress, respectively, and then the shear stress grous were each investigated at the time-points of 0h, 1h, 2h, 4h and 8h. Western blotting was used for detecting the expression of IL-8 receptor CXCR1 at the time-points. The results showed that, under 5.56 dyn/cm2 shear stress, the expression of CXCR1 increased with time significantly (P < 0.01). The maximum expression of CXCR1 appeared at 4 h and was 2.2 times that of the control. When exposed to 10.02 dyn/cm2, the expression of CXCR1 increased gradually with time and finally remained at a constant higher level. When exposed to 15.27 dyn/cm2, CXCR1 expression decreased significantly with time (P < 0.01). The minimum CXCR1 expression appeared at 8 h and was 62. 59 percent of that of the control. These results indicate that the expression of CXCR1 in endothelial cell is regulated by laminar shear stress.
Cell Line ; Endothelial Cells ; cytology ; metabolism ; Humans ; RNA, Messenger ; biosynthesis ; genetics ; Receptors, Interleukin-8A ; genetics ; metabolism ; Shear Strength ; Stress, Mechanical ; Umbilical Veins ; cytology

This study was conducted to elucidate the effects of different fluid shear stress on the expression of IL-8 receptors CXCR1 and CXCR2 mRNA in endothelial cells, EA. Hy926 cells. The HUVEC cell lines were cultured in vitro and then exposed to 5.56, 10.02, and 15.27 dyn/cm2 fluid shear stress respectively for 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 1 h, 2 h, 4 h and 8 h. Semi-quantitative reversal transcription-polymerase chain reaction (RT-PCR) was used for detecting IL-8 receptors mRNA expression at different times. The results showed that, under 5. 56 dyn/cm2 shear stress, both the expression of CXCR1 and CXCR2 mRNA increased significantly with time (P<0.05). When exposed to 10. 02 dyn/cm2, the expression of CXCR1 mRNA was down-regulated with time on every occasion. CXCR2 mRNA increased temporally at 30 min, then it decreased gradually with time and finally went on at a constant lower level. When exposed to 15.27 dyn/cm2, both CXCR1 and CXCR2 mRNA expression decreased significantly with time (P<0.01). These data indicate that the expression of CXCR1 and CXCR2 mRNA of endothelial cell is regulated by fluid shear stress.
Cell Line ; Endothelial Cells ; cytology ; metabolism ; Gene Expression Regulation ; Humans ; RNA, Messenger ; biosynthesis ; genetics ; Receptors, Interleukin-8A ; biosynthesis ; genetics ; Receptors, Interleukin-8B ; biosynthesis ; genetics ; Shear Strength ; Stress, Mechanical ; Umbilical Veins ; cytology

CXCR1 and CXCR2 are important receptors in regulating vascular endothelial cell activities. In order to elucidate the role of CXCR1/2 in shear stress-induced endothelial cell migration, we have investigated the expression levels of CXCR1 and CXCR2 in the endothelial cells exposed to shear stress. In the experiment, anti-IL8RA and anti-IL8RB were used to antagonize CXCR1 and CXCR2. Different shear stresses were generated in a flow chamber; scratch test was carried out to compare endothelial cell migration in the control group and the receptor-antagonized groups. The results indicated that the migration of endothelial cells was restrained effectively after CXCR1 and CXCR2 were antagonized by anti-IL8RA and anti-IL8RB. And anti-IL8RA showed a stronger inhibitive effect than did anti-IL8RB (P<0.05). In the group with both receptor antagonisms, the migration was further inhibited. These results suggest that both CXCR1 and CXCR2 are important factors in mediating the migration of endothelial cells induced by shear stress, and CXCR1 fulfills a more important role.
Cell Movement ; physiology ; Endothelial Cells ; cytology ; metabolism ; Humans ; Mechanotransduction, Cellular ; drug effects ; Receptors, Interleukin-8A ; antagonists & inhibitors ; physiology ; Receptors, Interleukin-8B ; antagonists & inhibitors ; physiology ; Shear Strength ; Stress, Mechanical ; Umbilical Veins ; cytology ; metabolism

BACKGROUND: Spinal cord injury (SCI) is a worldwide medical concern. This study aimed to elucidate the mechanism underlying the protective effect of hyperbaric oxygen (HBO) against SCI-induced neurologic defects in rats via exploring the stromal cell-derived factor-1 (SDF-1)/CXC chemokine receptor 4 (CXCR4) axis and expression of brain-derived neurotrophic factor (BDNF). METHODS: An acute SCI rat model was established in Sprague-Dawley rats using the Allen method. Sixty rats were divided into four groups (n = 15 in each group): sham-operated, SCI, SCI treated with HBO (SCI + HBO), and SCI treated with both HBO and AMD3100 (an antagonist of CXCR4; SCI + HBO + AMD) groups. The rats were treated with HBO twice a day for 3 days and thereafter once a day after the surgery for up to 28 days. Following the surgery, neurologic assessments were performed with the Basso-Bettie-Bresnahan (BBB) scoring system on postoperative day (POD) 7, 14, 21, and 28. Spinal cord tissues were harvested to assess the expression of SDF-1, CXCR4, and BDNF at mRNA and protein levels, using quantitative real-time polymerase chain reaction, Western blot analysis, and histopathologic analysis. RESULTS: HBO treatment recovered SCI-induced descent of BBB scores on POD 14, (1.25 ± 0.75 vs. 1.03 ± 0.66, P < 0.05), 21 (5.27 ± 0.89 vs. 2.56 ± 1.24, P < 0.05), and 28 (11.35 ± 0.56 vs. 4.23 ± 1.20, P < 0.05) compared with the SCI group. Significant differences were found in the mRNA levels of SDF-1 (mRNA: day 21, SCI + HBO vs. SCI + HBO + AMD, 2.89 ± 1.60 vs. 1.56 ± 0.98, P < 0.05), CXCR4 (mRNA: day 7, SCI + HBO vs. SCI, 2.99 ± 1.60 vs.1.31 ± 0.98, P < 0.05; day 14, SCI + HBO vs. SCI + HBO + AMD, 4.18 ± 1.60 vs. 0.80 ± 0.34, P < 0.05; day 21, SCI + HBO vs. SCI, 2.10 ± 1.01 vs.1.15 ± 0.03, P < 0.05), and BDNF (mRNA: day 7, SCI + HBO vs. SCI, 3.04 ± 0.41 vs. 2.75 ± 0.31, P < 0.05; day 14, SCI + HBO vs. SCI, 3.88 ± 1.59 vs. 1.11 ± 0.40, P < 0.05), indicating the involvement of SDF-1/CXCR4 axis in the protective effect of HBO. CONCLUSIONS HBO might promote the recovery of neurologic function after SCI in rats via activating the SDF-1/CXCR4 axis and promoting BDNF expression.
Animals ; Blotting, Western ; Brain-Derived Neurotrophic Factor ; metabolism ; Disease Models, Animal ; Hyperbaric Oxygenation ; methods ; Male ; Rats ; Rats, Sprague-Dawley ; Receptors, CXCR4 ; metabolism ; Receptors, Interleukin-8A ; metabolism ; Spinal Cord Injuries ; metabolism ; therapy

Recovery from hepatitis B virus (HBV) infection depends on the cellular immune responses. Chemokines and their receptors play significant roles in immune defense. This study was undertaken to investigate the association between HBV infection and single nucleotide polymorphisms (SNPs) of genes for the chemokines and their receptors. Between March 2002 and February 2004, a total of 957 single ethnic Korean patients were enrolled into two different groups; "HBV clearance group" (n=350), who have recovered from HBV infection, and "HBV persistence group" (n=607), who were repeatedly HBsAg-positive. The HBV persistence group was subdivided into "inactive carrier" and "HBV progression group (chronic hepatitis and cirrhosis)". We assessed polymorphisms in regulated and normal T-cell expressed and secreted (RANTES) at position -403, monocyte chemoattractant protein-1 (MCP-1) at position -2518, CCR2 V64I, CCR5 -2459, CXCR1 S276T and CXCR4 I138I using single primer extension assay. Genotype distributions of the "HBV clearance versus persistence group" and "inactive carrier versus HBV progression group" were compared. On the basis of unconditional logistic regression analysis with adjustment for age and sex, no statistically significant association with susceptibility to persistent HBV infection was observed with RANTES -403, MCP-1 -2518, CCR2 V64I, CCR5 -2459, CXCR1 S276T, and CXCR4 I138I polymorphisms. In addition, no association of analyzed SNPs with HBV disease progression was found.
Chemokine CCL2/*genetics ; Chemokine CCL5/*genetics ; Disease Progression ; Genotype ; Hepatitis B/ethnology/*genetics/*therapy ; Hepatitis B virus/metabolism ; Humans ; Korea ; *Polymorphism, Genetic ; Receptors, CCR2 ; Receptors, CCR5/*genetics ; Receptors, CXCR4/*genetics ; Receptors, Chemokine/*genetics ; Receptors, Interleukin-8A/*genetics ; Regression Analysis ; Treatment Outcome

To observe the effect of acupuncture on CXCL8 receptors (CXCR1 and CXCR2) in rat endometrium experiencing embryo implantation failure, 72 pregnant rats were randomly divided into four groups: normal group (N), embryo implantation failure group (M), acupuncture treatment group (A), and progestin treatment group (W). Then the rats in each group were equally randomized into a day-6 (D6) group, a day-8 (D8) group, and a day-10 (D10) group. The rats in group M, group A, and group W were treated with mifepristone-sesame oil solution on day 1, while the rats in group N were injected with the same amount of sesame oil. Meanwhile, "Housanli" and "Sanyinjiao" were selected for acupuncture. From day 1 to the time of death, the rats in group A were fastened up and then acupuncture was administered while the rats in group N and group M were only fixed, and the rats in group W were given progestin. The number of implanted embryos was calculated. The expression of CXCR1 and CXCR2 in rat endometrium was detected by immunohistochemistry, Western blotting and real-time PCR. Compared to group N, the average number of implanted embryos, the protein and mRNA expression of CXCR1 (D6, D8 and D10), and the protein and mRNA expression of CXCR2 (D8 and D10) in rat endometrium were significantly decreased in group M. Compared to group M, there was significant elevation in the average number of implanted embryos, the protein expression (D6, D8 and D10) and mRNA expression (D8) of CXCR1 in rat endometrium of group A, and the protein expression (D8 and D10) and mRNA expression (D8) of CXCR2 in rat endometrium of group W. These findings indicated that acupuncture can increase the number of implanted embryos in rats of embryo implantation failure, which may be relevant with up-regulation the expression of CXCR1 and CXCR2 at maternal-fetal interface of rats with embryo implantation failure.
Acupuncture Therapy ; methods ; Animals ; Blotting, Western ; Embryo Implantation ; drug effects ; genetics ; Endometrium ; drug effects ; metabolism ; Female ; Gene Expression Regulation, Developmental ; Hormone Antagonists ; pharmacology ; Immunohistochemistry ; Mifepristone ; pharmacology ; Pregnancy ; Progestins ; pharmacology ; Random Allocation ; Rats ; Rats, Wistar ; Receptors, Interleukin-8A ; genetics ; metabolism ; Receptors, Interleukin-8B ; genetics ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Time Factors ; Treatment Outcome ; Up-Regulation ; drug effects

OBJECTIVE: To investigate and analyze the effect of CXC chemokine receptor 1/2 (CXCR1/2) targeting inhibitor Reparixin combined with cytarabine (Ara-C) on the malignant biological behaviors of acute myeloid leukemia cells and its effect on the expression of the CXCR family, while exploring the accompanying molecular mechanism, providing scientific basis and reference for new molecular markers and targeted therapy for AML. METHODS: Acute myeloid leukemia U937 cells were treated with different concentrations of Reparixin, Ara-C alone or in combination, and the cell morphology was observed under an inverted microscope; Wright-Giemsa staining was used to detect cell morphological changes; CCK-8 method was used to detect cell proliferation; the ability of cell invasion was detected by Transwell chamber method; the ability of colony formation was detected by colony formation assay; cell apoptosis was detected by Hoechst 33258 fluorescent staining and Annexin V/PI double-staining flow cytometry; monodansylcadaverine(MDC) staining was used to detect cell autophagy; the expression of apoptosis, autophagy and related signaling pathway proteins was detected by Western blot and the expression changes of CXCR family were detected by real-time quantitative polymerase chain reaction (qRT-PCR). RESULTS: Reparixin could inhibit the proliferation, invasion, migration and clone formation ability of U937 cells. Compared with the single drug group, when U937 cells were intervened by Reparixin combined with Ara-C, the malignant biological behaviors such as proliferation, invasion and colony formation were significantly decreased, and the levels of apoptosis and autophagy were significantly increased (P<0.01). After Reparixin combined with Ara-C intervenes in U937 cells, it can up-regulate the expression of the pro-apoptotic protein Bax and significantly down-regulate the expression of the anti-apoptotic protein Bcl-2, and also hydrolyze and activate Caspase-3, thereby inducing cell apoptosis. Reparixin combined with Ara-C could up-regulate the expressions of LC3Ⅱ and Beclin-1 proteins in U937 cells, and the ratio of LC3Ⅱ/LC3Ⅰ in cells was significantly up-regulated compared with single drug or control group (P<0.01). MDC result showed that the green granules of vesicles increased significantly, and a large number of broken cells were seen (P<0.01). Reparixin combined with Ara-C can significantly inhibit the phosphorylation level of PI3K, AKT and NF-κB signaling molecule, inhibit the malignant biological behavior of cells by inhibiting the activation of PI3K/AKT/NF-κB pathway, and induce programmed cell death. Ara-C intervention in U937 cells had no effect on the expression of CXCR family (P>0.05). The expression of CXCR1, CXCR2, and CXCR4 mRNA could be down-regulated by Reparixin single-agent intervention in U937 cells (P<0.05), and the expression of CXCR2 was more significantly down-regulated than the control group and other CXCRs (P<0.01). When Reparixin and Ara-C intervened in combination, the down-regulated levels of CXCR1 and CXCR2 were more significant than those in the single-drug group (P<0.01), while the relative expressions of CXCR4 and CXCR7 mRNA had no significant difference compared with the single-drug group (P>0.05). CONCLUSION Reparixin combined with Ara-C can synergistically inhibit the malignant biological behaviors of U937 cells such as proliferation, invasion, migration and clone formation, and induce autophagy and apoptosis. The mechanism may be related to affecting the proteins expression of Bcl-2 family and down-regulating the proteins expression of CXCR family, while inhibiting the PI3K/AKT/NF-κB signaling pathway.
Humans ; U937 Cells ; Cytarabine/therapeutic use* ; Receptors, Interleukin-8A ; NF-kappa B ; Proto-Oncogene Proteins c-akt ; Phosphatidylinositol 3-Kinases ; Leukemia, Myeloid, Acute/genetics* ; Apoptosis ; Cell Proliferation ; Apoptosis Regulatory Proteins ; Proto-Oncogene Proteins c-bcl-2 ; RNA, Messenger ; Cell Line, Tumor