Adhesion Of HL-60 Cells Research Articles

Inhibition of TNF-α-Induced Inflammation by Andrographolide via Down-Regulation of the PI3K/Akt Signaling Pathway

Andrographolide (1), an active constituent of Andrographis paniculata, decreased tumor necrosis factor-α (TNF-α)-induced intercellular adhesion molecule-1 (ICAM-1) expression and adhesion of HL-60 cells onto human umbilical vein endothelial cells (HUVEC), which are associated with inflammatory diseases. Moreover, 1 abolished TNF-α-induced Akt phosphorylation. Transfection of an activated Akt1 cDNA vector increased Akt phosphorylation and ICAM-1 expression like TNF-α. In addition, 1 and LY294002 blocked TNF-α-induced IκB-α degradation and nuclear p65 protein accumulation, as well as the DNA-binding activity of NF-κB. Compound 1 exhibits anti-inflammatory properties through the inhibition of TNF-α-induced ICAM-1 expression. The anti-inflammatory activity of 1 may be associated with the inhibition of the PI3K/Akt pathway and downstream target NF-κB activation in HUVEC cells.

Inhibition of P-selectin-mediated inflammation cell adhesion by 6SCM-chitin

Here, we prepared several derivatives of chitin and detected their activities in blocking P-selectin-mediated inflammation cell (HL60 cell) adhesion. Our results showed that 6-O-sulfated chitin (6S-chitin) and 6-O-sulfated carboxymethyl chitin (6SCM-chitin), but not 6-O-carboxymethyl chitin (6CM-chitin), dramatically reduced P-selectin-mediated HL60 cell adhesion under static and flow conditions. Interestingly, 6SCM-chitin demonstrated stronger activity than 6S-chitin. Because 6SCM-chitin is obtained by the introduction of carboxymethyl group to C6 of 6S-chitin, we speculate that the synergy of sulfate and carboxymethyl groups in chitin might be indispensable for blocking P-selectin-mediated cell adhesion. The spacing arrangement of sulfate groups and carboxymethyl groups of modified chitin most probably meets the requirement of recognition by P-selectin. Our findings have a potential value for exploiting the biological use of chitin, especially for designing anti-inflammatory agents targeting P-selectin.

Andrographolide Inhibits ICAM-1 Expression and NF-κB Activation in TNF-α-Treated EA.hy926 Cells

Several lines of evidence indicate that inflammation and endothelial cell dysfunction are important initiating events in atherosclerosis. Tumor necrosis factor-α (TNF-α), a pro-inflammatory cytokine, induces the expression of cell adhesion molecules and results in monocyte adherence and atheromatous plaque formation. Andrographolide (AP) is a major bioactive diterpene lactone in Andrographis paniculata that has anti-inflammatory activity. A previous study demonstrated the role of heme oxygenase 1 (HO-1) in the inhibition of TNF-α-induced ICAM-1 expression by AP. The present study investigated the effect of AP on the IKK/NF-κB signaling pathway, which mediates TNF-α-induced ICAM-1 expression in EA.hy926 cells. Similar to the previous study, AP inhibited TNF-α-induced ICAM-1 mRNA and protein levels, its expression on the cell surface, and subsequent adhesion of HL-60 cells to EA.hy926 cells. AP inhibited TNF-α-induced κB inhibitor (IκB) kinase (IKK) and IκBα activation, p65 nuclear translocation, NF-κB and DNA binding activity, and promoter activity of ICAM-1. Although AP increased the intracellular cAMP concentration and induced the phosphorylation of cAMP response element-binding protein (CREB), knocking down CREB protein expression by transfecting the cells with CREB-specific small interfering RNA did not relieve the inhibition of ICAM-1 expression by AP. Taken together, these results suggest that AP down-regulates TNF-α-induced ICAM-1 expression at least in part via attenuation of activation of NF-κB in EA.hy926 cells rather than through activation of CREB. The results suggest that AP may have potential as a cardiovascular-protective agent.

All-transretinoic acid and a novel synthetic retinoid tamibarotene (Am80) differentially regulate CD38 expression in human leukemia HL-60 cells: possible involvement of protein kinase C-δ

ATRA and a synthetic RAR agonist tamibarotene (Am80) induce granulocytic differentiation of human acute leukemia HL-60 cells and have been used in antineoplastic therapy. ATRA induces CD38 antigen during HL-60 cell differentiation, which interacts with CD31 antigen on the vascular EC surface and may induce disadvantages in the therapy. We here examined the mechanisms of the ATRA-mediated CD38 induction and compared the difference between ATRA- and tamibarotene-mediated induction. Tamibarotene-induced HL-60 cell adhesion to ECs was 38% lower than ATRA, and NB4 cell adhesion to ECs by tamibarotene was equivalent to ATRA, which induced CD38 gene transcription biphasically in HL-60 cells, the early-phase induction via DR-RARE containing intron 1, and the delayed-phase induction via RARE lacking the 5'-flanking region. In contrast to ATRA, tamibarotene induced only the early-phase induction, resulting in its lower CD38 induction than ATRA. A PKCδ inhibitor, rottlerin, and siRNA-mediated PKCδ knockdown suppressed the ATRA-induced CD38 promoter activity of the 5'-flanking region, whereas a RAR antagonist, LE540, or RAR knockdown did not affect it. Cycloheximide and rottlerin suppressed the delayed-phase induction of CD38 expression by ATRA but did not affect the early-phase induction. Moreover, ATRA, but not tamibarotene, induced PKCδ expression without affecting its mRNA stability. The diminished effect of tamibarotene on CD38-mediated HL-60 cell adhesion to ECs compared with ATRA is likely a result of the lack of its delayed-phase induction of CD38 expression, which may be advantageous in antineoplastic therapy.

Induction of Heme Oxygenase 1 and Inhibition of Tumor Necrosis Factor α-Induced Intercellular Adhesion Molecule Expression by Andrographolide in EA.hy926 Cells

Andrographolide is the most abundant diterpene lactone in Andrographis paniculata, which is widely used as a traditional medicine in Southeast Asia. Heme oxygenase 1 (HO-1) is an antioxidant enzyme encoded by a stress-responsive gene. HO-1 has been reported to inhibit the expression of adhesion molecules in vascular endothelial cells (EC). Intercellular adhesion molecule (ICAM-1) is an inflammatory biomarker that is involved in the adhesion of monocytes to EC. In this study, we investigated the effect of andrographolide on the expression of ICAM-1 induced by tumor necrosis factor alpha (TNF-alpha) in EA.hy926 cells and the possible mechanisms involved. Andrographolide (2.5-7.5 microM) inhibited the TNF-alpha-induced expression of ICAM-1 in a dose-dependent manner and resulted in a decrease in HL-60 cell adhesion to EA.hy926 cells (p < 0.05). In parallel, andrographolide significantly induced the expression of HO-1 in a concentration-dependent fashion (p < 0.05). Andrographolide increased the rate of nuclear translocation of nuclear factor erythroid 2-related 2 (Nrf2) and induced antioxidant response element-luciferase reporter activity. Transfection with HO-1-specific small interfering RNA knocked down HO-1 expression, and the inhibition of expression of ICAM-1 by andrographolide was significantly reversed. These results suggest that stimulation of Nrf2-dependent HO-1 expression is involved in the suppression of TNF-alpha-induced ICAM-1 expression exerted by andrographolide.

Protective role of betulinic acid on TNF-α-induced cell adhesion molecules in vascular endothelial cells

Vascular inflammation is an important event in the development of vascular diseases such as tumor progression and atherosclerosis. In the present study, betulinic acid (BA) treatment was found to show potent inhibitory effect on vascular inflammation process by TNF-α in human umbilical vein endothelial cells (HUVEC). Pretreatment of HUVEC with BA was blocked TNF-α induced expression level of cell adhesion molecules such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), endothelial cell selectin (E-selectin) as well as gelatinase in TNF-α-activated HUVEC in a dose-dependent manner. When preincubated with BA, the adhesion of HL-60 cells to TNF-α-induced HUVEC was significantly decreased in a concentration-dependent manner. TNF-α-induced intracellular ROS was markedly decreased by pretreatment with BA. Furthermore, BA significantly inhibited the translocation and transcriptional activity of NF-κB increased by TNF-α. In conclusion, these results suggested a vascular protective role of BA via inhibition of ROS and NF-κB activation in HUVEC.

Exposure of HL-60 human leukaemic cells to 4-hydroxynonenal promotes the formation of adduct(s) with α-enolase devoid of plasminogen binding activity

HNE (4-hydroxynonenal), the major product of lipoperoxidation, easily reacts with proteins through adduct formation between its three main functional groups and lysyl, histidyl and cysteinyl residues of proteins. HNE is considered to be an ultimate mediator of toxic effects elicited by oxidative stress. It can be detected in several patho-physiological conditions, in which it affects cellular processes by addition to functional proteins. We demonstrated in the present study, by MS and confirmed by immunoblotting experiments, the formation of HNE-alpha-enolase adduct(s) in HL-60 human leukaemic cells. Alpha-enolase is a multifunctional protein that acts as a glycolytic enzyme, transcription factor [MBP-1 (c-myc binding protein-1)] and plasminogen receptor. HNE did not affect alpha-enolase enzymatic activity, expression or intracellular localization, and did not change the expression and localization of MBP-1 either. Confocal and electronic microscopy results confirmed the plasma membrane, cytosolic and nuclear localization of alpha-enolase in HL-60 cells and demonstrated that HNE was colocalized with alpha-enolase at the surface of cells early after its addition. HNE caused a dose- and time-dependent reduction of the binding of plasminogen to alpha-enolase. As a consequence, HNE reduced adhesion of HL-60 cells to HUVECs (human umbilical vein endothelial cells). These results could suggest a new role for HNE in the control of tumour growth and invasion.

Effect of Zanthoxylum schinifolium on TNF-α-induced vascular inflammation in human umbilical vein endothelial cells

Pro-inflammatory cytokines induce the injury of endothelial cells in response to increases of adhesion molecules, leading to vascular inflammation and the development of atherosclerosis. In this study, we evaluated an ethanol extract of Zanthoxylum schinifolium (EZS) to determine if it inhibits the expressions of cellular adhesion molecules in human umbilical vein endothelial cells (HUVEC). When pretreatment of HUVEC with EZS, EZS suppressed the expression levels of cell adhesion molecules such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and E-selectin induced by TNF-α. The adhesion of HL-60 cells to TNF-α-induced endothelial cells was decreased significantly in a concentration-dependent manner. Furthermore, TNF-α-induced MCP-1 and IL-8 mRNA expression levels were also attenuated by pretreatment with EZS. In addition, EZS suppressed TNF-α-induced production of reactive oxygen species (ROS). EZS inhibited NF-κB activation and IκB-α phosphorylation induced by TNF-α, subsequent degradation of IκB-α. Finally, EZS inhibited TNF-α-induced p38 MAPK and c-Jun N-terminal kinase (JNK) phosphorylation. Taken together, these results demonstrate that EZS suppresses vascular inflammatory process, which may be closely related to the inhibition of ROS, JNK, p38 MAPK and NF-κB activation in HUVEC.

Trans-Cinnamaldehyde Induces Granulocytic Differentiation and Impairs Survival and Migration of Acute Myeloid Leukemic Cells

Trans-cinnamaldehyde (TCA), the major active component of oil isolated from the stem bark of Cinnamomum cassia traditionally used to treat dyspepsia, gastritis and inflammatory disease world widely, has been shown to inhibit proliferation and promote apoptosis in a number of cancer cells. However, the functional roles TCA plays in hematopoietic system have not been fully investigated. In this study, we show the effects of TCA on acute promyelocytic leukemia (APL) cell line HL60 and primary bone marrow mononuclear cells (BMMNC) as well as bone marrow stromal cells (BMSC) from acute myeloid leukemia (AML) patients. We found that TCA affected HL60 cells in a time-and dose-dependent fashion. Low concentration of TCA (20 μM) arrested HL60 cells at G0/G1 phase at 72 h without significant apoptosis. Middle concentration of TCA (60 μM) accumulated HL60 cells at G2/M at 24 h with increased apoptosis when the treated time was prolonged. Both low and middle concentrations of TCA induced HL60 cells to differentiate toward mature granule cells characterized with up-regulation of CD11b on cells accompanied by decreased c-Myc protein and increased p27 protein. Consistently, the expression and cellular distribution of p16 and Cdc6 were also significantly changed in differentiated HL60 cells treated with TCA. On the other hand, high concentration of TCA (100 μM) rapidly inhibited NF-kappaB activity and induced apoptosis in HL60 cells. Importantly, TCA induced apoptosis of AML CD34+ cells and suppressed colony formation of AML BMMNC, while its cytotoxicity on normal BMMNC was minor. In addition, TCA synergized with AraC to kill AML BMMNC and AML CD34+ cells. Finally, TCA also decreased CXCR4 expression on HL60 cells, consistent with it ability to depress migration and invasion of HL60 cells induced by rhSDF-1α as well as the adhesion of HL60 cells to AML BMSC. Of note, TCA also impaired survival and SDF-1α secretion of AML BMSC, which may further suppress the interaction of HL60 with AML BMSC. Taken together, our data show that TCA is an effective agent for the treatment of hematopoietic malignancies, not only being the direct inducer of terminal differentiation and apoptosis of acute myeloid leukemic cells, but attenuating the protective effect of AML BMSC on leukemia cells via inhibiting SDF-CXCR4 axis, which highlights the potential of TCA to be a promising therapeutic agent for hematopoietic malignancies treatment.

Diallyl Disulfide and Diallyl Trisulfide Suppress Oxidized LDL–Induced Vascular Cell Adhesion Molecule and E-Selectin Expression through Protein Kinase A– and B–Dependent Signaling Pathways

Uptake of oxidized LDL (ox-LDL) by vascular endothelial cells is a critical step in the initiation and development of atherosclerosis. Adhesion molecules are upregulated by ox-LDL and numerous inflammatory cytokines and play a pivotal role in atherogenesis. In this study, we examined whether diallyl sulfide (DAS), diallyl disulfide (DADS), and diallyl trisulfide (DATS), 3 major organosulfur compounds of garlic oil, reduce adhesion molecule expression induced by ox-LDL and, if so, through what mechanism. Human umbilical vein endothelial cells were preincubated with 1 mmol/L DAS, 200μmol/L DADS, or 100μmol/L DATS for 16 h and then with 40 mg/L ox-LDL for an additional 24 h. ox-LDL induction of cellular and cell surface expression of E-selectin and vascular cell adhesion molecule (VCAM)-1 was suppressed by garlic allyl sulfides in the order DATS > DADS > DAS. The adhesion of HL-60 cells to endothelial cells was inhibited 27 and 33% and the production of cellular peroxides was inhibited 43 and 50% by DADS and DATS, respectively (P < 0.05). ox-LDL alone dephosphorylated protein kinase B (PKB) and cAMP responsive element binding protein (CREB); such deactivation was reversed by DADS and DATS. Electrophoretic mobility shift assay showed that the activation of CREB binding to DNA was consistent with changes in CREB phosphorylation. The protein kinase A (PKA) inhibitor H89 reversed the suppression of VCAM-1 by DADS and DATS, but the phosphoinositide 3-kinase (PI3K) inhibitor wortmannin had no effect. In contrast, wortmannin abolished DADS- and DATS-induced suppression of ox-LDL–induced E-selectin expression. These results suggest that the suppression of ox-LDL–induced E-selectin and VCAM-1 expression by DADS and DATS and, thus, monocyte adhesion to endothelial cells is likely dependent on the PI3K/PKB or PKA/CREB signaling pathway in an adhesion molecule-specific manner. To our knowledge, this is the first report that garlic modulates ox-LDL–mediated leukocyte adhesion to human endothelial cells through the PKB and PKA pathways.

Purified polysaccharide from Ginkgo biloba leaves inhibits P-selectin-mediated leucocyte adhesion and inflammation

To investigate the anti-inflammatory mechanism of the polysaccharides of Ginkgo biloba leaves (PGBL) by inhibiting leucocyte adhesion. The rough PGBL were isolated and purified. The anti-inflammatory effects of purified PGBL (p-PGBL) were assayed by ear edema induced by xylol and the acute peritonitis model in mice. The effect of p-PGBL on inhibiting the interaction between P-selectin and its ligands was investigated by flow cytometry and flow chamber. p-PGBL could effectively inhibit the acute inflammation in mice and interfere with the adhesion of HL-60 cells, a human leukaemia cell line, or neutrophils to P-selectin in static conditions, as well as the adhesion of neutrophils to Chinese hamster ovary cells expressing human P-selectin and human umbilical vein endothelial cells in flow conditions in a dose-dependant manner. p-PGBL can inhibit the inflammatory process through interfering with the interaction between P-selectin and its ligands.

Efficient Total Synthesis of Novel Bioactive Microbial Metabolites

Bioactive natural products produced by microbes have almost limitless potential in pharmaceutical applications, and the organic synthesis of such products as lead compounds will result in the creation of new and widely useful pharmaceutical products. A program of discovery of naturally occurring bioactive microbial metabolites has been ongoing at the Kitasato Institute. We have also developed efficient, rational, and highly flexible production methods for generation of target compounds, synthesis of related compounds, elucidation of their structure-activity relationships, and the possible creation of improved bioactive compounds. In this Account, the isolation and total synthesis of naturally occurring bioactive microbial metabolites in order to create novel medicines for specific illnesses is described. This covers diseases and conditions such as atherosclerosis, Alzheimer's disease, cancer, inflammation, and osteoporosis, among others, and focuses on six specific compounds. Pyripyropenes were discovered from Aspergillus fumigatus FO-1289 through our screening of microbial metabolites that strongly inhibit acyl-CoA cholesterol acyltransferase (ACAT) in order to develop a new class of cholesterol-lowering agents. These novel polyoxygenated mixed polyketide-terpenoid (meroterpenoid) metabolites contain a fused pyridyl alpha-pyrone moiety. We carried out the first total synthesis of (+)-pyripyropene A via a flexible, concise, and highly efficient route and also clarified the structure-activity relationships. Arisugacins were discovered from Penicillium sp. FO-4259 by our screening of microbial metabolites that strongly inhibit acetylcholinesterase (AChE) in order to create novel medicines for Alzheimer's disease (AD). Arisugacins are also meroterpenoids. We have achieved the first convergent total synthesis of arisugacins A and B. Lactacystin was isolated from Streptomyces sp. OM-6519 via our screening of microbial metabolites that promote the differentiation of the neuroblastoma cell to further discover new AD medicines. Lactacystin has a novel gamma-lactam thioester structure and is also a selective and strong proteasome inhibitor. We have developed a concise approach to synthesize lactacystin designed to afford easy access to the original compound and a variety of analogs. Macrosphelides were isolated from Microsphaeropsis sp. FO-5050 from our screening of microbial metabolites that inhibit the adhesion of HL-60 cells to human umbilical vein endothelial cells (HUVEC). Macrosphelides are the first 16-membered macrotriolides. Macrosphelides prevent cell-cell adhesion by inhibiting the binding of sialyl Lewis X to E-selectin. We have accomplished the first efficient total synthesis of macrosphelides. Madindolines were isolated from Streptomyces nitrosporeus K93-0711 by our program to discover new interleukin 6 (IL-6) modulators. Madindolines are comprised of a 3a-hydroxyfuroindoline ring connected at nitrogen via a methylene bridge to a cyclopentene-1,3-dione ring. We have developed an efficient and practical total synthesis of madindolines. Madindoline A binds to gp130 selectively and inhibits IL-6 activity. Neoxaline was isolated from Aspergillus japonicus Fg-551. Neoxaline is a member of a novel class of biologically active indole alkaloids characterized by a unique indoline spiroaminal framework and binds to tubulin, which results in inhibition of tubulin polymerization. We have developed a concise stereoselective synthesis of the indoline spiroaminal framework of neoxaline.

Up-regulation of the Cbl family of ubiquitin ligases is involved in ATRA and bufalin-induced cell adhesion but not cell differentiation

The Casitas B-lineage Lymphoma (Cbl) family of ubiquitin ligases is multifunctional proteins that play important roles in different cell signaling pathways. It has been reported that c-Cbl and Cbl-b mRNAs are up-regulated during TPA-induced U937 and HL-60 cell differentiation. But the mechanism of the up-regulation and the roles of the Cbl family of ubiquitin ligases still remain unclear. In the present study, we demonstrated that bufalin enhanced all- trans retinoic acid (ATRA) induced differentiation of HL-60 cells, accompanied by up-regulation of the Cbl family of ubiquitin ligases. CsA, an inhibitor of calcium mobilization, reversed this up-regulation. Pretreatment with CsA and PS-341 did not affect the expression of CD11b, but suppressed the percentage of adherent cells. Lipid raft localization of Cbl-b enhanced cell adhesion, while C-terminal deletion partially suppressed the effect. Moreover, the expression of the adhesion-related kinases Pyk2 and Paxillin was up-regulated in parallel with the increase of Cbl proteins. These results suggested that up-regulation of c-Cbl and Cbl-b was involved in the regulation of ATRA and bufalin-induced HL-60 cell adhesion rather than cell differentiation, which might be mediated by lipid raft localization, ubiquitin ligase activity and C-terminal structure of Cbl proteins. Meanwhile, up-regulation of proline-rich tyrosine kinase (Pyk2) and Paxillin might also be implicated in this regulation.

Binding of ADAM28 to P-selectin Glycoprotein Ligand-1 Enhances P-selectin-mediated Leukocyte Adhesion to Endothelial Cells

ADAMs (a disintegrin and metalloproteinases) are a recently discovered gene family of multifunctional proteins with the disintegrin-like and metalloproteinase domains. To analyze the biological functions of ADAM28, we screened binding molecules to secreted-type ADAM28 (ADAM28s) by the yeast two-hybrid system and identified P-selectin glycoprotein ligand-1 (PSGL-1). Binding between the disintegrin-like domain of ADAM28s and the extracellular portion of PSGL-1 was determined by yeast two-hybrid assays, binding assays of the domain-specific recombinant ADAM28s species using PSGL-1 stable transfectants and leukocyte cell lines expressing native PSGL-1 (HL-60 cells and Jurkat cells), and co-immunolocalization and co-immunoprecipitation of the molecules in these cells. Incubation of HL-60 cells with recombinant ADAM28s enhanced the binding to P-selectin-coated wells and P-selectin-expressing endothelial cells. In addition, intravenous injection of ADAM28s-treated HL-60 cells increased their accumulation in the pulmonary microcirculation and alveolar spaces in a mouse model of endotoxin-induced inflammation. These data suggest a novel function that ADAM28s promotes PSGL-1/P-selectin-mediated leukocyte rolling adhesion to endothelial cells and subsequent infiltration into tissue spaces through interaction with PSGL-1 on leukocytes under inflammatory conditions.

Osteoprotegerin increases leukocyte adhesion to endothelial cells both in vitro and in vivo

AbstractRecombinant osteoprotegerin (OPG) promoted the adhesion of both primary polymorphonuclear neutrophils (PMNs) and leukemic HL60 cells to endothelial cells. Leukocyte/endothelial cell adhesion was promoted by short (peak at 1 hour) preincubation of either endothelial cells or PMNs with OPG, and the peak of proadhesive activity was observed in the same range of OPG concentrations detected in the sera of patients affected by cardiovascular diseases. Although the cognate high-affinity ligands for OPG, membrane receptor activator of nuclear factor-κB ligand (RANKL) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), were detected at significant levels on both PMNs and HL60 cells, they were not expressed on the surface of endothelial cells. However, preincubation of OPG with heparin abrogated its proadhesive activity, whereas pretreatment of endothelial cells with chondroitinase plus heparinases significantly decreased the proadhesive activity of OPG. Taken together, these findings suggest the involvement of both the ligand binding and the N-terminal heparin-binding domains of OPG in mediating its pro-adhesive activity. The relevance of these in vitro findings was underscored by in vivo experiments, in which the topical administration of recombinant OPG increased leukocyte rolling and adhesion to rat mesenteric postcapillary venules. Our data suggest that a pathological increase of OPG serum levels might play an important role in promoting leukocyte/endothelial cell adhesion.

Cell-adhesion Inhibitors Produced by a Sea Hare-derived Periconia sp.

Peribysin J and macrosphelide M have been isolated from a strain of Periconia byssoides originally isolated from the sea hare Aplysia kurodai. Their absolute stereostructures have been elucidated on the basis of spectroscopic analyses using 1D and 2D NMR techniques and some chemical transformations including the modified Mosher's method. These fungal metabolites inhibited the adhesion of human-leukemia HL-60 cells to human-umbilical-vein endothelial cells (HUVEC).

Effects of anti-CXCR 4 monoclonal antibody 12G5 on proliferation and apoptosis of human acute myelocytic leukemia cell line HL-60

Objective To investigate the expression of CXCR 4 on HL-60 cell line and the proliferation. apoptosis of HL-60 cell line cocultured with bone marrow stromal cells, so as to assess the possibility of 12G5, an anti-CXCR 4 monoclonal antibody, in eradicating the minimal residual disease. Methods The activity of SDF-1 was inhibited by 10 μg/ml 12G5. After treatment with 12G5, the status of adhesion was observed, and the adhesion rates, apoptosis and cell cycles were detected after 24 h of treatment. Cell growth rates were measured by trypan blue exclusion. Cell growth curve was plotted, and the expression of PCNA and apoptosis related protein including PCNA, Bcl-2 and Fas were detected with immunohis-tochemical technique. Results (1) There was middling degree expression of CXCR 4 on HL-60 membrane. From 0 h to 6 h, as the time of 12G5 incubation along, the expression of CXCR 4 decreased gradually. (2) After treatment for 24 h, the adhesion rates in the experiment group and the control were (39.4 ± 7.9) and (51.4±5.9)%, respectively. (3) After treatment for 24 h, the percentage of HL-60 cells in G. G. phase were (55.21±4.9)%, and that in S phase and G 2/M phase were (30.40±4.1)%, and (14.39 = 5.2)%, respectively, with the corresponding proportions being (44.67±2.2)%, (45.30±3.7)%, and (10.03±2.6)% in the control. (4) The percentage of apoptotic HL-60 cells was (8.95±1.7)% in the experiment group, compared to (3.97±2.4)% in the control. (5) The survival rates of HL-60 cells decreased markedly at 48 h to 96 h, and the proliferation slowed down at this time duration. (6) The expression of PCNA and Bcl-2 down-regulated significantly, but the Fas protein expression was up-regulated. Conclusion 12G5 could inhibit the capability of adhesion and proliferation of HL-60 cells and it can induce more cells to enter G 0/G 1 phase and promote apoptosis. It may be helpful by inhibiting the bloactivity of SDF-1 with 12G5 in the therapy of marrow residual disease.

Cell-adhesion Inhibitors Produced by a Sea Hare-derived Periconia sp. II

Peribysins H (1) and I (2) have been isolated from a strain of Periconia byssoides originally separated from the sea hare Aplysia kurodai. Their absolute stereostructures have been elucidated on the basis of spectroscopic analyses using ID and 2D NMR techniques and some chemical transformations including the modified Mosher's method. These metabolites inhibited the adhesion of human-leukemia HL-60 cells to HUVEC.

Migration inhibitory factor up-regulates vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 via Src, PI3 kinase, and NFκB

AbstractCell adhesion molecules are critical in monocyte (MN) recruitment in immune-mediated and hematologic diseases. We investigated the novel role of recombinant human migration inhibitory factor (rhMIF) in up-regulating vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) and their signaling pathways in human MNs. rhMIF-induced expression of VCAM-1 and ICAM-1 was significantly higher compared with nonstimulated MNs. rhMIF induced MN VCAM-1 and ICAM-1 expression in a concentration-dependent manner (P < .05). Antisense oligodeoxynucleotides (ODNs) and inhibitors of Src, PI3K, p38, and NFκB significantly reduced rhMIF-induced MN VCAM-1 and ICAM-1 expression (P < .05). However, Erk1/2 and Jak2 were not involved. Silencing RNA directed against MIF, and inhibitors of Src, PI3K, NFκB, anti–VCAM-1, and anti–ICAM-1 significantly inhibited rhMIF-induced adhesion of HL-60 cells to human dermal microvascular endothelial cells (HMVECs) or an endothelial cell line, HMEC-1, in cell adhesion assays, suggesting the functional significance of MIF-induced adhesion molecules (P < .05). rhMIF also activated MN phospho-Src, -Akt, and -NFκB in a time-dependent manner. rhMIF induced VCAM-1 and ICAM-1 up-regulation in 12 hours via Src, PI3K, and NFκB as shown by Western blotting and immunofluorescence. MIF and MIF-dependent signaling pathways may be a potential target for treating diseases characterized by up-regulation of cell adhesion molecules.

2-Arachidonoylglycerol, an endogenous cannabinoid receptor ligand, enhances the adhesion of HL-60 cells differentiated into macrophage-like cells and human peripheral blood monocytes

2-Arachidonoylglycerol (2-AG), an endogenous cannabionoid receptor (CB1 and CB2) ligand, enhanced the adhesion of HL-60 cells differentiated into macrophage-like cells to fibronectin and the vascular cell adhesion molecule-1. The CB2 receptor, Gi/Go, intracellular free Ca 2+ and phosphatidylinositol 3-kinase were shown to be involved in 2-AG-induced augmented cell adhesion. 2-AG also enhanced the adhesion of human monocytic leukemia U937 cells and peripheral blood monocytes. These results strongly suggest that 2-AG plays some essential role in inflammatory reactions and immune responses by inducing robust adhesion to extracellular matrix proteins and adhesion molecules in several types of inflammatory cells and immune-competent cells.