Expression of adhesion molecules on CD34+ cells from steady-state bone marrow before and after mobilization and their association with the yield of CD34+ cells

BACKGROUND: Cell adhesion molecules (CAMs) expressed on hematopoietic progenitor cells (HPCs), endothelial cells, and stromal cells play a pivotal role in the mobilization of CD34+ cells. Herein, we conducted a non-randomized peripheral blood stem cell (PBSC) mobilization study aimed to compare the potential differences in the expressions of several CAMs and chemokines on CD34+ cells obtained from bone marrow aspirate before and after HPC mobilization from patients with hematologic malignancies and healthy donors. METHODS: Three-color cytofluorometric analysis was used to compare the expressions of CAMs and chemokines in the bone marrow before and after mobilization. RESULTS: For all studied groups, CAM expression among those with good and poor yields of CD34+ cells was significantly correlated with VCAM-1 (P=0.007), CD44 (P=0.027), and VLA-4 (P=0.014) expressions. VCAM-1 (P=0.001), FLT-3 (P=0.001), CD44 (P=0.011), VLA-4 (P=0.001), and LFA-1 (P=0.001) expressions were higher before HPC mobilization than after HPC mobilization. By contrast, the expression of CXCR4 significantly varied before and after mobilization only among those with successful PBSC mobilization (P=0.002). CONCLUSION: We attempted to identify particular aspects of CAMs involved in CD34+ cell mobilization, which is a highly complex mechanism that involves adhesion molecules and matrix metalloproteases. The mechanism by which CD34+ cell mobilization is activated through proteolytic enzymes is not fully understood. We believe that CXCR4, VLA-4, CD44, and VCAM-1 are the most important molecules implicated in HPC mobilization, particularly because they show a correlation with the yield of CD34+ cells collected via large volume leukapheresis.

Effect of AB serum on human terminal erythroid differentiation ex vivo / 中南大学学报(医学版)

To demonstrate the effect of AB serum on terminal erythroid differentiation ex vivo.
 Methods: After separation of CD34+ cells from cord blood, the cells were cultured and divided into a control group and an experimental group. The effects of AB serum were examined by the expressions of different markers (GPA, Band3 and α4-integrin) for erythroblast differentiation and enucleation by flow cytometry. 
 Results: The CD34+ cells were successfully differentiated to enucleated red blood cells. There were evident differences among the expressions of GPA, Band3 and α4-integrin between the 2 groups. The percentage of GPA positive cells in the experimental group was bigger than that in the control group in every time point. The expression of Band3 in the experimental group was higher than that in the control group. The expression of α4-integrin in the experimental group was lower than that in the control group. In addition, the enucleation rate in the experimental group was higher than that in the control group.
 Conclusion: AB serum can promote the cell differentiation and enucleation during terminal erythroid differentiation in vitro.

Relationship between macrophages and erythropoiesis / 中国当代儿科杂志

Macrophages have two major roles in regulating the dynamic equilibrium in erythropoiesis, promoting the differentiation and maturation of nucleated red blood cells into reticulocytes and removing old red blood cells. A recent mouse study has demonstrated that the phenotype of macrophages in erythroblastic islands is CD169+ VCAM-1+ ER-HR3+ CD11b+ F4/80+ Ly-6G+. Molecular connections between erythroid progenitor cells and central macrophages help to maintain the function and integrity of erythroblastic islands. New research advances in Kruppel-like factor 1 (KLF1) provide new evidence for the important role of macrophages in erythroblastic islands. Macrophages play an important role in erythropoiesis both in sickness and in health, and provide a potential targeted therapy for diseases such as polycythemia vera and beta-thalassemia in the future.

Simultaneous Inhibition of CXCR4 and VLA-4 Exhibits Combinatorial Effect in Overcoming Stroma-Mediated Chemotherapy Resistance in Mantle Cell Lymphoma Cells

There is growing evidence that crosstalk between mantle cell lymphoma (MCL) cells and stromal microenvironments, such as bone marrow and secondary lymphoid tissues, promotes tumor progression by enhancing survival and growth as well as drug resistance of MCL cells. Recent advances in the understanding of lymphoma microenvironment have led to the identification of crucial factors involved in the crosstalk and subsequent generation of their targeted agents. In the present study, we evaluated the combinatory effect of blocking antibodies (Ab) targeting CXCR4 and VLA-4, both of which were known to play significant roles in the induction of environment-mediated drug resistance (EMDR) in MCL cell line, Jeko-1. Simultaneous treatment with anti-CXCR4 and anti-VLA-4 Ab not only reduced the migration of Jeko-1 cells into the protective stromal cells, but also enhanced sensitivity of Jeko-1 to a chemotherapeutic agent to a greater degree than with either Ab alone. These combinatorial effects were associated with decreased phosphorylation of ERK1/2, AKT and NF-kappaB. Importantly, drug resistance could not be overcome once the adhesion of Jeko-1 to the stromal occurred despite the combined use of Abs, suggesting that the efforts to mitigate migration of MCLs should be attempted as much as possible. Our results provide a basis for a future development of therapeutic strategies targeting both CXCR4 and VLA-4, such as Ab combinations or bispecific antibodies, to improve treatment outcomes of MCL with grave prognosis.

Multiple sclerosis

Multiple sclerosis (MS) is the most common demyelinating disease affecting the central nervous system of young adults living in the western world. MS should be strongly suspected when a young adult develops one or more neurological episodes consistent with damage to white matter within the central nervous system (CNS), especially when these affect the optic nerves, brainstem, or spinal cord. The patient with relapses, each of which can be attributed to demyelination in the CNS, requires no investigation prior to establishing the diagnosis of clinically definite MS. For a diagnosis of MS, separate anatomical sites within the CNS must have been affected on different occasions, typically three. MS in Asian populations is characterized by the selective and dominant involvement of the optic nerve and spinal cord with some incidence of brainstem lesions. 35-40% of MS cases in Korea are of this optico-spinal type with or without brainstem lesions. Reported cases of neuromyelitis optica spectrum disease (NMOSD), causing severe optic neuritis (ON) and/or longitudinally extensive transverse myelitis, either monophase or with a relapse-remitting pattern, some of which were diagnosed previously as the optico-spinal form of MS in Asia, have increased annually in Korea with the development of the NMO-IgG or aquaporin4-antibody detecting technique. NMO-IgG detection is very important in the diagnosis of early stage of NMOSD and the differentiation of MS and other demyelinating disease. Many new convenient oral drugs or very potent intravenous monoclonal antibodies for targeting VLA-4, CD20, and CD52 may decrease the annual relapse rate and burden of brain-spinal cord lesionsin MS.

Effects of bone marrow stromal cells and VLA-4 antibody on apoptosis of childhood leukemia cells / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the protective effect of bone marrow stromal cells (BMSCs) upon childhood leukemia cells and the influence of VLA-4 antibody in vitro on leukemia cell apoptosis.</p><p><b>METHODS</b>BMSCs from children with acute leukemia-were isolated by human lymphocyte separation medium. BMSCs (adherent) and leukemia cells (suspended) were cultured in vitro. This study included four groups: leukemia cells alone (control), leukemia cells+BMSCs, leukemia cells+BMSCs supernatant and leukemia cells+BMSCs+VLA-4 antibody. The apoptosis rate of leukemia cells in the four groups was determined by Annexin Ⅴ-FITC double-labeled flow cytometry. The expression of survivin and bcl-2 genes in leukemia cells was ascertained by RT-PCR.</p><p><b>RESULTS</b>The apoptosis rate of leukemia cells in the leukemia cells+BMSCs and the leukemia cells+BMSCs supernatant groups was lower than that in the control group (P<0.05). Compared with the leukemia cells+BMSCs and the leukemia cells+BMSCs supernatant groups, the apoptosis rate of leukemia cells in the VLA-4 antibody group increased significantly (P<0.05). In the VLA-4 antibody group, the apoptosis rate of leukemia cells increased with prolonged culture time. There were significant differences in the apoptosis rate between 12 hrs and 24 hrs after VLA-4 antibody treatment (P<0.01). The expression of survivin and bcl-2 genes in leukemia cells from the VLA-4 antibody groups was reduced compared with that from the leukemia cells+BMSCs and the leukemia cells+BMSCs supernatant groups (P<0.05).</p><p><b>CONCLUSIONS</b>BMSCs play protective roles on leukemia cells. VLA-4 antibody can block the adhesion between BMSCs and leukemia cells and promote leukemia cell apoptosis.</p>

LFA-1 and VLA-4 involved in vasoendothelial adhesion and transendothelial migration of human high proliferative potential endothelial progenitor cells / 中国实验血液学杂志

To investigate whether lymphocyte function-associated antigen 1 (LFA-1) and very late antigen 4 (VLA-4) are involved in vasoendothelial adhesion and transendothelial migration of high proliferative potential endothelial progenitor cells (HPP-EPCs), flow cytometry was used to analyze the expression of integrin beta1 and beta2, the expression of intercellular adhesion molecule (ICAM-1, 2) and vascular cell adhesion molecule (VCAM-1) in mouse bone marrow endothelial cells (mBMECs). The adhesion and transmigration through endothelial cells of the HPP-EPCs blocked by functional grade neutralizing antibodies of VLA-4 and LFA-1 were studied in vitro. The results revealed that HPP-EPCs were positive for CD11a and CD49d in HPP-EPCs. The expression of ICAM-1and VCAM-1 of mBMECs increased after activated by IL-1beta and TNF-alpha. The results of adhesion in vitro revealed that the numbers of the adhered and migrated cells in the CD11a antibody group, in the CD49d antibody group and in the combinational antibody group were less than those in the isotype control antibody group. Furthermore, the number of adhered and migrated cells in the combinational antibody group was less than that in the CD11a or the CD49d antibody group (p < 0.05). It is concluded that both LFA-1 and VLA-4 are involved in vasoendothelial adhesion and transendothelial migration of HPP-EPCs.

The role of the alpha4 integrin-paxillin interaction in regulating leukocyte trafficking

The movement of leukocytes from the blood into peripheral tissues is a central feature of immune surveillance, but also contributes to the pathogenesis of inflammatory and autoimmune diseases. Integrins are a family of adhesion and signaling molecules made up of paired alpha and beta subunits, and the integrin alpha4beta1 plays a prominent role in the trafficking of mononuclear leukocytes. We have previously described the direct interaction of the signaling adaptor molecule paxillin with the cytoplasmic domain of the alpha4 integrin subunit. This interaction is critical for alpha4beta1 integrin dependent cell adhesion under shear flow conditions as it provides a needed connection to the actin cytoskeleton. Furthermore, the alpha4-paxillin interaction is required for effective alpha4beta1 dependent leukocyte migration and does so through the temporal and spatial regulation of the small GTPase Rac. These findings make the alpha4-paxillin interaction a potentially attractive therapeutic target in controlling leukocyte trafficking.

Effects of ligustrazine on expression of VCAM-1/VLA-4 in syngenic bone marrow transplantation of mice / 中国实验血液学杂志

To explore the effect of ligustrazine on the expression of adherent molecule VCAM-1/VLA-4 of bone marrow cells in syngenic bone marrow transplantation (BMT) mice, the mice were divided into 3 groups: normal group (which received no treatment), BMT control group and ligustrazine-treated groups. BMT mouse models were established. The BMT control group and the ligustrazine-treated group were orally administered 0.2 ml saline per mouse and 2 mg ligustrazine per mouse, respectively, twice a day. On the day 7, 14, 21, 28 after BMT, mice were respectively killed. Bone marrow nucleated cells were detected, and then the expression of VCAM-1/VLA-4 was assayed by immunohistochemistry, RT-PCR and flow cytometry analysis, respectively. The results showed that in ligustrazine-treated group, the accounts of bone marrow nucleated cells on the day 7, 14, 21, 28 after BMT were all higher than that in BMT control group. The expression level in the ligustrazine-treated group was significantly higher than that in the BMT control group (P < 0.05 or P < 0.01). It is concluded that ligustrazine can enhance VCAM-1/VLA-4 expression in bone marrow after syngenic bone marrow transplantation in mice, which may be related to the mechanisms underlying the ligustrazine accelerating hematopoietic reconstitution in allogenic bone marrow transplantation.

Stem Cells Expressing Homing Receptors Could be Expanded From Cryopreserved and Unselected Cord Blood

We assessed the cytokine combinations that are best for ex vivo expansion of cord blood (CB) and the increment for cell numbers of nucleated cells, as well as stem cells expressing homing receptors, by an ex vivo expansion of cryopreserved and unselected CB. Frozen leukocyte concentrates (LC) from CB were thawed and cultured at a concentration of 1x10(5)/mL in media supplemented with a combination of SCF (20 ng/mL)+TPO (50 ng/mL)+FL (50 ng/mL)+/-IL-6 (20 ng/mL)+/-G-CSF (20 ng/mL). After culturing for 14 days, the expansion folds of cell numbers were as follows: TNC 22.3+/-7.8~26.3+/-4.9, CFU-GM 4.7+/-5.1~11.7+/-2.6, CD34+CD38- cell 214.0+/-251.9~464.1+/-566.1, CD34+CXCR4+ cell 4384.5+/-1664.7~7087.2+/-4669.3, CD34+VLA4+ cell 1444.3+/-1264.0~2074.9+/-1537.0, CD34+VLA5+ cell 86.2+/-50.9~ 113.2+/-57.1. These results revealed that the number of stem cells expressing homing receptors could be increased by an ex vivo expansion of cryopreserved and unselected CB using 3 cytokines (SCF, TPO, FL) only. Further in vivo studies regarding the engraftment after expansion of the nucleated cells, as well as the stem cells expressing homing receptors will be required.

Regulation of Adhesion Molecule Expression and Stromal Cell-Derived Factor-1 Production in Human Bone Marrow Cells by Interferon-gamma, Tumor Necrosis Factor-alpha, and Transforming Growth Factor-beta1: Implications in Bone Marrow Homing of Hematopoietic / 대한혈액학회지

BACKGROUND: It is well known that harmonious interactions among adhesion molecules and stromal cell-derived factor-1 (SDF-1)-mediated chemoattraction signalling via CXCR4 are needed for bone marrow homing of hematopoietic stem cells and progenitor cells. The aim of this study was to define the role of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), and transforming growth factor-beta 1 (TFG-beta1), known as hematopoiesis-inhibitory cytokines, in the regulation of the molecules in relation to the homing. METHODS: We investigated the effects of these cytokines on the expression of CXCR4 and adhesion molecules and the production of SDF-1 in bone marrow cells including CD34+ cells, bone marrow endothelial cells (BMEC-1 cells), and bone marrow stromal cells (BMSCs). We also examined whether the cytokines influence in vitro transmigration of hematopoietic progenitors. RESULTS: None of the cytokines influenced CXCR4 expression on CD34+ cells or SDF-1- mediated chemotaxis of the cells. IFN-gamma and TNF-alpha, but not TGF-beta up-regulated the expression of L-selectin, ICAM-1, and VLA-4 on CD34+ cells. However, the up-regulation was not translated into the enhanced transendothelial migration. IFN-gamma and TNF-alpha up-regulated the expression of VCAM-1 and ICAM-1 on BMEC-1 cells, and rendered the endothelium more suitable for transendothelial migration of hematopoietic progenitors. IFN-gamma and TNF-alpha also up-regulated the expression of VCAM-1 and ICAM-1 on primary human BMSCs. All three cytokines significantly attenuated SDF-1 production from primary BMSCs, and TNF-alpha diminished SDF-1 production from BMEC-1 cells. CONCLUSION: These data indicate that IFN-gamma, TNF-alpha, and TGF-beta1 play a role in the regulation of bone marrow homing of hematopoietic cells via up-regulation of adhesion molecule expression and down-modulation of SDF-1 production in bone marrow cells.

Effects of BIO-1211 on eosinophil chemotaxis, recruitment and mediator release / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To study the effects of very late antigen(VLA) antagonist BIO-1211 on eosinophil chemotaxis, recruitment and mediator release.</p><p><b>METHODS</b>Eosinophil chemotaxis was induced by platelet activating factor(PAF) in vitro and eosinophil recruitment and release were determined in vivo.</p><p><b>RESULT</b>VLA antagonist BIO-1211 inhibited eosinophil chemotaxis induced by PAF. The inhibitory rates at 4x10(-11), 4x10(-10), 4x10(-9) mol x L(-1) were 24.9%, 29.9%, and 31.3%, respectively. Pretreatment by BIO-1211 1, 3 and 10 mg x kg(-1) intraperitoneally inhibited the recruitment of eosinophils in PAF in the rat induced by Sephadex in a dose dependent manner. Inhibitory rates were 60.3%, 68.9%, and 72.9%(P<0.05), respectively. BIO-1211 did not inhibit eosinophil peroxidase(EPO) release from eosinophils.</p><p><b>CONCLUSION</b>BIO-1211 inhibits eosinophil chemotaxis and recruitment, alleviates local inflammation, and may represent a new type of drug for allergic diseases.</p>

Correlation between VLA-4 integrin and hematopoietic cell migration / 中国实验血液学杂志

To clarify the relationship between VLA-4 (CD49d) expression and hematopoietic cell migrating direction, mice were injected subcutaneously with diluted rhG-CSF for different times. The expressions of CD49d on Sca-1(+) cells were examined by flow cytometry. The relations between CD49d expression and Sca-1(+) cell enumerations were performed by statistical analysis. The results showed that with the administration of G-CSF, the expressions of CD49d in bone marrow (BM) and peripheral blood (PB) declined, meanwhile the number of Sca-1(+) cells in peripheral blood reached the peak in sharp contrast to BM nucleated cell number dropping on the seventh to ninth day. When CD49d expression rose again, the PB Sca-1(+) cells descended with the rising of BM nucleated cell number. In conclusion, VLA-4 mediates the hematopoietic cell adhesion to BM microenvironment. The regulation of CD49d expression may result in different migrating direction of hematopoietic cell between bone marrow and peripheral blood.

Restoring beta1 integrin activation function in K562 cells transfected with antisense VEGF121 cDNA / 中国实验血液学杂志

To investigate the effect of vascular endothelial growth factor (VEGF) on beta1 integrin (VLA-4 and VLA-5) activation ability in K562 cells transfected with antisense VEGF121 cDNA, K562 cells were transfected with antisense (As), sense (S) and vector (V, pcDNA(3)). Flow cytometry was used to evaluate the expression rate of VLA-4 (CD49d/CD29) and VLA-5 (CD49e/CD29) and beta1 integrin activation ability in the transfected K562 cells. The results showed that the expression rates of VLA-4 and VLA-5 were more than 92% in the transfected K562 cells and there was no difference among the K562/V, K562/S and K562/As cells. However, beta1 integrin activated 9EG7 expression rate in K562/As cells was higher than that in K562/V cells [(75.6 +/- 10.5)% vs (41.2 +/- 2.1)%, P < 0.01)] after activation with beta1 integrin activator 8A2. It is concluded that function of beta1 integrin to be activated is restored in K562 cells transfected with antisense VEGF121 cDNA.

Expression of EIIIA-fibronectin in injured rat skin used in estimation of wound interval / 法医学杂志

OBJECTIVE@#To observe the means of fibronectin(FN) alternative splicing and the expression of EIIIA-FN variant in rat skin after bruise, for the sake of providing some help for forensic estimation of wound interval.@*METHODS@#Total RNA was isolated from wounded skin, and reverse transcription polymerase chain reaction was conducted to amplify target segments.@*RESULTS@#Detectable EIIIA+(526 bp) segments, lacked in normal organize, was amplified at 1 h after experimental wound, and the levels were increased within 24 h.@*CONCLUSION@#The alternative splicing EIIIA-fibronectin variant would be a satisfied criterion for research of skin injury.

Stem cell factor enhances the adhesion of hematopoietic cells to fibronectin / 中国实验血液学杂志

Adhesion to extracellular matrix plays important roles in the regulation of survival, proliferation, differentiation and homing of hematopoietic cells and is regulated by a wide variety of growth factors, adhesion receptors and other ligands that mediate the cell to matrix and cell to cell interaction. Stem cell factor (SCF) plays important roles in the regulating growth and self-renewal of hematopoietic stem/progenitor cells. In the report, the effects of stem cell factor on the adhesion of hematopoietic cells to fibronectin were observed by using a hematopoietic growth factor dependent cell line-Mo7e. Results showed that Mo7e cells express the very late antigen VLA-4 (beta1 alpha4) and VLA-5 (beta1 alpha5) integrins. The expression of the SCF receptor (c-kit) was also detected in the Mo7e cells. SCF enhances the adhesion of Mo7e cells to fibronectin in a concentration dependent manner. SCF enhanced adhesion of Mo7e cells to fibronectin was blocked by anti-beta1, alpha4 and alpha5 antibodies. Addition of PI-3 kinase inhibitors also blocked the adhesion of Mo7e cells to fibronectin induced by SCF. It was concluded that SCF enhances the adhesion of Mo7e cells to fibronectin, and this process is mediated by integrins and PI-3 kinase pathway.

Effects of Short-Term Incubation of Hematopoietic Cells with Hematopoietic Growth Factors on CXCR4 Expression and Stromal Cell-Derived Factor-1-Mediated Transendothelial Migration / 대한혈액학회지

BACKGROUND: There has been contradictory reports regarding the homing potential of hematopoietic cells briefly exposed to hematopoietic growth factors in vitro. To get a resolution to this controversy, we investigated the effects of short-term growth factor treatment of hematopoietic cells on the expression of CXCR4 and adhesion molecules, and the chemotaxis in response to stromal cell-derived factor-1 (SDF-1), which is widely accepted to play a critical role in bone marrow (BM) homing of hematopoietic stem cells. METHODS: BM and cord blood(CB) CD34+ cells were incubated with various hematopoietic growth factors including IL-1beta, IL-3, IL-6, G-CSF, GM-CSF, stem cell factor (SCF), flk-2 ligand, and thrombopoietin, alone or in combination for up to 48 hours. Before and after the incubation, the expression of CXCR4 and adhesion molecules of CD34+ cells was analyzed using flow cytometry. SDF-1-mediated transmembrane or transendothelial migration of CD34+ cells, cobblestone area-forming cells (CAFCs), and/or long-term culture-initiating cells (LTC-ICs) was measured using Transwell(TM) system. RESULTS: VLA-4 was moderately up-regulated by the incubation of the cells with IL-3 and SCF, and ICAM-1 was slightly up-regulated by IL-1 and IL-3. The expression of L-selectin, PECAM-1 or LFA-1 was not altered by any growth factors. With the incubation of the cells in the absence of growth factors or SDF-1, CXCR4 expression of CD34+ cells was rapidly increased, reaching a plateau at 24 hours. The spontaneous up-regulation was abrogated with the addition of SDF-1. In agreement with the up-regulation of CXCR4, CD34+ cells incubated for 40 hours showed much enhanced chemotaxis in response to SDF-1 compared to non-incubated cells (24.7 3.5% vs. 7.0 1.6%, P=0.01). Any growth factors examined in this study did not alter the CXCR4 expression of CD34+ cells. Neither did growth factors affect the transendothelial migration of LTC-ICs toward bone marrow stromal cells as well as the SDF-1-induced transmembrane chemotaxis of CD34+ cells and CAFCs. CONCLUSION: Short-term treatment of hemo-topoietic cells with hematopoietic growth factors does not alter the expression of CXCR4 or SDF-1-mediated transendothelial chemotaxis.

Investigation of signal transduction pathways involved in melanoma cell spreading.

Integrins are a major family of heterodimeric adhesion receptors that are responsible for anchoring cells to extracellular matrix and they also can initiate intracellular signal pathways. Here parental and alpha 4-expressing human malignant melanoma cell lines were used to study the effect of protein kinase C (PKC), protein tyrosine kinases (PTKs) and intracellular Ca2+ on alpha 4 beta 1-mediated cell spreading on VCAM-1. Incubation of melanoma cells with PKC inhibitor inhibited alpha 4 beta 1-mediated melanoma cell spreading completely. Effect of intracellular Ca2+ on melanoma cell spreading was also investigated by non-phorbol ester tumor promotor, thapsigargin, which blocks the ability of the endoplasmic reticulum to replenish stocks of calcium which naturally leak out into the cytosol leading to a transient increase in concentration of intracellular calcium. The results showed that alpha 4 beta 1-mediated spreading was also required intracellular calcium involvement. However, in the presence of PTKs inhibitor melanoma cells showed long, thin dendiritic projections compared to control cells. Previously, data was obtained from immunofluorescense experiments showed that after genistein treatment, alpha 4-expressing cells exhibited considerable amounts of alpha 4 integrin and PTKs in both the focal contact points as well as over the whole cell. PTKs inhibitor did not have any effect on alpha 4-expressing cells spreading. This could be related to the amount of the PTKs present in these cells.

The Effect of Dexamethasone and Transforming Growth Factor-beta1 on the Cytokine Induced Expression of VCAM-1 in Glomerular Endothelial Cells / 대한신장학회잡지

Endothelial cell have been shown to play an active role in many phases of immunologic process, including binding of T lymphocytes, neutrophils, platelets, and monocytes to the endothelium, as well as phagocytosis. Endothelial cells can also serve as targets that undergo cell injury. The most prominent mediators of endothelial cell activation are IL-1beta and TNF-alpha. VLA-4 was first identified as an endothelial cell surface receptor. We performed the culture of endothelial cells derived from human glomerular capillaries and studied the cytokine-regulated expression of VCAM-1, and the effect of dexamethasone and TGF-beta on the cytokine induced VCAM-1 expression using ELISA method. Expression of VCAM-1 was not detectable above background level in the basal unstimulated state. However, VCAM-1 was rapidly induced after exposure to IL-1beta (5ng/ml) or TNF-alpha (1, 10ng/ml) (O.D.=1.76+/-0.15, 1.95+/-0.35, 1.88+/-0.17, mean+/-S.E., control=0.36+/-0.028, n=8-24, P<0.05). But IFN-gamma did not increase the expression of VCAM-1. Addition of dexamethasone (10 micrometer) and TGF-beta1 (1ng, 10ng/ml) blunted IL-1beta and TNF-alpha induced expression of VCAM-1. Therefore, VCAM-1 could be inducible in human glomerular endothelial cells, and it was regulated by dexamethasone and TGF-beta1. The negative findings in histopathology may reflect the transience of VCAM-1 expression and does not necessarily exclude an important role of this molecule in the early stages of renal disease.