Effect of TLR4 activation on endothelium adhesion function and atorvastatin intervention

AIM：To investigate the modulation of LOX-1 and monocyte-endothelium adhesion by TLR4 activation in human umbilical vein endothelial cells (HUVECs),and explore LOX-1’s role in mediating monocyte-endothelium adhesion,and the effect of atorvastatin.METHODS：TLR4 and LOX-1 mRNA were measured by RT-PCR.The expression percentage of TLR4 and LOX-1 positive cells were detected by flow cytometry.The adhesive percentage between monocytes and HUVECs were determined by counting.RESULTS：Incubation by LPS (1 mg/L) for 24 hours upregulated TLR4,LOX-1 mRNA and protein expression in HUVECs，and increased the percentage of monocyte adhesion to endothelium.Pretreatment of cell with anti-LOX-1 partly abolished the increase of monocyte adhesion to endothelium.Atorvastatin (10 μmol/L) inhibited LPS-mediated effects above.CONCLUSION：TLR4 activation upregulates LOX-1 expression and increases monocyte-endothelium adhesion.LOX-1 partly involves in LPS-induced monocyte-endothelium adhesion,atorvastatin may have protective effects on endothelium by inhibiting TLR4 and TLR4-induced LOX-1 expression.     

Effects of oxidized HDL on the levels of MCP-1, ICAM-1 and free calcium in cultured human umbilical venous endothelial cells

AIM:To study the effects of oxidized high-density lipoprotein (oxHDL) on the expression of monocyte chemoattractant protein-1(MCP-1) and intercellular adhesion molecule-1(ICAM-1) and intracellular free calcium concentration ([Ca²⁺]i) level in cultured human umbilical venous endothelial cells(HUVECs). METHODS:The MCP-1 protein content in the medium of conditioned HUVEC was measured by ELISA, and the ICAM-1 on HUVECs was detected by indirect immunofluorescence, and [Ca²⁺]i was determined by Fluo-3/AM, the injury of cells was observed by scanning electron microscopy (SEM).RESULTS:oxHDL could induce the expression of MCP-1 and ICAM-1 in HUVECs. In oxHDL group (HUVECs were incubated with 100 mg protein/L oxHDL for 24 h), the levels of MCP-1, ICAM-1 and [Ca²⁺]i increased by 160%, 60% and 70% respectively compared with the control group (P＜0.01). When HUVECs were incubated with 300 mg protein/L oxHDL for 24 h, cells were injured obviously. CONCLUSION:By inducing the expression of ICAM-1 and MCP-1 in endothelial cells, oxHDL may promote monocyte-endothelium adhesion and monocyte migration to intima, it may promote atherosclerosis as oxidized low-density lipoprotein (oxLDL).     

Effect of monocyte-secreted VEGF induced by electrical burn serum on monocyte-endothelial cell adhesion

AIM: To observe the level of vascular endothelial growth factor (VEGF) secreted by monocytes cultured with electrical burn serum, and to explore the effect of VEGF on monocyte-endothelial cell adhesion.METHODS: The electrical burn serum of the rat was prepared. The normal serum from the rats without treating electric current was also collected for control. The contents of VEGF and its soluble receptor sFlt-1 in electrical burn group were determined by double-antibody sandwich ELISA. THP-1 cells were randomly divided into normal serum group and electrical burn serum group. The contents of VEGF and sFlt-1 in the culture supernatants were measured by double-antibody sandwich ELISA. THP-1 cells were also randomly divided into another 4 groups:normal serum group, electrical burn serum group, normal serum+inhibitor group and electrical burn serum+inhibitor group. THP-1 cells, which were incubated with the serum for 3 h and 6 h, were labeled with calcein-AM and then were added into the well with monolayer of endothelial cell line EA.hy926 to detect monocyte-endothelial cell adhesion.RESULTS: The levels of serum VEGF of the rats with electrical burns were significantly increased, the levels of serum sFlt-1 were significantly decreased as compared with the controls. The levels of VEGF secreted by THP-1 cells cultured with electrical burn serum were significantly increased, the levels of sFlt-1 were decreased correspondingly. Electrical burn serum enhanced monocyte-endothelial cell adhesion, sFlt-1 inhibited the adhesion between monocytes and endothelial cells.CONCLUSION: The monocytes exposed to the electrical burn serum secrete VEGF, which enhance the adhesion between monocytes and endothelial cells. Blockage of VEGF activity may effectively inhibit monocyte-endothelial cell adhesion.     

CD36/Src/ERK pathway is involved in process of monocyte differentiation into macrophages

AIM To investigate the role of fatty acid translocase (FAT/CD36) on differentiation of monocytes to macrophages. METHODS Human monocyte THP-1 cells were treated with phorbol 12-myristate 13-acetate (PMA) at 0, 100 and 200 μg /L. Small interfering RNA (siRNA) targeting CD36 (siCD36) was employed to knock down the expression of CD36 in THP-1 cells. The CD36 over-expression (CD36OE) cell line was constructed by transfection with a recombinant lentivirus containing CD36 cDNA. Optical microscopy and crystal violet staining were used to detect the monocyte morphological changes and adhesion ability. The protein expression of CD36 was measured by flow cytometry and Western blot. The mRNA levels of CD36, CD11b and CD80 were detected by real-time PCR. The protein levels of extracellular signal-regulated kinase (ERK） and Src tyrosine kinase were determined by Western blot. RESULTS The cellular adhesiveness of THP-1 cells was elevated in the process of monocytes differentiation, and the expression of CD36 was increased in this process as well (P<0.01). siCD36 was transfected into the THP-1 cells (CD36i group) and the silencing efficiency was approximately 80%. The cell surface area and cellular adhesiveness were significantly decreased in CD36i group compared with scrambled siRNA (NCi) group (P<0.01). The mRNA levels of CD11b and CD80 were decreased in CD36i group compared with NCi group (P<0.01). The cell surface area and cellular adhesiveness were increased in CD36OE group compared with empty vector (vector) group (P<0.05). The mRNA levels of CD11b and CD80 were increased in CD36OE group compared with vector group (P<0.01). The phosphorylation levels of ERK and Src were decreased in CD36i group compared with NCi group (P<0.05). CONCLUSION CD36 promotes the differentiation of human monocyte THP-1 cells to macrophages by increasing the phosphorylation of Src and further activating ERK.     

Effects of the Bushen Ningxin Chinese herb-containing serum on the adherence of human monocytes to endothelial cells

AIM: To study effect of the Bushen Ningxin decoction, a Chinese medicine, on the adherence of monocytes to endothelial cells and its mechanism. METHODS: Using cultured human umbilical vein endothelial cells (HUVECs) as target cells, oxidized low density lipoprotein (ox-LDL) was added to the endothelial cell culture to prepare the model of human endothelial cell injury. The serum of rabbits having been treated with Bushen Ningxin decoction was added to trial architecture, the adherence of monocyte-like cell line U937 to HUVECs was analyzed using Rose Bengal staining. In addition, the expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1(VCAM-1) and E-selectin in HUVECs was measured by flow cytometry. RESULTS: Treatment of HUVEC with ox-LDL (100 mg/L) for 24 hours significantly increased adhesion of U937 to HUVECs. If serum of the animal treated with Bushen Ningxin decoction was added to trial architecture, the adhesion decreased significantly. The flow cytometry analysis showed that ox-LDL could induce the expression of ICAM-1, VCAM-1 and E-selectin in HUVECs. Serum of the animal treated with Bushen Ningxin decoction significantly decreased the expression of ICAM-1, VCAM-1 and E-selectin in HUVECs. CONCLUSION: The Bushen Ningxin Chinese herb-containing serum has an inhibitory effect on the adherence of monocytes to endothelial cells, probably by way of down-regulating the expression of ICAM-1, VCAM-1 and E -selectin in endothelial cells.     

Effect of 4.25% peritoneal dialysis solution on CD40 expression in rat peritoneal mesothelial cells

AIM:To investigate the effect of 4.25%peritoneal dialysis solution (PDS) on CD40 expression in rat peritoneal mesothelial cells so as to reveal the potential mechanisms by which CD40-CD40 ligand (CD40L) interaction may be involved in the inflammation of peritoneal membrane. METHODS:Rat peritoneal mesothelial cells (MC) were harvested from the peritoneal cavity and maintained under defined in vitro conditions. Expression of CD40 on MC under normal culture or stimulation with 4.25%PDS or 4.25%PDS+IFN-γ was detected by RT-PCR and FACS analyses. After activation of CD40 on MC with CD40 mAb, the expression of intercellular adhesion molecule-1 (ICAM-1) on MC was analyzed by FCAS. RESULTS:MC cultured in vitro expressed CD40 constitutively. 4.25%PDS markedly up-regulated the expression of CD40 mRNA and its protein. The expression of CD40 mRNA and its protein following stimulation with 4.25%PDS+IFN-γ was significantly higher than 4.25%PDS alone. The expression of ICAM-1 on MC was significantly increased after activation of CD40 with CD40mAb.CONCLUSIONS: MC functionally express CD40.The up-regulated CD40 expression on MC fol owing stimulation with 4.25%PDS may play an important role in local peritoneal defense mechanisms and may be involved in the chronic inflammatory process of the peritoneum.     

Biological characteristics of primarily cultured microvascular endothelial cells in mouse myocardium

AIM：To investigate an effective and stable method to isolate myocardial microvascular endothelial cells (MMVECs) from the mouse heart and to observe their biological characteristics.METHODS：The cells from the mouse heart were isolated by collagenase II digestion followed by different speed adhesion. Then the cells were cultured on the dish coated with polylysine in endothelial cell-specific culture medium. The biological characteristics were observed by trypan blue staining. The cell growth curve and the cell proliferation were also evaluated by MTT assay at different passages. The expression of DiI-ac-LDL, FITC-UEA-1, specific markers of endothelial cells and the expression of CD31, vWF and CD34 were determined by immunofluoresence staining. To evaluate the function of the MMVECs, in vitro tube formation was evaluated under microscope.RESULTS：Two days after the enzyme digestion, the MMVECs formed small and isolated clusters. The MMVECs grew quickly in monolayer with the characteristics of endothelial cell shape at 4~5 d. The cells became confluent and cobblestone-like which were ready for passage at 7~8 d. After passage, the viability of the cells was more than 95%. The first and the third generation of the cells presented an S-shape growth curve. The cell proliferation of the first to the third generation was quick and slowed down after the fifth passage. MMVECs were highly positive for DiI-ac-LDL and FITC-UEA-1 ［(89.2±3.5)%］, indicating the cells were MMVECs. The other relative antigen expression (CD31, vWF and CD34) on the MMVECs was (56.7±3.7)%, (78.5±2.6)% and (67.8±4.2)%, respectively. The MMVECs formed the tubes in vitro after cultured for 6～12 h.CONCLUSION：We can obtain high-purity MMVECs using the combination of collagenase II digestion, the different speed adhesion process and the endothelial cell-specific culture medium for effective and reliable MMVECs isolation and culture.     

Study on the culture of rat myocardium microvascular endothelial cells and microarray analysis

AIM: To study the cytological characteristics of rat myocardium microvascular endothelial cells (RMMVEC) by microarray. METHODS: The RMMVEC were cultured by the method of planting myocardium tissue. The morphology of RMMVEC was studied by light and electronic microscopy. Its molecular markers were observed by immunocytochemistry. Cell proliferation kinetic was analyzed by counting the number of cells. The gene expression of the RMMVEC was studied by endothelial cell biology gene microarray and compared the change of gene expression among the cultured cells of primary, 2nd and 5th passage. RESULTS: The RMMVEC showed morphological characteristics of microvascular endothelial cells (MVEC): growing in a cobblestone pattern, forming tube-like structure or capillary network and having microvilli on cell surface. At the same time, the RMMVEC showed positive staining for vWF, CD34, CD31, CD105 and Tie-2. Gene microarray analysis indicated expression of VEGFR, ICAM-1, VCAM-1, angiopoietin1, PECAM1 (CD31) and other genes closely related to microvascular endothelial functions at relatively high level. But in cultured cells of 5th passage the characteristic gene expression of microvascular endothelial cells disappeared. CONCLUSION: The RMMVEC cultured by this method possess typical characteristics of MVEC. The cytological characteristics are steady in the cultured cells of primary and 2nd passage. It can be utilized to study the mechanisms of some cardiovascular diseases.     

Isolation of endothelial progenitor cells from cord blood with CD133 immunomagnetic sorting

AIM: To isolate, purify and differentiate endothelial progenitor cells from cord blood in vitro and to study their biological characteristics. METHODS: CD133+ cells were selected from fresh cord blood mononuclear cells (MNC) by magnetic activated cell-sorting system (MACS). EPC was studied by flow cytometry, immunocytochemistry and immunofluorescence staining. Isolated cells were cultured in IMDM medium supplemented with or without VEGF, bFGF, SCF. RESULTS: The percentage of CD133+ cells of cord blood MNC was (1.41±1.14)%, and purity was 75%-85% (FACS method). CD133+ cells were grown on fibronectin-coated chamber slides in the presence of VEGF, bFGF, SCF. Within 1-2 hours of culture cells became adherent. On day 7-10, the adherent cells displayed a typical “cobblestone” morphology. After 14 days of culture, the adherent cells revealed a heterogeneous cell population, comprising small-sized round cells, spindle-like cells and formed tube-like structure. Weibel-Palade bodies were shown on the transmission electron microscopy photomicrographs. Compared with the original, cell markers CD133 and CD34 decreased significantly (77.0%±3.3% to 1.6%±2.2% and 93.1%±4.7% to 37.4%±4.9%, P<0.05), while Flk-1 increased significantly (from 22.3%±3.3% to 94.3%±4.1%, P<0.05) after 14 days of culture with VEGF, bFGF, SCF. The vWF was strongly expressed (77.9%±3.3%) on the 14th day later. CONCLUSION: Vascular endothelial progenitor cells were isolated from cord blood with specific expression of CD133/CD34/Flk-1. With the stimulation of the growth factors, seven-ten days after culture EPCs could be turned to endothelial cells.     

Effect of basic fibroblast growth factor on synthesis of C-type natriuretic peptide in cultured human umbilical vein endothelial cells

AIM: To investigate the effect of basic fibroblast growth factor (bFGF) on C-type natriuretic peptide (CNP) production, release and mRNA expression. METHODS: Human endothelial cell cultured;CNP was mea sured by radioimmunoassay method;CNP mRNA expression was determined by RT-PCR technique.RESULTS: bFGF could augment CNP synthesis in human endothelial cells. Compared with control group,25 ng, 50 ng, 100 ng bFGF increased CNP contents in endothelial cells by 88% (P＜0.05), 95% (P＜0.05), 187% (P＜0.01), respectively.100 ng bFGF also stimulated CNP release from cultured human endothelial cell. In addition, 25 ng, 50 ng and 100 ng bFGF stimulated CNP mRNA expression of cultured human endothelial cells in a dose-dependent manner. CONCLUSION: bFGF might regulate CNP synthesis,release and mRNA expression in cultured umbilical human endothelial cells.     

Palmitate triggers inflammatory response by upregulating fatty acid translocase in THP-1 macrophages

AIM: To investigate the role of fatty acid translocase (FAT/CD36) on palmitate-induced inflammation in human monocyte-derived macrophage THP-1.METHODS: THP-1 cells were treated with palmitate (0, 0.1 and 0.2 mmol/L) for 24 h. Transwell chamber assay was used to examine the migration ability of THP-1 cells. The mRNA expression of CD36, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and monocyte chemotactic protein 1 (MCP-1) was measured by real-time PCR. The protein levels of TNF-α and IL-6 in the supernatant of cultured cells were measured by ELISA. The protein level of CD36 was examined by Western blot. Small interfering RNA (siRNA) targeting CD36 (siCD36) was used to inhibit the expression of CD36 in the THP-1 cells, and the changes of the cell migration and inflammatory response were monitored as mentioned above. RESULTS: Palmitate increased the expression of CD36 in the THP-1 cells (P<0.05). Palmitate also up-regulated inflammatory cytokine and chemokine levels, and the differences were statistically significant (P<0.05). Compared with control group, palmitate promoted migration of THP-1 cells. siCD36 was transfected into the THP-1 cells and the silencing efficiency was approximately 54%. The protein levels of TNF-α and IL-6 were also decreased in siCD36 group compared with scrambled RNA (scrRNA) group, and the differences were statistically significant (P<0.05). The migrated cells in siCD36 group were significantly less than those in scrRNA group (P<0.05).CONCLUSION: Palmitate promotes migration ability and triggers inflammatory response in the THP-1 macrophages by upregulating CD36 expression.     

Hypoxia upregulates CD73 expression in mouse microvascular endothelial cells

AIM: To study the effect of hypoxia on CD73 expression in mouse microvascular endothelial cell line bEnd.3. METHODS: ① bEnd.3 cells were exposed to different periods of hypoxia. ② Concentration of LDH released by bEnd.3 cells into the culture medium was detected. ③ Surface CD73 activity in bEnd.3 cells was measured by HPLC according to the conversion of E-AMP to E-ADO. ④ CD73 mRNA expression were analyzed by semiquantitative RT-PCR. ⑤ Cell surface proteins were biotinylated and CD73 was detected by avidin blots of immunoprecipitation with mAb TY23. RESULTS: ① bEnd.3 cells exposed to hypoxia for 24 h demonstrated a significant increase in LDH release (P<0.01). ②Hypoxia induced CD73 activity in bEnd.3 cells in a time-dependent manner. ③ CD73 mRNA expression increased markedly in hypoxia for 4 h and 8 h (P<0.05). ④ bEnd.3 cells exposured to hypoxia induced a time-dependent increase in expression of CD73 (P<0.05). CONCLUSION: Hypoxia induces CD73 mRNA, protein expression and increases CD73 activity in mouse microvascular endothelial cells.     

Mixed culture of human iPSCs with rabbit corneal endothelial cells induces differentiation of iPSCs

AIM:To investigate the morphology and protein expression of human induced pluripotent stem cells(iPSCs) in the mixed-culture environment with rabbit corneal endothelial cells(CECs) and to provide the experimental basis and the mechanism of iPSC differentiation into CECs. METHODS:Primary rabbit CECs were isolated with trypsin and subcultured. The human iPSCs were cultured and amplified by a feeder-free method and their characteristics were evaluated by Western blotting. iPSCs labeled with quantum dots of appropriate concentration were used to establish mixed-culture model with rabbit CECs. The morphology of iPSCs was evaluated by atomic force microscopy(AFM) and inverted microscopy. The protein expression of CD31, CD34, CD133 and aquaporin 1(AQP1) in iPSCs was tested by the method of immunofluorescence. RESULTS:The rabbit CECs were hexagonal and showed a typical cobblestone appearance. iPSCs grew in the cloning form, and 3 pluripotent proteins Oct4, Nanog and Sox2 were expressed positively. 1/4 suspension of iPSCs labeled with 10 nmol/L quantum dots and 60% confluence of rabbit CECs made best mixed culture for each other. Under AFM and inverted microscope, the volume of iPSC became bigger and the nuclear-cytoplasm ratio was decreased after 7 days of mixed culture. Some granular protrusions of the membrane were observed and the surface roughness of the cell membrane increased. The protein expression of CD31, CD34, CD133 and AQP1 in iPSCs was negative, while AQP1 was detected after mixed culture for 2 weeks. CONCLUSION:iPSCs morphologically change to endothelial-like cells after mixed culture with rabbit CECs and express the marker protein AQP1 of CECs at the same time.     

Cytological characteristics and gene micro-array analysis of a mouse brain microvascular endothelial cell strain: bEnd.3

AIM: To study the cytological characteristics and gene expression of normal cultured bEnd.3, a mouse brain microvascular endothelial cell strain. METHODS: The morphology of bEnd.3 was studied by light and electronic microscopy, its molecular markers were observed by immunocytochemistry. Cell proliferation kinetics and apoptosis were analyzed by flow cytometry and MTT assay, PGE₂ level was measured by ELISA, and expression of the genes that closely related with vascular endothelial functions was studied by gene micro-array. RESULTS: bEnd.3 had morphological characteristics of microvascular endothelial cells (MVEC) growing in a cobblestone pattern, forming tube-like structure or capillary network and having microvilli. Furthermore, bEnd.3 showed positive staining for vW factor and CD34 and secreted high level of PGE₂ (644.55±30.24 ng/L). Gene micro-array analysis showed CD31, CD36, CD105 expression, and other genes closely related to microvascular endothelial functions also expressed at relatively high level. In addition, bEnd.3 responsed sensitively to mitogen such as basic fibroblast growth factor. CONCLUSION: bEnd.3 is a kind of MVEC, and it can be utilized to study the mechanisms of some diseases such as cancers and cardio- cerebral vascular diseases.     

Effects of oxidized high-density lipoprotein on membrane fluidity and the expression of lymphocyte function associated antigen-1 of monocyte

AIM: To investigate the effects of oxidized high-density lipoprotein (oxHDL) on membrane fluidity and the expression of lymphocyte function associated antigen(LFA-1) of monocyte. METHODS: The membrane fluidity of THP-1 cells was assayed by fluorescence anisotropy with DPH (1,6-dipheny-1,3,5-hexatriene), a fluorescent probe; The LFA-1 expression on THP-1 cells were assayed by flow cytometry with indirect immunofluorescence.RESULTS: The membrane fluidity of THP-1 cells was reduced by 45% and 52% respectively (P＜0.01) after incubation with 100 μg protein/mL oxHDL and oxLDL for 20 h; oxHDL could stimulated the expression of LFA-1 on THP-1 cells, the positive cell rate and mean fluoresence intensity (MFI) increased by 39% and 45% respectively versus control group (P＜0.01) after incubation with cells for 24 h. CONCLUSIONS: By increasing the expression of LFA-1 on monocyte, oxHDL can promote the monocyte-endothelium adhesion; oxHDL also can reduce the membrane fluidity of monocyte, that will limit the returning of monocytes from subendothelium back to the circulation. This suggested that oxHDL may play an important role in atherogenesis.     

Effects of eicosapentaenoic acid on expression of nuclear factor κB and release of cytokines in human umbilical vein endothelial cells stimulated by lipopolysaccharide

AIM: To investigate the effects of eicosapentaenoic acid(EPA) on the expression of nuclear factor kappa B(NF-κB) and release of vascular endothelial growth factor(VEGF), IL-1α and IL-6 in cultured human umbilical vein endothelial cells(HUVECs) stimulated by lipopolysaccharide(LPS).METHODS: HUVECs were obtained from cell strain and cultured in vitro. HUVECs were divided into 4 groups: control group, LPS group, 0.030 g/L EPA treatment group and 0.050 g/L EPA treatment group. The cells were cultured with LPS alone in LPS group and incubated with EPA for 1 h in the EPA pretreatment groups at the concentrations of 0.030 g/L and 0.050 g/L before LPS stimulation. Twenty-four hours after stimulated by LPS, the protein expression of NF-κB p65 in HUVECs were assessed by Western blotting analysis at different time points. The production of VEGF, IL-1α and IL-6 in cultured HUVECs was evaluated by ELISA. The effects of EPA on the protein expression of NF-κB p65 and the production of VEGF, IL-1α and IL-6 in HUVECs challenged by LPS were also determined.RESULTS: Compared with control group, the protein expression of NF-κB p65 was significantly increased in HUVECs induced by LPS and was inhibited by EPA. Compared with control group, the protein expression of VEGF, IL-1α and IL-6 was dramatically increased in HUVECs induced by LPS and most of the increase was inhibited by EPA.CONCLUSION: LPS enhances the protein expression of NF-κB and the release of VEGF, IL-1α and IL-6. EPA inhibits the protein expression of NF-κB, and the production of VEGF and the inflammatory cytokines in cultured HUVECs stimulated by LPS, indicating that EPA may be useful for preventing and treating neovascular and inflammatory diseases.     

Effect of mininally modified low density lipoprotein on the adhesive function of vascular endothelial cell and its mechanism

AIM: To observe the effect of MM-LDL (minimally modified LDL) on the interaction between human umbilical vein endothelial cell (HUVEC) and U937 monocyte-like cell line and the exporession of vascular cell adhesion-1 (VCAM-1), intercellular adhesion molecule-1(ICAM-1), P-selectin.METHODS:The adhesive percentage between HUVEC treated with MM-LDL and U937 was determined by counting and the expression of VCAM-1, ICAM-1, P-selectin were examined by ELISA. RESULTS: Treatment of HUVEC with MM-LDL (75 mg/L) for 4 hours significantly increased adhesion of U937 to HUVEC ( P <0.01) and did not induce the surface expression of VCAM-1, ICAM-1, P-selectin . Recombination tumor necrosis factor-alpha (rTNF_α) 5.0 μg/L, as a positive control, induced the expression of these adhesion molecules ( P <0.05). Prolonged (18 h) exposure to MM-LDL resulted in the expression of P-selectin, but not VCAM-1.CONCLUSION: the adhesion of monocytes to endothelial cells induced by MM-LDL is not mediated by VCAM-1, ICAM-1. P-selectin induction may be partly involved in the process.