Localization of osteoblast inflammatory cytokines MCP-1 and VEGF to the matrix of the trabecula of the femur,a target area for metastatic breast cancer cell colonization

Bone likely provides a hospitable environment for cancer cells as suggested by their preferential localization to the skeleton. Previous work has shown that osteoblast-derived cytokines increased in the presence of metastatic breast cancer cells. Thus, we hypothesized that osteoblast-derived cytokines, in particular IL-6, MCP-1, and VEGF, would be localized to the bone metaphyses, an area to which breast cancer cells preferentially traffic. Human metastatic MDA-MB-231 breast cancer cells were inoculated into the left ventricle of the heart of athymic mice. Three to four weeks later, tumor localization within isolated femurs was examined using μCT and MRI. In addition, IL-6, MCP-1, and VEGF localization were assayed via immunohistochemistry. We found that MDA-MB-231 cells colonized trabecular bone, the area in which murine MCP-1 and VEGF were visualized in the bone matrix. In contrast, IL-6 was expressed by murine cells throughout the bone marrow. MDA-MB-231 cells produced VEGF, whose expression was not only associated with the breast cancer cells, but also increased with tumor growth. This is the first study to localize MCP-1, VEGF, and IL-6 in bone compartments via immunohistochemistry. These data suggest that metastatic cancer cells may co-opt bone cells into creating a niche facilitating cancer cell colonization.     

Expression and secretion of chemotactic cytokines IL-8 and MCP-1 by human endothelial cells after Rickettsia rickettsii infection: regulation by nuclear transcription factor NF-kappaB

Infection of endothelial cells (EC) with Rickettsia rickettsii results in Rocky Mountain spotted fever, an acute illness characterized by systemic inflammation. Interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) are important chemokines for activating neutrophils and monocytes, respectively, and recruiting these circulating immune cells to the sites of inflammation. In this study, we have measured the expression and secretion of these chemokines during R. rickettsii infection of cultured human EC. In comparison to uninfected controls, increased mRNA expression of IL-8 and MCP-1 in R. rickettsii-infected EC was evident as early as 3 h and was sustained up to 21 h. Subsequent analysis of culture supernatants revealed significantly enhanced secretion of both chemokines at 3, 8, and 18 h post-infection (5-28-fold increase in IL-8 and 4-16-fold increase in MCP-1). The presence of peptide-aldehyde compound MG132 to inhibit proteasome-mediated degradation of the inhibitory protein IkappaBalpha and synthetic peptide SN-50 to inhibit the nuclear translocation of nuclear factor-kappa B (NF-kappaB) resulted in significant inhibition of the chemokine response. Also, T24 cells expressing a super-repressor mutant of IkappaBalpha (to render NF-kappaB inactivatable) secreted significantly lower quantities of IL-8 than mock-transfected cells. A neutralizing antibody against IL-1alpha or an IL-1 specific receptor antagonist had no effect on the early phase of R. rickettsii-induced NF-kappaB activation and IL-8/ MCP-1 secretion at 3 h. Both of these treatments, however, diminished late-phase NF-kappaB activation by about 33% and only partially suppressed the infection-induced chemokine release at 21 h. Thus, while chemokine response early during the infection likely depends on the direct activation of NF-kappaB, subtle autocrine effects of newly synthesized IL-1alpha may contribute, in part, to the control of NF-kappaB activation and chemokine production at later times. These findings implicate a prominent role for host EC in recruiting immune cells to the site of inflammation during Rickettsia infection and provide important insights to further our understanding of the pathogenesis of spotted fever group rickettsioses.     

Growth factor regulation of neutrophil-endothelial cell interactions

The effects of the angiogenic factors basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) on human polymorphonuclear leukocyte (PMNL)-endothelial cell adhesion and transendothelial migration (TEM) were investigated. Stimulation of human umbilical vein endothelial cells by VEGF or bFGF for 18 h up-regulated intercellular adhesion molecule 1 and vascular cell adhesion molecule 1 expression and significantly increased PMNL adhesion and TEM in response to complement fragment 5a (C5a) or interleukin (IL)-8. In contrast, continued exposure to bFGF (24 h-6 days) down-regulated basal and IL-1- or tumor necrosis factor (TNF)-induced intercellular adhesion molecule 1, vascular cell adhesion molecule 1, and E-selectin expression as well as PMNL adhesion and TEM. These effects could be reversed by introduction of high concentrations of TNF-alpha, C5a, or IL-8. None of these inhibitory effects was observed with VEGF. The acute effects of bFGF and VEGF may facilitate PMNL emigration during acute inflammation, but continued bFGF production may have anti-inflammatory actions during chronic inflammation, angiogenesis, and tumor defense by inhibition of endothelial activation for leukocyte recruitment.     

Essential role for platelet-activating factor-induced NF-kappaB activation in macrophage-derived angiogenesis

Activated monocyte-macrophages have been implicated in tumor angiogenesis via their capacity to produce many potent angiogenic factors. However, the mechanisms leading to production of these angiogenic factors in macrophages remain to be elucidated. In this study, we demonstrated by use of a mouse Matrigel implantation model that mouse peritoneal macrophages induce angiogenesis. mRNA expression and protein synthesis of macrophage-derived crucial angiogenic factors such as IL-1, TNF-alpha, basic fibroblast growth factor, and vascular endothelial growth factor (VEGF) were blocked by platelet-activating factor (PAF) receptor antagonists. It was also observed that inhibitors of NF-kappaB blocked macrophage production of these angiogenic factors. Gene expression and protein synthesis of the angiogenic factors cited above were also inhibited in IkappaBalpha-mutated macrophages. VEGF is the most potent angiogenic factor in macrophage-induced angiogenesis. PAF antagonists or NF-kappaB inhibitors also inhibit the capacity of conditioned medium from LPS-stimulated human peripheral blood monocytes to induce sprouting of porcine pulmonary arterial endothelial cells. These data indicate that PAF-induced NF-kappaB activation is a common upstream pathway leading to the production of crucial macrophage-derived angiogenic factors. This will provide an important clue for a better understanding of mechanisms involved in tumor angiogenesis.     

The effect of interleukin-4 and amphiregulin on the proliferation of human airway smooth muscle cells and cytokine release

Airway smooth muscle (ASM) hyperplasia and angiogenesis are important features associated with airway remodeling. We investigated the effect of IL-4 and amphiregulin, an epidermal growth factor family member, on the proliferation of human ASM cells and on the release of vascular endothelial growth factor (VEGF) and monocyte chemotactic protein (MCP)-1 from human ASM cells. Human ASM cells were growth-arrested for 48 hr and incubated with platelet-derived growth factor (PDGF)- BB, interleukin (IL)-4, amphiregulin, and VEGF to evaluate cell proliferation. The cells were treated with PDGF, IL-4 and amphiregulin to evaluate the release of VEGF, MCP-1. IL-4 suppressed unstimulated and PDGF-stimulated ASM cell proliferation. Amphiregulin stimulated ASM cell proliferation in a dose-dependent manner. VEGF did not have any influence on ASM cell proliferation. IL-4 stimulated VEGF secretion by the ASM cells in a dose-dependent manner and showed added stimulatory effects when co-incubated with PDGF. Amphiregulin did not promote VEGF secretion. IL-4 and amphiregulin showed no stimulatory effects on MCP-1 secretion. The results of this study showed that IL-4 had bifunctional effects on airway remodeling, one was the suppression of the proliferation of the ASM cells and the other was the promotion of VEGF release by the ASM cells, and amphiregulin can promote human ASM cell proliferation.     

Toll-like receptor 2 ligand mediates the upregulation of angiogenic factor, vascular endothelial growth factor and interleukin-8/CXCL8 in human rheumatoid synovial fibroblasts

Rheumatoid arthritis (RA) is characterized by infiltrations of inflammatory cells accompanied by neovascularization in the joint. We hypothesized that cell activation via the toll-like receptor (TLR) may be involved in the induction of angiogenic molecules, which are relevant to the pathogenesis of RA. RA fibroblast like synoviocytes (FLS) were stimulated with TLR-2 ligand bacterial peptidoglycan (PGN), TLR-4 ligand lipopolysaccharide (LPS) and various cytokines. Vascular endothelial growth factor (VEGF) and IL-8 were measured by ELISA in culture supernatants; mRNA levels were assessed by RT-PCR and real time PCR. The levels of TLR-2, VEGF and IL-8 were analyzed by dual immunohistochemistry in RA synovium and compared with osteoarthritis (OA). Regulation of MyD88, IRAK4, IRAK1, IRAK-M and TRAF-6 mRNA expression levels by PGN were analyzed by RT-PCR. Phosphorylation of I kappa B alpha was evaluated by western blotting. Levels of VEGF and IL-8 were upregulated in culture supernatants of RA FLS stimulated with PGN, similar to the levels of IL-1beta and IL-17 stimulation. Neutralization of TLR-2 with a blocking monoclonal antibody significantly reduced both VEGF and IL-8 levels (P<0.05), which reflected the functional relevance of TLR-2 activation to the induction of VEGF and IL-8 production. Downstream intracellular signaling following TLR-2 stimulation involved MyD88-IRAK-4-TRAF-6 pathways, resulting in NF-kappaB activation. Thus, TLR-2 activation in RA FLS by microbial constituents could be involved in the induction of VEGF and IL-8 and thereby promote inflammation either directly or via angiogenesis. This possibly contributes to the perpetuation of synovitis in patients with RA.     

血管内皮细胞对骨髓基质细胞促成骨作用的研究

在骨组织工程研究中 ,因营养血管长入材料非常缓慢而影响材料深部的成骨作用一直是困扰科研人员的难题之一。骨髓基质细胞能分泌血管内皮生长因子 (VEGF) ,内皮细胞可以产生骨形态发生蛋白 (BMP) ,因此我们设想将骨髓基质细胞和内皮细胞联合种植在生物材料上构建组织工程化骨 ,则可能在促进成骨的同时 ,又促进局部血管生成 ,满足成骨过程的营养需要。在本实验中我们比较了内皮细胞培养液作用下的骨髓基质细胞、经诱导的骨髓基质细胞和未处理的骨髓基质细胞之间碱性磷酸酶 (AL P)活性和骨钙素 (OCN)分泌量的差别 ,结果表明内皮细胞培养液作用下的骨髓基质细胞和经诱导的骨髓基质细胞之间碱性磷酸酶活性和骨钙素分泌量无统计学差异 ,但均明显高于未处理的骨髓基质细胞 (P<0 .0 1) ,说明内皮细胞培养液中的分泌因子对骨髓基质细胞具有促成骨作用 ,可以达到和成骨诱导液相同的效果。     

Interleukin-31 induces cytokine and chemokine production from human bronchial epithelial cells through activation of mitogen-activated protein kinase signalling pathways: implications for the allergic response

Interleukin-31 (IL-31) is a novel T-helper-lymphocyte-derived cytokine that plays an important role in allergic skin inflammation and atopic dermatitis. It has recently been implicated in bronchial inflammation. We investigated the functions and mechanisms of IL-31-induced activation of human bronchial epithelial cells. The gene and protein expressions of candidate cytokines/chemokines from IL-31-stimulated human bronchial epithelial BEAS-2B cells were first quantified by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The activity of different mitogen-activated protein kinases (MAPKs) in IL-31-stimulated BEAS-2B cells was assessed by Western blot. The IL-31 could significantly elevate the gene and protein expressions of epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) and monocyte chemoattractant protein-1 (MCP-1/CCL2) of BEAS-2B cells in both time-dependently and dose-dependently. Combination of IL-31 with either IL-4 or IL-13 further enhanced VEGF and CCL2 production while IL-31 could synergistically augment the release of EGF, VEGF, CCL2, IL-6 and IL-8 in cocultures of BEAS-2B cells and eosinophils. In addition, IL-31 could activate p38 MAPK, extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) of BEAS-2B cells. Selective inhibitors of p38 MAPK (SB203580), ERK (PD98059), and JNK (SP600125) could differentially inhibit the production of EGF, VEGF and CCL2, thereby suggesting a role for MAPKs in IL-31 functions. In conclusion, the activation of MAPKs can be crucial for IL-31-mediated activation of bronchial epithelial cells, thereby providing an immunological role for IL-31 in bronchial inflammation, at least partly, via epithelial EGF, VEGF and CCL2 production.     

Interleukin-17 receptor expression on vascular endothelial cells of masses of skeletal extramedullary disease in myeloma patients

The goal of the study was to investigate the expression of interleukin-17 (IL-17) and IL-17 receptor (IL-17R) in patients with myeloma bone diseases (MBD) and skeletal extramedullary disease (skeletal EMD). The levels of IL-17 were determined using ELISA. The expression of IL-17R on vascular endothelial cells of bone marrow (BM) and masses of skeletal EMD was detected using immunohistochemistry. The results showed an elevated IL-17 level in BM of BMD and skeletal EMD patients. The microvessel density (MVD) was significantly increased in the masses of skeletal EMD. IL-17R was almost exclusively expressed by endothelial cells, not by myeloma cells in the masses of skeletal EMD patients. We concluded that EMD masses showed increased angiogenesis mediated by IL-17 pathway and in part this may help in myeloma cell-growth under these conditions.     

Identification of brain-derived neurotrophic factor as a novel angiogenic protein in multiple myeloma

Patients with multiple myeloma (MM) have increased bone marrow angiogenesis, but the angiogenic properties of myeloma cells and the mechanism of MM-induced angiogenesis have not been completely clarified. The brain-derived neurotrophic factor (BDNF) and its high-affinity receptor, TrkB, have been identified as critical factors in the regulation of vessel formation. In this study, we demonstrate that patients with MM had increased BDNF and vascular endothelial growth factor (VEGF) in their peripheral blood. We also found in particular that a decreased BDNF level was correlated with the remission of MM. BDNF was expressed by the human myeloma cell line RPMI8226 and primary myeloma cells, and TrkB was expressed by human umbilical vein endothelial cells (HUVEC) at the protein levels. In a coculture system, we observed that both RPMI8226 cells and primary myeloma cells induced the migration and formation of a net-like structure in HUVEC. The anti-BDNF monoclonal antibody significantly but partially restrained the angiogenesis effect of MM cells. Moreover, in an experimental model of angiogenesis in vivo, BDNF and VEGF significantly promoted vessel formation in Matrigel plug compared to the control. These effects were also blocked by anti-BDNF monoclonal antibody. Finally, our in vitro results were supported by the in vivo finding in human myeloma xenograft NOD/SCID models. Anti-BDNF mAb treatment resulted in inhibition of tumor growth, decreased vessel density, and tumor necrosis. Our study suggested that the BDNF/TrkB signaling pathway could be involved, at least in part, in MM-induced angiogenesis.     

LPS-induced MCP-1 expression in human microvascular endothelial cells is mediated by the tyrosine kinase, Pyk2 via the p38 MAPK/NF-kappaB-dependent pathway

Bacterial endotoxin (lipopolysaccharide or LPS) has potent pro-inflammatory properties and acts on many cell types including endothelial cells. Secretion of the CC chemokine, MCP-1 (CCL2) by LPS-activated endothelial cells contributes substantially to the pathogenesis of sepsis. However, the mechanism involved in LPS-induced MCP-1 production in endothelial cells is not well understood. Using human microvascular endothelial cells (HMVEC), we analyzed the involvement of the non-receptor tyrosine kinase, Pyk2, in LPS-mediated MCP-1 production. There was a marked activation of the non-receptor tyrosine kinase, Pyk2, in response to LPS. Inhibition of Pyk2 activity using a pharmacological inhibitor, Tyrphostin A9 significantly attenuated LPS-induced Pyk2 tyrosine phosphorylation, p38 MAP kinase (MAPK) activation, NF-kappaB activation, and MCP-1 expression. Furthermore, specific inactivation of Pyk2 activity by transducing microvascular endothelial cells with catalytically inactive Pyk2 mutant (AAV-Pyk2MT) or Pyk2-specific siRNA significantly blocked LPS-induced MCP-1 production. The supernatants of these LPS-stimulated cells with attenuated Pyk2 activity demonstrated decreased trans-endothelial monocyte migration in comparison to LPS-treated controls, thus confirming the inhibition of functional MCP-1 production. In summary, our data suggest a critical role for the Pyk2 mediated pathway involving p38 MAP kinase and NF-kappaB in LPS-induced MCP-1 production in human microvascular endothelial cells.     

Interleukin-17 augments tumor necrosis factor-alpha-induced elaboration of proangiogenic factors from fibroblasts

Interleukin-17 (IL-17) is a CD4 T cell cytokine. In this report, we investigated the effects of this cytokine on the elaboration of proangiogenic factors by lung fibroblasts. After stimulation with a wide range of doses of IL-17, fibroblasts produced more amount of various kinds of angiogenic factors including NO, HGF, MCP-1, KC, MIP-2, PGE1, PGE2 and VEGF in a dose-dependent manner. Treatment with a COX-1 and COX-2 inhibitor indomethacin did not impair IL-17-induced HGF and VEGF secretion in fibroblasts. In addition, TNF-alpha alone stimulated the elaboration of KC, MIP-2, PGE2 and VEGF in fibroblasts. IL-17 and TNF-alpha in combination up-regulated elaboration of these proangiogenic factors additively or synergistically. Moreover, conditioned media (CM) from IL-17-stimulated fibroblasts showed significantly higher activity on endothelial cell growth than those from non-treated control cells. These results indicate that IL-17 up-regulates elaboration of various proangiogenic factors, and modulates macrophage-derived TNF-alpha-induced production of KC, MIP-2, PGE2 and VEGF by fibroblasts. Our findings also demonstrate that IL-17 might be a potential contributor to the inflammatory angiogenesis via induction of proangiogenic factors by stromal fibroblasts.     

The effect of COX-2 inhibitor,nimesulide, on angiogenetic factors in primary endometrial carcinoma cell culture

Abstract Angiogenesis, the development of new blood vessels from preexisting capillaries, is essential for the development, growth and advancement of solid tumours. Angiogenesis is enhanced by prostaglandins (PGs) that are synthesised by the catalysis of cyclooxygenases (COX-1 and COX-2) from arachidonic acid. COX-2 is upregulated in a variety of malignancies and favours the growth of malignant cells by stimulating proliferation and angiogenesis. The aim of this study is to investigate the angiogenetic process by determining the levels of vascular endothelial growth factor (VEGF), monocyte chemoattractant protein (MCP)-1 and interleukin (IL)-8 in endometrial cancer cells and to study the effect of nimesulide, a selective COX-2 inhibitor, on these mediators using cell culture. Endometrial tissue specimens were obtained from subjects with endometrial cancer and intramural leiomyoma. Cells were incubated with either 10 or 50 μM nimesulide for 24 h. VEGF, MCP-1 and IL-8 concentrations were determined by sandwich quantitative enzyme immunoassay (ELISA). VEGF concentration was significantly higher in cancer cells than normal endometrial cells. VEGF was decreased with 10 μM nimesulide in cancer cells whereas it remained unaltered in normal cells. Both MCP-1 and IL-8 concentrations were lower in cancer cells than normal cells. MCP-1 levels were decreased with both doses of nimesulide in normal cells, whereas IL-8 levels were significantly affected only by 50 μM of nimesulide. These results suggest that COX-2 inhibitors may be effective in the treatment of endometrial cancer via suppression of angiogenesis.     

多发性骨髓瘤患者IL－1、IL－6测定及相关性研究

以ＥＬ４＋ＣＴＬＬ－２及７ＴＤ１细胞株增殖法分别检测ＩＬ－１和ＩＬ－６，发现多发性骨髓瘤患者ＰＢＭＣ及骨髓瘤细胞培养上清中ＩＬ－１与ＩＬ－６水平均高于正常对照，且ＩＬ－１和ＩＬ－６水平变化呈平行相关，基因重组ＩＬ－１α和β可剂量依赖性增强骨髓瘤细胞产生ＩＬ－６，提示ＩＬ－１可诱导人类多发性骨髓瘤细胞产生ＩＬ－６，进而刺激瘤细胞增殖。