Effects of C5a and FMLP on Interleukin-8 Production and Proliferation of Human Umbilical Vein Endothelial Cells

Interleukin-8 (IL-8), C5a and N-formyl-methionyl-leucyl-phenylalanine (fMLP) are chemotactic peptides with predominant effects on leukocytes during inflammation. With emphasis on C5a we studied the regulation of the production of IL-8 by human umbilical vein endothelial cells (HUVEC) in vitro. Primary HUVEC cultures were incubated with IL-1, TNF, C5a and fMLP for 24 h and 48 h prior to measurement of IL-8 in supernatants of the cells by an enzyme immunoassay. Whereas IL-1 and TNF significantly increased the levels of IL-8, C5a decreased the IL-8 production after 48 h. In addition, the ability of IL-1, TNF, C5a, fMLP and IL-8 to induce cell proliferation was compared by means of a ³H-thymidine incorporation assay. In contrast with IL-1 and TNF, both C5a and fMLP increased cell proliferation of HUVEC. This increase occurred with increasing concentrations of C5a contrary to IL-8, which showed increased cell proliferation at low, but not high IL-8 concentrations.     

Discovery of a novel COX-2 inhibitor as an orally potent anti-pyretic and anti-inflammatory drug: design, synthesis, and structure-activity relationship

Cyclooxygenase (COX) has been considered as a significant pharmacological target because of its pivotal roles in the prostaglandin biosynthesis and following cascades that lead to various (patho)physiological effects. Non-steroidal anti-inflammatory drugs (NSAIDs) that suppress COX activities have been used clinically for the treatment of fever, inflammation, and pain; however, nonselective COX inhibitors exhibit serious side-effects such as gastrointestinal damage because of their inhibitory activities against COX-1. Thus, COX-1 is constitutive and expressed ubiquitously and serves a housekeeping role, while COX-2 is inducible or upregulated by inflammatory/injury stimuli such as interleukin-1β, tumor necrosis factor-α, and lipopolysaccharide in macrophage, monocyte, synovial, liver, and lung, and is associated with prostaglandin E₂ and prostacyclin production that evokes or sustains systemic/peripheral inflammatory symptoms. Also, hypersensitivity of aspirin is a significant concern clinically. Hence, design, synthesis, and structure–activity relationship of [2-{[(4-substituted)-pyridin-2-yl]carbonyl}-(6- or 5-substituted)-1H-indol-3-yl]acetic acid analogues were investigated to discover novel acid-type COX-2 inhibitor as an orally potent new-class anti-pyretic and anti-inflammatory drug. As significant findings, compounds 1–3 demonstrated potent COX-2 inhibitory activities with high selectivities for COX-2 over COX-1 in human cells or whole-blood in vitro, and demonstrated orally potent anti-pyretic activity against lipopolysaccharide-induced systemic-inflammatory fever model in F344 rats. Also compound 1 demonstrated orally potent anti-inflammatory activity against edema formation and a suppressive effect against PGE₂ production in carrageenan-induced peripheral-inflammation model on the paw of SD rats. These results suggest that compounds 1–3 are potential agents for the treatment of inflammatory disease and are useful for further pharmacological COX-2 inhibitor investigations.     

RNA干扰技术下调CEACAMl基因表达对胶质瘤血管生成的影响

目的：利用RNA干扰技术下调胶质瘤细胞中癌胚抗原相关细胞黏附分子1（ CEACAM1）基因的表达情况,探讨胶质瘤细胞CEACAM1表达变化后其培养上清液诱导人脐静脉内皮细胞（ HUVEC）增殖、血管生成的情况及其可能机制。方法设计并化学合成针对CEACAM1的3对siRNA,脂质体法瞬时转染SHG44细胞,收集细胞培养上清液作为条件培养基。分别采用RT－PCR检测RNA干扰后细胞中CEACAM1及血管内皮生长因子（ VEGF） mRNA表达的变化情况,ELISA法检测上清液中VEGF蛋白的含量。 MTT比色法及Transwell侵袭实验检测共培养刺激后HUVEC增殖及迁移能力的变化,体外血管生成实验检测体外血管生成能力。结果与正常对照组和阴性对照组相比,转染CEACAM1－siRNA后胶质瘤细胞中CEACAM1 mRNA的表达水平下调（P＜0．01）,以CEACAM1－siRNA3组最为显著。 RNA干扰后SHG44细胞VEGF mRNA及上清液中的VEGF蛋白含量均减少,HUVEC的增殖受到抑制,迁移及体外血管生成能力下降。结论 CEACAM1－siRNA能够下调SHG44细胞中CEACAM1 mRNA的表达,并通过减少VEGF分泌,从而影响HUVEC的增殖、迁移和体外血管生成能力。     

Engineered peptides for the development of actively tumor targeted liposomal carriers of doxorubicin

Chemotherapy is still the treatment of choice for many types of cancer; but its effectiveness is hampered by dose limiting toxicity. Properly designed delivery systems can overcome this shortcoming by reducing the non-specific distribution and toxicity of chemotherapeutics in healthy organs and at the same time increasing drug concentrations at tumor tissue. In this study, we developed stealth liposomal formulations of doxorubicin (DOX) having a novel stable engineered peptide ligand, namely p18-4, that binds specifically to breast cancer cell line MDA-MB-435 on its surface. The coupling of p18-4 to liposomes was carried out through conventional, post insertion and post conjugation techniques and prepared liposomes were characterized for their size and level of peptide modification. The p18-4 decorated liposomal DOX formulations were then evaluated for their cellular uptake as well as cytotoxicity against the human breast cancer MDA-MB-435 cells. In this context, the effect of coupling technique on the uptake and cytotoxicity of p18-4 liposomal DOX in MDA-MB-435 cells was evaluated. The conventional and post conjugation methods of peptide incorporation were found to be more reliable for the preparation of p18-4 decorated liposomes for active DOX targeting to MDA-MB-435 cells. p18-4 decoration of liposomes by these methods did not have a notable effect on the size of prepared liposomes and DOX release, but increased the uptake and cytotoxicity of encapsulated DOX in MDA-MB-435 cells. The results show a potential for p18-4 decorated liposomes prepared by conventional and post conjugation method for tumor targeted delivery of DOX in breast tumor models.     

锰对人脐静脉内皮细胞及半胱天冬酶表达影响

目的探讨锰对人脐静脉内皮细胞系HUVEC-304细胞生长周期及半胱天冬酶-3（caspas-3）、半胱天冬酶-8（caspase-8）表达的影响。方法以100～800μmoml／L）的氯化锰分别处理HUVEC-304细胞24～72h后，四甲基偶氮噻唑蓝（MTT）法检测EVC-304细胞的生长活性；流式细胞仪（FCM）检测细胞凋亡情况；蛋白印迹法（Western blot）检捌HUVEC-304细胞在，氯化锰半数抑制浓度（IC50）400μmol／L作用24h时caspase．8、caspase-3的表达。结果氯化锰可呈时间及剂量依赖性抑制HUVEC-304细胞的增殖和诱导细胞凋亡，抑制率为22．34％～90．94％，凋亡率为10．20％～98．73％。氯化锰24hIC50约为400μmol／L，在此浓度下。HUVEC-304细胞caspase-8、caspase-3表达显著增高。（P〈0．05）。结论氯化锰能够抑制HUVEC-304细胞的增殖。星明显的时效和量效关系。caspase-8、cas-pase-3表达增高在细胞增殖和凋亡中起重要的作用，可能是其作用机制之一。     

中药独活及其单体蛇床子素体外抗血管生成的实验研究

目的：探讨独活醇提物及其单体蛇床子素对体外血管生成的抑制作用及其可能的机制.方法：采用MTT法观察中药独活醇提物及蛇床子素对人脐静脉血管内皮细胞（human umbilical vein endothelial cell.HUVEC）和人肠癌LoVo细胞增殖的影响,Transwell小室趋化实验、体外小管形成实验以及流式细胞术,观察并比较独活醇提物及蛇床子素对HUVEC迁移、小管形成、凋亡及周期的影响.结果：3.75-30μg/ml的独活醇提物及蛇床子素作用48h时对HUVEC的细胞增殖抑制率分别在5.16％-10.15％和22.64％-65.56％之间,对LoVo细胞增殖抑制率分别在2.86％-7.29％和5.15％-24.39％之间.体外小管及小管迁移实验显示,3.75-30μg/ml的蛇床子素作用24h时HUVEC小管形成数目减少,且管腔不完整.3.75-30μg/ml的独活醇提物和蛇床子素处理12h对HUVEC迁移抑制率分别在-2.16％至8.00％和13.70％至63.04％之间.3.75-30μg/ml的独活醇提物和蛇床子素诱导HUVEC细胞凋亡率分别在6.1％-14.4％和18.8％-89.5％之间.独活醇提物和蛇床子素作用HUVEC 24h后,使内皮细胞周期主要阻滞在G0-G1期,蛇床子素对细胞周期影响强于独活醇提物.结论：蛇床子素在体外抑制血管生成作用强于独活醇提物,说明蛇床子素可能是独活醇提物中发挥抗血管生成作用的主要成分,其作用机制可能与抑制HUVEC增殖、迁移和小管形成,诱导HUVEC凋亡,阻滞HUVEC细胞周期有关.     

Cyclopeptide RA-V inhibits angiogenesis by down-regulating ERK1/2 phosphorylation in HUVEC and HMEC-1 endothelial cells

BACKGROUND AND PURPOSE

Anti-angiogenic agents have recently become one of the major adjuvants for cancer therapy. A cyclopeptide, RA-V, has been shown to have anti-tumour activities. Its in vitro anti-angiogenic activities were evaluated in the present study, and the underlying mechanisms were also assessed.

EXPERIMENTAL APPROACH

Two endothelial cell lines, human umbilical vein endothelial cells (HUVEC) and human microvascular endothelial cells (HMEC-1), were used. The effects of RA-V on the proliferation, cell cycle phase distribution, migration, tube formation and adhesion were assessed. Western blots and real-time PCR were employed to examine the protein and mRNA expression of relevant molecules.

KEY RESULTS

RA-V inhibited HUVEC and HMEC-1 proliferation dose-dependently with IC₅₀ values of 1.42 and 4.0 nM respectively. RA-V inhibited migration and tube formation of endothelial cells as well as adhesion to extracellular matrix proteins. RA-V treatment down-regulated the protein and mRNA expression of matrix metalloproteinase-2. Regarding intracellular signal transduction, RA-V interfered with the activation of ERK1/2 in both cell lines. Furthermore, RA-V significantly decreased the phosphorylation of JNK in HUVEC whereas, in HMEC-1, p38 MAPK was decreased.

CONCLUSIONS AND IMPLICATIONS

RA-V exhibited anti-angiogenic activities in HUVEC and HMEC-1 cell lines with changes in function of these endothelial cells. The underlying mechanisms of action involved the ERK1/2 signalling pathway. However, RA-V may regulate different signalling pathways in different endothelial cells. These findings suggest that RA-V has the potential to be further developed as an anti-angiogenic agent.