NB-UVB辐射对HUVEC分泌sE-selectin及sICAM-1的影响

目的研究NB-UVB辐射对TNF-α刺激人脐静脉血管内皮细胞(HUVEC)表达可溶性E选择素(sE-se-lectin)及可溶性细胞间黏附分子(sICAM-1)的影响。方法体外培养人脐静脉血管内皮细胞(HU-VEC),将HUVEC接种于96孔塑料培养板,分为对照组,TNF-α组,TNF-α+NB-UVB60mJ/cm2剂量组,TNF-α+NB-UVB40mJ/cm2剂量组,TNF-α+NB-UVB20mJ/cm2剂量组。TNF-α刺激浓度为10ng/mL;NB-UVB高,中,低剂量组剂量分别为20,40,60mJ/cm2。采集上清,ELISA法检测可溶性E选择素(sE-selectin)和可溶性细胞间黏附分子1(sICAM-1)含量。结果 NB-UVB能剂量依赖性地抑制TNF-α刺激后HUVEC分泌sE-selectin和sICAM-1。结论 NB-UVB可能通过抑制血管内皮细胞表达黏附分子在治疗炎症性皮肤病中发挥免疫调节作用。     

Celecoxib modulates adhesion of HT29 colon cancer cells to vascular endothelial cells by inhibiting ICAM-1 and VCAM-1 expression

BACKGROUND AND PURPOSE: Cyclooxygenase-2 (COX-2) is highly expressed during inflammation and can promote the progression of colorectal cancer. Interactions between cancer cells and vascular endothelial cells are key events in this process. Recently, the selective COX-2 inhibitor, celecoxib, was shown to inhibit expression of the adhesion molecules, ICAM-1 and VCAM-1, in the human colon cancer cell line HT29 and to inhibit adhesion of HT29 cells to FCS-coated plastic wells. Here, we evaluated the effects of celecoxib on adhesion of HT29 cells to human umbilical vein endothelial cells (HUVEC), mediated by ICAM-1 and VCAM-1, to assess further the potential protective effects of celecoxib on cancer development. EXPERIMENTAL APPROACH: Celecoxib was incubated for 4 h with HT29 cells and HUVEC and adhesion was quantified by a computerized micro-imaging system. Expression analysis of ICAM-1 and VCAM-1 cell adhesion molecules was performed by western blot. KEY RESULTS: Celecoxib (1 nM-10 microM) inhibited, with the same potency, adhesion of HT29 cells to resting HUVEC or to HUVEC stimulated by tumour necrosis factor-alpha (TNF-alpha), mimicking inflammatory conditions. Analysis of ICAM-1 and VCAM-1 expression showed that celecoxib inhibited expression of both molecules in TNF-alpha-stimulated HUVEC, but not in resting HUVEC; inhibition was concentration-dependent and maximal (about 50%) at 10 microM celecoxib. CONCLUSIONS AND IMPLICATIONS: In conclusion, our data show that celecoxib inhibits HT29 cell adhesion to HUVEC and expression of ICAM-1 and VCAM-1, in stimulated endothelial cells. These effects may contribute to the chemopreventive activity of celecoxib in the development of colorectal cancer.     

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.     

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.     

Inhibition of tumor cell migration and metastasis by the proton-sensing GPR4 receptor

GPR4 is a member of the proton-sensing G protein-coupled receptor family. Within tumor microenvironments, the interstitial acidic pH may activate GPR4 to regulate the behavior of tumor cells. Mouse B16F10 melanoma cells and TRAMP-C1 prostate cancer cells, genetically engineered to overexpress GPR4 or the control vector, were subject to a series of cell migration, invasion and metastasis assays. Upon GPR4 overexpression and activation in an acidic pH, the migration of B16F10 and TRAMP-C1 cells was substantially inhibited in comparison to the vector control. Similar results were observed in the Matrigel invasion and transendothelial invasion assays. At the molecular level, stimulation of GPR4 by acidosis induced the activation of RhoA and the formation of actin stress fibers. In addition, treating B16F10 cells with the known Rho activator CN01 (calpeptin) strongly inhibited cell migration, recapitulating the acidosis/GPR4-induced motility inhibition phenotype. To examine the biological effects in vivo, B16F10 melanoma cells were intravenously injected into syngeneic C57BL/6 mice and pulmonary metastasis was inhibited by approximately 80% in GPR4-overexpressing B16F10 cells in comparison to the vector control. Upon treatment with the Rho activator CN01, the phenotype of the B16F10 vector cells paralleled that of the GPR4-overexpressing cells in cell migration and metastasis assays. These findings suggest that GPR4 activation by an acidic pH inhibits tumor cell migration and invasion, and the Rho GTPase is at least partly responsible for this phenotype.     

Cytoprotective role of astaxanthin against glycated protein/iron chelate‐induced toxicity in human umbilical vein endothelial cells

Astaxanthin (ASX), a red carotenoid pigment with no pro‐vitamin A activity, is a biological antioxidant that occurs naturally in a wide variety of plants, algae and seafoods. This study investigated whether ASX could inhibit glycated protein/iron chelate‐induced toxicity in human umbilical‐vein endothelial cells (HUVEC) by interfering with ROS generation in these cells. Glycated fetal bovine serum (GFBS) was prepared by incubating fetal bovine serum (FBS) with high‐concentration glucose. Stimulation of cultured HUVECs with 50 mm 1 mL of GFBS significantly enhanced lipid peroxidation and decreased antioxidant enzyme activities and levels of phase II enzymes. However, preincubation of the cultures with ASX resulted in a marked decrease in the level of lipid peroxide (LPO) and an increase in the levels of antioxidant enzymes in an ASX concentration‐dependent manner. These results demonstrate that ASX could inhibit LPO formation and enhance the antioxidant enzyme status in GFBS/iron chelate‐exposed endothelial cells by suppressing ROS generation, thereby limiting the effects of the AGE–RAGE interaction. The results indicate that ASX could have a beneficial role against glycated protein/iron chelate‐induced toxicity by preventing lipid and protein oxidation and increasing the activity of antioxidant enzymes. Copyright © 2009 John Wiley & Sons, Ltd.     

内皮细胞生长因子的分离纯化及生物活性的研究

介绍了内皮细胞生长因子(ECGF)一种分离纯化的方法,经硫酸铵分级盐析和肝素亲和层析可得到高纯度的ECGF。经SDS—PAGE电泳分析其分子量为17000,等电点为4.8。肝素与ECGF的生物活性密切相关,并可使已失活的(ECGF)恢复70%～80%的生物活性。