New cell-cell adhesion inhibitors from Streptomyces sp. UMA-044

Three compounds, NP25301 (1), NP25302 (2) and bohemamine (3), inhibitors of cell adhesion based on LFA-1/ICAM-1, were isolated from the cultured broth of the strain Streptomyces sp. UMA-044. New compounds 1 and 2 were identified as 2-(3'-carbamoylphenoxy)acrylic acid methyl ester and deoxybohemamine, respectively, based on spectroscopic analyses. Compounds 1 approximately 3 inhibited adhesion of HL-60 cells to CHO-ICAM-1 cells at IC50 values of 29.5 microg/ml for 1, 24.3 microg/ml for 2, and 27.2 microg/ml for 3.     

Inhibitory effects of manassantin A and B isolated from the roots of Saururus chinensis on PMA-induced ICAM-1 expression

Cell adhesion inhibitors were isolated from the methanol extract of Saururus chinensis roots by bioactivity-guided fractionation. The active compounds were identified as manassantin A ( 1) and B ( 2), dineolignan compounds. Compounds 1 and 2 inhibited PMA-induced ICAM-1/LFA-1-mediated homotypic aggregation of the HL-60 cells without cytotoxicity with MIC values of 1.0 and 5.5 nM, respectively. Even though 1 and 2 did not affect the adhesion of ICAM-1 to LFA-1, these compounds inhibited PMA-induced ICAM-1 expression in HL-60 cells in a dose-dependent fashion. These results suggest that 1 and 2 inhibit cell aggregation through down-regulation of ICAM-1 expression.     

Tyropeptins A and B, new proteasome inhibitors produced by Kitasatospora sp. MK993-dF2. I. Taxonomy, isolation, physico-chemical properties and biological activities

Tyropeptins A and B, new proteasome inhibitors, were isolated from the culture broth of Kitasatospora sp. MK993-dF2. They were purified using ethyl acetate extraction, silica gel column chromatography, Sephadex LH-20 column chromatography and HPLC. Tyropeptin A inhibited the chymotrypsin-like (ChT-L) and trypsin-like (T-L) activities of 20S proteasome with IC50 values of 0.1 microg/ml and 1.5 microg/ml respectively, but did not inhibit the peptidylglutamyl-peptide hydrolyzing (PGPH) activity of 20S proteasome at a concentration of 100 microg/ml. The inhibitory activities of tyropeptin A were about two times as strong as that of tyropeptin B. Taxonomy of the producing strain is also described.     

The inhibition of neutrophil-endothelial cell adhesion by hyaluronan independent of CD44

Objective: To study the effect of hyaluronan on cell adhesion and recruitment both in vitro and in vivo, since hyaluronan both inhibits restenosis and is anti-inflammatory. When administered to animals undergoing angioplasty the recruitment of cells into the restenotic plaque is inhibited, as well as into inflammatory lesions. The recent discovery that ICAM-1 binds hyaluronan and exhibits the B(X(7))B HA binding motif, led us also to investigate whether cell adhesion could be modulated by hyaluronan. Materials and methods: Human neutrophils were adhered to human umbilical vein (HUVEC) or Ea.hy.926 HUVEC cells stimulated with phorbol myristate acetate (PMA) or tumour necrosis factor (TNFα). Neutrophil binding in vivo utilized FMLP-stimulated hamster cheek pouch post-capillary venules. Results: Hyaluronan inhibited human neutrophil adhesion to both PMA and TNFα-stimulated HUVEC. Ea.hy.926 human immortal HUVECs expressed ICAM-1 in response to TNFα and PMA. E-selectin was also upregulated by 6 h with TNFα but not significantly with PMA. TNFα induced CD44 expression within 4 h, but PMA not significantly up to 6 h. However, specific binding of [¹²⁵I]hyaluronan to Ea.hy.926 cells was increased by PMA-stimulation at 4 h. Neutrophil adhesion to PMA-stimulated Ea.hy.926 HUVECs was inhibited in a concentration dependent fashion by both anti-ICAM-1 and hyaluronan (1 ng/ml-10 μg/ml) at 4 h. At 1 mg/ml adhesion was stimulated by hyaluronan. Hyaluronan had no effect on neutrophil adhesion to resting Ea.hy.926 cells. Hyaluronan (25 mg/kg, i.v.) inhibited cell adhesion to FMLP-stimulated post capillary venules of the hamster cheek pouch, whilst leaving cell rolling unaffected. Conclusions: These results show that hyaluronan, at concentrations below those where intramolecular associations occur, binds selectively to stimulated endothelial cells and inhibits neutrophil adhesion in vitro and in vivo via a mechanism which may involve molecules other than CD44, such as ICAM-1. Deceased.     

Withaferin A inhibits tumor necrosis factor-α-induced expression of cell adhesion molecules by inactivation of Akt and NF-κB in human pulmonary epithelial cells

We here investigated the functional effect of withaferin A on airway inflammation and its action mechanism. Withaferin A inhibited the expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in human lung epithelial A549 cells stimulated with tumor necrosis factor-α (TNF-α), resulting in the suppression of leukocyte adhesion to lung epithelial A549 cells. In addition, withaferin A inhibited TNF-α-induced expression of adhesion molecules (ICAM-1 and VCAM-1) protein and mRNA in a dose-dependent manner. Withaferin A prevented DNA binding activity of nuclear factor-κB (NF-κB) and nuclear translocation of NF-κB. It also inhibited phosphorylation of Akt and extracellular signal-regulated kinase (ERK), which are upstream in the regulation of adhesion molecules by TNF-α. Furthermore, withaferin A inhibited U937 monocyte adhesion to A549 cells stimulated by TNF-α, suggesting that it may inhibit the binding of these cells by regulating the expression of critical adhesion molecules by TNF-α. Taken together, these results suggest that withaferin A inhibits cell adhesion through inhibition of ICAM-1 and VCAM-1 expression, at least in part, by blocking Akt and down-regulating NF-κB activity.     

Secondary metabolites from marine cyanobacteria and algae inhibit LFA-1/ICAM-1 mediated cell adhesion

An assay for inhibitors of LFA-1/ICAM-1 mediated cell-cell adhesion has been employed to identify new pharmacologically active compounds from marine cyanobacteria and algae. From a panel of sixty unusual marine natural products, seventeen compounds inhibited LFA-1/ICAM-1-based cell aggregation without showing significant cytotoxicity in the primary assay. Six compounds inhibited the cell-cell adhesion of HL-60 cells to CHO-ICAM-1 cells. The unusual oxylipin Cymathere aldehyde methyl ester (IC (50) 3.5 microM), cyanobacterial lipopeptides microcolins B (IC (50) 0.15 microM) and D (IC (50) 0.9 microM), bromophenol avrainvilleol (IC (50) 2.2 microM), sesquiterpene cymopol (IC (50) 2.7 microM), and cryptophyte derived compound styrylchromone hormothamnione diacetate (IC (50) 1.5 microM) significantly inhibited LFA-1/ICAM-1 mediated cell adhesion. The pharmacological activity and structure-activity relationships of selected marine algal metabolites are described. Abbreviations. LFA-1:Lymphocyte function-associated molecule-1 ICAM-1:Intercellular cell adhesion molecule-1 PMA:Phorbol 12-myristate 13-acetate HL-60:Promyelocytic human leukemia-60 CHO:Chinese hamster ovary     

ICAM-1 and p38 MAPK mediate fibrinogen-induced migration of human vascular smooth muscle cells

Fibrinogen deposition in the vessel wall represents an independent atherogenic risk factor. In Boyden-chamber assays, fibrinogen concentration-dependently (1-100 microM) induced migration of human vascular smooth muscle cells (SMC). This was inhibited by antibodies to intercellular adhesion molecule-1 (ICAM-1, 10 microg/ml), and by inhibitors of PI3-kinase (LY294002, 10 microM) and MAPK (mitogen-activated protein kinase) p38 (SB203580, 10 microM). The MEK (MAP kinase kinase) inhibitor PD98059 (10 muM) and the GPIIb/IIIa antagonist abciximab (10 mug/ml) had no effect. ICAM-1 antibodies inhibited fibrinogen-induced Akt and p38 phosphorylation. Thus fibrinogen stimulates human SMC migration through binding to ICAM-1 and activation of Akt and p38.     

Manassantin a and b isolated fromSaururus chinensis inhibit TNF-α-induced Cell adhesion molecule expression of human umbilical vein endothelial cells

Leukocyte adhesion to the vascular endothelium is a critical initiating step in inflammation and atherosclerosis. We have herein studied the effect of manassantin A (1) and B (2), dineolignans, on interaction of THP-1 monocytic cells and human umbilical vein endothelial cells (HUVEC) and expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin in HUVEC. When HUVEC were pretreated with 1 and 2 followed by stimulation with TNF-alpha, adhesion of THP-1 cells to HUVEC decreased in dose-dependent manner with IC50 values of 5 ng/mL and 7 ng/mL, respectively, without cytotoxicity. Also, 1 and 2 inhibited TNF-alpha-induced up-regulation of ICAM-1, VCAM-1 and E-selectin. The present findings suggest that 1 and 2 prevent monocyte adhesion to HUVEC through the inhibition of ICAM-1, VCAM-1 and E-selectin expression stimulated by TNF-alpha, and may imply their usefulness for the prevention of atherosclerosis relevant to endothelial activation.     

Dexamethasone reduces lung eosinophilia,and VCAM-1 and ICAM-1 expression induced by Sephadex beads in rats

Airway eosinophilia is one of the key pathophysiologic features in asthma. The endothelial adhesion molecules, vascular cell adhesion molecule (VCAM-1) and intercellular adhesion molecule (ICAM-1), have previously been shown to play a crucial role in eosinophil recruitment into the inflamed airway. We have investigated the effects of dexamethasone on eosinophilia into the bronchoalveolar lavage fluid, and the upregulation of VCAM-1 and ICAM-1 expression, measured by immunoblotting, induced by i.v. injection of Sephadex beads into rats. The beads significantly increased the lung eosinophilia, and expression of VCAM-1 and ICAM-1 in the lung. Pretreatment with dexamethasone (0.1 to 2 mg/kg i.p.) strongly inhibited all the airway inflammatory events in a dose-dependent manner. In conclusion, glucocorticoids may be potent inhibitors of lung eosinophilia, at least in part, due to the prevention of the upregulation of VCAM-1 and ICAM-1 expression.     

Motorcycle exhaust particles up-regulate expression of vascular adhesion molecule-1 and intercellular adhesion molecule-1 in human umbilical vein endothelial cells

Epidemiological studies have shown that there is a strong correlation between atherosclerosis and ambient air pollution. In this study, we found that motorcycle exhaust particles (MEP) induced adhesion between cells of the human monocytic leukemia cell line (THP-1) and human umbilical vein endothelial cells (HUVECs) in a time-and dose-dependent manner. In addition, MEP treatment induced both mRNA and protein expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in HUVECs. The IκB degradation and p65 nuclear translocation was found in MEP-treated HUVECs, suggested the involvement of nuclear factor-κB (NF-κB). MEP-induced VCAM-1 and ICAM-1 protein expression was inhibited by NF-κB inhibitor BAY 11-7085. Oxidative stress was also involved in the signaling of VCAM-1 and ICAM-1 expression. MEP treatment caused hydrogen peroxide and superoxide formation. Pretreatment with α-tocopherol could inhibit MEP-induced reactive oxygen intermediates generation and suppressed MEP-induced IκB degradation and adhesion molecules expression. Furthermore, the carbon black (CB) nanoparticles with different diameters could induce VCAM-1 and ICAM-1 protein expression; however, polycyclic aromatic hydrocarbons (PAHs) only increased the expression of ICAM-1 but not that of VCAM-1 in HUVECs. In this study, we found that MEPs could induce ICAM-1 and VCAM-1 expression through oxidative stress and NF-κB activation in HUVECs.     

Adxanthromycins A and B, new inhibitors of ICAM-1/LFA-1 mediated cell adhesion molecule from Streptomyces sp. NA-148. II. Physico-chemical properties and structure elucidation

Adxanthromycins A and B are new inhibitors of ICAM-1/LFA-1 mediated cell adhesion molecule isolated from the fermentation broth of Streptomyces sp. NA-148. The molecular formula of adxanthromycins A and B were determined as C42H40O17 and C48H50O22, respectively by FAB-MS and NMR spectral analyses, and the structures of both compounds were elucidated to be a dimeric anthrone peroxide skeleton containing alpha-D-galactose by various NMR spectral analyses and chemical degradation.     

Effects of a Chinese herbal preparation on vascular cells in culture: mechanisms of cardiovascular protection

1. The use of traditional Chinese medicinal herbs or their pharmaceutical products for disease prevention and management is becoming increasingly popular in Western countries. Mixtures of various Chinese herbs have been used for the treatment of syndromes clinically overlapping Western cardiovascular syndromes. One modern preparation, known as the 'Cardiotonic Pill' (CP), is a pharmaceutical product derived mainly from a medicinal herb, Salvia miltiorrhiza bunge, and recently widely used in Chinese hospitals for the prevention and management of ischaemic cardiovascular diseases. Although the CP is believed to confer an extensive range of benefits, little is known about the physiological actions of this medicine, particularly at the cellular and molecular levels. Therefore, the aim of the present study was to explore possible cellular mechanisms of the CP on the cardiovascular system. 2. Cultured human vascular endothelial cells (EC) and vascular smooth muscle cells (VSMC) were exposed to the CP at various concentrations for periods ranging from hours to days. Cellular DNA synthesis was determined by a [(3)H]-thymidine incorporation assay, proliferation and death were assessed by investigations of cell numbers and apoptosis, whereas the expression of extracellular adhesion molecules was analysed by flow-cytometry and Western blotting. 3. The CP extract at concentrations of less than 200 microg/mL was not associated with cell damage. At doses beyond the therapeutic range (10-20 microg/mL), the CP appeared to exert a mild inhibitory effect on DNA synthesis and proliferation of EC in serum-enriched cultures. The CP significantly attenuated tumour necrosis factor-alpha-induced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in a dose-dependent manner, with 50 and 100 microg/mL CP producing decreases in the expression of ICAM-1 of 26-32% and 32-44%, respectively, and of VCAM-1 of approximately 23% and 27-42%, respectively. The CP did not affect apoptosis in EC under conditions of serum-deprivation. 4. In VSMC, the CP significantly inhibited platelet-derived growth factor BB-induced DNA synthesis and cell proliferation in a dose-dependent manner. The CP did not affect VSMC expression of adhesion molecules. 5. We conclude that the CP inhibits expression of ICAM-1 and VCAM-1 in EC and proliferation of VSMC in a manner that has potentially beneficial therapeutic effects.     

Characterization of Mycotypha metabolites found to be inhibitors of cell adhesion molecules

Three inhibitors of cell adhesion based on LFA-1/ICAM-1 were isolated from the cultured broth of the fungal strain Mycotypha sp. UMF-006. These compounds were identified by spectroscopy to be cytochalasin E (1), 5,6-dehydro-7-hydroxy derivative of cytochalasin E (2) and delta 6,12-isomer of 2 (3). All these components inhibited adhesion of HL-60 cells to CHO-ICAM-1 cells at IC50 values of 30 micrograms/ml for 1, 75 micrograms/ml for 2, and 90 micrograms/ml for 3.     

Novel human topoisomerase I inhibitors, topopyrones A, B, C and D. I. Producing strain, fermentation, isolation, physico-chemical properties and biological activity

In the course of a screening program for specific inhibitors of human topoisomerase I using a recombinant yeast, we have discovered four new active compounds. All four compounds were isolated from the culture broth of a fungus, Phoma sp. BAUA2861, and two of them were isolated from the culture broth of a fungus, Penicillium sp. BAUA4206. We designated these compounds as topopyrones A, B, C and D. Topopyrones A, B, C and D selectively inhibited recombinant yeast growth dependent on expression of human topoisomerase I with IC50 values of 1.22, 0.15, 4.88 and 19.63 ng/ml, respectively. The activity and selectivity of topopyrone B were comparable to those of camptothecin. The relaxation of supercoiled pBR322 DNA by human DNA topoisomerase I was inhibited by these compounds, however they did not inhibit human DNA topoisomerase II. Topopyrones A, B, C and D were cytotoxic to all tumor cell lines when tested in vitro. Topopyrone B has potent inhibitory activity against herpesvirus, especially varicella zoster virus (VZV). It inhibited VZV growth with EC50 value of 0.038 microg/ml, which is 24-fold stronger than that of acyclovir (0.9 microg/ml). Topopyrones A, B, and C were inhibitory to Gram-positive bacteria.     

Sanggenon C对人多形核白细胞和滑膜细胞粘附的抑制作用及其机制

目的:观察化合物Sanggenon C对人外周血多形核白细胞(PMN)与人滑膜细胞(HSC)粘附的抑制作用,并探讨其作用机制.方法:MTT比色法研究PMN与HSC粘附,Cell-ELISA及RT-PCR法研究HSC粘附分子ICAM-1和VCAM-1表达,EMSA研究核转录因子NF-κB的活化.结果:Sanggenon C在0.01-10μmol·L~(-1)范围内均可显著抑制TNF-α 5O kU·L~(-1)与IL-1β诱导的HSC与PMN粘附,其IC_(50)分别为27.29nmol. L~(-1)和54.45nmol·L~(-1);Sanggenon C可显著抑制HSC表面ICAM-1和VCAM-1蛋白表达,同时也显著抑制VCAM-1 mRNA表达,但对ICAM-1 mRNA表达无显著影响;Sanggenon C在1-10μmol·L~(-1)浓度下也可显著抑制TNF-α对NF-κB的活化.结论:Sanggenon C是一个有效的人PMN与HSC粘附抑制剂,其作用机制可能是通过抑制NF-κB的活化,进而抑制HSC表面VCAM-1的表达或抑制ICAM-1转录后调控过程而实现的.     

Inhibition of ICAM-1 expression by garlic component, allicin, in gamma-irradiated human vascular endothelial cells via downregulation of the JNK signaling pathway

Ionizing radiation used in cancer therapy frequently exerts damaging effects on normal tissues and induces a complex response including inflammation. Since the upregulation of adhesion molecules on endothelial cell surface has been known to be associated with inflammation and our previous data showed that irradiation enhanced adhesion molecules expression, interfering with the expression of adhesion molecules may be an important therapeutic target of inflammatory diseases. We examined the effect of allicin, a major component of garlic, on the induction of intercellular adhesion molecule-1 (ICAM-1) by gamma-irradiation (gamma IR) and the mechanisms of its effect in gamma-irradiated human umbilical vein endothelial cells (HUVECs). HUVECs were pretreated for 20 h with allicin (0.01-1 micro g/ml) and then exposed to 8 Gy radiation. Allicin significantly inhibited gamma IR-induced surface expression of ICAM-1 and ICAM mRNA in a dose-dependent manner. In addition, pretreatment with allicin resulted in the decrease of AP-1 activation and phosphorylation of the c-Jun NH2-terminal kinase (JNK) induced by gamma IR. These results suggest that allicin downregulates gamma IR-induced ICAM-1 expression via inhibition of both AP-1 activation and the JNK pathway and may be considered in therapeutic strategies for the management of patients treated with radiation therapy.     

Antiviral and immunomodulatory activity of the metal chelator ethylenediaminedisuccinic acid against cytomegalovirus in vitro and in vivo

Antiviral activity of the metal chelator ethylenediaminedisuccinic acid (EDDS) was examined in vitro against human cytomegalovirus (HCMV) wild type strains and strains that are resistant against ganciclovir (GCV) and cidofovir (HPMPC). EDDS inhibited the replication of wild-type as well as GCV- and HPMPC-resistant strains with a 50% effective concentration of 7.4-12 microg/ml. At concentrations of 100 microg/ml EDDS, unlike GCV or HPMPC, suppressed HCMV-induced up-regulation of intercellular adhesion molecule-1 (ICAM-1) and reduced T-cell adhesion to HCMV-infected cells in a monolayer adhesion model. In vitro EDDS inhibited murine cytomegalovirus (MCMV) replication (EC50 8.6 microg/ml) and caused in mice some protection against MCMV induced mortality at a non-toxic dose. Since immunopathological factors may play a significant role in HCMV disease it will be of interest to further study whether EDDS is effective in terms of modulation of inflammatory responses to HCMV infections.     

雷公藤内酯醇抑制炎症因子引起的肾小管上皮细胞主要组织相容性Ⅱ类抗原和B7共刺激分子过度表达

目的:观察雷公藤内酯醇对炎症因子引起的人肾小管上皮细胞(HKC)主要组织相容性II类抗原(class II MHC)、B7共刺激分子及细胞间粘附分子-1(ICAM-1)过量表达的影响.方法:采用干扰素γ(IFN-γ)和肿瘤坏死因子α(TNF-α)联合刺激人肾小管上皮HKC细胞,诱导细胞过度表达class II MHC、B7-1、B7-2和 ICAM-1.同时在细胞培养液中加入不同浓度的雷公藤内酯醇,观察其对上述过程的影响.采用流式细胞术检测细胞内class II MHC、B7-1、B7-2和 ICAM-1等细胞因子的表达,采用逆转录 PCR技术检测ICAM-1 mRNA表达的变化.结果:(1)IFN-γ和TNF-α以能显著上调class II MHC、B7-1、B7-2共刺激分子和ICAM-1在人肾小管上皮细胞中的表达.(2)雷公藤内酯醇剂量依赖性地抑制IFN-γ和TNF-α引起的class II MHC和B7共刺激分子过度表达,但对ICAM-1的过度表达无显著影响.结论:雷公藤内酯醇能抑制炎症因子引起的人肾小管上皮细胞class II MHC和B7共刺激分子过度表达.这也许是雷公藤内酯醇在一些免疫相关性肾脏疾病中的作用机制之一. (责任编辑 韩向晖)     

TAN-1813, a novel Ras-farnesyltransferase inhibitor produced by Phoma sp. taxonomy, fermentation, isolation and biological activities in vitro and in vivo

A novel Ras-farnesyltransferase inhibitor designated TAN-1813 was isolated from the culture broth of a fungus strain, FL-41510, isolated as a plant endophyte. The producer was taxonomically characterized as Phoma sp. FL-41510. TAN-1813 inhibited rat brain farnesyltransferase and geranylgeranyltransferase I activity with IC50 values of 23 microg/ml and 47/microg/ml, respectively. TAN-1813 showed mixed-type inhibition with respect to farnesylpyrophosphate and noncompetitive inhibition with respect to a K-Ras C-terminal peptide. It also inhibited the in situ farnesylation of cellular Ras proteins in a K-ras transformant (NIH3T3/K-ras) of mouse embryonic fibroblast cell line NIH3T3. TAN- 1813 inhibited the proliferation of various human cancer cells, some of which harbor activated ras alleles, with IC50 values of 15 approximately 110 ng/ml as well as that of NIH3T3 and NIH3T3/K-ras cells with IC50S of 540 and 310 ng/ml, respectively. Flow cytometric analysis indicated that TAN-1813 arrests NIH3T3/K-ras cells at both G1 and G2/M phases of the cell cycle. In addition, TAN-1813 was found to induce morphological reversion of NIH3T3/K-ras cells from the transformed phenotype. Antitumor activity of TAN-1813 against human fibrosarcoma HT-1080 and NIH3T3/K-ras tumors in nude mice was also verified.