Although leukocytes adhere in arteries in various vascular diseases, to date no endogenous proinflammatory molecule has been identified to initiate leukocyte adhesion in the arterial vasculature. This study was undertaken to assess angiotensin II (Ang II)-induced leukocyte adhesion in arterioles in vivo. Rats received intraperitoneal injections of Ang II; 4 hours later, leukocyte recruitment in mesenteric microcirculation was examined using intravital microscopy. Ang II (1 nM) produced significant arteriolar leukocyte adhesion of mononuclear cells. Using function-blocking monoclonal antibodies (mAbs) against different rat cell adhesion molecules (CAMs), we discovered that this effect was dependent on P-selectin and β₂-integrin. In postcapillary venules, Ang II also induced leukocyte infiltration, which was reduced by P-selectin and by β₂- and α₄-integrin blockade. Interestingly, neutrophils were the primary cells recruited in venules. Although β₂-integrin expression in peripheral leukocytes of Ang II-treated animals was not altered, it was increased in peritoneal cells. Immunohistochemical studies revealed increased P-selectin, E-selectin, intercellular cell adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) expression in response to Ang II in arterioles and venules. These findings provide the first evidence that Ang II causes leukocyte adhesion to the arterial endothelium in vivo at physiologically relevant doses. Therefore, Ang II may be a key molecule in cardiovascular diseases in which leukocyte adhesion to the arteries is a characteristic feature. (Blood. 2004;104:402-408)

Background— Angiotensin II (Ang II) is implicated in the development of cardiac ischemic disorders in which prominent neutrophil accumulation occurs. Ang II can be generated intravascularly by the renin-angiotensin system or extravascularly by mast cell chymase. In this study, we characterized the ability of Ang II to induce neutrophil accumulation. Methods and Results— Intraperitoneal administration of Ang II (1 nmol/L) induced significant neutrophil recruitment within 4 hours (13.3±2.3×10 ⁶ neutrophils per rat versus 0.7±0.5×10 ⁶ in control animals), which disappeared by 24 hours. Maximal levels of CXC chemokines were detected 1 hour after Ang II injection (577±224 pmol/L cytokine-inducible neutrophil chemoattractant [CINC]/keratinocyte-derived chemokine [KC] versus 5±3, and 281±120 pmol/L macrophage inflammatory protein [MIP-2] versus 14±6). Intravital microscopy within the rat mesenteric microcirculation showed that the short-term (30 to 60 minutes) leukocyte–endothelial cell interactions induced by Ang II were attenuated by an anti-rat CINC/KC antibody and nearly abolished by the CXCR2 antagonist SB-517785-M. In human umbilical vein endothelial cells (HUVECs) or human pulmonary artery media in culture, Ang II induced interleukin (IL)-8 mRNA expression at 1, 4, and 24 hours and the release of IL-8 at 4 hours through interaction with Ang II type 1 receptors. When HUVECs were pretreated with IL-1 for 24 hours to promote IL-8 storage in Weibel-Palade bodies, the Ang II–induced IL-8 release was more rapid and of greater magnitude. Conclusions— Ang II provokes rapid neutrophil recruitment, mediated through the release of CXC chemokines such as CINC/KC and MIP-2 in rats and IL-8 in humans, and may contribute to the infiltration of neutrophils observed in acute myocardial infarction.

Patients with non-small cell lung cancer (NSCLC) develop resistance to antitumor agents by mechanisms that involve the epithelial-to-mesenchymal transition (EMT). This necessitates the development of new complementary drugs, e.g., cannabinoid receptors (CB1 and CB2) agonists including tetrahydrocannabinol (THC) and cannabidiol (CBD). The combined use of THC and CBD confers greater benefits, as CBD enhances the effects of THC and reduces its psychotropic activity. We assessed the relationship between the expression levels of CB1 and CB2 to the clinical features of a cohort of patients with NSCLC, and the effect of THC and CBD (individually and in combination) on proliferation, EMT and migration in vitro in A549, H460 and H1792 lung cancer cell lines. Expression levels of CB1, CB2, EGFR, CDH1, CDH2 and VIM were evaluated by quantitative reverse transcription-polymerase chain reaction. THC and CBD (10–100 μM), individually or in combination (1:1 ratio), were used for in vitro assays. Cell proliferation was determined by BrdU incorporation assay. Morphological changes in the cells were visualized by phase-contrast and fluorescence microscopy. Migration was studied by scratch recolonization induced by 20 ng/ml epidermal growth factor (EGF). The tumor samples were classified according to the level of expression of CB1, CB2, or both. Patients with high expression levels of CB1, CB2, and CB1/CB2 showed increased survival reaching significance for CB1 and CB1/CB2 (p = 0.035 and 0.025, respectively). Both cannabinoid agonists inhibited the proliferation and expression of EGFR in lung cancer cells, and CBD potentiated the effect of THC. THC and CBD alone or in combination restored the epithelial phenotype, as evidenced by increased expression of CDH1 and reduced expression of CDH2 and VIM, as well as by fluorescence analysis of cellular cytoskeleton. Finally, both cannabinoids reduced the in vitro migration of the three lung cancer cells lines used. The expression levels of CB1 and CB2 have a potential use as markers of survival in patients with NSCLC. THC and CBD inhibited the proliferation and expression of EGFR in the lung cancer cells studied. Finally, the THC/CBD combination restored the epithelial phenotype in vitro.

Two strains of a novel bacterium were isolated independently of each other, from different depths in the Mediterranean Sea, within a time period of 7 months, using two different isolation approaches that were focused on different objectives. Both strains, designated ISO1 and ISO4T, were halophilic, Gram-negative, strictly aerobic, straight rods that were oxidase- and catalase-positive. Both strains produced mucoid colonies in some defined minimal media and were able to grow with organic acids and some alkanes; they were also able to accumulate intracellular poly-β-hydroxybutyrate granules. The G+C content of the DNA of strain ISO4T was 66 mol%. Comparative analysis of 16S rRNA gene sequences showed that the closest described species to the novel strains were Alcanivorax borkumensis and Fundibacter jadensis, both of the γ-Proteobacteria. Both of these recognized species were originally isolated from North Sea waters and are able to degrade aliphatic compounds, a property shared with strains ISO1 and ISO4T. However, strains ISO1 and ISO4T were different from A. borkumensis and F. jadensis, not only in their 16S rDNA sequences but also in the motility of their cells (by polar flagella) and by the presence of C19 : 0cyclo in their cellular fatty acids, among other differential features. On the basis of biochemical and molecular data, it is suggested that strains ISO1 and ISO4T be recognized as a novel species of the genus Alcanivorax, for which the name Alcanivorax venustensis (ISO4T =DSM 13974T =CECT 5388T) is proposed. On the basis of its high phenotypic similarity and close phylogenetic relatedness to A. borkumensis, it is also proposed that F. jadensis (DSM 12178T) be reclassified as Alcanivorax jadensis in the genus Alcanivorax, and that the description of the genus Alcanivorax be emended.