Aspirin reduces lipopolysaccharide-induced pulmonary inflammation in human models of ARDS.

RATIONALE: Platelets play an active role in the pathogenesis of acute respiratory distress syndrome (ARDS). Animal and observational studies have shown aspirin's antiplatelet and immunomodulatory effects may be beneficial in ARDS. OBJECTIVE: To test the hypothesis that aspirin reduces inflammation in clinically relevant human models that recapitulate pathophysiological mechanisms implicated in the development of ARDS. METHODS: Healthy volunteers were randomised to receive placebo or aspirin 75  or 1200 mg (1:1:1) for seven days prior to lipopolysaccharide (LPS) inhalation, in a double-blind, placebo-controlled, allocation-concealed study. Bronchoalveolar lavage (BAL) was performed 6 hours after inhaling 50 µg of LPS. The primary outcome measure was BAL IL-8. Secondary outcome measures included markers of alveolar inflammation (BAL neutrophils, cytokines, neutrophil proteases), alveolar epithelial cell injury, systemic inflammation (neutrophils and plasma C-reactive protein (CRP)) and platelet activation (thromboxane B2, TXB2). Human lungs, perfused and ventilated ex vivo (EVLP) were randomised to placebo or 24 mg aspirin and injured with LPS. BAL was carried out 4 hours later. Inflammation was assessed by BAL differential cell counts and histological changes. RESULTS: In the healthy volunteer (n=33) model, data for the aspirin groups were combined. Aspirin did not reduce BAL IL-8. However, aspirin reduced pulmonary neutrophilia and tissue damaging neutrophil proteases (Matrix Metalloproteinase (MMP)-8/-9), reduced BAL concentrations of tumour necrosis factor α and reduced systemic and pulmonary TXB2. There was no difference between high-dose and low-dose aspirin. In the EVLP model, aspirin reduced BAL neutrophilia and alveolar injury as measured by histological damage. CONCLUSIONS: These are the first prospective human data indicating that aspirin inhibits pulmonary neutrophilic inflammation, at both low and high doses. Further clinical studies are indicated to assess the role of aspirin in the prevention and treatment of ARDS. TRIAL REGISTRATION NUMBER: NCT01659307 Results.

STAT3 Activation in Circulating Monocytes Contributes to Neovascular Age-Related Macular Degeneration.

Infiltrating macrophages are critically involved in pathogenic angiogenesis such as neovascular agerelated macular degeneration (nAMD). Macrophages originate from circulating monocytes and three subtypes of monocyte exist in humans: classical (CD14(+)CD16(-)), non-classical (CD14(-)CD16(+)) and intermediate (CD14(+)CD16(+)) monocytes. The aim of this study was to investigate the role of circulating monocyte in neovascular age-related macular degeneration (nAMD). Flow cytometry analysis showed that the intermediate monocytes from nAMD patients expressed higher levels of CX3CR1 and HLA-DR compared to those from controls. Monocytes from nAMD patients expressed higher levels of phosphorylated Signal Transducer and Activator of Transcription 3 (pSTAT3), and produced higher amount of VEGF. In the mouse model of choroidal neovascularization (CNV), pSTAT3 expression was increased in the retina and RPE/choroid, and 49.24% of infiltrating macrophages express pSTAT3. Genetic deletion of the Suppressor of Cytokine Signalling 3 (SOCS3) in myeloid cells in the LysM-Cre(+/-):SOCS3(fl/fl) mice resulted in spontaneous STAT3 activation and accelerated CNV formation. Inhibition of STAT3 activation using a small peptide LLL12 suppressed laserinduced CNV. Our results suggest that monocytes, in particular the intermediate subset of monocytes are activated in nAMD patients. STAT3 activation in circulating monocytes may contribute to the development of choroidal neovascularisation in AMD.

Nanoencapsulation of ABT-737 and camptothecin enhances their clinical potential through synergistic antitumor effects and reduction of systemic toxicity.

The simultaneous delivery of multiple cancer drugs in combination therapies to achieve optimal therapeutic effects in patients can be challenging. This study investigated whether co-encapsulation of the BH3-mimetic ABT-737 and the topoisomerase I inhibitor camptothecin (CPT) in PEGylated polymeric nanoparticles (NPs) was a viable strategy for overcoming their clinical limitations and to deliver both compounds at optimal ratios. We found that thrombocytopenia induced by exposure to ABT-737 was diminished through its encapsulation in NPs. Similarly, CPT-associated leukopenia and gastrointestinal toxicity were reduced compared with the administration of free CPT. In addition to the reduction of dose-limiting side effects, the co-encapsulation of both anticancer compounds in a single NP produced synergistic induction of apoptosis in both in vitro and in vivo colorectal cancer models. This strategy may widen the therapeutic window of these and other drugs and may enhance the clinical efficacy of synergistic drug combinations.

The mouse and human IGSF6 (DORA) genes map to the inflammatory bowel disease 1 locus and are embedded in an intron of a gene of unknown function.

We have previously characterized IGSF6 (DORA), a novel member of the immunoglobulin superfamily (IGSF) from human and rat expressed in dendritic and myeloid cells. Using a probe from the open reading frame of the rat cDNA, we isolated a cosmid which contains the entire mouse gene. By comparative analysis and reverse transcriptase polymerase chain reaction, we defined the intron/exon structure and the mRNA of the mouse gene and, with respect to human BAC clones, the human gene. The genes span 10 kb (mouse) and 12 kb (human), with six exons arranged in a manner similar to other members of the IGSF. All intron/exon boundaries follow the GT-AG rule. Expression of the mouse Igsf6 gene is restricted to cells of the immune system, particularly macrophages. Northern blot revealed a single mRNA of 2.5 kb, in contrast to the human gene which is expressed as two mRNAs of 1 and 2.5 kb. The human and mouse genes were localized to a locus associated with inflammatory bowel disease. Analysis of the flanking regions of the Igsf6 gene revealed the presence of an unrelated gene, transcribed from the opposite strand of the DNA and oriented such that the Igsf6 gene is encoded entirely within an intron. An identical organization is seen in human. This gene of unknown function is transcribed and processed, contains homologues in Caenorhabditis elegans and prokaryotes, and is expressed in most organs in the mouse.

A maternal genetic effect on the composition of mouse aggregation chimaeras.

Two series of 12 1/2 day mouse chimaeric conceptuses were produced by aggregating (C57BL x CBA)F2 strain preimplantation embryos with embryos that differed at the Gpi-1s locus that encodes glucose phosphate isomerase, GPI-1. The composition of individual issues was evaluated by quantitative electrophoresis to estimate the % GPI-1A in the chimaeric tissue containing GPI-1A and GPI-1B. In one series of chimaeras, the GPI-1A cells were derived from a backcross between inbred BALB/c strain females and (BC x BALB/c)F1 males, where BC is the partly congenic strain C57BL/Ola.AKR-Gpi-lsa,c/Ws. In the other series of chimaeras, the GPI-1A cells were derived from the reciprocal backcross between (BC x BALB/c)F1 females and inbred BALB/c strain males. The [(BC x BALB/c)F1 female x BALB/c male]<==>(C57BL x CBA)F2 series of chimaeras was reasonably balanced so that GPI-1A and GPI-1B cells were fairly equally represented in the foetuses, placentas and extraembryonic membranes (tissue means: 37-51% GPI-1A). This series did not differ significantly in composition from an earlier series of (BC x BALB/c)F2<==>(C57BL x CBA)F2 chimaeras. However, the [BALB/c female x (BC x BALB/c)F1 male]<==>(C57BL x CBA)F2 series of chimaeras was unbalanced, with mean tissue compositions (28-33% GPI-1A) that were intermediate between the above two balanced series and the unbalanced (BALB/c x BALB/c)<==>(C57BL x CBA)F2 series (tissue means: 14-22% GPI-1A), that was studied previously. Thus, both (BALB/c x BALB/c) and [BALB/c x (BC x BALB/c)F1] embryos contributed less to the tissues of chimaeric conceptuses than either (BC x BALB/c)F2 or [BC x BALB/c)F1 x BALB/c] embryos. This implies that embryos from BALB/c mothers contributed less to the tissues of chimaeric conceptuses than embryos from (BC x BALB/c)F1 mothers. We, therefore, conclude that a maternal genetic effect is responsible for some of the differences in composition among the four groups of chimaeras. This maternal effect must act before the 8-cell stage but it is not yet known whether it is mediated via cytoplasmic inheritance, genomic imprinting or by the reproductive tract. Evidence that a maternal effect retards preimplantation development of embryos from BALB/c females is reviewed and the possibility that this might cause them to contribute poorly to chimaeric conceptuses when aggregated with more precociously developing embryos is discussed.