New frontiers for platelet CD154.

The role of platelets extends beyond hemostasis. The pivotal role of platelets in inflammation has shed new light on the natural history of conditions associated with acute or chronic inflammation. Beyond the preservation of vascular integrity, platelets are essential to tissue homeostasis and platelet-derived products are already used in the clinics. Unanticipated was the role of platelets in the adaptative immune response, allowing a renewed conceptual approach of auto-immune diseases. Platelets are also important players in cancer growth and dissemination. Platelets fulfill most of their functions through the expression of still incompletely characterized membrane-bound or soluble mediators. Among them, CD154 holds a peculiar position, as platelets represent a major source of CD154 and as CD154 contributes to most of these new platelet attributes. Here, we provide an overview of some of the new frontiers that the study of platelet CD154 is opening, in inflammation, tissue homeostasis, immune response, hematopoiesis and cancer.

Protection of lung epithelial cells from protease-mediated injury by trappin-2 A62L, an engineered inhibitor of neutrophil serine proteases.

Neutrophil serine proteases (NSPs), including elastase, proteinase 3 and cathepsin G, play critical roles in the pathogenesis of chronic inflammatory lung diseases. The release of excess NSPs leads to the destruction of lung tissue and an overexuberant, sustained inflammatory response. Antiproteases could be valuable tools for controlling these NSP-mediated inflammatory events. We have examined the capacity of trappin-2 A62L, a potent engineered inhibitor of all three NSPs, to protect human lung A549 epithelial cells from the deleterious effects of NSPs. Trappin-2 A62L, significantly inhibited the detachment of A549 cells and the degradation of the tight-junction proteins, E-cadherin, ß-catenin and ZO-1, induced by each individual NSP and by activated neutrophils. Trappin-2 A62L also decreased the release of the pro-inflammatory cytokines IL-6 and IL-8 from A549 cells that had been stimulated with elastase or LPS. Trappin-2 A62D/M63L, a trappin-2 variant that has no antiprotease activity, has similar properties, suggesting that the anti-inflammatory action of trappin-2 is independent of its antiprotease activity. Interestingly, we present evidence that trappin-2 A62L, as well as wild-type trappin-2, enter A549 cells and move rapidly to the cytoplasm and nucleus, where they are likely to exert their anti-inflammatory effects. We have also demonstrated that trappin-2 A62L inhibits the early apoptosis of A549 cells mediated by NSPs. Thus, our data indicate that trappin-2 A62L is a powerful anti-protease and anti-inflammatory agent that could be used to develop a treatment for patients with inflammatory lung diseases.

SLPI and trappin-2 as therapeutic agents to target airway serine proteases in inflammatory lung diseases: current and future directions.

It is now clear that NSPs (neutrophil serine proteases), including elastase, Pr3 (proteinase 3) and CatG (cathepsin G) are major pathogenic determinants in chronic inflammatory disorders of the lungs. Two unglycosylated natural protease inhibitors, SLPI (secretory leucocyte protease inhibitor) and elafin, and its precursor trappin-2 that are found in the lungs, have therapeutic potential for reducing the protease-induced inflammatory response. This review examines the multifaceted roles of SLPI and elafin/trappin-2 in the context of their possible use as inhaled drugs for treating chronic lung diseases such as CF (cystic fibrosis) and COPD (chronic obstructive pulmonary disease).

One-pot synthesis of 5-phenylimino, 5-thieno or 5-oxo-1,2,3-dithiazoles and evaluation of their antimicrobial and antitumor activity.

We here report the synthesis and biological evaluation of rare 4-substituted-5-phenylimino, 5-thieno- and 5-oxo-1,2,3-dithiazoles. Dithiazoles were selectively obtained in moderate to high yields (25-73%) via a one-pot reaction from various ethanoneoximes with sulfur monochloride, pyridine in acetonitrile followed by treatment by corresponding nucleophiles (aniline, thioacetamide and formic acid). All the synthesized compounds were screened for their antibacterial (against bacteria Escherichia coli, Salmonellaenterica serovar Typhimurium, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus, Enterococcus faecalis, Bacillus cereus and Listeria inocua), antifungal (against pathogenic strains Candida albicans, Candida glabrata, Candida tropicalis and Issatchenkia orientalis) and antitumor (on human cell lines MCF-7 and MDA-MB-231) activity. 4-(2-Pyridinyl)-5H-1,2,3-dithiazole-5-thione and 4-ethylcarboxyl-5H-1,2,3-dithiazole-5-thione (5d, 5h) that are active against Gram-positive bacteria are significantly active against fungi. 4-(2-Benzofuranyl)-5-phenylimino-5H-1,2,3-dithiazole (4e) exerts antiproliferative activity.