Binding of the integrin Mac-1 (CD11b/CD18) to the third immunoglobulin-like domain of ICAM-1 (CD54) and its regulation by glycosylation.

Both the integrins LFA-1 and Mac-1 bind to ICAM-1, an immunoglobulin superfamily member. Previously, we localized the binding sites of LFA-1 and the major group of human rhinoviruses to the first NH2-terminal immunoglobulin-like domain of ICAM-1. Here, we show that the binding site on ICAM-1 for Mac-1 is unexpectedly distinct from that for LFA-1 and maps to the third NH2-terminal immunoglobulin-like domain. These findings provide a function for the tandem duplication of immunoglobulin-like domains in ICAM-1 and have implications for other immunoglobulin superfamily members. Mutations at two sites in the third domain that destroy consensus sequences for N-linked glycosylation enhance binding to purified Mac-1. Agents that interfere with carbohydrate processing provide evidence that the size of the N-linked oligosaccharide side chains on ICAM-1 affects binding to Mac-1 but not to LFA-1. Thus, we suggest that the extent of glycosylation on ICAM-1 may regulate adhesion to LFA-1 or Mac-1 in vivo.     

Expression of the Blast-1 activation/adhesion molecule and its identification as CD48.

We have analyzed the induction and expression of Blast-1 at the mRNA and protein levels and demonstrated its identity with CD48. Blast-1/CD48 is expressed on a wider range of cell types, notably T cells and monocytes, than previously thought, but appears to be restricted to lymphoid and myeloid cells. Resting B and T cells express Blast-1/CD48 molecules at the cell surface; however, they lack the epitope recognized by the 17D6 mAb. Resting B cells express no detectable Blast-1/CD48 mRNA. Induction by EBV infection or stimulation with PMA, IL-4, or PHA results in increased levels of Blast-1/CD48 protein (both 6.28 and 17D6 epitopes) at the cell surface. Detailed analysis of EBV-induced expression revealed that it is due to increased steady-state levels of Blast-1/CD48 mRNA induced by transforming but not nontransforming strains of the virus. Induction by IL-1 beta, ionomycin, or suboptimal levels of PMA plus ionomycin results in increased expression of the 17D6 epitope only. In transfected Cos-7 cells Blast-1/CD48 at the cell surface expresses only the 6.28 epitope, whereas cytoplasmic molecules express both 17D6 and 6.28 epitopes. We suggest that these results are most consistent with the idea that Blast-1/CD48 molecules are complexed at the surface of resting cells and Cos-7 cells, resulting in masking of the 17D6 epitope. Activation causes dissociation of the complex, revealing the 17D6 epitope. The existence of 17D6+6.28- Blast-1/CD48 molecules was demonstrated by immunoprecipitation analysis, which also revealed that, unlike the rest of the molecules, this subset was resistant to digestion with glyosylphosphatidylinositol-specific phospholipase C.     

Large‐scale coral reef rehabilitation after blast fishing in Indonesia

The severely degraded condition of many coral reefs worldwide calls for active interventions to rehabilitate their physical and biological structure and function, in addition to effective management of fisheries and no‐take reserves. Rehabilitation efforts to stabilize reef substratum sufficiently to support coral growth have been limited in size. We documented a large coral reef rehabilitation in Indonesia aiming to restore ecosystem functions by increasing live coral cover on a reef severely damaged by blast fishing and coral mining. The project deployed small, modular, open structures to stabilize rubble and to support transplanted coral fragments. Between 2013 to 2015, approximately 11,000 structures covering 7,000 m² were deployed over 2 ha of a reef at a cost of US$174,000. Live coral cover on the structures increased from less than 10% initially to greater than 60% depending on depth, deployment date and location, and disturbances. The mean live coral cover in the rehabilitation area in October 2017 was higher than reported for reefs in many other areas in the Coral Triangle, including marine protected areas, but lower than in the no‐take reference reef. At least 42 coral species were observed growing on the structures. Surprisingly, during the massive coral bleaching in other regions during the 2014–2016 El Niño–Southern Oscillation event, bleaching in the rehabilitation area was less than 5% cover despite warm water (≥30°C). This project demonstrates that coral rehabilitation is achievable over large scales where coral reefs have been severely damaged and are under continuous anthropogenic disturbances in warming waters.     

Effect of pro-inflammatory stimuli on mucin expression and inhibition by secretory leucoprotease inhibitor

Stimuli-induced expression of certain mucin genes has been demonstrated to occur as a result of ligand-dependent activation of the epidermal growth factor receptor (EGFR). In particular, MUC5AC expression can be induced by cigarette-smoke, neutrophil elastase and lipopolysaccharide (LPS) following activation of tumour necrosis factor alpha-converting enzyme. We now show that a large of number of stimuli relevant to the cystic fibrosis lung - neutrophil elastase, LPS, Pam3Cys-Ser-(Lys)4 Hydrochloride (a lipopeptide analogue), CpG DNA (which mimics bacterial DNA) and cystic fibrosis bronchoalveolar lavage fluid - can activate MUC1 and 2 expression as well as MUC5AC expression in lung epithelial cells via an EGFR-dependent mechanism. In addition, we demonstrate that the immunomodulatory anti-protease, secretory leucoprotease inhibitor, can inhibit stimuli-induced MUC1, 2 and 5AC expression via a mechanism that is primarily dependent on the inhibition of transforming growth factor type alpha release. Therefore, mucin gene expression, induced by cystic fibrosis respiratory stimuli, can be inhibited by secretory leucoprotease inhibitor indicating its potential importance as an anti-mucin agent in cystic fibrosis and other chronic lung diseases characterized by mucus hypersecretion.     

Lead optimization of 2-(piperidin-3-yl)-1H-benzimidazoles: identification of 2-morpholin- and 2-thiomorpholin-2-yl-1H-benzimidazoles as selective and CNS penetrating H₁-antihistamines for insomnia

The structure-activity relationships of 2-(piperidin-3-yl)-1H-benzimidazoles, 2-morpholine and 2-thiomorpholin-2-yl-1H-benzimidazoles are described. In the lead optimization process, the pK(a) and/or logP of benzimidazole analogs were reduced either by attachment of polar substituents to the piperidine nitrogen or incorporation of heteroatoms into the piperidine heterocycle. Compounds 9a and 9b in the morpholine series and 10g in the thiomorpholine series demonstrated improved selectivity and CNS profiles compared to lead compound 2 and these are potential candidates for evaluation as sedative hypnotics.