Steroidal anti-inflammatory drugs induce proteins that inhibit phospholipase A2 (PLA2), including uteroglobin and lipocortin-1 (annexin I). Uteroglobin and lipocortin-1 retain several conserved sequences. Based on these sequences, several nonapeptides (antiflammins) were synthesized. These nonapeptides were shown to have anti-inflammatory effects in vitro and in vivo, possibly by inhibiting PLA2. Subsequent research showed that PLA2 is activated by transglutaminase 2 (TGase 2). We hypothesize here that TGase 2 inhibitors may increase the anti-inflammatory efficacy of inhibiting PLA2 activity. To test this theory, we constructed recombinant peptides containing sequences from pro-elafin (for inhibition of TGase 2), and from lipocortin-1, lipocortin-5, and uteroglobin (for inhibition of PLA2). The recombinant peptides, which had dual inhibitory effects on purified TGase 2 and PLA2, reversed the inflammation of allergic conjunctivitis to ragweed in a guinea pig model. The present work suggests that novel recombinant peptides may be safe and effective agents for the treatment of various inflammatory diseases.
Joonhong Sohn, Tae-Im Kim, Young-Hee Yoon, Joo-Yong Kim, Soo-Youl Kim
Acute liver failure caused by viral hepatitis or toxic damage involves both apoptotic and necrotic pathways. IGF binding protein-1 (IGFBP-1), a hepatocyte-derived secreted protein, is required for normal liver regeneration. To determine whether IGFBP-1 could prevent liver injury that entails direct stimulation of hepatocyte apoptosis, IGFBP-1–/– mice, IGFBP-1+/+ mice, and mice pretreated with Ab’s against IGFBP-1 were treated with a normally sublethal dose of Fas agonist. IGFBP-1 deficiency was associated with massive hepatocyte apoptosis and caspase activation within 3 hours of Fas agonist treatment, which could be corrected by pretreatment with IGFBP-1. IGFBP-1–deficient livers had enhanced signaling via the integrin receptor at early times (0.5 to 1 hour) after Fas agonist treatment accompanied by elevated activated matrix metalloproteinase-9 (MMP-9), a known target of fibronectin signaling and activator of TGF-β. Within 3 hours of Fas agonist treatment, elevated expression of active TGF-β1, a hepatocyte apoptogen, was observed in IGFBP-1–deficient livers that correlated with the appearance of the apoptotic process. Both MMP-9 and TGF-β1 expression were suppressed by IGFBP-1 treatment, supporting their role in the apoptotic process. IGFBP-1–/– mice also displayed increased injury in a toxic hepatic injury model caused by CCl4. These findings indicate that IGFBP-1 functions as a critical hepatic survival factor in the liver by reducing the level of proapoptotic signals.
Julia I. Leu, Mary Ann S. Crissey, Rebecca Taub
Using physiological, pharmacological, and gene disruption approaches, we demonstrate that proteinase-activated receptor-2 (PAR-2) plays a pivotal role in mediating chronic inflammation. Using an adjuvant monoarthritis model of chronic inflammation, joint swelling was substantially inhibited in PAR-2–deficient mice, being reduced by more than fourfold compared with wild-type mice, with virtually no histological evidence of joint damage. Mice heterozygous for PAR-2 gene disruption showed an intermediate phenotype. PAR-2 expression, normally limited to endothelial cells in small arterioles, was substantially upregulated 2 weeks after induction of inflammation, both in synovium and in other periarticular tissues. PAR-2 agonists showed potent proinflammatory effects as intra-articular injection of ASKH95, a novel synthetic PAR-2 agonist, induced prolonged joint swelling and synovial hyperemia. Given the absence of the chronic inflammatory response in the PAR-2–deficient mice, our findings demonstrate a key role for PAR-2 in mediating chronic inflammation, thereby identifying a novel and important therapeutic target for the management of chronic inflammatory diseases such as rheumatoid arthritis.
William R. Ferrell, John C. Lockhart, Elizabeth B. Kelso, Lynette Dunning, Robin Plevin, Stephen E. Meek, Andrew J.H. Smith, Gary D. Hunter, John S. McLean, Frances McGarry, Robert Ramage, Lu Jiang, Toru Kanke, Junichi Kawagoe
John A. Belperio, Michael P. Keane, Marie D. Burdick, Vedang Londhe, Ying Ying Xue, Kewang Li, Roderick J. Phillips, Robert M. Strieter
Dimitri Lodygin, Antje Menssen, Heiko Hermeking
Andrew P. Fontenot, Scott J. Canavera, Laia Gharavi, Lee S. Newman, Brian L. Kotzin
Roman A. Tuma, Rielle Giannino, Patrick Guirnalda, Ingrid Leiner, Eric G. Pamer
Wouter J. de Jonge, Karin L. Kwikkers, Anje A. te Velde, Sander J.H. van Deventer, Martijn A. Nolte, Reina E. Mebius, Jan M. Ruijter, Marinus C. Lamers, Wouter H. Lamers
Feng Lin, Henry J. Kaminski, Bianca M. Conti-Fine, Wei Wang, Chelliah Richmonds, M. Edward Medof
Khemissa Bejaoui, Yoshikazu Uchida, Satoshi Yasuda, Mengfatt Ho, Masahiro Nishijima, Robert H. Brown Jr., Walter M. Holleran, Kentaro Hanada
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