Noncovalent tripeptidic thrombin inhibitors incorporating amidrazone, amine and amidine functions at P1

A series of noncovalent tripeptidic thrombin inhibitors incorporating amidrazone, amine and amidine functions at P1 was investigated. While the amidrazone and the amine series displayed limited oral absorption, the amidine series demonstrated generally good oral absorption and strong antithrombotic activity; the single-digit picomolar K(i) achieved from this series is among the best yet reported. The present work highlights the benzamidine compound 11f (LB30812) that exhibits excellent overall profiles of potency, oral absorption and antithrombotic efficacy.     

Overexpression of Class III Beta Tubulin and Amplified HER2 Gene Predict Good Response to Paclitaxel and Trastuzumab Therapy

Through this study, we aimed to validate several biomarkers that have been known to possibly predict the outcomes of the trastuzumab and paclitaxel (TP). Human epidermal growth factor 2 (HER2) positive metastatic breast cancer (MBC) patients who had been treated with TP in single institute from 2006 to 2009 were included in this study. For procured formalin fixed paraffin embedded tumor tissues, HER2 amplification index (AI) and polymorphisms of the immunoglobulin G fragment C receptors (FCGR) were assessed as biomarkers to the trastuzumab and expression of class III beta tubulin (bTubIII) was evaluated as a predictive factor to the paclitaxel. Of 46 patients treated with TP, 27 patients could be evaluated for HER2 AI, 31 for bTubIII, and 26 for FCGR gene polymorphism. The median of the HER2 AI was 5.0 (range, 1.4−15.5) and a higher HER2 AI (≥5.0) was significantly correlated with better response rate (RR) (80% vs. 42%, P = 0.049) and longer progression-free survival (PFS) (13.6 vs. 6.9 months, P = 0.023). High bTubIII expression showed higher RRs than did low expression (81% vs. 40%, P = 0.040) in addition to longer PFS (16.2 months vs. 8.8 months, P = 0.04). However, polymorphisms in FCGR 2A-H131R or FCGR 3A-V158F were not predictive of RR or PFS. Our results suggest that a high HER2 AI and high bTubIII expression could be predictive of the outcomes to TP therapy but no evidence was found in terms of FCGR polymorphisms.     

The inhibitory effects of Nardostachys jatamansi on alcoholic chronic pancreatitis

Nardostachys jatamansi (NJ) belonging to the Valerianaceae family has been used as a remedy for gastrointestinal inflammatory diseases for decades. However, the potential for NJ to ameliorate alcoholic chronic pancreatitis (ACP) is unknown. The aim of this study was to examine the inhibitory effects of NJ on ACP. C57black/6 mice received ethanol injections intraperitoneally for 3 weeks against a background of cerulein-induced acute pancreatitis. During ACP, NJ was ad libitum administrated orally with water. After 3 weeks of treatment, the pancreas was harvested for histological examination. NJ treatment increased the pancreatic acinar cell survival (confirmed by amylase level testing) and reduced collagen deposition and pancreatic stellate cell (PSC) activation. In addition, NJ treatment reduced the activation but not death of PSC. In conclusion, our results suggest that NJ attenuated ACP through the inhibition of PSC activation.     

Physical and functional interactions of Caenorhabditis elegans WRN-1 helicase with RPA-1

The Caenorhabditis elegans Werner syndrome protein, WRN-1, a member of the RecQ helicase family, has a 3'-5' DNA helicase activity. Worms with defective wrn-1 exhibit premature aging phenotypes and an increased level of genome instability. In response to DNA damage, WRN-1 participates in the initial stages of checkpoint activation in concert with C. elegans replication protein A (RPA-1). WRN-1 helicase is stimulated by RPA-1 on long DNA duplex substrates. However, the mechanism by which RPA-1 stimulates DNA unwinding and the function of the WRN-1-RPA-1 interaction are not clearly understood. We have found that WRN-1 physically interacts with two RPA-1 subunits, CeRPA73 and CeRPA32; however, full-length WRN-1 helicase activity is stimulated by only the CeRPA73 subunit, while the WRN-1(162-1056) fragment that harbors the helicase activity requires both the CeRPA73 and CeRPA32 subunits for the stimulation. We also found that the CeRPA73(1-464) fragment can stimulate WRN-1 helicase activity and that residues 335-464 of CeRPA73 are important for physical interaction with WRN-1. Because CeRPA73 and the CeRPA73(1-464) fragment are able to bind single-stranded DNA (ssDNA), the stimulation of WRN-1 helicase by RPA-1 is most likely due to the ssDNA binding activity of CeRPA73 and the direct interaction of WRN-1 and CeRPA73.     

Scaffold Protein Connector Enhancer of Kinase Suppressor of Ras Isoform 3 (CNK3) Coordinates Assembly of a Multiprotein Epithelial Sodium Channel (ENaC)-regulatory Complex

Hormone regulation of ion transport in the kidney tubules is essential for fluid and electrolyte homeostasis in vertebrates. A large body of evidence has suggested that transporters and channels exist in multiprotein regulatory complexes; however, relatively little is known about the composition of these complexes or their assembly. The epithelial sodium channel (ENaC) in particular is tightly regulated by the salt-regulatory hormone aldosterone, which acts at least in part by increasing expression of the serine-threonine kinase SGK1. Here we show that aldosterone induces the formation of a 1.0–1.2-MDa plasma membrane complex, which includes ENaC, SGK1, and the ENaC inhibitor Nedd4-2, a key target of SGK1. We further show that this complex contains the PDZ domain-containing protein connector enhancer of kinase suppressor of Ras isoform 3 (CNK3). CNK3 physically interacts with ENaC, Nedd4-2, and SGK1; enhances the interactions among them; and stimulates ENaC function in a PDZ domain-dependent, aldosterone-induced manner. These results strongly suggest that CNK3 is a molecular scaffold, which coordinates the assembly of a multiprotein ENaC-regulatory complex and hence plays a central role in Na⁺ homeostasis.     

Enforced Expression of Roquin Protein in T Cells Exacerbates the Incidence and Severity of Experimental Arthritis

To investigate the role of Roquin, a RING-type ubiquitin ligase family member, we used transgenic mice with enforced Roquin expression in T cells, with collagen-induced arthritis (CIA). Wild-type (WT) and Roquin transgenic (Tg) mice were immunized with bovine type II collagen (CII). Arthritis severity was evaluated by clinical score; histopathologic CIA severity; proinflammatory and anti-inflammatory cytokine levels; anti-CII antibody levels; and populations of Th1, Th2, germinal center B cells, and follicular helper T cells in CIA. T cell proliferation in vitro and cytokine levels were determined to assess the response to CII. Roquin Tg mice developed more severe CIA and joint destruction compared with WT mice. Production of TNF-α, IFN-γ, IL-6, and pathogenic anti-collagen CII-specific IgG and IgG2a antibodies was increased in Roquin Tg mice. In addition, in vitro T cell assays showed increased proliferation and proinflammatory cytokine production in response to CII as a result of enforced Roquin expression in T cells. Furthermore, the Th1/Th2 balance was altered by an increased Th1 and decreased Th2 population. These findings suggest that overexpression of Roquin exacerbates the development of CIA and that enforced expression of Roquin in T cells may promote autoimmune diseases such as CIA.     

Molecular cloning of rock bream (Oplegnathus fasciatus) tumor necrosis factor-α and its effect on the respiratory burst activity of phagocytes

Rock bream (Oplegnathus fasciatus) tumor necrosis factor-α (rbTNF-α) gene was cloned, recombinantly produced, and the effect of the recombinant rbTNF-α on the respiratory burst activity of rock bream phagocytes was analyzed. Structurally, genomic DNA of rbTNF-α was comprised with four exons and three introns, and deduced amino acid sequence of its cDNA possessed the TNF family signature, a transmembrane domain, a protease cleavage site, and two cysteine residues, which are the typical characteristics of TNF-α gene in mammals and fish. The chemiluminescent (CL) response of rock bream phagocytes was significantly enhanced by pre-incubation with recombinant rbTNF-α, when opsonized zymosan was used as a stimulant of the respiratory burst. However, CL enhancing effect of the recombinant rbTNF-α was very weak when the respiratory burst activity of phagocytes was triggered with phorbol-12-myristate-13-acetate (PMA) instead of zymosan. These results suggest that rock bream TNF-α might have an ability to prime the respiratory burst activity of phagocytes against receptor-mediated phagocytosis inducing stimulants, such as zymosan, but have little ability against stimulants not accompanying receptor-mediated phagocytosis.     

Hyaluronic acid complexed to biodegradable poly L‐arginine for targeted delivery of siRNAs

Background

Small interfering RNA (siRNA) has been recognized as a new therapeutic drug to treat various diseases by inhibition of oncogene or viral gene expression. Because hyaluronic acid (HA) has been described as a biocompatible biomaterial, we tested the nanoparticles formed by electrostatic complexation of negatively‐charged HA and cationic poly L ‐arginine (PLR) for siRNA delivery systems.

Methods

Different electrostatic complexes of HA and PLR (HPs) were formulated: HP101 with 50% (w/w) HA and HP110 with 9% (w/w) HA.

Results

Gel retardation assays showed that HP101 and HP110 could form complexes with siRNAs. The diameters of these complexes were less than 200 nm. Cellular delivery efficiency of siRNAs by HPs depended on cell surface CD44 density. The HP‐mediated delivery of siRNAs was highest in WM266.4 cells followed by B16F10 cells and COS‐7 cells, in parallel with CD44 surface densities of these cell lines. TC₅₀ values (i.e. the HP concentrations at which 50% of cells were viable after treatment) were used as indicators of cytotoxicity. HP101 showed TC₅₀ values that were 2‐fold and 23‐fold higher than those of HP110 and PLR, respectively. After delivery into cells, siRNA exerted target‐specific RNA interference effects on mRNA and protein levels. Three days after treatment of red fluorescent protein (RFP)‐expressing B16F10 cells with RFP‐specific siRNA complexed to HP101, cellular fluorescence signals were reduced. Intratumoral administration of RFP‐specific siRNA via HP101 delivery significantly reduced the expression of RFP in tumor tissues.

Conclusions

HP101 may function as a biocompatible polymeric carrier of siRNAs and have possible application to localized siRNA delivery in vivo. Copyright © 2009 John Wiley & Sons, Ltd.