MicroRNA-663 activates the canonical Wnt signaling through the adenomatous polyposis coli suppression.

Rheumatoid arthritis (RA) is a symmetrical polyarticular autoimmune disease of unknown etiology. In this present study, we observed that the adenomatous polyposis coli (APC) expression is down-regulated and the expression of microRNA (miR)-663 increased significantly in synovium from RA patients compared with control. Target gene prediction for miR-663 revealed that the mRNA of APC gene, which is a member of the canonical Wnt signaling pathway, has a miR-663 binding site in its 3'-untranslated region (3'UTR). The result showed that increased miR-663 suppressed the APC expression significantly, and this down-regulation of APC expression triggered the activation of canonical Wnt signaling through accumulation of ß-catenin in fibroblast-like synoviocytes (FLS). In addition, increased miR-663 induced the FLS proliferation and the expression MMP3 and fibronectin during disease development. Therefore, miR-663 can be considered as a critical regulator of RA pathogenesis and can be utilized for developing miRNA-based therapeutic agents for RA patients.

Design of signal peptide bombyxin and its effect on secretory expression efficiency and levels of Helicobacter pylori urease subunit B in silkworm cells and larvae

This study employed a Bac-to-Bac/Bombyx mori bioreactor to mass-produce immunogenic urease subunit B (UreB) from Helicobacter pylori. The signal peptide bombyxin from B. mori was used to promote secretory expression to improve expression levels and was designed and integrated into the UreB gene to generate the Bacmid/BmNPV/(signal peptide)-UreB baculovirus expression system. To determine whether the bombyxin signal peptide resulted in secretory expression of recombinant UreB (rUreB) and to determine the secretory efficiency, we tested the secretory expression level of rUreB in Bm5 cells using ELISA. To further investigate whether secretory expression affected cell viability, cells were evaluated using 0.4% trypan blue staining, and Bacmid/BmNPV/UreB without the signal peptide served as a control. The above recombinant bacmid constructs were injected to silkworm larvae, and the secretory expression level of rUreB was detected using SDS-PAGE and semi-quantitative western blot analysis. The results indicated that the bombyxin signal peptide directed the secretory expression of rUreB and that this expression improved the viability of Bm5 cells. Moreover, the results showed that the expression level of rUreB was 1.5 times higher with the Bacmid/BmNPV constructs containing the bombyxin signal sequence than those without the signal sequence. These results demonstrate that secretory expression can enhance rUreB expression levels and is likely to aid in the large-scale expression and yield of rUreB in silkworm larvae.

The synthetic antimicrobial peptide pexiganan and its nanoparticles (PNPs) exhibit the anti-helicobacter pylori activity in vitro and in vivo.

The aim of this study was to probe the potential anti-H. pylori activity of the synthetic antimicrobial peptide pexiganan, which is an analog of the peptide magainin, and its nanoparticles (PNPs) that were prepared in our laboratory. To compare their antibacterial effects in vitro and in vivo, studies of H. pylori growth inhibition, kinetics and resistance assays were undertaken. The gastric mucoadhesive efficiency and H. pylori clearance efficiency of pexiganan and PNPs were evaluated in rats and mice infected with H. pylori. The eradication of H. pylori was determined using urease tests and a microbial culture method. We observed that PNPs adhered to gastric mucosa more effectively owing to a prolonged stay in the stomach, which resulted in a more effective H. pylori clearance. In addition, PNPs had greater anti-H. pylori effect than pexiganan in infected mice. The amount of pexiganan required to eradicate H. pylori was significantly less using PNPs than the corresponding pexiganan suspension. The results confirmed that PNPs improved peptide stability in the stomach and more effectively eradicated H. pylori from mice stomachs than pexiganan.

Resveratrol down-regulates Myosin light chain kinase, induces apoptosis and inhibits diethylnitrosamine-induced liver tumorigenesis in rats.

Hepatocellular carcinoma (HCC) is a serious healthcare problem worldwide because of its increasing morbidity and high mortality rates. However, our understanding of the mechanism of liver tumorigenesis remains incomplete. We report the expression of myosin light chain kinase (MLCK) in the livers of rats with diethylnitrosamine (DENA)-induced HCC and investigated the correlation between MLCK and liver tumorigenesis by observing the expression of MLCK in a rat model of HCC. HCC was induced in rats by an intraperitoneal injection of DENA, and resveratrol-treated rats were orally administered resveratrol with 50 mg/kg body weight/day. The livers of rats were excised after 20 weeks and immersed in 10% formaldehyde prior to immunohistochemical and Western blot analyses for determining the level of MLCK expression. These analyses indicated that the MLCK expression was higher in the livers of HCC rats than in normal and resveratrol-treated rats. High level of MLCK expression was responsible for proliferation and anti-apoptotic effects. However, resveratrol down-regulated the expression of MLCK, which induced cell apoptosis and inhibited liver tumorigenesis in rats with DENA-induced HCC. Our results suggest that the over expression of MLCK may be related to the development of liver tumorigenesis.

The effects of (±)-Praeruptorin A on airway inflammation, remodeling and transforming growth factor-ß1/Smad signaling pathway in a murine model of allergic asthma.

(±)-Praeruptorin A (PA) is a pair of coumarin enantiomers isolated from the root of Peucedanum praeruptorum Dunn (PPD), a common Chinese herbal medicine for the treatment of asthma. Considering its anti-inflammatory, anti-contractile and anti-hyperplasia activities, the effects of PA on airway inflammation and airway remodeling were investigated using a murine model of chronic asthma. Ovalbumin-sensitized BALB/c mice were challenged with ovalbumin to induce asthma every other day on eight successive weeks. PA was administered intragastrically before every ovalbumin challenge. Airway responsiveness was evaluated by a lung function analysis system 48 h after the last ovalbumin challenge. The total and differential leukocytes in bronchoalveolar lavage fluid (BALF) were counted using a hemocytometer and Diff-Quick-stained smears. Lung tissue samples were used for hematoxylin and eosin, periodic acid Schiff, Masson's trichrome and α-SMA immunohistochemistry staining. Levels of cytokines in BALF, immunoglobulin (Ig) E in serum as well as expression of TGF-ß1 and Smad proteins in lung tissue were measured by enzyme-linked immunosorbent assay, immunohistochemistry or western blot analysis. Compared with the model group, PA suppressed airway inflammation, airway hyperresponsive and remodeling, reduced levels of IL-4 and IL-13 in BALF, and IgE in serum, inhibited expression of TGF-ß1 and pSmad2/3, up-regulated the expression of Smad7 in lung tissue, and also increased the levels of INF-γ in BALF. These results suggested that PA significantly suppressed airway inflammation and airway remodeling induced by ovalbumin challenge, and is a potential candidate for the treatment of asthma.