Differential activation of the rice sucrose nonfermenting1-related protein kinase2 family by hyperosmotic stress and abscisic acid

To date, a large number of sequences of protein kinases that belong to the sucrose nonfermenting1-related protein kinase2 (SnRK2) family are found in databases. However, only limited numbers of the family members have been characterized and implicated in abscisic acid (ABA) and hyperosmotic stress signaling. We identified 10 SnRK2 protein kinases encoded by the rice (Oryza sativa) genome. Each of the 10 members was expressed in cultured cell protoplasts, and its regulation was analyzed. Here, we demonstrate that all family members are activated by hyperosmotic stress and that three of them are also activated by ABA. Surprisingly, there were no members that were activated only by ABA. The activation was found to be regulated via phosphorylation. In addition to the functional distinction with respect to ABA regulation, dependence of activation on the hyperosmotic strength was different among the members. We show that the relatively diverged C-terminal domain is mainly responsible for this functional distinction, although the kinase domain also contributes to these differences. The results indicated that the SnRK2 protein kinase family has evolved specifically for hyperosmotic stress signaling and that individual members have acquired distinct regulatory properties, including ABA responsiveness by modifying the C-terminal domain.     

Inhibition of joint inflammation and destruction induced by anti-type II collagen antibody/lipopolysaccharide (LPS)-induced arthritis in mice due to deletion of macrophage migration inhibitory factor (MIF)

OBJECTIVE: Previous studies have demonstrated that neutralization of macrophage migration inhibitory factor (MIF) by anti-MIF antibody decreases joint destruction in the collagen-induced arthritis model. The present study was undertaken to investigate whether selective deletion of MIF inhibits inflammation and joint destruction of the anti-type II collagen antibody (anti-CII Ab)/lipopolysaccharide (LPS)-induced arthritis in mice, in order to determine the role of this cytokine in inflammatory arthritis. DESIGN: Anti-CII Ab/LPS-induced arthritis was induced in MIF-deficient and wild-type mice. The effects of anti-MIF polyclonal antibody administration on anti-CII Ab-induced arthritis were also evaluated. RESULTS: The expression of MIF protein and mRNA was induced in anti-CII Ab/LPS-induced arthritis joint tissues. Histopathological arthritis scores for synovial inflammation induced by anti-CII Ab/LPS -induced arthritis were significantly decreased in anti-MIF Ab-treated mice and in MIF-deficient mice compared to wild-type mice. In addition, mRNA levels of MMP-13 and MIP-2 in anti-CII Ab/LPS-induced arthritis joint tissues were significantly reduced in MIF-deficient mice compared to wild-type control mice. CONCLUSIONS: These results indicate that MIF plays a critical role in inflammation and joint destruction in the anti-CII Ab/LPS-induced arthritis model in mice, in part via induction of MMP-13 and neutrophil infiltration through the induction of MIP-2.     

New broad-spectrum parenteral cephalosporins exhibiting potent activity against both methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. Part 3: 7beta-[2-(5-Amino-1,2,4-thiadiazol-3-yl)-2-ethoxyiminoacetamido] cephalosporins bearing 4-[3-(aminoalkyl)-ureido]-1-pyridinium at C-3'

Among the prepared C-3' substituted-pyridinium cephalosporins, a series of 7beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-ethoxyiminoacetamido] cephalosporins bearing 4-[3-(aminoalkyl)-ureido]-1-pyridinium at C-3' showed highly potent antibacterial activity against MRSA and Pseudomonas aeruginosa.     

Functional characterization of prostaglandin F2alpha receptor in the spinal cord for tactile pain (allodynia)

Prostaglandin F2alpha (PGF2alpha) binds to its receptor (FP) to increase the intracellular-free calcium concentration ([Ca2+]i) by coupling of FP with Gq protein. Spinal intrathecal administration of PGF2alpha to mouse induces touch-evoked pain (mechanical allodynia), in which capsaicin-insensitive primary afferent Abeta-fibres and N-methyl-d-aspartate receptor epsilon 4 subunit are involved. FP in the spinal cord, however, was not well characterized. Here, we showed constitutive expression of FP mRNA in mouse spinal cord, and functionally characterized spinal FP-expressing cells which were involved in PGF2alpha-induced mechanical allodynia. The method for repetitive administration of oligodeoxyribonucleotides through tubing to conscious mice was established for mechanical allodynia evaluation. We identified an antisense oligodeoxyribonucleotide targeting FP mRNA, causing both disappearance of PGF2alpha-induced mechanical allodynia and decrease of FP mRNA. With saline-administered mice, PGF2alpha rapidly increased [Ca2+]i of the cells in the deeper layer of the dorsal horn. In contrast, when the FP antisense oligodeoxyribonucleotide was repeatedly administered, the population of PGF2alpha-responsive cells in the slices reduced, and PGF2alpha-induced [Ca2+]i increase of these cells diminished. These data strongly suggested that, in the dorsal horn of the spinal cord, there are the FP-expressing cells which are involved in PGF2alpha-induced mechanical allodynia.     

Feasibility of polysaccharide hybrid materials for scaffolds in cartilage tissue engineering: evaluation of chondrocyte adhesion to polyion complex fibers prepared from alginate and chitosan

The ideal cell-carrier material for cartilage regeneration should be one that closely mimics the natural environment in a living articular cartilage matrix. In the current study, we considered that alginate-based chitosan hybrid biomaterials could provide excellent supports for chondrocyte adhesion. To test this hypothesis, we investigated the adhesion behavior of rabbit chondrocytes onto an alginate polymer versus the adhesion of the chondrocytes onto some alginate-based chitosan hybrid polymer fibers in vitro. We demonstrated that the alginate-based chitosan hybrid polymer fibers showed much improved adhesion capacity with chondrocytes in comparison with alginate polymer fiber. Additionally, morphologic studies revealed maintenance of the characteristic round morphology of the chondrocyte and the dense fiber of the type II collagen produced by the chondrocytes in the hybrid polymer. On the basis of these results, we conclude that an alginate-based chitosan hybrid polymer fiber has considerable potential as a desirable biomaterial for cartilage tissue scaffolds.     

A Confirmation of 125I-ω-Conotoxin Labeled Sites in a Crude Membrane Fraction from Chick Brain as the α1 Subunit of N-Type Calcium Channels

Omega-conotoxin GVIA (-CTX), as a selective blocker for an N-type Ca²⁺ channel, has been conveniently used in many molecular biochemical and pharmacological experiments. There has been little elucidation of ¹²⁵I--CTX binding sites (mainly the 135-kDa band) in the crude membranes from chick brain, although the characteristics of specific ¹²⁵I--CTX binding and labeling sites in chick brain membranes have been investigated in our previous research. In this work, our goal is to further identify ¹²⁵I--CTX labeling sites in chick brain membranes by using anti-B1Nt antibodies (against the N-terminal segment B1Nt of N- or P-type Ca²⁺ channel ₁-subunits). The ¹²⁵I--CTX–labeled sites in chick brain membranes could be solubilized and immunoprecipitated by using an anti B1Nt antibody. The molecular weight of the immunoprecipitated protein was determined as 135 kDa, which is inconsistent with that of the specific ¹²⁵I--CTX binding protein reported previously. Moreover, the ¹²⁵I--CTX–labeled protein could be purified by the method of preparative SDS-PAGE and recognized by anti-B1Nt antibodies in Western blotting analysis. These results indicated that anti-B1Nt antibodies could truly recognize ¹²⁵I--CTX–labeled sites as the main band of 135 kDa from chick brain membranes, and the -CTX–labeled site (mainly the 135-kDa band) should be N-type Ca²⁺ channel ₁-subunits.