Carabrol suppresses LPS-induced nitric oxide synthase expression by inactivation of p38 and JNK via inhibition of I-κBα degradation in RAW 264.7 cells

Carabrol, isolated from Carpesium macrocephalum, showed anti-inflammatory potential in LPS-induced RAW 264.7 murine macrophages. In present study, carabrol demonstrated the inhibitory activity on pro-inflammatory cytokines such as IL-1β, IL-6 and TNF-α. In addition, mRNA and protein levels of iNOS and COX-2 were reduced by carabrol. Molecular analysis revealed that these suppressive effects were correlated with the inactivation of p38 and JNK via inhibition of NF-κB activation. Immunoblotting showed that carabrol suppressed LPS-induced degradation of I-κBα and decreased nuclear translocation of p65. Taken together, these results suggest that carabrol can be a modulator of pro-inflammatory signal transduction pathway in RAW 264.7 cells.     

Inhibition of the JNK/Bim pathway by Hsp70 prevents Bax activation in UV-induced apoptosis

Here we studied the mechanism by which heat shock protein 70 (Hsp70) prevents Bax activation during ultraviolet (UV)-induced apoptosis. UV treatment led to c-Jun N-terminal kinase (JNK) phosphorylation, Bim redistribution and subsequent Bax activation. Bim depletion caused a smaller reduction in apoptosis than that by JNK inhibition, indicating that Bim activation is not entirely responsible for induction of apoptosis and other mechanisms are involved. Hsp70 knockdown resulted in high levels of activated JNK and Bax, while Hsp70 overexpression inhibited these processes. These findings demonstrate that Hsp70 prevented Bax activation via inhibiting the JNK/Bim pathway. Simultaneously, increased binding of Hsp70 to Bax was observed. Collectively, our results for the first time demonstrate that Hsp70 prevents Bax activation both by inhibiting the JNK/Bim pathway and by interacting with Bax in UV-induced apoptosis.     

Chiritopsis danxiaensis sp. nov. (Gesneriaceae) from Mount Danxiashan,south China

A new species of Chiritopsis (Gesneriaceae), C. danxiaensis W. B. Liao, S. S. Lin & R. J. Shen, is described and illustrated from Mount Danxiashan, Guangdong Province, China. The new species is morphologically closely related to C. lobulata and C. cordifolia, but is characterized by having denticulate bracts, yellowish corolla, 2 glabrous staminodes and longer style. A revised key to all species of the genus is also provided.     

Purification, characterization, and mode of action of a rhamnogalacturonan hydrolase from Irpex lacteus, tolerant to an acetylated substrate

A novel rhamnogalacturonase (RGase) acting on an acetylated substrate was detected in the commercial preparation Driselase, an enzymatic mixture derived from the basidiomycete Irpex lacteus. The activity was isolated by hydrophobic interaction chromatography, gel filtration, and preparative isoelectric focusing, resulting in the isolation of five different rhamnogalacturonan hydrolases exhibiting various isoelectric points from 6.2 to 7.7. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and mass spectrometry analyses after trypsin cleavage of the five fractions revealed that the five rhamnogalacturonases have a molar mass of 55 kDa without any divergences in the identified peptides. The RGase with a pI of 7.2 exhibited a pH optimum between 4.5 and 5 and a temperature optimum between 40°C and 50°C. Its mode of action was analyzed by mass spectrometry of the oligosaccharides produced after hydrolysis of acetylated and nonacetylated rhamnogalacturonan. Oligomers esterified by an acetyl group on the reducing galacturonic acid residue or fully acetylated were detected in the hydrolysate showing that the novel enzyme is able to bind acetylated galacturonic acid in its active site.     

Effects of 180 mT static magnetic fields on diabetic wound healing in rats

Diabetic wound (DW) problems are becoming a formidable clinical challenge due to the sharp increase in the diabetic population and the high incidence of DW. Static magnetic field (SMF) therapy, an inexpensive and accessible noninvasive method, has been proven to be effective on various tissue repairs. However, the issue of the therapeutic effect of SMF on DW healing has never been investigated. The objective of this study was to systematically evaluate the effect of a 180 mT moderate‐intensity gradient SMF on DW healing in streptozotocin‐induced diabetic rats. Forty‐eight 3‐month‐old male Sprague–Dawley rats (32 diabetic and 16 non‐diabetic rats) were assigned to three equal groups: normal wound, DW, and DW + SMF groups. An open circular wound with 1.5 cm diameter was created in the dorsum. The wound was covered with a dressing and the magnet was fixed on top of the dressing. On days 5, 12, and 19, four rats of each group were euthanized and gross wound area, histology and tensile strength were evaluated. The wound area determination suggested that SMF significantly increased the healing rate and reduced the gross healing time. This result was further confirmed by histological observations. The wound tensile strength, reflecting the amount and quality of collagen deposition, increased to a larger extent in the DW + SMF group on days 12 and 19 compared with the DW group. The results indicated that 180 mT SMF presented a beneficial effect on DW healing, and implied the clinical potential of SMF therapy in accelerating DW repair and releasing the psychological and physical burdens of diabetic patients. Bioelectromagnetics 31:640–648, 2010. © 2010 Wiley‐Liss, Inc.     

Morphological changes in the cephalic salivary glands of females and males of <Emphasis Type="Italic">Apis mellifera</Emphasis> and <Emphasis Type="Italic">Scaptotrigona postica</Emphasis> (Hymenoptera,Apidae)

The cephalic salivary glands of some species of bees are exclusive and well developed only in Apinae. These glands were studied with light and scanning electron microscopy in workers, queens and males from the honey bee Apis mellifera, and the stingless bee Scaptotrigona postica in different life phases. The results show that the cephalic salivary glands are present in females of both the species, and in males of S. postica. Nevertheless, they are poorly developed in young males of A. mellifera. In both species, gland growth is progressive from the time of emergence to the oldest age but, in A. mellifera males, the gland degenerates with age. Scanning electron microscopy shows that the secretory units of newly emerged workers are collapsed while in older workers they are turgid. Some pits on the surface of the secretory units correspond to open intercellular spaces. The possible functions of these glands in females and males of both species are discussed.     

Genetic diversity in the Maremmano horse and its relationship with other European horse breeds

The Maremmano is an Italian warmblood horse breed from central Italy. We characterized the genetic diversity and the degree of admixture in Maremmano in comparison to 14 other European horse breeds using 30 microsatellites. Between-breed diversity explained about 9 per cent of the total genetic diversity. Cluster analysis, genetic distances and genetic differentiation coefficients showed a close relationship of Maremmano with Hanoverian and Lusitano in accordance with breed history.     

Acidic and basic deprotection strategies of borane-protected phosphinothioesters for the traceless Staudinger ligation

The traceless Staudinger ligation has recently found various applications in the field of peptide synthesis and modification, including immobilization and cyclization strategies. In this report, we utilize the traceless Staudinger ligation in the formation of amide bonds, which allows the acquisition of acylated aminosugars and peptides as well as the cyclization of peptides. A key element in these synthetic procedures is the use of a borane-protected phosphinomethanethiol, which is demonstrated to be prone towards oxidation in its unprotected form, during the synthesis of phosphinothioesters. In combination with acidic and basic deprotection strategies for the borane-protected phosphinothioesters, amide bonds can be formed in the presence of azides in moderate to good overall yields.     

Comparative structural studies of two natural isoforms of ammodytoxin,phospholipases A2 from Vipera ammodytes ammodytes which differ in neurotoxicity and anticoagulant activity

Ammodytoxin A (AtxA) and its natural isoform AtxC from the venom of Vipera ammodytes ammodytes belong to group IIA-secreted phospholipases A₂ which catalyze the hydrolysis of glycerophospholipids and exhibit strong neurotoxic and anticoagulant effects. The two isoforms, which differ in sequence by only two amino acid residues (Phe124 > Ile and Lys128 > Glu), display significant differences in toxicity and anticoagulant properties and act on protein targets including neurotoxic proteic receptors and coagulation factor Xa with significantly different strengths of binding.In order to characterize the structural basis of these functional differences, we have determined the crystal structures of the two isoforms. Comparison of the structures shows that the mutation Lys128 > Glu in AtxC could perturb interactions with FXa, resulting in lower anticoagulant activity, since the side chain of Glu128 is partly buried, making a stabilizing hydrogen bond with the main-chain nitrogen atom of residue Thr35. This interaction leads to a displacement of the main polypeptide chain at positions 127 and 128 (identified by mutagenesis as important for interaction with FXa), and a different orientation of the side chain of unmutated Lys127. The mutation Phe124 > Ile in AtxC induces no significant conformational changes, suggesting that the differences in toxicity of the two isoforms are due essentially to differences in surface complementarity in the interaction of the toxin with the neurotoxic protein receptor. The crystal structures also reveal a novel dimeric quaternary association involving significant hydrophobic interactions between the N-terminal α-helices of two molecules of ammodytoxin related by crystallographic symmetry. Interactions at the dimer interface include important contributions from Met7, which is unique to ammodytoxin. Equilibrium sedimentation experiments are consistent with the crystallographic model.Competition experiments using SPR technology show complete inhibition of AtxA binding to FXa by calmodulin (CaM). The crystal structure shows that the C-terminal region, important for binding to FXa and CaM, is fully exposed and accessible for interaction with proteic receptors in both the monomeric and dimeric forms of ammodytoxin described here.