Seasonal changes of functional groups in coleopteran communities in pine forests

Fauna assemblages reflect their habitat relating to ecological function in an ecosystem. The functional groups are concerned with how a resource is processed by different species to provide a specific ecosystem service or function. We elucidated seasonal changes of coleopteran functional groups in forests, and evaluated their ecological roles related to available food resources. Coleopteran communities were collected weekly or biweekly using Malaise traps at nine study sites in Japanese red pine forests in Korea from late June to September 2005. Compositions of the functional groups were compared at the different sites and at sampling times with respect to taxa richness and abundance. Cluster analysis and non-metric multidimensional scaling were used to characterize spatial and temporal changes of functional groups. Herbivores and dead/live wood feeders regulating primary production in the pine forests were the dominant coleopteran groups in July, followed by detritivores and predators that dominated from July to August, resulting from the accumulation of detritus. Then, fungivores became dominant due to increased fungal biomass in the forest. Seasonal changes of coleopteran functional groups shifted from regulators of primary production to regulators of decomposition, reflecting their available food resources. In addition, abundance of detritivores and predators were dependent on total abundance of coleopterans, suggesting that these two groups reflect their habitat condition.     

Discovery of imidazo[1,2-b]pyridazine derivatives as IKKβ inhibitors. Part 1: Hit-to-lead study and structure–activity relationship

Imidazo[1,2-b]pyridazine derivatives from high-throughput screening were developed as IKKβ inhibitors. By the optimization of the 3- and 6-position of imidazo[1,2-b]pyridazine scaffold, cell-free IKKβ inhibitory activity and TNFα inhibitory activity in THP-1 cell increased. Also, these compounds showed high kinase selectivity. The structure–activity relationship was revealed and the interaction model of imidazo[1,2-b]pyridazine compounds with IKKβ was constructed.     

Dammarane-type saponins from the flower buds of Panax ginseng and their effects on human leukemia cells

Six dammarane-type saponins, including three new compounds, floralginsenosides Ta–Tc (1–3), and three known, floralginsenoside Td (4), ginsenoside F₁ (5), and ginsenoside F₅ (6), were isolated from the flower buds of Panax ginseng. Floralginsenoside Td (4) was first isolated from natural plant sources. Their structures were elucidated on the basis of extensive chemical and spectroscopic methods. Compounds 1, 5, and 6 showed cytotoxic activities towards the HL-60 human leukemia cell line with respective IC₅₀ values of 36.3, 23.2, and 62.4 μM. In addition, after the HL-60 cells were treated with these compounds, several apoptosis events, including chromatin condensation and increase in the population of sub-G1 hypodiploid cells, were observed.     

A stereo-controlled synthesis of 2,4-dimethyl-4-hydroxy-16-phenylhexadecanoic acid 1,4-lactone and its PPAR activities

A novel class of natural PPAR agonists, 2,4-dimethyl-4-hydroxy-16-phenylhexadecanoic acid 1,4-lactone (1), were discovered in marine natural product libraries. The synthesis of 1 was accomplished starting from vinylmethyl ketone. Ring formation of the α,γ dialkyl γ-lactone was achieved via the stereo-controlled reaction of a ketyl radical anion with a chiral methacrylate. In the PPAR agonistic assay, the most potent of the four stereoisomers had EC₅₀ values of 12 μM for mPPARα, 9 μM for mPPARδ and >100 μM for mPPARγ.     

Asymmetric synthesis of (S)-ethyl-4-chloro-3-hydroxy butanoate using a Saccharomyces cerevisiae reductase: Enantioselectivity and enzyme–substrate docking studies

Ethyl (S)-4-chloro-3-hydroxy butanoate (ECHB) is a building block for the synthesis of hypercholesterolemia drugs. In this study, various microbial reductases have been cloned and expressed in Escherichia coli. Their reductase activities toward ethyl-4-chloro oxobutanoate (ECOB) have been assayed. Amidst them, Baker's yeast YDL124W, YOR120W, and YOL151W reductases showed high activities. YDL124W produced (S)-ECHB exclusively, whereas YOR120W and YOL151W made (R)-form alcohol. The homology models and docking models with ECOB and NADPH elucidated their substrate specificities and enantioselectivities. A glucose dehydrogenase-coupling reaction was used as NADPH recycling system to perform continuously the reduction reaction. Recombinant E. coli cell co-expressing YDL124W and Bacillus subtilis glucose dehydrogenase produced (S)-ECHB exclusively.     

Proteomic analysis of human gastric juice: a shotgun approach

Gastric juice is the most proximal fluid surrounding the stomach tissue. The analysis of gastric juice protein contents will thus be able to accurately reflect the pathophysiology of the stomach. This biological fluid is also a potential reservoir of secreted biomarkers in higher concentration as compared to the serum. Unlike the rest of the gastrointestinal fluids, there were very few studies reported on gastric juice proteome. To date, the proteins that routinely populate this biofluid are largely unknown. This is partly due to the technical difficulties in processing a sample that contains a collection of other gastrointestinal fluids, especially saliva. In this study, we attempt to profile the protein components of the gastric fluids from chronic gastritis patients using a direct shotgun proteomics approach. These data represent the first report of the proteome of human gastric juice with gastritis background.     

Global gene expression profile of Orientia tsutsugamushi

Orientia tsutsugamushi, an obligate intracellular bacterium, is the causative agent of Scrub typhus. The control mechanisms for bacterial gene expression are largely unknown. Here, the global gene expression of O. tsutsugamushi within eukaryotic cells was examined using a microarray and proteomic approaches for the first time. These approaches identified 643 genes, corresponding to approximately 30% of the genes encoded in the genome. The majority of expressed genes belonged to several functional categories including protein translation, protein processing/secretion, and replication/repair. We also searched the conserved sequence blocks (CSBs) in the O. tsutsugamushi genome which is unique in that up to 40% of its genome consists of dispersed repeated sequences. Although extensive shuffling of genomic sequences was observed between two different strains, 204 CSBs, covering 48% of the genome, were identified. When combining the data of CSBs and global gene expression, the CSBs correlates well with the location of expressed genes, suggesting the functional conservation between gene expression and genomic location. Finally, we compared the gene expression of the bacteria‐infected fibroblasts and macrophages using microarray analysis. Some major changes were the downregulation of genes involved in translation, protein processing and secretion, which correlated with the reduction in bacterial translation rates and growth within macrophages.     

Differential expression of skeletal muscle proteins in high‐fat diet‐fed rats in response to capsaicin feeding

In this study, the effects of capsaicin on expression of skeletal muscle proteins in Sprague–Dawley rats fed with a high‐fat diet (HFD) were investigated. Rats were fed a HFD with or without capsaicin treatment for 8 wk. After HFD feeding, capsaicin‐treated rats weighed an average of 8% less than those of the HFD control group. Gastrocnemius muscle tissue from lean and obese rats with or without capsaicin treatment was arrayed using 2‐DE for detection of HFD‐associated markers. Proteomic analysis using 2‐DE demonstrated that 36 spots from a total of approximately 600 matched spots showed significantly different expression; 27 spots were identified as gastrocnemius muscle proteins that had been altered in response to capsaicin feeding, and 6 spots could not be identified by mass fingerprinting. Expression of various muscle proteins was determined by immunoblot analysis for the determination of molecular mechanisms, whereby capsaicin caused inhibition of adipogenesis. Immunoblot analysis revealed increased uncoupling protein 3 (UCP3) protein expression in HFD‐fed rats, whereas contents were reduced with capsaicin treatment. Compared with the HFD control group, capsaicin treatment increased phosphorylation of AMP‐activated protein kinase (AMPIC) CP3 and acetyl‐CoA carboxylase (ACC). To support this result, we also analyzed in vitro differential protein expression in L6 skeletal muscle cells. These data suggest that the AMPK‐ACC‐malonyl‐CoA metabolic signaling pathway is one of the targets of capsaicin action. To the best of our knowledge, this is the first proteomic study to report on analysis of diet‐induced alterations of protein expression that are essential for energy expenditure in rat muscle.