Many transcription coactivators interact with nuclear receptors in a ligandThe nuclear receptor superfamily is a group of proteins that regulate, in a ligand-dependent manner, transcriptional initiation of target genes by binding to specific DNA sequences named hormone response elements (reviewed in reference 23). Functional analysis of nuclear receptors has shown that there are two major activation domains. The N-terminal domain (AF1) contains a ligand-independent activation function, whereas the ligand-binding domain (LBD) exhibits ligand-dependent transactivation function (AF2). The AF2 core region, located at the extreme C terminus of the receptor LBDs, is conserved among nuclear receptors and undergoes a major conformational change upon ligand binding (23). This region has been shown to play a critical role in mediating transactivation by serving as a ligand-dependent interaction interface with many different coactivators (reviewed in reference 9). These coactivators, including the p160 family members (i.e., SRC-1, SRC-2/GRIP1/TIF2, and SRC-3/ACTR/pCIP/AIB1/ RAC3/TRAM1), CBP/p300, p/CAF, TRAP/DRIP, activating signal cointegrator 2 (ASC-2), and many others, bridge nuclear receptors and the basal transcription apparatus and/or remodel the chromatin structures (9).Chromatin, the physiological template of all eukaryotic genetic information, undergoes a diverse array of posttranslational modifications that largely impinge on histone amino termini, thereby regulating access to the underlying DNA (reviewed in reference 12). SRC-1 and the p160 family member ACTR, along with CBP and p300, were recently shown to contain histone acetyltransferase (HAT) activities and associate with yet another HAT protein, p/CAF (9). In contrast, SMRT and N-CoR, nuclear receptor corepressors, form complexes with Sin3 and histone deacetylase proteins (9). These results are consistent with the notion that the acetylation of histones destabilizes nucleosomes and relieves transcriptional repression by allowing transcription factors to access recognition elements, whereas deacetylation of the histones stabilizes the repressed state. More recently, the histone arginine methyltransferases CARM1 and PRMT1 were newly defined as transcriptional coactivators of nuclear receptors (4, 40). NSD1 and

Hyperglycemia in the diabetic state increases oxidative stress and antioxidant therapy can be strongly correlated with decreased risks for diabetic complications. The purpose of this study is to determine antioxidant effect of garlic and aged black garlic in animal model of type 2 diabetes. The antioxidant activity of garlic and aged black garlic was measured as the activity in scavenging free radicals by the trolox equivalent antioxidant capacity (TEAC) assay. Three week-old db/db mice were fed AIN-93G diet or diet containing 5% freeze-dried garlic or aged black garlic for 7 weeks after 1 week of adaptation. Hepatic levels of lipid peroxides and activities of antioxidant enzymes were measured. TEAC values of garlic and aged black garlic were 13.3 ± 0.5 and 59.2 ± 0.8 µmol/g wet weight, respectively. Consumption of aged black garlic significantly decreased hepatic thiobarbituric acid reactive substances (TBARS) level compared with the garlic group which showed lower TBARS level than control group (p<0.05). Activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) of garlic and aged black garlic group were significantly elevated compared to the control group. Catalase (CAT) activity of aged black garlic group was increased compared with the control group. These results show that aged black garlic exerts stronger antioxidant activity than garlic in vitro and in vivo, suggesting garlic and aged black garlic, to a greater extent, could be useful in preventing diabetic complications.

The objective of this study was to investigate the hypoglycemic effects of quercetin (QE) in animal models of diabetes mellitus (DM). A starch solution (1 g/kg) with and without QE (100 mg/kg) or acarbose (40 mg/kg) was orally administered to streptozotocin (STZ)-induced diabetic rats after an overnight fast. Postprandial plasma glucose levels were measured and incremental areas under the response curve were calculated. To study the effects of chronic feeding of QE, five-week-old db/db mice were fed an AIN-93G diet, a diet containing QE at 0.08%, or a diet containing acarbose at 0.03% for 7 weeks after 1 week of adaptation. Plasma glucose and insulin, blood glycated hemoglobin, and maltase activity of the small intestine were measured. Oral administration of QE (100 mg/kg) or acarbose (40 mg/kg) to STZ-treated rats significantly decreased incremental plasma glucose levels 30-180 min after a single oral dose of starch and the area under the postprandial glucose response, compared with the control group. QE (0.08% of diet) or acarbose (0.03% of diet) offered to db/db mice significantly reduced both plasma glucose and blood glycated hemoglobin compared to controls without significant influence on plasma insulin. Small intestine maltase activities were significantly reduced by consumption of QE or acarbose. Thus, QE could be effective in controlling fasting and postprandial blood glucose levels in animal models of DM.

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Insect survival depends on contact chemosensation to sense and avoid consuming plant-derived insecticides, such as l-canavanine. Members of a family of ~60 gustatory receptors (GRs) comprise the main peripheral receptors responsible for taste sensation in Drosophila. However, the roles of most Drosophila GRs are unknown. In addition to GRs, a G-protein coupled receptor (GPCR), DmXR, has been reported to be required for detecting l-canavanine. Here, we showed that GRs are essential for responding to l-canavanine, and that flies missing DmXR displayed normal l-canavanine avoidance and l-canavanine evoked action potentials. Mutations disrupting either Gr8a or Gr66a resulted in an inability to detect l-canavanine. We found that l-canavanine stimulated action potentials in S-type sensilla, which are where Gr8a and Gr66a were both expressed, but not in Gr66a-expressing sensilla that did not express Gr8a. l-canavanine-induced action potentials were also abolished in the Gr8a and Gr66a mutant animals. Gr8a was narrowly required for responding to l-canavanine, in contrast to Gr66a, which was broadly required for responding to other noxious tastants. Our data suggest that GR8a and GR66a are subunits of an l-canavanine receptor, and that GR8a contributes to the specificity for l-canavanine.

Numerous studies have demonstrated that aged black garlic (ABG) has strong anti-oxidant activity. Little is known however regarding the anti-inflammatory activity of ABG. This study was performed to identify and compare the anti-oxidant and anti-inflammatory effects of ABG extract (ABGE) with those of fresh raw garlic (FRG) extract (FRGE). In addition, we investigated which components are responsible for the observed effects. Hydrogen peroxide (H2O2) and lipopolysaccharide (LPS) were used as a pro-oxidant and pro-inflammatory stressor, respectively. ABGE showed high ABTS and DPPH radical scavenging activities and low ROS generation in RAW264.7 cells compared with FRGE. However, inhibition of cyclooxygenase-2 and 5-lipooxygenase activities by FRGE was stronger than that by ABGE. FRGE reduced PGE₂, NO, IL-6, IL-1β, LTD₄, and LTE₄ production in LPS-activated RAW264.7 cells more than did ABGE. The combination of FRGE and sugar (galactose, glucose, fructose, or sucrose), which is more abundant in ABGE than in FRGE, decreased the anti-inflammatory activity compared with FRGE. FRGE-induced inhibition of NF-κB activation and pro-inflammatory gene expression was blocked by combination with sugars. The lower anti-inflammatory activity in ABGE than FRGE could result from the presence of sugars. Our results suggest that ABGE might be helpful for the treatment of diseases mediated predominantly by ROS.

Human plasma is the most clinically valuable specimen, containing not only a dynamic concentration range of protein components, but also several groups of high-abundance proteins that seriously interfere with the detection of low-abundance potential biomarker proteins. To establish a high-throughput method for efficient depletion of high-abundance proteins and subsequent fractionation, prior to molecular analysis of proteins, we explored how coupled immunoaffinity columns, commercially available as multiple affinity removal columns (MARC) and free flow electrophoresis (FFE), could apply to the HUPO plasma proteome project. Here we report identification of proteins and construction of a human plasma 2-DE map devoid of six major abundance proteins (albumin, transferrin, IgG, IgA, haptoglobin, and antitrypsin) using MARC. The proteins were identified by PMF, matching with various internal 2-DE maps, resulting in a total of 144 nonredundant proteins that were identified from 398 spots. Tissue plasminogen activator, usually present at 10-60 ng/mL plasma, was also identified, indicative of a potentially low-abundance biomarker. Comparison of representative 2-D gel images of three ethnic groups (Caucasian, Asian-American, African-American) plasma exhibited minor differences in certain proteins between races and sample pretreatment. To establish a throughput fractionation of plasma samples by FFE, either MARC flow-through fractions or untreated samples of Korean serum were subjected to FFE. After separation of samples on FFE, an aliquot of each fraction was analyzed by 1-D gel, in which MARC separation was a prerequisite for FFE work. Thus, a working scheme of MARC --> FFE --> 1-D PAGE --> 2-D-nanoLC-MS/MS may be considered as a widely applicable standard platform technology for fractionation of complex samples like plasma.

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