Hepatic expression of cytochrome P450 in type 2 diabetic Goto-Kakizaki rats

Although hepatic expression of cytochrome P450 (CYP) changes markedly in diabetes, the role of ketone bodies in the regulation of CYP in diabetes is controversial. The present study was performed to determine the expression and activity of CYP in non-obese type II diabetic Goto-Kakizaki (GK) rats with normal levels of ketone bodies. In the present study, basal serum glucose levels increased 1.95-fold in GK rats, but acetoacetate and β-hydroxybutyrate levels were not significantly different. Hepatic expression of CYP reductase and CYP3A2 was up-regulated in the GK rats, and consequently, activities of CYP reductase and midazolam 4-hydroxylase, mainly catalyzed by CYP3A2, increased. In contrast, hepatic expression of CYP1A2 and CYP3A1 was down-regulated and the activities of 7-ethoxyresorufin-O-deethylase and 7-methoxyresorufin-O-demethylase, mainly catalyzed by CYP1A, also decreased in GK rats. Hepatic levels of microsomal protein and total CYP and hepatic expression of cytochrome b(5), CYP1B1, CYP2B1 and CYP2C11 were not significantly different between the GK rats and normal Wistar rats. Moreover, the expression and activity of CYP2E1, reported to be up-regulated in diabetes with hyperketonemia, were not significantly different between GK rats and control rats, suggesting that elevation of ketone bodies plays a critical role in the up-regulation of hepatic CYP2E1 in diabetic rats. Our results showed that the expression of hepatic CYP is regulated in an isoform-specific manner. The present results also show that the GK rat is a useful animal model for the pathophysiological study of non-obese type II diabetes with normal ketone body levels.     

Characteristics of DNase activities in excretory/secretory products of infective larvae of Haemonchus contortus

While multiple DNase activities occur in the excretory/secretory products (ESPs) of the adult Haemonchus contortus, the DNase activities in ESPs of the infective larvae (L3) have not been studied. Thus, the DNase activities in ESPs of H. contortus L3 were investigated and compared to those of adults for developmental stage-specific analysis. The DNase activities had relative molecular masses (M rs) of 34 and 36 kDa upon zymographic analysis at pH 5.0 and 7.0 when the larvae were incubated for over 48 h. The 34 and 36 kDa DNases of L3 ESPs were also detected in adult ESPs with similar characteristics. However, the 37 and 38.5 kDa DNases of the adult ESPs were not detected in the L3 ESPs. Since the 37 and 38.5 kDa DNase activities were mainly detected in adult ESPs, these activities appear to be specific to the adult stage whereas the other ESP DNase activities appear to be expressed during multiple stages of the parasite's life cycle. While the difference in DNase activities of L3 and adults remains obscure, the role of DNase in larval development should be further clarified and the identification of stage-specific developmental markers will lead to the discovery of specific factors that stimulate larval development.     

Draft Genome Sequencing of Bacillus sp. Strain M2-6, Isolated from the Roots of Korean Ginseng,Panax ginseng C. A. Meyer,after High-Hydrostatic-Pressure Processing

A bacterium, designated M2-6, was isolated from Korean ginseng, Panax ginseng C. A. Meyer, roots after high-hydrostatic-pressure processing. On the basis of 16 rRNA gene phylogeny, the isolate was presumptively identified as a Bacillus sp. Here we report the draft genome sequence of Bacillus sp. strain M2-6 (= KACC 16563).     

In vitro and in vivo osteogenic activity of licochalcone A

We investigated the in vitro and in vivo osteogenic activity of licochalcone A. At low concentrations, licochalcone A stimulated the differentiation of mouse pre-osteoblastic MC3T3-E1 subclone 4 (MC4) cells and enhanced the bone morphogenetic protein (BMP)-2-induced stimulation of mouse bi-potential mesenchymal precursor C2C12 cells to commit to the osteoblast differentiation pathway. This osteogenic activity of licochalcone A was accompanied by the activation of extracellular-signal regulated kinase (ERK). The involvement of ERK was confirmed in a pharmacologic inhibition study. Additionally, noggin (a BMP antagonist) inhibited the osteogenic activity of licochalcone A in C2C12 cells. Licochalcone A also enhanced the BMP-2-stimulated expression of various BMP mRNAs. This suggested that the osteogenic action of licochalcone A in C2C12 cells could be dependent on BMP signaling and/or expression. We then tested the in vivo osteogenic activity of licochalcone A in two independent animal models. Licochalcone A accelerated the rate of skeletal development in zebrafish and enhanced woven bone formation over the periosteum of mouse calvarial bones. In summary, licochalcone A induced osteoblast differentiation with ERK activation in both MC4 and C2C12 cells and it exhibited in vivo osteogenic activity in zebrafish skeletal development and mouse calvarial bone formation. The dual action of licochalcone A in stimulating bone formation and inhibiting bone resorption, as described in a previous study, might be beneficial in treating bone-related disorders.     

Dipeptidyl peptidase-4 inhibitor with β-amino amide scaffold: Synthesis, SAR and biological evaluation

Inhibitors of dipeptidyl peptidase-4 (DPP4) have been shown to be effective treatments for type 2 diabetes. Several series of β-amino amide containing piperazine derivatives have been prepared and evaluated as a inhibitor of DPP4. Finally compound 5m was selected for further evaluation.     

Synthesis of norlignans and in vitro inhibitory activity of antigen-induced degranulation

The synthesis and biological evaluation of a series of novel norlignans are described. Norlignans were evaluated for their inhibitory activity on the release of β-hexosaminidase, a marker of degranulation, from RBL-2H3 cells induced by the IgE-antigen complex. The results showed that norlignans 4c and 4e potently inhibited degranulation, with IC(50) values of 18.3 and 17.9 μM, respectively.     

Roles of four Arabidopsis u-box e3 ubiquitin ligases in negative regulation of abscisic Acid-mediated drought stress responses

AtPUB18 and AtPUB19 are homologous U-box E3 ubiquitin ligases in Arabidopsis (Arabidopsis thaliana). AtPUB19 is a negative regulator of abscisic acid (ABA)-mediated drought responses, whereas the role of AtPUB18 in drought responses is unknown. Here, loss-of-function and overexpression tests identified AtPUB18 as a negative regulator in ABA-mediated stomatal closure and water stress responses. The atpub18-2atpub19-3 double mutant line displayed more sensitivity to ABA and enhanced drought tolerance than each single mutant plant; therefore, AtPUB18 and AtPUB19 are agonistic. Stomatal closure of the atpub18-2atpub19-3 mutant was hypersensitive to hydrogen peroxide (H(2)O(2)) but not to calcium, suggesting that AtPUB18 and AtPUB19 exert negative effects on the ABA signaling pathway downstream of H(2)O(2) and upstream of calcium. AtPUB22 and AtPUB23 are other U-box E3 negative regulators of drought responses. Although atpub22atpub23 was more tolerant to drought stress relative to wild-type plants, its ABA-mediated stomatal movements were highly similar to those of wild-type plants. The atpub18-2atpub19-3atpub22atpub23 quadruple mutant exhibited enhanced tolerance to drought stress as compared with each atpub18-2atpub19-3 and atpub22atpub23 double mutant progeny; however, its stomatal behavior was almost identical to the atpub18-2atpub19-3 double mutant in the presence of ABA, H(2)O(2), and calcium. Overexpression of AtPUB18 and AtPUB19 in atpub22atpub23 effectively hindered ABA-dependent stomatal closure, but overexpression of AtPUB22 and AtPUB23 in atpub18-2atpub19-3 did not inhibit ABA-enhanced stomatal closure, highlighting their ABA-independent roles. Overall, these results suggest that AtPUB18 has a linked function with AtPUB19, but is independent from AtPUB22 and AtPUB23, in negative regulation of ABA-mediated drought stress responses.     

Fine mapping and identification of candidate rice genes associated with qSTV11 SG , a major QTL for rice stripe disease resistance

Rice stripe disease, caused by rice stripe virus (RSV) is a serious constraint to rice production in subtropical regions of East Asia. We performed fine mapping of a RSV resistance QTL on chromosome 11, qSTV11 ( SG ), using near-isogenic lines (NILs, BC(6)F(4)) derived from a cross between the highly resistant variety, Shingwang, and the highly susceptible variety, Ilpum, using 11 insertion and deletion (InDel) markers. qSTV11 ( SG ) was localized to a 150-kb region between InDel 11 (17.86 Mbp) and InDel 5 (18.01?Mbp). Among the two markers in this region, InDel 7 is diagnostic of RSV resistance in 55 Korean japonica and indica rice varieties. InDel 7 could also distinguish the allele type of Nagdong, Shingwang, Mudgo, and Pe-bi-hun from Zenith harboring the Stv-b ( i ) allele. As a result, qSTV11 ( SG ) is likely to be the Stv-b ( i ) allele. There were 21 genes in the 150-kb region harboring the qSTV11 ( SG ) locus. Three of these genes, LOC_Os11g31430, LOC_Os11g31450, and LOC_Os11g31470, were exclusively expressed in the susceptible variety. These expression profiles were consistent with the quantitative nature along with incomplete dominance of RSV resistance. Sequencing of these genes showed that there were several amino acid substitutions between susceptible and resistant varieties. Putative functions of these candidate genes for qSTV11 ( SG ) are discussed.     

Silencing of MicroRNA-21 Confers Radio-Sensitivity through Inhibition of the PI3K/AKT Pathway and Enhancing Autophagy in Malignant Glioma Cell Lines

Radiation is a core part of therapy for malignant glioma and is often provided following debulking surgery. However, resistance to radiation occurs in most patients, and the underlying molecular mechanisms of radio-resistance are not fully understood. Here, we demonstrated that microRNA 21 (miR-21), a well-known onco-microRNA in malignant glioma, is one of the major players in radio-resistance. Radio-resistance in different malignant glioma cell lines measured by cytotoxic cell survival assay was closely associated with miR-21 expression level. Blocking miR-21 with anti-miR-21 resulted in radio-sensitization of U373 and U87 cells, whereas overexpression of miR-21 lead to a decrease in radio-sensitivity of LN18 and LN428 cells. Anti-miR-21 sustained γ-H2AX DNA foci formation, which is an indicator of double-strand DNA damage, up to 24 hours and suppressed phospho-Akt (ser473) expression after exposure to γ-irradiation. In a cell cycle analysis, a significant increase in the G₂/M phase transition by anti-miR-21 was observed at 48 hours after irradiation. Interestingly, our results showed that anti-miR-21 increased factors associated with autophagosome formation and autophagy activity, which was measured by acid vesicular organelles, LC3 protein expression, and the percentage of GFP-LC3 positive cells. Furthermore, augmented autophagy by anti-miR-21 resulted in an increase in the apoptotic population after irradiation. Our results show that miR-21 is a pivotal molecule for circumventing radiation-induced cell death in malignant glioma cells through the regulation of autophagy and provide a novel phenomenon for the acquisition of radio-resistance.