Structural Requirements of 1-(2-Pyridinyl)-5-pyrazolones for Disproportionation of Boronic Acids.

We observed an unusual formation of four-coordinate boron(III) complexes from the reaction of 1-(2-pyridinyl)-5-pyrazolone derivatives with arylboronic acids in the basic media. The exact mechanism is not clear; however, the use of unprotected boronic acid and the presence of a bidentate ligand appeared to be the key structural requirements for the transformation. The results suggest that base-promoted disproportionation of arylboronic acid with the assistance of the [,]-bidentate ligation of 1-(2-pyridinyl)-5-pyrazolone should take place and facilitate the formation of pyrazole diarylborinate.

FcγR/ROS/CK2α Is the Key Inducer of NF-κB Activation in a Murine Model of Asthma.

Background: The transcription factor nuclear factor (NF)-κB plays a pivotal role in the development of allergic airway inflammation. However, the mechanism of NF-κB activation in asthma remains to be elucidated.

Methods: CK2α activation was assessed by CK2α phosphorylation and protein expression.

Glutamine Prevents Late-Phase Anaphylaxis via MAPK Phosphatase 1-Dependent Cytosolic Phospholipase A2 Deactivation.

Background: Cytosolic phospholipase A2 (cPLA2) plays a key role in the development of late-phase anaphylaxis. L-Glutamine (Gln), a nonessential amino acid, has anti-inflammatory activity via inhibiting cPLA2.

Methods: We used a penicillin-induced murine model of anaphylaxis, and late-phase anaphylaxis was quantified by measuring the increase in the hematocrit (Ht) value.

Hydrogen peroxide generated by DUOX1 regulates the expression levels of specific differentiation markers in normal human keratinocytes.

Background: Recent studies have demonstrated that the production of reactive oxygen species (ROS) itself plays an indispensable role in the process of differentiation in various tissues. However, it is unclear whether ROS have an effect on the differentiation of keratinocytes essential for the development of the epidermal permeability barrier.

Objective: The aim of the study is to determine a major H2O2-generating source by ionomycin in normal human keratinocytes (NHKs), and elucidate the physiological role of H2O2 generated by identified dual oxidase 1 (DUOX1) on differentiation markers of NHKs.

Inhibition of receptor internalization attenuates the TNFalpha-induced ROS generation in non-phagocytic cells.

Reactive oxygen species (ROS) are important regulatory molecules implicated in the signaling cascade triggered by tumor necrosis factor (TNF)alpha, although the events through which TNFalpha induces ROS generation are not well characterized. Here, we report that TNFalpha-induced ROS production was blocked by pretreatment with internalization inhibitor monodansyl cadaverine (MDC). Similarly, a transient expression of a GTP-binding and hydrolysis-defective dynamin mutant (dynamin(K44A)) that had been shown to be defective in internalization significantly attenuated the TNFalpha-induced intracellular ROS production.

Protein kinase Calpha can undergo membrane localization via an alternative phosphatidylinositol 4,5-bisphosphate-dependent pathway.

Protein kinase Calpha (PKCalpha) activation is known to be dependent on the metabolic product of phosphatidylinositol 4,5-bisphosphate (PIP2) by phospholipase C (PLC). Here we report that fibroblasts may have an additional PIP2-dependent mechanism for membrane localization of PKCalpha. We observed PKCalpha membrane localization in both wild type and PLCgamma1 -/- mouse embryonic fibroblasts.

An antioxidant system required for host protection against gut infection in Drosophila.

A fundamental question that applies to all organisms is how barrier epithelia efficiently manage continuous contact with microorganisms. Here, we show that in Drosophila an extracellular immune-regulated catalase (IRC) mediates a key host defense system that is needed during host-microbe interaction in the gastrointestinal tract. Strikingly, adult flies with severely reduced IRC expression show high mortality rates even after simple ingestion of microbe-contaminated foods.

Identification of domains directing specificity of coupling to G-proteins for the melanocortin MC3 and MC4 receptors.

The melanocortin receptors, MC3R and MC4R, are G protein-coupled receptors that are involved in regulating energy homeostasis. Using a luciferase reporter gene under the transcriptional control of a cAMP- responsive element (CRE), the coupling efficiency of the MC4R and MC3R to G-proteins was previously shown to be different. MC4R exhibited only 30-50% of the maximum activity induced by MC3R.