Interleukin 1 protects rats against oxygen toxicity

We studied the effect of interleukin 1 alpha (IL-1) in the protection against O2 toxicity. Tracheal insufflation of IL-1 resulted in a dose-dependent protection against O2 toxicity. All control rats died within 3 days of O2 exposure. In contrast, 84, 71, and 20% of rats insufflated with 5, 1, and 0.2 microgram(s) IL-1 (150, 30, and 6 x 10(4) U), respectively, survived 100% O2 exposure for greater than 11 days. At 2.3 days after O2 exposure, control rats showed severe pulmonary injury, which insufflation of 5 microgram(s) IL-1 markedly attenuated. The protection against O2 toxicity was associated with a selective enhancement of pulmonary Mn-superoxide dismutase (Mn-SOD) activity in IL-1-insufflated rats. In rats insufflated with IL-1 that survived exposure to 100% O2 for 7 days, the activities of pulmonary Mn-SOD, Cu,Zn-SOD, catalase, and glutathione peroxidase were all increased. The increased pulmonary Mn-SOD activity demonstrated in IL-1-insufflated rats at 2.3 days after O2 exposure may contribute to the protection against acute O2 toxicity, and the markedly increased activities of all pulmonary antioxidant enzymes shown in rats insufflated with IL-1 that survived O2 exposure for 7 days may in part be responsible for the chronic adaptation of these rats to a 100% O2 environment.     

Structures of the Gasdermin D C-Terminal Domains Reveal Mechanisms of Autoinhibition

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Effects of reserpine and adenosine agonist on α2-adrenergic receptor of rat vas deferens examined with [3H]yohimbine and [3H]clonidine

The changes of [³H]yohimbine and [³H]clonidine binding sites in rat vas deferens on treatments with adenosine receptor agonists (2-chloroadenosine, adenosine) or reserpine were examined. Treatment with adenosine agonist in vitro increased [³H]clonidine binding sites but had no influence on affinity and number of binding sites of α₂-antagonist, [³H]yohimbine. Amount of [³H]yohimbine binding sites was found to be higher than that of [³H]clonidine with or without the treatment. Inhibition curves of α₂-agonists, clonidine and norepinephrine, on [³H]yohimbine binding were less than unity though α₂-antagonist inhibited with about 1.0 of n_H. The treatment with adenosine agonist reduced the IC₅₀ value of agonists on the [³H]yohimbine binding but had no influence on the inhibitory effect of antagonist. These effect of adenosine agonists was completely blocked by theophylline. Accordingly it was considered that activation of adenosine receptor caused configurational change in α₂-adrenergic receptor from low affinity state for agonist to the high affinity state, though both states had same affinity for antagonist.On the other hand, treatment with reserpine in vivo increased the affinity of clonidine for α₂-adrenergic receptors and also increased the amount of the α₂-receptors.     

Induction of Mn SOD in human monocytes without inflammatory cytokine production by a mutant endotoxin

Endotoxin selectively induces monocyte Mn superoxide dismutase(SOD) without affecting levels of Cu,Zn SOD, catalase, or glutathione peroxidase. However, little is known about the structure-activity relationship and the mechanism by which endotoxin induces Mn SOD. Inthis study we demonstrated that a mutant Escherichiacoli endotoxin lacking myristoyl fatty acid at the3' R-3-hydroxymyristate position of the lipid A moiety retained its full capacity to coagulate Limulus amoebocyte lysate comparedwith the wild-type E. coli endotoxinand markedly stimulated the activation of human monocyte nuclearfactor-B and the induction of Mn SOD mRNA and enzyme activity.However, in contrast to the wild-type endotoxin, it failed to inducesignificant production of tumor necrosis factor- and macrophageinflammatory protein-1 by monocytes and did not induce thephosphorylation and nuclear translocation of mitogen-activated proteinkinase. These results suggest that1) lipid A myristoyl fatty acid,although it is important for the induction of inflammatory cytokineproduction by human monocytes, is not necessary for the induction of MnSOD, 2) endotoxin-mediated inductionof Mn SOD and inflammatory cytokines are regulated, at least in part,through different signal transduction pathways, and3) failure of the mutant endotoxinto induce tumor necrosis factor- production is, at least in part,due to its inability to activate mitogen-activated protein kinase.

     

The isoprostanes: Novel prostaglandin-like products of the free radical-catalyzed peroxidation of arachidonic acid

The isoprostanes (IsoPs) are a unique series of prostaglandin-like compounds formed in vivo from the free radical-catalyzed peroxidation of arachidonic acid. This review summarizes our current knowledge regarding these compounds. Novel aspects of the biochemistry and bioactivity of IsoPs are detailed and methods by which these compounds are analyzed are discussed. A considerable portion of this review deals with the utility of measuring IsoPs as markers of oxidant injury in human diseases particularly in association with risk factors that predispose to atherosclerosis, a condition in which excessive oxidative stress has been causally implicated.     

Pyrrolo[1,2-b]pyridazin-2-ones as potent inhibitors of HCV NS5B polymerase

Pyrrolo[1,2-b]pyridazin-2-one analogs were discovered as a novel class of inhibitors of genotype 1 HCV NS5B polymerase. Structure-based design led to the discovery of compound 3 k, which displayed potent inhibitory activities in biochemical and replicon assays (IC(50) (1b)<10nM; EC(50) (1b)=12 nM) as well as good stability towards human liver microsomes (HLM t(1/2)>60 min).     

4-(1,1-Dioxo-1,4-dihydro-1lambda6-benzo[1,4]thiazin-3-yl)-5-hydroxy-2H-pyridazin-3-ones as potent inhibitors of HCV NS5B polymerase

4-(1,1-Dioxo-1,4-dihydro-1lambda(6)-benzo[1,4]thiazin-3-yl)-5-hydroxy-2H-pyridazin-3-one analogs were discovered as a novel class of inhibitors of HCV NS5B polymerase. Structure-based design led to the identification of compound 3a that displayed potent inhibitory activities in biochemical and replicon assays (1b IC(50)<10 nM; 1b EC(50)=1.1 nM) as well as good stability toward human liver microsomes (HLM t(1/2)>60 min).     

The plant glycosyltransferase clone collection for functional genomics

The glycosyltransferases (GTs) are an important and functionally diverse family of enzymes involved in glycan and glycoside biosynthesis. Plants have evolved large families of GTs which undertake the array of glycosylation reactions that occur during plant development and growth. Based on the Carbohydrate‐Active enZymes (CAZy) database, the genome of the reference plant Arabidopsis thaliana codes for over 450 GTs, while the rice genome (Oryza sativa) contains over 600 members. Collectively, GTs from these reference plants can be classified into over 40 distinct GT families. Although these enzymes are involved in many important plant specific processes such as cell‐wall and secondary metabolite biosynthesis, few have been functionally characterized. We have sought to develop a plant GTs clone resource that will enable functional genomic approaches to be undertaken by the plant research community. In total, 403 (88%) of CAZy defined Arabidopsis GTs have been cloned, while 96 (15%) of the GTs coded by rice have been cloned. The collection resulted in the update of a number of Arabidopsis GT gene models. The clones represent full‐length coding sequences without termination codons and are Gateway^® compatible. To demonstrate the utility of this JBEI GT Collection, a set of efficient particle bombardment plasmids (pBullet) was also constructed with markers for the endomembrane. The utility of the pBullet collection was demonstrated by localizing all members of the Arabidopsis GT14 family to the Golgi apparatus or the endoplasmic reticulum (ER). Updates to these resources are available at the JBEI GT Collection website http://www.addgene.org/ .     

High density DNA methylation array with single CpG site resolution

We have developed a new generation of genome-wide DNA methylation BeadChip which allows high-throughput methylation profiling of the human genome. The new high density BeadChip can assay over 480K CpG sites and analyze twelve samples in parallel. The innovative content includes coverage of 99% of RefSeq genes with multiple probes per gene, 96% of CpG islands from the UCSC database, CpG island shores and additional content selected from whole-genome bisulfite sequencing data and input from DNA methylation experts. The well-characterized Infinium® Assay is used for analysis of CpG methylation using bisulfite-converted genomic DNA. We applied this technology to analyze DNA methylation in normal and tumor DNA samples and compared results with whole-genome bisulfite sequencing (WGBS) data obtained for the same samples. Highly comparable DNA methylation profiles were generated by the array and sequencing methods (average R² of 0.95). The ability to determine genome-wide methylation patterns will rapidly advance methylation research.