C1q/Tumor Necrosis Factor-Related Protein 9 Protects against Acute Myocardial Injury through an Adiponectin Receptor I-AMPK-Dependent Mechanism

Obesity is a risk factor for cardiovascular disease. C1q/tumor necrosis factor-related protein 9 (CTRP9) is an adipokine that is downregulated by obesity. We investigated the role of CTRP9 in cardiac injury with loss-of-function genetic manipulations and defined the receptor-mediated signaling pathway downstream of this adipokine. CTRP9-knockout (CTRP9-KO) mice at the age of 12 weeks were indistinguishable from wild-type (WT) mice under basal conditions. CTRP9-KO mice had exacerbated contractile left ventricle dysfunction following intraperitoneal injection of lipopolysaccharide (LPS) compared to WT mice. Administration of LPS to CTRP9-KO mice also resulted in increased expression of proinflammatory cytokines and oxidative stress markers in the heart compared to WT mice. Likewise, CTRP9-KO mice showed increased myocardial infarct size and elevated expression of inflammatory mediators in ischemic heart following ischemia and reperfusion compared to WT mice. Treatment of cardiac myocytes with CTRP9 protein led to suppression of LPS-induced expression of proinflammatory genes, which was reversed by blockade of AMPK or ablation of adiponectin receptor I (AdipoR1). Systemic delivery of CTRP9 attenuated LPS-induced cardiac dysfunction in WT mice but not in muscle-specific transgenic mice expressing dominant-negative mutant form of AMPK or in AdipoR1-knockout mice. CTRP9 protects against acute cardiac damage in response to pathological stimuli by suppressing inflammatory reactions through AdipoR1/AMPK-dependent mechanisms.     

Conditioned olfactory responses of a predatory mite, Neoseiulus womersleyi, to volatiles from prey-infested plants

To clarify the prey‐finding behavior of the predatory mite Neoseiulus womersleyi (Schicha) (Acari: Phytoseiidae), we studied its olfactory responses to volatiles from the prey‐infested plant on which the mites had been collected. We used a local N. womersleyi population called Kanaya collected from tea (Camellia sinensis L.) (Theaceae) plants infested by Tetranychus kanzawai Kishida (Acari: Tetranychidae) in Kanaya City, Japan. Neoseiulus womersleyi (Kanaya population) were more attracted to volatiles from tea plants infested with five female T. kanzawai per leaf for 7 days than to intact tea leaves in a Y‐tube olfactometer. Tetranychus kanzawai‐induced tea leaf volatiles were identified as (E)‐β‐ocimene, (E)‐4,8‐dimethyl‐1,3,7‐nonatriene, and (E,E)‐α‐farnesene. As olfactory responses are known to differ among local populations of N. womersleyi, we compared the responses of the Kanaya population with those of a Kikugawa population collected from tea plants infested by T. kanzawai in Kikugawa City. To test the influence of previous predation experience, we reared the two populations on tea plants infested by T. kanzawai or on kidney bean plants (Phaseolus vulgaris) infested by Tetranychus urticae Koch. The Kanaya population was more attracted to the volatiles from infested plants on which they had been reared. Because the Kanaya population was not attracted to the plant volatiles they had not previously experienced, the positive response to previously experienced volatiles might be the result of learning. By contrast, the Kikugawa population showed no preference for previously experienced volatiles from infested plants. The implications of this flexibility in foraging behavior are discussed.     

Regulatory changes in the K+, Cl- and water contents of HeLa cells incubated in an isosmotic high K(+)-medium

HeLa cells had their normal medium replaced by an isosmotic medium containing 80 mM K+, 70 mM Na+ and 100 microM ouabain. The cellular contents of K+ first increased and then decreased to the original values, that is, the cells showed a regulatory decrease (RVD) in size. The initial increase was not inhibited by various agents except by substitution of medium Cl- with gluconate. In contrast, the regulatory decrease was inhibited strongly by addition of either 1 mM quinine, 10 microM BAPTA-AM without medium Ca2+, or 0.5 mM DIDS, and partly by either 1 mM EGTA without medium Ca2+, 10 microM trifluoperazine, or substitution of medium Cl- with NO3-. Addition of DIDS to the NO3(-)-substituted medium further suppressed the K+ loss but the effect was incomplete. Intracellular Ca2+ showed a transient increase after the medium replacement. These results suggest that the initial increase in cell K+ is a phenomenon related to osmotic water movement toward Donnan equilibrium, whereas the regulatory K+ decrease is caused by K+ efflux through Ca(2+)-dependent K+ channels. The K+ decrease induced a decrease in cellular water, i.e., RVD. The K+ efflux may be more selectively associated with Cl- efflux through DIDS-sensitive channels than the efflux of other anions.     

Hepatic collagenolytic activity in rats after carbon tetrachloride poisoning

1. Collagenolytic activity towards acid-soluble collagen labelled with [(14)C]-proline was assayed in rat liver with and without carbon tetrachloride poisoning. The products of enzymic digestion were found to be free amino acids and peptides. 2. The hepatic collagenolytic activity increased under conditions of single-dose and subacute carbon tetrachloride poisoning, and correlated with hydroxyproline content. The highest activity was found during recovery from subacute poisoning. 3. Under the same experimental conditions, hepatic acid-proteinase activity changed independently of the collagenolytic activity and also of hepatic hydroxyproline content. 4. The increased collagenolytic activity during carbon tetrachloride poisoning was found mainly in the supernatant fraction. 5. The ratio of the collagenolytic activity to hepatic hydroxyproline content increased during recovery from single-dose and subacute poisoning, and decreased during subacute poisoning.     

Announcement

Aryl hydrocarbon hydroxylase (AHH) was present in explant cultures of human prostate obtained from surgery of benign prostatic hyperplasia and was inducible by benz[a]anthracene (BA). The induction of AHH ranged from 14- to 150-fold when compared with control values and 10-fold variation of AHH inducibility among individuals was observed. Epithelial cells grown from human prostate tissue also contained measurable AHH activity and AHH was inducible by BA and 7,12-dimethylbenz[a]anthracene (DMBA). Inducibility of AHH by BA ranged from 2- to 63-fold. The inducibility of AHH by DMBA was always less than that by BA. In cells treated with N-methyl-N′-nitro-N-nitrosoguanidine (MNNG), there were no changes in AHH activity. These findings support the view that the human prostate is susceptible to environmental polycyclic hydrocarbon carcinogens and that environmental and occupational factors might contribute to the etiology of human prostatic carcinoma.     

A newOphiostoma species isolated from Japanese oak infested byPlatypus quercivorus

A newOphiostoma species was isolated from the sapwood ofQuercus mongolica var.grosseserrata and described asOphiostoma longicollum sp. nov. The species is characterized by a long perithecial neck with a gelatinous cap at the apex and a constricted base, orange-section-shaped ascospores that accumulate in a yellow-orange drop at the apex of the neck, and itsSporothrix anamorph. Contribution No. 137, Laboratory of Plant Pathology and Mycology, Institute of Agriculture and Forestry, University of Tsukuba.     

Development and implementation of a database system to manage a large-scale mouse ENU-mutagenesis program

A mouse ENU-mutagenesis program at RIKEN GSC has been initiated to conduct a large-scale, genome-wide, early- and late-onset phenotypic screen of mutant mice. We screened about a hundred mice every week with a comprehensive set of phenotype assays including behavioral tests based on a modified SHIRPA protocol, blood tests (both clinical biochemical testing and hemogram), and measurement of locomotor activity in their home cages. To manage the entire program, we developed a client/server architecture database system and named it MUSDB (Mutagenesis Universal Support DataBase). It manages mouse husbandry, mating protocols, procedures for ENU injection and phenotypic screens, phenotype inheritance tests, preservation of sperm and organs, and other materials generated during the program. We have implemented MUSDB in quite a large-scale system that includes 150 client computers. It has, helped reduce typographical errors and provided simple and efficient operation via its front-end user interface. It significantly contributed to the communication within and between workgroups in the program and in the accumulation of various phenotypic and inheritance data.     

Discovery of selective and nonpeptidic cathepsin S inhibitors

Nonpeptidic, selective, and potent cathepsin S inhibitors were derived from an in-house pyrrolopyrimidine cathepsin K inhibitor by modification of the P2 and P3 moieties. The pyrrolopyrimidine-based inhibitors show nanomolar inhibition of cathepsin S with over 100-fold selectivity against other cysteine proteases, including cathepsin K and L. Some of the inhibitors showed cellular activities in mouse splenocytes as well as oral bioavailabilities in rats.