9,10-Phenanthrenequinone promotes secretion of pulmonary aldo-keto reductases with surfactant

9,10-Phenanthrenequinone (9,10-PQ), a major quinone in diesel exhaust particles, induces apoptosis via the generation of reactive oxygen species (ROS) because of 9,10-PQ redox cycling. We have found that intratracheal infusion of 9,10-PQ facilitates the secretion of surfactant into rat alveolus. In the cultured rat lung, treatment with 9,10-PQ results in an increase in a lower-density surfactant by ROS generation through redox cycling of the quinone. The surfactant contains aldo-keto reductase (AKR) 1C15, which reduces 9,10-PQ and the enzyme level in the surfactant increases on treatment with 9,10-PQ suggesting an involvement of AKR1C15 in the redox cycling of the quinone. In six human cell types (A549, MKN45, Caco2, Hela, Molt4 and U937) only type II epithelial A549 cells secrete three human AKR1C subfamily members (AKR1C1, AKR1C2 and AKR1C3) with the surfactant into the medium; this secretion is highly increased by 9,10-PQ treatment. Using in vitro enzyme inhibition analysis, we have identified AKR1C3 as the most abundantly secreted AKR1C member. The AKR1C enzymes in the medium efficiently reduce 9,10-PQ and initiate its redox cycling accompanied by ROS production. The exposure of A549 cells to 9,10-PQ provokes viability loss, which is significantly protected by the addition of the AKR1C3 inhibitor and antioxidant enzyme and by the removal of the surfactants from the culture medium. Thus, the AKR1C enzymes secreted in pulmonary surfactants probably participate in the toxic mechanism triggered by 9,10-PQ.     

Immunological characterization of tumor-rejection antigens on ultraviolet-light-induced tumors originating in the CB6F1 mouse

Six ultraviolet-light(UV)-induced tumors of (BALB/c×C57BL/6)F₁ (H-2^d/b) mouse origin were analyzed for the effector T cell subsets involved in tumor rejection the MHC class I to which cytolytic T lymphocytes (CTL) are restricted, and the effect of UV radiation on tumor rejection, to characterize their tumor-rejection antigens (TRA) recognized by CTL. All tumors were rejected in syngeneic normal mice but grew progressively in nude mice. CD8⁺ T cells mediated the antitumor responses for all tumors and CD4⁺ T cells could also do so for one tumor 6.1B. Each tumor induced potent CTL that recognized the specific TRA in preferential association with MHC class I haplotypes not from H-2^b but from H-2^d; that is, K^d, D^d or L^d. Profiles of TRA expression on two tumors were obtained by the analyses of their antigen-loss variants. 1A codominantly expressed at least four distinct TRA associated with K^d, all of which induced CTL. On the other hand, UV 1 had at least two distinct TRA, one of which, associated with K^d, exclusively induced CTL. However, in the absence of the dominant TRA, another TRA associated with L^d on R95C, a variant of UV, 1, induced CTL. Unlike other tumors, R95C grew progressively in short-term-UV-irradiated syngeneic mice. Nude mice reconstituted with a combination of CD4⁺ T cells from short-term-UV-irradiated mice and CD8⁺ T cells from normal mice did not reject R95C. An increase in the former T cell population led the reconstituted mice to reject the tumor. These findings suggest some functional defects of CD4⁺ T cells rather than the generation of suppressor cells in short-term-UV-irradiated mice. The UV-induced tumors used in the present study provide a unique system for analyzing the preferential sorting of TRA as well as for elucidation of the TRA itself.     

Phosphoproteome analysis of Lotus japonicus seeds

In this study, we report the first dataset of phosphoproteins of the seeds of a model plant, Lotus japonicus. This dataset might be useful in studying the regulatory mechanisms of seed germination in legume plants. By proteomic analysis of seeds following water absorption, we identified a total of 721 phosphopeptides derived from 343 phosphoproteins in cotyledons, and 931 phosphopeptides from 473 phosphoproteins in hypocotyls. Kinase‐specific prediction analyses revealed that different kinases were activated in cotyledons and hypocotyls. In particular, many peptides containing ATM‐kinase target motifs, X‐X‐pS/pT‐Q‐X‐X, were detected in cotyledons. Moreover, by real‐time RT‐PCR analysis, we found that expression of a homolog of ATM kinase is upregulated specifically in cotyledons, suggesting that this ATM‐kinase homolog plays a significant role in cell proliferation in the cotyledons of L. japonicus seeds. The data have been deposited to the ProteomeXchange with identifier PXD000053 ( http://proteomecentral.proteomexchange.org/dataset/PXD000053 ).     

Isolation of Z-3-Hexenal in Tea Leaves,Thea sinensis,and Synthesis Thereof

Z-3-Hexenal, a precursor in the biosynthesis of leaf alcohol and leaf aldehyde, was first isolated from fresh tea leaves, Thea sinensis and its structure was confirmed by unequivocal synthetic evidence.     

Evaluation of two biosynthetic pathways to delta-aminolevulinic acid in Euglena gracilis.

delta-Aminolevulinic acid (ALA), which is an intermediate in the biosynthesis of chlorophyll a, can be biosynthesized via the C5 pathway and the Shemin pathway in Euglena gracilis. Analysis of the (13)C-NMR spectrum of (13)C-labeled methyl pheophorbide a, derived from 13C-labeled chlorophyll a biosynthesized from d-[1-(13)C]glucose by E. gracilis, provided evidence suggesting that ALA incorporated in the (13)C-labeled chlorophyll a was synthesized via both the C5 pathway and the Shemin pathway in a ratio of between 1.5 and 1.7 to one. The methoxyl carbon of the methoxycarbonyl group at C-132 of chlorophyll a was labeled with (13)C. The phytyl moiety of chlorophyll a was labeled on C-P2, C-P3(1), C-P4, C-P6, C-P7(1), C-P8, C-P10, C-P11(1), C-P12, C-P14, C-P15(1) and C-P16.     

Distribution of lipoxygenase and hydroperoxide lyase in the leaves of various plant species

The enzyme activity responsible for volatile C₆-aldehyde formation was accompanied by lipoxygenase and hydroperoxide lyase in the green leaves of 28 plant species tested, but the level of each enzyme's activity varied. Lipoxygenase activity rather than hydroperoxide lyase activity appears to affect the overall C₆-aldehyde formation. There was a positive correlation (r = 0.712) between hydroperoxide lyase activity and the chlorophyll content of the green leaves; no correlation was found between lipoxygenase activity and chlorophyll content.     

Unmanned Aerial Survey of Fallen Trees in a Deciduous Broadleaved Forest in Eastern Japan

Since fallen trees are a key factor in biodiversity and biogeochemical cycling, information about their spatial distribution is of use in determining species distribution and nutrient and carbon cycling in forest ecosystems. Ground-based surveys are both time consuming and labour intensive. Remote-sensing technology can reduce these costs. Here, we used high-spatial-resolution aerial photographs (0.5–1.0 cm per pixel) taken from an unmanned aerial vehicle (UAV) to survey fallen trees in a deciduous broadleaved forest in eastern Japan. In nine sub-plots we found a total of 44 fallen trees by ground survey. From the aerial photographs, we identified 80% to 90% of fallen trees that were >30 cm in diameter or >10 m in length, but missed many that were narrower or shorter. This failure may be due to the similarity of fallen trees to trunks and branches of standing trees or masking by standing trees. Views of the same point from different angles may improve the detection rate because they would provide more opportunity to detect fallen trees hidden by standing trees. Our results suggest that UAV surveys will make it possible to monitor the spatial and temporal variations in forest structure and function at lower cost.     

Role of interleukin-17 in a murine community-associated methicillin-resistant Staphylococcus aureus pneumonia model

Interleukin (IL)-17 is a key member of the Th17 cytokines and has been reported to be involved in the pathomechanisms underlying various diseases, including infectious diseases. Infections with community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) have garnered worldwide attention, and the representative USA300 strain is known to cause pneumonia in healthy people, which can be lethal. However, little is known about the role of IL-17 in CA-MRSA pneumonia. In this study, we investigated the role of IL-17 in a CA-MRSA pneumonia animal model. Mortality was higher and occurred at an earlier stage of infection in the IL-17A-knockout mice than in the wild-type (P < 0.01) and IL-17A/F-knockout mice (P < 0.05); however, no significant difference in the intrapulmonary bacterial counts was observed among the three groups of mice. Moreover, the IL-17A-knockout group showed significantly higher levels of IL-17F and granulocyte-colony stimulating factor (G-CSF) and a significantly higher neutrophil count in the bronchoalveolar lavage fluid than the other groups. These results confirmed that G-CSF expression significantly increased, and significant neutrophilic inflammation occurred under conditions of IL-17A deficiency in the murine CA-MRSA pneumonia model.     

Na-K-dependent ATPase in red cells and thyroid status

The Relationship between ouabain-sensitive ATPase (Na-K ATPase) activity in erythrocytes and the thyroid status was studied in 36 patients with Graves' disease and 58 patients receiving L-thyroxine (T4) replacement therapy. Forty normal children served as control. Total ATPase activity in 4 untreated hypothyroid patients was significantly reduced (11.0 +/- 4.6 vs 17.3 +/- 4.1 micrograms-P/h/mg-protein, P less than 0.01), and Na-K ATPase was undetectable, both of which were normalized after 4 weeks of L-T4 therapy. Na-K ATPase in hyperthyroid patients was also decreased (0.9 +/- 0.8 vs. 4.0 +/- 2.7, P less than 0.01), but was gradually normalized after 3 months of euthyroid state. Clinically euthyroid children treated with L-T4 were divided into 2 groups with regard to Na-K ATPase activity, normal and low. Analysis of the possible factors producing this difference revealed that, in primary hypothyroidism, the factor appeared to be the endogenous T4 level, while in patients with dwarfism, the secretory capacity of TSH or TSH-releasing hormone (TRH) was contributory. Thus Na-K ATPase activity in red cells remains within the normal range after L-T4 replacement in the presence of a severe degree of primary hypothyroidism or in association with secondary or tertiary hypothyroidism. Other factors such as the L-T4 dose, duration of the therapy, serum T4 and T3 concentrations, were not significantly different in the two groups. These results indicate that (1) Na-K ATPase in red cells is decreased in hyper- or hypothyroid state, (2) restoration of normal activity requires 1-3 months of euthyroid period, and (3) it is a sensitive index of peripheral thyroid status over the preceding few months.