Effect of larval brain extracts derived from three swallowtail butterflies,Papilio helenus L., P. machaon L. and P. memnon L., on seasonal morph development of P. xuthus L. (Lepidoptera: Papilionidae)

Adults of the three papilionid butterflies, Papilio helenus L., Papilio machaon L. and Papilio memnon L., exhibit seasonal diphenism comprising spring and summer morphs. To elucidate the physiological mechanism underlying seasonal morph development in papilionid butterflies, we investigated whether a cerebral factor showing summer‐morph‐producing hormone (SMPH) activity is present in the brain of three Papilio species using an assay system with chilled male short‐day pupae of P. xuthus L. When 2% NaCl extracts derived from 20 larval brains of the three species were injected into abdomens of chilled male short‐day pupae of P. xuthus, all recipients destined to develop into spring‐morph adults developed into summer‐ and intermediate‐morph adults. On the other hand, all recipients injected with distilled water as a control developed into spring‐morph adults. These results indicate that a cerebral factor showing SMPH activity is present in the larval brain of the three Papilio species. Additionally, all recipients injected with 2% NaCl extracts derived from 20 adult brains of Bombyx mori L. also developed into summer‐ and intermediate‐morph adults. The results revealed that SMPH or a cerebral factor showing SMPH activity is widely distributed among lepidopteran insects.     

Induction of Cold Acclimation in Cornus stolonifera Michx

A warm (20 to 15 Celsius day or night) preconditioning treatment enhanced cold acclimation of Cornus stolonifera bark under short-day conditions when plants were preconditioned for at least 4 weeks. Warm preconditioning inhibited the acclimation of plants subjected to long photoperiods. Removing leaves from plants exposed to low temperatures and short days inhibited acclimation. Removal of buds did not affect acclimation. Plants did not acclimate unless they were exposed to at least 4 weeks of short photoperiods prior to defoliation. Plants began to acclimate to cold at the time of growth cessation but not before. When half of the leaves were removed from plants, the defoliated and foliated branches both acclimated as well as branches on completely foliated plants. Girdling the phloem between foliated and defoliated branches prevented acclimation of the latter regardless of the position of the girdle in relation to the root system and the defoliated branch. When all of the leaves of plants were covered with aluminum foil to exclude light after 0 or 4 weeks of exposure to short days, the results resembled a defoliation study, i.e., plants with leaves covered at the start of the experiment failed to acclimate, and those covered after 4 weeks acclimated to some extent but less than uncovered control plants. Under longday conditions plants with all leaves covered failed to acclimate, and plants with none or half of their leaves covered acclimated equally and to a limited extent. Under short-day conditions, however, the covered branches of partially covered plants acclimated more than their uncovered counterparts or branches of totally uncovered plants.     

Intercellular signaling between ameloblastoma and osteoblasts

Ameloblastoma is an odontogenic tumor located in the bone jaw with clinical characteristics of extensive bone resorption. It is a locally invasive tumor with a high recurrence rate despite adequate surgical removal. In bone disease, tumors and other cells including osteoblasts, osteoclasts, and osteocytes in the bone microenvironment contribute to the pathogenesis of tumor growth. However, the effect of osteoblasts on ameloblastoma cells is not well-understood, and there has been limited research on interactions between them.This study investigated interactions between ameloblastoma cells and osteoblasts using a human ameloblastoma cell line (AM-3 ameloblastoma cells) and a murine pre-osteoblast cell line (MC3T3-E1 cells). We treated each cell type with the conditioned medium by the other cell type. We analyzed the effect on cytokine production by MC3T3-E1 cells and the production of MMPs by AM-3 cells. Treatment with AM-3-conditioned medium induced inflammatory cytokine production of IL-6, MCP-1, and RANTES from MC3T3-E1 cells. The use of an IL-1 receptor antagonist suppressed the production of these inflammatory cytokines by MC3T3-E1 cells stimulated with AM-3-conditioned medium. The MC3T3-E1-conditioned medium triggered the expression of MMP-2 from AM-3 cells. Furthermore, we have shown that the proliferation and migration activity of AM-3 cells were accelerated by MC3T3-E1 conditioned media.In conclusion, these intercellular signalings between ameloblastoma cells and osteoblasts may play multiple roles in the pathogenesis of ameloblastoma.     

Quantitative and antioxidative behavior of Trolox in rats’ blood and brain by HPLC‐UV and SMFIA‐CL methods

Trolox, a water‐soluble vitamin E analogue has been used as a positive control in Trolox equivalent antioxidant capacity and oxygen radical antioxidant capacity assays due to its high antioxidative effect. In this study, the ex vivo antioxidative effects of Trolox and its concentration in blood and brain microdialysates from rat after administration were evaluated by newly established semi‐microflow injection analysis, chemiluminescence detection and HPLC‐UV. In the administration test, the antioxidative effect of Trolox in blood and brain microdialysates after a single administration of 200 mg/kg of Trolox to rats could be monitored. The antioxidative effects in blood (12.0 ± 2.1) and brain (8.4 ± 2.1, × 10³ antioxidative effect % × min) also increased. Additionally, the areas under the curve (AUC)s_0–360 (n = 3) for blood and brain calculated with quantitative data were 10.5 ± 1.2 and 9.7 ± 2.5 mg/mL × min, respectively. This result indicates that Trolox transferability through the blood–brain barrier is high. The increase in the antioxidative effects caused by Trolox in the blood and brain could be confirmed because good correlations between concentration and antioxidative effects (r ≥ 0.702) were obtained. The fact that Trolox can produce an antioxidative effect in rat brain was clarified. Copyright © 2015 John Wiley & Sons, Ltd.     

Attenuation of pattern recognition receptor signaling is mediated by a MAP kinase kinase kinase

Pattern recognition receptors (PRRs) play a key role in plant and animal innate immunity. PRR binding of their cognate ligand triggers a signaling network and activates an immune response. Activation of PRR signaling must be controlled prior to ligand binding to prevent spurious signaling and immune activation. Flagellin perception in Arabidopsis through FLAGELLIN‐SENSITIVE 2 (FLS2) induces the activation of mitogen‐activated protein kinases (MAPKs) and immunity. However, the precise molecular mechanism that connects activated FLS2 to downstream MAPK cascades remains unknown. Here, we report the identification of a differentially phosphorylated MAP kinase kinase kinase that also interacts with FLS2. Using targeted proteomics and functional analysis, we show that MKKK7 negatively regulates flagellin‐triggered signaling and basal immunity and this requires phosphorylation of MKKK7 on specific serine residues. MKKK7 attenuates MPK6 activity and defense gene expression. Moreover, MKKK7 suppresses the reactive oxygen species burst downstream of FLS2, suggesting that MKKK7‐mediated attenuation of FLS2 signaling occurs through direct modulation of the FLS2 complex.     

Possible roles of ENaC and Cl(-) channel in wound closure in Xenopus laevis embryos

Our previous report showed that rapid wound closure in Xenopus laevis embryos was associated with a decrease in the extracellular concentration of either Na(+) or Cl(-) ions. In this study, we examined the wound closure in Xenopus embryos when epithelial Na(+) channel (ENaC), Na(+)/K(+) ATPase (Na(+) pump) or CICs (members of Cl(-) channel) were blocked by each specific inhibitor. Blockage of ENaC and CIC restricted the rate of wound closure during the first 30 min PW and during the subsequent period, respectively. In contrast, inhibition of Na(+) pump had no effect on the rate of wound closure. Furthermore, simultaneous administration of both ENaC and CIC inhibitors resulted in the cumulative reduction of wound closure. Thus, it is plausible that these ion channels play active roles in wound closure in Xenopus embryos. NPPB is known to inhibit both CIC-2 and CIC-3. Immunohistochemical experiments showed that CIC-3, but not CIC-2, was expressed in Xenopus embryos, suggesting that the reduced wound closure by NPPB was due to blockage of CIC-3. A local enhancement of CIC-3 expression at the leading edge of the wounded epidermis was found to be specific to closing wounds that were kept in 10% NAM. An in vitro wounding assay also showed a pattern of CIC-3 expression at the margin of the scratch wound comparable to the results in vivo. These findings suggest that intracellular translocation of CIC-3 is involved in wound closure. We propose that the ion channels, including CIC-3, play a crucial role in wound closure in Xenopus embryos.     

Changes in N-acetyl-beta-D-glucosaminidase activity in the urine and urinary albumin excretion in magnesium deficient rats

To discover the details of the effects of magnesium (Mg) deficiency on kidney function, the course of changes in N-acetyl-beta-D-glucosaminidase (NAG) activity in the urine and in urinary albumin excretion were examined in rats fed a Mg-deficient diet. NAG activity in the urine and urinary albumin excretion in rats fed the Mg-deficient diet significantly increased from 7 d until the end of the feeding period. We suggest that Mg-deficient diet rapidly induces kidney function insufficiency.     

The relationship between photosystem II efficiency and quantum yield for CO(2) assimilation is not affected by nitrogen content in apple leaves

Bench-grafted Fuji/M.26 apple (Malus domestica Borkh.) trees were fertigated with different concentrations of nitrogen by using a modified Hoagland's solution for 45 d. CO(2) assimilation and photosystem II (PSII) quantum efficiency in response to incident photon flux density (PFD) were measured simultaneously in recent fully expanded leaves under low O(2) (2%) and saturated CO(2) (1300 micromol mol(-1)) conditions. A single curvilinear relationship was found between true quantum yield for CO(2) assimilation and PSII quantum efficiency for leaves with a wide range of leaf N content. The relationship was linear up to a quantum yield of approximately 0.05 mol CO(2) mol(-1) quanta. It then became curvilinear with a further rise in quantum yield in response to decreasing PFD. This relationship was subsequently used as a calibration curve to assess the rate of non-cyclic electron transport associated with Rubisco and the partitioning of electron flow between CO(2) assimilation and photorespiration in different N leaves in response to intercellular CO(2) concentration (C(i)) under normal O(2) conditions. Both the rate of non-cyclic electron flow and the rate of electron flow to CO(2) or O(2) increased with increasing leaf N at any given C(i). The percentage of non-cyclic electron flow to CO(2) assimilation, however, remained the same regardless of leaf N content. As C(i) increased, the percentage of non-cyclic electron flow to CO(2) assimilation increased. In conclusion, the relationship between PSII quantum efficiency and quantum yield for CO(2) assimilation and the partitioning of electron flow between CO(2) assimilation and photorespiration are not affected by N content in apple leaves.     

Effects of gender on kidney function in magnesium-deficient rats

This study investigated the gender differences in the kidney function of magnesium (Mg)-deficient rats. Male and female rats were fed a control diet or a Mg-deficient diet for 21 d. Mg-deficient diet had no significant effect on kidney calcium (Ca) or phosphorus (P) concentration in male rats, while Ca and P concentrations in female rats were significantly higher in Mg-deficient rats than in the control rats. With regard to indicators of kidney function, no significant differences in creatinine clearance and serum urea nitrogen concentration were observed among the groups. Serum albumin concentrations were significantly lower in rats fed the Mg-deficient diet than in rats fed the control diet. In both sexes, urinary albumin excretion was significantly higher in rats fed the Mg-deficient diet than in rats fed the control diet. Gender differences had no significant influence on creatinine clearance, serum urea nitrogen concentration, serum albumin concentration and urinary albumin excretion. These results suggest that gender differences have no effect on kidney function in Mg-deficient rats under the condition used.     

Abscisic Acid increases terrestrial plant cell resistance to hydrostatic pressure

Cells of the terrestrial plant species bromegrass (Bromus inermis L.) are not naturally adapted to withstand the hydrostatic pressures encountered in aquatic environments. However, after treatment with the natural plant growth hormone abscisic acid (75 micromolar), bromegrass cells survived a hydrostatic pressure of 101.3 megapascals, approximating the limits of ocean depth (10,860 m). The increased resistance to hydrostatic pressure from 1 to 7 days of abscisic acid treatment paralleled the induced elevation of cell tolerance to freezing stress.