A study of seed dispersal by flood flow in an artificially restored floodplain

Riverine floodplains play many important roles in river ecosystems. However, many floodplains have suffered degradation or loss of ecological function due to excessive river improvements or through changes in agricultural systems. As a result, many floodplain restoration projects are being conducted worldwide. One of the many methods being implemented to restore floodplain vegetation is flood water seed dispersal. In this technique, precisely estimating the effect of seed dispersal by flood water is important in order to achieve successful floodplain revegetation. Here, we focus our attention on sediment transport by flood water into the Azamenose Swamp, a restored floodplain. We attempt to estimate the function of seed deposition in the restored floodplain and explain how the seeds are deposited in the floodplain by flood water. The result suggests that the restored floodplain functions as a more appropriate deposition site for seeds than the riverbanks of the main river. It was also found that the distance from the inflow site and the weight of the sediment were related to seed deposition.     

Long-Term Culture of Astrocytes Attenuates the Readily Releasable Pool of Synaptic Vesicles

The astrocyte is a major glial cell type of the brain, and plays key roles in the formation, maturation, stabilization and elimination of synapses. Thus, changes in astrocyte condition and age can influence information processing at synapses. However, whether and how aging astrocytes affect synaptic function and maturation have not yet been thoroughly investigated. Here, we show the effects of prolonged culture on the ability of astrocytes to induce synapse formation and to modify synaptic transmission, using cultured autaptic neurons. By 9 weeks in culture, astrocytes derived from the mouse cerebral cortex demonstrated increases in β-galactosidase activity and glial fibrillary acidic protein (GFAP) expression, both of which are characteristic of aging and glial activation in vitro. Autaptic hippocampal neurons plated on these aging astrocytes showed a smaller amount of evoked release of the excitatory neurotransmitter glutamate, and a lower frequency of miniature release of glutamate, both of which were attributable to a reduction in the pool of readily releasable synaptic vesicles. Other features of synaptogenesis and synaptic transmission were retained, for example the ability to induce structural synapses, the presynaptic release probability, the fraction of functional presynaptic nerve terminals, and the ability to recruit functional AMPA and NMDA glutamate receptors to synapses. Thus the presence of aging astrocytes affects the efficiency of synaptic transmission. Given that the pool of readily releasable vesicles is also small at immature synapses, our results are consistent with astrocytic aging leading to retarded synapse maturation.     

Vasohibin-2 expressed in human serous ovarian adenocarcinoma accelerates tumor growth by promoting angiogenesis

Vasohibin-1 (VASH1) is a VEGF-inducible endothelium-derived angiogenesis inhibitor and VASH2 is its homolog. Our previous analysis revealed that VASH1 is expressed in endothelial cells to terminate angiogenesis, whereas VASH2 is expressed in infiltrating mononuclear cells mobilized from bone marrow to promote angiogenesis in a mouse model of hypoxia-induced subcutaneous angiogenesis. To test the possible involvement of VASH2 in the tumor, we examined human ovarian cancer cells for the presence of VASH2. Immunohistochemical analysis revealed that VASH2 protein was preferentially detected in cancer cells of serous ovarian adenocarcinoma. We then used SKOV-3 and DISS, two representative human serous adenocarcinoma cell lines, and examined the role of VASH2 in the tumor. The knockdown of VASH2 showed little effect on the proliferation of cancer cells in vitro but notably inhibited tumor growth, peritoneal dissemination, and tumor angiogenesis in a murine xenograft model. Next, we stably transfected the human VASH2 gene into two types of murine tumor cells, EL-4 and MLTC-1, in which endogenous VASH2 was absent. When either EL-4 or MLTC-1 cells were inoculated into VASH2 (-/-) mice, the VASH2 transfectants formed bigger tumors when compared with the controls, and the tumor microvessel density was significantly increased. VASH2 stimulated the migration of endothelial cells, and its increased expression in cancer cells is related to the decrease of mir-200b. These results indicate that VASH2 expressed in serous ovarian carcinoma cells promoted tumor growth and peritoneal dissemination by promoting angiogenesis. Mol Cancer Res; 10(9); 1135-46. ?2012 AACR.     

Inhibition of STAT3 promotes the efficacy of adoptive transfer therapy using type-1 CTLs by modulation of the immunological microenvironment in a murine intracranial glioma

A variety of cancers, including malignant gliomas, show aberrant activation of STAT3, which plays a pivotal role in negative regulation of antitumor immunity. We hypothesized that inhibition of STAT3 signals would improve the efficacy of T cell adoptive transfer therapy by reversal of STAT3-induced immunosuppression in a murine GL261 intracranial glioma model. In vitro treatment of GL261 cells with JSI-124, a STAT3 inhibitor, reversed highly phosphorylated status of STAT3. Systemic i.p. administration of JSI-124 in glioma-bearing immunocompetent mice, but not athymic mice, resulted in prolonged survival, suggesting a role of adaptive immunity in the antitumor effect. Furthermore, JSI-124 promoted maturation of tumor-infiltrating CD11c(+) dendritic cells and activation of tumor-conditioned cytotoxic T cells, enhanced dendritic cells and GL261 production of CXCL-10, a critical chemokine for attraction of Tc1 cells. When i.p. JSI-124 administration was combined with i.v. transfer of Pmel-I mouse-derived type-1 CTLs (Tc1), glioma-bearing mice exhibited prolonged survival compared with i.p. JSI-124 or i.v. Tc1 therapy alone. Flow cytometric analyses of brain infiltrating lymphocytes revealed that JSI-124-treatment enhanced the tumor-homing of i.v. transferred Tc1 cells in a CXCL-10-dependent fashion. Systemic JSI-124 administration also up-regulated serum IL-15 levels, and promoted the persistence of transferred Tc1 in the host. These data suggest that systemic inhibition of STAT3 signaling can reverse the suppressive immunological environment of intracranial tumor bearing mice both systemically and locally, thereby promoting the efficacy of adoptive transfer therapy with Tc1.     

Effects of Protoceratium reticulatum yessotoxin on feeding rates of Acartia hudsonica: A bioassay using artificial particles coated with purified toxin

Paralytic shellfish toxins produced by dinoflagellates are known to deter copepod grazing. Dinoflagellate species, including Protoceratium reticulatum, also produce disulfated polyether yessotoxins that were previously referred to as diarrheic shellfish toxins. However, the role of yessotoxins in predator–prey relationships is not yet clear. In the present study, the effects of purified yessotoxin (YTX) on feeding activities of Acartia hudsonica (Copepoda, Calanoida) were experimentally investigated. Polystyrene fluorescent microspheres (10 μm in diameter) colored bright blue or yellow-green were coated with cell extracts of P. reticulatum that do not produce yessotoxins. The bright blue microspheres were further coated with YTX, and the yellow-green microspheres were used as the reference. The microspheres were then given to the copepods separately or in combination to measure clearance rates and feeding selectivity. A. hudsonica was found to feed on the yellow-green microspheres without YTX at twice the rate of the bright blue microspheres with YTX. We also confirmed that microsphere color per se did not affect the feeding rates. The bright blue microspheres adsorbed 1.8–43.3 pg of YTX per microsphere, which is similar to the cell-specific yessotoxin content of toxic P. reticulatum found in natural environments. These results suggest that production of yessotoxin is advantageous for P. reticulatum by deterring predation by copepods.     

Functional modification of Sendai virus by siRNA

Sendai virus (hemagglutinating virus of Japan; HVJ) is a negative-strand RNA virus with robust fusion activity, and has been utilized for gene transfer and drug delivery. Hemagglutinin-neuraminidase (HN) protein on the viral membrane is important for cell fusion, but causes agglutination of red blood cells. HN-depleted HVJ has been desired for in vivo transfection in order to improve safety. Here, we succeeded in producing HN-depleted HVJ using HN-specific short interfering RNA (siRNA). Viral production was not affected by the siRNA. HN protein was markedly decreased in the new HVJ, while other viral proteins were retained. Consequently, the hemagglutinating activity was substantially reduced and infection activity was suppressed. When the HN-depleted HVJ was mixed with cultured cells and the mixture was centrifuged for 10min at 2000xg, the modified HVJ recovered its infectivity to approximately 80% of wild HVJ. However, infectivity was abolished in the presence of anti-F antibody. Moreover, transfection of FITC-labeled oligodeoxynucleotides using the modified HVJ was also recovered by centrifugation. Thus, the HN-depleted HVJ produced using siRNA technology will be applicable to a delivery vector.     

Alterations in manganese, copper, and zinc contents, and intracellular status of the metal-containing superoxide dismutase in human mesothelioma cells

BACKGROUND AND AIM: Molecular diagnostics and therapeutics of human mesothelioma using disease-related markers present major challenges in clinical practice. To identify biochemical alternations that would be markers of human mesothelioma, we measured the intracellular steady-state levels of biologically important trace metals such as manganese (Mn), copper (Cu), and zinc (Zn) in a human mesothelial cell line, MeT-5A, and in five human mesothelioma cell lines (MSTO-211H, NCI-H226, NCI-H2052, NCI-H2452, ACC-MESO-1) by inductively coupled plasma-mass spectrometry (ICP-MS). We also aimed to investigate whether the alterations were related to the intracellular status of metal-containing superoxide dismutase (SOD). RESULTS: There were no significant differences in the contents of the trace metals among MeT-5A, MSTO-211H, and ACC-MESO-1 cells. However, each of the other three mesothelioma cell lines had a unique characteristic in terms of the intracellular amounts of the metals; NCI-H226 contained an extremely high level of Mn, an amount 7.3-fold higher than that in MeT-5A. NCI-H2052 had significantly higher amounts of Cu (3.4-fold) and Zn (1.3-fold) compared with MeT-5A. NCI-H2452 contained about 5.8-fold the amount of Cu and 2.5-fold that of Mn compared with MeT-5A. As for the intracellular levels of copper/zinc-SOD (Cu/Zn-SOD) and manganese-SOD (Mn-SOD), those of Cu/Zn-SOD were relatively unchanged among the cells tested, and no notable correlation with Cu or Zn contents was observed. On the other hand, all mesothelioma cells highly expressed Mn-SOD compared with MeT-5A, and a very high expression of the enzyme with a robust activity was observed in the two mesothelioma cells (NCI-H226, NCI-H2452) containing a large amount of Mn. CONCLUSIONS: In comparison with MeT-5A human mesothelial cells, some human mesothelioma cells had significantly higher amounts of Mn or Cu and one mesothelioma cell had a significantly higher amount of Zn. Interestingly, all mesothelioma cells overexpressed Mn-SOD compared with MeT-5A, and the cells whose Mn-SOD activity was increased contained higher amounts of Mn. It seemed that intracellular Mn content was positively correlated with Mn-SOD, suggesting that the intracellular Mn level is associated with Mn-SOD activity. These biochemical signatures could be potential disease-related markers of mesothelioma.     

Variation in social behavior within a spider mite genus, Stigmaeopsis (Acari: Tetranychidae)

The spider mites belonging to the genus Stigmaeopsis constructextremely dense oval woven roofs (web-nests) over depressionson the lower surface of host leaves and are known to have akind of sociality. The four species that occur on bamboo plantsin Japan show different nest areas. The nest area of Stigmaeopsislongus is the largest, followed by that of S. celarius, S. takahashii,and S. saharai in decreasing order. Smaller nests effectivelyprevent adults of several predator mite species from intruding.We hypothesized that variation in nest size reflects differentanti-intruder adaptations of this mite group in relation totheir sociality. The larger nest makers may adopt an alternativeanti-intruder strategy, namely, counterattack by a large group,so as to compensate for the disadvantage of large nests. S.longus and S. celarius adults effectively defended their largenests against potential predators, and the effects of nest defenseincreased with the number of individuals in a nest. S. takahashiiand S. saharai revealed no counterattack effect. Counterattackabilities that increase with the adult density, and thus, socialitymay compensate for the vulnerability of larger nests.     

A monoclonal antibody (1D12) defines novel distribution patterns of prion protein (PrP) as granules in nucleus

A monoclonal antibody (mAb) panel to bovine prion protein (PrP) was studied by immunoblotting and immunohistochemistry for scrapie and bovine spongiform encephalopathy. A mAb panel recognized both normal (PrP^C) and abnormal (PrP^Sc) isoforms of PrP in murine, ovine and bovine brain tissues. Interestingly, an anti-bovine PrP mAb, 1D12, prepared by immunizing PrP gene-knockout mice with a synthetic polypeptides corresponding to codons 153-166 of the bovine PrP gene showed novel patterns of reactivity for prion-uninfected neuronal cells. An enzyme-linked immunosorbent assay-mapping of the mAb epitopes resulted in a reaction of monoclonal 1D12 to YEDRY and M corresponding to amino acids 156-160 and 165 of bovine PrP. Several patterns of bovine PrP^C distribution in PrP-deficient neuronal cells (HpL3-4) transfected with bovine PrP were observed after different fixation methods. Stained cell surface was observed after formalin fixation by immunofluorescent assay of 1D12 with confocal microscopy, whereas granules in nucleus were stained after acetone fixation. No reactivity in the nucleus was observed to HpL3-4, or HpL3-4mPrP cells expressing mouse PrP. This is the first paper that has reported the detection of the PrP^C at both cell surface and nuclei of prion-uninfected cell line.