Inspection of frass ejection could decrease the risk of white-spotted longicorn beetle Anoplophora malasiaca (Coleoptera: Cerambycidae) infestation of Japanese pine bonsais to negligible levels

Applied Entomology and Zoology - To evaluate the infection risk of Anoplophora malasiaca (Thomson) (Coleoptera: Cerambycidae) in two species of Japanese pine bonsais (Japanese black pine and...     

The distribution of respiration-related and swallowing-related motoneurons innervating the rat genioglossus muscle

The present study was an attempt to identify the location of genioglossal respiratory and swallowing motoneuron cell bodies within the hypoglossal (XII) nucleus using both electrophysiological and morphological studies. The genioglossus muscle is innervated by the genioglossal branch of the medial XII nerve. At the entrance to the muscle, the genioglossal branch divides in the directions of the mandible and tongue. Five of five rats displayed both respiratory-related and swallowing-related bursts in the medial XII branch towards the mandible. All five rats also displayed swallowing-related bursts in the medial XII branch towards the tongue. In addition, horseradish peroxidase conjugated to wheatgerm agglutinin (HRP:WGA) was injected into the proximal cut ends of each branch. When HRP:WGA was injected into the branch in the direction of the mandible, HRP-labeled cells were detected in the lateral region of the ventromedial subnucleus in the XII nucleus, extending from 0.7 to 1.2 mm rostral to the obex. On the other hand, after injection into the branch in the direction of the mandible, HRP-labeled cells were detected in the ventromedial subnucleus of the XII nucleus, extending from 0.3 to 1.2 mm rostral to the obex. These results provide evidence that genioglossal respiration-related and swallowing-related motoneurons are located in different portions within the ventromedial subnucleus of the XII nucleus.     

Stimulation of Bone Formation in Cortical Bone of Mice Treated with a Receptor Activator of Nuclear Factor-κB Ligand (RANKL)-binding Peptide That Possesses Osteoclastogenesis Inhibitory Activity

To date, parathyroid hormone is the only clinically available bone anabolic drug. The major difficulty in the development of such drugs is the lack of clarification of the mechanisms regulating osteoblast differentiation and bone formation. Here, we report a peptide (W9) known to abrogate osteoclast differentiation in vivo via blocking receptor activator of nuclear factor-κB ligand (RANKL)-RANK signaling that we surprisingly found exhibits a bone anabolic effect in vivo. Subcutaneous administration of W9 three times/day for 5 days significantly augmented bone mineral density in mouse cortical bone. Histomorphometric analysis showed a decrease in osteoclastogenesis in the distal femoral metaphysis and a significant increase in bone formation in the femoral diaphysis. Our findings suggest that W9 exerts bone anabolic activity. To clarify the mechanisms involved in this activity, we investigated the effects of W9 on osteoblast differentiation/mineralization in MC3T3-E1 (E1) cells. W9 markedly increased alkaline phosphatase (a marker enzyme of osteoblasts) activity and mineralization as shown by alizarin red staining. Gene expression of several osteogenesis-related factors was increased in W9-treated E1 cells. Addition of W9 activated p38 MAPK and Smad1/5/8 in E1 cells, and W9 showed osteogenesis stimulatory activity synergistically with BMP-2 in vitro and ectopic bone formation. Knockdown of RANKL expression in E1 cells reduced the effect of W9. Furthermore, W9 showed a weak effect on RANKL-deficient osteoblasts in alkaline phosphatase assay. Taken together, our findings suggest that this peptide may be useful for the treatment of bone diseases, and W9 achieves its bone anabolic activity through RANKL on osteoblasts accompanied by production of several autocrine factors.     

Actin Dynamics Regulated by the Balance of Neuronal Wiskott-Aldrich Syndrome Protein (N-WASP) and Cofilin Activities Determines the Biphasic Response of Glucose-induced Insulin Secretion

Actin dynamics in pancreatic β-cells is involved in insulin secretion. However, the molecular mechanisms of the regulation of actin dynamics by intracellular signals in pancreatic β-cells and its role in phasic insulin secretion are largely unknown. In this study, we elucidate the regulation of actin dynamics by neuronal Wiskott-Aldrich syndrome protein (N-WASP) and cofilin in pancreatic β-cells and demonstrate its role in glucose-induced insulin secretion (GIIS). N-WASP, which promotes actin polymerization through activation of the actin nucleation factor Arp2/3 complex, was found to be activated by glucose stimulation in insulin-secreting clonal pancreatic β-cells (MIN6-K8 β-cells). Introduction of a dominant-negative mutant of N-WASP, which lacks G-actin and Arp2/3 complex-binding region VCA, into MIN6-K8 β-cells or knockdown of N-WASP suppressed GIIS, especially the second phase. We also found that cofilin, which severs F-actin in its dephosphorylated (active) form, is converted to the phosphorylated (inactive) form by glucose stimulation in MIN6-K8 β-cells, thereby promoting F-actin remodeling. In addition, the dominant-negative mutant of cofilin, which inhibits activation of endogenous cofilin, or knockdown of cofilin reduced the second phase of GIIS. However, the first phase of GIIS occurs in the G-actin predominant state, in which cofilin activity predominates over N-WASP activity. Thus, actin dynamics regulated by the balance of N-WASP and cofilin activities determines the biphasic response of GIIS.     

Sulfation of keratan sulfate proteoglycan reduces radiation-induced apoptosis in human Burkitt’s lymphoma cell lines

This study focuses on clarifying the contribution of sulfation to radiation-induced apoptosis in human Burkitt’s lymphoma cell lines, using 3′-phosphoadenosine 5′-phosphosulfate transporters (PAPSTs). Overexpression of PAPST1 or PAPST2 reduced radiation-induced apoptosis in Namalwa cells, whereas the repression of PAPST1 expression enhanced apoptosis. Inhibition of PAPST slightly decreased keratan sulfate (KS) expression, so that depletion of KS significantly increased radiation-induced apoptosis. In addition, the repression of all three N-acetylglucosamine-6-O-sulfotransferases (CHST2, CHST6, and CHST7) increased apoptosis. In contrast, PAPST1 expression promoted the phosphorylation of p38 MAPK and Akt in irradiated Namalwa cells. These findings suggest that 6-O-sulfation of GlcNAc residues in KS reduces radiation-induced apoptosis of human Burkitt’s lymphoma cells.     

Effects of arbuscular mycorrhizal fungi on the abundance of foliar-feeding insects and their natural enemy

We investigated the effects of symbiotic association between a plant and an arbuscular mycorrhizal fungus (AMF) on the abundance of aboveground foliar-feeding insects that differed in feeding mode and their predator. We examined effects on insect abundance as the result of AMF-related changes in the quality and quantity of plants in the field. The numbers of three insects with different foliar-feeding mode (phloem feeder, chewer, and cell-content feeder) and their generalist predator Orius sauteri Poppius on soybean Glycine max (L.) Merrill with and without the AMF Gigaspora margarita Becker & Hall were compared over time. Symbiotic association between the AMF and the soybean increased shoot biomass, the concentration of phosphorus in the soybean, and the abundance of the phloem feeder Aulacorthum solani Kaltenbach, but did not affect the abundance of generalist chewers. In addition, the effects of the symbiotic association on the abundance of cell-content feeding Thrips spp. and the generalist predator O. sauteri differed between sample dates. These results indicated that the effects of the symbiotic association on the number of foliar-feeding insects depended on feeding mode and the number of predators.     

Piperine analogs in a hydrophobic fraction from Piper ribersoides (Piperaceae) and its insect antifeedant activity

Piper ribersoides Wall. (Piperaceae), which is called “Khua Sa khan” in the local language, is mainly grown in Laos. This plant is used as a food in Laos, but no report on its metabolites exists. Crushed stems were immersed in methanol. The ethyl acetate fraction showed potential insect antifeedant activity for Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae), and some of the active compounds were piperine analogs. Piperine and its geometrical isomer independently showed potent antifeedant activities, and piperine was presumably the main active compound in the methanol extract. Interestingly, we discovered that the antifeedant activity was reduced when they were mixed (50:50).     

Measurement of Allicin with N-Ethyl Maleimide

The reaction catalyzed by crystalline yeast phosphoglyceric acid mutase is inhibited by the substrate (d-2-phosphoglyceric acid). In order to elucidate the mechanism of this substrate inhibition, detailed investigations have been performed. It is proved that the substrate inhibition in this enzyme reaction is caused by the facts that the coenzyme-binding site on the enzyme is covered by the substrate and the combination of the coenzyme with the enzyme is interfered by the substrate. Consequently, it is concluded that the substrate is a competitive inhibitor of the coenzyme.     

Requirement of Retinoic Acid Receptor β for Genipin Derivative-Induced Optic Nerve Regeneration in Adult Rat Retina

Like other CNS neurons, mature retinal ganglion cells (RGCs) are unable to regenerate their axons after nerve injury due to a diminished intrinsic regenerative capacity. One of the reasons why they lose the capacity for axon regeneration seems to be associated with a dramatic shift in RGCs’ program of gene expression by epigenetic modulation. We recently reported that (1R)-isoPropyloxygenipin (IPRG001), a genipin derivative, has both neuroprotective and neurite outgrowth activities in murine RGC-5 retinal precursor cells. These effects were both mediated by nitric oxide (NO)/S-nitrosylation signaling. Neuritogenic activity was mediated by S-nitrosylation of histone deacetylase-2 (HDAC2), which subsequently induced retinoic acid receptor β (RARβ) expression via chromatin remodeling in vitro. RARβ plays important roles of neural growth and differentiation in development. However, the role of RARβ expression during adult rat optic nerve regeneration is not clear. In the present study, we extended this hypothesis to examine optic nerve regeneration by IPRG001 in adult rat RGCs in vivo. We found a correlation between RARβ expression and neurite outgrowth with age in the developing rat retina. Moreover, we found that IPRG001 significantly induced RARβ expression in adult rat RGCs through the S-nitrosylation of HDAC2 processing mechanism. Concomitant with RARβ expression, adult rat RGCs displayed a regenerative capacity for optic axons in vivo by IPRG001 treatment. These neuritogenic effects of IPRG001 were specifically suppressed by siRNA for RARβ. Thus, the dual neuroprotective and neuritogenic actions of genipin via S-nitrosylation might offer a powerful therapeutic tool for the treatment of RGC degenerative disorders.