Response of a parasitoid fly, Gymnosoma rotundatum (Linnaeus) (Diptera: Tachinidae) to the aggregation pheromone of Plautia stali Scott (Hemiptera: Pentatomidae) and its parasitism of hosts under field conditions

We studied the attraction of a tachinid fly, Gymnosoma rotundatum (Linnaeus) to the male-produced aggregation pheromone of the brown-winged green bug, Plautia stali Scott, its parasitism on the bug, and its seasonal occurrence in the field. The tachinid fly was continuously attracted to the aggregation pheromone from spring to autumn and utilized the bugs as hosts. Our field experiment to clarify the effect of the pheromone on parasitism demonstrated that parasitism occurred only in female bugs baited with synthetic aggregation pheromone and did not occur in females without the pheromone. The parasitoid flies therefore appeared to use the bug’s pheromone as a host-finding kairomone. The pheromone attracted not only female flies but also males. Male flies may increase their chance of encountering pheromone-attracted females by waiting near pheromone sources. The tachinid develops multiple generations in active hosts from spring to autumn and overwinters in dormant hosts. Thus, G. rotundatum seems to be highly adapted to using P. stali as its host, and it is a potentially important biological control agent of P. stali populations in the field.     

Enhanced autophagy and mitochondrial aberrations in murine G(M1)-gangliosidosis

G_M1-gangliosidosis is an autosomal recessive lysosomal lipid storage disorder, caused by mutations of the lysosomal β-galactosidase (β-gal) and results in the accumulation of G_M1. The underlying mechanisms of neurodegeneration are poorly understood. Here we demonstrate increased autophagy in β-gal-deficient (β-gal^−/−) mouse brains as evidenced by elevation of LC3-II and beclin-1 levels. Activation of autophagy in the β-gal^−/− brain was found to be accompanied with enhanced Akt-mTOR and Erk signaling. In addition, the mitochondrial cytochrome c oxidase activity was significantly decreased in brains and cultured astrocytes from β-gal^−/− mouse. Mitochondria isolated from β-gal^−/− astrocytes were morphologically abnormal and had a decreased membrane potential. These cells were more sensitive to oxidative stress than wild type cells and this sensitivity was suppressed by ATP, an autophagy inhibitor 3-methyladenine and a pan-caspase inhibitor z-VAD-fmk. These results suggest activation of autophagy leading to mitochondrial dysfunction in the brain of G_M1-gangliosidosis.     

Ubiquitin-proteasome system impairment caused by a missense cardiac myosin-binding protein C mutation and associated with cardiac dysfunction in hypertrophic cardiomyopathy

The ubiquitin-proteasome system is responsible for the disappearance of truncated cardiac myosin-binding protein C, and the suppression of its activity contributes to cardiac dysfunction. This study investigated whether missense cardiac myosin-binding protein C gene (MYBPC3) mutation in hypertrophic cardiomyopathy (HCM) leads to destabilization of its protein, causes UPS impairment, and is associated with cardiac dysfunction. Mutations were identified in Japanese HCM patients using denaturing HPLC and sequencing. Heterologous expression was investigated in COS-7 cells as well as neonatal rat cardiac myocytes to examine protein stability and proteasome activity. The cardiac function was measured using echocardiography. Five novel MYBPC3 mutations—E344K, ΔK814, Δ2864-2865GC, Q998E, and T1046M—were identified in this study. Compared with the wild type and other mutations, the E334K protein level was significantly lower, it was degraded faster, it had a higher level of polyubiquination, and increased in cells pretreated with the proteasome inhibitor MG132 (50 μM, 6 h). The electrical charge of its amino acid at position 334 influenced its stability, but E334K did not affect its phosphorylation. The E334K protein reduced cellular 20 S proteasome activity, increased the proapoptotic/antiapoptotic protein ratio, and enhanced apoptosis in transfected Cos-7 cells and neonatal rat cardiac myocytes. Patients carrying the E334K mutation presented significant left ventricular dysfunction and dilation. The conclusion is the missense MYBPC3 mutation E334K destabilizes its protein through UPS and may contribute to cardiac dysfunction in HCM through impairment of the ubiquitin-proteasome system.     

Small acidic protein 1 and SCFTIR1 ubiquitin proteasome pathway act in concert to induce 2,4‐dichlorophenoxyacetic acid‐mediated alteration of actin in Arabidopsis roots

2,4‐Dichlorophenoxyacetic acid (2,4‐D), a functional analogue of auxin, is used as an exogenous source of auxin as it evokes physiological responses like the endogenous auxin, indole‐3‐acetic acid (IAA). Previous molecular analyses of the auxin response pathway revealed that IAA and 2,4‐D share a common mode of action to elicit downstream physiological responses. However, recent findings with 2,4‐D‐specific mutants suggested that 2,4‐D and IAA might also use distinct pathways to modulate root growth in Arabidopsis. Using genetic and cellular approaches, we demonstrate that the distinct effects of 2,4‐D and IAA on actin filament organization partly dictate the differential responses of roots to these two auxin analogues. 2,4‐D but not IAA altered the actin structure in long‐term and short‐term assays. Analysis of the 2,4‐D‐specific mutant aar1‐1 revealed that small acidic protein 1 (SMAP1) functions positively to facilitate the 2,4‐D‐induced depolymerization of actin. The ubiquitin proteasome mutants tir1‐1 and axr1‐12, which show enhanced resistance to 2,4‐D compared with IAA for inhibition of root growth, were also found to have less disrupted actin filament networks after 2,4‐D exposure. Consistently, a chemical inhibitor of the ubiquitin proteasome pathway mitigated the disrupting effects of 2,4‐D on the organization of actin filaments. Roots of the double mutant aar1‐1 tir1‐1 also showed enhanced resistance to 2,4‐D‐induced inhibition of root growth and actin degradation compared with their respective parental lines. Collectively, these results suggest that the effects of 2,4‐D on actin filament organization and root growth are mediated through synergistic interactions between SMAP1 and SCF^TIR1 ubiquitin proteasome components.     

Effects of a cool environment on the health of female office workers and students

OBJECTIVE: The aim of this study was to evaluate the effect of a cool environment on the peripheral skin blood flow and subjective thermal sensations of female office workers and female students. METHODS: The subjects were 26 female bank employees (mean age, 38 years) who worked in a cool environment and 10 female college students (mean age, 22 years). The peripheral skin blood flow was measured using a laser Doppler blood flow meter. In each bank employee, peripheral skin blood flow was measured at three time points during the workday in the medical treatment room at their workplace. In the college students, peripheral skin blood flow was measured every hour between 9:00 and 17:00 in a laboratory. In both the medical treatment room and the laboratory, the room temperature was controlled at 24-26 degrees C with a relative humidity of 55+/-10%. The bank employees and students were each divided into those with hypersensitivity to cold (Group A) and those without hypersensitivity to cold (Group B). RESULTS: When the 10 college students were in the cool environment (24-26 degrees C), their peripheral skin blood flow generally decreased over time. The rate of decrease of this blood flow was greater in Group A than in Group B. In the female bank employees, the peripheral skin blood flow was the lowest at 12:00 (before lunch), was increased at 13:00 (after lunch), and then was decreased at 17:30. However, the degree of the increase from before lunch to after lunch in Group A was about half of that in Group B. CONCLUSION: Among female office workers and students, a cool environment reduced the peripheral skin blood flow of individuals with hypersensitivity to cold to a greater degree than in those without hypersensitivity to cold.     

ICRF heating in magnetic mirror plasmas

Waves in the ion cyclotron range of frequency are efficiently used to produce and heat magnetic mirror plasmas. In relatively low-density (lower than 10¹⁸ m^?3) plasmas, the fast Alfvén eigenmodes are formed in radial and axial directions and the excitation of these modes is strongly affected by the density. The slow Alfvén waves are also effectively used for plasma heating. The ion temperature above 10 keV is achieved, which is confirmed by the detection of fusion neutrons. The excitation of Alfvén eigenmodes is studied in the GAMMA 10 tandem mirror.     

Aryl-indolyl maleimides as inhibitors of CaMKIIdelta. Part 2: SAR of the amine tether

A family of aryl-substituted maleimides was prepared and studied for their activity against calmodulin-dependant kinase. Inhibitory activities against the enzyme ranged from 34nM to >20microM and were dependant upon both the nature of the aryl group and the tether joining the basic amine to the indolyl maleimide core. Key interactions with the kinase ATP site and hinge region, predicted by homology modeling, were confirmed.     

Biliary excretion of polystyrene microspheres depends on the type of receptor-mediated uptake in rat liver

Hepatic uptake and biliary excretion of fluorescein isothiocyanate-labeled polystyrene microspheres with a particle size of 50 nm (MS-50) were studied in rats. Liver perfusion studies revealed that not only apo-E-mediated but also asialoglycoprotein receptor-mediated uptake is involved in the mechanism of the serum protein-dependent uptake of MS-50 in the liver. The uptake of MS-50 mediated by apo-E contributes more to the total uptake of MS-50 by the hepatocytes than that via asialoglycoprotein receptor in the presence of serum in the perfusate. Furthermore, it was found that MS-50 is substantially excreted into the bile by transcytosis. The extent of exocytosis of MS-50 taken up by the hepatocytes was much higher after MS-50 was endocytosed via asialoglycoprotein receptor than after taken up via the process mediated by apo-E. On the basis of these results, a possible regulation of the intracellular sorting of ligands, depending on the receptor-mediated uptake mechanism, was inferred.     

Interaction of polystyrene microspheres with liver cells: roles of membrane receptors and serum proteins

Our previous studies have demonstrated that serum would play an important role in the hepatic disposition of polystyrene microspheres (MS) and that complement C3 should be involved as the serum opsonin. In this study, we tried to identify the entity of other serum opsonins and dysopsonin for the hepatic uptake of MSs with particle sizes of 50 nm (MS-50) and 500 nm (MS-500) by isolated liver perfusion studies using a recirculation procedure in rats. Pretreatment of the liver by trypsin significantly suppressed the serum-dependent hepatic uptake of both MSs, suggesting that some protein components on the cell surface should be necessary for the serum-dependent phagocytosis of MSs. Pretreatment of the serum by the anti-fibronectin antibody resulted in a significant reduction in the hepatic disposition of MS-500 (49% of control), suggesting that fibronectin should also work as the opsonin for the hepatic uptake of MS-500. The hepatic disposition of both MSs in the presence of serum was inhibited by the addition of N-acetylgalactosamine into the perfusate, suggesting the possible involvement of lectin in the serum-dependent hepatic uptake of MSs. Furthermore, a more intensive hepatic disposition of MSs was observed in the presence of plasma compared with that in the presence of serum in the perfusate, suggesting the possible involvement of blood coagulation factors, such as fibrinogen, as the opsonin in the hepatic disposition of MSs.     

Real-time Imaging of Plant Cell Surface Dynamics with Variable-angle Epifluorescence Microscopy

A plant’s cell surface is its interface for perceiving environmental cues; it responds with cell biological changes such as membrane trafficking and cytoskeletal rearrangement. Real-time and high-resolution image analysis of such intracellular events will increase the understanding of plant cell biology at the molecular level. Variable angle epifluorescence microscopy (VAEM) is an emerging technique that provides high-quality, time-lapse images of fluorescently-labeled proteins on the plant cell surface. In this article, practical procedures are described for VAEM specimen preparation, adjustment of the VAEM optical system, movie capturing and image analysis. As an example of VAEM observation, representative results are presented on the dynamics of PATROL1. This is a protein essential for stomatal movement, thought to be involved in proton pump delivery to plasma membranes in the stomatal complex of Arabidopsis thaliana. VAEM real-time observation of guard cells and subsidiary cells in A. thaliana cotyledons showed that fluorescently-tagged PATROL1 appeared as dot-like structures on plasma membranes for several seconds and then disappeared. Kymograph analysis of VAEM movie data determined the time distribution of the presence (termed ‘residence time’) of the dot-like structures. The use of VAEM is discussed in the context of this example.