Adipose-derived stromal cells inhibit prostate cancer cell proliferation inducing apoptosis

Mesenchymal stem cells (MSCs) have generated a great deal of interest in the field of regenerative medicine. Adipose-derived stromal cells (AdSCs) are known to exhibit extensive proliferation potential and can undergo multilineage differentiation, sharing similar characteristics to bone marrow-derived MSCs. However, as the effect of AdSCs on tumor growth has not been studied sufficiently, we assessed the degree to which AdSCs affect the proliferation of prostate cancer (PCa) cell. Human AdSCs exerted an inhibitory effect on the proliferation of androgen-responsive (LNCaP) and androgen-nonresponsive (PC3) human PCa cells, while normal human dermal fibroblasts (NHDFs) did not, and in fact promoted PCa cell proliferation to a degree. Moreover, AdSCs induced apoptosis of LNCaP cells and PC3 cells, activating the caspase3/7 signaling pathway. cDNA microarray analysis suggested that AdSC-induced apoptosis in both LNCaP and PC3 cells was related to the TGF-β signaling pathway. Consistent with our in vitro observations, local transplantation of AdSCs delayed the growth of tumors derived from both LNCaP- and PC3-xenografts in immunodeficient mice. This is the first preclinical study to have directly demonstrated that AdSC-induced PCa cell apoptosis may occur via the TGF-β signaling pathway, irrespective of androgen-responsiveness. Since autologous AdSCs can be easily isolated from adipose tissue without any ethical concerns, we suggest that therapy with these cells could be a novel approach for patients with PCa.     

Impacts of Small‐scale Clearings due to Selective logging on Dung Beetle Communities

Conservation of biodiversity in production forests is crucial for mitigating biodiversity loss in the tropics. The major ecological impacts of selective logging are often the result of small clearings for skid trails, logging roads, log yards, and logging camps; however, their impacts on forest biodiversity have rarely been examined. The purpose of this study was to assess the impacts of these clearings on a forest‐dependent faunal group, dung beetles, and to identify the environmental factors responsible. Abundance and species richness of dung beetles decreased drastically in clearings, but directly increased in forests with the distance from roads/trails; abundance and species richness at 10 m from roads/trails were almost comparable with those detected in further interior forests. Similarly, species composition was significantly different between forests and clearings (except skid trails) but recovered within a short distance from roads/trails. Canopy openness was the most important environmental factor affecting the abundance, and species richness and composition of dung beetles; most dung beetle species were concentrated under closed forest canopy with less than 10 percent of canopy openness, whereas canopy openness ranged from 16 to 53 percent in clearings. Our study demonstrates that even small‐scale, unpaved clearings affect dung beetle communities through increased canopy openness. Although the effective distance was not very large, a considerable portion of logged areas can be affected when road networks are dense therefore minimizing the density of road networks and enhancing canopy recovery after logging are important for retaining biodiversity in tropical production forests.     

Neurogenin2‐d4Venus and Gadd45g‐d4Venus transgenic mice: Visualizing mitotic and migratory behaviors of cells committed to the neuronal lineage in the developing mammalian brain

To achieve highly sensitive and comprehensive assessment of the morphology and dynamics of cells committed to the neuronal lineage in mammalian brain primordia, we generated two transgenic mouse lines expressing a destabilized (d4) Venus controlled by regulatory elements of the Neurogenin2 (Neurog2) or Gadd45g gene. In mid‐embryonic neocortical walls, expression of Neurog2‐d4Venus mostly overlapped with that of Neurog2 protein, with a slightly (1 h) delayed onset. Although Neurog2‐d4Venus and Gadd45g‐d4Venus mice exhibited very similar labeling patterns in the ventricular zone (VZ), in Gadd45g‐d4Venus mice cells could be visualized in more basal areas containing fully differentiated neurons, where Neurog2‐d4Venus fluorescence was absent. Time‐lapse monitoring revealed that most d4Venus⁺ cells in the VZ had processes extending to the apical surface; many of these cells eventually retracted their apical process and migrated basally to the subventricular zone, where neurons, as well as the intermediate neurogenic progenitors that undergo terminal neuron‐producing division, could be live‐monitored by d4Venus fluorescence. Some d4Venus⁺ VZ cells instead underwent nuclear migration to the apical surface, where they divided to generate two d4Venus⁺ daughter cells, suggesting that the symmetric terminal division that gives rise to neuron pairs at the apical surface can be reliably live‐monitored. Similar lineage‐committed cells were observed in other developing neural regions including retina, spinal cord, and cerebellum, as well as in regions of the peripheral nervous system such as dorsal root ganglia. These mouse lines will be useful for elucidating the cellular and molecular mechanisms underlying development of the mammalian nervous system.     

Comparisons of accumulation and excretion of iminosugars among mulberry-feeding specialist Bombyx larvae and non-specialist larvae

Silkworms (Bombyx mori L.) accumulate 1-deoxynojirimycin (DNJ), a mulberry iminosugar, by feeding on mulberry leaves. DNJ is a potent α-glucosidase inhibitor that helps prevent diabetes. However, iminosugars are toxic to many insects. In this study, we analyzed the concentrations of three major mulberry iminosugars—DNJ, 2-O-α-d-galactopyranosyl-DNJ (GAL-DNJ), and fagomine—in the larvae of mulberry-feeding insect species (two mulberry specialists and six non-specialists), to clarify the differences in accumulation, metabolism, and excretion of iminosugars between specialists and non-specialists. DNJ and fagomine concentrations in the two Bombyx larvae were much higher than those in the other larvae. GAL-DNJ concentrations were low in all species. DNJ and fagomine concentrations in the excrements of Agrotis segetum (Denis and Schiffermüller) and Sarcopolia illoba (Butler) larvae were lower than in those of the other larvae. Further, iminosugar concentrations in the hemolymph of B. mori, B. mandarina Moore, and S. illoba larvae were analyzed. DNJ and fagomine concentrations in the hemolymph of the two Bombyx larvae were much higher than in that of S. illoba. DNJ concentrations in the whole bodies of the two Bombyx larvae decreased as they developed. Similarly, DNJ, and fagomine concentrations in the hemolymph of B. mori larvae decreased with growth.     

Angptl 4 deficiency improves lipid metabolism, suppresses foam cell formation and protects against atherosclerosis

Angiopoietin-like protein family 4 (Angptl 4) has been shown to regulate lipoprotein metabolism through the inhibition of lipoprotein lipase (LPL). We generated ApoE^−/−Angptl 4^−/− mice to study the effect of Angptl 4 deficiency on lipid metabolism and atherosclerosis. Fasting and postolive oil-loaded triglyceride (TG) levels were largely decreased in ApoE^−/−Angptl 4^−/− mice compared with and ApoE^−/−Angptl 4^+/+ mice. There was a significant (75 ± 12%) reduction in atherosclerotic lesion size in ApoE^−/−Angptl 4^−/− mice compared with ApoE^−/− Angptl 4^+/+ mice. Peritoneal macrophages, isolated from Angptl 4^−/− mice to investigate the foam cell formation, showed a significant decrease in newly synthesized cholesteryl ester (CE) accumulation induced by acetyl low-density lipoprotein (acLDL) compared with those from Angptl 4^+/+ mice. Thus, genetic knockout of Angptl 4 protects ApoE^−/− mice against development and progression of atherosclerosis and strongly suppresses the ability of the macrophages to become foam cells in vitro.     

Real-time monitoring of RNA helicase activity using fluorescence resonance energy transfer in vitro

We have developed a continuous fluorescence assay based on fluorescence resonance energy transfer (FRET) for the monitoring of RNA helicase activity in vitro. The assay is tested using the hepatitis C virus (HCV) NS3 helicase as a model. We prepared a double-stranded RNA (dsRNA) substrate with a 5′ fluorophore-labeled strand hybridized to a 3′ quencher-labeled strand. When the dsRNA is unwound by helicase, the fluorescence of the fluorophore is emitted following the separation of the strands. Unlike in conventional gel-based assays, this new assay eliminates the complex and time-consuming steps, and can be used to simply measure the real-time kinetics in a single helicase reaction. Our results demonstrate that Alexa Fluor 488 and BHQ1 are an effective fluorophore-quencher pair, and this assay is suitable for the quantitative measurement of the RNA helicase activity of HCV NS3. Moreover, we found that several extracts of marine organisms exhibited different inhibitory effects on the RNA and DNA helicase activities of HCV NS3. We propose that this assay will be useful for monitoring the detailed kinetics of RNA unwinding mechanisms and screening RNA helicase inhibitors at high throughput.