Surfactin from Bacillus subtilis displays anti-proliferative effect via apoptosis induction, cell cycle arrest and survival signaling suppression

The effect of surfactin on the proliferation of LoVo cells, a human colon carcinoma cell line, was examined. Surfactin strongly blocked the proliferation of LoVo cells by inducing pro-apoptotic activity and arresting the cell cycle, according to several lines of evidence on DNA fragmentation, Annexin V staining, and altered levels of poly (ADP-ribose) polymerase, caspase-3, p21(WAF1/Cip1), p53, CDK2 and cyclin E. The anti-proliferative activity of surfactin was mediated by inhibiting extracellular-related protein kinase and phosphoinositide 3-kinase/Akt activation, as assessed by phosphorylation levels. Therefore, our data suggest that surfactin may have anti-cancer properties as a result of its ability to downregulate the cell cycle and suppress its survival.     

microRNAs in stroke pathogenesis

Stroke is one of the leading causes of death and disability worldwide. There are two major types of stroke: cerebral ischemia caused by obstruction of blood vessels in the brain and haemorrhagic stroke that is triggered by the disruption of blood vessels. Thrombolytic therapy involving recombinant tissue plasminogen activator (rtPA) has been shown to be beneficial only when used within 4.5 hours of onset of acute ischemic stroke. rtPA treatment beyond this time window has been found to be unsuitable and usually resulting in haemorrhagic transformation. Stroke is a multifactorial disease that forms a possible end state for majority of patients suffering from diabetes, atherosclerosis and hypertension which are known risk factors. Although the biochemistry of stroke and related diseases is quite well understood, the knowledge on the molecular mechanisms underlying these diseases is still at its infancy. microRNAs that form a unique class of endogenous riboregulators of gene function, offer tremendous potential in unraveling the mechanisms underlying stroke pathogenesis. microRNA expression also reflects the response of individuals to drugs and therapy. Several microRNAs and their target genes, known to be involved in endothelial dysfunction, dysregulation of neurovascular integrity, edema formation, pro-apoptosis, inflammation and extra-cellular matrix remodeling contribute to the critical processes in the pathogenesis of stroke. In this review, we will also be discussing the role of microRNAs as possible diagnostic and prognostic biomarkers as well as potential therapeutic targets in stroke pathogenesis.     

Effects of fetal calf serum, amino acids, vitamins and insulin on blastocoel formation and hatching of in vivo and IVM/IVF-derived porcine embryos developing in vitro

The objective of this study was to determine the effects of fetal calf serum (FCS), non-essential MEM amino acids, MEM vitamins and insulin on blastocoel formation, expansion and hatching in porcine embryos developing in vitro. Addition of 20% FCS to the NCSU 23 medium significantly (P < 0.05) decreased by the compaction and blastocoel formation of 1- to 2-cell embryos developing in vitro. In contrast, more 1- to 2-cell embryos commenced hatching in the media containing amino acids than in control medium (25.7 vs 2.6%, P < 0.01). Amino acids and insulin synergistically enhanced the incidence of blastocoel formation and hatching of porcine embryos developing in vitro (P < 0.05). When early compacted embryos which developed in vitro in NCSU 23 medium were cultured in BSA-free NCSU 23 medium supplemented with 20% FCS, the incidence of hatching was significantly increased compared with that of the control groups (35.7 vs 4.1%, P < 0.01). However, addition of amino acids, vitamins or insulin to the NCSU 23 medium did not enhance the development of early morulae to the hatched embryos (P > 0.1). When either in vivo or IVM/IVF-derived 1- to 2-cell stage embryos were cultured 4 d in the modified NCSU 23 and an additional 4 days in the modified NCSU 23 supplemented in the FCS, the percentages (61.8 and 17.8%, in vivo- and IVM/TVF-derived, respectively) of hatched blastocysts were significantly higher (P < 0.01) than in the control groups (2.9 and 0%, in vivo and IVM/IVF-derived, respectively). These results suggested that dual culture conditions are required to optimize an in vitro culture system for the development of the porcine embryo in vitro.     

Variability of <Emphasis Type="Italic">Mya arenaria</Emphasis> growth along an environmental gradient in the Plum Island Sound estuary,Massachusetts, USA

An understanding of the environmental factors that determine how clam growth varies in space and time improves effective mariculture and shellfish management. We examined the importance of temperature, salinity and chlorophyll-a in controlling the spatial pattern of Mya arenaria growth, the commercially important soft-shell clam, in the Plum Island Sound estuary in northeastern Massachusetts, USA. We collected clams (>5.08 cm) monthly during the April to November growing season from which we determined growth rate, maximum size (L-infinity), and time to reach a harvestable size. We also surveyed selected sites along the estuary to estimate the relationship between clam size and weight. We collected environmental data along the estuary, and our data were complemented with data collected and maintained by the Plum Island ecosystems long-term ecological research project. Clams reached harvestable size fastest and had the greatest L-infinity at the most oceanic site (Yacht Club) in the estuary. Clams had the smallest L-infinity and were slowest to reach the harvestable size at the least oceanic site (Railroad Meander). The spatial patterns of clam growth were best explained by a positive distribution of salinity. Salinity significantly accounted for 95 % of the spatial variation of clam growth in the estuary. Snow melt in spring increases freshwater input to the estuary and results in the lowest spring salinity during a year, and this explained the upper estuary limit of clam distribution. IPCC-projected climate change will cause sea-level rise and increasing precipitation in the northeastern USA, which will modify the spatial pattern of salinity in the region’s estuaries. Our research therefore suggests that future management of M. arenaria, an important economic resource for the local economy, should be concerned with the changes of salinity distribution under climate and land-use change.     

Belling the Chinese Dragon at Sea: Western Theories and Asian Realities

Against the backdrop of projections of either conflict escalation or legal settlement by Western international relations theories, this article provides a more nuanced and subtle balance between Western theories and Asian realities.     

Change in platelet endothelial cell adhesion molecule-1 immunoreactivity in the dentate gyrus in gerbils fed a folate-deficient diet

Folate deficiency increases stroke risk. We examined whether folate deficiency affects platelet endothelial cell adhesion molecule-1 (PECAM-1), which is an immunoglobulin-associated cell adhesion molecule and mediates the final common pathway of neutrophil transendothelial migration, in blood vessels in the gerbil dentate gyrus after transient forebrain ischemia. Gerbils were exposed to a folic acid-deficient diet (FAD) for 3 months and then subjected to common carotid artery occlusion for 5 min. In the control diet (CD)- and FAD-treated sham-operated groups, weak PECAM-1 immunoreactivity was detected in the blood vessels located in the dentate gyrus. PECAM-1 immunoreactivity in both groups was increased by 4 days after ischemic insult. PECAM-1 immunoreactivity in the FAD-treated group was twice as high that in the CD-treated-sham-operated group 4 days after ischemic insult. Western blot analyses showed that the change patterns in PECAM-1 protein levels in the dentate gyrus in both groups after ischemic insult were similar to changes in PECAM-1 immunohistochemistry in the ischemic dentate gyrus. Our results suggest that folate deficiency enhances PECAM-1 in the dentate gyrus induced by transient ischemia.     

Mind bomb 1-expressing intermediate progenitors generate notch signaling to maintain radial glial cells

Notch signaling is critical for the stemness of radial glial cells (RGCs) during embryonic neurogenesis. Although Notch-signal-receiving events in RGCs have been well characterized, the signal-sending mechanism by the adjacent cells is poorly understood. Here, we report that conditional inactivation of mind bomb-1 (mib1), an essential component for Notch ligand endocytosis, in mice using the nestin and hGFAP promoters resulted in complete loss of Notch activation, which leads to depletion of RGCs, and premature differentiation into intermediate progenitors (IPs) and finally neurons, which were reverted by the introduction of active Notch1. Interestingly, Mib1 expression is restricted in the migrating IPs and newborn neurons, but not in RGCs. Moreover, sorted Mib1+ IPs and neurons can send the Notch signal to neighboring cells. Our results reveal that not only newborn neurons but also IPs are essential Notch-ligand-presenting cells for maintaining RGC stemness during both symmetric and asymmetric divisions.     

Extraordinary tertiary constrictions of Tripsacum dactyloides chromosomes: implications for karyotype evolution of polyploids driven by segmental chromosome losses

Tripsacum dactyloides (2n = 2x = 36) is an ancient tetraploid species. Here we report that T. dactyloides chromosomes contain an extraordinary tertiary constriction, which causes a radical and distant separation of a terminal segment from the chromosome. The relationships between extraordinary tertiary constriction and segmental chromosome loss as well as karyotype evolution of polyploid species are discussed.     

Expression and Changes of Hyperoxidized Peroxiredoxins in Non-Pyramidal and Polymorphic Cells in the Gerbil Hippocampus During Normal Aging

Oxidative stress is one of predisposing factors to age-related neurodegeneration in the brain. In particular, thiol-containing groups are susceptible to oxidative stress, which induces the formation of the disulfide bond and/or hyperoxidized form of thiol-containing proteins. We observed the protein thiol levels in the hippocampal homogenates and also investigated changes in hyperoxidized form of peroxiredoxin (Prx–SO₃) immunoreactivity and proteins levels in the gerbil hippocampal subregions during normal aging. Levels of total thiol, non-protein thiol, and protein thiol were decreased in the hippocampal homogenates with age. At post-natal month 1 (PM 1), pyramidal and non-pyramidal cells in the hippocampal CA1 region (CA1) showed Prx–SO₃ immunoreactivity. Prx–SO₃ immunoreactivity in the cells was decreased by PM 12, thereafter, Prx–SO₃ immunoreactivity in the cells increased again with age. In the CA2/3, Prx–SO₃ immunoreactivity in pyramidal cells was not significantly changed; however, the immunoreactivity in pyramidal cells was very low at PM 12. Prx–SO₃ immunoreactivity in the dentate gyrus (DG) was distinctly changed during aging. At PM 1, Prx–SO₃ immunoreactivity in granule and polymorphic cells was weak and strong, respectively. The immunoreactivity in the neurons was decreased with age, not shown in any neurons at PM 12. Thereafter, Prx–SO₃ immunoreactivity increased again with age. In addition, Prx–SO₃ protein level in the hippocampus was lowest at PM 12. These results suggest that thiol-containing proteins are changed during aging and Prx–SO₃ immunoreactivity was different according to cells in the hippocampal subregion during aging.     

Contribution of mobile genetic elements to Desulfovibrio vulgaris genome plasticity

The genome of Desulfovibrio vulgaris strain DePue, a sulfate-reducing Deltaproteobacterium isolated from heavy metal-impacted lake sediment, was completely sequenced and compared with the type strain D. vulgaris Hildenborough. The two genomes share a high degree of relatedness and synteny, but harbour distinct prophage and signatures of past phage encounters. In addition to a highly variable phage contribution, the genome of strain DePue contains a cluster of open-reading frames not found in strain Hildenborough coding for the production and export of a capsule exopolysaccharide, possibly of relevance to heavy metal resistance. Comparative whole-genome microarray analysis on four additional D. vulgaris strains established greater interstrain variation within regions associated with phage insertion and exopolysaccharide biosynthesis.