Aminopropyl carbazole analogues as potent enhancers of neurogenesis.

Neural stem cells are multipotent and self-renewing cells that can differentiate into new neurons and hold great promise for treating various neurological disorders including multiple sclerosis, Parkinson's disease, and Alzheimer's disease. Small molecules that can trigger neurogenesis and neuroprotection are particularly useful not only because of their therapeutic implications but also because they can provide an invaluable tool to study the mechanisms of neurogenesis. In this report, we have developed and screened 25 aminopropyl carbazole derivatives that can enhance neurogenesis of cultured neural stem cells. Among these analogues, compound 9 demonstrated an excellent proneurogenic and neuroprotective activity with no apparent toxicity. We believe that compound 9 can serve as an excellent lead to develop various analogues and to study the underlying mechanisms of neurogenesis.

Comparison of ectopic gene expression methods in rat neural stem cells.

Neural stem cells (NSCs) have the ability to proliferate and differentiate into various types of cells that compose the nervous system. To study functions of genes in stem cell biology, genes or siRNAs need to be transfected. However, it is difficult to transfect ectopic genes into NSCs. Thus to identify the suitable method to achieve high transfection efficiency, we compared lipid transfection, electroporation, nucleofection and retroviral transduction. Among the methods that we tested, we found that nucleofection and retroviral transduction showed significantly increased transfection efficiency. In addition, with retroviral transduction of Ngn2 that is known to induce neurogenesis in various types of cells, we observed facilitated final cell division in rat NSCs. These data suggest that nucleofection and retroviral transduction provide high efficiency of gene delivery system to study functions of genes in rat NSCs.

Modified DCM-type materials for red fluorescent organic light-emitting diodes.

A series of red emitters 1-3 based on modified DCM were synthesized and their electroluminescent properties were investigated. A device employing red emitter 2 as a dopant exhibited efficient red emission with maximum luminous efficiency of 1.87 cd/A, maximum power efficiency of 0.78 lm/W, maximum external quantum efficiency of 1.52%, and CIE coordinates of (0.65, 0.35) at 7.0 V.

Spectroscopic and chromatographic characterization of wastewater organic matter from a biological treatment plant.

Spectroscopic and chromatographic changes in dissolved organic matter (DOM) characteristics of influent and treated sewage were investigated for a wastewater treatment plant (WWTP) with a biological advanced process. Refractory DOM (R-DOM) was defined as the dissolved organic carbon concentrations of the samples after 28-day incubation for this study. Specific UV absorbance (SUVA), hydrophobicity, synchronous fluorescence spectra and molecular weight (MW) distributions were selected as DOM characteristics. The percent distribution of R-DOM for the effluent was much higher than that of the influent, indicating that biodegradable DOM was selectively removed during the process. Comparison of the influent versus the effluent sewage revealed that SUVA, fulvic-like fluorescence (FLF), humic-like fluorescence (HLF), the apparent MW values were enhanced during the treatment. This suggests that more aromatic and humic-like compounds were enriched during the biological process. No significant difference in the DOM characteristics was observed between the original effluent (i.e., prior to the incubation) and the influent sewage after the incubation. This result suggests that the major changes in wastewater DOM characteristics occurring during the biological advanced process were similar to those for simple microbial incubation.

Effect of COVID-19 Non-Pharmaceutical Interventions and the Implications for Human Rights.

In response to the COVID-19 pandemic, many governments swiftly decided to order nationwide lockdowns based on limited evidence that such extreme measures were effective in containing the epidemic. A growing concern is that governments were given little time to adopt effective and proportional interventions protecting citizens' lives while observing their freedom and rights. This paper examines the effectiveness of non-pharmaceutical interventions (NPIs) in containing COVID-19, by conducting a linear regression over 108 countries, and the implication for human rights. The regression results are supported by evidence that shows the change in 10 selected countries' responding strategies and their effects as the confirmed cases increase. We found that school closures are effective in containing COVID-19 only when they are implemented along with complete contact tracing. Our findings imply that to contain COVID-19 effectively and minimize the risk of human rights abuses, governments should consider implementing prudently designed full contact tracing and school closure policies, among others. Minimizing the risk of human rights abuses should be a principle even when full contact tracing is implemented.

IgG and IgM responses to human papillomavirus L1 virus-like particle as a function of dosing schedule and vaccine formulation.

Most commercialized virus-like particle (VLP) vaccines use aluminum salt as adjuvant, even though VLPs provoke adequate antibody responses without adjuvant. We do not have detailed knowledge of how adjuvant affects the profile of anti-VLP antibodies. Meanwhile, there is evidence that differences between vaccination protocols influence the glycosylation of antibodies, which may alter their effector functions. In the present study a murine model was used to investigate the effects of dosing schedule and adjuvant on the antibody profiles and glycosylation levels of antigen-specific antibody responses to human papillomavirus type 16 L1 (HPV16 L1) VLPs. Mice received subcutaneously 2,000 ng of antigen divided into 4 or 7 doses. The HPV16 L1 VLPs elicited > 4 log10 anti-HPV16 L1 IgG titers without adjuvant, and aluminum hydroxide as adjuvant increased IgG titers 1.3- to 4-fold and reduced the anti-HPV16 L1 IgG2a / anti-HPV16 L1 IgG1 ratio value (use of aluminum hydroxide reduced the ratio of the IgG2a). Immunization with HPV16 L1 VLPs in combination with Freund's adjuvant enhanced IgG titers 5- to 12-fold. Seven-dose immunization markedly increased anti-HPV16 L1 IgM titers compared to four-dose immunization, as well as increasing the proportion of glycosylated antibodies. Our results suggest that antibody glycosylation can be controlled immunologically, and IgG and IgM profiles and glycosylation profiles of the vaccine-induced antibodies can be used as indicators reflecting the vaccine characteristics. These results indicate that the HPV16 L1 VLP dosing schedule can affect the quality of antigen-specific antibody responses. We suggest that dosing schedules should be noted in vaccination protocols for VLP-based vaccines.

Comparison of the size distributions and immunogenicity of human papillomavirus type 16 L1 virus-like particles produced in insect and yeast cells.

Insect and yeast cells are considered the expression systems of choice for producing virus-like particles (VLPs), and numerous types of VLPs have been produced in these systems. However, previous studies were restricted to identifying the characteristics of individual VLP preparations. No direct comparison of the structures and immunogenic properties of insect and yeast-derived VLPs has so far been made. In the present study, the size distribution and immunogenic properties of human papillomavirus type 16 (HPV16) L1 VLPs produced in Spodoptera frugipedra-9 insect cells and Saccharomyces cerevisiae were compared. The insect cell-derived VLPs were larger than the yeast ones (P < 0.0001), with median sizes of 34 and 26 nm, respectively. In addition, the insect-derived VLPs appeared to be more diverse in size than the yeast-derived VLPs. Immunization of mice with 30 ng per dose of VLPs elicited 2.7- and 2.4-fold higher anti-HPV16 L1 IgG and anti-HPV16 neutralizing antibody titers than immunization with the same amounts of the yeast-derived VLPs after the 4th immunizations, respectively. Our results suggest that the choice of expression system critically affects the particle size and immunogenic property of HPV16 L1 VLPs.

Kuwanon V inhibits proliferation, promotes cell survival and increases neurogenesis of neural stem cells.

Neural stem cells (NSCs) have the ability to proliferate and differentiate into neurons and glia. Regulation of NSC fate by small molecules is important for the generation of a certain type of cell. The identification of small molecules that can induce new neurons from NSCs could facilitate regenerative medicine and drug development for neurodegenerative diseases. In this study, we screened natural compounds to identify molecules that are effective on NSC cell fate determination. We found that Kuwanon V (KWV), which was isolated from the mulberry tree (Morus bombycis) root, increased neurogenesis in rat NSCs. In addition, during NSC differentiation, KWV increased cell survival and inhibited cell proliferation as shown by 5-bromo-2-deoxyuridine pulse experiments, Ki67 immunostaining and neurosphere forming assays. Interestingly, KWV enhanced neuronal differentiation and decreased NSC proliferation even in the presence of mitogens such as epidermal growth factor and fibroblast growth factor 2. KWV treatment of NSCs reduced the phosphorylation of extracellular signal-regulated kinase 1/2, increased mRNA expression levels of the cyclin-dependent kinase inhibitor p21, down-regulated Notch/Hairy expression levels and up-regulated microRNA miR-9, miR-29a and miR-181a. Taken together, our data suggest that KWV modulates NSC fate to induce neurogenesis, and it may be considered as a new drug candidate that can regenerate or protect neurons in neurodegenerative diseases.

Microbial transformation of dissolved leaf litter organic matter and its effects on selected organic matter operational descriptors.

Changes in selected spectroscopic and chromatographic characteristics of water-soluble organic matter (WSOM) extracted from leaf litter and its ability to bind pyrene were monitored throughout 14 day microbial incubation experiments. To provide additional insight into the microbial transformation of the WSOM, incubation experiments were similarly conducted with controlled-composition mixtures of glucose and dissolved humic substances (HS) that were base extracted from the same leaf litter source. Microbial transformation increased the specific ultraviolet absorbance and number-average molecular weight of residual WSOM while polydispersity values decreased. Fluorescence measurements revealed loss of protein-like fluorescence and enhancement of fulvic- and humic-like fluorescence in residual WSOM. Overall, the incubation results suggest that nonaromatic and smaller sized carbon structures were being degraded while the microbial activity produced humic-like aromatic components in solution. Together, these changes resulted in enhanced pyrene binding by the altered WSOM. Consistent findings resulted from mixtures of glucose and the leaf litter HS. Changes in measured operational descriptors were more pronounced for mixtures containing a higher percentage of glucose, suggesting that utilization of labile constituents may be necessary for formation of unknown structures associated with high pyrene binding capabilities. Simple mass balance, end member mixing models often failed to predict changes in pyrene binding brought about by microbial transformation, suggesting that microbial utilization of labile constituents is not the predominant process governing the enhanced pyrene binding.

Molecular basis for the local conformational rearrangement of human phosphoserine phosphatase.

Human phosphoserine phosphatase (HPSP) regulates the levels of glycine and d-serine, the putative co-agonists for the glycine site of the NMDA receptor in the brain. Here, we describe the first crystal structures of the HPSP in complexes with the competitive inhibitor 2-amino-3-phosphonopropionic acid (AP3) at 2.5 A, and the phosphate ion (Pi) and the product uncompetitive inhibitor l-serine (HPSP.l-Ser.Pi) at 2.8 A. The complex structures reveal that the open-closed environmental change of the active site, generated by local rearrangement of the alpha-helical bundle domain, is important to substrate recognition and hydrolysis. The maximal extent of this structural rearrangement is shown to be about 13 A at the L4 loop and about 25 degrees at the helix alpha3. Both the structural change and mutagenesis data suggest that Arg-65 and Glu-29 play an important role in the binding of the substrate. Interestingly, the AP3 binding mode turns out to be significantly different from that of the natural substrate, phospho-l-serine, and the HPSP.l-Ser.Pi structure provides a structural basis for the feedback control mechanism of serine. These analyses allow us to provide a clear model for the mechanism of HPSP and a framework for structure-based drug development.