Importance of rabies virus nucleoprotein in viral evasion of interferon response in the brain

By using a cultured neuroblastoma cell line, the present authors recently showed that the N protein of virulent rabies virus fixed strain Nishigahara (Ni), but not that of the attenuated derivative Ni‐CE, mediates evasion of induction of type I interferon (IFN). In this study, to determine whether Ni N protein indeed fulfills this function in vivo, the abilities to suppress IFN responses in the mouse brain of Ni‐CE and the virulent chimeric virus CE(NiN), which has the N gene from Ni in the genetic background of Ni‐CE, were compared. It was demonstrated that CE(NiN) propagates and spreads more efficiently than does Ni‐CE in the brain and that IFN response in brains infected with CE(NiN) is weaker than in those infected with Ni‐CE. It was also shown that amino acids at positions 273 and 394 in the N protein, which are known as pathogenic determinants, affect the ability of the viruses to suppress IFN response in the brain. These findings strongly suggest that, in the brain, rabies virus N protein plays important roles in evasion of innate immune responses and thereby in efficient propagation and spread of virus leading to lethal outcomes of infection.     

The role of the helper lipid dioleoylphosphatidylethanolamine (DOPE) for DNA transfection cooperating with a cationic lipid bearing ethylenediamine

Gene therapy is expected to treat various incurable diseases including viral infections, autoimmune disorders, and cancers. Cationic lipids (CL) have been used as carriers of therapeutic DNAs for gene therapy because they can form a complex with DNA and such a complex can be incorporated into cells and transport the bound DNA to cytosol. The CL/DNA complexes are called lipoplexes and categorized as a non-viral vector. Lipoplexes are often prepared by adding a neutral phospholipid dioleoylphosphatidylethanolamine (DOPE) to CL in order to enhance transfection. However, the role of DOPE is not fully understood. We synthesized a new CL having an ethylenediamine cationic head group, denoted by DA, and found that addition of DOPE to DA achieved a good efficiency, almost in the similar level of commonly used transfection reagent Lipofectamine 2000 (Invitrogen). The composition of DA:DOPE = 1:1 showed the highest efficiency. This lipoplex showed structural transition when pH was changed from 7 to 4, corresponding pH lowering in late endosome, while DOPE itself showed structural transition at more basic pH around 8. The present data showed that the DOPE/DA composition determines the structural transition pH and choosing a suitable pH, i.e., a suitable composition, is essential to increase the transfection efficiency.     

Polyethyleneimine-coating enhances adenoviral transduction of mesenchymal stem cells

Mesenchymal stem cells (MSCs) are non-hematopoietic cells with multi-lineage potential, which makes them attractive targets for regenerative medicine applications. Efficient gene transfer into MSCs is essential for basic research in developmental biology and for therapeutic applications involving gene-modification in regenerative medicine. Adenovirus vectors (Advs) can efficiently and transiently introduce an exogenous gene into many cell types via their primary receptors, the coxsackievirus and adenovirus receptors (CARs), but not into MSCs, which lack CAR expression. To overcome this problem, an Adv coated with cationic polymer polyethyleneimine (PEI) was developed. In this study, we demonstrated that PEI coating with an optimal ratio can enhance adenoviral transduction of MSCs without cytotoxicity. We also investigated the physicochemical properties and internalization mechanisms of the PEI-coated Adv. These results could help to evaluate the potentiality of the PEI-coated Adv as a prototype vector for efficient and safe transduction into MSCs.     

Biodegradation of Alkylbenzene Sulfonates (ABS) by Microorganisms in a Private Cesspool

In occidental countries, the biodegradation of synthetic detergents has become one of the important problems in relation to the water quality protection programs. Their detergent industries are going to change active ingredient in detergent formulation from the non-biodegradable tetrapropylene-derived ABS (TBS) to the biodegradable Linear Alkylate Sulfonates (LAS). In our country, cesspools are served as domestic sewage disposal systems in very many homes, so that, it is necessary to observe the biodegradability of LAS in the cesspool.     

Extracellular Matrix and Growth Factors Improve the Efficacy of Intramuscular Islet Transplantation

BackgroundThe efficacy of intramuscular islet transplantation is poor despite being technically simple, safe, and associated with reduced rates of severe complications. We evaluated the efficacy of combined treatment with extracellular matrix (ECM) and growth factors in intramuscular islet transplantation.MethodsMale BALB/C mice were used for the in vitro and transplantation studies. The following three groups were evaluated: islets without treatment (islets-only group), islets embedded in ECM with growth factors (Matrigel group), and islets embedded in ECM without growth factors [growth factor-reduced (GFR) Matrigel group]. The viability and insulin-releasing function of islets cultured for 96 h were significantly improved in Matrigel and GFR Matrigel groups compared with the islets-only group.ResultsBlood glucose and serum insulin levels immediately following transplantation were significantly improved in the Matrigel and GFR Matrigel groups and remained significantly improved in the Matrigel group at postoperative day (POD) 28. On histological examination, significantly decreased numbers of TdT-mediated deoxyuridine triphosphate-biotin nick end labeling-positive islet cells and significantly increased numbers of Ki67-positive cells were observed in the Matrigel and GFR Matrigel groups at POD 3. Peri-islet revascularization was most prominent in the Matrigel group at POD 14.ConclusionsThe efficacy of intramuscular islet transplantation was improved by combination treatment with ECM and growth factors through the inhibition of apoptosis, increased proliferation of islet cells, and promotion of revascularization.     

Cloning and identification of saprolmycin biosynthetic gene cluster from Streptomyces sp. TK08046

Saprolmycins A–E are anti-Saprolegnia parasitica antibiotics. To identify the gene cluster for saprolmycin biosynthesis in Streptomyces sp. TK08046, polymerase chain reaction using aromatase and cyclase gene-specific primers was performed; the spr gene cluster, which codes for angucycline biosynthesis, was obtained from the strain. The cluster consists of 36 open reading frames, including minimal polyketide synthase, ketoreductase, aromatase, cyclase, oxygenase, and deoxy sugar biosynthetic genes, as defined by homology to the corresponding genes of the urdamycin, Sch-47554, and grincamycin biosynthetic gene clusters in Streptomyces fradiae, Streptomyces sp. SCC-2136, and Streptomyces lusitanus, respectively. To establish the function of the gene cluster, an expression cosmid vector containing all 36 open reading frames was introduced into Streptomyces lividans TK23. The transformant was confirmed to express the biosynthetic genes and produce saprolmycins by liquid chromatography–mass spectrometry analysis of the extract.     

Competition for Mitogens Regulates Spermatogenic Stem Cell Homeostasis in an Open Niche

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