Myelin protein zero is one of the components of the detergent-resistant membrane microdomain fraction prepared from rat pituitary

Pituitary gland is a well-known endocrine tissue. The hypothalamo-neurohypophysial system, containing arginine vasopressin and oxytocin, shows a reversible morphological reorganization of both neurons and glial cells during chronic physiological stimulations. Since many signal transducing and cell adhesion molecules (CAMs) are recovered in membrane microdomain (MD) fractions, MDs are considered as signaling platforms of cells. In order to know the molecular background for these endocrine systems, we characterized MD-components derived from rat pituitary and found specific enrichment of several proteins in the fraction. One of them was identified as myelin protein zero (P0) with mass analysis and this result was further confirmed by a result that a specific antibody to this protein reacted to the authentic P0 protein in the myelin fraction of rat sciatic nerve. P0 is one of type-I transmembrane CAMs and a major structural component of mammalian peripheral nerve myelin. In mammals, expression of P0 has been considered to be restricted to peripheral nervous system. This result however indicates that P0 expresses more widely and its enrichment in the MD-fraction from rat pituitary suggests the participation in cell-cell communications.     

Estimating Antihypertensive Effects of Combination Therapy in an Observational Study Using Marginal Structural Models

The evaluation of the antihypertensive effect of multiple antihypertensive drugs using data from an observational study requires adjustment for time‐dependent confounders. Marginal structural models (MSMs) have been proposed to address this type of confounding through inverse probability weighting. Generally, the probabilities are estimated using logistic regression models that assume linearity between the logistic link and the predictors, but the linearity might be inaccurate. In this article, we proposed MSMs to assess the blood pressure‐lowering effects of combination therapy with olmesartan medoxomil (OLM) plus calcium channel blockers (CCB) (OLM+CCB) in an observational study of OLM, and extended estimation methods of the probabilities for the MSMs using generalized additive models (GAMs). The estimation using GAMs was suggested to improve the balance of the distributions of confounder values between the therapy groups in the pseudo‐population. We obtained estimated changes in systolic blood pressure (SBP) and diastolic blood pressure (DBP) for OLM+CCB combination therapy after 12 wk compared with OLM monotherapy of ?4.3 mmHg (95% confidence interval (CI): ?7.7 and ?0.9 mmHg) and ?2.9 mmHg (95% CI: ?5.1 and ?0.7 mmHg), respectively. The estimated target BP (SBP<140 mmHg and DBP<90 mmHg) achievement rates for OLM+CCB combination therapy and OLM monotherapy were 62.0 and 46.7%, respectively. The results of the MSMs were closer to those in the randomized controlled trial, such as the combination of OLM and amlodipine besylate in controlling high blood pressure study, than those of conventional methods. The proposed MSMs provided useful information to evaluate the effects of combination therapy of antihypertensive drugs in the context of an observational study.     

Population genetic structure,diversity and stocking effect of the oriental weatherloach (<Emphasis Type="Italic">Misgurnus anguillicaudatus</Emphasis>) in an isolated island

Genetic endemism of island organisms and the threat to such organisms provided by artificially introduced genes are aspects of major interest in evolutionary and conservation studies of fishes. In this paper the genetic population structure of the oriental weatherloach, Misgurnus anguillicaudatus, in Sado Island of Japan was elucidated by phylogeographic analysis based on partial mitochondrial control region sequences. The specimens were sampled at 62 sites in Sado Island and 14 sites on the mainland close to the island. We found various haplotypes of different origins, most of which had already been reported from the mainland and other places of Japan. This suggests that the loach has been historically introduced to the island from various regions of Japan. Of the 62 sites on the island, cultured/nonnative individuals were confirmed to have been stocked at eight specific sites for feeding of re-introduced Japanese crested ibis (Nipponia nippon). By a Mantel test, geographical and genetic distances were not significantly correlated among the local populations in Sado Island. However a significant correlation was found when the eight stocked local populations were excluded from the analysis. This implied that the genetic distribution pattern of the loach on the island has been disturbed by the stocking. In addition, the nucleotide diversity values of stocked local populations were significantly higher than those of other local populations, also a likely outcome of the stocking. In conclusion, the loach on the island likely had their origins in multiple historical introductions and colonizations, where more recent stocking for the ibis has caused further genetic disturbance to their local populations.     

Fatty acid elongase is required for shoot development in rice

Organisms are covered extracellularly with cuticular waxes that consist of various fatty acids. In higher plants, extracellular waxes act as indispensable barriers to protect the plants from physical and biological stresses such as drought and pathogen attacks. However, the effect of fatty acid composition on plant development under normal growth conditions is not well understood. Here we show that the ONION1 (ONI1) gene, which encodes a fatty acid elongase (β-ketoacyl CoA synthase) involved in the synthesis of very-long-chain fatty acids, is required for correct fatty acid composition and normal shoot development in rice. oni1 mutants containing a reduced amount of very-long-chain fatty acids produced very small shoots, with an aberrant outermost epidermal cell layer, and ceased to grow soon after germination. These mutants also showed abnormal expression of a KNOX family homeobox gene. ONI1 was specifically expressed in the outermost cell layer of the shoot apical meristem and developing lateral organs. These results show that fatty acid elongase is required for formation of the outermost cell layer, and this layer is indispensable for entire shoot development in rice.     

Anti-viral effects of interferon administration on sevenband grouper, Epinephelus septemfasciatus

Interferon (IFN) plays crucial roles in innate immune responses against viral infections. In the present study, we report cloning and characterization of the IFN gene from the sevenband grouper (Epinephelus septemfasciatus), and the anti-viral effects of its recombinant IFN protein in vivo. The isolated cDNA from sevenband grouper IFN encoded a protein consisting of 178 amino acids, and its first 22 amino acids represented a putative signal peptide. We named the identified sevenband grouper IFN gene as SgIFNa1 based on the result from phylogenetic analysis that categorized the deduced protein sequence into fish IFNa family. The expression of SgIFNa1 mRNA in the head kidney cells was induced by synthetic Poly(I:C), which is known as an inducer of IFN. It has also been confirmed that injection of recombinant SgIFNa1 protein (rSgIFNa1) upregulates expression of the Mx gene, which is known as an IFN-responsive gene, in head kidney cells. Moreover, we observed that preliminarily injection of rSgIFNa1 provided significant protection against a lethal challenge of nervous necrosis virus (NNV), which is a serious disease of sevenband grouper. These results demonstrate that SgIFNa1 has anti-viral activity and the administration of rSgIFNa1 to sevenband grouper is effective in preventing severe symptom development after NNV infection.     

A traditional medicinal herb Paeonia suffruticosa and its active constituent 1,2,3,4,6-penta-O-galloyl-β-d-glucopyranose have potent anti-aggregation effects on Alzheimer's amyloid β proteins in vitro and in vivo

The deposition of amyloid β (Aβ) protein is a consistent pathological hallmark of Alzheimer's disease (AD) brains; therefore, inhibition of Aβ fibril formation and destabilization of pre-formed Aβ fibrils is an attractive therapeutic and preventive strategy in the development of disease-modifying drugs for AD. This study demonstrated that Paeonia suffruticosa , a traditional medicinal herb, not only inhibited fibril formation of both Aβ_1–40 and Aβ_1–42 but it also destabilized pre-formed Aβ fibrils in a concentration-dependent manner. Memory function was examined using the passive-avoidance task followed by measurement of Aβ burden in the brains of Tg2576 transgenic mice. The herb improved long-term memory impairment in the transgenic mice and inhibited the accumulation of Aβ in the brain. Three-dimensional HPLC analysis revealed that a water extract of the herb contained several different chemical compounds including 1,2,3,4,6-penta- O -galloyl-β- d -glucopyranose (PGG). No obvious adverse/toxic were found following treatment with PGG. As was observed with Paeonia suffruticosa , PGG alone inhibited Aβ fibril formation and destabilized pre-formed Aβ fibrils in vitro and in vivo . Our results suggest that both Paeonia suffruticosa and its active constituent PGG have strong inhibitory effects on formation of Aβ fibrils in vitro and in vivo . PGG is likely to be a safe and promising lead compound in the development of disease-modifying drugs to prevent and/or cure AD.     

RET PLCγ phosphotyrosine binding domain regulates Ca2+ signaling and neocortical neuronal migration

The receptor tyrosine kinase RET plays an essential role during embryogenesis in regulating cell proliferation, differentiation, and migration. Upon glial cell line-derived neurotrophic factor (GDNF) stimulation, RET can trigger multiple intracellular signaling pathways that in concert activate various downstream effectors. Here we report that the RET receptor induces calcium (Ca(2+)) signaling and regulates neocortical neuronal progenitor migration through the Phospholipase-C gamma (PLCγ) binding domain Tyr1015. This signaling cascade releases Ca(2+) from the endoplasmic reticulum through the inositol 1,4,5-trisphosphate receptor and stimulates phosphorylation of ERK1/2 and CaMKII. A point mutation at Tyr1015 on RET or small interfering RNA gene silencing of PLCγ block the GDNF-induced signaling cascade. Delivery of the RET mutation to neuronal progenitors in the embryonic ventricular zone using in utero electroporation reveal that Tyr1015 is necessary for GDNF-stimulated migration of neurons to the cortical plate. These findings demonstrate a novel RET mediated signaling pathway that elevates cytosolic Ca(2+) and modulates neuronal migration in the developing neocortex through the PLCγ binding domain Tyr1015.     

Development of biodegradable scaffolds based on magnetically guided assembly of magnetic sugar particles

Biodegradable scaffolds with controlled pore layout and porosity have great significance in tissue engineering for cell penetration, tissue ingrowth, vascularization, and nutrient delivery. Porogen leaching has been commonly used to control pore size, pore structure and porosity in the scaffold. In this paper we focus on the use/development of two magnetically guided porogen assembly methods using magnetic sugar particles (MSPs) for scaffold fabrication. First, a patterning device is utilized to align MSPs following designed templates. Then a magnetic sheet film is fabricated by mixing poly(vinyl alcohol, PVA) and NdFeB powder for steering the MSPs. After poly(l-lactide-co-?-caprolactone) (PLCL) casting and removal of the sugar template, a scaffold with spherical pores is obtained. The surface and the inner structure of the scaffolds are evaluated using light and electron micrographs showing their interconnection of pores, pore wall morphology and porosity. Single layer scaffolds with the size of 8mm in width and 10mm in length were constructed with controllable pore diameters in the ranges of 105-150 μm, 250-300 μm and 425-500 μm.