Voluntary exercise induces neurogenesis in the hypothalamus and ependymal lining of the third ventricle.

In the adult hypothalamus and ependymal lining of the third ventricle, tanycytes function as multipotential progenitor cells that enable continuous neurogenesis, suggesting that tanycytes may be able to mediate the restoration of homeostatic function after stroke. Voluntary wheel running has been shown to alter neurochemistry and neuronal function and to increase neurogenesis in rodents. In the present study, we found that voluntary exercise improved the survival rate and energy balance of stroke-prone spontaneously hypertensive rats (SHRSP/Kpo). We also investigated the effect of exercise on the proliferation and differentiation of hypothalamic cells using immunoreactivity for tanycytes and neural markers. The proliferation of elongated cells, which may be the tanycytes, was enhanced in exercising SHRSP compared to sedentary rats before and after stroke. In addition, the proliferation of cells was correlated with the induction of fibroblast growth factor-2 in the subependymal cells of the third ventricle and in the cerebrospinal fluid. Some of the newborn cells of exercising SHRSP showed differentiation into mature neurons after stroke. Our results suggest that voluntary exercise correlates with hypothalamic neurogenesis, leading to recovery of homeostatic functions in the adult brain after stroke.

Rapid identification of ligand-binding sites by using an assignment-free NMR approach.

In this study, we developed an assignment-free approach for rapid identification of ligand-binding sites in target proteins by using NMR. With a sophisticated cell-free stable isotope-labeling procedure that introduces (15)N- or (13)C-labels to specific atoms of target proteins, this approach requires only a single series of ligand titrations with labeled targets. Using titration data, ligand-binding sites in the target protein can be identified without time-consuming assignment procedures. We demonstrated the feasibility of this approach by using structurally well-characterized interactions between mitogen-activated protein (MAP) kinase p38α and its inhibitor 2-amino-3-benzyloxypyridine. Furthermore, we confirmed the recently proposed fatty acid binding to p38α and confirmed the fatty acid-binding site in the MAP kinase insert region.

[Evaluation of antifungal effects of a traditional medicine containing 17 components on Trichophyton verrucosum and Malassezia pachydermatis by microdilution].

The minimum inhibitory concentration(MIC)of a traditional medicine containing 17 components against 9 strains of Trichophyton verrucosum and 13 strains of Malassezia pachydermatis was determined using a method recommended by the Clinical and Laboratory Standards Institute(CLSI). We also measured the MIC of each of the 17 components using the same method, and identified the main antifungal components.In order to evaluate MIC as a parameter of the antifungal effects using the microdilution method, we prepared 10% working solutions from 10% (w/v)medicines. The geometric mean MIC of the medicinal extract against T. verrucosum was 2.51%, and that against M. pachydermatis was 2.25%. The components that exhibited antifungal effects were Rheum palmatum, Glycyrrhiza uralensis, Magnolia obovata, Phellodendron amurense, and Geranium thunbergii.

Effects of single administration of Rokumi-gan (TJ-87) on serum amino acid concentration of 6 healthy Japanese male volunteers.

Rokumi-gan (TJ-87) has beneficial effects on renal diseases, including pollakisuria, dysuria and edema. We previously reported that its long-term administration clinically improved serum protein concentration and edema in renal failure. In this study, we focused on amino acid/protein contents in Rokumi-gan as one of its effectors. Commercially prepared Rokumi-gan contained arginine, aspartate and glutamate at the high levels, alanine, phenylalanine and serine at the moderate levels, and glycine, histidine, isoleucine, leucine, lysine and valine at the low levels. To examine effects of Rokumi-gan on serum amino acid concentrations, 6 healthy Japanese volunteers were treated with commercially prepared Rokumi-gan, an amino acid mixture, and lactose. In subjects treated with an amino acid mixture containing similar amounts of amino acids in Rokumi-gan (10 g), or lactose, serum amounts of many amino acids, except for arginine, gradually and significantly decreased until 6 hr after their treatments. In contrast, a single treatment with Rokumi-gan (10 g) increased serum levels of several amino acids, alanine, arginine, glutamate, glycine and serine. Serum concentrations of almost of all tested amino acids showed the peak value 1-2 hr after administration, and they were sustained at the basal level even 6 hr after the treatment. Our present results suggest that Rokumi-gan may be a beneficial amino acid supplier, because it could sustain serum amino acid concentration at the higher level than an amino acid mixture supplement.

Characterization of Oryza sativa telomerase reverse transcriptase and possible role of its phosphorylation in the control of telomerase activity.

Telomerase reverse transcriptase (TERT) has been characterized in the dicotyledon Arabidopsis thaliana. A TERT homolog has now been identified in the monocotyledon rice (Oryza sativa L.) on the basis of its predicted homology to the A. thaliana enzyme (AtTERT). At least five alternatively spliced transcripts of the rice TERT (OsTERT) gene were detected. The full-length OsTERT protein shares structural features with TERTs of other species, including a calculated molecular size of 144 kDa, an isoelectric point of 9.6, and conserved sequence motifs. Phylogenetic analysis showed that OsTERT clusters with AtTERT and is more related to the human and mouse enzymes than to those of yeast and ciliated protozoa, consistent with the evolutionary relations among these eukaryotes. Telomerase activity was abundant in shoot apices and cultured cells but was low or absent in leaves or roots of rice plants, whereas similarly spliced OsTERT transcripts were detected in all tissues examined and cultured cells. Similar to mouse and human TERT proteins, OsTERT contains two putative phosphorylation sites for Akt kinase. Incubation of a rice cell extract with Akt or with protein phosphatase 2A potentiated or inhibited telomerase activity, respectively, whereas Akt did not affect the activity in Arabidopsis cell extract. In addition, the kinase activated the telomerase in a leaf extract. The mechanism of telomerase regulation in rice thus appears to differ from that in Arabidopsis (which is mediated predominantly at the level of AtTERT transcription), possibly reflecting the taxonomic distance between monocotyledons and dicotyledons.