Involvement of Sema4A in the progression of experimental autoimmune myocarditis

Dilated cardiomyopathy often results from autoimmunity triggered by microbial infections during myocarditis. However, it remains unclear how immunological disorders are implicated in pathogenesis of autoimmune myocarditis. Here, we demonstrated that Sema4A, a class IV semaphorin, plays key roles in experimental autoimmune myocarditis (EAM). Dendritic cells pulsed with myosin heavy chain-α peptides induced severe myocarditis in wild-type mice, but not in Sema4A-deficient mice. In adoptive transfer experiments, CD4⁺ T-cells from wild-type mice induced severe myocarditis, while CD4⁺ T-cells from Sema4A-deficient mice exhibited considerably attenuated myocarditis. Our results indicated that Sema4A is critically involved in EAM by regulating differentiation of T-cells.     

Cloning, expression, purification and characterization of an isotype of clytin, a calcium-binding photoprotein from the luminous hydromedusa Clytia gregarium

The cDNA for an isotype of clytin, a calcium-binding photoprotein from the luminous jellyfish Clytia gregarium, was identified and named clytin-II. The histidine-tagged apoprotein of clytin-II expressed into the periplasmic space of Escherichia coli cells was isolated by nickel chelate affinity chromatography. Recombinant clytin-II regenerated from apoprotein by incubation with coelenterazine was purified. The yield of purified clytin-II was 13 mg from 2 l of cultured cells with purity >95%. The luminescence properties of clytin-II were characterized by comparison with clytin-I and aequorin, and semi-synthetic clytin-II was also prepared. The initial luminescence intensity of clytin-II triggered by Ca(2+) was 4.5 times higher than that of clytin-I and aequorin, but the luminescence capacity was close to clytin-I and aequorin. Thus, clytin-II is a useful protein, showing high sensitivity in the signal-to-noise ratio of luminescence intensity.     

Multipotent cells from the human third molar: feasibility of cell-based therapy for liver disease

Abstract Adult stem cells have been reported to exist in various tissues. The isolation of high-quality human stem cells that can be used for regeneration of fatal deseases from accessible resources is an important advance in stem cell research. In the present study, we identified a novel stem cell, which we named tooth germ progenitor cells (TGPCs), from discarded third molar, commonly called as wisdom teeth. We demonstrated the characterization and distinctiveness of the TGPCs, and found that TGPCs showed high proliferation activity and capability to differentiate in vitro into cells of three germ layers including osteoblasts, neural cells, and hepatocytes. TGPCs were examined by the transplantation into a carbon tetrachloride (CCl₄)-treated liver injured rat to determine whether this novel cell source might be useful for cell-based therapy to treat liver diseases. The successful engraftment of the TGPCs was demonstrated by PKH26 fluorescence in the recipient's rat as to liver at 4 weeks after transplantation. The TGPCs prevented the progression of liver fibrosis in the liver of CCl₄-treated rats and contributed to the restoration of liver function, as assessed by the measurement of hepatic serum markers aspartate aminotransferase and alanine aminotransferase. Furthermore, the liver functions, observed by the levels of serum bilirubin and albumin, appeared to be improved following transplantation of TGPCs. These findings suggest that multipotent TGPCs are one of the candidates for cell-based therapy to treat liver diseases and offer unprecedented opportunities for developing therapies in treating tissue repair and regeneration.     

Developmental anatomy of the reproductive shoot in <Emphasis Type="Italic">Hydrobryum japonicum</Emphasis> (Podostemaceae)

Podostemaceae are unusual aquatic angiosperms adapting to extreme habitats, i.e., rapids and waterfalls, and have unique morphologies. We investigated the developmental anatomy of reproductive shoots scattered on crustose roots of Hydrobryum japonicum by scanning electron microscopy and using semi-thin serial sections. Two developmental patterns were observed: bracts arise either continuously from an area of meristematic cells that has produced leaves, or within differentiated root ground tissue beneath, and internal to, leaf base scars after an interruption. In both patterns, the bract primordia arise endogenously at the base of youngest bracts in the absence of shoot apical meristem, involving vacuolated-cell detachment to each bract separately. The different transition patterns of reproductive shoot development may be caused by different stages of parental vegetative shoots. The floral meristem arises between the two youngest bracts, and is similarly accompanied by cell degeneration. In contrast, the floral organs, including the spathella, arise exogenously from the meristem. Bract development, like vegetative leaf development, is unique to this podostemad, while floral-organ development is conserved.     

Phylogeography of the genus <Emphasis Type="Italic">Ulva</Emphasis> (Ulvophyceae,Chlorophyta), with special reference to the Japanese freshwater and brackish taxa

The nuclear-encoded ITS and associated 5.8S rDNA regions were sequenced for 72 specimens of Ulva collected from 44 rivers across Japan, including U. prolifera Müller from the Shimanto River, Kochi Prefecture, as well as 26 samples originally identified as U. linza L. from 20 coastal marine areas. Sequence data revealed that the samples fall into six distinct clades: the U. flexuosa Wulfen clade (2 samples), the Ulva linza-procera-prolifera (LPP) complex clade (75 samples), Ulva sp. 1 clade (3 samples), Ulva sp. 2 clade (7 samples), Ulva sp. 3 clade (4 samples) and Ulva sp. 4 clade (7 samples). The LPP complex contained a mixture of 26 samples collected from seashores and 49 samples obtained from rivers, including U. prolifera from the Shimanto River, and GenBank data for U. linza and U. procera Ahlner. The samples of the LPP complex differed by only 0–7 substitutions (0–1.149%). Subsequent phylogeographic analyses of the LPP complex based on the 5S rDNA spacer region revealed the presence of two further groupings: a group including 22 strictly marine littoral U. linza samples and a U. prolifera group composed of a mixture of 4 marine samples and all 49 river samples. The monophyly of all river samples indicates that adaptation to low salinity might have occurred only once in the evolutionary history of the LPP complex.     

Structure-antibacterial activity relationship for 9-O,9'-O-demethyl (+)-virgatusin

The relationship between the antibacterial activity and structure of 9-O,9'-O-demethyl (+)-virgatusin (Virg 3) was examined. The conversion of hydroxy groups on the 9 and 9' positions to amino groups increased the activity. It was found that the 3'-methoxy group was more important for higher activity than the 4'-methoxy group on the 7'-phenyl group, and that the 3,4-methylenedioxy group on the 7-phenyl group was necessary for activity.     

Tricholoma matsutake 1-Ocen-3-ol and methyl cinnamate repel mycophagous Proisotoma minuta (Collembola: Insecta)

Two major volatiles produced by the mycelia and fruiting bodies of Tricholoma matsutake (1-octen-3-ol and methyl cinnamate) repel a mycophagous collembolan, Proisotoma minuta. Aggregation of the collembolans on their diet was significantly inhibited by exposure to 1 ppm methyl cinnamate or 10 to 100 ppm 1-octen-3-ol. The aggregation activity decreased dose-dependently upon exposure to 1-octen-3-ol at concentrations higher than 0.01 ppm. Aggregation in the presence of methyl cinnamate exhibited three phases: no significant effect at concentrations ranging from 0.001 to 0.1 ppm, significant inhibition from 1 to 100 ppm, and strong inhibition at 1,000 ppm. These results may explain why certain collembolan species do not prefer T. matsutake fruiting bodies.     

Drosophila optic lobe neuroblasts triggered by a wave of proneural gene expression that is negatively regulated by JAK/STAT

Neural stem cells called neuroblasts (NBs) generate a variety of neuronal and glial cells in the central nervous system of the Drosophila embryo. These NBs, few in number, are selected from a field of neuroepithelial (NE) cells. In the optic lobe of the third instar larva, all NE cells of the outer optic anlage (OOA) develop into either NBs that generate the medulla neurons or lamina neuron precursors of the adult visual system. The number of lamina and medulla neurons must be precisely regulated because photoreceptor neurons project their axons directly to corresponding lamina or medulla neurons. Here, we show that expression of the proneural protein Lethal of scute [L(1)sc] signals the transition of NE cells to NBs in the OOA. L(1)sc expression is transient, progressing in a synchronized and ordered ;proneural wave' that sweeps toward more lateral NEs. l(1)sc expression is sufficient to induce NBs and is necessary for timely onset of NB differentiation. Thus, proneural wave precedes and induces transition of NE cells to NBs. Unpaired (Upd), the ligand for the JAK/STAT signaling pathway, is expressed in the most lateral NE cells. JAK/STAT signaling negatively regulates proneural wave progression and controls the number of NBs in the optic lobe. Our findings suggest that NBs might be balanced with the number of lamina neurons by JAK/STAT regulation of proneural wave progression, thereby providing the developmental basis for the formation of a precise topographic map in the visual center.