Immunostimulatory effects of collagen from jellyfish in vivo

We focused on the biological activity of the collagen extracts obtained from the giant edible jellyfish, Nemopilema nomurai. Jellyfish collagen extracts stimulates the production of immunoglobulins (Igs) and cytokines by human hybridoma cells and human peripheral blood lymphocytes. Therefore, we examined the immunoregulatory function of jellyfish collagen extracts in mice. Intake of jellyfish collagen extracts facilitated the Ig production activity of lymphocytes from spleen and Peyer's patch. Furthermore, the levels of Igs in the serum clearly increased after the administration of jellyfish collagen extracts. Intake of bovine collagen from Achilles' tendon also activated lymphocytes activity in mice. The activity of total and antigen-specific Ig production in splenocytes from OVA-challenged mice was also enhanced by collagen intake. However, the total and OVA-specific IgE levels in the serum were not affected by the collagen intake. These results suggested that jellyfish collagen extracts stimulates an immune response in vivo, without inducing allergic complications.     

Effect of water flow velocity on growth and morphology of cultured <Emphasis Type="Italic">Undaria pinnatifida</Emphasis> sporophytes (Laminariales,Phaeophyceae) in Okirai Bay on the Sanriku coast,Northeast Japan

Undaria pinnatifida sporophytes, originating from the same strain, were cultured at the commercial cultivation site exposed to wave action and the uncultivated site protected from water action of Okirai Bay, Northeast Japan, from January to April 2007; simultaneously, water flow velocity, water temperature, salinity, NO₃ + NO₂, and chlorophyll a were monitored to investigate the effect of water environment on their growth and morphology. Water temperature and salinity fluctuated within the optimal range for their growth whereas water flow velocity at the cultivation site was greatly fast compared with that at the uncultivated site. Successive chlorophyll a increases synchronized with NO₃ + NO₂ decreases were observed only at the uncultivated site for over a month; indicating developments of phytoplankton blooms and their nutrient consumption under the low-flow condition. Meanwhile, blade growth rate of cultured sporophytes was higher at the cultivation site than at the uncultivated site. Their thallus size expressed by six morphological characters (blade length, stipe length, blade wet weight, stipe wet weight, blade width, and undivided blade width) at the cultivation site became large in comparison with that at the uncultivated site. Their three morphological correlations (correlations between blade length and thallus length; blade wet weight and thallus wet weight; and undivided blade width and blade width) differed between the sites. They produced a thick and flat blade at the cultivation site but formed a thin and wrinkled blade at the uncultivated site. These results show the significant impact of water flow velocity on their growth and morphology.     

Abnormal taste perception in mice lacking the type 3 inositol 1,4,5-trisphosphate receptor

Inositol 1,4,5-trisphosphate receptor (IP3R) is one of the important calcium channels expressed in the endoplasmic reticulum and has been shown to play crucial roles in various physiological phenomena. Type 3 IP3R is expressed in taste cells, but the physiological relevance of this receptor in taste perception in vivo is still unknown. Here, we show that mice lacking IP3R3 show abnormal behavioral and electrophysiological responses to sweet, umami, and bitter substances that trigger G-protein-coupled receptor activation. In contrast, responses to salty and acid tastes are largely normal in the mutant mice. We conclude that IP3R3 is a principal mediator of sweet, bitter, and umami taste perception and would be a missing molecule linking phospholipase C beta2 to TRPM5 activation.     

Sex-specific differences in rat soleus muscle signaling pathway responses to a bout of horizontal and downhill running

Journal of Physiology and Biochemistry - Males and females of many species, including humans, exhibit different muscle responses and adaptations to exercise stress; however, the molecular...     

Pyrazole-O-glucosides as novel Na(+)-glucose cotransporter (SGLT) inhibitors

O-glucuronides and O-glucosides of a series of pyrazoles analogues were synthesized and evaluated for their SGLT inhibitory activity in brush border membrane vehicles (BBMVs) of rat kidney. O-glucosides of certain pyrazole analogues inhibited the transport of [(14)C]-glucose in BBMVs, and induced glucosuria in Wistar rats by intravenous injection.     

Demethylesterification of the primary wall by PECTIN METHYLESTERASE35 provides mechanical support to the Arabidopsis stem

Secondary cell walls, which contain lignin, have traditionally been considered essential for the mechanical strength of the shoot of land plants, whereas pectin, which is a characteristic component of the primary wall, is not considered to be involved in the mechanical support of the plant. Contradicting this conventional knowledge, loss-of-function mutant alleles of Arabidopsis thaliana PECTIN METHYLESTERASE35 (PME35), which encodes a pectin methylesterase, showed a pendant stem phenotype and an increased deformation rate of the stem, indicating that the mechanical strength of the stem was impaired by the mutation. PME35 was expressed specifically in the basal part of the inflorescence stem. Biochemical characterization showed that the activity of pectin methylesterase was significantly reduced in the basal part of the mutant stem. Immunofluorescence microscopy and immunogold electron microscopy analyses using JIM5, JIM7, and LM20 monoclonal antibodies revealed that demethylesterification of methylesterified homogalacturonans in the primary cell wall of the cortex and interfascicular fibers was suppressed in the mutant, but lignified cell walls in the interfascicular and xylary fibers were not affected. These phenotypic analyses indicate that PME35-mediated demethylesterification of the primary cell wall directly regulates the mechanical strength of the supporting tissue.     

Synthesis of human amyloid restricted to liver results in an Alzheimer disease–like neurodegenerative phenotype

Several lines of study suggest that peripheral metabolism of amyloid beta (Aß) is associated with risk for Alzheimer disease (AD). In blood, greater than 90% of Aß is complexed as an apolipoprotein, raising the possibility of a lipoprotein-mediated axis for AD risk. In this study, we report that genetic modification of C57BL/6J mice engineered to synthesise human Aß only in liver (hepatocyte-specific human amyloid (HSHA) strain) has marked neurodegeneration concomitant with capillary dysfunction, parenchymal extravasation of lipoprotein-Aß, and neurovascular inflammation. Moreover, the HSHA mice showed impaired performance in the passive avoidance test, suggesting impairment in hippocampal-dependent learning. Transmission electron microscopy shows marked neurovascular disruption in HSHA mice. This study provides causal evidence of a lipoprotein-Aß /capillary axis for onset and progression of a neurodegenerative process.

It has been suggested that peripheral metabolism of amyloid-beta is associated with risk for Alzheimer’s disease. This study reveals that the expression of human amyloid exclusively in the liver induces Alzheimer’s disease-like pathologies in mice, potentially indicating a completely novel pathway of Alzheimer’s disease aetiology and therapies.     

Possible role of a taurine transporter in the deep-sea mussel Bathymodiolus septemdierum in adaptation to hydrothermal vents

Various invertebrates inhabiting hydrothermal vents possess sulfur-oxidizing bacteria in their tissues; however, the mechanisms by which toxic sulfides are delivered to these endosymbionts remain unknown. Recently, detoxification of sulfides using thiotaurine, a sulfur-containing amino acid, has been suggested. In this study, we propose the involvement of a taurine transporter in sulfide detoxification in the deep-sea mussel Bathymodiolus septemdierum by demonstrating: (i) the abundance of its mRNA in the gill; (ii) its activity under a wide range of salinities; (iii) its low Michaelis constant value in taurine transportation; and (iv) its affinity for thiotaurine and the thiotaurine precursor, hypotaurine.     

Amiloride-sensitive NaCl taste responses are associated with genetic variation of ENaC alpha-subunit in mice

An epithelial Na(+) channel (ENaC) is expressed in taste cells and may be involved in the salt taste transduction. ENaC activity is blocked by amiloride, which in several mammalian species also inhibits taste responses to NaCl. In mice, lingual application of amiloride inhibits NaCl responses in the chorda tympani (CT) gustatory nerve much stronger in the C57BL/6 (B6) strain than in the 129P3/J (129) strain. We examined whether this strain difference is related to gene sequence variation or mRNA expression of three ENaC subunits (alpha, beta, gamma). Real-time RT-PCR and in situ hybridization detected no significant strain differences in expression of all three ENaC subunits in fungiform papillae. Sequences of the beta- and gammaENaC subunit genes were also similar in the B6 and 129 strains, but alphaENaC gene had three single nucleotide polymorphisms (SNPs). One of these SNPs resulted in a substitution of arginine in the B6 strain to tryptophan in the 129 strain (R616W) in the alphaENaC protein. To examine association of this SNP with amiloride sensitivity of CT responses to NaCl, we produced F(2) hybrids between B6 and 129 strains. Amiloride inhibited CT responses to NaCl in F(2) hybrids with B6/129 and B6/B6 alphaENaC R616W genotypes stronger than in F(2) hybrids with 129/129 genotype. This suggests that the R616W variation in the alphaENaC subunit affects amiloride sensitivity of the ENaC channel and provides evidence that ENaC is involved in amiloride-sensitive salt taste responses in mice.