A Lactobacillus mutant capable of accumulating long-chain polyphosphates that enhance intestinal barrier function

Inorganic polyphosphate (polyP) was previously identified as a probiotic-derived substance that enhances intestinal barrier function. PolyP-accumulating bacteria are expected to have beneficial effects on the human gastrointestinal tract. In this study, we selected Lactobacillus paracasei JCM 1163 as a strain with the potential to accumulate polyP, because among the probiotic bacteria stored in our laboratory, it had the largest amount of polyP. The chain length of polyP accumulated in L. paracasei JCM 1163 was approximately 700 phosphate (Pi) residues. L. paracasei JCM 1163 accumulated polyP when Pi was added to Pi-starved cells. We further improved the ability of L. paracasei JCM 1163 to accumulate polyP by nitrosoguanidine mutagenesis. The mutant accumulated polyP at a level of 1500 nmol/mg protein—approximately 190 times that of the wild-type strain. PolyP extracted from the L. paracasei JCM 1163 significantly suppressed the oxidant-induced intestinal permeability in mouse small intestine. In conclusion, we have succeeded in breeding the polyP-accumulating Lactobacillus mutant that is expected to enhance intestinal barrier function.     

Vitamin B12 deficiency-induced increase of osteoclastic bone resorption caused by abnormal renal resorption of inorganic phosphorus via Napi2a

Vitamin B₁₂ deficiency is a risk factor for bone disorders via mechanisms not fully understood. In this study, an increase in serum inorganic phosphorus (Pi) concentrations was associated with a vitamin B₁₂ deficiency. Napi2a, a renal cotransporter for Pi reabsorption, accumulated on plasma membranes in a vitamin B₁₂ deficiency suggests that vitamin B₁₂ plays an important role in Pi homeostasis.     

Comparison between humic-like peaks in excitation-emission matrix spectra and resin-fractionated humic substances in aquatic environments

Limnology - The intensity of the 340/430-nm peak in the three-dimensional excitation-emission matrix spectra of water samples has been used as an index of the concentration of aquatic humic...     

Analysis of finger vein variety in patients with various diseases using vein authentication technology

In finger vein authentication technology, near‐infrared rays penetrate the finger and are absorbed by the hemoglobin in blood. The veins appear as dark areas. The finger vein pattern images of patients with various diseases were acquired; a new evaluation method applying image processing technique (“E value”) was developed, and it was examined whether the patterns have any characteristics differentiating them from those of healthy volunteers. As a result, low E values appeared in systemic sclerosis, mixed connective tissue disease, Sjögren's syndrome, and polymyositis/dermatomyositis. No statistical reduction in E value was shown in patients with rheumatoid arthritis, pernio (without rheumatic diseases), arteriosclerosis obliterans, diabetes, hypertension, hypothyroidism and alopecia areata. This technology could be used for screening and evaluation of some diseases and their conditions with impaired peripheral venous circulation. E value may be useful as an indicator of venous circulation.      

Analysis of internal structure changes in black human hair keratin fibers with aging using Raman spectroscopy

To investigate the internal structure changes in virgin black human hair keratin fibers due to aging, the structure of cross-sections at various depths of virgin black human hair (sections of new growth hair: 2 mm from the scalp) from a group of eight Japanese females in their twenties and another group of eight Japanese females in their fifties were analyzed using Raman spectroscopy. For the first time, we have succeeded in recording the Raman spectra of virgin black human hair, which had been impossible due to high melanin granule content. The key points of this method are to cross-section hair samples to a thickness of 1.50-microm, to select points at various depths of the cortex with the fewest possible melanin granules, and to optimize laser power, cross slit width as well as total acquisition time. The reproducibility of the Raman bands, namely the alpha-helix (alpha) content, the beta-sheet and/or random coil (beta/R) content, the disulfide (--SS--) content, and random coil content of two adjoining cross-sections of a single hair keratin fiber was clearly good. The --SS-- content of virgin black human hair from the Japanese females in their fifties for the cortex region decreased compared with that of the Japanese females in their twenties. On the other hand, the beta/R and alpha contents of the cortex region did not change.     

Intramolecular and intermolecular perturbation on electronic state of FAD free in solution and bound to flavoproteins: FTIR spectroscopic study by using the C = O stretching vibrations as probes

The intramolecular and intermolecular perturbation on the electronic state of FAD was investigated by FTIR spectroscopy by using the C=O stretching vibrations as probes in D(2)O solution. Natural and artificial FADs, i.e. 8-CN-, 8-Cl-, 8-H-, 8-OCH(3)-, and 8-NH(2)-FAD labelled by 2-(13)C, (18)O=C(2), or 4,10a-(13)C(2) were used for band assignments. The C(2)=O and C(4)=O stretching vibrations of oxidized FAD were shifted systematically by the substitution at the 8-position, i.e. the stronger the electron-donating ability (NH(2) > OCH(3) > CH(3) > H > Cl > CN) of the substituent, the lower the wavenumber region where both the C(2)=O and C(4)=O bands appear. In contrast, the C(4)=O band of anionic reduced FAD scarcely shifted. The 1,645-cm(-1) band containing C(2)=O stretching vibration shifted to 1,630 cm(-1) in the medium-chain acyl-CoA dehydrogenase (MCAD)-bound state, which can be explained by hydrogen bonds at C(2)=O of the flavin ring. The band was observed at 1,607 cm(-1) in the complex of MCAD with 3-thiaoctanoyl-CoA. The 23 cm(-1) shift was explained by the charge-transfer interaction between oxidized flavin and the anionic acyl-CoA. In the case of electron-transferring flavoprotein, two bands associated with the C(4)=O stretching vibration were obtained at 1,712 and 1,686 cm(-1), providing evidence for the multiple conformations of the protein.     

Structure of the antitumour enzyme L-methionine gamma-lyase from Pseudomonas putida at 1.8 A resolution

l-Methionine gamma-lyase (EC 4.4.1.11, MGL_Pp) from Pseudomonas putida is a multifunctional enzyme, which belongs to the gamma-family of pyridoxal-5'-phosphate (PLP) dependent enzymes. In this report, we demonstrate that the three-dimensional structure of MGL_Pp has been completely solved by the molecular replacement method to an R-factor of 20.4% at 1.8 A resolution. Detailed information of the overall structure of MGL_Pp supplies a clear picture of the substrate- and PLP-binding pockets. Tyr59 and Arg61 of neighbouring subunits, which are strongly conserved in other gamma-family enzymes, contact the phosphate group of PLP. These residues are important as the main anchor within the active site. Lys240, Asp241 and Arg61 of one partner monomer and Tyr114 and Cys116 of the other partner monomer form a hydrogen-bond network in the MGL active site which is specific for MGLs. It is also suggested that electrostatic interactions at the subunit interface are involved in the stabilization of the structural conformation. The detailed structure will facilitate the development of MGL_Pp as an anticancer drug.     

Thrombomodulin is a clock-controlled gene in vascular endothelial cells

Cardiovascular diseases are closely related to circadian rhythm, which is under the control of an internal biological clock mechanism. Although a biological clock exists not only in the hypothalamus but also in each peripheral tissue, the biological relevance of the peripheral clock remains to be elucidated. In this study we searched for clock-controlled genes in vascular endothelial cells using microarray technology. The expression of a total of 229 genes was up-regulated by CLOCK/BMAL2. Among the genes that we identified, we examined the thrombomodulin (TM) gene further, because TM is an integral membrane glycoprotein that is expressed primarily in vascular endothelial cells and plays a major role in the regulation of intravascular coagulation. TM mRNA and protein expression showed a clear circadian oscillation in the mouse lung and heart. Reporter analyses, gel shift assays, and chromatin immunoprecipitation analyses using the TM promoter revealed that a heterodimer of CLOCK and BMAL2 binds directly to the E-box of the TM promoter, resulting in TM promoter transactivation. Indeed, the oscillation of TM gene expression was abolished in clock mutant mice, suggesting that TM expression is regulated by the clock gene in vivo. Finally, the phase of circadian oscillation of TM mRNA expression was altered by temporal feeding restriction, suggesting TM gene expression is regulated by the peripheral clock system. In conclusion, these data suggest that the peripheral clock in vascular endothelial cells regulates TM gene expression and that the oscillation of TM expression may contribute to the circadian variation of cardiovascular events.