Promotive effects of far-infrared ray on full-thickness skin wound healing in rats

The biological effects of far-infrared ray (FIR) on whole organisms remain poorly understood. The aim of our study was to investigate not only the hyperthermic effect of the FIR irradiation, but also the biological effects of FIR on wound healing. To evaluate the effect of FIR on a skin wound site, the speed of full-thickness skin wound healing was compared among groups with and without FIR using a rat model. We measured the skin wound area, skin blood flow, and skin temperature before and during FIR irradiation, and we performed histological inspection. Wound healing was significantly more rapid with than without FIR. Skin blood flow and skin temperature did not change significantly before or during FIR irradiation. Histological findings revealed greater collagen regeneration and infiltration of fibroblasts that expressed transforming growth factor-beta1 (TGF-beta1) in wounds in the FIR group than in the group without FIR. Stimulation of the secretion of TGF-beta1 or the activation of fibroblasts may be considered as a possible mechanisms for the promotive effect of FIR on wound healing independent of skin blood flow and skin temperature.     

Novel Plant Immune-Priming Compounds Identified via High-Throughput Chemical Screening Target Salicylic Acid Glucosyltransferases in Arabidopsis

Plant activators are compounds, such as analogs of the defense hormone salicylic acid (SA), that protect plants from pathogens by activating the plant immune system. Although some plant activators have been widely used in agriculture, the molecular mechanisms of immune induction are largely unknown. Using a newly established high-throughput screening procedure that screens for compounds that specifically potentiate pathogen-activated cell death in Arabidopsis thaliana cultured suspension cells, we identified five compounds that prime the immune response. These compounds enhanced disease resistance against pathogenic Pseudomonas bacteria in Arabidopsis plants. Pretreatments increased the accumulation of endogenous SA, but reduced its metabolite, SA-O-β-d-glucoside. Inducing compounds inhibited two SA glucosyltransferases (SAGTs) in vitro. Double knockout plants that lack both SAGTs consistently exhibited enhanced disease resistance. Our results demonstrate that manipulation of the active free SA pool via SA-inactivating enzymes can be a useful strategy for fortifying plant disease resistance and may identify useful crop protectants.     

Increased prevalence of tumor-infiltrating regulatory T cells is closely related to their lower sensitivity to H2O2-induced apoptosis in gastric and esophageal cancer

Purpose and experimental design

Although an increase in regulatory T cells (Tregs) is observed in tumor microenvironments, the underlying mechanism is not fully clarified. Since it was suggested that Tregs showed a lower sensitivity toward oxidative stress in comparison with conventional T cells, in the present study, we investigated the H₂O₂ production and apoptosis of Tregs in gastric and esophageal cancer tissues, employing flow cytometric analysis using fresh samples (n = 93) and immunohistochemical analysis (n = 203).

Results

The increased tumor-infiltrating Tregs coexisted with elevated H₂O₂ production according to disease progression. The grade of apoptosis in Tregs was less pronounced than that in conventional T cells, and there was a positive correlation between H₂O₂ production and the grade of apoptosis in conventional T cells, while there was no correlation between H₂O₂ production and the grade of apoptosis in Tregs. Moreover, Tregs were less sensitive to H₂O₂-induced apoptosis compared with conventional T cells in vitro.

Conclusions

We have demonstrated that the increased prevalence of tumor-infiltrating Tregs closely related to their lower sensitivity to H₂O₂-induced apoptosis.     

The membrane-spanning domain of CD98 heavy chain promotes alpha(v)beta3 integrin signals in human extravillous trophoblasts

CD98 heavy chain (CD98hc) is expressed highly in developing human placental trophoblast. CD98hc is an amino acid transporter and is thought to function in cell fusion, adhesion, and invasion by interacting with integrins. In invasive extravillous trophoblast, alpha(v)beta(3) integrin is expressed in a temporally and spatially specific manner, which prompted us to investigate the potential role of CD98hc in signal transduction of alpha(v)beta(3) integrin. Immunocytochemistry of extravillous trophoblast derived from human placenta revealed that CD98hc colocalized with alpha(v)beta(3) integrin and with alpha(v)beta(3)-associated cytoplasmic proteins including paxillin, vinculin, and focal adhesion kinase. Coimmunoprecipitation of CD98hc and its mutants revealed that the transmembrane domain of CD98hc is necessary for the association of CD98hc with alpha(v)beta(3) integrin. When CD98hc negative liver cells (FLC4) were stably transfected with CD98hc and the extracellular domain of CD98hc was cross-linked by anti-CD98 antibody, FLC4 cells binding affinity to fibronectin and cell motility increased. The anti-CD98 antibody cross-linking promoted actin stress fiber formation and activation of signal transduction downstream of RhoA GTPase, and elevated the phosphorylation of focal adhesion kinase, paxillin, and protein kinase B. Pretreatment of transfected FLC4 cells with specific inhibitors for alpha(v)beta(3)integrin, phosphatidylinositol 3-kinase, and RhoA diminished these effects caused by anti-CD98 antibody cross-linking. These results suggest that notoriously invasive activity of extravillous trophoblast is mediated by CD98hc, which promotes alpha(v)beta(3) integrin-dependent signals.     

Regulation of nitrogen-fixation by different nitrogen sources in the marine non-heterocystous cyanobacterium Trichodesmium sp. NIBB1067

The effect of various nitrogen sources on the synthesis and activity of nitrogenase was studied in the marine, non-heterocystous cyanobacterium Trichodesmium sp. NIBB1067 grown under defined culture conditions. Cells grown with N₂ as the sole inorganic nitrogen source showed light-dependent nitrogenase activity (acetylene reduction). Nitrogenase activity in cells grown on N₂ was not suppressed after 7 h incubation with 2 mM NaNO₃ or 0.02 mM NH₄Cl. However, after 3 h of exposure to 0.5 mM of urea, nitrogenase was inactivated. Cells grown in medium containing 2 mM NaNO₃, 0.5 mM urea or 0.02 mM NH₄Cl completely lacked the ability to reduce acetylene. Western immunoblots tested with polyclonal antisera against the Fe-protein and the Mo–Fe protein, revealed the following: (1) both the Fe-protein and the Mo–Fe protein were synthesized in cells grown with N₂ as well as in cells grown with NaNO₃ or low concentration of NH₄Cl; (2) two bands (apparent molecular mass of 38 000 and 40 000) which cross-reacted with the antiserum to the Fe-protein, were found in nitrogen-fixing cells; (3) only one protein band, corresponding to the high molecular mass form of the Fe-protein, was found in cells grown with NaNO₃ or low concentration of NH₄Cl; (4) neither the Fe-protein nor the Mo–Fe protein was found in cells grown with urea; (5) the apparent molecular mass of the Fe-protein of Trichodesmium sp. NIBB1067 was about 5000 dalton higher than that of the heterocystous cyanobacterium, Anabaena cylindrica IAM-M1.     

Laminin α1 is essential for mouse cerebellar development

Laminin α1 (Lama1), which is a subunit of laminin-1 (laminin-111), a heterotrimeric ECM protein, is essential for embryonic development and promotes neurite outgrowth in culture. Because the deletion of Lama1 causes lethality at early embryonic stages in mice, the in vivo role of Lama1 in neural development and functions has not yet been possible to determine. In this study, we generated conditional Lama1 knockout (Lama1(CKO)) mice in the epiblast lineage using Sox2-Cre mice. These Lama1(CKO) mice survived, but displayed behavioral disorders and impaired formation of the cerebellum. Deficiency of Lama1 in the pial basement membrane of the meninges resulted in defects in the conformation of the meninges. During cerebellar development, Lama1 deficiency also caused a decrease in the proliferation and migration of granule cell precursors, disorganization of Bergmann glial fibers and endfeet, and a transient reduction in the activity of Akt. A marked reduction in numbers of dendritic processes in Purkinje cells was observed in Lama1(CKO) mice. Together, these results indicate that Lama1 is required for cerebellar development and functions.     

Potencies of phosphine peptide inhibitors of mammalian thimet oligopeptidase and neurolysin on two bacterial pz peptidases

Pz peptidases A and B, from a thermophile Geobacillus collagenovorans MO-1, recognize collagen-specific tripeptide units (Gly-Pro-Xaa). They share similarities in function but extremely low identities in primary sequence with mammalian thimet oligopeptidase (TOP) and neurolysin. Three phosphine peptide inhibitors that selectively inhibit TOP and neurolysin on two bacterial Pz peptidases were investigated. They showed potent inhibition of both Pz peptidases in a range from 10 to 100 nM.     

A Highly Accurate Inclusive Cancer Screening Test Using Caenorhabditis elegans Scent Detection

Early detection and treatment are of vital importance to the successful eradication of various cancers, and development of economical and non-invasive novel cancer screening systems is critical. Previous reports using canine scent detection demonstrated the existence of cancer-specific odours. However, it is difficult to introduce canine scent recognition into clinical practice because of the need to maintain accuracy. In this study, we developed a Nematode Scent Detection Test (NSDT) using Caenorhabditis elegans to provide a novel highly accurate cancer detection system that is economical, painless, rapid and convenient. We demonstrated wild-type C. elegans displayed attractive chemotaxis towards human cancer cell secretions, cancer tissues and urine from cancer patients but avoided control urine; in parallel, the response of the olfactory neurons of C. elegans to the urine from cancer patients was significantly stronger than to control urine. In contrast, G protein α mutants and olfactory neurons-ablated animals were not attracted to cancer patient urine, suggesting that C. elegans senses odours in urine. We tested 242 samples to measure the performance of the NSDT, and found the sensitivity was 95.8%; this is markedly higher than that of other existing tumour markers. Furthermore, the specificity was 95.0%. Importantly, this test was able to diagnose various cancer types tested at the early stage (stage 0 or 1). To conclude, C. elegans scent-based analyses might provide a new strategy to detect and study disease-associated scents.