Metal-ion-induced expression of gene fragments from subseafloor micro-organisms in the Kumano forearc basin, Nankai Trough.

AIMS: Using substrate-induced gene-expression (SIGEX) screening on subseafloor sediment samples from the Nankai Trough, Japan, we identified gene fragments showing an induction response to metal ions. METHODS AND RESULTS: Environmental DNA libraries in Escherichia coli host cells were tested by the addition of metal ions (Ni2+ , Co2+ , Ga3+ or Mo6+ ), followed by cell sorting of clones exhibiting green fluorescence upon co-expression of green fluorescence protein downstream of the inserted gene fragments. One clone displayed Ni2+ -specific induction, three clones displayed Ga3+ -specific induction and three clones displayed an induction response to multiple metal ions. DNA sequence analysis showed that a variety of genes showed induction responses in the screened clones. CONCLUSIONS: Using the SIGEX approach, we retrieved gene fragments with no previously identified response to metal ions that exhibited metal-ion-induced expression. This method has the potential to promote exploration of gene function through gene-induction response. SIGNIFICANCE AND IMPACT OF THE STUDY: We successfully linked gene-induction response with sequence information for gene fragments of previously unknown function. The SIGEX-based approach exhibited the potential to identify genetic function in unknown gene pools from the deep subseafloor biosphere, as well as novel genetic components for future biotechnological applications.

Hepatitis B virus (HBV) variants fluctuate in paired plasma and peripheral blood mononuclear cells among patient cohorts during different chronic hepatitis B (CHB) disease phases.

Hepatitis B virus is classically considered a hepatotropic virus but also infects peripheral blood mononuclear cells. Chronic hepatitis B has different disease phases modulated by host immunity. We compared HBV variability, drug resistance and immune escape mutations in the overlapping HBV polymerase/surface gene in plasma and peripheral blood mononuclear cells in different disease phases. Plasma and peripheral blood mononuclear cells were isolated from 22 treatment naïve patient cohorts (five inactive, six immune-active, nine HBeAg negative and two immune-tolerant). HBV was genotyped via line probe assay, hepatitis B surface antigen titres were determined by an in-house immunoassay, and HBV DNA was quantified by kinetic PCR. The HBV polymerase/surface region, including full genome in some, was PCR-amplified and cloned, and ~20 clones/sample were sequenced. The sequences were subjected to various mutational and phylogenetic analyses. Clonal sequencing showed that only three of 22 patients had identical HBV genotype profiles in both sites. In immune-active chronic hepatitis B, viral diversity in plasma was higher compared with peripheral blood mononuclear cells. Mutations at residues, in a minority of clones, associated with drug resistance, and/or immune escape were found in both compartments but were more common in plasma. Immune escape mutations were more often observed in the peripheral blood mononuclear cells of immune-active CHB carriers, compared with other disease phases. During all CHB disease phases, differences exist between HBV variants found in peripheral blood mononuclear cells and plasma. Moreover, these data indicate that HBV evolution occurs in a compartment and disease phase-specific fashion.

CD10 as a novel marker of therapeutic resistance and cancer stem cells in head and neck squamous cell carcinoma.

BACKGROUND: Cancer stem cells (CSCs) are responsible for treatment failure. However, their identification and roles in resistance are not well established in head and neck squamous cell carcinoma (HNSCC). METHODS: Three HNSCC cell lines (FaDu, Detroit562 and BICR6) were treated with cisplatin or radiation. Cell surface antigens were analysed by LyoPlate, a novel cell surface antigen array. The expression levels of antigens highly expressed after treatments were further compared between cisplatin-resistant Detroit562 cells and its parental line. Association of the candidate antigen with CSCs properties, namely sphere formation and in vivo tumourigenicity, was also examined. RESULTS: CD10, CD15s, CD146 and CD282 were upregulated across the treated cell lines, while the increased expression of CD10 was prominent in the cisplatin-resistant cell line. Isolation mediated by FACS revealed that the CD10-positive subpopulation was more refractory to cisplatin, fluorouracil and radiation than the CD10-negative subpopulation. It also showed an increased ability to form spheres in vitro and tumours in vivo. Moreover, the CD10-positive subpopulation expressed the CSC marker OCT3/4 at a higher level than that in the CD10-negative subpopulation. CONCLUSIONS: CD10 is associated with therapeutic resistance and CSC-like properties of HNSCC. CD10 may serve as a target molecule in the treatment of refractory HNSCC.

Antifungal effects of palmitic acid salt and ultrapure soft water on Scedosporium apiospermum.

AIMS: Scedosporium apiospermum sometimes causes serious infectious diseases on the skin of immunodeficient subjects. Antifungal effects of fatty acid salts in soap against S. apiospermum were investigated under different water conditions. METHODS AND RESULTS: Ultrapure soft water (UPSW) was generated by the water softener with cation-exchange resin. The calcium and magnesium ions were replaced with sodium ions in UPSW. Scedosporium apiospermum was incubated with different fatty acid salts that constituted soap in distilled water (DW), tap water (TW) and UPSW. After incubation, the number of fungi was counted. Among the fatty acids, palmitic acid salt (C16) reduced the number of S. apiospermum. UPSW enhanced the antifungal effect of C16 on S. apiospermum. The absence of both calcium and magnesium ions and the existence of sodium chloride in UPSW were responsible for its antifungal effect. In addition, repeated short-term treatment with UPSW and C16 decreased the number of S. apiospermum. CONCLUSIONS: Antifungal effects of C16 on S. apiospermum were demonstrated. Moreover, the use of UPSW promoted the antifungal effect of C16. SIGNIFICANCE AND IMPACT OF STUDY: This study provides the preventive method for diseases associated with S. apiospermum infection using novel palmitic acid soap in UPSW.

[Lung resection for patients with lung cancer and chronic obstructive pulmonary disease].

The number of lung resection for patients with lung cancer has been increasing lineally for last two decades in Japan. It reached more than 30,000 in 2009. Subsequently those combined with chronic obstructive pulmonary disease (COPD) also have increased. As pulmonary vascular bed has already been lost to some extent due to chronic alveolar destruction, a careful preoperative physiologic assessment according to a guideline by American College of Chest Physicians (ACCP) or European Respiratory Society( ERS)/European Society of Thoracic Surgeons( ESTS) is important to select patients to be underwent lung resection within acceptable risk. The process to evaluate the risk of lung resection for a lung cancer patient has three steps structured by forced expiratory volume in 1 sec( FEV1), diffusion capacitiy for carbon monoxide (DLco), and exercise capacity. We suggested that it would be more practical to add global initiative for obstructive lung disease( GOLD) staging of each patient and distribution of emphysematous lung obtained by functional imaging modarities to the pathway of flow chart of the guideline. Some patients with very low FEV1 demonstrate increase in FEV1 after lung resection by so called lung volume reduction effect. To utilize lots of findings and experiences obtained from lung volume reduction surgery( LVRS) contributes to select patients with lung cancer and COPD and to perform lung resection and perioperative care properly.

A complex linkage in the developmental pathway of endothelial and hematopoietic cells.

During normal vertebrate development, hematopoietic and endothelial cells form closely situated and interacting populations. Although the close proximity of cells to each other does not necessarily mean that they are relatives, accumulating evidence indicates that hematopoietic and endothelial cells are indeed close kin; they share common progenitors and each is able to become the other under certain circumstances. This article summarizes recent advances in the developmental relationship between hematopoietic and endothelial cells.

Ribozyme rescue of photoreceptor cells in a transgenic rat model of autosomal dominant retinitis pigmentosa.

Ribozymes, catalytic RNA molecules that cleave a complementary mRNA sequence, have potential as therapeutics for dominantly inherited disease. Twelve percent of American patients with the blinding disease autosomal dominant retinitis pigmentosa (ADRP) carry a substitution of histidine for proline at codon 23 (P23H) in their rhodopsin gene, resulting in photoreceptor cell death from the synthesis of the abnormal gene product. Ribozymes can discriminate and catalyze the in vitro destruction of P23H mutant mRNAs from a transgenic rat model of ADRP. Here, we demonstrate that in vivo expression of either a hammerhead or hairpin ribozyme in this rat model considerably slows the rate of photoreceptor degeneration for at least three months. Catalytically inactive control ribozymes had less effect on the retinal degeneration. Intracellular production of ribozymes in photoreceptors was achieved by transduction with a recombinant adeno-associated virus (rAAV) incorporating a rod opsin promoter. Ribozyme-directed cleavage of mutant mRNAs, therefore, may be an effective therapy for ADRP and also may be applicable to other inherited diseases.

VEGF-D promotes the metastatic spread of tumor cells via the lymphatics.

Metastasis to local lymph nodes via the lymphatic vessels is a common step in the spread of solid tumors. To investigate the molecular mechanisms underlying the spread of cancer by the lymphatics, we examined the ability of vascular endothelial growth factor (VEGF)-D, a ligand for the lymphatic growth factor receptor VEGFR-3/Flt-4, to induce formation of lymphatics in a mouse tumor model. Staining with markers specific for lymphatic endothelium demonstrated that VEGF-D induced the formation of lymphatics within tumors. Moreover, expression of VEGF-D in tumor cells led to spread of the tumor to lymph nodes, whereas expression of VEGF, an angiogenic growth factor which activates VEGFR-2 but not VEGFR-3, did not. VEGF-D also promoted tumor angiogenesis and growth. Lymphatic spread induced by VEGF-D could be blocked with an antibody specific for VEGF-D. This study demonstrates that lymphatics can be established in solid tumors and implicates VEGF family members in determining the route of metastatic spread.

Inhibition of lymphangiogenesis with resulting lymphedema in transgenic mice expressing soluble VEGF receptor-3.

The lymphatic vasculature transports extravasated tissue fluid, macromolecules and cells back into the blood circulation. Recent reports have focused on the molecular mechanisms regulating the lymphatic vessels. Vascular endothelial growth factor (VEGF)-C and VEGF-D have been shown to stimulate lymphangiogenesis and their receptor, VEGFR-3, has been linked to human hereditary lymphedema. Here we show that a soluble form of VEGFR-3 is a potent inhibitor of VEGF-C/VEGF-D signaling, and when expressed in the skin of transgenic mice, it inhibits fetal lymphangiogenesis and induces a regression of already formed lymphatic vessels, though the blood vasculature remains normal. Transgenic mice develop a lymphedema-like phenotype characterized by swelling of feet, edema and dermal fibrosis. They survive the neonatal period in spite of a virtually complete lack of lymphatic vessels in several tissues, and later show regeneration of the lymphatic vasculature, indicating that induction of lymphatic regeneration may also be possible in humans.

Preferential proliferation of murine colony-forming units in culture in a chemically defined condition with a macrophage colony-stimulating factor-negative stromal cell clone.

The establishment of culture conditions that selectively support hematopoietic stem cells is an important goal of hematology. In this study, we investigated the possibility of using for this purpose a defined medium, mSFO2, which was developed for stromal cell-dependent bone marrow cultures. We found that a combination of epidermal growth factor (EGF), the OP9 stromal cell line, which lacks macrophage colony-stimulating factor, recombinant stem cell factor, and the chemically defined medium mSFO2 provides a microenvironment where c-Kit+ Thy-1+/lo Mac-1+/lo B220- TER119- common beta + IL-2R gamma + gp130+ cells are selectively propagated from normal, unfractionated bone marrow cells. This cell population produced an in vitro colony at a very high efficiency (50%), whereas it has only limited proliferative ability in the irradiated recipient. Thus, the cells selected in this culture condition might represent colony-forming units in culture (CFU-c) with short-term reconstituting ability. Transferring this cell population into medium containing differentiation signals resulted in the rapid production of mature myelomonocytic and B cell lineages in vitro and in vivo. The fact that a similar culture condition was created by erb-B2-transduced OP9 in the absence of EGF indicated that EGF exerts its effect by acting on OP9 rather than directly on CFU-c. These results suggested that the balance between self-renewal and differentiation of CFU-c can be regulated by extra-cellular signals.

Cell cycle control of c-kit+IL-7R+ B precursor cells by two distinct signals derived from IL-7 receptor and c-kit in a fully defined medium.

An important goal for the investigation of the proliferation of mammalian cells is to establish a fully defined condition for culturing them in vitro. Here, we report establishment of a fully defined culture condition that supports the primary culture of normal c-kit+IL-7 receptor (IL-7R)+ B precursor cells without the aid of stromal cell lines. This defined culture condition contains IL-7, the ligand for c-kit, transferrin, insulin, and bovine serum albumin as protein components. By using the cell lines derived from RAG2(-/-) mice, which do not differentiate into c-kit- stage, we have evaluated the role of each protein in the cell cycle progression of c-kit+IL-7R+ B precursor cells. Since B precursor cells can grow without insulin, c-kit remains a sole functional receptor tyrosine kinase for their growth. While both c-kit ligand (KL) and IL-7 are the requisite molecules for sustained proliferation of B precursor cells, each molecule plays distinct roles. IL-7 starvation results in prompt arrest of the cells at G1. An accumulation of the cells in the mitotic phase was also detected. Thus, the major role of IL-7 is to regulate the G1/S transition and the process of cytokinesis of B precursor cells. Although prolonged KL starvation over 48 h resulted in accumulation of G1 cells, its effect could not be detected within 24 h, which is long enough for all the cells to complete one cell cycle. This suggests that KL might be involved in the cell cycle progression of B precursor cells in a manner that its signal could still be effective in the one or two cell cycles that follow. Although molecular nature of the signals underlying the present observation awaits future investigation, the method described in this report would provide a useful model system for investigating the signaling pathways that are involved in the cell cycle progression of B precursor cells.

In vitro proliferation of primitive hemopoietic stem cells supported by stromal cells: evidence for the presence of a mechanism(s) other than that involving c-kit receptor and its ligand.

The preadipose cell line, PA6, can support long-term hemopoiesis. Frequency of the hemopoietic stem cells capable of sustaining hemopoiesis in cocultures of bone marrow cells and PA6 cells for 6 wk was 1/5.3 x 10(4) bone marrow cells. In the group of dishes into which bone marrow cells had been inoculated at 2.5 x 10(4) cells/dish, 3 of 19 dishes (16%) contained stem cells capable of reconstituting erythropoiesis of WBB6F1-W/Wv mice, indicating that PA6 cells can support the proliferation of primitive hemopoietic stem cells. When the cocultures were treated with an antagonistic anti-c-kit monoclonal antibody, ACK2, only a small number of day 12 spleen colony-forming units survived; and hemopoiesis was severely reduced. However, when the cocultures were continued with antibody-free medium, hemopoiesis dramatically recovered. To examine the proliferative properties of the ACK2-resistant stem cells, we developed a colony assay system by modifying our coculture system. Sequential observations of the development of individual colonies and their disappearance demonstrated that the stem cells having higher proliferative capacity preferentially survive the ACK2 treatment. Furthermore, cells of subclones of the PA6 clone that were incapable of supporting long-term hemopoiesis expressed mRNA for the c-kit ligand. These results suggest that a mechanism(s) other than that involving c-kit receptor and its ligand plays an important role in the survival and proliferation of primitive hemopoietic stem cells.

Stepwise progression of B lineage differentiation supported by interleukin 7 and other stromal cell molecules.

Growth of early B precursor cells was investigated in vitro by using rIL-7 and IL-7-defective stromal cell line PA6 as separate growth signals. B cell development proceeds through three sequential stages different from the growth signal requirement. The cells in the first stage require PA6 alone for the proliferation, and differentiate into the second stage, which requires both PA6 and IL-7 for its growth. When IL-7 is available for the cells in the second stage, they proliferate extensively on the PA6 layer, and some acquire the ability to proliferate in response to IL-7 alone. This sequential change of growth signal requirement, however, does not proceed autonomously along the time schedule. The possibility that it is primarily directed by the result of Ig gene rearrangement is considered. This mode of growth control may explain why only functional B cells are selected in the error-prone process of Ig gene rearrangement during B lineage differentiation.

Expression and function of c-kit in hemopoietic progenitor cells.

The expression and function of a receptor tyrosine kinase, c-kit, in the adult bone marrow of the mouse were investigated by using monoclonal antibodies (mAbs) against the extracellular domain of murine c-kit. In adult C57BL/6 mouse, 7.8% of total bone marrow cells express c-kit on their surface. Half of the c-kit+ cells do not express lineage markers including Mac-1, Gr-1, TER-119, and B220, while the remainder coexpress myeloid lineage markers such as Mac-1 and Gr-1. After c-kit+ cells were removed from the bone marrow cell preparation, hemopoietic progenitor cells reactive to IL-3, GM-CSF, or M-CSF and also those which give rise to spleen colonies in irradiated recipients disappeared almost completely. Thus, most hemopoietic progenitors in the adult bone marrow express c-kit. To investigate whether or not c-kit has any role in the hemopoiesis of adult bone marrow, we took the advantage of one of the anti-c-kit mAbs that can antagonize the function of c-kit. As early as two days after the injection of 1 milligram of an antagonistic antibody, ACK2, almost all hemopoietic progenitor cells disappeared from the bone marrow, which eventually resulted in the absence of mature myeloid and erythroid cells in the bone marrow. These results provide direct evidence that c-kit is an essential molecule for constitutive intramarrow hemopoiesis, especially for the self-renewal of hemopoietic progenitor cells at various stages of differentiation.

Vascular endothelial growth factor can substitute for macrophage colony-stimulating factor in the support of osteoclastic bone resorption.

We demonstrated previously that a single injection of recombinant human macrophage colony-stimulating factor (rhM-CSF) is sufficient for osteoclast recruitment and survival in osteopetrotic (op/op) mice with a deficiency in osteoclasts resulting from a mutation in M-CSF gene. In this study, we show that a single injection of recombinant human vascular endothelial growth factor (rhVEGF) can similarly induce osteoclast recruitment in op/op mice. Osteoclasts predominantly expressed VEGF receptor 1 (VEGFR-1), and activity of recombinant human placenta growth factor 1 on osteoclast recruitment was comparable to that of rhVEGF, showing that the VEGF signal is mediated through VEGFR-1. The rhM-CSF-induced osteoclasts died after injections of VEGFR-1/Fc chimeric protein, and its effect was abrogated by concomitant injections of rhM-CSF. Osteoclasts supported by rhM-CSF or endogenous VEGF showed no significant difference in the bone-resorbing activity. op/op mice undergo an age-related resolution of osteopetrosis accompanied by an increase in osteoclast number. Most of the osteoclasts disappeared after injections of anti-VEGF antibody, demonstrating that endogenously produced VEGF is responsible for the appearance of osteoclasts in the mutant mice. In addition, rhVEGF replaced rhM-CSF in the support of in vitro osteoclast differentiation. These results demonstrate that M-CSF and VEGF have overlapping functions in the support of osteoclastic bone resorption.

High frequency of lambda gene activation in bone marrow pre-B cells.

The frequency of lambda light chain (L) producing cells in immunoglobulin-producing cells that have been generated in vitro from bone marrow pre-B cells was investigated. The frequency of lambda-producing cells obtained in such a culture was three- to eightfold higher than that observed in the culture of mature spleen B cells. These results suggest that the activation of lambda gene at pre-B cell stage occurs far more frequently than the frequency presumed from the percentage of lambda-bearing cells in mature B cells.

Characterization of c-kit positive intrathymic stem cells that are restricted to lymphoid differentiation.

We found that c-kit-positive, lineage marker-negative, Thy-1lo cells are present in both bone marrow and thymus ("BM c-kit" and "thymus c-kit" cells). Although the two cell types are phenotypically similar, only BM c-kit cells showed the potential to form colonies in vitro as well as in vivo. However, both of them revealed extensive growth and differentiation potential to T cells after direct transfer into an irradiated adult thymus, or a deoxyguanosine-treated fetal thymus. Time course analysis showed that thymus c-kit cells differentiated into CD4CD8 double-positive cells approximately 4 d earlier than BM c-kit cells did. In addition, anti-c-kit antibody blocked T cell generation of BM c-kit cells but not of thymus c-kit cells. Intravenous injection of thymus c-kit resulted in the generation of not only T cells, but B as well as NK1.1+ cells. These data provide evidence that thymus c-kit cells represent common lymphoid progenitors with the differentiation potential to T, B, and possibly NK cells. The c-kit-mediated signaling appears to be essential in the transition from BM c-kit to thymus c-kit cells.

Expression of recombination activating genes in germinal center B cells: involvement of interleukin 7 (IL-7) and the IL-7 receptor.

Mouse germinal center (GC) B cells have been shown to undergo secondary V(D)J (V, variable; D, diversity; J, joining) recombination (receptor editing) mediated by the reexpressed products of recombination activating gene (RAG)-1 and RAG-2. We show here that interleukin (IL)-7 as well as IL-4 was effective in inducing functional RAG products in mouse IgD+ B cells activated via CD40 in vitro. Blocking of the IL-7 receptor (IL-7R) by injecting an anti- IL-7R monoclonal antibody resulted in a marked suppression of the reexpression of RAG-2 and subsequent V(D)J recombination in the draining lymph node of immunized mice, whereas RAG-2 expression was not impaired in immunized IL-4-deficient mice. Further, these peripheral B cells activated in vitro or in vivo were found to express IL-7R. These findings indicate a novel role for IL-7 and IL-7R in inducing receptor editing in GC B cells.

Molecular basis for hematopoietic/mesenchymal interaction during initiation of Peyer's patch organogenesis.

Mice deficient in lymphotoxin beta receptor (LTbetaR) or interleukin 7 receptor alpha (IL-7Ralpha) lack Peyer's patches (PPs). Deficiency in CXC chemokine receptor 5 (CXCR5) also severely affects the development of PPs. A molecular network involving these three signaling pathways has been implicated in PP organogenesis, but it remains unclear how they are connected during this process. We have shown that PP organogenesis is initiated at sites containing IL-7Ralpha(+) lymphoid cells and vascular cell adhesion molecule (VCAM)-1/intercellular adhesion molecule (ICAM)-1 expressing nonlymphoid elements. Here we characterize these lymphoid and nonlymphoid components in terms of chemokine signals. The lymphoid population expresses CXCR5 and has a strong chemotactic response to B lymphocyte chemoattractant (BLC). Importantly, chemokines produced by VCAM-1(+)ICAM-1(+) nonlymphoid cells mediate the recruitment of lymphoid cells. Furthermore, we show that these VCAM-1(+)ICAM-1(+) cells are mesenchymal cells that are activated by lymphoid cells through the LTbetaR to express adhesion molecules and chemokines. Thus, promotion of PP development relies on mutual interaction between mesenchymal and lymphoid cells.