bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential Expression of Two Distinct Phenylalanine Ammonia-Lyase Genes in Condensed Tannin-Accumulating and Lignifying Cells of Quaking Aspen
Authors: Kao Yu-Ying , Harding Scott A. , Tsai Chung-Jui 
Published: October 2002

Abstract
Lignins, along with condensed tannins (CTs) and salicylate-derived phenolic glycosides, constitute potentially large phenylpropanoid carbon sinks in tissues of quaking aspen (Populus tremuloides Michx.). Metabolic commitment to each of these sinks varies during development and adaptation, and depends onl-phenylalanine ammonia-lyase (PAL), an enzyme catalyzing the deamination of l-phenylalanine to initiate phenylpropanoid metabolism. In Populus spp., PAL is encoded by multiple genes whose expression has been associated with lignification in primary and secondary tissues. We now report cloning two differentially expressed PAL cDNAs that exhibit distinct spatial associations with CT and lignin biosynthesis in developing shoot and root tissues of aspen. PtPAL1 was expressed in certain CT-accumulating, non-lignifying cells of stems, leaves, and roots, and the pattern of PtPAL1 expression varied coordinately with that of CT accumulation along the primary to secondary growth transition in stems. PtPAL2 was expressed in heavily lignified structural cells of shoots, but was also expressed in non-lignifying cells of root tips. Evidence of a role forPt4CL2, encoding 4-coumarate:coenzyme A ligase, in determining CT sink strength was gained from cellular co-expression analysis with PAL1 and CTs, and from experiments in which leaf wounding increased PAL1 and4CL2 expression as well as the relative allocation of carbon to CT with respect to phenolic glycoside, the dominant phenolic sink in aspen leaves. Leaf wounding also increased PAL2and lignin pathway gene expression, but to a smaller extent. The absence of PAL2 in most CT-accumulating cells provides in situ support for the idea that PAL isoforms function in specific metabolic milieus.
Inventory and Functional Characterization of the HAK Potassium Transporters of Rice
Authors: Bañuelos Marı́a A. , Garciadeblas Blanca , Cubero Beatriz , Rodrı́guez-Navarro Alonso 
Published: October 2002

Abstract
Plants take up large amounts of K+ from the soil solution and distribute it to the cells of all organs, where it fulfills important physiological functions. Transport of K+from the soil solution to its final destination is mediated by channels and transporters. To better understand K+ movements in plants, we intended to characterize the function of the large KT-HAK-KUP family of transporters in rice (Oryza sativacv Nipponbare). By searching in databases and cDNA cloning, we have identified 17 genes (OsHAK1–17) encoding transporters of this family and obtained evidence of the existence of other two genes. Phylogenetic analysis of the encoded transporters reveals a great diversity among them, and three distant transporters, OsHAK1, OsHAK7, and OsHAK10, were expressed in yeast (Saccharomyces cerevisiae) and bacterial mutants to determine their functions. The three transporters mediate K+ influxes or effluxes, depending on the conditions of the experiment. A comparative kinetic analysis of HAK-mediated K+ influx in yeast and in roots of K+-starved rice seedlings demonstrated the involvement of HAK transporters in root K+ uptake. We discuss that all HAK transporters may mediate K+ transport, but probably not only in the plasma membrane. Transient expression of the OsHAK10-green fluorescent protein fusion protein in living onion epidermal cells targeted this protein to the tonoplast.
Refinement of hydrogen positions in natural chondrodite by powder neutron diffraction: implications for the stability of humite minerals
Authors: Berry A. J. , James M. 
Published: October 2002

AbstractThe structure of a natural sample of chondrodite (Mg4.89Fe0.07Si2.04O8F1.54(OH)0.46) was refined using powder neutron diffraction data and the Rietveld technique (P21/b;Z= 2;a= 4.7204(1)Å;b= 10.2360(3)Å;c= 7.8252(2)Å; α = 109.11(1)°;V= 357.26(2)Å3). Hydrogen was found to occupy the H1 site. The significance of hydrogen at this site is discussed in terms of hydrogen-bond stabilization of humite structures containing varying amounts of OH, F and Ti. Arguments are proposed as to why the F and Ti contents of natural humites usually result in only one H per formula unit when there is no crystal-chemical reason why fully hydrated samples should not be favoured.
Trafficking machinery of NKT cells: shared and differential chemokine receptor expression among Vα24+Vβ11+ NKT cell subsets with distinct cytokine-producing capacity
Authors: Kim Chang H. , Johnston Brent , Butcher Eugene C. 
Published: October 2002

AbstractNatural killer T (NKT) cells are important regulators of the immune system, but their trafficking machinery, including expression of chemokine receptors, has been poorly defined. Unlike other conventional T-cell populations, we show that most NKT cells express receptors for extralymphoid tissue or inflammation-related chemokines (CCR2, CCR5, and CXCR3), while few NKT cells express lymphoid tissue–homing chemokine receptors (CCR7 and CXCR5). A population with homing potential for lymph nodes (L selectin+ CCR7+) exists only within a small subset of CD4 NKT cells. We show differential expression of chemokine receptors among NKT cell subsets: CCR4 is mainly expressed by a high cytokine (interleukin-4/interleukin-2)–producing (CD4) NKT subset, while CCR1, CCR6, and CXCR6 are preferentially expressed by the low cytokine-producing CD8 and CD4−CD8− subsets. In line with this, TARC/CCL17 (a CCR4 ligand) induces preferential chemotaxis of the CD4 NKT subset, while chemotactic activities of LARC/CCL20 (a CCR6 ligand) and MIP-1α/CCL3 (a CCR1 ligand) are focused on the CD8 and CD4−CD8− NKT cells. We conclude that, unlike conventional naive, memory, or effector T cells, the entire NKT cell population expresses nonlymphoid tissue homing chemokine receptors, yet NKT cell subsets differ considerably from each other by displaying distinct and reciprocal expression patterns of some chemokine receptors. Our results identify chemokine receptors that are potentially important for trafficking of human blood NKT cell subsets and reveal their function (cytokine production capacity)–dependent differential trafficking potentials.
Hematopoietic progenitor kinase 1 supports apoptosis of T lymphocytes
Authors: Schulze-Luehrmann Jan , Santner-Nanan Brigitte , Jha Mithilesh Kumar , Schimpl Anneliese , Avots Andris , Serfling Edgar 
Published: October 2002

Abstract
Hematopoietic progenitor kinase 1 (HPK1) is a member of germinal center kinases that is predominantly expressed in hematopoietic cells and transiently activated by T-cell receptor (TCR) triggering. We show here that HPK1 supports apoptosis of T cells. When HPK1 was overexpressed in murine CD4+ T cells, a substantial increase was observed in spontaneous and TCR/CD3-mediated apoptosis as well as in Fas ligand (FasL) expression. In H2O2-treated EL-4 thymoma cells, which show an increase in reactive oxygen species (ROS) and apoptosis, overexpression of HPK1 enhanced ROS-mediated apoptosis, whereas expression of HPK1 antisense (AS) RNA impaired apoptosis. HPK1 expression also led to a sustained increase in c-Jun N-terminal kinase (JNK) activity, suggesting that JNK activation contributes to the HPK1-mediated apoptosis in H2O2-treated EL-4 cells. Under the same conditions, a rapid cleavage of HPK1 was observed, and overexpression of N- and C-terminal cleavage products in CD4+ T cells resulted in, similar to full-length HPK1, an increase in apoptosis. In agreement with published data, we show that the C-terminal portion of HPK1 suppresses IκBα degradation, thereby inhibiting nuclear factor (NF)–κB activation. These findings suggest that by inhibiting the antiapoptotic action of NF-κB and inducing the proapoptotic activity of JNK, OHPK1 supports apoptosis in T cells.
Activity of STI571 in chronic myelomonocytic leukemia with a platelet-derived growth factor β receptor fusion oncogene
Authors: Magnusson Magnus K. , Meade Kristin E. , Nakamura Ryotaro , Barrett John , Dunbar Cynthia E. 
Published: October 2002

Abstract
Platelet-derived growth factor β receptor (PDGFβR) fusion genes have been shown to be critical transforming oncogenes in a subset of patients with chronic myelomonocytic leukemia (CMML). The sensitivity of dysregulated tyrosine kinase oncogenes to the tyrosine kinase inhibitor STI571 (imatinib mesylate) makes it a potentially attractive treatment option in this subset of patients. We have recently cloned a novel member of the PDGFβR fusion oncogene family, rabaptin-5-PDGFβR. A patient with CMML carrying the rabaptin-5-PDGFβR fusion gene underwent allogeneic stem cell transplantation (SCT) and was monitored closely with a sensitive reverse transcriptase–polymerase chain assay to detect the novel fusion gene transcript. After achieving a molecular remission at 5 months after transplantation, 15 months after SCT the patient showed persistent and progressive evidence of molecular relapse. After demonstrating in vitro that cells transformed with this specific fusion oncogene are efficiently killed by STI571, the patient was started on STI571. The patient responded rapidly and entered molecular remission after 6 weeks of therapy, and he continues to be in remission 6 months later. These results suggest that STI571 may be an effective targeted therapy in patients with CMML related to PDGFβR fusion oncogenes.
Overcoming STI571 resistance with the farnesyl transferase inhibitor SCH66336
Authors: Hoover Russell R. , Mahon Francois-Xavier , Melo Junia V. , Daley George Q. 
Published: October 2002

Abstract
The development of chronic myeloid leukemia (CML) is dependent on the deregulated tyrosine kinase of the oncoprotein BCR-ABL. STI571 (imatinib mesylate), an abl tyrosine kinase inhibitor, has proven remarkably effective for the treatment of CML. However, resistance to STI571 because of enhanced expression or mutation of theBCR-ABL gene has been detected in patients. In the current study we show that the farnesyl transferase inhibitor (FTI) SCH66336 (lonafarnib) inhibits the proliferation of STI571-resistant BCR-ABL–positive cell lines and hematopoietic colony formation from peripheral blood samples of STI571-resistant patients with CML. Moreover, SCH66336 enhances STI571-induced apoptosis in STI571-sensitive cells and, in patients with STI571 resistance from gene amplification, cooperates with STI571 to induce apoptosis. Our data provide a rationale for combination clinical trials of STI571 and SCH66336 in CML patients and suggest that combination therapy may be effective in patients with STI571 resistance.
Development of a murine hematopoietic progenitor complementary DNA microarray using a subtracted complementary DNA library
Authors: Ma Xianyong , Husain Tupur , Peng Hui , Lin Sharon , Mironenko Olga , Maun Noel , Johnson Steven , Tuck David , Berliner Nancy , Krause Diane S. , Perkins Archibald S. 
Published: October 2002

AbstractWith the goal of creating a resource for in-depth study of myelopoiesis, we have executed a 2-pronged strategy to obtain a complementary DNA (cDNA) clone set enriched in hematopoietic genes. One aspect is a library subtraction to enrich for underrepresented transcripts present at early stages of hematopoiesis. For this, a hematopoietic cDNA library from primary murine bone marrow cells enriched for primitive progenitors was used as tester. The subtraction used 10 000 known genes and expressed sequence tags (ESTs) as driver. The 2304 randomly picked clones from the subtracted cDNA libraries represent 1255 distinct genes, of which 622 (50%) are named genes, 386 (30%) match uncharacterized ESTs, and 247 (20%) are novel. The second aspect of our strategy was to complement this subtracted library with genes known to be involved in myeloid cell differentiation and function. The resulting cDNAs were arrayed on polylysine-coated glass slides. The microarrays were used to analyze gene expression in primary and cultured murine bone marrow–derived progenitors. We found expression of various types of genes, including regulatory cytokines and their receptors, signal transduction genes, and transcription factors. To assess gene expression during myeloid differentiation, we examined patterns of change during induced differentiation of EML cells. Several hundred of the genes underwent fluctuations in expression level during myeloid cell differentiation. The complete database, accessible on the World Wide Web at http://yale130132115135.med.yale.edu/, allows for retrieval of information regarding these genes. Our microarray allows for genomewide expression analysis of myeloid stem cells, which will help in defining the regulatory mechanisms of stem cell differentiation.
Long-term support of hematopoiesis by a single stem cell clone in patients with paroxysmal nocturnal hemoglobinuria
Authors: Nishimura Jun-ichi , Hirota Toshiyuki , Kanakura Yuzuru , Machii Takashi , Kageyama Takashi , Doi Shoichi , Wada Hiroshi , Masaoka Toru , Kanayama Yoshio , Fujii Hiroshi , Inoue Nobumasa , Kuwayama Maki , Inoue Norimitsu , Ohishi Kazuhito , Kinoshita Taroh 
Published: October 2002

Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematopoietic stem cell disorder characterized by clonal blood cells that are deficient in glycosylphosphatidylinositol-anchored proteins because of somatic mutations of the PIG-A gene. Many patients with PNH have more than one PNH clone, but it is unclear whether a single PNH clone remains dominant or minor clones eventually become dominant. Furthermore, it is unknown how many hematopoietic stem cells (HSCs) sustain hematopoiesis and how long a single HSC can support hematopoiesis in humans. To understand dynamics of HSCs, we reanalyzed the PIG-A gene mutations in 9 patients 6 to 10 years after the previous analyses. The proportion of affected peripheral blood polymorphonuclear cells (PMNs) in each patient was highly variable; it increased in 2 (from 50% and 65% to 98% and 97%, respectively), was stable in 4 (changed less than 20%), and diminished in 3 (94%, 99%, and 98% to 33%, 57%, and 43%, respectively) patients. The complexity of these results reflects the high variability of the clinical course of PNH. In all patients, the previously predominant clone was still present and dominant. Therefore, one stem cell clone can sustain hematopoiesis for 6 to 10 years in patients with PNH. Two patients whose affected PMNs decreased because of a decline of the predominant PNH clone and who have been followed up for 24 and 31 years now have an aplastic condition, suggesting that aplasia is a terminal feature of PNH.
Plasmin activity is required for myogenesis in vitro and skeletal muscle regeneration in vivo
Authors: Suelves Mònica , López-Alemany Roser , Lluı́s Frederic , Aniorte Gloria , Serrano Erika , Parra Maribel , Carmeliet Peter , Muñoz-Cánoves Pura 
Published: October 2002

AbstractPlasmin, the primary fibrinolytic enzyme, has a broad substrate spectrum and is implicated in biologic processes dependent upon proteolytic activity, such as tissue remodeling and cell migration. Active plasmin is generated from proteolytic cleavage of the zymogen plasminogen (Plg) by urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA). Here, we have investigated the role of plasmin in C2C12 myoblast fusion and differentiation in vitro, as well as in skeletal muscle regeneration in vivo, in wild-type and Plg-deficient mice. Wild-type mice completely repaired experimentally damaged skeletal muscle. In contrast, Plg−/− mice presented a severe regeneration defect with decreased recruitment of blood-derived monocytes and lymphocytes to the site of injury and persistent myotube degeneration. In addition, Plg-deficient mice accumulated fibrin in the degenerating muscle fibers; however, fibrinogen depletion of Plg-deficient mice resulted in a correction of the muscular regeneration defect. Because we found that uPA, but not tPA, was induced in skeletal muscle regeneration, and persistent fibrin deposition was also reproducible in uPA-deficient mice following injury, we propose that fibrinolysis by uPA-dependent plasmin activity plays a fundamental role in skeletal muscle regeneration. In summary, we identify plasmin as a critical component of the mammalian skeletal muscle regeneration process, possibly by preventing intramuscular fibrin accumulation and by contributing to the adequate inflammatory response after injury. Finally, we found that inhibition of plasmin activity with α2-antiplasmin resulted in decreased myoblast fusion and differentiation in vitro. Altogether, these studies demonstrate the requirement of plasmin during myogenesis in vitro and muscle regeneration in vivo.
Flt3 ligand as a vaccine adjuvant in association with HER-2/neu peptide-based vaccines in patients with HER-2/neu–overexpressing cancers
Authors: Disis Mary L. , Rinn Kristine , Knutson Keith L. , Davis Donna , Caron Dania , dela Rosa Corazon , Schiffman Kathy 
Published: October 2002

AbstractDendritic cells (DCs) are potent antigen-presenting cells and have shown promise to function as “natural” vaccine adjuvants. Currently, most cancer vaccine trials using DCs generate autologous DCs ex vivo for each patient. Systemic treatment with Flt3 ligand (FL) results in a marked increase of DCs in tissues such as spleen and lymph nodes in mice and in the peripheral blood and skin of humans. In light of these observations, we questioned whether FL could be used systemically as a vaccine adjuvant to stimulate DC mobilization in vivo, circumventing the need to generate DCs ex vivo. Ten patients with HER-2/neu–overexpressing cancer were enrolled in a phase 1 study to receive a HER-2/neu peptide-based vaccine targeting the intracellular domain of the HER-2/neu protein. All patients received 20 μg/kg FL per day subcutaneously for 14 days. Five patients received the HER-2/neu peptide-based vaccine alone on day 7 of the 14-day cycle, and 5 patients received the vaccine admixed with 150 μg granulocyte macrophage–colony-stimulating factor (GM-CSF) on day 7 of the FL cycle. T-cell proliferative responses to HER-2/neu peptides and intracellular domain protein suggest that vaccine regimens including FL as an adjuvant were not effective in eliciting a significant HER-2/neu protein-specific T-cell proliferative response. However, including FL as a vaccine adjuvant was effective in boosting the precursor frequency of interferon-γ–secreting HER-2/neu–specific T cells. The small sample size of each group, however, did not allow a statistically significant comparison of immune responses between the FL alone and FL with GM-CSF arms. Finally, vaccine regimens including FL as a vaccine adjuvant were associated with the development of apparent autoimmune phenomena in some patients.
Murine acute graft-versus-host disease can be prevented by depletion of alloreactive T lymphocytes using activation-induced cell death
Authors: Hartwig Udo F. , Robbers Michael , Wickenhauser Claudia , Huber Christoph 
Published: October 2002

AbstractDepletion of T lymphocytes from allogeneic bone marrow transplants successfully prevents the development of graft-versus-host disease (GvHD) but is associated with impaired engraftment, immunosuppression, and abrogation of the graft-versus-leukemia effect. We therefore explored the possibility of selectively eliminating alloreactive T cells by CD95/CD95L–mediated activation-induced cell death (AICD) in a major histocompatibility complex allogeneic murine model system. Activation of resting or preactivated T lymphocytes from C3H/HeJ (H-2k) mice was induced with irradiated BALB/cJ (H-2d) mouse-derived stimulators. Substantial decrease (≥ 80%) of proliferative and lytic responses by activated alloreactive T cells was subsequently achieved by incubating the mixed lymphocyte culture with an agonistic monoclonal antibody to CD95, and residual T cells recovered did not elicit alloreactivity upon challenge to H-2d. Depletion of alloreactive T lymphocytes by AICD was specific because reactivity to an I-Ad–restricted ovalbumin (OVA) peptide by OVA-specific CD4+ T cells mixed into the allogeneic T-cell pool and subjected to induction of AICD in the absence of OVA peptide could be preserved. Adoptive transfer of donor-derived allogeneic T lymphocytes, depleted from alloreactive T cells by AICD in vitro, in the parent (C3H/He) to F1 (C3H/He × BALB/c) GvHD model prevented lethal GvHD. The results presented suggest that alloreactive T cells can effectively be depleted from allogeneic T cells by induction of AICD to prevent GvHD and might introduce a new strategy for the separation of GvH-reactive T cells and T cells mediating antiviral and possibly graft-versus-leukemia effects.
Prevention of graft-versus-host disease while preserving graft-versus-leukemia effect after selective depletion of host-reactive T cells by photodynamic cell purging process
Authors: Chen Benny J. , Cui Xiuyu , Liu Congxiao , Chao Nelson J. 
Published: October 2002

AbstractIn this study, we investigated the possibility of selective depletion of donor alloantigen-specific T cells from C57BL/6 (H-2b) mice to prevent graft-versus-host disease (GVHD). These cells were first activated with irradiated BALB/c (H-2d) host spleen cells in a 5-day mixed lymphocyte culture. Following this activation, a photoactive rhodamine derivative called 4,5-dibromorhodamine 123 (TH9402), was added. This compound is selectively retained in the mitochondria of activated host-reactive cells but not tumor- or third-party–specific resting cells. The treated cells were subsequently exposed to visible light (514 nm) to deplete the TH9402-enriched activated host-reactive cells. Treatment with photodynamic cell purging process (PDP) inhibited antihost responses measured by cytotoxic T lymphocytes (CTL) by 93%, and interferon-γ production by 66%. By contrast, anti-BCL1 (BALB/c-origin leukemia/lymphoma) and anti–third-party C3H/HeJ (H-2k) responses were preserved. PDP-treated primed C57BL/6 cells were further tested in vivo. All lethally irradiated BALB/c mice inoculated with BCL1 cells and T-cell–depleted bone marrow cells developed leukemia by day +30, with 50% mortality by 100 days. All mice died of GVHD after addition of 5 × 106untreated primed C57BL/6 cells. However, addition of same numbers of PDP-treated cells allowed 90% of the recipients to survive more than 100 days without detectable BCL1 tumor cells and free of GVHD. Moreover, PDP-treated primed C57BL/6 cells retained the ability to induce GVHD in the third-party C3H/HeJ mice. These data suggest that PDP can selectively deplete host alloantigen-specific T cells for GVHD prevention and immune and antileukemia function preserve.