bluuebunny/crossref_metadata_2025_split huggingface dataset:
The RAR-RXR as well as the RXR-RXR pathway is involved in signaling growth inhibition of human CD34+ erythroid progenitor cells
Authors: Rusten LS , Dybedal I , Blomhoff HK , Blomhoff R , Smeland EB , Jacobsen SE 
Published: October 2019

Abstract
Previous studies have shown that retinoic acid (RA), similar to tumor necrosis factor-alpha (TNF-alpha), can act as a bifunctional regulator of the growth of bone marrow progenitors, in that it can stimulate granulocyte-macrophage colony-stimulating factor (GM-CSF)- or interleukin-3 (IL-3)-induced GM colony formation, but potently inhibit G-CSF-induced growth. The present study, using highly enriched human CD34+ as well as Lin- murine bone marrow progenitor cells, demonstrates a potent inhibitory effect of 9-cis-RA on burst-forming unit-erythroid (BFU-E) colony formation regardless of the cytokine stimulating growth. Specifically, 9-cis-RA potently inhibited the growth of BFU-E response to erythropoietin (Epo) (100%), stem cell factor (SCF) + Epo (92%), IL- 3 + Epo (97%), IL-4 + Epo (88%), and IL-9 + Epo (100%). Erythroid colony growth was also inhibited when CD34+ progenitors were seeded at one cell per well, suggesting a direct action of RA. Using synthetic ligands to retinoic acid receptors (RARs) and retinoid X receptors (RXRs) that selectively bind and activate RAR-RXR or RXR-RXR dimers, respectively, we dissected the involvement of the two retinoid response pathways in the regulation of normal myeloid and erythroid progenitor cell growth. Transactivation studies showed that both the RAR (Ro 13– 7410) and RXR (Ro 25–6603 and Ro 25–7386) ligands were highly selective at 100 nmol/L. At this concentration, Ro 13–7410 potently inhibited G- CSF-stimulated myeloid as well as SCF + Epo-induced erythroid colony growth. At the same concentration, Ro 25–6603 and Ro 25–7386 had little or no effect on G-CSF-induced colony formation, whereas they inhibited 75% and 53%, respectively, of SCF + Epo-stimulated BFU-E colony growth. Thus, the RAR-RXR response pathway can signal growth inhibition of normal bone marrow myeloid and erythroid progenitor cells. In addition, we demonstrate a unique involvement of the RXR-RXR pathway in mediating growth inhibition of erythroid but not myeloid progenitor cells.
Normal human peripheral blood mononuclear cells mobilized with granulocyte colony-stimulating factor have increased osteoclastogenic potential compared to nonmobilized blood
Authors: Purton LE , Lee MY , Torok-Storb B 
Published: October 2019

Abstract
Single-cell suspensions of granulocyte colony-stimulating factor (G- CSF)-mobilized peripheral blood mononuclear cells (G-PBMC) cultured in alpha minimal essential medium (alphaMEM) containing 10% fetal bovine serum formed multicellular aggregates within 24 hours. In six separate experiments, formation of aggregates appeared to be dependent on cell density per surface area, so that 5.8 +/- 1.3 aggregates formed per 1 x 10(5) cells when G-PBMC were cultured at densities greater than or equal to 1 x 10(5) cells/cm2. The frequency of aggregate formation was less than 1 per 10(5) cells when G-PBMC were cultured at densities less than 1 x 10(5) cells/cm2. Once formed, aggregates became adherent within 72 hours, and then, over the course of 21 days, released CD3/CD4/CD25-positive cells into the supernatant. This T-cell production peaked between days 7 and 14, reaching a total of 1,269 +/- 125.9 cells released per aggregate by day 21. Between days 14 and 21, the aggregates also generated macroscopic clusters of adherent mononuclear and giant multinucleated cells that stained positive for tartrate-resistant acid phosphatase (TRAP). At 4 weeks, the macroscopic foci coalesced into monolayers. Multinucleated TRAP-positive cells were distinguished from macrophage polykaryons by the absence of CD14 expression and the presence of osteoclast-specific membrane receptors for calcitonin and alphavbeta3-vitronectin. The osteoclast nature of these cells was further demonstrated by their ability to form resorption lacunae on dentine slices. Comparable osteoclast formation was not detected in cultures of normal marrow or normal nonmobilized peripheral blood.
The synthesis and localization of alternatively spliced fibronectin EIIIB in resting and thrombin-treated megakaryocytes
Authors: Schick PK , Wojenski CM , Bennett VD , Ivanova T 
Published: October 2019

Abstract
There are several species of alternatively spliced fibronectin (FN). One of these, FN EIIIB, is primarily present in embryonic and in proliferating and migrating cells and is believed to be important for cell maturation. We have studied the synthesis, localization, and secretion of this FN isoform in isolated guinea pig megakaryocytes, nonmegakaryocytic bone marrow cells, and platelets. There was 7.5 times more general FN in megakaryocytes than in nonmegakaryocytic cells based on the analysis of equivalent amounts of protein. FN EIIIB was detected by Western blotting in megakaryocytes but not in nonmegakaryocytic cells present in bone marrow. Neither megakaryocytes nor platelets secreted FN EIIIB, while megakaryocytes secreted 25.3% +/- 4.6% general FN and platelets secreted about 61% general FN in response to thrombin. Analysis of immunostained cells by confocal microscopy revealed that FN EIIIB had been redistributed to the surface of megakaryocytes in response to thrombin. Synthesis was studied by metabolic labeling, and megakaryocytes were shown to synthesize FN and FN EIIIB. Thus, megakaryocytes and platelets are among a small number of adult cells and tissues that synthesize and contain FN EIIIB. The expression of FN EIIIB on the megakaryocyte surface may influence migration and maturation.
Cloning of murine gp91phox cDNA and functional expression in a human X- linked chronic granulomatous disease cell line
Authors: Bjorgvinsdottir H , Zhen L , Dinauer MC 
Published: October 2019

Abstract
The phagocyte cytochrome b558, a heterodimer comprised of gp91phox and p22phox, is a flavocytochrome that mediates the transfer of electrons from NADPH to molecular oxygen in the respiratory burst oxidase. The human gene encoding the glycosylated gp91phox subunit is the site of mutations in X-linked chronic granulomatous disease (CGD). Reverse transcriptase-polymerase chain reaction was used to obtain a full- length clone for the murine gp91phox cDNA, which was 87% identical to the human gp91phox cDNA. The encoded murine protein had 39 amino acids out of 570 that differed from the human, many of which were conservative substitutions. Nonconservative replacements occurred in hydrophilic regions outside of domains previously implicated in binding to NADPH, flavin, and the cytosolic oxidase subunit p47phox. Some substitutions altered potential N-glycosylation sites, which is likely to explain why the glycosylated murine protein migrates with an apparent molecular mass of 58 kD instead of 91 kD as seen for the human protein. Expression of murine gp91phox in a human myeloid cell line with a null gp91phox allele using a mammalian expression plasmid or a retroviral vector rescued stable expression of the p22phox subunit and fully reconstituted respiratory burst activity. This suggests that the murine gp91phox subunit forms a functional cytochrome b558 heterodimer with human oxidase subunits, consistent with the high degree of identity between the mouse and human proteins in domains implicated in cytochrome function.
Nucleic acid composition of bone marrow mononuclear cells in cobalamin deficiency
Authors: Ramsahoye BH , Burnett AK , Taylor C 
Published: October 2019

Abstract
Recent studies using anion exclusion chromatography have suggested that uracil is misincorporated into the DNA of patients with megaloblastic anemia to levels detectable by nonradioactive methods. We have investigated the nucleotide composition of DNA from the bone marrow mononuclear cells of eight patients with cobalamin deficiency and compared this with that found in normal subjects. The median level of uracil in the megaloblastic group was 0.082 mol% of cytosine (approx. 0.02 mol% of all bases in DNA), which was similar to that found in the control group (median 0.085 mol% of cytosine) and may be attributable, at least in part, to artefactual deamination of deoxycytidine monophosphate during the DNA hydrolysis. Our findings give no support for the view that, by overwhelming the uracil N-glycosidase mechanism, the degree of uracil misincorporation in megaloblastic anemia is sufficient to increase the steady state level of uracil in the DNA by amounts detectable by nonradioactive methods. Using high performance liquid chromatography, we have also demonstrated normal levels of methylcytosine in the DNA of megaloblastic subjects.
Sustained, retransplantable, multilineage engraftment of highly purified adult human bone marrow stem cells in vivo
Authors: Civin CI , Almeida-Porada G , Lee MJ , Olweus J , Terstappen LW , Zanjani ED 
Published: October 2019

Abstract
Data from many laboratory and clinical investigations indicate that CD34+ cells comprise approximately 1% of human bone marrow (BM) mononuclear cells, including the progenitor cells of all the lymphohematopoietic lineages and lymphohematopoietic stem cells (stem cells). Because stem cells are an important but rare cell type in the CD34+ cell population, investigators have subdivided the CD34+ cell population to further enrich stem cells. The CD34+/CD38-cell subset comprises less than 10% of human CD34+ adult BM cells (equivalent to < 0.1% of marrow mononuclear cells), lacks lineage (lin) antigens, contains cells with in vitro replating capacity, and is predicted to be highly enriched for stem cells. The present investigation tested whether the CD34+/CD38-subset of adult human marrow generates human hematopoiesis after transfer to preimmune fetal sheep. CD34+/ CD38- cells purified from marrow using immunomagnetic microspheres or fluorescence-activated cell sorting generated easily detectable, long- term, multilineage human hematopoiesis in the human-fetal sheep in vivo model. In contrast, transfer of CD34+/CD38+ cells to preimmune fetal sheep generated only short-term human hematopoiesis, possibly suggesting that the CD34+/CD38+ cell population contains relatively early multipotent hematopoletic progenitor cells, but not stem cells. This work extends the prior in vitro evidence that the earliest cells in fetal and adult human marrow lack CD38 expression. In summary, the CD34+/ CD38-cell population has a high capacity for long-term multilineage hematopoietic engraftment, suggesting the presence of stem cells in this minor adult human marrow cell subset.
CD10/neutral endopeptidase 24.11 is phosphorylated by casein kinase II and coassociates with other phosphoproteins including the lyn src- related kinase
Authors: Ganju RK , Shpektor RG , Brenner DG , Shipp MA 
Published: October 2019

Abstract
CD10/neutral endopeptidase 24.11 (NEP) regulates peptidemediated proliferation of lymphoid progenitors and certain epithelial cells and is itself regulated by cellular proliferation. To further characterize mechanisms by which cell-surface signaling might regulate CD10/NEP expression, we determined whether CD10/NEP was phosphorylated and whether the enzyme co-associated with additional cellular phosphoproteins. The CD10/NEP cytoplasmic tall contains two consensus recognition sequences for casein kinase II (CKII), a serine and threonine kinase that increases in activity following peptide signaling. In standard in vitro kinase assays, CKII phosphorylated full-length recombinant CD10/NEP but did not phosphorylate a truncated CD10/NEP protein that lacked the transmembrane region and cytoplasmic tail. To determine whether CD10/NEP might interact with additional cellular phosphoproteins, in vitro kinase assays were performed on CD10/NEP immune complexes from Nalm-6 cells. Three additional tyrosine phosphoproteins of approximately 40 kD, approximately 58 kD, and approximately 75 kD were identified in the CD10/NEP immunoprecipitates. The approximately 56-kD CD10/NEP-associated phosphoprotein was immunoprecipitated with an anti-lyn antibody confirming its identity as the lyn src-related kinase. Taken together, these data indicate that CD10/NEP is itself phosphorylated by CKII and that CD10/NEP co- associates with additional tyrosine phosphoproteins including lyn.
Transplantation and gene transfer of the human glucocerebrosidase gene into immunoselected primate CD34+Thy-1+ cells
Authors: Donahue RE , Byrne ER , Thomas TE , Kirby MR , Agricola BA , Sellers SE , Gaudernack G , Karisson S , Lansdorp PM 
Published: October 2019

Abstract
In an attempt to improve our gene transfer efficiency into hematopoietic stem cells and to evaluate the capacity of immunoselected CD34+Thy-1+(CDw90) cells to reconstitute hematopoiesis following myeloablation, bone marrow (BM) transplantation was performed using autologous, immunoselected CD34+Thy-1+ cells in rhesus macaques. BM samples were positively selected for cells that express CD34, further subdivided using high gradient immunomagnetic selection for cells that express Thy-1, and transduced using a 7-day supernatant transduction protocol with a replication-defective retroviral vector that contained the human glucocerebrosidase (GC) gene. Circulating leukocytes were evaluated using a semiquantitative polymerase chain reaction (PCR) assay for the human GC gene, with the longest surviving animal evaluated at day 558. Provirus was detected at all time points in both CD20+ B cells and CD2+ dim T cells, but long-term gene transfer was not observed in the granulocyte population. The CD2+ dim population was phenotypically identified as being CD8+ natural killer cells. By day 302 and day 330, both the CD2+ bright and dim cell populations and sorted CD4+ and CD8+ cells had detectable provirus. Vector-derived GC mRNA was detected by reverse transcriptase (RT)-PCR analysis as far out as day 588. Thus, CD34+Thy-1+ cells isolated using high gradient magnetic separation techniques can engraft, be transduced with a replication-defective retroviral vector, and contribute to CD20+ B lymphocytes, CD8+ T lymphocytes, and CD4+ T lymphocytes; making them a suitable cell population to target for gene therapies involving lymphocytes.
Phorbol ester stimulation increases sickle erythrocyte adherence to endothelium: a novel pathway involving alpha 4 beta 1 integrin receptors on sickle reticulocytes and fibronectin
Authors: Kumar A , Eckmam JR , Swerlick RA , Wick TM 
Published: October 2019

Abstract
Sickle-cell adherence to endothelium has been hypothesized to initiate or contribute to microvascular occlusion and pain episodes. Adherence involves plasma proteins, endothelial-cell adhesion molecules, and receptors on sickle erythrocytes. It has previously been reported that sickle reticulocytes express the alpha 4 beta 1 integrin receptor and bind to cytokine-activated endothelium via an alpha 4 beta 1/vascular-cell adhesion molecule-1 (VCAM-1) interaction. To elucidate other roles for alpha 4 beta 1 in sickle-cell adherence, the ability of activated alpha 4 beta 1 to promote adhesion to endothelium via a ligand different than VCAM-1 was explored. Adherence assays were performed under dynamic conditions at a shear stress of 1 dyne/cm2. Preincubation of sickle erythrocytes with phorbol 12,13-dibutyrate (PDBu) increased adherence of sickle cells eightfold as compared with untreated sickle cells. Normal erythrocytes, whether treated with PDBu or not, did not adhere to the endothelium. Activating anti-beta 1 antibodies 4B4 and 8A2 also increased the adhesion of sickle, but not normal, red blood cell (RBC) adhesion to endothelium. Anti-alpha 4 antibodies HP1/2 and HP2/1, inhibitory antibody 4B5, or an RGD peptide inhibited sickle-cell adherence induced by PDBu. Additional studies were undertaken to examine if fibronectin, a ligand for activated alpha 4 beta 1, was involved in PDBu-induced sickle erythrocyte adherence. Adherence of PDBu-treated sickle cells was completely inhibited by the CS-1 peptide of fibronectin. Fibronectin was detected on the surface of washed endothelium using an antifibronectin antibody in enzyme-linked immunosorbent assays. Antifibronectin antibody pretreatment of endothelial cells inhibited PDBu-induced adherence by 79% +/-17%. Incubation of sickle RBCs with exogenous fibronectin after PDBu treatment inhibited adherence 86% +/- 8%. Taken together, these data suggest that endothelial-bound fibronectin mediates adherence of PDBu- treated sickle cells. Interleukin-8 (IL-8), a chemokine released in response to bacterial infection, viral infection, or other injurious agents, and known to activate integrins, also increased adherence of sickle erythrocytes to endothelial cells via fibronectin. This novel adherence pathway involving sickle-cell alpha 4 beta 1 activated by PDBu or IL-8 may therefore be relevant in vivo at vascular sites that produce IL-8 or similar agonists in response to vascular injury or immune activation. These observations describe ways in which inflammation and immune responses cause vasoocclusive complications in sickle-cell disease.
The effect of the Fanconi anemia polypeptide, FAC, upon p53 induction and G2 checkpoint regulation
Authors: Kupfer GM , D'Andrea AD 
Published: October 2019

Abstract
Fanconi anemia (FA) is an autosomal recessive disease marked by developmental defects, bone marrow failure, and cancer susceptibility. FA cells are hypersensitive to DNA cross-linking and alkylating agents and accumulate in the G2 phase of the cell cycle in response to these agents. FA cells also display genomic instability, suggesting a possible defect in the p53 pathway. To test the effect of heterologous expression of FAC cDNA on drug-induced cytotoxicity, G2 accumulation, and p53 induction in FA cells, we compared two isogenic FA cell lines: HSC536N (mock), a FA type C cell line sensitive to mitomycin C (MMC), and the same cell line transfected (corrected) with wild-type FAC cDNA (HSC536N [+FAC]). HSC536N (+FAC) cells showed a 30-fold increase in resistance to MMC concentration. Similarly, increases in resistance were observed following exposure to cisplatin, carboplatin, and cyclophosphamide. In addition, HSC536N (+FAC) cells showed a twofold lower G2 accumulation following MMC treatment. To analyze the possible interaction of FAC with the p53 pathway, we analyzed p53 induction in mock and corrected cell lines following exposure to MMC. HSC536N (mock) cells induced p53 at lower MMC concentrations than HSC536N (corrected). Caffeine, a known G2 checkpoint inhibitor, not only inhibited G2 accumulation seen in both cell lines but also caused the resistant HSC536N (+FAC) to become as sensitive to MMC as HSC536N (mock) cell line. We conclude that the FAC protein has a specific cytoprotective effect and may function as a cell cycle regulator of the G2 phase of the cell cycle.
Interleukin-10 gene expression in adult T-cell leukemia
Authors: Mori N , Gill PS , Mougdil T , Murakami S , Eto S , Prager D 
Published: October 2019

Abstract
We studied the serum levels of interleukin-10 (IL-10), in patients with adult T-cell leukemia (ATL) caused by human T-cell leukemia virus type I (HTLV-I) infection. Elevated IL-10 levels were observed in 33 of 45 patients with ATL. Fresh leukemic cells from ATL patients as well as HTLV-I-infected T-cell lines MT-2, SLB-1, and C10/MJ expressed IL-10 mRNA by reverse transcription-polymerase chain reaction analysis, whereas IL-10 mRNA was not detected in normal peripheral mononuclear cells and an uninfected T-cell line Jurkat. IL-10 protein was also detected in the culture medium of leukemic cells from ATL patients as well as these HTLV-I-infected cell lines, and in the extracellular fluids of ATL patients. Interestingly, MT-4 cells, which did not express Tax although transformed by HTLV-I, did not express IL-10 at either the mRNA or protein level. To elucidate the role of the HTLV-I encoded transactivator Tax in IL-10 gene expression, Jurkat cells were transfected with a Tax expression plasmid. In transiently transfected Jurkat cells, endogenous IL-10 mRNA expression was induced by Tax. Stably transfected Jurkat cell lines expressed IL-10 mRNA and secreted IL-10 protein into the culture medium. The nuclear factor (NF)-kappa B pathway is a target for Tax transactivation. We treated MT-2 cells with phosphorothioate antisense oligonucleotides to the p65 subunit of NF- kappa B. A reduction in the expression of p65 was accompanied by a reduction in IL-10 gene expression and IL-10 production. We showed that the IL-10 kappa B-like sites ( kappa B1,-2,034 to -2,025; kappa B2, - 1,961 to -1,952; kappa B3, -452 to -443) specifically formed a complex with NF-kappa B-containing nuclear extract from MT-2 cells and that NF- kappa B bound with the highest affinity to the kappa B2 element (kappa B2 > kappa B3 > kappa B1). These data suggest a general role for NF- kappa B activation in the induction of IL-10 gene transcription. Activation of IL-10 in HTLV-I-infected cells may contribute to the pathology associated with HTLV-I infection.
TEL-AML1 translocations with TEL and CDKN2 inactivation in acute lymphoblastic leukemia cell lines
Authors: Kim DH , Moldwin RL , Vignon C , Bohlander SK , Suto Y , Giordano L , Gupta R , Fears S , Nucifora G , Rowley JD 
Published: October 2019

Abstract
The t(12;21) (p 13; q22) results in the fusion of the TEL gene located on chromosome 12 with the AML1 gene located on the derivative chromosome 21. Because this translocation is difficult to detect using standard cytogenetic techniques, 27 previously karyotyped B-lineage acute lymphoblastic leukemia (ALL) cell lines were evaluated for the presence of the TEL-AML1 fusion using the reverse transcriptase- polymerase chain reaction (RT-PCR), fluorescence in situ hybridization (FISH), and cDNA sequencing. Six cell lines expressed the TEL-AML1 chimeric transcript by RT-PCR and the t(12;21) was confirmed by FISH analysis with probes for TEL, AML1, and chromosome 12. While only one of the 6 cell lines with the t(12;21) lost the der(12)t(12;21)-encoded AML1-TEL fusion transcript, 4 cell lines lacked expression of the nontranslocated allele of TEL and 5 cell lines lacked expression of CDKN2. Moreover, in 2 patients (1 with the TEL-AML1 transcript and 1 without), TEL expression was lost with disease progression; le, TEL was expressed in the initial cell lines (established at diagnosis or first relapse) whereas TEL was not expressed in the cell lines established from these patients in late-stage disease. These data show the coexistence of multiple genetic defects in childhood B-lineage ALL Cell lines with t(12;21) will facilitate the study of TEL-AML1 and AML1-TEL fusion proteins as well as TEL and CDKN2 gene inactivation in leukemia transformation and progression.