bluuebunny/crossref_metadata_2025_split huggingface dataset:
Foxo3 Modulation of ATM and Oxidative Stress Mediates Distinct Functions in the Regulation of Hematopoietic Stem and Progenitor Cell Fate.
Authors: Yalcin Safak , Luciano Julia P. , Zhang Xin , Vercherat Cecile , Taneja Reshma , Ghaffari Saghi 
Published: October 2019

Abstract
FOXO transcription factors are required for hematopoietic stem cell self renewal. In this study, we demonstrate that Foxo3 plays a specific and essential function in the regulation of both hematopoietic stem and progenitor cell fate. Foxo3 null mice display a myeloproliferative syndrome characterized by splenomegaly, a major expansion of the myeloid compartment in the blood, bone marrow and spleen, cytokine hypersensitivity of progenitors in hematopoietic organs and associated with the repression of the B lymphoid compartment. In addition, loss of Foxo3 leads to significant defects in hematopoietic stem cell numbers and activity. In particular, the numbers of long-term culture initiating cells (LTC-IC) was significantly reduced and the ability to repopulate lethally irradiated mice was severely compromised in Foxo3-defcient mice. This effect was mediated at least partially by enhanced accumulation of reactive oxygen species (ROS) in Foxo3-deficient hematopoietic stem cells as demonstrated
by reduced QRT-PCR expression of several anti-oxidant enzymes leading to accumulation of ROS, (as measured by chloromethyl,dichlorodihydrofluorescein diacetate assay) in Foxo3 null hematopoietic stem cells, and in vitro and in vivo rescue of the phenotype using ROS scavengers.
Furthermore, we demonstrate that while ROS accumulation results in suppression of Foxo3 null hematopoietic stem cell compartment, it enhances the activity of multipotential cells. By measuring RNA versus DNA content, and BrdU uptake, we determined that Foxo3-deficient hematopoietic stem cells exit quiescence (G0) and are impaired in their cycling at the G2/M phase. In particular, we identified ROS activation of p19ARF/p53 pathway and ROS-independent modulation of ataxia telangiectasia mutated (ATM) gene and p16INK4a, as major contributors to the interference with Foxo3-deficient hematopoietic stem cell self renewal and cycling. Loss of ATM has been shown to lead to hematopoietic stem cell deficiency. Importantly, we show that ATM gene expression is significantly suppressed in Foxo3-deficient hematopoietic stem cells suggesting that ATM lies downstream of Foxo3. Retroviral expression of a constitutively active form of Foxo3 in Foxo3-deficient bone marrow mononuclear cells enhances significantly the ATM expression suggesting that Foxo3 regulate expression of ATM gene. These combined findings suggest that Foxo3 functions in a tumor suppressor network to protect hematopoietic stem cells against deleterious effects of oxidative damage, to maintain hematopoietic lineage fate determination and to restrict the activity of long term repopulating hematopoietic stem cells. These findings provide insights into the mechanisms underlying hematopoietic stem cell fate.
Association of γ’ Fibrinogen with Risk Factors and Prevalent Cardiovascular Disease in the Framingham Heart Study.
Authors: Lovely Rehana S. , Massaro Joseph F. , D’Agostino Ralph B. , Benjamin Emelia J. , Kazmierczak Steven C. , O’Donnell Christopher J. , Farrell David H. 
Published: October 2019

Abstract
Background: γ’ fibrinogen is a newly-emerging cardiovascular disease (CVD) biomarker that has shown significant associations with coronary artery disease in small case/control studies. γ’ fibrinogen is an isoform with an altered γ chain, and constitutes ∼10% of total fibrinogen. Both elevated γ’ and total fibrinogen cause fibrinolytic resistance in vitro. However, data are lacking from community based studies on the association of γ’ fibrinogen with CVD risk factors or with clinical CVD.
Methods: γ’ fibrinogen levels were measured using an ELISA assay in 3284 men and women in the Framingham Heart Study Offspring Cohort 7th examination cycle (2002–05). Associations of γ’ fibrinogen were examined using linear regression for continuous CVD risk factors and logistic regression for prevalent CVD and other dichotomous measures.
Results: The ELISA CV was 9.3% at mean γ’ fibrinogen levels. Participants (mean age 60 years, 53.4% women) with prevalent CVD (0.297 ± 0.007 mg/ml; mean ± SE) had significantly higher mean concentrations than those without CVD (0.255 ± 0.002 mg/ml). There were significant (all p<0.05) associations between γ’ fibrinogen levels with several cardiovascular risk factors, including age, BMI, systolic blood pressure, diabetes mellitus, cigarette smoking, and total cholesterol, and an inverse association with HDL cholesterol. γ’ fibrinogen was associated with prevalent CVD with an odds ratio of 1.76 (95% CI 1.06–2.92) for the highest compared to the lowest tertile, after adjustment for all of the above risk factors. As expected, since γ’ fibrinogen constitutes a subset of total fibrinogen, γ’ fibrinogen was correlated with total fibrinogen. However, if we included both γ’ and total fibrinogen in further analyses of association with CVD, the odds ratio was 3.08 (95% CI 1.41–6.72) for the combined tertile of both the highest γ’ fibrinogen and highest total fibrinogen, an odds ratio that was substantially higher than that for either marker alone.
Conclusions: γ’ fibrinogen is associated with multiple CVD risk factors and with prevalent CVD, accounting for CVD risk factors, over and above total fibrinogen alone. Prospective studies are warranted to examine the ability of γ’ fibrinogen to predict CVD.
Interleukin-7 Produced by Antigen Presenting Cells Regulates the Homeostatic Peripheral Expansion of Naive CD4 T Cells.
Authors: Guimond Martin , Veenstra Rachelle G. , Grindler David J. , Cui Yongzi , Na Risu , Hennighausen Lothar , Zhang Hua , Merchant Melinda S. , Mackall Crystal 
Published: October 2019

Abstract
Interleukin-7 (IL-7) is the only cytokine demonstrated thus far to directly support the development and maintenance of naive T cells. Interleukin-7 is produced mainly by the stroma of lymphoid organs but also to a lesser extent by antigen presenting cells. Dynamic changes in the relative availability of IL-7 during lymphopenia support T cell homeostatic peripheral expansion (HPE). Whereas HPE is very efficient at reconstituting the pool of mature CD8 T lymphocytes, regeneration of CD4 T lymphocytes via HPE is more problematic and deficits in CD4 T lymphocytes persist for years in humans following lymphodepletion. We demonstrate that in mice, CD4+ T cells undergo substantially diminished HPE compared to CD8+ T cells during lymphopenia. We hypothesized that CD4+ T cells uniquely require both MHC Class II plus IL-7 for survival and expansion during lymphopenia and that the availability of these signals are limited by the availability of IL-7 producing APCs. Consistent with this hypothesis, studies performed in chimeric mice showed that cells derived from APCs, but not stromal cells, provided the endogenous IL-7 that is require for naive CD4+ T cell HPE. Furthermore, whereas systemic exposure to high levels of rhIL-7 did not induce efficient homeostatic peripheral expansion of CD4+ cells, in vivo modulation of Class II expressing cells by flt3 ligand promoted homeostatic expansion of CD4+ T cells. Surprisingly however, we found that APCs respond to elevated systemic IL-7 by diminishing production of IL-7, a loop mediated by IL-7Rα and Stat5. As a result, elevated systemic IL-7 levels present during lymphopenia paradoxically diminish the production of IL-7 by APCs and thereby diminish CD4 HPE. This was directly demonstrated by experiments wherein CD4+ HPE was dramatically augmented in chimeric mice generated such that bone marrow derived cells lacked IL7Rα or Stat5. This work demonstrates a critical role for APC derived IL-7 in CD4+ regeneration and provides a new paradigm for understanding why prolonged CD4+ lymphopenia occurs following T cell depletion in humans.
B Cell Lineage-Specific Deletion of Icsbp/IRF8 Reveals Roles for IRF8 in the Regulation of Marginal Zone and Follicular B Cell Development.
Authors: Wang Hongsheng , Feng Jianxun , Lee Chang Hoon , Morse Herbert 
Published: October 2019

Abstract
Interferon regulatory factor 8 (IRF8), also known as interferon consensus sequence-binding protein (ICSBP), is a transcription factor that expresses in T cells, B cells and macrophages and plays a role in myeloid development. Targeted deletion of IRF8 in mice (IRF8−/−) induced progressive increase in the numbers of granulocytes in various lymphoid organs and development of a syndrome similar to human chronic myelogenous leukemia. In addition to defective development of macrophages and dendritic cells, B cell development was also impaired in IRF8−/− mice. This includes decreased numbers of early B cells, expanded marginal zone (MZ) B cells and diminished follicular (OF) B2 cells. Because abnormal myeloid cells could alter microenvironment required for normal B cell development, we have generated IRF8 conditional knockout mice to specifically investigate the function of IRF8 in B lineage cells. Mice were engineered to have exon 2, encoding the DNA binding domain of IRF8, flanked by loxP sites (designated IRF8f/+). These mice were then crossed with the CD19Cre strain in which the expression of Cre-recombinase is controlled by the endogenous CD19 locus. Homozygous mice (designated (IRF8f/f x Cre)F1) underwent germline excision of IRF8 in CD19+ B lineage cells. As a result, there was no detectable mRNA and protein of IRF8 in their splenic B cells. Flow cytometry analysis revealed expanded MZ B cells and reduced OF B2 cells in the spleen of (IRF8f/f x Cre)F1 mice. Interestingly, the expression level of CD23 on OF B cells was significantly decreased in (IRF8f/f x Cre)F1 mice, indicating that IRF8 is required for maintaining a normal OF phenotype. In the peritoneum of (IRF8f/f x Cre)F1 mice, while the numbers of B1a and B2 cells were slightly decreased, the number of B1b cells was slightly increased. Furthermore, BXH2 mice carrying a mutation (C915T) in the Icsbp1 gene exhibited similar expansion of MZ B cells and low expression of CD23 in OF B cells. Taken together, these analyses indicate that IRF8 is required for development of normal MZ and B2 cells.
Transcriptional Regulation of NGAL by the Pro-Inflammatory Cytokines IL-17 and TNFα.
Authors: Karlsen Joachim R. , Borregaard Niels , Cowland Jack B. 
Published: October 2019

Abstract
IL-17 is a proinflammatory cytokine synthesized by a newly discovered subset of helper T-cells called TH17. In our search for targets that are regulated by IL-17, we have found that the gene for the bacteriostatic protein neutrophil gelatinase associated lipocalin (NGAL) is strongly induced in epithelial cells by this cytokine. NGAL is a siderophore-binding protein that binds bacterial catecholate-type ferric siderophores and exerts a bacteriostatic effect under iron limiting conditions. It has been observed that NGAL synthesis is induced in inflamed epithelium of the lungs and colon. Using the type II pneumocyt-derived cell line A549 as a model, we found that NGAL was up-regulated 27-fold at RNA level, and 14-fold at protein level, when co-stimulated for 24 hours with IL-17 (200ng/ml) and TNFα (20ng/ml), whereas no induction was seen with either cytokine alone compared to unstimulated cells. The expression of NGAL in A549 cells, when stimulated with IL-17 and TNFα, was dependent on de novo protein synthesis as demonstrated by inhibition of NGAL mRNA production by cycloheximide. Deletion and substitution analysis of the NGAL promoter and subsequent stimulation of transfected cells with IL-17 and TNFα showed that a functional NF-κB-binding site was essential for promoter activation whereas AP-1 and C/EBP-sites were dispensable. Quantitative RT-PCR showed a 13-fold induction of IkB-ζ mRNA in A549 cells when stimulated with IL-17 and TNFα with peak level at 1½ hours and a slow decline for up to 24 hours. Cells stimulated with IL-17 alone resulted in 8-fold mRNA induction at 1½ hours followed by a decline to a 3-fold induction level of mRNA, which lasted for 24 hours. In contrast, cells stimulated with TNFα showed a 9-fold mRNA induction at 1½ hours but then rapidly returned to back-ground level at 3 hours post-induction. These data, and previous studies of the NGAL promoter (Cowland et al. (2006), 176, 5559), demonstrates that the NGAL promoter requires binding of the transcription factor NF-κB as well as the NF-κB-binding co-factor IkB-ζ for transcriptional activation. Our data indicate that TNFα stimulates transcription of the IkB-ζ gene and NF-κB binding to the NGAL promoter whereas IL-17 stabilizes IkB-ζ mRNA and thus enables translation of this co-factor. Only when acting together the two cytokines induce the formation of an NF-κB:IκB-ζ-complex that can stimulate NGAL transcription. We have found that human b-defensin 2 (hBD2) is regulated in the same manner. The functions of NGAL and hBD2 in the innate immune response are well characterized, and the present data demonstrates that IL-17, which is synthesized only by the newly discovered TH-17 cell population, is involved in transcriptional regulation of these effector molecules. The data furthermore demonstrate that cells of the adaptive immune system is able to activate genes of the innate immune system.
Critical Role for CD81 in B Cell Activation.
Authors: Sanyal Mrinmoy , Fernandez Rosemary , Levy Shoshana 
Published: October 2019

Abstract
CD81 is a component of the CD19/CD21 signaling complex in B cells. CD81 was originally discovered as target of an anti-proliferative antibody in a human B cell lymphoma. However, the exact role of CD81 in B cell function is not known. Here we studied B cells from CD81 knockout mice. We demonstrate that upon BCR induction these B cells
flux higher intracellular free calcium ion; increase the phosphorylation of BCR-related proximal and distal substrates and increase their proliferation. Similarly, polyclonal activation of CD81-deficient B cells with LPS induced increased proliferation and antibody secretion.
Consistent with these intrinsic B cell capabilities, CD81-deficient mice mounted significantly higher immune response upon antigenic stimulation. In addition, bone marrow perisinusoidal B cells (IgM+IgD+) capable of mounting T-independent immune responses against blood-borne pathogens were over represented in CD81-deficient mice. These cells also displayed increased calcium influx kinetics as splenic B cells and produced higher amounts of antibody after polyclonal stimulation. Taken together, these results suggest that CD81 is involved in suppressing B cell activation.
Treatment of Primary CNS Lymphoma with Induction High-Dose Methotrexate, Temozolomide, Rituximab Followed by Consolidation Cytarabine/Etoposide: A Pilot Study with Biomarker Analysis.
Authors: Issa Samar , Shen Arthur , Karch Jon , Kadoch Cigall , Shuman Marc , Damon Lloyd , Rubenstein James 
Published: October 2019

Abstract
Background: There is no consensus on the optimal treatment for patients diagnosed with primary CNS lymphoma (PCNSL). The goals of this study were:
to determine the safety and efficacy of a methotrexate (MTX)-based induction therapy followed by high-dose consolidation chemotherapy and the elimination or deferral of whole brain irradiation, to identify molecular markers in PCNSL which predict sensitivity to chemotherapy and outcome.
Methods: 23 newly diagnosed, CD20-positive, immunocompetent PCNSL patients were treated with combination high-dose intravenous MTX (8 gm/m2), temozolomide (150 mg/m2/day) and intravenous rituximab (375 mg/m2) (MTR). Patients in complete remission (CR) after eight courses of MTX were offered consolidation with high-dose cytarabine (2 g/m2 x 8 doses) and etoposide (40 mg/kg over 96 hours) (AE). Candidate markers of outcome in PCNSL were identified by gene expression profile analysis of an independent, multicenter dataset of PCNSL tumors. Immunohistochemical analysis of one of these markers, death-associated protein-1 (DAP-1), was performed on paraffin sections of tumors from 18 of the patients treated with the MTR regimen.
Results: MTR induction followed by AE consolidation was well tolerated with no treatment-related mortality or evidence for neurotoxicity. Thirteen patients (56.5%) attained CR with induction; 8 received consolidation; 5 in CR refused AE. Median progression-free (PFS) and overall survival (OS) has not yet been reached with a median follow-up of 33 months. Karnovsky performance status (KPS) correlated with improved survival (p<0.0281). Expression by lymphoma cells of DAP-1, a regulator of apoptosis, was associated with improved progression-free survival (p<0.03) and overall survival (p<0.038).
Conclusions: Combination MTR followed by AE is well tolerated in PCNSL. PFS appears at least similar to regimens that contain whole brain irradiation. A multi-center study has been initiated to further evaluate this regimen. DAP-1 may be a tumor suppressor whose expression in PCNSL predicts a favorable response to MTX-based therapy.
A Phase 1/2a Study Evaluating the Safety, Pharmacokinetics, and Efficacy of ABT-263 in Subjects with Refractory or Relapsed Lymphoid Malignancies.
Authors: Wilson Wyndham H. , Tulpule Anil , Levine Alexandra M. , Dunleavy Kieron , Krivoshik Andrew P. , Hagey Anne E. , Shovlin Margaret , Gloria Melanie A. , Greco Renee , Xiong Hao , Chiu Yi-Lin , Elmore Steven W. , O’Connor Owen A. 
Published: October 2019

Abstract
Background: ABT-263 is a novel small molecule Bcl-2 family protein inhibitor that binds with high affinity (Ki ≤ 1 nM) to multiple antiapoptotic Bcl-2 family proteins including Bcl-XL, Bcl-2, Bcl-w, and Bcl-B. ABT-263 displays potent mechanism-based cytotoxicity (EC50 ≤ 1 mM) against human tumor cell lines derived from lymphoid malignancies and small cell lung cancer (SCLC). Pre-clinical experiments on primary patient derived chronic lymphocytic leukemia (CLL) samples with ABT-737, a first generation Bcl-2 family protein inhibitor, induced robust, concentration-dependent apoptosis. The anticipated ABT-263 associated toxicities are mechanism based, in particular, Bcl-XL mediated decrease in circulating platelet survival, Bcl-w mediated testicular toxicity, and Bcl-2 mediated effects on lymphocytes. ABT-263 is currently being investigated in 3 Phase 1/2a studies in patients with lymphoid malignancies, SCLC/solid tumors, and CLL.
Methods: In this Phase 1/2a study of ABT-263 in subjects with lymphoid malignancies, the Phase 1 dose escalation portion of the study was designed to determine the maximum tolerated dose (MTD), dose limiting toxicity (DLT), and recommended Phase 2 dose (RPTD). For each 21-day cycle, subjects receive ABT-263 orally QD for 14 consecutive days followed by 7 days off drug. Pharmacokinetic (PK) assessment was performed at study initiation and on Day 14 of drug dosing. The Phase 2a portion of the study will evaluate ABT-263 at the RPTD in up to 40 subjects with follicular and aggressive NHL to obtain additional safety information and a preliminary assessment of efficacy.
Results: Currently 17 subjects have been enrolled in the lymphoma study. Three subjects completed each of the 10, 20, 40, and 80 mg cohorts enrolled thus far. A Grade 3 DLT (URI resulting in hospitalization treated with antibiotics) occurred in the 160 mg cohort, thus the cohort was expanded to 6. Two patients with bulky SLL/CLL in the 40 and 160 mg cohorts had 95% and 64% tumor reductions after cycles 4 and 2, respectively, and continue on treatment. The PK profile of ABT-263 appeared to be linear between the 10 mg and 160 mg dose levels. The average terminal half-life of ABT-263 varied between 14 and 25 hours across all dose levels. ABT-263 reduced the platelet level in a dose-dependent manner. One subject experienced a Grade 3 thrombocytopenia (platelets 45K/uL) on C1D14, 4 hours post-dosing with 80 mg, resolving 8 hours post-dosing to a platelet count of 162 K/uL. The decreased platelet count did not result in any medical sequelae.
Conclusions: ABT-263 is a novel, orally bioavailable and active small molecule Bcl-2 family protein inhibitor that has shown preliminary evidence of activity in lymphoid malignancies.
Biomarkers of Vorinostat Resistance in Cutaneous T-Cell Lymphoma.
Authors: Zhang Chunlei , Li Baoqiang , Talpur Rakhshandra , Yin C. Cameron , Duvic Madeleine 
Published: October 2019

Abstract
Profiling gene expression with DNA microarray technology has elucidated novel therapeutic targets and led the approval of a number of targeted therapeutic agents for the treatment of cancer. Vorinostat (suberoylanilide hydroxamic acid, SAHA) is a pan-histone deacetylase (HDAC) inhibitor that has demonstrated an overall response rate of approximately 24–30% in two phase II studies of cutaneous T cell lymphoma (CTCL) patients. There are currently no known specific biomarkers to indicate resistance to vorinostat. To identify genes resistant to vorinostat we compared profiles using the Aligent whole human genome oligo microarrays containing ∼41,000 genes/transcripts in vitro in vorinostat-resistant MJ and -sensitive HH CTCL cell lines treated with 1 μM of vorinostat for 24 hours and compared them to patients’ peripheral blood mononuclear cells (PBMCs) before and during oral therapy. There were 3151 (7.7%) genes/transcripts differentially expressed in vitro in treated resistant MJ cells compared to untreated vehicle control (p < 0.001). We also studied differential gene expression in two clinically resistant Sézary patients’ PBMCs taken at baseline and four weeks after oral vorinostat (400 mg daily or 300 mg bid 3 days/wk). In patients’ PBMCs, 585 (1.4%) and 2744 (6.7%) differentially expressed genes/transcripts (p < 0.001) were identified, respectively. Genes that were up-regulated both in vitro and in vivo included a tumor necrosis factor receptor super-family member 11a (TNFRSF11a or RANK), matrix metallopeptidase 9 (MMP9), suppressor of cytokine signaling 3 (SOCS3), vinculin (VCL) and KIAA1840. Genes that were down-regulated in both included adenylate kinase 3-like 1 (AK3L1), leucine rich repeat and fibronectin type III domain containing 4 (LRFN4), and AL359650. Increased RANK, MMP9 and SOCS3 mRNA expression in MJ compared to HH cells and in three resistant versus three vorinostat responding Sézary patients’ PBMCs was confirmed using quantitative real-time PCR. In conclusion, our results suggest that oligonucleotide microarray analysis may identify biomarkers of resistance to vorinostat which would be helpful to select patients who may not benefit from treatment. These findings provide the rationale for future functional studies and development of more effective use of HDAC inhibitors for CTCL patients.