39 research outputs found
Interactions of the CCAAT-binding trimer NF-Y with nucleosomes
NF-Y is a sequence-specific evolutionary conserved activator binding to CCAAT boxes with high affinity and specificity. It is a trimer formed by NF-YA and two putative histone-like subunits, NF-YB and NF-YC, showing similarity to histones H2B and H2A, respectively. We investigated the relationships between NF-Y and chromatin using an Artemia franciscana chromatin assembly system with plasmids containing the Major HistoCompatibility complex class II Ea promoter. The NF-Y trimer, but not single subunits, protects the Y box in the presence of reconstituted chromatin, and it can bind the target sequence during and after assembly. Using reconstitution assays with purified chicken histones, we show that NF-Y associates with preformed nucleosomes. Translational analysis of various Ea fragments of identical length in which the CCAAT box is at different positions indicated that the lateral fragment was slightly more prone to NF-Y binding. In competition experiments, NF-Y is able to prevent formation of nucleosomes significantly. These data support the idea that NF-Y is a gene-specific activator with a built-in capacity to interface with chromatin structures
Significant CD4, CD8, and CD19 Lymphopenia in Peripheral Blood of Sarcoidosis Patients Correlates with Severe Disease Manifestations
BACKGROUND: Sarcoidosis is a poorly understood chronic inflammatory condition. Infiltration of affected organs by lymphocytes is characteristic of sarcoidosis, however previous reports suggest that circulating lymphocyte counts are low in some patients with the disease. The goal of this study was to evaluate lymphocyte subsets in peripheral blood in a cohort of sarcoidosis patients to determine the prevalence, severity, and clinical features associated with lymphopenia in major lymphocyte subsets. METHODOLOGY/PRINCIPAL FINDINGS: Lymphocyte subsets in 28 sarcoid patients were analyzed using flow cytometry to determine the percentage of CD4, CD8, and CD19 positive cells. Greater than 50% of patients had abnormally low CD4, CD8, or CD19 counts (p<4x10(-10)). Lymphopenia was profound in some cases, and five of the patients had absolute CD4 counts below 200. CD4, CD8, and CD19 lymphocyte subset counts were significantly correlated (Spearman's rho 0.57, p = 0.0017), and 10 patients had low counts in all three subsets. Patients with severe organ system involvement including neurologic, cardiac, ocular, and advanced pulmonary disease had lower lymphocyte subset counts as a group than those patients with less severe manifestations (CD4 p = 0.0043, CD8 p = 0.026, CD19 p = 0.033). No significant relationships were observed between various medical therapies and lymphocyte counts, and lymphopenia was present in patients who were not receiving any medical therapy. CONCLUSIONS/SIGNIFICANCE: Significant lymphopenia involving CD4, CD8, and CD19 positive cells was common in sarcoidosis patients and correlated with disease severity. Our findings suggest that lymphopenia relates more to disease pathology than medical treatment
Oligodendrogenesis in iron-deficient rats: Effect of apotransferrin
In rats, iron deficiency produces an alteration in myelinformation. However, there is limited information on theeffects of this condition on oligodendroglial cell (OLGc)proliferation and maturation. In the present study, wefurther analyzed the hypomyelination associated withiron deficiency by studying the dynamics of oligodendrogenesis.Rats were fed control (40 mg Fe/kg) oriron-deficient (4 mg Fe/kg) diets from gestation day 5until postnatal day 3 (P3) or 11 (P11). OLGc proliferation,migration and differentiation were investigatedbefore and after an intracranial injection of apotransferrinat 3 days of age (P3). The proliferating cell populationwas evaluated at P3. Iron-deficient (ID) animalsshowed an increase in the oligodendrocyte precursorscell (OPC) population in comparison with controls. Theoverall pattern of migration of cells labeled with BrdUwas investigated at P11. Iron deficiency increased theamount of BrdU1 cells in the corpus callosum (CC) anddecreased OLGc maturation and myelin formation.Changes in nerve conduction were analyzed by measuringvisual evoked potentials. Latency and amplitudewere significantly disturbed in ID rats compared withcontrols. Both parameters were substantially normalizedwhen animals were treated with a single intracranialinjection of 350 ng apotransferrin (aTf). The currentresults give support to the idea that iron deficiencyincreases the number of proliferating and undifferentiatedcells in the CC compared with the control. Treatmentwith aTf almost completely reverted the effects ofiron deficiency, both changing the migration patternand increasing the number of mature cells in the CCand myelin formation.Fil: Rosato Siri, MarĂa Victoria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de BiologĂa Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de BiologĂa Celular y Neurociencia; ArgentinaFil: Badaracco, M. E.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; ArgentinaFil: Ortiz, E. H.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; ArgentinaFil: Belforte, Nicolás Adalberto. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Centro de Estudios FarmacolĂłgicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios FarmacolĂłgicos y Botánicos; ArgentinaFil: Guardia Clausi, Mariano. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; ArgentinaFil: Soto, Eduardo Francisco. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; ArgentinaFil: Bernabeu, Ramon Oscar. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de BiologĂa Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de BiologĂa Celular y Neurociencia; ArgentinaFil: Pasquini, Juana Maria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; Argentin
Design and implementation of a seismic Newtonian-noise cancellation system for the Virgo gravitational-wave detector
Terrestrial gravity perturbations caused by seismic fields produce the
so-called Newtonian noise in gravitational-wave detectors, which is predicted
to limit their sensitivity in the upcoming observing runs. In the past, this
noise was seen as an infrastructural limitation, i.e., something that cannot be
overcome without major investments to improve a detector's infrastructure.
However, it is possible to have at least an indirect estimate of this noise by
using the data from a large number of seismometers deployed around a detector's
suspended test masses. The noise estimate can be subtracted from the
gravitational-wave data; a process called Newtonian-noise cancellation (NNC).
In this article, we present the design and implementation of the first NNC
system at the Virgo detector as part of its AdV+ upgrade. It uses data from 110
vertical geophones deployed inside the Virgo buildings in optimized array
configurations. We use a separate tiltmeter channel to test the pipeline in a
proof-of-principle. The system has been running with good performance over
months
IgA Anti-β2-Glycoprotein I Autoantibodies Are Associated with an Increased Risk of Thromboembolic Events in Patients with Systemic Lupus Erythematosus
The clinical utility of testing for antiphospholipid antibodies (aPL) of IgA isotype remains controversial.To address this issue, we reasoned that if IgA aPL contribute to the clinical manifestations of the antiphospholipid syndrome, then an association with thromboembolic events should manifest in patients whose only aPL is of IgA isotype. We performed a retrospective chart review of 56 patients (31 with systemic lupus erythematosus [SLE] and 25 without SLE) whose only positive aPL was IgA anti-beta2-glycoprotein I (isolated IgA anti-beta2GPI) and compared their clinical features with 56 individually matched control patients without any aPL. Patients with isolated IgA anti-beta2GPI had a significantly increased number of thromboembolic events, as compared to controls. When patients were stratified into those with and without SLE, the association between isolated IgA anti-beta2GPI and thromboembolic events persisted for patients with SLE, but was lost for those without SLE. Titers of IgA anti-beta2GPI were significantly higher in SLE patients who suffered a thromboembolic event. Among patients with isolated IgA anti-beta2GPI, there was an increased prevalence of diseases or morbidities involving organs of mucosal immunity (i.e., gastrointestinal system, pulmonary system, and skin).The presence of isolated IgA anti-beta2GPI is associated with an increased risk of thromboembolic events, especially among patients with SLE. IgA anti-beta2GPI is associated with an increased prevalence of morbidities involving organs of mucosal immunity
Lunar Gravitational-Wave Antenna
Monitoring of vibrational eigenmodes of an elastic body excited by
gravitational waves was one of the first concepts proposed for the detection of
gravitational waves. At laboratory scale, these experiments became known as
resonant-bar detectors first developed by Joseph Weber in the 1960s. Due to the
dimensions of these bars, the targeted signal frequencies were in the kHz
range. Weber also pointed out that monitoring of vibrations of Earth or Moon
could reveal gravitational waves in the mHz band. His Lunar Surface Gravimeter
experiment deployed on the Moon by the Apollo 17 crew had a technical failure
rendering the data useless. In this article, we revisit the idea and propose a
Lunar Gravitational-Wave Antenna (LGWA). We find that LGWA could become an
important partner observatory for joint observations with the space-borne,
laser-interferometric detector LISA, and at the same time contribute an
independent science case due to LGWA's unique features. Technical challenges
need to be overcome for the deployment of the experiment, and development of
inertial vibration sensor technology lays out a future path for this exciting
detector concept.Comment: 29 pages, 17 figure
Glatiramer promotes oligodendroglial cell maturation in a cuprizone-induced demyelination model
The therapeutic potential of glatiramer acetate (GA) in Multiple Sclerosis has been apparent for many years and has been proven effective in experimental allergic encephalomyelitis, one of its animal models. The cuprizone (CPZ) model for the CNS de/remyelination has gained a renewed interest during the past decade. CPZ-induced demyelination is considered to be primarily an oligodendrocyte loss with participation of the inflammatory response. As the blood brain barrier remains intact, we found this model advantageous for studying GA effects on CNS remyelination with minimum influence of the peripheral immune cellular component. Our results show that GA, given one week before the CPZ treatment, had a maturational effect functional to remyelination. However, myelin was unorganized as compared to controls. When GA was concomitantly injected with CPZ, oligodendroglial precursor proliferation diminished in favor of maturation and myelin recovered an organized disposition. GA-treated animals also show microglial cell (MG) activation. In vitro assays demonstrated that GA-primed MG cultures had a significant increase in IL-10 and IL-4 secretion. GA-challenged MG-conditioned media induced oligodendrocyte proliferation and subsequent differentiation. Our results suggest that, in addition to its well-recognized immunoregulatory properties, GA also has an effect on resident immuno-response, which leads mature oligodendrocytes towards CPZ-induced demyelination repair.Fil: Rosato Siri, MarĂa Victoria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FisicoquĂmica BiolĂłgicas; ArgentinaFil: Badaracco, M. E.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FisicoquĂmica BiolĂłgicas; ArgentinaFil: Pasquini, Juana Maria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FisicoquĂmica BiolĂłgicas; Argentin
Iron Availability Compromises Not Only Oligodendrocytes But Also Astrocytes and Microglial Cells
When disrupted, iron homeostasis negatively impacts oligodendrocyte (OLG) differentiation and impairs myelination. To better understand myelin formation and OLG maturation, in vivo and in vitro studies were conducted to evaluate the effect of iron deficiency (ID) not only on OLG maturation but also on astrocytes (AST) and microglial cells (MG). In vivo experiments in an ID model were carried out to describe maturational events during OLG and AST development and the reactive profile of MG during myelination when iron availability is lower than normal. In turn, in vitro assays were conducted to explore proliferating and maturational states of each glial cell type derived from control or ID conditions. Studies targeted NG2, PDGFRα, CNPAse, CC1, and MBP expression in OLG, GFAP and S100 expression in AST, and CD11b, ED1, and cytokine expression in MG, as well as BrDU incorporation in the three cell types. Our results show that ID affected OLG development at early stages, not only reducing their maturation capacity but also increasing their proliferation and affecting their morphological complexity. AST ID proliferated more than control ones and were more immature, much like OLG. Cytokine expression in ID animals reflected an anti-inflammatory state which probably influenced OLG maturation. These results show that ID conditions alter all glial cells and may impact myelin formation, which could be regulated by a mechanism involving a cross talk between AST, MG, and oligodendrocyte progenitors (OPC).Fil: Rosato Siri, MarĂa Victoria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; ArgentinaFil: Marziali, Leandro Nazareno. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; ArgentinaFil: Guitart, MarĂa Eugenia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; ArgentinaFil: Badaracco, MarĂa Elvira. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; ArgentinaFil: Puntel, Mariana. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones BioquĂmicas de Buenos Aires. FundaciĂłn Instituto Leloir. Instituto de Investigaciones BioquĂmicas de Buenos Aires; ArgentinaFil: Pitossi, Fernando Juan. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones BioquĂmicas de Buenos Aires. FundaciĂłn Instituto Leloir. Instituto de Investigaciones BioquĂmicas de Buenos Aires; ArgentinaFil: Correale, Jorge. FundaciĂłn para la Lucha contra las Enfermedades NeurolĂłgicas de la Infancia; ArgentinaFil: Pasquini, Juana Maria. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Houssay. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas "Prof. Alejandro C. Paladini". Universidad de Buenos Aires. Facultad de Farmacia y BioquĂmica. Instituto de QuĂmica y FĂsico-QuĂmica BiolĂłgicas; Argentin