35 research outputs found
The Drosophila gypsy Insulator Supports Transvection in the Presence of the vestigial Enhancer
Though operationally defined as cis-regulatory elements, enhancers can also communicate with promoters on a separate homolog in trans, a mechanism that has been suggested to account for the ability of certain alleles of the same gene to complement one another in a process otherwise known as transvection. This homolog-pairing dependent process is facilitated in Drosophila by chromatin-associated pairing proteins, many of which remain unknown and their mechanism of action uncharacterized. Here we have tested the role of the gypsy chromatin insulator in facilitating pairing and communication between enhancers and promoters in trans using a transgenic eGFP reporter system engineered to allow for targeted deletions in the vestigial Boundary Enhancer (vgBE) and the hsp70 minimal promoter, along with one or two flanking gypsy elements. We found a modest 2.5-3x increase in eGFP reporter levels from homozygotes carrying an intact copy of the reporter on each homolog compared to unpaired hemizygotes, although this behavior was independent of gypsy. However, detectable levels of GFP protein along the DV wing boundary in trans-heterozygotes lacking a single enhancer and promoter was only observed in the presence of two flanking gypsy elements. Our results demonstrate that gypsy can stimulate enhancer-promoter communication in trans throughout the genome in a context-dependent manner, likely through modulation of local chromatin dynamics once pairing has been established by other elements and highlights chromatin structure as the master regulator of this phenomenon.
DOI: 10.1371/journal.pone.008133
Improving the Performance of 3-D Radiative Transfer Model FLIGHT to Simulate Optical Properties of a Tree-Grass Ecosystem
The 3-D Radiative Transfer Model (RTM) FLIGHT can represent scattering in open forest or savannas featuring underlying bare soils. However, FLIGHT might not be suitable for multilayered tree-grass ecosystems (TGE), where a grass understory can dominate the reflectance factor (RF) dynamics due to strong seasonal variability and low tree fractional cover. To address this issue, we coupled FLIGHT with the 1-D RTM PROSAIL. The model is evaluated against spectral observations of proximal and remote sensing sensors: the ASD Fieldspec® 3 spectroradiometer, the Airborne Spectrographic Imager (CASI) and the MultiSpectral Instrument (MSI) onboard Sentinel-2. We tested the capability of both PROSAIL and PROSAIL+FLIGHT to reproduce the variability of different phenological stages determined by 16-year time series analysis of Moderate Resolution Imaging Spectroradiometer-Normalized Difference Vegetation Index (MODIS-NDVI). Then, we combined concomitant observations of biophysical variables and RF to test the capability of the models to reproduce observed RF. PROSAIL achieved a Relative Root Mean Square Error (RRMSE) between 6% to 32% at proximal sensing scale. PROSAIL+FLIGHT RRMSE ranged between 7% to 31% at remote sensing scales. RRMSE increased in periods when large fractions of standing dead material mixed with emergent green grasses —especially in autumn—; suggesting that the model cannot represent the spectral features of this material. PROSAIL+FLIGHT improves RF simulation especially in summer and at mid-high view angles.This research was funded by Ministerio de Economía y Competitividad, CGL2012-34383 and CGL2015-G9095-R and Ministerio de Educación, Cultura y Deporte, FPU15/03558.Peer reviewe
Recovery of polyclonal immunoglobulins one year after autologous stem cell transplantation as a long-term predictor marker of progression and survival in multiple myeloma
Immunoparesis or suppression of polyclonal immunoglobulins is a very common condition in newly diagnosed myeloma patients. However, the recovery of polyclonal immunoglobulins in the setting of immune reconstitution after autologous stem cell transplantation and its effect on outcome has not yet been explored. We conducted this study in a cohort of 295 patients who had undergone autologous transplantation. In order to explore the potential role of immunoglubulin recovery as a dynamic predictor of progression or survival after transplantation, conditional probabilities of progression-free survival and overall survival were estimated according to immunoglobulin recovery at different time points using a landmark approach. One year after transplant, when B-cell reconstitution is expected to be completed, among 169 patients alive and progression free, 88 patients (52%) showed immunoglobulin recovery and 81 (48%) did not. Interestingly, the group with immunoglobulin recovery had a significantly longer median progression-free survival than the group with persistent immunoparesis (median 60.4 vs. 27.9 months, respectively; Hazard Ratio: 0.45, 95%Confidence Interval: 0.31–0.66;
Spanish cohort of VEXAS syndrome : clinical manifestations, outcome of treatments and novel evidences about UBA1 mosaicism
The vacuoles, E1-enzyme, X linked, autoinflammatory and somatic (VEXAS) syndrome is an adult-onset autoinflammatory disease (AID) due to postzygotic UBA1 variants. To investigate the presence of VEXAS syndrome among patients with adult-onset undiagnosed AID. Additional studies evaluated the mosaicism distribution and the circulating cytokines. Gene analyses were performed by both Sanger and amplicon-based deep sequencing. Patients' data were collected from their medical charts. Cytokines were quantified by Luminex. Genetic analyses of enrolled patients (n=42) identified 30 patients carrying UBA1 pathogenic variants, with frequencies compatible for postzygotic variants. All patients were male individuals who presented with a late-onset disease (mean 67.5 years; median 67.0 years) characterised by cutaneous lesions (90%), fever (66.7%), pulmonary manifestations (66.7%) and arthritis (53.3%). Macrocytic anaemia and increased erythrocyte sedimentation rate and ferritin were the most relevant analytical abnormalities. Glucocorticoids ameliorated the inflammatory manifestations, but most patients became glucocorticoid-dependent. Positive responses were obtained when targeting the haematopoietic component of the disease with either decitabine or allogeneic haematopoietic stem cell transplantation. Additional analyses detected the UBA1 variants in both haematopoietic and non-haematopoietic tissues. Finally, analysis of circulating cytokines did not identify inflammatory mediators of the disease. Thirty patients with adult-onset AID were definitively diagnosed with VEXAS syndrome through genetic analyses. Despite minor interindividual differences, their main characteristics were in concordance with previous reports. We detected for the first time the UBA1 mosaicism in non-haematopoietic tissue, which questions the previous concept of myeloid-restricted mosaicism and may have conceptual consequences for the disease mechanisms
DataSheet_1_CD8+ NKs as a potential biomarker of complete response and survival with lenalidomide plus R-GDP in the R2-GDP-GOTEL trial in recurrent/refractory diffuse large B cell lymphoma.pdf
[Background] Diffuse large B cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma worldwide. DLBCL is an aggressive disease that can be cured with upfront standard chemoimmunotherapy schedules. However, in approximately 35-40% of the patients DLBCL relapses, and therefore, especially in this setting, the search for new prognostic and predictive biomarkers is an urgent need. Natural killer (NK) are effector cells characterized by playing an important role in antitumor immunity due to their cytotoxic capacity and a subset of circulating NK that express CD8 have a higher cytotoxic function. In this substudy of the R2-GDP-GOTEL trial, we have evaluated blood CD8+ NK cells as a predictor of treatment response and survival in relapsed/refractory (R/R) DLBCL patients.[Methods] 78 patients received the R2-GDP schedule in the phase II trial. Blood samples were analyzed by flow cytometry. Statistical analyses were carried out in order to identify the prognostic potential of CD8+ NKs at baseline in R/R DLBCL patients.[Results] Our results showed that the number of circulating CD8+ NKs in R/R DLBCL patients were lower than in healthy donors, and it did not change during and after treatment. Nevertheless, the level of blood CD8+ NKs at baseline was associated with complete responses in patients with R/R DLBCL. In addition, we also demonstrated that CD8+ NKs levels have potential prognostic value in terms of overall survival in R/R DLBCL patients.[Conclusion] CD8+ NKs represent a new biomarker with prediction and prognosis potential to be considered in the clinical management of patients with R/R DLBCL.[Clinical trial registration] https://www.clinicaltrialsregister.eu/ctr-search/search?query=2014-001620-29 EudraCT, ID:2014-001620-29.Peer reviewe
CD8+ NKs as a potential biomarker of complete response and survival with lenalidomide plus R-GDP in the R2-GDP-GOTEL trial in recurrent/refractory diffuse large B cell lymphoma
Diffuse large B cell lymphoma (DLBCL) is the most common non-Hodgkin lymphoma worldwide. DLBCL is an aggressive disease that can be cured with upfront standard chemoimmunotherapy schedules. However, in approximately 35-40% of the patients DLBCL relapses, and therefore, especially in this setting, the search for new prognostic and predictive biomarkers is an urgent need. Natural killer (NK) are effector cells characterized by playing an important role in antitumor immunity due to their cytotoxic capacity and a subset of circulating NK that express CD8 have a higher cytotoxic function. In this substudy of the R2-GDP-GOTEL trial, we have evaluated blood CD8+ NK cells as a predictor of treatment response and survival in relapsed/refractory (R/R) DLBCL patients.This research was funded by the Spanish Lymphoma Oncology Group (GOTEL) with the financial support of Celgene (Investigator Initiated Trials Program); no grant numbers applicable. LH-P is supported by the Consejería de Salud y Familias, Junta de Andalucía (RH-0047-2021) and Miguel Servet Researcher Fellow from the Instituto de Salud Carlos III. DG-D is supported by the VII Plan Propio de Investigacioín y Transferencia of Universidad de Sevilla [Contrato de Acceso (II.4)/VII PPIT-US]. CJ-C is supported by the Margarita Salas fellowship, granted by the University of Seville (Seville, Spain).Peer reviewe
Extensive Exon Reshuffling Over Evolutionary Time Coupled to Trans-Splicing in Drosophila
The relative position of exons in genes can be altered only after large structural mutations. These mutations are frequently deleterious, impairing transcription, splicing, RNA stability, or protein function, as well as imposing strong inflexibility to protein evolution. Alternative cis- or trans-splicing may overcome the need for genomic structural stability, allowing genes to encode new proteins without the need to maintain a specific exon order. Trans-splicing in the Drosophila melanogaster modifier of mdg4 (mod[mdg4]) gene is the best documented example in which this process plays a major role in the maturation of mRNAs. Comparison of the genomic organization of this locus among several insect species suggests that the divergence between the lineages of the mosquito Anopheles gambiae and D. melanogaster involved an extensive exon rearrangement, requiring >11 breakpoints within the mod(mdg4) gene. The massive reorganization of the locus also included the deletion or addition of a new function as well as exon duplications. Whereas both DNA strands are sense strands in the Drosophila gene, the coding region in mosquito lays in a single strand, suggesting that trans-splicing may have originated in the Drosophila lineage and might have been the triggering factor for such a dramatic reorganization