Publications by authors named "L Burgos Pratx"

8 Publications

Functional polymorphisms of DNA repair genes in Latin America reinforces the heterogeneity of Myelodysplastic Syndrome.

Hematol Transfus Cell Ther 2021 Sep 9. Epub 2021 Sep 9.

Cancer Cytogenomic Laboratory, Universidade Federal do Ceara (UFC), Fortaleza, CE, Brazil; Post Graduate Program in Medical Science, Federal University of Ceara, Fortaleza, CE, Brazil. Electronic address:

Nucleotide excision repair pathway (NER) is an essential mechanism for single-strand breaks (SSB) repair while xeroderma pigmentosum family (XPA to XPG) is the most important system to NER. Myelodysplastic syndrome (MDS) is a heterogeneous hematological cancer characterized by cytopenias and risk of acute myeloid leukemia (AML) transformation. MDS pathogenesis has been associated with problems of DNA repair system. This report aimed to evaluate NER polymorphisms (XPA rs1800975, XPC rs2228000, XPD rs1799793 and XPF rs1800067) in 269 MDS patients of different populations in Latin America (173 Brazilian and 96 Argentinean). Genotypes were identified in DNA samples by RT-qPCR using TaqMan SNP Genotyping Assay. Regarding rs1799793 polymorphism of XPD for Brazilian population, the heterozygous genotype AG presented a high odds ratio (OR) to have a normal karyotype (p = 0.012, OR=3.000) and the mutant homozygous genotype AA was associated to a high OR of AML transformation (p = 0.034, OR=7.4). In Argentine population, the homozygous mutant AA genotype of rs1800975 polymorphism of XPA was associated with an increased odd to have hemoglobin levels below 8g/dL (p = 0.013, OR=10.000) while for the rs1799793 polymorphism of XPD, the heterozygous AG genotype decreased OR to be classified as good (p < 0.001, OR=9.05 × 10), and intermediate (p < 0.001, OR=3.08 × 10), according to Revised-International Prognostic Scoring System. Regarding the rs1800067 polymorphisms of XPF, the homozygous mutant AA genotype showed a decreased OR to be classified as good (p < 0.001, OR=4.03 × 10) and intermediate (p < 0.001, OR=2.54 × 10). Our report reinforces the heterogeneity of MDS and demonstrates the importance of ethnic differences and regional influences in pathogenesis and prognosis of MDS.
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http://dx.doi.org/10.1016/j.htct.2021.08.002DOI Listing
September 2021

Epigenetic regulation of abiotic stress memory: maintaining the good things while they last.

Curr Opin Plant Biol 2021 06 8;61:102007. Epub 2021 Feb 8.

University of Potsdam, Institute for Biochemistry and Biology, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany. Electronic address:

As sessile organisms, plants have evolved sophisticated ways to constantly gauge and adapt to changing environmental conditions including extremes that may be harmful to their growth and development and are thus perceived as stress. In nature, stressful events are often chronic or recurring and thus an initial stress may prime a plant to respond more efficiently to a subsequent stress event. An epigenetic basis of such stress memory was long postulated and in recent years it has been shown that this is indeed the case. High temperature stress has proven an excellent system to unpick the molecular basis of somatic stress memory, which includes histone modifications and nucleosome occupancy. This review discusses recent findings and pinpoints open questions in the field.
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http://dx.doi.org/10.1016/j.pbi.2021.102007DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8250047PMC
June 2021

Gene copy number variations as signatures of adaptive evolution in the parthenogenetic, plant-parasitic nematode Meloidogyne incognita.

Mol Ecol 2019 05 29;28(10):2559-2572. Epub 2019 Apr 29.

INRA, Université Côte d'Azur, CNRS, ISA, Sophia Antipolis, France.

Adaptation to changing environmental conditions represents a challenge to parthenogenetic organisms, and until now, how phenotypic variants are generated in clones in response to the selection pressure of their environment remains poorly known. The obligatory parthenogenetic root-knot nematode species Meloidogyne incognita has a worldwide distribution and is the most devastating plant-parasitic nematode. Despite its asexual reproduction, this species exhibits an unexpected capacity of adaptation to environmental constraints, for example, resistant hosts. Here, we used a genomewide comparative hybridization strategy to evaluate variations in gene copy numbers between genotypes of M. incognita resulting from two parallel experimental evolution assays on a susceptible vs. resistant host plant. We detected gene copy number variations (CNVs) associated with the ability of the nematodes to overcome resistance of the host plant, and this genetic variation may reflect an adaptive response to host resistance in this parthenogenetic species. The CNV distribution throughout the nematode genome is not random and suggests the occurrence of genomic regions more prone to undergo duplications and losses in response to the selection pressure of the host resistance. Furthermore, our analysis revealed an outstanding level of gene loss events in nematode genotypes that have overcome the resistance. Overall, our results support the view that gene loss could be a common class of adaptive genetic mechanism in response to a challenging new biotic environment in clonal animals.
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http://dx.doi.org/10.1111/mec.15095DOI Listing
May 2019

Development of apheresis techniques and equipment designed for patients weighing less than 10 kg.

Transfus Apher Sci 2018 Jun 10;57(3):331-336. Epub 2018 May 10.

Sanatorio Güemes, Transfusion Medicine Service, Ciudad Autónoma de Buenos Aires, Argentina.

The procedure of apheresis in pediatric patients, particularly in those with low weight (body weight<10 kg) presents an important challenge due to particularities of this group. There are no specific guidelines or enough scientific evidence to standardize the practice in this group of patients. In addition to the psychological aspect, the correct calculation of the total blood volume, the extracorporeal volume of the cell separator and an estimated decrease in hematocrit must be considered. Personalized protocols for priming of the apheresis equipment, sufficient blood flow and adequate anticoagulation are essential for patient comfort and therapeutic success. The purpose of this article is to present the results of the national study of apheresis practices in low weight group of children conducted from 2012 to 2018. Protocols and patients' data collected from various apheresis centers in Argentina were compared with the apheresis protocols around the world. Our protocols and data were similar to those in other countries; however, no detailed and specific guidelines for apheresis practices in this population of patients with unique requirements have been developed to date.
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http://dx.doi.org/10.1016/j.transci.2018.05.014DOI Listing
June 2018

Genome-wide expert annotation of the epigenetic machinery of the plant-parasitic nematodes Meloidogyne spp., with a focus on the asexually reproducing species.

BMC Genomics 2018 May 3;19(1):321. Epub 2018 May 3.

Université Côte d'Azur, INRA, ISA, Sophia Antipolis, France.

Background: The renewed interest in epigenetics has led to the understanding that both the environment and individual lifestyle can directly interact with the epigenome to influence its dynamics. Epigenetic phenomena are mediated by DNA methylation, stable chromatin modifications and non-coding RNA-associated gene silencing involving specific proteins called epigenetic factors. Multiple organisms, ranging from plants to yeast and mammals, have been used as model systems to study epigenetics. The interactions between parasites and their hosts are models of choice to study these mechanisms because the selective pressures are strong and the evolution is fast. The asexually reproducing root-knot nematodes (RKN) offer different advantages to study the processes and mechanisms involved in epigenetic regulation. RKN genomes sequencing and annotation have identified numerous genes, however, which of those are involved in the adaption to an environment and potentially relevant to the evolution of plant-parasitism is yet to be discovered.

Results: Here, we used a functional comparative annotation strategy combining orthology data, mining of curated genomics as well as protein domain databases and phylogenetic reconstructions. Overall, we show that (i) neither RKN, nor the model nematode Caenorhabditis elegans possess any DNA methyltransferases (DNMT) (ii) RKN do not possess the complete machinery for DNA methylation on the 6th position of adenine (6mA) (iii) histone (de)acetylation and (de)methylation pathways are conserved between C. elegans and RKN, and the corresponding genes are amplified in asexually reproducing RKN (iv) some specific non-coding RNA families found in plant-parasitic nematodes are dissimilar from those in C. elegans. In the asexually reproducing RKN Meloidogyne incognita, expression data from various developmental stages supported the putative role of these proteins in epigenetic regulations.

Conclusions: Our results refine previous predictions on the epigenetic machinery of model species and constitute the most comprehensive description of epigenetic factors relevant to the plant-parasitic lifestyle and/or asexual mode of reproduction of RKN. Providing an atlas of epigenetic factors in RKN is an informative resource that will enable researchers to explore their potential role in adaptation of these parasites to their environment.
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http://dx.doi.org/10.1186/s12864-018-4686-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5934874PMC
May 2018
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