EXPLORING THE ROLE OF WNT10B AS LEUKEMIA DRIVER IN ZEBRAFISH MODEL

ABSTRACT Acute myeloid leukemia (AML) is a heterogeneous clonal disorder characterized by a misregulation in the differentiation program of myeloid progenitor cells that proliferate abnormally and arrest in their maturation. In the effort to reveal the mechanism that confers self-renewal potential to Leukemia Stem Cells (LSCs), Wnt pathway came out as a candidate. The Wnt pathway has a central role in the hematopoiesis regulating the hematopoietic stem cells (HSCs) self-renewal. A recent study showed an increase of WNT proteins (i.e. WNT10B) expression and release within the microenvironment in both leukemic blasts and stromal-like cells of AML patients, indicating its possible autocrine/paracrine involvement in the bone marrow microenvironment, and suggesting that the regenerative WNT signaling is a stem cell-associated function altered in AML stem cell fraction. The aim of this work is to elucidate the role of WNT10B in AML generating an animal model in which this signaling is disregulated.\u2028The striking similarities of zebrafish and human hematopoiesis make this fish an excellent model for elucidating physiologic and pathological mechanisms. Furthermore, various hematopoietic zebrafish mutants, mimicking the human hematopoietic system diseases, have been generated. wnt10b was transiently upregulated in zebrafish embryos and effects of such misregulation on embryonic hematopoiesis were analyzed. In-situ hybridization assays, performed using myeloid and HSCs markers (pu.1 and scl, respectively), and in vivo observation of transgenic fish lines expressing fluorescent proteins in erythroid progenitors and mature neutrophils - Tg(gata1:dsRed) and Tg(mpx:EGFP) - demonstrated an abnormal accumulation of HSCs, myeloid and erythroid progenitors in the embryo hematopoietic tissue, at the expense of more differentiated cells. Moreover, wnt10b overexpression affects the migration of myeloid cells in the ALM (Anterior Lateral Mesoderm). Taken together, these results support the notion of an involvement of wnt10b in vertebrate hematopoiesis.\u2028A plasmid construct with zebrafish wnt10b under the control of runx1 (a pivotal gene in definitive hematopoiesis) promoter and flanked by trasposase-responsive elements has been generated; injection of this plasmid in zebrafish embryos together with trasposase mRNA will lead to the generation of a transgenic line in which wnt10b expression can be induced only in definitive HSCs. Future plans include the temporal control of the transgene expression through the insertion in the plasmid of a lox-P cassette flanking a STOP signal and the outcross of the resulting transgenic line with a line expressing Cre recombinase under the control of hsp70 (heat-shock protein) promoter. This model will provide the chance to better understand the Wnt-mediated early mechanisms that lead to leukemia development

Therapeutic educational robot enhancing social interactions in the management of obesity

Obesity is a chronic multifactorial pathology determined by many factors, including incorrect eating habits and a low level of physical activity. There is an urgent need to promote a persistent change in lifestyle in obese subjects, but very few individuals maintain long-term results achieved after diet therapies. Therapeutic Education (TE) has taken over an important role as a multidisciplinary intervention aimed at improving lifestyle and at acquiring new skills for the management of the disease. However, only a small portion of patients can maintain participation in such programs and fully benefit from them. Assistive technologies, and in particular assistive social robots, are powerful tools to boost independence and improve participation in educational activities. The aim of the research work described in this article is to evaluate the effect of employing a social robot as a therapeutic educational robot helping the expert therapist in the education activity. This article describes the implementation, deployment, and evaluation of a social educational robot used as a TE assistant. Although we cannot provide statistically significant results due to the limited number of people involved in the experimental protocol, all experimental results show a positive trend, indicating that the robot can enhance the social interactions between the patients and the therapist and among the patients, thus bringing to better overall results of the TE sessions, measured with standard tests for obesity management

Microsatellite diversity and broad scale geographic structure in a model legume: building a set of nested core collection for studying naturally occurring variation in Medicago truncatula

BACKGROUND: Exploiting genetic diversity requires previous knowledge of the extent and structure of the variation occurring in a species. Such knowledge can in turn be used to build a core-collection, i.e. a subset of accessions that aim at representing the genetic diversity of this species with a minimum of repetitiveness. We investigate the patterns of genetic diversity and population structure in a collection of 346 inbred lines representing the breadth of naturally occurring diversity in the Legume plant model Medicago truncatula using 13 microsatellite loci distributed throughout the genome. RESULTS: We confirm the uniqueness of all these genotypes and reveal a large amount of genetic diversity and allelic variation within this autogamous species. Spatial genetic correlation was found only for individuals originating from the same population and between neighbouring populations. Using a model-based clustering algorithm, we identified four main genetic clusters in the set of individuals analyzed. This stratification matches broad geographic regions. We also identified a set of "admixed" individuals that do not fit with this population structure scheme. CONCLUSION: The stratification inferred is discussed considering potential historical events like expansion, refuge history and admixture between neighbouring groups. Information on the allelic richness and the inferred population structure are used to build a nested core-collection. The set of inbred lines and the core collections are publicly available and will help coordinating efforts for the study of naturally occurring variation in the growing Medicago truncatula community