ArtScience

My thesis show opened on Friday, March 11, 2016 at the 410 project\u27s art gallery, located in downtown Mankato. The artwork consisted of sculptures displayed on pedestals, hanging on the walls, sitting on specifically constructed arrangements, and hanging from the ceiling. The materials I used to create these sculptures have a dramatically contrasting appearance, but have one universal similarity. At some point most of the materials used were liquid or fluid. I used metals, ceramics, hand blown glass, plastics, and wax. I like to work with these materials in that fluid state because of the added flexibility and forgiveness they provide when sculpting. A lot of the reason I make art is to explore and experiment with materials. My thesis show titled ArtScience showcased how art can be done experimentally and likewise science can be done for aesthetic purposes. The work is primarily abstract but exhibits figural qualities, forms from nature, and industrial objects. Installation and presentation played a crucial role in creating a laboratory like environment. My overall goal was to work both as a scientist and as an artist, and create work that expresses both fields of thought. These two worlds are often viewed separately but I have proven they can be effectively integrated

ENGAGE: Guided Activity-Based Gaming in Neurorehabilitation after Stroke: A Pilot Study

Introduction. Stroke is a leading cause of disability in healthy adults. The purpose of this pilot study was to assess the feasibility and outcomes of a novel video gaming repetitive practice paradigm, (ENGAGE) enhanced neurorehabilitation: guided activity-based gaming exercise. Methods. Sixteen individuals at least three months after stroke served as participants. All participants received concurrent outpatient therapy or took part in a stroke exercise class and completed at least 500 minutes of gaming. Primary baseline and posttest outcome measures included the Wolf motor function test (WMFT) and the Fugl-Meyer assessment (FMA). ENGAGE uses a game selection algorithm providing focused, graded activity-based repetitive practice that is highly individualized and directed. The Wilcoxon signed ranks test was used to determine statistical significance. Results. There were improvements in the WMFT (=0.003) and the FMA (=0.002) that exceeded established values of minimal clinically important difference. Conclusions. ENGAGE was feasible and an effective adjunct to concurrent therapy after stroke

Isoform-specific potentiation of stem and progenitor cell engraftment by AML1/RUNX1

Background: AML1/RUNX1 is the most frequently mutated gene in leukaemia and is central to the normal biology of hematopoietic stem and progenitor cells. However, the role of different AML1 isoforms within these primitive compartments is unclear. Here we investigate whether altering relative expression of AML1 isoforms impacts the balance between cell self-renewal and differentiation in vitro and in vivo. Methods and Findings: The human AML1a isoform encodes a truncated molecule with DNA-binding but no transactivation capacity. We used a retrovirus-based approach to transduce AML1a into primitive haematopoietic cells isolated from the mouse. We observed that enforced AML1a expression increased the competitive engraftment potential of murine long-term reconstituting stem cells with the proportion of AML1a-expressing cells increasing over time in both primary and secondary recipients. Furthermore, AML1a expression dramatically increased primitive and committed progenitor activity in engrafted animals as assessed by long-term culture, cobblestone formation, and colony assays. In contrast, expression of the full-length isoform AML1b abrogated engraftment potential. In vitro, AML1b promoted differentiation while AML1a promoted proliferation of progenitors capable of short-term lymphomyeloid engraftment. Consistent with these findings, the relative abundance of AML1a was highest in the primitive stem/progenitor compartment of human cord blood, and forced expression of AML1a in these cells enhanced maintenance of primitive potential both in vitro and in vivo. Conclusions: These data demonstrate that the "a" isoform of AML1 has the capacity to potentiate stem and progenitor cell engraftment, both of which are required for successful clinical transplantation. This activity is consistent with its expression pattern in both normal and leukaemic cells. Manipulating the balance of AML1 isoform expression may offer novel therapeutic strategies, exploitable in the contexts of leukaemia and also in cord blood transplantation in adults, in whom stem and progenitor cell numbers are often limiting. © 2007 Tsuzuki et al

Tracing the origin of the HSC hierarchy reveals an SCF-Dependent, IL-3-Independent CD43^- embryonic precursor

SummaryDefinitive hematopoietic stem cells (HSCs) develop in the aorta gonad mesonephros (AGM) region in a stepwise manner. Type I pre-HSCs express CD41 but lack CD45 expression, which is subsequently upregulated in type II pre-HSCs prior to their maturation into definitive HSCs. Here, using ex vivo modeling of HSC development, we identify precursors of definitive HSCs in the trunk of the embryonic day 9.5 (E9.5) mouse embryo. These precursors, termed here pro-HSCs, are less mature than type I and II pre-HSCs. Although pro-HSCs are CD41+, they lack the CD43 marker, which is gradually upregulated in the developing HSC lineage. We show that stem cell factor (SCF), but not interleukin-3 (IL-3), is a major effector of HSC maturation during E9–E10. This study extends further the previously established hierarchical organization of the developing HSC lineage and presents it as a differentially regulated four-step process and identifies additional targets that could facilitate the generation of transplantable HSCs from pluripotent cells for clinical needs

The transcriptional programme controlled by Runx1 during early embryonic blood development

AbstractTranscription factors have long been recognised as powerful regulators of mammalian development yet it is largely unknown how individual key regulators operate within wider regulatory networks. Here we have used a combination of global gene expression and chromatin-immunoprecipitation approaches during the early stages of haematopoietic development to define the transcriptional programme controlled by Runx1, an essential regulator of blood cell specification. Integrated analysis of these complementary genome-wide datasets allowed us to construct a global regulatory network model, which suggested that key regulators are activated sequentially during blood specification, but will ultimately collaborate to control many haematopoietically expressed genes. Using the CD41/integrin alpha 2b gene as a model, cellular and in vivo studies showed that CD41 is controlled by both Scl/Tal1 and Runx1 in fully specified blood cells, and initiation of CD41 expression in E7.5 embryos is severely compromised in the absence of Runx1. Taken together, this study represents the first global analysis of the transcriptional programme controlled by any key haematopoietic regulator during the process of early blood cell specification. Moreover, the concept of interplay between sequentially deployed core regulators is likely to represent a design principle widely applicable to the transcriptional control of mammalian development

Primordial germ cells: the first cell lineage or the last cells standing?

Embryos of many animal models express germ line determinants that suppress transcription and mediate early germ line commitment, which occurs before the somatic cell lineages are established. However, not all animals segregate their germ line in this manner. The ‘last cell standing’ model describes primordial germ cell (PGC) development in axolotls, in which PGCs are maintained by an extracellular signalling niche, and germ line commitment occurs after gastrulation. Here, we propose that this ‘stochastic’ mode of PGC specification is conserved in vertebrates, including non-rodent mammals. We postulate that early germ line segregation liberates genetic regulatory networks for somatic development to evolve, and that it therefore emerged repeatedly in the animal kingdom in response to natural selection

Hematopoietic (stem) cell development-how divergent are the roads taken?

textabstractThe development of the hematopoietic system during early embryonic stages occurs in spatially and temporally distinct waves. Hematopoietic stem cells (HSC), the most potent and self-renewing cells of this system, are produced in the final ‘definitive’ wave of hematopoietic cell generation. In contrast to HSCs in the adult, which differentiate via intermediate progenitor populations to produce functional blood cells, the generation of hematopoietic cells in the embryo prior to HSC generation occurs in the early waves by producing blood cells without intermediate progenitors (such as the ‘primitive’ hematopoietic cells). The lineage relationship between the early hematopoietic cells and the cells giving rise to HSCs, the genetic networks controlling their emergence, and the precise temporal determination of HSC fate remain topics of intense research and debate. This Review article discusses the current knowledge on the step-wise embryonic establishment of the adult hematopoietic system, examines the roles of pivotal intrinsic regulators in this process, and raises questions concerning the temporal onset of HSC fate determination

Epigenetic reprogramming of breast cancer cells with oocyte extracts

<p>Abstract</p> <p>Background</p> <p>Breast cancer is a disease characterised by both genetic and epigenetic alterations. Epigenetic silencing of tumour suppressor genes is an early event in breast carcinogenesis and reversion of gene silencing by epigenetic reprogramming can provide clues to the mechanisms responsible for tumour initiation and progression. In this study we apply the reprogramming capacity of oocytes to cancer cells in order to study breast oncogenesis.</p> <p>Results</p> <p>We show that breast cancer cells can be directly reprogrammed by amphibian oocyte extracts. The reprogramming effect, after six hours of treatment, in the absence of DNA replication, includes DNA demethylation and removal of repressive histone marks at the promoters of tumour suppressor genes; also, expression of the silenced genes is re-activated in response to treatment. This activity is specific to oocytes as it is not elicited by extracts from ovulated eggs, and is present at very limited levels in extracts from mouse embryonic stem cells. Epigenetic reprogramming in oocyte extracts results in reduction of cancer cell growth under anchorage independent conditions and a reduction in tumour growth in mouse xenografts.</p> <p>Conclusions</p> <p>This study presents a new method to investigate tumour reversion by epigenetic reprogramming. After testing extracts from different sources, we found that axolotl oocyte extracts possess superior reprogramming ability, which reverses epigenetic silencing of tumour suppressor genes and tumorigenicity of breast cancer cells in a mouse xenograft model. Therefore this system can be extremely valuable for dissecting the mechanisms involved in tumour suppressor gene silencing and identifying molecular activities capable of arresting tumour growth. These applications can ultimately shed light on the contribution of epigenetic alterations in breast cancer and advance the development of epigenetic therapies.</p

In vivo single cell analysis reveals Gata2 dynamics in cells transitioning to hematopoietic fate

Cell fate is established through coordinated gene expression programs in individual cells. Regulatory networks that include the Gata2 transcription factor play central roles in hematopoietic fate establishment. Although Gata2 is essential to the embryonic development and function of hematopoietic stem cells that form the adult hierarchy, little is known about the in vivo expression dynamics of Gata2 in single cells. Here, we examine Gata2 expression in single aortic cells as they establish hematopoietic fate in Gata2Venus mouse embryos. Time-lapse imaging reveals rapid pulsatile level changes in Gata2 reporter expression in cells undergoing endothelial-to-hematopoietic transition. Moreover, Gata2 reporter pulsatile expression is dramatically altered in Gata2+/- aortic cells, which undergo fewer transitions and are reduced in hematopoietic potential. Our novel finding of dynamic pulsatile expression of Gata2 suggests a highly unstable genetic state in single cells concomitant with their transition to hematopoietic fate. This reinforces the notion that threshold levels of Gata2 influence fate establishment and has implications for transcription factor-related hematologic dysfunctions

Single-cell analyses of regulatory network perturbations using enhancer-targeting TALEs suggest novel roles for PU.1 during haematopoietic specification.

Transcription factors (TFs) act within wider regulatory networks to control cell identity and fate. Numerous TFs, including Scl (Tal1) and PU.1 (Spi1), are known regulators of developmental and adult haematopoiesis, but how they act within wider TF networks is still poorly understood. Transcription activator-like effectors (TALEs) are a novel class of genetic tool based on the modular DNA-binding domains of Xanthomonas TAL proteins, which enable DNA sequence-specific targeting and the manipulation of endogenous gene expression. Here, we report TALEs engineered to target the PU.1-14kb and Scl+40kb transcriptional enhancers as efficient new tools to perturb the expression of these key haematopoietic TFs. We confirmed the efficiency of these TALEs at the single-cell level using high-throughput RT-qPCR, which also allowed us to assess the consequences of both PU.1 activation and repression on wider TF networks during developmental haematopoiesis. Combined with comprehensive cellular assays, these experiments uncovered novel roles for PU.1 during early haematopoietic specification. Finally, transgenic mouse studies confirmed that the PU.1-14kb element is active at sites of definitive haematopoiesis in vivo and PU.1 is detectable in haemogenic endothelium and early committing blood cells. We therefore establish TALEs as powerful new tools to study the functionality of transcriptional networks that control developmental processes such as early haematopoiesis.Research in the authors’ laboratories was supported by Leukaemia and Lymphoma Research, The Wellcome Trust, Cancer Research UK, the Biotechnology and Biological Sciences Research Council, the National Institute of Health Research, the Medical Research Council and core support grants by the Wellcome Trust to the Cambridge Institute for Medical Research and Wellcome Trust–MRC Cambridge Stem Cell Institute. V.K.S.K. was supported by a Japan Society for the Promotion of Science (JSPS) Research Fellowship for Young Scientists.This is the final version. It was first published by the Company of Biologists http://dev.biologists.org/content/141/20/4018.long