Current therapies for the treatment of myocardial infarction and heart failure include medical, surgical, mechanical assist, and transplantation. These therapies have been based on the dogma that ventricular myocytes themselves are terminally differentiated and, therefore, cannot regenerate. This concept has been recently challenged with stem cell therapy. A potential problem is the ability of cardiac tissue to mobilize, recruit, and transdifferentiate adult stem cells from other tissues. We believe that there is a unique failure of the damaged myocardium to provide the appropriate molecular signals for stem cells engraftment related to age. Our hypothesis is that the overexpression of IL-10 in the aged population reduces cardiac cellular proliferation subsequent to myocardial injury. This hypothesis is supported by aging models, where elevated levels of IL-10 are associated with reduced healing response to noncardiac tissue injury. We demonstrated an increased cardiac gene expression of IL-10 that may be associated with a reduced proliferative response in the border regions of the infarcted myocardium that are proportional with age. In conclusion, myocardial infarction and heart failure has presented a significant challenge for the clinician to provide reparative therapies. The use of therapeutics to modulate IL-10 and, thereby, optimizing regenerative processes in the injured myocardium may provide a unique means for the cardiac patient.

Recruitment of circulating cells towards target sites is primarily dependent on E-selectin receptor/ligand adhesive interactions. Glycosyltransferase (GTs) are involved in the creation of E-selectin ligands. A sialofucosylated terminal tetrasaccharide like glycan structure known as sialyl Lewis x (sLex), is the most recognized ligand by selectins. This structure is found on the surface of cancer cells and leukocytes but is often absent on the surface of many adult stem cell populations. In order to synthesize sLex, GTs must be endogenously expressed and remain active within the cells. Generally, these stem cells express terminal sialylated lactosamine structures on their glycoproteins which require the addition of alpha-(1,3)-fucose to be converted into an E-selectin ligand. There are a number of fucosyltransferases (FUTs) that are able to modify terminal lactosamine structures to create sLex such as FUT6. In this work we focused on expressing and purifying active recombinant FUTs as a tool to help create sLex structures on the surface of adult stem cells in order to enhance their migration.

The number of robotics competitions has steadily increased over the past 30 years. Schools are implementing robotics competitions to increase student content knowledge and interest in science, technology, engineering, and mathematics (STEM). Companies in STEM-related fields are financially supporting robotics competitions to help increase the number of students pursuing careers in STEM among other reasons. These financial supporters and school administrations are asking what the outcomes of students participating in competitive robotics are. Few studies have been conducted to investigate these outcomes. The studies that have been conducted usually compare students in robotics to students not in robotics. There have not been any studies that compare students to themselves before and after participating in robotics competitions. This may be due to the lack of available instruments to measure student outcomes. This study developed an instrument to measure the self-efficacy of students participating in VEX Robotics Competitions (VRC). The VRC is the world’s largest and fastest growing robotics competition available for middle and high school students. Self-efficacy was measured because of its importance to the education community. Students with higher self-efficacy tend to persevere through difficult tasks more frequently than students with low self-efficacy. A person’s self-efficacy has major influence over what interests, activities, classes, college majors, and careers he or she will pursue in life. The self-efficacy survey instrument created through this study was developed through an occupational and task analysis (OTA), and initial content and face validity was established through the OTA process. Exploratory and confirmatory factor analyses were also conducted to assist in instrument validation. The reliability was calculated using Cronbach’s alpha. Face validity was established through the OTA process. Construct validity was established through the factor analyses. The processes of the OTA and factor analyses have created an instrument that results indicate is reliable and valid to use in further research studies.

Indiana University-Purdue University Indianapolis (IUPUI) / The number of women working in STEM areas of academia declines as rank progresses—a phenomenon termed the “leaky pipeline” (Burke, 2007). The leaky pipeline is due in part to discrimination. Women in STEM report high perceived discrimination, which is associated with negative career outcomes (Settles, Cortina, Stewart, & Malley, 2007; Pascoe & Richman, 2009). No research to date has examined whether mentoring might buffer the negative effects of perceived discrimination for female professors working in STEM areas of academia. This study examines whether mentoring relationships moderate the relationships between perceived discrimination and career outcomes including job satisfaction and work engagement for women in STEM. 118 women faculty in STEM completed an online survey of perceived discrimination, job satisfaction, and engagement. Although results revealed main effects of perceived discrimination and mentoring, mentoring did not moderate the relationship between perceived discrimination and outcomes. Exploratory analyses provide future research directions to understand the leaky pipeline.

Indiana University-Purdue University Indianapolis (IUPUI) / In glaucoma, the connection between the eye and the brain is severed leading to the degeneration of retinal ganglion cells (RGCs) and eventual blindness. A need exists to better understand the maturation of human RGCs as well as their degeneration, with the goal of developing new therapeutics diseases like glaucoma. Human pluripotent stem cells (hPSCs) provide an advantageous model for the study of RGC development and disease as they can be differentiated into RGCs in large, reproducible quantities. Efforts of the current studies initially focused on the development and maturation of RGCs from hPSCs. RGCs derived from hPSCs were a diverse population of cells and matured in a temporal fashion, yielding morphological and functional characteristics similar to their in vivo counterpart. CRISPR/Cas9 gene editing was then utilized to insert the OPTN(E50K) glaucomatous mutation into hPSCs to model RGC degeneration. RGCs harboring this mutation exhibited numerous degenerative phenotypes including neurite retraction an autophagy dysfunction. Within the retina, many cell types contribute to the health and maturation of RGCs including astrocytes. As such, a co-culture system of hPSC-derived RGCs and astrocytes was developed to better understand the interaction between these two cell types. When grown in co-culture with astrocytes, hPSC-derived RGCs demonstrated significantly enhanced and accelerated morphological and functional maturation, indicating an important relationship between these cells in a healthy state. Astrocytes have also been shown to encompass neurodegenerative phenotypes in other diseases of the CNS, with these deficits profoundly effecting the health of surrounding neurons. hPSC-derived astrocytes grown from OPTN(E50K)-hPSCs demonstrated cell autonomous deficits and exhibited significant effects on the degeneration of RGCs. Taken together, results of this study demonstrated the utilization of hPSCs to model RGC maturation and degeneration in glaucoma. More so, these results are one of the first to characterize astrocyte deficits caused by the OPTN(E50K) mutation and could provide a new therapeutic target for pharmacological screenings and cell replacement therapies to reverse blindness in optic neuropathies.

As the prevalence of Parkinson’s disease is expected to increase gradually over the years based on recent scientific predictions, developing a treatment plan to mitigate the development of this disease is essential. Previous research tried to tackle the motor and non-motor symptoms associated with the disease. That said, some symptoms seem to persist, and the quality of life of PD patients continues to decline. Zebrafish have emerged as a strong model to study the regeneration of DAergic neurons as they have the ability to show robust adult neurogenesis. Here, we used adult zebrafish to investigate DAergic neuron regeneration following ablation in various brain regions. In addition, we tested the efficacy of Nifurpirinol, an alternative substrate to MTZ, in ablating DAergic neurons in the adult zebrafish brain. Lastly, we tracked how the ablation of DAergic neurons influences the motor activity of adult zebrafish and how they tend to recover over time. Results showed a significant reduction in DAergic neurons at 7 days following the MTZ treatment in the olfactory bulb, telencephalon, and the periventricular pretectal nucleus. NFP also caused similar changes, albeit they were less statistically significant. In response to ablated DAergic neurons, MTZ-treated fish showed a significant increase in the number of neural stem cells undergoing proliferation at 1 dpt. However, the highest spike in proliferative cells, especially neural stem cells, was found at 7 dpt. This time point corresponded with the greatest decrease in DAergic neurons following ablation. These cellular changes were observed in the olfactory bulb and the telencephalon. That said, more drastic changes were noticed in the rostral and medial telencephalon. Results also showed that the adult zebrafish brain was not able to significantly replenish the number of DAergic neurons as early as 15 dpt. Based on previous observations, it seems that adult zebrafish need at least 45 days to regenerate their DAergic neurons to levels comparable to the DMSO control. Lastly, behaviour analysis showed that NFP has the most significant impact on motor activity across three different parameters at 0 hpt. MTZ also had similar effects on motor activity; however, it was less pronounced. The impact on the behaviour level seems more transient as some recovery was observed at 7 dpt. Overall, this transgenic zebrafish line allowed us to explore how and when the adult zebrafish brain was able to efficiently recover following the specific ablation of DAergic neurons. In addition, it expanded our understanding of adult neurogenesis which will hopefully allow us to better approach patients with Parkinson’s disease.

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18893号 / 医博第4004号 / 新制||医||1009(附属図書館) / 31844 / 京都大学大学院医学研究科医学専攻 / (主査)教授 山下 潤, 教授 羽賀 博典, 教授 瀬原 淳子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第13157号 / 論医博第2144号 / 新制||医||1028(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 影山 龍一郎, 教授 別所 和久, 教授 辻川 明孝 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DFAM

Thesis advisor: Katherine McNeill / Gaining popular recognition in the U.S. with the advent of the first White House Maker Faire in 2014, makerspaces have become an increasingly popular feature of the K-12 educational landscape. While makerspaces have been subject to critique related to the lack of inclusivity within the broader predominantly white and male ‘maker culture’, they have also been recognized for their potential to include and attract students that have been historically underrepresented in the STEM fields, specifically female, African-American and Latinx students (Halverson & Sheridan, 2014; Kafai et al., 2014; Vossoughi, et al., 2016). However, despite their popularity and the growing body of empirical evidence documenting their use in the K-12 context, there are many topics that warrant further exploration, from teachers’ experiences with making, to the processes involved in their long term success or failure, and issues related to leadership, professional development and teacher expertise (Haron & Hughes, 2018). Responding to the need for greater understanding of these issues, this exploratory case study examines the organizational and curricular role of an established middle school makerspace through observations, student surveys, and individual interviews with teachers and school leaders. Findings of this study revealed themes related to (a) discrepancies between participants’ aspirational ideals and the practical reality of their experiences; (b) the important role of flexibility and rigidity within the curriculum and school structures; and (c) the mutually influential relationships that exist between materials, identity, expertise and participation. Each of these themes held specific consequences for equity and inclusion. The findings of this study highlight the critical importance of attending to equity in the implementation of maker learning environments and the central role that school structures, materials and perceptions play in addressing historical inequities in making and STEAM. This study concludes with recommendations for researchers, teachers and school leaders that place equity at the center of plans for school-based making and directions for future research. / Thesis (PhD) — Boston College, 2021. / Submitted to: Boston College. Lynch School of Education. / Discipline: Teacher Education, Special Education, Curriculum and Instruction.

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