Browsing by Subject "Stem Cell Biology"

Now showing 1 - 3 of 3
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    Examination of the ZIKV pathogenesis in the Human Fetal Brain
    (2017-12) Vaid, Shivanshi
    Zika virus (ZIKV) is a single-stranded RNA virus of the Flaviviridae family, genus Flavivirus. Infection with ZIKV is associated with severe neurological disorders and congenital deformities like microcephaly. Even though outbreaks of ZIKV have been reported worldwide the mode of entry and the mechanism of action of this virus still remains unclear. The cellular receptors and determinants that mediate entry of ZIKV in the human fetal brain are still unclear. Previous studies have reported that AXL,TYRO-3,MERTK and TIM-1 receptors aid in the ZIKV entry to the human body. This study focuses on analyzing the presence of these receptors in the human fetal brain. We performed RT-PCR and RNA sequencing which showed an increased expression of AXL and TYRO-3 receptors in the brain samples infected with ZIKV for 3 and 4 days as compared to the infected aged- matched samples. RNA sequencing analysis revealed differential expression of the receptors previously known to be involved in Flavivirus entry. A slight increase in expression of these receptors was observed in the brain samples infected with ZIKV for 3 and 4 days as compared to the uninfected brain tissue samples. This finding provided further evidence for involvement of AXL, MERTK, and TYRO3 receptors in ZIKV infection in the human fetal brain and provided insights into the ZIKV host interactions. Interestingly, RNA sequencing analysis revealed the key biological pathways related to immune system response, negative regulation of viral processes, apoptosis and autophagy that were affected by infection. These findings provided insights in the molecular signatures associated with ZIKV infection. Further studies could potentially reveal the cellular responses that can be targeted to develop antiviral drugs and other related therapies to prevent ZIKV infection.
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    Modeling Normal and Malignant Hematopoiesis Using Human Pluripotent Stem Cells
    (2011-01) Walsh, Patrick Joseph
    This thesis outlines progress made in creating several human pluripotent stem cell based models for studying hematopoiesis. Induced pluripotent stem cells were generated from human umbilical cord blood cells selected for the early hematopoietic progenitor marker CD34. Furthermore, reprogramming was attempted on primary leukemia samples to generate an induced pluripotent stem cell line with a genetic background harboring the mutations necessary for malignant hematopoiesis. Strategies for manipulating human embryonic stem cells to either express the bcr-abl oncogene or be deficient in the putative tumor suppressor gene sh2b3 were also developed, both genes of which are linked to the expansion of early hematopoietic progenitors.
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    Regulation of Type VII Collagen in Patients with Recessive Dystrophic Epidermolysis Bullosa
    (2017-08) Vanden Oever, Michael
    Recessive Dystrophic Epidermolysis Bullosa (RDEB) is a complex, life-threatening genetic skin disorder with painful complications. Currently, there is no cure, but there have been recent developments in both the basic biological research aspects and the translational therapies which make effectively treating this disease more likely in the near future. These advances include the use of stem cells and gene editing as well as new insights into the molecular mechanisms for certain aspects of RDEB pathology. The overall goals of our lab are to better define and characterize RDEB pathology, develop novel approaches for treating RDEB, and to improve upon the ways in which we analyze and understand the outcomes of those therapies. These goals are inherently dependent upon a comprehensive understanding of how type VII collagen is regulated, both during the normal wound healing process and over the course of therapeutic intervention. To that aim, we set out to understand two aspects of regulation of type VII collagen that were poorly understood: one focused on the nature of type VII collagen regulation during wound healing and the other focused on type VII collagen regulation during the hematopoietic stem cell transplantation process. We identified a particular micro RNA, miR-29, which regulates COL7A1 transcriptionally and post-transcriptionally. We also demonstrated that fludarabine, a key component of the hematopoietic cell transplantation (HCT) preparative regimen, modulates type VII collagen expression during hematopoietic stem cell transplantation. Our studies have identified a novel mechanism of regulation for type VII collagen that will hopefully give valuable insight into how to treat RDEB, ameliorate RDEB pathology, and properly evaluate clinical outcomes in patients that have receive HCT to treat RDEB.