Cell Biology Commons^™

Investigation Of Cell-Penetrating Peptide Transformation In Two Regenerable Tissue Culture Systems, Atiyyah S. Ferouz

Electronic Thesis and Dissertation Repository

The genetic engineering of plants allows for the modification of plant genomes, subsequently improving plant traits. There are, however, plants recalcitrant to established transformation methods, requiring the implementation of novel techniques. This study investigates the viability of cell-penetrating peptide (CPP) transformation using Tat₂, a CPP with demonstrated transformation efficiency in plant and animal systems, in two regenerable tissue culture systems, soybean somatic embryos and Arabidopsis protoplasts. Assessments of complex formation, Tat₂ cellular translocation, complex uptake, and CPP-mediated transformation were carried out. The results show the formation of a Tat₂-plasmid complex and the uptake of Tat …

Hd2d Is A Regulator Of Abscisic Acid Responses In Arabidopsis, Joshua A. Farhi

Electronic Thesis and Dissertation Repository

Histone deacetylases have important roles in development and stress response in plants. To further investigate their function, the HD2D gene, of the plant specific HD2 family, was studied. An hd2d-1 mutant and two HD2D overexpression lines were used in this study. Germination was delayed in hd2d-1 and HD2D overexpression seeds only in the presence of ABA. HD2D was found to positively regulate the expression of members of the ABA-response pathway (ABI1, ABI5, and RD29A) leading to increased resistance to drought and salinity treatments. Furthermore, HD2D expression delayed flowering by positively regulating FLC expression. Using bimolecular fluorescence complementation, the HD2D protein …

Mechanisms Of Neuroprotection Against Ischemic Insult By Stress-Inducible Phosphoprotein-1, Jason Xu

Electronic Thesis and Dissertation Repository

Stress-inducible phosphoprotein-1 (STI1) levels are increased in the brain following ischemia. STI1 is a co-chaperone for Hsp70/Hsp90 modulating protein folding. STI1 can also be secreted by a number of cells and function to activate extracellular signalling by the prion protein (PrP^C) and type-I bone morphogenetic protein receptor ALK2. However, the mechanisms by which STI1 can protect neurons against ischemia are currently unknown. A caspase-3 reporter mouse line was used to evaluate the consequences of increased extracellular STI1 levels. Neurons were treated with recombinant STI1 and specific agonists/antagonists for PrP^C, α7nAChR, and ALK2 prior to oxygen-glucose deprivation …

Application Of 3d Printing Technology In Porous Anode Fabrication For Enhanced Power Output Of Microbial Fuel Cells, Bin Bian

Electronic Thesis and Dissertation Repository

Microbial fuel cells (MFCs) are widely researched for application in wastewater treatment. However, the current anodes used in MFCs often suffer from high fabrication cost and uncontrollable pore sizes. In this thesis, three-dimensional printing technique was utilized to fabricate anodes with different micro pore sizes for MFCs. Copper coating and carbonization were applied to the printed polymer anodes to increase the conductivity and specific surface area. Voltages of MFCs with various anodes were measured as well as other electrochemical tests such as linear sweep voltammetry and electrochemical impedance spectroscopy. 3D copper porous anode produced higher maximum voltages and power densities …

Characterizing The C-Terminal Region Of Human Adenovirus E1a: An Undiscovered Country, Michael J. Cohen

Electronic Thesis and Dissertation Repository

Human Adenovirus (HAdV) E1A is the first protein expressed during viral infection. The primary function of E1A is to reprogram the cell for viral replication, but it is additionally capable of transforming primary rodent cells in co-operation with other oncogenes such as HAdV E1B. Despite extensive study, little is known about the function and cellular targets of the C-terminal region of E1A. Importantly, this region is required for the transforming ability of E1A with E1B, but can also suppress transformation with Ras. Previous studies showed that interaction with the C-terminal Binding Protein (CtBP) plays a role in both functions described …

Purification Of Recombinant Proteins In Plants Using Small-Molecule Dependent Inteins Fused To Elp Or Hfbi, Kira Liu

Electronic Thesis and Dissertation Repository

Elastin-like polypeptides (ELP) and hydrophobins (HFBI) are fusion tags which enhance the accumulation levels of recombinant proteins in plants and aid in the non-chromatographic purification of these proteins. An intein is inserted between the target protein and fusion tag to replace the protease cleavage site. In this study, transient expression of intein-GFP fused to ELP or HFBI in Nicotiana benthamiana yielded the full size fusion protein. The ELP-fused proteins were successfully purified using inverse transition cycling (ITC) with 1.0 M NH4(SO4)2 at room temperature. However, the purification using membrane ITC was unsuccessful due to clogged membrane pores. Purification of HFBI-fused …

Analyzing A-Series Gangliosides In Neurons Following Exposure To Glutamate, Dae Hee Park

Electronic Thesis and Dissertation Repository

Neurons within different brain regions have varying levels of vulnerability to external stress and therefore respond differently to injury. A potential reason to explain this may lie within a key lipid class of the cell’s plasma membrane called gangliosides. These glycosphingolipid species have been shown to play various roles in the maintenance of neuronal viability. The purpose of this study is to use electrospray ionization mass spectrometry (ESI-MS) technique and immunohistochemistry to evaluate the temporal changes in the expression profiles of various ganglioside species during the course of neurodegeneration in rat primary cortical neurons exposed to glutamate toxicity. Primary embryonic …

Underlying Mechanisms Regulating Gingival Healing And Fibrosis, Shawna Soheun Kim

Electronic Thesis and Dissertation Repository

Successful wound healing involves tightly controlled regulation of extracellular matrix (ECM) deposition and remodeling, and myofibroblast-mediated wound contraction, to restore normal tissue function. However, these events involved in healing are also associated with development of tissue fibrosis, which is characterized by excessive deposition of ECM and the presence of myofibroblasts. Increasing evidence suggests that periostin is a critical player in regulating skin healing and fibrosis. In contrast to most adult tissues, gingival connective tissue is known to heal more rapidly and with less scarring, yet is still associated with fibrosis, such as drug-induced gingival enlargement. The aim of this study …

Investigating The Fibroblastic Origin Of Skin-Derived Precursors And The Role Of Ccn2 As A Mediator Of Myofibroblastic Differentiation, Matthew Tsang

Electronic Thesis and Dissertation Repository

Skin-derived precursors (SKPs) are defined as multipotent spheroid-forming cells cultured from the dermis that express markers of neural crest origin. Recent evidence suggests that tissue fibrosis can occur through the differentiation of progenitor cells into smooth muscle-like myofibroblasts. CCN2, a marker and mediator of fibrosis, is highly expressed during myofibroblast differentiation and is required for skin fibrogenesis. Here, I clarify the cellular origin of SKPs, and the molecular contribution of CCN2 in the myofibroblastic differentiation of SKPs. Using lineage tracing, I show that SKPs originate primarily from Col1a2-expressing dermal fibroblasts. Furthermore, I show that differentiation of SKPs into myofibroblasts requires …

Diabetic Bone Marrow & Stem Cell Dysfunction, Meghan A. Piccinin

Electronic Thesis and Dissertation Repository

ii Abstract Abstract Defects in the proliferation, differentiation, and activity of bone marrow (BM)-derived vasculogenic/vascular stem cells (VSCs) have been observed in diabetes and contribute to the development of vascular complications. Diabetes leads to enhanced bone marrow adipogenesis, altering the composition of the BM stem cell (SC) niche and potentially disrupting the normal functioning of resident VSCs. Here, I establish that adipocytes have a negative influence on SC survival in culture. I also show that adipocytes and osteoblasts are responsible for the creation of distinct extracellular microenvironments, with unique expression patterns of several pro- and anti-angiogenic factors with known effects …

Soybean Isoflavonoid Biosynthesis: Constituents And Circumstance At The Transcriptomic And Molecular Levels, Mehran Dastmalchi

Electronic Thesis and Dissertation Repository

Isoflavonoids are specialized metabolites, almost exclusive to the legume family of plants. They are actors in symbiosis with nitrogen-fixing bacteria and in plant stress response. Isoflavonoids are noted for their human health benefits. Isoflavonoid content in legumes has proven to be a complex trait. The goal of the present research is to determine the mechanisms underlying isoflavonoid biosynthesis in soybean.

The first approach was to unravel the genetic factors of isoflavonoid biosynthesis. A branch-point enzyme of the phenylpropanoid pathway, chalcone isomerase (CHI), catalyzes the reaction producing flavanones, the nucleus for many downstream metabolites such as isoflavonoids. I identified twelve soybean …