We attempted to understand the molecular regulators that impact inflammation using a rat model of human sensation-seeking/risk-taking trait for drug and stress vulnerability, based on their exploratory behavior displaying high rates (HRs) or low rates of locomotor reactivity (LRs) to environmental stress. We found that HRs have a pro-inflammatory phenotype as indicated by increased protein expression of the inflammatory cytokine TNF-(Sa(B. Furthermore, we found that HRs have a lower gene expression of the glucocorticoid receptor and histone deacetylase 2 which are known to play an immunosuppressive role. Autophagy (macroautophagy) is a homeostatic process needed for cell maintenance, growth and proliferation and known to assist in tumor survival. FYVE and coiled-coil domain containing 1 (FYCO1) is a novel protein implicated to assist in the plus-end directed trafficking and fusion of autophagosomes. In these studies, we show that FYCO1 gene expression among human breast cell lines of varying degrees of malignancy. / Lillian C. Onwuka-Ekpete. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Metastatic cancers are problematic because they spread throughout the body. A crucial step in cancer metastasis is the separation of the cancer cells from their surrounding normal cells. This occurs due to suppression or destruction of cell adhesion molecules such as E-cadherin, occludin, and various claudins. The Snail and Slug transcription factors play a direct role in suppressing these cell adhesion molecules through their SNAG repression domain. We explored the possibility of developing an ELISA diagnostics capable of detecting soluble E-cadherin, occludin, and claudin fragments in the serum of cancer patients. Using several bioinformatics tools, unique extracellular antigenic sequences were identified on claudins-1, 4, 16, occludin, and E-cadherin. These sequences were cloned as GST fusion proteins, expressed, and purified in large quantities to raise antibodies. In parallel, expression profiling of metastatic cancer cell lines was carried out to derive a correlation between Snail-Slug expression and suppression of cell adhesion molecules. / by Michael Irvine. / Thesis (M.S.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

Small conductance calcium-activated potassium (SK) channels are found ubiquitously throughout the brain and modulate the encoding of learning and memory. Systemic injection of 1-ethyl-2-benzimidalzolinoe (EBIO), a SK channel activator, impairs the encoding of novel object memory and locomotion but spares fear memory encoding in C57BL/6NHsd mice. The memory impairments discovered were not due to non-cognitive performance confounds such as ataxia, anxiety, attention or analgesia. Further investigation with intra-hippocampal application of EBIO revealed SK channels in dorsal CA1 contribute to the encoding deficits seen systemically, but do not account for the full extent of the impairment. Concentrated activation of dorsal CA1 SK channels do not influence fear memory encoding or locomotor impairments. Taken together, these data indicate SK channels, especially in the dorsal hippocampus, have a modulatory role on novel object memory encoding, but not retrieval; however, pharmacological activation of hippocampal SK channels does not appear to influence fear memory encoding. / by Kyle A. Vick, IV. / Thesis (M.A.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

p-21-activated kinase 6 (PAK6) is a serine-threonine protein kinase originally identified as an Androgen Receptor (AR) interacting protein. In current study, we determined the subcellular localization of PAK6 through mutational analysis. We have found that the N-terminal CRIB domain is partly responsible for plasma membrane targeting, the region between amino acid residues #292 to #368 is functionally relevant to plasma membrane localization and that amino acid residues #119 through #190 are responsible for nuclear targeting of PAK6, in addition to a stretch of positively charged N-terminal residues (#2-#11) since mutants lacking this sequence mis-localizes to cytoplasm. In junction forming epithelial cells, PAK6 is demonstrated to co-localize with B-catenin at adherens junctions, suggesting that PAK6 is an activation-dependent event and that PAK6 translocates from plasma membrane to the cytoplasm in response activation via the PKA signal pathway. / by Ciny John. / Thesis (M.S.)--Florida Atlantic University, 2012. / Includes bibliography. / Mode of access: World Wide Web. / System requirements: Adobe Reader.

Neuronal cell adhesion molecules of L1 family play a critical role in proper nervous system development. Various mutations on human L1-CAM that lead to severe neurodevelopmental disorders like retardation, spasticity etc. termed under L1 syndrome. The vertebrr their roles in axon pathfinding, neurite extension and cell migration, howeverate L1CAM and its homolog in Drosophila, neuroglian (nrg) have been well studied fo, much less is known about the mechanisms by which they fine tune synaptic connectivity to control the development and maintenance of synaptic connections within neuronal circuits. Here we characterized the essential role of nrg in regulating synaptic structure and function in vivo in a well characterized Drosophila central synapse model neuron, the Giant Fiber (GF) system. Previous studies from our lab revealed that the phosphorylation status of the tyrosine in the Ankyrin binding FIGQY motif in the intracellular domain of Nrg iscrucial for synapse formation of the GF to Tergo-Trochanteral Motor neuron (TTMn) synapse in the GF circuit. The present work provided us with novel insights into the role of Nrg-Ank interaction in regulating Nrg function during synapse formation and maintenance. By utilizing a sophisticated Pacman based genomic rescue strategy we have shown that dynamic regulation of the Neuroglian–Ankyrin interaction is required to coordinate transsynaptic development in the GF–TTMn synapse. In contrast, the strength of Ankyrin binding directly controls the balance between synapse formation and maintenance at the NMJ. Human L1 pathological mutations affect different biological processes distinctively and thus their proper characterization in vivo is essential to understand L1CAM function. By utilizing nrg14;P[nrg180ΔFIGQY] mutants that have exclusive synaptic defects and the previously characterized nrg849 allele that affected both GF guidance and synaptic function, we were able to analyze pathological L1CAM missense mutations with respect to their effects on guidance and synapse formation in vivo. We found that the human pathological H210Q, R184Q and Y1070C, but not the E309K and L120V L1CAM mutations affect outside-in signaling via the FIGQY Ankyrin binding domain which is required for synapse formation and not for axon guidance while L1CAM homophilic binding and signaling via the ERM motif is essential for axon guidance in Drosophila. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection

Aging is a biological process that has many detrimental effects due to the accumulation of oxidative damage to key biomolecules due to the action of free radicals. Methionine sulfoxide reductase (Msr) functions to repair oxidative damage to methionine residues. Msr comes in two forms, MsrA and MsrB, each form has been shown to reduce a specific enantiomer of bound and free oxidized methionine. Effects of Msr have yet to be studied in the major developmental stages of Drosophila melanogaster despite the enzymes elevated expression during these stages. A developmental timeline was determined for MsrA mutant, MsrB mutant, and double null mutants against a wild type control. Results show that the Msr double mutant is delayed approximately 20 hours in the early/mid third instar stage while each of the single mutants showed no significant difference to the wild type. Data suggests that the reasoning of this phenomenon is due to an issue gaining mass. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2013. / FAU Electronic Theses and Dissertations Collection

Transcription factors are macromolecules that are involved in transcriptional regulation by interacting with specific DNA regions, and they can cause activation or silencing of their target genes. Gene regulation by transcriptional control explains different biological processes such as development, function, and disease. Even though transcriptional control has been of great interest for molecular biology, much still remains unknown. This study was designed to generate the most current list of human transcription factor genes. Unique entries of transcription factor genes were collected and entered into Microsoft Office 2007 Access Database along with information about each gene. Microsoft Office 2007 Access tools were used to analyze and group collected entries according to different properties such as activator or repressor record, or presence of certain protein domains. Furthermore, protein sequence alignments of members of different groups were performed, and phylogenetic trees were used to analyze relationship between different members of each group. This work contributes to the existing knowledge of transcriptional regulation in humans. / by Ala Savitskaya. / Thesis (M.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.

RNA damage occurring under oxidative stress has been shown to cause RNA dysfunction and must be detrimental to cells and organisms. We propose that damaged RNA can be removed by specific RNA surveillance activities. In this work, we investigated the role of polynucleotide phosphorylase (PNPase), a 3'->5' exoribonuclease, in protecting the cells against oxidative stress and eliminating oxidatively-damaged RNA. Previously, it was reported that E. coli PNPase has a higher affinity to poly(8-oxoG:A). We further confirmed that E. coli PNPase can specifically bind to an oxidized RNA with a high affinity. An E. coli strain deficient in PNPase (pnp) is hypersensitive to hydrogen peroxide (H2O2). Importantly, the level of H2O2-induced RNA damage, measured by the content of 8-hydroxyguanosine, increases significantly in the pnp mutant cells. Consistent with the notion that PNPase plays a direct role in these processes, introduction of the pnp gene encoding E. coli PNPase can restore the viability and RNA oxidation level of the pnp mutant cells in response to H2O2 treatment. Interestingly, degradosome-association is not required for PNPase to protect cell against oxidative stress. PNPase is evolutionary conserved in most of organisms of all domains of life. The human polynucleotide phosphorylase (hPNPase) localizes mainly in mitochondria and plays pleiotropic roles in cell differentiation and has been previously shown to bind 8- oxoG-RNA with a high affinity. Here we show that similar to E. coli PNPase, hPNPase plays an indispensable role in protecting HeLa cells against oxidative stress. The viability in HeLa cell and 8-oxoG levels in RNA are inversely correlated in response to H2O2- treatment. After removal of oxidative challenge, the elevated level of 8-oxoG in RNA decreases, suggesting the existence of surveillance mechanism(s) for cleaning up oxidized RNA. / We have shown that hPNPase may be responsible for the surveillance of oxidized RNA in mammalian cells.Overexpresion of hPNPase reduces RNA oxidation and increases HeLa cell viability against H2O2 insult. Conversely, hPNPase knockdown decreases the viability and increases 8-oxoG level in HeLa cells exposed to H2O2. Taken together, our results suggest that RNA oxidation is a challenging problem for living organisms, and PNPase may play an important role in protecting both prokaryotic and eukaryotic cells by limiting damage to RNA under oxidative stress. / by Jinhua Wu. / Thesis (Ph.D.)--Florida Atlantic University, 2008. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2008. Mode of access: World Wide Web.

Experimentally naive rats exhibit varying degrees of novelty exploration. Some rats display high rates of locomotor reactivity to novelty (high responders; HR), and others display low rates (low responders; LR). The novelty-seeking phenotype (LRHR) is introduced as a model of stress responsiveness. In this thesis I examined effects of chronic variable physical and social stress or control handling on the levels of various neurotrophins in the hippocampus, and changes in mossy fibre terminal fields in LRHR rats. A positive correlation is seen between histone deacetylase 2 and brain-derived neurotrophic factor (BDNF) levels both of which are oppositely regulated in LRHR CA3 fields in response to chronic social stress. Increase in BDNF levels in CA3 field accompanied increase in supra-pyramidal mossy fibre terminal field size (SP-MF) in HRs, and decrease in BDNF levels accompanied decrease in SP-MF volume in LRs. Epigenetic regulation of neurotrophic support underlying these structural changes is discussed. / by Ozge Oztan. / Thesis (M.S.)--Florida Atlantic University, 2009. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2009. Mode of access: World Wide Web.

Alterações genéticas nos genes RET, RAS e BRAF resultam na ativação constitutiva da sinalização MAPK e estão presentes em aproximadamente 70% dos carcinomas papilífero de tiroide, a forma mais prevalente de câncer de tiroide. Múltiplas vias de sinalização podem atuar em conjunto com a via MAPK na oncogênese tiroidiana. Nesse estudo, testamos a hipótese que a via MAPK regula a sinalização Notch e que o crosstalk entre as vias de sinalizações são importantes na regulação da diferenciação e proliferação celular no câncer de tiroide. A ativação condicional dos oncogenes RET/PTC3 e BRAFT1799A em linhagem de célula folicular normal de tiroide aumentou a atividade da via de sinalização Notch. Por outro lado, o bloqueio farmacológico da sinalização MAPK reduziu a sinalização Notch na linhagem celular TPC-1 derivada de carcinoma papilífero de tiroide. Glândulas tiroide de animais transgênicos expressando BRAFT1799A e amostras de carcinoma papilífero de tiroide apresentaram elevados níveis de NOTCH1. A superexpressão de NOTCH1 em célula folicular normal de tiroide aumentou a expressão proteica de NIS. A inibição farmacológica e por RNA de interferência da sinalização Notch apresentou um efeito anti-proliferativo em linhagem de CPT. Além disso, a combinação do inibidor farmacológico de Notch e MAPK diminuiu a proliferação de células de carcinoma papilífero de tiroide. Esses dados sugerem um importante papel da sinalização Notch na oncogênese do carcinoma papilífero de tiroide induzida pela sinalização MAPK e que a via Notch pode ser uma potencial terapia adjuvante no câncer de tiroide. / Genetic alterations in RET, RAS and BRAF result in constitutive activation of the MAPK signaling and are present in approximately 70% of papillary thyroid carcinomas, the most prevalent form of thyroid cancer. Multiple signaling pathways can act with MAPK pathway in thyroid oncogenesis. In this study, we tested the hypothesis that MAPK pathway control Notch signaling and that the crosstalk between these pathways plays an important role in thyroid cancer cell differentiation and proliferation. The conditional activation of RET/PTC3 and BRAFT1799A enhanced Notch signaling pathway in normal follicular thyroid cell. By contrast, pharmacological inhibition of MAPK reduced Notch signaling in TPC-1 cell line derived from papillary thyroid carcinoma. Transgenic mice expressing BRAFT1799A restrict in thyroid gland and human papillary thyroid carcinoma samples showed higher Notch1 expression. NOTCH1 overexpression in normal thyroid follicular cell increased NIS protein expression. Pharmacological inhibition and RNA interference of Notch signaling showed an anti-proliferative effect in papillary thyroid carcinoma cells. Furthermore, the combination of MAPK and Notch signaling inhibitors reduced papillary thyroid carcinoma proliferation. These data suggest an important role of Notch signaling in papillary thyroid carcinoma induced by MAPK-related oncogenes and that Notch signaling pathway could be a potential adjuvant therapy in thyroid cancer.