Molecular Biology Commons^™

Chemoenzymatic Studies To Enhance The Chemical Space Of Natural Products, Jhong-Min Chen

Theses and Dissertations--Pharmacy

Natural products provide some of the most potent anticancer agents and offer a template for new drug design or improvement with the advantage of an enormous chemical space. The overall goal of this thesis research is to enhance the chemical space of two natural products in order to generate novel drugs with better in vivo bioactivities than the original natural products.

Polycarcin V (PV) is a gilvocarcin-type antitumor agent with similar structure and comparable bioactivity with the principle compound of this group, gilvocarcin V (GV). Modest modifications of the polyketide-derived tetracyclic core of GV had been accomplished, but the most …

An Nmr-Guided Approach To The Isolation Of Secondary Metabolites From Nrps And Pks Gene Clusters, Connor Craig

Honors Theses

Secondary metabolites continue to offer a promising source of novel chemical entities with therapeutic bioactivities. Our research aims to isolate secondary metabolites produced by non-ribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) constructs. A metagenomic library was created from the marine bacterium Pseudoalteromonas sp., which was isolated from the Chesapeake Bay sponge Halichondria bowerbanki. Using a functional screen for PPTase activity we were able to identify colonies that contained NRPS and PKS gene clusters. Cultures of this microbe have been produced and analyzed using a combination of chromatography and 1H, 13C, HMBC, HSQC, COSY, AND NOESY NMR spectra. …

Development Of A Genetic Over-Expression System For The Freshwater Sponge Ephydatia Muelleri, Joe Walsh

Honors Theses

The aim of this work is to develop an over-expression system for Ephydatia muelleri. Preliminary work by Klaske Schippers (Schippers, 2013) showed sponges were induced to transcribe reporter genes driven by the widely used cytomegalovirus promoter (CMV). Building off Schippers work, newly identified native Ephydatia promoters were identified from the genome and verified to drive expression ofreporter genes. Validated over-expression vectors and transfection technology will allow researchers around the world who are working with this organism to ask questions about cell specification, gene regulation and animal development.

Purification And Characterization Of Bcsc; An Integral Component Of Bacterial Cellulose Export, Emily D. Wilson Ms

Theses and Dissertations (Comprehensive)

Biofilms are a growing concern in the medical field due to their increased resistance to antibiotics. When found in a biofilm, bacteria can have antibiotic resistance 10-1000 times that of their planktonic counterparts. Therefore, it is important to study the formation of biofilms. Cellulose biofilms are formed by Enterobacteriaceae, such as many Escherichia coli and Salmonella spp. strains. Biofilms provide these species with benefits including antimicrobial protection, development of bacterial communities, promotion of DNA exchange, uptake of nutrients, and, in the case of cellulose biofilms, immune system evasion. Cellulose biofilms are controlled by the Bacterial cellulose synthesis (Bcs) complex located …

Evaluation Of Inhibitors Of Histone Deacetylases As Potential Neurotrophic Agents, Surabhi Shukla

Electronic Theses and Dissertations

The inhibitors of histone deacetylases (HDACs) have shown promising neuroprotective and neuroactive properties. A set of pan- and isoform-specific HDAC inhibitors were evaluated for neurotrophic activity on Neuroscreen-1 (NS-1) cells, a subclone of PC-12 (rat pheochromocytoma) cells.

The HDAC inhibitors were tested alone and in combination with nerve growth factor (NGF). An in vitro method has been standardized that measures neurite outgrowth along with cytotoxicity of test compounds in a single assay. The neurotrophin signaling pathways were interrogated with selective inhibitors of MEK1/2 (PD98059/U0126) PI3K (LY294002) and TrkA (GW441756) and phosphorylation of target kinases. Associated factors namely, acetylation of histones …

Cross-Talk Between The Tumor Suppressors Par-4 And P53, Tripti Shrestha Bhattarai

Theses and Dissertations--Toxicology and Cancer Biology

This work describes the fascinating interplay between two tumor suppressors Prostate apoptosis response-4 (Par-4) and p53. The guardian of the genome, p53, is frequently mutated in human cancers, and may contribute to therapeutic resistance. However, p53 is intact and functional in normal tissues, and we observed that specific activation of p53 in normal fibroblasts could induce apoptosis selectively in p53-deficient cancer cells. This paracrine apoptotic effect was executed by Par-4 secreted in response to p53 activation. Accordingly, activation of p53 in wild-type mice, but not in p53^-/- or Par-4^-/- mice, caused systemic elevation of Par-4 that induced apoptosis …

Altered Connexin 43 Expression Underlies Age-Dependent Decrease Of Regulatory T Cell Suppressor Function In Nonobese Diabetic Mice, Michel Kuczma, Cong-Yi Wang, Leszek Ignatowicz, Robert Gourdi, Piotr Kraj

Biological Sciences Faculty Publications

Type 1 diabetes is one of the most extensively studied autoimmune diseases, but the cellular and molecular mechanisms leading to T cell–mediated destruction of insulin-producing β cells are still not well understood. In this study, we show that regulatory T cells (T_regs) in NOD mice undergo age-dependent loss of suppressor functions exacerbated by the decreased ability of activated effector T cells to upregulate Foxp3 and generate T_regs in the peripheral organs. This age-dependent loss is associated with reduced intercellular communication mediated by gap junctions, which is caused by impaired upregulation and decreased expression of connexin 43. Regulatory …

Parental Rna Interference Of Genes Involved In Embryonic Development Of The Western Corn Rootworm, Diabrotica Virgifera Virgifera Leconte, Chitvan Khajuria, Ana Maria Vélez, Murugesan Rangasamy, Haichuan Wang, Elane Fishilevich, Meghan L.F. Frey, Newton Portilho Carneiro, Premchand Gandra, Kenneth E. Narva, B. D. Siegfried

Department of Entomology: Faculty Publications

RNA interference (RNAi) is being developed as a potential tool for insect pest management and one of the most likely target pest species for transgenic plants that express double stranded RNA (dsRNA) is the western corn rootworm. Thus far, most genes proposed as targets for RNAi in rootworm cause lethality in the larval stage. In this study, we describe RNAi-mediated knockdown of two developmental genes, hunchback (hb) and brahma (brm), in the western corn rootworm delivered via dsRNA fed to adult females. dsRNA feeding caused a significant decrease in hb and brm transcripts in the adult …

The Mir-17-92 Cluster Contributes To Mll Leukemia Development Through The Repression Of The Meis1 Competitor Pknox1, Yousaf Anwar Mian

Dissertations

Mixed lineage leukemias have a relatively poor prognosis and arise as a result of translocations between the MLL gene and one of multiple partner genes. Downstream targets of MLL are aberrantly upregulated and include the developmentally important HOX genes and MEIS1, as well as multiple miRNAs, including the miR-17-92 cluster and miR-196b. Here I utilize custom anti-miRNA oligonucleotides to examine the contribution of specific miRNAs to MLL leukemias both as individual miRNAs and in cooperation with other miRNAs. Combinatorial treatment with antagomirs against miR-17 and miR-19a of the miR-17-92 cluster dramatically reduces colony forming ability of MLL-fusion containing cell lines …

Identifying The Amino Acids Important For Hiv Rev-Tubulin Interactions, Bruce E. Dukes Ii

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The Rev protein is Human Immunodeficiency virus's "switch" from events occurring early in infection to later events. Early in infection, the 13 KDa Rev protein begins to accumulate in the host cell nucleus. Once enough Rev is produced, Rev stimulates a switch in viral gene expression by multimerizing onto nuclear viral RNAs and stimulating their export into the cytoplasm. Multimerization occurs on an RNA structure called the Rev Response Element (RRE). Several Rev monomers bind the RRE and once that threshold is met the Rev-RRE complex is exported out of the nucleus. Once out of the nucleus the Rev-RRE complex …

Drosophila Cyclin J And The Somatic Pirna Pathway Cooperate To Regulate Germline Stem Cells, Paul Michael Albosta

Wayne State University Dissertations

Cyclin J (CycJ) is a highly conserved cyclin that is uniquely expressed specifically in ovaries in Drosophila. Deletion of the genomic region containing CycJ and adjacent genes resulted in a genetic interaction with neighboring piRNA pathway gene, armitage (armi). Here I assessed oogenesis in CycJ null in the presence or absence of mutations in armi or other piRNA pathway genes. Although CycJ null flies had decreased egg laying and hatching rates, ovaries appeared normal indicating that CycJ is dispensable for oogenesis under normal conditions. Further double mutant analysis of CycJ and neighbor armi, as well as two other piRNA pathway …

Analyzing The Interactions Of Kdm5/Lid And Sin3 In Drosophila Melanogaster, Ambikai Gajan

Wayne State University Dissertations

SIN3, the scaffold protein of a histone modifying complex is conserved from yeast to mammals. Drosophila SIN3 associates with both a histone deactylase RPD3 and a histone demethylase dKDM5/LID. Immunopurification of dKDM5/LID verifies a previously observed interaction with SIN3 and RPD3. Furthermore, deficiency of dKDM5/LID phenocopies deficiency of SIN3 in many cellular and developmental processes. Knockdown of both Sin3A and lid hinder cell proliferation in Drosophila cultured cells and developing flies. Knockdown of these genes also results in a curved wing phenotype implicating a role in wing development. Analysis of underlying gene expression changes upon decreased expression of SIN3, dKDM5/LID …

The Role Of Crebh In Hepatic Energy Regulation Under Metabolic Stress, Roberto Mendez

Wayne State University Dissertations

Lipid metabolism is tightly regulated by nuclear receptors, transcription factors, and cellular enzymes in response to nutritional, hormonal, and stress signals. Hepatocyte specific, cyclic AMP responsive element-binding protein (CREBH) is a transcription factor that is preferentially expressed in the liver and localized in the endoplasmic reticulum (ER) membrane. CREBH is known to be activated by ER stress, inflammatory stimuli, and metabolic signals to regulate hepatic acute-phase response, lipid metabolism, and glucose metabolism. In my thesis research, I have characterized the roles and mechanisms of CREBH in these functions, as well as the overall phenotype of CrebH-null mice. I demonstrated that …

Crebh, A Novel Liver Clock Keeper For Energy Metabolism, Ze Zheng

Wayne State University Dissertations

Circadian rhythms play crucial roles in orchestrating diverse physiological processes that are critical for health and disease. Cyclic AMP responsive element binding protein 3-like 3 (CREB3L3, also known as CREBH) is a liver-enriched, endoplasmic reticulum (ER)-tethered transcription factor known to regulate hepatic acute-phase response and energy homeostasis under stress conditions. Here, we demonstrate that CREBH is regulated by the circadian clock and functions as a diurnal regulator of hepatic lipid and glucose metabolism. CREBH is required to maintain circadian profiles of blood triglycerides, fatty acids, and glucose as well as hepatic glycogen storage. CREBH rhythmically regulates expression levels and amplitudes …

Hrd1 Partners In Endoplasmic Reticulum-Associated Degradation, Aaron Alexander Burr

Wayne State University Dissertations

Protein Quality Control (PQC) comprises cellular pathways that regulate the turnover of short-lived, misfolded proteins. A main component of PQC is Endoplasmic Reticulum (ER)-Associated Degradation (ERAD), which controls the degradation of proteins synthesized in the ER. Aberrations in ERAD have been linked to malignancies such as sarcomas, breast, and pancreatic carcinomas, as well as neurodegenerative disease. The machinery in this system is complex and while significant progress has been made to understand ERAD, it is not clear how the different components come together, or how they are regulated. HRD1 is a resident ubiquitin ligase that has been proposed as a …

Soy Isoflavones Mediate Radioprotection Of Normal Lung Tissue By Modulating The Radiation-Induced Inflammatory Response, Lisa Marie Abernathy

Wayne State University Dissertations

Radiation-induced lung injury (RILI) is caused by an early inflammatory process triggered by damage to lung parenchyma, epithelial cells, vascular endothelial cells and stroma. Initially, oxidative injuries after radiation induce altered expression of pro-inflammatory cytokines. Infiltrating inflammatory cells are stimulated and activated, producing additional mediators, resulting in a cytokine cascade. The expansion and perpetual activation of inflammatory cells, as well as lung parenchyma, lead to clinical pneumonitis. Activated cells produce molecular mediators and growth factors that affect the proliferation and gene expression of lung fibroblasts. This process leads to increased collagen synthesis and deposition, eventually leading to the development of …

Functional Analysis Of A Highly Conserved Cyclin, Cyclin Y, In Drosophila Melanogaster, Nermin Gerges

Wayne State University Dissertations

Cyclin Y is a highly conserved member of the Cyclin superfamily of proteins. In Drosophila the Cyclin Y gene (CycY) is required for progression through several stages of development but the specific pathways that Cyclin Y belongs to and that account for its requirement are not known. Studies in human and Drosophila cell lines have shown that membrane-localized Cyclin Y is required for phosphorylation of the wingless/Wnt co-receptor, arrow/LRP6, and for full activation of the canonical wingless/Wnt pathway. CycY null Drosophila, however, do not phenocopy loss-of-function mutations in canonical wingless pathway genes, suggesting that Cyclin Y may have additional roles …

Towards A Unified Model Of Sperm Chromatin Structure, Graham Johnson

Wayne State University Dissertations

Sperm possess several layers of information that are delivered to the oocyte alongside the paternal DNA. Examples of potential sperm borne molecular cues of probable use to the embryo include RNAs and local and global chromatin structure. To identify candidate sperm RNAs that likely reach the oocyte cytoplasm following fertilization patterns of transcript compartmentalization in the mature gamete were identified. Though all sperm RNAs exhibited a preferential peripheral enrichment, a subset of RNAs were identified in which this trend was reduced. These RNAs are thought to be embedded with perinuclear theca and are correlated with late spermatogenic transcription. Malat1, a …

Liver Perilipin 5 Expression Worsens Hepatosteatosis But Not Insulin Resistance In High Fat-Fed Mice, Michelle B. Trevino, David Mazur-Hart, Yui Machida, Timothy King, Joseph Nadler, Elena V. Galkina, Arjun Poddar, Sucharita Dutta, Yumi Imai

Mathematics & Statistics Faculty Publications

Perilipin 5 (PLIN5) is a lipid droplet (LD) protein highly expressed in oxidative tissues, including the fasted liver. However, its expression also increases in nonalcoholic fatty liver. To determine whether PLIN5 regulates metabolic phenotypes of hepatosteatosis under nutritional excess, liver targeted overexpression of PLIN5 was achieved using adenoviral vector (Ad-PLIN5) in male C57BL/6J mice fed high-fat diet. Mice treated with adenovirus expressing green fluorescent protein (GFP) (Ad-GFP) served as control. Ad-PLIN5 livers increased LD in the liver section, and liquid chromatography with tandem mass spectrometry revealed increases in lipid classes associated with LD, including triacylglycerol, cholesterol ester, and phospholipid classes, …

The Endosomal Sorting Complex Required For Transport Pathway Mediates Chemokine Receptor Cxcr4 Akt Signaling By Promoting Lysosomal Degradation Of Mtor Antagonist Deptor, Rita Ramkaran Verma

Dissertations

The chemokine receptor CXCR4 is a member of the G protein-coupled receptor (GPCR) family. The cognate ligand for CXCR4 is the C-X-C chemokine known as CXCL12. The CXCL12/CXCR4 signaling axis is essential for a number of developmental processes including organogenesis, vascularization of the GI tract and hematopoiesis. Dysregulated CXCR4 signaling is also implicated in a variety of pathological conditions such as WHIM (Warts, Hypogammaglobunemia, Infections and myelokathexis) syndrome, cardiovascular disease and cancer. Despite its role in several pathologies, the molecular mechanisms mediating CXCR4 signaling are not completely understood. Upon CXCL12 binding to CXCR4, several signaling pathways are activated including the …

Characterization Of The Nodamura Virus Rna Dependent Rna Polymerase And Formation Of Rna Replication Complexes In Mammalian Cells, Vincent Ulysses Gant

Open Access Theses & Dissertations

Positive-strand RNA viruses amplify their genomes in membrane-bound structures associated with intracellular membranes and organelles called replication complexes (RCs). Here, we begin to elucidate mechanisms of Nodamura virus (NoV; family Nodaviridae) RC assembly. The literature reports that NoV-infected muscle tissue exhibits mitochondrial aggregation and rearrangement of mitochondrial structure, leading to disorganization of the muscle fibrils. However, the molecular basis for this pathogenesis and the role of mitochondria in NoV infection remained unclear until now. We tested the hypoThesis that NoV establishes RCs in association with mitochondria in cultured mammalian cells at physiological temperature. We used immunofluorescence confocal microscopy and biochemical …

Ex Vivo Dna Cloning, Adam B. Fisher

Theses and Dissertations

Genetic engineering of microbes has developed rapidly along with our ability to synthesize DNA de novo. Yet, even with decreasing DNA synthesis costs there remains a need for inexpensive, rapid and reliable methods for assembling synthetic DNA into larger constructs or combinatorial libraries. While technological advances have resulted in powerful techniques for in vitro and in vivo assembly of DNA, each suffers inherent disadvantages. Here, an ex vivo DNA cloning suite using crude cellular lysates derived from E. coli is demonstrated to amplify and assemble DNA containing small sequence homologies. Further, the advantages of an ex vivo approach are …

Functional Characterization Of Rai1 In Zebrafish, Joshua S. Beach

Theses and Dissertations

Smith-Magenis Syndrome (SMS; OMIM #182290) is a multiple congenital abnormality and intellectual disability (ID) disorder caused by either an interstitial deletion of the 17p11.2 region containing the retinoic acid induced-1 (RAI1) gene or a mutation of the RAI1 gene. Individuals diagnosed with SMS typically present characteristics such as ID, self-injurious behavior, sleep disturbance, ocular and otolaryngological abnormalities, craniofacial and skeletal abnormalities, neurological and behavioral abnormalities, as well as other systemic defects and manifestations. Previous work by Vyas in 2009 showed temporal expression of rai1 in zebrafish embryos as early as 9 hpf. We hypothesize that there is maternal …

Rheb Dynamics On Lysosomal Membranes Determines Mtorc1 Activity After Loss Of P53 Or Activation Of Ampk, Catherine M. Bell

Theses and Dissertations

The tumor suppressor TP53 is the most frequently altered gene in human cancers. The growth-promoting complex, mTORC1 plays a part of the oncogenic profile caused by dysfunctional p53. mTORC1 sits downstream of AMPK and other crucial tumor suppressors/oncogenes, PTEN, LKB1, and Akt. The antifolate pemetrexed was found by this laboratory to activate AMPK via the inhibition of the enzyme AICART in de novo purine synthesis. This work presents a mechanism of mTORC1 activation with p53 loss, as well as of mTORC1 inhibition by pemetrexed-induced AMPK. We have found that mTORC1 activity was substantially upregulated by the loss …

Distinguishing Melanocytic Nevi From Melanoma By Dna Copy Number Changes: Array-Comparative Genomic Hybridization As A Research Tool, Ahmed Ibrahim Mahas

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Skin melanocytes can give rise to different benign and malignant neoplasms. Discrimination of an early melanoma from an unusual/atypical benign nevus can represent a significant challenge. However, previous studies have shown that in contrast to benign nevi, melanoma demonstrates pervasive chromosomal aberrations. This substantial difference between melanoma and benign nevi formed the idea of exploiting this difference to discriminate between melanoma and benign nevi. Array-comparative genomic hybridization (aCGH) is an approach that can be used on DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissues to assess the entire genome for the presence of changes in DNA copy number. In this study, …

Improving Dna Quality Using Ffpe Tissues For Array Comparative Genomic Hybridization To Find Single Nucleotide Polymorphisms (Snps) In Melanoma, Keerti Potluri

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Important classes of benign and malignant neoplasms are composed of melanocytic cells which produce a pigment called melanin. Benign nevi, which are non-malignant melanocytic lesions, can sometimes give rise to malignant melanoma. Melanoma can be a lethal melanocytic neoplasm, a deadly and aggressive form of skin cancer. Finding prognostic or diagnostic markers can be very useful to reduce the deaths caused by melanoma. Array Comparative Genomic Hybridization (aCGH), a cytogenetic technique, analyzes the whole genome or chromosome for detecting genetic aberrations/variations such as single nucleotide polymorphisms (SNPs) in a cancer. formalin fixed paraffin embedded FFPE tissues are usually taken from …

Profiling Fatty Acid Composition Of Brown Adipose Tissue, White Adipose Tissue And Bone Marrow Adipose Tissue Of Healthy And Diet-Induced Obese Mice, Urszula Osinska Warncke

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Bone marrow adipose tissue (MAT) contains a fat depot of unknown function. Characterization of this tissue in healthy and pathophysiological conditions may be an important step in order to understand MAT contribution to development of osteoporosis and perhaps to develop means to improve bone health by manipulation with a phenotype of MAT. Here we demonstrate that MAT, brown adipose tissue (BAT), and white adipose tissue (WAT) derived from healthy mice differ in fatty acid and phospholipid composition. The profile of MAT changed to resemble a less-metabolically active tissue upon metabolic impairment as seen in diet-induced obesity. Additionally, PPARγ activation alters …

Purification Of Recombinant Δ Np63 Α And Characterization Of Peptide Binding, Amal Abdulah Albati

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δ NP63α, the primary p63 isoform of the p53 transcription factor family, is a proto-oncogene implicated in non-melanoma skin cancers. Expressed in the basal layer of the epidermis, δ NP63α promotes cell survival and proliferation. Inhibition of this protein could potentially be beneficial in non-melanoma skin cancer patients. The first goal of this project was the purification of recombinant δ NP63α in Escherichia Coli. Recombinant δ NP63α was expressed as GST-δ NP63α followed by GST cleavage using GST trap affinity column chromatography yielding pure δ NP63α The second objective of this project was to test the binding capabilities of peptides …

Differences In Fecal Metabolite Profiles From Geographically Distinct Populations Of Adolescents, Jessica Moncivaiz

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Microbiota of the gastrointestinal tract have a variety of functions within the human body. They participate in protection of the host from pathogens, aid in immune system development and regulation, and carry out a variety of metabolic functions. This study focuses on the ability of gut microbiota to create metabolites through the degradation of food products. Using 1H NMR on fecal water extracts, I compared the metabolite profiles of two geographically distinct cohorts: healthy adolescents from Egypt (n=28) and healthy adolescents from the United States (n=14). Multivariate statistical analyses of binned NMR data confirmed that samples separated into groups corresponding …

Physical Interactions Between Neuropilin And Vegfrs, Integrins In Regulating Endothelial Cell Functions, Xiaobo Li

Theses and Dissertations--Molecular and Cellular Biochemistry

The neuropilin (Nrp) family consists of multifunctional cell surface receptors with critical roles in a number of different cell and tissue types. A core aspect of Nrp function is ligand-dependent cellular adhesion and migration, where it controls the multistep process of cellular motility through integration of ligand binding, receptor coupling and signaling via the coordinated action of its extracellular and intracellular domains. While Nrp regulates cellular adhesion and motility in the cardiovascular and nervous systems under physiological conditions, the emerging pathological role of Nrp in tumor cell migration and metastasis has been identified and provides motivation for continued efforts toward …