Biotechnology Commons^™

Apolipoprotein-Ai Regulates Hepatic Vldl Secretion By Controlling Intracellular Vldl-Trafficking, Bhavesh Gurwani

Electronic Theses and Dissertations

Cardiovascular diseases cause 17 million deaths annually, which is estimated to increase to 23 million deaths by the year 2030. One of the major risk factors for the pathogenesis of cardiovascular diseases is increased secretion of very-low density lipoproteins (VLDL) by the liver; however, reduced VLDL-secretion causes fatty liver disease. Synthesis and secretion of VLDL by the liver plays an important role in maintaining overall lipoprotein homeostasis. Assembly of VLDL occurs along with the expression of apolipoproteinB-100 (apoB100) and its lipidation at the endoplasmic reticulum (ER) level. Once formed in the ER lumen, the nascent VLDL is transported to the …

Towards Elucidation Of The Mechanism Of Biological Nanomotors, Zhengyi Zhao

Theses and Dissertations--Pharmacy

Biological functions such as cell mitosis, bacterial binary fission, DNA replication or repair, homologous recombination, Holliday junction resolution, viral genome packaging, and cell entry all involve biomotor-driven DNA translocation. In the past, the ubiquitous biological nanomotors were classified into two categories: linear and rotation motors. In 2013, we discovered a third type of biomotor, revolving motor without rotation. The revolving motion is further found to be widespread among many biological systems. In addition, the detailed sequential action mechanism of the ATPase ring in the phi29 dsDNA packaging motor has been elucidated: ATP binding induces a conformational entropy alternation of ATPase …

Development Of New Biological Nanopores And Their Application For Biosensing And Disease Detection, Shaoying Wang

Theses and Dissertations--Pharmacy

Nanopore technology has recently emerged as a new real-time single molecule sensing method. The current dominant technologies, such as mass spectrometry and immunoassay, for protein analysis is still slow and complex, which can’t meet the urgent need and fields of use. Development of a highly simple, portable and sensitive detection system for pathogen detection, disease diagnosis, and environmental monitoring is in great need. Membrane embedded Phi29 connector nanopore, the first protein nanopore coming from bacteriophage, was mainly focusing on DNA and RNA translocation in previous studies. Here, Phi29 connector nanopore was first time established for antibody detection by engineering Epithelial …

Rna Nanotechnology For Next Generation Targeted Drug Delivery, Fengmei Pi

Theses and Dissertations--Pharmacy

The emerging field of RNA nanotechnology is developing into a promising platform for therapeutically application. Utilizing the state-of-art RNA nanotechnology, RNA nanoparticles can be designed and constructed with controllable shape, size for both RNA therapeutics and chemical drug delivery. The high homogeneity in particle size and ease for RNA therapeutic module conjugation, made it feasible to explore versatile RNA nanoparticle designs for preclinical studies.

One vital module for therapeutic RNA nanoparticle design is RNA aptamer, which can enable the RNA nanoparticles find its specific target for targeted drug delivery. A system of screening divalent RNA aptamers for cancer cell targeting …

Molecular And Biochemical Signaling Underlying Arabidopsis-Bacterial/Virus/Fungal Interactions, Mohamed H. El-Shetehy

Theses and Dissertations--Plant Pathology

Systemic acquired resistance (SAR) is a form of inducible defense response triggered upon localized infection that confers broad-spectrum disease resistance against secondary infections. Several factors are known to regulate SAR and these include phenolic phytohormone salicylic acid (SA), phosphorylated sugar glycerol-3-phosphate (G3P), and dicarboxylic acid azelaic acid (AzA). This study evaluated a role for free radicals nitric oxide (NO) and reactive oxygen species (ROS) in SAR. Normal accumulation of both NO and ROS was required for normal SAR and mutations preventing NO/ROS accumulation and/or biosynthesis compromised SAR. A role for NO and ROS was further established using pharmacological approaches. Notably, …

Synthetic Functionalized Scaffolds For Culture And Maintenance Of Primary Human Hepatocytes, Douglas Macpherson

Dissertations and Theses

There is deficit in the number of human livers that are available for transplantation. Additionally, there is no reliable model for the liver environment available for laboratory research. Tissue engineering provides alternatives for organ transplantation. We have created a supramolecular biomaterial out of simple peptide and saccharide building blocks to act as a hydrogel scaffold to support culture of liver cells. Using a self-­‐assembling peptide fiber decorated with functional molecules, we were able to culture primary human hepatocytes demonstrate their viability and maintenance of phenotype. The hydrogel material was formed by co-assembly in aqueous buffer and characterized using transmission electron …

Insights Into Triterpene Metabolism In Model Monocotyledonous And Oilseed Plants Genetically Engineered With Genes From Botryococcus Braunii, Chase F. Kempinski

Theses and Dissertations--Plant and Soil Sciences

Isoprenoids are one of the most diverse classes of natural products and are all derived from universal five carbon, prenyl precursors. Squalene and botryococcene are linear, hydrocarbon triterpenes (thirty carbon compounds with six prenyl units) that have industrial and medicinal values. Squalene is produced by all eukaryotes as it is the first committed precursor to sterols, while botryococcene is uniquely produced by the green algae, Botryococcus braunii (race B). Natural sources for these compounds exist, but there is a desire for more renewable production platforms. The model plant Arabidopsis thaliana was engineered to accumulate botryococcene and squalene in its oil …

Controlling Microbial Safety Challenges Of Meat Using High Voltage Atmospheric Cold Plasma, Lu Han, Dana Ziuzina, Caitlin Marie Heslin, Daniela Boehm, Apurva Patange, David Millan-Sango, Vasilis Valdramidis, Patrick J. Cullen, Paula Bourke

Articles

Atmospheric cold plasma (ACP) is a non-thermal technology, effective against a wide range of pathogenic microorganisms. Inactivation efficacy results from plasma generated reactive species. These may interact with any organic components in a test matrix including the target microorganism, thus food components may exert a protective effect against the antimicrobial mode of action. The effect of an in-package high voltage ACP process applied in conjunction with common meat processing MAP gas compositions as well as bacteria type and meat model media composition have been investigated to determine the applicability of this technology for decontamination of safety challenges associated with meat …

Atmospheric Cold Plasma Interactions With Modified Atmosphere Packaging Inducer Gases For Safe Food Preservation., Lu Han, Daniela Boehm, Vladimir Milosavljević, Ester Amias, Patrick J. Cullen, Paula Bourke

Articles

Diverse microbiological challenges and pervasive microbial resistance drive technological development in food processing, where increasing process complexity and consumer demand for less processed goods leads to strong demand for effective decontamination. Atmospheric cold plasma (ACP) has wide potential for decontamination application in the food sector. We investigated the effect of Modified Atmosphere Packaging (MAP) gas mixtures on reactive species generated, their efficacy and mechanism of inactivation against Escherichia coli, Listeria monocytogenes and Staphylococcus aureus. Oxygen levels in the applied working gas had positive interactive effects on ROS generation, in-package inactivation efficacy in conjunction with post-treatment storage time. …

Genetic Diversity And Population Structure Of Brassica Oleracea Germplasm In Ireland Using Ssr Markers, Mohamed El-Esawi, Paula Bourke, Renee Malone, Kieran Germaine

Articles

The most economically important Brassica oleracea species is endangered in Ireland, with no prior reported genetic characterization studies. This study assesses the genetic diversity, population structure and relationships of B. oleracea germplasm in Ireland using microsatellite (SSRs) markers. A total of 118 individuals from 25 accessions of Irish B. oleracea were genotyped. The SSR loci used revealed a total of 47 alleles. The observed heterozygosity (0.699) was higher than the expected one (0.417). Moreover, the average values of fixation indices (F) were negative, indicating excess of heterozygotes in all accessions. Polymorphic information content (PIC) values of SSR loci ranged from …

The Impact Of Oxygen On Bacterial Enteric Pathogens, Nathan Wallace, Ashley N. Zani, Elizabeth A. Abrams, Yvonne Sun

Biology Faculty Publications

Bacterial enteric pathogens are responsible for a tremendous amount of foodborne illnesses every year through the consumption of contaminated food products. During their transit from contaminated food sources to the host gastrointestinal tract, these pathogens are exposed and must adapt to fluctuating oxygen levels to successfully colonize the host and cause diseases. However, the majority of enteric infection research has been conducted under aerobic conditions. To raise awareness of the importance in understanding the impact of oxygen, or lack of oxygen, on enteric pathogenesis, we describe in this review the metabolic and physiological responses of nine bacterial enteric pathogens exposed …

The Role Of E-Cadherin Force In The Maintenance Of Homeostasis In Epithelial Acini, Fnu Vani Narayanan

Theses and Dissertations

Numerous three-dimensional model systems have emerged for emulating the biochemical and physiological states of native tissue. Yet little is known about the effects of mechanical forces on cell behavior in the context of an organized tissue structure in three-dimensional cell-culture. Epithelial cells cultured in a three-dimensional environment comprised of extracellular matrix proteins form spheroids of polarized cells. Cellular responses to mechanical cues, generated from dynamic interactions with the extracellular matrix and neighboring cells, are known to influence cellular behavior to a great extent. Previous studies have shown that tumorigenic progression has been frequently linked to the down regulation of E-cadherin, …

Fatty Acid Transport Proteins: Targeting Fatp2 As A Gatekeeper Involved In The Transport Of Exogenous Fatty Acids, Paul N. Black, Constance Ahowesso, David Montefusco, Nipun Saini, Concetta C. Dirusso

Department of Biochemistry: Faculty Publications

The fatty acid transport proteins (FATP) are classified as members of the solute carrier 27 (Slc27) family of proteins based on their ability to function in the transport of exogenous fatty acids. These proteins, when localized to the plasma membrane or at intracellular membrane junctions with the endoplasmic reticulum, function as a gate in the regulated transport of fatty acids and thus represent a therapeutic target to delimit the acquisition of fatty acids that contribute to disease as in the case of fatty acid overload. To date, FATP1, FATP2, and FATP4 have been used as targets in the selection of …

Endoplasmic Reticulum-Associated Degradation Of Pca1p, A Polytopic Protein, Via Interaction With The Proteasome At The Membrane, Nathan Smith, David J. Adle, Miaoyun Zhao, Xiaojuan Quin, Heejeong Kim, Jaekwon Lee

Department of Biochemistry: Faculty Publications

Endoplasmic reticulum-associated degradation (ERAD) plays a critical role for destruction of terminally misfolded proteins at the secretory pathway. The system also regulates expression levels of several proteins such as Pca1p, a cadmium exporter in yeast. To gain better insight into the mechanisms underlying ERAD of Pca1p and other polytopic proteins by the proteasome in the cytosol, our study determined the roles for the molecular factors of ERAD in dislodging Pca1p from the ER. Inactivation of the 20S proteasome leads to accumulation of ubiquitinylated Pca1p in the ER membrane, suggesting a role for the proteasome in extraction of Pca1p from the …

Endoplasmic Reticulum-Associated Degradation Of Pca1p, A Polytopic Protein, Via Interaction With The Proteasome At The Membrane, Nathan Smith, David J. Adle, Miaoyun Zhao, Xiaojuan Qin, Heejeong Kim, Jaekwon Lee

Department of Biochemistry: Faculty Publications

Endoplasmic reticulum-associated degradation (ERAD) plays a critical role in the destruction of terminally misfolded proteins at the secretory pathway. The system also regulates expression levels of several proteins such as Pca1p, a cadmium exporter in yeast. To gain better insight into the mechanisms underlying ERAD of Pca1p and other polytopic proteins by the proteasome in the cytosol, our study determined the roles for the molecular factors of ERAD in dislodging Pca1p from the endoplasmic reticulum (ER). Inactivation of the 20S proteasome leads to accumulation of ubiquitinated Pca1p in the ER membrane, suggesting a role for the proteasome in extraction of …

Caloric Restriction Of Db/Db Mice Reverts Hepatic Steatosis And Body Weight With Divergent Hepatic Metabolism, Kyung Eun Kim, Youngae Jung, Soonki Min, Miso Nam, Rok Won Heo, Byeong Tak Jeon, Dae Hyun Song, Chin-Ok Yi, Eun Ae Jeong, Hwajin Kim, Jeonghyun Kim, Seon-Yong Jeong, Woori Kwak, Do Hyun Ryu, Tamas L. Horvath, Gu Seob Roh, Geum-Sook Hwang

Department of Biochemistry: Faculty Publications

Non-alcoholic fatty liver disease (NAFLD) is one of the most frequent causes of liver disease and its prevalence is a serious and growing clinical problem. Caloric restriction (CR) is commonly recommended for improvement of obesity-related diseases such as NAFLD. However, the effects of CR on hepatic metabolism remain unknown. We investigated the effects of CR on metabolic dysfunction in the liver of obese diabetic db/db mice. We found that CR of db/db mice reverted insulin resistance, hepatic steatosis, body weight and adiposity to those of db/m mice. H-NMR- and UPLC-QTOF-MS-based metabolite profiling data showed significant metabolic alterations related to lipogenesis, …

Synthesis And Transfer Of Galactolipids In The Chloroplast Envelope Membranes Of Arabidopsis Thaliana, Amélie Kelly, Barbara Kalisch, Georg Hölzl, Sandra Schulze, Juliane Thiele, Michael Melzer, Rebecca L. Roston, Christoph Benning, Peter Dörmann

Department of Biochemistry: Faculty Publications

Galactolipids [monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol

(DGDG)] are the hallmark lipids of photosynthetic

membranes. The galactolipid synthases MGD1 and DGD1

catalyze consecutive galactosyltransfer reactions but localize to the

inner and outer chloroplast envelopes, respectively, necessitating

intermembrane lipid transfer. Here we show that the N-terminal

sequence of DGD1 (NDGD1) is required for galactolipid transfer

between the envelopes. Different diglycosyllipid synthases (DGD1,

DGD2, and Chloroflexus glucosyltransferase) were introduced into

the dgd1-1 mutant of Arabidopsis in fusion with N-terminal extensions

(NDGD1 and NDGD2) targeting to the outer envelope. Reconstruction

of DGDG synthesis in the outer envelope membrane was

observed only with diglycosyllipid synthase fusion …

Evidence For Pipecolate Oxidase In Mediating Protection Against Hydrogen Peroxide Stress, Sathish Kumar Natarajan, Ezhumalai Muthukrishnan, Oleh Khalimonchuk, Justin L. Mott, Donald F. Becker

Department of Biochemistry: Faculty Publications

Pipecolate, an intermediate of the lysine catabolic pathway, is oxidized to Δ¹-piperideine-6-carboxylate (P6C) by the flavoenzyme lpipecolate oxidase (PIPOX). P6C spontaneously hydrolyzes to generate α-aminoadipate semialdehyde, which is then converted into α-aminoadipate acid by α-aminoadipatesemialdehyde dehydrogenase. l-pipecolate was previously reported to protect mammalian cells against oxidative stress. Here, we examined whether PIPOX is involved in the mechanism of pipecolate stress protection. Knockdown of PIPOX by small interference RNA abolished pipecolate protection against hydrogen peroxide-induced cell death in HEK293 cells suggesting a critical role for PIPOX. Subcellular fractionation analysis showed that PIPOX is localized in the mitochondria of HEK293 …

Ceramide Induces Human Hepcidin Gene Transcription Through Jak/Stat3 Pathway, Sizhao Lu, Sathish Kumar Natarajan, Justin L. Mott, Kusum K. Kharbanda, Duygu Dee Harrison-Findik

Department of Biochemistry: Faculty Publications

Changes in lipid metabolism and iron content are observed in the livers of patients with fatty liver disease. The expression of hepcidin, an iron-regulatory and acute phase protein synthesized by the liver, is also modulated. The potential interaction of lipid and iron metabolism is largely unknown.We investigated the role of lipid intermediate, ceramide in the regulation of human hepcidin gene, HAMP. Human hepatoma HepG2 cells were treated with cell-permeable ceramide analogs. Ceramide induced significant up-regulation of HAMP mRNA expression in HepG2 cells. The effect of ceramide on HAMP expression was mediated through transcriptional mechanisms because it was completely blocked …

Logical Modeling And Dynamical Analysis Of Cellular Networks, Wassim Abou-Jaoudé, Pauline Traynard, Pedro T. Monteiro, Julio Saez-Rodriguez, Tomáš Helikar, Denis Thieffry, Claudine Chaouiya

Department of Biochemistry: Faculty Publications

The logical (or logic) formalism is increasingly used to model regulatory and signaling networks. Complementing these applications, several groups contributed various methods and tools to support the definition and analysis of logical models. After an introduction to the logical modeling framework and to several of its variants, we review here a number of recent methodological advances to ease the analysis of large and intricate networks. In particular, we survey approaches to determine model attractors and their reachability properties, to assess the dynamical impact of variations of external signals, and to consistently reduce large models. To illustrate these developments, we further …