Biochemistry, Biophysics, and Structural Biology Commons^™

Viewing The Extracellular Matrix: An Imaging Method For Tissue Engineering, Michael Drakopoulos, Sarah Calve

The Summer Undergraduate Research Fellowship (SURF) Symposium

The field of regenerative medicine seeks to create replacement tissues and organs, both to repair deficiencies in biological function and to treat structural damage caused by injury. Scaffoldings mimicking extracellular matrix (ECM), the structure to which cells attach to form tissues, have been developed from synthetic polymers and also been prepared by decellularizing adult tissue. However, the structure of ECM undergoes significant remodeling during natural tissue repair, suggesting that ECM-replacement constructs that mirror developing tissues may promote better regeneration than those modeled on adult tissues. This work investigated the effectiveness of a method of viewing the extracellular matrix of developing …

Gating Mechanisms Of The Canonical Trp Channel Isoform Trpc4, Dhananjay P. Thakur

Dissertations and Theses (Open Access)

Non-selective cation channels formed by Transient Receptor Potential Canonical (TRPC) proteins play important roles in regulatory and pathophysiological processes. These channels are known to be activated downstream from phospholipase C (PLC) signaling. However, the mechanism by which the PLC pathway activates TRPC4/C5 remains unclear. Uniquely, TRPC4 is maximally activated only when two separate G protein pathways, G_q/11 and G_i/o, are co-stimulated, making it a coincidence detector of G_q/11- and G_i/o -coupled receptor activation. Using HEK293 cells co-expressing mouse TRPC4β and selected G protein-coupled receptors, I observed that coincident stimulation of G_i/o proteins and …

Investigating The Interaction Of Aurka And Ube2c In Colorectal Cancer Cells, Apurva M. Hegde

Dissertations and Theses (Open Access)

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths in the US. Among the many genomic aberrations previously implicated in colorectal cancer, recurrent amplification of chromosome 20q is frequently associated with liver metastasis. Previous research in our lab identified a gene signature on chromosome 20q associated with colorectal cancer progression. In this study, one of the genes in the signature, the ubiquitin conjugating enzyme UBE2C, was identified through preliminary bioinformatics analysis as a candidate for further examination of its role in CRC progression. Co-expression analysis of UBE2C in tumor-normal datasets from the public database Oncomine revealed all the …

Prophylactic Cranial Irradiation Reduces The Incidence Of Brain Metastasis In A Mouse Model Of Metastatic Breast Cancer, Daniel L. Smith

Dissertations and Theses (Open Access)

Prophylactic cranial irradiation (PCI) is a preventative whole-brain irradiation technique used to reduce the incidence of brain metastasis and improve overall survival in select patients with small cell lung cancer and acute lymphoblastic leukemia. A population of breast cancer patients – stage IV, HER2+ or triple-negative – has emerged as having a high risk of developing brain metastases. Because only 10-20% of breast cancer patients diagnosed with brain metastases survive longer than one year, in this high-risk population the benefit of PCI – potential for reduced incidence of brain metastasis and improved overall survival – may outweigh the risks – …

Computational Modeling Of Rna-Small Molecule And Rna-Protein Interactions, Lu Chen

Dissertations and Theses (Open Access)

The past decade has witnessed an era of RNA biology; despite the considerable discoveries nowadays, challenges still remain when one aims to screen RNA-interacting small molecule or RNA-interacting protein. These challenges imply an immediate need for cost-efficient while predictive computational tools capable of generating insightful hypotheses to discover novel RNA-interacting small molecule or RNA-interacting protein. Thus, we implemented novel computational models in this dissertation to predict RNA-ligand interactions (Chapter 1) and RNA-protein interactions (Chapter 2).

Targeting RNA has not garnered comparable interest as protein, and is restricted by lack of computational tools for structure-based drug design. To test the potential …

The Presence Of Clostridium Difficile On Environmental Surfaces In Healthcare Facilities Pre- And Post-Decontamination Of Patient Rooms, Theresa Trice

UNLV Theses, Dissertations, Professional Papers, and Capstones

Healthcare-associated infections (HAIs) are infections related to receiving medical care. HAIs are responsible for an excess of morbidity and mortality among hospitalized patients. Though most HAIs rates are on the decline, Clostridium difficile infection rates are at an all-time high, primarily due to the persistence of C. difficile spores in the environment. In the United States, Clostridium difficile-related mortality rates per million have increased from 5.7 in 1999 to 23.7 in 2004, with an estimated 26,642 deaths due to Clostridium difficile infections (CDIs). Clostridium difficile is transmitted via the fecal-oral route or aerosolized endospores, but it can also be transmitted …

Editorial: Phosphoinositides And Their Phosphatases: Linking Electrical And Chemical Signals In Biological Processes, Susy C. Kohout, Carlos A. Villalba-Galea

School of Pharmacy Faculty Articles

No abstract provided.

Ganoderma Lucidum Reduces Obesity In Mice By Modulating The Composition Of The Gut Microbiota, Chih-Jung Chang, Chuan-Sheng Lin, Chia-Chen Lu, Jan Martel, Yun-Fei Ko, David M. Ojcius, Shun-Fu Tseng, Tsung-Ru Wu, Yi-Yuan Margaret Chen, John Ding-E. Young, Hsin-Chih Lai

All Dugoni School of Dentistry Faculty Articles

Obesity is associated with low-grade chronic inflammation and intestinal dysbiosis. Ganoderma lucidum is a medicinal mushroom used in traditional Chinese medicine with putative anti-diabetic effects. Here, we show that a water extract of Ganoderma lucidum mycelium (WEGL) reduces body weight, inflammation and insulin resistance in mice fed a high-fat diet (HFD). Our data indicate that WEGL not only reverses HFD-induced gut dysbiosis—as indicated by the decreased Firmicutes-to-Bacteroidetes ratios and endotoxin-bearing Proteobacteria levels—but also maintains intestinal barrier integrity and reduces metabolic endotoxemia. The anti-obesity and microbiota-modulating effects are transmissible via horizontal faeces transfer from WEGL-treated mice to HFD-fed mice. We further …

World-Class Research: Biomedical Science Beyond Experimentation

Colby Magazine

Faculty and relationships with Maine’s big-three research labs propel Colby’s opportunities in biomedical science

Could childhood nutrition set late-life brain function?

Hitting the lab running

Ahmad wins grant for study of neurodegenerative disease

Cyclic Rhamnosylated Elongation Factor P Establishes Antibiotic Resistance In Pseudomonas Aeruginosa, Andrei Rajkovic, Sarah Erickson, Anne Witzky, Owen E. Branson, Jin Seo, Philip R. Gafken, Michael A. Frietas, Julian P. Whitelegge, Kym F. Faull, William Wiley Navarre, Andrew J. Darwin, Michael Ibba

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Elongation factor P (EF-P) is a ubiquitous bacterial protein that is required for the synthesis of poly-proline motifs during translation. In Escherichia coli and Salmonella enterica, the posttranslational β-lysylation of Lys34 by the PoxA protein is critical for EF-P activity. PoxA is absent from many bacterial species such as Pseudomonas aeruginosa, prompting a search for alternative EF-P posttranslation modification pathways. Structural analyses of P. aeruginosa EF-P revealed the attachment of a single cyclic rhamnose moiety to an Arg residue at a position equivalent to that at which β-Lys is attached to E. coli EF-P. Analysis of the genomes …

Thyroxine Replacement In Patients On Parenteral Nutrition: A Clinical Conundrum, Abdul Rehman, Noor Ul-Ain Baloch, Muhammad Awais

Department of Biological & Biomedical Sciences

No abstract provided.

Evolutionary Convergence Of The Caffeine Biosynthetic Pathway In Chocolate Followed Duplication Of A Constrained Ancestral Enzyme, Andrew J. O'Donnell

Masters Theses

Caffeine biosynthesis is widely distributed in flowering plants and requires three consecutive methylation steps of xanthine alkaloids. Genes that have previously been reported to participate in the multi-step pathway in Coffea sp. (coffee) and Camellia sinensis (tea) encode members of the SABATH family of methyltransferases. Two genes highly expressed in fruits of Theobroma cacao (cacao) are orthologous to the caffeine genes in tea and appear to have diversified following gene duplication. Biochemical characterization of the enzymes (XMTs) encoded by these genes strongly suggest an unprecedented major pathway to theobromine, a precursor to caffeine. These findings imply that caffeine biosynthesis evolved …

Curcumin: A Multi-Dimensional Approach To Pancreatic Cancer Targeting Cell Death And Exosomes, Carlos J. Diaz Osterman

Loma Linda University Electronic Theses, Dissertations & Projects

Pancreatic cancer is currently one of the most difficult diseases to treat due to difficulty of detection and the aggressive nature of the disease. In addition, pancreatic cancer has the highest mortality rates compared to other cancer types. These mortality rates are attributable in part to increasing resistance to cancer therapy. Cancer therapy resistance is caused by adaptations that favor survival within cancer cells and their environment, termed the tumor microenvironment. Intracellular adaptations include the overexpression of resistance-linked genes, such as the inhibitor of apoptosis (IAP) family of proteins and overall resistance to cell death. Adaptations in the tumor microenvironment …

Crotalus Snake Venom Preconditioning To Prevent Surgical Brain Injury, Cherine Hee-Sun Kim

Loma Linda University Electronic Theses, Dissertations & Projects

Preventive measures are increasingly relevant to medical practice. Preconditioning, a preemptive therapy that administers mildly harmful stimuli to induce endogenous protective mechanisms before major injury, has been shown to minimize injury in many animal models. Given the elective nature of most neurosurgical procedures, the surgical brain injury (SBI) rodent model provides an ideal platform for preconditioning. Our work shows that preconditioning with Crotalus rattlesnake venom, known for its hemorrhagic and inflammatory effects, mitigates some harmful effects of SBI. We have identified two proteins of interest in Crotalus venom: snake venom metalloproteinase (SVMP), an enzyme with hemorrhagic effects, and phospholipase A2 …

Structural And Functional Interactions Between Bro1 Domain Of Human Alix Protein And Nucleocapsid Packaging Rna Complex From Hiv, Scott Gross

Graduate School of Biomedical Sciences Theses and Dissertations

A virus is only as powerful as its ability to spread. Enveloped retroviruses, namely HIV-1, use exocytosis pathways that normal host cells use to release particles from the plasma membrane. The main pathways of interest in this study are the Endosomal Sorting Complex Required for Transport (ESCRT) and adjacent ALIX pathways. The ESCRT pathway is especially important for degradation of receptor/cargo complexes that form Multi-Vesicular Bodies (MVBs). Currently, there is no known therapy that targets this endosomal pathway, which would prevent the spread of the virus to other cells. The virus has adapted to jump from pathway to pathway when …

Age-Dependent Breakdown Of The Blood Brain Barrier And Associated Changes In S100b Ko Mice, Eric V. Brown

Graduate School of Biomedical Sciences Theses and Dissertations

Autoantibodies play an important role in many autoimmune diseases. Recent research has shown that breakdown of the blood brain barrier (BBB) occurs concomitant to generation of brain reactive autoantibodies in many neurodegenerative diseases, which serve as biomarkers and drivers of pathology. SI00B, a calcium binding protein found most highly expressed in astrocytes which ensheathe the BBB, has many functions in neural development and signaling. Currently literature indicates that S100B KO mice develop normally, with no phenotypic abnormalities. Here, it is demonstrated that S100B KO mice seem to develop a chronic BBB breakdown similar to that seen in human neurodegenerative diseases. …

Efficient In Vitro Development Of Photoreceptors From Human Pluripotent Stem Cells, Joseph C. Reynolds

Dissertations, Masters Theses, Capstones, and Culminating Projects

Degeneration of the rod and cone photoreceptors in the human retina is among the most common causes of blindness. Replacing these damaged photoreceptors may help to restore vision. Repairing the damaged retina relies on the insertion of new, healthy cells. Embryonic stem (ES) cells and induced pluripotent stem (iPS) cells are two possible sources of photoreceptors to restore vision. Previous data shows that human ES cells and iPS cells can be differentiated into photoreceptors and transplanted into the eye to restore some vision. However, this process is inefficient, and costly. Here, we show a new method for inducing photoreceptor production …

The Use Of Shape Memory Polymers As A Tool To Study Human Fibrosarcoma And Murine Mesenchymal Stem Cell Migration, Justin N. Elkhechen

Renée Crown University Honors Thesis Projects - All

Shape memory polymers (SMPs) are a class of “smart” materials that can transform between two distinct conformations through external stimuli, such as heat or electricity. Their usage in bioengineering has led to a promising field of research that lies at the interface of cell and mechanobiology, potentially providing insight into cancer therapies and tissue development—two processes that exist in dynamic environments in vivo. The present work involves creating new, shape changing, scaffolds for studies to analyze cell migration upon changes to the environmental topography. Specifically, this Capstone has been primarily focused on the development of a “half and half” fibrous …

Characterization Of Ghrelin O-Acyltransferase Active Site, Leslie Patton

Renée Crown University Honors Thesis Projects - All

Ghrelin, first discovered in 1999, is a 28-amino acid peptide hormone involved in the regulation of appetite, insulin secretion and sensitivity, and many neurological effects such as learning, memory, and depression.^1-6 Ghrelin has been identified to have a unique posttranslational octanoylation carried out by the enzyme ghrelin O-acyltransferase (GOAT). This distinctive modification is a point of interest in studying GOAT whereby blocking the acylation of the ghrelin could potentially halt the activity of the peptide hormone and provide a means of treating obesity, diabetes, and other diseases affected by ghrelin levels. The duration of my project involved working …

The Development Of Skeletal Muscle In Young Horses: An Ultrasonography And Satellite Cell Approach, Emma K. Lavigne

Honors Scholar Theses

Muscle growth in young horses is characterized by an increase in muscle cross-sectional area, which can be accomplished through the activation and differentiation of satellite cells. Satellite cells can be stimulated or inhibited in response to different cytokines and growth factors and are key mediators of muscle hypertrophy and regeneration. The aim of this study was to investigate the growth of the longissimus dorsi (LD) muscle in horses under 5 years of age and to obtain preliminary data on satellite cell behavior in foals. The area, width, height, and subcutaneous fat were measured using ultrasonography at 6-month increments over the …

Osteomyelitis Associated With Nocardiopsis Composta In A Dog, Elisa N. Salas, Debra Royal, Lance Kurz, J. Dustin Loy

School of Veterinary and Biomedical Sciences: Faculty Publications

Osteomyelitis can be caused by bacterial or fungal agents or may be idiopathic. Cocci, bacilli, and filamentous bacteria such as members of the Actinomycetes have all been determined to be causes of osteomyelitis. Differential diagnoses for Gram-positive filamentous rods in the family Actinomycetales causing osteomyelitis in the dog, include members of the more frequently encountered genera Nocardia and Actinomyces. Bacteria gain access to the bone via several routes but are most often associated with direct inoculation (such as percutaneous injuries, compound fractures, or secondary to foreign bodies such as surgical or other material including dirt and wood) and fracture …

The Effect Of Activation Induced Cytidine Deaminase Phosphorylation And Herpes Virus Uracil Dna Glycosylase On Antibody Diversification, Marc Macaluso

Dissertations and Theses (Open Access)

Activation-induced cytidine deaminase (AID) is a mutagenic enzyme that is expressed in mammalian B-cells and initiates the antibody diversification processes of somatic hypermuntation (SHM) and isotype class switch recombination (CSR). AID is targeted to the immunoglobulin gene locus where it deaminates cytosines to generate uracil residues in DNA. This generates guanine-uracil (U:G) mismatch lesion which are recognized by uracil DNA glycosylase (UNG), a DNA repair enzyme that removes uracil from DNA and triggers downstream repair of the lesion. While UNG is a ubiquitously expressed DNA repair enzyme, its recognition and removal of AID introduced uracils is essential in both SHM …

Investigation Of The Role Of The Scaffold Protein Shc In Erk Signaling, Kin Man Suen

Dissertations and Theses (Open Access)

Cells respond to environmental changes by converting extracellular signals into intracellular events. Scaffolding proteins play important roles in generating specificity in intracellular signaling through the combinatorial use of protein domains and posttranslational modifications. Using the scaffold Shc (Src-homology collagen-like) as a model system, we explored novel mechanisms whereby this class of protein shapes signaling output. In the present work, we focused on the role of Shc in the MAP kinase Erk signaling both prior to and post-growth factor stimulation. Prior to growth factor stimulation, we found Erk to be a direct interacting partner of Shc. The two proteins associate through …

Dna Polymerase Θ (Polq) And The Cellular Defense Against Dna Damage, Matthew J. Yousefzadeh

Dissertations and Theses (Open Access)

In mammalian cells, DNA polymerase θ (POLQ) is an unusual specialized DNA polymerase whose in vivo function is under active investigation. The protein is comprised of an N-terminal helicase-like domain, a C-terminal DNA polymerase domain, and a large central domain that spans between the two. This arrangement is also found in the Drosophila Mus308 protein, which helps confer resistance to DNA interstrand crosslinking agents. Homologs of POLQ and Mus308 are found in eukaryotes, including plants, but a comparison of phenotypes suggests that not all of these genes are functional orthologs. Flies with defective Mus308 are sensitive to DNA interstrand crosslinking …

Developmental Origins Of Renal Connecting Tubule And Collecting Duct: Role Of Aqp2+ Progenitor Cells, Lihe Chen

Dissertations and Theses (Open Access)

The connecting tubule interconnects the nephron and collecting duct, which arise from kidney mesenchyme and the ureteric bud, respectively, to generate the functional tubular networks. The collecting duct is comprised of principal cells and intercalated cells, which bear different molecular signatures and regulate sodium/water and acid/base balance, respectively. The progenitor cells of the connecting tubule and the collecting duct remain virtually unknown.

We generated two Aqp2 lineage tracing mouse models. In these models, Aqp2Cre transgene drives Cre expression by the Aqp2 promoter to exclusively either inactivate histone H3 K79 methyltransferase Dot1l (Dot1l^f/f Aqp2Cre) or activate RFP in …

Selection Methods For Genetically-Modified T Cells: In Support Of Translational Therapy, David Rushworth

Dissertations and Theses (Open Access)

T cells are blood cells which organize the immune system of the host. These cells are necessary for the host to respond appropriately to threats from foreign organisms and cancerous growth. However, in the case of certain infections and cancer, T cells are unable to respond appropriately to a threat and establish immunity. This leads to disease when the infection or cancer is not sufficiently eliminated. On the other hand, T cells can lack tolerance for healthy tissue and perceive healthy tissue as infected. The ensuing over-reactive immune response also leads to disease. A delicate balance must exist between immunity …

Investigating The Roles Of P63 And P73 Isoforms To Therapeutically Treat P53-Altered Cancers, Avinashnarayan Venkatanarayan

Dissertations and Theses (Open Access)

Investigating the roles of p63 & p73 isoforms to therapeutically treat

p53-altered cancers

Avinashnarayan Venkatanarayan, M.S.

Supervisory Professor: Elsa R. Flores, Ph.D.

The TP53 tumor suppressor is mutated in approximately 50% of human cancers rendering cancer therapies ineffective. p53 reactivation suppresses tumor formation in mice. However, this strategy has proven difficult to implement therapeutically. An alternate approach to overcome p53 loss is to manipulate the p53-family members, p63 and p73, which interact and share structural similarities to p53. p63 and p73, unlike p53 are less frequently mutated and have two major isoforms with distinct functions …

Measuring Single Cell Responses To Lapatinib In A Heterogeneous Population, Preety Priya

Dissertations and Theses (Open Access)

Cancer is notonedisease butasaga of diseases and is the outcome of disturbed homeostasis in the normal cells due to the deregulation of its genetic makeup. With advent of technologies thatallowdetailed molecular characterizationoftumors, targeted therapies have emerged as a more promising and specific mode of treatment. However, a major challenge with targeted therapy is the acquired resistance in the cancer cells to these therapies, quite often very rapidly in the course of a few months. One of the major targets in cancer has been the EGFR/ErbB2 network in breast and other cancer types. Prior work from our lab and others have …

Regulation Of Cell Adhesion By The Ferm Proteins, Ptpn14 And Merlin, Patty Dimarco Hewitt

Dissertations and Theses (Open Access)

Cell-cell adhesion is critical for the control of tissue organization and homeostasis. A family of proteins that regulate cell-cell adhesions is the FERM (4.1 protein, Ezrin, Radixin, Moesin) domain-containing proteins.One FERM domain protein, the non-receptor tyrosine phosphatase PTPN14, is mutated or deleted in several human cancers suggesting that it may be involved in tumor development and/or progression. Additionally, the loss of the FERM domain protein Merlin is associated with tumor development and metastasis.Both PTPN14 and Merlin have been shown to localize and possibly regulate adherens junction (AJ) functions. This work sought to determine if …

Local Modulation And Measurement Of Macrophage-Derived Bioactive Proteins From Implanted Biomaterials In Rat, Geetika Bajpai

Graduate Theses and Dissertations

Fibrosis around the implanted medical devices is a severe problem that can plague long-term device reliability. Activation of macrophage phenotype (macrophage polarization) has emerged as a new and possible means for reducing fibrosis in the fields of biomaterials and regenerative medicine. Macrophages are phagocytic cells that respond to microenvironmental cues that direct their phenotype. Macrophage activation has been widely studied in mouse and human in the context of tumor biology, yet little information is available regarding how macrophage activation could be used in a biomaterials context. Further, rats rather than mice are the common subjects in biomaterials experiments. A significant …