Cell and Developmental Biology Commons^™

Response Of Mammalian Macrophages To Challenge With The Chlorovirus Atcv-1, Thomas M. Petro, Irina V. Agarkova, You Zhou, Robert H. Yolken, James L. Van Etten, David D. Dunigan

Nebraska Center for Virology: Faculty Publications

It was recently reported that 44% of healthy humans in a study cohort had DNA sequences similar to Chlorovirus ATCV-1 (family Phycodnaviridae) in oropharyngeal samples and had decreases in visual processing and visual motor speed compared with individuals in whom no virus was detected. Moreover, mice inoculated orally with ATCV-1 developed immune responses to ATCV-1 proteins and had decreases in certain cognitive domains. Because heightened IL-6, nitric oxide (NO), and ERK MAP kinase activation from macrophages are linked to cognitive impairments, we evaluated cellular responses and viral plaque forming units in murine RAW264.7 and primary macrophages after exposure to …

Clinical Significance Of The Integrin Α6Β4 In Human Malignancies, Rachel L Stewart, Kathleen L O'Connor

Pathology and Laboratory Medicine Faculty Publications

Integrin α6β4 is a cellular adhesion molecule that binds to laminins in the extracellular matrix and nucleates the formation of hemidesmosomes. During carcinoma progression, integrin α6β4 is released from hemidesmosomes, where it can then signal to facilitate multiple aspects of tumor progression including sustaining proliferative signaling, tumor invasion and metastasis, evasion of apoptosis, and stimulation of angiogenesis. The integrin achieves these ends by cooperating with growth factor receptors including EGFR, ErbB-2, and c-Met to amplify downstream pathways such as PI3K, AKT, MAPK, and the Rho family small GTPases. Furthermore, it dramatically alters the transcriptome …

Trim21 Regulates Nmi-Ifi35 Complex-Mediated Inhibition Of Innate Antiviral Response, Anshuman Das, Phat X. Dinh, Asit K. Pattnaik

School of Veterinary and Biomedical Sciences: Faculty Publications

In this study, using an immunoprecipitation coupled with mass spectrometry approach, we have identified the E3 ubiquitin ligase Trim21 as an interacting partner of IFI35 and Nmi. We found that this interaction leads to K63-linked ubiquitination on K22 residue of Nmi, but not IFI35. Using domain deletion analysis, we found that the interaction is mediated via the coiled-coil domain of Nmi and the carboxyl-terminal SPRY domain of Trim21. Furthermore, we show that depletion of Trim21 leads to significantly reduced interaction of Nmi with IFI35, which results in the abrogation of the negative regulatory function of the Nmi-IFI35 complex on innate …

Drosophila Eye Model To Study Neuroprotective Role Of Creb Binding Protein (Cbp) In Alzheimer’S Disease, Timothy Cutler, Ankita Sarkar, Michael Moran, Andrew Steffensmeier, Oorvashi Roy Puli, Greg Mancini, Meghana Tare

Biology Faculty Publications

Background: The progressive neurodegenerative disorder Alzheimer’s disease (AD) manifests as loss of cognitive functions, and finally leads to death of the affected individual. AD may result from accumulation of amyloid plaques. These amyloid plaques comprising of amyloid-beta 42 (Aβ42) polypeptides results from the improper cleavage of amyloid precursor protein (APP) in the brain. The Aβ42 plaques have been shown to disrupt the normal cellular processes and thereby trigger abnormal signaling which results in the death of neurons. However, the molecular-genetic mechanism(s) responsible for Aβ42 mediated neurodegeneration is yet to be fully understood.

Methodology/Principal Findings: We have utilized Gal4/UAS system to …

The Cababc Operon Essential For Biofilm And Rugose Colony Development In Vibrio Vulnificus, Jin Hwan Park, Youmi Jo, Song Yee Jang, Haenaem Kwon, Yasuhiko Irie, Matthew R. Parsek, Myung Hee Kim, Sang Ho Choi

Biology Faculty Publications

A transcriptome analysis identified Vibrio vulnificus cabABC genes which were preferentially expressed in biofilms. The cabABC genes were transcribed as a single operon. The cabA gene was induced by elevated 3′,5′-cyclic diguanylic acid (c-di-GMP) and encoded a calcium-binding protein CabA. Comparison of the biofilms produced by the cabA mutant and its parent strain JN111 in microtiter plates using crystal-violet staining demonstrated that CabA contributed to biofilm formation in a calcium-dependent manner under elevated c-di-GMP conditions. Genetic and biochemical analyses revealed that CabA was secreted to the cell exterior through functional CabB and CabC, distributed throughout the biofilm matrix, and produced …

Deletion Of Panx3 Prevents The Development Of Surgically Induced Osteoarthritis, Paxton M. Moon, Silvia Penuela, Kevin Barr, Sami Khan, Christopher L. Pin, Ian Welch, Mukundan Attur, Steven B. Abramson, Dale W. Laird, Frank Beier

Anatomy and Cell Biology Publications

© 2015, Springer-Verlag Berlin Heidelberg. Abstract: Osteoarthritis (OA) is a highly prevalent, disabling joint disease with no existing therapies to slow or halt its progression. Cartilage degeneration hallmarks OA pathogenesis, and pannexin 3 (Panx3), a member of a novel family of channel proteins, is upregulated during this process. The function of Panx3 remains poorly understood, but we consistently observed a strong increase in Panx3 immunostaining in OA lesions in both mice and humans. Here, we developed and characterized the first global and conditional Panx3 knockout mice to investigate the role of Panx3 in OA. Interestingly, global Panx3 deletion produced no …

Hexabromocyclododecane And Tetrabromobisphenol A Alter Secretion Of Interferon Gamma (Ifn-Γ) From Human Immune Cells, Haifa Almughamsi, Margaret M. Whalen

Chemistry Faculty Research

Hexabromocyclododecane (HBCD) and tetrabromobisphenol A (TBBPA) are brominated flame-retardant compounds used in a variety of applications including insulation, upholstery, and epoxy resin circuit boards. Interferon gamma (IFN-γ) is an inflammatory cytokine produced by activated T and NK cells that regulates immune responsiveness. HBCD and TBBPA are found in human blood, and previous studies have shown that they alter the ability of human natural killer (NK) lymphocytes to destroy tumor cells. This study examines whether HBCD and TBBPA affect the secretion of IFN-γ from increasingly complex preparations of human immune cells—purified NK cells, monocyte-depleted (MD) peripheral blood mononuclear cells (PBMCs), and …

A Mitochondria-Anchored Isoform Of The Actin-Nucleating Spire Protein Regulates Mitochondrial Division, Uri Manor, Sadie Bartholomew, Gonen Golani, Eric Christenson, Michael Kozlov, Henry Higgs, James Spudich, Jennifer Lippincott-Schwartz

Dartmouth Scholarship

Mitochondrial division, essential for survival in mammals, is enhanced by an inter-organellar process involving ER tubules encircling and constricting mitochondria. The force for constriction is thought to involve actin polymerization by the ER-anchored isoform of the formin protein inverted formin 2 (INF2). Unknown is the mechanism triggering INF2-mediated actin polymerization at ER-mitochondria intersections. We show that a novel isoform of the formin-binding, actin-nucleating protein Spire, Spire1C, localizes to mitochondria and directly links mitochondria to the actin cytoskeleton and the ER. Spire1C binds INF2 and promotes actin assembly on mitochondrial surfaces. Disrupting either Spire1C actin- or formin-binding activities reduces mitochondrial constriction …

The Involvement Of Let-7 Mirna In The Regulation Of Retinal Progenitor Cells, Xiaohuan Xia

Theses & Dissertations

Emerging evidence has shown that miRNA-mediated gene regulation plays an important role in the development of the central nervous system (CNS). One of the developmental mechanisms may involve let-7 miRNAs and their up-stream regulator, Lin28a and Lin28b in regulating neural stem cells (NSCs). Recently, let-7 has been observed to influence the differentiation of NSCs along neuronal versus glial lineage. However, there is also a report suggesting that the neurogliogenic decision is independent of let-7. These paradoxical results might represent contextual roles of let-7 and lin28 during the CNS development. We have tested this premise in the mammalian retina, a reliable …

Lgr5 Activates Tgfβ Signaling And Suppresses Metastasis In Colon Cancer, Xiaolin Zhou

Theses & Dissertations

Metastasis is the major cause of death in colorectal cancer patients, mainly due to the ineffectiveness of current therapies once metastases begin to form. Further insight into the biology of colorectal cancer metastasis is, therefore, essential in order to gain a greater understanding of this process and ultimately to develop better cancer therapies to prevent or target metastasis. LGR5 is leucine-rich repeat containing G protein-coupled receptor (GPCR) and was discovered as a marker for proliferating adult stem cells in the small intestine. LGR5 and its homologs LGR4 and LGR6 are receptors of R-spondins (RSPOs), which are secreted agonists of canonical …

Functional Characterization Of The Roles Of Endocytic Recycling Regulator Ehd1 Using In Vivo And In Vitro Analyses, Priyanka Arya

Theses & Dissertations

Endocytic recycling is a fundamental cellular process that allows the precise regulation of the membrane components and receptors at the cell surface. Recent studies have established that the C-terminal Eps15 homology domain-containing (EHD) proteins function as key regulators of this process. Four highly-conserved members of the EHD protein family in mammals, EHD1-EHD4, play shared as well as unique roles in endocytic trafficking. Studies presented here demonstrate a critical role of EHD1 in the normal ocular development in mice. Ehd1 knockout mice generated in our laboratory displayed gross ocular phenotypes including the anophthalmia, microphthalmia, and congenital cataracts. Hematoxylin and eosin (H&E) …

Role Of Hippo-Yap Signaling In Mitosis And Prostate Cancer, Lin Zhang

Theses & Dissertations

The Hippo pathway controls organ size and tumorigenesis by inhibiting cell proliferation and promoting apoptosis. KIBRA [kidney and brain expressed protein] is an upstream regulator of the Hippo-YAP signaling. The role KIBRA plays in mitosis has not been established. We show that KIBRA activates the Aurora kinases during mitosis and KIBRA promotes the phosphorylation of large tumor suppressor 2 by activating Aurora-A. We further show that knockdown of KIBRA causes mitotic abnormalities, including defects of spindle and centrosome formation and chromosome misalignment. The transcriptional co-activator with PDZ-binding motif is a downstream effector of the Hippo tumor suppressor pathway. In the …

Role Of Macrophages In Muscle Transfection With Pdna/Pluronic Formulation, Vivek Mahajan

Theses & Dissertations

Non-ionic amphiphilic block copolymers of poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO), Pluronics, arranged in a tri-block structure PEO-PPO-PEO, have raised a considerable interest in skeletal muscle Gene Therapy. Previous studies have demonstrated that co-administration of Pluronics with naked plasmid DNA (pDNA) by direct i.m. injection enhanced transgene expression not only in muscle but also in distal lymphoid organs (spleen and lymph nodes) and this response was strain-dependent; not observed in athymic (BALB/c nu/nu) mouse; suggesting a role of immune cells in gene transfer to skeletal muscles. Therefore, we first evaluated the role of inflammation and inflammatory cells, on muscle …

A Screen To Identify Saga-Activated Genes That Are Required For Proper Photoreceptor Axon Targeting In Drosophila Melanogaster, Kaelan J. Brennan, Vikki M. Weake, Jingqun Q. Ma

The Summer Undergraduate Research Fellowship (SURF) Symposium

The inherited human genetic disease spinocerebellar ataxia type 7 (SCA7) is characterized by progressive neurodegeneration and visual impairment that ultimately leads to blindness. SCA7 results from a mutation in the human ATXN7 gene that causes an expansion of polyglutamine tracts in this gene’s corresponding protein. Human ATXN7 protein serves as a component of the deubiquitylase (DUB) module of the large, multi-subunit complex Spt-Ada-Gcn acetyltransferase, or SAGA. SAGA is a transcriptional coactivator and histone modifier that functions to deubiquitylate histone H2B and allow for transcription of SAGA-mediated genes to occur. In Drosophila, mutations in SAGA DUB’s Nonstop and sgf11 components …

Analysis Of Mitochondrial Turnover In Neuromuscular Junctions Of Parkin Mutants, Kenny Nguyen, Hyun Sung, Peter J. Hollenbeck

The Summer Undergraduate Research Fellowship (SURF) Symposium

The accumulation of dysfunctional or damaged mitochondria in neurons has been linked to the pathogenesis of many neurodegenerative diseases, such as Parkinson’s disease. It has been proposed that proteins PINK1 and Parkin regulate mitochondrial quality control by selectively targeting depolarized mitochondria for autophagic degradation, a process known as mitophagy. Though previously analyzed in the cell bodies and axons of neurons, the role of the PINK1/Parkin pathway in the synapse is unclear, and it is not known whether mitochondrial turnover occurs in the neuromuscular junctions (NMJs). To study this, intact Drosophila nervous systems were analyzed in vivo by performing gentle dissections …

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 …

Detection Of Ubiquitination On Syk And Documenting Syk Stability, Izabela Mazur, Wen Horng Wang, Robert J. Geahlen

The Summer Undergraduate Research Fellowship (SURF) Symposium

Post-translational modifications regulate the activities of proteins important to numerous diseases. Spleen Tyrosine Kinase (Syk) is particularly interesting to researchers because it modifies many targets and plays multiple roles in regulating cells in our bodies and its abnormal modifications may contribute to cancer, Alzheimer’s disease and allergies. In an attempt to study these modifications of Syk, we first looked at detecting ubiquitination on Syk protein. Ubiquitin, a small 8 kDa molecule, attaches to lysine residues on protein. The attachment of ubiquitin to Syk may cause Syk to either propagate signals onwards to activate other proteins or signal it to undergo …

Elucidating The Role Of Hausp Ubiquitin Like Domains In The Catalytic Function Of Usp7, Anuj Patel, Nicole Davis, Andrew Mesecar

The Summer Undergraduate Research Fellowship (SURF) Symposium

Ubiquitin specific proteases (USPs) are a class of enzymes involved in myriad cellular processes. One USP of great interest due to its oncogenic properties is USP7. In normal conditions USP7 is closely regulated due to its responsibility for destabilizing the tumor suppressor, p53, through the deubiquitination of MDM2. In multiple myeloma cases, it appears the regulation of USP7 subsides, as it is largely overexpressed, leading to the inappropriate degradation of p53. Inhibition of USP7 could, therefore, prove a viable target for cancer therapy. A greater understanding of USP7’s function and structure can lead to more insight into how this enzyme …

Beclin-1 Expression Is Retained In High-Grade Serous Ovarian Cancer Yet Is Not Essential For Autophagy Induction In Vitro, Rohann J.M. Correa, Yudith R. Valdes, Trevor G. Shepherd, Gabriel E. Dimattia

Anatomy and Cell Biology Publications

Background: Autophagy is a conserved cellular self-digestion mechanism that can either suppress or promote cancer in a context-dependent manner. In ovarian cancer, prevalent mono-allelic deletion of BECN1 (a canonical autophagy-inducer) suggests that autophagy is impaired to promote carcinogenesis and that Beclin-1 is a haploinsufficient tumor suppressor. Nonetheless, autophagy is known to be readily inducible in ovarian cancer cells. We sought to clarify whether Beclin-1 expression is in fact disrupted in ovarian cancer and whether this impacts autophagy regulation.

Methods: BECN1 expression levels were assessed using The Cancer Genome Atlas (TCGA) datasets from 398 ovarian high-grade serous cystadenocarcinomas (HGSC) and protein …

Chemical Oxygen Demand Reduction Using The Algae Dunaliella Primolecta And Chlorella Vulgaris, Angeles L. Mora, Alejandro Hernandez, Alejandro Calderón-Urrea

STAR Program Research Presentations

Farm industry wastewater is characterized by high organic materials and by high chemical oxygen demand (COD). Farms with large livestock and poultry operations can be a major source of wastewater thus a major concern for effective environmental and industrial management. Effective environmental and industrial management are high in cost therefor biofuels produced from plants have a potential of replacing a portion of fossil fuel consumption with a renewable efficient alternative. Due to California’s water crisis in the recent years, it is questioned if a biological treatment system that uses algal growth to create renewable energy in the form of biodiesel …