Medical Pathology Commons^™

Cryo-Electron Tomography Elucidates The Molecular Architecture Of Treponema Pallidum, The Syphilis Spirochete, Jacques Izard, Christian Renken, Chyong-Ere Hsieh, Daniel C. Desrosiers, Star Dunham-Ems, Carson La Vake, Linda L. Gebhardt, Ronald J. Limberger, David L. Cox, Michael Marko, Justin D. Radolf

Department of Food Science and Technology: Faculty Publications

Cryo-electron tomography (CET) was used to examine the native cellular organization of Treponema pallidum, the syphilis spirochete. T. pallidum cells appeared to form flat waves, did not contain an outer coat and, except for bulges over the basal bodies and widening in the vicinity of flagellar filaments, displayed a uniform periplasmic space. Although the outer membrane (OM) generally was smooth in contour, OM extrusions and blebs frequently were observed, highlighting the structure’s fluidity and lack of attachment to underlying periplasmic constituents. Cytoplasmic filaments converged from their attachment points opposite the basal bodies to form arrays that ran roughly …

Human Ubc9 Contributes To Production Of Fully Infectious Human Immunodeficiency Virus Type 1 Virions, Tareq Jaber, Christopher R. Bohl, Gentry L. Lewis, Charles Wood, John T. West Jr., Robert A. Weldon Jr.

Nebraska Center for Virology: Faculty Publications

Ubc9 was identified as a cellular protein that interacts with the Gag protein of Mason-Pfizer monkey virus. We show here that Ubc9 also interacts with the human immunodeficiency virus type 1 (HIV-1) Gag protein and that their interaction is important for virus replication. Gag was found to colocalize with Ubc9 predominantly at perinuclear puncta. While cells in which Ubc9 expression was suppressed with RNA interference produced normal numbers of virions, these particles were 8- to 10-fold less infectious than those produced in the presence of Ubc9. The nature of this defect was assayed for dependence on Ubc9 during viral assembly, …

Expression Of Hpv16 E5 Produces Enlarged Nuclei And Polyploidy Through Endoreplication, Lulin Hu, Tamara A. Potapova, Shibo Li, Susannah Rankin, Gary J. Gorbsky, Peter C. Angeletti, Brian P. Ceresa

Nebraska Center for Virology: Faculty Publications

Anogenital cancers and head and neck cancers are causally-associated with infection by high-risk

human papillomavirus (HPV). The mechanism by which high-risk HPVs contribute to

oncogenesis is poorly understood. HPV16 encodes three genes (HPV16 E5, E6, and E7) that can

transform cells when expressed independently. HPV16 E6 and E7 have well-described roles

causing genomic instability and unregulated cell cycle progression. The role of HPV16 E5 in cell

transformation remains to be elucidated. Expression of HPV16 E5 results in enlarged, polyploid

nuclei that are dependent on the level and duration of HPV16 E5 expression. Live-cell imaging

data indicate these changes do not …

Human Papillomavirus 16 E5 Induces Bi-Nucleated Cell Formation By Cell-Cell Fusion, Lulin Ha, Kendra Plafker, Valeriya Vorozhoko, Rosemary E. Zuna, Marie H. Hanigan, Gary J. Gorbsky, Scott M. Plafker, Peter C. Angeletti, Brian P. Ceresa

Nebraska Center for Virology: Faculty Publications

Human Papillomaviruses (HPV) 16 is a DNA virus encoding three oncogenes – E5, E6, and E7. The E6 and E7 proteins have well-established roles as inhibitors of tumor suppression, but the contribution of E5 to malignant transformation is controversial. Using spontaneously immortalized human keratinocytes (HaCaT cells), we demonstrate that expression of HPV16 E5 is necessary and sufficient for the formation of bi-nucleated cells, a common characteristic of precancerous cervical lesions. Expression of E5 from non-carcinogenic HPV6b does not produce bi-nucleate cells. Video microscopy and biochemical analyses reveal that bi-nucleates arise through cell-cell fusion. Although most E5-induced bi-nucleates fail to propagate, …

A Comparative Study Of Hiv-1 Clade C Env Evolution In A Zambian Infant With An Infected Rhesus Macaque During Disease Progression, For Yue Tso, Federico G. Hoffmann, Damien C. Tully, Philippe Lemey, Robert A. Rasmussen, Hong Zhang, Ruth M. Ruprecht, Charles Wood

Nebraska Center for Virology: Faculty Publications

Objective—To evaluate whether HIV-1 clade C (HIV-C) envelope variations that arise during disease progression in rhesus macaque model reflect changes that occur naturally in human infection.

Design—An infant macaque was infected with SHIV-1157i, an R5 tropic clade C SHIV (SHIV-C) which expresses a primary HIV-C envelope derived from an infected human infant, and monitored over a five-year period. Genetic variation of the V1-V5 envelope region, which is the main target for humoral immune responses, derived from the infected macaque and infant was examined.

Methods—V1-V5 envelope region were cloned and sequenced from longitudinal PBMC samples collected from the infected macaque and …

Protection Against Mucosal Shiv Challenge By Peptide And Helper-Dependent Adenovirus Vaccines, Eric A. Weaver, Pramod N. Nehete, Bharti P. Nehete, Stephanie J. Buchl, Donna Palmer, David C. Montefiori, Philip Ng, K. Jagannadha Sastry, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Groups of rhesus macaques that had previously been immunized with HIV-1 envelope (env) peptides and first generation adenovirus serotype 5 (FG-Ad5) vaccines expressing the same peptides were immunized intramuscularly three times with helper- dependent adenovirus (HD-Ad) vaccines expressing only the HIV-1 envelope from JRFL. No gag, pol, or other SHIV genes were used for vaccination. One group of the FG-Ad5- immune animals was immunized three times with HD-Ad5 expressing env. One group was immunized by serotype-switching with HD-Ad6, HD-Ad1, and HD-Ad2 expressing env. Previous work demonstrated that serum antibody levels against env were significantly higher in the serotype-switched group than …

Graft-Versus-Host Disease-Like Pattern In Mycophenolate Mofetil Related Colon Mucosal Injury: Role Of Fish In Establishing The Diagnosis., Kathryn C Behling, Dorothy M J Foster, Tina B Edmonston, Agnieszka K Witkiewicz

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Mycophenolate mofetil (CellCept®), a commonly used immunosuppressive drug in solid organ transplantation, has recently been shown to cause graft-versus-host disease (GVHD)-like changes in the gastrointestinal tract. On rare occasions, true GVHD has also been documented in the gastrointestinal tract of solid organ transplant patients. Because the treatment for these two entities is different, i.e. removal of the offending agent versus the administration of steroids, proper identification of the cause is imperative. We present a case of mycophenolate mofetil colitis mimicking grade I GVHD of the gut. In our study, we used fluorescence in situ hybridization for the Y chromosome to …

Developing Tta Transgenic Rats For Inducible And Reversible Gene Expression., Hongxia Zhou, Cao Huang, Min Yang, Carlisle P Landel, Pedro Yuxing Xia, Yong-Jian Liu, Xu Gang Xia

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

To develop transgenic lines for conditional expression of desired genes in rats, we generated several lines of the transgenic rats carrying the tetracycline-controlled transactivator (tTA) gene. Using a vigorous, ubiquitous promoter to drive the tTA transgene, we obtained widespread expression of tTA in various tissues. Expression of tTA was sufficient to strongly activate its reporter gene, but was below the toxicity threshold. We examined the dynamics of Doxycycline (Dox)-regulated gene expression in transgenic rats. In the two transmittable lines, tTA-mediated activation of the reporter gene was fully subject to regulation by Dox. Dox dose-dependently suppressed tTA-activated gene expression. The washout …

Effects Of Shielding Adenoviral Vectors With Polyethylene Glycol On Vector-Specific And Vaccine-Mediated Immune Responses, Eric A. Weaver, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Many individuals have been previously exposed to human adenovirus serotype 5 (Ad5). This prior immunity has long been known to hinder its use for gene therapy and as a gene-based vaccine. Given these immunogenicity problems, we have tested whether polyethylene glycol (PEG) can blunt immune effects against Ad5 during systemic and mucosal vaccination. Ad5 vectors were covalently modified with 5-, 20-, and 35-kDa linear PEG polymers and evaluated for their ability to produce immune responses against transgene antigen products and the vector itself. We show that shielding Ad5 with different-sized PEGs generally reduces transduction and primary antibody responses by the …

Neutralization Of Botulinum Neurotoxin By A Human Monoclonal Antibody Specific For The Catalytic Light Chain., Sharad P Adekar, Tsuyoshi Takahashi, R Mark Jones, Fetweh H Al-Saleem, Denise M Ancharski, Michael J Root, B P Kapadnis, Lance L Simpson, Scott K Dessain

Department of Biochemistry and Molecular Biology Faculty Papers

BACKGROUND: Botulinum neurotoxins (BoNT) are a family of category A select bioterror agents and the most potent biological toxins known. Cloned antibody therapeutics hold considerable promise as BoNT therapeutics, but the therapeutic utility of antibodies that bind the BoNT light chain domain (LC), a metalloprotease that functions in the cytosol of cholinergic neurons, has not been thoroughly explored.

METHODS AND FINDINGS: We used an optimized hybridoma method to clone a fully human antibody specific for the LC of serotype A BoNT (BoNT/A). The 4LCA antibody demonstrated potent in vivo neutralization when administered alone and collaborated with an antibody specific for …

A New Model For Hemoglobin Ingestion And Transport By The Human Malaria Parasite Plasmodium Falciparum., Michelle D Lazarus, Timothy G Schneider, Theodore F Taraschi

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

The current model for hemoglobin ingestion and transport by intraerythrocytic Plasmodium falciparum malaria parasites shares similarities with endocytosis. However, the model is largely hypothetical, and the mechanisms responsible for the ingestion and transport of host cell hemoglobin to the lysosome-like food vacuole (FV) of the parasite are poorly understood. Because actin dynamics play key roles in vesicle formation and transport in endocytosis, we used the actin-perturbing agents jasplakinolide and cytochalasin D to investigate the role of parasite actin in hemoglobin ingestion and transport to the FV. In addition, we tested the current hemoglobin trafficking model through extensive analysis of serial …

In Vitro Exploration Of Macrophage Migration Inhibitory Factor (Mif) As A Possible Agent Of Lymphatic Dilation In The Pathogenesis Of Lymphatic Filiariasis, Lauren Rosen

Honors Scholar Theses

Abstract:Macrophage Migration Inhibitory Factor (MIF) is a human cytokine that is well known for its role in modulating macrophage function. It has also been shown to cause smooth muscle cell death. A homolog of the MIF protein (BmMIF) has been found in Brugia malayi, one of the etiological agents of lymphatic filariasis. BmMIF shares a significant portion of its sequence homology with human MIF. Infection by Brugia malayi leads to a consistent finding of lymphatic dilation with surrounding smooth muscle cell apoptosis. We hypothesize that Brugia malayi releases BmMIF as a mediator of host smooth muscle cell death in the …

Nucleoplasmic And Cytoplasmic Degradation Of Telomerase: Implications Toward Telomerase-Based Cancer Therapy, Binh Nguyen

Theses and Dissertations

Telomerase is a ribonucleoprotein that is reactivated in cancer cells to allow for continuous cellular division and indefinite growth. With telomerase being expressed in more than 85% of all cancer, it is imperative that we understand how to selectively inactivate and degrade this unique DNA polymerase. In doing so, we can specifically target tumor cells to erode their telomeres so that they will undergo apoptosis or senescence. Through this research, we have learned that telomerase can be degraded in the nucleoplasm by Hsp90 chaperone inhibition and in the cytoplasm by the dominant negative mutant, D712A V713I. These findings should guide …

Gating Charge Immobilization In Kv4.2 Channels: The Basis Of Closed-State Inactivation., Kevin Dougherty, Jose A De Santiago-Castillo, Manuel Covarrubias

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Kv4 channels mediate the somatodendritic A-type K+ current (I(SA)) in neurons. The availability of functional Kv4 channels is dynamically regulated by the membrane potential such that subthreshold depolarizations render Kv4 channels unavailable. The underlying process involves inactivation from closed states along the main activation pathway. Although classical inactivation mechanisms such as N- and P/C-type inactivation have been excluded, a clear understanding of closed-state inactivation in Kv4 channels has remained elusive. This is in part due to the lack of crucial information about the interactions between gating charge (Q) movement, activation, and inactivation. To overcome this limitation, we engineered a charybdotoxin …

Method For Treating A Viral Infection Related Or A Chemical Toxin Related Hepatic Injury With Deltorphin D, Peter R. Oeltgen, Paul D. Bishop, Craig J. Mcclain, Shirish Barve

Pathology and Laboratory Medicine Faculty Patents

A method of modulating cytokine mediated hepatic injury by administering compound-D SEQ ID NO:1 to a mammal. A concentration of the compound in the range of about 0.5 mg/kg to about 20 mg/kg in a physiologically acceptable formulation blocks a cytokine cascade. A therapeutic method of modulating cytokine mediated acute inflammatory, trauma induced and toxin induced hepatic injury, particularly via tumor necrosis factor modulation, is thus disclosed.

Primers And Probe To Identify Mycobacterium Tuberculosis Complex, Subodh M. Lele, Manjiri S. Lele, Nada H. Khattar

Pathology and Laboratory Medicine Faculty Patents

Methods and nucleic acids for rapid, reliable and sensitive detection of Mycobacterium tuberculosis (MTB) complex pathogen in a biological sample. Oligonucleotides are provided which amplify MTB DNA and which are useful in carrying out real time PCR of DNA obtained from formalin-fixed and paraffin-embedded tissue samples.

Manganese Superoxide Dismutase Contributes To Cisplatin-Induced Cytotoxicity Rather Than All-Trans Retinoic Acid-Dependent Chemoresistance, Zina-Ann Cardozo

Theses, Dissertations and Capstones

Neuroblastoma is an extra-cranial solid tumor of the nervous system occurring predominantly in infants and children younger than five years of age. Neuroblastoma presents a challenge to therapy primarily due to a decreased responsiveness to anticancer agents like cisplatin (CDDP), leading to recurrence. Vitamin A and its derivatives, known as retinoids, are preventive against cancer and induce differentiation in some cell lines. Retinoids are now being tested clinically for the treatment of neuroblastoma. One major limitation to retinoid therapy is the development of chemoresistance. In the present study human SK-N-SH neuroblastoma cells pretreated with 10 μM all-trans retinoic acid (ATRA) …

A Versatile Assay For The Identification Of Rna Silencing Suppressors Based On Complementation Of Viral Movement, Jason G. Powers, Tim L. Sit, Feng Qu, T. Jack Morris, Kook-Hyung Kim, Steven A. Lommel

Nebraska Center for Virology: Faculty Publications

The cell-to-cell movement of Turnip crinkle virus (TCV) in Nicotiana benthamiana requires the presence of its coat protein (CP), a known suppressor of RNA silencing. RNA transcripts of a TCV construct containing a reporter gene (green fluorescent protein) (TCV-sGFP) in place of the CP open reading frame generated foci of three to five cells. TCV CP delivered in trans by Agrobacterium tumefaciens infiltration potentiated movement of TCV-sGFP and increased foci diameter, on average, by a factor of four. Deletion of the TCV movement proteins in TCV-sGFP (construct TCVΔ92-sGFP) abolished the movement complementation ability of TCV CP. Other known suppressors of …

Development Of An Immunofluorescence Assay Using Recombinant Proteins Expressed In Insect Cells To Screen And Confirm Presence Of Human Herpesvirus 8-Specific Antibodies, Veenu Minhas, Lynsey N. Crosby, Kay L. Crabtree, Saul Phiri, Tendai J. M'Soka, Chipepo Kankasa, William J. Harrington, Charles D. Mitchell, Charles Wood

Nebraska Center for Virology: Faculty Publications

Human herpesvirus 8 (HHV-8), or Kaposi’s sarcoma (KS)-associated herpesvirus, has been linked to all forms of KS. The results of most current serological assays for the detection of HHV-8-specific antibodies have low levels of concordance among themselves. To establish a sensitive and specific testing strategy that can be used to screen for HHV-8-specific antibodies, three HHV-8 proteins, ORF65, ORF73, and K8.1A, were expressed by using baculoviral vectors in insect cells and incorporated into a monoclonal antibodyenhanced immunofluorescence assay (mIFA) termed the Sf9 three-antigen mIFA. The results obtained by this mIFA were compared to those obtained by a standard mIFA with …

Small-Molecule Cd4 Mimics Interact With A Highly Conserved Pocket On Hiv-1 Gp120, Navid Madani, Arne Schön, Amy M. Princiotto, Judith M. Lalonde, Joel R. Cpurter, Takahiro Soeta, Danny Ng, Liping Wang, Evan T. Brower, Shi-Hua Xiang, Young Do Kwon, Chih-Chin Huang, Richard Wyatt, Peter D. Kwong, Ernesto Freire, Amos B. Smith Iii, Joseph Sodroski

Nebraska Center for Virology: Faculty Publications

Human immunodeficiency virus (HIV-1) interaction with the primary receptor, CD4, induces conformational changes in the viral envelope glycoproteins that allow binding to the CCR5 second receptor and virus entry into the host cell. The small molecule NBD-556 mimics CD4 by binding the gp120 exterior envelope glycoprotein, moderately inhibiting virus entry into CD4-expressing target cells, and enhancing CCR5 binding and virus entry into CCR5-expressing cells lacking CD4. Studies of NBD-556 analogues and gp120 mutants suggest that: 1) NBD-556 binds within the Phe 43 cavity, a highly conserved, functionally important pocket formed as gp120 assumes the CD4- bound conformation; 2) the NBD-556 …

The Human Immunodeficiency Virus Type 1 Envelope Confers Higher Rates Of Replicative Fitness To Perinatally Transmitted Viruses Than To Nontransmitted Viruses, Xiaohong Kong, John T. West, Hong Zhang, Danielle M. Shea, Tendai J. M’Soka, Charles Wood

Nebraska Center for Virology: Faculty Publications

Selection of a minor viral genotype during perinatal transmission of human Immunodeficiency virus type 1

(HIV-1) has been observed, but there is a lack of information on the correlation of the restrictive transmission

with biological properties of the virus, such as replicative fitness. Recombinant viruses expressing the enhanced

green fluorescent protein or the Discosoma sp. red fluorescent (DsRed2) protein carrying the V1 to V5

regions of env from seven mother-infant pairs (MIPs) infected by subtype C HIV-1 were constructed, and

competition assays were carried out to compare the fitness between the transmitted and nontransmitted

viruses. Flow cytometry was used to …

Varying Efficiency Of Long-Term Replication Of Papillomaviruses In Saccharomyces Cerevisiae, Adam J. Rogers, Malte Loggen, Karen Lee, Peter C. Angeletti

Nebraska Center for Virology: Faculty Publications

Human papillomaviruses (HPVs) replicate in mitotically active basal keratinocytes. Two virally encoded proteins, E1, a helicase, and E2, a transcription factor, are important players in replication and maintenance of HPV episomes. We previously showed that HPV16 could replicate stably in Saccharomyces cerevisiae [Angeletti, P.C., Kim, K., Fernandes, F.J., and Lambert, P.F. (2002)] and we identified cis-elements that mediate replication and maintenance [J. Virol. 76(7), 3350-3358.; Kim, K., Angeletti, P.C., Hassebroek, E.C., and Lambert, P.F. (2005)]. Here, we demonstrate that although multiple HPV genomes replicate stably in yeast, they do so with differing long-term efficiency; HPV6-Ura3 is replicated at the …

Effects Of Shielding Adenoviral Vectors With Polyethylene Glycol On Vector-Specific And Vaccine-Mediated Immune Responses, Eric A. Weaver, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Many individuals have been previously exposed to human adenovirus serotype 5 (Ad5). This prior immunity has long been known to hinder its use for gene therapy and as a gene-based vaccine. Given these immunogenicity problems, we have tested whether polyethylene glycol (PEG) can blunt immune effects against Ad5 during systemic and mucosal vaccination. Ad5 vectors were covalently modified with 5-, 20-, and 35-kDa linear PEG polymers and evaluated for their ability to produce immune responses against transgene antigen prod- ucts and the vector itself. We show that shielding Ad5 with different-sized PEGs generally reduces transduction and primary antibody responses by …

Oral Immunization Of Rhesus Macaques With Adenoviral Hiv Vaccines Using Enteric-Coated Capsules, George T. Mercier, Pramod N. Nehete, Marco F. Passeri, Bharti N. Nehete, Eric A. Weaver, Nancy Smyth Templeton, Kimberly Schluns, Stephanie S. Buchl, K. Buchl, Michael A. Barry

Nebraska Center for Virology: Faculty Publications

Targeted delivery of vaccine candidates to the gastrointestinal (GI) tract holds potential for mucosal immunization, particularly against mucosal pathogens like the human immunodeficiency virus (HIV). Among the different strategies for achieving targeted release in the GI tract, namely the small intestine, pH sensitive enteric coating polymers have been shown to protect solid oral dosage forms from the harsh digestive environment of the stomach and dissolve relatively rapidly in the small intestine by taking advantage of the luminal pH gradient. We developed an enteric polymethacrylate formulation for coating hydroxy-propyl-methyl-cellulose (HPMC) capsules containing lyophilized Adenoviral type 5 (Ad5) vectors expressing HIV-1 gag …

A Group M Consensus Envelope Glycoprotein Induces Antibodies That Neutralize Subsets Of Subtype B And C Hiv-1 Primary Viruses, Hua-Xin Liao, Laura L. Sutherland, Shi-Mao Xia, Mary E. Brock, Richard M. Scearce, Stacie Vanleeuwen, S. Munir Alam, Mildred Mcadams, Eric A. Weaver, Zenaido T. Camacho, Ben-Jiang Ma, Yingying Li, Julie M. Decker, Gary J. Nabel, David C. Montefiori, Beatrice H. Hahn, Bette T. Korber, Feng Gao, Barton F. Haynes

Nebraska Center for Virology: Faculty Publications

HIV-1 subtype C is the most common HIV-1 group M subtype in Africa and many parts of Asia. However, to date HIV-1 vaccine candidate immunogens have not induced potent and broadly neutralizing antibodies against subtype C primary isolates. We have used a centralized gene strategy to address HIV-1 diversity, and generated a group M consensus envelope gene with shortened consensus variable loops (CON-S) for comparative studies with wildtype (WT) Env immunogens. Our results indicate that the consensus HIV-1 group M CON-S Env elicited cross-subtype neutralizing antibodies of similar or greater breadth and titer than the WT Envs tested, indicating the …

Poor Knowledge--Predictor Of Nonadherence To Universal Precautions For Blood Borne Pathogens At First Level Care Facilities In Pakistan, Naveed Z. Janjua, Mahreen Razaq, Subhash Chandir, Shafquat Rozi, Bushra Mahmood

Community Health Sciences

Background: We conducted an assessment of knowledge about blood borne pathogens (BBP) and use of universal precautions at first level care facilities (FLCF) in two districts of Pakistan.Methods: We conducted a cross-sectional survey and selected three different types of FLCFs ; public, general practitioners and unqualified practitioners through stratified random sampling technique. At each facility, we interviewed a prescriber, a dispenser, and a housekeeper for knowledge of BBPs transmission and preventive practices, risk perception, and use of universal precautions. We performed multiple linear regression to assess the effect of knowledge score (11 items) on the practice of universal precautions score …

Phenotypic Alterations In Type Ii Alveolar Epithelial Cells In Cd4+ T Cell Mediated Lung Inflammation, Marcus Gereke, Lothar Gröbe, Silvia Prettin, Michael Kasper, Stefanie Deppenmeier, Achim D. Gruber, Richard I. Enelow, Jan Buer, Dunja Bruder

Dartmouth Scholarship

Although the contribution of alveolar type II epithelial cell (AEC II) activities in various aspects of respiratory immune regulation has become increasingly appreciated, our understanding of the contribution of AEC II transcriptosome in immunopathologic lung injury remains poorly understood. We have previously established a mouse model for chronic T cell-mediated pulmonary inflammation in which influenza hemagglutinin (HA) is expressed as a transgene in AEC II, in mice expressing a transgenic T cell receptor specific for a class II-restricted epitope of HA. Pulmonary inflammation in these mice occurs as a result of CD4+ T cell recognition of alveolar antigen. This model …

Formation Of Native Prions From Minimal Components In Vitro, Nathan R. Deleault, Brent T. Harris, Judy R. Rees, Surachai Supattapone

Dartmouth Scholarship

The conformational change of a host protein, PrPC, into a disease-associated isoform, PrPSc, appears to play a critical role in the pathogenesis of prion diseases such as Creutzfeldt–Jakob disease and scrapie. However, the fundamental mechanism by which infectious prions are produced in neurons remains unknown. To investigate the mechanism of prion formation biochemically, we conducted a series of experiments using the protein misfolding cyclic amplification (PMCA) technique with a preparation containing only native PrPC and copurified lipid molecules. These experiments showed that successful PMCA propagation of PrPScmolecules in a purified system requires accessory polyanion molecules. In addition, we found that …

Alzheimer's Disease: Cholesterol, Membrane Rafts, Isoprenoids And Statins, Patrick C. Reid, Yasuomi Urano, Tatsuhiko Kodama, Takao Hamakubo

Dartmouth Scholarship

Alzheimer's disease (AD) is a heterogeneous neurodegenerative disorder and the most prevalent form of dementia worldwide. AD is characterized pathologically by amyloid-? plaques, neurofibrillary tangles and neuronal loss, and clinically by a progressive loss of cognitive abilities. At present, the fundamental molecular mechanisms underlying the disease are unclear and no treatment for AD is known. Epidemiological evidence continues to mount linking vascular diseases, such as hypertension and diabetes, and hypercholesterolaemia with an increased risk for developing AD. A growing amount of evidence suggests a mechanistic link between cholesterol metabolism in the brain and the formation of amyloid plaques in AD …

The Nestin Progenitor Lineage Is The Compartment Of Origin For Pancreatic Intraepithelial Neoplasia, Catherine Carriere, Elliot S. Seeley, Tobias Goetze, Daniel S. Longnecker, Murray Korc

Dartmouth Scholarship

To determine the cell compartment in which initial oncogenic mutations occur in pancreatic ductal adenocarcinoma (PDAC), we generated a mouse model in which endogenous expression of mutated Kras (Kras(G12D)) was initially directed to a population of pancreatic exocrine progenitors characterized by the expression of Nestin. Targeting of oncogenic Kras to such a restricted cell compartment was sufficient for the formation of pancreatic intraepithelial neoplasias (PanINs), putative precursors to PDAC. PanINs appeared with the same grade and frequency as observed when Kras(G12D) was targeted to the whole pancreas by a Pdx1-driven Cre recombinase strategy. Thus, the Nestin cell lineage is highly …