Medicine and Health Sciences Commons^™

Diabetic Retinopathy: Variations In Patient Therapeutic Outcomes And Pharmacogenomics., Aniruddha Agarwal, Mohamed K. Soliman, Yasir J. Sepah, Diana V. Do, Quan Dong Nguyen

Journal Articles: Ophthalmology

Diabetes and its microvascular complications in patients poses a significant challenge and constitutes a major health problem. When it comes to manifestations in the eye, each case of diabetic retinopathy (DR) is unique, in terms of the phenotype, genotype, and, more importantly, the therapeutic response. It is therefore important to identify factors that distinguish one patient from another. Personalized therapy in DR is a new trend aimed at achieving maximum therapeutic response in patients by identifying genotypic and phenotypic factors that may result in less than optimal response to conventional therapy, and consequently, lead to poorer outcome. With advances in …

Inhibition Of Rac1 Gtpase Sensitizes Pancreatic Cancer Cells To Γ-Irradiation., Y Yan, Ashley L. Hein, Asserewou Etekpo, Katrina M. Burchett, Chi Lin, Charles A. Enke, Surinder K. Batra, Kenneth Cowan, M Ouellette

Journal Articles: Radiation Oncology

Radiation therapy is a staple treatment for pancreatic cancer. However, owing to the intrinsic radioresistance of pancreatic cancer cells, radiation therapy often fails to increase survival of pancreatic cancer patients. Radiation impedes cancer cells by inducing DNA damage, which can activate cell cycle checkpoints. Normal cells possess both a G1 and G2 checkpoint. However, cancer cells are often defective in G1 checkpoint due to mutations/alterations in key regulators of this checkpoint. Accordingly, our results show that normal pancreatic ductal cells respond to ionizing radiation (IR) with activation of both checkpoints whereas pancreatic cancer cells respond to IR with G2/M arrest …

Novel Ubiquitin Neuropathology In Frontotemporal Dementia With Valosin-Containing Protein Gene Mutations, Mark Forman, Ian Mackenzie, Nigel Cairns, Eric Swanson, Philip Boyer, David Drachman, Bharati Jhaveri, Jason Karlawish, Alan Pestronk, Thomas Smith, Pang-Hsien Tu, Giles Watts, William Markesbery, Charles Smith, Virginia Kimonis

Jason Karlawish

Frontotemporal dementia (FTD) with inclusion body myopathy and Paget disease of bone (IBMPFD) is a rare, autosomal-dominant disorder caused by mutations in the valosin-containing protein (VCP) gene, a member of the AAA-ATPase gene superfamily. The neuropathology associated with sporadic FTD is heterogeneous and includes tauopathies and frontotemporal lobar degeneration with ubiquitin-positive inclusions (FTLD-U). However, there is limited information on the neuropathology in IBMPFD. We performed a detailed, systematic analysis of the neuropathologic changes in 8 patients with VCP mutations. A novel pattern of ubiquitin pathology was identified in IBMPFD that was distinct from sporadic and familial FTLD-U without VCP gene …

Exploiting High-Throughput Cell Line Drug Screening Studies To Identify Candidate Therapeutic Agents In Head And Neck Cancer, Anthony C Nichols, Morgan Black, John Yoo, Nicole Pinto, Andrew Fernandes, Benjamin Haibe-Kains, Paul C Boutros, John W Barrett

Oncology Publications

BACKGROUND: There is an urgent need for better therapeutics in head and neck squamous cell cancer (HNSCC) to improve survival and decrease treatment morbidity. Recent advances in high-throughput drug screening techniques and next-generation sequencing have identified new therapeutic targets in other cancer types, but an HNSCC-specific study has not yet been carried out. We have exploited data from two large-scale cell line projects to clearly describe the mutational and copy number status of HNSCC cell lines and identify candidate drugs with elevated efficacy in HNSCC.

METHODS: The genetic landscape of 42 HNSCC cell lines including mutational and copy number data …

The P38alpha Mitogen-Activated Protein Kinase Limits The Cns Proinflammatory Cytokine Response To Systemic Lipopolysaccharide, Potentially Through An Il-10 Dependent Mechanism, Adam D. Bachstetter, Bin Xing, Linda J. Van Eldik

Sanders-Brown Center on Aging Faculty Publications

BACKGROUND: The p38α mitogen-activated protein kinase (MAPK) is a well-characterized intracellular kinase involved in the overproduction of proinflammatory cytokines from glia. As such, p38α appears to be a promising therapeutic target for neurodegenerative diseases associated with neuroinflammation. However, the in vivo role of p38α in cytokine production in the CNS is poorly defined, and prior work suggests that p38α may be affecting a yet to be identified negative feedback mechanism that limits the acute, injury-induced proinflammatory cytokine surge in the CNS.

METHODS: To attempt to define this negative feedback mechanism, we used two in vitro and two in vivo models …

Analysis Of Candida Albicans Mutants Defective In The Cdk8 Module Of Mediator Reveal Links Between Metabolism And Biofilm Formation, Allia K. Lindsay, Diana K. Morales, Zhongle Liu, Nora Grahl, Anda Zhang, Sven D. Willger, Lawrence C. Myers, Deborah A. Hogan

Dartmouth Scholarship

Candida albicans biofilm formation is a key virulence trait that involves hyphal growth and adhesin expression. Pyocyanin (PYO), a phenazine secreted by Pseudomonas aeruginosa, inhibits both C. albicans biofilm formation and development of wrinkled colonies. Using a genetic screen, we identified two mutants, ssn3Δ/Δ and ssn8Δ/Δ, which continued to wrinkle in the presence of PYO. Ssn8 is a cyclin-like protein and Ssn3 is similar to cyclin-dependent kinases; both proteins are part of the heterotetrameric Cdk8 module that forms a complex with the transcriptional co-regulator, Mediator. Ssn3 kinase activity was also required for PYO sensitivity as a kinase dead mutant maintained …

The Association Of The Vanin-1 N131s Variant With Blood Pressure Is Mediated By Endoplasmic Reticulum-Associated Degradation And Loss Of Function, Ya-Juan Wang, Bamidele O. Tayo, Anupam Bandyopadhyay, Heming Wang, Tao Feng, Nora Franceschini, Hua Tang, Jianmin Gao, Yun Ju Sung, The Cogent Bp Consortium, Robert C. Elston, Scott M. Williams, Richard S. Cooper, Ting-Wei Mu, Xiaofeng Zhu

Dartmouth Scholarship

High blood pressure (BP) is the most common cardiovascular risk factor worldwide and a major contributor to heart disease and stroke. We previously discovered a BP-associated missense SNP (single nucleotide polymorphism)–rs2272996–in the gene encoding vanin-1, a glycosylphosphatidylinositol (GPI)-anchored membrane pantetheinase. In the present study, we first replicated the association of rs2272996 and BP traits with a total sample size of nearly 30,000 individuals from the Continental Origins and Genetic Epidemiology Network (COGENT) of African Americans (P = 0.01). This association was further validated using patient plasma samples; we observed that the N131S mutation is associated with significantly lower plasma vanin-1 …

Mst1 Directs Myosin Iia Partitioning Of Low And Higher Affinity Integrins During T Cell Migration, Xiaolu Xu, Emily R. Jaeger, Xinxin Wang, Erica Lagler-Ferrez, Serge Batalov, Nancy L. Mathis, Tim Wiltshire, John R. Walker, Michael P. Cooke, Karsten Sauer, Yina H. Huang

Dartmouth Scholarship

Chemokines promote T cell migration by transmitting signals that induce T cell polarization and integrin activation and adhesion. Mst1 kinase is a key signal mediator required for both of these processes; however, its molecular mechanism remains unclear. Here, we present a mouse model in which Mst1 function is disrupted by a hypomorphic mutation. Microscopic analysis of Mst1-deficient CD4 T cells revealed a necessary role for Mst1 in controlling the localization and activity of Myosin IIa, a molecular motor that moves along actin filaments. Using affinity specific LFA-1 antibodies, we identified a requirement for Myosin IIa-dependent contraction in the precise …

Cc2d1a Regulates Human Intellectual And Social Function As Well As Nf-Κb Signaling Homeostasis., M. Chiara Manzini, Lan Xiong, Ranad Shaheen, Dimira E Tambunan, Stefania Di Costanzo, Vanessa Mitisalis, +15 Additional Authors

Pharmacology and Physiology Faculty Publications

Autism spectrum disorder (ASD) and intellectual disability (ID) are often comorbid, but the extent to which they share common genetic causes remains controversial. Here, we present two autosomal-recessive "founder" mutations in the CC2D1A gene causing fully penetrant cognitive phenotypes, including mild-to-severe ID, ASD, as well as seizures, suggesting shared developmental mechanisms. CC2D1A regulates multiple intracellular signaling pathways, and we found its strongest effect to be on the transcription factor nuclear factor κB (NF-κB). Cc2d1a gain and loss of function both increase activation of NF-κB, revealing a critical role of Cc2d1a in homeostatic control of intracellular signaling. Cc2d1a knockdown in neurons …

Obesity And Diabetes Cause Cognitive Dysfunction In The Absence Of Accelerated Β-Amyloid Deposition In A Novel Murine Model Of Mixed Or Vascular Dementia, Dana M. Niedowicz, Valerie L. Reeves, Thomas L. Platt, Katharina Kohler, Tina L. Beckett, David K. Powell, Tiffany L. Lee, Travis R. Sexton, Eun Suk Song, Lawrence D. Brewer, Caitlin S. Latimer, Susan D. Kraner, Kara L. Larson, Sabire Özcan, Christopher M. Norris, Louis B. Hersh, Nada M. Porter, Donna M. Wilcock, Michael Paul Murphy

Sanders-Brown Center on Aging Faculty Publications

Mid-life obesity and type 2 diabetes mellitus (T2DM) confer a modest, increased risk for Alzheimer's disease (AD), though the underlying mechanisms are unknown. We have created a novel mouse model that recapitulates features of T2DM and AD by crossing morbidly obese and diabetic db/db mice with APP^ΔNL/ΔNLx PS1^P264L/P264L knock-in mice. These mice (db/AD) retain many features of the parental lines (e.g. extreme obesity, diabetes, and parenchymal deposition of β-amyloid (Aβ)). The combination of the two diseases led to additional pathologies-perhaps most striking of which was the presence of severe cerebrovascular pathology, including aneurysms and small …

Modeling The Adaptive Immune Response To Mutation-Generated Antigens, Rory J. Geyer

University Scholar Projects

Somatic mutations may drive tumorigenesis or lead to new, immunogenic epitopes (neoantigens). The immune system is thought to represses neoplastic growths through the recognition of neoantigens presented only by tumor cells. To study mutations as well as the immune response to mutation-generated antigens, we have created a conditional knockin mouse line with a gene encoding, 5’ to 3’, yellow fluorescent protein (YFP), ovalbumin (which is processed to the immunologically recognizable peptide, SIINFEKL), and cyan fluorescent protein (CFP), or, YFP-ovalbumin-CFP. A frame shift mutation has been created at the 5’ end of the ovalbumin gene, hence YFP should always be expressed, …

Modeling The Adaptive Immune Response To Mutation-Generated Antigens, Rory J. Geyer

Honors Scholar Theses

Somatic mutations may drive tumorigenesis or lead to new, immunogenic epitopes (neoantigens). The immune system is thought to represses neoplastic growths through the recognition of neoantigens presented only by tumor cells. To study mutations as well as the immune response to mutation-generated antigens, we have created a conditional knockin mouse line with a gene encoding, 5’ to 3’, yellow fluorescent protein (YFP), ovalbumin (which is processed to the immunologically recognizable peptide, SIINFEKL), and cyan fluorescent protein (CFP), or, YFP-ovalbumin-CFP. A frame shift mutation has been created at the 5’ end of the ovalbumin gene, hence YFP should always be expressed, …

Evidence For Aberrant Astrocyte Hemichannel Activity In Juvenile Neuronal Ceroid Lipofuscinosis (Jncl)., Maria Burkovetskaya, Nikolay Karpuk, Juan Xiong, Megan Bosch, Michael D. Boska, Hideyuki Takeuchi, Akio Suzumura, Tammy Kielian

Journal Articles: Pathology and Microbiology

Juvenile Neuronal Ceroid Lipofuscinosis (JNCL) is a lysosomal storage disease caused by an autosomal recessive mutation in CLN3 that leads to vision loss, progressive cognitive and motor decline, and premature death. Morphological evidence of astrocyte activation occurs early in the disease process and coincides with regions where neuronal loss eventually ensues. However, the consequences of CLN3 mutation on astrocyte function remain relatively ill-defined. Astrocytes play a critical role in CNS homeostasis, in part, by their ability to regulate the extracellular milieu via the formation of extensive syncytial networks coupled by gap junction (GJ) channels. In contrast, unopposed hemichannels (HCs) have …

Skin Disease And Non-Syndromic Hearing Loss-Linked Cx30 Mutations Exhibit Several Distinct Cellular Pathologies, Amy Berger, John Kelly, Patrick Lajoie, Qing Shao, Dale Laird

Anatomy and Cell Biology Publications

Connexin 30 (Cx30), a member of the large gap junction protein family, plays a role in the homeostasis of the epidermis and inner ear through gap junctional intercellular communication (GJIC). Here, we investigated the underlying mechanisms of four autosomal dominant Cx30 gene mutations linked to hearing loss and/or various skin diseases. First, the T5M mutant linked to non-syndromic hearing loss formed functional gap junction channels and hemichannels, similar to wild type Cx30. The loss-of-function V37E mutant associated with Clouston syndrome or keratitis-ichthyosis-deafness syndrome was retained in the endoplasmic reticulum and significantly induced apoptosis. The G59R mutant linked to Vohwinkel and …

The Molecular Biology And Treatment Of Malignant Melanoma With Brafv600 Mutations, Michael P. Mullane

Journal of Patient-Centered Research and Reviews

Since 2011, the treatment options for metastatic malignant melanoma have significantly changed. In that year, ipilimumab, an anti-CTLA4 monoclonal antibody, and vemurafenib, a potent inhibitor of mutated-BRAF (V600E and V600K), were approved by the U.S. Food and Drug Administration (FDA). In 2013, dabrafenib, another inhibitor of mutated-BRAF, and trametinib, a MEK inhibitor, were approved by the FDA. Most recently, combination therapy with dabrafenib and trametinib was approved. This article will describe a patient with metastatic malignant melanoma with BRAF^V600E who has responded very well to vemurafenib monotherapy. We will then explore the molecular basis, pharmacologic development and clinical outcomes …

The Rak/Frk Tyrosine Kinase Associates With And Internalizes The Epidermal Growth Factor Receptor, Ling Jin, Rolf J. Craven

Pharmacology and Nutritional Sciences Faculty Publications

Src is the founding member of a diverse family of intracellular tyrosine kinases, and Src has a key role in promoting cancer growth, in part, through its association with receptor tyrosine kinases. However, some Src-related proteins have widely divergent physiological roles, and these proteins include the Rak/Frk tyrosine kinase (Frk stands for Fyn-related kinase), which inhibits cancer cell growth and suppresses tumorigenesis. Rak/Frk phosphorylates and stabilizes the Pten tumor suppressor, protecting it from degradation, and Rak/Frk associates with the retinoblastoma (Rb) tumor suppressor. However, the role of Rak/Frk in receptor-mediated signaling is largely unknown. Here, we demonstrate that Rak/Frk associates …

Inhibition Of Rac1 Gtpase Sensitizes Pancreatic Cancer Cells To Γ-Irradiation, Y Yan, Ashley L. Hein, Asserewou Etekpo, Katrina M. Burchett, Chi Lin, Charles A. Enke, Surinder K. Batra, Kenneth Cowan, Michel M. Ouellette

Journal Articles: Biochemistry & Molecular Biology

Radiation therapy is a staple treatment for pancreatic cancer. However, owing to the intrinsic radioresistance of pancreatic cancer cells, radiation therapy often fails to increase survival of pancreatic cancer patients. Radiation impedes cancer cells by inducing DNA damage, which can activate cell cycle checkpoints. Normal cells possess both a G1 and G2 checkpoint. However, cancer cells are often defective in G1 checkpoint due to mutations/alterations in key regulators of this checkpoint. Accordingly, our results show that normal pancreatic ductal cells respond to ionizing radiation (IR) with activation of both checkpoints whereas pancreatic cancer cells respond to IR with G2/M arrest …

Importance Of Bacillithiol In The Oxidative Stress Response Of Staphylococcus Aureus, Ana C. Posada, Stacey L. Kolar, Renata G. Dusi, Patrica Francois

Dartmouth Scholarship

In Staphylococcus aureus, the low-molecular-weight thiol called bacillithiol (BSH), together with cognate S-transferases, is believed to be the counterpart to the glutathione system of other organisms. To explore the physiological role of BSH in S. aureus, we constructed mutants with the deletion of bshA (sa1291), which encodes the glycosyltransferase that catalyzes the first step of BSH biosynthesis, and fosB (sa2124), which encodes a BSH-S-transferase that confers fosfomycin resistance, in several S. aureus strains, including clinical isolates. Mutation of fosB or bshA caused a 16- to 60-fold reduction in fosfomycin resistance in these S. aureus strains. High-pressure liquid chromatography analysis, which …

A Study Of 17 Short Tandem Repeat Loci Mutation In Thai Population, K Vongpaisarnsin, N Tansrisawad, U Hoonwijit, T. Jongsakul

Chulalongkorn Medical Journal

Background : In paternity testing, differences at genetic loci between the alleged parent and the child would lead to the exclusion of biological paternity. Although rare, transmission inconsistent in paternity testing or single mismatches in DNA profiles may occur, possibly due to either germline or somatic mutation. When single locus discrepancy is present, the mutant allele is hypothesized that mutation occurs possibly in either father or mother. Objective : The objective of this paper is to report the mutation events related to many short tandem repeat (STR) loci that are frequently used and applied in various scenarios of forensic statistics. …

Effect Of Bdnf Val66met On Memory Decline And Hippocampal Atrophy In Prodromal Alzheimer's Disease: A Preliminary Study, Yen Y. Lim, Victor L. Villemagne, Simon M. Laws, David Ames, Robert H. Pietrzak, Kathryn A. Ellis, Karra Harrington, Pierrick Bourgeat, Ashley I. Bush, Ralph N. Martins, Colin L. Masters, Christopher C. Rowe, Paul Maruff

Research outputs 2014 to 2021

Objective: Cross-sectional genetic association studies have reported equivocal results on the relationship between the brain-derived neurotrophic factor (BDNF) Val66Met and risk of Alzheimer's disease (AD). As AD is a neurodegenerative disease, genetic influences may become clearer from prospective study. We aimed to determine whether BDNF Val66Met polymorphism influences changes in memory performance, hippocampal volume, and Aβ accumulation in adults with amnestic mild cognitive impairment (aMCI) and high Aβ. Methods: Thirty-four adults with aMCI were recruited from the Australian, Imaging, Biomarkers and Lifestyle (AIBL) Study. Participants underwent PiB-PET and structural MRI neuroimaging, neuropsychological assessments and BDNF genotyping at baseline, 18 month, …

The Place Of Androgen Receptor Gene Mutation Analysis In The Molecular Diagnosis Of Prostate Cancer And Genotype–Phenotype Relationship, Fuat Kizilay, Mustafa Serdar Kalemci̇, Adnan Şi̇mşi̇r, Burak Turna, Oktay Nazli, Afi̇g Berdeli̇

Turkish Journal of Medical Sciences

To determine the relationship between androgen receptor (AR) gene polymorphism and prostate cancer in our society. Materials and methods: Thirty-nine patients diagnosed with prostate cancer and 34 benign prostatic hyperplasia (BPH) patients who were diagnosed in 2010 met the study criteria. The inclusion criteria included patients whose diagnosis was confirmed with a biopsy, with the presence of adequate pathologic material for review, between the ages of 40 and 80, and who were healthy men without a family history of prostate cancer. The exclusion criteria excluded men diagnosed with another cancer and those who had kin with a history of prostate …

Structure-Functional Prediction And Analysis Of Cancer Mutation Effects In Protein Kinases, Anshuman Dixit, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

A central goal of cancer research is to discover and characterize the functional effects of mutated genes that contribute to tumorigenesis. In this study, we provide a detailed structural classification and analysis of functional dynamics for members of protein kinase families that are known to harbor cancer mutations. We also present a systematic computational analysis that combines sequence and structure-based prediction models to characterize the effect of cancer mutations in protein kinases. We focus on the differential effects of activating point mutations that increase protein kinase activity and kinase-inactivating mutations that decrease activity. Mapping of cancer mutations onto the conformational …