Chemicals and Drugs Commons^™

Molecular Mechanisms And Metabolic Consequences Of Glucocorticoid Resistance, Genesee J. Martinez

Theses and Dissertations--Pharmacology and Nutritional Sciences

Glucocorticoids are vital steroid hormones that govern metabolism, stress responses, and immune functions through intricate, tissue-specific mechanisms, both genomic and non-genomic. These hormones bind to the glucocorticoid receptor (GR), which then acts as a transcription factor to modulate gene expression. Chronic elevation of glucocorticoid levels may lead to glucocorticoid resistance, resulting in adiposity, inflammation, and insulin resistance, thereby adversely affecting multiple metabolic tissues. Whether produced endogenously or administered exogenously, excessive, chronic glucocorticoid concentrations impair glucocorticoid signaling. Although there are two primary isoforms of the receptor, GR⍺ and GRβ, only GR⍺ interacts with glucocorticoids.Through the research conducted in this dissertation, we …

Estrogen Deprivation During Primate (Papio Anubis) Pregnancy: Impact On Systemic Microvascular Flow And Cardiovascular Development And Function After Birth In Offspring, Sifa Turan, Jeffery S. Babischkin, Graham W. Aberdeen, Gerald J. Pepe, Eugene D. Albrecht

Department of Biomedical and Translational Sciences Faculty Publications

Background

Suppressing estradiol (E₂) during baboon pregnancy lowers offspring skeletal muscle capillary density, vital for insulin-mediated glucose uptake, and induces insulin resistance. We examined whether E₂ deprivation also impairs microvascular flow and cardiac function.

Methods

Offspring of untreated baboons, letrozole-treated baboons, or letrozole plus E₂ (maternal s.c. injections during the second half of gestation) underwent contrast-enhanced microbubble ultrasonography to quantify microvessel flow and echocardiography to assess cardiac performance.

Results

Letrozole reduced maternal serum E₂ by 95% (p <  0.01). In letrozole offspring, microbubble flux rate (β) fell 55% (p <  0.02), replenishment was 5 s slower (p <  0.03), and microvessel flow declined 40% (p = 0.05); all were restored by added E₂. Indices of systolic (isovolumic contraction), diastolic (isovolumic relaxation), global performance (Tei index), and cardiac output were unchanged.

Conclusion

Prolonged gestational E₂ deprivation programs a reduction in microvascular flow without altering cardiac function; maternal E₂ prevents this, supporting E₂'s role in …

Comparative Mass Spectrometry Analysis Of High And Low Centrifugation Extracellular Vesicle (Ev) Pellets From Healthy Urine Following Tamm-Horsfall Protein Removal, Dana Bielopolski, Luca Musante, Henrik Molina, Douglas Barrows, Samantha Upson, Lifang Yang, Thomas Carrol, Jonathan N. Tobin, Rhonda G. Kost, U. Erdbrügger

Department of Biomedical and Translational Sciences Faculty Publications

Objectives

Urinary extracellular vesicles (uEVs) are potential biomarkers for renal physiology and disease. Their isolation is challenged by Tamm-Horsfall protein (THP) contamination, particularly in high-speed ultracentrifugation (P100) fractions. Low-speed (P20) fractions contain biologically relevant uEVs, yet their proteomic composition is underexplored. This study evaluates strategies for THP removal to optimize mass spectrometry analysis and characterizes P20 and P100 uEV proteomes and its combination in healthy urine.

Methods

Urine from a healthy volunteer was processed via sequential centrifugation at 21,200 g (P20) and 164,244 g (P100). THP removal was performed using low ionic strength buffer (P20) and size-exclusion chromatography (P100). Western …

Absolute Quantification And Identification Of Rna From Rna-Lipid Nanoparticles Using High Resolution Mass Spectrometry, Jason C. Funderburk

Theses and Dissertations

RNA therapeutics are a rising drug category with potential use for a range of conditions encompassing infectious diseases to therapies for cancer, diseases, and genetic disorders. RNA-lipid nanoparticles (RNA-LNPs) are the prominent delivery method for these therapeutics approved products include mRNA vaccines and polyneuropathy treatments. The emergency use authorizations and orphan drug status of current RNA-LNP drugs has allowed approval without finalization of the regulatory analytical procedures for quality monitoring. The objective of the study was to develop an LC-MS assay to simultaneously measure identity and concentration of two therapeutically relevant intact RNA constructs extracted from RNA-LNPs to enhance quality …

Exploring Anticholinergic Neurotoxicity: Diphenhydramine's Impact On Neuro-2a Cell Morphology, Expression, And Viability, Jordan B. Mcintyre

Honors Undergraduate Theses

Anticholinergic medications, such as diphenhydramine (commonly known as Benadryl), are increasingly recognized for their association with cognitive impairment and neurodegenerative disease. These medications, which inhibit the action of acetylcholine, a neurotransmitter essential for the formation and utilization of the central and peripheral nervous system, have been implicated in conditions such as dementia and may impact fundamental cellular processes like neurogenesis and cell proliferation. This study investigates the effects of diphenhydramine on neurogenesis when introduced to Neuro-2a cells during differentiation. For all studies cells were plated on coverslips or in 6-well plates with differentiation media containing 0 ng/mL, 50 ng/mL, …

Leveraging Cross-Reactivity For Dual Serological Detection Of Closely Related Schistosoma Species, Oyetunde T. Oyeyemi, Lisa M. Shollenberger

Biological Sciences Faculty Publications

Schistosomiasis is a disease of poverty that is highly prevalent in Sub-Saharan African countries. Cross-reacting proteins in Schistosoma mansoni (Sm) and S. haematobium (Sh) have been reported to pose diagnostic challenges. Proteins from these two parasites may help overcome diagnostic limitations caused by cross-reactivity and poor species discrimination in serological assays. The study aims to identify cross-reacting protein markers from S. mansoni and S. haematobium for possible concurrent diagnosis of the two parasites. High-quality protein extracts were prepared from the eggs (soluble egg antigen, SEA) and adult worms (Schistosoma worm antigens preparation, SWAP) of S. haematobium and S. mansoni …

Investigating The Role Of Traditional Chinese Herbal Medicine For Cancer Symptom Management In Older Adults: A Rapid Review, Isabelle C. Karshner

Honors Undergraduate Theses

Background: Patients with cancer often experience symptoms related to disease, complications, and treatment. One potential method of alleviating these symptoms is traditional Chinese herbal medications (TCHM). This rapid review explores the role of traditional Chinese herbal medications in treating cancer-related symptoms in older adults.

Purpose: The purpose of this rapid review is to gain and provide a better understanding of the effects of TCHM on cancer-symptom management in the older adult population. This review explores the association between TCHM and effects on cancer symptoms in older adults, including interactions, toxicity, and signs/symptoms of TCHM use that may be useful information …

Synthesis And Characterization Of Succinate Dehydrogenase Inhibitors H2/Z14 And C6/Z96 In Order To Combat Small Cell Lung Cancer, Lauren M. Graves

Honors Undergraduate Theses

The use of ubiquinone inhibitors to combat cancer is a recent development in medicinal science and procedures to efficiently synthesize these drugs remain limited. C6/Z96 and H2/Z14, two succinate dehydrogenase inhibitors, have been previously tested in vitro against NSCLC with positive results. Their similarity to ubiquinone is what makes them a strong candidate for a succinate dehydrogenase inhibitor at the ubiquinone binding site. The heterocyclic scaffolds and substituents are proposed to bind strongly through a combination of electronics, hydrogen-bonding, and fit, allowing them to bind well and prove to be more favorable than ubiquinone when competing for the Q-site. By …

The Myopia Epidemic: Integrating Genetic, Environmental, And Epigenetic Pathways To Define A Critical Window For Intervention, Pranavika Balaji

UROP Posters

Myopia, or nearsightedness, has increased rapidly worldwide and is now a major public health concern caused by both genetic and environmental factors. Current understanding shows that too much near work, limited time spent outdoors, and prolonged screen use contribute to abnormal eye growth in individuals who may already have a genetic predisposition. At the molecular level, epigenetic changes and shifts in DNA activity, often influenced by environmental conditions, affect the signaling pathways that regulate eye development and may help explain why myopia is increasingly common among children. This paper synthesizes recent environmental, genetic, and epigenetic research to explain how these …

Gastrointestinal Symptoms Associated With Sodium Bicarbonate Supplementation Protocols: A Systematic Review, Ian P. Winter, Paul Sarac, Patrick B. Wilson

Exercise Science Faculty Publications

Sodium bicarbonate positively impacts performance, but its associated gastrointestinal symptoms (GIS) may limit use. This systematic review synthesized literature that has evaluated GIS with sodium bicarbonate supplementation. Literature searches were performed from February 2024-March 2026. Eligible studies provided ≥ 5 g of sodium bicarbonate within a 24-h period or, if a multi-day protocol, at least one day involving ≥ 5 g. Included studies had a placebo group/condition or a comparison group/condition that created a contrast related to delivery method, form, or dose. In total, 101 investigations were summarized in six categories: acute single dosing (n = 35); acute spread dosing …

Absolute Quantification And Identification Of Rna From Rna-Lipid Nanoparticles Using High Resolution Mass Spectrometry, Jason C. Funderburk, Yasir A. Alshehry, Matthew S. Halquist Phd, Sandro R.P. Da Rocha Phd

Graduate Research Posters

Background

RNA therapeutics are a rising drug category with potential use for a range of conditions encompassing infectious diseases to therapies for cancer, diseases, and genetic disorders. RNA-lipid nanoparticles (RNA-LNPs) are the prominent delivery method for these therapeutics approved products include mRNA vaccines and polyneuropathy treatments. The emergency use authorizations and orphan drug status of current RNA-LNP drugs has allowed approval without finalization of the regulatory analytical procedures for quality monitoring. The objective of the study was to develop an LC-MS assay to simultaneously measure identity and concentration of two therapeutically relevant intact RNA constructs extracted from RNA-LNPs to enhance …

Drug-Induced Lichen Planus Associated With Ocrelizumab, Avery Seward, John D. Strickley, Jeffrey P. Callen

Department of Medicine Faculty Publications

This case report highlights recurrent cutaneous lichen planus as a rare adverse effect of ocrelizumab, with flares occurring after each infusion and improving with prophylactic prednisone. Recognizing this association may help clinicians diagnose and manage similar cases while allowing patients to continue an otherwise effective therapy.

Acute Fatty Liver Of Pregnancy And Fetal Fatty Acid Oxidation Disorders: A Systematic Review, Dante Varotsis, Sarah Araji, Rebecca Horgan, Jennifer E. Powel, Rodney Mclaren Jr., Brian Kirmse, Mona Makhamreh, Huda B. Al-Kouatly

Department of Obstetrics & Gynecology Faculty Publications

OBJECTIVE:

To evaluate the association between maternal acute fatty liver of pregnancy (AFLP) and fetal fatty acid oxidation (FAO) disorders and to define the clinical and genetic characteristics of mothers with AFLP and their fetuses affected by FAO disorders, we performed a systematic literature review of all reported cases of AFLP that underwent genetic testing for FAO disorders.

DATA SOURCES:

We searched PubMed, Ovid MEDLINE, Cochrane Library, CINAHL (EBSCO), Scopus, and ClinicalTrials.gov. Terms included were related to AFLP and FAO testing.

METHODS OF STUDY SELECTION:

We conducted a systematic literature review from inception through May 18, 2025, to evaluate the …

Antibody-Drug Conjugates Beyond Her2 In Non-Small Cell Lung Cancer (Nsclc): Mechanisms, Emerging Targets, And Future Directions, Ahmed Ismail, Akash Desai, George R. Simon, Yanis Boumber

Department of Medicine Faculty Publications

Antibody–drug conjugates (ADCs) are a rapidly evolving class of oncology therapeutics that enable precise delivery of potent cytotoxic agents to tumor cells while minimizing systemic toxicity. While HER2-targeted ADCs such as trastuzumab deruxtecan (T-DXd) in HER2-mutant, Datopotamab deruxtecan (Dato-Dxd) in EGFR-mutant, and telisotumumab vedotin (Teliso-V) in MET IHC 3+ expressing lung cancer have already established a clinical role in non-small cell lung cancer (NSCLC), multiple ADCs targeting alternative antigens, including additional TROP2 ADCs, HER3, MET, CEACAM5, B7-H3, Nectin-4, and others, are now in advanced clinical development. This review synthesizes the current evidence for non-HER2 ADCs in NSCLC, highlighting mechanisms of …

Attention-Based Multi-Omics Fusion For Drug Synergy Prediction, Kusal Debnath, Pratip Rana, Preetam Ghosh

Computer Science Faculty Publications

Drug combination therapy in disease management gained popularity in the last few decades. Computational modeling of such combinations is an active area of research in the drug discovery domain. While earlier approaches solely emphasized on the structural features of participating drugs for designing synergistic models, they lack other crucial factors directly linked with drug administration - omics expressions. As differential omics expression is a downstream consequence of the administered drug combinations, utilizing such expressions while designing synergistic models promises robust and dynamic modeling. In this work, we propose SynergyLM that fuses multi-omics features with drug embeddings to build an omics-aware …

Photo And Spatial Control Of Rna Structures And Functions: Exploring Positional Effects And Photo-Responsiveness Of Azobenzene Modified Nucleotides, Jinxi Du

Electronic Theses & Dissertations (2024 - present)

RNA molecules perform many important biological functions by forming complex three-dimensional structures stabilized by base pairing, tertiary interactions, and metal ion coordination. Because RNA function depends strongly on its structure, methods that allow reversible control of RNA conformation and activity are important for understanding RNA behavior and for potential therapeutic applications. However, achieving reversible and site-specific control of RNA structure, especially at the single-nucleotide level, remains challenging. In this dissertation, I developed and applied azobenzene-modified nucleotides as a chemical tool to enable optical and spatial control of RNA structure and function.

The first part of this dissertation focuses on establishing …

Microglial Expression Of Serotonin Receptors Reveals Parallel Regulation Of 5-Ht2b And Bdnf In The Rat Hippocampus, Andrei Turkin, Maria Sidorova, Ekaterina Kurilova, Natalia Alenina, Oksana Tuchina, Friederike Klempin

School of Graduate Studies Faculty Publications

Growing evidence suggests that psychiatric disorders are characterized by a prolonged inflammatory state, which may influence the efficacy of compounds targeting serotonin. Serotonin is a key signaling molecule in neuroplasticity of the adult hippocampus and involved in antidepressant action. Recent in vitro studies indicate the neurotransmitter may also facilitate the response to inflammation and potentially modulate microglial function towards neuroprotection. Using Tph2−/− rats depleted of brain serotonin, we examined microglial expression of various serotonin receptors (5-HTRs) in vivo in both the hippocampus and prefrontal cortex and assessed mRNA levels of cytokines and brain-derived neurotrophic factor (BDNF). We observed age-dependent and …

Hepatocyte-Specific Lrp1 Silencing Exacerbates Brain Amyloidosis Without Compensatory Ldl Receptor Family Involvement, Brian Carson, Josephine Chu, Devaraj V. Chandrashekar, Jerome Garcia, Rachita K. Sumbria, Derick Han

Pharmacy Faculty Articles and Research

Background

LDL receptor related protein 1 (LRP1) is a major hepatic receptor involved in lipoprotein metabolism, protease degradation, transmembrane receptor modulation, and clearance of excess protein, such as Aβ. Decreased expression of LRP1 due to liver injury can impair receptor-mediated clearance, increasing Aβ availability in the periphery. We investigated the effects of hepato-specific silencing of LRP1 on Aβ deposition in the brain. Additionally, other LDL family members (LRP5, LRP6, and LDLR) that may participate in Aβ clearance were monitored in the liver to ensure non-compensatory effects of LRP1 silencing.

Method

4-month-old male double transgenic (APP/PS1) AD mice were injected with …

The Mitochondria Is The Source Of Hepatic Amyloid Precursor Protein And Peripheral Amyloid Beta: Implications Of Alcohol-Induced Liver Steatosis In Alzheimer's Disease, Josephine Chu, Ross A. Steinberg, Brian Carson, Devaraj Venkatapura Chandrashekar, Rachita K. Sumbria, Derick Han

Pharmacy Faculty Articles and Research

Background

Alcohol-induced liver injury occurs in the pericentral region of the liver and can induce mitochondrial remodeling and exacerbate Alzheimer's Disease (AD) progression. Subpopulations of mitochondria: general mitochondria (GM), peridroplet mitochondria (PDM) and endoplasmic reticulum(ER)-bound mitochondria (ERM) maintain cellular homeostasis via energy synthesis, lipid homeostasis, and regulation of intracellular calcium. Hepatic amyloid precursor protein (APP) is a source of peripheral amyloid beta (aB) and affects AD pathology in the brain. Understanding the localization and expression of hepatic APP in mitochondrial subpopulations are critical to understanding aB metabolism and may play a role in identifying a potential mechanism for metabolic dysfunction. …

Developing A Tool To Measure Resistance To Sustainable Food Choices: A Pilot Study In Ireland And The Netherlands, Kate Flanagan, Bart Sinteur, Patricia J. Bulsing, John M. Kearney

SURE Journal: Science Undergraduate Research Experience Journal

Consumer uptake of a sustainable diet is critical for addressing environmental challenges and promoting public health. Understanding why consumers resist adopting sustainable eating habits can inform targeted interventions and policies. This pilot study examines whether a newly developed scale can effectively detect consumer resistance to a sustainable diet. Currently, there is a lack of research on a tool to measure consumer resistance to a sustainable diet, highlighting the need for a reliable instrument.

The aim of this study is to develop a scale, based on existing literature, to measure consumer resistance to a sustainable diet. Additionally, the study aims to …

Editorial-Sure Journal Volume 7, Issue 2, Geraldine M. Dowling, Eva Campion, Sinead Loughran, Ariane Perez-Gavilan, Josephine Treacy

SURE Journal: Science Undergraduate Research Experience Journal

No abstract provided.

Early Intervention In Helminth Infections: Investigating Albendazole’S Effects On C. Elegans Egg Hatch Rate And Health, Giselle Domingo Diaz

Student Scholar Symposium

Over 1.5 billion of the poorest people are infected with soil-transmitted helminths (STH) such as whipworm, hookworm, and Ascaris which have devastating effects on human growth, nutrition, and cognition, perpetuating the cycle of poverty. The World Health Organization only approves four anthelmintic drugs to treat STH for mass drug administration (MDA), with Albendazole being the drug of choice. Due to these drugs only having two mechanisms of action, resistance to these drugs has been reported over the years. We aim to better understand STH susceptibility to drugs at multiple points in their life stage. Previously, the effects of Albendazole and …

6ppd-Quinone In Middle Tennessee Waters: Assessing Ecological Impact, Andrew Davis Todd, Raphael Marquise Chandler, Kerolos Gerges Basalos, Denise Lori Loewinger

Student Scholar Symposium

This poster presents the dangers of a toxic chemical used on car tires that is entering aquatic ecosystems and harming fish populations.

Investigation Of Aldehyde Oxidase Inhibition By Clopidogrel And Its Thiol Metabolite, Rachel Crouch, Merna Kamal, Hilina Woldeamanuel

Student Scholar Symposium

Aldehyde oxidase (AO) is an enzyme that metabolizes drugs containing aromatic azaheterocycles. Small thiol-containing molecules have been reported to inactivate AO. Clopidogrel is an antiplatelet agent used to treat cardiovascular diseases. Clopidogrel is a prodrug that is bioactivated in vivo by cytochrome P450 enzymes CYP3A4 and CYP2C19 into a thiol metabolite. Our research aims to explore whether the clopidogrel thiol metabolite can inhibit AO, leading to potential drug-drug interactions when co-administered with other drugs that are metabolized by AO. In order to determine whether the prodrug clopidogrel and/or its thiol metabolite inhibit AO, O6-benzylguanine (AO substrate) was incubated with human …

Have You Had Your Vitamins Today? Development Of An Lc-Ms/Ms Method With A 100% Aqueous Gradient To Simultaneously Measure B Vitamins In Plasma From Study Participants In A “Greens” Nutritional Supplement Clinical Trial, Kennedy Brothers, Abigail Davis, Anna Losher, Yusra Ahmed, Sora Ghanem, Matthew J. Vergne

Student Scholar Symposium

This study assessed the absorption of key micronutrients from the multi-ingredient supplement using a novel developed LC-MS/MS method capable of analyzing B vitamins in a single run.

The study a randomized, double-blind, placebo-controlled crossover trial with 16 healthy participants (8 males, 8 females) to measure plasma nutrient appearance over 8 hours after supplement consumption. Serial blood samples were collected pre-consumption and at specified intervals post-ingestion. The novel LC-MS/MS method simultaneously quantified biotin, nicotinamide, pyridoxine, riboflavin, and thiamin in blood samples.

Results:The LC-MS/MS method had a range of 0.1 ng/mL to 1000 ng/mL and it proved to be robust and …

Increased Intermembrane Space [Ca2+] Drives Mitochondrial Structural Damage In Cpvt, Shanna Hamilton, Radmila Terentyeva, Roland Veress, Fruzsina Perger, Zuzana Nichtova, Mark Bannister, Jinxi Wang, Sage Quiggle, Rachel Battershell, Matthew Gorr, Sandor Györke, Bum-Rak Choi, Christopher George, Andriy Belevych, György Csordás, Dmitry Terentyev

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Mitochondrial dysfunction caused by abnormally high RyR2 (ryanodine receptor) activity is a common finding in cardiovascular diseases. Mechanisms linking RyR2 gain of function with mitochondrial remodeling remain elusive. We hypothesized that RyR2 hyperactivity in cardiac disease increases [Ca 2+ ] in the mitochondrial intermembrane space (IMS) and activates the Ca 2+ -sensitive protease calpain, driving remodeling of mitochondrial cristae architecture through cleavage of structural protein OPA1 (optic atrophy protein 1).

METHODS: We generated a highly arrhythmogenic rat model of catecholaminergic polymorphic ventricular tachycardia, induced by RyR2 gain-of-function mutation S2236L(Ser2336Leu)(+/-) . We created a new biosensor to measure IMS-[Ca2+ ] …

Protein-Protein Interaction–Interfering Peptide Rescues Dysregulated Nmda Receptor Signaling, Robert E. Featherstone, Hongbin Li, Ameet S. Sengar, Karin E. Borgmann-Winter, Olya Melnychenko, Lindsey M. Crown, Ray L. Gifford, Felix Amirfathi, Anamika Banerjee, Aivi Tran, Krishna Parekh, Margaret Heller, Wenyu Zhang, Robert J. Gallop, Adam D. Marc, Pragya Komal, Michael W. Salter, Steven J. Siegel, Chang-Gyu Hahn

Farber Institute for Neuroscience Faculty Papers

The complex and heterogeneous genetic architecture of neuropsychiatric illnesses compels us to look beyond individual risk genes for therapeutic strategies and target the interactive dynamics and convergence of their protein products. A mechanistic substrate for convergence of synaptic neuropsychiatric risk genes are protein-protein interactions (PPIs) in the N-methyl-D-aspartate receptor (NMDAR) complex. NMDAR hypofunction in schizophrenia is associated with hypoactivity of Src kinase, resulting from convergent alterations in PPIs of Src with its partners. Of these, the association of Src with PSD-95, which inhibits the activity of this kinase in the NMDAR complex, is known to be increased in schizophrenia. Here, …

Optimizing Endothelial Cell Specific Polymersome-Based Atheroprotective Therapies, Ally C. Brawner

All Theses

Atherosclerotic cardiovascular disease is the number one cause of death in the United States and the world. Every year, billions of dollars are spent in the US alone for direct treatments of this disease, especially on prescription medicines like statins. However, these medications have been unable to curtail global mortality rates, partially because they do not target the entirety of atherosclerotic pathophysiology. A key area of this pathophysiology is that atheroprone arteries typically include pro-inflammatory endothelial cells that exhibit decreased levels of apoAI-mediated cholesterol efflux and an increased release of adhesion molecules, such as VCAM-1. The objective of my project …

Decomposition Processes And Insect Indicators In Forensic Investigations, Eli Taylor

University Honors Theses

Insects play an essential biological and ecological role in human life, and their predictable relationship with decomposing remains has positioned them as a cornerstone of modern forensic science. Since the early 20th century, forensic entomology has provided critical evidence for estimating the postmortem interval (PMI), relying on patterns of colonization, species succession, and insect developmental timelines. Accurate PMI estimations are vital to medicolegal investigations, influencing the interpretation of biological evidence, guiding resource allocation, and informing determinations of cause and manner of death. However, insect activity is profoundly shaped by environmental and ecological variables, including temperature, humidity, seasonal shifts, and geographic …

Dna Extrusion Size Determines Pathway Choice During Cag Repeat Expansion, Mayuri Bhatia, Ashutosh S. Phadte, Anna Lakhina, Anthony R. Monte Carloi Iii, Sarah Barndt, Anna Pluciennik

Department of Biochemistry and Molecular Biology Faculty Papers

DNA triplet repeat expansion causes several primarly neurological disorders like Huntington's disease, myotonic dystrophy type 1, and fragile-X related disorders. There is general consensus that recognition of extrahelical extrusions or hairpin-loop structures (formed by strand slippage) by the DNA mismatch repair protein MutSβ leads to repeat expansion by a mutagenic process. By contrast, the FAN1 nuclease attenuates triplet repeat expansion, the molecular basis of which was explained by our recent finding that FAN1 nuclease cleaves and initiates removal of extrahelical extrusions. Here we show that extrusions containing two or more triplet repeats are subject to recognition and processing by either …