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Fructose Causes Liver Damage, Polyploidy, And Dysplasia In The Setting Of Short Telomeres And P53 Loss, Christopher Chronowski, Viktor Akhanov, Doug Chan, Andre Catic, Milton Finegold, Ergün Sahin

Faculty, Staff and Students Publications

Studies in humans and model systems have established an important role of short telomeres in predisposing to liver fibrosis through pathways that are incompletely understood. Recent studies have shown that telomere dysfunction impairs cellular metabolism, but whether and how these metabolic alterations contribute to liver fibrosis is not well understood. Here, we investigated whether short telomeres change the hepatic response to metabolic stress induced by fructose, a sugar that is highly implicated in non-alcoholic fatty liver disease. We find that telomere shortening in telomerase knockout mice (TKO) imparts a pronounced susceptibility to fructose as reflected in the activation of p53, …

Nlrp3 Inflammasome Is A Key Driver Of Obesity-Induced Atrial Arrhythmias, Larry Scott, Anke C Fender, Arnela Saljic, Luge Li, Xiaohui Chen, Xiaolei Wang, Dominik Linz, Jilu Lang, Mathias Hohl, Darragh Twomey, Thuy T Pham, Rodrigo Diaz-Lankenau, Mihail G Chelu, Markus Kamler, Mark L Entman, George E Taffet, Prashanthan Sanders, Dobromir Dobrev, Na Li

Faculty, Staff and Students Publications

AIMS: Obesity, an established risk factor of atrial fibrillation (AF), is frequently associated with enhanced inflammatory response. However, whether inflammatory signaling is causally linked to AF pathogenesis in obesity remains elusive. We recently demonstrated that the constitutive activation of the 'NACHT, LRR, and PYD Domains-containing Protein 3' (NLRP3) inflammasome promotes AF susceptibility. In this study, we hypothesized that the NLRP3 inflammasome is a key driver of obesity-induced AF.

METHODS AND RESULTS: Western blotting was performed to determine the level of NLRP3 inflammasome activation in atrial tissues of obese patients, sheep, and diet-induced obese (DIO) mice. The increased body weight in …

Targeting The Apoa1 Locus For Liver-Directed Gene Therapy, Marco De Giorgi, Ang Li, Ayrea Hurley, Mercedes Barzi, Alexandria M Doerfler, Nikitha A Cherayil, Harrison E Smith, Jonathan D Brown, Charles Y Lin, Karl-Dimiter Bissig, Gang Bao, William R Lagor

Faculty, Staff and Students Publications

Clinical application of somatic genome editing requires therapeutics that are generalizable to a broad range of patients. Targeted insertion of promoterless transgenes can ensure that edits are permanent and broadly applicable while minimizing risks of off-target integration. In the liver, the Albumin (Alb) locus is currently the only well-characterized site for promoterless transgene insertion. Here, we target the Apoa1 locus with adeno-associated viral (AAV) delivery of CRISPR-Cas9 and achieve rates of 6% to 16% of targeted hepatocytes, with no evidence of toxicity. We further show that the endogenous Apoa1 promoter can drive robust and sustained expression of therapeutic …

Deciphering An Agrp-Serotoninergic Neural Circuit In Distinct Control Of Energy Metabolism From Feeding, Yong Han, Guobin Xia, Dollada Srisai, Fantao Meng, Yanlin He, Yali Ran, Yang He, Monica Farias, Giang Hoang, István Tóth, Marcelo O Dietrich, Miao-Hsueh Chen, Yong Xu, Qi Wu

Children’s Nutrition Research Center Staff Publications

Contrasting to the established role of the hypothalamic agouti-related protein (AgRP) neurons in feeding regulation, the neural circuit and signaling mechanisms by which they control energy expenditure remains unclear. Here, we report that energy expenditure is regulated by a subgroup of AgRP neurons that send non-collateral projections to neurons within the dorsal lateral part of dorsal raphe nucleus (dlDRN) expressing the melanocortin 4 receptor (MC4R), which in turn innervate nearby serotonergic (5-HT) neurons. Genetic manipulations reveal a bi-directional control of energy expenditure by this circuit without affecting food intake. Fiber photometry and electrophysiological results indicate that the thermo-sensing MC4RdlDRN neurons …

Rap1 In The Vmh Regulates Glucose Homeostasis, Kentaro Kaneko, Hsiao-Yun Lin, Yukiko Fu, Pradip K Saha, Ana B De La Puente-Gomez, Yong Xu, Kousaku Ohinata, Peter Chen, Alexei Morozov, Makoto Fukuda

Faculty, Staff and Students Publications

The hypothalamus is a critical regulator of glucose metabolism and is capable of correcting diabetes conditions independently of an effect on energy balance. The small GTPase Rap1 in the forebrain is implicated in high-fat diet-induced (HFD-induced) obesity and glucose imbalance. Here, we report that increasing Rap1 activity selectively in the medial hypothalamus elevated blood glucose without increasing the body weight of HFD-fed mice. In contrast, decreasing hypothalamic Rap1 activity protected mice from diet-induced hyperglycemia but did not prevent weight gain. The remarkable glycemic effect of Rap1 was reproduced when Rap1 was specifically deleted in steroidogenic factor-1-positive (SF-1-positive) neurons in the …

Subchronic Tolerance Trials Of Graded Oral Supplementation With Phenylalanine Or Serine In Healthy Adults, Naoki Miura, Hideki Matsumoto, Luc Cynober, Patrick J Stover, Rajavel Elango, Motoni Kadowaki, Dennis M Bier, Miro Smriga

Children’s Nutrition Research Center Staff Publications

Phenylalanine and serine are amino acids used in dietary supplements and nutritional products consumed by healthy consumers; however, the safe level of phenylalanine or serine supplementation is unknown. The objective of this study was to conduct two 4-week clinical trials to evaluate the safety and tolerability of graded dosages of oral phenylalanine and oral serine. Healthy male adults (n = 60, 38.2 ± 1.8y) completed graded dosages of either phenylalanine or serine supplement (3, 6, 9 and 12 g/d) for 4 weeks with 2-week wash-out periods in between. Primary outcomes included vitals, a broad spectrum of circulating biochemical analytes, …

Gene Expression Analysis Of Environmental Temperature And High-Fat Diet-Induced Changes In Mouse Supraclavicular Brown Adipose Tissue, Yufeng Shi, Honglei Zhai, Sharon John, Yi-Ting Shen, Yali Ran, Giang Hoang, Miao-Hsueh Chen

Children’s Nutrition Research Center Staff Publications

Obesity, a dysregulation of adipose tissue, is a major health risk factor associated with many diseases. Brown adipose tissue (BAT)-mediated thermogenesis can potentially regulate energy expenditure, making it an attractive therapeutic target to combat obesity. Here, we characterize the effects of cold exposure, thermoneutrality, and high-fat diet (HFD) feeding on mouse supraclavicular BAT (scBAT) morphology and BAT-associated gene expression compared to other adipose depots, including the interscapular BAT (iBAT). scBAT was as sensitive to cold induced thermogenesis as iBAT and showed reduced thermogenic effect under thermoneutrality. While both scBAT and iBAT are sensitive to cold, the expression of genes involved …

Positional Installation Of Intranasal Corticosteroids In The Treatment Of Chronic Rhinosinusitis: A Systematic Review Of The Literature, Emily L Cummings, Scott N Fassas, Kevin J Sykes, Amy Sisson, Alexander G Chiu, Meha G Fox

Library Staff Publications

OBJECTIVES: First-line treatment of chronic rhinosinusitis includes topical corticosteroids aimed at decreasing inflammation of sinonasal mucosa. No guidelines exist regarding the effect of head position during administration of corticosteroids. We hypothesize certain positions enhance delivery to the paranasal sinuses, with further improvement in delivery after sinus surgery.

METHODS: A systematic review of the literature was conducted using Medline Ovid, Embase, Scopus, and Cochrane databases. All studies evaluating intranasal medications administered in 2 or more head positions were included. Study population, head position(s), method/volume of delivery, and outcome metrics were recorded.

RESULTS: Twenty-four studies compared head positions and their role in …

Defining Vdr Expression In The Brain Using A Novel Vdrcre Mouse, Hailan Liu, Yang He, Jessie Beck, Silvania Da Silva Teixeira, Keisha Harrison, Yong Xu, Stephanie Sisley

Children’s Nutrition Research Center Staff Publications

Vitamin D action has been linked to several diseases regulated by the brain including obesity, diabetes, autism, and Parkinson’s. However, the location of the vitamin D receptor (VDR) in the brain is not clear due to conflicting reports. We found that two antibodies previously published as specific in peripheral tissues are not specific in the brain. We thus created a new knockin mouse with cre recombinase expression under the control of the endogenous VDR promoter (VDRCre). We demonstrated that the cre activity in the VDRCre mouse brain (as reported by a cre-dependent tdTomato expression) is highly overlapping with endogenous VDR …

Ube2i Deletion In Adipocytes Causes Lipoatrophy In Mice, Aaron R Cox, Natasha Chernis, Kang Ho Kim, Peter M Masschelin, Pradip K Saha, Shawn M Briley, Robert Sharp, Xin Li, Jessica B Felix, Zheng Sun, David D Moore, Stephanie A Pangas, Sean M Hartig

Faculty, Staff and Students Publications

OBJECTIVE: White adipose tissue (WAT) expansion regulates energy balance and overall metabolic homeostasis. The absence or loss of WAT occurring through lipodystrophy and lipoatrophy contributes to the development of hepatic steatosis and insulin resistance. We previously demonstrated that sole small ubiquitin-like modifier (SUMO) E2-conjugating enzyme Ube2i represses human adipocyte differentiation. The role of Ube2i during WAT development remains unknown.

METHODS: To determine how Ube2i impacts body composition and energy balance, we generated adipocyte-specific Ube2i knockout mice (Ube2i

RESULTS: Surprisingly, Ube2i

CONCLUSIONS: Our results demonstrate that Ube2i expression in mature adipocytes allows WAT expansion during postnatal growth. Deletion of Ube2i in …

The Synergy Of Bet Inhibitors With Aurora A Kinase Inhibitors In Mycn-Amplified Neuroblastoma Is Heightened With Functional Tp53, Joanna S Yi, Oscar Sias-Garcia, Nicole Nasholm, Xiaoyu Hu, Amanda Balboni Iniguez, Matthew D Hall, Mindy Davis, Rajarshi Guha, Myrthala Moreno-Smith, Eveline Barbieri, Kevin Duong, Jessica Koach, Jun Qi, James E Bradner, Kimberly Stegmaier, William A Weiss, W Clay Gustafson

Faculty, Staff and Students Publications

Amplification of MYCN is a poor prognostic feature in neuroblastoma (NBL) indicating aggressive disease. We and others have shown BET bromodomain inhibitors (BETi) target MYCN indirectly by downregulating its transcription. Here we sought to identify agents that synergize with BETi and to identify biomarkers of resistance. We previously performed a viability screen of ∼1,900 oncology-focused compounds combined with BET bromodomain inhibitors against MYCN-amplified NBL cell lines. Reanalysis of our screening results prominently identified inhibitors of aurora kinase A (AURKAi) to be highly synergistic with BETi. We confirmed the anti-proliferative effects of several BETi+AURKAi combinations in MYCN-amplified NBL cell lines. Compared …

Cell Lineage Tracing Links Erα Loss In Erbb2-Positive Breast Cancers To The Arising Of A Highly Aggressive Breast Cancer Subtype, Yunfeng Ding, Yonghong Liu, Dong-Kee Lee, Zhangwei Tong, Xiaobin Yu, Yi Li, Yong Xu, Rainer B Lanz, Bert W O'Malley, Jianming Xu

Children’s Nutrition Research Center Staff Publications

HER2-positive (HER2+) breast cancers (BrCs) contain approximately equal numbers of ERα+HER2+ and ERα−HER2+ cases. An enduring obstacle is the unclear cell lineage-related characteristics of these BrCs. Although ERα+HER2+ BrCs could lose ERα to become ERα−HER2+ BrCs, direct evidence is missing. To investigate ERα dependencies and their implications during BrC growth and metastasis, we generated ERαCreRFP-T mice that produce an RFP-marked ERα+ mammary gland epithelial cell (MGEC) lineage. RCAS virus-mediated expression of Erbb2, a rodent Her2 homolog, first produced comparable numbers of ERα+RFP+Erbb2+ and ERα−RFP−Erbb2+ MGECs. Early hyperplasia developed mostly from ERα+RFP+Erbb2+ cells and ERα−RFP−Erbb2+ cells in these lesions were rare. …

Esomeprazole Attenuates Inflammatory And Fibrotic Response In Lung Cells Through The Mapk/Nrf2/Ho1 Pathway, Afshin Ebrahimpour, Min Wang, Li Li, Anil G Jegga, Mark D Bonnen, N Tony Eissa, Ganesh Raghu, Soma Jyothula, Farrah Kheradmand, Nicola A Hanania, Ivan O Rosas, Yohannes T Ghebre

Faculty, Staff and Students Publications

INTRODUCTION: Idiopathic pulmonary fibrosis (IPF) is an orphan disease characterized by progressive loss of lung function resulting in shortness of breath and often death within 3-4 years of diagnosis. Repetitive lung injury in susceptible individuals is believed to promote chronic oxidative stress, inflammation, and uncontrolled collagen deposition. Several preclinical and retrospective clinical studies in IPF have reported beneficial outcomes associated with the use of proton pump inhibitors (PPIs) such as esomeprazole. Accordingly, we sought to investigate molecular mechanism(s) by which PPIs favorably regulate the disease process.

METHODS: We stimulated oxidative stress, pro-inflammatory and profibrotic phenotypes in primary human lung epithelial …

Opportunities And Challenges In Developing A Cryptosporidium Controlled Human Infection Model For Testing Antiparasitic Agents, Rajiv S Jumani, Johanne Blais, Hanns-Christian Tillmann, Florencia Segal, Dean Wetty, Christian Ostermeier, Natko Nuber, Jay Lakshman, Natasha Aziz, Richa Chandra, Wilbur H Chen, Cynthia L Chappell, Thierry T Diagana, Ujjini H Manjunatha

Faculty, Staff and Student Publications

Cryptosporidiosis is a leading cause of moderate-to-severe diarrhea in low- and middle-income countries, responsible for high mortality in children younger than two years of age, and it is also strongly associated with childhood malnutrition and growth stunting. There is no vaccine for cryptosporidiosis and existing therapeutic options are suboptimal to prevent morbidity and mortality in young children. Recently, novel therapeutic agents have been discovered through high-throughput phenotypic and target-based screening strategies, repurposing malaria hits, etc., and these agents have a promising preclinical in vitro and in vivo anti-

A Neural Basis For Brain Leptin Action On Reducing Type 1 Diabetic Hyperglycemia, Shengjie Fan, Yuanzhong Xu, Yungang Lu, Zhiying Jiang, Hongli Li, Jessie C Morrill, Jing Cai, Qi Wu, Yong Xu, Mingshan Xue, Benjamin R Arenkiel, Cheng Huang, Qingchun Tong

Children’s Nutrition Research Center Staff Publications

Central leptin action rescues type 1 diabetic (T1D) hyperglycemia; however, the underlying mechanism and the identity of mediating neurons remain elusive. Here, we show that leptin receptor (LepR)-expressing neurons in arcuate (LepRArc) are selectively activated in T1D. Activation of LepRArc neurons, Arc GABAergic (GABAArc) neurons, or arcuate AgRP neurons, is able to reverse the leptin’s rescuing effect. Conversely, inhibition of GABAArc neurons, but not AgRP neurons, produces leptin-mimicking rescuing effects. Further, AgRP neuron function is not required for T1D hyperglycemia or leptin’s rescuing effects. Finally, T1D LepRArc neurons show defective nutrient sensing and signs of cellular energy deprivation, which are …

Consumption Of High-Fructose Corn Syrup Compared With Sucrose Promotes Adiposity And Increased Triglyceridemia But Comparable Nafld Severity In Juvenile Iberian Pigs, Magdalena Maj, Brooke Harbottle, Payton A Thomas, Gabriella V Hernandez, Victoria A Smith, Mark S Edwards, Rob K Fanter, Hunter S Glanz, Chad Immoos, Douglas G Burrin, Tasha M Santiago-Rodriguez, Michael R La Frano, Rodrigo Manjarín

Children’s Nutrition Research Center Staff Publications

Background: Fructose consumption has been linked to nonalcoholic fatty liver disease (NAFLD) in children. However, the effect of high-fructose corn syrup (HFCS) compared with sucrose in pediatric NAFLD has not been investigated.

Objectives: We tested whether the isocaloric substitution of dietary sucrose by HFCS would increase the severity of NAFLD in juvenile pigs, and whether this effect would be associated with changes in gut histology, SCFA production, and microbial diversity.

Methods: Iberian pigs, 53-d-old and pair-housed in pens balanced for weight and sex, were randomly assigned to receive a mash diet top-dressed with increasing amounts of sucrose (SUC; n = …

Invasive Therapies For Acute Coronary Syndromes In The Covid-19 Era, Sanket Borgaonkar, Joshua Hahn, Marilyne Daher, Waleed Kayani, Hani Jneid

Faculty, Staff and Students Publications

PURPOSE OF REVIEW: To identify and address the challenges associated with the care of ACS patients during the coronavirus 2019 pandemic.

RECENT FINDINGS: The COVID-19 pandemic has had a considerable global impact with over 2.0 million deaths worldwide so far. There has been considerable evidence suggesting that COVID-19 increases the risk of acute coronary syndromes (ACS). We propose characterizing ACS patients into 3 distinct categories to better assist in appropriate triage and management: critically ill patients, non-critically ill ST elevation myocardial infarction (STEMI) patients, and non-critically ill non-ST elevation myocardial infarction (NSTEMI)/unstable angina (UA) patients. We thoroughly review treatments strategies, …

Genetics Of Atrial Fibrillation, Jitae A Kim, Mihail G Chelu, Na Li

Faculty, Staff and Students Publications

PURPOSE OF REVIEW: Atrial fibrillation is the most common sustained cardiac arrhythmia. In addition to traditional risk factors, it is increasingly recognized that a genetic component underlies atrial fibrillation development. This review aims to provide an overview of the genetic cause of atrial fibrillation and clinical applications, with a focus on recent developments.

RECENT FINDINGS: Genome-wide association studies have now identified around 140 genetic loci associated with atrial fibrillation. Studies into the effects of several loci and their tentative gene targets have identified novel pathways associated with atrial fibrillation development. However, further validations of causality are still needed for many …

Pathological Mechanisms Of Vacuolar Aggregate Myopathy Arising From A Casq1 Mutation, Amy D Hanna, Chang Seok Lee, Lyle Babcock, Hui Wang, Joseph Recio, Susan L Hamilton

Faculty, Staff and Students Publications

Mice with a mutation (D244G, DG) in calsequestrin 1 (CASQ1), analogous to a human mutation in CASQ1 associated with a delayed onset human myopathy (vacuolar aggregate myopathy), display a progressive myopathy characterized by decreased activity, decreased ability of fast twitch muscles to generate force and low body weight after one year of age. The DG mutation causes CASQ1 to partially dissociate from the junctional sarcoplasmic reticulum (SR) and accumulate in the endoplasmic reticulum (ER). Decreased junctional CASQ1 reduces SR Ca

Genetic Pathway Analysis Of Abnormal Facial Development In Nonsyndromic Cleft Lip And Palate, Lorena Maili

Dissertations and Theses (Open Access)

Nonsyndromic cleft lip with or without cleft palate (NSCLP) is the most common craniofacial birth defect resulting from incomplete fusion of the facial prominences during development, which leaves a gap in the lip, primary palate and/or the secondary palate. NSCLP affects 135,000 NSCLP newborns worldwide each year based on a birth prevalence of 1 per 700 live births. While surgical treatments have dramatically improved, many long-term health issues persist, imposing significant medical, psychosocial and economic burdens. Familial aggregation and segregation analyses suggest genetic contributions underlie NSCLP, but despite decades of study, only a small portion of the NSCLP genetic liability …

Investigating Mechanisms In Nociceptors Driving Ongoing Activity And Ongoing Pain, Elia Lopez

Dissertations and Theses (Open Access)

Ongoing (apparently spontaneous) pain at rest is a major complaint of patients suffering from many forms of acute and chronic pain, including acute and persistent postsurgical pain. Accumulating evidence suggests ongoing activity in nociceptors is a major driver of ongoing pain. Ongoing activity can be generated in sensory neurons in the absence of sensory generator potentials if one or more of three neurophysiological alterations occur – prolonged depolarization of resting membrane potential (RMP), hyperpolarization of action potential (AP) threshold, and/or increased amplitude of depolarizing spontaneous fluctuations of membrane potential (DSFs) to bridge the gap between RMP and AP threshold. Cellular …

A Hindbrain Dopaminergic Neural Circuit Prevents Weight Gain By Reinforcing Food Satiation, Yong Han, Guobin Xia, Yanlin He, Yang He, Monica Farias, Yong Xu, Qi Wu

Children’s Nutrition Research Center Staff Publications

The neural circuitry mechanism that underlies dopaminergic (DA) control of innate feeding behavior is largely uncharacterized. Here, we identified a subpopulation of DA neurons situated in the caudal ventral tegmental area (cVTA) directly innervating DRD1-expressing neurons within the lateral parabrachial nucleus (LPBN). This neural circuit potently suppresses food intake via enhanced satiation response. Notably, this cohort of DAcVTA neurons is activated immediately before the cessation of each feeding bout. Acute inhibition of these DA neurons before bout termination substantially suppresses satiety and prolongs the consummatory feeding. Activation of postsynaptic DRD1LPBN neurons inhibits feeding, whereas genetic deletion of Drd1 within the …

Endogenous Mechanisms Regulating Myeloid Cell Mediated Inflammation During Acute Lung Injuries, Nathaniel Berg

Dissertations and Theses (Open Access)

Acute lung injuries (ALI) can result from both direct insults (e.g. pneumonia or inhalation injury), or systemic conditions such as sepsis or trauma. Current treatment options for patients are limited to supportive care and novel approaches are urgently needed. Appreciating the role of excessive inflammation that underlies the pathophysiology of ALI, we sought to identify endogenous mechanisms that dampen inflammation. Here we investigated two pathways that worked to limit excessive pulmonary inflammation in myeloid cells using a mouse model of sepsis-associated ALI. In the first approach we screened for microRNAs during the recovery phase of ALI that could potentially regulate …

Assessing The Outcomes Of Blocking Ccl2-Ccr2 Signaling Axis On Breast Cancer Brain Metastasis, Yutao Qi

Dissertations and Theses (Open Access)

Breast cancer brain metastases have remained one of the most intense challenges for precision cancer therapeutics, but current treatment options are limited and not curative. Recently, our lab reported that adoptive PTEN downregulation in metastatic breast tumor cells activates PI3K/NF-ƙB signaling and increases the secretion of the chemokine CCL2, which enhances the chemotaxis of CCR2⁺ myeloid cells, a major subpopulation of bone marrow-derived myeloid cells (BMDMs), from peripheral blood into the brain tumor microenvironment (TME), eventually promoting brain metastasis outgrowth by driving immune suppression. Here, in this project we have been aiming to develop effective therapies by immune-modulating the …

Unraveling Host-Gut Microbiota Dialogue And Its Impact On Response To Immune Checkpoint Blockade, Alexandria Cogdill

Dissertations and Theses (Open Access)

Cancer is a disease with only one degree of separation, affecting one in two men and one in three women in their lifetimes; accounting for 1 of every 6 deaths. While cancer mortality rates continue to improve, incidence rates are expected to rise and shift through 2050 due to epidemiological and demographic transitions worldwide. As such, it is imperative to continue to investigate and improve our understanding of both disease etiology and hallmarks of response to treatment. Currently, conventional therapies include, but are not limited to, surgery, chemotherapy, and radiotherapy. However, within the past decade, major advances have been made …

The Impact Of Synchrony On Neuronal Coding And Behavior, Natasha Kharas

Dissertations and Theses (Open Access)

Cortical columns represent the elementary functional and computational module of the neocortex. Although much is known about its laminar structure and synaptic connectivity, how patterns of spiking activity propagate within columnar circuits when the state of the brain changes remains poorly understood. We used multi-electrode laminar arrays to reveal that brain state modulates the propagation of neural activity across the layers of early and mid-level visual cortex (areas V1 and V4). We found a high prevalence of neuronal synchrony (vigorous (On) and weak (Off) spiking) in rest but low prevalence of synchrony during wakefulness. We next tested whether propagation of …

Functions Of Dcp2 And Ski7 In Mrna Degradation, Minseon Kim, Ambro Van Hoof

Dissertations and Theses (Open Access)

Posttranscriptional gene regulation is essential to maintain gene expression fidelity. This is partially achieved by mRNA decay. When no longer required, mRNA is degraded by two alternative pathways. The decapping enzyme Dcp2 removes the 5` <sup>m7</sup>G cap of mRNAs, allowing Xrn1 to degrade the mRNA from the 5` end. Alternatively, mRNA is degraded from the 3` end by the RNA exosome.

While decapping by Dcp2 is a critical step in mRNA decay, its physiological function has been unclear. Null mutations of Saccharomyces cerevisiae DCP2 have been reported to be lethal in some studies but slow-growing in others. In this …

Role Of Methyltransferase Like-3 (Mettl3) In Pancreatic Ductal Adenocarcinoma (Pdac) Progression, Bhargavi Brahmendra Barathi

Dissertations and Theses (Open Access)

Pancreatic Ductal Adenocarcinoma (PDAC) is an aggressive cancer with about a 10% five-year survival rate. The grim prognostic situation of pancreatic cancer patients underlines the need to identify novel molecular targets. Recent studies have brought to attention, the need to therapeutically exploit epigenetic pathways, apart from only targeting genetic mutations to effectively combat PDAC. To that effect, METTL3-mediated post-transcriptional methylation of RNA transcripts have been shown to contribute to cancer progression in multiple cancer types.

METTL3 deposits methyl groups onto adenosine bases within specific consensus sequences in RNA, resulting in the formation of N-6 methyl adenosine (m6A). m6A is the …

The Functional Contribution Of Adaptive Immunity In The Biology Of Pancreatic Cancer And Therapeutic Targeting Of Oncogenic Kras, Krishnan Mahadevan

Dissertations and Theses (Open Access)

The Functional Contribution Of Adaptive Immunity In The Biology Of Pancreatic Cancer And Therapeutic Targeting Of Oncogenic Kras

Krishnan K. Mahadevan M.B.B.S*

Advisory professor: Dr. Raghu Kalluri

Pancreatic ductal adenocarcinoma (PDAC) is the third leading cause of cancer related deaths in the USA(https://seer.cancer.gov/statfacts/html/pancreas.html), whereby survival remains poor despite advances in surgical technique and new combination chemotherapies. Immune checkpoint blockade has revolutionized the treatment of cancers such as melanoma, bladder cancer and non-small cell lung carcinomas. Unfortunately, PDAC is among the tumor types that remain refractory to checkpoint immunotherapy(Royal et al., 2010, Le et al., 2013), with no survival benefits in …

Investigating Diffusion Tensor Imaging Correlates Of Cognitive Impairment In Idiopathic Normal Pressure Hydrocephalus And Alzheimer's Disease, Omar Hasan, Omar Hasan

Dissertations and Theses (Open Access)

Modest expansion of the human brain cerebrospinal fluid (CSF)-filled ventricles is normal with aging, and because of this, it can be difficult for physicians to accurately diagnose and treat enlarged ventricles (ventriculomegaly), called hydrocephalus¹ (fluid or water in the brain) Ventriculomegaly occurs due to an obstruction (such as a blood clot or tumor), or a change in CSF absorption². Primary hydrocephalus, also called idiopathic normal pressure hydrocephalus (iNPH), is non-obstructive and may be comorbid with other neurodegenerative diseases such as Alzheimer’s disease (AD) or frontotemporal dementia (FTD). Clinically, it can be difficult to tell whether the pathophysiological …