Digital Commons Network^™

Combined Lenvatinib And Pembrolizumab As Salvage Therapy In Advanced Adrenal Cortical Carcinoma, Sara Bedrose, Kevin Charles Miller, Lina Altameemi, Mohamed S Ali, Sameh Nassar, Naveen Garg, Marilyne Daher, Keith D Eaton, Jeffrey Thomas Yorio, Davey B Daniel, Matthew Campbell, Keith C Bible, Mabel Ryder, Ashish V Chintakuntlawar, Mouhammed Amir Habra

Faculty, Staff and Students Publications

BACKGROUND: There is no effective systemic therapy for metastatic adrenal cortical carcinoma (ACC) after failure of platinum-based chemotherapy. The efficacies of single-agent oral multikinase inhibitors (MKIs) or salvage immune checkpoint inhibitors (CPIs) have been very limited. It is unknown whether combining CPIs, such as pembrolizumab (PEM), with other therapies, such as MKIs, could yield higher response rates in ACC, yet this combination has shown promise in other cancers. Herein, we describe the first case series using PEM in combination with the MKI lenvatinib (LEN) in patients with progressive, metastatic ACC.

METHODS: A retrospective case series describing the use of LEN/PEM …

Correction: Double-Blind, Placebo-Controlled, Dose-Ranging Trial Of Intravenous Ketamine As Adjunctive Therapy In Treatment-Resistant Depression (Trd), Maurizio Fava, Marlene P Freeman, Martina Flynn, Heidi Judge, Bettina B Hoeppner, Cristina Cusin, Dawn F Ionescu, Sanjay J Mathew, Lee C Chang, Dan V Iosifescu, James Murrough, Charles Debattista, Alan F Schatzberg, Madhukar H Trivedi, Manish K Jha, Gerard Sanacora, Samuel T Wilkinson, George I Papakostas

Faculty, Staff and Students Publications

Numerous placebo-controlled studies have demonstrated the ability of ketamine, an NMDA receptor antagonist, to induce rapid (within hours), transient antidepressant effects when administered intravenously (IV) at subanesthetic doses (0.5 mg/kg over 40 min). However, the optimal antidepressant dose remains unknown. We aimed to compare to active placebo the rapid acting antidepressant properties of a broad range of subanesthetic doses of IV ketamine among outpatients with treatment-resistant depression (TRD). A range of IV ketamine doses were compared to active placebo in the treatment of adult TRD over a 3-day period following a single infusion over 40 min. This was an outpatient …

Etiology Of Lumbosacral Radiculoplexopathy: Sacral Insufficiency Fracture On Magnetic Resonance Imaging, Christian Geannette, Susan C Lee, Darryl B Sneag

Faculty, Staff and Students Publications

BACKGROUND: Sacral insufficiency fracture (SIF) can cause lumbosacral radiculoplexopathy (LSRP) and is probably under-recognized. Symptoms may include nonspecific lumbar spine or buttock pain that is exacerbated by physical activity and alleviated with rest. The frequency of LSRP secondary to SIF has not been reported.

QUESTIONS/PURPOSES: We aimed to determine the frequency of LSRP associated with SIF using magnetic resonance imaging (MRI) of the lumbar spine.

METHODS: We searched a radiology database at our institution using the keywords "sacral insufficiency fracture" and "lumbar spine MRI" for patient records from January 2014 through December 2017. We assessed for the presence of LSRP, …

Dynamic Ultrasound Uniquely Reveals Anterior Capsular Tear Communicating With Vastus Intermedius Fibers, Shiv J Patel, Jasvinder A Singh, Max H Epstein, Prathap Jayaram

Faculty, Staff and Students Publications

We present a case of an anterior capsular tear of the right knee in a previously healthy, active individual. The patient was a 31-year-old male seen one month after the onset of throbbing anterior right knee pain, which progressed to sharp suprapatellar pain over the next three months. Both dynamic ultrasound (US) and MRI were obtained. Dynamic US revealed a tear of the anterior capsule of the right knee complicated by a suprapatellar effusion communicating into the vastus intermedius fibers of the quadriceps tendon. However, these findings were not evident on MRI. In addition to discussing this unique pathology, we …

Dermatology Resident Training On Depression Screening: A Cross-Sectional Survey, Kaitlyn L Streight, Harry Dao, Soo Jung Kim

Faculty, Staff and Students Publications

Background

Many dermatologic diseases are implicated in the development of depression. Currently, there is no literature addressing the extent of dermatology residency training on depression screening.

Objective

Our study aimed to determine the extent of dermatology residency training on depression screening to potentially improve education in this area.

Methods

We designed a 12-question survey to assess the level of resident training and comfort in depression screening for patients with acne vulgaris, atopic dermatitis, psoriasis, hidradenitis suppurativa, and skin cancer. Fifty-six residents completed the survey, and data for each question was analysed in aggregate.

Results

Participants found depression screening most important …

Nuclear Localization Of A Novel Calpain-2 Mediated Junctophilin-2 C-Terminal Cleavage Peptide Promotes Cardiomyocyte Remodeling, Satadru K Lahiri, Ann P Quick, Benoit Samson-Couterie, Mohit Hulsurkar, Ies Elzenaar, Ralph J Van Oort, Xander H T Wehrens

Faculty, Staff and Students Publications

Heart failure (HF) is a leading cause of morbidity and mortality worldwide. Patients with HF exhibit a loss of junctophilin-2 (JPH2), a structural protein critical in forming junctional membrane complexes in which excitation-contraction takes place. Several mechanisms have been proposed to mediate the loss of JPH2, one being cleavage by the calcium-dependent protease calpain. The downstream mechanisms underlying HF progression after JPH2 cleavage are presently poorly understood. In this study, we used Labcas to bioinformatically predict putative calpain cleavage sites on JPH2. We identified a cleavage site that produces a novel C-terminal JPH2 peptide (JPH2-CTP) using several domain-specific antibodies. Western …

Veterinarians’ Attitudes And Practices Regarding Opioid-Related Vet Shopping Practices In Tri-State Appalachian Counties: An Exploratory Study, Falguni C Patel, Jeffrey A Raines, Richard W Kim, Karen Gruszynski, Robert E Davis, Manoj Sharma, Gilbert Patterson, Jason W Johnson, Vinayak K Nahar

Faculty, Staff and Students Publications

BACKGROUND: The opioid crisis continues to grow in the United States with 46,700 drug overdose deaths due to opioids in 2017 alone. Vet shopping, the practice of soliciting veterinarians for prescription medications, has been receiving national media attention in recent years. A 2014 review of Prescription Monitoring Drug Programs found less than 10 veterinary shoppers nationwide. Still much is unknown about the role of vet shopping and the opioid crisis. This study sought to understand the practice of vet shopping through the eyes of veterinarians practicing in Appalachian counties within the states of Kentucky, Tennessee, and Virginia, United States.

RESULTS: …

Mechanism Of Allosteric Inhibition In The Plasmodium Falciparum Cgmp-Dependent Protein Kinase, Jung Ah Byun, Katherine Van, Jinfeng Huang, Philipp Henning, Eugen Franz, Madoka Akimoto, Friedrich W Herberg, Choel Kim, Giuseppe Melacini

Faculty, Staff and Students Publications

Most malaria deaths are caused by the protozoan parasite Plasmodium falciparum. Its life cycle is regulated by a cGMP-dependent protein kinase (PfPKG), whose inhibition is a promising antimalaria strategy. Allosteric kinase inhibitors, such as cGMP analogs, offer enhanced selectivity relative to competitive kinase inhibitors. However, the mechanisms underlying allosteric PfPKG inhibition are incompletely understood. Here, we show that 8-NBD-cGMP is an effective PfPKG antagonist. Using comparative NMR analyses of a key regulatory domain, PfD, in its apo, cGMP-bound, and cGMP analog–bound states, we elucidated its inhibition mechanism of action. Using NMR chemical shift …

Highlights Of Studies In Cardiovascular Disease Prevention Presented At The 2020 American College Of Cardiology Annual Scientific Session, Xiaoming Jia, Mahmoud Al Rifai, Jing Liu, Anandita Agarwala, Martha Gulati, Salim S Virani

Faculty, Staff and Students Publications

PURPOSE OF REVIEW: The review highlights selected studies related to cardiovascular disease (CVD) prevention that were presented at the American College of Cardiology 2020 Virtual Scientific Session (ACC.20)/World Cardiology Congress (WCC).

RECENT FINDINGS: The studies reviewed include clinical trials on the efficacy and safety of alirocumab (Study in Participants with Homozygous Familial Hypercholesterolemia [ODYSSEY HoFH]) and evinacumab in the treatment of homozygous familial hypercholesterolemia (HoFH); Evaluating the Efficacy of E-cigarettes for Smoking Cessation (E3); the use of renal denervation in the treatment of hypertension (SPYRAL HTN-OFF MED PIVOTAL); and the assessment of vericiguat in the treatment of heart failure (A …

Acute Tubular Injury In A Patient On A Proprotein Convertase Subtilisin/Kexin Type 9 Inhibitor, June K Pickett, Maulin Shah, Michael Gillette, Peter Jones, Salim Virani, Christie Ballantyne, Vijay Nambi

Faculty, Staff and Students Publications

A 72-year-old man with coronary artery disease, statin intolerance, and chronic kidney disease stage IIIa was initiated on alirocumab, a proprotein convertase subtilisin/kexin type 9 inhibitor, and developed acute kidney injury. A kidney biopsy was performed and suggested acute tubular injury. The serum creatinine returned to baseline after discontinuation of alirocumab. (Level of Difficulty: Intermediate.)

A Genome-Wide Association Study Identifies Two Novel Susceptible Regions For Squamous Cell Carcinoma Of The Head And Neck, Sanjay Shete, Hongliang Liu, Jian Wang, Robert Yu, Erich M Sturgis, Guojun Li, Kristina R Dahlstrom, Zhensheng Liu, Christopher I Amos, Qingyi Wei

Faculty, Staff and Students Publications

To identify genetic variants for risk of squamous cell carcinoma of the head and neck (SCCHN), we conducted a two-phase genome-wide association study consisting of 7,858,089 SNPs in 2,171 cases and 4,493 controls of non-Hispanic white, of which 434,839 typed and 7,423,250 imputed SNPs as the discovery. SNPs with P <1×10–3 were further validated in the OncoArray study of oral and pharynx cancer (5,205 cases and 3,232 controls of European ancestry) from dbGaP. Meta-analysis of the discovery and replication studies identified one novel locus 6p22.1 (P = 2.96×10–9 for the leading rs259919) and two cancer susceptibility loci 6p21.32 (rs3135001, HLA-DQB1) and 6p21.33 (rs1265081, CCHCR1) associated with SCCHN risk. Further stratification by tumor site revealed four known cancer loci (5p15.33, 6p21.32, 6p21.33, and 2p23.1) associated with oral cavity cancer risk and oropharyngeal cancer risk, respectively. In addition, one novel locus 18q22.2 (P = 2.54×10–9 for the leading SNP rs142021700) was identified for hypo-pharynx and larynx cancer risk. For SNPs in those reported or novel loci, we also performed functional annotations by bioinformatics prediction and eQTL analysis. Collectively, our identification of four reported loci (2p23.1, 5p15.33, 6p21.32, and 6p21.33) and two novel loci (6p22.1 and 18q22.2) for SCCHN risk highlight the importance of HLA loci for oropharyngeal cancer risk, suggesting that immunologic mechanisms are implicated in the etiology of this subset of SCCHN.

Multi-Community Cardiopulmonary Resuscitation Education By Medical Students, Kenton L Anderson, Kian Niknam, Larry Laufman, Stefanie S Sebok-Syer, Sara Andrabi

Faculty, Staff and Students Publications

Introduction One purpose of the hands-only cardiopulmonary resuscitation (HOCPR) program is to simplify CPR instruction to encourage more bystanders to take action during cardiac arrest. Although the program has been successfully implemented in traditional classroom settings, the utility of large-scale training events has not been well-explored. We hypothesized that CPR knowledge and comfort levels would increase through a large-scale, multi-community HOCPR training event. We also explored what effect this training event had on perceived barriers to bystander-performed CPR. Methods A convenience sample participated in HOCPR training on a single day across 10 Texas cities. A sub-sample completed training questionnaires, including …

Systemic Proteome Alterations Linked To Early Stage Pancreatic Cancer In Diabetic Patients, Hong Peng, Sheng Pan, Yuanqing Yan, Randall E Brand, Gloria M Petersen, Suresh T Chari, Lisa A Lai, Jimmy K Eng, Teresa A Brentnall, Ru Chen

Faculty, Staff and Students Publications

BACKGROUND: Diabetes is a risk factor associated with pancreatic ductal adenocarcinoma (PDAC), and new adult-onset diabetes can be an early sign of pancreatic malignancy. Development of blood-based biomarkers to identify diabetic patients who warrant imaging tests for cancer detection may represent a realistic approach to facilitate earlier diagnosis of PDAC in a risk population.

METHODS: A spectral library-based proteomic platform was applied to interrogate biomarker candidates in plasma samples from clinically well-defined diabetic cohorts with and without PDAC. Random forest algorithm was used for prediction model building and receiver operating characteristic (ROC) curve analysis was applied to evaluate the prediction …

Aav-Crispr Gene Editing Is Negated By Pre-Existing Immunity To Cas9, Ang Li, Mark R Tanner, Ciaran M Lee, Ayrea E Hurley, Marco De Giorgi, Kelsey E Jarrett, Timothy H Davis, Alexandria M Doerfler, Gang Bao, Christine Beeton, William R Lagor

Faculty, Staff and Students Publications

Adeno-associated viral (AAV) vectors are a leading candidate for the delivery of CRISPR-Cas9 for therapeutic genome editing in vivo. However, AAV-based delivery involves persistent expression of the Cas9 nuclease, a bacterial protein. Recent studies indicate a high prevalence of neutralizing antibodies and T cells specific to the commonly used Cas9 orthologs from Streptococcus pyogenes (SpCas9) and Staphylococcus aureus (SaCas9) in humans. We tested in a mouse model whether pre-existing immunity to SaCas9 would pose a barrier to liver genome editing with AAV packaging CRISPR-Cas9. Although efficient genome editing occurred in mouse liver with pre-existing SaCas9 immunity, this was accompanied by …

Discovery Of A Selective Inhibitor Of Doublecortin Like Kinase 1, Fleur M Ferguson, Behnam Nabet, Srivatsan Raghavan, Yan Liu, Alan L Leggett, Miljan Kuljanin, Radha L Kalekar, Annan Yang, Shuning He, Jinhua Wang, Raymond W S Ng, Rita Sulahian, Lianbo Li, Emily J Poulin, Ling Huang, Jost Koren, Nora Dieguez-Martinez, Sergio Espinosa, Zhiyang Zeng, Cesear R Corona, James D Vasta, Ryoma Ohi, Taebo Sim, Nam Doo Kim, Wayne Harshbarger, Jose M Lizcano, Matthew B Robers, Senthil Muthaswamy, Charles Y Lin, A Thomas Look, Kevin M Haigis, Joseph D Mancias, Brian M Wolpin, Andrew J Aguirre, William C Hahn, Kenneth D Westover, Nathanael S Gray

Faculty, Staff and Students Publications

Doublecortin like kinase 1 (DCLK1) is an understudied kinase that is upregulated in a wide range of cancers, including pancreatic ductal adenocarcinoma (PDAC). However, little is known about its potential as a therapeutic target. We used chemoproteomic profiling and structure-based design to develop a selective, in vivo-compatible chemical probe of the DCLK1 kinase domain, DCLK1-IN-1. We demonstrate activity of DCLK1-IN-1 against clinically relevant patient-derived PDAC organoid models and use a combination of RNA-sequencing, proteomics and phosphoproteomics analysis to reveal that DCLK1 inhibition modulates proteins and pathways associated with cell motility in this context. DCLK1-IN-1 will serve as a versatile tool …

Ipledge Must Abstain From Abstinence, Kami Lowery, Theodore Rosen, Janet Malek

Faculty, Staff and Students Publications

Isotretinoin has unmatched efficacy in the treatment of acne. However, because isotretinoin is a teratogen that can cause profound birth defects, the iPLEDGE program regulates the drug's distribution in the United States. To minimize fetal exposure to isotretinoin, the program requires that female patients capable of becoming pregnant use two forms of contraception or commit to abstinence while using this therapy. This manuscript argues that iPLEDGE should be revised to remove abstinence as an acceptable contraceptive option in the face of evidence that disputes its efficacy. All patients, regardless of reported sexual activity, should be required to use data-proven contraception. …

Emergency Potassium Normalization Treatment Including Sodium Zirconium Cyclosilicate: A Phase Ii, Randomized, Double-Blind, Placebo-Controlled Study (Energize), W Frank Peacock, Zubaid Rafique, Konstantin Vishnevskiy, Edward Michelson, Elena Vishneva, Tatiana Zvereva, Rajaa Nahra, Dao Li, Joseph Miller

Faculty, Staff and Students Publications

OBJECTIVES: Sodium zirconium cyclosilicate (SZC) is a novel, highly selective potassium binder currently approved in the United States and European Union for treatment of hyperkalemia. This pilot evaluation explored the efficacy of SZC with insulin and glucose as hyperkalemia treatment in the emergency department (ED).

METHODS:This exploratory, phase II, multicenter, randomized, double‐blind, placebo‐controlled study (NCT03337477) enrolled adult ED patients with blood potassium ≥ 5.8 mmol/L. Patients were randomized 1:1 to receive SZC 10 g or placebo, up to three times during a 10‐hour period, with insulin and glucose. The primary efficacy outcome was the mean change in serum …

Acute Maltodextrin Supplementation During Resistance Exercise, Dylan T Wilburn, Steven B Machek, Thomas D Cardaci, Paul S Hwang, Darryn S Willoughby

Faculty, Staff and Students Publications

Most of the research investigating the ergogenic enhancing mechanisms of carbohydrate have been conducted using aerobic based exercise. Therefore, the purpose of this study was to investigate the effects of pre-exercise maltodextrin ingestion on resistance exercise performance, serum insulin, epinephrine, glucose, and muscle glycogen concentrations. In a double blind, cross over, repeated measures design, participants completed four sets to failure at 70% of 1-RM with 45s rest on the angled leg press with or without pre-exercise maltodextrin (2g/kg) after a 3hr fast. Serum glucose, epinephrine, and insulin were assessed at baseline, 30 min post-ingestion, immediately after, and 1hr post-exercise with …

Pooled Crispr Screens With Imaging On Microraft Arrays Reveals Stress Granule-Regulatory Factors, Emily C Wheeler, Anthony Q Vu, Jaclyn M Einstein, Matthew Disalvo, Noorsher Ahmed, Eric L Van Nostrand, Alexander A Shishkin, Wenhao Jin, Nancy L Allbritton, Gene W Yeo

Faculty, Staff and Students Publications

Genetic screens using pooled CRISPR-based approaches are scalable and inexpensive, but restricted to standard readouts, including survival, proliferation and sortable markers. However, many biologically relevant cell states involve cellular and subcellular changes that are only accessible by microscopic visualization, and are currently impossible to screen with pooled methods. Here we combine pooled CRISPR-Cas9 screening with microraft array technology and high-content imaging to screen image-based phenotypes (CRaft-ID; CRISPR-based microRaft followed by guide RNA identification). By isolating microrafts that contain genetic clones harboring individual guide RNAs (gRNA), we identify RNA-binding proteins (RBPs) that influence the formation of stress granules, the punctate protein-RNA …

Rapid And Efficient Synthetic Assembly Of Multiplex Luciferase Reporter Plasmids For The Simultaneous Monitoring Of Up To Six Cellular Signaling Pathways, Alejandro Sarrion-Perdigones, Yezabel Gonzalez, Koen J T Venken

Faculty, Staff and Students Publications

High-throughput cell-based screening assays are valuable tools in the discovery of chemical probes and therapeutic agents. Such assays are designed to examine the effects of small compounds on targets, pathways, or phenotypes participating in normal and disease processes. While most cell-based assays measure single quantities, multiplexed assays seek to address these limitations by obtaining multiple simultaneous measurements. The signals from such measurements should be independently detectable and cover large dynamic ranges. Luciferases are good candidates for generation of such signals. They are genetically encoded, versatile, and cost-effective, and their output signals can be sensitively detected. We recently developed a multiplex …

Simultaneous Examination Of Cellular Pathways Using Multiplex Hextuple Luciferase Assaying, Alejandro Sarrion-Perdigones, Lyra Chang, Yezabel Gonzalez, Tatiana Gallego-Flores, Damian W Young, Koen J T Venken

Faculty, Staff and Students Publications

Multiplex experimentation that can assay multiple cellular signaling pathways in the same cells requires orthogonal genetically encoded reporters that report over large dynamic ranges. Luciferases are cost-effective, versatile candidates whose output signals can be sensitively detected in a multiplex fashion. Commonly used dual luciferase reporter assays detect one luciferase that is coupled to a single cellular pathway, and a second that is coupled to a control pathway for normalization purposes. We expanded this approach to multiplex hextuple luciferase assaying that can report on five cellular signaling pathways and one control, each of which is encoded by a unique luciferase. Light …

Myeloma Cells Shift Osteoblastogenesis To Adipogenesis By Inhibiting The Ubiquitin Ligase Murf1 In Mesenchymal Stem Cells, Zhiqiang Liu, Huan Liu, Jin He, Pei Lin, Qiang Tong, Jing Yang

Faculty, Staff and Students Publications

The suppression of bone formation is a hallmark of multiple myeloma. Myeloma cells inhibit osteoblastogenesis from mesenchymal stem cells (MSCs), which can also differentiate into adipocytes. We investigated myeloma-MSC interactions and the effects of such interactions on the differentiation of MSCs into adipocytes or osteoblasts using single-cell RNA sequencing, in vitro co-culture, and subcutaneous injection of MSCs and myeloma cells into mice. Our results revealed that the α4 subunit of integrin on myeloma cells stimulated vascular cell adhesion molecule 1 (VCAM1) on MSCs, leading to the activation of protein kinase C β1 (PKCβ1) signaling and repression of the muscle ring-finger …

A Rare Clinical Presentation Of Metastatic Crohn's Disease, Kaitlyn L Streight, Tara L Braun, Nicholas Lowe, Soo Jung Kim

Faculty, Staff and Students Publications

A 31-year-old female with a history of systemic lupus erythematous, IgA nephropathy, and psoriasis presented with a one-month history of a painful, pruritic rash under the bilateral breasts and in the genital region. Cutaneous examination revealed a large, tender ulcer under the left breast with a shiny erythematous base and peripheral hypertrophic changes. Small ulcers were present on the bilateral inguinal folds, and the labia majora were edematous with multiple erythematous papules. Histological examination of the left breast revealed ulceration with granulomatous dermatitis, consistent with a diagnosis of metastatic Crohn's disease. Metastatic Crohn's disease is a rare cutaneous manifestation of …

Age-Dependent Involvement Of Gut Mast Cells And Histamine In Post-Stroke Inflammation, Maria Pilar Blasco, Anjali Chauhan, Pedram Honarpisheh, Hilda Ahnstedt, John D'Aigle, Arunkumar Ganesan, Sriram Ayyaswamy, Frank Blixt, Susan Venable, Angela Major, David Durgan, Anthony Haag, Julia Kofler, Robert Bryan, Louise D Mccullough, Bhanu Priya Ganesh

Faculty, Staff and Students Publications

BACKGROUND: Risk of stroke-related morbidity and mortality increases significantly with age. Aging is associated with chronic, low-grade inflammation, which is thought to contribute to the poorer outcomes after stroke seen in the elderly. Histamine (HA) is a major molecular mediator of inflammation, and mast cells residing in the gut are a primary source of histamine.

METHODS: Stroke was induced in male C57BL/6 J mice at 3 months (young) and 20 months (aged) of age. Role of histamine after stroke was examined using young (Yg) and aged (Ag) mice; mice underwent MCAO surgery and were euthanized at 6 h, 24 h, …

Tfeb Regulates Murine Liver Cell Fate During Development And Regeneration, Nunzia Pastore, Tuong Huynh, Niculin J Herz, Alessia Calcagni', Tiemo J Klisch, Lorenzo Brunetti, Kangho Ho Kim, Marco De Giorgi, Ayrea Hurley, Annamaria Carissimo, Margherita Mutarelli, Niya Aleksieva, Luca D'Orsi, William R Lagor, David D Moore, Carmine Settembre, Milton J Finegold, Stuart J Forbes, Andrea Ballabio

Faculty, Staff and Students Publications

It is well established that pluripotent stem cells in fetal and postnatal liver (LPCs) can differentiate into both hepatocytes and cholangiocytes. However, the signaling pathways implicated in the differentiation of LPCs are still incompletely understood. Transcription Factor EB (TFEB), a master regulator of lysosomal biogenesis and autophagy, is known to be involved in osteoblast and myeloid differentiation, but its role in lineage commitment in the liver has not been investigated. Here we show that during development and upon regeneration TFEB drives the differentiation status of murine LPCs into the progenitor/cholangiocyte lineage while inhibiting hepatocyte differentiation. Genetic interaction studies show that …

Proteolysis-Targeting Chimera (Protac) For Targeted Protein Degradation And Cancer Therapy, Xin Li, Yongcheng Song

Faculty, Staff and Students Publications

Proteolysis-targeting chimera (PROTAC) has been developed to be a useful technology for targeted protein degradation. A bifunctional PROTAC molecule consists of a ligand (mostly small-molecule inhibitor) of the protein of interest (POI) and a covalently linked ligand of an E3 ubiquitin ligase (E3). Upon binding to the POI, the PROTAC can recruit E3 for POI ubiquitination, which is subjected to proteasome-mediated degradation. PROTAC complements nucleic acid-based gene knockdown/out technologies for targeted protein reduction and could mimic pharmacological protein inhibition. To date, PROTACs targeting ~ 50 proteins, many of which are clinically validated drug targets, have been successfully developed with several …

A Goldenbraid Cloning System For Synthetic Biology In Social Amoebae, Peter Kundert, Alejandro Sarrion-Perdigones, Yezabel Gonzalez, Mariko Katoh-Kurasawa, Shigenori Hirose, Peter Lehmann, Koen J T Venken, Gad Shaulsky

Faculty, Staff and Students Publications

GoldenBraid is a rapid, modular, and robust cloning system used to assemble and combine genetic elements. Dictyostelium amoebae represent an intriguing synthetic biological chassis with tractable applications in development, chemotaxis, bacteria-host interactions, and allorecognition. We present GoldenBraid as a synthetic biological framework for Dictyostelium, including a library of 250 DNA parts and assemblies and a proof-of-concept strain that illustrates cAMP-chemotaxis with four fluorescent reporters coded by one plasmid.

Ubiquitination Of The Dna-Damage Checkpoint Kinase Chk1 By Traf4 Is Required For Chk1 Activation, Xinfang Yu, Wei Li, Haidan Liu, Qipan Deng, Xu Wang, Hui Hu, Zijun Y Xu-Monette, Wei Xiong, Zhongxin Lu, Ken H Young, Wei Wang, Yong Li

Faculty, Staff and Students Publications

BACKGROUND: Aberrant activation of DNA damage response (DDR) is a major cause of chemoresistance in colorectal cancer (CRC). CHK1 is upregulated in CRC and contributes to therapeutic resistance. We investigated the upstream signaling pathways governing CHK1 activation in CRC.

METHODS: We identified CHK1-binding proteins by mass spectrometry analysis. We analyzed the biologic consequences of knockout or overexpression of TRAF4 using immunoblotting, immunoprecipitation, and immunofluorescence. CHK1 and TRAF4 ubiquitination was studied in vitro and in vivo. We tested the functions of TRAF4 in CHK1 phosphorylation and CRC chemoresistance by measuring cell viability and proliferation, anchorage-dependent and -independent cell growth, and mouse …

A Descriptive Study Of Racial Inequalities In Mortality From Hepatocellular Cancer Before And After Licensure Of Lifesaving Drugs For Hepatitis C Virus In The United States, Robert S Levine, Maria C Mejia, Jason L Salemi, Sandra J Gonzalez, Muktar H Aliyu, Baqar A Husaini, Roger J Zoorob, Charles H Hennekens

Faculty, Staff and Students Publications

BACKGROUND: Since 1979, mortality from hepatocellular cancer (HCC) has doubled in the United States (US). Lifesaving drugs, prohibitively expensive for some, were approved and marketed to treat hepatitis C virus (HCV), a major risk factor for HCC, beginning in 1997. After the prior introduction of other lifesaving innovations, including active retroviral drug therapy for human immunodeficiency virus and surfactant for respiratory distress syndrome of the newborn, racial inequalities in their mortalities increased in the US. In this descriptive study, we explored racial inequalities in mortality from HCC before and after licensure of HCV drugs in the US.

METHODS: The US …

Structure And Mechanism Of Human Diacylglycerol O-Acyltransferase 1, Lie Wang, Hongwu Qian, Yin Nian, Yimo Han, Zhenning Ren, Hanzhi Zhang, Liya Hu, B V Venkataram Prasad, Arthur Laganowsky, Nieng Yan, Ming Zhou

Faculty, Staff and Students Publications

Diacylglycerol O-acyltransferase-1 (DGAT1) synthesizes triacylglycerides and is required for dietary fat absorption and fat storage in humans1. DGAT1 belongs to the superfamily of membrane-bound O-acyltransferases (MBOAT) that are found in all kingdoms of life and involved in acylation of lipids and proteins2,3. It remains unclear how human DGAT1 (hDGAT1) or other mammalian members of the MBOAT family recognize their substrates and catalyze their reactions. The absence of three-dimensional structures also hampers rational targeting of hDGAT1 for therapeutic purposes. Here we present the structure of hDGAT1 in complex with a substrate oleoyl Coenzyme A solved …