Biochemistry, Biophysics, and Structural Biology Commons^™

A Noncoding Rna Modulator Potentiates Phenylalanine Metabolism In Mice, Yajuan Li, Zhi Tan, Yaohua Zhang, Zhao Zhang, Qingsong Hu, Ke Liang, Yao Jun, Youqiong Ye, Yi-Chuan Li, Chunlai Li, Lan Liao, Jianming Xu, Zhen Xing, Yinghong Pan, Sujash S Chatterjee, Tina K Nguyen, Heidi Hsiao, Sergey D Egranov, Nagireddy Putluri, Cristian Coarfa, David H Hawke, Preethi H Gunaratne, Kuang-Lei Tsai, Leng Han, Mien-Chie Hung, George A Calin, Fares Namour, Jean-Louis Guéant, Ania C Muntau, Nenad Blau, V Reid Sutton, Manuel Schiff, François Feillet, Shuxing Zhang, Chunru Lin, Liuqing Yang

Faculty, Staff and Students Publications

The functional role of long noncoding RNAs (lncRNAs) in inherited metabolic disorders, including phenylketonuria (PKU), is unknown. We demonstrated that the mouse lncRNA Pair and human HULC associate with phenylalanine hydroxylase (PAH). Pair-knockout mice exhibited excessive blood phenylalanine, musty odor, hypopigmentation, growth retardation, and progressive neurological symptoms including seizures, which faithfully models human PKU. HULC depletion led to reduced PAH enzymatic activities in human induced pluripotent stem cell (hiPSC)-differentiated hepatocytes. Mechanistically, HULC modulated the enzymatic activities of PAH by facilitating PAH-substrate and PAH-cofactor interactions. To develop a therapeutic strategy for restoring liver lncRNAs, we designed GalNAc-tagged lncRNA mimics that …

Sugar-Sweetened Beverage Consumption May Modify Associations Between Genetic Variants In The Chrebp (Carbohydrate Responsive Element Binding Protein) Locus And Hdl-C (High-Density Lipoprotein Cholesterol) And Triglyceride Concentrations, Danielle E Haslam, Gina M Peloso, Melanie Guirette, Fumiaki Imamura, Traci M Bartz, Achilleas N Pitsillides, Carol A Wang, Ruifang Li-Gao, Jason M Westra, Niina Pitkänen, Kristin L Young, Mariaelisa Graff, Alexis C Wood, Kim V E Braun, Jian'an Luan, Mika Kähönen, Jessica C Kiefte-De Jong, Mohsen Ghanbari, Nathan Tintle, Rozenn N Lemaitre, Dennis O Mook-Kanamori, Kari North, Mika Helminen, Yasmin Mossavar-Rahmani, Linda Snetselaar, Lisa W Martin, Jorma S Viikari, Wendy H Oddy, Craig E Pennell, Frits R Rosendall, M Arfan Ikram, Andre G Uitterlinden, Bruce M Psaty, Dariush Mozaffarian, Jerome I Rotter, Kent D Taylor, Terho Lehtimäki, Olli T Raitakari, Kara A Livingston, Trudy Voortman, Nita G Forouhi, Nick J Wareham, Renée De Mutsert, Steven S Rich, Joann E Manson, Samia Mora, Paul M Ridker, Jordi Merino, James B Meigs, Hassan S Dashti, Daniel I Chasman, Alice H Lichtenstein, Caren E Smith, Josée Dupuis, Mark A Herman, Nicola M Mckeown

Faculty, Staff and Students Publications

BACKGROUND: ChREBP (carbohydrate responsive element binding protein) is a transcription factor that responds to sugar consumption. Sugar-sweetened beverage (SSB) consumption and genetic variants in the

METHODS: Data from 11 cohorts from the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium (N=63 599) and the UK Biobank (N=59 220) were used to quantify associations of SSB consumption, genetic variants, and their interaction on HDL-C and triglyceride concentrations using linear regression models. A total of 1606 single nucleotide polymorphisms within or near

RESULTS: In a meta-analysis, rs71556729 was significantly associated with higher HDL-C concentrations only among the highest SSB consumers …

Metabolomics Profiling Of Patients With A-Β+ Ketosis-Prone Diabetes During Diabetic Ketoacidosis, Farook Jahoor, Jean W Hsu, Paras B Mehta, Kelly R Keene, Ruchi Gaba, Surya Narayan Mulukutla, Eunice Caducoy, W Frank Peacock, Sanjeet G Patel, Rasmus Bennet, Ake Lernmark, Ashok Balasubramanyam

Faculty, Staff and Students Publications

When stable and near-normoglycemic, patients with “A−β+” ketosis-prone diabetes (KPD) manifest accelerated leucine catabolism and blunted ketone oxidation, which may underlie their proclivity to develop diabetic ketoacidosis (DKA). To understand metabolic derangements in A−β+ KPD patients during DKA, we compared serum metabolomics profiles of adults during acute hyperglycemic crises, without (n = 21) or with (n = 74) DKA, and healthy control subjects (n = 17). Based on 65 kDa GAD islet autoantibody status, C-peptide, and clinical features, 53 DKA patients were categorized as having KPD and 21 type 1 diabetes (T1D); 21 nonketotic patients were categorized as …

Factors Associated With Access To And Receipt Of Liver Transplantation In Veterans With End-Stage Liver Disease, Fasiha Kanwal, Ruben Hernaez, Yan Liu, Thomas J Taylor, Abbas Rana, Jennifer R Kramer, Aanand D Naik, Donna Smith, Tamar Taddei, Steven M Asch

Faculty, Staff and Students Publications

IMPORTANCE: Organ scarcity means few patients with advanced liver disease undergo a transplant, making equitable distribution all the more crucial. Disparities may arise at any stage in the complex process leading up to this curative therapy.

OBJECTIVE: To examine the rate of and factors associated with referral, wait-listing, and receipt of liver allografts.

DESIGN, SETTING, AND PARTICIPANTS: This retrospective cohort study used linked data from comprehensive electronic medical records and the United Network of Organ Sharing. Adult patients with cirrhosis and a Model for End-Stage Liver Disease with addition of sodium score of at least 15 points between October 1, …

High Burden Of Subclinical And Cardiovascular Disease Risk In Adults With Metabolically Healthy Obesity: The Atherosclerosis Risk In Communities (Aric) Study, Yvonne Commodore-Mensah, Mariana Lazo, Olive Tang, Justin B Echouffo-Tcheugui, Chiadi E Ndumele, Vijay Nambi, Dan Wang, Christie Ballantyne, Elizabeth Selvin

Faculty, Staff and Students Publications

OBJECTIVE: It is controversial whether adults who are obese but "metabolically healthy" have cardiovascular disease (CVD) risk comparable with that of normal-weight adults. High-sensitivity cardiac troponin T (hs-cTnT), a biomarker of myocardial damage, is useful in characterizing subclinical CVD. We categorized obesity phenotypes and studied their associations with subclinical and clinical CVD and CVD subtypes, including heart failure (HF).

RESEARCH DESIGN AND METHODS: We conducted cross-sectional and prospective analyses of 9,477 adults in the Atherosclerosis Risk in Communities (ARIC) study. We used the Adult Treatment Panel III criteria and BMI to define obesity phenotypes as follows: metabolically healthy normal weight, …

Sex-Related Disparities In Cardiovascular Health Care Among Patients With Premature Atherosclerotic Cardiovascular Disease, Michelle T Lee, Dhruv Mahtta, David J Ramsey, Jing Liu, Arunima Misra, Khurram Nasir, Zainab Samad, Dipti Itchhaporia, Safi U Khan, Richard S Schofield, Christie M Ballantyne, Laura A Petersen, Salim S Virani

Faculty, Staff and Students Publications

IMPORTANCE: There is a paucity of data regarding secondary prevention care disparities in women with premature and extremely premature atherosclerotic cardiovascular disease (ASCVD), defined as an ASCVD event at 55 years or younger and 40 years or younger, respectively.

OBJECTIVE: To evaluate sex-based differences in antiplatelet agents, any statin, high-intensity statin (HIS) therapy, and statin adherence in patients with premature and extremely premature ASCVD.

DESIGN, SETTING, AND PARTICIPANTS: This was a cross-sectional, multicenter, nationwide VA health care system-based study with patients enrolled in the Veterans With Premature Atherosclerosis (VITAL) registry. The study assessed patients who had at least 1 primary …

Development And Validation Of Machine Learning-Based Race-Specific Models To Predict 10-Year Risk Of Heart Failure: A Multicohort Analysis, Matthew W Segar, Byron C Jaeger, Kershaw V Patel, Vijay Nambi, Chiadi E Ndumele, Adolfo Correa, Javed Butler, Alvin Chandra, Colby Ayers, Shreya Rao, Alana A Lewis, Laura M Raffield, Carlos J Rodriguez, Erin D Michos, Christie M Ballantyne, Michael E Hall, Robert J Mentz, James A De Lemos, Ambarish Pandey

Faculty, Staff and Students Publications

BACKGROUND: Heart failure (HF) risk and the underlying risk factors vary by race. Traditional models for HF risk prediction treat race as a covariate in risk prediction and do not account for significant parameters such as cardiac biomarkers. Machine learning (ML) may offer advantages over traditional modeling techniques to develop race-specific HF risk prediction models and to elucidate important contributors of HF development across races.

METHODS: We performed a retrospective analysis of 4 large, community cohort studies (ARIC [Atherosclerosis Risk in Communities], DHS [Dallas Heart Study], JHS [Jackson Heart Study], and MESA [Multi-Ethnic Study of Atherosclerosis]) with adjudicated HF events. …

Advantage Of 16s Rrna Amplicon Sequencing In Helicobacter Pylori Diagnosis, Boldbaatar Gantuya, Hashem B El Serag, Batsaikhan Saruuljavkhlan, Dashdorj Azzaya, Takashi Matsumoto, Tomohisa Uchida, Khasag Oyuntsetseg, Nyamdorj Oyunbileg, Duger Davaadorj, Yoshio Yamaoka

Faculty, Staff and Students Publications

BACKGROUND: 16S rRNA amplicon sequencing is an accurate method of detecting microbial infection without culture. It is unclear if sequencing has additional benefits over routine diagnostic methods for Helicobacter pylori testing.

METHODS: We enrolled Mongolian volunteers with dyspepsia. Using routine diagnostic methods, positive H. pylori was defined as positive results on histology/immunohistochemistry, culture, rapid urease test, or serology; negative H. pylori was defined by negative results from all these tests. We performed 16S rRNA sequencing on gastric biopsy specimens and calculated cutoffs for operational taxonomic units (OTUs) and relative abundance (RA) to define positive results using ROC curves.

RESULTS: We …

Psychological Impact Of Genetic And Clinical Screening For Pulmonary Fibrosis On Asymptomatic First-Degree Relatives Of Affected Individuals, Nikkola Carmichael, Jose M Martinez Manzano, Luisa D Quesada-Arias, Sergio De Frías Poli, Maura Alvarez Baumgartner, Maria A Planchart Ferretto, Lisa Digianni, Shannon Gampala-Sagar, Dominick A Leone, Swati Gulati, Souheil Y El-Chemaly, Hilary J Goldberg, Rachel Putman, Hiroto Hatabu, Ivan O Rosas, Gary M Hunninghake, Benjamin A Raby

Faculty, Staff and Students Publications

Screening for pulmonary fibrosis may help to identify early stages of the disease. We assessed the psychological impact of screening undiagnosed first-degree relatives of patients with pulmonary fibrosis by administering two validated measures after participants received their results: the Decisional Regret Scale and the Feelings About genomiC Testing Results Questionnaire. More than 90% of relatives reported either no or mild decisional regret. Increased measures of decisional regret and negative feelings were present in those found to have a low diffusion capacity of carbon monoxide or interstitial lung abnormalities. Results of telomere length and genetic testing did not significantly impact regret.

Soluble Angiotensin-Converting Enzyme 2, Cardiac Biomarkers, Structure, And Function, And Cardiovascular Events (From The Atherosclerosis Risk In Communities Study), Aliza Hussain, Olive Tang, Caroline Sun, Xiaoming Jia, Elizabeth Selvin, Vijay Nambi, Aaron Folsom, Gerardo Heiss, Faiez Zannad, Thomas Mosley, Salim S Virani, Josef Coresh, Eric Boerwinkle, Bing Yu, Jonathan W Cunningham, Amil M Shah, Scott D Solomon, James A De Lemos, Ron C Hoogeveen, Christie M Ballantyne

Faculty, Staff and Students Publications

Membrane-bound angiotensin-converting enzyme 2 is important in regulation of the renin-angiotensin-aldosterone system, but the association of cleaved soluble ACE2 (sACE2) with cardiovascular disease (CVD) is unclear. We evaluated the association of sACE2 with cardiac biomarkers, structure, and function and cardiovascular events in the Atherosclerosis Risk in Communities Study. sACE2 was measured in a subset of 497 participants (mean age 78±5.4 years, 53% men, 27% black); Cox regression analyses assessed prospective associations of sACE2 with time to first CVD event at median 6.1-year follow-up. sACE2 was higher in men, blacks, and participants with prevalent CVD, diabetes, or hypertension. Higher sACE2 levels …

Tocilizumab In Hospitalized Patients With Severe Covid-19 Pneumonia, Ivan O Rosas, Norbert Bräu, Michael Waters, Ronaldo C Go, Bradley D Hunter, Sanjay Bhagani, Daniel Skiest, Mariam S Aziz, Nichola Cooper, Ivor S Douglas, Sinisa Savic, Taryn Youngstein, Lorenzo Del Sorbo, Antonio Cubillo Gracian, David J De La Zerda, Andrew Ustianowski, Min Bao, Sophie Dimonaco, Emily Graham, Balpreet Matharu, Helen Spotswood, Larry Tsai, Atul Malhotra

Faculty, Staff and Students Publications

BACKGROUND: Coronavirus disease 2019 (Covid-19) is associated with immune dysregulation and hyperinflammation, including elevated interleukin-6 levels. The use of tocilizumab, a monoclonal antibody against the interleukin-6 receptor, has resulted in better outcomes in patients with severe Covid-19 pneumonia in case reports and retrospective observational cohort studies. Data are needed from randomized, placebo-controlled trials.

METHODS: In this phase 3 trial, we randomly assigned patients who were hospitalized with severe Covid-19 pneumonia in a 2:1 ratio receive a single intravenous infusion of tocilizumab (at a dose of 8 mg per kilogram of body weight) or placebo. Approximately one quarter of the participants …

Association Of Blood Pressure Variability And Diuretics With Cardiovascular Events In Patients With Chronic Kidney Disease Stages 1-5, L Parker Gregg, S Susan Hedayati, Hui Yang, Peter N Van Buren, Subhash Banerjee, Sankar D Navaneethan, Salim S Virani, Wolfgang C Winkelmayer, Carlos A Alvarez

Faculty, Staff and Students Publications

Visit-to-visit blood pressure variability (BPV) is associated with cardiovascular events in the general population. Data are scarce in chronic kidney disease (CKD). We hypothesized that BPV would be associated with cardiovascular outcomes, death, and end-stage kidney disease (ESKD) and that diuretics would modify these associations in patients with CKD.

We studied U.S. Veterans with non-dialysis CKD stages 1-5 and hypertension on non-diuretic antihypertensive monotherapy. At the time of second antihypertensive agent prescription, we propensity-matched for exposure to a loop or thiazide diuretic vs. any other antihypertensive. BPV was defined as the coefficient of variation of systolic blood pressure over …

Tbx5-Encoded T-Box Transcription Factor 5 Variant T223m Is Associated With Long Qt Syndrome And Pediatric Sudden Cardiac Death, Alexandra M Markunas, Perathu K R Manivannan, Jordan E Ezekian, Agnim Agarwal, William Eisner, Katherina Alsina, Hugh D Allen, Gregory A Wray, Jeffrey J Kim, Xander H T Wehrens, Andrew P Landstrom

Faculty, Staff and Students Publications

Long QT syndrome (LQTS) is a genetic disease resulting in a prolonged QT interval on a resting electrocardiogram, predisposing affected individuals to polymorphic ventricular tachycardia and sudden death. Although a number of genes have been implicated in this disease, nearly one in four individuals exhibiting the LQTS phenotype are genotype-negative. Whole-exome sequencing identified a missense T223M variant in TBX5 that cosegregates with prolonged QT interval in a family with otherwise genotype-negative LQTS and sudden death. The TBX5-T223M variant was absent among large ostensibly healthy populations (gnomAD) and predicted to be pathogenic by in silico modeling based on Panther, PolyPhen-2, Provean, …

The Rac-Gef Tiam1 Promotes Dendrite And Synapse Stabilization Of Dentate Granule Cells And Restricts Hippocampal-Dependent Memory Functions, Jinxuan Cheng, Federico Scala, Francisco A Blanco, Sanyong Niu, Karen Firozi, Laura Keehan, Shalaka Mulherkar, Emmanouil Froudarakis, Lingyong Li, Joseph G Duman, Xiaolong Jiang, Kimberley F Tolias

Faculty, Staff and Students Publications

The dentate gyrus (DG) controls information flow into the hippocampus and is critical for learning, memory, pattern separation, and spatial coding, while DG dysfunction is associated with neuropsychiatric disorders. Despite its importance, the molecular mechanisms regulating DG neural circuit assembly and function remain unclear. Here, we identify the Rac-GEF Tiam1 as an important regulator of DG development and associated memory processes. In the hippocampus, Tiam1 is predominantly expressed in the DG throughout life. Global deletion of Tiam1 in male mice results in DG granule cells with simplified dendritic arbors, reduced dendritic spine density, and diminished excitatory synaptic transmission. Notably, DG …

Association Of Nt-Probnp, Blood Pressure, And Cardiovascular Events: The Aric Study, Aliza Hussain, Wensheng Sun, Anita Deswal, James A De Lemos, John W Mcevoy, Ron C Hoogeveen, Kunihiro Matsushita, David Aguilar, Biykem Bozkurt, Salim S Virani, Amil M Shah, Elizabeth Selvin, Chiadi Ndumule, Christie M Ballantyne, Vijay Nambi

Faculty, Staff and Students Publications

BACKGROUND: Although intensive blood pressure reduction has cardiovascular benefits, the absolute benefit is greater in those at higher cardiovascular disease (CVD) risk.

OBJECTIVES: This study examined whether N-terminal pro-B-type natriuretic peptide (NT-proBNP) helps identify subjects at higher risk for CVD events across systolic blood pressure (SBP), diastolic blood pressure (DBP), or pulse pressure (PP) categories.

METHODS: Participants from the ARIC (Atherosclerosis Risk In Communities) study visit 4 (1996 to 98) were grouped according to SBP, DBP, or PP categories and further stratified by NT-proBNP categories. Cox regression models were used to estimate hazard ratios for incident CVD (coronary heart disease, …

Efficacy And Safety Of The Mrna-1273 Sars-Cov-2 Vaccine, Lindsey R Baden, Hana M El Sahly, Brandon Essink, Karen Kotloff, Sharon Frey, Rick Novak, David Diemert, Stephen A Spector, Nadine Rouphael, C Buddy Creech, John Mcgettigan, Shishir Khetan, Nathan Segall, Joel Solis, Adam Brosz, Carlos Fierro, Howard Schwartz, Kathleen Neuzil, Larry Corey, Peter Gilbert, Holly Janes, Dean Follmann, Mary Marovich, John Mascola, Laura Polakowski, Julie Ledgerwood, Barney S Graham, Hamilton Bennett, Rolando Pajon, Conor Knightly, Brett Leav, Weiping Deng, Honghong Zhou, Shu Han, Melanie Ivarsson, Jacqueline Miller, Tal Zaks, Cove Study Group

Faculty, Staff and Students Publications

BACKGROUND: Vaccines are needed to prevent coronavirus disease 2019 (Covid-19) and to protect persons who are at high risk for complications. The mRNA-1273 vaccine is a lipid nanoparticle-encapsulated mRNA-based vaccine that encodes the prefusion stabilized full-length spike protein of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes Covid-19.

METHODS: This phase 3 randomized, observer-blinded, placebo-controlled trial was conducted at 99 centers across the United States. Persons at high risk for SARS-CoV-2 infection or its complications were randomly assigned in a 1:1 ratio to receive two intramuscular injections of mRNA-1273 (100 μg) or placebo 28 days apart. …

Relation Of Magnetic Resonance Imaging Based Arterial Signal Enhancement To Markers Of Peripheral Artery Disease, Olga A Gimnich, Jonathan Holbrook, Tatiana Belousova, Christina M Short, Addison A Taylor, Vijay Nambi, Joel D Morrisett, Christie M Ballantyne, Jean Bismuth, Dipan J Shah, Gerd Brunner

Faculty, Staff and Students Publications

Peripheral artery disease (PAD) is associated with impaired lower extremity function. We hypothesized that contrast-enhanced magnetic resonance imaging (CE-MRI) based arterial signal enhancement (SE) measures are associated with markers of PAD. A total of 66 participants were enrolled, 10 were excluded due to incomplete data, resulting in 56 participants for the final analyses (36 PAD, 20 matched controls). MR imaging was performed postreactive hyperemia using bilateral thigh blood-pressure cuffs. First pass-perfusion images were acquired at the mid-calf region with a high-resolution saturation recovery gradient echo pulse sequence, and arterial SE was measured for the lower extremity arteries. As expected, peak …

The Association Of Pre-Kidney Transplant Dialysis Modality With De Novo Posttransplant Heart Failure, Colin R Lenihan, Sai Liu, Medha Airy, Carl Walther, Maria E Montez-Rath, Wolfgang C Winkelmayer

Faculty, Staff and Students Publications

BACKGROUND: Heart failure (HF) after kidney transplantation is a significant but understudied problem. Pretransplant dialysis modality could influence incident HF risk through differing cardiac stressors. However, whether pretransplant dialysis modality is associated with the development of posttransplant HF is unknown.

METHODS: We used the US Renal Data System to assemble a cohort of 27,701 patients who underwent their first kidney transplant in the USA between the years 2005 and 2012 and who had Medicare fee-for-service coverage for >6 months preceding their transplant date. Patients with any HF diagnosis prior to transplant were excluded. Detailed baseline patient characteristics and comorbidities were …

Rapid Induction Of The Unfolded Protein Response And Apoptosis By Estrogen Mimic Ttc-352 For The Treatment Of Endocrine-Resistant Breast Cancer, Balkees Abderrahman, Philipp Y Maximov, Ramona F Curpan, Sean W Fanning, Jay S Hanspal, Ping Fan, Charles E Foulds, Yue Chen, Anna Malovannaya, Antrix Jain, Rui Xiong, Geoffrey L Greene, Debra A Tonetti, Gregory R J Thatcher, V Craig Jordan

Faculty, Staff and Students Publications

Patients with long-term estrogen-deprived breast cancer (BC), after resistance to tamoxifen or aromatase inhibitors develops, can experience tumor regression when treated with estrogens. Estrogen’s anti-tumor effect is attributed to apoptosis via the estrogen receptor (ER). Estrogen treatment can have unpleasant gynecological and non-gynecological adverse events thus the development of safer estrogenic agents remains a clinical priority. Here, we study synthetic selective estrogen mimics (SEMs) BMI-135 and TTC-352, and the naturally-occurring estrogen estetrol (E4), which are proposed as safer estrogenic agents compared to 17β-estradiol (E2), for the treatment of endocrine-resistant BC. TTC-352 and E4 are being evaluated in BC clinical trials. …

Inferior St-Elevation Myocardial Infarction Presenting When Urgent Primary Percutaneous Coronary Intervention Is Unavailable: Should We Adhere To Current Guidelines?, Yochai Birnbaum, Glenn N Levine, John French, Juan Carlos Kaski, Dan Atar, Mahboob Alam, David Hasdai, Hani Jneid, Barry F Uretsky

Faculty, Staff and Students Publications

The pivotal studies that led to the recommendations for emergent reperfusion therapy for ST-elevation myocardial infarction (STEMI) were conducted for the most part over 25 years ago. At that time, contemporary standard treatments including aspirin, statin, and even anticoagulation were not commonly used. The 2013 American College of Cardiology Foundation (ACCF)/American Heart Association (AHA) guidelines and the 2017 European Society of Cardiology guidelines give a class I recommendation (with the level of evidence A) for primary percutaneous coronary intervention (pPCI) in patients with STEMI and ischemic symptoms of less than 12 h. However, if the patient presents to a hospital …

Chronic Ulcers And Malnutrition In An African Patient\, Timothy G Singer, Monica A Bray, Audrey Chan, Saki Ikeda, Brittany Walters, Maren Y Fuller, Carla Falco

Faculty, Staff and Students Publications

An 11-year-old female with a congenitally malformed left hand, sickle-cell trait, asthma, and history of appendicitis was transferred from Zambia for evaluation and treatment of widespread suppurative and ulcerative skin lesions that typically appeared following trauma to her skin. The ulcers first presented 3 years earlier but had markedly worsened in the 9 months prior to transfer, spreading circumferentially on her extremities and abdomen at the site of an appendectomy. They were painful and did not resolve with multiple courses of intravenous (IV) antibiotics and close management by a Pediatric Infectious Disease specialist working for a non-governmental organization (NGO) in …

Adaptive Thermogenesis Enhances The Life-Threatening Response To Heat In Mice With An Ryr1 Mutation, Hui J Wang, Chang Seok Lee, Rachel Sue Zhen Yee, Linda Groom, Inbar Friedman, Lyle Babcock, Dimitra K Georgiou, Jin Hong, Amy D Hanna, Joseph Recio, Jong Min Choi, Ting Chang, Nadia H Agha, Jonathan Romero, Poonam Sarkar, Nicol Voermans, M Waleed Gaber, Sung Yun Jung, Matthew L Baker, Robia G Pautler, Robert T Dirksen, Sheila Riazi, Susan L Hamilton

Faculty, Staff and Students Publications

Mutations in the skeletal muscle Ca2+ release channel, the type 1 ryanodine receptor (RYR1), cause malignant hyperthermia susceptibility (MHS) and a life-threatening sensitivity to heat, which is most severe in children. Mice with an MHS-associated mutation in Ryr1 (Y524S, YS) display lethal muscle contractures in response to heat. Here we show that the heat response in the YS mice is exacerbated by brown fat adaptive thermogenesis. In addition, the YS mice have more brown adipose tissue thermogenic capacity than their littermate controls. Blood lactate levels are elevated in both heat-sensitive MHS patients with RYR1 mutations and YS mice due to …

An Autism-Linked Missense Mutation In Shank3 Reveals The Modularity Of Shank3 Function, Li Wang, Kaifang Pang, Kihoon Han, Carolyn J Adamski, Wei Wang, Lingjie He, Jason K Lai, Vitaliy V Bondar, Joseph G Duman, Ronald Richman, Kimberley F Tolias, Patrick Barth, Timothy Palzkill, Zhandong Liu, J Lloyd Holder, Huda Y Zoghbi

Faculty, Staff and Students Publications

Genome sequencing has revealed an increasing number of genetic variations that are associated with neuropsychiatric disorders. Frequently, studies limit their focus to likely gene-disrupting mutations because they are relatively easy to interpret. Missense variants, instead, have often been undervalued. However, some missense variants can be informative for developing a more profound understanding of disease pathogenesis and ultimately targeted therapies. Here we present an example of this by studying a missense variant in a well-known autism spectrum disorder (ASD) causing gene SHANK3. We analyzed Shank3's in vivo phosphorylation profile and identified S685 as one phosphorylation site where one ASD-linked variant has …

Low-Shot Deep Learning Of Diabetic Retinopathy With Potential Applications To Address Artificial Intelligence Bias In Retinal Diagnostics And Rare Ophthalmic Diseases, Philippe Burlina, William Paul, Philip Mathew, Neil Joshi, Katia D Pacheco, Neil M Bressler

Faculty, Staff and Students Publications

IMPORTANCE: Recent studies have demonstrated the successful application of artificial intelligence (AI) for automated retinal disease diagnostics but have not addressed a fundamental challenge for deep learning systems: the current need for large, criterion standard-annotated retinal data sets for training. Low-shot learning algorithms, aiming to learn from a relatively low number of training data, may be beneficial for clinical situations involving rare retinal diseases or when addressing potential bias resulting from data that may not adequately represent certain groups for training, such as individuals older than 85 years.

OBJECTIVE: To evaluate whether low-shot deep learning methods are beneficial when using …

Atrial Myocyte Nlrp3/Camkii Nexus Forms A Substrate For Postoperative Atrial Fibrillation, Jordi Heijman, Azinwi Phina Muna, Tina Veleva, Cristina E Molina, Henry Sutanto, Marcel Tekook, Qiongling Wang, Issam H Abu-Taha, Marcel Gorka, Stephan Künzel, Ali El-Armouche, Hermann Reichenspurner, Markus Kamler, Viacheslav Nikolaev, Ursula Ravens, Na Li, Stanley Nattel, Xander H T Wehrens, Dobromir Dobrev

Faculty, Staff and Students Publications

RATIONALE: Postoperative atrial fibrillation (POAF) is a common and troublesome complication of cardiac surgery. POAF is generally believed to occur when postoperative triggers act on a preexisting vulnerable substrate, but the underlying cellular and molecular mechanisms are largely unknown.

OBJECTIVE: To identify cellular POAF mechanisms in right atrial samples from patients without a history of atrial fibrillation undergoing open-heart surgery.

METHODS AND RESULTS: Multicellular action potentials, membrane ion-currents (perforated patch-clamp), or simultaneous membrane-current (ruptured patch-clamp) and [Ca

CONCLUSIONS: Preexisting Ca

Loss Of Speg Inhibitory Phosphorylation Of Ryanodine Receptor Type-2 Promotes Atrial Fibrillation, Hannah M Campbell, Ann P Quick, Issam Abu-Taha, David Y Chiang, Carlos F Kramm, Tarah A Word, Sören Brandenburg, Mohit Hulsurkar, Katherina M Alsina, Hui-Bin Liu, Brian Martin, Dennis Uhlenkamp, Oliver M Moore, Satadru K Lahiri, Eleonora Corradini, Markus Kamler, Albert J R Heck, Stephan E Lehnart, Dobromir Dobrev, Xander H T Wehrens

Faculty, Staff and Students Publications

BACKGROUND: Enhanced diastolic calcium (Ca

METHODS: Western blotting was performed with right atrial biopsies from patients with paroxysmal AF. SPEG atrial knockout mice were generated using adeno-associated virus 9. In mice, AF inducibility was determined using intracardiac programmed electric stimulation, and diastolic Ca

RESULTS: Western blotting revealed decreased SPEG protein levels in atrial biopsies from patients with paroxysmal AF in comparison with patients in sinus rhythm. SPEG atrial-specific knockout mice exhibited increased susceptibility to pacing-induced AF by programmed electric stimulation and enhanced Ca

CONCLUSIONS: Unlike other kinases (PKA, CaMKII) that increase RyR2 activity, SPEG phosphorylation reduces RyR2-mediated sarcoplasmic reticulum Ca

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 …

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.)

Acetylation Of Histone H3k27 Signals The Transcriptional Elongation For Estrogen Receptor Alpha, Yujing Gao, Lijia Chen, Yali Han, Fangrui Wu, Wen-Si Yang, Zheng Zhang, Tong Huo, Yingmin Zhu, Chengtai Yu, Hong Kim, Mark Lee, Zhen Tang, Kevin Phillips, Bin He, Sung Yun Jung, Yongcheng Song, Bokai Zhu, Rui-Ming Xu, Qin Feng

Faculty, Staff and Students Publications

As approximately 70% of human breast tumors are estrogen receptor α (ERα)-positive, estrogen and ERα play essential roles in breast cancer development. By interrupting the ERα signaling pathway, endocrine therapy has been proven to be an effective therapeutic strategy. In this study, we identified a mechanism by which Transcription Start Site (TSS)-associated histone H3K27 acetylation signals the Super Elongation Complex (SEC) to regulate transcriptional elongation of the ESR1 (ERα) gene. SEC interacts with H3K27ac on ESR1 TSS through its scaffold protein AFF4. Depletion of AFF4 by siRNA or CRISPR/Cas9 dramatically reduces expression of ESR1 and its target genes, consequently inhibiting …

Nr2f1 Heterozygous Knockout Mice Recapitulate Neurological Phenotypes Of Bosch-Boonstra-Schaaf Optic Atrophy Syndrome And Show Impaired Hippocampal Synaptic Plasticity, Chun-An Chen, Wei Wang, Steen E Pedersen, Ayush Raman, Michelle L Seymour, Fernanda R Ruiz, Anping Xia, Meike E Van Der Heijden, Li Wang, Jiani Yin, Joanna Lopez, Megan E Rech, Richard A Lewis, Samuel M Wu, Zhandong Liu, Fred A Pereira, Robia G Pautler, Huda Y Zoghbi, Christian P Schaaf

Faculty, Staff and Students Publications

Bosch-Boonstra-Schaaf optic atrophy syndrome (BBSOAS) has been identified as an autosomal-dominant disorder characterized by a complex neurological phenotype, with high prevalence of intellectual disability and optic nerve atrophy/hypoplasia. The syndrome is caused by loss-of-function mutations in NR2F1, which encodes a highly conserved nuclear receptor that serves as a transcriptional regulator. Previous investigations to understand the protein's role in neurodevelopment have mostly used mouse models with constitutive and tissue-specific homozygous knockout of Nr2f1. In order to represent the human disease more accurately, which is caused by heterozygous NR2F1 mutations, we investigated a heterozygous knockout mouse model and found that this model …