Digital Commons Network^™

Evidence For The Misfolding Of The A1 Domain Within Multimeric Von Willebrand Factor In Type 2 Von Willebrand Disease, Alexander Tischer, Maria A Brehm, Venkata R Machha, Laurie Moon-Tasson, Linda M Benson, Katelynn J Nelton, Rachel R Leger, Tobias Obser, Marina Martinez-Vargas, Steven T Whitten, Dong Chen, Rajiv K Pruthi, H Robert Bergen, Miguel A Cruz, Reinhard Schneppenheim, Matthew Auton

Faculty, Staff and Students Publications

Von Willebrand factor (VWF), an exceptionally large multimeric plasma glycoprotein, functions to initiate coagulation by agglutinating platelets in the blood stream to sites of vascular injury. This primary hemostatic function is perturbed in type 2 dysfunctional subtypes of von Willebrand disease (VWD) by mutations that alter the structure and function of the platelet GPIbα adhesive VWF A1 domains. The resulting amino acid substitutions cause local disorder and misfold the native structure of the isolated platelet GPIbα-adhesive A1 domain of VWF in both gain-of-function (type 2B) and loss-of-function (type 2M) phenotypes. These structural effects have not been explicitly observed in A1 …

Development And Characterization Of A Wee1 Kinase Degrader, Zhengnian Li, Benika J Pinch, Calla M Olson, Katherine A Donovan, Radosław P Nowak, Caitlin E Mills, David A Scott, Zainab M Doctor, Nicholas A Eleuteri, Mirra Chung, Peter K Sorger, Eric S Fischer, Nathanael S Gray

Faculty, Staff and Students Publications

The G1/S cell cycle checkpoint is frequently dysregulated in cancer, leaving cancer cells reliant on a functional G2/M checkpoint to prevent excessive DNA damage. Wee1 regulates the G2/M checkpoint by phosphorylating CDK1 at Tyr15 to prevent mitotic entry. Previous drug development efforts targeting Wee1 resulted in the clinical-grade inhibitor, AZD1775. However, AZD1775 is burdened by dose-limiting adverse events, and has off-target PLK1 activity. In an attempt to overcome these limitations, we developed Wee1 degraders by conjugating AZD1775 to the cereblon (CRBN)-binding ligand, pomalidomide. The resulting lead compound, ZNL-02-096, degrades Wee1 while sparing PLK1, induces G2/M accumulation at 10-fold lower doses …

Prevalence Of Chronic Hepatitis B In Oro Province, Papua New Guinea, Alice Unah Lee, Luke Mair, Bob Kevin, Lily Gandi, Olive Tarumuri, Caroline Lee, Sue Huntley, David Carl Hilmers

Faculty, Staff and Students Publications

Chronic hepatitis B (CHB) affects over 250 million people worldwide. In Papua New Guinea, the prevalence of CHB has been estimated to be over 8%, and it is a leading cause of death. To address this problem, an alliance was formed between the government of Oro Province, a large private employer and an Australian nongovernmental organization, which established a CHB test and treatment programme. Between 2014 and 2019, rapid hepatitis B surface antigen testing was performed on 4068 individuals in Oro Province. The crude prevalence rate was 12.98% and was significantly higher in males (15.26%) than females (10.94%) (P < 0.001). The rate was 4.72% among children aged 10 years and under, 12.81% among women of childbearing age (19–35 years) and 18.48% among health-care workers. These results indicate that the rates of vaccination at birth and later among women of childbearing age and health-care workers must be improved to prevent transmission of CHB.

Broken And Forgotten: A Case Of Unintentionally Retained Foreign Object, Hong Loan Nguyen, Lauren Nicholas Herrera, Ali Cheema, Pralay Kumar Sarkar

Faculty, Staff and Students Publications

Central venous catheter have become ubiquitous with greater than 15 million catheter days/year in the intensive care setting alone. However, the procedure carries with it several immediate and other delayed complications that can result in significant morbidity, mortality, and increased healthcare cost. We report a rare case of significantly delayed complications associated with intravascular loss of guide wire during central venous catheter placement and its impact on patient's long term management. The case highlights not only the importance of proper technique and safety precaution in performing an increasingly common procedure, but also the need for timely identification and rectification of …

A Remarkable Response Of Granulomatous Hypophysitis To Infliximab In A Patient With A Background Of Crohn's Disease-A Case Report, Bahar K Force, Tiphanie P Vogel, Dang M Nguyen, Kent A Heck, Sherly Sebastian, Mas Takashima, Daniel Yoshor, Susan L Samson

Faculty, Staff and Students Publications

Associated Data

Non-Uniformity Of Projection Distributions Attenuates Resolution In Cryo-Em, Philip R Baldwin, Dmitry Lyumkis

Faculty, Staff and Students Publications

Virtually all single-particle cryo-EM experiments currently suffer from specimen adherence to the air-water interface, leading to a non-uniform distribution in the set of projection views. Whereas it is well accepted that uniform projection distributions can lead to high-resolution reconstructions, non-uniform (anisotropic) distributions can negatively affect map quality, elongate structural features, and in some cases, prohibit interpretation altogether. Although some consequences of non-uniform sampling have been described qualitatively, we know little about how sampling quantitatively affects resolution in cryo-EM. Here, we show how inhomogeneity in any projection distribution scheme attenuates the global Fourier Shell Correlation (FSC) in relation to the number …

Protocatechuic Acid As A Topical Antimicrobial For Surgical Skin Antisepsis: Preclinical Investigations, Omid Jalali, Molly Best, Alison Wong, Brett Schaeffer, Brendon Bauer, Lanny Johnson

Faculty, Staff and Students Publications

BACKGROUND: There is a need for novel skin antiseptic agents to combat the health-care burdens associated with surgical site infection (SSI) and bacterial resistance. The purpose of this proof-of-principle pilot study was to investigate the potential of the phenolic compound protocatechuic acid (PCA) as a topical antimicrobial for surgical skin antisepsis.

METHODS: The Kirby-Bauer method of disc diffusion was used to investigate the in vitro antimicrobial activity and comparative effectiveness of PCA and 7 related compounds against SSI pathogens. To explore the in vivo efficacy of topical PCA for providing deep, penetrating skin antisepsis, living

RESULTS: Compared with other polyphenols, …

Utilization Of A Continuous Pericapsular Nerve Group (Peng) Block With An Opioid-Sparing Repair Of A Femoral Neck Fracture In A Pediatric Patient, Karla Wyatt, Moustafa Zidane, Chyong-Jy Joyce Liu

Faculty, Staff and Students Publications

In the pediatric population, femoral neck fractures are usually associated with high-impact trauma and often present with pain in the groin area. Regional anesthesia can offer adjunctive therapy for acute pain management. Various techniques have been employed to circumvent pain related to hip fractures and resultant hip surgery. Neuraxial, lumbar plexus, caudal, epidural, fascia iliaca, and femoral continuous nerve block techniques are advantageous in mitigating hip pain. However, these approaches require patient repositioning during placement and carry the potential for motor blockade with resultant weakness. A newly described method, the Pericapsular Nerve Group (PENG) block, allows for analgesia of the …

The Longitudinal Parallel Process Analysis Of Biomarkers Of Oxidative Stress, Symptom Clusters, And Cognitive Function In Children With Leukemia, Mary C Hooke, Daniel Hatch, Marilyn J Hockenberry, Susan Whitman, Ida Moore, David Montgomery, Kari Marano, Pauline Mitby, Michael E Scheurer, Olga Taylor, Wei Pan

Faculty, Staff and Students Publications

Background: During treatment for acute lymphoblastic leukemia (ALL), children report co-occurring symptoms of fatigue, sleep disturbance, pain, nausea, and depression as a symptom cluster. Central nervous system–directed ALL therapies also put children at risk for cognitive impairments. Cancer therapies can cause an increase in oxidative stress, which may contribute to treatment-related symptoms. This study examined the longitudinal relationships between biomarkers of oxidative stress in the cerebrospinal fluid, the Childhood Cancer Symptom Cluster–Leukemia (CCSC-L), and cognition, in children over the first year of ALL treatment. Methods: Glutathione (GSH) biomarkers of oxidative stress were measured in cerebrospinal fluid collected during treatment lumbar …

The Vimentin Rod Domain Blocks P-Selectin-P-Selectin Glycoprotein Ligand 1 Interactions To Attenuate Leukocyte Adhesion To Inflamed Endothelium, Fong Wilson Lam, Cameron August Brown, Christian Valladolid, Dabel Cynthia Emebo, Timothy Gerald Palzkill, Miguel Angel Cruz

Faculty, Staff and Students Publications

Acute inflammation begins with leukocyte P-selectin glycoprotein ligand-1 (PSGL-1) binding to P-selectin on inflamed endothelium and platelets. In pathologic conditions, this process may contribute to secondary organ damage, like sepsis-induced liver injury. Therefore, developing novel therapies to attenuate inflammation may be beneficial. We previously reported that recombinant human vimentin (rhVim) binds P-selectin to block leukocyte adhesion to endothelium and platelets. In this study, we used SPOT-peptide arrays to identify the rod domain as the active region within rhVim that interacts with P-selectin. Indeed, recombinant human rod domain of vimentin (rhRod) binds to P-selectin with high affinity, with in silico modeling …

Acute Lymphoblastic Leukemia Presenting Initially As Spinal Cord Compression: When Chemotherapy Alone Is Enough, Albert Jang, Kallie N Kram, Scott N Berger, Mahmoud R Gaballa, Lee B Lu, David R Dunaway, Courtney N Miller-Chism

Faculty, Staff and Students Publications

Spinal cord compression (SCC) is a rare initial presentation and complication of acute lymphoblastic leukemia (ALL) with nearly all reported cases occurring in the pediatric population. We report a 38-year-old previously healthy man who presented with acute on chronic lower back pain, gait instability, urinary retention, and severe thrombocytopenia. Radiologic examination revealed two soft tissue masses of the thoracic spine associated with compression fractures causing spinal canal narrowing and cord compression. Bone marrow biopsy confirmed the diagnosis of ALL. Immediate initiation of high-dose corticosteroids and systemic chemotherapy resolved the patient's symptoms without radiation therapy or surgical intervention. After two courses …

Aromatase Inhibitors Plus Weight Loss Improves The Hormonal Profile Of Obese Hypogonadal Men Without Causing Major Side Effects, Georgia Colleluori, Rui Chen, Christie G Turin, Francesca Vigevano, Clifford Qualls, Biju Johnson, Sanjay Mediwala, Dennis T Villareal, Reina Armamento-Villareal

Faculty, Staff and Students Publications

Objective: In obese men, the increased expression of the aromatase enzyme in adipose tissue leads to high conversion of androgens to estrogens contributing to hypogonadotropic hypogonadism (HHG). Our objective is to evaluate efficacy and safety of weight loss (WL) plus aromatase inhibitor (AI) therapy in severely obese men with HHG. We hypothesize that AI+WL will be more effective as compared to WL alone in improving the hormonal profile, thus muscle strength and symptoms of HHG (primary outcomes), with no significant adverse effects on lean mass, metabolic profile, and bone mineral density (secondary outcomes).

Design: Randomized double-blind placebo-controlled pilot trial.

Methods: …

Lisinopril-Induced Angioedema In A Patient With Plasma Prekallikrein Deficiency, Swapan K Dasgupta, Stefanie Rivera, Perumal Thiagarajan

Faculty, Staff and Students Publications

Angiotensin-converting enzyme (ACE) inhibitors are extensively prescribed to treat patients with hypertension, congestive heart failure, and diabetic nephropathy. A small fraction of these patients (approximately 0.7%) develop angioedema, manifested by swelling of the lips and oropharynx. Angioedema of oropharynx is a medical emergency that can lead to asphyxiation and death. The angioedema is due to bradykinin generated from high molecular weight kininogen by kallikrein, which is derived from plasma prekallikrein by action of the factor XIIa, factor Xia, or prolylcarboxypeptidase. Bradykinin induces vasodilation and increased vascular permeability. ACE is the major degrading enzyme of bradykinin in the intravascular department. ACE …

Extracellular Mitochondria Released From Traumatized Brains Induced Platelet Procoagulant Activity, Zilong Zhao, Yuan Zhou, Tristan Hilton, Fanjian Li, Cha Han, Li Liu, Hengjie Yuan, Ying Li, Xin Xu, Xiaoping Wu, Fangyi Zhang, Perumal Thiagarajan, Andrew Cap, Fu-Dong Shi, Jianning Zhang, Jing-Fei Dong

Faculty, Staff and Students Publications

Coagulopathy often develops soon after acute traumatic brain injury and its cause remains poorly understood. We have shown that injured brains release cellular microvesicles that disrupt the endothelial barrier and induce consumptive coagulopathy. Morphologically intact extracellular mitochondria accounted for 55.2% of these microvesicles, leading to the hypothesis that these extracellular mitochondria are metabolically active and serve as a source of oxidative stress that activates platelets and renders them procoagulant. In testing this hypothesis experimentally, we found that the extracellular mitochondria purified from brain trauma mice and those released from brains subjected to freeze-thaw injury remained metabolically active and produced reactive …

Reduced Bacterial Burden Of The Skin Surrounding The Shoulder Joint Following Topical Protocatechuic Acid Application: Results Of A Pilot Study, Omid Jalali, Molly Best, Alison Wong, Brett Schaeffer, Brendon Bauer, Lanny Johnson

Faculty, Staff and Students Publications

BACKGROUND: Reducing the rising health-care burden associated with shoulder surgical site infection (SSI) is of paramount importance. The purpose of this study was to investigate the antimicrobial efficacy of protocatechuic acid (PCA) as a topical reagent for surgical skin antisepsis surrounding the shoulder joint.

METHODS: This was a 2-phase skin-disinfection trial involving the human shoulder. The shoulders of healthy volunteers were randomized to topical treatment with PCA (a 10% concentration of PCA in Phase I [11 subjects] and a 17% concentration in Phase II [12 subjects]), with a control of isopropyl alcohol (IPA) applied to the contralateral shoulder. Mechanical scraping …

Pregnancy And Lactation In A 67-Year-Old Elderly Gravida Following Donor Oocyte, Leila Magistrado, Mary C Tolcher, Anju Suhag, Sonal Zambare, Kjersti M Aagaard

Faculty, Staff and Students Publications

There is limited data on the anticipated perinatal course among gravidae in their sixth and seventh decades. Our objective was to describe the relatively uncomplicated prenatal, intrapartum, and postpartum course of a 67-year-old essential primigravida. Briefly, our patient conceived a singleton pregnancy via IVF with donor oocytes, then presented at 13 6/7 weeks of gestation to initiate prenatal care. Her medical history was significant for chronic hypertension, hyperlipidemia, and obesity. Her cardiac function was monitored throughout pregnancy, and she delivered at 36 1/7 weeks by cesarean for a decline in left ventricular function with mitral regurgitation. Her intrapartum and postpartum …

Perioperative Acute Kidney Injury, Sam D Gumbert, Felix Kork, Maisie L Jackson, Naveen Vanga, Semhar J Ghebremichael, Christy Y Wang, Holger K Eltzschig

Faculty, Staff and Students Publications

Perioperative organ injury is among the leading causes of morbidity and mortality of surgical patients. Among different types of perioperative organ injury, acute kidney injury occurs particularly frequently and has an exceptionally detrimental effect on surgical outcomes. Currently, acute kidney injury is most commonly diagnosed by assessing increases in serum creatinine concentration or decreased urine output. Recently, novel biomarkers have become a focus of translational research for improving timely detection and prognosis for acute kidney injury. However, specificity and timing of biomarker release continue to present challenges to their integration into existing diagnostic regimens. Despite many clinical trials using various …

Metaproteomic Analysis Of Human Gut Microbiome In Digestive And Metabolic Diseases, Sheng Pan, Ru Chen

Faculty, Staff and Students Publications

Metaproteomics, as a subfield of proteomics, has quickly emerged as a pivotal tool for global characterization of a microbiome system at a functional level. It has been increasingly applied in studying human digestive and metabolic diseases, and provides information-rich data to identify the dysbiosis of human gut microbiome related to healthy or disease states to elucidate the molecular events underlying host-microbiota interplays. While significant technical challenges still exist, this emerging technology has been demonstrated to provide essential information in interrogating functional changes in the human gut microbiome, complementary to metagenomics and metatranscriptomics. This chapter overviews the overall metaproteomic work flow …

Spironolactone In Pulmonary Arterial Hypertension: Results Of A Cross-Over Study, Zeenat Safdar, Adaani Frost, Arya Basant, Anita Deswal, E O'Brian Smith, Mark Entman

Faculty, Staff and Students Publications

The renin–angiotensin–aldosterone system is implicated in the pathophysiology of pulmonary arterial hypertension. We undertook this study to determine the effects of spironolactone, a mineralocorticoid receptor blocker, on collagen metabolism in pulmonary arterial hypertension patients. After obtaining institutional review board approval and informed consent, 42 pulmonary arterial hypertension patients were prospectively enrolled and 35 patients completed the 16-week randomized double-blinded crossover clinical trial. Subjects received 50 mg spironolactone or placebo and at the end of week 8, treatment arm was switched. Circulating levels of collagen biomarkers, brain natriuretic peptide, and aldosterone levels were measured, and six-minute walk distance, liver function tests, …

Meta-Analysis Comparing Watchmantm And Amplatzer Devices For Stroke Prevention In Atrial Fibrillation, Indranill Basu Ray, Dibbendhu Khanra, Sumit Shah, Sudhanva Char, Xiaoming Jia, Wilson Lam, Nilesh Mathuria, Mehdi Razavi, Bhavna Jain, Dhanunjaya Lakkireddy, Saibal Kar, Andrea Natale, Adedayo Adeboye, John Lynn Jefferies, Sripal Bangalore, Samuel Asirvatham, Mohammad Saeed

Faculty, Staff and Students Publications

Background: For patients with atrial fibrillation who are at high risk for bleeding or who cannot tolerate oral anticoagulation, left atrial appendage (LAA) closure represents an alternative therapy for reducing risk for thromboembolic events.

Objectives: To compare the efficacy and safety of the Amplatzer and Watchman^TM LAA closure devices.

Methods: A meta-analysis was performed of studies comparing the safety and efficacy outcomes of the two devices. The Newcastle-Ottawa Scale was used to appraise study quality.

Results: Six studies encompassing 614 patients were included in the meta-analysis. Overall event rates were low for both devices. No significant differences between the …

Large Sinus Of Valsalva Aneurysm Complicated By Thrombus Formation, Milan Ravishankar, Ali Ghergherehchi, Jing Liu, Ernesto Jimenez, Umair Khalid

Faculty, Staff and Students Publications

Sinus of Valsalva aneurysm (SOVA) is an unusual cardiac anomaly that is potentially fatal with rupture. It is often asymptomatic but has various presentations. We describe a case of a 67-year-old male who presented with atypical chest pain. Transthoracic echocardiogram and cardiac computed tomography scan confirmed a large SOVA complicated by thrombus formation and compression of the left atrium and left ventricular outflow tract. The patient successfully underwent a Bentall procedure-surgical aortic aneurysm repair with mechanical aortic valve conduit. We discuss several clinical decision-making branch points to highlight the complexity of managing this condition. Even in asymptomatic or minimally symptomatic …

Hypogonadism, Type-2 Diabetes Mellitus, And Bone Health: A Narrative Review, Vittoria Russo, Rui Chen, Reina Armamento-Villareal

Faculty, Staff and Students Publications

One of the complications from chronic hyperglycemia and insulin resistance due to type 2 diabetes mellitus (T2DM) on the hypothalamic-pituitary-gonadal axis in men is the high prevalence of hypogonadotropic hypogonadism (HH). Both T2DM and hypogonadism are associated with impaired bone health and increased fracture risk but whether the combination results in even worse bone disease than either one alone is not well-studied. It is possible that having both conditions predisposes men to an even greater risk for fracture than either one alone. Given the common occurrence of HH or hypogonadism in general in T2DM, a significant number of men could …

Development Of A Hybrid, Interprofessional, Interactive Quality Improvement Curriculum As A Model For Continuing Professional Development, Isabelle S Kusters, Megan E Gregory, Jennifer L Bryan, Sylvia J Hysong, Lechauncy D Woodard, Aanand D Naik, Kyler M Godwin

Faculty, Staff and Students Publications

Over the past 20 years, there has been an increased focus on quality improvement (QI) in health care, which is critical in achieving care that is patient-centered, safer, timelier, and more effective, efficient, and equitable. At the center of this movement is QI education, which is known to lead to learning, behavior change, and improved outcomes. However, there is a need for the development and provision of long-duration, interactive, interprofessional training in QI, to allow for in-depth learning and application of learned skills. To this end, we designed a curriculum for an established interprofessional, interactive, web-based QI fellowship for doctorally …

Sirt3 Promotes Lipophagy And Chaperon-Mediated Autophagy To Protect Hepatocytes Against Lipotoxicity, Tian Zhang, Jingxin Liu, Shengnan Shen, Qiang Tong, Xiaojun Ma, Ligen Lin

Faculty, Staff and Students Publications

Lipophagy is a lysosomal lipolytic pathway that complements the actions of cytosolic neutral lipases. Chaperon-mediated autophagy (CMA) triggers lipid droplets (LDs) breakdown, to initiate lipolysis via either cytosolic lipases or macroautophagy. SIRT3, a mitochondrial NAD+-dependent deacetylase, regulates the acetylation status and activity of many substrates involving in energy metabolism. However, the role of SIRT3 in regulating lipophagy is controversial. The current study showed that SIRT3 expression was decreased and the macroautophagy flux was blocked in the primary hepatocytes from high-fat diet fed mice and P/O (palmitic acid and oleic acid mixture) treated AML12 mouse hepatocytes, compared with the corresponding controls. …

Effectiveness Of A 24/7 Dad® Curriculum In Improving Father Involvement: Profiles Of Engagement, Roneé E Wilson, Renice Obure, Precious Omokaro, Hamisu M Salihu, Estrellita Lo Berry, Deborah A Austin, Jennifer G Christner

Faculty, Staff and Students Publications

BACKGROUND OR OBJECTIVES: Father involvement is a key component in maintaining healthy families and communities. This study presents quantitative results of the first five years of a comprehensive fatherhood training program offered by REACHUP, Inc. in Florida, United States.

METHODS: The program utilized the 24/7 Dad ® curriculum for the fatherhood training program. Key program outcome was differences in pre and post-test scores on self-awareness, fathering skills, parenting skills, relationship skills, and self-care. Demographic and pretest-posttest data collected between 2013 and 2017 were analyzed using chi-square test for categorical variables, McNemar's test for differences in proportions pre- and post-intervention, paired …

Single-Nuclei Rna-Seq On Human Retinal Tissue Provides Improved Transcriptome Profiling, Qingnan Liang, Rachayata Dharmat, Leah Owen, Akbar Shakoor, Yumei Li, Sangbae Kim, Albert Vitale, Ivana Kim, Denise Morgan, Shaoheng Liang, Nathaniel Wu, Ken Chen, Margaret M Deangelis, Rui Chen

Faculty, Staff and Students Publications

Single-cell RNA-seq is a powerful tool in decoding the heterogeneity in complex tissues by generating transcriptomic profiles of the individual cell. Here, we report a single-nuclei RNA-seq (snRNA-seq) transcriptomic study on human retinal tissue, which is composed of multiple cell types with distinct functions. Six samples from three healthy donors are profiled and high-quality RNA-seq data is obtained for 5873 single nuclei. All major retinal cell types are observed and marker genes for each cell type are identified. The gene expression of the macular and peripheral retina is compared to each other at cell-type level. Furthermore, our dataset shows an …

Electrochemical Hydrogen Evolution Over Hydrothermally Synthesized Re-Doped Mos2 Flower-Like Microspheres, Juan Aliaga, Pablo Vera, Juan Araya, Luis Ballesteros, Julio Urzúa, Mario Farías, Francisco Paraguay-Delgado, Gabriel Alonso-Núñez, Guillermo González, Eglantina Benavente

Faculty, Staff and Students Publications

In this research, we report a simple hydrothermal synthesis to prepare rhenium (Re)- doped MoS2 flower-like microspheres and the tuning of their structural, electronic, and electrocatalytic properties by modulating the insertion of Re. The obtained compounds were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). Structural, morphological, and chemical analyses confirmed the synthesis of poorly crystalline Re-doped MoS2 flower-like microspheres composed of few stacked layers. They exhibit enhanced hydrogen evolution reaction (HER) performance with low overpotential of 210 mV at current density of 10 mA/cm2, with a …

Examining Multiple Cellular Pathways At Once 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

Sensitive simultaneous assessment of multiple signaling pathways within the same cells requires orthogonal reporters that can assay over large dynamic ranges. Luciferases are such genetically encoded candidates due to their sensitivity, versatility, and cost-effectiveness. We expand luciferase multiplexing in post-lysis endpoint luciferase assays from two to six. Light emissions are distinguished by a combination of distinct substrates and emission spectra deconvolution. All six luciferase reporter units are stitched together into one plasmid facilitating delivery of all reporter units through a process we termed solotransfection, minimizing experimental errors. We engineer a multiplex hextuple luciferase assay to probe pathway fluxes through five …

Residues And Residue Pairs Of Evolutionary Importance Differentially Direct Signaling Bias Of D2 Dopamine Receptors, María E Terrón-Díaz, Sara J Wright, Melina A Agosto, Olivier Lichtarge, Theodore G Wensel

Faculty, Staff and Students Publications

The D2 dopamine receptor and the serotonin 5-hydroxytryptamine 2A receptor (5-HT2A) are closely-related G-protein–coupled receptors (GPCRs) from the class A bioamine subfamily. Despite structural similarity, they respond to distinct ligands through distinct downstream pathways, whose dysregulation is linked to depression, bipolar disorder, addiction, and psychosis. They are important drug targets, and it is important to understand how their bias toward G-protein versus β-arrestin signaling pathways is regulated. Previously, evolution-based computational approaches, difference Evolutionary Trace and Evolutionary Trace–Mutual information (ET-Mip), revealed residues and residue pairs that, when switched in the D2 receptor to the corresponding residues from 5-HT2A, altered ligand potency …

Ultrafast Two-Photon Imaging Of A High-Gain Voltage Indicator In Awake Behaving Mice, Vincent Villette, Mariya Chavarha, Ivan K Dimov, Jonathan Bradley, Lagnajeet Pradhan, Benjamin Mathieu, Stephen W Evans, Simon Chamberland, Dongqing Shi, Renzhi Yang, Benjamin B Kim, Annick Ayon, Abdelali Jalil, François St-Pierre, Mark J Schnitzer, Guoqiang Bi, Katalin Toth, Jun Ding, Stéphane Dieudonné, Michael Z Lin

Faculty, Staff and Students Publications

Optical interrogation of voltage in deep brain locations with cellular resolution would be immensely useful for understanding how neuronal circuits process information. Here, we report ASAP3, a genetically encoded voltage indicator with 51% fluorescence modulation by physiological voltages, submillisecond activation kinetics, and full responsivity under two-photon excitation. We also introduce an ultrafast local volume excitation (ULoVE) method for kilohertz-rate two-photon sampling in vivo with increased stability and sensitivity. Combining a soma-targeted ASAP3 variant and ULoVE, we show single-trial tracking of spikes and subthreshold events for minutes in deep locations, with subcellular resolution and with repeated sampling over days. In the …