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Gain-Of-Signal Assays For Probing Inhibition Of Sars-Cov-2 Mpro/3clpro In Living Cells, Seyed Arad Moghadasi, Morgan A Esler, Yuka Otsuka, Jordan T Becker, Sofia N Moraes, Constance B Anderson, Srinivas Chamakuri, Christopher Belica, Chloe Wick, Daniel A Harki, Damian W Young, Louis Scampavia, Timothy P Spicer, Ke Shi, Hideki Aihara, William L Brown, Reuben S Harris

Faculty, Staff and Students Publications

The main protease, Mpro, of SARS-CoV-2 is required to cleave the viral polyprotein into precise functional units for virus replication and pathogenesis. Here, we report quantitative reporters for Mpro function in living cells in which protease inhibition by genetic or chemical methods results in robust signal readouts by fluorescence (enhanced green fluorescent protein [eGFP]) or bioluminescence (firefly luciferase). These gain-of-signal systems are scalable to high-throughput platforms for quantitative discrimination between Mpro mutants and/or inhibitor potencies as evidenced by validation of several reported inhibitors. Additional utility is shown by single Mpro amino acid variants and structural information combining to demonstrate that …

Retinal Organoids Derived From Rhesus Macaque Ipscs Undergo Accelerated Differentiation Compared To Human Stem Cells, Antonio Jacobo Lopez, Sangbae Kim, Xinye Qian, Jeffrey Rogers, J Timothy Stout, Sara M Thomasy, Anna La Torre, Rui Chen, Ala Moshiri

Faculty, Staff and Students Publications

PURPOSE: To compare the timing and efficiency of the development of Macaca mulatta, a nonhuman primate (NHP), induced pluripotent stem cell (rhiPSC) derived retinal organoids to those derived from human embryonic stem cells (hESCs).

RESULTS: Generation of retinal organoids was achieved from both human and several NHP pluripotent stem cell lines. All rhiPSC lines resulted in retinal differentiation with the formation of optic vesicle-like structures similar to what has been observed in hESC retinal organoids. NHP retinal organoids had laminated structure and were composed of mature retinal cell types including cone and rod photoreceptors. Single-cell RNA sequencing was conducted at …

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

Faculty, Staff and Students Publications

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

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

Structure, Function And Inhibition Of Critical Protein-Protein Interactions Involving Mixed Lineage Leukemia 1 And Its Fusion Oncoproteins, Xin Li, Yongcheng Song

Faculty, Staff and Students Publications

Mixed lineage leukemia 1 (MLL1, also known as MLL or KMT2A) is an important transcription factor and histone-H3 lysine-4 (H3K4) methyltransferase. It is a master regulator for transcription of important genes (e.g., Hox genes) for embryonic development and hematopoiesis. However, it is largely dispensable in matured cells. Dysregulation of MLL1 leads to overexpression of certain Hox genes and eventually leukemia initiation. Chromosome translocations involving MLL1 cause ~ 75% of acute leukemia in infants and 5-10% in children and adults with a poor prognosis. Targeted therapeutics against oncogenic fusion MLL1 (onco-MLL1) are therefore needed. Onco-MLL1 consists of the N-terminal DNA-interacting domains …

Discovery And Characterization Of Bromodomain 2-Specific Inhibitors Of Brdt, Zhifeng Yu, Angela F Ku, Justin L Anglin, Rajesh Sharma, Melek Nihan Ucisik, John C Faver, Feng Li, Pranavanand Nyshadham, Nicholas Simmons, Kiran L Sharma, Sureshbabu Nagarajan, Kevin Riehle, Gundeep Kaur, Banumathi Sankaran, Marta Storl-Desmond, Stephen S Palmer, Damian W Young, Choel Kim, Martin M Matzuk

Faculty, Staff and Students Publications

Bromodomain testis (BRDT), a member of the bromodomain and extraterminal (BET) subfamily that includes the cancer targets BRD2, BRD3, and BRD4, is a validated contraceptive target. All BET subfamily members have two tandem bromodomains (BD1 and BD2). Knockout mice lacking BRDT-BD1 or both bromodomains are infertile. Treatment of mice with JQ1, a BET BD1/BD2 nonselective inhibitor with the highest affinity for BRD4, disrupts spermatogenesis and reduces sperm number and motility. To assess the contribution of each BRDT bromodomain, we screened our collection of DNA-encoded chemical libraries for BRDT-BD1 and BRDT-BD2 binders. High-enrichment hits were identified and resynthesized off-DNA and examined …

Inhibition Of Camkk2 Impairs Autophagy And Castration-Resistant Prostate Cancer Via Suppression Of Ampk-Ulk1 Signaling, Chenchu Lin, Alicia M Blessing, Thomas L Pulliam, Yan Shi, Sandi R Wilkenfeld, Jenny J Han, Mollianne M Murray, Alexander H Pham, Kevin Duong, Sonja N Brun, Reuben J Shaw, Michael M Ittmann, Daniel E Frigo

Faculty, Staff and Students Publications

Previous work has suggested androgen receptor (AR) signaling mediates prostate cancer progression in part through the modulation of autophagy. However, clinical trials testing autophagy inhibition using chloroquine derivatives in men with castration-resistant prostate cancer (CRPC) have yet to yield promising results, potentially due to the side effects of this class of compounds. We hypothesized that identification of the upstream activators of autophagy in prostate cancer could highlight alternative, context-dependent targets for blocking this important cellular process during disease progression. Here, we used molecular, genetic and pharmacological approaches to elucidate an AR-mediated autophagy cascade involving Ca2+/calmodulin-dependent protein kinase kinase 2 (CAMKK2; …

Tools For Visualizing And Analyzing Fourier Space Sampling In Cryo-Em, Philip R Baldwin, Dmitry Lyumkis

Faculty, Staff and Students Publications

A complete understanding of how an orientation distribution contributes to a cryo-EM reconstruction remains lacking. It is necessary to begin critically assessing the set of views to gain an understanding of its effect on experimental reconstructions. Toward that end, we recently suggested that the type of orientation distribution may alter resolution measures in a systematic manner. We introduced the sampling compensation factor (SCF), which incorporates how the collection geometry might change the spectral signal-to-noise ratio (SSNR), irrespective of the other experimental aspects. We show here that knowledge of the sampling restricted to spherical surfaces of sufficiently large radii in Fourier …

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. …

Small-Molecule Inhibitor Of Af9/Enl-Dot1l/Af4/Aff4 Interactions Suppresses Malignant Gene Expression And Tumor Grow, Fangrui Wu, Shenyou Nie, Yuan Yao, Tong Huo, Xin Li, Xiaowei Wu, Jidong Zhao, Yi-Lun Lin, Yinjie Zhang, Qianxing Mo, Yongcheng Song

Faculty, Staff and Students Publications

Chromosome translocations involving mixed lineage leukemia (MLL) gene cause acute leukemia with a poor prognosis. MLL is frequently fused with transcription cofactors AF4 (~35%), AF9 (25%) or its paralog ENL (10%). The AHD domain of AF9/ENL binds to AF4, its paralog AFF4, or histone-H3 lysine-79 (H3K79) methyltransferase DOT1L. Formation of AF9/ENL/AF4/AFF4-containing super elongation complexes (SEC) and the catalytic activity of DOT1L are essential for MLL-rearranged leukemia. Protein-protein interactions (PPI) between AF9/ENL and DOT1L/AF4/AFF4 are therefore a potential drug target.

Methods: Compound screening followed by medicinal chemistry was used to find inhibitors of such PPIs, which were examined for their biological …

Ampk Regulation Of Raptor And Tsc2 Mediate Metformin Effects On Transcriptional Control Of Anabolism And Inflammation, Jeanine L Van Nostrand, Kristina Hellberg, En-Ching Luo, Eric L Van Nostrand, Alina Dayn, Jingting Yu, Maxim N Shokhirev, Yelena Dayn, Gene W Yeo, Reuben J Shaw

Faculty, Staff and Students Publications

Despite being the frontline therapy for type 2 diabetes, the mechanisms of action of the biguanide drug metformin are still being discovered. In particular, the detailed molecular interplays between the AMPK and the mTORC1 pathway in the hepatic benefits of metformin are still ill defined. Metformin-dependent activation of AMPK classically inhibits mTORC1 via TSC/RHEB, but several lines of evidence suggest additional mechanisms at play in metformin inhibition of mTORC1. Here we investigated the role of direct AMPK-mediated serine phosphorylation of RAPTOR in a new

Metabolism Of Jq1, An Inhibitor Of Bromodomain And Extra Terminal Bromodomain Proteins, In Human And Mouse Liver Microsomes†, Feng Li, Kevin R Mackenzie, Prashi Jain, Conrad Santini, Damian W Young, Martin M Matzuk

Faculty, Staff and Students Publications

JQ1 is a small-molecule inhibitor of the bromodomain and extra terminal (BET) protein family that potently inhibits the bromodomain testis-specific protein (BRDT), which is essential for spermatogenesis. JQ1 treatment produces a reversible contraceptive effect by targeting the activity of BRDT in mouse male germ cells, validating BRDT as a male contraceptive target. Although JQ1 possesses favourable physical properties, it exhibits a short half-life. Because the details of xenobiotic metabolism play important roles in the optimization of drug candidates and in determining the role of metabolism in drug efficacy, we investigated the metabolism of JQ1 in human and mouse liver microsomes. …

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 …

Metabolic Dysregulation In The Atp7b-/- Wilson's Disease Mouse Model, Clavia Ruth Wooton-Kee, Matthew Robertson, Ying Zhou, Bingning Dong, Zhen Sun, Kang Ho Kim, Hailan Liu, Yong Xu, Nagireddy Putluri, Pradip Saha, Cristian Coarfa, David D Moore, Alli M Nuotio-Antar

Faculty, Staff and Students Publications

Inactivating mutations in the copper transporter Atp7b result in Wilson’s disease. The Atp7b−/− mouse develops hallmarks of Wilson’s disease. The activity of several nuclear receptors decreased in Atp7b−/− mice, and nuclear receptors are critical for maintaining metabolic homeostasis. Therefore, we anticipated that Atp7b−/− mice would exhibit altered progression of diet-induced obesity, fatty liver, and insulin resistance. Following 10 wk on a chow or Western-type diet (40% kcal fat), parameters of glucose and lipid homeostasis were measured. Hepatic metabolites were measured by liquid chromatography–mass spectrometry and correlated with transcriptomic data. Atp7b−/− mice fed a chow diet presented …

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 …

Genome Engineering: Drosophila Melanogaster And Beyond, Kjt Venken, A Sarrion-Perdigones, Pj Vandeventer, Ns Abel, Ae Christiansen, Kl Hoffman

Faculty, Staff and Students Publications

A central challenge in investigating biological phenomena is the development of techniques to modify genomic DNA with nucleotide precision that can be transmitted through the germ line. Recent years have brought a boon in these technologies, now collectively known as genome engineering. Defined genomic manipulations at the nucleotide level enable a variety of reverse engineering paradigms, providing new opportunities to interrogate diverse biological functions. These genetic modifications include controlled removal, insertion, and substitution of genetic fragments, both small and large. Small fragments up to a few kilobases (e.g., single nucleotide mutations, small deletions, or gene tagging at single or multiple …