Digital Commons Network^™

Intratumoral Biosynthesis Of Gold Nanoclusters By Pancreatic Cancer To Overcome Delivery Barriers To Radiosensitization, Aaron S Schwartz-Duval, Yuri Mackeyev, Iqbal Mahmud, Philip L Lorenzi, Mihai Gagea, Sunil Krishnan, Konstantin V Sokolov

Faculty, Staff and Student Publications

Nanoparticle delivery to solid tumors is a prime challenge in nanomedicine. Here, we approach this challenge through the lens of biogeochemistry, the field that studies the flow of chemical elements within ecosystems as manipulated by living cellular organisms and their environments. We leverage biogeochemistry concepts related to gold cycling against pancreatic cancer, considering mammalian organisms as drivers for gold nanoparticle biosynthesis. Sequestration of gold nanoparticles within tumors has been demonstrated as an effective strategy to enhance radiotherapy; however, the desmoplasia of pancreatic cancer impedes nanoparticle delivery. Our strategy overcomes this barrier by applying an atomic-scale agent, ionic gold, for intratumoral …

Non-Canonical Hedgehog Signaling Mediates Profibrotic Hematopoiesis-Stroma Crosstalk In Myeloproliferative Neoplasms, Jessica E Pritchard, Juliette E Pearce, Inge A M Snoeren, Stijn N R Fuchs, Katrin Götz, Fabian Peisker, Silke Wagner, Adam Benabid, Niklas Lutterbach, Vanessa Klöker, James S Nagai, Monica T Hannani, Anna K Galyga, Ellen Sistemich, Bella Banjanin, Niclas Flosdorf, Eric Bindels, Kathrin Olschok, Katharina Biaesch, Nicolas Chatain, Neha Bhagwat, Andrew Dunbar, Rita Sarkis, Olaia Naveiras, Marie-Luise Berres, Steffen Koschmieder, Ross L Levine, Ivan G Costa, Hélène F E Gleitz, Rafael Kramann, Rebekka K Schneider

Faculty, Staff and Student Publications

The role of hematopoietic Hedgehog signaling in myeloproliferative neoplasms (MPNs) remains incompletely understood despite data suggesting that Hedgehog (Hh) pathway inhibitors have therapeutic activity in patients. We aim to systematically interrogate the role of canonical vs. non-canonical Hh signaling in MPNs. We show that Gli1 protein levels in patient peripheral blood mononuclear cells (PBMCs) mark fibrotic progression and that, in murine MPN models, absence of hematopoietic Gli1, but not Gli2 or Smo, significantly reduces MPN phenotype and fibrosis, indicating that GLI1 in the MPN clone can be activated in a non-canonical fashion. Additionally, we establish that hematopoietic Gli1 has a …

Intratumoral Biosynthesis Of Gold Nanoclusters By Pancreatic Cancer To Overcome Delivery Barriers To Radiosensitization, Aaron S Schwartz-Duval, Yuri Mackeyev, Iqbal Mahmud, Philip L Lorenzi, Mihai Gagea, Sunil Krishnan, Konstantin V Sokolov

Faculty, Staff and Student Publications

Nanoparticle delivery to solid tumors is a prime challenge in nanomedicine. Here, we approach this challenge through the lens of biogeochemistry, the field that studies the flow of chemical elements within ecosystems as manipulated by living cellular organisms and their environments. We leverage biogeochemistry concepts related to gold cycling against pancreatic cancer, considering mammalian organisms as drivers for gold nanoparticle biosynthesis. Sequestration of gold nanoparticles within tumors has been demonstrated as an effective strategy to enhance radiotherapy; however, the desmoplasia of pancreatic cancer impedes nanoparticle delivery. Our strategy overcomes this barrier by applying an atomic-scale agent, ionic gold, for intratumoral …

Trex2 Deficiency Suppresses Spontaneous And Genotoxin-Associated Mutagenesis, Teresa Marple, Mi Young Son, Xiaodong Cheng, Jun Ho Ko, Patrick Sung, Paul Hasty

Faculty, Staff and Student Publications

TREX2, a 3'-5' exonuclease, is a part of the DNA damage tolerance (DDT) pathway that stabilizes replication forks (RFs) by ubiquitinating PCNA along with the ubiquitin E3 ligase RAD18 and other DDT factors. Mismatch repair (MMR) corrects DNA polymerase errors, including base mismatches and slippage. Here we demonstrate that TREX2 deletion reduces mutations in cells upon exposure to genotoxins, including those that cause base lesions and DNA polymerase slippage. Importantly, we show that TREX2 generates most of the spontaneous mutations in MMR-mutant cells derived from mice and people. TREX2-induced mutagenesis is dependent on the nuclease and DNA-binding attributes of TREX2. …

Neuronal Deletion Of The Circadian Clock Gene Bmal1 Induces Cell-Autonomous Dopaminergic Neurodegeneration, Michael K. Kanan, Patrick W. Sheehan, Jessica N. Haines, Pedro G. Gomez, Adya Dhuler, Collin J. Nadarajah, Zachary M. Wargel, Brittany M. Freeberg, Hemanth R. Nelvagal, Mariko Izumo, Joseph S. Takahashi, Jonathan D. Cooper, Albert A. Davis, Erik S. Musiek

2020-Current year OA Pubs

Circadian rhythm dysfunction is a hallmark of Parkinson disease (PD), and diminished expression of the core clock gene Bmal1 has been described in patients with PD. BMAL1 is required for core circadian clock function but also serves nonrhythmic functions. Germline Bmal1 deletion can cause brain oxidative stress and synapse loss in mice, and it can exacerbate dopaminergic neurodegeneration in response to the toxin MPTP. Here we examined the effect of cell type-specific Bmal1 deletion on dopaminergic neuron viability in vivo. We observed that global, postnatal deletion of Bmal1 caused spontaneous loss of tyrosine hydroxylase+ (TH+) dopaminergic neurons in the substantia …

An Orally Available Compound Suppresses Glucagon Hypersecretion And Normalizes Hyperglycemia In Type 1 Diabetes, Farzad Asadi, Subhadra C. Gunawardana, Roland E. Dolle, David W. Piston

2020-Current year OA Pubs

Suppression of glucagon hypersecretion can normalize hyperglycemia during type 1 diabetes (T1D). Activating erythropoietin-producing human hepatocellular receptor type-A4 (EphA4) on α cells reduced glucagon hypersecretion from dispersed α cells and T1D islets from both human donor and mouse models. We synthesized a high-affinity small molecule agonist for the EphA4 receptor, WCDD301, which showed robust plasma and liver microsome metabolic stability in both mouse and human preparations. In islets and dispersed islet cells from nondiabetic and T1D human donors, WCDD301 reduced glucagon secretion comparable to the natural EphA4 ligand, Ephrin-A5. In diabetic NOD and streptozotocin-treated mice, once-daily oral administration of WCDD301 …

A New Perspective On Intervertebral Disc Calcification-From Bench To Bedside, Emanuel Novais, Rajkishen Narayanan, Jose Canseco, Koen Van De Wetering, Christopher Kepler, Alan Hilibrand, Alex Vaccaro, Makarand Risbud

Department of Orthopaedic Surgery Faculty Papers

Disc degeneration primarily contributes to chronic low back and neck pain. Consequently, there is an urgent need to understand the spectrum of disc degeneration phenotypes such as fibrosis, ectopic calcification, herniation, or mixed phenotypes. Amongst these phenotypes, disc calcification is the least studied. Ectopic calcification, by definition, is the pathological mineralization of soft tissues, widely studied in the context of conditions that afflict vasculature, skin, and cartilage. Clinically, disc calcification is associated with poor surgical outcomes and back pain refractory to conservative treatment. It is frequently seen as a consequence of disc aging and progressive degeneration but exhibits unique molecular …

Microglia-Derived Exosomes Modulate Myelin Regeneration Via Mir-615-5p/Myrf Axis, Xiao-Yu Ji, Yu-Xin Guo, Li-Bin Wang, Wen-Cheng Wu, Jia-Qi Wang, Jin He, Rui Gao, Javad Rasouli, Meng-Yuan Gao, Zhen-Hai Wang, Dan Xiao, Wei-Feng Zhang, Bogoljub Ciric, Yuan Zhang, Xing Li

Department of Neurology Faculty Papers

Demyelination and failure of remyelination in the central nervous system (CNS) characterize a number of neurological disorders. Spontaneous remyelination in demyelinating diseases is limited, as oligodendrocyte precursor cells (OPCs), which are often present in demyelinated lesions in abundance, mostly fail to differentiate into oligodendrocytes, the myelinating cells in the CNS. In addition to OPCs, the lesions are assembled numbers of activated resident microglia/infiltrated macrophages; however, the mechanisms and potential role of interactions between the microglia/macrophages and OPCs are poorly understood. Here, we generated a transcriptional profile of exosomes from activated microglia, and found that miR-615-5p was elevated. miR-615-5p bound to …

Dietary Folate And Cofactors Accelerate Age-Dependent P16 Epimutation To Promote Intestinal Tumorigenesis, Li Yang, Robert C Peery, Leah M Farmer, Xia Gao, Yiqun Zhang, Chad J Creighton, Lanjing Zhang, Lanlan Shen

Faculty, Staff and Students Publications

The extent to which non-genetic environmental factors, such as diet, contribute to carcinogenesis has been long debated. One potential mechanism for the effects of environmental factors is through epigenetic modifications that affect gene expression without changing the underlying DNA sequence. However, the functional cooperation between dietary factors and cancer-causing epigenetic regulation is largely unknown. Here, we use a mouse model of age-dependent p16 epimutation, in which the p16 gene activity is directly controlled by promoter DNA methylation. We show p16 epimutation is modulated by folate and cofactors in dietary supplementation, which leads to increased colon cancer risk. Importantly, our findings …

Cdk4/6 Inhibition Sensitizes Intracranial Tumors To Pd-1 Blockade In Preclinical Models Of Brain Metastasis, Naema Nayyar, Magali A De Sauvage, Jane Chuprin, Emily M Sullivan, Mohini Singh, Consuelo Torrini, Britney S Zhang, Sushobhana Bandyopadhyay, Keith A Daniels, Christopher Alvarez-Breckenridge, Ashish Dahal, Michael A Brehm, Priscilla K Brastianos

Faculty, Staff and Student Publications

PURPOSE: Brain metastases are associated with high morbidity and are often resistant to immune checkpoint inhibitors. We evaluated whether CDK4/6 inhibitor (CDKi) abemaciclib can sensitize intracranial tumors to programmed cell death protein 1 (PD-1) inhibition in mouse models of melanoma and breast cancer brain metastasis.

EXPERIMENTAL DESIGN: Treatment response was evaluated in vivo using immunocompetent mouse models of brain metastasis bearing concurrent intracranial and extracranial tumors. Treatment effect on intracranial and extracranial tumor-immune microenvironments (TIME) was evaluated using immunofluorescence, multiplex immunoassays, high-parameter flow cytometry, and T-cell receptor profiling. Mice with humanized immune systems were evaluated using flow cytometry to study …

The Respiratory Enzyme Complex Rnf Is Vital For Metabolic Adaptation And Virulence In Fusobacterium Nucleatum, Timmie A Britton, Chenggang Wu, Yi-Wei Chen, Dana Franklin, Yimin Chen, Martha I Camacho, Truc T Luong, Asis Das, Hung Ton-That

Faculty, Staff and Student Publications

The Gram-negative oral pathobiont Fusobacterium nucleatum can traverse to extra-oral sites such as placenta and colon, promoting adverse pregnancy outcomes and colorectal cancer, respectively. How this anaerobe sustains many metabolically changing environments enabling its virulence potential remains unclear. Informed by our genome-wide transposon mutagenesis, we report here that the highly conserved Rhodobacter nitrogen-fixation (Rnf) complex, encoded by the rnfCDGEAB gene cluster, is key to fusobacterial metabolic adaptation and virulence. Genetic disruption of the Rnf complex via non-polar, in-frame deletion of rnfC (ΔrnfC) abrogates polymicrobial interaction (or coaggregation) associated with adhesin RadD and biofilm formation. The defect in coaggregation …

In-Patient Evolution Of A High-Persister Escherichia Coli Strain With Reduced In Vivo Antibiotic Susceptibility, Joshua B Parsons, Ashelyn E Sidders, Amanda Z Velez, Blake M Hanson, Michelle Angeles-Solano, Felicia Ruffin, Sarah E Rowe, Cesar A Arias, Vance G Fowler, Joshua T Thaden, Brian P Conlon

Faculty, Staff and Student Publications

Gram-negative bacterial bloodstream infections (GNB-BSI) are common and frequently lethal. Despite appropriate antibiotic treatment, relapse of GNB-BSI with the same bacterial strain is common and associated with poor clinical outcomes and high healthcare costs. The role of persister cells, which are sub-populations of bacteria that survive for prolonged periods in the presence of bactericidal antibiotics, in relapse of GNB-BSI is unclear. Using a cohort of patients with relapsed GNB-BSI, we aimed to determine how the pathogen evolves within the patient between the initial and subsequent episodes of GNB-BSI and how these changes impact persistence. Using

Novel Pan-Err Agonists Ameliorate Heart Failure Through Enhancing Cardiac Fatty Acid Metabolism And Mitochondrial Function, Weiyi Xu, Cyrielle Billon, Hui Li, Andrea Wilderman, Lei Qi, Andrea Graves, Jernie Rae Dela Cruz Rideb, Yuanbiao Zhao, Matthew Hayes, Keyang Yu, Mckenna Losby, Carissa S Hampton, Christiana M Adeyemi, Seok Jae Hong, Eleni Nasiotis, Chen Fu, Tae Gyu Oh, Weiwei Fan, Michael Downes, Ryan D Welch, Ronald M Evans, Aleksandar Milosavljevic, John K Walker, Brian C Jensen, Liming Pei, Thomas Burris, Lilei Zhang

Faculty, Staff and Students Publications

BACKGROUND: Cardiac metabolic dysfunction is a hallmark of heart failure (HF). Estrogen-related receptors ERRα and ERRγ are essential regulators of cardiac metabolism. Therefore, activation of ERR could be a potential therapeutic intervention for HF. However, in vivo studies demonstrating the potential usefulness of ERR agonist for HF treatment are lacking, because compounds with pharmacokinetics appropriate for in vivo use have not been available.

METHODS: Using a structure-based design approach, we designed and synthesized 2 structurally distinct pan-ERR agonists, SLU-PP-332 and SLU-PP-915. We investigated the effect of ERR agonist on cardiac function in a pressure overload-induced HF model in vivo. We …

Catalytic Isoforms Of Amp-Activated Protein Kinase Differentially Regulate Impdh Activity And Photoreceptor Neuron Function, Tae Jun Lee, Yo Sasaki, Philip A. Ruzycki, Norimitsu Ban, Joseph B. Lin, Hung-Ting Wu, Andrea Santeford, Rajendra S. Apte

2020-Current year OA Pubs

AMP-activated protein kinase (AMPK) plays a crucial role in maintaining ATP homeostasis in photoreceptor neurons. AMPK is a heterotrimeric protein consisting of α, β, and γ subunits. The independent functions of the 2 isoforms of the catalytic α subunit, PRKAA1 and PRKAA2, are uncharacterized in specialized neurons, such as photoreceptors. Here, we demonstrate in mice that rod photoreceptors lacking PRKAA2, but not PRKAA1, showed altered levels of cGMP, GTP, and ATP, suggesting isoform-specific regulation of photoreceptor metabolism. Furthermore, PRKAA2-deficient mice displayed visual functional deficits on electroretinography and photoreceptor outer segment structural abnormalities on transmission electron microscopy consistent with neuronal dysfunction, …

Ephrinb2 Knockdown In Cervical Spinal Cord Preserves Diaphragm Innervation In A Mutant Sod1 Mouse Model Of Als, Mark W. Urban, Brittany A. Charsar, Nicolette M. Heinsinger, Shashirekha S. Markandaiah, Lindsay Sprimont, Wei Zhou, Eric V. Brown, Nathan T. Henderson, Samantha J. Thomas, Biswarup Ghosh, Rachel E. Cain, Davide Trotti, Piera Pasinelli, Megan C. Wright, Matthew B. Dalva, Angelo C. Lepore

Farber Institute for Neuroscience Staff Papers and Presentations

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by motor neuron loss. Importantly, non-neuronal cell types such as astrocytes also play significant roles in disease pathogenesis. However, mechanisms of astrocyte contribution to ALS remain incompletely understood. Astrocyte involvement suggests that transcellular signaling may play a role in disease. We examined contribution of transmembrane signaling molecule ephrinB2 to ALS pathogenesis, in particular its role in driving motor neuron damage by spinal cord astrocytes. In symptomatic SOD1G93A mice (a well-established ALS model), ephrinB2 expression was dramatically increased in ventral horn astrocytes. Reducing ephrinB2 in the cervical spinal cord ventral horn via …

Armc5 Controls The Degradation Of Most Pol Ii Subunits, And Armc5 Mutation Increases Neural Tube Defect Risks In Mice And Humans, Hongyu Luo, Linjiang Lao, Kit Sing Au, Hope Northrup, Xiao He, Diane Forget, Marie-Soleil Gauthier, Benoit Coulombe, Isabelle Bourdeau, Wei Shi, Lucia Gagliardi, Maria Candida Barisson Villares Fragoso, Junzheng Peng, Jiangping Wu

Faculty, Staff and Student Publications

BACKGROUND: Neural tube defects (NTDs) are caused by genetic and environmental factors. ARMC5 is part of a novel ubiquitin ligase specific for POLR2A, the largest subunit of RNA polymerase II (Pol II).

RESULTS: We find that ARMC5 knockout mice have increased incidence of NTDs, such as spina bifida and exencephaly. Surprisingly, the absence of ARMC5 causes the accumulation of not only POLR2A but also most of the other 11 Pol II subunits, indicating that the degradation of the whole Pol II complex is compromised. The enlarged Pol II pool does not lead to generalized Pol II stalling or a generalized …

Rreb1 Regulates Neuronal Proteostasis And The Microtubule Network., Emily N Griffin, Thomas Jucius, Su-Eon Sim, Belinda S. Harris, Sven Heinz, Susan L Ackerman

Faculty Research 2024

Transcription factors play vital roles in neuron development; however, little is known about the role of these proteins in maintaining neuronal homeostasis. Here, we show that the transcription factor RREB1 (Ras-responsive element-binding protein 1) is essential for neuron survival in the mammalian brain. A spontaneous mouse mutation causing loss of a nervous system–enriched Rreb1 transcript is associated with progressive loss of cerebellar Purkinje cells and ataxia. Analysis of chromatin immunoprecipitation and sequencing, along with RNA sequencing data revealed dysregulation of RREB1 targets associated with the microtubule cytoskeleton. In agreement with the known role of microtubules in dendritic development, dendritic complexity …

Fecal Pharmacokinetics And Gut Microbiome Effects Of Oral Omadacycline Versus Vancomycin In Healthy Volunteers, Jinhee Jo, Chenlin Hu, Khurshida Begum, Weiqun Wang, Thanh M Le, Samantha Agyapong, Blake M Hanson, Hossaena Ayele, Chris Lancaster, M Jahangir Alam, Anne J Gonzales-Luna, Kevin W Garey

Faculty, Staff and Student Publications

BACKGROUND: Clostridioides difficile infection (CDI) is a common healthcare-associated infection with limited treatment options. Omadacycline, an aminomethylcycline tetracycline, has potent in vitro activity against C difficile and a low propensity to cause CDI in clinical trials. We aimed to assess fecal pharmacokinetics and gut microbiome effects of oral omadacycline compared to oral vancomycin in healthy adults.

METHODS: This was a phase 1, nonblinded, randomized clinical trial conducted in healthy volunteers aged 18-40 years. Subjects received a 10-day course of omadacycline or vancomycin. Stool samples were collected at baseline, daily during therapy, and at follow-up visits. Omadacycline and vancomycin stool concentrations …

Tfeb Drives Mtorc1 Hyperactivation And Kidney Disease In Tuberous Sclerosis Complex, Nicola Alesi, Damir Khabibullin, Dean M Rosenthal, Elie W Akl, Pieter M Cory, Michel Alchoueiry, Samer Salem, Melissa Daou, William F Gibbons, Jennifer A Chen, Long Zhang, Harilaos Filippakis, Laura Graciotti, Caterina Miceli, Jlenia Monfregola, Claudia Vilardo, Manrico Morroni, Chiara Di Malta, Gennaro Napolitano, Andrea Ballabio, Elizabeth P Henske

Duncan NRI Faculty and Staff Publications

Tuberous Sclerosis Complex (TSC) is caused by TSC1 or TSC2 mutations, leading to hyperactivation of mechanistic target of rapamycin complex 1 (mTORC1) and lesions in multiple organs including lung (lymphangioleiomyomatosis) and kidney (angiomyolipoma and renal cell carcinoma). Previously, we found that TFEB is constitutively active in TSC. Here, we generated two mouse models of TSC in which kidney pathology is the primary phenotype. Knockout of TFEB rescues kidney pathology and overall survival, indicating that TFEB is the primary driver of renal disease in TSC. Importantly, increased mTORC1 activity in the TSC2 knockout kidneys is normalized by TFEB knockout. In TSC2-deficient …

Gut Epithelial Interleukin-17 Receptor A Signaling Can Modulate Distant Tumors Growth Through Microbial Regulation, Vidhi Chandra, Le Li, Olivereen Le Roux, Yu Zhang, Rian M Howell, Dhwani N Rupani, Seyda Baydogan, Haiyan D Miller, Erick Riquelme, Joseph Petrosino, Michael P Kim, Krishna P L Bhat, James R White, Jay K Kolls, Yuliya Pylayeva-Gupta, Florencia Mcallister

Faculty, Staff and Student Publications

Microbes influence cancer initiation, progression and therapy responsiveness. IL-17 signaling contributes to gut barrier immunity by regulating microbes but also drives tumor growth. A knowledge gap remains regarding the influence of enteric IL-17-IL-17RA signaling and their microbial regulation on the behavior of distant tumors. We demonstrate that gut dysbiosis induced by systemic or gut epithelial deletion of IL-17RA induces growth of pancreatic and brain tumors due to excessive development of Th17, primary source of IL-17 in human and mouse pancreatic ductal adenocarcinoma, as well as B cells that circulate to distant tumors. Microbial dependent IL-17 signaling increases DUOX2 signaling in …

D-Mannose Reduces Cellular Senescence And Nlrp3/Gasdermind/Il-1Β-Driven Pyroptotic Uroepithelial Cell Shedding In The Murine Bladder, Chetanchandra S Joshi, Arnold M Salazar, Caihong Wang, Marianne M Ligon, Rayvanth R Chappidi, Bisiayo E Fashemi, Paul A Felder, Amy Mora, Sandra L Grimm, Cristian Coarfa, Indira U Mysorekar

Faculty, Staff and Students Publications

Aging is a risk factor for disease via increased susceptibility to infection, decreased ability to maintain homeostasis, inefficiency in combating stress, and decreased regenerative capacity. Multiple diseases, including urinary tract infection (UTI), are more prevalent with age; however, the mechanisms underlying the impact of aging on the urinary tract mucosa and the correlation between aging and disease remain poorly understood. Here, we show that, relative to young (8-12 weeks) mice, the urothelium of aged (18-24 months) female mice accumulates large lysosomes with reduced acid phosphatase activity and decreased overall autophagic flux in the aged urothelium, indicative of compromised cellular homeostasis. …

Investigating Clot-Flow Interactions By Integrating Intravital Imaging With In Silico Modeling For Analysis Of Flow, Transport, And Hemodynamic Forces, Chayut Teeraratkul, Maurizio Tomaiuolo, Timothy Stalker, Debanjan Mukherjee

Cardeza Foundation for Hematologic Research

As a blood clot forms, grows, deforms, and embolizes following a vascular injury, local clot-flow interactions lead to a highly dynamic flow environment. The local flow influences transport of biochemical species relevant for clotting, and determines the forces on the clot that in turn lead to clot deformation and embolization. Despite this central role, quantitative characterization of this dynamic clot-flow interaction and flow environment in the clot neighborhood remains a major challenge. Here, we propose an approach that integrates dynamic intravital imaging with computer geometric modeling and computational flow and transport modeling to develop a unified in silico framework to …

Secreted Igm Modulates Il-10 Expression In B Cells, Shannon Mcgettigan, Lazaro Aira, Gaurav Kumar, Romain Ballet, Eugene Butcher, Nicole Baumgarth, Gudrun Debes

Department of Microbiology and Immunology Faculty Papers

IL-10⁺ B cells are critical for immune homeostasis and restraining immune responses in infection, cancer, and inflammation; however, the signals that govern IL-10⁺ B cell differentiation are ill-defined. Here we find that IL-10⁺ B cells expand in mice lacking secreted IgM ((s)IgM^–/–) up to 10-fold relative to wildtype (WT) among all major B cell and regulatory B cell subsets. The IL-10⁺ B cell increase is polyclonal and presents within 24 hours of birth. In WT mice, sIgM is produced prenatally and limits the expansion of IL-10⁺ B cells. Lack of the high affinity …

Sirtuin 2 Inhibition Modulates Chromatin Landscapes Genome-Wide To Induce Senescence In Atrx-Deficient Malignant Glioma, Prit Benny Malgulwar, Carla Danussi, Sharvari Dharmaiah, William Johnson, Anand Singh, Kunal Rai, Arvind Rao, Jason T Huse

Faculty, Staff and Student Publications

BACKGROUND: Functional inactivation of ATRX characterizes large subgroups of malignant gliomas in adults and children. ATRX deficiency in glioma induces widespread chromatin remodeling, driving transcriptional shifts and oncogenic phenotypes. Effective strategies to therapeutically target these broad epigenomic sequelae remain undeveloped.

METHODS: We utilized integrated multiomics and the Broad Institute Connectivity Map (CMAP) to identify drug candidates that could potentially revert ATRX-deficient transcriptional changes. We then employed disease-relevant experimental models to evaluate functional phenotypes, coupling these studies with epigenomic profiling to elucidate molecular mechanism(s).

RESULTS: CMAP analysis and transcriptional/epigenomic profiling implicated the Class III HDAC Sirtuin2 (SIRT2) as a central mediator …

Dimerization Of The 4ig Isoform Of B7-H3 In Tumor Cells Mediates Enhanced Proliferation And Tumorigenic Signaling, Margie N Sutton, Sarah E Glazer, Riccardo Muzzioli, Ping Yang, Seth T Gammon, David Piwnica-Worms

Faculty, Staff and Student Publications

B7-H3 (CD276) has two isoforms (2Ig and 4Ig), no confirmed cognate receptor, and physiological functions that remain elusive. While differentially expressed on many solid tumors correlating with poor survival, mechanisms of how B7-H3 signals in cis (tumor cell) versus in trans (immune cell co-regulator) to elicit pro-tumorigenic phenotypes remain poorly defined. Herein, we characterized a tumorigenic and signaling role for tumor cell-expressed 4Ig-B7-H3, the dominant human isoform, in gynecological cancers that could be abrogated upon CRISPR/Cas9 knockout of B7-H3; tumorigenesis was rescued upon re-expression of 4Ig-B7-H3. Size exclusion chromatography revealed dimerization states for the extracellular domains of both human 4Ig- …

A High-Protein Diet Promotes Atrial Arrhythmogenesis Via Absent-In-Melanoma 2 Inflammasome, Jia Song, Jiao Wu, Dexter J Robichaux, Tingting Li, Shuyue Wang, Maria J Arredondo Sancristobal, Bingning Dong, Dobromir Dobrev, Jason Karch, Sandhya S Thomas, Na Li

Faculty, Staff and Students Publications

High-protein diets (HPDs) offer health benefits, such as weight management and improved metabolic profiles. The effects of HPD on cardiac arrhythmogenesis remain unclear. Atrial fibrillation (AF), the most common arrhythmia, is associated with inflammasome activation. The role of the Absent-in-Melanoma 2 (AIM2) inflammasome in AF pathogenesis remains unexplored. In this study, we discovered that HPD increased susceptibility to AF. To demonstrate the involvement of AIM2 signaling in the pathogenesis of HPD-induced AF, wildtype (WT) and Aim2^−/− mice were fed normal-chow (NC) and HPD, respectively. Four weeks later, inflammasome activity was upregulated in the atria of WT-HPD mice, but not …

Doxycycline For Transgene Control Disrupts Gut Microbiome Diversity Without Compromising Acute Neuroinflammatory Response, Emily J Koller, Caleb A Wood, Zoe Lai, Ella Borgenheimer, Kristi L Hoffman, Joanna L Jankowsky

Faculty, Staff and Students Publications

The tetracycline transactivator (tTA) system provides controllable transgene expression through oral administration of the broad-spectrum antibiotic doxycycline. Antibiotic treatment for transgene control in mouse models of disease might have undesirable systemic effects resulting from changes in the gut microbiome. Here we assessed the impact of doxycycline on gut microbiome diversity in a tTA-controlled model of Alzheimer's disease and then examined neuroimmune effects of these microbiome alterations following acute LPS challenge. We show that doxycycline decreased microbiome diversity in both transgenic and wild-type mice and that these changes persisted long after drug withdrawal. Despite the change in microbiome composition, doxycycline treatment …

Inhibiting Metabotropic Glutamate Receptor 5 After Stroke Restores Brain Function And Connectivity, Jakob Hakon, Miriana J Quattromani, Carin Sjölund, Daniela Talhada, Byungchan Kim, Slavianka Moyanova, Federica Mastroiacovo, Luisa Di Menna, Roger Olsson, Elisabet Englund, Ferdinando Nicoletti, Karsten Ruscher, Adam Q Bauer, Tadeusz Wieloch

2020-Current year OA Pubs

Stroke results in local neural disconnection and brain-wide neuronal network dysfunction leading to neurological deficits. Beyond the hyper-acute phase of ischaemic stroke, there is no clinically-approved pharmacological treatment that alleviates sensorimotor impairments. Functional recovery after stroke involves the formation of new or alternative neuronal circuits including existing neural connections. The type-5 metabotropic glutamate receptor (mGluR5) has been shown to modulate brain plasticity and function and is a therapeutic target in neurological diseases outside of stroke. We investigated whether mGluR5 influences functional recovery and network reorganization rodent models of focal ischaemia. Using multiple behavioural tests, we observed that treatment with negative …

Sarm1 Knockout Prevents Type 1 Diabetic Bone Disease In Females Independent Of Neuropathy, Jennifer M. Brazill, Ivana R. Shen, Clarissa S. Craft, Kristann L. Magee, Jay S. Park, Madelyn Lorenz, Amy Strickland, Natalie K. Wee, Xiao Zhang, Alec T. Beeve, Gretchen A. Meyer, Jeffrey Milbrandt, Aaron Diantonio, Erica L. Scheller

2020-Current year OA Pubs

Patients with diabetes have a high risk of developing skeletal diseases accompanied by diabetic peripheral neuropathy (DPN). In this study, we isolated the role of DPN in skeletal disease with global and conditional knockout models of sterile-α and TIR-motif-containing protein-1 (Sarm1). SARM1, an NADase highly expressed in the nervous system, regulates axon degeneration upon a range of insults, including DPN. Global knockout of Sarm1 prevented DPN, but not skeletal disease, in male mice with type 1 diabetes (T1D). Female wild-type mice also developed diabetic bone disease but without DPN. Unexpectedly, global Sarm1 knockout completely protected female mice from T1D-associated bone …

Targeting Dna Repair And Survival Signaling In Diffuse Intrinsic Pontine Gliomas To Prevent Tumor Recurrence, Monika Sharma, Ivana Barravecchia, Robert Teis, Jeanette Cruz, Rachel Mumby, Elizabeth K Ziemke, Carlos E Espinoza, Varunkumar Krishnamoorthy, Brian Magnuson, Mats Ljungman, Carl Koschmann, Joya Chandra, Christopher E Whitehead, Judith S Sebolt-Leopold, Stefanie Galban

Faculty, Staff and Student Publications

Therapeutic resistance remains a major obstacle to successful clinical management of diffuse intrinsic pontine glioma (DIPG), a high-grade pediatric tumor of the brain stem. In nearly all patients, available therapies fail to prevent progression. Innovative combinatorial therapies that penetrate the blood-brain barrier and lead to long-term control of tumor growth are desperately needed. We identified mechanisms of resistance to radiotherapy, the standard of care for DIPG. On the basis of these findings, we rationally designed a brain-penetrant small molecule, MTX-241F, that is a highly selective inhibitor of EGFR and PI3 kinase family members, including the DNA repair protein DNA-PK. Preliminary …