Digital Commons Network^™

Novel Il-4/Hb-Egf-Dependent Crosstalk Between Eosinophils And Macrophages Controls Liver Regeneration After Ischaemia And Reperfusion Injury, Yang Yang, Long Xu, Constance Atkins, Lily Kuhlman, Jie Zhao, Jong-Min Jeong, Yankai Wen, Nicolas Moreno, Kang Ho Kim, Yu A An, Fenfen Wang, Steve Bynon, Vincenzo Villani, Bin Gao, Frank Brombacher, Raymond Harris, Holger K Eltzschig, Elizabeth Jacobsen, Cynthia Ju

Faculty, Staff and Student Publications

OBJECTIVE: Previous studies indicate that eosinophils are recruited into the allograft following orthotopic liver transplantation and protect from ischaemia reperfusion (IR) injury. In the current studies, we aim to explore whether their protective function could outlast during liver repair.

DESIGN: Eosinophil-deficient mice and adoptive transfer of bone marrow-derived eosinophils (bmEos) were employed to investigate the effects of eosinophils on tissue repair and regeneration after hepatic IR injury. Aside from exogenous cytokine or neutralising antibody treatments, mechanistic studies made use of a panel of mouse models of eosinophil-specific IL-4/IL-13-deletion, cell-specific IL-4rα-deletion in liver macrophages and hepatocytes and macrophage-specific deletion of heparin-binding …

Stem-Loop And Circle-Loop Tads Generated By Directional Pairing Of Boundary Elements Have Distinct Physical And Regulatory Properties, Wenfan Ke, Miki Fujioka, Paul Schedl, James Jaynes

Department of Biochemistry and Molecular Biology Faculty Papers

The chromosomes in multicellular eukaryotes are organized into a series of topologically independent loops called TADs. In flies, TADs are formed by physical interactions between neighboring boundaries. Fly boundaries exhibit distinct partner preferences, and pairing interactions between boundaries are typically orientation-dependent. Pairing can be head-to-tail or head-to-head. The former generates a stem-loop TAD, while the latter gives a circle-loop TAD. The TAD that encompasses the Drosophila even skipped (eve) gene is formed by the head-to-tail pairing of the nhomie and homie boundaries. To explore the relationship between loop topology and the physical and regulatory landscape, we flanked the nhomie boundary …

Pkd1 Mutant Clones Within Cirrhotic Livers Inhibit Steatohepatitis Without Promoting Cancer, Min Zhu, Yunguan Wang, Tianshi Lu, Jason Guo, Lin Li, Meng-Hsiung Hsieh, Purva Gopal, Yi Han, Naoto Fujiwara, Darren P Wallace, Alan S L Yu, Xiangyi Fang, Crystal Ransom, Sara Verschleisser, David Hsiehchen, Yujin Hoshida, Amit G Singal, Adam Yopp, Tao Wang, Hao Zhu

Faculty, Staff and Student Publications

Somatic mutations in non-malignant tissues are selected for because they confer increased clonal fitness. However, it is uncertain whether these clones can benefit organ health. Here, ultra-deep targeted sequencing of 150 liver samples from 30 chronic liver disease patients revealed recurrent somatic mutations. PKD1 mutations were observed in 30% of patients, whereas they were only detected in 1.3% of hepatocellular carcinomas (HCCs). To interrogate tumor suppressor functionality, we perturbed PKD1 in two HCC cell lines and six in vivo models, in some cases showing that PKD1 loss protected against HCC, but in most cases showing no impact. However, Pkd1 haploinsufficiency …

Identification And Characterization Of A Skin Microbiome On Caenorhabditis Elegans Suggests Environmental Microbes Confer Cuticle Protection, Nadia B Haghani, Robert H Lampe, Buck S Samuel, Sreekanth H Chalasani, Molly A Matty

Faculty, Staff and Students Publications

In the wild, C. elegans are emersed in environments teeming with a veritable menagerie of microorganisms. The C. elegans cuticular surface serves as a barrier and first point of contact with their microbial environments. In this study, we identify microbes from C. elegans natural habitats that associate with its cuticle, constituting a simple “skin microbiome.” We rear our animals on a modified CeMbio, mCeMbio, a consortium of ecologically relevant microbes. We first combine standard microbiological methods with an adapted micro skin-swabbing tool to describe the skin-resident bacteria on the C. elegans surface. Furthermore, we conduct 16S rRNA gene sequencing studies …

Large-Scale Mutational Analysis Identifies Unc93b1 Variants That Drive Tlr-Mediated Autoimmunity In Mice And Humans., Victoria E. Rael, Julian A. Yano, John P. Huizar, Leianna C. Slayden, Madeleine A. Weiss, Elizabeth A. Turcotte, Jacob M. Terry, Wenqi Zuo, Isabelle Thiffault, Tomi Pastinen, Emily G. Farrow, Janda L. Jenkins, Mara L. Becker, Stephen C. Wong, Anne M. Stevens, Catherine Otten, Eric J. Allenspach, Devon E. Bonner, Jonathan A. Bernstein, Matthew T. Wheeler, Robert A. Saxton, Undiagnosed Diseases Network, Bo Liu, Olivia Majer, Gregory M. Barton

Manuscripts, Articles, Book Chapters and Other Papers

Nucleic acid-sensing Toll-like receptors (TLR) 3, 7/8, and 9 are key innate immune sensors whose activities must be tightly regulated to prevent systemic autoimmune or autoinflammatory disease or virus-associated immunopathology. Here, we report a systematic scanning-alanine mutagenesis screen of all cytosolic and luminal residues of the TLR chaperone protein UNC93B1, which identified both negative and positive regulatory regions affecting TLR3, TLR7, and TLR9 responses. We subsequently identified two families harboring heterozygous coding mutations in UNC93B1, UNC93B1+/T93I and UNC93B1+/R336C, both in key negative regulatory regions identified in our screen. These patients presented with cutaneous tumid lupus and juvenile idiopathic arthritis plus …

Tumour-Intrinsic Endomembrane Trafficking By Arf6 Shapes An Immunosuppressive Microenvironment That Drives Melanomagenesis And Response To Checkpoint Blockade Therapy, Yinshen Wee, Junhua Wang, Emily C Wilson, Coulson P Rich, Aaron Rogers, Zongzhong Tong, Evelyn Degroot, Y N Vashisht Gopal, Michael A Davies, H Atakan Ekiz, Joshua K H Tay, Chris Stubben, Kenneth M Boucher, Juan M Oviedo, Keke C Fairfax, Matthew A Williams, Sheri L Holmen, Roger K Wolff, Allie H Grossmann

Faculty, Staff and Student Publications

Tumour-host immune interactions lead to complex changes in the tumour microenvironment (TME), impacting progression, metastasis and response to therapy. While it is clear that cancer cells can have the capacity to alter immune landscapes, our understanding of this process is incomplete. Herein we show that endocytic trafficking at the plasma membrane, mediated by the small GTPase ARF6, enables melanoma cells to impose an immunosuppressive TME that accelerates tumour development. This ARF6-dependent TME is vulnerable to immune checkpoint blockade therapy (ICB) but in murine melanoma, loss of Arf6 causes resistance to ICB. Likewise, downregulation of ARF6 in patient tumours correlates with …

G12/13 Signaling In Asthma, Elizabeth L. Mcduffie, Reynold A Panettieri, Charles P. Scott

Department of Biochemistry and Molecular Biology Faculty Papers

Shortening of airway smooth muscle and bronchoconstriction are pathognomonic for asthma. Airway shortening occurs through calcium-dependent activation of myosin light chain kinase, and RhoA-dependent calcium sensitization, which inhibits myosin light chain phosphatase. The mechanism through which pro-contractile stimuli activate calcium sensitization is poorly understood. Our review of the literature suggests that pro-contractile G protein coupled receptors likely signal through G12/13 to activate RhoA and mediate calcium sensitization. This hypothesis is consistent with the effects of pro-contractile agonists on RhoA and Rho kinase activation, actin polymerization and myosin light chain phosphorylation. Recognizing the likely role of G12/13 signaling in the pathophysiology …

Mucosal Immunization With Chad-Sars-Cov-2-S Prevents Sequential Transmission Of Sars-Cov-2 To Unvaccinated Hamsters, Tamarand L Darling, Houda H Harastani, Astha Joshi, Traci L Bricker, Nadia Soudani, Kuljeet Seehra, Ahmed O Hassan, Michael S Diamond, Adrianus C M Boon

2020-Current year OA Pubs

COVID-19 vaccines have successfully reduced severe disease and death after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Nonetheless, COVID-19 vaccines are variably effective in preventing transmission and symptomatic SARS-CoV-2 infection. Here, we evaluated the impact of mucosal or intramuscular vaccine immunization on airborne infection and transmission of SARS-CoV-2 in Syrian hamsters. Immunization of the primary contact hamsters with a mucosal chimpanzee adenoviral-vectored vaccine (ChAd-CoV-2-S), but not intramuscular messenger RNA (mRNA) vaccine, reduced infectious virus titers ~100-fold and 100,000-fold in the upper and lower respiratory tract of the primary contact hamster following SARS-CoV-2 exposure. This reduction in virus titer in …

Lipid Droplet-Associated Hydrolase Mobilizes Stores Of Liver X Receptor Sterol Ligands And Protects Against Atherosclerosis, Young-Hwa Goo, Janeesh Plakkal Ayyappan, Francis D Cheeran, Sushant Bangru, Pradip K Saha, Paula Baar, Sabine Schulz, Todd A Lydic, Bernhard Spengler, Andreas H Wagner, Auinash Kalsotra, Vijay K Yechoor, Antoni Paul

Faculty, Staff and Students Publications

Foam cells in atheroma are engorged with lipid droplets (LDs) that contain esters of regulatory lipids whose metabolism remains poorly understood. LD-associated hydrolase (LDAH) has a lipase structure and high affinity for LDs of foam cells. Using knockout and transgenic mice of both sexes, here we show that LDAH inhibits atherosclerosis development and promotes stable lesion architectures. Broad and targeted lipidomic analyzes of primary macrophages and comparative lipid profiling of atheroma identified a broad impact of LDAH on esterified sterols, including natural liver X receptor (LXR) sterol ligands. Transcriptomic analyzes coupled with rescue experiments show that LDAH modulates the expression …

Znf397 Deficiency Triggers Tet2-Driven Lineage Plasticity And Ar-Targeted Therapy Resistance In Prostate Cancer, Yaru Xu, Yuqiu Yang, Zhaoning Wang, Martin Sjöström, Yuyin Jiang, Yitao Tang, Siyuan Cheng, Su Deng, Choushi Wang, Julisa Gonzalez, Nickolas A Johnson, Xiang Li, Xiaoling Li, Lauren A Metang, Atreyi Mukherji, Quanhui Xu, Carla R Tirado, Garrett Wainwright, Xinzhe Yu, Spencer Barnes, Mia Hofstad, Yu Chen, Hong Zhu, Ariella B Hanker, Ganesh V Raj, Guanghui Zhu, Housheng H He, Zhao Wang, Carlos L Arteaga, Han Liang, Felix Y Feng, Yunguan Wang, Tao Wang, Ping Mu

Faculty, Staff and Students Publications

Cancer cells exhibit phenotypical plasticity and epigenetic reprogramming that allows them to evade lineage-dependent targeted treatments by adopting lineage plasticity. The underlying mechanisms by which cancer cells exploit the epigenetic regulatory machinery to acquire lineage plasticity and therapy resistance remain poorly understood. We identified zinc finger protein 397 (ZNF397) as a bona fide coactivator of the androgen receptor (AR), essential for the transcriptional program governing AR-driven luminal lineage. ZNF397 deficiency facilitates the transition of cancer cell from an AR-driven luminal lineage to a ten-eleven translocation 2 (TET2)-driven lineage plastic state, ultimately promoting resistance to therapies inhibiting AR signaling. Intriguingly, our …

Current Protocols: Alopecia Areata Mouse Models For Drug Efficacy And Mechanism Studies., John P Sundberg, Eddy H C Wang, Kevin J Mcelwee

Faculty Research 2024

Alopecia areata is the second most common form of hair loss in humans after androgenetic alopecia. Although a variety of animal models for alopecia areata have been described, currently the C3H/HeJ mouse model is the most commonly used and accepted. Spontaneous hair loss occurs in 15%-25% of older mice in which the lesions wax and wane, similar to the human disease, with alopecia being more common and severe in female mice. Full-thickness skin grafts from mice with spontaneous alopecia areata to young, normal-haired, histocompatible mice provide a highly reproducible model with progressive lesions that makes it useful for drug efficacy …

Phenotype Distinctions In Mice Deficient In The Neuron-Specific Α3 Subunit Of Na,K-Atpase:, Yi Bessie Liu, Elena Arystarkhova, Amanda N Sacino, Margit V Szabari, Cathleen Lutz, Markus Terrey, Natalia S Morsci, Tatjana C Jakobs, Karin Lykke-Hartmann, Allison Brashear, Elenora Napoli, Kathleen J Sweadner

Faculty Research 2024

TP1A3 is a Na,K-ATPase gene expressed specifically in neurons in the brain. Human mutations are dominant and produce an unusually wide spectrum of neurological phenotypes, most notably rapid-onset dystonia parkinsonism (RDP) and alternating hemiplegia of childhood (AHC). Here we compared hetero- zygotes of two mouse lines, a line with little or no expression (Atp1a3tm1Ling/+ ) and a knock-in expressing p.Asp801Tyr (D801Y, Atp1a3+/D801Y ). Both mouse lines had normal lifespans, but Atp1a3+/D801Y had mild perinatal mortality contrasting with D801N mice (Atp1a3+/D801N ), which had high mortality. The pheno- types of Atp1a3tm1Ling/+ and Atp1a3+/D801Y were different, and testing of each strain was …

Neoantigen-Specific Cytotoxic Tr1 Cd4 T Cells Suppress Cancer Immunotherapy, Hussein Sultan, Yoshiko Takeuchi, Jeffrey P Ward, Naveen Sharma, Tian-Tian Liu, Vladimir Sukhov, Maria Firulyova, Yuang Song, Samuel Ameh, Simone Brioschi, Darya Khantakova, Cora D Arthur, J Michael White, Heather Kohlmiller, Andres M Salazar, Robert Burns, Helio A Costa, Kelly D Moynihan, Yik Andy Yeung, Ivana Djuretic, Ton N Schumacher, Kathleen C F Sheehan, Marco Colonna, James P Allison, Kenneth M Murphy, Maxim N Artyomov, Robert D Schreiber

Faculty, Staff and Student Publications

CD4+ T cells can either enhance or inhibit tumour immunity. Although regulatory T cells have long been known to impede antitumour responses1-5, other CD4+ T cells have recently been implicated in inhibiting this response6,7. Yet, the nature and function of the latter remain unclear. Here, using vaccines containing MHC class I (MHC-I) neoantigens (neoAgs) and different doses of tumour-derived MHC-II neoAgs, we discovered that whereas the inclusion of vaccines with low doses of MHC-II-restricted peptides (LDVax) promoted tumour rejection, vaccines containing high doses of the same MHC-II neoAgs (HDVax) inhibited rejection. Characterization of the inhibitory cells induced by HDVax identified …

Autophagic Signaling Promotes Systems-Wide Remodeling In Skeletal Muscle Upon Oncometabolic Stress By D2-Hg, Yaqi Gao, Kyoungmin Kim, Heidi Vitrac, Rebecca L Salazar, Benjamin D Gould, Daniel Soedkamp, Weston Spivia, Koen Raedschelders, An Q Dinh, Anna G Guzman, Lin Tan, Stavros Azinas, David J R Taylor, Walter Schiffer, Daniel Mcnavish, Helen B Burks, Roberta A Gottlieb, Philip L Lorenzi, Blake M Hanson, Jennifer E Van Eyk, Heinrich Taegtmeyer, Anja Karlstaedt

Faculty, Staff and Student Publications

OBJECTIVES: Cachexia is a metabolic disorder and comorbidity with cancer and heart failure. The syndrome impacts more than thirty million people worldwide, accounting for 20% of all cancer deaths. In acute myeloid leukemia, somatic mutations of the metabolic enzyme isocitrate dehydrogenase 1 and 2 cause the production of the oncometabolite D2-hydroxyglutarate (D2-HG). Increased production of D2-HG is associated with heart and skeletal muscle atrophy, but the mechanistic links between metabolic and proteomic remodeling remain poorly understood. Therefore, we assessed how oncometabolic stress by D2-HG activates autophagy and drives skeletal muscle loss.

METHODS: We quantified genomic, metabolomic, and proteomic changes in …

Nf1 Mutation Disrupts Activity-Dependent Oligodendroglial Plasticity And Motor Learning In Mice, Yuan Pan, Jared D Hysinger, Belgin Yalçın, James J Lennon, Youkyeong Gloria Byun, Preethi Raghavan, Nicole F Schindler, Corina Anastasaki, Jit Chatterjee, Lijun Ni, Haojun Xu, Karen Malacon, Samin M Jahan, Alexis E Ivec, Benjamin E Aghoghovwia, Christopher W Mount, Surya Nagaraja, Suzanne Scheaffer, Laura D Attardi, David H Gutmann, Michelle Monje

Faculty, Staff and Student Publications

Neurogenetic disorders, such as neurofibromatosis type 1 (NF1), can cause cognitive and motor impairments, traditionally attributed to intrinsic neuronal defects such as disruption of synaptic function. Activity-regulated oligodendroglial plasticity also contributes to cognitive and motor functions by tuning neural circuit dynamics. However, the relevance of oligodendroglial plasticity to neurological dysfunction in NF1 is unclear. Here we explore the contribution of oligodendrocyte progenitor cells (OPCs) to pathological features of the NF1 syndrome in mice. Both male and female littermates (4-24 weeks of age) were used equally in this study. We demonstrate that mice with global or OPC-specific Nf1 heterozygosity exhibit defects …

Structure Of Adenylyl Cyclase 5 In Complex With Gβγ Offers Insights Into Adcy5-Related Dyskinesia, Yu-Chen Yen, Yong Li, Chun-Liang Chen, Thomas Klose, Val J Watts, Carmen W Dessauer, John J G Tesmer

Faculty, Staff and Student Publications

The nine different membrane-anchored adenylyl cyclase isoforms (AC1-9) in mammals are stimulated by the heterotrimeric G protein, Gαs, but their response to Gβγ regulation is isoform specific. In the present study, we report cryo-electron microscope structures of ligand-free AC5 in complex with Gβγ and a dimeric form of AC5 that could be involved in its regulation. Gβγ binds to a coiled-coil domain that links the AC transmembrane region to its catalytic core as well as to a region (C1b) that is known to be a hub for isoform-specific regulation. We confirmed the Gβγ interaction with both purified proteins and cell-based …

Circuit-Specific Deep Brain Stimulation Provides Insights Into Movement Control., Aryn H Gittis, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

Deep brain stimulation (DBS), a method in which electrical stimulation is delivered to specific areas of the brain, is an effective treatment for managing symptoms of a number of neurological and neuropsychiatric disorders. Clinical access to neural circuits during DBS provides an opportunity to study the functional link between neural circuits and behavior. This review discusses how the use of DBS in Parkinson's disease and dystonia has provided insights into the brain networks and physiological mechanisms that underlie motor control. In parallel, insights from basic science about how patterns of electrical stimulation impact plasticity and communication within neural circuits are …

Sequential Inhibition Of Parp And Bet As A Rational Therapeutic Strategy For Glioblastoma, Xin Peng, Xin Huang, Shaolu Zhang, Naixin Zhang, Shengfan Huang, Yingying Wang, Zhenxing Zhong, Shan Zhu, Haiwang Gao, Zixiang Yu, Xiaotong Yan, Zhennan Tao, Yuxiang Dai, Zhe Zhang, Xi Chen, Feng Wang, Francois X Claret, Moshe Elkabets, Ning Ji, Yuxu Zhong, Dexin Kong

Faculty, Staff and Student Publications

PARP inhibitors (PARPi) hold substantial promise in treating glioblastoma (GBM). However, the adverse effects have restricted their broad application. Through unbiased transcriptomic and proteomic sequencing, it is discovered that the BET inhibitor (BETi) Birabresib profoundly alters the processes of DNA replication and cell cycle progression in GBM cells, beyond the previously reported impact of BET inhibition on homologous recombination repair. Through in vitro experiments using established GBM cell lines and patient-derived primary GBM cells, as well as in vivo orthotopic transplantation tumor experiments in zebrafish and nude mice, it is demonstrated that the concurrent administration of PARPi and BETi can …

Antitumor Activity Of A Novel Lair1 Antagonist In Combination With Anti-Pd1 To Treat Collagen-Rich Solid Tumors, Bertha L Rodriguez, Jiawei Huang, Laura Gibson, Jared J Fradette, Hung-I H Chen, Kikuye Koyano, Czrina Cortez, Betty Li, Carmence Ho, Amir M Ashique, Vicky Y Lin, Suzanne Crawley, Julie M Roda, Peirong Chen, Bin Fan, Jeong Kim, James Sissons, Jonathan Sitrin, Daniel D Kaplan, Don L Gibbons, Lee B Rivera

Faculty, Staff and Student Publications

We recently reported that resistance to PD-1 blockade in a refractory lung cancer-derived model involved increased collagen deposition and the collagen-binding inhibitory receptor leukocyte-associated immunoglobulin-like receptor 1 (LAIR1). Thus, we hypothesized that LAIR1 and collagen cooperated to suppress therapeutic response. In this study, we report that LAIR1 is associated with tumor stroma and is highly expressed by intratumoral myeloid cells in both human tumors and mouse models of cancer. Stroma-associated myeloid cells exhibit a suppressive phenotype and correlate with LAIR1 expression in human cancer. NGM438, a novel humanized LAIR1 antagonist mAb, elicits myeloid inflammation and allogeneic T-cell responses by binding …

A Cell Cycle-Aware Network For Data Integration And Label Transferring Of Single-Cell Rna-Seq And Atac-Seq, Jiajia Liu, Jian Ma, Jianguo Wen, Xiaobo Zhou

Faculty, Staff and Student Publications

In recent years, the integration of single-cell multi-omics data has provided a more comprehensive understanding of cell functions and internal regulatory mechanisms from a non-single omics perspective, but it still suffers many challenges, such as omics-variance, sparsity, cell heterogeneity, and confounding factors. As it is known, the cell cycle is regarded as a confounder when analyzing other factors in single-cell RNA-seq data, but it is not clear how it will work on the integrated single-cell multi-omics data. Here, a cell cycle-aware network (CCAN) is developed to remove cell cycle effects from the integrated single-cell multi-omics data while keeping the cell …

Hue And Orientation Pinwheels In Macaque Area V4, Arun Parajuli, Daniel J Felleman

Faculty, Staff and Student Publications

Area V4 is an intermediate-level area of the macaque visual cortical hierarchy that serves key functions in visual processing by integrating inputs from lower areas such as V1 and V2 and providing feedforward inputs to many higher cortical areas. Previous V4 imaging studies have focused on differential responses to color, orientation, disparity, and motion stimuli, but many details of the spatial organization of significant hue and orientation tuning have not been fully described. We used support vector machine (SVM) decoding of intrinsic cortical single-condition responses to generate high-resolution maps of hue and orientation tuning and to describe the organization of …

Enolase Inhibitors As Therapeutic Leads For Naegleria Fowleri Infection, Jillian E Milanes, Victoria C Yan, Cong-Dat Pham, Florian Muller, Samuel Kwain, Kerrick C Rees, Brian N Dominy, Daniel C Whitehead, Steven W Millward, Madison Bolejack, Roger Shek, Logan Tillery, Isabelle Q Phan, Bart Staker, E Ashley Moseman, Xiang Zhang, Xipeng Ma, Audriy Jebet, Xinmin Yin, James C Morris

Faculty, Staff and Student Publications

Infections with the pathogenic free-living amoebae Naegleria fowleri can lead to life-threatening illnesses including catastrophic primary amoebic meningoencephalitis (PAM). Efficacious treatment options for these infections are lacking and the mortality rate remains >95% in the US. Glycolysis is very important for the infectious trophozoite lifecycle stage and inhibitors of glucose metabolism have been found to be toxic to the pathogen. Recently, human enolase 2 (ENO2) phosphonate inhibitors have been developed as lead agents to treat glioblastoma multiforme (GBM). These compounds, which cure GBM in a rodent model, are well-tolerated in mammals because enolase 1 (ENO1) is the predominant isoform used …

Cholesterol Accumulation Promotes Photoreceptor Senescence And Retinal Degeneration, Ryo Terao, Brian S Sohn, Taku Yamamoto, Tae Jun Lee, Jason Colasanti, Charles W Pfeifer, Joseph B Lin, Andrea Santeford, Shinobu Yamaguchi, Mitsukuni Yoshida, Rajendra S Apte

2020-Current year OA Pubs

PURPOSE: Dysregulated cholesterol metabolism is critical in the pathogenesis of AMD. Cellular senescence contributes to the development of numerous age-associated diseases. In this study, we investigated the link between cholesterol burden and the cellular senescence of photoreceptors.

METHODS: Retinas from rod-specific ATP binding cassette subfamily A member 1 (Abca1) and G member 1 (Abcg1) (Abca1/g1-rod/-rod) knockout mice fed with a high-fat diet were analyzed for the signs of cellular senescence. Real-time quantitative PCR and immunofluorescence were used to characterize the senescence profile of the retina and cholesterol-treated photoreceptor cell line (661W). Inducible elimination of p16(Ink4a)-positive senescent cells (INK-ATTAC) mice or …

Deletion Of Mipep In Adipocytes Protects Against Obesity And Insulin Resistance By Boosting Muscle Metabolism, Alexis Diaz-Vegas, Kristen C Cooke, Harry B Cutler, Belinda Yau, Stewart W C Masson, Dylan Harney, Oliver K Fuller, Meg Potter, Søren Madsen, Niamh R Craw, Yiju Zhang, Cesar L Moreno, Melkam A Kebede, G Gregory Neely, Jacqueline Stöckli, James G Burchfield, David E James

Faculty, Staff and Students Publications

Mitochondria facilitate thousands of biochemical reactions, covering a broad spectrum of anabolic and catabolic processes. Here we demonstrate that the adipocyte mitochondrial proteome is markedly altered across multiple models of insulin resistance and reveal a consistent decrease in the level of the mitochondrial processing peptidase miPEP.

OBJECTIVE: To determine the role of miPEP in insulin resistance.

METHODS: To experimentally test this observation, we generated adipocyte-specific miPEP knockout mice to interrogate its role in the aetiology of insulin resistance.

RESULTS: We observed a strong phenotype characterised by enhanced insulin sensitivity and reduced adiposity, despite normal food intake and physical activity. Strikingly, …

A Group 3 Medulloblastoma Stem Cell Program Is Maintained By Otx2-Mediated Alternative Splicing, Olivier Saulnier, Jamie Zagozewski, Lisa Liang, Liam D Hendrikse, Paul Layug, Victor Gordon, Kimberly A Aldinger, Parthiv Haldipur, Stephanie Borlase, Ludivine Coudière-Morrison, Ting Cai, Emma Martell, Naomi M Gonzales, Gareth Palidwor, Christopher J Porter, Stéphane Richard, Tanveer Sharif, Kathleen J Millen, Brad W Doble, Michael D Taylor, Tamra E Werbowetski-Ogilvie

Faculty, Staff and Students Publications

OTX2 is a transcription factor and known driver in medulloblastoma (MB), where it is amplified in a subset of tumours and overexpressed in most cases of group 3 and group 4 MB. Here we demonstrate a noncanonical role for OTX2 in group 3 MB alternative splicing. OTX2 associates with the large assembly of splicing regulators complex through protein-protein interactions and regulates a stem cell splicing program. OTX2 can directly or indirectly bind RNA and this may be partially independent of its DNA regulatory functions. OTX2 controls a pro-tumorigenic splicing program that is mirrored in human cerebellar rhombic lip origins. Among …

An Atypical Form Of 60s Ribosomal Subunit In Diamond-Blackfan Anemia Linked To Rpl17 Variants., Florence Fellmann, Carol J. Saunders, Marie-Françoise O'Donohue, David W. Reid, Kelsey A. Mcfadden, Nathalie Montel-Lehry, Cong Yu, Mingyan Fang, Jianguo Zhang, Beryl Royer-Bertrand, Pietro Farinelli, Narjesse Karboul, Jason R. Willer, Lorraine Fievet, Zahurul Alam Bhuiyan, Alissa Lw Kleinhenz, Julie Jadeau, Joy M. Fulbright, Carlo Rivolta, Raffaele Renella, Nicholas Katsanis, Jacques S. Beckmann, Christopher V. Nicchitta, Lydie Da Costa, Erica E. Davis, Pierre-Emmanuel Gleizes

Manuscripts, Articles, Book Chapters and Other Papers

Diamond-Blackfan anemia syndrome (DBA) is a ribosomopathy associated with loss-of-function variants in more than 20 ribosomal protein (RP) genes. Here, we report the genetic, functional, and biochemical dissection of 2 multigenerational pedigrees with variants in RPL17, a large ribosomal subunit protein-encoding gene. Affected individuals had clinical features and erythroid proliferation defects consistent with DBA. Further, RPL17/uL22 depletion resulted in anemia and micrognathia in zebrafish larvae, and in vivo complementation studies indicated that RPL17 variants were pathogenic. Lymphoblastoid cell lines (LCLs) derived from patients displayed a ribosomal RNA maturation defect reflecting haploinsufficiency of RPL17. The proteins encoded by RPL17 variants were …

Cerebellar Functions Beyond Movement And Learning, Linda H Kim, Detlef H Heck, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

The cerebellum has a well-established role in controlling motor functions, including coordination, posture, and the learning of skilled movements. The mechanisms for how it carries out motor behavior remain under intense investigation. Interestingly though, in recent years the mechanisms of cerebellar function have faced additional scrutiny since nonmotor behaviors may also be controlled by the cerebellum. With such complexity arising, there is now a pressing need to better understand how cerebellar structure, function, and behavior intersect to influence behaviors that are dynamically called upon as an animal experiences its environment. Here, we discuss recent experimental work that frames possible neural …

Potential Targeting Mechanisms For Bone-Directed Therapies, Betul Celik, Andrés Leal, Shunji Tomatsu

Department of Pediatrics Faculty Papers

Bone development is characterized by complex regulation mechanisms, including signal transduction and transcription factor-related pathways, glycobiological processes, cellular interactions, transportation mechanisms, and, importantly, chemical formation resulting from hydroxyapatite. Any abnormal regulation in the bone development processes causes skeletal system-related problems. To some extent, the avascularity of cartilage and bone makes drug delivery more challenging than that of soft tissues. Recent studies have implemented many novel bone-targeting approaches to overcome drawbacks. However, none of these strategies fully corrects skeletal dysfunction, particularly in growth plate-related ones. Although direct recombinant enzymes (e.g., Vimizim for Morquio, Cerezyme for Gaucher, Elaprase for Hunter, Mepsevii for …

The Isr Downstream Target Atf4 Represses Long-Term Memory In A Cell Type-Specific Manner, Niaz Mahmood, Jung-Hyun Choi, Pei You Wu, Sean W Dooling, Trent A Watkins, Ziying Huang, Jesse Lipman, Hanjie Zhao, Anqi Yang, Jake Silversmith, Yanis Inglebert, Constantinos Koumenis, Vijendra Sharma, Jean-Claude Lacaille, Wayne S Sossin, Arkady Khoutorsky, R Anne Mckinney, Mauro Costa-Mattioli, Nahum Sonenberg

Faculty, Staff and Students Publications

The integrated stress response (ISR), a pivotal protein homeostasis network, plays a critical role in the formation of long-term memory (LTM). The precise mechanism by which the ISR controls LTM is not well understood. Here, we report insights into how the ISR modulates the mnemonic process by using targeted deletion of the activating transcription factor 4 (ATF4), a key downstream effector of the ISR, in various neuronal and non-neuronal cell types. We found that the removal of ATF4 from forebrain excitatory neurons (but not from inhibitory neurons, cholinergic neurons, or astrocytes) enhances LTM formation. Furthermore, the deletion of ATF4 in …

Cerebellar Nuclei Cells Produce Distinct Pathogenic Spike Signatures In Mouse Models Of Ataxia, Dystonia, And Tremor, Meike E Van Der Heijden, Amanda M Brown, Dominic J Kizek, Roy V Sillitoe

Duncan NRI Faculty and Staff Publications

The cerebellum contributes to a diverse array of motor conditions, including ataxia, dystonia, and tremor. The neural substrates that encode this diversity are unclear. Here, we tested whether the neural spike activity of cerebellar output neurons is distinct between movement disorders with different impairments, generalizable across movement disorders with similar impairments, and capable of causing distinct movement impairments. Using in vivo awake recordings as input data, we trained a supervised classifier model to differentiate the spike parameters between mouse models for ataxia, dystonia, and tremor. The classifier model correctly assigned mouse phenotypes based on single-neuron signatures. Spike signatures were shared …