Biochemistry, Biophysics, and Structural Biology Commons^™

Hematopoiesis Under Telomere Attrition At The Single-Cell Resolution, Natthakan Thongon, Feiyang Ma, Andrea Santoni, Matteo Marchesini, Elena Fiorini, Ashley Rose, Vera Adema, Irene Ganan-Gomez, Emma M Groarke, Fernanda Gutierrez-Rodrigues, Shuaitong Chen, Pamela Lockyer, Sarah Schneider, Carlos Bueso-Ramos, Guillermo Montalban-Bravo, Caleb A Class, Kelly A Soltysiak, Matteo Pellegrini, Ergun Sahin, Alison A Bertuch, Courtney D Dinardo, Guillermo Garcia-Manero, Neal S Young, Karen Dwyer, Simona Colla

Faculty, Staff and Students Publications

The molecular mechanisms that drive hematopoietic stem cell functional decline under conditions of telomere shortening are not completely understood. In light of recent advances in single-cell technologies, we sought to redefine the transcriptional and epigenetic landscape of mouse and human hematopoietic stem cells under telomere attrition, as induced by pathogenic germline variants in telomerase complex genes. Here, we show that telomere attrition maintains hematopoietic stem cells under persistent metabolic activation and differentiation towards the megakaryocytic lineage through the cell-intrinsic upregulation of the innate immune signaling response, which directly compromises hematopoietic stem cells' self-renewal capabilities and eventually leads to their exhaustion. …

Computational Simulation Of The Lung Doses Of Air-Borne Fine And Ultrafine Particles Inhaled By Humans At Industrial Workplaces, Mohammed Ali

Technology Faculty Publications and Presentations

This study correlates computational predictions with in-vivo experimental results of inhaled fine and ultrafine particulate matters (PMs) transport, dissemination, and deposition in the human respiratory airways. Epidemiological studies suggest that workplace exposure of anthropogenic pollutant PMs as a risk factor for increased susceptibility to acute broncho-pulmonary infections. However, investigations on detailed human inhalation and PM transport processes are restrictive from time, cost, and ethical perspectives. To overcome this problem, computational simulation of particle deposition based on the Multiple Path Particle Dosimetry (MPPD) model was employed. Here, the physical, mechanical, and electrical properties of PMs of carbon black and nanoparticles from …

Ckb Inhibits Epithelial-Mesenchymal Transition And Prostate Cancer Progression By Sequestering And Inhibiting Akt Activation, Zheng Wang, Mohit Hulsurkar, Lijuan Zhuo, Jinbang Xu, Han Yang, Samira Naderinezhad, Lin Wang, Guoliang Zhang, Nanping Ai, Linna Li, Jeffrey T Chang, Songlin Zhang, Ladan Fazli, Chad J Creighton, Fang Bai, Michael M Ittmann, Martin E Gleave, Wenliang Li

Faculty, Staff and Students Publications

Epithelial-mesenchymal transition (EMT) contributes to tumor invasion, metastasis and drug resistance. AKT activation is key in a number of cellular processes. While many positive regulators for either EMT or AKT activation have been reported, few negative regulators are established. Through kinase cDNA screen, we identified brain-type creatine kinase (CKB or BCK) as a potent suppressor for both. As a ubiquitously expressed kinase in normal tissues, CKB is significantly downregulated in several solid cancer types. Lower CKB expression is significantly associated with worse prognosis. Phenotypically, CKB overexpression suppresses, while its silencing promotes, EMT and cell migration, xenograft tumor growth and metastasis …

Super-Resolution Microscopy Reveals Photoreceptor-Specific Subciliary Location And Function Of Ciliopathy-Associated Protein Cep290, Valencia L Potter, Abigail R Moye, Michael A Robichaux, Theodore G Wensel

Faculty, Staff and Students Publications

Mutations in the cilium-associated protein CEP290 cause retinal degeneration as part of multiorgan ciliopathies or as retina-specific diseases. The precise location and the functional roles of CEP290 within cilia and, specifically, the connecting cilia (CC) of photoreceptors, remain unclear. We used super-resolution fluorescence microscopy and electron microscopy to localize CEP290 in the CC and in the primary cilia of cultured cells with subdiffraction resolution and to determine effects of CEP290 deficiency in 3 mutant models. Radially, CEP290 localizes in close proximity to the microtubule doublets in the region between the doublets and the ciliary membrane. Longitudinally, it is distributed throughout …

Cellular Regeneration As A Potential Strategy To Treat Cardiac Conduction Disorders, Satadru K Lahiri, Mohit M Hulsurkar, Xander Ht Wehrens

Faculty, Staff and Students Publications

Loss of atrioventricular conduction system (AVCS) cells due to either inherited or acquired deficits leads to conduction diseases, which can deteriorate into fatal cardiac arrhythmias and sudden death. In this issue of the JCI, Wang et al. constructed a mouse model of atrioventricular block (AVB) by inducing AVCS cell-specific injury using the Cx30.2 enhancer to drive expression of diphtheria toxin fragment A. AVCS cell ablation in adult mice led to irreversible AVB. jkjkIn contrast, AVCS cell injury in neonatal mice was followed by spontaneous recovery in a subset of mice, revealing a limited postnatal time window during which the regeneration …

Neuron-Specific Mitochondrial Oxidative Stress Results In Epilepsy, Glucose Dysregulation And A Striking Astrocyte Response, Ruth E Fulton, Jennifer N Pearson-Smith, Christopher Q Huynh, Timothy Fabisiak, Li-Ping Liang, Stefanos Aivazidis, Brigit A High, Georgia Buscaglia, Timothy Corrigan, Robert Valdez, Takahiko Shimizu, Manisha N Patel

Faculty, Staff and Students Publications

Mitochondrial superoxide (O2.−) production is implicated in aging, neurodegenerative disease, and most recently epilepsy. Yet the specific contribution of neuronal O2.− to these phenomena is unclear. Here, we selectively deleted superoxide dismutase-2 (SOD2) in neuronal basic helix-loop-helix transcription factor (NEX)-expressing cells restricting deletion to a subset of excitatory principle neurons primarily in the forebrain (cortex and hippocampus). This resulted in nSOD2 KO mice that lived into adulthood (2-3 months) with epilepsy, selective loss of neurons, metabolic rewiring and a marked mitohormetic gene response. Surprisingly, expression of an astrocytic gene, glial fibrillary acidic protein (GFAP) was significantly increased relative …

Zfta-Rela Dictates Oncogenic Transcriptional Programs To Drive Aggressive Supratentorial Ependymoma, Amir Arabzade, Yanhua Zhao, Srinidhi Varadharajan, Hsiao-Chi Chen, Selin Jessa, Bryan Rivas, Austin J Stuckert, Minerva Solis, Alisha Kardian, Dana Tlais, Brian J Golbourn, Ann-Catherine J Stanton, Yuen San Chan, Calla Olson, Kristen L Karlin, Kathleen Kong, Robert Kupp, Baoli Hu, Sarah G Injac, Madeline Ngo, Peter R Wang, Luz A De León, Felix Sahm, Daisuke Kawauchi, Stefan M Pfister, Charles Y Lin, H Courtney Hodges, Irtisha Singh, Thomas F Westbrook, Murali M Chintagumpala, Susan M Blaney, Donald W Parsons, Kristian W Pajtler, Sameer Agnihotri, Richard J Gilbertson, Joanna Yi, Nada Jabado, Claudia L Kleinman, Kelsey C Bertrand, Benjamin Deneen, Stephen C Mack

Faculty, Staff and Students Publications

Over 60% of supratentorial (ST) ependymomas harbor a ZFTA-RELA (ZRfus) gene fusion (formerly C11orf95-RELA). To study the biology of ZRfus, we developed an autochthonous mouse tumor model using in utero electroporation (IUE) of the embryonic mouse brain. Integrative epigenomic and transcriptomic mapping was performed on IUE driven ZRfus tumors by CUT&RUN, ChIP, ATAC, and RNA sequencing and compared to human ZRfus driven ependymoma. In addition to direct canonical NF-κB pathway activation, ZRfus dictates a neoplastic transcriptional program and binds to thousands of unique sites across the genome that are enriched with Plagl family transcription factor (TF) motifs. ZRfus activates …

Pgc1Α Is Required For The Renoprotective Effect Of Lncrna Tug1 In Vivo And Links Tug1 With Urea Cycle Metabolites, Li Li, Jianyin Long, Koki Mise, Daniel L Galvan, Paul A Overbeek, Lin Tan, Shwetha V Kumar, Wai Kin Chan, Phillip L Lorenzi, Benny H Chang, Farhad R Danesh

Faculty, Staff and Students Publications

lncRNA taurine-upregulated gene 1 (Tug1) is a promising therapeutic target in the progression of diabetic nephropathy (DN), but the molecular basis of its protection remains poorly understood. Here, we generate a triple-mutant diabetic mouse model coupled with metabolomic profiling data to interrogate whether Tug1 interaction with peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1α) is required for mitochondrial remodeling and progression of DN in vivo. We find that, compared with diabetic conditional deletion of Pgc1α in podocytes alone (db/db; Pgc1αPod-f/f), diabetic Pgc1α knockout combined with podocyte-specific Tug1 overexpression (db/db; TugPodTg; Pgc1αPod-f/f) reverses the protective phenotype of …

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

Faculty, Staff and Students Publications

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

Cd148 Deficiency In Fibroblasts Promotes The Development Of Pulmonary Fibrosis, Konstantin Tsoyi, Xiaoliang Liang, Giulia De Rossi, Stefan W Ryter, Kevin Xiong, Sarah G Chu, Xiaoli Liu, Bonna Ith, Lindsay J Celada, Freddy Romero, Matthew J Robertson, Anthony J Esposito, Sergio Poli, Souheil El-Chemaly, Mark A Perrella, Yuanyuan Shi, James Whiteford, Ivan O Rosas

Faculty, Staff and Students Publications

Rationale: CD148/PTRJ (receptor-like protein tyrosine phosphatase η) exerts antifibrotic effects in experimental pulmonary fibrosis via interactions with its ligand syndecan-2; however, the role of CD148 in human pulmonary fibrosis remains incompletely characterized.

Objectives: We investigated the role of CD148 in the profibrotic phenotype of fibroblasts in idiopathic pulmonary fibrosis (IPF).

Methods: Conditional CD148 fibroblast-specific knockout mice were generated and exposed to bleomycin and then assessed for pulmonary fibrosis. Lung fibroblasts (mouse lung and human IPF lung), and precision-cut lung slices from human patients with IPF were isolated and subjected to experimental treatments. A CD148-activating 18-aa mimetic peptide (SDC2-pep) derived from …

Gene Therapy Knockdown Of Hippo Signaling Induces Cardiomyocyte Renewal In Pigs After Myocardial Infarction, Shijie Liu, Ke Li, Leonardo Wagner Florencio, Li Tang, Todd R Heallen, John P Leach, Yidan Wang, Francisco Grisanti, James T Willerson, Emerson C Perin, Sui Zhang, James F Martin

Faculty, Staff and Students Publications

Human heart failure, a leading cause of death worldwide, is a prominent example of a chronic disease that may result from poor cell renewal. The Hippo signaling pathway is an inhibitory kinase cascade that represses adult heart muscle cell (cardiomyocyte) proliferation and renewal after myocardial infarction in genetically modified mice. Here, we investigated an adeno-associated virus 9 (AAV9)–based gene therapy to locally knock down the Hippo pathway gene Salvador (Sav) in border zone cardiomyocytes in a pig model of ischemia/reperfusion-induced myocardial infarction. Two weeks after myocardial infarction, when pigs had left ventricular systolic dysfunction, we administered AAV9-Sav …

Pathological Mechanisms Of Vacuolar Aggregate Myopathy Arising From A Casq1 Mutation, Amy D Hanna, Chang Seok Lee, Lyle Babcock, Hui Wang, Joseph Recio, Susan L Hamilton

Faculty, Staff and Students Publications

Mice with a mutation (D244G, DG) in calsequestrin 1 (CASQ1), analogous to a human mutation in CASQ1 associated with a delayed onset human myopathy (vacuolar aggregate myopathy), display a progressive myopathy characterized by decreased activity, decreased ability of fast twitch muscles to generate force and low body weight after one year of age. The DG mutation causes CASQ1 to partially dissociate from the junctional sarcoplasmic reticulum (SR) and accumulate in the endoplasmic reticulum (ER). Decreased junctional CASQ1 reduces SR Ca

Mitochondrial Transfer From Mesenchymal Stem Cells Improves Neuronal Metabolism After Oxidant Injury In Vitro: The Role Of Miro1, Nancy Tseng, Scott C Lambie, Christopher Q Huynh, Bridget Sanford, Manisha Patel, Paco S Herson, D Ryan Ormond

Faculty, Staff and Students Publications

Stroke-induced cerebral ischemia is a major cause of death and disability. The disruption of blood flow results in neuronal and glial cell death leading to brain injury. Reperfusion restores oxygen to the affected tissue, but can also cause damage through an enhanced oxidative stress and inflammatory response. This study examines mitochondrial transfer from MSC to neurons and the role it plays in neuronal preservation after oxidant injury. We observed the transfer of mitochondria from MSC to mouse neurons in vitro following hydrogen peroxide exposure. The observed transfer was dependent on cell-to-cell contact and led to increased neuronal survival and improved …

Synthesis, Structure-Activity Relationships, And Antiviral Activity Of Allosteric Inhibitors Of Flavivirus Ns2b-Ns3 Protease, Shenyou Nie, Yuan Yao, Fangrui Wu, Xiaowei Wu, Jidong Zhao, Yuanda Hua, Jingyu Wu, Tong Huo, Yi-Lun Lin, Alexander R Kneubehl, Megan B Vogt, Josephine Ferreon, Rebecca Rico-Hesse, Yongcheng Song

Faculty, Staff and Students Publications

Flaviviruses, including Zika, dengue and West Nile virus, are important human pathogens. The highly conserved NS2B-NS3 protease of Flavivirus is essential for viral replication and therefore a promising drug target. Through compound screen followed by medicinal chemistry studies, a novel series of 2,5,6-trisubstituted pyrazine compounds are found to be potent, allosteric inhibitors of Zika virus protease (ZVpro) with IC50 values as low as 130 nM. Their structure-activity relationships are discussed. The ZVpro inhibitors also inhibit homologous proteases of dengue and West Nile virus and their inhibitory activities are correlated. The most potent compounds 47 and 103 potently inhibited Zika virus …

Ceramide Synthase Tlcd3b Is A Novel Gene Associated With Human Recessive Retinal Dystrophy, Renae Elaine Bertrand, Jun Wang, Kaitlyn H Xiong, Chinthana Thangavel, Xinye Qian, Rola Ba-Abbad, Qingnan Liang, Renata T Simões, Shirley A M Sampaio, Keren J Carss, F Lucy Raymond, Anthony G Robson, Andrew R Webster, Gavin Arno, Fernanda Belga Ottoni Porto, Rui Chen

Faculty, Staff and Students Publications

PURPOSE: Previous studies suggest that ceramide is a proapoptotic lipid as high levels of ceramides can lead to apoptosis of neuronal cells, including photoreceptors. However, no pathogenic variant in ceramide synthases has been identified in human patients and knockout of various ceramide synthases in mice has not led to photoreceptor degeneration.

METHODS: Exome sequencing was used to identify candidate disease genes in patients with vision loss as confirmed by standard evaluation methods, including electroretinography (ERG) and optical coherence tomography. The vision loss phenotype in mice was evaluated by ERG and histological analyses.

RESULTS: Here we have identified four patients with …

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

Faculty, Staff and Students Publications

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

Hermansky-Pudlak Syndrome-2 Alters Mitochondrial Homeostasis In The Alveolar Epithelium Of The Lung, Karina Cuevas-Mora, Willy Roque, Hoora Shaghaghi, Bernadette R Gochuico, Ivan O Rosas, Ross Summer, Freddy Romero

Faculty, Staff and Students Publications

BACKGROUND: Mitochondrial dysfunction has emerged as an important player in the pathogenesis of idiopathic pulmonary fibrosis (IPF), a common cause of idiopathic interstitial lung disease in adults. Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder that causes a similar type of pulmonary fibrosis in younger adults, although the role of mitochondrial dysfunction in this condition is not understood.

METHODS: We performed a detailed characterization of mitochondrial structure and function in lung tissues and alveolar epithelial cells deficient in the adaptor protein complex 3 beta 1 (Ap3b1) subunit, the gene responsible for causing subtype 2 of HPS (HPS-2).

RESULTS: We …

Lkb1 And Ampk Instruct Cone Nuclear Position To Modify Visual Function, Courtney A Burger, Nicholas E Albrecht, Danye Jiang, Justine H Liang, Ross A Poché, Melanie A Samuel

Faculty, Staff and Students Publications

Cone photoreceptors detect light and are responsible for color vision. These cells display a distinct polarized morphology where nuclei are precisely aligned in the apical retina. However, little is known about the mechanisms involved in cone nuclear positioning or the impact of this organization on retina function. We show that the serine/threonine kinase LKB1 and one of its substrates, AMPK, regulate cone nuclear positioning. In the absence of either molecule, cone nuclei are misplaced along the axon, resulting in altered nuclear lamination. LKB1 is required specifically in cones to mediate this process, and disruptions in nuclear alignment result in reduced …

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 …

Lrrtm4 Is A Member Of The Transsynaptic Complex Between Rod Photoreceptors And Bipolar Cells, Melina A Agosto, Theodore G Wensel

Faculty, Staff and Students Publications

Leucine rich repeat transmembrane (LRRTM) proteins are synaptic adhesion molecules with roles in synapse formation and signaling. LRRTM4 transcripts were previously shown to be enriched in rod bipolar cells (BCs), secondary neurons of the retina that form synapses with rod photoreceptors. Using two different antibodies, LRRTM4 was found to reside primarily at rod BC dendritic tips, where it colocalized with the transduction channel protein, TRPM1. LRRTM4 was not detected at dendritic tips of ON-cone BCs. Following somatic knockout of LRRTM4 in BCs by subretinal injection and electroporation of CRISPR/Cas9, LRRTM4 was abolished or reduced in the dendritic tips of transfected …

A Steroid Receptor Coactivator Stimulator (Mcb-613) Attenuates Adverse Remodeling After Myocardial Infarction, Lisa K Mullany, Aarti D Rohira, John P Leach, Jong H Kim, Tanner O Monroe, Andrea R Ortiz, Brittany Stork, M Waleed Gaber, Poonam Sarkar, Andrew G Sikora, Todd K Rosengart, Brian York, Yongcheng Song, Clifford C Dacso, David M Lonard, James F Martin, Bert W O'Malley

Faculty, Staff and Students Publications

Progressive remodeling of the heart, resulting in cardiomyocyte (CM) loss and increased inflammation, fibrosis, and a progressive decrease in cardiac function, are hallmarks of myocardial infarction (MI)-induced heart failure. We show that MCB-613, a potent small molecule stimulator of steroid receptor coactivators (SRCs) attenuates pathological remodeling post-MI. MCB-613 decreases infarct size, apoptosis, hypertrophy, and fibrosis while maintaining significant cardiac function. MCB-613, when given within hours post MI, induces lasting protection from adverse remodeling concomitant with: 1) inhibition of macrophage inflammatory signaling and interleukin 1 (IL-1) signaling, which attenuates the acute inflammatory response, 2) attenuation of fibroblast differentiation, and 3) promotion …

Mouse Models To Study The Pathophysiology Of Combined Methylmalonic Acidemia And Homocystinuria, Cblc Type, Tiffany Chern, Annita Achilleos, Xuefei Tong, Chih-Wei Hsu, Leeyean Wong, Ross A Poché

Faculty, Staff and Students Publications

Combined methylmalonic acidemia and homocystinuria, cblC type, is the most common inherited disorder of cobalamin metabolism and is characterized by severe fetal developmental defects primarily impacting the central nervous system, hematopoietic system, and heart. CblC was previously shown to be due to mutations in the MMACHC gene, which encodes a protein thought to function in intracellular cobalamin trafficking and biosynthesis of adenosylcobalamin (AdoCbl) and methylcobalamin (MeCbl). These coenzymes are required for the production of succinyl-CoA and methionine, respectively. However, it is currently unclear whether additional roles for MMACHC exist outside of cobalamin metabolism. Furthermore, due to a lack of sufficient …

Depletion Of Essential Isoprenoids And Er Stress Induction Following Acute Liver-Specific Deletion Of Hmg-Coa Reductase, Marco De Giorgi, Kelsey E Jarrett, Jason C Burton, Alexandria M Doerfler, Ayrea Hurley, Ang Li, Rachel H Hsu, Mia Furgurson, Kalyani R Patel, Jun Han, Christoph H Borchers, William R Lagor

Faculty, Staff and Students Publications

HMG-CoA reductase (Hmgcr) is the rate-limiting enzyme in the mevalonate pathway and is inhibited by statins. In addition to cholesterol, Hmgcr activity is also required for synthesizing nonsterol isoprenoids, such as dolichol, ubiquinone, and farnesylated and geranylgeranylated proteins. Here, we investigated the effects of Hmgcr inhibition on nonsterol isoprenoids in the liver. We have generated new genetic models to acutely delete genes in the mevalonate pathway in the liver using AAV-mediated delivery of Cre-recombinase (AAV-Cre) or CRISPR/Cas9 (AAV-CRISPR). The genetic deletion of Hmgcr by AAV-Cre resulted in extensive hepatocyte apoptosis and compensatory liver regeneration. At the biochemical …

The Impact Of Microbial Experience On The Murine Innate Immune Response, Cody Thomas Morrison

Masters Theses

The hygiene hypothesis predicts that certain environmental factors shape overall immune system function in animals and humans. While current specific pathogen free (SPF) mouse models are invaluable for studying the immune system, they have limitations for comparison with humans who have microbial exposures throughout their lifetimes. Several studies have shown that the composition of the immune system of SPF mice more closely resembles that of newborns, whereas the immune system from mice exposed to microbial pathogens more closely reflect adult immunity. In this study we have established a model using traditional SPF mice (“clean mice”) and SPF mice that were …

Role For Carbohydrate Response Element-Binding Protein (Chrebp) In High Glucose-Mediated Repression Of Long Noncoding Rna Tug1, Jianyin Long, Daniel L Galvan, Koki Mise, Yashpal S Kanwar, Li Li, Naravat Poungavrin, Paul A Overbeek, Benny H Chang, Farhad R Danesh

Faculty, Staff and Students Publications

Long noncoding RNAs (lncRNAs) have been shown to play key roles in a variety of biological activities of the cell. However, less is known about how lncRNAs respond to environmental cues and what transcriptional mechanisms regulate their expression. Studies from our laboratory have shown that the lncRNA Tug1 (taurine upregulated gene 1) is crucial for the progression of diabetic kidney disease, a major microvascular complication of diabetes. Using a combination of proximity labeling with the engineered soybean ascorbate peroxidase (APEX2), ChIP-qPCR, biotin-labeled oligonucleotide pulldown, and classical promoter luciferase assays in kidney podocytes, we extend our initial observations in the current …

Myosight-Semi-Automated Image Analysis Of Skeletal Muscle Cross Sections, Lyle W Babcock, Amy D Hanna, Nadia H Agha, Susan L Hamilton

Faculty, Staff and Students Publications

BACKGROUND: Manual analysis of cross-sectional area, fiber-type distribution, and total and centralized nuclei in skeletal muscle cross sections is tedious and time consuming, necessitating an accurate, automated method of analysis. While several excellent programs are available, our analyses of skeletal muscle disease models suggest the need for additional features and flexibility to adequately describe disease pathology. We introduce a new semi-automated analysis program, MyoSight, which is designed to facilitate image analysis of skeletal muscle cross sections and provide additional flexibility in the analyses.

RESULTS: We describe staining and imaging methods that generate high-quality images of immunofluorescent-labelled cross sections from mouse …

Young Versus Aged Microbiota Transplants To Germ-Free Mice: Increased Short-Chain Fatty Acids And Improved Cognitive Performance, Juneyoung Lee, Venugopal R Venna, David J Durgan, Huanan Shi, Jacob Hudobenko, Nagireddy Putluri, Joseph Petrosino, Louise D Mccullough, Robert M Bryan

Faculty, Staff and Students Publications

Aging is associated with cognitive decline and decreased concentrations of short-chain fatty acids (SCFAs) in the gut. SCFAs are significant in that they are protective to the gut and other organs. We tested the hypothesis that the aged gut microbiome alone is sufficient to decrease SCFAs in the host and produce cognitive decline. Fecal transplant gavages (FTGs) from aged (18–20 months) or young (2–3 months) male C57BL/6 mice into germ-free male C57BL/6 mice (N = 11 per group) were initiated at ~3 months of age. Fecal samples were collected and behavioral testing was performed over the study period. Bacterial community …

Zmat3 Is A Key Splicing Regulator In The P53 Tumor Suppression Program, Kathryn T Bieging-Rolett, Alyssa M Kaiser, David W Morgens, Anthony M Boutelle, Jose A Seoane, Eric L Van Nostrand, Changyu Zhu, Shauna L Houlihan, Stephano S Mello, Brian A Yee, Jacob Mcclendon, Sarah E Pierce, Ian P Winters, Mengxiong Wang, Andrew J Connolly, Scott W Lowe, Christina Curtis, Gene W Yeo, Monte M Winslow, Michael C Bassik, Laura D Attardi

Faculty, Staff and Students Publications

Although TP53 is the most commonly mutated gene in human cancers, the p53-dependent transcriptional programs mediating tumor suppression remain incompletely understood. Here, to uncover critical components downstream of p53 in tumor suppression, we perform unbiased RNAi and CRISPR-Cas9-based genetic screens in vivo. These screens converge upon the p53-inducible gene Zmat3, encoding an RNA-binding protein, and we demonstrate that ZMAT3 is an important tumor suppressor downstream of p53 in mouse Kras

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

Faculty, Staff and Students Publications

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

Mir-30a Targets Gene Networks That Promote Browning Of Human And Mouse Adipocytes, Pradip K Saha, Mark P Hamilton, Kimal Rajapakshe, Vasanta Putluri, Jessica B Felix, Peter Masschelin, Aaron R Cox, Mandeep Bajaj, Nagireddy Putluri, Cristian Coarfa, Sean M Hartig

Faculty, Staff and Students Publications

MicroRNA-30a (miR-30a) impacts adipocyte function, and its expression in white adipose tissue (WAT) correlates with insulin sensitivity in obesity. Bioinformatic analysis demonstrates that miR-30a expression contributes to 2% of all miRNA expression in human tissues. However, molecular mechanisms of miR-30a function in fat cells remain unclear. Here, we expanded our understanding of how miR-30a expression contributes to antidiabetic peroxisome proliferator-activated receptor-γ (PPARγ) agonist activity and metabolic functions in adipocytes. We found that WAT isolated from diabetic patients shows reduced miR-30a levels and diminished expression of the canonical PPARγ target genes ADIPOQ and FABP4 relative to lean counterparts. In human adipocytes, …