Digital Commons Network^™

Anesthesia For Echocardiography And Magnetic Resonance Imaging In The African Clawed Frog (Xenopus Laevis), Antonio F Corno, Noelia E Flores, Wen Li, Thomas H Gomez, Jorge D Salazar

Faculty, Staff and Student Publications

This report describes an anesthesia technique that we used to study cardiovascular anatomy and physiology with echocardiography and cardiac magnetic resonance (CMR) in 46 African clawed frogs (Xenopus laevis) (n = 24 for electrocardiography and n = 22 for CMR). For administration of anesthesia, 3 holding tanks, one each for transportation, sedation, and recovery, were filled with filtered water, with 0.05% buffered tricaine methasulfonate solution (MS-222) added into the sedation tank. Fifteen minutes after the frog was placed in the sedation tank, a paper towel was soaked in MS-222 solution, and the frog was placed in a …

Hepatic Recruitment Of Eosinophils And Their Protective Function During Acute Liver Injury, Long Xu, Yang Yang, Yankai Wen, Jong-Min Jeong, Christoph Emontzpohl, Constance L Atkins, Zhaoli Sun, Kyle L Poulsen, David R Hall, J Steve Bynon, Bin Gao, William M Lee, Jody Rule, Elizabeth A Jacobsen, Hua Wang, Cynthia Ju

Faculty, Staff and Student Publications

BACKGROUND & AIMS: Beyond the classical description of eosinophil functions in parasite infections and allergic diseases, emerging evidence supports a critical role of eosinophils in resolving inflammation and promoting tissue remodeling. However, the role of eosinophils in liver injury and the underlying mechanism of their recruitment into the liver remain unclear.

METHODS: Hepatic eosinophils were detected and quantified using flow cytometry and immunohistochemical staining. Eosinophil-deficient (ΔdblGata1) mice were used to investigate the role of eosinophils in 3 models of acute liver injury. In vivo experiments using Il33

RESULTS: Hepatic accumulation of eosinophils was observed in patients with acetaminophen (APAP)-induced liver …

Mir-103-3p Promotes Hepatic Steatosis To Aggravate Nonalcoholic Fatty Liver Disease By Targeting Of Acox1, Jiexia Ding, Caixia Xia, Panpan Cen, Siying Li, Lifei Yu, Jing Zhu, Jie Jin

Faculty, Staff and Student Publications

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is a major risk factor for hepatocellular carcinoma, and alterations in miRNA expression are related to the development of NAFLD. However, the role of miRNAs in regulating the development of NAFLD is still poorly understood.

METHODS: We used qRT-PCR to detect the level of miR-103-3p in both cell and mouse models of NAFLD. Biochemical assays, DCF-DA assays, Oil red O staining and HE staining were used to detect the role of miR-103-3p in NAFLD development. Target genes of miR-103-3p were predicted using the TargetScan database and verified by qRT-PCR, western blot and dual-luciferase assays. …

Spatial Charting Of Single-Cell Transcriptomes In Tissues, Runmin Wei, Siyuan He, Shanshan Bai, Emi Sei, Min Hu, Alastair Thompson, Ken Chen, Savitri Krishnamurthy, Nicholas E Navin

Faculty, Staff and Student Publications

Single-cell RNA sequencing methods can profile the transcriptomes of single cells but cannot preserve spatial information. Conversely, spatial transcriptomics assays can profile spatial regions in tissue sections, but do not have single-cell resolution. Here, we developed a computational method called CellTrek that combines these two datasets to achieve single-cell spatial mapping through coembedding and metric learning approaches. We benchmarked CellTrek using simulation and in situ hybridization datasets, which demonstrated its accuracy and robustness. We then applied CellTrek to existing mouse brain and kidney datasets and showed that CellTrek can detect topological patterns of different cell types and cell states. We …

Plasma Metabolomics Analysis Of Aspirin Treatment And Risk Of Colorectal Adenomas, Elizabeth L Barry, Veronika Fedirko, Yutong Jin, Ken Liu, Leila A Mott, Janet L Peacock, Michael N Passarelli, John A Baron, Dean P Jones

Faculty, Staff and Student Publications

Despite substantial observational and experimental evidence that aspirin use can provide protection against the development of colorectal neoplasia, our understanding of the molecular mechanisms involved is inadequate and limits our ability to use this drug effectively and safely for chemoprevention. We employed an untargeted plasma metabolomics approach using liquid chromatography with high-resolution mass spectroscopy to explore novel metabolites that may contribute to the chemopreventive effects of aspirin. Associations between levels of metabolic features in plasma and aspirin treatment were investigated among 523 participants in a randomized placebo-controlled clinical trial of two doses of aspirin (81 or 325 mg/day) and were …

Immune Phenotype Of The Cd4+ T Cells In The Aged Lymphoid Organs And Lacrimal Glands, Claudia M Trujillo-Vargas, Kelsey E Mauk, Humberto Hernandez, Rodrigo G De Souza, Zhiyuan Yu, Jeremias G Galletti, Jana Dietrich, Friedrich Paulsen, Cintia S De Paiva

Faculty, Staff and Students Publications

Aging is associated with a massive infiltration of T lymphocytes in the lacrimal gland. Here, we aimed to characterize the immune phenotype of aged CD4+ T cells in this tissue as compared with lymphoid organs. To perform this, we sorted regulatory T cells (Tregs, CD4+CD25+GITR+) and non-Tregs (CD4+CD25negGITRneg) in lymphoid organs from female C57BL/6J mice and subjected these cells to an immunology NanoString® panel. These results were confirmed by flow cytometry, live imaging, and tissue immunostaining in the lacrimal gland. Importantly, effector T helper 1 (Th1) genes were highly upregulated on aged Tregs, including the master regulator Tbx21. Among …

Identifying Bone Matrix Impairments In A Mouse Model Of Neurofibromatosis Type 1 (Nf1) By Clinically Translatable Techniques, Rafay Ahmed, Sasidhar Uppuganti, Shrey Derasari, Joshua Meyer, Jacquelyn S Pennings, Florent Elefteriou, Jeffry S Nyman

Faculty, Staff and Students Publications

Three-to-four percent of children with neurofibromatosis type 1 (NF1) present with unilateral tibia bowing, fracture, and recalcitrant healing. Alkaline phosphatase enzyme therapy prevented poor bone mineralization and poor mechanical properties in mouse models of NF1 skeletal dysplasia; but transition to clinical trials is hampered by the lack of a technique that i) identifies NF1 patients at risk of tibia bowing and fracture making them eligible for trial enrollment and ii) monitors treatment effects on matrix characteristics related to bone strength. Therefore, we assessed the ability of matrix-sensitive techniques to provide characteristics that differentiate between cortical bone from mice characterized by …

Sex-Specific Phenotypes In The Aging Mouse Heart And Consequences For Chronic Fibrosis, Aude Angelini, Jesus Ortiz-Urbina, Joann Trial, Anilkumar K Reddy, Anna Malovannaya, Antrix Jain, Mark L Entman, George E Taffet, Katarzyna A Cieslik

Faculty, Staff and Students Publications

The incidence of diastolic dysfunction increases with age in both humans and mice. This is characterized by increased passive stiffness and slower relaxation of the left ventricle. The stiffness arises at least partially from progressively increased interstitial collagen deposition because of highly secretory fibroblasts. In the past, we demonstrated that AMPK activation via the drug 5-aminoimidazole-4-carboxamide riboside (AICAR) in middle-aged mice reduced adverse remodeling after myocardial infarction. Therefore, as an attempt to normalize the fibroblast phenotype, we used 21-mo-old male and female mice and treated them with AICAR (0.166 mg/g body wt) where each mouse was followed in a functional …

Glutathione Peroxidase 2 Is A Metabolic Driver Of The Tumor Immune Microenvironment And Immune Checkpoint Inhibitor Response, Kazi Mokim Ahmed, Ratna Veeramachaneni, Defeng Deng, Nagireddy Putluri, Vasanta Putluri, Maria F Cardenas, David A Wheeler, William K Decker, Andy I Frederick, Sawad Kazi, Andrew G Sikora, Vlad C Sandulache, Mitchell J Frederick

Faculty, Staff and Students Publications

BACKGROUND: The existence of immunologically 'cold tumors' frequently found across a wide spectrum of tumor types represents a significant challenge for cancer immunotherapy. Cold tumors have poor baseline pan-leukocyte infiltration, including a low prevalence of cytotoxic lymphocytes, and not surprisingly respond unfavorably to immune checkpoint (IC) inhibitors. We hypothesized that cold tumors harbor a mechanism of immune escape upstream and independent of ICs that may be driven by tumor biology rather than differences in mutational neoantigen burden.

METHODS: Using a bioinformatic approach to analyze TCGA (The Cancer Genome Atlas) RNA sequencing data we identified genes upregulated in cold versus hot …

Il-34 Deficiency Impairs Foxp3+ Treg Function In A Model Of Autoimmune Colitis And Decreases Immune Tolerance Homeostasis, Antoine Freuchet, Marco Colonna, Et Al

2020-Current year OA Pubs

BACKGROUND: Immune homeostasis requires fully functional Tregs with a stable phenotype to control autoimmunity. Although IL-34 is a cytokine first described as mainly involved in monocyte cell survival and differentiation, we recently described its expression by CD8

METHODS: We generated Il34

RESULTS: Here we report that the absence of expression of IL-34 in Il34

CONCLUSION: Altogether, our data emphasize on the crucial necessity of IL-34 for immune homeostasis and for CD4

HIGHLIGHTS: -Absence of expression of IL-34 in Il34

The Lupus Susceptibility Allele Drb1*03:01 Encodes A Disease-Driving Epitope, Bruna Miglioranza Scavuzzi, Vincent Van Drongelen, Bhavneet Kaur, Jennifer Callahan Fox, Jianhua Liu, Raquel A Mesquita-Ferrari, J Michelle Kahlenberg, Evan A Farkash, Fernando Benavides, Frederick W Miller, Amr H Sawalha, Joseph Holoshitz

Faculty, Staff and Student Publications

The HLA-DRB1*03:01 allele is a major genetic risk factor in systemic lupus erythematosus (SLE), but the mechanistic basis of the association is unclear. Here we show that in the presence of interferon gamma (IFN-γ), a short DRB1*03:01-encoded allelic epitope activates a characteristic lupus transcriptome in mouse and human macrophages. It also triggers a cascade of SLE-associated cellular aberrations, including endoplasmic reticulum stress, unfolded protein response, mitochondrial dysfunction, necroptotic cell death, and production of pro-inflammatory cytokines. Parenteral administration of IFN-γ to naïve DRB1*03:01 transgenic mice causes increased serum levels of anti-double stranded DNA antibodies, glomerular immune complex deposition and histopathological renal …

Targeting De Novo Lipogenesis And The Lands Cycle Induces Ferroptosis In Kras-Mutant Lung Cancer, Caterina Bartolacci, Cristina Andreani, Gonçalo Vale, Stefano Berto, Margherita Melegari, Anna Colleen Crouch, Dodge L Baluya, George Kemble, Kurt Hodges, Jacqueline Starrett, Katerina Politi, Sandra L Starnes, Daniele Lorenzini, Maria Gabriela Raso, Luisa M Solis Soto, Carmen Behrens, Humam Kadara, Boning Gao, Ignacio I Wistuba, John D Minna, Jeffrey G Mcdonald, Pier Paolo Scaglioni

Faculty, Staff and Student Publications

Mutant KRAS (KM), the most common oncogene in lung cancer (LC), regulates fatty acid (FA) metabolism. However, the role of FA in LC tumorigenesis is still not sufficiently characterized. Here, we show that KMLC has a specific lipid profile, with high triacylglycerides and phosphatidylcholines (PC). We demonstrate that FASN, the rate-limiting enzyme in FA synthesis, while being dispensable in EGFR-mutant or wild-type KRAS LC, is required for the viability of KMLC cells. Integrating lipidomic, transcriptomic and functional analyses, we demonstrate that FASN provides saturated and monounsaturated FA to the Lands cycle, the process remodeling oxidized phospholipids, such as PC. Accordingly, …

Altered Genome-Wide Hippocampal Gene Expression Profiles Following Early Life Lead Exposure And Their Potential For Reversal By Environmental Enrichment, Garima Singh, V Singh, T Kim, A Ertel, W Fu, J S Schneider

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Early life lead (Pb) exposure is detrimental to neurobehavioral development. The quality of the environment can modify negative influences from Pb exposure, impacting the developmental trajectory following Pb exposure. Little is known about the molecular underpinnings in the brain of the interaction between Pb and the quality of the environment. We examined relationships between early life Pb exposure and living in an enriched versus a non-enriched postnatal environment on genome-wide transcription profiles in hippocampus CA1. RNA-seq identified differences in the transcriptome of enriched vs. non-enriched Pb-exposed animals. Most of the gene expression changes associated with Pb exposure were reversed by …

Regulated Dicing Of Pre-Mir-144 Via Reshaping Of Its Terminal Loop., Renfu Shang, Dmitry A Kretov, Scott I Adamson, Thomas Treiber, Nora Treiber, Jeffrey Vedanayagam, Jeffrey H Chuang, Gunter Meister, Daniel Cifuentes, Eric C Lai

Faculty Research 2022

Although the route to generate microRNAs (miRNAs) is often depicted as a linear series of sequential and constitutive cleavages, we now appreciate multiple alternative pathways as well as diverse strategies to modulate their processing and function. Here, we identify an unusually profound regulatory role of conserved loop sequences in vertebrate pre-mir-144, which are essential for its cleavage by the Dicer RNase III enzyme in human and zebrafish models. Our data indicate that pre-mir-144 dicing is positively regulated via its terminal loop, and involves the ILF3 complex (NF90 and its partner NF45/ILF2). We provide further evidence that this regulatory switch involves …

Myt1l In The Making: Emerging Insights On Functions Of A Neurodevelopmental Disorder Gene, Jiayang Chen, Allen Yen, Colin P Florian, Joseph D Dougherty

2020-Current year OA Pubs

Large scale human genetic studies have shown that loss of function (LoF) mutations in MYT1L are implicated in neurodevelopmental disorders (NDDs). Here, we provide an overview of the growing number of published MYT1L patient cases, and summarize prior studies in cells, zebrafish, and mice, both to understand MYT1L's molecular and cellular role during brain development and consider how its dysfunction can lead to NDDs. We integrate the conclusions from these studies and highlight conflicting findings to reassess the current model of the role of MYT1L as a transcriptional activator and/or repressor based on the biological context. Finally, we highlight additional …

Sirpα Mediates Igf1 Receptor In Cardiomyopathy-Induced By Chronic Kidney Disease, Sandhya S Thomas, Jiao Wu, Giovanni Davogustto, Michael W Holliday, Kristin Eckel-Mahan, Daniela Verzola, Giacomo Garibotto, Zhaoyong Hu, William E Mitch, Heinrich Taegtmeyer

Faculty, Staff and Student Publications

BACKGROUND: Chronic kidney disease (CKD) is characterized by increased myocardial mass despite near-normal blood pressure, suggesting the presence of a separate trigger. A potential driver is SIRPα (signal regulatory protein alpha)-a mediator impairing insulin signaling. The objective of this study is to assess the role of circulating SIRPα in CKD-induced adverse cardiac remodeling.

METHODS: SIRPα expression was evaluated in mouse models and patients with CKD. Specifically, mutant, muscle-specific, or cardiac muscle-specific SIRPα KO (knockout) mice were examined after subtotal nephrectomy. Cardiac function was assessed by echocardiography. Metabolic responses were confirmed in cultured muscle cells or cardiomyocytes.

RESULTS: We demonstrate that …

A Phospholipid Mimetic Targeting Lrh-1 Ameliorates Colitis, Suzanne G Mays, Emma H D'Agostino, Autumn R Flynn, Xiangsheng Huang, Guohui Wang, Xu Liu, Elizabeth J Millings, C Denise Okafor, Anamika Patel, Michael L Cato, Jeffery L Cornelison, Diana Melchers, René Houtman, David D Moore, John W Calvert, Nathan T Jui, Eric A Ortlund

Faculty, Staff and Students Publications

Phospholipids are ligands for nuclear hormone receptors (NRs) that regulate transcriptional programs relevant to normal physiology and disease. Here, we demonstrate that mimicking phospholipid-NR interactions is a robust strategy to improve agonists of liver receptor homolog-1 (LRH-1), a therapeutic target for colitis. Conventional LRH-1 modulators only partially occupy the binding pocket, leaving vacant a region important for phospholipid binding and allostery. Therefore, we constructed a set of molecules with elements of natural phospholipids appended to a synthetic LRH-1 agonist. We show that the phospholipid-mimicking groups interact with the targeted residues in crystal structures and improve binding affinity, LRH-1 transcriptional activity, …

Kathryn V. Holmes: A Career Of Contributions To The Coronavirus Field, Aurelio Bonavia, Samuel R Dominguez, Gabriela Dveksler, Sara Gagneten, Megan Howard, Scott Jeffers, Zhaohui Qian, Mary Kathryn Smith, Larissa B Thackray, Dina B Tresnan, David E Wentworth, David R Wessner, Richard K Williams, Tanya A Miura

2020-Current year OA Pubs

Over the past two years, scientific research has moved at an unprecedented rate in response to the COVID-19 pandemic. The rapid development of effective vaccines and therapeutics would not have been possible without extensive background knowledge on coronaviruses developed over decades by researchers, including Kathryn (Kay) Holmes. Kay's research team discovered the first coronavirus receptors for mouse hepatitis virus and human coronavirus 229E and contributed a wealth of information on coronaviral spike glycoproteins and receptor interactions that are critical determinants of host and tissue specificity. She collaborated with several research laboratories to contribute knowledge in additional areas, including coronaviral pathogenesis, …

Paclitaxel And Urolithin A Prevent Histamine-Induced Neurovascular Breakdown Alike, In An, Srijayaprakash Uppada, Dianxiong Zou, Erin M Scott, Gladys Ko, Stephen Pflugfelder, M N V Ravi Kumar, Raghu Ganugula

Faculty, Staff and Students Publications

Neurovascular eye problems are better prevented than managed or treated. Despite growing concern of occurrence in aging populations and development secondary to diseases such as diabetes and hypertension, we currently have very few options to tackle this global problem. Creating effective and high-throughput screening strategies is as important as the intervention itself. Here, we present for the first time a robust ex vivo rat eye model of histamine-induced vascular damage for investigating the therapeutic potential of paclitaxel (PTX) and urolithin A (UA) as alternatives to dexamethasone for preventing vascular damage in the retina. Extensive loss of vascularization and apoptosis were …

Sox9 Directs Divergent Epigenomic States In Brain Tumor Subtypes, Debosmita Sardar, Hsiao-Chi Chen, Amanda Reyes, Srinidhi Varadharajan, Antrix Jain, Carrie Mohila, Rachel Curry, Brittney Lozzi, Kavitha Rajendran, Alexis Cervantes, Kwanha Yu, Ali Jalali, Ganesh Rao, Stephen C Mack, Benjamin Deneen

Duncan NRI Faculty and Staff Publications

Epigenetic dysregulation is a universal feature of cancer that results in altered patterns of gene expression that drive malignancy. Brain tumors exhibit subtype-specific epigenetic alterations; however, the molecular mechanisms responsible for these diverse epigenetic states remain unclear. Here, we show that the developmental transcription factor Sox9 differentially regulates epigenomic states in high-grade glioma (HGG) and ependymoma (EPN). Using our autochthonous mouse models, we found that Sox9 suppresses HGG growth and expands associated H3K27ac states, while promoting ZFTA-RELA (ZR

Hippo-Taz Signaling Is The Master Regulator Of The Onset Of Triple-Negative Basal-Like Breast Cancers, Hirotoshi Soyama, Miki Nishio, Junji Otani, Toshiko Sakuma, Shintaro Takao, Shigeo Hara, Takaaki Masuda, Koshi Mimori, Shinya Toyokuni, John P Lydon, Kazuwa Nakao, Hiroshi Nishina, Takumi Fukumoto, Tomohiko Maehama, Akira Suzuki

Faculty, Staff and Students Publications

A universal oncogenic driver of basal-like breast cancer (BLBC) has resisted identification. We show that continuous transcriptional coactivator with PDZ-binding motif (TAZ) activation in precancerous murine luminal cells generates luminal cancers that later become BLBCs. Subsequent TP53 alteration, a feature of invasive human BLBCs, accelerates tumor progression. Because BLBC development is inhibited by TAZ inactivation in vivo, our work provides a sound rationale for targeting Hippo-TAZ signaling as therapy for human BLBC. Our mouse model of BLBC represents a powerful tool for evaluating such drugs.

The Hippo Pathway Regulates Axis Formation And Morphogenesis In Hydra, Maria Brooun, Willi Salvenmoser, Catherine Dana, Marius Sudol, Robert Steele, Bert Hobmayer, Helen Mcneill

2020-Current year OA Pubs

How did cells of early metazoan organisms first organize themselves to form a body axis? The canonical Wnt pathway has been shown to be sufficient for induction of axis in Cnidaria, a sister group to Bilateria, and is important in bilaterian axis formation. Here, we provide experimental evidence that in cnidarian

Cranial Base Synchondrosis Lacks Pthrp-Expressing Column-Forming Chondrocytes, Shawn A Hallett, Annabelle Zhou, Curtis Herzog, Ariel Arbiv, Wanida Ono, Noriaki Ono

Faculty, Staff and Student Publications

The cranial base contains a special type of growth plate termed the synchondrosis, which functions as the growth center of the skull. The synchondrosis is composed of bidirectional opposite-facing layers of resting, proliferating, and hypertrophic chondrocytes, and lacks the secondary ossification center. In long bones, the resting zone of the epiphyseal growth plate houses a population of parathyroid hormone-related protein (PTHrP)-expressing chondrocytes that contribute to the formation of columnar chondrocytes. Whether PTHrP+ chondrocytes in the synchondrosis possess similar functions remains undefined. Using Pthrp-mCherry knock-in mice, we found that PTHrP+ chondrocytes predominantly occupied the lateral wedge-shaped area of the synchondrosis, unlike …

Α-Synuclein Conformational Plasticity: Physiologic States, Pathologic Strains, And Biotechnological Applications, Amanda Li, Cyrus Rastegar, Xiaobo Mao

2020-Current year OA Pubs

α-Synuclein (αS) is remarkable for both its extensive conformational plasticity and pathologic prion-like properties. Physiologically, αS may populate disordered monomeric, helically folded tetrameric, or membrane-bound oligomeric states. Pathologically, αS may assemble into toxic oligomers and subsequently fibrils, the prion-like transmission of which is implicated in a class of neurodegenerative disorders collectively termed α-synucleinopathies. Notably, αS does not adopt a single "amyloid fold", but rather exists as structurally distinct amyloid-like conformations referred to as "strains". The inoculation of animal models with different strains induces distinct pathologies, and emerging evidence suggests that the propagation of disease-specific strains underlies the differential pathologies observed …

Impairing Proliferation Of Glioblastoma Multiforme With Cd44+ Selective Conjugated Polymer Nanoparticles, Dorota Lubanska, Sami Alrashed, Gage T. Mason, Fatima Nadeem, Angela Awada, Mitchell Dipasquale, Alexandra Sorge, Aleena Malik, Monika Kojic, Mohamed A. R Soliman, Ana C. De Carvalho, Abdalla Shamisa, Swati Kulkarni, Drew Marquardt, Lisa A. Porter, Simon Rondeau-Gagné

Neurosurgery Articles

Glioblastoma is one of the most aggressive types of cancer with success of therapy being hampered by the existence of treatment resistant populations of stem-like Tumour Initiating Cells (TICs) and poor blood-brain barrier drug penetration. Therapies capable of effectively targeting the TIC population are in high demand. Here, we synthesize spherical diketopyrrolopyrrole-based Conjugated Polymer Nanoparticles (CPNs) with an average diameter of 109 nm. CPNs were designed to include fluorescein-conjugated Hyaluronic Acid (HA), a ligand for the CD44 receptor present on one population of TICs. We demonstrate blood-brain barrier permeability of this system and concentration and cell cycle phase-dependent selective uptake …

Cd11b Suppresses Tlr Activation Of Nonclassical Monocytes To Reduce Primary Graft Dysfunction After Lung Transplantation, Melissa Querrey, Stephen Chiu, Emilia Lecuona, Qiang Wu, Haiying Sun, Megan Anderson, Megan Kelly, Sowmya Ravi, Alexander V. Misharin, Daniel Kreisel, Ankit Bharat, G. R. Scott Budinger

2020-Current year OA Pubs

Primary graft dysfunction (PGD) is the leading cause of postoperative mortality in lung transplant recipients and the most important risk factor for development of chronic lung allograft dysfunction. The mechanistic basis for the variability in the incidence and severity of PGD between lung transplant recipients is not known. Using a murine orthotopic vascularized lung transplant model, we found that redundant activation of Toll-like receptors 2 and 4 (TLR2 and -4) on nonclassical monocytes activates MyD88, inducing the release of the neutrophil attractant chemokine CXCL2. Deletion of Itgam (encodes CD11b) in nonclassical monocytes enhanced their production of CXCL2 and worsened PGD, …

Neuronal Activity Induces Glucosylceramide That Is Secreted Via Exosomes For Lysosomal Degradation In Glia, Liping Wang, Guang Lin, Zhongyuan Zuo, Yarong Li, Seul Kee Byeon, Akhilesh Pandey, Hugo J Bellen

Duncan NRI Faculty and Staff Publications

Recessive variants in GBA1 cause Gaucher disease, a prevalent form of lysosome storage disease. GBA1 encodes a lysosomal enzyme that hydrolyzes glucosylceramide (GlcCer) into glucose and ceramide. Its loss causes lysosomal dysfunction and increased levels of GlcCer. We generated a null allele of the Drosophila ortholog Gba1b by inserting the Gal4 using CRISPR-Cas9. Here, we show that Gba1b is expressed in glia but not in neurons. Glial-specific knockdown recapitulates the defects found in Gba1b mutants, and these can be rescued by glial expression of human GBA1. We show that GlcCer is synthesized upon neuronal activity, and it is transported …

Gut Bacterial Isoamylamine Promotes Age-Related Cognitive Dysfunction By Promoting Microglial Cell Death, Yun Teng, Jingyao Mu, Fangyi Xu, Xiangcheng Zhang, Mukesh K Sriwastva, Qiaohong M Liu, Xiaohong Li, Chao Lei, Kumaran Sundaram, Xin Hu, Lifeng Zhang, Juw Won Park, Jae Yeon Hwang, Eric C Rouchka, Xiang Zhang, Jun Yan, Michael L Merchant, Huang-Ge Zhang

Faculty, Staff and Student Publications

The intestinal microbiome releases a plethora of small molecules. Here, we show that the Ruminococcaceae metabolite isoamylamine (IAA) is enriched in aged mice and elderly people, whereas Ruminococcaceae phages, belonging to the Myoviridae family, are reduced. Young mice orally administered IAA show cognitive decline, whereas Myoviridae phage administration reduces IAA levels. Mechanistically, IAA promotes apoptosis of microglial cells by recruiting the transcriptional regulator p53 to the S100A8 promoter region. Specifically, IAA recognizes and binds the S100A8 promoter region to facilitate the unwinding of its self-complementary hairpin structure, thereby subsequently enabling p53 to access the S100A8 promoter and enhance S100A8 expression. …

The Testis-Specific E3 Ubiquitin Ligase Rnf133 Is Required For Fecundity In Mice, Kaori Nozawa, Yoshitaka Fujihara, Darius J Devlin, Ricardo E Deras, Katarzyna Kent, Irina V Larina, Kohei Umezu, Zhifeng Yu, Courtney M Sutton, Qiuji Ye, Laura K Dean, Chihiro Emori, Masahito Ikawa, Thomas X Garcia, Martin M Matzuk

Faculty, Staff and Students Publications

BACKGROUND: Ubiquitination is a post-translational modification required for a number of physiological functions regulating protein homeostasis, such as protein degradation. The endoplasmic reticulum (ER) quality control system recognizes and degrades proteins no longer needed in the ER through the ubiquitin-proteasome pathway. E2 and E3 enzymes containing a transmembrane domain have been shown to function in ER quality control. The ER transmembrane protein UBE2J1 is a E2 ubiquitin-conjugating enzyme reported to be essential for spermiogenesis at the elongating spermatid stage. Spermatids from Ube2j1 KO male mice are believed to have defects in the dislocation step of ER quality control. However, associated …

Renin-Angiotensin System In Huntington's Disease: Evidence From Animal Models And Human Patients, Lucas M Kangussu, Natalia P Rocha, Priscila A C Valadão, Thatiane C G Machado, Kívia B Soares, Julliane V Joviano-Santos, Leigh B Latham, Gabriela D Colpo, Ana Flávia Almeida-Santos, Erin Furr Stimming, Ana Cristina Simões E Silva, Antônio L Teixeira, Aline Silva Miranda, Cristina Guatimosim

Faculty, Staff and Student Publications

The Renin-Angiotensin System (RAS) is expressed in the central nervous system and has important functions that go beyond blood pressure regulation. Clinical and experimental studies have suggested that alterations in the brain RAS contribute to the development and progression of neurodegenerative diseases. However, there is limited information regarding the involvement of RAS components in Huntington's disease (HD). Herein, we used the HD murine model, (BACHD), as well as samples from patients with HD to investigate the role of both the classical and alternative axes of RAS in HD pathophysiology. BACHD mice displayed worse motor performance in different behavioral tests alongside …