Medical Specialties Commons^™

Time Dependent Analysis Of Rat Microglial Surface Markers In Traumatic Brain Injury Reveals Dynamics Of Distinct Cell Subpopulations, Assaf Gottlieb, Naama Toledano-Furman, Karthik S Prabhakara, Akshita Kumar, Henry W Caplan, Supinder Bedi, Charles S Cox, Scott D Olson

Faculty, Staff and Student Publications

Traumatic brain injury (TBI) results in a cascade of cellular responses, which produce neuroinflammation, partly due to the activation of microglia. Accurate identification of microglial populations is key to understanding therapeutic approaches that modify microglial responses to TBI and improve long-term outcome measures. Notably, previous studies often utilized an outdated convention to describe microglial phenotypes. We conducted a temporal analysis of the response to controlled cortical impact (CCI) in rat microglia between ipsilateral and contralateral hemispheres across seven time points, identified microglia through expression of activation markers including CD45, CD11b/c, and p2y12 receptor and evaluated their activation state using additional …

G Protein-Coupled Receptor Kinase 5 Regulates Thrombin Signaling In Platelets Via Par-1., Kate Downes, Xuefei Zhao, Nicholas S Gleadall, Harriet Mckinney, Carly Kempster, Joana Batista, Patrick L Thomas, Matthew Cooper, James V Michael, Roman Kreuzhuber, Katherine Wedderburn, Kathryn Waller, Bianca Varney, Hippolyte Verdier, Neline Kriek, Sofie E Ashford, Kathleen E Stirrups, Joanne L Dunster, Steven E Mckenzie, Willem H Ouwehand, Jonathan M Gibbins, Jing Yang, William J Astle, Peisong Ma

Cardeza Foundation for Hematologic Research

The interindividual variation in the functional response of platelets to activation by agonists is heritable. Genome-wide association studies (GWASs) of quantitative measures of platelet function have identified fewer than 20 distinctly associated variants, some with unknown mechanisms. Here, we report GWASs of pathway-specific functional responses to agonism by adenosine 5'-diphosphate, a glycoprotein VI-specific collagen mimetic, and thrombin receptor-agonist peptides, each specific to 1 of the G protein-coupled receptors PAR-1 and PAR-4, in subsets of 1562 individuals. We identified an association (P = 2.75 × 10-40) between a common intronic variant, rs10886430, in the G protein-coupled receptor kinase 5 gene (GRK5) …

Ndrg1 In Aggressive Breast Cancer Progression And Brain Metastasis, Emilly S Villodre, Xiaoding Hu, Bedrich L Eckhardt, Richard Larson, Lei Huo, Ester C Yoon, Yun Gong, Juhee Song, Shuying Liu, Naoto T Ueno, Savitri Krishnamurthy, Stefan Pusch, Debu Tripathy, Wendy A Woodward, Bisrat G Debeb

Faculty, Staff and Student Publications

BACKGROUND: N-Myc downstream regulated gene 1 (NDRG1) suppresses metastasis in many human malignancies, including breast cancer, yet has been associated with worse survival in patients with inflammatory breast cancer. The role of NDRG1 in the pathobiology of aggressive breast cancers remains elusive.

METHODS: To study the role of NDRG1 in tumor growth and brain metastasis in vivo, we transplanted cells into cleared mammary fat pads or injected them in tail veins of SCID/Beige mice (n = 7-10 per group). NDRG1 protein expression in patient breast tumors (n = 216) was assessed by immunohistochemical staining. Kaplan-Meier method with 2-sided log-rank test …

Exploiting 4–1bb Immune Checkpoint To Enhance The Efficacy Of Oncolytic Virotherapy For Diffuse Intrinsic Pontine Gliomas, Virginia Laspidea, Montserrat Puigdelloses, Sara Labiano, Lucía Marrodán, Marc Garcia-Moure, Marta Zalacain, Marisol Gonzalez-Huarriz, Naiara Martínez-Vélez, Iker Ausejo-Mauleon, Daniel De La Nava, Guillermo Herrador-Cañete, Javier Marco-Sanz, Elisabeth Guruceaga, Carlos E De Andrea, María Villalba, Oren Becher, Massimo Squatrito, Verónica Matía, Jaime Gállego Pérez-Larraya, Ana Patiño-García, Sumit Gupta, Candelaria Gomez-Manzano, Juan Fueyo, Marta M Alonso

Faculty, Staff and Student Publications

Diffuse intrinsic pontine gliomas (DIPGs) are aggressive pediatric brain tumors, and patient survival has not changed despite many therapeutic efforts, emphasizing the urgent need for effective treatments. Here, we evaluated the anti-DIPG effect of the oncolytic adenovirus Delta-24-ACT, which was engineered to express the costimulatory ligand 4-1BBL to potentiate the antitumor immune response of the virus. Delta-24-ACT induced the expression of functional 4-1BBL on the membranes of infected DIPG cells, which enhanced the costimulation of CD8+ T lymphocytes. In vivo, Delta-24-ACT treatment of murine DIPG orthotopic tumors significantly improved the survival of treated mice, leading to long-term survivors that developed …

Spata7 Is Required For Maintenance Of The Retinal Connecting Cilium, Jiaxiong Lu, Kaitlyn Xiong, Xinye Qian, Jongsu Choi, Yoon-Kyung Shim, Jacob Burnett, Graeme Mardon, Rui Chen

Faculty, Staff and Students Publications

SPATA7, an early onset LCA3 retinal disease gene, encodes a putative scaffold protein that is essential for the proper assembly of the connecting cilium (CC) complex in photoreceptors. Previous studies have shown that SPATA7 interacts with other photoreceptor-specific ciliary proteins, such as RPGR and RPGRIP1, and maintains the integrity of CC integrity. However, although it is known that Spata7 is required for early formation of the CC, it is unclear if Spata7 is also required for the maintenance of the CC. To investigate Spata7 function in the retina at the adult stage, loss of function was induced in the …

The Role Of Palmitoleic Acid In Regulating Hepatic Gluconeogenesis Through Sirt3 In Obese Mice, Xin Guo, Xiaofan Jiang, Keyun Chen, Qijian Liang, Shixiu Zhang, Juan Zheng, Xiaomin Ma, Hongmei Jiang, Hao Wu, Qiang Tong

Faculty, Staff and Students Publications

Hepatic gluconeogenesis is a crucial process to maintain glucose level during starvation. However, unabated glucose production in diabetic patients is a major contributor to hyperglycemia. Palmitoleic acid is a monounsaturated fatty acid (16:1n7) that is available from dietary sources. Palmitoleic acid exhibits health beneficial effects on diabetes, insulin resistance, inflammation, and metabolic syndrome. However, the mechanism by which palmitoleate reduces blood glucose is still unclear. SIRT3 is a key metabolism-regulating NAD+-dependent protein deacetylase. It is known that fasting elevates the expression of SIRT3 in the liver and it regulates many aspects of liver’s response to nutrient deprivation, such as fatty …

Β-Carotene Oxygenase 2 Genotype Modulates The Impact Of Dietary Lycopene On Gene Expression During Early Tramp Prostate Carcinogenesis, Nancy E Moran, Jennifer M Thomas-Ahner, Joshua W Smith, Ceasar Silva, Noor A Hason, John W Erdman, Steven K Clinton

Children’s Nutrition Research Center Staff Publications

Background: Epidemiologic studies suggest lycopene and tomato intake are inversely associated with human prostate cancer incidence. In the genetically driven murine prostate carcinogenesis model transgenic adenocarcinoma of the mouse prostate (TRAMP), prostate cancer is inhibited by feeding of lycopene or tomatoes, and these effects are modulated by the β-carotene oxygenase 2 (Bco2) genotype.

Objective: We sought insight into this interaction through evaluation of prostate gene expression patterns during early TRAMP carcinogenesis.

Methods: Three-week-old TRAMP/+ or TRAMP/- × Bco2+/+ or Bco2-/- mice were fed a control, lycopene beadlet, or 10% tomato powder-containing semipurified diet (providing 0, 384 and 462 mg lycopene/kg …

Disrupting The Myc-Tfeb Circuit Impairs Amino Acid Homeostasis And Provokes Metabolic Anergy, Mario R Fernandez, Franz X Schaub, Chunying Yang, Weimin Li, Seongseok Yun, Stephanie K Schaub, Frank C Dorsey, Min Liu, Meredith A Steeves, Andrea Ballabio, Alexandar Tzankov, Zhihua Chen, John M Koomen, Anders E Berglund, John L Cleveland

Duncan NRI Faculty and Staff Publications

MYC family oncoproteins are regulators of metabolic reprogramming that sustains cancer cell anabolism. Normal cells adapt to nutrient-limiting conditions by activating autophagy, which is required for amino acid (AA) homeostasis. Here we report that the autophagy pathway is suppressed by Myc in normal B cells, in premalignant and neoplastic B cells of Eμ-Myc transgenic mice, and in human MYC-driven Burkitt lymphoma. Myc suppresses autophagy by antagonizing the expression and function of transcription factor EB (TFEB), a master regulator of autophagy. Mechanisms that sustained AA pools in MYC-expressing B cells include coordinated induction of the proteasome and increases in AA …

Intestinal Deletion Of 3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase Promotes Expansion Of The Resident Stem Cell Compartment, Alexandria M Doerfler, Jun Han, Kelsey E Jarrett, Li Tang, Antrix Jain, Alexander Saltzman, Marco De Giorgi, Marcel Chuecos, Ayrea E Hurley, Ang Li, Pauline Morand, Claudia Ayala, David R Goodlett, Anna Malovannaya, James F Martin, Thomas Q De Aguiar Vallim, Noah Shroyer, William R Lagor

Faculty, Staff and Students Publications

BACKGROUND: The intestine occupies the critical interface between cholesterol absorption and excretion. Surprisingly little is known about the role of de novo cholesterol synthesis in this organ, and its relationship to whole body cholesterol homeostasis. Here, we investigate the physiological importance of this pathway through genetic deletion of the rate-limiting enzyme.

METHODS: Mice lacking 3-hydroxy-3-methylglutaryl-coenzyme A reductase (Hmgcr) in intestinal villus and crypt epithelial cells were generated using a Villin-Cre transgene. Plasma lipids, intestinal morphology, mevalonate pathway metabolites, and gene expression were analyzed.

RESULTS: Mice with intestine-specific loss of Hmgcr were markedly smaller at birth, but gain …

Perturbed Hematopoiesis In Individuals With Germline Dnmt3a Overgrowth Tatton-Brown-Rahman Syndrome, Ayala Tovy, Carina Rosas, Amos S Gaikwad, Geraldo Medrano, Linda Zhang, Jaime M Reyes, Yung-Hsin Huang, Tastuhiko Arakawa, Kristen Kurtz, Shannon E Conneely, Anna G Guzman, Rogelio Aguilar, Anne Gao, Chun-Wei Chen, Jean J Kim, Melissa T Carter, Amaia Lasa-Aranzasti, Irene Valenzuela, Lionel Van Maldergem, Lorenzo Brunetti, M John Hicks, Andrea N Marcogliese, Margaret A Goodell, Rachel E Rau

Faculty, Staff and Students Publications

Tatton-Brown-Rahman syndrome (TBRS) is an overgrowth disorder caused by germline heterozygous mutations in the DNA methyltransferase DNMT3A. DNMT3A is a critical regulator of hematopoietic stem cell (HSC) differentiation and somatic DNMT3A mutations are frequent in hematologic malignancies and clonal hematopoiesis. Yet, the impact of constitutive DNMT3A mutation on hematopoiesis in TBRS is undefined. In order to establish how constitutive mutation of DNMT3A impacts blood development in TBRS we gathered clinical data and analyzed blood parameters in 18 individuals with TBRS. We also determined the distribution of major peripheral blood cell lineages by flow cytometric analyses. Our analyses revealed non-anemic macrocytosis, …

Single-Cell Transcriptional Profiling Of Murine Conjunctival Immune Cells Reveals Distinct Populations Expressing Homeostatic And Regulatory Genes, Jehan Alam, Ghasem Yazdanpanah, Rinki Ratnapriya, Nicholas Borcherding, Cintia S De Paiva, Dequan Li, Stephen C Pflugfelder

Faculty, Staff and Students Publications

Immune cells in the exposed conjunctiva mucosa defend against environmental and microbial stresses. Expression profiling by single-cell RNA sequencing was performed to identify conjunctival immune cell populations expressing homeostatic and regulatory genes. Fourteen distinct clusters were identified, including myeloid cells (neutrophils, monocytes, macrophages), dendritic cells (DC), and lymphoid cells (B, T, γδT, ILC2, and NK) lineages. Novel neutrophil [lipocalin (Lcn2) high and low), and MHCIIlo macrophage (MP) clusters were identified. More than half of the cells map to myeloid and dendritic cell populations with differential expression profiles that include genes with homeostatic and regulatory functions: Serpinb2 (MHCIIlo macrophage), …

Foxo1 Represses Sprouty 2 And Sprouty 4 Expression To Promote Arterial Specification And Vascular Remodeling In The Mouse Yolk Sac, Nanbing Li-Villarreal, Rebecca Lee Yean Wong, Monica D Garcia, Ryan S Udan, Ross A Poché, Tara L Rasmussen, Alexander M Rhyner, Joshua D Wythe, Mary E Dickinson

Faculty, Staff and Students Publications

Establishing a functional circulatory system is required for post-implantation development during murine embryogenesis. Previous studies in loss-of-function mouse models showed that FOXO1, a Forkhead family transcription factor, is required for yolk sac (YS) vascular remodeling and survival beyond embryonic day (E) 11. Here, we demonstrate that at E8.25, loss of Foxo1 in Tie2-cre expressing cells resulted in increased sprouty 2 (Spry2) and Spry4 expression, reduced arterial gene expression and reduced Kdr (also known as Vegfr2 and Flk1) transcripts without affecting overall endothelial cell identity, survival or proliferation. Using a Dll4-BAC-nlacZ reporter line, we found that one of the earliest expressed …

Pgc1Α/Β Expression Predicts Therapeutic Response To Oxidative Phosphorylation Inhibition In Ovarian Cancer, Carmen Ghilardi, Catarina Moreira-Barbosa, Laura Brunelli, Paola Ostano, Nicolò Panini, Monica Lupi, Alessia Anastasia, Fabio Fiordaliso, Monica Salio, Laura Formenti, Massimo Russo, Edoardo Arrigoni, Ferdinando Chiaradonna, Giovanna Chiorino, Giulio Draetta, Joseph R Marszalek, Christopher P Vellano, Roberta Pastorelli, Mariarosa Bani, Alessandra Decio, Raffaella Giavazzi

Faculty, Staff and Student Publications

Ovarian cancer is the deadliest gynecologic cancer, and novel therapeutic options are crucial to improve overall survival. Here we provide evidence that impairment of oxidative phosphorylation (OXPHOS) can help control ovarian cancer progression, and this benefit correlates with expression of the two mitochondrial master regulators PGC1α and PGC1β. In orthotopic patient-derived ovarian cancer xenografts (OC-PDX), concomitant high expression of PGC1α and PGC1β (PGC1α/β) fostered a unique transcriptional signature, leading to increased mitochondrial abundance, enhanced tricarboxylic acid cycling, and elevated cellular respiration that ultimately conferred vulnerability to OXPHOS inhibition. Treatment with the respiratory chain complex I inhibitor IACS-010759 caused mitochondrial swelling …

Camk2/Camkii Activates Mlkl In Short-Term Starvation To Facilitate Autophagic Flux, Qionghui Zhan, Jaepyo Jeon, Ying Li, Yu Huang, Jian Xiong, Qiaochu Wang, Tian-Le Xu, Yong Li, Fu-Hai Ji, Guangwei Du, Michael X Zhu

Faculty, Staff and Student Publications

MLKL (mixed lineage kinase domain like pseudokinase) is a well-known core component of necrosome that executes necroptotic cell death upon phosphorylation by RIPK3 (receptor interacting serine/threonine kinase 3). Recent studies also implicate a role of MLKL in endosomal trafficking, which is not always dependent on RIPK3. Using mouse Neuro-2a and L929 as well as human HEK293 and HT29 cells, we show here that MLKL is phosphorylated in response to serum and amino acid deprivation from the culture medium, in a manner that depends on CAMK2/CaMKII (calcium/calmodulin dependent protein kinase II) but not RIPK3. The starvation-induced increase in MLKL phosphorylation was …

Alterations Of The Mdm2 C-Terminus Differentially Impact Its Function In Vivo, Vinod Pant, Neeraj K Aryal, Shunbin Xiong, Gilda P Chau, Natalie W Fowlkes, Guillermina Lozano

Faculty, Staff and Student Publications

Murine double minute 2 (Mdm2) is the principal E3-ubiquitin ligase for p53 and contains a C2H2C4 type RING domain wherein the last cysteine residue is followed by an evolutionarily conserved 13 amino acid C-terminal tail. Previous studies have indicated that integrity of the C-terminal tail is critical for Mdm2 function. Recently, a mutation extending the MDM2 length by five amino acids was identified and associated with enhanced p53 response in fibroblasts and premature aging in a human patient. To investigate the importance of the conserved Mdm2 C-terminal length on p53 regulatory function in vivo, we engineered three novel mouse alleles …

Inhibiting Type I Arginine Methyltransferase Activity Promotes T Cell-Mediated Antitumor Immune Responses, Andrew Fedoriw, Leilei Shi, Shane O'Brien, Kimberly N Smitheman, Yunfei Wang, Jiakai Hou, Christian Sherk, Satyajit Rajapurkar, Jenny Laraio, Leila J Williams, Chunyu Xu, Guangchun Han, Qin Feng, Mark T Bedford, Linghua Wang, Olena Barbash, Ryan G Kruger, Patrick Hwu, Helai P Mohammad, Weiyi Peng

Faculty, Staff and Student Publications

Protein arginine methyltransferases (PRMT) are a widely expressed class of enzymes responsible for catalyzing arginine methylation on numerous protein substrates. Among them, type I PRMTs are responsible for generating asymmetric dimethylarginine. By controlling multiple basic cellular processes, such as DNA damage responses, transcriptional regulation, and mRNA splicing, type I PRMTs contribute to cancer initiation and progression. A type I PRMT inhibitor, GSK3368715, has been developed and has entered clinical trials for solid and hematologic malignancies. Although type I PRMTs have been reported to play roles in modulating immune cell function, the immunologic role of tumor-intrinsic pathways controlled by type I …

Comparative Molecular Genomic Analyses Of A Spontaneous Rhesus Macaque Model Of Mismatch Repair-Deficient Colorectal Cancer, Nejla Ozirmak Lermi, Stanton B Gray, Charles M Bowen, Laura Reyes-Uribe, Beth K Dray, Nan Deng, R Alan Harris, Muthuswamy Raveendran, Fernando Benavides, Carolyn L Hodo, Melissa W Taggart, Karen Colbert Maresso, Krishna M Sinha, Jeffrey Rogers, Eduardo Vilar

Faculty, Staff and Student Publications

Colorectal cancer (CRC) remains the third most common cancer in the US with 15% of cases displaying Microsatellite Instability (MSI) secondary to Lynch Syndrome (LS) or somatic hypermethylation of the MLH1 promoter. A cohort of rhesus macaques from our institution developed spontaneous mismatch repair deficient (MMRd) CRC with a notable fraction harboring a pathogenic germline mutation in MLH1 (c.1029C

Effect Of Perfluorocarbon Composition On Activation Of Phase-Changing Ultrasound Contrast Agents, Trevor M Mitcham, Dmitry Nevozhay, Yunyun Chen, Linh D Nguyen, Gianmarco F Pinton, Stephen Y Lai, Konstantin V Sokolov, Richard R Bouchard

Faculty, Staff and Student Publications

BACKGROUND: While microbubble contrast agents (MCAs) are commonly used in ultrasound (US), they are inherently limited to vascular targets due to their size. Alternatively, phase-changing nanodroplet contrast agents (PNCAs) can be delivered as nanoscale agents (i.e., small enough to extravasate), but when exposed to a US field of sufficient mechanical index (MI), they convert to MCAs, which can be visualized with high contrast using nonlinear US.

PURPOSE: To investigate the effect of perfluorocarbon (PFC) core composition and presence of cholesterol in particle coatings on stability and image contrast generated from acoustic activation of PNCAs using high-frequency US suitable for clinical …

Notch-Induced Mdsc Recruitment After Ohsv Virotherapy In Cns Cancer Models Modulates Antitumor Immunotherapy, Yoshihiro Otani, Ji Young Yoo, Cole T Lewis, Samantha Chao, Jessica Swanner, Toshihiko Shimizu, Jin Muk Kang, Sara A Murphy, Kimberly Rivera-Caraballo, Bangxing Hong, Joseph C Glorioso, Hiroshi Nakashima, Sean E Lawler, Yeshavanth Banasavadi-Siddegowda, John D Heiss, Yuanqing Yan, Guangsheng Pei, Michael A Caligiuri, Zhongming Zhao, E Antonio Chiocca, Jianhua Yu, Balveen Kaur

Faculty, Staff and Student Publications

PURPOSE: Oncolytic herpes simplex virus-1 (oHSV) infection of brain tumors activates NOTCH, however the consequences of NOTCH on oHSV-induced immunotherapy is largely unknown. Here we evaluated the impact of NOTCH blockade on virus-induced immunotherapy.

EXPERIMENTAL DESIGN: RNA sequencing (RNA-seq), TCGA data analysis, flow cytometry, Luminex- and ELISA-based assays, brain tumor animal models, and serum analysis of patients with recurrent glioblastoma (GBM) treated with oHSV was used to evaluate the effect of NOTCH signaling on virus-induced immunotherapy.

RESULTS: TCGA data analysis of patients with grade IV glioma and oHSV treatment of experimental brain tumors in mice showed that NOTCH signaling significantly …

Loss Of Rnf43 Accelerates Kras-Mediated Neoplasia And Remodels The Tumor Immune Microenvironment In Pancreatic Adenocarcinoma, Abdel Nasser Hosein, Gita Dangol, Takashi Okumura, Jason Roszik, Kimal Rajapakshe, Megan Siemann, Mohamed Zaid, Bidyut Ghosh, Maria Monberg, Paola A Guerrero, Aatur Singhi, Cara L Haymaker, Hans Clevers, Lotfi Abou-Elkacem, Sonja M Woermann, Anirban Maitra

Faculty, Staff and Student Publications

Background & aims: RNF43 is an E3 ubiquitin ligase that is recurrently mutated in pancreatic ductal adenocarcinoma (PDAC) and precursor cystic neoplasms of the pancreas. The impact of RNF43 mutations on PDAC is poorly understood and autochthonous models have not been characterized sufficiently. In this study, we describe a genetically engineered mouse model (GEMM) of PDAC with conditional expression of oncogenic Kras and deletion of the catalytic domain of Rnf43 in exocrine cells.

Methods: We generated Ptf1a-Cre;LSL-KrasG12D;Rnf43flox/flox (KRC) and Ptf1a-Cre; LSL-KrasG12D (KC) mice and animal survival was assessed. KRC mice were sacrificed at 2 months, 4 months, and at moribund …

Oleic Acid Is An Endogenous Ligand Of Tlx/Nr2e1 That Triggers Hippocampal Neurogenesis, Prasanna Kandel, Fatih Semerci, Rachana Mishra, William Choi, Aleksandar Bajic, Dodge Baluya, Lihua Ma, Kevin Chen, Austin C Cao, Tipwarin Phongmekhin, Nick Matinyan, Alba Jiménez-Panizo, Srinivas Chamakuri, Idris O Raji, Lyra Chang, Pablo Fuentes-Prior, Kevin R Mackenzie, Caroline L Benn, Eva Estébanez-Perpiñá, Koen Venken, David D Moore, Damian W Young, Mirjana Maletic-Savatic

Faculty, Staff and Students Publications

Neural stem cells, the source of newborn neurons in the adult hippocampus, are intimately involved in learning and memory, mood, and stress response. Despite considerable progress in understanding the biology of neural stem cells and neurogenesis, regulating the neural stem cell population precisely has remained elusive because we have lacked the specific targets to stimulate their proliferation and neurogenesis. The orphan nuclear receptor TLX/NR2E1 governs neural stem and progenitor cell self-renewal and proliferation, but the precise mechanism by which it accomplishes this is not well understood because its endogenous ligand is not known. Here, we identify oleic acid (18:1ω9 monounsaturated …

Wwox Binding To The Murine Brca1-Brct Domain Regulates Timing Of Brip1 And Ctip Phospho-Protein Interactions With This Domain At Dna Double-Strand Breaks, And Repair Pathway Choice, Dongju Park, Mehdi Gharghabi, Colleen R Reczek, Rebecca Plow, Charles Yungvirt, C Marcelo Aldaz, Kay Huebner

Faculty, Staff and Student Publications

Wwox-deficient human cells show elevated homologous recombination, leading to resistance to killing by double-strand break-inducing agents. Human Wwox binds to the Brca1 981-PPLF-984 Wwox-binding motif, likely blocking the pChk2 phosphorylation site at Brca1-S988. This phosphorylation site is conserved across mammalian species; the PPLF motif is conserved in primates but not in rodents. We now show that murine Wwox does not bind Brca1 near the conserved mouse Brca1 phospho-S971 site, leaving it open for Chk2 phosphorylation and Brca1 activation. Instead, murine Wwox binds to Brca1 through its BRCT domain, where pAbraxas, pBrip1, and pCtIP, of the A, B, and C binding …

Gut-Derived Butyrate Suppresses Ocular Surface Inflammation, Laura Schaefer, Humberto Hernandez, Rosalind A Coats, Zhiyuan Yu, Stephen C Pflugfelder, Robert A Britton, Cintia S De Paiva

Faculty, Staff and Students Publications

Dry eye is a common ocular inflammatory disorder characterized by tear film instability and reduced tear production. There is increasing evidence that homeostasis of the ocular surface is impacted by the intestinal microbiome. We are interested in investigating the potential role of microbially produced small molecules in mediating the interaction between the intestinal microbiota and the ocular surface. One such molecule is butyrate, a short-chain fatty acid (SCFA) produced by certain members of the gut microbiota through fermentation of dietary fiber. Here we show that SCFA transporter SLC5A8 is expressed in vivo in murine conjunctival and corneal epithelium. Pre-treatment of …

Gut-Derived Butyrate Suppresses Ocular Surface Inflammation, Laura Schaefer, Humberto Hernandez, Rosalind A Coats, Zhiyuan Yu, Stephen C Pflugfelder, Robert A Britton, Cintia S De Paiva

Faculty, Staff and Students Publications

Dry eye is a common ocular inflammatory disorder characterized by tear film instability and reduced tear production. There is increasing evidence that homeostasis of the ocular surface is impacted by the intestinal microbiome. We are interested in investigating the potential role of microbially produced small molecules in mediating the interaction between the intestinal microbiota and the ocular surface. One such molecule is butyrate, a short-chain fatty acid (SCFA) produced by certain members of the gut microbiota through fermentation of dietary fiber. Here we show that SCFA transporter SLC5A8 is expressed in vivo in murine conjunctival and corneal epithelium. Pre-treatment of …

Defining The Mammalian Coactivation Of Hepatic 12-H Clock And Lipid Metabolism, Huan Meng, Naomi M Gonzales, Sung Yun Jung, Yue Lu, Nagireddy Putluri, Bokai Zhu, Clifford C Dacso, David M Lonard, Bert W O'Malley

Faculty, Staff and Students Publications

The 12-h clock coordinates lipid homeostasis, energy metabolism, and stress rhythms via the transcriptional regulator XBP1. However, the biochemical and physiological bases for integrated control of the 12-h clock and diverse metabolic pathways remain unclear. Here, we show that steroid receptor coactivator SRC-3 coactivates XBP1 transcription and regulates hepatic 12-h cistrome and gene rhythmicity. Mice lacking SRC-3 show abnormal 12-h rhythms in hepatic transcription, metabolic functions, systemic energetics, and rate-limiting lipid metabolic processes, including triglyceride, phospholipid, and cardiolipin pathways. Notably, 12-h clock coactivation is not only preserved, with its cistromic activation priming ahead of the zeitgeber cue of light, but …

Ezh2 And Endometrial Cancer Development: Insights From A Mouse Model, Xin Fang, Nan Ni, Xiaofang Wang, Yanan Tian, Ivan Ivanov, Monique Rijnkels, Kayla J Bayless, John P Lydon, Qinglei Li

Faculty, Staff and Students Publications

Enhancer of zeste homolog 2 (EZH2), a core component of polycomb repressive complex 2, plays an important role in cancer development. As both oncogenic and tumor suppressive functions of EZH2 have been documented in the literature, the objective of this study is to determine the impact of Ezh2 deletion on the development and progression of endometrial cancer induced by inactivation of phosphatase and tensin homolog (PTEN), a tumor suppressor gene frequently dysregulated in endometrial cancer patients. To this end, we created mice harboring uterine deletion of both Ezh2 and Pten using Cre recombinase driven by the progesterone receptor …

Glynac (Glycine And N-Acetylcysteine) Supplementation In Mice Increases Length Of Life By Correcting Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Abnormalities In Mitophagy And Nutrient Sensing, And Genomic Damage, Premranjan Kumar, Ob W Osahon, Rajagopal V Sekhar

Faculty, Staff and Students Publications

Determinants of length of life are not well understood, and therefore increasing lifespan is a challenge. Cardinal theories of aging suggest that oxidative stress (OxS) and mitochondrial dysfunction contribute to the aging process, but it is unclear if they could also impact lifespan. Glutathione (GSH), the most abundant intracellular antioxidant, protects cells from OxS and is necessary for maintaining mitochondrial health, but GSH levels decline with aging. Based on published human studies where we found that supplementing glycine and N-acetylcysteine (GlyNAC) improved/corrected GSH deficiency, OxS and mitochondrial dysfunction, we hypothesized that GlyNAC supplementation could increase longevity. We tested our hypothesis …

Depletion Of Transmembrane Mucin 4 (Muc4) Alters Intestinal Homeostasis In A Genetically Engineered Mouse Model Of Colorectal Cancer, Ramesh Pothuraju, Priya Pai, Sanjib Chaudhary, Jawed A Siddiqui, Jesse L Cox, Sukhwinder Kaur, Satyanarayana Rachagani, Hemant K Roy, Michael Bouvet, Surinder K Batra

Faculty, Staff and Students Publications

Mucins are components of the mucus layer overlying the intestinal epithelial cells, which maintains physiological homeostasis. Altered mucin expression is associated with disease progression. Expression of MUC4 decreases in colorectal cancer (CRC); however, its functional role and implications in the intestinal pathology in CRC are not studied well. Therefore, we generated a genetically engineered Muc4 knockout (Muc4-/-) CRC mouse model by crossing with Muc4-/- and Apc^flox/flox mice in the presence of colon-specific inducible Cre. We observed that deficiency of Muc4 results in an increased number of macroscopic tumors in the colon and rectal region and leads to poor survival. …

Daam2 Regulates Myelin Structure And The Oligodendrocyte Actin Cytoskeleton Through Rac1 And Gelsolin, Carlo D Cristobal, Chih-Yen Wang, Zhongyuan Zuo, Joshua A Smith, Aaron Lindeke-Myers, Hugo J Bellen, Hyun Kyoung Lee

Duncan NRI Faculty and Staff Publications

Myelin is essential to neuronal health and CNS function, and oligodendrocytes (OLs) undergo a complex process of cytoskeletal remodeling to form compact myelin sheaths. We previously discovered that a formin protein, Dishevelled associated activator of morphogenesis 2 (Daam2), suppresses OL differentiation through Wnt signaling; however, its role in cytoskeletal control remains unknown. To investigate this, we used OL-specific Daam2 conditional knockout (Daam2 cKO) mice of either sex and found myelin decompaction during an active period of myelination in postnatal development and motor coordination deficits in adulthood. Using primary OL cultures, we found Daam2-depleted OLs showed morphologic dysregulation during differentiation, suggesting …

Visual Pigment-Deficient Cones Survive And Mediate Visual Signaling Despite The Lack Of Outer Segments, Hui Xu, Nange Jin, Jen-Zen Chuang, Zhao Zhang, Xiaoyue Zhong, Zhijing Zhang, Ching-Hwa Sung, Christophe P Ribelayga, Yingbin Fu

Faculty, Staff and Students Publications

Rhodopsin and cone opsins are essential for light detection in vertebrate rods and cones, respectively. It is well established that rhodopsin is required for rod phototransduction, outer segment disk morphogenesis, and rod viability. However, the roles of cone opsins are less well understood. In this study, we adopted a loss-of-function approach to investigate the physiological roles of cone opsins in mice. We showed that cones lacking cone opsins do not form normal outer segments due to the lack of disk morphogenesis. Surprisingly, cone opsin-deficient cones survive for at least 12 mo, which is in stark contrast to the rapid rod …