IU Indianapolis ScholarWorks :: Browsing by Subject "mice"

Browsing by Subject "mice"

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Characterization of Two Distinct Structural Classes of Selective Aldehyde Dehydrogenase 1A1 Inhibitors.
(ACS, 2015-02-26) Morgan, Cynthia A.; Hurley, Thomas D.; Department of Biochemistry & Molecular Biology, IU School of Medicine
Aldehyde dehydrogenases (ALDH) catalyze the irreversible oxidation of aldehydes to their corresponding carboxylic acid. Alterations in ALDH1A1 activity are associated with such diverse diseases as cancer, Parkinson?s disease, obesity, and cataracts. Inhibitors of ALDH1A1 could aid in illuminating the role of this enzyme in disease processes. However, there are no commercially available selective inhibitors for ALDH1A1. Here we characterize two distinct chemical classes of inhibitors that are selective for human ALDH1A1 compared to eight other ALDH isoenzymes. The prototypical members of each structural class, CM026 and CM037, exhibit submicromolar inhibition constants but have different mechanisms of inhibition. The crystal structures of these compounds bound to ALDH1A1 demonstrate that they bind within the aldehyde binding pocket of ALDH1A1 and exploit the presence of a unique glycine residue to achieve their selectivity. These two novel and selective ALDH1A1 inhibitors may serve as chemical tools to better understand the contributions of ALDH1A1 to normal biology and to disease states.
Combined loss of Tet1 and Tet2 promotes B-cell, but not myeloid malignancies in mice.
(Elsevier, 2015-11-24) Zhao, Zhigang; Chen, Li; Dawlaty, Meelad M.; Pan, Feng; Weeks, Ophelia; Zhou, Yuan; Cao, Zeng; Shi, Hui; Wang, Jiapeng; Lin, Li; Chen, Shi; Yuan, Weiping; Qin, Zhaohui; Ni, Hongyu; Nimer, Stephen D.; Yang, Feng-Chun; Jaenisch, Rudolf; Jin, Peng; Xu, Mingjiang; Department of Pediatrics, IU School of Medicine
TET1/2/3 are methylcytosine dioxygenases that regulate cytosine hydroxymethylation. Tet1/2 are abundantly expressed in HSC/HPCs and are implicated in hematological malignancies. Tet2-deletion in mice causes myeloid malignancies, while Tet1-null mice develop B-cell lymphoma after an extended period of latency. Interestingly, TET1/2 are often concomitantly downregulated in acute B-lymphocytic leukemia. Here, we investigated the overlapping and non-redundant functions of Tet1/2 in HSC maintenance and development of hematological malignancies using Tet1/2 double knockout (DKO) mice. DKO and Tet2−/− HSC/HPCs showed overlapping and unique 5hmC and 5mC profiles, and behaved differently. DKO mice exhibited strikingly decreased incidence and delayed-onset of myeloid malignancies compared to Tet2−/− mice, and in contrast developed lethal B-cell malignancies. Transcriptome analysis of DKO tumors revealed expression changes in many genes dysregulated in human B-cell malignancies, such as LMO2, BCL6 and MYC. These results highlight the critical roles of TET1/2 individually and together via communication in the pathogenesis of hematological malignancies.
Development of a Model of the Acute and Delayed Effects of High Dose Radiation Exposure in Jackson Diversity Outbred Mice; Comparison to Inbred C57BL/6 Mice
(Wolters Kluwer, 2020-11) Patterson, Andrea M.; Plett, P. Artur; Chua, Hui Lin; Sampson, Carol H.; Fisher, Alexa; Feng, Hailin; Unthank, Joseph L.; Miller, Steve J.; Katz, Barry P.; MacVittie, Thomas J.; Orschell, Christie M.; Medicine, School of Medicine
Development of medical countermeasures against radiation relies on robust animal models for efficacy testing. Mouse models have advantages over larger species due to economics, ease of conducting aging studies, existence of historical databases, and research tools allowing for sophisticated mechanistic studies. However, the radiation dose-response relationship of inbred strains is inherently steep and sensitive to experimental variables, and inbred models have been criticized for lacking genetic diversity. Jackson Diversity Outbred (JDO) mice are the most genetically diverse strain available, developed by the Collaborative Cross Consortium using eight founder strains, and may represent a more accurate model of humans than inbred strains. Herein, models of the Hematopoietic-Acute Radiation Syndrome and the Delayed Effects of Acute Radiation Exposure were developed in JDO mice and compared to inbred C57BL/6. The dose response relationship curve in JDO mice mirrored the more shallow curves of primates and humans, characteristic of genetic diversity. JDO mice were more radioresistant than C57BL/6 and differed in sensitivity to antibiotic countermeasures. The model was validated with pegylated-G-CSF, which provided significantly enhanced 30-d survival and accelerated blood recovery. Long-term JDO survivors exhibited increased recovery of blood cells and functional bone marrow hematopoietic progenitors compared to C57BL/6. While JDO hematopoietic stem cells declined more in number, they maintained a greater degree of quiescence compared to C57BL/6, which is essential for maintaining function. These JDO radiation models offer many of the advantages of small animals with the genetic diversity of large animals, providing an attractive alternative to currently available radiation animal models.
Ex Vivo Method for Assessing the Mouse Reproductive Tract Spontaneous Motility and a MATLAB-based Uterus Motion Tracking Algorithm for Data Analysis
(Journal of Visualized Experiments, 2019-09-01) Liang, Kaley L.; Bursova, Julia O.; Lam, Frank; Chen, Xingjuan; Obukhov, Alexander G.; Cellular and Integrative Physiology, School of Medicine
Dysmenorrhea, or painful cramping, is the most common symptom associated with menses in females and its severity can hinder women's everyday lives. Here, we present an easy and inexpensive method that would be instrumental for testing new drugs decreasing uterine contractility. This method utilizes the unique ability of the entire mouse reproductive tract to exhibit spontaneous motility when maintained ex vivo in a Petri dish containing oxygenated Krebs buffer. This spontaneous motility resembles the wave-like myometrial activity of the human uterus, referred to as endometrial waves. To demonstrate the effectiveness of the method, we employed a well-known uterine relaxant drug, epinephrine. We demonstrate that the spontaneous motility of the entire mouse reproductive tract can be quickly and reversibly inhibited by 1 µM epinephrine in this Petri dish model. Documenting the changes of uterine motility can be easily done using an ordinary smart phone or a sophisticated digital camera. We developed a MATLAB-based algorithm allowing motion tracking to quantify spontaneous uterine motility changes by measuring the rate of uterine horn movements. A major advantage of this ex vivo approach is that the reproductive tract remains intact throughout the entire experiment, preserving all intrinsic intrauterine cellular interactions. The major limitation of this approach is that up to 10-20% of uteri may exhibit no spontaneous motility. Thus far, this is the first quantitative ex vivo method for assessing spontaneous uterine motility in a Petri dish model.
GPR68 Is a Neuroprotective Proton Receptor in Brain Ischemia
(Lippincott, Williams & Wilkins, 2020-12) Wang, Tao; Zhou, Guokun; He, Mindi; Xu, Yuanyuan; Rusyniak, W.G.; Xu, Yan; Ji, Yonghua; Simon, Roger P.; Xiong, Zhi-Gang; Zha, Xiang-ming; Obstetrics and Gynecology, School of Medicine
Brain acidosis is prevalent in stroke and other neurological diseases. Acidosis can have paradoxical injurious and protective effects. The purpose of this study is to determine whether a proton receptor exists in neurons to counteract acidosis-induced injury. Methods: We analyzed the expression of proton-sensitive GPCRs (G protein-coupled receptors) in the brain, examined acidosis-induced signaling in vitro, and studied neuronal injury using in vitro and in vivo mouse models. Results: GPR68, a proton-sensitive GPCR, was present in both mouse and human brain, and elicited neuroprotection in acidotic and ischemic conditions. GPR68 exhibited wide expression in brain neurons and mediated acidosis-induced PKC (protein kinase C) activation. PKC inhibition exacerbated pH 6-induced neuronal injury in a GPR68-dependent manner. Consistent with its neuroprotective function, GPR68 overexpression alleviated middle cerebral artery occlusion–induced brain injury. Conclusions: These data expand our knowledge on neuronal acid signaling to include a neuroprotective metabotropic dimension and offer GPR68 as a novel therapeutic target to alleviate neuronal injuries in ischemia and multiple other neurological diseases.
Immunology of murine Pneumocystis carinii infection
(1998) Bellagamba, Juan Miguel Pascale
Impaired Annulus Fibrosis Development and Vertebral Fusion Cause Severe Scoliosis in Mice with Deficiency of JNK1 and JNK2
(Elsevier, 2019) Ulici, Veronica; Kelley, Kathryn L.; Longobardi, Lara; McNulty, Margaret A.; Livingston, Eric W.; Bateman, Ted A.; Séguin, Cheryle A.; Louer, Craig R.; Loeser, Richard F.; Anatomy and Cell Biology, IU School of Medicine
MAP kinases, including JNK, play an important role in the development and function of a large variety of tissues. We analyzed the skeletal phenotype of JNK1 and JNK2 double knockout (dKO) mice (JNK1fl/flCol2-Cre/JNK2-/-) and control genotypes, including single knockouts, at different embryonic and postnatal stages. The JNK1/2 dKO mice displayed a severe scoliotic phenotype that began during development and was grossly apparent around weaning age. Alcian blue staining of embryos (E17.5) showed abnormal fusion of the posterior spinal elements. In the adult mice, fusion of vertebral bodies and of spinous and transverse processes was noted by microCT, Alcian blue/Alizarin red stain and histology. The long bones developed normally and histological sections of the growth plate and articular cartilage did not reveal significant abnormalities. Histological sections of the vertebral column at E15.5 and E17.5 revealed an abnormal organization of the annulus fibrosus in the dKOs, with chondrocyte-like cells and fusion of dorsal processes. Spinal sections in 10-week–old dKO mice showed replacement of intervertebral disc structures (annulus fibrosus and nucleus pulposus) by cartilage and bone tissues, with cells staining for markers of hypertrophic chondrocytes including collagen X and Runx2. These findings demonstrate a requirement for both JNK1 and JNK2 in the normal development of the axial skeleton with loss of JNK signaling resulting in abnormal endochondral bone formation and subsequent severe scoliosis.
Ionizing Radiation Affects Epigenetic Programming in Adolescent Mice
(Office of the Vice Chancellor for Research, 2014-04-11) Watkins, Darryl S.; Mendonca, Marc; Lossie, Amy; Zhou, Feng C.
Humans are exposed to low and mild doses of radiation frequently, ranging from the natural environment to medical procedures like x-ray and CT scans. Ionizing radiation of various doses has been known to potentially cause not only cellular but also genomic changes. Here, we demonstrate that epigenetics is also altered by the radiation. Epigenetics is a chemical coding above the gene, which plays critical roles in brain development, cognitive aberrations and other neurological impairments. How radiation, as an external environmental factor, causes epigenetic change is not understood. DNA methylation, key in epigenetics, including 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) have been shown to either suppress or activate gene transcription. To aid in elucidating the role in which radiation affects epigenetic outcomes, we examined the effects of radiation on both epigenetic and phenotypic markers within the hippocampus. In this study we treated, via x-ray C57BL/6 mice, postnatal day (P) 21 with various doses (2Gy-4.5Gy) of radiation coupled with varying frequencies (0.5 Gy x 4, 1.5 Gy x 3, or 4.5Gy x 1) during a 4-week period. We used immunohistochemistry staining with cell proliferation, transcription and epigenetic markers. We found loss of 5mC in the sub-granular layer of the dentate gyrus (DG) in the upper and lower arms. Likewise a loss of 5hmC in the sub-granular layer of the DG, as well as in the cornu Ammonis (CA) layers 1 and 2. There was also loss of a transcriptional activation marker within the DG of the hippocampus. Furthermore, decreased cell proliferation in the adult neurogenesis in the hippocampus was found. Exposure to ionizing radiation altered the normal epigenetic profile of the mice. Understanding the mechanism by which ionizing radiation affects epigenetic programming will provide insight into how to develop protection against the potentially harmful risks associated with radiation exposure.
MOLECULAR MECHANISMS ALTERING SKELETAL DEVELOPMENT AND HOMEOSTASIS IN TS65NDN DOWN SYNDROME MICE
(Office of the Vice Chancellor for Research, 2012-04-13) Blazek, Joshua D.; Malik, Ahmed; Roper, Randall J.
Down syndrome (DS) is caused by three copies of human chromosome 21 (HSA21) and results in abnormal craniofacial and appendicular bone phe-notypes. The Ts65Dn mouse model of DS contains three copies of nearly half of the genes found on HSA21, and exhibits craniofacial skeletal phenotypes similar to those observed in humans with DS. We recently demonstrated ab-normalities in the development and homeostasis of the appendicular skele-ton of Ts65Dn mice. Femurs from trisomic mice exhibit alterations in trabec-ular bone architecture and overall bone strength. Furthermore, bone for-mation rates were found to be significantly reduced, suggesting trisomy im-pacts bone development and maintenance in Ts65Dn mice, and by extension humans with DS. DYRK1A is triplicated in both humans with DS and Ts65Dn mice and its protein acts as a kinase critical during development. Dyrk1A negatively regulates the nuclear localization and activation of Nfatc, a tran-scription factor critical to signaling pathways associated with cell proliferation and bone development, and is overexpressed in the E9.5 Ts65Dn mandible precursor. We hypothesize that the previously documented Ts65Dn bone phenotype originates during embryonic development, and the presence of an extra copy of Dyrk1a contributes to the abnormal bone phenotype observed in Ts65Dn mice and humans with DS. To test our first hypothesis, analysis of the cartilage template and early bone precursor is being conducted on the femurs from embryonic day 17.5 trisomic and euploid embryos. To implicate the involvement of Dyrk1a in the DS bone phenotype, Ts65Dn mice are be-ing treated with a known Dyrk1a inhibitor, EGCG, to determine if correcting the functional expression of Dyrk1a impacts the development of the Ts65Dn postnatal bone phenotype. Understanding the molecular mechanisms under-lying DS bone phenotypes may help improve the quality of life for individuals with DS and provide viable options for the treatment of osteoporosis.
The Need for Speed in Rodent Locomotion Analyses.
(Wiley, 2014-10) Batka, Richard J.; Brown, Todd J.; Mcmillan, Kathryn P.; Meadows, Rena M.; Jones, Kathryn J.; Haulcomb, Melissa M.; Department of Anatomy & Cell Biology, IU School of Medicine
Locomotion analysis is now widely used across many animal species to understand the motor defects in disease, functional recovery following neural injury, and the effectiveness of various treatments. More recently, rodent locomotion analysis has become an increasingly popular method in a diverse range of research. Speed is an inseparable aspect of locomotion that is still not fully understood, and its effects are often not properly incorporated while analyzing data. In this hybrid manuscript, we accomplish three things: (1) review the interaction between speed and locomotion variables in rodent studies, (2) comprehensively analyze the relationship between speed and 162 locomotion variables in a group of 16 wild-type mice using the CatWalk gait analysis system, and (3) develop and test a statistical method in which locomotion variables are analyzed and reported in the context of speed. Notable results include the following: (1) over 90% of variables, reported by CatWalk, were dependent on speed with an average R2 value of 0.624, (2) most variables were related to speed in a nonlinear manner, (3) current methods of controlling for speed are insufficient, and (4) the linear mixed model is an appropriate and effective statistical method for locomotion analyses that is inclusive of speed-dependent relationships. Given the pervasive dependency of locomotion variables on speed, we maintain that valid conclusions from locomotion analyses cannot be made unless they are analyzed and reported within the context of speed.

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