Specific expression and function of inositol 1,4,5-trisphosphate 3-kinase C (ITPKC) in wild type and knock-out mice

Freeze-fracture electron microscopy (FFEM) of kidney collecting duct, muscle, astrocytes in brain, and other mammalian tissues has revealed regular square arrays of intramembrane particles called orthogonal arrays of particles (OAPs). Their possible role in membrane structure and transport have been proposed, and their absence or decrease has been noted in a variety of hereditary and acquired diseases. A transgenic mouse lacking water channel AQP4 was used to show that AQP4 is the OAP protein. FFEM was done on kidney, skeletal muscle, and brain from AQP4 wild-type [+/+], heterozygous [+/−] and knock-out [-/-] mice. The [-/-] mice did not express detectable AQP4 protein, but were grossly indistinguishable from [+/+] mice. FFEM was done on blinded samples of kidney, brain and muscle from 9 mice. In all 6 kidney samples from [+/+] and [+/−] mice, OAPs similar to those in AQP4-transfected CHO cells were found in basolateral membranes of collecting duct principal cells. In all muscle and brain samples from [+/+] and [+/−] mice, OAPs of identical ultrastructure to those in kidney were seen, but in smaller patch sizes. OAPs were not seen in any sample from [-/-] mice. Label-fracture analysis using a peptide-derived AQP4 polyclonal antibody showed immunogold labeling of OAPs in AQP4-expressing CHO cells. These studies provide direct evidence that AQP4 is required for formation of OAPs and is a component of OAPs, thus establishing the identity and function of OAPs.

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High-bandwidth atomic force microscopy (AFM) based rheology of murine cartilage reveals degeneration of collagen IX knock out mice cartilage compared to wild type cartilage in terms of equilibrium and dynamic fluid-solid interaction properties

Osteoarthritis and Cartilage ◽

10.1016/j.joca.2018.02.132 ◽

2018 ◽

Vol 26 ◽

pp. S61-S62

Author(s):

R. Oftadeh ◽

J. Heilig ◽

F. Zaucke ◽

A. Niehoff ◽

A.J. Grodzinsky

Keyword(s):

Atomic Force Microscopy ◽

Wild Type ◽

Knock Out ◽

Force Microscopy ◽

Atomic Force ◽

High Bandwidth ◽

Knock Out Mice ◽

Collagen Ix ◽

Fluid Solid Interaction

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Difference in Perseverative Errors during a Visual Attention Task with Auditory Distractors in Alpha-9 Nicotinic Receptor Subunit Wild Type and Knock-Out Mice

Frontiers in Cellular Neuroscience ◽

10.3389/fncel.2017.00357 ◽

2017 ◽

Vol 11 ◽

Cited By ~ 4

Author(s):

Pascal Jorratt ◽

Paul H. Delano ◽

Carolina Delgado ◽

Alexies Dagnino-Subiabre ◽

Gonzalo Terreros

Keyword(s):

Visual Attention ◽

Nicotinic Receptor ◽

Receptor Subunit ◽

Wild Type ◽

Attention Task ◽

Knock Out ◽

Perseverative Errors ◽

Knock Out Mice ◽

Auditory Distractors

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Retinol Saturase Knock-Out Mice are Characterized by Impaired Clearance of Apoptotic Cells and Develop Mild Autoimmunity

Biomolecules ◽

10.3390/biom9110737 ◽

2019 ◽

Vol 9 (11) ◽

pp. 737 ◽

Cited By ~ 2

Author(s):

Zsolt Sarang ◽

Tibor Sághy ◽

Zsófia Budai ◽

László Ujlaky-Nagy ◽

Judit Bedekovics ◽

...

Keyword(s):

Transglutaminase 2 ◽

Tissue Homeostasis ◽

Apoptotic Cells ◽

Wild Type ◽

Integrin Receptors ◽

Macrophage Differentiation ◽

Phagocytic Capacity ◽

Knock Out ◽

Knock Out Mice ◽

Number Of Cells

Apoptosis and the proper clearance of apoptotic cells play a central role in maintaining tissue homeostasis. Previous work in our laboratory has shown that when a high number of cells enters apoptosis in a tissue, the macrophages that engulf them produce retinoids to enhance their own phagocytic capacity by upregulating several phagocytic genes. Our data indicated that these retinoids might be dihydroretinoids, which are products of the retinol saturase (RetSat) pathway. In the present study, the efferocytosis of RetSat-null mice was investigated. We show that among the retinoid-sensitive phagocytic genes, only transglutaminase 2 responded in macrophages and in differentiating monocytes to dihydroretinol. Administration of dihydroretinol did not affect the expression of the tested genes differently between differentiating wild type and RetSat-null monocytes, despite the fact that the expression of RetSat was induced. However, in the absence of RetSat, the expression of numerous differentiation-related genes was altered. Among these, impaired production of MFG-E8, a protein that bridges apoptotic cells to the αvβ3/β5 integrin receptors of macrophages, resulted in impaired efferocytosis, very likely causing the development of mild autoimmunity in aged female mice. Our data indicate that RetSat affects monocyte/macrophage differentiation independently of its capability to produce dihydroretinol at this stage.

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One-Mutation Model Can Explain Age Incidence in AML Carrying Nucleophosmin (NPM1) Mutations.

Blood ◽

10.1182/blood.v110.11.4312.4312 ◽

2007 ◽

Vol 110 (11) ◽

pp. 4312-4312

Author(s):

Arcangelo Liso ◽

Filippo Castiglione ◽

Antonio Cappuccio ◽

Fabrizio Stracci ◽

Christian Thiede ◽

...

Keyword(s):

Leukemic Cells ◽

Specific Rate ◽

Wild Type ◽

Genetic Event ◽

Knock Out ◽

Incidence Data ◽

Molecular Alterations ◽

Moran Process ◽

Mutation Model ◽

Knock Out Mice

Abstract Acute myeloid leukemia (AML) carrying nucleophosmin (NPM1) mutations and cytoplasmic NPM (NPMc+ AML) accounts for about one-third of all AML patients, and exhibits distinctive biological and clinical features. The role of NPM1 mutations in leukemogenesis remains elusive. Mathematical models have been developed that, starting from cancer incidence data, allow to infer the somatic mutation rate, or the number of genetic events required to cause cancer. We collected data on age at diagnosis of AML patients from four centers in three different countries, and calculated age-specific rates of NPMc+ AML. A total of 4,155 AML patients were investigated. NPM1 mutations these were detected in 1288. Patients carrying NPM1 mutations with age below 20 years and above 59 years were excluded from the study because of the low number of younger cases and because older patients are not always referred to major institutions for diagnosis and treatment. To investigate NPMc+ AML we adapted one-mutation model published by Michor et al (PNAS, 2006; 103: 14931). The mathematical model consider a population of N (hemopoietic stem) cells that at beginning are wild-type. These cells proliferate according to the Moran process. The growth follows a logistic law with a saturation term. Our process follows the “classical” Moran process up to the appearance of a successful mutant. After that, the clone expands to a limiting population size. This is done to account for the dramatic expansion of the initial compartment peculiar of AML. Finally the rate of AML detection is proportional to the number of mutated cells. Experimental incidence curves of AML in Germany (Ge), Netherlands (Nl), and Italy (It) plotted simultaneously with predicted one-mutation model estimates are shown in Fig. 1. Linear regression of curves representing age-specific rate of diagnoses per year showed similar slopes (about 4 on a double-log scale) in different countries. The one-event model reproduces well the “exponential phenotype” of NPMc+ AML. In conclusion the model is in accordance with the hypothesis that NPM1 mutations by themselves are sufficient to cause NPMc+ AML. Alternatively, it is still possible that NPM1 mutations might cooperate with other molecular alterations to cause AML. In particular, since NPM1 mutations cause haploinsufficiency of wild-type NPM in leukemic cells and in knock-out mice NPM haploinsufficiency results in a MDS-like syndrome and given that the NPM1 mutant has oncogenic properties, these alterations could act in concert to cause AML. Indeed, the effect of these two alterations occurring simultaneously could be seen as a single genetic event. Figure Figure

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Contribution of Lipocalin-2 from Both Myeloid Cells and Epithelium/Liver Is Required for Optimal Resistance to K. Pneumonia Infection

Blood ◽

10.1182/blood.v126.23.883.883 ◽

2015 ◽

Vol 126 (23) ◽

pp. 883-883

Author(s):

Elisabeth Præstekjær Cramer ◽

Sara Louise Dahl ◽

Björn Rozell ◽

Kasper Jermiin Knudsen ◽

Kim Thomsen ◽

...

Keyword(s):

Bone Marrow ◽

Epithelial Cells ◽

Conflicts Of Interest ◽

Neutrophil Migration ◽

Myeloid Cells ◽

Infection Model ◽

Lipocalin 2 ◽

Wild Type ◽

Knock Out ◽

Knock Out Mice

Abstract Introduction NGAL/lipocalin-2 is a siderophore-binding protein stored in high amounts in specific granules of neutrophils. In addition, expression and constitutive secretion of lipocalin-2 can be induced in macrophages and epithelial cells under inflammatory conditions. In mice, lipocalin-2 is furthermore an acute phase-protein. Siderophores are the strongest iron chelators known and are produced by certain microorganisms to retrieve soluble iron from the host. By preventing uptake of siderophore bound iron, lipocalin-2 is bacteriostatic to bacteria that are dependent on this mechanism for uptake of iron. In accordance, lipocalin-2 knock-out mice are susceptible to infection by such bacteria. It is, however, not known whether it is the induced production of lipocalin-2 in epithelial cells and liver or the delivery of lipocalin-2 from infiltrating myeloid cells (neutrophils and macrophages) that is most important for these mechanisms of host defense against invading pathogens. Methods To study the contributions of lipocalin-2 from epithelial cells and liver compared to infiltrating myeloid cells, we used a Klebsiella pneumoniae lung infection model in C57BL/6 mice with chimeric expression of lipocalin-2. Bone marrow transplantation of lethally irradiated mice generated wild type-mice with a lipocalin-2 knock-out bone marrow (WT/KO) expressing lipocalin-2 in epithelium and liver but not in myeloid cells, and conversely knock out-mice with wild-type bone marrow (KO/WT) expressing lipocalin-2 in myeloid cells and not in epithelium and liver. Wild-type mice transplanted with wild-type bone marrow (WT/WT) and knock-out mice transplanted with knock-out bone marrow (KO/KO) were also generated. After 7 weeks of reconstitution, mice were nasally challenged with K. pneumoniae for induction of pneumonia and potential dissemination of the infection. The mice were sacrificed twenty-four hours after inoculation and examined. Results Lipocalin-2 levels in broncho alveolar lavage (BAL) fluid were comparable between WT/KO and KO/WT mice. Consistent with this, no difference in bacterial counts (CFU) in BAL fluid was seen. No differences in spleen CFUs were evident between the two chimeric subgroups WT/KO and KO/WT despite a quantitatively larger mean lipocalin-2 plasma level in WT/KO mice (almost 50 times) derived from epithelium and liver compared to the contribution from myeloid cells in KO/WT mice. However, mean CFU in spleen homogenates from KO/KO mice were more than 870 times higher compared to WT/WT mice. Both the lipocalin-2 contribution from myeloid cells and from epithelium and liver appeared to be indispensable judged by the higher spleen CFUs in mice lacking lipocalin-2 from either of the two compartments. Lipocalin-2 mRNA in the liver was present in equal amounts in mice with wild-type background despite the presence or absence of lipocalin-2 in the myeloid cells. No differences in neutrophil influx to the lungs were seen between groups as determined by MPO ELISA on lung homogenates. We conclude that lipocalin-2 derived both from myeloid cells and from epithelium and liver is required for full resistance to a siderophore-producing pathogen. Despite the higher levels of plasma lipocalin-2 in WT/KO mice compared to KO/WT mice, their bacteriostatic capacity is equal. The induction of lipocalin-2 in the liver is not dependent on the presence of lipocalin-2 in the myeloid cells, just as the migration of neutrophils to the infected lung is not, thus refuting a recent report that lipocalin-2 affects neutrophil migration. Disclosures No relevant conflicts of interest to declare.

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