scholarly journals Polyamine homeostasis in arginase knockout mice

2007 ◽  
Vol 293 (4) ◽  
pp. C1296-C1301 ◽  
Author(s):  
Joshua L. Deignan ◽  
Justin C. Livesay ◽  
Lisa M. Shantz ◽  
Anthony E. Pegg ◽  
William E. O'Brien ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Polyamine Metabolism ◽  
Mrna Levels ◽  
Ornithine Aminotransferase ◽  
Double Knockout ◽  
Mammalian Tissues ◽  
Knockout Animals ◽  
Regulatory Functions ◽  
Arginase I

The role of ornithine decarboxylase (ODC) in polyamine metabolism has long been established, but the exact source of ornithine has always been unclear. The arginase enzymes are capable of producing ornithine for the production of polyamines and may hold important regulatory functions in the maintenance of this pathway. Utilizing our unique set of arginase single and double knockout mice, we analyzed polyamine levels in the livers, brains, kidneys, and small intestines of the mice at 2 wk of age, the latest timepoint at which all of them are still alive, to determine whether tissue polyamine levels were altered in response to a disruption of arginase I (AI) and II (AII) enzymatic activity. Whereas putrescine was minimally increased in the liver and kidneys from the AII knockout mice, spermidine and spermine were maintained. ODC activity was not greatly altered in the knockout animals and did not correlate with the fluctuations in putrescine. mRNA levels of ornithine aminotransferase (OAT), antizyme 1 (AZ1), and spermidine/spermine- N1-acetyltransferase (SSAT) were also measured and only minor alterations were seen, most notably an increase in OAT expression seen in the liver of AI knockout and double knockout mice. It appears that putrescine catabolism may be affected in the liver when AI is disrupted and ornithine levels are highly reduced. These results suggest that endogenous arginase-derived ornithine may not directly contribute to polyamine homeostasis in mice. Alternate sources such as diet may provide sufficient polyamines for maintenance in mammalian tissues.

Role of GM-CSF in a mouse model of experimental autoimmune prostatitis

2019 ◽  
Vol 317 (1) ◽  
pp. F23-F29 ◽  
Author(s):  
Yaxiao Liu ◽  
Yan Li ◽  
Qinggang Liu ◽  
Zonglong Wu ◽  
Jianfeng Cui ◽  
...  
Keyword(s):  
Mouse Model ◽  
Dorsal Root Ganglia ◽  
Knockout Mice ◽  
Dorsal Root ◽  
Prostate Tissue ◽  
Mrna Levels ◽  
Gm Csf ◽  
Mouse Prostate ◽  
Experimental Autoimmune

The etiology of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is still unknown. Granulocyte macrophage colony-stimulating factor (GM-CSF) has been shown to play an important role in the development of autoimmune and inflammatory diseases. Here, we investigated the expression and function of GM-CSF in patients with CP/CPPS and in a mouse model of experimental autoimmune prostatitis (EAP). GM-CSF mRNA levels were detected in expressed prostatic secretions samples from patients with CP/CPPS and in prostate tissue from a mouse model of EAP. The expression of GM-CSF receptor in mouse prostate and dorsal root ganglia were determined using PCR and immunohistochemistry. Behavioral testing and inflammation scoring were performed to evaluate the role of GM-CSF in disease development and symptom severity of EAP using GM-CSF knockout mice. mRNA levels of putative nociceptive and inflammatory markers were measured in the prostate after the induction of EAP. Elevated GM-CSF mRNA levels were observed in expressed prostatic secretions samples from patients with CP/CPPS compared with healthy volunteers. GM-CSF mRNA was also significantly increased in prostate tissue of the EAP mice model. The expression of GM-CSF receptors was confirmed in mouse prostate and dorsal root ganglia. GM-CSF knockout mice showed fewer Infiltrating leukocytes and pain symptoms after the induction of EAP. Deletion of GM-CSF significantly diminished EAP-induced increases of chemokine (C-C motif) ligand 2, chemokine (C-C motif) ligand 3, and nerve growth factor mRNA expression. The results indicated that GM-CSF plays a functional role in the pathogenesis of EAP. GM-CSF may function as a signaling mediator for both inflammation and pain transduction in CP/CPPS.

scholarly journals Athyroid Pax8−/− Mice Cannot Be Rescued by the Inactivation of Thyroid Hormone Receptor α1

Endocrinology ◽  
2005 ◽  
Vol 146 (7) ◽  
pp. 3179-3184 ◽  
Author(s):  
Jens Mittag ◽  
Sönke Friedrichsen ◽  
Heike Heuer ◽  
Silke Polsfuss ◽  
Theo J. Visser ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Thyroid Hormones ◽  
Hormone Receptor ◽  
Thyroid Hormone Receptor ◽  
Postnatal Life ◽  
Mrna Levels ◽  
Negative Effects ◽  
Double Knockout ◽  
Short Life Span ◽  
Knockout Animals

Abstract The Pax8−/− mouse provides an ideal animal model to study the consequences of congenital hypothyroidism, because its only known defect is the absence of thyroid follicular cells. Pax8−/− mice are, therefore, completely athyroid in postnatal life and die around weaning unless they are substituted with thyroid hormones. As reported recently, Pax8−/− mice can also be rescued and survive to adulthood by the additional elimination of the entire thyroid hormone receptor α (TRα) gene, yielding Pax8−/−TRαo/o double-knockout animals. This observation has led to the hypothesis that unliganded TRα1 might be responsible for the lethal phenotype observed in Pax8−/− animals. In this study we report the generation of Pax8−/−TRα1−/− double-knockout mice that still express the non-T3-binding TR isoforms α2 and Δα2. These animals closely resemble the phenotype of Pax8−/− mice, including growth retardation and a completely distorted appearance of the pituitary with thyrotroph hyperplasia and hypertrophy, extremely high TSH mRNA levels, reduced GH mRNA expression, and the almost complete absence of lactotrophs. Like Pax8−/− mice, Pax8−/−TRα1−/− compound mutants die around weaning unless they are substituted with thyroid hormones. These findings do not support the previous interpretation that the short life span of Pax8−/− mice is due to the negative effects of the TRα1 aporeceptor, but, rather, suggest a more complex mechanism involving TRα2 and an unliganded TR isoform.

scholarly journals Dendritic spine morphology and memory formation depend on postsynaptic Caskin proteins

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Norbert Bencsik ◽  
Szilvia Pusztai ◽  
Sándor Borbély ◽  
Anna Fekete ◽  
Metta Dülk ◽  
...  
Keyword(s):  
Dendritic Spine ◽  
Knockout Mice ◽  
Hippocampal Neurons ◽  
Pain Perception ◽  
Hippocampal Slices ◽  
Scaffold Proteins ◽  
Double Knockout ◽  
Learning Abilities ◽  
Spine Morphology

AbstractCASK-interactive proteins, Caskin1 and Caskin2, are multidomain neuronal scaffold proteins. Recent data from Caskin1 knockout animals indicated only a mild role of Caskin1 in anxiety and pain perception. In this work, we show that deletion of both Caskins leads to severe deficits in novelty recognition and spatial memory. Ultrastructural analyses revealed a reduction in synaptic profiles and dendritic spine areas of CA1 hippocampal pyramidal neurons of double knockout mice. Loss of Caskin proteins impaired LTP induction in hippocampal slices, while miniature EPSCs in dissociated hippocampal cultures appeared to be unaffected. In cultured Caskin knockout hippocampal neurons, overexpressed Caskin1 was enriched in dendritic spine heads and increased the amount of mushroom-shaped dendritic spines. Chemically induced LTP (cLTP) mediated enlargement of spine heads was augmented in the knockout mice and was not influenced by Caskin1. Immunocytochemistry and immunoprecipitation confirmed that Shank2, a master scaffold of the postsynaptic density, and Caskin1 co-localized within the same complex. Phosphorylation of AMPA receptors was specifically altered by Caskin deficiency and was not elevated by cLTP treatment further. Taken together, our results prove a previously unnoticed postsynaptic role of Caskin scaffold proteins and indicate that Caskins influence learning abilities via regulating spine morphology and AMPA receptor localisation.

Investigating the role of interleukin-17 in radiation dermatitis.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e24094-e24094
Author(s):  
Karolina Mieczkowska ◽  
Alana Deutsch ◽  
Beth McLellan ◽  
Rafi Kabarriti ◽  
N. Patrik Brodin ◽  
...  
Keyword(s):  
Knockout Mice ◽  
Target Genes ◽  
Neutralizing Antibody ◽  
Cell Types ◽  
Radiation Dermatitis ◽  
Interleukin 17 ◽  
Mrna Levels ◽  
Inflammatory Dermatoses ◽  
Skin Stretching

e24094 Background: Up to 95% of patients receiving radiation therapy (RT) develop radiation dermatitis (RD), which can be therapy-limiting and detrimental to quality of life. Despite its ubiquity, no evidence-based gold standard for the management of RD exists, which highlights the inadequate understanding of its pathogenesis. Prior studies have suggested a role of the pro-inflammatory cytokine interleukin 17 (IL-17) in RD pathogenesis. Its pathway is known to be vital in other inflammatory dermatoses and anti-IL-17 antibodies are already in clinical use. Our goal is to mechanistically understand how RT leads to inflammation in the skin and demonstrate that we can inhibit these pathways and effectively manage RD. Methods: To test the effect of irradiation on the IL-17 pathway, mice were anesthetized and flank skin was stretched to form an exposure area. A single dose of 25 Gy was given. Controls were sham-irradiated and subjected to the same anesthesia and skin stretching. Three weeks after irradiation, we analyzed mRNA levels of IL-17 target genes by qRT-PCR. Furthermore, we utilized single cell RNA-sequencing (scRNA-seq) to profile cells from sham and irradiated skin. To elucidate the role of IL-17, we tested the effect of IL-17A blockade on RD severity in our mouse model. Of note, IL-17A utilizes IL-17 Receptor Type C (IL-17RC) as the membrane-bound receptor in its signaling cascade. Three treatment groups were established: sham receiving no radiation or drug, control receiving saline and radiation, and experimental receiving IL-17A neutralizing antibody and radiation. Mice receiving saline or neutralizing antibody had an intravenous infusion prior to irradiation and weekly thereafter. At the end of week 4, radiated skin was dissected and used for gene expression analysis and histology. To more meticulously study the contribution and requirement of keratinocyte IL-17RC for the development of RD, we generated keratinocyte-specific IL-17RC knockout mice and applied the abovementioned protocol to knockout and control cohorts. RD severity was assessed 8 weeks post irradiation. Results: mRNA levels of S100a8 and S100a9, markers of IL-17 pathway activation, are upregulated in irradiated skin and their expression strongly correlates with increased RD severity ( P < 0.001). From the scRNA-seq, we found that CD103+ dendritic cells and natural killer cells, known immunologic cell types of cutaneous radiation syndrome, were more abundant in irradiated skin. We also identified a novel keratinocyte subtype with abundant IL-17RC mRNA that was exclusive to the irradiated group. Mice receiving IL-17A neutralizing antibody as well as keratinocyte-specific IL-17RC knockout mice, showed a significant reduction in RD severity as compared to controls ( P = 0.0022). Conclusions: The IL-17 pathway plays a significant role in the pathogenesis of RD. Inhibition of this signaling within keratinocytes prevented the development of severe RD in a murine model.

scholarly journals Protective Role of Interleukin-1 in Mycobacterial Infection in IL-1 α/β Double-Knockout Mice

2000 ◽  
Vol 80 (5) ◽  
pp. 759-767 ◽  
Author(s):  
Hiroyuki Yamada ◽  
Satoru Mizumo ◽  
Reiko Horai ◽  
Yoichiro Iwakura ◽  
Isamu Sugawara
Keyword(s):  
Knockout Mice ◽  
Interleukin 1 ◽  
Mycobacterial Infection ◽  
Protective Role ◽  
Double Knockout

scholarly journals Compensation by Fibroblast Growth Factor 1 (FGF1) Does Not Account for the Mild Phenotypic Defects Observed in FGF2 Null Mice

2000 ◽  
Vol 20 (6) ◽  
pp. 2260-2268 ◽  
Author(s):  
David L. Miller ◽  
Sagrario Ortega ◽  
Omar Bashayan ◽  
Ross Basch ◽  
Claudio Basilico
Keyword(s):  
Wound Healing ◽  
Growth Factor ◽  
Fibroblast Growth Factor ◽  
Knockout Mice ◽  
Fibroblast Growth ◽  
Pressure Regulation ◽  
Double Knockout ◽  
Physiological Conditions ◽  
Gene Knockouts ◽  
Knockout Animals

ABSTRACT Fibroblast growth factor 1 (FGF1) and FGF2, the prototypic members of the FGF family of growth factors, have been implicated in a variety of physiological and pathological processes. Unlike most other FGFs, FGF1 and FGF2 are ubiquitously expressed and are not efficiently secreted. Gene knockouts in mice have previously demonstrated a role for FGF2 in brain development, blood pressure regulation, and wound healing. The relatively mild phenotypic defects associated with FGF2 deletion led to the hypothesis that the continued expression of other FGFs partially compensated for the absence of FGF2 in these mice. We now report our generation of mice lacking FGF1 and their use, in combination with our previously described FGF2 null mice, to produce mice lacking both FGF1 and FGF2. FGF1-FGF2 double-knockout mice are viable and fertile and do not display any gross phenotypic defects. In the double-knockout mice we observed defects that were similar in extent to those previously described for the FGF2 null mice. Differences in the organization of neurons of the frontal motor cortex and in the rates of wound healing were observed. We also observed in FGF2−/− mice and in FGF1-FGF2 double-knockout mice novel impairments in hematopoiesis that were similar in severity. Essentially no abnormalities were found in mice lacking only FGF1. Our results suggest that the relatively mild defects in FGF2 knockout animals are not a consequence of compensation by FGF1 and suggest highly restricted roles for both factors under normal developmental and physiological conditions.

scholarly journals Hypothalamic-Pituitary Cytokine Network

Endocrinology ◽  
2004 ◽  
Vol 145 (1) ◽  
pp. 104-112 ◽  
Author(s):  
Anastasia Kariagina ◽  
Dmitry Romanenko ◽  
Song-Guang Ren ◽  
Vera Chesnokova
Keyword(s):  
Hpa Axis ◽  
Knockout Mice ◽  
Single Gene ◽  
Pituitary Cells ◽  
Mrna Levels ◽  
Acth Secretion ◽  
Double Knockout ◽  
Cytokine Network ◽  
Human Pituitary

Abstract Cytokines expressed in the brain and involved in regulating the hypothalamus-pituitary-adrenal (HPA) axis contribute to the neuroendocrine interface. Leukemia inhibitory factor (LIF) and LIF receptors are expressed in human pituitary cells and murine hypothalamus and pituitary. LIF potently induces pituitary proopiomelanocortin (POMC) gene transcription and ACTH secretion and potentiates CRH induction of POMC. In vivo, LIF, along with CRH, enhances POMC expression and ACTH secretion in response to emotional and inflammatory stress. To further elucidate specific roles for both CRH and LIF in activating the inflammatory HPA response, double-knockout mice (CRH/LIFKO) were generated by breeding the null mutants for each respective single gene. Inflammation produced by ip injection of lipopolysaccharide (1 μg/mouse) to double CRH and LIF-deficient mice elicited pituitary POMC induction similar to wild type and markedly higher than in single null animals (P &lt; 0.0.01). Double-knockout mice also demonstrated robust corticosterone response to inflammation. High pituitary POMC mRNA levels may reflect abundant TNFα, IL-1β, and IL-6 activation observed in the hypothalamus and pituitary of these animals. Our results suggest that increased central proinflammatory cytokine expression can compensate for the impaired HPA axis function and activates inflammatory ACTH and corticosterone responses in mice-deficient in both CRH and LIF.

scholarly journals Individual Somatic H1 Subtypes Are Dispensable for Mouse Development Even in Mice Lacking the H10Replacement Subtype

2001 ◽  
Vol 21 (23) ◽  
pp. 7933-7943 ◽  
Author(s):  
Yuhong Fan ◽  
Allen Sirotkin ◽  
Robert G. Russell ◽  
Julianna Ayala ◽  
Arthur I. Skoultchi
Keyword(s):  
Knockout Mice ◽  
Knockout Mouse ◽  
Embryonic Stem ◽  
Mouse Development ◽  
Double Knockout ◽  
Linker Histones ◽  
Deficient Mice ◽  
Mouse Lines

ABSTRACT H1 linker histones are involved in facilitating the folding of chromatin into a 30-nm fiber. Mice contain eight H1 subtypes that differ in amino acid sequence and expression during development. Previous work showed that mice lacking H10, the most divergent subtype, develop normally. Examination of chromatin in H10−/− mice showed that other H1s, especially H1c, H1d, and H1e, compensate for the loss of H10 to maintain a normal H1-to-nucleosome stoichiometry, even in tissues that normally contain abundant amounts of H10 (A. M. Sirotkin et al., Proc. Natl. Acad. Sci. USA 92:6434–6438, 1995). To further investigate the in vivo role of individual mammalian H1s in development, we generated mice lacking H1c, H1d, or H1e by homologous recombination in mouse embryonic stem cells. Mice lacking any one of these H1 subtypes grew and reproduced normally and did not exhibit any obvious phenotype. To determine whether one of these H1s, in particular, was responsible for the compensation present in H10−/− mice, each of the three H1 knockout mouse lines was bred with H10 knockout mice to generate H1c/H10, H1d/H10, or H1e/H10double-knockout mice. Each of these doubly H1-deficient mice also was fertile and exhibited no anatomic or histological abnormalities. Chromatin from the three double-knockout strains showed no significant change in the ratio of total H1 to nucleosomes. These results suggest that any individual H1 subtype is dispensable for mouse development and that loss of even two subtypes is tolerated if a normal H1-to-nucleosome stoichiometry is maintained. Multiple compound H1 knockouts will probably be needed to disrupt the compensation within this multigene family.

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