Search results for " Transgenic"
showing 10 items of 522 documents
Creating a conditional mutation of Wnt-1 by antisense transgenesis provides evidence that Wnt-1 is not essential for spermatogenesis.
1993
We have used mice transgenic for an antisense construct for Wnt-1 to study the role of this gene in post-meiotic sperm development. The human PGK-2 promoter provided levels of Wnt-1 antisense mRNA in testes in 5 transgenic lines greatly in excess of Wnt-1 mRNA concentrations, and Wnt-1 mRNA levels were greatly decreased in the lines, by 98% in three of them. There was a general correlation between copy number of the insert, levels of antisense RNA, and decreases in mRNA. There was little effect of the antisense transgene on fertility or testicular histology suggesting that normal levels of Wnt-1 transcript are not essential for spermatogenesis.
Quantitation of Microcomputed Tomography-Imaged Ocular Microvasculature
2010
To quantitatively assess microvascular dimensions in the eyes of neonatal wild-type and VEGF(120)-tg mice, using a novel combination of techniques which permit three-dimensional (3D) image reconstruction.A novel combination of techniques was developed for the accurate 3D imaging of the microvasculature and demonstrated on the hyaloid vasculature of the neonatal mouse eye. Vascular corrosion casting is used to create a stable replica of the vascular network and X-ray microcomputed tomography (muCT) to obtain the 3D images. In-house computer-aided image analysis techniques were then used to perform a quantitative morphological analysis of the images.With the use of these methods, differences …
The endocannabinoid system controls key epileptogenic circuits in the hippocampus.
2006
SummaryBalanced control of neuronal activity is central in maintaining function and viability of neuronal circuits. The endocannabinoid system tightly controls neuronal excitability. Here, we show that endocannabinoids directly target hippocampal glutamatergic neurons to provide protection against acute epileptiform seizures in mice. Functional CB1 cannabinoid receptors are present on glutamatergic terminals of the hippocampal formation, colocalizing with vesicular glutamate transporter 1 (VGluT1). Conditional deletion of the CB1 gene either in cortical glutamatergic neurons or in forebrain GABAergic neurons, as well as virally induced deletion of the CB1 gene in the hippocampus, demonstrat…
Farnesoid X receptor activation increases cholesteryl ester transfer protein expression in humans and transgenic mice
2013
International audience; Cholesteryl ester transfer protein (CETP) activity results in a proatherogenic lipoprotein profile. In cholestatic conditions, farnesoid X receptor (FXR) signaling by bile acids (BA) is activated and plasma HDL cholesterol (HDL-C) levels are low. This study tested the hypothesis that FXR-mediated induction of CETP contributes to this phenotype. Patients with cholestasis and high plasma BA had lower HDL-C levels and higher plasma CETP activity and mass compared with matched controls with low plasma BA (each P < 0.01). BA feeding in APOE3*Leiden transgenic mice expressing the human CETP transgene controlled by its endogenous promoter increased cholesterol within apoB-c…
Analysis of the immune response induced by a single xenoantigen in vivo
2004
Transgenic mice expressing human major histocompatibility complex (MHC) class II molecules would provide a valuable model system for studying murine anti-human MHC immune response. We have previously shown that skin from HLA-DR1 transgenic mice was rejected by control littermates and spleen cells from rejecting mice were able to proliferate to donor cells. The aim of this paper is to analyze the mechanism of recognition of this xenoantigen and the possible involvement of antibody response in anti-HLA-DR1 immune response. Control littermates were immunized with spleen cells from HLA-DR1 transgenic (TG) mice; at indicated times, xenoantigen-specific proliferation and IFNgamma production was a…
Anti-aging activity of the Ink4/Arf locus.
2009
The proteins encoded by the Ink4/Arf locus, p16Ink4a, p19Arf and p15Ink4b are major tumour suppressors that oppose aberrant mitogenic signals. The expression levels of the locus are progressively increased during aging and genome-wide association studies have linked the locus to a number of aging-associated diseases and frailty in humans. However, direct measurement of the global impact of the Ink4/Arf locus on organismal aging and longevity was lacking. In this work, we have examined the fertility, cancer susceptibility, aging and longevity of mice genetically modified to carry one (Ink4/Arf-tg) or two (Ink4/Arf-tg/tg) intact additional copies of the locus. First, increased gene dosage of …
Mesenchymal Stem Cells Improve Motor Functions and Decrease Neurodegeneration in Ataxic Mice
2014
The main objective of this work is to demonstrate the feasibility of using bone marrow-derived stem cells in treating a neurodegenerative disorder such as Friedreich's ataxia. In this disease, the dorsal root ganglia of the spinal cord are the first to degenerate. Two groups of mice were injected intrathecally with mesenchymal stem cells isolated from either wild-type or Fxntm1Mkn/Tg(FXN)YG8Pook (YG8) mice. As a result, both groups presented improved motor skills compared to nontreated mice. Also, frataxin expression was increased in the dorsal root ganglia of the treated groups, along with lower expression of the apoptotic markers analyzed. Furthermore, the injected stem cells expressed th…
Adolescent binge‐ethanol accelerates cognitive impairment and β‐amyloid production and dysregulates endocannabinoid signaling in the hippocampus of A…
2019
Previous research in rodents suggests that the long‐term neurobehavioral disturbances induced by chronic ethanol (EtOH) exposure could be due to endocannabinoid system (ECS) alterations. Moreover, ECS failure has been proposed to mediate the cognitive impairment and β‐amyloid production in Alzheimer disease (AD). Thus, in the present study, we evaluated the effects of adolescent EtOH binge drinking on the cognitive disturbances, hippocampal β‐amyloid levels, and in the ECS expression on a transgenic mouse model (APP/PSEN, AZ) of AD. We exposed AZ and wild‐type mice to a binge‐drinking treatment during adolescence. At 6 and 12 months of age, we evaluated hippocampal‐dependent learning and me…
Effect of circulating growth hormone on muscle IGF-I protein concentration in female mice with growth hormone receptor gene disruption.
2009
Growth hormone (GH) is a potent secretague for circulating insulin-like growth factor-I (IGF-I). The purpose of this study was to examine the effect of circulating GH on muscle IGF-I protein expression using GH transgenic animal models. Three different models were used: mice that overexpress bovine GH (bGH; n=10), mice without a functional GH receptor (GHR-/-; n=10), and wildtype mice (n=10). All mice were 16-week old females and each group differed in their basic phenotypic characteristics. Immediately after euthanization the triceps surae muscle group (soleus, plantaris, and gastrocnemius muscles) was removed. IGF-I was extracted from the muscle with an acid-ethanol solution (12.5% 2N hyd…
MORT1/FADD is involved in liver regeneration
2006
AIM: To explore the role of the adaptor molecule in liver regeneration after partial hepatectomy (PH). METHODS: We used transgenic mice expressing an N-terminal truncated form of MORT1/FADD under the control of the albumin promoter. As previously shown, this transgenic protein abrogated CD95- and CD120a-mediated apoptosis in the liver. Cyclin A expression was detected using Western blotting. ELISA and RT-PCR were used to detect IL-6 and IL-6 mRNA, respectively. DNA synthesis in liver tissue was measured by BrdU staining. RESULTS: Resection of 70% of the liver was followed by a reduced early regenerative response in the transgenic group at 36 h. Accordingly, 36 h after hepatectomy, cyclin A …