Search results for "Knockout"
showing 10 items of 806 documents
Toll-like receptor 4 defective mice carrying point or null mutations do not show increased susceptibility toCandida albicansin a model of hematogenou…
2006
We have studied the role of TLR4 in murine defenses against Candida albicans in two TLR4-defective mouse strains: C3H/HeJ mice which have defective TLR4 signaling, and TLR4-/- knockout mice. Both TLR4-defective mice strains experimentally infected with virulent C. albicans cells showed no significant difference in survival as compared with their respective controls. Recruitment of neutrophils to the peritoneal cavity of i.p. infected mice was not affected in TLR4-/-animals, but significantly enhanced in C3H/HeJ mice, compared with their control mice. In vitro production of TNF-alpha by macrophages from both types of TLR4-defective mice, in response to yeasts and hyphae of C. albicans, was n…
Role of CB2 cannabinoid receptors in the rewarding, reinforcing, and physical effects of nicotine.
2013
This study was aimed to evaluate the involvement of CB2 cannabinoid receptors (CB2r) in the rewarding, reinforcing and motivational effects of nicotine. Conditioned place preference (CPP) and intravenous self-administration experiments were carried out in knockout mice lacking CB2r (CB2KO) and wild-type (WT) littermates treated with the CB2r antagonist AM630 (1 and 3 mg/kg). Gene expression analyses of tyrosine hydroxylase (TH) and α3- and α4-nicotinic acetylcholine receptor subunits (nAChRs) in the ventral tegmental area (VTA) and immunohistochemical studies to elucidate whether CB2r colocalized with α3- and α4-nAChRs in the nucleus accumbens and VTA were performed. Mecamylamine-precipitat…
Cholinergic Responses of Ophthalmic Arteries in M3and M5Muscarinic Acetylcholine Receptor Knockout Mice
2009
PURPOSE. To determine the functional role of M 3 and M 5 muscarinic acetylcholine receptor subtypes in ophthalmic arteries using gene-targeted mice. METHODS. Muscarinic receptor gene expression was quantified in murine ophthalmic arteries using real-time PCR. To test the functional relevance of M 3 and M 5 receptors, ophthalmic arteries from mice deficient in either subtype (M3R -/- , M5R -/- , respectively) and wild-type controls were isolated, cannulated with micropipettes, and pressurized. Changes in luminal vessel diameter in response to muscarinic and nonmuscarinic receptor agonists were measured by video microscopy. RESULTS. With the use of real-time PCR, all five muscarinic receptor …
Identification of the Muscarinic Acetylcholine Receptor Subtype Mediating Cholinergic Vasodilation in Murine Retinal Arterioles
2011
To identify the muscarinic acetylcholine receptor subtype that mediates cholinergic vasodilation in murine retinal arterioles.Muscarinic receptor gene expression was determined in murine retinal arterioles using real-time PCR. To assess the functional relevance of muscarinic receptors for mediating vascular responses, retinal vascular preparations from muscarinic receptor-deficient mice were studied in vitro. Changes in luminal arteriole diameter in response to muscarinic and nonmuscarinic vasoactive substances were measured by video microscopy.Only mRNA for the M(3) receptor was detected in retinal arterioles. Thus, M(3) receptor-deficient mice (M3R(-/-)) and respective wild-type controls …
Contribution of nitric oxide synthase isoforms to cholinergic vasodilation in murine retinal arterioles.
2013
Abstract Nitric oxide synthases (NOSs) are critically involved in regulation of ocular perfusion. However, the contribution of the individual NOS isoforms to vascular responses is unknown in the retina. Because some previous findings suggested an involvement of inducible nitric oxide synthase (iNOS) in the regulation of retinal vascular tone, a major goal of the present study was to examine the hypothesis that iNOS is involved in mediating cholinergic vasodilation responses of murine retinal arterioles. Another subject of this study was to test the contribution of the other two NOS isoforms, neuronal (nNOS) and endothelial NOS (eNOS), to cholinergic retinal arteriole responses. Expression o…
Role of M1, M3, and M5 muscarinic acetylcholine receptors in cholinergic dilation of small arteries studied with gene-targeted mice
2011
Acetylcholine regulates perfusion of numerous organs via changes in local blood flow involving muscarinic receptor-induced release of vasorelaxing agents from the endothelium. The purpose of the present study was to determine the role of M1, M3, and M5 muscarinic acetylcholine receptors in vasodilation of small arteries using gene-targeted mice deficient in either of the three receptor subtypes (M1R−/−, M3R−/−, or M5R−/− mice, respectively). Muscarinic receptor gene expression was determined in murine cutaneous, skeletal muscle, and renal interlobar arteries using real-time PCR. Moreover, respective arteries from M1R−/−, M3R−/−, M5R−/−, and wild-type mice were isolated, cannulated with mic…
The endocannabinoid system controls food intake via olfactory processes
2014
Comment in Sensory systems: the hungry sense. [Nat Rev Neurosci. 2014] Inhaling: endocannabinoids and food intake. [Nat Neurosci. 2014]; International audience; Hunger arouses sensory perception, eventually leading to an increase in food intake, but the underlying mechanisms remain poorly understood. We found that cannabinoid type-1 (CB1) receptors promote food intake in fasted mice by increasing odor detection. CB1 receptors were abundantly expressed on axon terminals of centrifugal cortical glutamatergic neurons that project to inhibitory granule cells of the main olfactory bulb (MOB). Local pharmacological and genetic manipulations revealed that endocannabinoids and exogenous cannabinoid…
Recognition of Neisseria meningitidis by the long pentraxin PTX3 and its role as an endogenous adjuvant.
2015
Long pentraxin 3 (PTX3) is a non-redundant component of the humoral arm of innate immunity. The present study was designed to investigate the interaction of PTX3 with Neisseria meningitidis. PTX3 bound acapsular meningococcus, Neisseria-derived outer membrane vesicles (OMV) and 3 selected meningococcal antigens (GNA0667, GNA1030 and GNA2091). PTX3-recognized microbial moieties are conserved structures which fulfil essential microbial functions. Ptx3-deficient mice had a lower antibody response in vaccination protocols with OMV and co-administration of PTX3 increased the antibody response, particularly in Ptx3-deficient mice. Administration of PTX3 reduced the bacterial load in infant rats c…
Gene Expression Profiling of Facilitated L-LTP in VP16-CREB Mice Reveals that BDNF Is Critical for the Maintenance of LTP and Its Synaptic Capture
2011
Expression of VP16-CREB, a constitutively active form of CREB, in hippocampal neurons of the CA1 region lowers the threshold for eliciting the late, persistent phase of long-term potentiation (L-LTP) in the Schaffer collateral pathway. This VP16-CREB-mediated L-LTP differs from the conventional late phase of LTP in not being dependent on new transcription. This finding suggests that in the transgenic mice the mRNA transcript(s) encoding the protein(s) necessary for this form of L-LTP might already be present in CA1 neurons in the basal condition. We used high-density oligonucleotide arrays to identify the mRNAs differentially expressed in the hippocampus of transgenic and wild-type mice. We…
Bone marrow stroma CD40 expression correlates with inflammatory mast cell infiltration and disease progression in splenic marginal zone lymphoma
2014
Splenic marginal zone lymphoma (SMZL) is a mature B-cell neoplasm characterized by rather indolent clinical course. However, nearly one third of patients experience a rapidly progressive disease with a dismal outcome. Despite the characterization of clone geneticsandthe recognition of deregulated immunologic stimulation in the pathogenesis of SMZL, little is known about microenvironment dynamics and their potential biological influence on disease outcome. Here we investigate the effect of stroma-intrinsic features on SMZL disease progression by focusing on the microenvironment of the bone marrow (BM), which represents an elective disease localization endorsing diagnostic and prognostic rele…