Search results for " messenger"
showing 10 items of 1295 documents
Expressional down-regulation of neuronal-type nitric oxide synthase I by glucocorticoids in N1E-115 neuroblastoma cells.
1998
Neuronal-type nitric oxide synthase (NOS I) is involved in ischemia-induced brain damage, and glucocorticoids have been reported to protect from brain damage. This prompted us to investigate if the activity or expression of NOS I was influenced by glucocorticoids. We used the murine neuroblastoma cell line N1E-115 as our experimental model. Short-term incubation (30 min) of the N1E-115 cells with dexamethasone (10 nM to 1 microM) or hydrocortisone (100 nM to 10 microM) did not change the enzymatic activity of NOS I. However, the glucocorticoids inhibited NOS I mRNA expression in a concentration-dependent fashion (down to 53.3 +/- 2. 5% of control). In time-course experiments with 100 nM dex…
Cyclic AMP-dependent and independent stimulations of ovarian steroidogenesis by brain factors in the blowfly, Phormia regina.
2000
0303-7207 doi: DOI: 10.1016/S0303-7207(00)00312-9; The involvement of cyclic-AMP (cAMP) as a potential second messenger in the neurohormonal control of ovarian steroidogenesis was investigated in the adult female blowfly Phormia regina. Individual measurements of ovarian cAMP concentrations and of ovarian biosynthesis of ecdysteroids, stimulated after a protein meal, demonstrated that steroidogenesis is preceded by a peak of cAMP in the ovaries. In vitro, ovarian steroidogenesis was stimulated by cell-permeable analogues of cAMP and by forskolin. Crude brain extracts were also able to elicit a rise of cAMP in the ovaries in vitro and the secretion of ecdysteroids into the medium: such extra…
Congenital secondary hypothyroidism caused by exon skipping due to a homozygous donor splice site mutation in the TSHbeta-subunit gene.
2002
Isolated TSH deficiency as a cause for congenital hypothyroidism is relatively uncommon. Even more rare is the identification of mutations in the TSHβ gene, only four of which have been identified. We here report a 4-month-old girl with isolated TSH deficiency born to consanguineous parents. Sequencing of the TSHβ-subunit gene revealed a homozygous G to A transition at position +5 of the donor splice site of intron 2. TSHβ gene transcript could not be obtained from fibroblasts or white blood cells by illegitimate amplification. Thus, to investigate further the mechanism leading to TSH deficiency in this patient, we used an in vitro exon-trapping system. The mutation at position +5 of the do…
Role of the M3 Muscarinic Acetylcholine Receptor Subtype in Murine Ophthalmic Arteries After Endothelial Removal
2014
We tested the hypothesis that the M3 muscarinic acetylcholine receptor subtype mediates cholinergic responses in murine ophthalmic arteries after endothelial removal.Muscarinic receptor gene expression was determined in ophthalmic arteries with intact and with removed endothelium using real-time PCR. To examine the role of the M3 receptor in mediating vascular responses, ophthalmic arteries from M3 receptor-deficient mice (M3R(-/-)) and respective wild-type controls were studied in vitro. Functional studies were performed in nonpreconstricted arteries with either intact or removed endothelium using video microscopy.In endothelium-intact ophthalmic arteries, mRNA for all five muscarinic rece…
Potential involvement of fas and its ligand in the pathogenesis of Hashimoto's thyroiditis
1997
The mechanisms responsible for thyrocyte destruction in Hashimoto's thyroiditis (HT) are poorly understood. Thyrocytes from HT glands, but not from nonautoimmune thyroids, expressed Fas. Interleukin-1β (IL-1β), abundantly produced in HT glands, induced Fas expression in normal thyrocytes, and cross-linking of Fas resulted in massive thyrocyte apoptosis. The ligand for Fas (FasL) was shown to be constitutively expressed both in normal and HT thyrocytes and was able to kill Fas-sensitive targets. Exposure to IL-1β induced thyrocyte apoptosis, which was prevented by antibodies that block Fas, suggesting that IL-1β-induced Fas expression serves as a limiting factor for thyrocyte destruction. Th…
The impact of alpha1-adrenoceptors up-regulation accompanied by the impairment of beta-adrenergic vasodilatation in hypertension
2008
9 pages, 7 figures, 3 tables.-- PMID: 19060223 [PubMed]
Distribution of osteonectin mRNA and protein during human embryonic and fetal development.
1992
We investigated the temporal and spatial distribution of osteonectin during human embryonic and fetal development, using in situ hybridization and immunohistochemistry. Osteonectin gene expression was generally found in cells exhibiting high rates of matrix production/proliferation. In mineralized tissue, a strong signal was obtained in osteoblasts, odontoblasts, and chondrocytes of the upper hypertrophic and proliferative zones. Chondrocytes of the mineralized zone showed no expression throughout the different stages of development. Strong osteonectin expression was found in odontoblasts of developing teeth. In addition, osteonectin mRNA and protein were detected in several non-mineralize…
Inhibition of ovarian steroidogenesis by cyclic-GMP in a fly
2003
1479-6805 0022-0795; Previous investigations in the female blowfly Phormia regina have shown that 3-isobutyl-1-methylxanthine (IBMX), a broad spectrum inhibitor of phosphodiesterases (PDEs), fails to mimic the steroidogenic effects of cAMP on ovaries, although it efficiently increases the concentrations of this second messenger. In this study, experiments carried out to clear up this contradiction demonstrated that IBMX, besides its effect on cAMP, also increased cGMP concentrations in blowfly ovary and that these two cyclic nucleotides controlled ovarian steroidogenesis antagonistically. In particular, a selective inhibitor of cGMP-specific PDEs, unlike IBMX, had a very strong negative eff…
Acetylcholine mediates the release of IL-8 in human bronchial epithelial cells by a NFkB/ERK-dependent mechanism
2007
Acetylcholine may play a role in cell activation and airway inflammation. We evaluated the levels of both mRNA and protein of muscarinic M(1), M(2), M(3) receptors in human bronchial epithelial cell line (16HBE). 16HBE cells were also stimulated with acetylcholine and extracellular signal-regulated kinase1/2 (ERK1/2) and NFkB pathway activation as well as the IL-8 release was assessed in the presence or absence of the inhibitor of Protein-kinase (PKC) (GF109203X), of the inhibitor of mitogenic activated protein-kinase kinase (MAPKK) (PDO9805), of the inhibitor of kinaseB-alpha phosphorilation (pIkBalpha) (BAY11-7082), and of muscarinic receptor antagonists tiotropium bromide, 4-Diphenylacet…
Effects of Long-Term Nitroglycerin Treatment on Endothelial Nitric Oxide Synthase (NOS III) Gene Expression, NOS III–Mediated Superoxide Production, …
2000
Abstract —Long-term nitroglycerin (NTG) treatment has been shown to be associated with cross-tolerance to endothelium-dependent vasodilators. It may involve increased production of reactive oxygen species (such as superoxide, O 2 ·− ) that rapidly inactivate the nitric oxide (NO) released from the endothelial cells. It remains to be elucidated, however, whether long-term treatment with NTG alters the activity and expression of the endothelial NO synthase (NOS III) and whether this enzyme can contribute to O 2 ·− formation. We studied the influence of long-term NTG treatment on the expression of NOS III as assessed by RNase protection assay and Western blot. Tolerance was measured ex vivo i…