Search results for "regulation"
showing 10 items of 4463 documents
Involvement of Oxysterols and Lysophosphatidylcholine in the Oxidized LDL–Induced Impairment of Serum Albumin Synthesis by HEPG2 Cells
2000
Abstract —Oxidized low density lipoproteins (Ox-LDLs) are increasingly thought to be a key element in atherogenesis. We have previously reported that serum albumin has important antioxidant properties and that a reduced synthesis of albumin may represent a crucial point in the overall antioxidant defense. In the present work, we aimed at determining whether Ox-LDL could modulate albumin synthesis in cultured human hepatocytes (HepG2 cells). With the use of enzyme immunoassay and radiolabeled leucine incorporation followed by specific immunoprecipitation, Ox-LDL was found to lead to a dose-dependent decrease in albumin secretion. Moreover, the protein synthesis and mRNA levels were decrease…
The nicotinic acetylcholine receptor agonist (±)-epibatidine increases FGF-2 mRNA and protein levels in the rat brain
2000
Abstract In a previous work, we showed that acute intermittent nicotine treatment up-regulates the level of fibroblast growth factor-2 (FGF-2) mRNA in brain regions of tel- and mesencephalon of rats suggesting that neuroprotective effect of (−)nicotine may, at least in part, involve an activation of the neuronal FGF-2 signalling. The present experiments were designed to extend the study on the nicotinic receptor mediated up-regulation of FGF-2 mRNA levels to the use of the potent nicotinic acetylcholine receptor (nAChR) agonist (±)-epibatidine. The (±)-epibatidine treatment led to a strong and long lasting up-regulation of FGF-2 mRNA expression in the cerebral cortex, in the hippocampal for…
Addition of NMDA-receptor antagonist MK801 during oxygen/glucose deprivation moderately attenuates the upregulation of glucose uptake after subsequen…
2011
During stroke the blood–brain barrier (BBB) is damaged which can result in vasogenic brain edema and inflammation. The reduced blood supply leads to decreased delivery of oxygen and glucose to affected areas of the brain. Oxygen and glucose deprivation (OGD) can cause upregulation of glucose uptake of brain endothelial cells. In this letter, we investigated the influence of MK801, a non-competitive inhibitor of the NMDA-receptor, on the regulation of the glucose uptake and of the main glucose transporters glut1 and sglt1 in murine BBB cell line cerebEND during OGD. mRNA expression of glut1 was upregulated 68.7- fold after 6 h OGD, which was significantly reduced by 10 μM MK801 to 28.9-fold.…
Acute exercise induced changes in rat skeletal muscle mRNAs and proteins regulating type IV collagen content
2001
This experiment tested the hypothesis that running-induced damage to rat skeletal muscle causes changes in synthesis and degradation of basement membrane type IV collagen and to proteins regulating its degradation. Samples from soleus muscle and red and white parts of quadriceps femoris muscle (MQF) were collected 6 h or 1, 2, 4, or 7 days after downhill running. Increased muscle β-glucuronidase activity indicated greater muscle damage in the red part of MQF than in the white part of MQF or soleus. In the red part of MQF, type IV collagen expression was upregulated at the pretranslational level and the protein concentration decreased, whereas matrix metalloproteinase-2 (MMP-2), a protein th…
Differential regulation of interleukin-6 expression in human fibroblasts by tumor necrosis factor-alpha and lymphotoxin.
1990
The treatment of human diploid fibroblasts with tumor necrosis factor (TNF)-alpha and with lymphotoxin (LT) is associated with induction of interleukin-6 (IL-6) transcripts with TNF-alpha being 10-fold more potent than LT. Here we report on the TNF-alpha/LT-induced signaling mechanisms responsible for the regulation of IL-6 gene expression in these cells. Run-on assays demonstrated that both TNF-alpha and LT increase IL-6 mRNA levels by transcriptional activation of this gene. Stability studies of IL-6 transcripts in fibroblasts showed that TNF-alpha delayed IL-6 mRNA decay but not LT. The induction of IL-6 transcripts by TNF-alpha and LT was not inhibited by the isoquinoline sulfonamide de…
Zoledronate, ibandronate and clodronate enhance osteoblast differentiation in a dose dependent manner – A quantitative in vitro gene expression analy…
2010
Bisphosphonates are widely used in the clinical treatment of bone diseases with increased bone resorption. In terms of side effects, they are known to be associated with osteonecrosis of the jaw (BONJ). There are two groups of bisphosphonates: the nitrogen-containing bisphosphonates, e.g. zoledronate and ibandronate, and the non-nitrogen-containing bisphosphonates, e.g. clodronate. Their impact on bone metabolism seems to differ. The objective of this study was to compare the osteogenic differentiation potency of these two pharmacologic groups. Human osteoblasts were stimulated with zoledronate and ibandronate at concentrations of 5×10(-5) M, 5×10(-6) M and 5×10(-7) M over the experimental …
Regulation of glomerular basement membrane collagen expression by LMX1B contributes to renal disease in nail patella syndrome.
2001
Basement membrane (BM) morphogenesis is critical for normal kidney function. Heterotrimeric type IV collagen, composed of different combinations of six alpha-chains (1-6), is a major matrix component of all BMs (ref. 2). Unlike in other BMs, glomerular BM (GBM) contains primarily the alpha 3(IV) and alpha 4(IV) chains, together with the alpha 5(IV) chain. A poorly understood, coordinated temporal and spatial switch in gene expression from ubiquitously expressed alpha 1(IV) and alpha 2(IV) collagen to the alpha 3(IV), alpha 4(IV) and alpha 5(IV) chains occurs during normal embryogenesis of GBM (ref. 4). Structural abnormalities of type IV collagen have been associated with diverse biological…
A common mechanism of action of the selective serotonin reuptake inhibitors citalopram and fluoxetine: Reversal of chronic psychosocial stress-induce…
2010
The transcription factor CREB regulates adaptive responses like memory consolidation, addiction, and synaptic refinement. Recently, chronic psychosocial stress as animal model of depression has been shown to stimulate CREB transcriptional activity in the brain; this stimulation was prevented by treatment with the antidepressant imipramine, which inhibits both noradrenaline and serotonin reuptake. However, it was unknown whether the selective inhibition of serotonin reuptake is sufficient for inhibition of stress-induced CREB activation, as it is for the clinical antidepressant effect. Therefore, the effect of two selective serotonin reuptake inhibitors (SSRIs), citalopram and fluoxetine, wa…
Regulation of PTHrP and PTH/PTHrP receptor by extracellular Ca2+ concentration and hormones in the breast cancer cell line 8701-BC.
2000
AbstractIt was previously reported that 8701-BC breast tumour cells express the gene for parathyroid hormonerelated peptide (PTHrP) and PTH/PTHrP receptor (PTHrPR) and release immunoreactive PTHrP (iPTHrP) into the extracellular medium. Since the regulation of PTHrP and PTHrPR by breast cancer cells has been poorly investigated so far, we have chosen the 8701- BC cell line as a model system to investigate whether alterations in the extracellular Ca[2+] concentration ([Ca[2+]]) and treatment with some wellknown differentiation agents for breast cells, such as dimethyl sulfoxide, hydrocortisone, progesterone, prolactin, alltrans retinoic acid and transforming growth factorβ1 might (i) modulat…
p53 Involvement in the control of murine hair follicle regression.
2001
p53 is a transcription factor mediating a variety of biological responses including apoptotic cell death. p53 was recently shown to control apoptosis in the hair follicle induced by ionizing radiation and chemotherapy, but its role in the apoptosis-driven physiological hair follicle regression (catagen) remains to be elucidated. Here, we show that p53 protein is strongly expressed and co-localized with apoptotic markers in the regressing hair follicle compartments during catagen. In contrast to wild-type mice, p53 knockout mice show significant retardation of catagen accompanied by significant decrease in the number of apoptotic cells in the hair matrix. Furthermore, p53 null hair follicles…