Search results for " signaling."
showing 10 items of 1032 documents
Caspase-3 contributes to ZO-1 and Cl-5 tight-junction disruption in rapid anoxic neurovascular unit damage.
2011
BACKGROUND: Tight-junction (TJ) protein degradation is a decisive step in hypoxic blood-brain barrier (BBB) breakdown in stroke. In this study we elucidated the impact of acute cerebral ischemia on TJ protein arrangement and the role of the apoptotic effector protease caspase-3 in this context. METHODOLOGY/PRINCIPAL FINDINGS: We used an in vitro model of the neurovascular unit and the guinea pig whole brain preparation to analyze with immunohistochemical methods the BBB properties and neurovascular integrity. In both methodological approaches we observed rapid TJ protein disruptions after 30 min of oxygen and glucose deprivation or middle cerebral artery occlusion, which were accompanied by…
Triclosan induces Fas receptor-dependent apoptosis in mouse neocortical neurons in vitro
2014
Triclosan (TCS) is a commonly used antimicrobial agent in personal care and sanitizing products, as well as in household items. Numerous studies have demonstrated the presence of TCS in various human tissues. Several studies have reported the accumulation of TCS in fish and human brain tissue. The aim of the present study was to investigate the effect of TCS on apoptosis in mouse neocortical neurons after 7 days of culture in vitro following 3, 6 and 24 h of exposure. To explore the mechanism underlying the effects of TCS in neurons, we studied the activation and protein expression of the Fas receptor (FasR) and caspase- 8, caspase-9 and caspase-3, as well as DNA fragmentation in TCS-treate…
D2R striatopallidal neurons inhibit both locomotor and drug reward processes.
2009
The specific functions of dopamine D(2) receptor-positive (D(2)R) striatopallidal neurons remain poorly understood. Using a genetic mouse model, we found that ablation of D(2)R neurons in the entire striatum induced hyperlocomotion, whereas ablation in the ventral striatum increased amphetamine conditioned place preference. Thus D(2)R striatopallidal neurons limit both locomotion and, unexpectedly, drug reinforcement.
Signalling molecules and growth factors for tissue engineering of cartilage-what can we learn from the growth plate?
2009
Modern tissue engineering concepts integrate cells, scaffolds, signalling molecules and growth factors. For the purposes of regenerative medicine, fetal development is of great interest because it is widely accepted that regeneration recapitulates in part developmental processes. In tissue engineering of cartilage the growth plate of the long bone represents an interesting, well-organized developmental structure with a spatial distribution of chondrocytes in different proliferation and differentiation stages, embedded in a scaffold of extracellular matrix components. The proliferation and differentiation of these chondrocytes is regulated by various hormonal and paracrine factors. Thus, mem…
IL-6 trans-Signaling
2004
The molecular consequence of the fever response has been illuminated by a recent study showing that a temperature shift to 40 degrees C resulted in increased leukocyte adhesion to tissue sections, which was mediated by L-selectin activation in lymphocytes. This L-selectin activation during heat responses was dependent on IL-6 trans-signaling via the soluble IL-6R.
High miR-196a levels promote the oncogenic phenotype of colorectal cancer cells.
2009
AIM: To analyze the relevance of the microRNA miR-196a for colorectal oncogenesis. METHODS: The impact of miR-196a on the restriction targets HoxA7, HoxB8, HoxC8 and HoxD8 was analyzed by reverse transcription polymerase chain reaction (RT-PCR) after transient transfection of SW480 cancer cells. The miR-196a transcription profile in colorectal cancer samples, mucosa samples and diverse cancer cell lines was quantified by RT-PCR. Transiently miR-196a-transfected colorectal cancer cells were used for diverse functional assays in vitro and for a xenograft lung metastasis model in vivo. RESULTS: HoxA7, HoxB8, HoxC8 and HoxD8 were restricted by miR-196a in a dose-dependent and gene-specific mann…
Dual effect of ceramide on human endothelial cells: induction of oxidative stress and transcriptional upregulation of endothelial nitric oxide syntha…
2002
Background— Generation of the second-messenger molecule ceramide by stimulated sphingomyelinase activity has been implicated in the inflammatory processes contributing to the pathogenesis of atherosclerosis. However, reports of stimulatory effects of ceramide on endothelial NO production in animal models suggest antiatherosclerotic effects of the molecule. Therefore, we investigated long-term effects of ceramide on NO generation in human endothelial cells. Methods and Results— In human umbilical vein endothelial cells (HUVECs) and in HUVEC-derived EA.hy 926 endothelial cells, C6-ceramide ( N -hexanoyl- d -erythro-sphingosine) reduced the generation of bioactive NO (RFL-6 reporter-cell assa…
Hypoxia-inducible factor 1Α may regulate the commitment of mesenchymal stromal cells toward angio-osteogenesis by mirna-675-5P
2017
Abstract Background aims During bone formation, angiogenesis and osteogenesis are regulated by hypoxia, which is able to induce blood vessel formation, as well as recruit and differentiate human mesenchymal stromal cells (hMSCs). The molecular mechanisms involved in HIF-1α response and hMSC differentiation during bone formation are still unclear. This study aimed to investigate the synergistic role of hypoxia and hypoxia-mimetic microRNA miR-675-5p in angiogenesis response and osteo-chondroblast commitment of hMSCs. Methods By using a suitable in vitro cell model of hMSCs (maintained in hypoxia or normoxia), the role of HIF-1α and miR-675-5p in angiogenesis and osteogenesis coupling was inv…
Impairing Otp homeodomain function in oral ectoderm cells affects skeletogenesis in sea urchin embryos
2003
AbstractIn the sea urchin embryo skeletogenesis is the result of a complex series of molecular and cellular events that coordinate the morphogenetic process. Past and recent evidence strongly indicate that skeletal initiation and growth are strictly dependent on signals emanating from the oral ectodermal wall. As previously suggested, Orthopedia (Otp), a homeodomain-containing transcription factor specifically expressed in a small subset of oral ectoderm cells, might be implicated in this signalling pathway. In this study, we utilize three different strategies to address the issue of whether Otp is an upstream regulator of sketelogenesis. We describe the effects of microinjection of Otp mor…
Acidic Environment Leads to ROS-Induced MAPK Signaling in Cancer Cells
2011
Tumor micromilieu often shows pronounced acidosis forcing cells to adapt their phenotype towards enhanced tumorigenesis induced by altered cellular signalling and transcriptional regulation. In the presents study mechanisms and potential consequences of the crosstalk between extra- and intracellular pH (pH(e), pH(i)) and mitogen-activated-protein-kinases (ERK1/2, p38) was analyzed. Data were obtained mainly in AT1 R-3327 prostate carcinoma cells, but the principle importance was confirmed in 5 other cell types. Extracellular acidosis leads to a rapid and sustained decrease of pH(i) in parallel to p38 phosphorylation in all cell types and to ERK1/2 phosphorylation in 3 of 6 cell types. Furth…