Encontrados 7 documentos, a visualizar página 1 de 1
The proteasome regulates the interaction between Cx43 and ZO-1
Girão, Henrique; Pereira, PauloGap junction (GJ) intercellular communication (GJIC) is vital to ensure proper cell and tissue function. GJ are multimeric structures composed of proteins called connexins. Modifications on stability or subcellular distribution of connexins have a direct impact on the extent of GJIC. In this study we have investigated the role of the proteasome in regulation of connexin 43 (Cx43) internalization. Although the p...
Subcellular redistribution of components of the ubiquitin-proteasome pathway du...
Girão, Henrique; Pereira, Paulo; Taylor, Allen; Shang, FuPURPOSE: To determine the subcellular distribution of components of the ubiquitin-proteasome pathway (UPP) in lens epithelium and differentiating fibers and to evaluate potential roles of the UPP in eliminating nuclei and other organelles during maturation of lens fibers. METHODS: Adult bovine lens cryosections were stained for immunofluorescence and analyzed by confocal microscopy. The specificities of the ant...
High glucose down-regulates intercellular communication in retinal endothelial ...
Fernandes, Rosa; Girão, Henrique; Pereira, PauloIntercellular communication through gap junctions (GJIC) is most likely relevant to maintaining the integrity of the blood-retinal barrier. In this study, we investigated the mechanism whereby high glucose enhances degradation of connexin 43 (Cx43), thus contributing to a decrease in GJIC. The levels of Cx43 in bovine retinal endothelial cells exposed to high glucose (25 mm) decreased about 50% as compared with...
7-Ketocholesterol modulates intercellular communication through gap-junction in...
Girão, Henrique; Catarino, Steve; Pereira, PauloBackground: Connexin43 (Cx43) is an integral membrane protein that forms intercellular channels called gap junctions. Intercellular communication in the eye lens relies on an extensive network of gap junctions essential for the maintenance of lens transparency. The association of Cx43 with cholesterol enriched lipid raft domains was recently demonstrated. The objective of this study is to assess if products of ...
Lens fibers have a fully functional ubiquitin-proteasome pathway
Pereira, Paulo; Shang, Fu; Hobbs, Marisa; Girão, Henrique; Taylor, AllenWe previously showed that lens epithelial cells have a fully functional ubiquitin-proteasome pathway (UPP) and that ubiquitin-conjugating activity is up-regulated in response to oxidative stress. In this study we assessed the protein levels and activities of different components of the UPP in lens fibers. Calf lenses were dissected into four different regions: epithelial layer, outer cortex, inner cortex and nu...
Phosphorylation of connexin 43 acts as a stimuli for proteasome-dependent degra...
Girão, Henrique; Pereira, PauloPurpose: The lens is an avascular organ in which gap junctions provide a pathway for intercellular communication, which is vital to maintain lens transparency. Connexin43 (Cx43) is the main gap-junctional protein in lens epithelial cells. Phosphorylation of connexins is implicated in the regulation of intercellular communication. The objective of this report is to determine whether phosphorylation of Cx43 in le...
7-ketocholesterol stimulates differentiation of lens epithelial cells
Girão, Henrique; Shang, Fu; Pereira, PauloPURPOSE: To establish if oxysterols stimulate differentiation of lens epithelial cells (LEC). METHODS: Primary cultures of lens epithelial cells were incubated with 7-ketocholesterol (7-keto), 25-hydroxycholesterol (25-OH) or cholesterol at 10 microg/ml for 10 days. Cells incubated with 100 ng/ml basic fibroblast growth factor (b-FGF) were used as positive controls for differentiation. The expression of the dif...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||