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The expression of carbonic anhydrase 1 is reduced at the mRNA and protein level in active ulcerative colitis.
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Effect of butyrate on carbonic anhydrase 1 expression in colonocytes of patients with ulcerative colitis.
No full textThe new murine hepatic 3A cell line responds to stress stimuli by activating an efficient Unfolded Protein Response (UPR)
Full text linkIn the present study we have investigated the properties of a novel cell line (3A cells) obtained from the liver of 14.5days post coitum (dpc) wild-type mouse embryo. 3A cells morphology was characterized by fluorescent localization of F-actin and β-catenin. The expression of specific genes and proteins essential to liver function in these cells was comparable or even more efficient then in the differentiated hepatocytic cell line MMH-D6. 3A cells also showed the capability to excrete molecules in extracellular spaces resembling functional bile canaliculi, glycogen storage activity and the ability to control retinol-binding protein 4 secretion in response to retinol deprivation. Their response to the exogenous stress stimulus induced by tunicamycin was analysed by PCR Pathway Array containing 84 genes involved in the Unfolded Protein Response (UPR). 3A cells were shown to activate the UPR following a typical stressful event, indicating that this cellular model could be further exploited to investigate hepatic proteins secretion and specific reaction to different injuries
Age-related modulation of vascular smooth muscle cells proliferation following arterial wall damage
No full textThe proliferative response of vascular smooth muscle cells (SMC) to an arterial wall injury has been investigated in young (3-6 months) and old (30-52 months) rabbits, employing two different experimental models. In the first model the lesion was produced by passing an inflated balloon catheter along the abdominal and descending thoracic aorta, while in the second, the endothelium was removed from a segment of the right carotid artery by air-drying. Both experimental models produced very heterogeneous lesions in which the de-endothelialization of the arteries was often accompanied by foci of cellular necrosis of variable extension throughout the vascular wall. The autoradiographic evaluation of the proliferative response of arterial SMCs following in vivo administration of 3H-thymidine revealed different patterns of labeling according to the type of lesion produced. A significant negative correlation (p less than 0.001) was found between the proliferative response and the cellular density of the vascular district. An age-related decrease in the proliferative response of SMCs was observed only in the thoracic aorta where the damage to the tunica media was less extensive as compared to the other vascular districts
Ultrastructural studies of spontaneous in vitro transformation of cultured marrow monocyte-macrophage cells from a patient with congenital hypoplastic anemia
No full textThe CM-S cell line was established from the bone marrow of a patient suffering from congenital hypoplastic anemia (syndrome of Diamond-Blackfan). The cells grew in suspension in liquid culture and were dependent for their continuous replication in vitro on growth factors produced by the same cells seeded at high density. Initially, undifferentiated blasts, immature myeloid, megakaryocytic and, rarely, erythroid cells were observed. Eventually, a population of cells with characteristics of monocyte-macrophage precursors predominated. These cells could be induced to terminal macrophage differentiation by incubation with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate. During this period (over 150 continuous passages), the cells failed to form colonies in agar and to give rise to tumors when inoculated into athymic mice. On prolonged passages, however, the cells gradually increased their growth capacity in liquid culture and became capable of forming colonies in agar and tumors in animals. Ultrastructural studies revealed that the expression of differentiated traits markedly changed as a function of time: after 277 passages, the transformed cells, although displaying characteristics of monocyte precursors, appeared blocked at this stage and no longer responded to 12-O-tetradecanoylphorbol-13-acetate
Carbonic anhydrase 1 expression in colorectal biopsies and colonocyte primary cultures from patients with ulcerative colitis.
No full textGuanidine transport across the apical and basolateral membranes of human intestinal Caco-2 cells is mediated by two different mechanisms
No full textThe functional characteristics of the intestinal absorption and secretion of guanidine as a model
of a nutritionally and metabolically essential organic cation were examined in the Caco-2 human intestinal cell
line. Both apical and basolateral transport of [14C]-guanidine were studied using Caco-2 cells grown on polycarbonate
permeable membranes. The basolateral-to-apical flux of [14C]-guanidine (i.e., its secretion) was quantitatively
higher than the apical-to-basolateral transport (i.e., its absorption). When Na was replaced by K or Li,
both apical and basolateral accumulation were significantly inhibited. Studies using the cell monolayers and apical
membrane vesicles obtained from Caco-2 cells showed a potential-independent mechanism of guanidine apical
uptake and efflux. Conversely, basolateral uptake and efflux were membrane potential dependent. Kinetic analysis
revealed that both saturable and nonsaturable mechanisms accounted for the apical and basolateral accumulations.
The [14C]-guanidine efflux from cells through the apical and basolateral membranes was significantly
reduced at 4°C, suggesting carrier-mediated mechanisms. Moreover, the apical efflux was stimulated by an
inwardly directed H gradient. Influx and efflux of [14C]-guanidine were unaffected by the presence of tetraethylammonium,
cimetidine or decynium-22 in the donor compartment. Only quinine significantly reduced [14C]-
guanidine entrance through apical and basolateral membranes and its exit through the basolateral membrane. In
conclusion, our results suggest that the influx and the efflux through the apical membrane is mediated by different
transporters, whereas transport across the basolateral membrane is mediated by a member of the organic cation
transporter family with high affinity for guanidine
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