scholarly journals Ultrastructure of blebbing and phagocytosis of blebs by hyperplastic thyroid epithelial cells in vivo.

1977 ◽  
Vol 72 (3) ◽  
pp. 584-594 ◽  
Author(s):  
J D Zeligs ◽  
S H Wollman
Keyword(s):  
Thyroid Gland ◽  
Epithelial Cells ◽  
Cultured Cells ◽  
Ultrastructural Organization ◽  
Contractile Ring ◽  
Phagocytic Process ◽  
Different Types ◽  
Rat Thyroid

In addition to pseudopods, somewhat pleomorphic blebs were consistently found protruding from the apical surfaces of hyperplastic rat thyroid epithelial cells into the follicular lumens in vivo. Many blebs were knobby, roughly hemispherical protrusions, with a diameter of 2-3 mum. Such blebs had a densely packed microfilamentous core and contained numerous apparent ribosomes. They were morphologically similar to blebs that have been observed in a variety of cultured cells. Other blebs were larger, more elongate, and less knobby, but had a similar ultrastructural organization. Blebs of all sizes appeared to be phagocytosed on some occasions by nearby epithelial cells. The phagocytic process involved partial engulfment of the bleb by a typical epithelial pseudopod, followed by an apparent pinching-off process, presumably resulting in the separation of the bleb from its cells or origin. The pinching-off process was associated with a band of approx. 6-nm diameter microfilaments that developed within the pseudopod cytoplasm surrounding the base of the bleb and is postulated to function as a contractile ring. The finding of blebbing is an intact tissue in vivo indicates that this phenomenon is not restricted to cultured cells, and thus tends to extend the significance of in vitro observations of the process. In relation to their occurrence in the hyperplastic thyroid gland in vivo, possible interconversions are considered between different types of blebs, and between blebs and pseudopods.

The VSL#3 probiotic formula induces mucin gene expression and secretion in colonic epithelial cells

2007 ◽  
Vol 292 (1) ◽  
pp. G315-G322 ◽  
Author(s):  
C. Caballero-Franco ◽  
K. Keller ◽  
C. De Simone ◽  
K. Chadee
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Cultured Cells ◽  
In Vivo Studies ◽  
Lactobacillus Species ◽  
Mucin Secretion ◽  
Colonic Epithelial Cells ◽  
Dnase Treatment

Several studies have stressed the importance of the microbiota in the maintenance of the gastrointestinal epithelium. Administration of probiotic bacteria, supplements composed of microbiota constituents, was previously shown to diminish symptoms in patients suffering from inflammatory bowel diseases. This raises the possibility that probiotics may play an active role in enhancing the intestinal barrier at the mucosal surface. In this study, we investigated whether the clinically tested VSL#3 probiotic formula and/or its secreted components can augment the protective mucus layer in vivo and in vitro. For in vivo studies, Wistar rats were orally administered the probiotic mixture VSL#3 on a daily basis for seven days. After treatment, basal luminal mucin content increased by 60%. In addition, we exposed isolated rat colonic loops to the VSL#3 probiotic formula, which significantly stimulated colonic mucin (MUC) secretion and MUC2 gene expression; however, MUC1 and MUC3 gene expression were only slightly elevated. The effect of the VSL#3 mucin secretagogue was also tested in vitro by use of LS 174T colonic epithelial cells. In contrast to the animal studies, cultured cells incubated with VSL#3 bacteria did not exhibit increased mucin secretion. However, the bacterial secreted products contained in the conditioned media stimulated a remarkable mucin secretion effect. Among the three bacterial groups ( Lactobacilli, Bifidobacteria, and Streptococci) contained in VSL#3, the Lactobacillus species were the strongest potentiator of mucin secretion in vitro. A preliminary characterization of the putative mucin secretagogue suggested that it was a heat-resistant soluble compound, which is not sensitive to protease and DNase treatment. These findings contribute to a better understanding of the complex and beneficial interaction between colonic epithelial cells and intestinal bacteria.

IODINATED PARTICLES IN THE RAT THYROID

1975 ◽  
Vol 79 (3) ◽  
pp. 459-473 ◽  
Author(s):  
J. Dang ◽  
R. Miquelis ◽  
P. Bastiani ◽  
C. Simon
Keyword(s):  
Acid Phosphatase ◽  
Thyroid Gland ◽  
Phosphatase Activity ◽  
Acid Phosphatase Activity ◽  
High Turnover ◽  
Secondary Lysosomes ◽  
Rat Thyroid ◽  
Tsh Stimulation

ABSTRACT In a previous study (Simon et al. 1971) a procedure for the preparation and separation of iodinated particles was described in the rat. The present paper deals with further investigations on the nature of these particles. Acid phosphatase and iodine are conjointly sedimentable and display a latency that is unmasked on dilution in a hypo-osmotic medium and under acidification to pH 5.0. These properties together with the sensitivity to Triton X-100 are best accounted for by assuming that iodinated particles of the thyroid gland are lysosomes. Part of the particulate iodine is soluble in n-butanol (BEI fraction). The existence of this BEI fraction demonstrates that hydrolysis of thyroglobulin occurs within the particles which thus exhibit an acid protease activity. Both the sedimentable iodine pool and acid phosphatase are increased under TSH stimulation and decreased after thyroxine treatment. In addition, the general activity of the iodinated particles is dependent on the daily iodine intake as shown by the variation of their iodine pool, acid phosphatase activity and BEI fraction with the iodine diet. It is concluded that iodinated particles of the thyroid gland are secondary lysosomes which participate in iodine secretion under TSH control. By in vitro treatment with destabilizing media or after in vivo treatment with thyroxine, iodinated particles exhibit a parallel loss of iodine and acid phosphatase. After a short-term TSH treatment in vivo, their iodine pool is more increased than their acid phosphatase activity. It is concluded that, at least in the normal rat thyroid, iodinated particles are essentially secondary lysosomes; true colloid droplets actually accumulate only after sufficient TSH stimulation. After ultracentrifugation, 3 main subpopulations are separated for which iodine and acid phosphatase patterns are superimposed. In addition, they all exhibit properties characteristic of secondary lysosomes. Finally, the presence of a fourth sedimentable iodinated fraction with a high turnover rate is postulated.

scholarly journals Testing the Efficacy and Toxicity of Adenylyl Cyclase Inhibitors against Enteric Pathogens Using In Vitro and In Vivo Models of Infection

2010 ◽  
Vol 78 (4) ◽  
pp. 1740-1749 ◽  
Author(s):  
Scott T. Moen ◽  
Carla A. Blumentritt ◽  
Terry M. Slater ◽  
Shilpa D. Patel ◽  
Christopher B. Tutt ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Adenylyl Cyclase ◽  
Cultured Cells ◽  
Potent Inhibitor ◽  
Suppressive Effect ◽  
Intestinal Epithelial ◽  
In Vivo Models ◽  
Adp Ribosyltransferase

ABSTRACT Enterotoxigenic Escherichia coli (ETEC) produces the ADP-ribosyltransferase toxin known as heat-labile enterotoxin (LT). In addition to the toxic effect of LT resulting in increases of cyclic AMP (cAMP) and disturbance of cellular metabolic processes, this toxin promotes bacterial adherence to intestinal epithelial cells (A. M. Johnson, R. S. Kaushik, D. H. Francis, J. M. Fleckenstein, and P. R. Hardwidge, J. Bacteriol. 191:178-186, 2009). Therefore, we hypothesized that the identification of a compound that inhibits the activity of the toxin would have a suppressive effect on the ETEC colonization capabilities. Using in vivo and in vitro approaches, we present evidence demonstrating that a fluorenone-based compound, DC5, which inhibits the accumulation of cAMP in intoxicated cultured cells, significantly decreases the colonization abilities of adenylyl cyclase toxin-producing bacteria, such as ETEC. These findings established that DC5 is a potent inhibitor both of toxin-induced cAMP accumulation and of ETEC adherence to epithelial cells. Thus, DC5 may be a promising compound for treatment of diarrhea caused by ETEC and other adenylyl cyclase toxin-producing bacteria.

scholarly journals Proteolytic processing of endogenous and recombinant beta 4 integrin subunit.

1992 ◽  
Vol 118 (4) ◽  
pp. 951-959 ◽  
Author(s):  
F G Giancotti ◽  
M A Stepp ◽  
S Suzuki ◽  
E Engvall ◽  
E Ruoslahti
Keyword(s):  
Epithelial Cells ◽  
Cultured Cells ◽  
Cytoplasmic Domain ◽  
Basement Membranes ◽  
Proteolytic Processing ◽  
In Vitro Assays ◽  
Integrin Subunit ◽  
Calcium Dependent

The alpha 6 beta 4 integrin is a receptor involved in the interaction of epithelial cells with basement membranes. This integrin is unique among the known integrins in that its beta 4 subunit has a large cytoplasmic domain. The function of this cytoplasmic domain is not known. In this paper we show that the beta 4 subunit undergoes proteolytic processing in cultured cells and provide evidence that this also happens in tissues. Immunoprecipitation experiments indicated that the cytoplasmic domain of beta 4 is susceptible to a calcium-dependent protease present in cellular extracts. In vitro assays with purified calpain showed that this enzyme can cleave beta 4 at two distinct sites in the cytoplasmic domain, generating truncated molecules of 165 and 130 kD. Immunoblotting experiments performed on cultured epithelial cells using an antibody to a peptide modeled after the COOH-terminus of the beta 4 subunit showed 70-kD fragments and several fragments of molecular masses between 185 and 115 kD. Similar fragments were detected in CHO cells transfected with the full-length beta 4 cDNA, but not in control transfected cells or in cells transfected with a mutant cDNA lacking the epitope of the cytoplasmic peptide antibody. The sizes of the fragments indicated that both the intracellular and extracellular domains of beta 4 are proteolytically processed. To examine the processing of the beta 4 subunit in epithelial tissues in vivo, human skin frozen sections were stained with antibodies to the ectodomain or the cytoplasmic domain of beta 4. The distinct staining patterns obtained with the two types of antibodies provided evidence that beta 4 is proteolytically processed in vivo in skin. Analogous experiments performed on sections of the cornea suggested that beta 4 is not proteolytically processed at a detectable level in this tissue. Thus, cleavage of the beta 4 subunit occurs in a tissue-specific fashion. These results suggest a potential mechanism of modulating the activities of the alpha 6 beta 4 integrin.

IODINATED THYROLIPIDS: THEIR POSSIBLE ROLE IN HORMONOGENESIS

1973 ◽  
Vol 74 (3) ◽  
pp. 461-474 ◽  
Author(s):  
D. H. Shah ◽  
U. R. Thakare ◽  
R. C. Shownkeen ◽  
D. N. Pahuja ◽  
M. Y. Mandlik
Keyword(s):  
Thyroid Gland ◽  
Lipid Fraction ◽  
Human Thyroid ◽  
Cystic Degeneration ◽  
Nodular Goitre ◽  
Thyroid Glands ◽  
Rat Thyroid ◽  
Rat Thyroid Gland

ABSTRACT A total of 42 human thyroid glands (nodular goitre 9, adenoma with cystic degeneration 6; toxic goitre 10; carcinoma 14; and normal thyroid gland 3) were examined in vitro for iodination of an unidentified polar non-phosphatide lipid fraction (fraction II). The radioiodine incorporation in fraction II was 49.3 %, 43.6 %, 32.8 %, 20.7 %, and 22.0 % respectively in normal, nodular goitre, adenoma with cystic degeneration, toxic goitre and thyroid carcinoma. In vitro studies with surviving sheep thyroid slices did not show any relation between the iodination of fraction II and thyroxine formation over a period of 120 min. However, a highly significant correlation (r-value= 0.96375) was observed between the iodination of fraction II and thyroxine formation in vivo in the rat thyroid gland over a period of 24 h. We have previously postulated that iodination of fraction II may be interrelated to thyroxine formation. In the light of this hypothesis and the above results we suggest that the iodination of fraction II and thyroxine formation in the thyroid gland may be interrelated, the degree of iodination of fraction II being modulated by the amount of thyroxine formed within the thyroid gland.

Observations on the growth of Eimeria tenella in cultured cells from the parasitized chorioallantoic membranes of the developing chick embryo

Parasitology ◽  
1969 ◽  
Vol 59 (4) ◽  
pp. 757-765 ◽  
Author(s):  
P. L. Long
Keyword(s):  
Technical Assistance ◽  
Cultured Cells ◽  
Simple Procedure ◽  
Eimeria Tenella ◽  
Nutritional Requirements ◽  
Chick Embryos ◽  
Large Numbers ◽  
Different Types

Eimeria tenella infections were established in the chorioallantoic membranes CAM) of developing chick embryos. At different times after infection the CAM ells were cultured in vitro in modified 199 medium. Different types of schizont were grown, some similar to those occurring in infections of the usual in vivo site and others markedly different. In schizogony of one type the merozoites appeared to develop by growing out from the periphery of cellular masses; a process similar to that described by Hammond et al. (1966) for E. bovis.Gametocytes and infective oocysts were also grown by the tissue culture of CAM cells but only in cells infected 4–6 days previously in embryo; CAM cells infected for only 3 days before culture supported the growth of large numbers of schizonts of different types.The majority of the stages grown developed within densely populated areas of epithelial-like cells. A temperature of 41 °C was found to be necessary for the growth of the parasite. The nutritional requirements for the growth of E. tenella are fairly well provided by the medium used. The relatively simple procedure described should be of value for the observation of E. tenella at various stages of its growth and provide a means of in vitro testing of antiparasitic substances.I wish to thank Dr P. P. Levine for his interest and encouragement during the course of the work and Mr D. L'Amoreaux for technical assistance.

scholarly journals Minireview: Putting Physiology Back into Estrogens' Mechanism of Action

Endocrinology ◽  
2011 ◽  
Vol 152 (12) ◽  
pp. 4481-4488 ◽  
Author(s):  
Robert D. Koos
Keyword(s):  
Epithelial Cells ◽  
Cultured Cells ◽  
Hypoxia Inducible Factor ◽  
Estrogen Receptor Α ◽  
Proliferative Effect ◽  
High Oxygen Level ◽  
Endothelial Growth Factor ◽  
Endometrial Epithelial Cells

After decades of research, the mechanism by which estrogens stimulate the proliferation of epithelial cells in the endometrium and mammary gland, and in the carcinomas that arise in those tissues, is still not understood. Cells do not proliferate in response to 17β-estradiol (E2) alone, and although it is widely recognized that growth factors play a role in E2's proliferative effect, exactly how they are involved is unclear. It has long been known that the proliferation of endometrial epithelial cells is preceded by dramatic increases in blood flow and microvascular permeability, filling the subepithelial stroma with plasma and the proteins it contains, such as IGF-I, which is known to synergize with E2 in the induction of cell proliferation. The hyperpermeability is caused by vascular endothelial growth factor (VEGF), which is rapidly induced by E2, via the transcription factors hypoxia-inducible factor 1 and estrogen receptor α, in luminal epithelial cells in vivo. As we recently showed, VEGF is also strongly induced in endometrial cancer cells in vitro when excessive degradation of hypoxia-inducible factor 1α, caused by the abnormally high oxygen level to which cultured cells are exposed, is prevented. Putting these facts together, we now propose a new model of E2-induced proliferation in which VEGF-induced vascular hyperpermeability plays an essential role. E2 first induces the expression by endometrial epithelial cells of VEGF, which then acts in a paracrine manner to induce interendothelial cell gaps in subepithelial blood vessels, through which plasma and the proteins therein enter the adjacent stroma. Plasma carries even more E2, which circulates bound to proteins, and IGF-l, which together drive epithelial cells completely through the cell cycle.

Increased mRNA expression of selected pro-inflammatory factors in inflamed bovine endometrium in vivo as well as in endometrial epithelial cells exposed to Bacillus pumilus in vitro

2016 ◽  
Vol 28 (7) ◽  
pp. 982 ◽  
Author(s):  
Martina A. Gärtner ◽  
Sarah Peter ◽  
Markus Jung ◽  
Marc Drillich ◽  
Ralf Einspanier ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Mrna Expression ◽  
Bacillus Pumilus ◽  
Cultured Cells ◽  
Inflammatory Factors ◽  
Endometrial Cells ◽  
Subclinical Endometritis ◽  
Endometrial Epithelial Cells

Endometrial epithelium plays a crucial role in the first immune response to invading bacteria by producing cytokines and chemokines. The aim of this study was to investigate the first inflammatory response of the endometrium in vivo and in vitro. Gene expression of several pro-inflammatory factors and Toll-like receptors (TLR2, -4, -6) was determined in endometrial cytobrush samples obtained from healthy cows and cows with clinical or subclinical endometritis. Endometrial epithelial cells were co-cultured with an isolated autochthonous uterine bacterial strain Bacillus pumilus. Total RNA was extracted from in vivo and in vitro samples and subjected to real-time reverse transcription polymerase chain reaction. CXC ligands (CXCL) 1/2 and CXC chemokine receptor (CXCR) 2 mRNA expression was higher in cows with subclinical endometritis and CXCL3 mRNA expression was higher in cows with clinical endometritis compared with healthy cows. B. pumilus induced cell death of epithelial cells within 24 h of co-culturing. The presence of B. pumilus resulted in significantly higher mRNA expression of interleukin 1α (IL1A), IL6, IL8, CXCL1–3 and prostaglandin–endoperoxide synthase 2 in co-cultured cells compared with untreated controls. The maximum increase was mainly detected after 2 h. These results support the hypothesis that bacterial infection of endometrial cells might induce prompt synthesis of pro-inflammatory cytokines resulting in a local inflammatory reaction.

Growth and characterization of porcine urinary bladder epithelial cells in vitro

1994 ◽  
Vol 266 (2) ◽  
pp. F298-F308 ◽  
Author(s):  
C. Guhe ◽  
W. Follmann
Keyword(s):  
Epithelial Cells ◽  
Urinary Bladder ◽  
Cultured Cells ◽  
Apical Cell ◽  
Membrane Integrity ◽  
Membrane Vesicles ◽  
Lactate Dehydrogenase Activity ◽  
And Function

Dividing long-term monolayer cultures of porcine urinary bladder epithelial cells were obtained by a combined mechanical and enzymatic isolation method. The serum-free cultured cells were investigated morphologically and characterized according to their growth characteristics and enzymatic functions. Investigations over a period up to 12 wk demonstrated that the cells regain their in vivo polarization with apically situated membrane vesicles and tight junctions between neighboring cells when they have built up a confluent monolayer. Activities of most marker enzymes for cell-differentiated status and function of such cells observed over a period of 4 wk in culture were conserved compared with the original tissue. Lactate dehydrogenase activity release into the medium was at low levels (< or = 5% of the total amount), indicating a good membrane integrity and cell viability. The chromosome set (2n = 38) did not change significantly during the first 5 wk, but, with additional culture time, the degree of polyploid and polynucleated cells increased comparable to the in vivo situation, in which the apical cell layer of the bladder mucosa also showed a high degree of polynucleation and polyploidy, indicative of a senescence process.

scholarly journals Sortilin Is a Putative Postendocytic Receptor of Thyroglobulin

Endocrinology ◽  
2008 ◽  
Vol 150 (1) ◽  
pp. 509-518 ◽  
Author(s):  
Roberta Botta ◽  
Simonetta Lisi ◽  
Aldo Pinchera ◽  
Franco Giorgi ◽  
Claudio Marcocci ◽  
...  
Keyword(s):  
Thyroid Gland ◽  
Protein Trafficking ◽  
Cultured Cells ◽  
Endocytic Pathway ◽  
Dependent Manner ◽  
Binding Assays ◽  
Concentration Dependent Manner ◽  
High Affinity ◽  
Rat Thyroid

The Vps10p family member sortilin is involved in various cell processes, including protein trafficking. Here we found that sortilin is expressed in thyroid epithelial cells (thyrocytes) in a TSH-dependent manner, that the hormone precursor thyroglobulin (Tg) is a high-affinity sortilin ligand, and that binding to sortilin occurs after Tg endocytosis, resulting in Tg recycling. Sortilin was found to be expressed intracellularly in thyrocytes, as observed in mouse, human, and rat thyroid as well as in FRTL-5 cells. Sortilin expression was demonstrated to be TSH dependent, both in FRTL-5 cells and in mice treated with methimazole and perchlorate. Plasmon resonance binding assays showed that Tg binds to sortilin in a concentration-dependent manner and with high affinity, with Kd values that paralleled the hormone content of Tg. In addition, we found that Tg and sortilin interact in vivo and in cultured cells, as observed by immunoprecipitation, in mouse thyroid extracts and in COS-7 cells transiently cotransfected with sortilin and Tg. After incubation of FRTL-5 cells with exogenous, labeled Tg, sortilin and Tg interacted intracellularly, presumably within the endocytic pathway, as observed by immunofluorescence and immunoelectron microscopy, the latter technique showing some degree of Tg recycling. This was confirmed in FRTL-5 cells in which Tg recycling was reduced by silencing of the sortilin gene and in CHO cells transfected with sortilin in which recycling was increased. Our findings provide a novel pathway of Tg trafficking and a novel function of sortilin in the thyroid gland, the functional impact of which remains to be established. Evidence for a novel pathway of thyroglobulin trafficking and for a possible novel function of sortilin in the thyroid gland is discussed.

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