Secretory Process in Thyroid Cells

2015 ◽  
pp. 423-442
Author(s):  
N. J. Nadler
2005 ◽  
Vol 25 (7) ◽  
pp. 2846-2852 ◽  
Author(s):  
Jens Behrends ◽  
Serge Clément ◽  
Bernard Pajak ◽  
Viviane Pohl ◽  
Carine Maenhaut ◽  
...  

ABSTRACT Rhophilin 2 is a Rho GTPase binding protein initially isolated by differential screening of a chronically thyrotropin (TSH)-stimulated dog thyroid cDNA library. In thyroid cell culture, expression of rhophilin 2 mRNA and protein is enhanced following TSH stimulation of the cyclic AMP (cAMP) transduction cascade. Yeast two-hybrid screening and coimmunoprecipitation have revealed that the GTP-bound form of RhoB and components of the cytoskeleton are protein partners of rhophilin 2. These results led us to suggest that rhophilin 2 could play an important role downstream of RhoB in the control of endocytosis during the thyroid secretory process which follows stimulation of the TSH/cAMP pathway. To validate this hypothesis, we generated rhophilin 2-deficient mice and analyzed their thyroid structure and function. Mice lacking rhophilin 2 develop normally, have normal life spans, and are fertile. They have no visible goiter and no obvious clinical signs of hyper- or hypothyroidism. The morphology of thyroid cells and follicles in these mice were normal, as were the different biological tests performed to investigate thyroid function. Our results indicate that rhophilin 2 does not play an essential role in thyroid physiology.


Author(s):  
W.N. Bentham ◽  
V. Rocha

It has been an interest of our lab to develop a mammary epethelial cell culture system that faithfully duplicates the in vivo condition of the lactating gland. Since the introduction of collagen as a matrix on which cells are cultivated other E.C.M. type matrices have been made available and are used in many cell culture techniques. We have previously demonstrated that cells cultured on collagen and Matrigel do not differentiate as they do in vivo. It seems that these cultures often produce cells that show a disruption in the secretory process. The appearance of large ribosomal studded vesicles, that specifically label with antibody to casein, suggest an interruption of both protein maturation and secretion at the E.R. to golgi transition. In this report we have examined cultures on collagen and Matrigel at relative high and low seeding densities and compared them to cells from the in vivo condition.


2002 ◽  
Vol 41 (04) ◽  
pp. 178-183 ◽  
Author(s):  
V. Fidler ◽  
K. Zaletel ◽  
S. Gaberšček ◽  
S. Hojker ◽  
E. Pirnat

Summary Aim: In spite of extensive use of 131I for treatment of hyperthyroidism, the results of early outcome are variable. In our prospective clinical study we tested whether 131I induced necrosis causing clinical aggravation of hyperthyroidism and increasing the free thyroid hormone concentration in the serum of patients with solitary toxic adenoma not pretreated with antithyroid drugs. Patients and methods: 30 consecutive patients were treated with 925 MBq 131I. Serum concentration of thyrotropin (TSH), free thyroxine (fT4), free triiodothyronine (fT3), thyroglobulin (Tg), and interleukin-6 (IL-6) were measured before and after application of 131I. Results: After application of 131I no clinical worsening was observed. FT4 and fT3 concentration did not change significantly within the first five days, whereas both of them significantly decreased after 12 days (p <0.0001). Slight and clinically irrelevant increase in the level of the two thyroid hormones was observed in 9 patients. Furthermore, we observed a prolonged increase in Tg concentration and a transient increase in IL-6 concentration. Conclusion: Neither evidence of any clinical aggravation of hyperthyroidism nor any significant increase in thyroid hormone concentration by 131I induced necrosis of thyroid cells was found. Therefore, the application of 131I may be considered as a safe and effective treatment for patients with hyperthyroidism due to toxic adenoma.


2006 ◽  
Vol 114 (S 1) ◽  
Author(s):  
M Bröcker-Preuss ◽  
M Bollepalli ◽  
M Schmidt ◽  
J Baten ◽  
K Mann

1980 ◽  
Vol 92 (4_Suppla) ◽  
pp. 1-43 ◽  
Author(s):  
M.K. O'Connor ◽  
J.F. Malone ◽  
M.J. Cullen
Keyword(s):  

1985 ◽  
Vol 110 (1_Suppla) ◽  
pp. S83
Author(s):  
B. E. WENZEL ◽  
T. MANSKY ◽  
P. C. SCRIBA

2018 ◽  
Vol XIII (2) ◽  
Author(s):  
N.S. Sergeeva ◽  
Yu.D. Hesuani ◽  
A.P. Poljakov ◽  
V.А. Mironov ◽  
А.D. Kaprin
Keyword(s):  

2012 ◽  
Vol 51 (05) ◽  
pp. 179-185 ◽  
Author(s):  
M. Wendisch ◽  
D. Aurich ◽  
R. Runge ◽  
R. Freudenberg ◽  
J. Kotzerke ◽  
...  

SummaryTechnetium radiopharmaceuticals are well established in nuclear medicine. Besides its well-known gamma radiation, 99mTc emits an average of five Auger and internal conversion electrons per decay. The biological toxicity of these low-energy, high-LET (linear energy transfer) emissions is a controversial subject. One aim of this study was to estimate in a cell model how much 99mTc can be present in exposed cells and which radiobiological effects could be estimated in 99mTc-overloaded cells. Methods: Sodium iodine symporter (NIS)- positive thyroid cells were used. 99mTc-uptake studies were performed after preincubation with a non-radioactive (cold) stannous pyro - phosphate kit solution or as a standard 99mTc pyrophosphate kit preparation or with pure pertechnetate solution. Survival curves were analyzed from colony-forming assays. Results: Preincubation with stannous complexes causes irreversible intracellular radioactivity retention of 99mTc and is followed by further pertechnetate influx to an unexpectedly high 99mTc level. The uptake of 99mTc pertechnetate in NIS-positive cells can be modified using stannous pyrophosphate from 3–5% to >80%. The maximum possible cellular uptake of 99mTc was 90 Bq/cell. Compared with nearly pure extracellular irradiation from routine 99mTc complexes, cell survival was reduced by 3–4 orders of magnitude after preincubation with stannous pyrophosphate. Conclusions: Intra cellular 99mTc retention is related to reduced survival, which is most likely mediated by the emission of low-energy electrons. Our findings show that the described experiments constitute a simple and useful in vitro model for radiobiological investigations in a cell model.


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