Seasonal Changes in the Fine Structure of the Basal Granular Cells of the Bat Thyroid

1967 ◽  
Vol 2 (3) ◽  
pp. 401-410
Author(s):  
E. A. NUNEZ ◽  
R. P. GOULD ◽  
D. W. HAMILTON ◽  
J. S. HAYWARD ◽  
S. J. HOLT
Keyword(s):  
Fine Structure ◽  
Seasonal Changes ◽  
Follicular Epithelium ◽  
Thyroid Cell ◽  
Basal Region ◽  
Basal Cells ◽  
Uniform Size ◽  
Thyroid Cells ◽  
Cytoplasmic Matrix ◽  
Dense Granules

The fine structure of the thyroid gland of non-hibernating, hibernating, and intermittently aroused hibernating bats was examined. It was found that in addition to the ordinary follicular cell, another widespread thyroid cell type is present in all bats examined. This cell is situated in the basal region of the thyroid follicle and is characterized by a cytoplasm full of secretory-like granules. In the basal cells of bats captured in April and June the granules consist of an extremely dense core and are of a uniform size averaging from 0.1-0.5 µ in diameter. In bats caught in August the solid dense granules vary greatly in size and large granules of diameters from 2 to 5 µ are common. These large granules are often found concentrated in groups in the most basal region of the follicular epithelium. Hibernating bats are characterized by partly or totally degranulated basal thyroid cells. The cytoplasmic granules in the partly degranulated cell vary greatly in appearance, ranging from solid dense granules to empty vesicles. In totally degranulated basal cells, empty vesicles fill the cytoplasmic matrix. The granular endoplasmic reticulum of the basal thyroid cell also shows seasonal changes, while the Golgi complex remains a well-developed organelle throughout the year. These observations suggest that the thyroid basal granular cell is involved in secretory activities; its possible functional role is discussed.

scholarly journals Selenium has a protective role in caspase-3-dependent apoptosis induced by H2O2 in primary cultured pig thyrocytes

2004 ◽  
pp. 841-849 ◽  
Author(s):  
A Demelash ◽  
JO Karlsson ◽  
M Nilsson ◽  
U Bjorkman
Keyword(s):  
Caspase 3 ◽  
Selenium Deficiency ◽  
Protective Role ◽  
Follicular Epithelium ◽  
Thyroid Cell ◽  
Specific Substrate ◽  
Apical Surface ◽  
Thyroid Cells ◽  
Induced Apoptosis ◽  
Gpx Activity

OBJECTIVE: Hydrogen peroxide (H2O2), necessary for thyroid hormonogenesis, is produced at the apical surface of the thyroid follicular epithelium. Excess H2O2 is potentially cytotoxic and may contribute to the development of hypothyroidism, e.g. in severe selenium deficiency. Yet it is unclear how H2O2 contributes to thyroid cell death. DESIGN AND METHODS: H2O2-induced apoptosis and necrosis were studied in primary cultured pig thyroid cells. Glutathione peroxidase (GPx) activity was altered by culture in low serum with or without selenite substitution. Apoptosis was evaluated by spectrofluorometric measurement of caspase-3-specific substrate cleavage, and by analysis of DNA fragmentation by agarose gel electrophoresis. Necrosis was detected by 51Cr release from prelabeled cells. RESULTS: Exogenous H2O2 dose-dependently (100-400 micromol/l) activated caspase-3 within 3-12 h, and DNA degradation was observed after 24 h. The potency of H2O2 to induce apoptosis was low compared with that of staurosporine, a strong proapoptotic agent. H2O2-treated cells with reduced GPx activity showed increased caspase-3 activation. Incubation of serum-starved cells with selenite (10-100 nmol/l) normalized the GPx activity and reduced the activation of caspase-3 by H2O2. High H2O2 concentrations (400-800 micromol/l) were required to obtain necrosis. The H2O2-induced necrosis was exaggerated by both low GPx activity and catalase inhibition. CONCLUSIONS: Cytotoxic effects of H2O2 on thyroid cells include caspase-3-dependent apoptosis that occurs at H2O2 concentrations insufficient to induce necrosis. Selenium deficiency aggravates the apoptotic response, probably due to impaired capacity of GPx to degrade H2O2.

Seasonal changes in morphology of the thyroid gland of a hibernator, Spermophilus richardsoni

1981 ◽  
Vol 59 (6) ◽  
pp. 1022-1031 ◽  
Author(s):  
Brent W. Winston ◽  
Nancy E. Henderson
Keyword(s):  
Thyroid Gland ◽  
Seasonal Changes ◽  
Thyroid Tissue ◽  
Ground Squirrels ◽  
Physiological Data ◽  
Thyroid Cell ◽  
Apparent Contradiction ◽  
Dense Granules ◽  
Apical Vesicles ◽  
Circulating Levels

Seasonal changes in morphology of the thyroid gland were studied in Richardson's ground squirrels, Spermophilus richardsoni. Animals were sampled at six times during the annual cycle, and thyroid tissue was examined at the light and electron microscope levels. Synthesis and resorption of thyroglobulin were assessed on the bases of numbers of apical vesicles, colloid droplets, dense granules, and dense bodies, development of the Golgi apparatus and RER, and number and appearance of microvilli and mitochondria.Synthetic and resorptive activities of the throid-hormone-producing cells are high during the early prehibernation or preparative phase and decrease to moderate levels before entry into hibernation. Onset of hibernation is accompanied by further reductions in thyroid cell activities which reach minimal levels by midhibernation. Synthetic and resorptive functions increase slightly toward the end of hibernation. The reproductive phase following emergence is marked by a return to high levels of activities. Colloid storage in the follicles increases between early prehibernation and midhibernation and then decreases. The morphological observations suggest that triiodo-L-thyronine (T3) and L-thyroxine (T4) production and secretion are markedly reduced in hibernating ground squirrels. However, measurements of the circulating levels of the hormones have shown that the titres of both T3 and T4 are elevated in hibernating animals. The apparent contradiction between morphological and physiological data is discussed.

scholarly journals PANCREATIC MICROSOMES

1956 ◽  
Vol 2 (6) ◽  
pp. 671-690 ◽  
Author(s):  
G. E. Palade ◽  
P. Siekevitz
Keyword(s):  
Endoplasmic Reticulum ◽  
Islet Cells ◽  
Reductase Activity ◽  
Liver Microsomes ◽  
Basal Region ◽  
Cytoplasmic Matrix ◽  
Exocrine Cells ◽  
Dense Granules ◽  
Microsome Fraction ◽  
Pancreatic Exocrine

The pancreatic exocrine cell of the guinea pig has a voluminous endoplasmic reticulum distinguished by extensive association with small, dense particles, and by its orderly disposition in the basal region of the cell. In addition to the small, (∼15 mµ), dense particles attached to the limiting membrane of the endoplasmic reticulum, numerous particles of similar appearance are found freely scattered in the cytoplasmic matrix. The various cell structures of pancreatic exocrine cells can be satisfactorily identified in pancreatic homogenates. The microsome fraction consists primarily of spherical vesicles (80 to 300 mµ), limited by a thin membrane (7 mµ) which bears small (∼15 mµ) dense particles attached on its outer surface. The content of the microsomal vesicles is usually of high density. Pancreatic microsomes derive by extensive fragmentation mainly from the rough surfaced parts of the endoplasmic reticula of exocrine cells. A few damaged mitochondria and certain dense granules (∼150 mµ) originating probably from islet cells, contaminate the microsome fraction. Pancreatic microsomes contain RNA, protein, and a relatively small amount of phospholipide and hemochromogen. They do not have DPNH-cytochrome c reductase activity. In six experiments the RNA/protein N ratios were found grouped around two different means, namely 0.6 and 1.3. Pancreatic microsomes are more labile than liver microsomes but react in a similar way to RN-ase-(loss of the particulate component and RNA), and deoxycholate treatment (loss of the membranous component and of phospholipide, hemochromogen, and most of the protein). Postmicrosomal fractions consisting primarly of small (∼15 mµ), dense particles of ribonucleoprotein (RNA/protein N ratio = 1 to 2) were obtained by further centrifugation of the microsomal supernatant. The small nucleoprotein particles of these fractions are frequently found associated in chains or clusters.

scholarly journals Some Observations on the Fine Structure of the Sinus Gland of a Land Crab, Gecarcinus lateralis

1958 ◽  
Vol 4 (5) ◽  
pp. 571-574 ◽  
Author(s):  
Mary H. Hodge ◽  
George B. Chapman
Keyword(s):  
Fine Structure ◽  
Size Range ◽  
Sinus Gland ◽  
Uniform Size ◽  
Brachyuran Crab ◽  
Land Crab ◽  
Dense Granules ◽  
The Core ◽  
Gecarcinus Lateralis ◽  
Cytoplasmic Processes

The dilated axon endings of the sinus glands of the brachyuran crab, Gecarcinus lateralis, are filled with homogeneously dense granules, each granule being bounded by a delicate membrane. The granules are of two orders of magnitude: 0.05 to 0.1 µ and 0.15 to 0.2 µ in diameter. Each axon ending contains granules of a nearly uniform size. Endings with granules of the larger size range predominate. Non-nervous cells endogenous to the sinus gland are scattered among the nerve endings. The cell contours are irregular, and cytoplasmic processes ramify between endings. The axons are unmyelinated, having only thin limiting membranes, and they possess many neurofibrils. Granules in preterminal portions of the axons tend to lie at the periphery of the fiber, and in some cases in chains at the core of the fiber. The granules appear to be storage and release centers for neurosecretory substances or their precursors.

scholarly journals THE FINE STRUCTURE OF THE URINARY BLADDER OF THE TOAD, BUFO MARINUS

1963 ◽  
Vol 16 (1) ◽  
pp. 53-72 ◽  
Author(s):  
Jae Kwon Choi
Keyword(s):  
Fine Structure ◽  
Urinary Bladder ◽  
Bladder Wall ◽  
Single Layer ◽  
Bufo Marinus ◽  
Cell Junctions ◽  
Basal Region ◽  
Basal Cells ◽  
Migratory Cells ◽  
Toad Bufo

The urinary bladder of the toad (Bufo marinus) was studied with both the light and the electron microscope. The bladder wall consists of epithelium, submucosa, and serosa. In the epithelium, four different cell types were recognized on the basis of their fine structure and staining properties with several different dyes. These four were designated as granular cells, mitochondria-rich cells, mucous cells, and basal cells. In addition, migratory cells of a different type were found in the basal region of the epithelium. The luminal surface of the epithelial cells presents irregular microvilli and is coated by PAS-positive material which has been further investigated by histochemical procedures and radioautography. Included is a description of the fine structural details of cell membranes, cell junctions, and intracellular components. The submucosa consists of a delicate stroma of fibroblasts and collagen fibers and also contains blood and lymph vessels, unmyelinated nerves, migratory cells, and smooth muscle cells. The serosa consists of a single layer of serosal (mesothelial) cells which form an uninterrupted covering of the viscus. Possible pathways of sodium and water transport across the bladder wall are discussed.

scholarly journals Modulation of ACE-2 mRNA by inflammatory cytokines in human thyroid cells: a pilot study

Endocrine ◽  
2021 ◽  
Author(s):  
Francesca Coperchini ◽  
Gianluca Ricci ◽  
Laura Croce ◽  
Marco Denegri ◽  
Rubina Ruggiero ◽  
...  
Keyword(s):  
Inflammatory Cytokines ◽  
Combination Treatment ◽  
Primary Cultures ◽  
Human Thyroid ◽  
Thyroid Cell ◽  
Mrna Levels ◽  
Thyroid Cells ◽  
Tnf Α ◽  
Ifn Γ ◽  
Pro Inflammatory Cytokines

Abstract Introduction Angiotensin-converting-enzyme-2 (ACE-2) was demonstrated to be the receptor for cellular entry of SARS-CoV-2. ACE-2 mRNA was identified in several human tissues and recently also in thyroid cells in vitro. Purpose Aim of the present study was to investigate the effect of pro-inflammatory cytokines on the ACE-2 mRNA levels in human thyroid cells in primary cultures. Methods Primary thyroid cell cultures were treated with IFN-γ and TNF-α alone or in combination for 24 h. ACE-2 mRNA levels were measured by RT-PCR. As a control, the levels of IFN-γ inducible chemokine (CXCL10) were measured in the respective cell culture supernatants. Results The mean levels of ACE-2 mRNA increased after treatment with IFN-γ and TNF-α in all the thyroid cell preparations, while the combination treatment did not consistently synergically increase ACE-2-mRNA. At difference, CXCL10 was consistently increased by IFN-γ and synergically further increased by the combination treatment with IFN-γ + TNF-α, with respect to IFN-γ alone. Conclusions The results of the present study show that IFN-γ and, to a lesser extent TNF-α consistently increase ACE-2 mRNA levels in NHT primary cultures. More interestingly, the combined stimulation (proven to be effective according to the synergic effect registered for CXCL10) produces different responses in terms of ACE-2 mRNA modulation. These results would suggest that elevated levels of pro-inflammatory cytokines could facilitate the entering of the virus in cells by further increasing ACE-2 expression and/or account for the different degree of severity of SARS-COV-2 infection. This hypothesis deserves to be confirmed by further specific studies.

scholarly journals Trace Amine-Associated Receptor 1 Trafficking to Cilia of Thyroid Epithelial Cells

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1518
Author(s):  
Maria Qatato ◽  
Vaishnavi Venugopalan ◽  
Alaa Al-Hashimi ◽  
Maren Rehders ◽  
Aaron D. Valentine ◽  
...  
Keyword(s):  
Cell Surface ◽  
Cell Lines ◽  
Human Thyroid ◽  
Apical Plasma Membrane ◽  
Thyroid Cell ◽  
Thyroid Cells ◽  
Trace Amine ◽  
Rat Thyroid

Trace amine-associated receptor 1 (rodent Taar1/human TAAR1) is a G protein-coupled receptor that is mainly recognized for its functions in neuromodulation. Previous in vitro studies suggested that Taar1 may signal from intracellular compartments. However, we have shown Taar1 to localize apically and on ciliary extensions in rodent thyrocytes, suggesting that at least in the thyroid, Taar1 may signal from the cilia at the apical plasma membrane domain of thyrocytes in situ, where it is exposed to the content of the follicle lumen containing putative Taar1 ligands. This study was designed to explore mouse Taar1 (mTaar1) trafficking, heterologously expressed in human and rat thyroid cell lines in order to establish an in vitro system in which Taar1 signaling from the cell surface can be studied in future. The results showed that chimeric mTaar1-EGFP traffics to the apical cell surface and localizes particularly to spherical structures of polarized thyroid cells, procilia, and primary cilia upon serum-starvation. Moreover, mTaar1-EGFP appears to form high molecular mass forms, possibly homodimers and tetramers, in stably expressing human thyroid cell lines. However, only monomeric mTaar1-EGFP was cell surface biotinylated in polarized human thyrocytes. In polarized rat thyrocytes, mTaar1-EGFP is retained in the endoplasmic reticulum, while cilia were reached by mTaar1-EGFP transiently co-expressed in combination with an HA-tagged construct of the related mTaar5. We conclude that Taar1 trafficking to cilia depends on their integrity. The results further suggest that an in vitro cell model was established that recapitulates Taar1 trafficking in thyrocytes in situ, in principle, and will enable studying Taar1 signaling in future, thus extending our general understanding of its potential significance for thyroid autoregulation.

AN INVESTIGATION OF THE PATHOGENESIS OF HASHIMOTO'S DISEASE BY THYROID TISSUE CULTURE

1960 ◽  
Vol 20 (2) ◽  
pp. 83-NP ◽  
Author(s):  
W. J. IRVINE
Keyword(s):  
Tissue Culture ◽  
Alternative Hypothesis ◽  
Thyroid Tissue ◽  
Human Thyroid ◽  
Rabbit Serum ◽  
Thyroid Cell ◽  
Thyroid Extract ◽  
Thyroid Cells ◽  
Hashimoto’S Disease ◽  
Hashimoto's Disease

SUMMARY Human thyroid cells were grown in tissue culture in media containing normal human serum, Hashimoto serum, and rabbit sera containing antibodies to purified human thyroglobulin and to crude thyroid extract, respectively. The thyroid cells grew equally well in all media, with the exception of the rabbit serum containing antibodies to crude thyroid extract. Intact thyroid cells obtained from tissue culture failed to fix Hashimoto antibodies in the presence of complement, whereas the constituents of disrupted thyroid cells gave a strongly positive complement-fixation test with Hashimoto serum. It is therefore suggested that the intact thyroid cell is impermeable to complement-fixing Hashimoto antibody. The evidence afforded by the present work adds further weight to the belief that Hashimoto's disease may not be due to a simple auto-immunizing process consequent upon the interaction of thyroid antigen and the known circulating auto-antibodies. Evidence in support of an alternative hypothesis involving 'cell-bound' antibodies with disruption of the follicular basement membrane is discussed.

scholarly journals Normal Thyroid Structure and Function in Rhophilin 2-Deficient Mice

2005 ◽  
Vol 25 (7) ◽  
pp. 2846-2852 ◽  
Author(s):  
Jens Behrends ◽  
Serge Clément ◽  
Bernard Pajak ◽  
Viviane Pohl ◽  
Carine Maenhaut ◽  
...  
Keyword(s):  
Rho Gtpase ◽  
Clinical Signs ◽  
Structure And Function ◽  
Secretory Process ◽  
Thyroid Cell ◽  
Thyroid Cells ◽  
Thyroid Cell Culture ◽  
And Function ◽  
Deficient Mice ◽  
Stimulation Of

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.

scholarly journals Detection of SARS-COV-2 receptor ACE-2 mRNA in thyroid cells: a clue for COVID-19-related subacute thyroiditis

2020 ◽  
Author(s):  
M. Rotondi ◽  
F. Coperchini ◽  
G. Ricci ◽  
M. Denegri ◽  
L. Croce ◽  
...  
Keyword(s):  
Primary Cultures ◽  
Thyroid Tissue ◽  
Subacute Thyroiditis ◽  
Human Thyroid ◽  
Thyroid Cell ◽  
Type I ◽  
Rt Pcr ◽  
Follicular Cells ◽  
Thyroid Cells ◽  
Tissue Samples

Abstract Purpose SARS-COV-2 is a pathogenic agent belonging to the coronavirus family, responsible for the current global world pandemic. Angiotensin-converting enzyme 2 (ACE-2) is the receptor for cellular entry of SARS-CoV-2. ACE-2 is a type I transmembrane metallo-carboxypeptidase involved in the Renin-Angiotensin pathway. By analyzing two independent databases, ACE-2 was identified in several human tissues including the thyroid. Although some cases of COVID-19-related subacute thyroiditis were recently described, direct proof for the expression of the ACE-2 mRNA in thyroid cells is still lacking. Aim of the present study was to investigate by RT-PCR whether the mRNA encoding for ACE-2 is present in human thyroid cells. Methods RT-PCR was performed on in vitro ex vivo study on thyroid tissue samples (15 patients undergoing thyroidectomy for benign thyroid nodules) and primary thyroid cell cultures. Results The ACE-2 mRNA was detected in all surgical thyroid tissue samples (n = 15). Compared with two reporter genes (GAPDH: 0.052 ± 0.0026 Cycles−1; β-actin: 0.044 ± 0.0025 Cycles−1; ACE-2: 0.035 ± 0.0024 Cycles−1), the mean level of transcript expression for ACE-2 mRNA was abundant. The expression of ACE-2 mRNA in follicular cells was confirmed by analyzing primary cultures of thyroid cells, which expressed the ACE-2 mRNA at levels similar to tissues. Conclusions The results of the present study demonstrate that the mRNA encoding for the ACE-2 receptor is expressed in thyroid follicular cells, making them a potential target for SARS-COV-2 entry. Future clinical studies in patients with COVID-19 will be required for increase our understanding of the thyroid repercussions of SARS-CoV-2 infection.

Sign in / Sign up

Export Citation Format

Share Document