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J Golstein

Publications and source records attributed to J Golstein.

At least 19 recordsLinked to original sources
PubMed2001

Regulation of thyroid cell proliferation by TSH and other factors: a critical evaluation of in vitro models.

TSH via cAMP, and various growth factors, in cooperation with insulin or IGF-I stimulate cell cycle progression and proliferation in various thyrocyte culture systems, including rat thyroid cell lines (FRTL-5, WRT, PC Cl3) and primary cultures of rat, dog, sheep and human thyroid. The available data on cell signaling cascades, cell cycle kinetics, and cell cycle-regulatory proteins are thoroughly and critically reviewed in these experimental systems. In most FRTL-5 cells, TSH (cAMP) merely acts as a priming/competence factor amplifying PI3K and MAPK pathway activation and DNA synthesis elicited by insulin/IGF-I. In WRT cells, TSH and insulin/IGF-I can independently activate Ras and PI3K pathways and DNA synthesis. In dog thyroid primary cultures, TSH (cAMP) does not activate Ras and PI3K, and cAMP must be continuously elevated by TSH to directly control the progression through G(1) phase. This effect is exerted, at least in part, via the cAMP-dependent activation of the required cyclin D3, itself synthesized in response to insulin/IGF-I. This and other discrepancies show that the mechanistic logics of cell cycle stimulation by cAMP profoundly diverge in these different in vitro models of the same cell. Therefore, although these different thyrocyte systems constitute interesting models of the wide diversity of possible mechanisms of cAMP-dependent proliferation in various cell types, extrapolation of in vitro mechanistic data to TSH-dependent goitrogenesis in man can only be accepted in the cases where independent validation is provided.

Animals↗
PubMed1999

Loss of several cell functions including okadaic acid-induced apoptosis after multiple passages in FRTL-5 cells.

In FRTL-5 cells, cultured over a period of more than 3 years, different properties of the cells have been observed to undergo spontaneous changes in the course of aging, i.e. after an increase in the number of passages. This consists mainly in alterations in their morphological phenotype and in some of their functional properties. The morphology of the cells displayed a progressive disruption of the monolayer organization with a loss of cell-cell contacts and a marked rounding-up of the cells. The uptake of iodide was not modified nor was the expression of thyroglobulin (Tg) mRNA as determined at various time intervals in the course of the cells culturing. Estimation of the proliferation by counting the frequency of [3H]thymidine labeled nuclei revealed an age-related decline in the sensitivity to TSH mitogenic action associated with a reciprocal increase in the insulin synergistic effect. Aged cells (+/- 40 passages) lost their apoptosis sensitivity to the phosphatase inhibitor, okadaic acid (OA) but not to cycloheximide (CHX) and/or actinomycin D (act. D) exposure. Altogether these observations favor the existence of a shift towards transformed properties with only partial loss of differentiated functions.

Animals↗
PubMed1999

Insulin and TSH promote growth in size of PC Cl3 rat thyroid cells, possibly via a pathway different from DNA synthesis: comparison with FRTL-5 cells.

In the rat thyroid cell lines PC Cl3, FRTL- 5 and WRT, proliferation is mainly regulated by insulin or IGF, and TSH. However, the mechanism regulating cell mass doubling prior to division is still unknown. Our laboratory has shown that in dog thyroid cells insulin promotes growth in size while TSH in the presence of insulin triggers DNA replication. In the absence of insulin, TSH has no effect on cell growth. In this report we investigated insulin action on both cell mass and DNA synthesis and its modulation by TSH and insulin in PC Cl3 and FRTL-5 cells. In PC Cl3 cells, insulin activated not only DNA synthesis but also protein synthesis and accumulation. Although TSH potentiated the stimulation of DNA synthesis induced by insulin, enhancement of protein synthesis by both agents was additive. All TSH effects were reproduced by forskolin. Similar effects were also obtained in FRTL-5 cells. This suggests that insulin and TSH, via cAMP, modulate both growth in size and DNA replication in these cell lines. Lovastatin, which blocks 3-hydroxy-3-methylglutaryl coenzyme A reductase, decreased the induction of DNA synthesis, but not of protein synthesis induced by insulin or TSH in PC Cl3 cells. In FRTL-5 cells, lovastatin reduced protein and DNA synthesis stimulated by insulin but not TSH-induced protein synthesis. Taking these data together, we propose that insulin and/or TSH both modulate cell mass doubling and DNA synthesis in these cell lines, presumably via different pathways, and that there are at least two pathways which regulate growth in size in FRTL-5 thyroid cells: one triggered by insulin, which is lovastatin sensitive, and the other activated by TSH, which is not sensitive to lovastatin.

Animals↗
PubMed1996

Cytotoxic effects of iodide on thyroid cells: difference between rat thyroid FRTL-5 cell and primary dog thyrocyte responsiveness.

In order to investigate whether the cytotoxic effect of iodide observed in the thyroid gland represented an apoptotic phenomenon, in vitro experiments were performed using the FRTL-5 thyroid cell line and dog thyrocytes in primary culture. These cells were exposed to iodide under various incubation conditions. Apoptosis was assessed through the analysis of DNA breakdown, i.e. the electrophoresis of internucleosomal DNA fragments generating a typical "ladder" and quantification of prelabelled DNA cleavage products. The FRTL-5 cells appeared to be sensitive only to high doses of iodide, far in excess of physiological levels. They exhibited the different characteristics of two different cell death phenomena: apoptosis and necrosis. The toxicity of iodide appeared to be partially relieved by anti-thyroid agents. This effect constitutes an additional example of the general paradigm of iodide action through oxidized intermediates. In contrast dog thyrocytes in primary culture did not appear to be sensitive to iodide under similar incubation conditions; species differences and/or types of culture could account for these discrepant effects.

Animals↗
PubMed1995

Fine mapping of 28S rRNA sites specifically cleaved in cells undergoing apoptosis.

Bona fide apoptosis in rat and human leukemia cells, rat thymocytes, and bovine endothelial cells was accompanied by limited and specific cleavage of polysome-associated and monosome-associated 28S rRNA, with 18S rRNA being spared. Specific 28S rRNA cleavage was observed in all instances of apoptotic death accompanied by internucleosomal DNA fragmentation, with cleavage of 28S rRNA and of DNA being linked temporally. This indicates that 28S rRNA fragmentation may be as general a feature of apoptosis as internucleosomal DNA fragmentation and that concerted specific cleavage of intra- and extranuclear polynucleotides occurs in apoptosis. Apoptosis-associated cleavage sites were mapped to the 28S rRNA divergent domains D2, D6 (endothelial cells), and D8. The D2 cuts occurred in hairpin loop junctions considered to be buried in the intact ribosome, suggesting that this rRNA region becomes a target for RNase attack in apoptotic cells. D8 was cleaved in two exposed UU(U) sequences in bulge loops. Treatment with agents causing necrotic cell death or aging of cell lysates failed to produce any detectable limited D2 cleavage but did produce a more generalized cleavage in the D8 region. Of potential functional interest was the finding that the primary cuts in D2 exactly flanked a 0.3-kb hypervariable subdomain (D2c), allowing excision of the latter. The implication of hypervariable rRNA domains in apoptosis represents the first association of any functional process with these enigmatic parts of the ribosomes.

Animals↗
PubMed1995

Comparative cytotoxic effects of two protein phosphatase inhibitors, okadaic acid and calyculin A, on thyroid cells.

The cytotoxicity of two inhibitors of protein phosphatases PP1 and PP2A has been investigated on primary cultures of dog thyrocytes. Both compounds, okadaic acid and calyculin A elicited dose- and time- related effects, i.e. apoptosis and necrosis. In addition a pronounced detachment of the cells from the monolayer was also observed. Based on the different patterns of morphological alterations and on the biochemical data, it was concluded that each compound induced different types of cell death; this provides additional evidence that a specific cell type can initiate distinct programs of death depending on the triggering stimulus. To explain the effects recorded when both compounds were added concomitantly, a functional interaction between PP1 and PP2A has been proposed. Finally, all the effects appeared modulated, to different extent, by cycloheximide and by actinomycin D. This supports the view that de novo RNA synthesis is required for the induction of death by these phosphatase inhibitors in these cells.

Journal Article↗
PubMed1994

Apoptosis in dog thyroid cells.

Apoptosis, a physiological cell death, has been shown to be involved in tissue homeostasis as well as in tissue regression due to hormone deprivation. The cell population slowly turns over, with cell loss compensating mitogenicity. In the absence of thyrotropin, the cell population decreases. The possible involvement of apoptosis in this loss has been studied. We show in this report that deprivation of serum, epidermal growth factor and thyrotropin triggers internucleosomal DNA fragmentation and morphological modifications characteristic of apoptotic cell death in dog thyroid cells in primary culture; cycloheximide treatment has the same effect. This indicates that thyrocytes are endowed with a constitutive apoptosis "program" and that the latter might be involved in the thyroid regression observed in vivo in the absence of full growth stimulation of the gland.

Animals↗
PubMed1994

FB1, a monoclonal antibody reacting with a keratin 14 epitope, stains only a small subset of psoriatic basal keratinocytes.

A murine monoclonal antibody, FB1, reacted with the basal keratinocytes of human stratified epithelia. One-dimensional and two-dimensional immunoblotting assays, performed on keratins extracted from HaCat cells and normal human keratinocytes, showed that FB1 recognizes K14. When LL002, another K14 monoclonal antibody is added, the FB1 stained area in the 2D-immunoblot seems to cover a fraction of the LL002 spot. Immunohistochemical data obtained from studies on normal human tissues supported the K14 specificity of FB1, but when compared with two other monoclonal antibodies, LL002 and RCK107 reacting with K14, some differences appeared. These differences were mainly seen in sweat glands, hair follicles, psoriatic epidermis and salivary glands. In psoriatic epidermis, FB1 showed a heterogeneous pattern of staining of the basal cell compartment. Intense reactivity was only observed at the bottom of the rete ridges. Staining diminished and finally disappeared in the basal cells above the dermal papillae. This observation supports the view that an increased germinative cell population in psoriasis involves a partially differentiated amplifying compartment in which the number of cell divisions is increased.

Animals↗
PubMed1991

Insulin-like growth factor I: a good indicator of functional hepatocellular capacity in alcoholic liver cirrhosis.

To assess the value of serum insulin-like growth factor I (IGF-I) determination in liver disease, 21 patients hospitalized for active alcoholic cirrhosis (19 males, 2 females), 56 +/- 2 y (mean +/- SE) were studied at admission. Individual scores of hepatic alterations (Child score) ranged from 6 to 12 (mean: 9 +/- 1). Basal IGF-I levels were dramatically decreased, averaging 0.11 +/- 0.02 U/ml vs 0.70 +/- 0.08 U/ml in 15 control subjects. In cirrhotic patients, IGF-I values were inversely correlated with the modified Child index (r = 0.57, p less than 0.01). A highly significant positive correlation (r = 0.68, p less than 0.001) was evidenced between IGF-I levels and aminopyrine breath test values (which provide quantitative estimates of the hepatic functional capacity). In contrast, no significant relationship was found between IGF-I levels and various nutritional parameters (albumin, prealbumin, retinol binding protein) after partial correlation analysis. The present data suggest that, in alcoholic cirrhosis, the decrease of circulating IGF-I values is mainly related to alterations of liver function, and that IGF-I can be used as a good indicator of functional hepatocellular capacity.

Adult↗
PubMed1990

Placental growth hormone as a potential regulator of maternal IGF-I during human pregnancy.

Ninety-three healthy women were investigated during normal pregnancy, and 177 blood samples were obtained at various gestational stages. In 8 of the women, serial measurements were obtained over a period of 16-34 wk from 8 to 40 wk of gestation. In 13 women, daily blood samples were obtained from day 0 to day 6 after delivery. Insulin-like growth factor I (IGF-I) and human placental lactogen (hPL) were measured by radioimmunoassays. Growth hormone (GH) was estimated by two monoclonal antibody-based radioimmunoassays insensitive to physiological concentrations of hPL: the K24 assay, which recognizes only pituitary hGH, and the 5B4 assay, which reacts with all the known pituitary as well as placental GH variants. Placental GH was distinguished from the main pituitary variant through its specific immunoreactivity pattern. Mean plasma levels of IGF-I were relatively stable until 29-30 wk gestation, then increased progressively to reach a maximum at 35-36 wk. Regardless of gestational age, individual IGF-I values exhibited a highly significant positive correlation with placental GH, reflected by 5B4 immunoreactivity, whereas the correlation between IGF-I and hPL was not statistically significant. Considering each 2-wk gestational period separately, we found a positive correlation between IGF-I and 5B4 hGH at 31-32 wk. Conversely, no evidence of correlation was found between IGF-I and hPL at any period. After delivery, IGF-I evolution exhibited a biphasic pattern, with an initial decrease to low values followed by a progressive return toward levels found in nonpregnant healthy women. These results strengthen our previous hypothesis that placental growth hormone is involved in the control mechanism of serum IGF-I levels in normal pregnant women.

Antibodies, Monoclonal↗
PubMed1988

[Neuroendocrine rhythms in uni- and bipolar depressions].

Eighteen patients with major depressive disorder of the endogenous subtype (8 unipolars and 10 bipolars) were submitted to blood sampling at 15 min interval for 24 h with polygraphic sleep recording during an acute episode of depression. Plasma growth hormone (GH), adrenocorticotrophin (ACTH) and cortisol were measured in each sample. The depressed patients hypersecreted GH during the daytime and had hypercortisolism which was evident throughout the 24 h span. The nadir of ACTH and cortisol rhythms was advanced by an average of 3 h as compared to the timing observed in normal subjects. These abnormalities were more pronounced and more consistent in patients with unipolar rather than bipolar depression. These results are consistent with the hypothesis that disorders of circadian time-keeping may characterize major endogenous depression.

Adrenal Cortex Hormones↗
PubMed1988

The effect of beta-endorphin on basal and TRH-stimulated TSH release in conscious male rats.

The inhibitory effect of beta-endorphin (EP) or other opioids on TSH secretion is, in contrast to their stimulating properties on PRL release, still a matter of debate. In the present study a dose of 1 microgram beta-EP injected intracerebroventricularly (IVT) in unstressed conscious male rats, though highly effective on PRL release, did not affect basal TSH levels, nor the TRH-induced TSH secretion. The previously reported inhibition of TSH release by opioids may therefore be an effect only seen when pharmacological doses are used.

Animals↗
PubMed1988

Effects of iodine intake on thyroid secondary lysosomes after subtotal thyroidectomy.

This study tested the effects of different iodine intakes on thyroid ultrastructure and function in thyroid remnants after subtotal thyroidectomy (sub-tx). Removal of most of the thyroid gland causes an elevation of endogenous TSH, which chronically stimulates the residual tissue. Male Sprague-Dawley rats were divided into three groups; Low Iodine Group (LIG), Moderate Iodine Group (MIG), and High Iodine Group (HIG). There was no significant difference among total thyroid weights removed by sub-tx, but thyroid remnant weights and TSH levels were higher at death (6 weeks after sub-tx) in LIG than in MIG and HIG. Total specific activities of cathepsin D and of arylsulfatase A in the sedimentable and nonsedimentable subcellular fractions were at least 38% lower in LIG than in MIG and HIG. The ratio between relative follicular volume and colloid volume determined by morphometry was higher in LIG than in MIG and lower in HIG than in MIG. Ultrastructurally, the relative volume occupied by secondary lysosomes was higher in HIG than in MIG, whereas the number of secondary lysosomes was not higher in LIG than in controls. Autoradiographic studies with 125I revealed that a large part of the radioactivity was in thyroid cell secondary lysosomes in MIG and HIG when radioiodine was injected 3 weeks before death. It is concluded that after sub-tx, iodine 1) regulates the weight of thyroid remnants, perhaps only indirectly through TSH, 2) modulates the number of secondary lysosomes in thyroid cells, and 3) slows down the turnover of secondary lysosomes. An iodine-deficient regimen impedes the secondary lysosomes to increase. Because of these findings, we postulate that chronic TSH stimulation along with a possible toxic role of iodine after sub-tx could induce an accumulation of lysosomal bodies.

Animals↗
PubMed1988

Effects of a selenium deficient diet on thyroid function of normal and perchlorate treated rats.

Pregnant rats were submitted to a selenium-deficient diet immediately after mating; it was continued for 4 weeks after delivery. The pups were sacrificed at 3 and 4 weeks of age. Perchlorate, an antithyroid agent inhibiting iodide trapping in the thyroid, was administered via the drinking water to half of the rats. Rats submitted to a normal laboratory diet and to the experimental diet supplemented with selenium were used as controls. The effects of selenium deficiency were an increase in the number of growth abnormalities, growth retardation, and decreased seleno-dependent glutathione peroxidase (GSH-Px) activity in plasma and in various organs. These effects were relieved by selenium supplementation in the diet. Perchlorate treatment induced the classic picture of primary hypothyroidism. Selenium deficiency increased thyroid hormone levels in perchlorate-treated rats and in controls drinking tap water. In the latter group, it also decreased TSH plasma concentration and thyroid weight. These effects were partially reversed by Se supplementation. In vitro experiments, performed on adult rats, revealed increased radioiodide uptake and organification in glands from the rats submitted to the selenium-free diet. Plasma T3 half-life was similar in control and Se-deficient rats. These data suggest a higher efficiency of thyroid hormone synthesis in the thyroids of selenium-deficient rats, despite a lower thyroid stimulation as evaluated by serum TSH. They are compatible with the hypothesis that decreased selenium supply, leading to a decreased GSH-Px in the thyroid, increases hydrogen peroxide steady state level and thus thyroid peroxidase activity and thyroid hormone synthesis.

Animals↗
PubMed1987

In vivo and in vitro effect of naloxone on prolactin response to TRH in rat.

In adult male Wistar rats submitted to a standardized noise stress, intravenous TRH induced a prolactin (PRL) secretory response. Prior IV naloxone administration not only lowered plasma PRL levels in those stressed rats but abolished also the stimulatory action of TRH. This effect was further studied by superfusion experiments on enriched PRL cell suspensions (70% lactotrophs) from female adult Wistar rats. Naloxone kept unaffected the basal PRL secretion but lowered significantly that induced by TRH. These experiments suggest a dual effect of naloxone on rat PRL secretion, one exerted on central opioid receptors lowering stress-related increased basal PRL levels, the other inhibiting the TRH-dependent PRL secretion exerted at the lactotroph level itself.

Animals↗
PubMed1987

Opioid modulation of thyrotropin releasing hormone induced prolactin secretion.

It is known that opioids stimulate prolactin (PRL) secretion by an action on hypothalamic neurons, but in vitro studies have suggested a direct action on the lactotrophs. The present study was performed on male rats known to have little or no PRL response to TRH. A beta-endorphin (beta EP) injection in the third ventricle stimulated PRL secretion and induced furthermore a PRL secretory reaction to TRH injected intravenously 20 min later. Pretreatment with naloxone 10 min before beta EP injection abolished not only the PRL response to beta EP but also the conjugated effect of beta EP and TRH. Pretreatment with naloxone methyl bromide (Br-naloxone), a quaternary naloxone derivative, which does not cross the blood-brain barrier, had no effect on the PRL response to beta EP but prevented the conjugated effect of beta EP and TRH on PRL secretion. Pretreatment of the animals with -methyl-parathyrosine resulting in a dopamine depletion or with haloperidol, a dopamine antagonist, could not induce lactotroph responsiveness to TRH. These results suggest that beta EP in male rat sensitizes the PRL cell to TRH by a direct effect and not through an inhibition of the dopaminergic tone.

Animals↗
PubMed1987

Low somatomedin-C (Sm-C) concentrations measured by direct radioimmunoassay in patients with chronic renal failure.

Ten patients suffering from chronic renal failure and undergoing regular hemodialysis were tested immediately before and immediately after a 3-hour dialysis. Serum levels of immunoreactive Sm-C, estimated on unextracted non acidified serum at non equilibrium, were significantly lower than in normal controls and no consistent modifications were observed after dialysis.

Adult↗