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Paulus S Wang - One of the best experts on this subject based on the ideXlab platform.
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effects of vitamin e on steroidogenesis in rat Zona fasciculata reticularis cells
調適醫學, 2012Co-Authors: Lingling Chang, Paulus S WangAbstract:Vitamin E is an antioxidant which can prevent reduction in endothelial nitric oxide release in diabetic rat heart. However, the effects and action mechanisms of vitamin E on rat adrenal Zona fasciculata-reticularis (ZFR) cells are still unclear. This study explored the effects of vitamin E on corticosterone release, the functions of cytochrome P450 side-chain cleavage enzyme (P450scc), and protein expression of steroidogenic acute regulator (StAR) protein and P450scc. ZFR cells were incubated with vitamin E in the presence or absence of adrenocorticotropin (ACTH), 8-bromo-cyclic 3': 5' adenosine monophosphate (8-Br-cAMP), 25-OH-cholesterol, pregnenolone, progesterone, or deoxycorticosterone at 37°C for 1 h or 3 h. The media were collected to measure the concentration of corticosterone or pregnenolone by radioimmunoassay (RIA). The cells were used to measure the StAR or P450scc protein expression by Western blotting analysis. The data demonstrated that [1] vitamin E inhibited ACTH-, 8-Br-cAMP-, or steroidogenic precursors-stimulated corticosterone release; [2] vitamin E increased the Michaelis constants of P450scc from 4.908 M to 11.997 M; [3] vitamin E might affect StAR protein expression.
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mechanisms of inhibition of dehydroepiandrosterone upon corticosterone release from rat Zona fasciculata reticularis cells
Journal of Cellular Biochemistry, 2008Co-Authors: Lingling Chang, Paulus S WangAbstract:We have demonstrated that dehydroepiandrosterone (DHEA) acts directly on rat Zona fasciculata-reticularis (ZFR) cells to diminish corticosterone secretion by an inhibition of post-cAMP pathway, and decreases functions of steroidogenic enzymes after P450scc as well as steroidogenic acute regulatory (StAR) protein expression. However, the mechanisms by which DHEA engages with environmental messenger signals which translate into interfering StAR protein expression are still unclear. This study explored the effects of DHEA on the phosphorylation/activation of extracellular signal-regulated kinases (ERKs). ERK activation resulted in enhancing phosphorylation of steroidogenic factor-1 (SF-1) and increased StAR protein expression. ZFR cells were incubated in the presence or absence of adrenocorticotropin (ACTH), forskolin (FSK), 25-OH-cholesterol, U0126, and H89 at 37°C. The concentration of corticosterone released into the media was measured by radioimmunoassay (RIA). The cells were used to extract protein for Western blot analysis of ERKs or StAR protein expression or immunoprecipitation of SF-1 analysis. The results suggested that (1) ERK pathway of rat ZFR cells might be PKA dependent, (2) ERK activity was required for SF-1 phosphorylation to upregulate steroidogenesis in rat ZFR cells, and (3) DHEA did not affect ERK phosphorylation, however, it attenuated forskolin-stimulated SF-1 phosphorylation to affect StAR protein expression. J. Cell. Biochem. 104: 359–368, 2008. © 2007 Wiley-Liss, Inc.
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effects of dehydroepiandrosterone on corticosterone release in rat Zona fasciculata reticularis cells
Naunyn-schmiedebergs Archives of Pharmacology, 2003Co-Authors: Lingling Chang, Paulus S Wang, Lowtone L HoAbstract:The decline of plasma dehydroepiandrosterone (DHEA) and maintenance of glucocorticoid levels with increasing age contribute to excess body fat accumulation, hyperglycaemia, hyperlipidaemia, hyperinsulinaemia and cancer. Although opposing actions of DHEA and corticosterone have been proposed in a rat model, the effects and action mechanisms of DHEA on rat adrenal Zona fasciculata-reticularis (ZFR) cells are still unclear. This study addressed the effects of DHEA on corticosterone release, cellular cAMP production, the functions of steroidogenic enzymes and the expression levels of steroidogenic acute regulatory protein (StAR) and cytochrome P450 side-chain cleavage enzyme (P450scc). ZFR cells were incubated with DHEA in the presence or absence of adrenocorticotropin (ACTH), 8-Br-cAMP, forskolin, 25-OH-cholesterol, pregnenolone, progesterone or deoxycorticosterone at 37 °C for 30 min, 1 h or 5 h and the concentration of corticosterone or pregnenolone measured subsequently in the media by RIA. The cells were used to measure the content of cAMP by RIA and to extract protein for Western blot or mRNA for RT-PCR analysis. The data demonstrated that (1) DHEA inhibited ACTH-, 8-Br-cAMP-, 25-OH-cholesterol-, pregnenolone-, progesterone- or deoxycorticosterone-stimulated corticosterone release; (2) DHEA increased 25-OH-cholesterol-stimulated pregnenolone release but not when 25-OH-cholesterol was combined with trilostane; (3) DHEA increased the K m of 11β-hydroxylase but not P450scc; (4) DHEA affected the expression levels of StAR protein but not of P450scc. These results suggest that DHEA acts directly on rat ZFR cells to diminish corticosterone secretion by inhibition within the post-cAMP pathway, by inhibiting steroidogenic enzymes downstream from P450scc and by inhibiting StAR expression.
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Effects of fasting on corticosterone production by Zona fasciculata-reticularis cells in ovariectomized rats.
Journal of Investigative Medicine, 2002Co-Authors: Lingling Chang, Lowtone Ho, Paulus S WangAbstract:BACKGROUND: To investigate the function and mechanism of fasting on the production of corticosterone in vitro by Zona fasciculata-reticularis (ZFR) cells from ovariectomized (OVX) rats. METHODS: Female rats were OVX for 4 days before decapitation. Rats were fed or fasted for 1 day before experiment. ZFR cells from fed and fasted rats were incubated with adrenocorticotropic hormone (ACTH), forskolin, 8-bromo-3',5'-cyclic adenosine monophosphate, SQ22536, nifedipine, chelerythrine chloride, trilostane or steroidogenic precursors at 37 degrees C for either 60 or 30 minutes. Corticosterone, pregnenolone concentrations in spent media, and the intracellular adenosine 3',5'-cyclic monophosphate (cAMP) concentration were determined by radioimmunoassay. The effects of fasting in response to ACTH on the protein expressions of steroidogenic acute regulatory protein (StAR) or cytochrome P450 side-chain cleavage enzyme (P450scc) in ZFR cells were determined by Western blot analysis. RESULTS: The concentration of plasma corticosterone in fasted rats was significantly higher than that in fed rats (P
B C Williams - One of the best experts on this subject based on the ideXlab platform.
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Acetylcholine induces oscillations in intracellular calcium in isolated bovine adrenal Zona fasciculata/reticularis cells.
Endocrine Research, 1995Co-Authors: C Clyne, S W Walker, Ian M Bird, B C WilliamsAbstract:The effects of acetylcholine (ACh) on intracellular free calcium were studied in primary cultures of purified bovine adrenal Zona fasciculata/reticularis (ZFR) cells. In fura-2 loaded single cells, concentrations of ACh which stimulated cortisol secretion and phosphoinositol production were found to promote an increase in free cytosolic calcium ([Ca2+]i). This response was heterogeneous, showing either (i) an initial increase in [Ca2+]i followed by a fall to a level above that in unstimulated cells, or (ii) an initial increase followed by oscillations about the original resting level or a higher resting level. The frequencies of [Ca2+]i oscillations to ACh showed a dose-dependent trend. The sustained [Ca2+]i oscillations were abolished by the muscarinic antagonist atropine, or by removal of extracellular Ca2+. These data demonstrate for the first time in adrenocortical cells that: (i) ACh can induce [Ca2+]i oscillations in single ZFR cells; (ii) these oscillations occur in a dose-dependent manner; (iii) t...
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acetylcholine induces oscillations in intracellular calcium in isolated bovine adrenal Zona fasciculata reticularis cells
Endocrine Research, 1995Co-Authors: C Clyne, S W Walker, Ian M Bird, B C WilliamsAbstract:The effects of acetylcholine (ACh) on intracellular free calcium were studied in primary cultures of purified bovine adrenal Zona fasciculata/reticularis (ZFR) cells. In fura-2 loaded single cells, concentrations of ACh which stimulated cortisol secretion and phosphoinositol production were found to promote an increase in free cytosolic calcium ([Ca2+]i). This response was heterogeneous, showing either (i) an initial increase in [Ca2+]i followed by a fall to a level above that in unstimulated cells, or (ii) an initial increase followed by oscillations about the original resting level or a higher resting level. The frequencies of [Ca2+]i oscillations to ACh showed a dose-dependent trend. The sustained [Ca2+]i oscillations were abolished by the muscarinic antagonist atropine, or by removal of extracellular Ca2+. These data demonstrate for the first time in adrenocortical cells that: (i) ACh can induce [Ca2+]i oscillations in single ZFR cells; (ii) these oscillations occur in a dose-dependent manner; (iii) t...
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angiotensin ii stimulates growth and steroidogenesis in Zona fasciculata reticularis cells from bovine adrenal cortex via the at1 receptor subtype
Endocrinology, 1993Co-Authors: C Clyne, Moira R Nicol, B C Williams, Steven T Macdonald, S W WalkerAbstract:Primary cultures of bovine adrenocortical Zona fasciculata/reticularis (zfr) cells responded to angiotensin II (AII) with a dose-dependent increase in [3H]thymidine incorporation into DNA. The effect was maximal at 100 nmol/liter AII, and was dose dependently inhibited by (sar1, ala8)-AII (saralasin) and DuP753, but not by PD123177. Both AII-stimulated cortisol secretion and phosphoinositidase C activity were also inhibited by saralasin and DuP753, but not by PD123177. Pharmacological analysis of the antagonism of AII-stimulated cortisol secretion by saralasin and DuP753 produced pA2 values of 8.79 and 7.02, respectively. Whereas the pA2 for saralasin agreed closely with previous measurements in other systems, DuP753 was at least one order of magnitude less potent in inhibiting the action of AII in bovine zfr cells compared to previous measurements in rabbit vascular smooth muscle. We conclude that the steroidogenic and mitogenic effects of AII in bovine zfr cells are mediated by the AT1 receptor.
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Angiotensin II stimulates growth and steroidogenesis in Zona fasciculata/reticularis cells from bovine adrenal cortex via the AT1 receptor subtype
Endocrinology, 1993Co-Authors: C Clyne, Moira R Nicol, B C Williams, Steven T Macdonald, S W WalkerAbstract:Primary cultures of bovine adrenocortical Zona fasciculata/reticularis (zfr) cells responded to angiotensin II (AII) with a dose-dependent increase in [3H]thymidine incorporation into DNA. The effect was maximal at 100 nmol/liter AII, and was dose dependently inhibited by (sar1, ala8)-AII (saralasin) and DuP753, but not by PD123177. Both AII-stimulated cortisol secretion and phosphoinositidase C activity were also inhibited by saralasin and DuP753, but not by PD123177. Pharmacological analysis of the antagonism of AII-stimulated cortisol secretion by saralasin and DuP753 produced pA2 values of 8.79 and 7.02, respectively. Whereas the pA2 for saralasin agreed closely with previous measurements in other systems, DuP753 was at least one order of magnitude less potent in inhibiting the action of AII in bovine zfr cells compared to previous measurements in rabbit vascular smooth muscle. We conclude that the steroidogenic and mitogenic effects of AII in bovine zfr cells are mediated by the AT1 receptor.
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Subclassification of β-adrenoceptors responsible for steroidogenesis in primary cultures of bovine adrenocortical Zona fasciculata/reticularis cells
British Journal of Pharmacology, 1990Co-Authors: E R T Lightly, S W Walker, I M Bird, B C WilliamsAbstract:Abstract 1. Forty eight hour primary cultures of purified bovine adrenocortical Zona fasciculata/reticularis cells secreted hydrocortisone in response to stimulation with beta-adrenoceptor agonists. The observed order of potency was isoprenaline greater than noradrenaline greater than dobutamine greater than salbutamol greater than BRL37344. 2. Salbutamol acted as a partial agonist on these cells hence suggesting the presence of a beta 1-adrenoceptor. 3. Schild analysis of the hydrocortisone response to isoprenaline showed that the selective beta 1-antagonist practolol and the selective beta 2-antagonist ICI118,551 gave pA2 values of 6.85 and 7.17, respectively. These values were in close agreement with corresponding pA2 values previously obtained for the beta 1-adrenoceptor. 4. We conclude that beta 1-adrenoceptors are responsible for mediating catecholamine-stimulated hydrocortisone secretion from primary cultures of bovine Zona fasciculata/reticularis cells.
Allan M Judd - One of the best experts on this subject based on the ideXlab platform.
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involvement of adenosine monophosphate activated kinase in interleukin 6 regulation of steroidogenic acute regulatory protein and cholesterol side chain cleavage enzyme in the bovine Zona fasciculata and Zona reticularis
Steroids, 2018Co-Authors: Matharage S I De Silva, Adam Wesley Dayton, Lance R Rhoten, John W Mallett, Jared C Reese, Mathieu D Squires, Andrew P Dalley, James P Porter, Allan M JuddAbstract:Abstract In bovine adrenal Zona fasciculata (ZF) and NCI-H295R cells, interleukin-6 (IL-6) increases cortisol release, increases expression of steroidogenic acute regulatory protein (StAR), cholesterol side chain cleavage enzyme (P450scc), and steroidogenic factor 1 (SF-1) (increases steroidogenic proteins), and decreases the expression of adrenal hypoplasia congenita-like protein (DAX-1) (inhibits steroidogenic proteins). In contrast, IL-6 decreases bovine adrenal Zona reticularis (ZR) androgen release, StAR, P450scc, and SF-1 expression, and increases DAX-1 expression. Adenosine monophosphate (AMP) activated kinase (AMPK) regulates steroidogenesis, but its role in IL-6 regulation of adrenal steroidogenesis is unknown. In the present study, an AMPK activator (AICAR) increased ( P P P P P
Lingling Chang - One of the best experts on this subject based on the ideXlab platform.
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effects of vitamin e on steroidogenesis in rat Zona fasciculata reticularis cells
調適醫學, 2012Co-Authors: Lingling Chang, Paulus S WangAbstract:Vitamin E is an antioxidant which can prevent reduction in endothelial nitric oxide release in diabetic rat heart. However, the effects and action mechanisms of vitamin E on rat adrenal Zona fasciculata-reticularis (ZFR) cells are still unclear. This study explored the effects of vitamin E on corticosterone release, the functions of cytochrome P450 side-chain cleavage enzyme (P450scc), and protein expression of steroidogenic acute regulator (StAR) protein and P450scc. ZFR cells were incubated with vitamin E in the presence or absence of adrenocorticotropin (ACTH), 8-bromo-cyclic 3': 5' adenosine monophosphate (8-Br-cAMP), 25-OH-cholesterol, pregnenolone, progesterone, or deoxycorticosterone at 37°C for 1 h or 3 h. The media were collected to measure the concentration of corticosterone or pregnenolone by radioimmunoassay (RIA). The cells were used to measure the StAR or P450scc protein expression by Western blotting analysis. The data demonstrated that [1] vitamin E inhibited ACTH-, 8-Br-cAMP-, or steroidogenic precursors-stimulated corticosterone release; [2] vitamin E increased the Michaelis constants of P450scc from 4.908 M to 11.997 M; [3] vitamin E might affect StAR protein expression.
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effects of crude adlay hull acetone extract on steroidogenesis from rat Zona fasciculata reticularis cells
華岡工程學報, 2010Co-Authors: Lingling ChangAbstract:Adlay is a grass crop which has been used in traditional Chinese medicine and also as a nourishing food. It has been shown to posses anti-allergic, antimutagenic and hypolipemic effects. However, the steroidogenic effects of crude adlay hull acetone extract (AHA) on adrenal Zona fasciculata-reticularis (ZFR) cells are still unclear. ZFR cells were incubated with AHA in the presence or absence of 25-hydroxy cholesterol (25-OH-cholesterol), pregnenolone, progesterone or deoxycorticosterone. The concentrations of corticosterone or pregnenolone in the media were measured by radioimmunoassay (RIA). The present data demonstrated that (1) AHA (800μg/ml) caused more pregnenolone release in control group, but not in 25-OH-cholesterol, trilostane or 25-OH-cholesterol+trilostane group; (2) kinetic study showed an uncompetitive inhibition model of AHA to P450 side chain cleavage enzyme (P450scc); (3) kinetic study showed a noncompetitive inhibition model of AHA to 11β-hydroxylase.
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mechanisms of inhibition of dehydroepiandrosterone upon corticosterone release from rat Zona fasciculata reticularis cells
Journal of Cellular Biochemistry, 2008Co-Authors: Lingling Chang, Paulus S WangAbstract:We have demonstrated that dehydroepiandrosterone (DHEA) acts directly on rat Zona fasciculata-reticularis (ZFR) cells to diminish corticosterone secretion by an inhibition of post-cAMP pathway, and decreases functions of steroidogenic enzymes after P450scc as well as steroidogenic acute regulatory (StAR) protein expression. However, the mechanisms by which DHEA engages with environmental messenger signals which translate into interfering StAR protein expression are still unclear. This study explored the effects of DHEA on the phosphorylation/activation of extracellular signal-regulated kinases (ERKs). ERK activation resulted in enhancing phosphorylation of steroidogenic factor-1 (SF-1) and increased StAR protein expression. ZFR cells were incubated in the presence or absence of adrenocorticotropin (ACTH), forskolin (FSK), 25-OH-cholesterol, U0126, and H89 at 37°C. The concentration of corticosterone released into the media was measured by radioimmunoassay (RIA). The cells were used to extract protein for Western blot analysis of ERKs or StAR protein expression or immunoprecipitation of SF-1 analysis. The results suggested that (1) ERK pathway of rat ZFR cells might be PKA dependent, (2) ERK activity was required for SF-1 phosphorylation to upregulate steroidogenesis in rat ZFR cells, and (3) DHEA did not affect ERK phosphorylation, however, it attenuated forskolin-stimulated SF-1 phosphorylation to affect StAR protein expression. J. Cell. Biochem. 104: 359–368, 2008. © 2007 Wiley-Liss, Inc.
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effects of dehydroepiandrosterone on corticosterone release in rat Zona fasciculata reticularis cells
Naunyn-schmiedebergs Archives of Pharmacology, 2003Co-Authors: Lingling Chang, Paulus S Wang, Lowtone L HoAbstract:The decline of plasma dehydroepiandrosterone (DHEA) and maintenance of glucocorticoid levels with increasing age contribute to excess body fat accumulation, hyperglycaemia, hyperlipidaemia, hyperinsulinaemia and cancer. Although opposing actions of DHEA and corticosterone have been proposed in a rat model, the effects and action mechanisms of DHEA on rat adrenal Zona fasciculata-reticularis (ZFR) cells are still unclear. This study addressed the effects of DHEA on corticosterone release, cellular cAMP production, the functions of steroidogenic enzymes and the expression levels of steroidogenic acute regulatory protein (StAR) and cytochrome P450 side-chain cleavage enzyme (P450scc). ZFR cells were incubated with DHEA in the presence or absence of adrenocorticotropin (ACTH), 8-Br-cAMP, forskolin, 25-OH-cholesterol, pregnenolone, progesterone or deoxycorticosterone at 37 °C for 30 min, 1 h or 5 h and the concentration of corticosterone or pregnenolone measured subsequently in the media by RIA. The cells were used to measure the content of cAMP by RIA and to extract protein for Western blot or mRNA for RT-PCR analysis. The data demonstrated that (1) DHEA inhibited ACTH-, 8-Br-cAMP-, 25-OH-cholesterol-, pregnenolone-, progesterone- or deoxycorticosterone-stimulated corticosterone release; (2) DHEA increased 25-OH-cholesterol-stimulated pregnenolone release but not when 25-OH-cholesterol was combined with trilostane; (3) DHEA increased the K m of 11β-hydroxylase but not P450scc; (4) DHEA affected the expression levels of StAR protein but not of P450scc. These results suggest that DHEA acts directly on rat ZFR cells to diminish corticosterone secretion by inhibition within the post-cAMP pathway, by inhibiting steroidogenic enzymes downstream from P450scc and by inhibiting StAR expression.
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Effects of fasting on corticosterone production by Zona fasciculata-reticularis cells in ovariectomized rats.
Journal of Investigative Medicine, 2002Co-Authors: Lingling Chang, Lowtone Ho, Paulus S WangAbstract:BACKGROUND: To investigate the function and mechanism of fasting on the production of corticosterone in vitro by Zona fasciculata-reticularis (ZFR) cells from ovariectomized (OVX) rats. METHODS: Female rats were OVX for 4 days before decapitation. Rats were fed or fasted for 1 day before experiment. ZFR cells from fed and fasted rats were incubated with adrenocorticotropic hormone (ACTH), forskolin, 8-bromo-3',5'-cyclic adenosine monophosphate, SQ22536, nifedipine, chelerythrine chloride, trilostane or steroidogenic precursors at 37 degrees C for either 60 or 30 minutes. Corticosterone, pregnenolone concentrations in spent media, and the intracellular adenosine 3',5'-cyclic monophosphate (cAMP) concentration were determined by radioimmunoassay. The effects of fasting in response to ACTH on the protein expressions of steroidogenic acute regulatory protein (StAR) or cytochrome P450 side-chain cleavage enzyme (P450scc) in ZFR cells were determined by Western blot analysis. RESULTS: The concentration of plasma corticosterone in fasted rats was significantly higher than that in fed rats (P
Adam Wesley Dayton - One of the best experts on this subject based on the ideXlab platform.
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involvement of adenosine monophosphate activated kinase in interleukin 6 regulation of steroidogenic acute regulatory protein and cholesterol side chain cleavage enzyme in the bovine Zona fasciculata and Zona reticularis
Steroids, 2018Co-Authors: Matharage S I De Silva, Adam Wesley Dayton, Lance R Rhoten, John W Mallett, Jared C Reese, Mathieu D Squires, Andrew P Dalley, James P Porter, Allan M JuddAbstract:Abstract In bovine adrenal Zona fasciculata (ZF) and NCI-H295R cells, interleukin-6 (IL-6) increases cortisol release, increases expression of steroidogenic acute regulatory protein (StAR), cholesterol side chain cleavage enzyme (P450scc), and steroidogenic factor 1 (SF-1) (increases steroidogenic proteins), and decreases the expression of adrenal hypoplasia congenita-like protein (DAX-1) (inhibits steroidogenic proteins). In contrast, IL-6 decreases bovine adrenal Zona reticularis (ZR) androgen release, StAR, P450scc, and SF-1 expression, and increases DAX-1 expression. Adenosine monophosphate (AMP) activated kinase (AMPK) regulates steroidogenesis, but its role in IL-6 regulation of adrenal steroidogenesis is unknown. In the present study, an AMPK activator (AICAR) increased ( P P P P P
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role of ampk in the upregulation of steroidogenic acute regulatory protein in the Zona fasciculata of the adrenal cortex
2010Co-Authors: Adam Wesley DaytonAbstract:Role of AMPK in the Upregulation of Steroidogenic Acute Regulatory Protein in the Zona fasciculata of the Adrenal Cortex
