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Glucocorticoid-related molecular signaling pathways regulating hippocampal neurogenesis.

Anacker C, Cattaneo A, Luoni A, Musaelyan K, Zunszain PA, Milanesi E, Rybka J, Berry A, Cirulli F, Thuret S, Price J, Riva MA, Gennarelli M, Pariante CM - Neuropsychopharmacology (2012)

Bottom Line: These effects were dependent on the glucocorticoid receptor (GR), blocked by the GR antagonist RU486, and mimicked by the GR-agonist, dexamethasone.Mechanistically, we show that reduced Hedgehog signaling indeed critically contributes to the cortisol-induced reduction in neuronal differentiation.In conclusion, our data demonstrate novel molecular signaling pathways that are regulated by glucocorticoids in vitro, in human hippocampal progenitor cells, and by stress in vivo, in the rat hippocampus.

View Article: PubMed Central - PubMed

Affiliation: Section of Perinatal Psychiatry and Stress, Psychiatry and Immunology (SPI-Lab), Institute of Psychiatry, Department of Psychological Medicine, King's College London, London, UK. Christoph.Anacker@kcl.ac.uk

ABSTRACT
Stress and glucocorticoid hormones regulate hippocampal neurogenesis, but the molecular mechanisms underlying their effects are unknown. We, therefore, investigated the molecular signaling pathways mediating the effects of cortisol on proliferation, neuronal differentiation, and astrogliogenesis, in an immortalized human hippocampal progenitor cell line. In addition, we examined the molecular signaling pathways activated in the hippocampus of prenatally stressed rats, characterized by persistently elevated glucocorticoid levels in adulthood. In human hippocampal progenitor cells, we found that low concentrations of cortisol (100 nM) increased proliferation (+16%), decreased neurogenesis into microtubule-associated protein 2 (MAP2)-positive neurons (-24%) and doublecortin (Dcx)-positive neuroblasts (-21%), and increased differentiation into S100β-positive astrocytes (+23%). These effects were dependent on the mineralocorticoid receptor (MR) as they were abolished by the MR antagonist, spironolactone, and mimicked by the MR-agonist, aldosterone. In contrast, high concentrations of cortisol (100 μM) decreased proliferation (-17%) and neuronal differentiation into MAP2-positive neurons (-22%) and into Dcx-positive neuroblasts (-27%), without regulating astrogliogenesis. These effects were dependent on the glucocorticoid receptor (GR), blocked by the GR antagonist RU486, and mimicked by the GR-agonist, dexamethasone. Gene expression microarray and pathway analysis showed that the low concentration of cortisol enhances Notch/Hes-signaling, the high concentration inhibits TGFβ-SMAD2/3-signaling, and both concentrations inhibit Hedgehog signaling. Mechanistically, we show that reduced Hedgehog signaling indeed critically contributes to the cortisol-induced reduction in neuronal differentiation. Accordingly, TGFβ-SMAD2/3 and Hedgehog signaling were also inhibited in the hippocampus of adult prenatally stressed rats with high glucocorticoid levels. In conclusion, our data demonstrate novel molecular signaling pathways that are regulated by glucocorticoids in vitro, in human hippocampal progenitor cells, and by stress in vivo, in the rat hippocampus.

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Differential effects of mineralocorticoid receptor (MR)- and glucocorticoid receptor (GR)-activation on human hippocampal progenitor cell proliferation. 5′-bromodeoxyuridine (BrdU, 10 μℳ) incorporation and immunocytochemistry was used to assess proliferation of HPC03A/07 cells (a). Cortisol exerts bimodal, dose-dependent effects on proliferation (b). Spironolactone (1 μℳ) blocks the increase in cell proliferation upon treatment with low concentrations of cortisol (c). RU486 (50 nM) blocks the decrease in cell proliferation upon treatment with high concentrations of cortisol (100 μℳ) (d). The MR-agonist, aldosterone (1 nM–1 μℳ), increases cell proliferation (e), while the GR-agonist, dexamethasone (10 nℳ–5 μℳ), decreases cell proliferation (f). GR transactivation is dose-dependently increased by cortisol concentrations (10 μℳ–1 mℳ) (g). Three to four independent experiments were conducted on independent cultures (indicated as n). In proliferation experiments, four wells were analyzed per treatment condition in each experiment and three random, non-overlapping pictures were analyzed for each well. All data are mean±s.e.m. *P<0.05, **P<0.01; ***P<0.001 compared with the vehicle-treated control condition.
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fig1: Differential effects of mineralocorticoid receptor (MR)- and glucocorticoid receptor (GR)-activation on human hippocampal progenitor cell proliferation. 5′-bromodeoxyuridine (BrdU, 10 μℳ) incorporation and immunocytochemistry was used to assess proliferation of HPC03A/07 cells (a). Cortisol exerts bimodal, dose-dependent effects on proliferation (b). Spironolactone (1 μℳ) blocks the increase in cell proliferation upon treatment with low concentrations of cortisol (c). RU486 (50 nM) blocks the decrease in cell proliferation upon treatment with high concentrations of cortisol (100 μℳ) (d). The MR-agonist, aldosterone (1 nM–1 μℳ), increases cell proliferation (e), while the GR-agonist, dexamethasone (10 nℳ–5 μℳ), decreases cell proliferation (f). GR transactivation is dose-dependently increased by cortisol concentrations (10 μℳ–1 mℳ) (g). Three to four independent experiments were conducted on independent cultures (indicated as n). In proliferation experiments, four wells were analyzed per treatment condition in each experiment and three random, non-overlapping pictures were analyzed for each well. All data are mean±s.e.m. *P<0.05, **P<0.01; ***P<0.001 compared with the vehicle-treated control condition.

Mentions: We first analyzed the effects of a wide range of cortisol concentrations (1 nM–100 μM) on proliferation of human hippocampal progenitor cells after 3 days of treatment, using BrdU incorporation and immunocytochemistry (Figure 1a).


Glucocorticoid-related molecular signaling pathways regulating hippocampal neurogenesis.

Anacker C, Cattaneo A, Luoni A, Musaelyan K, Zunszain PA, Milanesi E, Rybka J, Berry A, Cirulli F, Thuret S, Price J, Riva MA, Gennarelli M, Pariante CM - Neuropsychopharmacology (2012)

Differential effects of mineralocorticoid receptor (MR)- and glucocorticoid receptor (GR)-activation on human hippocampal progenitor cell proliferation. 5′-bromodeoxyuridine (BrdU, 10 μℳ) incorporation and immunocytochemistry was used to assess proliferation of HPC03A/07 cells (a). Cortisol exerts bimodal, dose-dependent effects on proliferation (b). Spironolactone (1 μℳ) blocks the increase in cell proliferation upon treatment with low concentrations of cortisol (c). RU486 (50 nM) blocks the decrease in cell proliferation upon treatment with high concentrations of cortisol (100 μℳ) (d). The MR-agonist, aldosterone (1 nM–1 μℳ), increases cell proliferation (e), while the GR-agonist, dexamethasone (10 nℳ–5 μℳ), decreases cell proliferation (f). GR transactivation is dose-dependently increased by cortisol concentrations (10 μℳ–1 mℳ) (g). Three to four independent experiments were conducted on independent cultures (indicated as n). In proliferation experiments, four wells were analyzed per treatment condition in each experiment and three random, non-overlapping pictures were analyzed for each well. All data are mean±s.e.m. *P<0.05, **P<0.01; ***P<0.001 compared with the vehicle-treated control condition.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3672002&req=5

fig1: Differential effects of mineralocorticoid receptor (MR)- and glucocorticoid receptor (GR)-activation on human hippocampal progenitor cell proliferation. 5′-bromodeoxyuridine (BrdU, 10 μℳ) incorporation and immunocytochemistry was used to assess proliferation of HPC03A/07 cells (a). Cortisol exerts bimodal, dose-dependent effects on proliferation (b). Spironolactone (1 μℳ) blocks the increase in cell proliferation upon treatment with low concentrations of cortisol (c). RU486 (50 nM) blocks the decrease in cell proliferation upon treatment with high concentrations of cortisol (100 μℳ) (d). The MR-agonist, aldosterone (1 nM–1 μℳ), increases cell proliferation (e), while the GR-agonist, dexamethasone (10 nℳ–5 μℳ), decreases cell proliferation (f). GR transactivation is dose-dependently increased by cortisol concentrations (10 μℳ–1 mℳ) (g). Three to four independent experiments were conducted on independent cultures (indicated as n). In proliferation experiments, four wells were analyzed per treatment condition in each experiment and three random, non-overlapping pictures were analyzed for each well. All data are mean±s.e.m. *P<0.05, **P<0.01; ***P<0.001 compared with the vehicle-treated control condition.
Mentions: We first analyzed the effects of a wide range of cortisol concentrations (1 nM–100 μM) on proliferation of human hippocampal progenitor cells after 3 days of treatment, using BrdU incorporation and immunocytochemistry (Figure 1a).

Bottom Line: These effects were dependent on the glucocorticoid receptor (GR), blocked by the GR antagonist RU486, and mimicked by the GR-agonist, dexamethasone.Mechanistically, we show that reduced Hedgehog signaling indeed critically contributes to the cortisol-induced reduction in neuronal differentiation.In conclusion, our data demonstrate novel molecular signaling pathways that are regulated by glucocorticoids in vitro, in human hippocampal progenitor cells, and by stress in vivo, in the rat hippocampus.

View Article: PubMed Central - PubMed

Affiliation: Section of Perinatal Psychiatry and Stress, Psychiatry and Immunology (SPI-Lab), Institute of Psychiatry, Department of Psychological Medicine, King's College London, London, UK. Christoph.Anacker@kcl.ac.uk

ABSTRACT
Stress and glucocorticoid hormones regulate hippocampal neurogenesis, but the molecular mechanisms underlying their effects are unknown. We, therefore, investigated the molecular signaling pathways mediating the effects of cortisol on proliferation, neuronal differentiation, and astrogliogenesis, in an immortalized human hippocampal progenitor cell line. In addition, we examined the molecular signaling pathways activated in the hippocampus of prenatally stressed rats, characterized by persistently elevated glucocorticoid levels in adulthood. In human hippocampal progenitor cells, we found that low concentrations of cortisol (100 nM) increased proliferation (+16%), decreased neurogenesis into microtubule-associated protein 2 (MAP2)-positive neurons (-24%) and doublecortin (Dcx)-positive neuroblasts (-21%), and increased differentiation into S100β-positive astrocytes (+23%). These effects were dependent on the mineralocorticoid receptor (MR) as they were abolished by the MR antagonist, spironolactone, and mimicked by the MR-agonist, aldosterone. In contrast, high concentrations of cortisol (100 μM) decreased proliferation (-17%) and neuronal differentiation into MAP2-positive neurons (-22%) and into Dcx-positive neuroblasts (-27%), without regulating astrogliogenesis. These effects were dependent on the glucocorticoid receptor (GR), blocked by the GR antagonist RU486, and mimicked by the GR-agonist, dexamethasone. Gene expression microarray and pathway analysis showed that the low concentration of cortisol enhances Notch/Hes-signaling, the high concentration inhibits TGFβ-SMAD2/3-signaling, and both concentrations inhibit Hedgehog signaling. Mechanistically, we show that reduced Hedgehog signaling indeed critically contributes to the cortisol-induced reduction in neuronal differentiation. Accordingly, TGFβ-SMAD2/3 and Hedgehog signaling were also inhibited in the hippocampus of adult prenatally stressed rats with high glucocorticoid levels. In conclusion, our data demonstrate novel molecular signaling pathways that are regulated by glucocorticoids in vitro, in human hippocampal progenitor cells, and by stress in vivo, in the rat hippocampus.

Show MeSH
Related in: MedlinePlus