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P.2.d.030 Glucocorticoid induced reduction in neural stem cell proliferation is counteracted by antidepressants
S446
P.2.d Affective disorders and antidepressants - Antidepressants (basic)
the brain, on pro-inflammatory interleukins TNFa, IL-6 and IL10 production after lipopolisaccharide (LPS) acute administration in chronic mild stress (CMS) anhedonic rats. Methods: The study was performed using two groups of male Wistar rats subjected or not to CMS for 6 weeks, respectively. Control of anhedonia development was done with weekly test of 1% glucose solution drinking. Next, the groups of rats were treated with MIAN (lOmg/kg i.p., 2x daily) for 21 consecutive days. The control groups were given the corresponding volume of vehicle. Two hours before decapitation each group was divided into matched subgroups and LPS (100 !J.g/kg, Lp) or saline were administered to rats. Serum samples were obtained by centrifugation and stored in aliquots at -80°C. Determination of rat serum levels ofTNF-a, IL-6 and IL-IO was performed using ELISA kits. Results: It has been found out that MIAN significantly (p < 0.05) alleviated anhedonia in CMS animals. The levels of TNFa and IL-6 were significantly higher in CMS rats when compared with non-stressed animals, however there were no significant differences between the levels of IL-I0 in these two groups. Acute LPS administration resulted in significant rises in plasma TNFa, IL-6 and IL-IO levels (61%, 15%,21%, respectively) in CMS animals as compared to non-LPS treated animals. Treatment with MIAN decreased significantly TNFa and IL-6 serum concentrations (62%, 30%, respectively) in anhedonic rats when compared with the proper control values, whereas there was no effect of the drug on IL-I0 levels. MIAN administration resulted in significant lowering ofTNFa, IL-6 and IL-I0 levels (63%, 58%, 43%, respectively) in CMS animals exposed to LPS as compared to LPS exposed but MIAN-non-treated animals. Conclusion: The results showed that MIAN produced a normalisation of both CMS-induced and LPS-induced ofTNFa, IL-6 levels what can be considered as part of its antidepressant action, however the observed effect of MIAN on lowering IL-I0 level is not so clear. It may be a sign for different immunological mechanism of action of this drug in connection with acute stress (LPS) when compared with the effect of other antidepressants [2,3]. References
[1] Schiepers, O.lG., Wichers, M.C., Maes, M., 2005 Cytokines in major depression. Progress in Neuro-Psychopharmacology & Biological Psychiatry 29, 201-217. [2] Maes, M., Bosmans, E., Suy, E., Minner, B., Raus, l, 1989 The impaired mitogen lymphocyte stimulation in severely depressed patients: a complex interface between HPA-axis hyperfunction, noradrenergic activity and the aging process. British Journal of Psychiatry 155, 793798. [3] Kubera, M., Maes, M., Holan, v., Basta-Kaim, A., Roman, A., Shani, l, 2001 Prolonged desipramine treatment increases the production of intedeukin-lO, an anti-inflammatory cytokine, in C57BL/6 mice subjected to the chronic mild stress model of depression. Journal of Affective Disorders 63,171-178.
1P.2.d.0301 Glucocorticoid induced reduction in neural stem cell proliferation is counteracted by antidepressants C. Anacker1 " P. Zunszain1 , L. Carvalho 1, S. Thuret1, 1. Price 1 , C.M. Pariante 1 . 1Institute ofPsychiatry King's College London, Centre for the Cellular Basis of Behaviour, London, United Kingdom A large body of evidence has emerged establishing a link between stressful life events and exacerbation or development of depression. Stress induced depression is associated with hyperactivity
of the hypothalamus-pituitary-adrenal (HPA) axis, resulting in elevated levels of glucocorticoids [1]. On a cellular level, stress and depression are related to neuronal cell death and inhibition of adult hippocampal neurogenesis. It has been suggested that these cellular deficiencies are caused by the high levels of glucocorticoids in the brain [2]. Accordingly, chronic antidepressant treatment has been shown to counteract HPA axis hyperactivity and increase adult hippocampal neurogenesis in animals [3]. Using a novel in vitro assay in human neural stem cells, we want to investigate whether the effects of antidepressants are dependent on glucocorticoid mediated changes in cell proliferation. A human multipotent hippocampal stem cell line (HPCOA07, ReNeuron, UK) was incubated for 72 hours with glucocorticoids in the presence or absence of antidepressants. Cells were treated with different concentrations of the glucocorticoids dexamethasone (DEX) and cortisol (CORT). Additionally, DEX was co-treated with the four antidepressants sertraline (SERT), clomipramine (CM!), desipramine (DESIP) and amitriptyline (AMI). Cell proliferation was assessed by Ki67 immunostaining. Cell death of adhesive cells was evaluated by propidium iodide (PI) staining. The fraction of Ki67 and PI positive cells over total cells was determined by cell counting. Results are expressed as the % of Ki67 positive cells (mean value±SD). DEX significantly decreased the percentage of Ki67 positive cells compared to vehicle treated cells, thus decreasing proliferation (proliferation for vehicle treated cells was 67.4±7.9, for DEX 100nM 59.5±7.2, for DEX I!J.M 54.8±5.3, for DEX 5!J.M 42.3±8.5, One-Way ANOVA was P < 0.0001). In the presence of antidepressants, this decrease in proliferation was reversed: at DEX I!J.M in the presence ofSERT (I!J.M), proliferation was 68.6±6.3, in the presence of AMI (1!J.M) proliferation was 66.9±7.4, in the presence ofCMI (1!J.M) it was 68.5±5.8, in the presence of DESIP (I!J.M) it was 65.9±2.5 (P < 0.001 for all antidepressants plus DEX compared with DEX alone). CORT treatment also decreased cell proliferation compared to vehicle treated cells (proliferation for vehicle treated cells was 66.l±6.4, for CORT lO!J.M it was 59.2±8.4 and for CORT 100!J.M it was 58.7±5.7; One-Way ANOVA was P < 0.01). Experiments on the effect of antidepressants on CORT induced reduction in proliferation are currently being conducted. Cell death of adhesive cells was not affected by DEX and CORT treatment for all doses tested. SERT at I!J.M also did not affect cell death when compared to vehicle treated cells (P>0.05); data on other antidepressants were not yet available. In conclusion, we demonstrate that the two glucocorticoids DEX and CORT reduce proliferation of human hippocampal stem cells in vitro. Moreover, co-treatment with different antidepressants counteracts the DEX induced reduction in proliferation. Our results support the notion that antidepressant induced changes in neural stem cell proliferation are mediated by an effect on glucocorticoid dependent mechanisms. Professor Jack Price acted as a consultant and received payment from ReNeuron Group within the last 2 years. References
[1] Pariante, C.M., Lightman S.L., 2008 The HPA axis in major depression: classical theories and new developments. Trends Neurosci, 31(9), 464-8. [2] Gould, E., Cameron H.A., Daniels D.C., Woolley C.S., McEwan B.S., 1992 Adrenal hormones suppress cell division in the adult rat dentate gyrus. J Neurosci. 12(9), 3642-50. [3] Malberg, lE., Eisch A.l, Nestler E.l, Duman R.S., 2000 Chronic antidepressant treatment increases neurogenesis in adult rat hippocampus. J Neurosci. 20(24), 9104-10.
P.2.d Affective disorders and antidepressants - Antidepressants (basic)
the brain, on pro-inflammatory interleukins TNFa, IL-6 and IL10 production after lipopolisaccharide (LPS) acute administration in chronic mild stress (CMS) anhedonic rats. Methods: The study was performed using two groups of male Wistar rats subjected or not to CMS for 6 weeks, respectively. Control of anhedonia development was done with weekly test of 1% glucose solution drinking. Next, the groups of rats were treated with MIAN (lOmg/kg i.p., 2x daily) for 21 consecutive days. The control groups were given the corresponding volume of vehicle. Two hours before decapitation each group was divided into matched subgroups and LPS (100 !J.g/kg, Lp) or saline were administered to rats. Serum samples were obtained by centrifugation and stored in aliquots at -80°C. Determination of rat serum levels ofTNF-a, IL-6 and IL-IO was performed using ELISA kits. Results: It has been found out that MIAN significantly (p < 0.05) alleviated anhedonia in CMS animals. The levels of TNFa and IL-6 were significantly higher in CMS rats when compared with non-stressed animals, however there were no significant differences between the levels of IL-I0 in these two groups. Acute LPS administration resulted in significant rises in plasma TNFa, IL-6 and IL-IO levels (61%, 15%,21%, respectively) in CMS animals as compared to non-LPS treated animals. Treatment with MIAN decreased significantly TNFa and IL-6 serum concentrations (62%, 30%, respectively) in anhedonic rats when compared with the proper control values, whereas there was no effect of the drug on IL-I0 levels. MIAN administration resulted in significant lowering ofTNFa, IL-6 and IL-I0 levels (63%, 58%, 43%, respectively) in CMS animals exposed to LPS as compared to LPS exposed but MIAN-non-treated animals. Conclusion: The results showed that MIAN produced a normalisation of both CMS-induced and LPS-induced ofTNFa, IL-6 levels what can be considered as part of its antidepressant action, however the observed effect of MIAN on lowering IL-I0 level is not so clear. It may be a sign for different immunological mechanism of action of this drug in connection with acute stress (LPS) when compared with the effect of other antidepressants [2,3]. References
[1] Schiepers, O.lG., Wichers, M.C., Maes, M., 2005 Cytokines in major depression. Progress in Neuro-Psychopharmacology & Biological Psychiatry 29, 201-217. [2] Maes, M., Bosmans, E., Suy, E., Minner, B., Raus, l, 1989 The impaired mitogen lymphocyte stimulation in severely depressed patients: a complex interface between HPA-axis hyperfunction, noradrenergic activity and the aging process. British Journal of Psychiatry 155, 793798. [3] Kubera, M., Maes, M., Holan, v., Basta-Kaim, A., Roman, A., Shani, l, 2001 Prolonged desipramine treatment increases the production of intedeukin-lO, an anti-inflammatory cytokine, in C57BL/6 mice subjected to the chronic mild stress model of depression. Journal of Affective Disorders 63,171-178.
1P.2.d.0301 Glucocorticoid induced reduction in neural stem cell proliferation is counteracted by antidepressants C. Anacker1 " P. Zunszain1 , L. Carvalho 1, S. Thuret1, 1. Price 1 , C.M. Pariante 1 . 1Institute ofPsychiatry King's College London, Centre for the Cellular Basis of Behaviour, London, United Kingdom A large body of evidence has emerged establishing a link between stressful life events and exacerbation or development of depression. Stress induced depression is associated with hyperactivity
of the hypothalamus-pituitary-adrenal (HPA) axis, resulting in elevated levels of glucocorticoids [1]. On a cellular level, stress and depression are related to neuronal cell death and inhibition of adult hippocampal neurogenesis. It has been suggested that these cellular deficiencies are caused by the high levels of glucocorticoids in the brain [2]. Accordingly, chronic antidepressant treatment has been shown to counteract HPA axis hyperactivity and increase adult hippocampal neurogenesis in animals [3]. Using a novel in vitro assay in human neural stem cells, we want to investigate whether the effects of antidepressants are dependent on glucocorticoid mediated changes in cell proliferation. A human multipotent hippocampal stem cell line (HPCOA07, ReNeuron, UK) was incubated for 72 hours with glucocorticoids in the presence or absence of antidepressants. Cells were treated with different concentrations of the glucocorticoids dexamethasone (DEX) and cortisol (CORT). Additionally, DEX was co-treated with the four antidepressants sertraline (SERT), clomipramine (CM!), desipramine (DESIP) and amitriptyline (AMI). Cell proliferation was assessed by Ki67 immunostaining. Cell death of adhesive cells was evaluated by propidium iodide (PI) staining. The fraction of Ki67 and PI positive cells over total cells was determined by cell counting. Results are expressed as the % of Ki67 positive cells (mean value±SD). DEX significantly decreased the percentage of Ki67 positive cells compared to vehicle treated cells, thus decreasing proliferation (proliferation for vehicle treated cells was 67.4±7.9, for DEX 100nM 59.5±7.2, for DEX I!J.M 54.8±5.3, for DEX 5!J.M 42.3±8.5, One-Way ANOVA was P < 0.0001). In the presence of antidepressants, this decrease in proliferation was reversed: at DEX I!J.M in the presence ofSERT (I!J.M), proliferation was 68.6±6.3, in the presence of AMI (1!J.M) proliferation was 66.9±7.4, in the presence ofCMI (1!J.M) it was 68.5±5.8, in the presence of DESIP (I!J.M) it was 65.9±2.5 (P < 0.001 for all antidepressants plus DEX compared with DEX alone). CORT treatment also decreased cell proliferation compared to vehicle treated cells (proliferation for vehicle treated cells was 66.l±6.4, for CORT lO!J.M it was 59.2±8.4 and for CORT 100!J.M it was 58.7±5.7; One-Way ANOVA was P < 0.01). Experiments on the effect of antidepressants on CORT induced reduction in proliferation are currently being conducted. Cell death of adhesive cells was not affected by DEX and CORT treatment for all doses tested. SERT at I!J.M also did not affect cell death when compared to vehicle treated cells (P>0.05); data on other antidepressants were not yet available. In conclusion, we demonstrate that the two glucocorticoids DEX and CORT reduce proliferation of human hippocampal stem cells in vitro. Moreover, co-treatment with different antidepressants counteracts the DEX induced reduction in proliferation. Our results support the notion that antidepressant induced changes in neural stem cell proliferation are mediated by an effect on glucocorticoid dependent mechanisms. Professor Jack Price acted as a consultant and received payment from ReNeuron Group within the last 2 years. References
[1] Pariante, C.M., Lightman S.L., 2008 The HPA axis in major depression: classical theories and new developments. Trends Neurosci, 31(9), 464-8. [2] Gould, E., Cameron H.A., Daniels D.C., Woolley C.S., McEwan B.S., 1992 Adrenal hormones suppress cell division in the adult rat dentate gyrus. J Neurosci. 12(9), 3642-50. [3] Malberg, lE., Eisch A.l, Nestler E.l, Duman R.S., 2000 Chronic antidepressant treatment increases neurogenesis in adult rat hippocampus. J Neurosci. 20(24), 9104-10.