Limits...
Trazodone regulates neurotrophic/growth factors, mitogen-activated protein kinases and lactate release in human primary astrocytes.

Daniele S, Zappelli E, Martini C - J Neuroinflammation (2015)

Bottom Line: TDZ had no effect on cell proliferation, but it decreased pro-inflammatory mediator release and modulated trophic and transcription factor mRNA expression.These effects mainly involved an activation of 5-HT1A and an antagonism at 5-HT2A/C serotonin receptors.Fluoxetine, used in parallel, showed similar final effects nevertheless it activates different receptors/intracellular pathways.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacy, University of Pisa, Via Bonanno Pisano, 6, Pisa, 56126, PI, Italy. simona.daniele@for.unipi.it.

ABSTRACT

Background: In the central nervous system, glial cells provide metabolic and trophic support to neurons and respond to protracted stress and insults by up-regulating inflammatory processes. Reactive astrocytes and microglia are associated with the pathophysiology of neuronal injury, neurodegenerative diseases and major depression, in both animal models and human brains. Several studies have reported clear anti-inflammatory effects of anti-depressant treatment on astrocytes, especially in models of neurological disorders. Trazodone (TDZ) is a triazolopyridine derivative that is structurally unrelated to other major classes of antidepressants. Although the molecular mechanisms of TDZ in neurons have been investigated, it is unclear whether astrocytes are also a TDZ target.

Methods: The effects of TDZ on human astrocytes were investigated in physiological conditions and following inflammatory insult with lipopolysaccharide (LPS) and tumour necrosis factor-α (TNF-α). Astrocytes were assessed for their responses to pro-inflammatory mediators and cytokines, and the receptors and signalling pathways involved in TDZ-mediated effects were evaluated.

Results: TDZ had no effect on cell proliferation, but it decreased pro-inflammatory mediator release and modulated trophic and transcription factor mRNA expression. Following TDZ treatment, the AKT pathway was activated, whereas extracellular signal-regulated kinase and c-Jun NH2-terminal kinase were inhibited. Most importantly, a 72-h TDZ pre-treatment before inflammatory insult completely reversed the anti-proliferative effects induced by LPS-TNF-α. The expression or the activity of inflammatory mediators, including interleukin-6, c-Jun NH2-terminal kinase and nuclear factor κB, were also reduced. Furthermore, TDZ affected astrocyte metabolic support to neurons by counteracting the inflammation-mediated lactate decrease. Finally, TDZ protected neuronal-like cells against neurotoxicity mediated by activated astrocytes. These effects mainly involved an activation of 5-HT1A and an antagonism at 5-HT2A/C serotonin receptors. Fluoxetine, used in parallel, showed similar final effects nevertheless it activates different receptors/intracellular pathways.

Conclusions: Altogether, our results demonstrated that TDZ directly acts on astrocytes by regulating intracellular signalling pathways and increasing specific astrocyte-derived neurotrophic factor expression and lactate release. TDZ may contribute to neuronal support by normalizing trophic and metabolic support during neuroinflammation, which is associated with neurological diseases, including major depression.

No MeSH data available.


Related in: MedlinePlus

Effect of TDZ on pro-inflammatory gene, trophic and transcription factor expression. a, b Human astrocytes were treated with medium alone (control), or different concentrations of TDZ (100 nM-1 μM) or FLUOX (10 μM) for 24 h (a) or 72 h (b). At the end of treatment, total RNA was extracted, and relative mRNA quantification of NF-kB, CREB, mTOR and BDNF was performed by real-time RT-PCR. The data are expressed as fold changes vs. control and represent the mean ± SEM of three different experiments, each performed in duplicate. Statistical significance was determined using a one-way ANOVA-Tukey HSD post hoc test: *P < 0.05, **P < 0.01, ***P < 0.001 vs. control. c, d Human astrocytes were treated with medium alone (control), TDZ (10 μM) or FLUOX (10 μM) for 72 h. Following incubation, the protein levels of GFAP were evaluated by western blot analysis. GAPDH was the loading control. c Representative western blots. d Densitometric analysis of the immunoreactive bands was performed using ImageJ. The data are expressed as the percentage of optical density of the immunoreactive band relative to that of the control, which was set at 100 %, and are the mean values ± SEM of three different experiments. Statistical significance was determined using a one-way ANOVA-Tukey HSD post hoc test
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4666178&req=5

Fig4: Effect of TDZ on pro-inflammatory gene, trophic and transcription factor expression. a, b Human astrocytes were treated with medium alone (control), or different concentrations of TDZ (100 nM-1 μM) or FLUOX (10 μM) for 24 h (a) or 72 h (b). At the end of treatment, total RNA was extracted, and relative mRNA quantification of NF-kB, CREB, mTOR and BDNF was performed by real-time RT-PCR. The data are expressed as fold changes vs. control and represent the mean ± SEM of three different experiments, each performed in duplicate. Statistical significance was determined using a one-way ANOVA-Tukey HSD post hoc test: *P < 0.05, **P < 0.01, ***P < 0.001 vs. control. c, d Human astrocytes were treated with medium alone (control), TDZ (10 μM) or FLUOX (10 μM) for 72 h. Following incubation, the protein levels of GFAP were evaluated by western blot analysis. GAPDH was the loading control. c Representative western blots. d Densitometric analysis of the immunoreactive bands was performed using ImageJ. The data are expressed as the percentage of optical density of the immunoreactive band relative to that of the control, which was set at 100 %, and are the mean values ± SEM of three different experiments. Statistical significance was determined using a one-way ANOVA-Tukey HSD post hoc test

Mentions: After 24 h of TDZ treatment, a significant up-regulation of the mRNA levels of brain-derived nerve factor (BDNF) and the cAMP response element-binding protein (CREB) was observed (Fig. 4a), suggesting that TDZ alone induced the expression trophic and transcription factors. In contrast, the pro-inflammatory gene NF-kB and mammalian target of rapamycin (mTOR) mRNA levels significantly decreased (Fig. 4a). These results confirmed the anti-inflammatory effect of TDZ, as mTOR inhibition has been demonstrated to elicit anti-inflammatory effects in glial cells [47].Fig. 4


Trazodone regulates neurotrophic/growth factors, mitogen-activated protein kinases and lactate release in human primary astrocytes.

Daniele S, Zappelli E, Martini C - J Neuroinflammation (2015)

Effect of TDZ on pro-inflammatory gene, trophic and transcription factor expression. a, b Human astrocytes were treated with medium alone (control), or different concentrations of TDZ (100 nM-1 μM) or FLUOX (10 μM) for 24 h (a) or 72 h (b). At the end of treatment, total RNA was extracted, and relative mRNA quantification of NF-kB, CREB, mTOR and BDNF was performed by real-time RT-PCR. The data are expressed as fold changes vs. control and represent the mean ± SEM of three different experiments, each performed in duplicate. Statistical significance was determined using a one-way ANOVA-Tukey HSD post hoc test: *P < 0.05, **P < 0.01, ***P < 0.001 vs. control. c, d Human astrocytes were treated with medium alone (control), TDZ (10 μM) or FLUOX (10 μM) for 72 h. Following incubation, the protein levels of GFAP were evaluated by western blot analysis. GAPDH was the loading control. c Representative western blots. d Densitometric analysis of the immunoreactive bands was performed using ImageJ. The data are expressed as the percentage of optical density of the immunoreactive band relative to that of the control, which was set at 100 %, and are the mean values ± SEM of three different experiments. Statistical significance was determined using a one-way ANOVA-Tukey HSD post hoc test
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4666178&req=5

Fig4: Effect of TDZ on pro-inflammatory gene, trophic and transcription factor expression. a, b Human astrocytes were treated with medium alone (control), or different concentrations of TDZ (100 nM-1 μM) or FLUOX (10 μM) for 24 h (a) or 72 h (b). At the end of treatment, total RNA was extracted, and relative mRNA quantification of NF-kB, CREB, mTOR and BDNF was performed by real-time RT-PCR. The data are expressed as fold changes vs. control and represent the mean ± SEM of three different experiments, each performed in duplicate. Statistical significance was determined using a one-way ANOVA-Tukey HSD post hoc test: *P < 0.05, **P < 0.01, ***P < 0.001 vs. control. c, d Human astrocytes were treated with medium alone (control), TDZ (10 μM) or FLUOX (10 μM) for 72 h. Following incubation, the protein levels of GFAP were evaluated by western blot analysis. GAPDH was the loading control. c Representative western blots. d Densitometric analysis of the immunoreactive bands was performed using ImageJ. The data are expressed as the percentage of optical density of the immunoreactive band relative to that of the control, which was set at 100 %, and are the mean values ± SEM of three different experiments. Statistical significance was determined using a one-way ANOVA-Tukey HSD post hoc test
Mentions: After 24 h of TDZ treatment, a significant up-regulation of the mRNA levels of brain-derived nerve factor (BDNF) and the cAMP response element-binding protein (CREB) was observed (Fig. 4a), suggesting that TDZ alone induced the expression trophic and transcription factors. In contrast, the pro-inflammatory gene NF-kB and mammalian target of rapamycin (mTOR) mRNA levels significantly decreased (Fig. 4a). These results confirmed the anti-inflammatory effect of TDZ, as mTOR inhibition has been demonstrated to elicit anti-inflammatory effects in glial cells [47].Fig. 4

Bottom Line: TDZ had no effect on cell proliferation, but it decreased pro-inflammatory mediator release and modulated trophic and transcription factor mRNA expression.These effects mainly involved an activation of 5-HT1A and an antagonism at 5-HT2A/C serotonin receptors.Fluoxetine, used in parallel, showed similar final effects nevertheless it activates different receptors/intracellular pathways.

View Article: PubMed Central - PubMed

Affiliation: Department of Pharmacy, University of Pisa, Via Bonanno Pisano, 6, Pisa, 56126, PI, Italy. simona.daniele@for.unipi.it.

ABSTRACT

Background: In the central nervous system, glial cells provide metabolic and trophic support to neurons and respond to protracted stress and insults by up-regulating inflammatory processes. Reactive astrocytes and microglia are associated with the pathophysiology of neuronal injury, neurodegenerative diseases and major depression, in both animal models and human brains. Several studies have reported clear anti-inflammatory effects of anti-depressant treatment on astrocytes, especially in models of neurological disorders. Trazodone (TDZ) is a triazolopyridine derivative that is structurally unrelated to other major classes of antidepressants. Although the molecular mechanisms of TDZ in neurons have been investigated, it is unclear whether astrocytes are also a TDZ target.

Methods: The effects of TDZ on human astrocytes were investigated in physiological conditions and following inflammatory insult with lipopolysaccharide (LPS) and tumour necrosis factor-α (TNF-α). Astrocytes were assessed for their responses to pro-inflammatory mediators and cytokines, and the receptors and signalling pathways involved in TDZ-mediated effects were evaluated.

Results: TDZ had no effect on cell proliferation, but it decreased pro-inflammatory mediator release and modulated trophic and transcription factor mRNA expression. Following TDZ treatment, the AKT pathway was activated, whereas extracellular signal-regulated kinase and c-Jun NH2-terminal kinase were inhibited. Most importantly, a 72-h TDZ pre-treatment before inflammatory insult completely reversed the anti-proliferative effects induced by LPS-TNF-α. The expression or the activity of inflammatory mediators, including interleukin-6, c-Jun NH2-terminal kinase and nuclear factor κB, were also reduced. Furthermore, TDZ affected astrocyte metabolic support to neurons by counteracting the inflammation-mediated lactate decrease. Finally, TDZ protected neuronal-like cells against neurotoxicity mediated by activated astrocytes. These effects mainly involved an activation of 5-HT1A and an antagonism at 5-HT2A/C serotonin receptors. Fluoxetine, used in parallel, showed similar final effects nevertheless it activates different receptors/intracellular pathways.

Conclusions: Altogether, our results demonstrated that TDZ directly acts on astrocytes by regulating intracellular signalling pathways and increasing specific astrocyte-derived neurotrophic factor expression and lactate release. TDZ may contribute to neuronal support by normalizing trophic and metabolic support during neuroinflammation, which is associated with neurological diseases, including major depression.

No MeSH data available.


Related in: MedlinePlus