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Subventricular zone neural progenitors reverse TNF-alpha effects in cortical neurons.

Morini R, Ghirardini E, Butti E, Verderio C, Martino G, Matteoli M - Stem Cell Res Ther (2015)

Bottom Line: In this study, we demonstrate that aNPCs from the subventricular zone reverse the effects induced by the cytokine.Moreover, we show that the effect of aNPCs on cortical neurons is mediated by cannabinoid CB1 receptor activation.These data suggest that the role of aNPCs in preventing excitatory neurotransmission potentiation induced by TNFα on cortical neurons may have important implications for pathologies characterized by an inflammatory component affecting cortical neurons such as Alzheimer's disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Biotechnology and Traslational Medicine, University of Milano, via Vanvitelli 32, 20129, Milan, Italy. raffaella.morini@humanitasresearch.it.

ABSTRACT

Introduction: Tumor necrosis factor alpha (TNFα) plays a physiological role in controlling synaptic transmission and plasticity in the healthy central nervous system by modulating glutamate receptor trafficking to the plasma membrane. TNFα expression is also rapidly induced in response to tissue injury and infection. By promoting the insertion of Ca(2+) permeable-AMPA receptors into the neuronal plasma membrane, this cytokine may cause excessive Ca(2+) influx into neurons, thus enhancing neuronal death.

Methods: Primary cultures of cortical neurons were obtained from E18 foetal mice and incubated for 24 h with adult neural stem cells (aNPCs) either stimulated with lipopolysaccharide (LPS(+)aNPCs) or not (aNPCs). Cultures were treated with TNFα (100 ng/ml), and electrophysiological recordings were performed in different conditions to evaluate the effect of the cytokine on neuronal transmission.

Results: In this study, we demonstrate that aNPCs from the subventricular zone reverse the effects induced by the cytokine. Moreover, we show that the effect of aNPCs on cortical neurons is mediated by cannabinoid CB1 receptor activation.

Conclusion: These data suggest that the role of aNPCs in preventing excitatory neurotransmission potentiation induced by TNFα on cortical neurons may have important implications for pathologies characterized by an inflammatory component affecting cortical neurons such as Alzheimer's disease.

No MeSH data available.


Related in: MedlinePlus

The CB1 antagonist AM251 blocks the rescue of mEPSC changes sustained by LPS+aNPCs in TNFα-treated cultures. a Representative electrophysiological traces of mEPSCs under the different treatment conditions. b, c Group data of average mEPSC amplitude and frequency of untreated (n = 15), TNFα-treated (n = 13), LPS+aNPCs + TNFα (n = 10), and LPS+aNPCs + TNFα + AM 251-treated (n = 9) cells. LPS+aNPC treatment fails to revert TNF effect in the presence of AM 251 (P < 0.05, P < 0.01). d Confocal microscopy images showing expression of CB1 receptor in cultured cortical neurons. Immunofluorescence for CB1 (green), VGAT (red), and Merge in the upper panels and for CB1 (green), VGLUT (red) and Merge in lower panels is shown. Scale bars, 20 μm. e Summary bar graphs showing the colocalization of CB1 and VGAT or VGLUT. All data are expressed as mean ± standard error of the mean. Statistical test: one-way analysis of variance, Dunn’s multiple comparisons test. CB1 type 1 cannabinoid receptor, LPS+aNPC lipopolysaccharide-stimulated adult neural stem cell, mEPSC miniature excitatory post-synaptic current, TNFα tumor necrosis factor alpha
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Fig3: The CB1 antagonist AM251 blocks the rescue of mEPSC changes sustained by LPS+aNPCs in TNFα-treated cultures. a Representative electrophysiological traces of mEPSCs under the different treatment conditions. b, c Group data of average mEPSC amplitude and frequency of untreated (n = 15), TNFα-treated (n = 13), LPS+aNPCs + TNFα (n = 10), and LPS+aNPCs + TNFα + AM 251-treated (n = 9) cells. LPS+aNPC treatment fails to revert TNF effect in the presence of AM 251 (P < 0.05, P < 0.01). d Confocal microscopy images showing expression of CB1 receptor in cultured cortical neurons. Immunofluorescence for CB1 (green), VGAT (red), and Merge in the upper panels and for CB1 (green), VGLUT (red) and Merge in lower panels is shown. Scale bars, 20 μm. e Summary bar graphs showing the colocalization of CB1 and VGAT or VGLUT. All data are expressed as mean ± standard error of the mean. Statistical test: one-way analysis of variance, Dunn’s multiple comparisons test. CB1 type 1 cannabinoid receptor, LPS+aNPC lipopolysaccharide-stimulated adult neural stem cell, mEPSC miniature excitatory post-synaptic current, TNFα tumor necrosis factor alpha

Mentions: The protective role of type 1 cannabinoid receptors (CB1), against enhanced excitotoxic death caused by TNFα and other harmful agents, has been demonstrated by several studies [34, 35]. Furthermore, it has been found that aNPCs are capable of secreting endogenous cannabinoids [24, 36]. We therefore aimed to test whether, in our experimental conditions, aNPCs exert their described effect through CB1 receptor activation. To this end, we recorded mEPSCs in TNFα-treated cortical neurons incubated with aNPCs in the presence of the CB1 antagonist AM251 (Fig. 3). The results showed that LPS+aNPC treatment fails to revert TNFα effects in the presence of AM251, indicating that aNPCs act through CB1 receptor activation. As already shown in previous reports [37–39], CB1 receptors were expressed mainly in inhibitory neurons (Fig. 3d) and their localization did not change when neurons were exposed to AM251 (Fig. 3e). Our results demonstrate that CB1 is present in both inhibitory and excitatory synapses but that the signal overlap is approximately 10 times higher in inhibitory synapses than in excitatory ones (Fig. 3e). Additional file 1: Figure S1 shows that AM251 per se did not significantly change mEPSC frequency and amplitude (A), did not display cytotoxic effects (B), and did not change the synaptic expression of CB1 receptors (C, D).Fig. 3


Subventricular zone neural progenitors reverse TNF-alpha effects in cortical neurons.

Morini R, Ghirardini E, Butti E, Verderio C, Martino G, Matteoli M - Stem Cell Res Ther (2015)

The CB1 antagonist AM251 blocks the rescue of mEPSC changes sustained by LPS+aNPCs in TNFα-treated cultures. a Representative electrophysiological traces of mEPSCs under the different treatment conditions. b, c Group data of average mEPSC amplitude and frequency of untreated (n = 15), TNFα-treated (n = 13), LPS+aNPCs + TNFα (n = 10), and LPS+aNPCs + TNFα + AM 251-treated (n = 9) cells. LPS+aNPC treatment fails to revert TNF effect in the presence of AM 251 (P < 0.05, P < 0.01). d Confocal microscopy images showing expression of CB1 receptor in cultured cortical neurons. Immunofluorescence for CB1 (green), VGAT (red), and Merge in the upper panels and for CB1 (green), VGLUT (red) and Merge in lower panels is shown. Scale bars, 20 μm. e Summary bar graphs showing the colocalization of CB1 and VGAT or VGLUT. All data are expressed as mean ± standard error of the mean. Statistical test: one-way analysis of variance, Dunn’s multiple comparisons test. CB1 type 1 cannabinoid receptor, LPS+aNPC lipopolysaccharide-stimulated adult neural stem cell, mEPSC miniature excitatory post-synaptic current, TNFα tumor necrosis factor alpha
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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Fig3: The CB1 antagonist AM251 blocks the rescue of mEPSC changes sustained by LPS+aNPCs in TNFα-treated cultures. a Representative electrophysiological traces of mEPSCs under the different treatment conditions. b, c Group data of average mEPSC amplitude and frequency of untreated (n = 15), TNFα-treated (n = 13), LPS+aNPCs + TNFα (n = 10), and LPS+aNPCs + TNFα + AM 251-treated (n = 9) cells. LPS+aNPC treatment fails to revert TNF effect in the presence of AM 251 (P < 0.05, P < 0.01). d Confocal microscopy images showing expression of CB1 receptor in cultured cortical neurons. Immunofluorescence for CB1 (green), VGAT (red), and Merge in the upper panels and for CB1 (green), VGLUT (red) and Merge in lower panels is shown. Scale bars, 20 μm. e Summary bar graphs showing the colocalization of CB1 and VGAT or VGLUT. All data are expressed as mean ± standard error of the mean. Statistical test: one-way analysis of variance, Dunn’s multiple comparisons test. CB1 type 1 cannabinoid receptor, LPS+aNPC lipopolysaccharide-stimulated adult neural stem cell, mEPSC miniature excitatory post-synaptic current, TNFα tumor necrosis factor alpha
Mentions: The protective role of type 1 cannabinoid receptors (CB1), against enhanced excitotoxic death caused by TNFα and other harmful agents, has been demonstrated by several studies [34, 35]. Furthermore, it has been found that aNPCs are capable of secreting endogenous cannabinoids [24, 36]. We therefore aimed to test whether, in our experimental conditions, aNPCs exert their described effect through CB1 receptor activation. To this end, we recorded mEPSCs in TNFα-treated cortical neurons incubated with aNPCs in the presence of the CB1 antagonist AM251 (Fig. 3). The results showed that LPS+aNPC treatment fails to revert TNFα effects in the presence of AM251, indicating that aNPCs act through CB1 receptor activation. As already shown in previous reports [37–39], CB1 receptors were expressed mainly in inhibitory neurons (Fig. 3d) and their localization did not change when neurons were exposed to AM251 (Fig. 3e). Our results demonstrate that CB1 is present in both inhibitory and excitatory synapses but that the signal overlap is approximately 10 times higher in inhibitory synapses than in excitatory ones (Fig. 3e). Additional file 1: Figure S1 shows that AM251 per se did not significantly change mEPSC frequency and amplitude (A), did not display cytotoxic effects (B), and did not change the synaptic expression of CB1 receptors (C, D).Fig. 3

Bottom Line: In this study, we demonstrate that aNPCs from the subventricular zone reverse the effects induced by the cytokine.Moreover, we show that the effect of aNPCs on cortical neurons is mediated by cannabinoid CB1 receptor activation.These data suggest that the role of aNPCs in preventing excitatory neurotransmission potentiation induced by TNFα on cortical neurons may have important implications for pathologies characterized by an inflammatory component affecting cortical neurons such as Alzheimer's disease.

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Biotechnology and Traslational Medicine, University of Milano, via Vanvitelli 32, 20129, Milan, Italy. raffaella.morini@humanitasresearch.it.

ABSTRACT

Introduction: Tumor necrosis factor alpha (TNFα) plays a physiological role in controlling synaptic transmission and plasticity in the healthy central nervous system by modulating glutamate receptor trafficking to the plasma membrane. TNFα expression is also rapidly induced in response to tissue injury and infection. By promoting the insertion of Ca(2+) permeable-AMPA receptors into the neuronal plasma membrane, this cytokine may cause excessive Ca(2+) influx into neurons, thus enhancing neuronal death.

Methods: Primary cultures of cortical neurons were obtained from E18 foetal mice and incubated for 24 h with adult neural stem cells (aNPCs) either stimulated with lipopolysaccharide (LPS(+)aNPCs) or not (aNPCs). Cultures were treated with TNFα (100 ng/ml), and electrophysiological recordings were performed in different conditions to evaluate the effect of the cytokine on neuronal transmission.

Results: In this study, we demonstrate that aNPCs from the subventricular zone reverse the effects induced by the cytokine. Moreover, we show that the effect of aNPCs on cortical neurons is mediated by cannabinoid CB1 receptor activation.

Conclusion: These data suggest that the role of aNPCs in preventing excitatory neurotransmission potentiation induced by TNFα on cortical neurons may have important implications for pathologies characterized by an inflammatory component affecting cortical neurons such as Alzheimer's disease.

No MeSH data available.


Related in: MedlinePlus