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Induction of COX-2-PGE2 synthesis by activation of the MAPK/ERK pathway contributes to neuronal death triggered by TDP-43-depleted microglia.

Xia Q, Hu Q, Wang H, Yang H, Gao F, Ren H, Chen D, Fu C, Zheng L, Zhen X, Ying Z, Wang G - Cell Death Dis (2015)

Bottom Line: Previous studies have shown the contribution of glial cells such as astrocytes in TDP-43-linked ALS.However, the role of microglia in TDP-43-mediated motor neuron degeneration remains poorly understood.Taken together, our results reveal a previously unrecognized non-cell-autonomous mechanism in TDP-43-mediated neurodegeneration, identifying COX-2-PGE2 as the molecular events of microglia- but not astrocyte-initiated neurotoxicity and identifying celecoxib as a novel potential therapy for TDP-43-linked ALS and possibly other types of ALS.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China.

ABSTRACT
Neuroinflammation is a striking hallmark of amyotrophic lateral sclerosis (ALS) and other neurodegenerative disorders. Previous studies have shown the contribution of glial cells such as astrocytes in TDP-43-linked ALS. However, the role of microglia in TDP-43-mediated motor neuron degeneration remains poorly understood. In this study, we show that depletion of TDP-43 in microglia, but not in astrocytes, strikingly upregulates cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production through the activation of MAPK/ERK signaling and initiates neurotoxicity. Moreover, we find that administration of celecoxib, a specific COX-2 inhibitor, greatly diminishes the neurotoxicity triggered by TDP-43-depleted microglia. Taken together, our results reveal a previously unrecognized non-cell-autonomous mechanism in TDP-43-mediated neurodegeneration, identifying COX-2-PGE2 as the molecular events of microglia- but not astrocyte-initiated neurotoxicity and identifying celecoxib as a novel potential therapy for TDP-43-linked ALS and possibly other types of ALS.

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Celecoxib alleviates neuronal death mediated by TDP-43-deficient microglia. (a and b) BV2 cells were transfected with si-control and si-TDP-43. After 72 h, BV2 cells were treated with DMSO or celecoxib for another 24 h. The culture media from the last 24 h were harvested and used to culture primary cortical neurons transfected with lentiviral EGFP for 8 h (the conditioned medium assay as described for Figure 5). Then, the cells were visualized using confocal microscopy. Scale bars, 30 μm (a); 10 μm (b). The percentage of cortical neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; **P<0.01; one-way ANOVA. (c) Similar experiments as in (a and b) were performed in primary cultured motor neurons. The cells were fixed, stained with an antibody against MAP2 and visualized using fluorescence microscopy. Scale bar, 10 μm. The percentage of motor neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; **P<0.01; one-way ANOVA. (d) Primary cultured cortical neurons were transfected with lentiviral EGFP. After 72 h, the cortical neurons were treated with DMSO or celecoxib for another 24 h. Then, the cells were visualized using confocal microscopy. Scale bars, 30 μm, upper panel; 10 μm, lower panel. The percentage of cortical neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; ns, not significantly different; one-way ANOVA. (e) Similar experiments as in (d) were performed in primary cultured motor neurons instead of primary cultured cortical neurons. The cells were fixed, stained with an antibody against MAP2, and visualized using fluorescence microscopy. Scale bar, 10 μm. The percentage of motor neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; ns, not significantly different; one-way ANOVA
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fig6: Celecoxib alleviates neuronal death mediated by TDP-43-deficient microglia. (a and b) BV2 cells were transfected with si-control and si-TDP-43. After 72 h, BV2 cells were treated with DMSO or celecoxib for another 24 h. The culture media from the last 24 h were harvested and used to culture primary cortical neurons transfected with lentiviral EGFP for 8 h (the conditioned medium assay as described for Figure 5). Then, the cells were visualized using confocal microscopy. Scale bars, 30 μm (a); 10 μm (b). The percentage of cortical neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; **P<0.01; one-way ANOVA. (c) Similar experiments as in (a and b) were performed in primary cultured motor neurons. The cells were fixed, stained with an antibody against MAP2 and visualized using fluorescence microscopy. Scale bar, 10 μm. The percentage of motor neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; **P<0.01; one-way ANOVA. (d) Primary cultured cortical neurons were transfected with lentiviral EGFP. After 72 h, the cortical neurons were treated with DMSO or celecoxib for another 24 h. Then, the cells were visualized using confocal microscopy. Scale bars, 30 μm, upper panel; 10 μm, lower panel. The percentage of cortical neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; ns, not significantly different; one-way ANOVA. (e) Similar experiments as in (d) were performed in primary cultured motor neurons instead of primary cultured cortical neurons. The cells were fixed, stained with an antibody against MAP2, and visualized using fluorescence microscopy. Scale bar, 10 μm. The percentage of motor neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; ns, not significantly different; one-way ANOVA

Mentions: We next investigated whether the COX-2 inhibitor celecoxib could alleviate neuronal death driven by TDP-43-depleted microglia. We performed the conditioned medium assay as described in Figures 5a and c, and we found that the impaired viability of both cortical neurons and motor neurons were restored upon incubating TDP-43-depleted microglia with celecoxib (Figures 6a and c). Meanwhile, celecoxib alone had no effect on the viability of cortical or motor neurons (Figures 6d and e).


Induction of COX-2-PGE2 synthesis by activation of the MAPK/ERK pathway contributes to neuronal death triggered by TDP-43-depleted microglia.

Xia Q, Hu Q, Wang H, Yang H, Gao F, Ren H, Chen D, Fu C, Zheng L, Zhen X, Ying Z, Wang G - Cell Death Dis (2015)

Celecoxib alleviates neuronal death mediated by TDP-43-deficient microglia. (a and b) BV2 cells were transfected with si-control and si-TDP-43. After 72 h, BV2 cells were treated with DMSO or celecoxib for another 24 h. The culture media from the last 24 h were harvested and used to culture primary cortical neurons transfected with lentiviral EGFP for 8 h (the conditioned medium assay as described for Figure 5). Then, the cells were visualized using confocal microscopy. Scale bars, 30 μm (a); 10 μm (b). The percentage of cortical neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; **P<0.01; one-way ANOVA. (c) Similar experiments as in (a and b) were performed in primary cultured motor neurons. The cells were fixed, stained with an antibody against MAP2 and visualized using fluorescence microscopy. Scale bar, 10 μm. The percentage of motor neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; **P<0.01; one-way ANOVA. (d) Primary cultured cortical neurons were transfected with lentiviral EGFP. After 72 h, the cortical neurons were treated with DMSO or celecoxib for another 24 h. Then, the cells were visualized using confocal microscopy. Scale bars, 30 μm, upper panel; 10 μm, lower panel. The percentage of cortical neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; ns, not significantly different; one-way ANOVA. (e) Similar experiments as in (d) were performed in primary cultured motor neurons instead of primary cultured cortical neurons. The cells were fixed, stained with an antibody against MAP2, and visualized using fluorescence microscopy. Scale bar, 10 μm. The percentage of motor neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; ns, not significantly different; one-way ANOVA
© Copyright Policy - open-access
Related In: Results  -  Collection

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fig6: Celecoxib alleviates neuronal death mediated by TDP-43-deficient microglia. (a and b) BV2 cells were transfected with si-control and si-TDP-43. After 72 h, BV2 cells were treated with DMSO or celecoxib for another 24 h. The culture media from the last 24 h were harvested and used to culture primary cortical neurons transfected with lentiviral EGFP for 8 h (the conditioned medium assay as described for Figure 5). Then, the cells were visualized using confocal microscopy. Scale bars, 30 μm (a); 10 μm (b). The percentage of cortical neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; **P<0.01; one-way ANOVA. (c) Similar experiments as in (a and b) were performed in primary cultured motor neurons. The cells were fixed, stained with an antibody against MAP2 and visualized using fluorescence microscopy. Scale bar, 10 μm. The percentage of motor neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; **P<0.01; one-way ANOVA. (d) Primary cultured cortical neurons were transfected with lentiviral EGFP. After 72 h, the cortical neurons were treated with DMSO or celecoxib for another 24 h. Then, the cells were visualized using confocal microscopy. Scale bars, 30 μm, upper panel; 10 μm, lower panel. The percentage of cortical neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; ns, not significantly different; one-way ANOVA. (e) Similar experiments as in (d) were performed in primary cultured motor neurons instead of primary cultured cortical neurons. The cells were fixed, stained with an antibody against MAP2, and visualized using fluorescence microscopy. Scale bar, 10 μm. The percentage of motor neurons that were viable is shown on the right side. The data from three independent experiments are presented as the means±S.E.M.; ns, not significantly different; one-way ANOVA
Mentions: We next investigated whether the COX-2 inhibitor celecoxib could alleviate neuronal death driven by TDP-43-depleted microglia. We performed the conditioned medium assay as described in Figures 5a and c, and we found that the impaired viability of both cortical neurons and motor neurons were restored upon incubating TDP-43-depleted microglia with celecoxib (Figures 6a and c). Meanwhile, celecoxib alone had no effect on the viability of cortical or motor neurons (Figures 6d and e).

Bottom Line: Previous studies have shown the contribution of glial cells such as astrocytes in TDP-43-linked ALS.However, the role of microglia in TDP-43-mediated motor neuron degeneration remains poorly understood.Taken together, our results reveal a previously unrecognized non-cell-autonomous mechanism in TDP-43-mediated neurodegeneration, identifying COX-2-PGE2 as the molecular events of microglia- but not astrocyte-initiated neurotoxicity and identifying celecoxib as a novel potential therapy for TDP-43-linked ALS and possibly other types of ALS.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Molecular Neuropathology, Jiangsu Key Laboratory of Translational Research and Therapy for Neuro-Psycho-Diseases and College of Pharmaceutical Sciences, Soochow University, Suzhou, Jiangsu, China.

ABSTRACT
Neuroinflammation is a striking hallmark of amyotrophic lateral sclerosis (ALS) and other neurodegenerative disorders. Previous studies have shown the contribution of glial cells such as astrocytes in TDP-43-linked ALS. However, the role of microglia in TDP-43-mediated motor neuron degeneration remains poorly understood. In this study, we show that depletion of TDP-43 in microglia, but not in astrocytes, strikingly upregulates cyclooxygenase-2 (COX-2) expression and prostaglandin E2 (PGE2) production through the activation of MAPK/ERK signaling and initiates neurotoxicity. Moreover, we find that administration of celecoxib, a specific COX-2 inhibitor, greatly diminishes the neurotoxicity triggered by TDP-43-depleted microglia. Taken together, our results reveal a previously unrecognized non-cell-autonomous mechanism in TDP-43-mediated neurodegeneration, identifying COX-2-PGE2 as the molecular events of microglia- but not astrocyte-initiated neurotoxicity and identifying celecoxib as a novel potential therapy for TDP-43-linked ALS and possibly other types of ALS.

Show MeSH
Related in: MedlinePlus