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IL-10 regulates adult neurogenesis by modulating ERK and STAT3 activity.

Pereira L, Font-Nieves M, Van den Haute C, Baekelandt V, Planas AM, Pozas E - Front Cell Neurosci (2015)

Bottom Line: We found that, in vitro and in vivo, IL-10 targets Nestin+ progenitors and activates the phosphorylation of ERK and STAT3.The action of IL-10 on Nestin+ progenitors is reversed by treatment with a MEK/ERK inhibitor, thus restoring neurogenesis to normal levels.Our findings unveil ERK and STAT3 as effectors of IL-10 in adult SVZ neurogenesis.

View Article: PubMed Central - PubMed

Affiliation: Unit of Brain Ischemia, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona Spain ; Department of Brain Ischemia and Neurodegeneration, Institute of Biomedical Research of Barcelona, Consejo Superior de Investigaciones Científicas, Barcelona Spain.

ABSTRACT
The adult subventricular zone (SVZ) contains Nestin+ progenitors that differentiate mainly into neuroblasts. Our previous data showed that interleukin-10 (IL-10) regulates SVZ adult neurogenesis by up-regulating the expression of pro-neural genes and modulating cell cycle exit. Here we addressed the specific mechanism through which IL-10 carries out its signaling on SVZ progenitors. We found that, in vitro and in vivo, IL-10 targets Nestin+ progenitors and activates the phosphorylation of ERK and STAT3. The action of IL-10 on Nestin+ progenitors is reversed by treatment with a MEK/ERK inhibitor, thus restoring neurogenesis to normal levels. Silencing STAT3 expression by lentiviral vectors also impaired neurogenesis by blocking the effects of IL-10. Our findings unveil ERK and STAT3 as effectors of IL-10 in adult SVZ neurogenesis.

No MeSH data available.


Related in: MedlinePlus

ERK1/2 acts upstream of STAT3 and mediates IL-10 actions on SVZ progenitors. (A) MAPK pathway inhibition by U0126 (25 μM) prevents STAT3Ser727 activation induced by IL-10. Actin was the loading control (n = 4). (B) Western blotting of neural protein expression after U0126 treatment during 48 h. UO126 prevents the up-regulation of Musashi, NICD and Numb induced by IL-10 (n = 4) (C) Pictures of dissociated cultures stain against Nestin and TUBB3 in the presence of IL-10 or IL-10+U0126. MEK inhibitor induced a decrease in the number of progenitors (Nestin+) and increases the number of neuroblasts (TUBB3+). Hoechst (blue) stained all nuclei. (D) Graph summarizes the effect of U0126 on the numbers of Nestin+ and TUBB3+ cells in the control situation and after IL-10 treatment. In control and IL-10-treated cultures U0126 reduced the presence of Nestin+ cells while it increased neuroblast number (TUBB3+). Values are expressed as the percentage of control (n = 5). Scale bar: 30 μm. Data are represented as the mean ± SEM. *P < 0.05.
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Figure 4: ERK1/2 acts upstream of STAT3 and mediates IL-10 actions on SVZ progenitors. (A) MAPK pathway inhibition by U0126 (25 μM) prevents STAT3Ser727 activation induced by IL-10. Actin was the loading control (n = 4). (B) Western blotting of neural protein expression after U0126 treatment during 48 h. UO126 prevents the up-regulation of Musashi, NICD and Numb induced by IL-10 (n = 4) (C) Pictures of dissociated cultures stain against Nestin and TUBB3 in the presence of IL-10 or IL-10+U0126. MEK inhibitor induced a decrease in the number of progenitors (Nestin+) and increases the number of neuroblasts (TUBB3+). Hoechst (blue) stained all nuclei. (D) Graph summarizes the effect of U0126 on the numbers of Nestin+ and TUBB3+ cells in the control situation and after IL-10 treatment. In control and IL-10-treated cultures U0126 reduced the presence of Nestin+ cells while it increased neuroblast number (TUBB3+). Values are expressed as the percentage of control (n = 5). Scale bar: 30 μm. Data are represented as the mean ± SEM. *P < 0.05.

Mentions: Inhibition of the MAPK pathway by the MEK1/2 inhibitor U0126 prevented the induction of pSTAT3ser727 by IL-10 in SVZ primary cells (Figure 4A), thereby strongly suggesting that ERK1/2 activation is required for STAT3 phosphorylation. In a previous study we described that IL-10 modulates the undifferentiated state of SVZ neural progenitors by up-regulating neural markers, such as Nestin, Musashi, and NICD, while it decreases the expression of NUMB, a protein involved in neuronal differentiation (Perez-Asensio et al., 2013). Inhibition of the MAPK pathway abolished the IL10-mediated induction of the pro-neural markers Musashi and NICD and reduced NUMB expression (Figure 4B). Further analysis at the cellular level demonstrated that inhibition of ERK1/2 phosphorylation had considerable effects on the expression of neural markers. Indeed, U0126 induced a significant decrease in the number of Nestin+ cells, with a parallel increase in TUBB3+ cells (Figures 4C,D). This alteration was observed in control and IL-10-treated cultures, thus indicating that the ERK1/2 pathway not only is functional under basal conditions but it also mediates the biological effects induced by IL-10. Given that the ERK signaling pathway is involved in CNS specification of glial progenitors (Wang et al., 2012), we evaluated the effects of ERK inhibition on glial phenotype markers. In this regard, we observed that the number of GFAP+ cells was unaltered by the presence of the inhibitor in any condition, while the number of Olig2+ cells was reduced, independently of the presence or absence of IL-10 (Supplementary Figure S2).


IL-10 regulates adult neurogenesis by modulating ERK and STAT3 activity.

Pereira L, Font-Nieves M, Van den Haute C, Baekelandt V, Planas AM, Pozas E - Front Cell Neurosci (2015)

ERK1/2 acts upstream of STAT3 and mediates IL-10 actions on SVZ progenitors. (A) MAPK pathway inhibition by U0126 (25 μM) prevents STAT3Ser727 activation induced by IL-10. Actin was the loading control (n = 4). (B) Western blotting of neural protein expression after U0126 treatment during 48 h. UO126 prevents the up-regulation of Musashi, NICD and Numb induced by IL-10 (n = 4) (C) Pictures of dissociated cultures stain against Nestin and TUBB3 in the presence of IL-10 or IL-10+U0126. MEK inhibitor induced a decrease in the number of progenitors (Nestin+) and increases the number of neuroblasts (TUBB3+). Hoechst (blue) stained all nuclei. (D) Graph summarizes the effect of U0126 on the numbers of Nestin+ and TUBB3+ cells in the control situation and after IL-10 treatment. In control and IL-10-treated cultures U0126 reduced the presence of Nestin+ cells while it increased neuroblast number (TUBB3+). Values are expressed as the percentage of control (n = 5). Scale bar: 30 μm. Data are represented as the mean ± SEM. *P < 0.05.
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Figure 4: ERK1/2 acts upstream of STAT3 and mediates IL-10 actions on SVZ progenitors. (A) MAPK pathway inhibition by U0126 (25 μM) prevents STAT3Ser727 activation induced by IL-10. Actin was the loading control (n = 4). (B) Western blotting of neural protein expression after U0126 treatment during 48 h. UO126 prevents the up-regulation of Musashi, NICD and Numb induced by IL-10 (n = 4) (C) Pictures of dissociated cultures stain against Nestin and TUBB3 in the presence of IL-10 or IL-10+U0126. MEK inhibitor induced a decrease in the number of progenitors (Nestin+) and increases the number of neuroblasts (TUBB3+). Hoechst (blue) stained all nuclei. (D) Graph summarizes the effect of U0126 on the numbers of Nestin+ and TUBB3+ cells in the control situation and after IL-10 treatment. In control and IL-10-treated cultures U0126 reduced the presence of Nestin+ cells while it increased neuroblast number (TUBB3+). Values are expressed as the percentage of control (n = 5). Scale bar: 30 μm. Data are represented as the mean ± SEM. *P < 0.05.
Mentions: Inhibition of the MAPK pathway by the MEK1/2 inhibitor U0126 prevented the induction of pSTAT3ser727 by IL-10 in SVZ primary cells (Figure 4A), thereby strongly suggesting that ERK1/2 activation is required for STAT3 phosphorylation. In a previous study we described that IL-10 modulates the undifferentiated state of SVZ neural progenitors by up-regulating neural markers, such as Nestin, Musashi, and NICD, while it decreases the expression of NUMB, a protein involved in neuronal differentiation (Perez-Asensio et al., 2013). Inhibition of the MAPK pathway abolished the IL10-mediated induction of the pro-neural markers Musashi and NICD and reduced NUMB expression (Figure 4B). Further analysis at the cellular level demonstrated that inhibition of ERK1/2 phosphorylation had considerable effects on the expression of neural markers. Indeed, U0126 induced a significant decrease in the number of Nestin+ cells, with a parallel increase in TUBB3+ cells (Figures 4C,D). This alteration was observed in control and IL-10-treated cultures, thus indicating that the ERK1/2 pathway not only is functional under basal conditions but it also mediates the biological effects induced by IL-10. Given that the ERK signaling pathway is involved in CNS specification of glial progenitors (Wang et al., 2012), we evaluated the effects of ERK inhibition on glial phenotype markers. In this regard, we observed that the number of GFAP+ cells was unaltered by the presence of the inhibitor in any condition, while the number of Olig2+ cells was reduced, independently of the presence or absence of IL-10 (Supplementary Figure S2).

Bottom Line: We found that, in vitro and in vivo, IL-10 targets Nestin+ progenitors and activates the phosphorylation of ERK and STAT3.The action of IL-10 on Nestin+ progenitors is reversed by treatment with a MEK/ERK inhibitor, thus restoring neurogenesis to normal levels.Our findings unveil ERK and STAT3 as effectors of IL-10 in adult SVZ neurogenesis.

View Article: PubMed Central - PubMed

Affiliation: Unit of Brain Ischemia, Institut d'Investigacions Biomèdiques August Pi i Sunyer, Barcelona Spain ; Department of Brain Ischemia and Neurodegeneration, Institute of Biomedical Research of Barcelona, Consejo Superior de Investigaciones Científicas, Barcelona Spain.

ABSTRACT
The adult subventricular zone (SVZ) contains Nestin+ progenitors that differentiate mainly into neuroblasts. Our previous data showed that interleukin-10 (IL-10) regulates SVZ adult neurogenesis by up-regulating the expression of pro-neural genes and modulating cell cycle exit. Here we addressed the specific mechanism through which IL-10 carries out its signaling on SVZ progenitors. We found that, in vitro and in vivo, IL-10 targets Nestin+ progenitors and activates the phosphorylation of ERK and STAT3. The action of IL-10 on Nestin+ progenitors is reversed by treatment with a MEK/ERK inhibitor, thus restoring neurogenesis to normal levels. Silencing STAT3 expression by lentiviral vectors also impaired neurogenesis by blocking the effects of IL-10. Our findings unveil ERK and STAT3 as effectors of IL-10 in adult SVZ neurogenesis.

No MeSH data available.


Related in: MedlinePlus