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Reduced Nrf2 expression mediates the decline in neural stem cell function during a critical middle-age period.

Corenblum MJ, Ray S, Remley QW, Long M, Harder B, Zhang DD, Barnes CA, Madhavan L - Aging Cell (2016)

Bottom Line: These studies indicate that although NSPC function continuously declines with advancing age, there is a critical time period during middle age (13-15 months) when a striking reduction in NSPC survival and regeneration (proliferation and neuronal differentiation) occurs.When Nrf2 expression was suppressed in 'young' NSPCs, using short interfering RNAs, the survival and regeneration of the NSPCs was significantly compromised and mirrored 'old' NSPCs.These results identify a novel regulatory role for Nrf2 in NSPC function during aging and have important implications for developing NSPC-based strategies to support healthy aging and to treat age-related neurodegenerative disorders.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, University of Arizona, Tucson, AZ, USA.

No MeSH data available.


Related in: MedlinePlus

Effect of altered Nrf2 expression on NSPC survival and function. Panel A shows examples of Nrf2 expression with or without knockdown of Nrf2 in the N cells. Graphs in B and C show results from live–dead and BrdU assays conducted on untreated (U), control siRNA (siC), and Nrf2 siRNA (siNrf2)‐treated N cells. Panel D shows Nrf2 expression with and without Nrf2 overexpression in MA cells, with parallel results from live–dead and BrdU assays conducted on untreated MA cells compared to those transfected with Nrf2 in E and F. I and J convey results from similar experiments in which N cells were treated with conditioned medium (CM) from MA cells (MACM), with corresponding Nrf2 expression shown in panel G. The effect of CM from newborn NSPC cultures (NCM) on MA cells is in K and L, with corresponding changes in Nrf2 expression in panel H. The effects of NCM or MACM, on the MA and N cells, respectively, with Nrf2 knockdown or overexpression are shown in M‐P [*P < 0.05, ***P < 0.001; one‐way ANOVA with post hoc Tukey's test for B, C, and M–P, unpaired t‐test for E, F, I‐L]. Scale bar: 25 μm.
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acel12482-fig-0004: Effect of altered Nrf2 expression on NSPC survival and function. Panel A shows examples of Nrf2 expression with or without knockdown of Nrf2 in the N cells. Graphs in B and C show results from live–dead and BrdU assays conducted on untreated (U), control siRNA (siC), and Nrf2 siRNA (siNrf2)‐treated N cells. Panel D shows Nrf2 expression with and without Nrf2 overexpression in MA cells, with parallel results from live–dead and BrdU assays conducted on untreated MA cells compared to those transfected with Nrf2 in E and F. I and J convey results from similar experiments in which N cells were treated with conditioned medium (CM) from MA cells (MACM), with corresponding Nrf2 expression shown in panel G. The effect of CM from newborn NSPC cultures (NCM) on MA cells is in K and L, with corresponding changes in Nrf2 expression in panel H. The effects of NCM or MACM, on the MA and N cells, respectively, with Nrf2 knockdown or overexpression are shown in M‐P [*P < 0.05, ***P < 0.001; one‐way ANOVA with post hoc Tukey's test for B, C, and M–P, unpaired t‐test for E, F, I‐L]. Scale bar: 25 μm.

Mentions: Given the data on its significantly declining expression in SVZ NSPCs, we further assessed Nrf2 through in vitro knockdown (RNA interference) and overexpression assays. Using targeted short interfering RNAs, Nrf2 was silenced in newborn (N) cells after which the cells were analyzed via live–dead and BrdU assays (Fig. 4A shows Nrf2 expression with and without knockdown). These data indicate that Nrf2 knockdown renders the N cells similar to ‘older’ cells, with low survival (Fig. 4B, P < 0.05, F2,6 = 6.9, one‐way ANOVA) and low proliferative rates (Fig. 4C, P < 0.001, F2,6 = 108.3, one‐way ANOVA), as compared to untreated (U) and silencing controls (siC). On the other hand, when MA NSPCs were transfected with Nrf2 (Fig. 4D shows Nrf2 expression with and without overexpression), their survival (Fig. 4E, P < 0.05, unpaired t‐test, t = 3.2, df = 3) and proliferation (Fig. 4F, P < 0.05, unpaired t‐test, t = 3.4, df = 3) was significantly improved, making them akin to ‘younger’ cells. These data indicated that simply altering intrinsic Nrf2 expression was sufficient to significantly change NSPC survival and function, supporting an important regulatory role for this factor in NSPC function during aging.


Reduced Nrf2 expression mediates the decline in neural stem cell function during a critical middle-age period.

Corenblum MJ, Ray S, Remley QW, Long M, Harder B, Zhang DD, Barnes CA, Madhavan L - Aging Cell (2016)

Effect of altered Nrf2 expression on NSPC survival and function. Panel A shows examples of Nrf2 expression with or without knockdown of Nrf2 in the N cells. Graphs in B and C show results from live–dead and BrdU assays conducted on untreated (U), control siRNA (siC), and Nrf2 siRNA (siNrf2)‐treated N cells. Panel D shows Nrf2 expression with and without Nrf2 overexpression in MA cells, with parallel results from live–dead and BrdU assays conducted on untreated MA cells compared to those transfected with Nrf2 in E and F. I and J convey results from similar experiments in which N cells were treated with conditioned medium (CM) from MA cells (MACM), with corresponding Nrf2 expression shown in panel G. The effect of CM from newborn NSPC cultures (NCM) on MA cells is in K and L, with corresponding changes in Nrf2 expression in panel H. The effects of NCM or MACM, on the MA and N cells, respectively, with Nrf2 knockdown or overexpression are shown in M‐P [*P < 0.05, ***P < 0.001; one‐way ANOVA with post hoc Tukey's test for B, C, and M–P, unpaired t‐test for E, F, I‐L]. Scale bar: 25 μm.
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acel12482-fig-0004: Effect of altered Nrf2 expression on NSPC survival and function. Panel A shows examples of Nrf2 expression with or without knockdown of Nrf2 in the N cells. Graphs in B and C show results from live–dead and BrdU assays conducted on untreated (U), control siRNA (siC), and Nrf2 siRNA (siNrf2)‐treated N cells. Panel D shows Nrf2 expression with and without Nrf2 overexpression in MA cells, with parallel results from live–dead and BrdU assays conducted on untreated MA cells compared to those transfected with Nrf2 in E and F. I and J convey results from similar experiments in which N cells were treated with conditioned medium (CM) from MA cells (MACM), with corresponding Nrf2 expression shown in panel G. The effect of CM from newborn NSPC cultures (NCM) on MA cells is in K and L, with corresponding changes in Nrf2 expression in panel H. The effects of NCM or MACM, on the MA and N cells, respectively, with Nrf2 knockdown or overexpression are shown in M‐P [*P < 0.05, ***P < 0.001; one‐way ANOVA with post hoc Tukey's test for B, C, and M–P, unpaired t‐test for E, F, I‐L]. Scale bar: 25 μm.
Mentions: Given the data on its significantly declining expression in SVZ NSPCs, we further assessed Nrf2 through in vitro knockdown (RNA interference) and overexpression assays. Using targeted short interfering RNAs, Nrf2 was silenced in newborn (N) cells after which the cells were analyzed via live–dead and BrdU assays (Fig. 4A shows Nrf2 expression with and without knockdown). These data indicate that Nrf2 knockdown renders the N cells similar to ‘older’ cells, with low survival (Fig. 4B, P < 0.05, F2,6 = 6.9, one‐way ANOVA) and low proliferative rates (Fig. 4C, P < 0.001, F2,6 = 108.3, one‐way ANOVA), as compared to untreated (U) and silencing controls (siC). On the other hand, when MA NSPCs were transfected with Nrf2 (Fig. 4D shows Nrf2 expression with and without overexpression), their survival (Fig. 4E, P < 0.05, unpaired t‐test, t = 3.2, df = 3) and proliferation (Fig. 4F, P < 0.05, unpaired t‐test, t = 3.4, df = 3) was significantly improved, making them akin to ‘younger’ cells. These data indicated that simply altering intrinsic Nrf2 expression was sufficient to significantly change NSPC survival and function, supporting an important regulatory role for this factor in NSPC function during aging.

Bottom Line: These studies indicate that although NSPC function continuously declines with advancing age, there is a critical time period during middle age (13-15 months) when a striking reduction in NSPC survival and regeneration (proliferation and neuronal differentiation) occurs.When Nrf2 expression was suppressed in 'young' NSPCs, using short interfering RNAs, the survival and regeneration of the NSPCs was significantly compromised and mirrored 'old' NSPCs.These results identify a novel regulatory role for Nrf2 in NSPC function during aging and have important implications for developing NSPC-based strategies to support healthy aging and to treat age-related neurodegenerative disorders.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, University of Arizona, Tucson, AZ, USA.

No MeSH data available.


Related in: MedlinePlus