Limits...
Temporal changes in cell marker expression and cellular infiltration in a controlled cortical impact model in adult male C57BL/6 mice.

Jin X, Ishii H, Bai Z, Itokazu T, Yamashita T - PLoS ONE (2012)

Bottom Line: In contrast, some immune responses have neuroprotective effects.These results suggest that different subsets of microglia increased in the acute and chronic phases after CCI.The data from this study provide useful information on the dynamics of immune cells in CNS injuries.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita-shi, Osaka, Japan.

ABSTRACT

Background: Traumatic injury to the central nervous system (CNS) triggers a robust inflammatory response that leads to axonal damage and secondary degeneration of spared tissue. In contrast, some immune responses have neuroprotective effects. However, detailed information regarding the dynamics of immune responses after traumatic CNS injury is still unavailable.

Methods: In the present study, changes in the immune cells present in the injured brain, spleen, and cervical lymph nodes (CLNs), which are draining lymphatic organs from the CNS, were analyzed after controlled cortical impact (CCI) by flow cytometry and immunohistochemistry.

Results: The number of neutrophils and macrophages that infiltrated the injured brain immediately increased 1 d post-injury and declined rapidly thereafter. In the injured brain, resident microglia showed a bimodal increase during the first week and in the chronic phase (≥3 weeks) after injury. Increase in the Iba-1(+) microglia/macrophages was observed around the injured site. Morphologic analysis showed that Iba-1(+) cells were round at 1 week, whereas those at 3 weeks were more ramified. Furthermore, CD86(+)/CD11b(+) M1-like microglia increased at 4 weeks after CCI, whereas CD206(+)/CD11b(+) M2-like microglia increased at 1 week. These results suggest that different subsets of microglia increased in the acute and chronic phases after CCI. Dendritic cells and T cells increased transiently within 1 week in the injured brain. In the CLNs and the spleen, T cells showed dynamic changes after CCI. In particular, the alteration in the number of T cells in the CLNs showed a similar pattern, with a 1-week delay, to that of microglia in the injured brain.

Conclusion: The data from this study provide useful information on the dynamics of immune cells in CNS injuries.

Show MeSH

Related in: MedlinePlus

Analysis of neutrophils, macrophages, and microglia in the injured brain.A: Dot plots of isolated immune cells in the brain, gated for live cell analysis. B: Representative cytometry data for neutrophils (CD45+/Gr-1+ cells) in the injured brain at the indicated days after CCI. C: Representative cytometry data for macrophages (CD45high/CD11b+ cells) and microglia (CD45low/CD11b+ cells) in the injured brain at the indicated days after CCI. D: Graph illustrating quantitative data for accumulated neutrophils, macrophages, and microglia in the injured brain up to 28 d after CCI. All the values are presented in terms of mean ± standard error of mean (n = 3–6). Macrophages/neutrophils: ** p<0.01 at 1, 3, and 14 dpi compared with no injury; microglia: ** p<0.01 at 14 and 28 dpi compared with no injury, * p<0.05 at 14 dpi compared with 1 dpi.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3404031&req=5

pone-0041892-g001: Analysis of neutrophils, macrophages, and microglia in the injured brain.A: Dot plots of isolated immune cells in the brain, gated for live cell analysis. B: Representative cytometry data for neutrophils (CD45+/Gr-1+ cells) in the injured brain at the indicated days after CCI. C: Representative cytometry data for macrophages (CD45high/CD11b+ cells) and microglia (CD45low/CD11b+ cells) in the injured brain at the indicated days after CCI. D: Graph illustrating quantitative data for accumulated neutrophils, macrophages, and microglia in the injured brain up to 28 d after CCI. All the values are presented in terms of mean ± standard error of mean (n = 3–6). Macrophages/neutrophils: ** p<0.01 at 1, 3, and 14 dpi compared with no injury; microglia: ** p<0.01 at 14 and 28 dpi compared with no injury, * p<0.05 at 14 dpi compared with 1 dpi.

Mentions: The time course of the accumulation of immune cells in the injured brain was analyzed using isolated cells from the injured side of the cerebral cortex that were gated for live cell analysis (Figure 1A). Neutrophils positive for CD45 and Gr-1 accumulated in the injured brain, increasing to approximately 12% of the gated cells at 1 dpi and then decreased by 7 dpi (Figure 1B). CD45 and CD11b were used as markers for identification of macrophages and microglia. Two distinct populations of macrophages and microglia were observed: CD45high/CD11b+ cells and CD45low/CD11b+ cells. CD45high/CD11b+ cells were considered macrophages and CD45low/CD11b+ cells were considered microglia [34], [35]. A transient increase in the number of macrophages was observed at 1 and 3 dpi (Figure 1C, D) and the number of macrophages decreased thereafter. In contrast, the number of microglia gradually increased to approximately 10% of the gated cells at 7 dpi (Figure 1C, D), followed by a decrease to below the baseline level at 2 weeks (14 dpi), and then another increase at 3 and 4 weeks (21 and 28 dpi, respectively). Therefore, microglia show a bimodal increase in the injured brain after CCI.


Temporal changes in cell marker expression and cellular infiltration in a controlled cortical impact model in adult male C57BL/6 mice.

Jin X, Ishii H, Bai Z, Itokazu T, Yamashita T - PLoS ONE (2012)

Analysis of neutrophils, macrophages, and microglia in the injured brain.A: Dot plots of isolated immune cells in the brain, gated for live cell analysis. B: Representative cytometry data for neutrophils (CD45+/Gr-1+ cells) in the injured brain at the indicated days after CCI. C: Representative cytometry data for macrophages (CD45high/CD11b+ cells) and microglia (CD45low/CD11b+ cells) in the injured brain at the indicated days after CCI. D: Graph illustrating quantitative data for accumulated neutrophils, macrophages, and microglia in the injured brain up to 28 d after CCI. All the values are presented in terms of mean ± standard error of mean (n = 3–6). Macrophages/neutrophils: ** p<0.01 at 1, 3, and 14 dpi compared with no injury; microglia: ** p<0.01 at 14 and 28 dpi compared with no injury, * p<0.05 at 14 dpi compared with 1 dpi.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3404031&req=5

pone-0041892-g001: Analysis of neutrophils, macrophages, and microglia in the injured brain.A: Dot plots of isolated immune cells in the brain, gated for live cell analysis. B: Representative cytometry data for neutrophils (CD45+/Gr-1+ cells) in the injured brain at the indicated days after CCI. C: Representative cytometry data for macrophages (CD45high/CD11b+ cells) and microglia (CD45low/CD11b+ cells) in the injured brain at the indicated days after CCI. D: Graph illustrating quantitative data for accumulated neutrophils, macrophages, and microglia in the injured brain up to 28 d after CCI. All the values are presented in terms of mean ± standard error of mean (n = 3–6). Macrophages/neutrophils: ** p<0.01 at 1, 3, and 14 dpi compared with no injury; microglia: ** p<0.01 at 14 and 28 dpi compared with no injury, * p<0.05 at 14 dpi compared with 1 dpi.
Mentions: The time course of the accumulation of immune cells in the injured brain was analyzed using isolated cells from the injured side of the cerebral cortex that were gated for live cell analysis (Figure 1A). Neutrophils positive for CD45 and Gr-1 accumulated in the injured brain, increasing to approximately 12% of the gated cells at 1 dpi and then decreased by 7 dpi (Figure 1B). CD45 and CD11b were used as markers for identification of macrophages and microglia. Two distinct populations of macrophages and microglia were observed: CD45high/CD11b+ cells and CD45low/CD11b+ cells. CD45high/CD11b+ cells were considered macrophages and CD45low/CD11b+ cells were considered microglia [34], [35]. A transient increase in the number of macrophages was observed at 1 and 3 dpi (Figure 1C, D) and the number of macrophages decreased thereafter. In contrast, the number of microglia gradually increased to approximately 10% of the gated cells at 7 dpi (Figure 1C, D), followed by a decrease to below the baseline level at 2 weeks (14 dpi), and then another increase at 3 and 4 weeks (21 and 28 dpi, respectively). Therefore, microglia show a bimodal increase in the injured brain after CCI.

Bottom Line: In contrast, some immune responses have neuroprotective effects.These results suggest that different subsets of microglia increased in the acute and chronic phases after CCI.The data from this study provide useful information on the dynamics of immune cells in CNS injuries.

View Article: PubMed Central - PubMed

Affiliation: Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, Suita-shi, Osaka, Japan.

ABSTRACT

Background: Traumatic injury to the central nervous system (CNS) triggers a robust inflammatory response that leads to axonal damage and secondary degeneration of spared tissue. In contrast, some immune responses have neuroprotective effects. However, detailed information regarding the dynamics of immune responses after traumatic CNS injury is still unavailable.

Methods: In the present study, changes in the immune cells present in the injured brain, spleen, and cervical lymph nodes (CLNs), which are draining lymphatic organs from the CNS, were analyzed after controlled cortical impact (CCI) by flow cytometry and immunohistochemistry.

Results: The number of neutrophils and macrophages that infiltrated the injured brain immediately increased 1 d post-injury and declined rapidly thereafter. In the injured brain, resident microglia showed a bimodal increase during the first week and in the chronic phase (≥3 weeks) after injury. Increase in the Iba-1(+) microglia/macrophages was observed around the injured site. Morphologic analysis showed that Iba-1(+) cells were round at 1 week, whereas those at 3 weeks were more ramified. Furthermore, CD86(+)/CD11b(+) M1-like microglia increased at 4 weeks after CCI, whereas CD206(+)/CD11b(+) M2-like microglia increased at 1 week. These results suggest that different subsets of microglia increased in the acute and chronic phases after CCI. Dendritic cells and T cells increased transiently within 1 week in the injured brain. In the CLNs and the spleen, T cells showed dynamic changes after CCI. In particular, the alteration in the number of T cells in the CLNs showed a similar pattern, with a 1-week delay, to that of microglia in the injured brain.

Conclusion: The data from this study provide useful information on the dynamics of immune cells in CNS injuries.

Show MeSH
Related in: MedlinePlus