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Stem- and progenitor cell proliferation in the dentate gyrus of the reeler mouse.

Sibbe M, Kuner E, Althof D, Frotscher M - PLoS ONE (2015)

Bottom Line: Here, we examined the local interrelation between Reelin expressing interneurons and putative hippocampal stem cells and investigated the effects of Reelin deficiency on stem cell and progenitor cell proliferation.Reelin-positive cells are found in close vicinity to putative stem cell processes, which would allow for stem cell regulation by Reelin.We investigated the proliferation of stem cells in the Reelin-deficient reeler hippocampus by Ki67 labeling and found a strong reduction of mitotic cells.

View Article: PubMed Central - PubMed

Affiliation: Center for Neuroscience, Institute of Anatomy and Cell Biology, University of Freiburg, Albertstr. 23, D-79104, Freiburg, Germany.

ABSTRACT
Adult hippocampal neurogenesis has been implicated in hippocampus-dependent learning and memory. Furthermore, the decline of neurogenesis accompanying aging could be involved in age-related cognitive deficits. It is believed that the neural stem cell niche comprises a specialized microenvironment regulating stem cell activation and maintenance. However, little is known about the significance of the extracellular matrix in controlling adult stem cells. Reelin is a large glycoprotein of the extracelluar matrix known to be of crucial importance for neuronal migration. Here, we examined the local interrelation between Reelin expressing interneurons and putative hippocampal stem cells and investigated the effects of Reelin deficiency on stem cell and progenitor cell proliferation. Reelin-positive cells are found in close vicinity to putative stem cell processes, which would allow for stem cell regulation by Reelin. We investigated the proliferation of stem cells in the Reelin-deficient reeler hippocampus by Ki67 labeling and found a strong reduction of mitotic cells. A detailed analysis of dividing Type 1, type 2 and type 3 cells indicated that once a stem cell is recruited for proliferation, the progression to the next progenitor stage as well as the number of mitotic cycles is not altered in reeler. Our data point to a role for Reelin in either regulating stem cell quiescence or maintenance.

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Type 1, type 2 and type 3 cells undergoing mitosis.A-C show an example of a Nestin+/GFAP+/Ki67+ type 1 cell in the control dentate gyrus (arrow: Ki67, blue), D-F in the reeler dentate gyrus (arrow: Ki67). In D-F additionally a Nestin+/GFAP−/Ki67+ is labelled (short arrow). G-I display a DCX+/Nestin−/Ki67+ type 3 cell (arrow) in a wild-type animal, J-L in reeler. In G-I an additional DCX-/Nestin+/Ki67+, presumptive type 1 cell is present (short arrow). M, N Quantified cell fractions among all mitotic cells in the dentate gyrus for the two triple-staining experiments performed. O Incidence of Ki67+ cluster size in control and reeler dentate gyrus. In control animals cell clusters often consisted of only three cells, whereas clusters in reeler contained significantly more, often five cells. Data are represented by mean values; * p < 0.05, *** p < 0.0001. Scale bars: 10 μm.
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pone.0119643.g002: Type 1, type 2 and type 3 cells undergoing mitosis.A-C show an example of a Nestin+/GFAP+/Ki67+ type 1 cell in the control dentate gyrus (arrow: Ki67, blue), D-F in the reeler dentate gyrus (arrow: Ki67). In D-F additionally a Nestin+/GFAP−/Ki67+ is labelled (short arrow). G-I display a DCX+/Nestin−/Ki67+ type 3 cell (arrow) in a wild-type animal, J-L in reeler. In G-I an additional DCX-/Nestin+/Ki67+, presumptive type 1 cell is present (short arrow). M, N Quantified cell fractions among all mitotic cells in the dentate gyrus for the two triple-staining experiments performed. O Incidence of Ki67+ cluster size in control and reeler dentate gyrus. In control animals cell clusters often consisted of only three cells, whereas clusters in reeler contained significantly more, often five cells. Data are represented by mean values; * p < 0.05, *** p < 0.0001. Scale bars: 10 μm.

Mentions: Within the hippocampal stem cell niche a heterogeneous population of stem- and progenitor cells reside. According to a classification proposed by Kempermann et al. [27] the Nestin− as well as GFAP− positive, putative type 1 stem cells can be discriminated from Nestin+/GFAP− type 2a and Nestin+/DCX+ type 2b cells. Type 3 cells finally exhibit DCX but have lost Nestin expression. Does the reduced proliferation observed in reeler mutants result from Reelin influencing proliferation or differentiation of a certain type of stem cell or progenitor cell? To analyze this, the numbers of stem cells and progenitor cells among Ki67+ dividing cells were determined using Ki67 labeling in combination with GFAP and Nestin or Ki67 in combination with Nestin and DCX (Fig. 2). In reeler animals 20.4 ± 4.0% of Ki67+ cells were Nestin+/GFAP+, therefore could be classified as type 1 cells. 42.9 ± 3.6% were Nestin+/GFAP− type 2, and 42.6 ± 7.4% DCX+/Nestin− type 3 cells. It should be noted that these values derive from two different labeling experiments. The number of type 1, type 2 and type 3 cells in control animals were 28.9 ± 1.9%, 39.2 ± 2.7 and 30.9 ± 0.5%, respectively, and did not differ significantly from reeler animals (Student’s t-test, p > 0.05).


Stem- and progenitor cell proliferation in the dentate gyrus of the reeler mouse.

Sibbe M, Kuner E, Althof D, Frotscher M - PLoS ONE (2015)

Type 1, type 2 and type 3 cells undergoing mitosis.A-C show an example of a Nestin+/GFAP+/Ki67+ type 1 cell in the control dentate gyrus (arrow: Ki67, blue), D-F in the reeler dentate gyrus (arrow: Ki67). In D-F additionally a Nestin+/GFAP−/Ki67+ is labelled (short arrow). G-I display a DCX+/Nestin−/Ki67+ type 3 cell (arrow) in a wild-type animal, J-L in reeler. In G-I an additional DCX-/Nestin+/Ki67+, presumptive type 1 cell is present (short arrow). M, N Quantified cell fractions among all mitotic cells in the dentate gyrus for the two triple-staining experiments performed. O Incidence of Ki67+ cluster size in control and reeler dentate gyrus. In control animals cell clusters often consisted of only three cells, whereas clusters in reeler contained significantly more, often five cells. Data are represented by mean values; * p < 0.05, *** p < 0.0001. Scale bars: 10 μm.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4356578&req=5

pone.0119643.g002: Type 1, type 2 and type 3 cells undergoing mitosis.A-C show an example of a Nestin+/GFAP+/Ki67+ type 1 cell in the control dentate gyrus (arrow: Ki67, blue), D-F in the reeler dentate gyrus (arrow: Ki67). In D-F additionally a Nestin+/GFAP−/Ki67+ is labelled (short arrow). G-I display a DCX+/Nestin−/Ki67+ type 3 cell (arrow) in a wild-type animal, J-L in reeler. In G-I an additional DCX-/Nestin+/Ki67+, presumptive type 1 cell is present (short arrow). M, N Quantified cell fractions among all mitotic cells in the dentate gyrus for the two triple-staining experiments performed. O Incidence of Ki67+ cluster size in control and reeler dentate gyrus. In control animals cell clusters often consisted of only three cells, whereas clusters in reeler contained significantly more, often five cells. Data are represented by mean values; * p < 0.05, *** p < 0.0001. Scale bars: 10 μm.
Mentions: Within the hippocampal stem cell niche a heterogeneous population of stem- and progenitor cells reside. According to a classification proposed by Kempermann et al. [27] the Nestin− as well as GFAP− positive, putative type 1 stem cells can be discriminated from Nestin+/GFAP− type 2a and Nestin+/DCX+ type 2b cells. Type 3 cells finally exhibit DCX but have lost Nestin expression. Does the reduced proliferation observed in reeler mutants result from Reelin influencing proliferation or differentiation of a certain type of stem cell or progenitor cell? To analyze this, the numbers of stem cells and progenitor cells among Ki67+ dividing cells were determined using Ki67 labeling in combination with GFAP and Nestin or Ki67 in combination with Nestin and DCX (Fig. 2). In reeler animals 20.4 ± 4.0% of Ki67+ cells were Nestin+/GFAP+, therefore could be classified as type 1 cells. 42.9 ± 3.6% were Nestin+/GFAP− type 2, and 42.6 ± 7.4% DCX+/Nestin− type 3 cells. It should be noted that these values derive from two different labeling experiments. The number of type 1, type 2 and type 3 cells in control animals were 28.9 ± 1.9%, 39.2 ± 2.7 and 30.9 ± 0.5%, respectively, and did not differ significantly from reeler animals (Student’s t-test, p > 0.05).

Bottom Line: Here, we examined the local interrelation between Reelin expressing interneurons and putative hippocampal stem cells and investigated the effects of Reelin deficiency on stem cell and progenitor cell proliferation.Reelin-positive cells are found in close vicinity to putative stem cell processes, which would allow for stem cell regulation by Reelin.We investigated the proliferation of stem cells in the Reelin-deficient reeler hippocampus by Ki67 labeling and found a strong reduction of mitotic cells.

View Article: PubMed Central - PubMed

Affiliation: Center for Neuroscience, Institute of Anatomy and Cell Biology, University of Freiburg, Albertstr. 23, D-79104, Freiburg, Germany.

ABSTRACT
Adult hippocampal neurogenesis has been implicated in hippocampus-dependent learning and memory. Furthermore, the decline of neurogenesis accompanying aging could be involved in age-related cognitive deficits. It is believed that the neural stem cell niche comprises a specialized microenvironment regulating stem cell activation and maintenance. However, little is known about the significance of the extracellular matrix in controlling adult stem cells. Reelin is a large glycoprotein of the extracelluar matrix known to be of crucial importance for neuronal migration. Here, we examined the local interrelation between Reelin expressing interneurons and putative hippocampal stem cells and investigated the effects of Reelin deficiency on stem cell and progenitor cell proliferation. Reelin-positive cells are found in close vicinity to putative stem cell processes, which would allow for stem cell regulation by Reelin. We investigated the proliferation of stem cells in the Reelin-deficient reeler hippocampus by Ki67 labeling and found a strong reduction of mitotic cells. A detailed analysis of dividing Type 1, type 2 and type 3 cells indicated that once a stem cell is recruited for proliferation, the progression to the next progenitor stage as well as the number of mitotic cycles is not altered in reeler. Our data point to a role for Reelin in either regulating stem cell quiescence or maintenance.

Show MeSH
Related in: MedlinePlus