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Zebrafish Müller glia-derived progenitors are multipotent, exhibit proliferative biases and regenerate excess neurons.

Powell C, Cornblath E, Elsaeidi F, Wan J, Goldman D - Sci Rep (2016)

Bottom Line: Our data indicate that regardless of which nuclear layer was damaged, MG respond by generating multipotent progenitors that migrate to all nuclear layers and differentiate into layer-specific cell types, suggesting that MG-derived progenitors in the injured retina are intrinsically multipotent.However, our analysis of progenitor proliferation reveals a proliferative advantage in nuclear layers where neurons were ablated.This suggests that feedback inhibition from surviving neurons may skew neuronal regeneration towards ablated cell types.

View Article: PubMed Central - PubMed

Affiliation: Molecular and Behavioral Neuroscience Institute, Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109 USA.

ABSTRACT
Unlike mammals, zebrafish can regenerate a damaged retina. Key to this regenerative response are Müller glia (MG) that respond to injury by reprogramming and adopting retinal stem cell properties. These reprogrammed MG divide to produce a proliferating population of retinal progenitors that migrate to areas of retinal damage and regenerate lost neurons. Previous studies have suggested that MG-derived progenitors may be biased to produce that are lost with injury. Here we investigated MG multipotency using injury paradigms that target different retinal nuclear layers for cell ablation. Our data indicate that regardless of which nuclear layer was damaged, MG respond by generating multipotent progenitors that migrate to all nuclear layers and differentiate into layer-specific cell types, suggesting that MG-derived progenitors in the injured retina are intrinsically multipotent. However, our analysis of progenitor proliferation reveals a proliferative advantage in nuclear layers where neurons were ablated. This suggests that feedback inhibition from surviving neurons may skew neuronal regeneration towards ablated cell types.

No MeSH data available.


Related in: MedlinePlus

The ultimate localization of MG-derived progenitors becomes progressively more biased at later rounds of proliferation.Fish were given an intraperitoneal injection of BrdU at 2 dpi, followed by an injection of EdU at 3, 6, or 12 dpi. Each sample was harvested at 14dpi. (A–C) EdU+ nuclei were counted at the times indicated and the percentage of EdU+ nuclei residing in the (A) ONL, (B) INL and (C) GCL was determined for each injury model. Data represents means ± s.d. (n ≥ 3). *P < 0.02941. (D,E) The percentage of ONL EdU+ nuclei residing in (D) the upper region or (E) the lower region was determined for each injury model. (F) Co-staining samples for BrdU and EdU demonstrates that the cells proliferating at later times are a subpopulation of those proliferating at earlier times. (G–L) Representative images of retinal sections analyzed in (A–F) that were stained for EdU at (G–I) 3 dpi or (J–L) 6 dpi following (G,J) needle poke, (H,K) PA or (I–L) NMDA injury. Scale bar is equal to 50 μm. Abbreviations are as in Fig. 1.
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f4: The ultimate localization of MG-derived progenitors becomes progressively more biased at later rounds of proliferation.Fish were given an intraperitoneal injection of BrdU at 2 dpi, followed by an injection of EdU at 3, 6, or 12 dpi. Each sample was harvested at 14dpi. (A–C) EdU+ nuclei were counted at the times indicated and the percentage of EdU+ nuclei residing in the (A) ONL, (B) INL and (C) GCL was determined for each injury model. Data represents means ± s.d. (n ≥ 3). *P < 0.02941. (D,E) The percentage of ONL EdU+ nuclei residing in (D) the upper region or (E) the lower region was determined for each injury model. (F) Co-staining samples for BrdU and EdU demonstrates that the cells proliferating at later times are a subpopulation of those proliferating at earlier times. (G–L) Representative images of retinal sections analyzed in (A–F) that were stained for EdU at (G–I) 3 dpi or (J–L) 6 dpi following (G,J) needle poke, (H,K) PA or (I–L) NMDA injury. Scale bar is equal to 50 μm. Abbreviations are as in Fig. 1.

Mentions: The above data indicate that although MG-derived progenitors contribute cells to all nuclear layers regardless of the injury paradigm, the ratio of BrdU+ cells localized to each layer is ultimately biased by which neurons were ablated. It is possible that disparities in progenitor cell migration and/or dissimilar levels of progenitor proliferation after migration generate these differences. In an attempt to uncover how these differences between injury paradigms arise, injured fish were given an IP injection of EdU at 3, 6 or 12 dpi and sacrificed at 14 dpi. Retinal sections were prepared and stained for EdU incorporation. We found that progenitors labelled with EdU at 3 dpi and harvested at 14 dpi showed comparable injury-paradigm dependent biases to those labeled with BrdU at 2 dpi and harvested at 14 dpi (Figs 3A–C and 4A–C). However, these biases increased with EdU pulses at 6 or 12 dpi (Fig. 4A–C,G–L). These results suggest that the ablated cell types impact MG-derived progenitor proliferation less at early times than at later times in the regenerative response. Thus, it is possible that the retinal progenitors receive feedback inhibition from surviving neurons that suppresses their proliferation.


Zebrafish Müller glia-derived progenitors are multipotent, exhibit proliferative biases and regenerate excess neurons.

Powell C, Cornblath E, Elsaeidi F, Wan J, Goldman D - Sci Rep (2016)

The ultimate localization of MG-derived progenitors becomes progressively more biased at later rounds of proliferation.Fish were given an intraperitoneal injection of BrdU at 2 dpi, followed by an injection of EdU at 3, 6, or 12 dpi. Each sample was harvested at 14dpi. (A–C) EdU+ nuclei were counted at the times indicated and the percentage of EdU+ nuclei residing in the (A) ONL, (B) INL and (C) GCL was determined for each injury model. Data represents means ± s.d. (n ≥ 3). *P < 0.02941. (D,E) The percentage of ONL EdU+ nuclei residing in (D) the upper region or (E) the lower region was determined for each injury model. (F) Co-staining samples for BrdU and EdU demonstrates that the cells proliferating at later times are a subpopulation of those proliferating at earlier times. (G–L) Representative images of retinal sections analyzed in (A–F) that were stained for EdU at (G–I) 3 dpi or (J–L) 6 dpi following (G,J) needle poke, (H,K) PA or (I–L) NMDA injury. Scale bar is equal to 50 μm. Abbreviations are as in Fig. 1.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4837407&req=5

f4: The ultimate localization of MG-derived progenitors becomes progressively more biased at later rounds of proliferation.Fish were given an intraperitoneal injection of BrdU at 2 dpi, followed by an injection of EdU at 3, 6, or 12 dpi. Each sample was harvested at 14dpi. (A–C) EdU+ nuclei were counted at the times indicated and the percentage of EdU+ nuclei residing in the (A) ONL, (B) INL and (C) GCL was determined for each injury model. Data represents means ± s.d. (n ≥ 3). *P < 0.02941. (D,E) The percentage of ONL EdU+ nuclei residing in (D) the upper region or (E) the lower region was determined for each injury model. (F) Co-staining samples for BrdU and EdU demonstrates that the cells proliferating at later times are a subpopulation of those proliferating at earlier times. (G–L) Representative images of retinal sections analyzed in (A–F) that were stained for EdU at (G–I) 3 dpi or (J–L) 6 dpi following (G,J) needle poke, (H,K) PA or (I–L) NMDA injury. Scale bar is equal to 50 μm. Abbreviations are as in Fig. 1.
Mentions: The above data indicate that although MG-derived progenitors contribute cells to all nuclear layers regardless of the injury paradigm, the ratio of BrdU+ cells localized to each layer is ultimately biased by which neurons were ablated. It is possible that disparities in progenitor cell migration and/or dissimilar levels of progenitor proliferation after migration generate these differences. In an attempt to uncover how these differences between injury paradigms arise, injured fish were given an IP injection of EdU at 3, 6 or 12 dpi and sacrificed at 14 dpi. Retinal sections were prepared and stained for EdU incorporation. We found that progenitors labelled with EdU at 3 dpi and harvested at 14 dpi showed comparable injury-paradigm dependent biases to those labeled with BrdU at 2 dpi and harvested at 14 dpi (Figs 3A–C and 4A–C). However, these biases increased with EdU pulses at 6 or 12 dpi (Fig. 4A–C,G–L). These results suggest that the ablated cell types impact MG-derived progenitor proliferation less at early times than at later times in the regenerative response. Thus, it is possible that the retinal progenitors receive feedback inhibition from surviving neurons that suppresses their proliferation.

Bottom Line: Our data indicate that regardless of which nuclear layer was damaged, MG respond by generating multipotent progenitors that migrate to all nuclear layers and differentiate into layer-specific cell types, suggesting that MG-derived progenitors in the injured retina are intrinsically multipotent.However, our analysis of progenitor proliferation reveals a proliferative advantage in nuclear layers where neurons were ablated.This suggests that feedback inhibition from surviving neurons may skew neuronal regeneration towards ablated cell types.

View Article: PubMed Central - PubMed

Affiliation: Molecular and Behavioral Neuroscience Institute, Department of Biological Chemistry, University of Michigan, Ann Arbor, MI 48109 USA.

ABSTRACT
Unlike mammals, zebrafish can regenerate a damaged retina. Key to this regenerative response are Müller glia (MG) that respond to injury by reprogramming and adopting retinal stem cell properties. These reprogrammed MG divide to produce a proliferating population of retinal progenitors that migrate to areas of retinal damage and regenerate lost neurons. Previous studies have suggested that MG-derived progenitors may be biased to produce that are lost with injury. Here we investigated MG multipotency using injury paradigms that target different retinal nuclear layers for cell ablation. Our data indicate that regardless of which nuclear layer was damaged, MG respond by generating multipotent progenitors that migrate to all nuclear layers and differentiate into layer-specific cell types, suggesting that MG-derived progenitors in the injured retina are intrinsically multipotent. However, our analysis of progenitor proliferation reveals a proliferative advantage in nuclear layers where neurons were ablated. This suggests that feedback inhibition from surviving neurons may skew neuronal regeneration towards ablated cell types.

No MeSH data available.


Related in: MedlinePlus