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c-kit+ cells minimally contribute cardiomyocytes to the heart.

van Berlo JH, Kanisicak O, Maillet M, Vagnozzi RJ, Karch J, Lin SC, Middleton RC, Marbán E, Molkentin JD - Nature (2014)

Bottom Line: Endogenous c-kit(+) cells did produce new cardiomyocytes within the heart, although at a percentage of approximately 0.03 or less, and if a preponderance towards cellular fusion is considered, the percentage falls to below approximately 0.008.By contrast, c-kit(+) cells amply generated cardiac endothelial cells.Thus, endogenous c-kit(+) cells can generate cardiomyocytes within the heart, although probably at a functionally insignificant level.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA [2] Department of Medicine, division of Cardiology, Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota 55455, USA [3].

ABSTRACT
If and how the heart regenerates after an injury event is highly debated. c-kit-expressing cardiac progenitor cells have been reported as the primary source for generation of new myocardium after injury. Here we generated two genetic approaches in mice to examine whether endogenous c-kit(+) cells contribute differentiated cardiomyocytes to the heart during development, with ageing or after injury in adulthood. A complementary DNA encoding either Cre recombinase or a tamoxifen-inducible MerCreMer chimaeric protein was targeted to the Kit locus in mice and then bred with reporter lines to permanently mark cell lineage. Endogenous c-kit(+) cells did produce new cardiomyocytes within the heart, although at a percentage of approximately 0.03 or less, and if a preponderance towards cellular fusion is considered, the percentage falls to below approximately 0.008. By contrast, c-kit(+) cells amply generated cardiac endothelial cells. Thus, endogenous c-kit(+) cells can generate cardiomyocytes within the heart, although probably at a functionally insignificant level.

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Related in: MedlinePlus

Analysis of c-kit lineage labeling in the heart at P0 (birth)a, Diagram of the timing whereby newborn Kit+/Cre × R-GFP mice were analyzed for all subsequent experiments in this figure. b, Histological sections for eGFP fluorescence (green) from the ileum and lung at P0 showing the characteristic c-kit labeling pattern as observed at other time points or in other studies when antibodies were employed. Blue shows nuclei c, Histological section for eGFP fluorescence (green) from the heart at P0. Blue shows nuclei and magnification was 40X. d, Immunohistochemical tissue section from the P0 heart of Kit+/Cre × R-GFP mice stained with sarcomeric α-actin (red) to show all underlying cardiomyocytes (right panel) or with eGFP expression in green (left panel) as being c-kit derived. The green cells noted by the arrows are non-myocytes that do not express sarcomeric α-actin. e, eGFP expression alone (left) or eGFP with co-staining for cardiomyocytes in red (sarcomeric α-actin) from heart sections at P0 of Kit+/Cre × R-GFP mice. Blue staining depicts nuclei. The cardiomyocyte that is shown has clear striations in the eGFP staining pattern, while the 2 non-myocytes do not show striated eGFP and also lack sarcomeric α-actin staining. f, eGFP expression alone in green (left) with nuclei in blue or eGFP with sarcomeric α-actin co-staining (red) from heart sections at P0 of Kit+/Cre × R-GFP mice. All eGFP+ cells shown lack striations and are non-myocytes although the 2 cells in the center sit directly on top of cardiomyocytes and could be easily mis-interpreted. Great care is needed in scoring myocytes in the P0 heart because they are small and often the same size as eGFP+ non-myocytes. g, eGFP expression (green) with nuclei in blue and cardiomyocytes identified in red with sarcomeric α-actin antibody from heart histological sections at P0 of Kit+/Cre × R-GFP mice. Here the data show c-kit lineage derived cardiomyocytes that appear in a loose cluster (arrows), presumably from a clonal expansion event earlier in development.
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Figure 7: Analysis of c-kit lineage labeling in the heart at P0 (birth)a, Diagram of the timing whereby newborn Kit+/Cre × R-GFP mice were analyzed for all subsequent experiments in this figure. b, Histological sections for eGFP fluorescence (green) from the ileum and lung at P0 showing the characteristic c-kit labeling pattern as observed at other time points or in other studies when antibodies were employed. Blue shows nuclei c, Histological section for eGFP fluorescence (green) from the heart at P0. Blue shows nuclei and magnification was 40X. d, Immunohistochemical tissue section from the P0 heart of Kit+/Cre × R-GFP mice stained with sarcomeric α-actin (red) to show all underlying cardiomyocytes (right panel) or with eGFP expression in green (left panel) as being c-kit derived. The green cells noted by the arrows are non-myocytes that do not express sarcomeric α-actin. e, eGFP expression alone (left) or eGFP with co-staining for cardiomyocytes in red (sarcomeric α-actin) from heart sections at P0 of Kit+/Cre × R-GFP mice. Blue staining depicts nuclei. The cardiomyocyte that is shown has clear striations in the eGFP staining pattern, while the 2 non-myocytes do not show striated eGFP and also lack sarcomeric α-actin staining. f, eGFP expression alone in green (left) with nuclei in blue or eGFP with sarcomeric α-actin co-staining (red) from heart sections at P0 of Kit+/Cre × R-GFP mice. All eGFP+ cells shown lack striations and are non-myocytes although the 2 cells in the center sit directly on top of cardiomyocytes and could be easily mis-interpreted. Great care is needed in scoring myocytes in the P0 heart because they are small and often the same size as eGFP+ non-myocytes. g, eGFP expression (green) with nuclei in blue and cardiomyocytes identified in red with sarcomeric α-actin antibody from heart histological sections at P0 of Kit+/Cre × R-GFP mice. Here the data show c-kit lineage derived cardiomyocytes that appear in a loose cluster (arrows), presumably from a clonal expansion event earlier in development.

Mentions: We also harvested Kit+/Cre × R-GFP mice at birth (P0) to analyze the contributions of c-kit+ cells to the heart during embryonic and fetal development (Extended Data Fig. 3a). Control histological sections from the ileum and lung showed the expected distribution of c-kit+ cells (Extended Data Fig. 3b), and the heart also showed numerous eGFP+ cells throughout (Extended Data Fig. 3c). Immunohistochemical analysis of the P0 heart with a sarcomeric cardiomyocyte marker showed that nearly all of the eGFP+ cells were non-myocytes, although definable cardiomyocytes were clearly present at very low levels, including rare areas of cardiomyocyte clonal expansion (Extended Data Fig. 3d–g).


c-kit+ cells minimally contribute cardiomyocytes to the heart.

van Berlo JH, Kanisicak O, Maillet M, Vagnozzi RJ, Karch J, Lin SC, Middleton RC, Marbán E, Molkentin JD - Nature (2014)

Analysis of c-kit lineage labeling in the heart at P0 (birth)a, Diagram of the timing whereby newborn Kit+/Cre × R-GFP mice were analyzed for all subsequent experiments in this figure. b, Histological sections for eGFP fluorescence (green) from the ileum and lung at P0 showing the characteristic c-kit labeling pattern as observed at other time points or in other studies when antibodies were employed. Blue shows nuclei c, Histological section for eGFP fluorescence (green) from the heart at P0. Blue shows nuclei and magnification was 40X. d, Immunohistochemical tissue section from the P0 heart of Kit+/Cre × R-GFP mice stained with sarcomeric α-actin (red) to show all underlying cardiomyocytes (right panel) or with eGFP expression in green (left panel) as being c-kit derived. The green cells noted by the arrows are non-myocytes that do not express sarcomeric α-actin. e, eGFP expression alone (left) or eGFP with co-staining for cardiomyocytes in red (sarcomeric α-actin) from heart sections at P0 of Kit+/Cre × R-GFP mice. Blue staining depicts nuclei. The cardiomyocyte that is shown has clear striations in the eGFP staining pattern, while the 2 non-myocytes do not show striated eGFP and also lack sarcomeric α-actin staining. f, eGFP expression alone in green (left) with nuclei in blue or eGFP with sarcomeric α-actin co-staining (red) from heart sections at P0 of Kit+/Cre × R-GFP mice. All eGFP+ cells shown lack striations and are non-myocytes although the 2 cells in the center sit directly on top of cardiomyocytes and could be easily mis-interpreted. Great care is needed in scoring myocytes in the P0 heart because they are small and often the same size as eGFP+ non-myocytes. g, eGFP expression (green) with nuclei in blue and cardiomyocytes identified in red with sarcomeric α-actin antibody from heart histological sections at P0 of Kit+/Cre × R-GFP mice. Here the data show c-kit lineage derived cardiomyocytes that appear in a loose cluster (arrows), presumably from a clonal expansion event earlier in development.
© Copyright Policy
Related In: Results  -  Collection

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Show All Figures
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Figure 7: Analysis of c-kit lineage labeling in the heart at P0 (birth)a, Diagram of the timing whereby newborn Kit+/Cre × R-GFP mice were analyzed for all subsequent experiments in this figure. b, Histological sections for eGFP fluorescence (green) from the ileum and lung at P0 showing the characteristic c-kit labeling pattern as observed at other time points or in other studies when antibodies were employed. Blue shows nuclei c, Histological section for eGFP fluorescence (green) from the heart at P0. Blue shows nuclei and magnification was 40X. d, Immunohistochemical tissue section from the P0 heart of Kit+/Cre × R-GFP mice stained with sarcomeric α-actin (red) to show all underlying cardiomyocytes (right panel) or with eGFP expression in green (left panel) as being c-kit derived. The green cells noted by the arrows are non-myocytes that do not express sarcomeric α-actin. e, eGFP expression alone (left) or eGFP with co-staining for cardiomyocytes in red (sarcomeric α-actin) from heart sections at P0 of Kit+/Cre × R-GFP mice. Blue staining depicts nuclei. The cardiomyocyte that is shown has clear striations in the eGFP staining pattern, while the 2 non-myocytes do not show striated eGFP and also lack sarcomeric α-actin staining. f, eGFP expression alone in green (left) with nuclei in blue or eGFP with sarcomeric α-actin co-staining (red) from heart sections at P0 of Kit+/Cre × R-GFP mice. All eGFP+ cells shown lack striations and are non-myocytes although the 2 cells in the center sit directly on top of cardiomyocytes and could be easily mis-interpreted. Great care is needed in scoring myocytes in the P0 heart because they are small and often the same size as eGFP+ non-myocytes. g, eGFP expression (green) with nuclei in blue and cardiomyocytes identified in red with sarcomeric α-actin antibody from heart histological sections at P0 of Kit+/Cre × R-GFP mice. Here the data show c-kit lineage derived cardiomyocytes that appear in a loose cluster (arrows), presumably from a clonal expansion event earlier in development.
Mentions: We also harvested Kit+/Cre × R-GFP mice at birth (P0) to analyze the contributions of c-kit+ cells to the heart during embryonic and fetal development (Extended Data Fig. 3a). Control histological sections from the ileum and lung showed the expected distribution of c-kit+ cells (Extended Data Fig. 3b), and the heart also showed numerous eGFP+ cells throughout (Extended Data Fig. 3c). Immunohistochemical analysis of the P0 heart with a sarcomeric cardiomyocyte marker showed that nearly all of the eGFP+ cells were non-myocytes, although definable cardiomyocytes were clearly present at very low levels, including rare areas of cardiomyocyte clonal expansion (Extended Data Fig. 3d–g).

Bottom Line: Endogenous c-kit(+) cells did produce new cardiomyocytes within the heart, although at a percentage of approximately 0.03 or less, and if a preponderance towards cellular fusion is considered, the percentage falls to below approximately 0.008.By contrast, c-kit(+) cells amply generated cardiac endothelial cells.Thus, endogenous c-kit(+) cells can generate cardiomyocytes within the heart, although probably at a functionally insignificant level.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio 45229, USA [2] Department of Medicine, division of Cardiology, Lillehei Heart Institute, University of Minnesota, Minneapolis, Minnesota 55455, USA [3].

ABSTRACT
If and how the heart regenerates after an injury event is highly debated. c-kit-expressing cardiac progenitor cells have been reported as the primary source for generation of new myocardium after injury. Here we generated two genetic approaches in mice to examine whether endogenous c-kit(+) cells contribute differentiated cardiomyocytes to the heart during development, with ageing or after injury in adulthood. A complementary DNA encoding either Cre recombinase or a tamoxifen-inducible MerCreMer chimaeric protein was targeted to the Kit locus in mice and then bred with reporter lines to permanently mark cell lineage. Endogenous c-kit(+) cells did produce new cardiomyocytes within the heart, although at a percentage of approximately 0.03 or less, and if a preponderance towards cellular fusion is considered, the percentage falls to below approximately 0.008. By contrast, c-kit(+) cells amply generated cardiac endothelial cells. Thus, endogenous c-kit(+) cells can generate cardiomyocytes within the heart, although probably at a functionally insignificant level.

Show MeSH
Related in: MedlinePlus