Limits...
Extracellular matrix formation after transplantation of human embryonic stem cell-derived cardiomyocytes.

van Laake LW, van Donselaar EG, Monshouwer-Kloots J, Schreurs C, Passier R, Humbel BM, Doevendans PA, Sonnenberg A, Verkleij AJ, Mummery CL - Cell. Mol. Life Sci. (2009)

Bottom Line: Transplantation of human embryonic stem cell-derived cardiomyocytes (hESC-CM) for cardiac regeneration is hampered by the formation of fibrotic tissue around the grafts, preventing electrophysiological coupling.Investigating this process, we found that: (1) beating hESC-CM in vitro are embedded in collagens, laminin and fibronectin, which they bind via appropriate integrins; (2) after transplantation into the mouse heart, hESC-CM continue to secrete collagen IV, XVIII and fibronectin; (3) integrin expression on hESC-CM largely matches the matrix type they encounter or secrete in vivo; (4) co-transplantation of hESC-derived endothelial cells and/or cardiac progenitors with hESC-CM results in the formation of functional capillaries; and (5) transplanted hESC-CM survive and mature in vivo for at least 24 weeks.These results form the basis of future developments aiming to reduce the adverse fibrotic reaction that currently complicates cell-based therapies for cardiac disease, and to provide an additional clue towards successful engraftment of cardiomyocytes by co-transplanting endothelial cells.

View Article: PubMed Central - PubMed

Affiliation: Heart Lung Center Utrecht, Utrecht, The Netherlands.

ABSTRACT
Transplantation of human embryonic stem cell-derived cardiomyocytes (hESC-CM) for cardiac regeneration is hampered by the formation of fibrotic tissue around the grafts, preventing electrophysiological coupling. Investigating this process, we found that: (1) beating hESC-CM in vitro are embedded in collagens, laminin and fibronectin, which they bind via appropriate integrins; (2) after transplantation into the mouse heart, hESC-CM continue to secrete collagen IV, XVIII and fibronectin; (3) integrin expression on hESC-CM largely matches the matrix type they encounter or secrete in vivo; (4) co-transplantation of hESC-derived endothelial cells and/or cardiac progenitors with hESC-CM results in the formation of functional capillaries; and (5) transplanted hESC-CM survive and mature in vivo for at least 24 weeks. These results form the basis of future developments aiming to reduce the adverse fibrotic reaction that currently complicates cell-based therapies for cardiac disease, and to provide an additional clue towards successful engraftment of cardiomyocytes by co-transplanting endothelial cells.

Show MeSH

Related in: MedlinePlus

hESC-CM secrete extracellular matrix and evoke excessive matrix production by host cells after intramyocardial transplantation. a–b Large amounts of collagen I surrounding grafts 2 days and 12 weeks after transplantation. c–d Human collagen IV in the immediate proximity of hESC-CM. e–f Human collagen XVIII in the immediate proximity of hESC-CM. g–h Laminin envelops hESC-CM in similar amounts as host cardiomyocytes. i–j Laminin-211 is increasingly present around transplanted hESC-CM and eventually in similar amounts as host cardiomyocytes. k–l hESC-CM secrete fibronectin at early time-points after transplantation, but this is reduced over time. Scale bars 20 μm
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2801836&req=5

Fig2: hESC-CM secrete extracellular matrix and evoke excessive matrix production by host cells after intramyocardial transplantation. a–b Large amounts of collagen I surrounding grafts 2 days and 12 weeks after transplantation. c–d Human collagen IV in the immediate proximity of hESC-CM. e–f Human collagen XVIII in the immediate proximity of hESC-CM. g–h Laminin envelops hESC-CM in similar amounts as host cardiomyocytes. i–j Laminin-211 is increasingly present around transplanted hESC-CM and eventually in similar amounts as host cardiomyocytes. k–l hESC-CM secrete fibronectin at early time-points after transplantation, but this is reduced over time. Scale bars 20 μm

Mentions: We then analyzed grafts, identified by GFP-fluorescence as previously [10], 2 days, and 4 and 12 weeks after transplantation in non-infarcted hearts of NOD-SCID mice. From 4 weeks onwards, these grafts consisted almost exclusively of cardiomyocytes due to their preferential survival, as described [10, 28]. At all time-points, collagen I was expressed homogeneously throughout the myocardium and in the scar tissue resulting from the intramyocardial injection (Fig. 2a–b). However, at 4 and 12 weeks, excessive quantities of collagen I encapsulated most of the grafted cells (Fig. 2b). This over-secretion may be host-derived since collagen I is secreted by fibroblasts and not cardiomyocytes, and no human fibroblasts were found in the mouse heart despite an extensive search using EM. Using human-specific antibodies, human collagen IV and human collagen XVIII were identified around hESC-CM at all time-points (Fig. 2c–f). Moreover, at 4 and 12 weeks after transplantation, patches of human collagen IV and XVIII were also present at some distance from the grafts. Thus, hESC-CM secreted substantial amounts of collagen IV and XVIII in vivo in the mouse heart. Laminin also enveloped hESC-CM at all time-points but not excessively (Fig. 2g, h). Laminin-211 was absent in grafts 2 days post-transplantation, but became expressed thereafter in the same moderate quantities as laminin (Fig. 2i, j). Thus, laminins may be donor- and/or host-derived, but do not contribute significantly to the fibrotic tissue separating donor from host cells. Fibronectin filled the graft area abundantly 2 days after transplantation but this decreased over time (Fig. 2k, l). Human fibronectin was less prevalent by 4 weeks after transplantation, while mouse fibronectin was reduced by 12 weeks. Taken together, the results show that hESC-CM secrete fibronectin which is downregulated after transplantation in the non-infarcted heart. Secretion of mouse fibronectin, on the other hand, appears to be a response to the cell transplantation but is eventually resolved.Fig. 2


Extracellular matrix formation after transplantation of human embryonic stem cell-derived cardiomyocytes.

van Laake LW, van Donselaar EG, Monshouwer-Kloots J, Schreurs C, Passier R, Humbel BM, Doevendans PA, Sonnenberg A, Verkleij AJ, Mummery CL - Cell. Mol. Life Sci. (2009)

hESC-CM secrete extracellular matrix and evoke excessive matrix production by host cells after intramyocardial transplantation. a–b Large amounts of collagen I surrounding grafts 2 days and 12 weeks after transplantation. c–d Human collagen IV in the immediate proximity of hESC-CM. e–f Human collagen XVIII in the immediate proximity of hESC-CM. g–h Laminin envelops hESC-CM in similar amounts as host cardiomyocytes. i–j Laminin-211 is increasingly present around transplanted hESC-CM and eventually in similar amounts as host cardiomyocytes. k–l hESC-CM secrete fibronectin at early time-points after transplantation, but this is reduced over time. Scale bars 20 μm
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2801836&req=5

Fig2: hESC-CM secrete extracellular matrix and evoke excessive matrix production by host cells after intramyocardial transplantation. a–b Large amounts of collagen I surrounding grafts 2 days and 12 weeks after transplantation. c–d Human collagen IV in the immediate proximity of hESC-CM. e–f Human collagen XVIII in the immediate proximity of hESC-CM. g–h Laminin envelops hESC-CM in similar amounts as host cardiomyocytes. i–j Laminin-211 is increasingly present around transplanted hESC-CM and eventually in similar amounts as host cardiomyocytes. k–l hESC-CM secrete fibronectin at early time-points after transplantation, but this is reduced over time. Scale bars 20 μm
Mentions: We then analyzed grafts, identified by GFP-fluorescence as previously [10], 2 days, and 4 and 12 weeks after transplantation in non-infarcted hearts of NOD-SCID mice. From 4 weeks onwards, these grafts consisted almost exclusively of cardiomyocytes due to their preferential survival, as described [10, 28]. At all time-points, collagen I was expressed homogeneously throughout the myocardium and in the scar tissue resulting from the intramyocardial injection (Fig. 2a–b). However, at 4 and 12 weeks, excessive quantities of collagen I encapsulated most of the grafted cells (Fig. 2b). This over-secretion may be host-derived since collagen I is secreted by fibroblasts and not cardiomyocytes, and no human fibroblasts were found in the mouse heart despite an extensive search using EM. Using human-specific antibodies, human collagen IV and human collagen XVIII were identified around hESC-CM at all time-points (Fig. 2c–f). Moreover, at 4 and 12 weeks after transplantation, patches of human collagen IV and XVIII were also present at some distance from the grafts. Thus, hESC-CM secreted substantial amounts of collagen IV and XVIII in vivo in the mouse heart. Laminin also enveloped hESC-CM at all time-points but not excessively (Fig. 2g, h). Laminin-211 was absent in grafts 2 days post-transplantation, but became expressed thereafter in the same moderate quantities as laminin (Fig. 2i, j). Thus, laminins may be donor- and/or host-derived, but do not contribute significantly to the fibrotic tissue separating donor from host cells. Fibronectin filled the graft area abundantly 2 days after transplantation but this decreased over time (Fig. 2k, l). Human fibronectin was less prevalent by 4 weeks after transplantation, while mouse fibronectin was reduced by 12 weeks. Taken together, the results show that hESC-CM secrete fibronectin which is downregulated after transplantation in the non-infarcted heart. Secretion of mouse fibronectin, on the other hand, appears to be a response to the cell transplantation but is eventually resolved.Fig. 2

Bottom Line: Transplantation of human embryonic stem cell-derived cardiomyocytes (hESC-CM) for cardiac regeneration is hampered by the formation of fibrotic tissue around the grafts, preventing electrophysiological coupling.Investigating this process, we found that: (1) beating hESC-CM in vitro are embedded in collagens, laminin and fibronectin, which they bind via appropriate integrins; (2) after transplantation into the mouse heart, hESC-CM continue to secrete collagen IV, XVIII and fibronectin; (3) integrin expression on hESC-CM largely matches the matrix type they encounter or secrete in vivo; (4) co-transplantation of hESC-derived endothelial cells and/or cardiac progenitors with hESC-CM results in the formation of functional capillaries; and (5) transplanted hESC-CM survive and mature in vivo for at least 24 weeks.These results form the basis of future developments aiming to reduce the adverse fibrotic reaction that currently complicates cell-based therapies for cardiac disease, and to provide an additional clue towards successful engraftment of cardiomyocytes by co-transplanting endothelial cells.

View Article: PubMed Central - PubMed

Affiliation: Heart Lung Center Utrecht, Utrecht, The Netherlands.

ABSTRACT
Transplantation of human embryonic stem cell-derived cardiomyocytes (hESC-CM) for cardiac regeneration is hampered by the formation of fibrotic tissue around the grafts, preventing electrophysiological coupling. Investigating this process, we found that: (1) beating hESC-CM in vitro are embedded in collagens, laminin and fibronectin, which they bind via appropriate integrins; (2) after transplantation into the mouse heart, hESC-CM continue to secrete collagen IV, XVIII and fibronectin; (3) integrin expression on hESC-CM largely matches the matrix type they encounter or secrete in vivo; (4) co-transplantation of hESC-derived endothelial cells and/or cardiac progenitors with hESC-CM results in the formation of functional capillaries; and (5) transplanted hESC-CM survive and mature in vivo for at least 24 weeks. These results form the basis of future developments aiming to reduce the adverse fibrotic reaction that currently complicates cell-based therapies for cardiac disease, and to provide an additional clue towards successful engraftment of cardiomyocytes by co-transplanting endothelial cells.

Show MeSH
Related in: MedlinePlus