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Early homing of adult mesenchymal stem cells in normal and infarcted isolated beating hearts.

Penna C, Raimondo S, Ronchi G, Rastaldo R, Mancardi D, Cappello S, Losano G, Geuna S, Pagliaro P - J. Cell. Mol. Med. (2008)

Bottom Line: Moreover, a few hours after injection connexin-43 is well evident between cardiomyocytes and injected cells.This study indicates for the first time that the isolated beating heart is a good model to study early features of MSC homing without external interferences.The results show (i) that MSCs start to change marker expression few hours after injection into a beating heart and (ii) that infarcted myocardium influences transplanted MSC morphology and mobility within the heart.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical and Biological Sciences, University of Turin, Italy.

ABSTRACT
Little is known on the early homing features of transplanted mesenchymal stem cells (MSCs). We used the isolated rat heart model to study the homing of MSCs injected in the ventricular wall of a beating heart. In this model all types of cells and matrix elements with their interactions are represented, while external interferences by endothelial/neutrophil interaction and neurohormonal factors are excluded. We studied the morphology and marker expression of MSCs implanted in normal hearts and in the border-zone of infarcted myocardium. Early morphological adaptation of MSC homing differs between normal and infarcted hearts over the first 6 hrs after transplantation. In normal hearts, MSCs migrate very early through the interstitial milieu and begin to show morphological changes. Yet, in infarcted hearts MSCs remain in the site of injection forming clusters of round-shaped cells in the border-zone of the infarcted area. Both in normal and infarcted hearts, immuno-histochemistry and confocal imaging showed that, besides the proliferative marker proliferating cell nuclear agent (PCNA), some transplanted cells early express myoblastic maker GATA-4, and some of them show a VWF immunopositivity. Moreover, a few hours after injection connexin-43 is well evident between cardiomyocytes and injected cells. This study indicates for the first time that the isolated beating heart is a good model to study early features of MSC homing without external interferences. The results show (i) that MSCs start to change marker expression few hours after injection into a beating heart and (ii) that infarcted myocardium influences transplanted MSC morphology and mobility within the heart.

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Confocal image reconstruction of the whole heart profile for migration analysis. (A) Reconstruction of normal heart 4hrs after MSCs injection. (B) Reconstruction of infarcted heart 4hrs after MSCs injection. White points: presence of green MSCs. White lines: area of migration. Scale bars: 500 μm.
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fig03: Confocal image reconstruction of the whole heart profile for migration analysis. (A) Reconstruction of normal heart 4hrs after MSCs injection. (B) Reconstruction of infarcted heart 4hrs after MSCs injection. White points: presence of green MSCs. White lines: area of migration. Scale bars: 500 μm.

Mentions: The whole heart was cut in 10 μm thick slices transversally to the axis and starting from the apex. All sections were analysed by confocal laser microscopy (see later on for technical details) to detect the presence of GFP-positive transplanted cells. On the sections where GFP-positive cells were found, either double immunofluorescence or haematoxylin and eosin staining were carried out as described below. Although the objective of this analysis was to describe qualitatively the changes occurring to transplanted MSCs, in two hearts (one normal and one infarcted, at 4 hrs after injection) quantitative estimation of the volume of cell migration was also carried out by the Cavalieri method [25]. In one section out of each 50 sections, the area of migration was measured on reconstructed pictures of the whole heart profile (Fig. 3). Then, the mean area was finally multiplied by the number of sections obtaining thus an estimation of the entire myocardial volume through which GFP-positive cells migrated.


Early homing of adult mesenchymal stem cells in normal and infarcted isolated beating hearts.

Penna C, Raimondo S, Ronchi G, Rastaldo R, Mancardi D, Cappello S, Losano G, Geuna S, Pagliaro P - J. Cell. Mol. Med. (2008)

Confocal image reconstruction of the whole heart profile for migration analysis. (A) Reconstruction of normal heart 4hrs after MSCs injection. (B) Reconstruction of infarcted heart 4hrs after MSCs injection. White points: presence of green MSCs. White lines: area of migration. Scale bars: 500 μm.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3822539&req=5

fig03: Confocal image reconstruction of the whole heart profile for migration analysis. (A) Reconstruction of normal heart 4hrs after MSCs injection. (B) Reconstruction of infarcted heart 4hrs after MSCs injection. White points: presence of green MSCs. White lines: area of migration. Scale bars: 500 μm.
Mentions: The whole heart was cut in 10 μm thick slices transversally to the axis and starting from the apex. All sections were analysed by confocal laser microscopy (see later on for technical details) to detect the presence of GFP-positive transplanted cells. On the sections where GFP-positive cells were found, either double immunofluorescence or haematoxylin and eosin staining were carried out as described below. Although the objective of this analysis was to describe qualitatively the changes occurring to transplanted MSCs, in two hearts (one normal and one infarcted, at 4 hrs after injection) quantitative estimation of the volume of cell migration was also carried out by the Cavalieri method [25]. In one section out of each 50 sections, the area of migration was measured on reconstructed pictures of the whole heart profile (Fig. 3). Then, the mean area was finally multiplied by the number of sections obtaining thus an estimation of the entire myocardial volume through which GFP-positive cells migrated.

Bottom Line: Moreover, a few hours after injection connexin-43 is well evident between cardiomyocytes and injected cells.This study indicates for the first time that the isolated beating heart is a good model to study early features of MSC homing without external interferences.The results show (i) that MSCs start to change marker expression few hours after injection into a beating heart and (ii) that infarcted myocardium influences transplanted MSC morphology and mobility within the heart.

View Article: PubMed Central - PubMed

Affiliation: Department of Clinical and Biological Sciences, University of Turin, Italy.

ABSTRACT
Little is known on the early homing features of transplanted mesenchymal stem cells (MSCs). We used the isolated rat heart model to study the homing of MSCs injected in the ventricular wall of a beating heart. In this model all types of cells and matrix elements with their interactions are represented, while external interferences by endothelial/neutrophil interaction and neurohormonal factors are excluded. We studied the morphology and marker expression of MSCs implanted in normal hearts and in the border-zone of infarcted myocardium. Early morphological adaptation of MSC homing differs between normal and infarcted hearts over the first 6 hrs after transplantation. In normal hearts, MSCs migrate very early through the interstitial milieu and begin to show morphological changes. Yet, in infarcted hearts MSCs remain in the site of injection forming clusters of round-shaped cells in the border-zone of the infarcted area. Both in normal and infarcted hearts, immuno-histochemistry and confocal imaging showed that, besides the proliferative marker proliferating cell nuclear agent (PCNA), some transplanted cells early express myoblastic maker GATA-4, and some of them show a VWF immunopositivity. Moreover, a few hours after injection connexin-43 is well evident between cardiomyocytes and injected cells. This study indicates for the first time that the isolated beating heart is a good model to study early features of MSC homing without external interferences. The results show (i) that MSCs start to change marker expression few hours after injection into a beating heart and (ii) that infarcted myocardium influences transplanted MSC morphology and mobility within the heart.

Show MeSH