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The immature heart: the roles of bone marrow stromal stem cells in growth and myocardial repair.

Jun L, Minh D, Calvin W, Carolyn J T, Ray C J C, Dominique ST - Open Cardiovasc Med J (2007)

Bottom Line: Labeled MSCs were found to home into the bone marrow in all rats of different developmental stages.In contrast to that reported in the developing fetus, MSCs did not appear to contribute to the growth of non-injured hearts after birth.However, they can be recruited from the bone marrow and regenerate damaged myocardium both in the adult and in the immature hearts.

View Article: PubMed Central - PubMed

Affiliation: Division of Cardiothoracic Surgery, the Montreal General Hospital, MUHC, Canada.

ABSTRACT
Studies have shown that adult bone marrow derived stem cells (MSCs) can participate in repair of myocardial injury in adult hearts, as well as in cardiac growth during fetal development in utero. Yet, no studies have evaluated the role of MSCs with respect to normal growth or tissue repair in immature hearts after birth. The present study examines whether MSCs may participate in the myocardial growth and injury in the post-natal immature hearts. MSCs were isolated from adult Lewis rats and labeled with Lac-Z gene using retroviral vectors. These MSCs were injected systemically into groups of neonatal (NB=2days-old), immature (B=30days-old) and adult (A=>3months-old) isogeneic Lewis rats. Additionally, left coronary artery ligation was carried out in subgroups of immature (BL) and adult (AL) rats one week after MSCs injection. The hearts were harvested serially from 2-days to 6-weeks, stained with X-Gal for labeled MSCs. Cardiomyocyte phenotypic expression was evaluated by immunohistological staining for Troponin I-C and Connexin-43. Labeled MSCs were found to home into the bone marrow in all rats of different developmental stages. They could be recruited from bone marrow into the infarcted site of myocardium only in groups AL and BL. They were also capable of differentiating into cardiomyocyte phenotype after myocardial injury. In contrast to that reported in the developing fetus, MSCs did not appear to contribute to the growth of non-injured hearts after birth. However, they can be recruited from the bone marrow and regenerate damaged myocardium both in the adult and in the immature hearts.

No MeSH data available.


Related in: MedlinePlus

A:Lac-Z labeled MSCs (blue) prior to implantation in culture dish. B: (Group NB) Cross-section of myocardium 3 weeks after implantation showed no labeled MSCs in a normal growing heart. Stained with X-gal and counterstained with hematoxylin and eosin. C: (Group AL) Cross-section of myocardium 1 week after implantation showed Lac-Z positive cells in the infarcted area. Stained with X-gal and counterstained with hematoxylin and eosin. Black arrows show X-gal positively stained cells. D: (Group BL) Cross-section of myocardium 1 week after implantation showed Lac-Z positive cells in the infarcted area. Stained with X-gal and counterstained with hematoxylin and eosin. Black arrows show X-gall positively stained cells. E: (Group AL) Cross-section of myocardial scar 6 weeks after coronary ligation showed Troponin I-c positive cells. Brown color in the cytoplasm indicates positive stain. Counterstained with hematoxylin. Black arrow showed Lac-Z positive cell. F: (Group BL) Cross-section of myocardial scar 6 weeks after coronary ligation showed Connexin-43 positive cells in the peri-infarcted area. Counterstained with hematoxylin. The red arrows show Connexin-43 positive staining. Black arrow shows Lac-Z positive stained cells.
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Figure 1: A:Lac-Z labeled MSCs (blue) prior to implantation in culture dish. B: (Group NB) Cross-section of myocardium 3 weeks after implantation showed no labeled MSCs in a normal growing heart. Stained with X-gal and counterstained with hematoxylin and eosin. C: (Group AL) Cross-section of myocardium 1 week after implantation showed Lac-Z positive cells in the infarcted area. Stained with X-gal and counterstained with hematoxylin and eosin. Black arrows show X-gal positively stained cells. D: (Group BL) Cross-section of myocardium 1 week after implantation showed Lac-Z positive cells in the infarcted area. Stained with X-gal and counterstained with hematoxylin and eosin. Black arrows show X-gall positively stained cells. E: (Group AL) Cross-section of myocardial scar 6 weeks after coronary ligation showed Troponin I-c positive cells. Brown color in the cytoplasm indicates positive stain. Counterstained with hematoxylin. Black arrow showed Lac-Z positive cell. F: (Group BL) Cross-section of myocardial scar 6 weeks after coronary ligation showed Connexin-43 positive cells in the peri-infarcted area. Counterstained with hematoxylin. The red arrows show Connexin-43 positive staining. Black arrow shows Lac-Z positive stained cells.

Mentions: The MSCs usually become confluent in the culture flask after three to four passages of medium changes. At the end of Lac-Z gene transfection, the attached MSCs in the flask were nearly 100% labeled. The labeled cells stained with X-Gal solution shows blue nuclei under the inverted microscopy (Fig. 1A).


The immature heart: the roles of bone marrow stromal stem cells in growth and myocardial repair.

Jun L, Minh D, Calvin W, Carolyn J T, Ray C J C, Dominique ST - Open Cardiovasc Med J (2007)

A:Lac-Z labeled MSCs (blue) prior to implantation in culture dish. B: (Group NB) Cross-section of myocardium 3 weeks after implantation showed no labeled MSCs in a normal growing heart. Stained with X-gal and counterstained with hematoxylin and eosin. C: (Group AL) Cross-section of myocardium 1 week after implantation showed Lac-Z positive cells in the infarcted area. Stained with X-gal and counterstained with hematoxylin and eosin. Black arrows show X-gal positively stained cells. D: (Group BL) Cross-section of myocardium 1 week after implantation showed Lac-Z positive cells in the infarcted area. Stained with X-gal and counterstained with hematoxylin and eosin. Black arrows show X-gall positively stained cells. E: (Group AL) Cross-section of myocardial scar 6 weeks after coronary ligation showed Troponin I-c positive cells. Brown color in the cytoplasm indicates positive stain. Counterstained with hematoxylin. Black arrow showed Lac-Z positive cell. F: (Group BL) Cross-section of myocardial scar 6 weeks after coronary ligation showed Connexin-43 positive cells in the peri-infarcted area. Counterstained with hematoxylin. The red arrows show Connexin-43 positive staining. Black arrow shows Lac-Z positive stained cells.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2570564&req=5

Figure 1: A:Lac-Z labeled MSCs (blue) prior to implantation in culture dish. B: (Group NB) Cross-section of myocardium 3 weeks after implantation showed no labeled MSCs in a normal growing heart. Stained with X-gal and counterstained with hematoxylin and eosin. C: (Group AL) Cross-section of myocardium 1 week after implantation showed Lac-Z positive cells in the infarcted area. Stained with X-gal and counterstained with hematoxylin and eosin. Black arrows show X-gal positively stained cells. D: (Group BL) Cross-section of myocardium 1 week after implantation showed Lac-Z positive cells in the infarcted area. Stained with X-gal and counterstained with hematoxylin and eosin. Black arrows show X-gall positively stained cells. E: (Group AL) Cross-section of myocardial scar 6 weeks after coronary ligation showed Troponin I-c positive cells. Brown color in the cytoplasm indicates positive stain. Counterstained with hematoxylin. Black arrow showed Lac-Z positive cell. F: (Group BL) Cross-section of myocardial scar 6 weeks after coronary ligation showed Connexin-43 positive cells in the peri-infarcted area. Counterstained with hematoxylin. The red arrows show Connexin-43 positive staining. Black arrow shows Lac-Z positive stained cells.
Mentions: The MSCs usually become confluent in the culture flask after three to four passages of medium changes. At the end of Lac-Z gene transfection, the attached MSCs in the flask were nearly 100% labeled. The labeled cells stained with X-Gal solution shows blue nuclei under the inverted microscopy (Fig. 1A).

Bottom Line: Labeled MSCs were found to home into the bone marrow in all rats of different developmental stages.In contrast to that reported in the developing fetus, MSCs did not appear to contribute to the growth of non-injured hearts after birth.However, they can be recruited from the bone marrow and regenerate damaged myocardium both in the adult and in the immature hearts.

View Article: PubMed Central - PubMed

Affiliation: Division of Cardiothoracic Surgery, the Montreal General Hospital, MUHC, Canada.

ABSTRACT
Studies have shown that adult bone marrow derived stem cells (MSCs) can participate in repair of myocardial injury in adult hearts, as well as in cardiac growth during fetal development in utero. Yet, no studies have evaluated the role of MSCs with respect to normal growth or tissue repair in immature hearts after birth. The present study examines whether MSCs may participate in the myocardial growth and injury in the post-natal immature hearts. MSCs were isolated from adult Lewis rats and labeled with Lac-Z gene using retroviral vectors. These MSCs were injected systemically into groups of neonatal (NB=2days-old), immature (B=30days-old) and adult (A=>3months-old) isogeneic Lewis rats. Additionally, left coronary artery ligation was carried out in subgroups of immature (BL) and adult (AL) rats one week after MSCs injection. The hearts were harvested serially from 2-days to 6-weeks, stained with X-Gal for labeled MSCs. Cardiomyocyte phenotypic expression was evaluated by immunohistological staining for Troponin I-C and Connexin-43. Labeled MSCs were found to home into the bone marrow in all rats of different developmental stages. They could be recruited from bone marrow into the infarcted site of myocardium only in groups AL and BL. They were also capable of differentiating into cardiomyocyte phenotype after myocardial injury. In contrast to that reported in the developing fetus, MSCs did not appear to contribute to the growth of non-injured hearts after birth. However, they can be recruited from the bone marrow and regenerate damaged myocardium both in the adult and in the immature hearts.

No MeSH data available.


Related in: MedlinePlus