Objectives In the heart most of the non-cardiomyocyte cells are interstitial cells (IC), which differentiate mainly into myofibroblasts and vascular cells, while only in a limited number express the markers of cardiac stem cells (CSC) committed to produce new cardiomyocytes (CM). Heart repair has been recently attributed mainly to CSC, while the bone marrow mesenchimal stem cells (MSC) are believed to differentiate into myofibroblasts and to protect against ischemia/reperfusion injury via the release of the stromal cell derived factor-1 (SDF-1). The present investigation aims at understanding whether MSC exert a trophic activity on cardiac IC. Materials and methods MSC were isolated from the femurs of green flurescent protein stable transfected (GFP-MSC) rats. Cells were grown in complete <alpha>-MEM culture medium. The adherent GFP-MSC were repetitively grown to 90% confluence in passage 3. IC were isolated from rat hearts with CM (CM+ IC) by enzymatic dissociation. 104 CM with IC were plated on slides coated with laminin. After CM+IC were incubated for 2 hours, 104 GFP-MSC were added. Green fluorescence allowed to distinguish GFP-MSC from other cells. Coculture was examined after 3 and 5 days. Other cultures were set up with CM+IC and GFP-MSC separately. Results RT-PCR showed the expression of c-Kit, GATA-4, <beta>myosin, connexin-43, and <beta>2, but not of <beta>1-receptors, by IC. After 3 days of culture without GFP-MSC, IC were about 300, of which 190 (63%) expressed GATA-4. After 5 days of culture IC were 1600, of which 600 (37%) expressed GATA-4. In the presence of GFP-MSC, after 3 days of coculture IC were 2400, of which 740 (31%) were GATA-4+. After 5 days in the same coculture, IC were 4000, of which 1500 (37%) were GATA-4+. Conclusion Bone marrow MSC favour the proliferation of IC, possibly via a paracrine mechanism. The proliferation involves also GATA-4 expressing cells, although the increase in total number is not accompanied by an increase in percent. Moreover, GATA-4 and <alpha>-actinin appeared in a few GFP-MSC. The expression of <beta>2-receptors suggests that IC are committed to the differentiation into vascular smooth muscle cells, whereas <beta>-myosin is in favor of a differentiation into CM.
Cross-talk among bone marrow mesenchymal stem cells, cardiac interstitial cells and cardiomyocytes in vitro
RASTALDO, Raffaella;FOLINO, Anna;CAPPELLO, SANDRA;SPRIO, ANDREA ELIO;DI SCIPIO, FEDERICA;BERTA, Giovanni Nicolao;LOSANO, Giovanni
2009-01-01
Abstract
Objectives In the heart most of the non-cardiomyocyte cells are interstitial cells (IC), which differentiate mainly into myofibroblasts and vascular cells, while only in a limited number express the markers of cardiac stem cells (CSC) committed to produce new cardiomyocytes (CM). Heart repair has been recently attributed mainly to CSC, while the bone marrow mesenchimal stem cells (MSC) are believed to differentiate into myofibroblasts and to protect against ischemia/reperfusion injury via the release of the stromal cell derived factor-1 (SDF-1). The present investigation aims at understanding whether MSC exert a trophic activity on cardiac IC. Materials and methods MSC were isolated from the femurs of green flurescent protein stable transfected (GFP-MSC) rats. Cells were grown in completeI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.