Long-term (1 year) functional and histological results of autologous skeletal muscle cells transplantation in rat.
BACKGROUND
Several studies have demonstrated the short-term benefits of autologous skeletal muscle cell transplantation on postinfarction left ventricular function. The present experiments were designed to assess the long-term effects of the procedure.


RESULTS
Thirteen Wistar rats that had undergone skeletal muscle cell transplantation (n=6) or injection of control culture medium (n=7) in isoforms areas after myocardial infarction created by coronary artery ligation and survived for 1 year were functionally assessed by combining echocardiography and pressure-volume loops. At 1 year after transplantation, both contractile and relaxation indices were significantly improved in the skeletal muscle cell-grafted group compared with controls. One-year echocardiographic measurements of ejection fraction were similar to those recorded 2 months after the procedure. The stability of the functional outcome contrasted with a decrease in the number of histologically detectable skeletal myotubes over time. However, the proportion of the slow and composite (fast and slow) myosin isoforms expressed by skeletal muscle fibers still present after 1 year was greater than that found in animals sacrificed after 2 months.


CONCLUSIONS
The functional benefits of autologous skeletal muscle cell transplantation are sustained over time and are associated with either selection, preservation or an increased expression of slow myosin heavy chain isoforms. The discrepancy between maintenance of this improvement and the decay in the engrafted myotubes suggests protective mechanisms operative from the early post-transplantation stage and possibly involving modulation of extracellular matrix remodelling or paracrinally induced maturation of putative cardiac resident stem cells.
Al Attar
Nawwar
N
Department of Cardiovascular Surgery and INSERM U 572, Hôpital Européen Georges Pompidou, Paris, France.
Carrion
Claire
C
Ghostine
Said
S
Garcin
Isabelle
I
Vilquin
Jean-Thomas
JT
Hagège
Albert A
AA
Menasché
Philippe
P
D000818:Animals; D004452:Echocardiography; D008297:Male; D023421:Models, Animal; D018485:Muscle Fibers, Skeletal / Q000637:transplantation*; D009203:Myocardial Infarction / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery*; D009206:Myocardium / Q000378:metabolism / Q000473:pathology*; D009218:Myosins / Q000378:metabolism; D020033:Protein Isoforms / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013318:Stroke Volume; D013997:Time Factors; D016277:Ventricular Function, Left
D020033:Protein Isoforms; D009218:Myosins