Role of stem cells in regeneration of myocardium in experimentally induced myocardial infarction

ABSTRACT

Stem cells have generated a great deal of excitement and promise as a potential source for cell based therapeutic strategies. Primarily owing to their intrinsic ability to self re-new and differentiation into multiple functional cell types. Emberyonic stem cells [EBCs] and bone marrow-derived cells [BMCs] have been studied and dramatic advances have been achieved in their clinical application in ischemic and non- ischemic heart failure. The present study was done to investigate the healing capacity of autologous bone marrow-derived mesenchymal stem cells [BM-Mscs] and its regenerative rote in experimentally induced myocardial infarction. The study included two groups of albino rabbits. Group I [n=10] was used a negative control and received no treatment. Group II was used as an experimental group and was divided into subgroup IIa [n=10] used as positive control and subgroup IIb [n=10]. Animals of subgroup IIa and subgroup IIb received a single subcutaneous [s.c.] injection of isoproterenol [150mg/kg] to induce myocardial infarction. Group lIb were received undifferentiated mesenchymal stem cells in a dose of [1.4- 1.6 X 10[6] ml. in 5 ml sterile saline] intravenously [iv.] 2 weeks after injury. The animals were anaesthetized by ether and killed 2 weeks after transplantation. The regeneration capacity of the engrafied cells was detected by H and E and immunostaining using antivimentin antibodies. Damaged myocardium revealed regeneration denoted by increased content of vimentin proteins in the cytoplasm of the regenerated cardiac myocytes and in the wall of the newly formed small blood vessels. Transplantation of autologous undifferentiated mesenchymal stem cells injected i.v. in rabbits is an effective method of myocardial regeneration in cases of myocardial infarction