Bone marrow stromal cell transplantation combined with angiotensin-converting enzyme inhibitor treatment in rat with acute myocardial infarction and the role of insulin-like growth factor-1.

BACKGROUND AIMS: We investigated bone marrow stromal cell (BMSC) transplantation combined with angiotensin-converting enzyme inhibitor (ACEI) treatment in acute myocardial infarction (AMI) and the role of insulin-like growth factor-1 (IGF-1). METHODS: AMI models were established in Sprague-Dawley rats by ligation of the left anterior descending coronary artery and grouped into blank control (BC), ACEI treatment (ACEI), BMSC transplantation (BMSC) and BMSC transplantation plus ACEI (combined). Perindopril (2.5 mg/kg) was administered by gavage to ACEI and combined groups from the day after AMI. BMSC (2 × 10(8)) were injected into the border of the MI area a week later in the BMSC and combined groups. RESULTS: After 4 weeks, hemodynamics in the BMSC and combined groups were significantly improved (P < 0.05 versus BC), with the greatest improvement in the combined group (P < 0.05). In addition, an increased number of BMSC survived in the combined group (P < 0.05 versus BMSC). A proportion of BMSC was positive for troponin T, as detected by immunofluorescence. The number of apoptotic cardiomyocytes was decreased in the BMSC and ACEI groups, and even further in the combined group (P < 0.05). IGF-1 expression was up-regulated in the BMSC and combined groups (P < 0.05 versus BC), but not in the ACEI group. B cell lymphoma-2 (Bcl-2) expression was up-regulated in the ACEI, BMSC and combined groups, with the highest expression in the combined group (P < 0.05). CONCLUSIONS: Our results show that BMSC engrafted in AMI can survive well and secrete IGF-1 and preserve cardiac function significantly. These data suggest that BMSC transplantation inhibits apoptosis of cardiomyocytes by up-regulation of Bcl-2 expression in the myocardium, and this effect might be sensitized by ACEI.

Effects of insulin-like growth factor-1 on the properties of mesenchymal stem cells in vitro.

OBJECTIVE: To explore the effects of insulin-like growth factor-1 (IGF-1) on migration, proliferation and differentiation of mesenchymal stem cells (MSCs). METHODS: MSCs were obtained from Sprague-Dawley rats by a combination of gradient centrifugation and cell culture techniques and treated with IGF-1 at concentrations of 5-20 ng/ml. Proliferation of MSCs was determined as the mean doubling time. Expression of CXC chemokine receptor 4 (CXCR4) and migration property were determined by flow cytometry and transwell migration essay, respectively. mRNA expression of GATA-4 and collagen II was determined by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The mean doubling time of MSC proliferation was decreased, and the expression of CXCR4 on MSCs and migration of MSCs were increased by IGF-1, all in a dose-dependent manner, while the optimal concentration of IGF-1 on proliferation and migration was different. IGF-1 did not affect the expression of GATA-4 or collagen II mRNA. CONCLUSIONS: IGF-1 dose-dependently stimulated the proliferation of MSCs, upregulated the expression of CXCR4, and accelerated migration. There was no apparent differentiation of MSCs to cardiomyocytes or chondrocytes after culturing with IGF-1 alone.