| 김용숙, 안영근, 박혜정, 신영희, 주수연, 이상록, 김계훈, 박형욱, 홍영준, 김주한, 정명호, 조정관, 박종춘, 강정채 |
Background: Mesenchymal stem cells (MSCs) have therapeutic potential after myocardial infarction. We hypothesized that cytokines released from infarcted myocardium play important roles in recruit and potentiation of MSCs. We elucidated whether TNF-α, one of cytokine released from infarcted myocardium, modulate the behavior of rat bone marrow-MSCs in vitro and in vivo system. Methods: Allogeneic MSCs were isolated from the femoral bone of Sprague-Dawley rats, characterized, cultured, and labeled with flurorescnet dye DAPI. To examine the effect of TNF-α on MSCs, cells were treated with TNF-α (10ng/mL) for 24 hours prior to study. For in vitro study, MSCs were co-culture with neonatal rat cardiomyocytes for 30 minutes to quantify the adhesive MSCs. The migration capacity of MSCs were assessed by incubation onto gelatin coated transwell membrane. The viability of H2O2-stimulated MSCs was assayed. For in vivo study, rat myocardial infarction was induced by left anterior descending coronary artery ligation for 30 minutes followed by release. Two weeks later, the number of DAPI-labelled MSCs on myocardium was counted. Results: The expression of BMP-2 was increased by TNF-α in mRNA (2.7-fold of control, p<0.05) and protein level (p<0.05). The levels of TNF-α receptor (TNFR)I, TNFRII, monocyte chemoattractant protein (MCP)-1, interleukin (IL)-6, vascular endothelial growth factor (VEGF), phosphorylated extracellular signal-regulated kinase (ERK), and phosphorylated signal transducer and activator of transcription (STAT)-3 were also increased by TNF-α. The adhesiveness and migration of MSCs were increased by TNF-α(1.8-fold and 2.5-fold increased (p<0.05)). Noggin, an antagonist of BMP-2, and AG490, an inhibitor of STAT-3, attenuated the adhesiveness. In addition, TNF-α-pretreated MSCs were more resistant to oxidative stress. The number of TNF-α-stimulated MSCs on rat myocardium was larger than non-treated MSCs (1.82-fold, p<0.05). Noggin reduced the adhesiveness of TNF-α-activated MSCs on myocardium. Conclusion: Our results demonstrated that TNF-α improved the homing of MSCs on infarcted myocardium through increase its adhesiveness, migration capacity and survival rate through BMP-2 pathway.
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