The Optimal Intervention Time of Bone Marrow Mesenchymal Stem Cells in Ameliorating Cardiac Fibrosis Induced by Viral Myocarditis: A Randomized Controlled Trial in Mice

Figure 1

Histological findings of myocardial tissues after BMSCs transplantation. The scale bars are equal to 100 μm in all of the images. (a) Control group. Histological findings of myocardial tissues in 4 weeks after PBS intraperitoneal injection. The myocardium was arranged neatly with clear contours and no obvious inflammatory cell infiltration (H&E, ×200). (b) VMC, the myocarditis group. Histological findings of myocardial tissues within 4 weeks after CVB3 intraperitoneal injection. The myocardium was disordered and showed residual inflammatory infiltration and necrotic lesions (H&E, ×200). (c–f) The BMSCs treatment subgroups. Histological findings of myocardial tissues within 4 weeks after CVB3 intraperitoneal injection. Mice in the VMC1d + BMSCs, VMC3d + BMSCs, VMC1w + BMSCs, and VMC2w + BMSCs subgroups were injected with BMSCs (1 × 10⁶ cells of each mouse with 100 μl PBS) into their tail vein on the 1st day, 3rd day, 1st week, and 2nd week after they were infected by CVB3, respectively. The myocardium showed clear contours and no obvious inflammatory cell infiltration (H&E, ×200).

(a) Control

(b) VMC

(c) VMC1d + BMSCs

(d) VMC3d + BMSCs

(e) VMC1w + BMSCs

(f) VMC2w + BMSCs