Abstract
Background aims. This study was initiated to investigate the efficacy of myocardial fibrosis intervention via signal transducer and activators of transcription (STAT) signaling using bone marrow (BM) mesenchymal stromal cells (MSC) with the aid of bispecific antibody (BiAb) and ultrasound-mediated microbubbles (MB). Methods. BiAb (anti-CD29 × anti-myosin light chain antibody; AMLCA) was prepared and combined with isolated MSC from male mice and transfused into female mice with isoproterenol-induced myocardial fibrosis via the tail vein, followed by MB (MSC + BiAb + MB). This study included seven groups: MSC + BiAb + MB; MSC; BiAb; MB; MSC + BiAb; untreated; and control. Five weeks after treatment, expression levels of the sex-determining region of Y-chromosome (SRY), matrix metalloproteinases (MMP)-9, tissue inhibitor of metalloproteinase (TIMP)-1 and vascular endothelial growth factor (VEGF) in myocardium were detected by fluorescent quantitative real-time polymerase chain reaction (qRT-PCR). Collagen distribution was observed using Sirius Red staining. The protein expression of signal transducer and activators of transcription (STAT)1 and STAT3 was detected by Western blot. Results. The highest homing number of MSC was in the MSC + BiAb + MB group, second highest in the MSC + BiAb group, and lowest in MSC alone. Compared with the untreated group, MSC + BiAb + MB, MSC + BiAb and MSC groups had decreased levels of MMP-9, TIMP-1, STAT1 and collagen deposition, and increased levels of STAT3. Upregulated STAT3 and downregulated TIMP-1 were significantly different in MSC + BiAb + MB compared with MSC alone or MSC + BiAb. Conclusions. The homing rate and repairing efficacy of MSC improved with treatment utilizing a combination of BiAb and MB. MSC can improve MMP–TIMP expression in injured myocardium and interfere with myocardial fibrosis after homing, a mechanism that may be related to the STAT-mediated signaling pathway.
Acknowledgments
The present study was completed in the Center of Molecular Medicine and Tumor Research and the Institute of Basic Medical Sciences in Chongqing Medical University from September 2009 to May 2010. This work was supported by a grant from the National Natural Science Foundation of China (number 30970826). The authors are thankful to all of the involved laboratories and related research members.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.