Abstract 12211: Exosomal Transfer of Mir-130a Excreted From Gata-4-Modified Mesenchymal Progenitor Cells Promotes Angiogenesis
Background: It is well known that exosomes play an important role in cell-cell communication and cellular functions. Bioactive molecules, components of exosomes released from stem cells may regulate angiogenesis. Here, we investigated the involvement of microRNAs excreted from GATA-4-modified mesenchymal progenitor cells (MPCGATA-4) on the angiogenesis.
Methods and Results: MPCGATA-4 was constructed using retrovirus carrying GATA-4 gene. MPCGFP was used as counterpart to MPCGATA-4. The conditioned medium (CdM) was collected from MPC and human umbilical vein endothelial cells (HUVEC) were incubated with CdM. [[Unable to Display Character: ⑴]] Concentrated CdM from MPCGATA-4 (CdMGATA-4) exerted greater potent pro-angiogenic effects than CdM obtained from MPCGFP (CdMGFP). The total tube length in HUVEC treated with CdMGATA-4 was 44.0 ± 4.8 mm/14.8 mm2 field, whereas it was only 31.3 ± 3.6 mm/14.8 mm2 field in the CdMGFP treated group. Similarly, the cumulative sprout length per HUVEC spheroid treated with CdMGATA-4 was significantly longer than that of the CdMGFP treated group. [[Unable to Display Character: ⑵]] Pro-angiogenic miR-130a expression level in CdMGATA-4 was 2.6 fold higher than that in CdMGFP. To confirm the pro-angiogenic effect of miR-130a from CdMGATA-4, we overexpressed miR-130a in MPC and collected the CdM (CdMmiR-130a). The pro-angiogenic capacity of CdMmiR-130a was significantly greater than its negative control, CdMsramble, assessed by both tube formation and spheroid-based angiogenesis assay. [[Unable to Display Character: ⑶]] The expression of miR-130a in CdMGATA-4 was decreased dramatically when MPCGATA-4 treated with GW4869 (10μM), an exosome release inhibitor. The total tube length in HUVEC treated with CdMGATA-4+GW4869 was significantly shorter than that of CdMGATA-4 treated group. Then, exosomes were isolated from CdMGATA-4 and CD63-GFP Cyto-Tracers™ lentivirus was used to label exosomes in MPC (exoCD63-GFP). ExoCD63-GFP were internalized by HUVEC and the expression of CD63 was detectable in HUVEC. Finally, the exosomes in CdMmiR-130a (exomiR-130a) exerted more pronounced pro-angiogenic effects than those in CdMsramble (exosramble).
Conclusion: Exosome-mediated transfer of miR-130a from MPCGATA-4 to HUVEC promoted angiogenesis. Exosomes may be therapeutically used in various cardiovascular diseases.
Author Disclosures: M. Gong: None. B. Yu: None. J. Wang: None. Y. Wang: None. R.W. Millard: None. M. Ashraf: None. M. Xu: None.
- © 2014 by American Heart Association, Inc.