Abstract 15272: Wnt11 Delivered in Mesenchymal Stem Cell-Derived Media Promotes Angiogenesis Through Non-canonical Wnt-PKC-JNK Pathway
Background: Wnt11 is involved in many developmental and cellular processes. We have previously reported that Wnt11 overexpressing (MSCWnt11) significantly improved cardiac function and increased angiogenesis. Here, we aimed to elucidate how Wnt11 delivered by MSC increase blood vessel formation.
Methods and Results: An acute myocardial infarction (MI) model in SD rats was developed by ligation of the left anterior descending (LAD) coronary artery. Conditioned medium (CdM) collected from MSCWnt11 (CdMWnt11) was injected immediately into the ischemic border area. Rats treated with CdMWnt11 showed a significantly improved cardiac function. Furthermore, CdMWnt11 increased blood vessel density and regional blood flow in ischemic myocardium. Fluorescent immunostaining showed that both vWF-positive single endothelial cell numbers and microvessel numbers were significantly increased in CdMWnt11 treated myocardium. In vitro studies showed that CdMWnt11 significantly increased number and length of capillary-like structure (CLS) formation and promoted human umbilical vein endothelial cells (HUVECs) migration. These results were confirmed by directly treating HUVECs with recombinant Wnt11 proteins (5μg/ml) or over-expressing Wnt11 in HUVECs (HWnt11). However, these effects could be abolished by using a Wnt11 neutralizing antibody. Immunostaining and Western blotting results revealed upregulation of p-pan-PKC and p-JNK in HWnt11. Real-time PCR analysis indicated that the expression of novel PKCs including PKCδ, PKCε, PKCη, and PKCθ was significantly upregulated in HWnt11. Moreover, the effect of Wnt11 on CLT formation and HUVECs migration were abrogated when the JNK inhibitor SP600125 at 5 μM and the PKC inhibitor Calphostin-C at 0.1 μM were added to the culture system.
Conclusion: Our data suggests, for the first time, that Wnt11 in MSC-derived media improved cardiac function and promoted angiogenesis in ischemic myocardium. The effect of Wnt11 in angiogenesis is mediated by novel PKCs, with JNK as its downstream mediator.
Author Disclosures: J. Wang: None. B. Yu: None. M. Gong: None. H. Liu: None. Y. Wang: None. R. Millard: None. M. Xu: None.
- © 2014 by American Heart Association, Inc.