WNT11-Conditioned Medium Promotes Angiogenesis through the Activation of Non-Canonical WNT-PKC-JNK Signaling Pathway

Background: We demonstrated that the transduction of Wnt11 into mesenchymal stem cells (MSCs) (MSC(Wnt11)) promotes these cells differentiation into cardiac phenotypes. In the present study, we investigated the paracrine effects of MSC(Wnt11) on cardiac function and angiogenesis. Methods and Results: Conditioned medium was collected from MSC(Wnt11) (CdM(Wnt11)) and their control cells (CdM(GFP)). CdM(Wnt11), especially obtained from MSC(Wnt11) exposed to hypoxia, significantly promoted human umbilical vein endothelial cells (HUVECs) migration and increased capillary-like tube (CLT) formation, which was blocked by Wnt11 neutralizing antibody. Wnt11 protein was significantly higher in CdM(Wnt11) compared to that in CdM(GFP). Directly treating HUVECs with recombinant Wnt11 protein significantly increased CLT formation, which was abrogated by treating cells with the JNK inhibitor SP600125, as well as the PKC inhibitor Calphostin-C. Moreover, the transfection of Wnt11 to HUVECs (H(Wnt11)) significantly increased CLT formation and HUVEC migration, as well as upregulated p-pan-PKC and p-JNK expression. Injection of CdM(Wnt11) into the peri-infarct region in a rat acute myocardial infarction (AMI) model significantly improved cardiac function, reduced infarct size, and increased myocardial blood flow and blood vessel density in the ischemic area. Conclusion: Wnt11 released from MSC(Wnt11) increased angiogenesis and improved cardiac function via non-canonical Wnt-PKC-JNK dependent pathways.