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

Abstract

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.

Keywords: Wnt-PKC-JNK pathways; Wnt11; angiogenesis; ischemic myocardium; mesenchymal stem cells.