Wnt5a increases cardiac gene expressions of cultured human circulating progenitor cells via a PKC delta activation.
BACKGROUND
Wnt signaling controls the balance between stem cell proliferation and differentiation and body patterning throughout development. Previous data demonstrated that non-canonical Wnts (Wnt5a, Wnt11) increased cardiac gene expression of circulating endothelial progenitor cells (EPC) and bone marrow-derived stem cells cultured in vitro. Since previous studies suggested a contribution of the protein kinase C (PKC) family to the Wnt5a-induced signalling, we investigated which PKC isoforms are activated by non-canonical Wnt5a in human EPC.


RESULTS
Immunoblot experiments demonstrated that Wnt5a selectively activated the novel PKC isoform, PKC delta, as evidenced by phosphorylation and translocation. In contrast, the classical Ca(2+)-dependent PKC isoforms, PKC alpha and beta2, and one of the other novel PKC isoforms, PKC epsilon, were not activated by Wnt5a. The PKC delta inhibitor rottlerin significantly blocked co-culture-induced cardiac differentiation in vitro, whereas inhibitors directed against the classical Ca(2+)-dependent PKC isoforms or a PKC epsilon-inhibitory peptide did not block cardiac differentiation. In accordance, EPC derived from PKC delta heterozygous mice exhibited a significant reduction of Wnt5a-induced cardiac gene expression compared to wild type mice derived EPC.


CONCLUSIONS
These data indicate that Wnt5a enhances cardiac gene expressions of EPC via an activation of PKC delta.
Koyanagi
Masamichi
M
Institute of Cardiovascular Regeneration, Center for Molecular Medicine, JW Goethe University, Frankfurt, Germany.
Iwasaki
Masayoshi
M
Haendeler
Judith
J
Leitges
Michael
M
Zeiher
Andreas M
AM
Dimmeler
Stefanie
S
D000818:Animals; D001854:Bone Marrow Cells / Q000166:cytology; D018920:Coculture Techniques; D004789:Enzyme Activation; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology; D051379:Mice; D008954:Models, Biological; D051745:Protein Kinase C-delta / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis* / Q000502:physiology*; D051381:Rats; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology*; D051153:Wnt Proteins / Q000096:biosynthesis* / Q000502:physiology*; D000071818:Wnt-5a Protein
D011518:Proto-Oncogene Proteins; C085389:WNT5A protein, human; D051153:Wnt Proteins; D000071818:Wnt-5a Protein; D051745:Protein Kinase C-delta