Research article

Wnt and Frizzled RNA expression in human mesenchymal and embryonic (H7) stem cells

Ujunwa C Okoye¹ , Craig C Malbon² and Hsien-yu Wang³

¹  Department of Pharmacology, Undergraduate Pharmacology Program, School of Medicine, State University of New York at Stony Brook, Stony Brook, NY 11794-8661, USA

²  Department of Pharmacology, Diabetes & Metabolic Diseases Research Center, School of Medicine, State University of New York at Stony Brook, Stony Brook, NY 11794-8661, USA

³  Department of Physiology & Biophysics, School of Medicine, State University of New York at Stony Brook, Stony Brook, NY 11794-8661, USA

author email corresponding author email

Journal of Molecular Signaling 2008, 3:16doi:10.1186/1750-2187-3-16

Published:	26 September 2008

Abstract

Background

Wnt signals are important for embryonic stem cells renewal, growth and differentiation. Although 19 Wnt, 10 Frizzled genes have been identified in mammals, their expression patterns in stem cells were largely unknown.

Results

We conducted RNA expression profiling for the Wnt ligands, their cellular receptors "Frizzleds" and co-receptors LRP5/6 in human embryonic stem cells (H7), human bone marrow mesenchymal cells, as well as mouse totipotent F9 teratocarcinoma embryonal cells. Except failing to express Wnt2 gene, totipotent F9 cells expressed RNA for all other 18 Wnt genes as well as all 10 members of Frizzled gene family. H7 cells expressed RNA for each of the 19 Wnt genes. In contrast, human mesenchymal cells did not display detectable RNA expression of Wnt1, Wnt8a, Wnt8b, Wnt9b, Wnt10a, and Wnt11. Analysis of Frizzled RNAs in H7 and human mesechymal cells revealed expression of 9 members of the receptor gene family, except Frizzled8. Expression of the Frizzled co-receptor LRP5 and LRP6 genes were detected in all three cell lines. Human H7 and mouse F9 cells express nearly a full complement of both Wnts and Frizzleds genes. The human mesenchymal cells, in contrast, have lost the expression of six Wnt ligands, i.e. Wnt1, 8a, 8b, 9b, 10a and 11.

Conclusion

Puripotent human H7 and mouse F9 embryonal cells express the genes for most of the Wnts and Frizzleds. In contrast, multipotent human mesenchymal cells are deficient in expression of Frizzled-8 and of 6 Wnt genes.