Project description:miRNA expression was compared in skin from control newborn mice and littermate mice ectopically expressing the potent secreted WNT inhibitor Dickkopf 1 (DKK1) in the epidermis. DKK1 completely suppresses hair follicle development. Multiple miRNAs were identified that reproducibly produced signals above background in both types of skin sample. Several miRNAs were identified for which hybridization signals were on average more than 2.5 fold higher in control samples than in Dkk1-expressing samples, suggesting these may be upregulated in hair follicles, and/or are direct or indirect targets of WNT inhibition in the skin. Keywords: miRNA expression array, transgenic mouse, skin, WNT Low molecular weight RNA was isolated using the mirVana RNA extraction kit (Ambion) from full thickness dorsal skin of three K5-rtTA; tetO-Dkk1 newborn mice and three control littermates following doxycycline treatment from E0.5 to induce expression of Dkk1 in double transgenic epidermis [1]. Control and Dkk1âexpressing transgenic samples were tagged for labeling with Cy3 and Cy5 dyes respectively using the Ncode miRNA Labeling System (Invitrogen), mixed by equal mass, and co-hybridized to miRNA arrays that have been described previously [2]. Background-corrected median signals for pixels from each probe spot in both the Cy3 and Cy5 channels were used for analysis. Cy3 (control samples C2, C4, C5) was detected at 532nm and Cy5 (Dkk1âexpressing transgenic samples TG1, TG2, TG4) at 635 nm. References: [1] Chu, E.Y., Hens, J., Andl, T., Kairo, A., Yamaguchi, T.P., Brisken, C., Glick, A., Wysolmerski, J.J., and Millar, S.E. (2004). Canonical WNT signaling promotes mammary placode development and is essential for initiation of mammary gland morphogenesis. Development 131, 4819-4829. [2] Nelson, P.T., Baldwin, D.A., Scearce, L.M., Oberholtzer, J.C., Tobias, J.W., and Mourelatos, Z. (2004). Microarray-based, high-throughput gene expression profiling of microRNAs. Nat Methods 1, 155-161.
2010-06-11 | E-GEOD-4723 | biostudies-arrayexpress
