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Wnt'er in Mouse Liver
Author(s) -
Awan Farrukh,
Otruba Wade,
Muller Peggy,
Zeng Gang,
Monga Satdarshan P.S.
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.a1089-c
Subject(s) - wnt signaling pathway , hepatic stellate cell , frizzled , biology , microbiology and biotechnology , lrp5 , receptor , liver cytology , lrp6 , medicine , endocrinology , signal transduction , biochemistry , liver metabolism
Wnt/β‐catenin pathway has been implicated in cancers of the colon, lung, ovary, breast, and liver. Wnts are extracellular ligands that bind to ‘frizzled’ membrane receptors and eventually induce β‐catenin nuclear translocation. Although 19 Wnts & 11 frizzled receptors are known, their expression in liver is unknown. We report a comprehensive investigation of their expression in liver by reverse transcription (RT)‐PCR. Oligonucleotides for the 19 Wnts and 11 frizzled genes were synthesized based on the available sequence. All primer combinations except Wnt‐6 worked efficaciously. Gene expression was assessed in whole mouse livers as well as in various mouse liver cells including freshly isolated (active) or plated (resting) hepatocytes, biliary epithelial cells and resting and activated stellate and Kupffer cells. Wnt‐10a, 16, 3a and 9a were absent in normal liver, however, while Wnt‐3a was observed in active hepatocytes only, Wnt‐9a was observed in hepatocytes and resting stellate/Kupffer cells. In addition, Wnts 7a, 7b, 8a, 8b & 11 were observed in freshly isolated hepatocytes and disappeared upon plating. All Wnts except 3a, 5b, 9a, 9b & 10b were expressed in biliary epithelial cells. Lastly, Wnt‐7a was absent in resting stellate cells and appeared in activated stellate cells, while all other Wnts were uniformly present in stellate cells. All 11 frizzleds were expressed in resting and activated hepatocytes except fz‐b and fz‐10, which were present only in the latter. All frizzled genes were expressed in stellate and biliary epithelial cells except Fz‐b, which was absent in the latter. These data indicate that majority of Wnt and frizzled genes are expressed in mouse liver and might be capable of initiating β‐catenin signaling, which plays an important role in liver pathobiology. (Supported by RSG‐03‐141‐01‐CNE to SPSM).