Identification of the functional expression of adenosine A sub(3) receptor in pancreas using transgenic mice expressing jellyfish apoaequorin

• Published in: Transgenic research 2007-08, Vol.16 (4), p.429-435
• Main Authors: Yamano, Kazuya, Mori, Katsuhiro, Nakano, Ryosuke, Kusunoki, Machi, Inoue, Miho, Satoh, Mitsuo
• Format: Article
• Language: English
• ISSN: 0962-8819
• DOI: 10.1007/s11248-007-9084-0

To investigate the functional expression of adenosine A sub(3) receptor (A3AR) in mammalian living tissues, we generated an apoaequorin-transgenic mouse that expresses jellyfish apoaequorin throughout its body. The expression of apoaequorin under the control of a strong CAG promoter was detected in various tissues, including the abdominal skin, adipose, ear, brain, esophagus, heart, inferior vena cava vessel, kidney, lens, liver, lung, pancreas, skeletal muscle, spleen, tail, testis, and thymus. The transgene was mapped to the C1-2 region of chromosome 16 by Fluorescence in situ hybridization analysis. Among these transgenic mouse tissues, we succeeded in detecting elevated responses of intracellular Ca super(2+) as a light emission of aequorin induced by the A3AR agonist in the pancreas, brain, and testis, the last two of which are known to be main tissues abundantly expressing A3AR. The A3AR agonist led to the phosphorylation of both extracellular signal-regulated kinase 1/2 and protein kinase B in mouse pancreas, and all the intracellular responses via A3AR were antagonized by the A3AR-specific antagonist. In addition, the mRNA expression of A3AR and the A3AR-induced intracellular responses were also found in the rat pancreatic acinar cell line AR42J. These results suggest that pancreas is one of the main tissues functionally expressing A3AR in mammalians in vivo, and that the present approach using transgenic mice that express apoaequorin throughout their bodies will facilitate the functional analysis of proteins of interest.