Opposite Actions of Transforming Growth Factor-β1 on the Gene Expression of Atrial Natriuretic Peptide Biological and Clearance Receptors in a Murine Thymic Stromal Cell Line

• Published in: Journal of biochemistry (Tokyo) 1995-09, Vol.118 (3), p.500-507
• Main Authors: Agui, Takashi, Xin, Xiaonan, Cai, Yiqiang, Shim, Giljin, Muramatsu, Youji, Yamada, Takahisa, Fujiwara, Hiromi, Matsumotoup, Kozo
• Format: Article
• Language: English
• Subjects: atrial natriuretic peptide receptor; gene expression; thymic stromal cell; transforming growth factor
• ISSN: 0021-924X
• DOI: 10.1093/oxfordjournals.jbchem.a124936

The regulation of the gene expression of the atrial natriuretic peptide receptor (ANPR)subtypes, ANPR-A, ANPR-B, and ANPR-C, was investigated in a murine thymic stromal cell line, MRL 104.8a. When MRL 104.8a cells were cultured with transforming growth factor (TGF)-β1,[126I]ANP binding sites increased with increasing dose of TGF-β. These binding sites were identified as ANPR-C by a displacement experiment with ANPR-C-specific ligand, C-ANF, and by the affinity cross-linking of the [125I] ANP binding sites with a chemical cross-linker to determine the molecular weight of the ANPR. This augmentation of the ANPR-C expression was elucidated to occur at the transcriptional level by Northern blot experiment, comparison of the relative amounts of mRNA by reverse transcription (RT)-PCR, and in vitro nuclear transcription assay. Conversely, the expression of the ANP biological receptors, ANPR-A and ANPR-B, was shown to be down-regulated by TGF-β1. These data suggest that TGF-β1regulates the gene expression of ANPRs in the thymic stromal cells and that ANP and TGF-β1might affect the thymic stromal cell functions.