Effect of 1,25-dihydroxyvitamin D 3 on spontaneous calcium responses in rat dental epithelial SF2 cells revealed by long-term imaging

• Published in: Biomedical research (Tokyo) Vol. 37; no. 6; p. 329
• Main Authors: Murata, Kaori, Takahashi, Ayumi, Morita, Takao, Nezu, Akihiro, Fukumoto, Satoshi, Saitoh, Masato, Tanimura, Akihiro
• Format: Journal Article
• Language: English
• Published: Japan 2016
• Subjects: Animals; Calcium - metabolism; Calcium Signaling - drug effects; Cell Line; Epithelial Cells - drug effects; Epithelial Cells - metabolism; Gene Expression; Genes, Reporter; Humans; Molecular Imaging; Rats; Vitamin D - analogs & derivatives; Vitamin D - pharmacology
• ISSN: 1880-313X
• DOI: 10.2220/biomedres.37.329

Genetically encoded calcium indicators (GECIs) are suitable for long-term imaging studies. In this study, we employed a highly sensitive GECI, G-GECO, and achieved efficient gene delivery with an adenoviral vector. The adenoviral vector allowed us to express G-GECO in more than 80% of cells. More than 80% of G-GECO-expressing cells showed an ATP-induced increase in fluorescence intensity due to Ca release from intracellular stores and subsequent Ca entry. The fluorescence intensity of these cells was increased more than 2-fold by stimulation with 10 μM ATP. We applied long-term imaging (for ~10 h) to monitor Ca responses in SF2, a rat dental epithelial cell line, in culture conditions. SF2 cells showed intermittent rises in the intracellular Ca concentration in the presence of 100 nM 1,25-dihydroxyvitamin D . Many of these Ca responses began at a specific location in the cytoplasm and spread throughout the entire cytoplasm. The combination of efficient gene delivery with an adenoviral vector and long-term imaging with a highly sensitive GECI enabled detection of intermittent Ca responses that occur only 3-10 times/h/100 cells. This method could be useful to study the effects of Ca responses for regulating longterm processes, such as gene expression, cell migration, and cell division, in many cell types.