Ultrasensitive imaging of Ca2+ dynamics in pancreatic acinar cells of yellow cameleon-nano transgenic mice.
Yellow Cameleons are genetically encoded Ca2+ indicators in which cyan and yellow fluorescent proteins and calmodulin work together as a fluorescence (Förster) resonance energy transfer Ca2+-sensor probe. To achieve ultrasensitive Ca2+ imaging for low resting Ca2+ or small Ca2+ transients in various organs, we generated a transgenic mouse line expressing the highest-sensitive genetically encoded Ca2+ indicator (Yellow Cameleon-Nano 15) in the whole body. We then focused on the mechanism of exocytotic events mediated by intracellular Ca2+ signaling in acinar cells of the mice with an agonist and observed them by two-photon excitation microscopy. In the results, two-photon excitation imaging of Yellow Cameleon-Nano 15 successfully visualized intracellular Ca2+ concentration under stimulation with the agonist at nanomolar levels. This is the first demonstration for application of genetically encoded Ca2+ indicators to pancreatic acinar cells. We also simultaneously observed exocytotic events and an intracellular Ca2+ concentration under in vivo condition. Yellow Cameleon-Nano 15 mice are healthy and no significant deteriorative effect was observed on physiological response regarding the pancreatic acinar cells. The dynamic range of 165% was calculated from Rmax and Rmin values under in vivo condition. The mice will be useful for ultrasensitive Ca2+ imaging in vivo.
Molecular Medicine for Pathogenesis, Graduate School of Medicine, Ehime University, Toon City, Ehime 791-0295, Japan. oshima-ehm@umin.ac.jp.
Yusuke
Y
Oshima
Molecular Medicine for Pathogenesis, Graduate School of Medicine, Ehime University, Toon City, Ehime 791-0295, Japan. timamura-ind@umin.ac.jp.
Takeshi
T
Imamura
Laboratory for Spatiotemporal Regulations, National Institute for Basic Biology, Okazaki, Aichi 444-8585, Japan. ashin@ims.ac.jp.
Atsuko
A
Shintani
Laboratory for Spatiotemporal Regulations, National Institute for Basic Biology, Okazaki, Aichi 444-8585, Japan. hiroko@nibb.ac.jp.
Hiroko
H
Kajiura-Kobayashi
Laboratory of Molecular and Cellular Biophysics, Research Institute for Electronic Science, Hokkaido University, Sapporo, Hokkaido 001-0020, Japan. thibi@es.hokudai.ac.jp.
Terumasa
T
Hibi
The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan. ng1@sanken.osaka-u.ac.jp.
Takeharu
T
Nagai
Laboratory for Spatiotemporal Regulations, National Institute for Basic Biology, Okazaki, Aichi 444-8585, Japan. snonaka@nibb.ac.jp.
Shigenori
S
Nonaka
Laboratory of Molecular and Cellular Biophysics, Research Institute for Electronic Science, Hokkaido University, Sapporo, Hokkaido 001-0020, Japan. tn@es.hokudai.ac.jp.
Tomomi
T
Nemoto
D000109:Acetylcholine / Q000494:pharmacology; D061354:Acinar Cells / Q000166:cytology / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D061207:Calcium Ionophores / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D002478:Cells, Cultured; D005089:Exocytosis / Q000187:drug effects; D031541:Fluorescence Resonance Energy Transfer; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D036641:Microscopy, Fluorescence, Multiphoton; D010179:Pancreas / Q000166:cytology*; D012333:RNA, Messenger / Q000378:metabolism
D061207:Calcium Ionophores; D002135:Calcium-Binding Proteins; D012333:RNA, Messenger; C495639:yellow cameleon; D000109:Acetylcholine; D002118:Calcium