Glucagon-Secreting Alpha Cell Selective Two-Photon Fluorescent Probe TP-α: For Live Pancreatic Islet Imaging

• Published in: Journal of the American Chemical Society 2015-04, Vol.137 (16), p.5355-5362
• Main Authors: Agrawalla, Bikram Keshari, Chandran, Yogeswari, Phue, Wut-Hmone, Lee, Sung-Chan, Jeong, Yun-Mi, Wan, Si Yan Diana, Kang, Nam-Young, Chang, Young-Tae
• Format: Article
• Language: English
• Subjects: Animals; Cell Line; Cell Survival; Fluorescent Dyes - chemistry; Glucagon-Secreting Cells - cytology; Mice; Microscopy, Fluorescence, Multiphoton - methods; Optical Imaging - methods
• ISSN: 0002-7863; 1520-5126
• DOI: 10.1021/ja5115776

Two-photon (TP) microscopy has an advantage for live tissue imaging which allows a deeper tissue penetration up to 1 mm comparing to one-photon (OP) microscopy. While there are several OP fluorescence probes in use for pancreatic islet imaging, TP imaging of selective cells in live islet still remains a challenge. Herein, we report the discovery of first TP live pancreatic islet imaging probe; TP-α (Two Photon-alpha) which can selectively stain glucagon secreting alpha cells. Through fluorescent image based screening using three pancreatic cell lines, we discovered TP-α from a TP fluorescent dye library TPG (TP-Green). In vitro fluorescence test showed that TP-α have direct interaction and appear glucagon with a significant fluorescence increase, but not with insulin or other hormones/analytes. Finally, TP-α was successfully applied for 3D imaging of live islets by staining alpha cell directly. The newly developed TP-α can be a practical tool to evaluate and identify live alpha cells in terms of localization, distribution and availability in the intact islets.