A Versatile, Portable Intravital Microscopy Platform for Studying Beta-cell Biology In Vivo

• Published in: Scientific reports 2019-06, Vol.9 (1), p.8449, Article 8449
• Main Authors: Reissaus, Christopher A., Piñeros, Annie R., Twigg, Ashley N., Orr, Kara S., Conteh, Abass M., Martinez, Michelle M., Kamocka, Malgorzata M., Day, Richard N., Tersey, Sarah A., Mirmira, Raghavendra G., Dunn, Kenneth W., Linnemann, Amelia K.
• Format: Article
• Language: English
• Subjects: 14/19; 14/69; 42/44; 631/1647/767; 692/163/2743; Animals; Beta cells; Biosensing Techniques; Biosensors; Calcium Signaling - genetics; Calcium Signaling - immunology; Calcium signalling; Cytology; Diabetes mellitus; Disease Models, Animal; Endothelial cells; Endothelial Cells - metabolism; Endothelial Cells - pathology; Endothelial Cells - ultrastructure; Humanities and Social Sciences; Humans; Insulin-Secreting Cells - metabolism; Insulin-Secreting Cells - pathology; Insulin-Secreting Cells - ultrastructure; Intravital Microscopy - methods; Islets of Langerhans - metabolism; Islets of Langerhans - pathology; Islets of Langerhans - ultrastructure; Islets of Langerhans Transplantation; Mice; Microscopy; multidisciplinary; Pancreas; Physiology; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-44777-0

The pancreatic islet is a complex micro-organ containing numerous cell types, including endocrine, immune, and endothelial cells. The communication of these systems is lost upon isolation of the islets, and therefore the pathogenesis of diabetes can only be fully understood by studying this organized, multicellular environment in vivo . We have developed several adaptable tools to create a versatile platform to interrogate β-cell function in vivo . Specifically, we developed β-cell-selective virally-encoded fluorescent protein biosensors that can be rapidly and easily introduced into any mouse. We then coupled the use of these biosensors with intravital microscopy, a powerful tool that can be used to collect cellular and subcellular data from living tissues. Together, these approaches allowed the observation of in vivo β-cell-specific ROS dynamics using the Grx1-roGFP2 biosensor and calcium signaling using the GcAMP6s biosensor. Next, we utilized abdominal imaging windows (AIW) to extend our in vivo observations beyond single-point terminal measurements to collect longitudinal physiological and biosensor data through repeated imaging of the same mice over time. This platform represents a significant advancement in our ability to study β-cell structure and signaling in vivo , and its portability for use in virtually any mouse model will enable meaningful studies of β-cell physiology in the endogenous islet niche.