The pancreatic islets of Langerhans consist of endocrine cells that secrete peptide hormones into the blood circulation in response to metabolic stimuli. When transplanted into the anterior chamber of the eye (ACE), pancreatic islets engraft and maintain morphological features of native islets as well as islet‐specific vascularization and innervation patterns. In sufficient amounts, intraocular islets are able to maintain glucose homeostasis in diabetic mice. Islet organoids (pseudo-islets), which are formed by self‐reassembly of islet cells following disaggregation and genetic manipulation, behave similarly to native islets. Here, we tested the hypothesis that genetically engineered intraocular islet organoids can serve as production sites for leptin. To test this hypothesis, we chose the leptin‐deficient ob/ob mouse as a model system, which becomes severely obese, hyperinsulinemic, hyperglycemic, and insulin resistant. We generated a Tet‐OFF‐based beta‐cell‐specific adenoviral expression construct for mouse leptin, which allowed efficient transduction of native beta‐cells, optical monitoring of leptin expression by co‐expressed fluorescent proteins, and the possibility to switch‐off leptin expression by treatment with doxycycline. Intraocular transplantation of islet organoids formed from transduced islet cells, which lack functional leptin receptors, to ob/ob mice allowed optical monitoring of leptin expression and ameliorated their metabolic phenotype by improving bodyweight, glucose tolerance, serum insulin, and C‐peptide levels.
Bibliographical noteFunding Information:
Funding: This research was funded by Karolinska Institutet, Swedish Research Council, The Erling‐ Persson Family Foundation, the Novo Nordisk Foundation, the Stichting af Jochnick Foundation, Di‐ abetesfonden (Sweden), Scandia Insurance Company Limited, the Diabetes Research and Wellness Foundation, the Berth von Kantzows Foundation, the Strategic Research Program in Diabetes at Ka‐ rolinska Institutet, the European Research Council grant number ERC‐2018‐AdG 834860 EYELETS, the Swedish Foundation for Strategic Research and the Knut and Alice Wallenbergs Foundation.
© 2021 by the authors. Licensee MDPI, Basel, Switzerland.
- In vivo imaging
- Pancreatic islets
- Viral transduction