121 Transplantation and Non-Invasive Longitudinal in Vivo Imaging of Parathyroid Cells – A Proof-of-Concept Study

Abstract Background The parathyroid cell is a vital regulator of extracellular calcium levels, operating through the secretion of parathyroid hormone (PTH). Despite its importance, the regulation of PTH secretion remains complex and not fully understood, representing a unique interplay between extracellular calcium, intracellular calcium, and hormone secretion. One significant challenge in parathyroid research has been the difficulty in maintaining cells ex vivo for in-depth cellular investigations. Methods We introduce a novel platform for parathyroid cell transplantation and non-invasive in vivo imaging using the anterior chamber of the eye as a transplantation site. Results We found that parathyroid tissue transplanted into the mouse eye engrafted onto the iris, became vascularized, and retained cellular composition. Transplanted animals exhibited elevated PTH levels, indicating a functional graft. With in vivo confocal microscopy, we were able to repetitively monitor parathyroid graft morphology and vascularization. Conclusions In summary, there is a pressing need for new methods to study complex cellular processes in parathyroid cells. Our study provides a novel approach for non-invasive in vivo investigations that can be applied to understand parathyroid physiology and pathology under physiological and pathological conditions. This innovative strategy can deepen our knowledge on parathyroid function and disease.