BACKGROUND: It is still a matter of investigation how angiogenesis and restoration of gland perfusion determine graft function after free parathyroid autotransplantation. We provide a new animal model allowing simultaneous and repetitive in vivo assessment of angiogenesis and endocrine function of parathyroid transplants. METHODS: Fresh human parathyroid tissue from patients with secondary hyperparathyroidism was grafted into dorsal skinfold chamber preparations of athymic nude mice (CD1-nu; n=8). Equivalent pieces of the same human donor specimens were heat-inactivated and served as control grafts (n=7). RESULTS: In all animals receiving parathyroid transplants, intact human parathyroid hormone levels were detectable by species-specific enzyme-linked immunosorbent assay analysis of plasma samples on day 5 after transplantation and increased by 2.5-fold over the observation period (19 days) in contrast with controls. Plasma Ca levels revealed no differences between the groups. On day 5 after transplantation, intravital fluorescence microscopy revealed murine angiogenic microvessels sprouting along nonperfused human donor vessels, and 1 week later functional microvasculature was established in all parathyroid transplants. Histologic analysis revealed well-vascularized endocrine tissue. In contrast, control grafts were necrotic and partly resorbed; they exhibited no angiogenic activity or well-vascularized fat cells indicating fatty degeneration. In addition, species-specific Western blot analysis revealed vascular endothelial growth factor expression of parathyroid transplants rather than functional vessel density as the functional parameter of angiogenesis determining transplant function in vivo. CONCLUSION: This model may serve to understand mechanisms associated with specific parathyroid transplant angiogenesis and its significance for transplant function to optimize clinical success of autotransplantation in therapy-resistant patients.
BACKGROUND: It is still a matter of investigation how angiogenesis and restoration of gland perfusion determine graft function after free parathyroid autotransplantation. We provide a new animal model allowing simultaneous and repetitive in vivo assessment of angiogenesis and endocrine function of parathyroid transplants. METHODS: Fresh human parathyroid tissue from patients with secondary hyperparathyroidism was grafted into dorsal skinfold chamber preparations of athymic nude mice (CD1-nu; n=8). Equivalent pieces of the same humandonor specimens were heat-inactivated and served as control grafts (n=7). RESULTS: In all animals receiving parathyroid transplants, intact human parathyroid hormone levels were detectable by species-specific enzyme-linked immunosorbent assay analysis of plasma samples on day 5 after transplantation and increased by 2.5-fold over the observation period (19 days) in contrast with controls. Plasma Ca levels revealed no differences between the groups. On day 5 after transplantation, intravital fluorescence microscopy revealed murine angiogenic microvessels sprouting along nonperfused humandonor vessels, and 1 week later functional microvasculature was established in all parathyroid transplants. Histologic analysis revealed well-vascularized endocrine tissue. In contrast, control grafts were necrotic and partly resorbed; they exhibited no angiogenic activity or well-vascularized fat cells indicating fatty degeneration. In addition, species-specific Western blot analysis revealed vascular endothelial growth factor expression of parathyroid transplants rather than functional vessel density as the functional parameter of angiogenesis determining transplant function in vivo. CONCLUSION: This model may serve to understand mechanisms associated with specific parathyroid transplant angiogenesis and its significance for transplant function to optimize clinical success of autotransplantation in therapy-resistant patients.
Authors: Abiramy Jeyagaran; Chuan-En Lu; Aline Zbinden; Andreas L Birkenfeld; Sara Y Brucker; Shannon L Layland Journal: Adv Drug Deliv Rev Date: 2022-08-21 Impact factor: 17.873
Authors: Timon Hussain; Donata Gellrich; Svenja Siemer; Christoph A Reichel; Jonas Eckrich; Dimo Dietrich; Shirley K Knauer; Roland H Stauber; Sebastian Strieth Journal: Tissue Eng Regen Med Date: 2021-01-30 Impact factor: 4.169