Schematic diagram of thyroid regeneration in the spleen (left) and staining image of reconstructed thyroid tissue in the spleen (right). *Redon.
Patients undergoing total thyroidectomy typically require lifelong oral levothyroxine sodium (L-T4)*While this ** is effective in maintaining basal serum hormone levels, it falls short in restoring the dynamic, reactive regulatory capacity of triiodothyronine (T3), which is essential for critical physiological regulatory functions. Clinical data suggest that T3 deficiency increases the risk of hypertension, cardiac dysfunction, and other metabolic or mental health conditions.
Regenerative medicine, which involves the use of tissue engineering to create transplants of cells and tissues, has the potential to replace the need for hormone replacement**. However, previous experiments with autologous thyroid transplantation in animals and humans targeting muscle or subcutaneous sites have yielded unsatisfactory results. The efficiency of tissue or cell regeneration depends on a variety of factors, including the condition, location, and method of transplanting the tissue.
In a recent study published in Advanced Science, Dong's research team proposed an innovative solution to address the transplant challenge by growing a thyroid gland in the spleen. Taking advantage of the unique characteristics of the spleen structure and abundant blood**, the research team explored a new strategy for thyroid regeneration. Intrasplenic thyroid transplantation is performed without affecting the structure and function of the spleen.
Total thyroidectomy mice are grafted in the spleen with an intact network of follicles and reconstructed blood vessels. This approach successfully generalized the vascular follicular unit (AFU), resulting in a complete recovery of hormone levels in mice.
In addition, studies have shown that this method is more effective than hormone replacement in responding to physiological signals**. In addition, the long-term evaluation of the effect of hormone replacement** has proved that the thyroid gland regenerated by the spleen after total thyroidectomy completely restores the physiological homeostasis of mice, without any adverse effects***, has great potential for clinical application.
Serum hormone levels in hypothyroidism mice fully recovered within 4 weeks of receiving intrasplenic thyroid transplantation and remained stable for 16 weeks thereafter. Hormone levels in these ST mice drop immediately after splenectomy of the thyroid-containing spleen. *Redon.
The regeneration of complex organs is the most significant challenge in the field of regenerative medicine. The main obstacle to progress in this field stems from the lack of effective methods to regenerate a fully developed large-scale circulatory system in adult animals.
This circulatory system is essential to support the regeneration of the targeted organs. To address this challenge, Professor Dong Lei and his collaborators have recently proposed an innovative approach.
They take advantage of the unique structural features of the spleen, such as abundant blood**, loose internal structure, and the ability to accommodate large numbers of implanted cells and tissues, as a regenerative platform for the ectopic regeneration of complex tissues and organs in vivo.
Over the past few years, they have developed a range of technological methods to alter the spleen structure of living animals to align it with the regenerative needs of target tissues and organs. Notable achievements in their early studies included the successful regeneration of the liver within the spleen.
The concept of regenerating one organ in another introduces the prospect of a novel technological approach to the regeneration of large and complex organs that differ from traditional methods. This innovative approach has the potential to drive major breakthroughs in the field of regenerative medicine.
More information: Xue-Jiao Tian et al, Splenic thyroid regeneration restores homeostasis in thyroidectomy mice, Advanced Science (2023). doi： 10.1002/advs.202305913