Minoxidil Restores Thymic Growth in 22q11.2 Deletion Syndrome by Limiting Sox9+ Chondrocyte Expansion

The study explores the effects of Minoxidil on thymic growth in a mouse model of 22q11.2 deletion syndrome (22q11.2DS), which is characterized by thymic hypoplasia. Minoxidil treatment in pregnant mice was found to limit the expansion of Sox9+ chondrocytes, leading to a restoration of thymus size and improved vascular integrity. The treatment reduced collagen and extracellular matrix (ECM) deposition, which are typically elevated in 22q11.2DS thymuses, and corrected the abnormal positioning of the parathyroid. These findings suggest that Minoxidil can reverse mesenchymal cell reprogramming, offering a potential therapeutic approach for thymic hypoplasia in 22q11.2DS. However, the treatment had limited effects on peripheral T cell lymphopenia, indicating other factors may contribute to this condition.