A research group led by Professor Takashi Shinohara of Kyoto University discovered in an experiment using model mice that sperm stem cells could be autologously transplanted to treat congenital male infertility.
Sperm stem cells continue to produce huge numbers of sperm every day.The testis is basically a structure in which tubes called elongated seminiferous tubules are connected. Prevents entry into the tube.Analysis of gene-deficient mice reveals that disruption of the blood-testis barrier results in the arrest of meiosis during spermatogenesis and the development of autoimmune diseases against sperm.
The research group focused on the Cldn11 molecule, which is essential for the construction of this blood-testis barrier. Cldn11-deficient mice are congenitally infertile with spermatogenesis arrested during meiosis. Since even blood cells cannot cross the blood-testis barrier with Cldn11, we thought that removing Cldn11 could improve the efficiency of transplantation of larger sperm stem cells.
Therefore, when the testis cells on the right side of this mouse were disintegrated and transplanted into the fine duct of the testis on the left side, spermatogenesis was restored.Cldn11 family molecules (Cldn3, Cldn5) are also expressed in the testis.Therefore, when the expression of these molecules was suppressed, spermatogenesis could be restored.Intracytoplasmic sperm injection using the sperm thus produced yielded normal offspring without foreign genes.
These results overturn the conventional view that the blood-testis barrier is required for spermatogenesis and show that even congenital infertility has a certain degree of plasticity and may restore fertility.In general, stem cell transplantation is a method of transplanting normal stem cells into a normal environment for treatment, but if it can be treated by autologous transplantation of abnormal tissue like this time, it is said that there is a similar treatment possibility in other tissues.
