The National Institutes of Health, Bethesda, have found out that mice having reduced levels of Sphk2 (Sphk1-/-Sphk2+/- mice) and lack of protein known as Sphingosine kinase were found to be infertile. The discovery has provided a key reason for early pregnancy loss in humans.
Female mice lacking a protein known as sphingosine kinase 1 (Sphk1) and expressing reduced levels of Sphk2 (Sphk1-/-Sphk2+/- mice) were found to be infertile. Although embryos implanted into the womb, the womb failed to respond correctly to this — the structures that support the developing embryo before a functional placenta is established (the decidua) were defective.
In particular, there was increased death of decidual cells and breakage of decidual blood vessels, which led to hemorrhaging and early pregnancy loss. As Sphk1 and Sphk2 are involved in metabolizing a group of fats known as sphingolipids, the authors suggested that disturbances in sphingolipid metabolism might be a cause of early pregnancy loss in humans.