L-selenomethionine is metabolized by cystathionine gamma-lysase. Dysregulation of cystathionine gamma-lyase would dysregulate selenoprotein synthesis from L-selenomethionine, which is the food form of selenium. In the N171-82Q Huntington’s disease mouse model various selenoprotein levels are changed compared to controls. Changed levels of selenoproteins in the N171-82Q Huntington’s disease mouse model compared to controls could be due to dysregulation of cystathionine gamma-lyase.
Supplemental Se-methylselenocysteine could be useful in the treatment of Huntington’s disease as metabolism of Se-methylselenocysteine does not depend on cystathionine gamma-lyase. Se-methylselenocysteine is metabolized by kynurenine aminotransferase 1. Supplementation of Se-methylselenocysteine taken alone would be far from a completely effective treatment for Huntington’s disease as decreases in cystathionine gamma-lyase would dysregulate various pathways downstream from the transsulfuration pathway. Se-methylselenocysteine could be of assistance in the treatment of cognitive symptoms of Huntington’s disease. Se-methylselenocysteine taken daily in two divided dosages is more effective than Se-methylselenocysteine taken once daily.