Improvements of autism-like behaviors but limited effects on immune cell metabolism after mitochondrial replacement in BTBR TItpr3/J mice.

Mitochondria-mediated metabolic impairment and dysfunction are highly related with autism. Herein, the mitochondria-mediated metabolism of BTBR TItpr3/J (BTBR) mice with autistic-like behaviors was investigated. A new BTBR-mt strain generated by deriving BTBR mice with C57BL/6J (B6) mitochondria was used to determine the role of the mitochondrial genome. The BTBR-mt mice had improved social behaviors, higher levels of glutamate and astrocytes in the brain and less neuroinflammation than the BTBR mice; however, many of the metabolic parameters of BTBR mice such as enhanced fatty acid β-oxidation and lower glycolysis and glutaminolysis in immune cells compared to B6 mice were not or only partial improved in the BTBR-mt strain. The BTBR and BTBR-mt mice also had equivalent ETC (enhanced electron transport chain) activity of mitochondria, with an increase of reactive oxygen species (ROS) and decreased mitochondrial membrane potential compared to the B6 mice. The results suggest that the mitochondrial replacement with its metabolic alterations affect brain functions more than peripheral immune cell activities.