Mitochondrial Dysfunction in Primary Mixed Culture of Hippocampal Neurons in the Hprt1del8Val Mouse Model
摘要
Biochemical processes in the brain are closely linked to purinemetabolism. Cells synthesize purines de novo or by recycling decayproducts with the participation of the enzyme hypoxanthine guaninephosphoribosyltransferase (HGPRT), which catalyzes the recyclingof purines via the salvage pathway. Deficiency of HGPRT leads tochanges in mitochondrial respiration. The aim of the work was tostudy the mitochondrial bioenergetics of the primary mixed cultureof hippocampal neurons on a strain of mice with a patient-specificmutation in the Hprt1 del8Val gene.The study established a violation of the mitochondrial bioenergeticsof the primary mixed culture of hippocampal neurons both at the stageof embryonic and postnatal development. A bioenergetic index ofcellular health was calculated based on data obtained during a mitochondrialstress test, during which known inhibitors of cellular respirationwere sequentially added to the cell culture to assess the mitochondrialprofile and the cell’s ability to produce energy. The BioenergeticIndex of Cellular Health combines mitochondrial functional parameterssuch as ATP-coupled respiration, maximum respiratory capacity, protonleak and non-mitochondrial respiration into a single value. This studyimpaired mitochondrial bioenergetics in a primary mixed cultureof hippocampal neurons during both embryonic and postnatal development.A decrease in mitochondrial respiratory reserve in the embryonicperiod in mice with a mutation in the Hprt1 del8Val genewas accompanied by a decrease in ATP production. In the cultureof postnatal neurons ATP production decreased while non-mitochondrial respirationincreased. The bioenergetic index of cellular health in the P2 cultureis reduced compared to the E18 culture. The dysfunctions in mitochondrial bioenergeticsreveal new mechanisms in understanding the molecular nature underlyingthe development of severe neurological phenotypes associated withimpaired purine metabolism in the brain. Mice with a patient-specificmutation in the Hprt1 del8Val geneare a unique model with altered energy homeostasis making them areliable tool for finding therapeutic targets aimed at correctingmetabolic disorders in Lesch–Nyhan syndrome.