p2rx3 Knockout Mice Have Altered Energy Metabolism in Hippocampal Neurons

The hippocampus is a key component of the brain that is associated with the formation of longterm memory, the energy metabolism of neurons playing a pivotal role in its mechanisms. The P2X3 receptor in the hippocampus is considered an attractive target when searching for novel biologically active substances that could work to reduce anxiety, epileptic conditions, and improve cognitive functions. In this work, the intensity of mitochondrial respiration, the glycolytic capacity, and the energy phenotype of hippocampal neurons were studied in p2rx3 knockout mice. The p2rx3 knockout mice were engineered by genome editing using the CRISPR/Cas9 system. The primary mixed culture of hippocampal neurons was derived from two-day-old newborn mice with the p2rx3^-/- and p2rx3^+/- genotypes. Mitochondrial respiration was measured on a Seahorse Bioscience HS mini Cell Metabolism Analyzer (Agilent, USA) using the appropriate kits for the Mitostress test, glycotest, and energy phenotype assessment test. The transgenic mice with the p2rx3^-/- genotype were characterized by an aerobic type of mitochondrial respiration, an increase in ATP production by 84.4% (p < 0.05), an increase in maximum respiration by 72.3% (p < 0.05), and a 36% (p < 0.05) increase in the respiratory reserve. Meanwhile, the spare respiratory capacity of mitochondria, the rate of glycolysis, and the glycolytic capacity in these mice were reduced by 36.6, 75.7 and 78.6% (p < 0.05), respectively. Our findings indicate that mitochondria work at close to maximum energy capacity. The p2rx3 knockout animals are a unique model for the search for pharmacological targets that can help correct the energy metabolism of brain cells and eliminate cognitive dysfunctions.