Effects of Lyrm1 knockdown on mitochondrial function in 3 T3-L1 murine adipocytes

Abstract

To explore the effects of Lyrm1 knockdown on the mitochondrial function of 3 T3-L1 adipocytes using small interfering RNA (siRNA). 3 T3-L1 preadipocytes were infected with either a negative control (NC) expression lentivirus or a Lyrm1-shRNA expression lentivirus and induced to differentiate. The knockdown efficiency of Lrym1-specific shRNA in 3 T3-L1 cells was evaluated by real-time PCR. The ultrastructure of the mitochondria in adipocytes was visualized using transmission electron microscopy after differentiation. The levels of mitochondrial DNA copy numbers and Ucp2 mRNA were detected by real-time quantitative PCR. The levels of ATP production was detected using a photon-counting luminometer. The mitochondrial membrane potential and ROS levels of cells were analyzed with a FACScan flow cytometer using Cell Quest software. Cells transfected with lentiviral-Lyrm1-shRNA showed a significantly reduced transcription of Lyrm1 mRNA compared with NC cells. The size and ultrastructure of mitochondria in Lyrm1 knockdown adipocytes was similar to those of the NC cells. There was no significant difference in mtDNA copy number between the two groups. The total level of ATP production, mitochondrial membrane potential and Ucp2 mRNA expression levels were dramatically increased in adipocytes transfected with Lyrm1 RNAi. Furthermore, the level of ROS was dramatically decreased in Lyrm1 knockdown adipocytes. Knockdown of the Lyrm1 gene in adipocytes resulted in dramatically increased cellular ATP production, mitochondrial membrane potentials and levels Ucp2 mRNA, while ROS levels were significantly decreased. These results imply that mitochondrial function is improved in adipocytes after the knockdown of Lyrm1.