Intraventricular Injection of LKB1 Inhibits the Formation of Diet-Induced Obesity in Rats by Activating the AMPK-POMC Neurons-Sympathetic Nervous System Axis

Abstract

Background/Aims: Obesity is increasingly becoming a major public health problem worldwide. Peripheral LKB1 inhibits white fat generation, but the effect of central LKB1 on diet-induced obesity (DIO) is unknown. Therefore, we examined whether LKB1 over-expression in the hypothalamus can inhibit the development of obesity. Methods: Adult male Sprague-Dawley rats were anesthetized and placed in a stereotaxic apparatus. LKB1-AAV-EGFP (2.0 × 108 or 2.0 × 1010 vector genomes) or Control-AAV-EGFP (2.0 × 108 vector genomes) was injected into the third ventricle. After administration, the rats were fed a high-fat diet (HFD) for 9 weeks to induce obesity. Rats fed a chow fat diet were used as normal controls. Results: LKB1 delivery decreased body weight, energy intake, fat mass, and serum lipid levels. LKB1 also improved HFD-induced hepatic fatty degeneration. Interestingly, LKB1 over-expression in the hypothalamus activated the AMPK-POMC neurons-sympathetic nervous system (SNS) axis, which can release epinephrine to promote white fat browning. Conversely, the elevated expression of MC3R/MC4R inhibited food intake. These two factors worked together to inhibit the development of obesity. Conclusions: LKB1 in the hypothalamus may have therapeutic potential for DIO through the activation of the AMPK-POMC neurons-SNS axis.