Low-intensity pulsed ultrasound induces metabolic lipolysis of adipocytes

Abstract

We used low-intensity pulsed ultrasound (LIPUS) to uncover underlying lipolysis mechanism of 3T3-L1 adipocyte. Ultrasound pulses with the center frequency of 2 MHz were applied for 10 min/day to promote the lipolysis of white adipocyte. Lipolysis is the process of breaking down lipids and the metabolic pathway through which lipid triglycerides are hydrolyzed into a glycerol and three fatty acids. The proliferation of 3T3-L1 adipocytes was detected by cell viability XXT assay, RT-PCR and Western blot. The Triglyceride Assay quantitatively measures triglycerides levels in differentiated adipocytes. LIPUS reduced the triglycerol content significantly in adipocytes. The differences between transcriptional genes and metabolites were analyzed by transcript analysis and metabolomic profiling experiments. The results of RT-PCR, and Western blot after LIPUS showed the increased lipolysis. The expression of genes related to lipolysis-related factors, ATGLand HSL, was up-regulated. In addition, cellular RNA-sequencing (RNA-Seq) showed an increase in lipolysis and adaptive immune cells under ultrasound stimulation. The algorithm and additional analysis reveals a gene network that is predicted to be associated and potentially drive adipocyte lipolysis and heterogeneity. LIPUS can promote the lipolytic capacity of 3T3-L1 cells in the differentiated state. This study provides an important experimental and theoretical basis for the clinical application of LIPUS in promoting the lipolysis of 3T3-L1 adipocytes.