Shockwaves Suppress Adipocyte Differentiation via Decrease in PPAR gamma

Abstract

Adipogenesis is a crucial cellular process that contributes to the expansion of adipose tissue in obesity. Shockwaves are mechanical stimuli that transmit signals to cause biological responses. The purpose of this study is to evaluate the effects of shockwaves on adipogenesis. We treated 3T3L-1 cells and human primary preadipocytes for differentiation with or without shockwaves. Western blots and quantitative real-time reverse transcriptase PCR (qRT-PCR) for adipocyte markers including peroxisome proliferator-activated receptor gamma (PPAR gamma) and CCAAT-enhancer-binding proteins (C/EBP alpha) were performed. Extracellular adenosine triphosphate (ATP) and intracellular cyclic adenosine monophosphate (cAMP) levels, which are known to affect adipocyte differentiation, were measured. Shockwave treatment decreased intracellular lipid droplet accumulation in primary human preadipocytes and 3T3-L1 cells after 11-12 days of differentiation. Levels of key adipogenic transcriptional factors PPAR gamma and/or C/EBP alpha were lower in shockwave-treated human primary preadipocytes and 3T3L-1 cells after 12-13 days of differentiation than in shockwave-untreated cells. Shockwave treatment induced release of extracellular ATP from preadipocytes and decreased intracellular cAMP levels. Shockwave-treated preadipocytes showed a higher level of beta-catenin and less PPAR gamma expression than shockwave-untreated cells. Supplementation with 8-bromo-cAMP analog after shockwave treatment rescued adipocyte differentiation by preventing the effect of shockwaves on beta-catenin, Wnt10b mRNA, and PPAR gamma expression. Low-energy shockwaves suppressed adipocyte differentiation by decreasing PPAR gamma. Our study suggests an insight into potential uses of shockwave-treatment for obesity.