Background and purpose: Obesity is becoming a major global health issue and is mainly induced by the accumulation of adipose tissues mediated by adipogenesis, which is reported to be regulated by peroxisome proliferator-activated receptor γ (PPARγ) and CCAAT enhancer-binding protein α (C/EBPα). Trichostatin A (TSA) is a novel histone deacetylase inhibitor (HDACI) that was recently reported to exert multiple pharmacological functions. The present study will investigate the inhibitory effect of TSA on adipogenesis, as well as the underlying mechanism.

Methods: The adipogenesis of 3T3-L1 cells was induced by stimulation with a differentiation cocktail (DMI) medium for 8 days. MTT assay was used to measure the cell viability and Oil Red O staining was used to evaluate the adipogenesis of 3T3-L1 cells. The total level of triglyceride and released glycerol were detected to evaluate the lipolysis during 3T3-L1 adipogenesis. The expression levels of Leptin, fatty acid-binding protein 4 (FABP4), and sterol regulatory element-binding protein (SREBP1C) were determined by qRT-PCR. qRT-PCR assay was utilized to detect the expression levels of PPARγ and C/EBPα in 3T3-L1 cells. A high-fat diet (HFD) was used to construct an obese mice model, followed by the treatment with TSA. HE staining was conducted to evaluate the pathological state of adipose tissues. Body weights and the weights of adipose tissues were recorded to evaluate the anti-obesity property of TSA.

Results: Firstly, the promoted lipid accumulation induced by DMI incubation was significantly reversed by the treatment with TSA in a dose-dependent manner. The elevated expression levels of Leptin, FABP4, SREBP1C, PPARγ, and C/EBPα induced by the stimulation with DMI incubation were dramatically inhibited by the introduction of TSA, accompanied by the upregulation of phosphorylated AMP-activated protein kinase (p-AMPK). Secondly, the inhibitory effect of TSA against the expression level of PPARγ and lipid accumulation was greatly abolished by an AMPK inhibitor. Lastly, the increased body weights and visceral adipocyte tissue weight, as well as the enlarged size of adipocytes induced by HFD were pronouncedly reversed by the administration of TSA.

Conclusion: TSA inhibited adipogenesis in 3T3-L1 preadipocytes by activating the AMPK pathway.