Mechanism of Wendan decoction in preventing obesity by regulating multiple signal pathway networks based on gene promoter methylation

Abstract

Objective: To investigate the potential mechanism of Wendan decoction in obesity by screening target genes with promoter region methylation changes and constructing a multiple signaling pathways network based on promoter methylation. Methods: The methylation degree of Itgad, Col8a1, Adra2b, Jund, Rab2a, Wnt8b, Fzd9, B4galt7, Pik3cd, Creb1, Stard8, and Mmp1 in the abdominal adipose tissue of obese rats was determined using the Agena MassARRAY system. Western blot was performed to assess protein expression levels. Target genes were identified based on the methylation degree in the promoter region and protein expression. Enrichment analysis of signaling pathways was conducted to identify relevant target genes and obtain a multiple signaling pathway network associated with obesity. Core and terminal effector molecules in the pathway networks were selected as research targets for reverse transcription-polymerase chain reaction (RT-PCR) analysis. Results: Four genes (Adra2b, Creb1, Itgad, and Pik3cd) showed a degree of promoter methylation consistent with their respective protein expression levels. Among them, Adra2b, Creb1, and Pik3cd expression increased, while that of Itgad decreased. Enrichment analysis revealed that Creb1 and Pik3cd were involved in 6 signaling pathways related to obesity: tumor necrosis factor (TNF) signaling pathway, growth hormone synthesis/secretion and action, adenosine 5′-monophosphate-activated protein kinase (AMPK) signaling pathway, relaxin signaling pathway, cyclic nucleotide (cAMP) signaling pathway, and phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling pathway. Subsequently, a multiple signaling pathways network was constructed based on promoter methylation. Key molecules including protein kinase B (AKT), mechanistic target of rapamycin complex 1 (mTORC1), and unc-51 like autophagy activating kinase 1 (ULK1), as well as terminal effector molecules interleukin-1β (IL-1β), interleukin-6 (IL-6), and chemokine (C-X-C motif) ligand 2 (CXCL2) were selected as research targets. Wendan decoction decreased the expressions of AKT, mTORC1, IL-1β, IL-6, and CXCL2 while up-regulating ULK1 expression. Conclusion: The mechanism of Wendan decoction in preventing obesity involves the regulation of multiple signaling pathways through the control of Creb1 and Pik3cd gene promoter methylation. However, the associated multi-path gene regulation mechanism in preventing obesity is complex. Thus, further exploration is needed to elucidate the role of methylation changes in this mechanism.

Keywords

• Wendan decoction
• Obesity
• Signal pathway
• Methylation