Exenatide through PPARδ improved hepatic insulin resistance in patients of type 2 diabetes mellitus via suppressing pyroptosis.

Exenatide, the first glucagon-like peptide-1 receptor agonist (GLP-1RA), exerted multiple beneficial effects, including stimulating insulin secretion, slowing gastric emptying, and improving insulin resistance (IR). Our previous work demonstrated that the peroxisome proliferator-activated receptor delta (PPARδ) gene (PPARD) polymorphisms correlated with exenatide monotherapy efficacy, possibly due to the pivotal role of PPARδ in regulating IR. Specifically, PPARδ has been shown to modulate the nucleotide-binding domain and leucine-rich repeat pyrin domain-containing 3 (NLRP3) inflammasome, a key regulator of pyroptosis, thereby participating in the regulation of this inflammatory cell death pathway. However, the underlying mechanisms by which exenatide ameliorated hepatic IR in patients with type 2 Diabetes Mellitus (T2DM) remained incompletely understood. Herein, we found that exenatide suppressed pyroptosis and ameliorated hepatic IR; furthermore, it could bind to PPARδ and upregulate PPARδ protein expression both in vitro and in vivo. Notably, PPARδ knockdown abolished the protective effects of exenatide against pyroptosis and hepatic IR, whereas pharmacological activation of PPARδ enhanced these beneficial effects. Moreover, T2DM patients carrying the AA genotype at PPARD rs3777744 and exhibiting higher baseline homeostasis model assessment of insulin resistance (HOMA-IR) showed a superior response to exenatide. Collectively, our findings revealed that exenatide ameliorated hepatic IR by suppressing pyroptosis via PPARδ, underscoring the potential of PPARD rs3777744 as a biomarker for personalized exenatide therapy in T2DM.