The daily caloric restriction and alternate-day fasting ameliorated lipid dysregulation in type 2 diabetic mice by downregulating hepatic pescadillo 1.

Abstract

A possible link between pescadillo 1 (PES1) and lipid metabolism has been reported. However, whether PES1 is involved in the effects of daily caloric restriction (CR) and alternate-day fasting (ADF) interventions on diabetes-related lipid dysregulation is not elucidated. The current study aims are to explore the role of PES1 in effects of CR and ADF on diabetic mice and related mechanism. Eight-week-old male db/db mice with type 2 diabetes mellitus (T2DM) were randomly divided into untreated T2DM, CR and ADF groups. McArdle hepatocytes were treated with 48h high glucose (HG), 48h normal glucose (NG) and 24h HG plus 24h NG, respectively. Pes1 siRNA and overexpression plasmid were, respectively, transfected into liver cells, and AAV9-Pes1-shRNA was injected into db/db mice. After 12-week interventions, the peroxisome proliferator-activated receptor alpha (PPAR-α) and carnitine palmitoyltransferase 1A (CPT1A) levels in livers of T2DM mice were enhanced by CR and ADF interventions with reductions of hepatic and plasma triglycerides. Unexpectedly, hepatic PES1 levels were downregulated by two interventions, consistent with the results of 48h NG and 24h HG plus 24h NG-treated cells. Moreover, CPT1A level was upregulated in Pes1-siRNA-treated cells and AAV9-Pes1-shRNA injected murine livers, in contrast to Pes1 overexpression in cultured cells. Mechanistically, 48h NG or 24h HG plus 24h NG treatment increased PPAR-α binding to Pes1 promoter, suppressing the PES1 expression, thereby lowering the PES1-mediated ubiquitination of CPT1A. The present study suggests that CR and ADF may improve lipid dysregulation in diabetic mice by downregulating hepatic PES1.