Ectopic expression of porcine peroxisome proliferator-activated receptor δ regulates adipogenesis in mouse myoblasts
Journal
Journal of Animal Science
Journal Volume
86
Journal Issue
1
Pages
64-72
Date Issued
2008
Author(s)
Abstract
Peroxisome proliferator-activated receptor γ (PPARγ) plays a critical role in regulating adipogenesis. The expression of peroxisome proliferatoractivated receptor δ (PPARδ) precedes that of PPARγ during adipocyte differentiation in rodents. The current experiment was designed to study the function of porcine PPARδ and the interaction of PPARδ and PPARγ in adipocyte differentiation. Inhibition of myogenesis was observed in mouse myoblasts expressing porcine PPARδ, similar to myoblasts expressing PPARγ. Treatment of myoblasts expressing PPARδ with ligands for both PPARδ and PPARγ enhanced lipogenesis and adipogenesis to a greater extent than treatment with a PPARγ ligand alone, suggesting that both genes were involved in regulating lipogenesis and adipogenesis. The ability to transdifferentiate myoblasts into adipocytes was decreased in myoblasts coexpressing PPARδ with either wild type or mutated PPARγ (Ser 112 was mutated to Ala; the mutated PPARγ is more active than the wild type) compared with myoblasts expressing PPARγ alone. Adipocyte differentiation in myoblasts coexpressing PPARδ and mutated PPARγ was greater than in myoblasts coexpressing PPARδ and wild type PPARγ, confirming that Ser 112 is important for the function of PPARγ. Taken together, our results demonstrate that overexpression of PPARδ inhibits myotube formation and also enhances adipocyte differentiation. However, the complexity and interaction of PPARδ and PPARγ in adipogenesis are not clearly understood. © 2008 American Society of Animal Science. All rights reserved.
Type
journal article