Sortilin derived propeptide regulation during adipocyte differentiation and inflammation.
In this work, we aimed to correlate the expression of sortilin with the production of sortilin-derived propeptide (PE) during adipocyte differentiation, insulin resistance and inflammation. We also investigated the effect of spadin, a shorter analogue of PE that exerts a potent antidepressant in mice, on adipocyte functions. During adipogenesis, insulin resistance and inflammation, we measured the mRNA and protein expression of sortilin, by quantitative PCR and Western-blot, and quantified the expression of PE by a specific dosing method. We observed that the production of PE was correlated with the sortilin expression during adipogenesis. Immunostaining experiments allowed to visualize the co-localization of sortilin, PE and VAMP2 in 3T3-L1 adipocytes. TNFα treatment induced insulin resistance and a decrease of sortilin expression (mRNA and protein), correlated with the decrease of the PE production. By contrast, treatment with dexamethasone, which also induced insulin resistance, was without effect on sortilin expression and PE production. As a putative bioactive peptide, we have evaluated its autocrine effect by the use of spadin on 3T3-L1 adipocytes by performing glucose uptake and signalling experiments. Any effect was measured on adipocytes indicating that the use of spadin as an antidepressant would have no side effects on adipocyte physiology.
Université Côte d'Azur, CNRS, IPMC, France.
Céline
C
Hivelin
Université Côte d'Azur, CNRS, IPMC, France.
Jean
J
Mazella
Université Côte d'Azur, INSERM, CNRS, IPMC, France. Electronic address: coppola@ipmc.cnrs.fr.
Thierry
T
Coppola
D041721:3T3-L1 Cells; D033942:Adaptor Proteins, Vesicular Transport / Q000276:immunology; D017667:Adipocytes / Q000276:immunology* / Q000473:pathology*; D050156:Adipogenesis / Q000276:immunology*; D000818:Animals; D002454:Cell Differentiation / Q000276:immunology; D051379:Mice; D015434:Panniculitis / Q000276:immunology* / Q000473:pathology*; D010455:Peptides / Q000276:immunology*; D000099183:Sortilin
D033942:Adaptor Proteins, Vesicular Transport; D010455:Peptides; D000099183:Sortilin; C551795:spadin peptide
Adipocyte; Inflammation; Sortilin; Sortilin-derived-propeptide; Spadin; TNFalpha