Lactosylceramide induced by elastin-derived peptides decreases adipocyte differentiation
Résumé
Elastin, major protein of extracellular matrix, is specially found in cardiovascular tissues and contributing to 30-50% of the dry weight of blood vessels. Elastin regulates cell signalling pathways involved in morphogenesis, injury response, and inflammation. The function of elastin is frequently compromised in damaged or aged elastic tissues. Indeed, elastin degradation, observed during ageing, and the resulting production of elastin derived peptides (EDP), have crucial impacts on cardiovascular disease (atherosclerosis, thrombosis) or on metabolism disease progressions (type 2 diabetes or non-alcoholic steatohepatitis). In the present study, we analysed the EDP effects on 3T3 pre-adipocyte cell differentiation. In a first part, we treated 3T3-L1 cells with EDP and visualized the lipid droplet accumulation by the oil redO staining and measured the expression of various transcription factors and adipocyte-specific mRNAs by real-time RT-PCR. We demonstrated that elastin receptor complex, ERC, is activated by EDPs and decreased adipocyte differentiation by a modulation of crucial adipogenesis transcriptional factor particularly PPARγ. In a second part, we identified the signalling pathway implicated in EDP-reduced cell differentiation. The flow cytometry and immunocytochemistry approaches showed that ERC activated by EDP, produced a second messenger, lactosylceramide (Lac-Cer). Moreover, this Lac-Cer production favoured the phosphorylation of ERK1-2 (p-ERK1-2), to decrease adipocyte differentiation by a modulation of adipogenesis transcriptional factor PPARγ. To conclude, the EDP/Lac-Cer/p-ERK1-2 signalling pathway may be studied further as a critical target for treating complications associated with adipocyte dedifferentiation such as obesity and diabetes insulin resistance. KEY POINTS Elastin Derived Peptides (EDP) decreased PPAR expression. EDP reduced adipocytes differentiation. Adipocytes differentiation is reduced by Lac-cer production and ERK1/2 activation.
Domaines
Sciences du Vivant [q-bio]
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