NOTCH Receptors and DLK Proteins Enhance Brown Adipogenesis in Mesenchymal C3H10T1/2 Cells

Abstract

The NOTCH family of receptors and ligands is involved in numerous cell differentiation processes, including adipogenesis. We recently showed that overexpression of each of the four NOTCH receptors in 3T3-L1 preadipocytes enhances adipogenesis and modulates the acquisition of the mature adipocyte phenotype. We also revealed that DLK proteins modulate the adipogenesis of 3T3-L1 preadipocytes and mesenchymal C3H10T1/2 cells in an opposite way, despite their function as non-canonical inhibitory ligands of NOTCH receptors. In this work, we used multipotent C3H10T1/2 cells as an adipogenic model. We used standard adipogenic procedures and analyzed different parameters by using quantitative-polymerase chain reaction (qPCR), quantitative reverse transcription-polymerase chain reaction (qRT-PCR), luciferase, Western blot, and metabolic assays. We revealed that C3H10T1/2 multipotent cells show higher levels of NOTCH receptors expression and activity and lower Dlk gene expression levels than 3T3-L1 preadipocytes. We found that the overexpression of NOTCH receptors enhanced C3H10T1/2 adipogenesis levels, and the overexpression of NOTCH receptors and DLK (DELTA-like homolog) proteins modulated the conversion of cells towards a brown-like adipocyte phenotype. These and our prior results with 3T3-L1 preadipocytes strengthen the idea that, depending on the cellular context, a precise and highly regulated level of global NOTCH signaling is necessary to allow adipogenesis and determine the mature adipocyte phenotype.

Notch pathway inhibitor DAPT accelerates in vitro proliferation and adipogenesis in infantile hemangioma stem cells

“…The activation of the Notch signaling pathway inhibits adipogenesis through autophagy activation and the PTEN-PI3K/AKT/mTOR signaling pathway (20). The Notch signaling pathway inhibitors suppress this process and promote adipocyte differentiation (19)(20)51). It was hypothesized that the inhibition of the Notch signaling pathway might influence the proliferation of HemSCs and this hypothesis was examined by measuring cell proliferation after treatment with five concentrations of DAPT (0, 10, 20, 40 and 60 µM).…”

Deletion of delta‐like 1 homologue accelerates renal inflammation by modulating the Th17 immune response

“…In our study, total NOTCH2 and NOTCH4 receptor protein levels are decreased in Dlk1 ‐null mice as compared to WT, indicating that this could be an effect of Dlk1 deletion or of concomitant Dlk2 overexpression. Recent findings indicate that both DLK1 and DLK2 can modulate the activity of the four NOTCH receptors, 46,47 albeit in a different manner. This was not dissected in our study and awaits further analysis.…”

Emerging Roles of DLK1 in the Stem Cell Niche and Cancer Stemness

“…48,79 At last, in different in vitro models of glucocorticoids and insulin-induced adipocyte differentiation, a quick temporary increase in the levels of the membranebound variant of Dlk1 was observed just after induction of differentiation, while the full-length, cleavable Dlk1 started to decrease just after induction and both became undetectable by the end of the differentiation process. [80][81][82][83] Both the initial overexpression of the membrane-bound DLK1 and the drop in the levels of secreted DLK1 play a role in adipocyte differentiation, and the switch between the two forms of DLK1 is necessary to induce a permissive state for differentiation in response to extracellular stimuli (Fig. 1B).…”