NOTCH1, 2, and 3 receptors enhance osteoblastogenesis of mesenchymal C3H10T1/2 cells and inhibit this process in preosteoblastic MC3T3-E1 cells.

Abstract

Osteoblastogenesis is governed by complex interplays among signaling pathways, which modulate the expression of specific markers at each differentiation stage. This process enables osteoblast precursor cells to adopt the morphological and biochemical characteristics of mature bone cells. Our study investigates the role of NOTCH signaling in osteogenesis in MC3T3-E1 and C3H10T1/2 cell lines. MC3T3-E1 cells are preosteoblast precursors widely recognized as a model for bone biology research, offering a convenient and physiologically relevant system to study osteoblast transcriptional regulation. Conversely, the mesenchymal C3H10T1/2 cells are multipotent, capable of differentiating into osteoblasts, adipocytes, and chondrocytes under specific extracellular cues. The core of this in vitro study is the comparative analysis of the impact of overexpressing each mammalian NOTCH receptor on osteoblastogenesis in two cell lines reflecting different cell differentiation stages. We generated stable transfectant pools of both cell lines for each of the four NOTCH receptors and characterized their effect on osteoblastogenesis. We successfully obtained transfectant pools that overexpress Notch1, Notch2 and Notch3 at both mRNA and protein levels. However, we were unable to obtain cells overexpressing Notch4 at protein level. Our findings reveal that the overexpression of NOTCH1, NOTCH2, and NOTCH3 receptors promotes osteoblast differentiation in mesenchymal C3H10T1/2 cells, while inhibiting it in preosteoblastic MC3T3-E1 cells. These results provide novel insights into the distinct roles of NOTCH receptors in osteoblastogenesis across two different precursor cell types, potentially guiding the development of new therapeutic approaches for bone diseases.