Substrate-dependent Wnt signaling in MSC differentiation within biomaterial-derived 3D spheroids

Availability of extracellular matrix biopolymers and differentiation state of human mesenchymal stem cells determine tissue-like growth in vitro

“…The expression of stemness marker genes (Oct4, Sox2, and Nanog) of cells in membrane associated spheroids was enhanced compared to cells cultured in planar monolayer culture [22], suggesting a higher degree of maintenance of stem cell characteristics in this setting. Furthermore, functional features such as increased expression of Wnt genes/proteins and correlations of Wnt signaling and crosstalk with other pathways such as ERK1/2 or Smad2/3 were observed for MSC spheroids but not for the conventional 2D cultured cells [23]. In an attempt to recapitulate the first events occurring during limb development (cell condensation and expansion of an undifferentiated mesenchymal population) 3D cultures of human bone marrow-derived MSC were primed toward the chondrogenic route.…”

Three-Dimensional Aggregates of Mesenchymal Stem Cells: Cellular Mechanisms, Biological Properties, and Applications

“…Analyses at molecular level have been attempted to elucidate the possible pathways activated in 3D MSC aggregates. 5,6,79,100 For example, genes related to MSC adhesion, including ECM proteins, antioxidant activities, and molecular signaling, were upregulated. 5 Especially, several Wnt genes and proteins, such as Wnt3a and Wnt5a, were found to be differentially upregulated in biomaterial-derived A-MSC aggregates.…”

“…99 A switch from N-cadherin to OB-cadherin was observed to reduce chondrogenic differentiation but increase osteogenic differentiation. 100 Besides regulating MSC differentiation, N-cadherin also modulates the secretion of proangiogenic factors. For instance, N-cadherin increased VEGF expression in CB-MSCs by the activation of extracellular signal-regulated kinases (ERKs) and enhancing cell-cell contacts.…”

“…5 Especially, several Wnt genes and proteins, such as Wnt3a and Wnt5a, were found to be differentially upregulated in biomaterial-derived A-MSC aggregates. 100 The Wnt3a-mediated canonical signaling and Wnt5a-mediated noncanonical signaling cross-talked with ERK1/2 or Smad2/3 pathways to regulate osteogenic or chondrogenic differentiations, respectively. 100 Consistent with the reduced proliferation, a downregulation of cell cycle genes, actin binding proteins, and cytoskeleton organization was also observed.…”

“…100 The Wnt3a-mediated canonical signaling and Wnt5a-mediated noncanonical signaling cross-talked with ERK1/2 or Smad2/3 pathways to regulate osteogenic or chondrogenic differentiations, respectively. 100 Consistent with the reduced proliferation, a downregulation of cell cycle genes, actin binding proteins, and cytoskeleton organization was also observed. 5,79 While these studies provide mechanistic insight, it is important to note that the regulatory mechanisms are multifactorial and likely involve multiple signaling pathways and their convergence.…”