Spatiotemporal proliferation of human stromal cells adjusts to nutrient availability and leads to stanniocalcin-1 expression in vitro and in vivo

Abstract

Cells and tissues are intrinsically adapted to molecular gradients and use them to maintain or change their activity. The effect of such gradients is particularly important for cell populations that have an intrinsic capacity to differentiate into multiple cell lineages, such as bone marrow derived mesenchymal stromal cells (MSCs). Our results showed that nutrient gradients prompt the spatiotemporal organization of MSCs in 3D culture. Cells adapted to their 3D environment without significant cell death or cell differentiation. Kinetics data and whole-genome gene expression analysis suggest that a low proliferation activity phenotype predominates in stromal cells cultured in 3D, likely due to increasing nutrient limitation. These differences implied that despite similar surface areas available for cell attachment, higher cell concentrations in 3D reduced MSCs proliferation, while activating hypoxia related-pathways. To further understand the in vivo effects of both proliferation and cell concentrations, we increased cell concentrations in small (1.8 μl) implantable wells. We found that MSCs accumulation and conditioning by nutrient competition in small volumes leads to an ideal threshold of cell-concentration for the induction of blood vessel formation, possibly signaled by the hypoxia-related stanniocalcin-1 gene.

Mechanosensitive regulation of stanniocalcin-1 by zyxin and actin-myosin in human mesenchymal stromal cells

“…Previous reports have shown that STC1 is upregulated in different 3D culture systems. [14][15][16][17] We have previously shown that hMSCs in 3D electrospun (ESP) scaffolds have fewer stress fibers and focal adhesions than in 2D. 35,36 We have also seen that 3D alginate hydrogels show the same trend, in line with results published by others.…”

“…13 STC1 has also been reported to increase in 3D culture platforms, such as spheroids and 3D-additive manufactured scaffolds, compared to 2D cultures such as tissue culture polystyrene (TCP). [14][15][16][17] Despite these efforts, the molecular mechanisms by which STC1 expression and secretion are regulated are still unclear.…”

Myriad Functions of Stanniocalcin-1 (STC1) Cover Multiple Therapeutic Targets in the Complicated Pathogenesis of Idiopathic Pulmonary Fibrosis (IPF)

“…They also expressed high levels of three anticancer proteins: IL-24, TNFα-related apoptosis-inducing ligand, and CD82. 15 , 47 STC1 transgenic mice do not show any carcinogenic character in their natural history. 48 Intermittent inhalation of STC1 might be safe in terms of carcinogenesis, but further data are needed to confirm its safety as a treatment for IPF.…”

Probing the pH Microenvironment of Mesenchymal Stromal Cell Cultures on Additive‐Manufactured Scaffolds

“…As the cells divided over time and started to occupy the empty pores in the scaffolds, they disposed themselves in a spiral-like shape, which is typical of hMSCs growth in these scaffolds as previously observed. [60,61] At instances, where the pore is in the process of filling, it will be referred to as a filling pore. A filled pore on the other hand will denote a pore completely filled with cells.…”