A nanoporous surface is essential for glomerular podocyte differentiation in three-dimensional culture

Abstract

Although it is well recognized that cell–matrix interactions are based on both molecular and geometrical characteristics, the relationship between specific cell types and the three-dimensional morphology of the surface to which they are attached is poorly understood. This is particularly true for glomerular podocytes – the gatekeepers of glomerular filtration – which completely enwrap the glomerular basement membrane with their primary and secondary ramifications. Nanotechnologies produce biocompatible materials which offer the possibility to build substrates which differ only by topology in order to mimic the spatial organization of diverse basement membranes. With this in mind, we produced and utilized rough and porous surfaces obtained from silicon to analyze the behavior of two diverse ramified cells: glomerular podocytes and a neuronal cell line used as a control. Proper differentiation and development of ramifications of both cell types was largely influenced by topographical characteristics. Confirming previous data, the neuronal cell line acquired features of maturation on rough nanosurfaces. In contrast, podocytes developed and matured preferentially on nanoporous surfaces provided with grooves, as shown by the organization of the actin cytoskeleton stress fibers and the proper development of vinculin-positive focal adhesions. On the basis of these findings, we suggest that in vitro studies regarding podocyte attachment to the glomerular basement membrane should take into account the geometrical properties of the surface on which the tests are conducted because physiological cellular activity depends on the three-dimensional microenvironment.

Cell-Specific Response of NSIP- and IPF-Derived Fibroblasts to the Modification of the Elasticity, Biological Properties, and 3D Architecture of the Substrate

“…and 70 deg. [ 70 , 88 , 89 ], which are close to the values reported for proteins [ 90 , 91 , 92 , 93 ]. Therefore, the observed increase in the number of cells on substrates decorated with proteins may be related also to modified nonspecific hydrophobic/hydrophilic interactions.…”

Mechanophysical Cues in Extracellular Matrix Regulation of Cell Behavior

“…For neuron cells, the rough surface led to cell differentiation, but the porous surface had no effect on it. In contrast, for glomerular podocyte, porous surface induced cell differentiation effectively relative to the rough surface …”

Cell‐Derived Extracellular Matrix‐Rich Biomimetic Substrate Supports Podocyte Proliferation, Differentiation, and Maintenance of Native Phenotype

“…Nanoporous substrates constructed with grooves shows a better network of the actin cytoskeleton and focal adhesions of podocytes. [ 33 ] Podocytes sense the stiffness of substrate that regulates proliferation, migration, and spreading of podocyte. A marked stiffness sensitivity of podocytes has been revealed on gelatin microbial transglutaminase cell culture platform.…”