Temporal Changes in Nucleus Morphology, Lamin A/C and Histone Methylation During Nanotopography-Induced Neuronal Differentiation of Stem Cells

Abstract

Stem cell differentiation can be regulated by biophysical cues such as nanotopography. It involves sensing and integration of these biophysical cues into their transcriptome with a mechanism that is yet to be discovered. In addition to the cytoskeletal and focal adhesion remodeling, nanotopography has also been shown to modulate nucleus morphology. Here, we studied the effect of nanotopography on the temporal changes in nuclei of human embryonic stem cells (hESCs) and human mesenchymal stem cells (hMSCs). Using a high throughput Multi-architecture (MARC) chip analysis, the circularity of the stem cell nuclei changed significantly on different patterns. Human ESCs and MSCs showed different temporal changes in nucleus morphology, lamin A/C expression and histone methylation during topography-induced neuronal differentiation. In hESCs, the expression of nuclear matrix protein, lamin A/C during neuronal differentiation of hESCs on PDMS samples were weakly detected in the first 7 days of differentiation. The histone 3 trimethylation on Lysine 9 (H3K9me3) decreased after differentiation initiated and showed temporal changes in their expression and organization during neuronal differentiation. In hMSCs, the expression of lamin A/C was significantly increased after the first 24 h of cell culture. The quantitative analysis of histone methylation also showed a significant increase in hMSCs histone methylation on 250 nm anisotropic nanogratings within the first 24 h of seeding. This reiterates the importance of cell-substrate sensing within the first 24 h for adult stem cells. The lamin A/C expression and histone methylation shows a correlation of epigenetic changes in early events of differentiation, giving an insight on how extracellular nanotopographical cues are transduced into nuclear biochemical signals. Collectively, these results provide more understanding into the nuclear regulation of the mechanotransduction of nanotopographical cues in stem cell differentiation.

Development of endomyocardial fibrosis model using a cell patterning technique: In vitro interaction of cell coculture of 3T3 fibroblasts and RL-14 cardiomyocytes

“…The changes presented in the nuclei of cardiomyocytes in interaction with fibroblasts in the EMF model could be correlated with alterations in the cytoskeleton, which leads to variations in the index of circularity of the nuclei and finally changes in cell morphology. These results are related to those reported by Ankam et al [34], in which changes in cell nucleus sizes are associated with different types of cell pattern topographies.…”

“…Likewise, the delimited cell growth areas for each type of pattern were reduced as the incubation period increased, due to the increase in the fibroblast cell population. This behavior is similar to that reported in the investigations of Shivashankar et.al and Ankar et.al [33,34], in which cell agglomerates as a result of confined geometries were denoted, which finally led to perturbations in the extracellular matrix topography, an important factor in cell homeostasis.…”

Dimensionality changes actin network through lamin A and C and zyxin

“…[11,12] Indeed, lamin A and C expression, indirectly attached to actin stress fibers, has also been shown to increase on stiffer materials. [6] Besides material stiffness, other factors such as material chemistry and topography have also been shown to influence focal adhesions, actin stress fibers and lamin A and C. [13][14][15] Yes-associated protein 1 (YAP1) is an important mechanosensitive co-transcription factor that translocates to the nucleus at higher cellular tension to transduce these mechanical changes in the cell to changes in gene expression. [16] On stiffer materials and with more cellular tension human mesenchymal stromal cells (hMSCs) show increased osteogenic differentiation, while softer materials and lower cellular tension enhance differentiation to chondro-and adipogenic lineages.…”

Emerging Methods for Enhancing Pluripotent Stem Cell Expansion

“…Topography plays a key role in determining PSC fate (Ankam et al, 2013(Ankam et al, , 2015(Ankam et al, , 2018Chan et al, 2013), including maintaining pluripotency and regulating self-renewal and proliferation. Table 2 lists examples of studies of micro and nanotopographies on PSC maintenance and expansion.…”