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Early differentiation patterning of mouse embryonic stem cells in response to variations in alginate substrate stiffness.

Candiello J, Singh SS, Task K, Kumta PN, Banerjee I - J Biol Eng (2013)

Bottom Line: Upon generation of functionally mature ESC derived islet-like cells, they need to be implanted into diabetic patients to restore the loss of islet activity.Encapsulation in alginate microcapsules is a promising route of implantation, which can protect the cells from the recipient's immune system.The insight into these biophysical phenomena found in this study can be used along with other cues to enhance the differentiation of embryonic stem cells toward a specific lineage fate.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA. pkumta@pitt.edu.

ABSTRACT

Background: Embryonic stem cells (ESCs) have been implicated to have tremendous impact in regenerative therapeutics of various diseases, including Type 1 Diabetes. Upon generation of functionally mature ESC derived islet-like cells, they need to be implanted into diabetic patients to restore the loss of islet activity. Encapsulation in alginate microcapsules is a promising route of implantation, which can protect the cells from the recipient's immune system. While there has been a significant investigation into islet encapsulation over the past decade, the feasibility of encapsulation and differentiation of ESCs has been less explored. Research over the past few years has identified the cellular mechanical microenvironment to play a central role in phenotype commitment of stem cells. Therefore it will be important to design the encapsulation material to be supportive to cellular functionality and maturation.

Results: This work investigated the effect of stiffness of alginate substrate on initial differentiation and phenotype commitment of murine ESCs. ESCs grown on alginate substrates tuned to similar biomechanical properties of native pancreatic tissue elicited both an enhanced and incrementally responsive differentiation towards endodermal lineage traits.

Conclusions: The insight into these biophysical phenomena found in this study can be used along with other cues to enhance the differentiation of embryonic stem cells toward a specific lineage fate.

No MeSH data available.


Related in: MedlinePlus

P-value demonstrating the strength of correlation between the changes in gene expression and the changes in the alginate gel stiffness. Values were determined for each gene marker investigated, and also for both linear and quadtratic relationships.
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Figure 7: P-value demonstrating the strength of correlation between the changes in gene expression and the changes in the alginate gel stiffness. Values were determined for each gene marker investigated, and also for both linear and quadtratic relationships.

Mentions: In addition to up-regulation, a qualitative inspection of the PCR data reveals that several of the endoderm genes are sensitive and strongly responsive to substrate stiffness. In particular, many genes show a bi-modal trend with a preferential up-regulation in a certain range of stiffness. However, a qualitative analysis is restrictive when describing this complex non-linear behavior, and a more quantitative approach is necessary to accurately compare the substrate responsiveness between genes. Therefore, we performed a more rigorous statistical correlation analysis of all of the analyzed genes for all germ layers, across all gel conditions. For each gene, we obtained a mathematical relationship of the gene expression responsiveness to gel condition by regressing the PCR data onto substrate stiffness. For each of these regressions, the p-value characterizing the significance of the mathematical relationship between the gene expression and gel stiffness was calculated (Figure 7). In this way, we were able to determine which genes show a strong correlation (p ≤ 0.05), either linear or quadratic, to the stiffness of the alginate gel. The genes TTR, GATA4, HNF1-β, CLDN6, CXCR4, and GSC were found to have gene expression strongly correlated to the variations in the substrates elastic properties. A summary of correlation is presented in Table 2 (endoderm) and Table 3 (mesoderm, ectoderm, and pluripotency) along with the summary of the up-regulation.


Early differentiation patterning of mouse embryonic stem cells in response to variations in alginate substrate stiffness.

Candiello J, Singh SS, Task K, Kumta PN, Banerjee I - J Biol Eng (2013)

P-value demonstrating the strength of correlation between the changes in gene expression and the changes in the alginate gel stiffness. Values were determined for each gene marker investigated, and also for both linear and quadtratic relationships.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3643844&req=5

Figure 7: P-value demonstrating the strength of correlation between the changes in gene expression and the changes in the alginate gel stiffness. Values were determined for each gene marker investigated, and also for both linear and quadtratic relationships.
Mentions: In addition to up-regulation, a qualitative inspection of the PCR data reveals that several of the endoderm genes are sensitive and strongly responsive to substrate stiffness. In particular, many genes show a bi-modal trend with a preferential up-regulation in a certain range of stiffness. However, a qualitative analysis is restrictive when describing this complex non-linear behavior, and a more quantitative approach is necessary to accurately compare the substrate responsiveness between genes. Therefore, we performed a more rigorous statistical correlation analysis of all of the analyzed genes for all germ layers, across all gel conditions. For each gene, we obtained a mathematical relationship of the gene expression responsiveness to gel condition by regressing the PCR data onto substrate stiffness. For each of these regressions, the p-value characterizing the significance of the mathematical relationship between the gene expression and gel stiffness was calculated (Figure 7). In this way, we were able to determine which genes show a strong correlation (p ≤ 0.05), either linear or quadratic, to the stiffness of the alginate gel. The genes TTR, GATA4, HNF1-β, CLDN6, CXCR4, and GSC were found to have gene expression strongly correlated to the variations in the substrates elastic properties. A summary of correlation is presented in Table 2 (endoderm) and Table 3 (mesoderm, ectoderm, and pluripotency) along with the summary of the up-regulation.

Bottom Line: Upon generation of functionally mature ESC derived islet-like cells, they need to be implanted into diabetic patients to restore the loss of islet activity.Encapsulation in alginate microcapsules is a promising route of implantation, which can protect the cells from the recipient's immune system.The insight into these biophysical phenomena found in this study can be used along with other cues to enhance the differentiation of embryonic stem cells toward a specific lineage fate.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA, USA. pkumta@pitt.edu.

ABSTRACT

Background: Embryonic stem cells (ESCs) have been implicated to have tremendous impact in regenerative therapeutics of various diseases, including Type 1 Diabetes. Upon generation of functionally mature ESC derived islet-like cells, they need to be implanted into diabetic patients to restore the loss of islet activity. Encapsulation in alginate microcapsules is a promising route of implantation, which can protect the cells from the recipient's immune system. While there has been a significant investigation into islet encapsulation over the past decade, the feasibility of encapsulation and differentiation of ESCs has been less explored. Research over the past few years has identified the cellular mechanical microenvironment to play a central role in phenotype commitment of stem cells. Therefore it will be important to design the encapsulation material to be supportive to cellular functionality and maturation.

Results: This work investigated the effect of stiffness of alginate substrate on initial differentiation and phenotype commitment of murine ESCs. ESCs grown on alginate substrates tuned to similar biomechanical properties of native pancreatic tissue elicited both an enhanced and incrementally responsive differentiation towards endodermal lineage traits.

Conclusions: The insight into these biophysical phenomena found in this study can be used along with other cues to enhance the differentiation of embryonic stem cells toward a specific lineage fate.

No MeSH data available.


Related in: MedlinePlus