Interrogating Cadherin/Matrix Rigidity Dependent Neural Differentiation and Neuromuscular Junction Formation of Multipotent Stem Cells

University Of Illinois At Urbana-Champaign, Urbana IL

Investigators

Abstract

PI: Kong, Hyunjoon Proposal Number: 1403491 Institution: University of Illinois at Urbana-Champaign Title: Interrogating Cadherin/Matrix Rigidity Dependent Neural Differentiation and Neuromuscular Junction Formation of Multipotent Stem Cells Understanding and recreating neural networks represents a major scientific and engineering challenge with ramifications ranging from fundamental biology to clinical translation. Stem cells residing in bone and fat tissue possess the potential to be converted to neurons that constitute neural networks. This cell conversion process is stimulated when cells contact each other and are cultured on a substrate that is not ?too hard? or ?too soft?, but that is ?just right?. These neurons will help control muscle tissue movement, thus serving to create various biomedical tools used for fundamental and applied bioscience studies. The studies in this proposal use a Jello-like hydrogel system linked with proteins involved in cell-cell communication and tuned to present a ?just right? softness. The successful completion of this project will therefore create an advanced cell culture platform that will be broadly useful for studying a wide array of stem cells and for exploiting this in neural tissue engineering. The proposed work will also uncover the coordinate effects of cell-cell adhesions and matrix softness on stem cell fates, including differentiation into neurons. Finally, the results of the proposed study will be highly useful in creating various neural implants more efficiently than previously possible and intelligent, biological robots. Utilization of the results of this study as an educational module will have broad impacts by attracting future young scientists and encouraging them to pursue engineering careers. This proposal is co-funded by the Biomedical Engineering Program in the Chemical, Bioengineering, Environmental and Transport Systems Division, and by the Biomaterials Program in the Division of Materials Research. There have been numerous attempts to reproduce neural networks and neuromuscular junctions in vitro for both fundamental and applied neuroscience studies that used neuronal cells differentiated from multipotent stem cells. Therefore, it is crucial to regulate neural differentiation of stem cells in an elaborate manner, in terms of differentiation levels and glial-to-neural cell population. The proposed research seeks to systematically understand and modulate the potential interplay between cell-cell adhesion and cell-matrix adhesion in regulating the neural differentiation of stem cells. To this end, the goals of this proposed study are (1) to modulate the neural differentiation of multipotent, bone marrow stromal cells (BMSCs) by combining the effects of cadherin, a cell-cell adhesion protein, and matrix stiffness; and (2) to use the differentiated cholinergic neurons to build a functional, neuromuscular junction in vitro. This goal will be accomplished by culturing BMSCs on a hydrogel chemically linked with a specific number of recombinant N- or E-cadherin, and further tailored to present controlled stiffness. The integrative effects of cadherin and matrix rigidity on cellular differentiation, cell traction force, and Rac1-GTPase signal activation will be analyzed. Finally, differentiated cholinergic neurons will be co-cultured with skeletal myoblasts to form a neuromuscular junction and evaluate neural control over muscular contraction and relaxation. Successful completion of the proposed studies is expected to result in significant contributions in neuroscience and neuroengineering and stem cell technology.