title: Concentration dependent survival and neural differentiation of murine embryonic stem cells cultured on polyethylene glycol dimethacrylate hydrogels possessing a continuous concentration gradient of n-cadherin derived peptide His-Ala-Val-Asp-Lle.
abstract: N-cadherin cell-cell signaling plays a key role in the structure and function of the nervous system. However, few studies have incorporated bioactive signaling from n-cadherin into tissue engineering matrices. The present study uses a continuous gradient approach in polyethylene glycol dimethacrylate hydrogels to identify concentration dependent effects of n-cadherin peptide, His-Ala-Val-Asp-Lle (HAVDI), on murine embryonic stem cell survival and neural differentiation. The n-cadherin peptide was found to affect the expression of pluripotency marker, alkaline phosphatase, in murine embryonic stem cells cultured on n-cadherin peptide containing hydrogels in a concentration dependent manner. Increasing n-cadherin peptide concentrations in the hydrogels elicited a biphasic response in neurite extension length and mRNA expression of neural differentiation marker, neuron-specific class III β-tubulin, in murine embryonic stem cells cultured on the hydrogels. High concentrations of n-cadherin peptide in the hydrogels were found to increase the expression of apoptotic marker, caspase 3/7, in murine embryonic stem cells compared to that of murine embryonic stem cell cultures on hydrogels containing lower concentrations of n-cadherin peptide. Increasing the n-cadherin peptide concentration in the hydrogels facilitated greater survival of murine embryonic stem cells exposed to increasing oxidative stress caused by hydrogen peroxide exposure. The combinatorial approach presented in this work demonstrates concentration dependent effects of n-cadherin signaling on mouse embryonic stem cell behavior, underscoring the need for the greater use of systematic approaches in tissue engineering matrix design in order to understand and optimize bioactive signaling in the matrix for tissue formation.
  
  
  
  Single cell encapsulation is common in tissue engineering matrices. This eliminates cellular access to cell-cell signaling. N-cadherin, a cell-cell signaling molecule, plays a vital role in the development of neural tissues, but has not been well studied as a bioactive signaling element in neural tissue engineering matrices. The present study uses a systematic continuous gradient approach to identify concentration dependent effects of n-cadherin derived peptide, HAVDI, on the survival and neural differentiation of murine embryonic stem cells. This work underscores the need for greater use to combinatorial strategies to understand the effect complex bioactive signaling, such as n-cadherin, and the need to optimize the concentration of such bioactive signaling within tissue engineering matrices for maximal cellular response.
authors.affiliation: The Vivian L. Smith Department of Neurosurgery, McGovern Medical School at The University of Texas Health Science Center at Houston, United States; Center for Stem Cell and Regenerative Medicine, Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, United States.
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Lim
authors.affiliation: The Vivian L. Smith Department of Neurosurgery, McGovern Medical School at The University of Texas Health Science Center at Houston, United States; Center for Stem Cell and Regenerative Medicine, Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, United States.
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Mosley
authors.affiliation: The Vivian L. Smith Department of Neurosurgery, McGovern Medical School at The University of Texas Health Science Center at Houston, United States; Center for Stem Cell and Regenerative Medicine, Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, United States.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Kurosu
authors.affiliation: The Vivian L. Smith Department of Neurosurgery, McGovern Medical School at The University of Texas Health Science Center at Houston, United States; Center for Stem Cell and Regenerative Medicine, Brown Foundation Institute of Molecular Medicine, The University of Texas Health Science Center at Houston, United States; The Department of Nanomedicine and Biomedical Engineering, University of Texas Health Science Center at Houston, United States; The Graduate School of Biomedical Sciences, University of Texas Health Science Center at Houston, United States. Electronic address: laura.a.smithcallahan@uth.tmc.edu.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Smith Callahan
mesh_terms: D000818:Animals; D015820:Cadherins / Q000737:chemistry / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D051379:Mice; D000066450:Mouse Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D015820:Cadherins; C489083:Cdh2 protein, mouse; D010455:Peptides; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate
keywords: Combinatory method; Gradient; HAVDI; Hydrogel; Mouse embryonic stem cell; n-Cadherin