Directing stem cell fate by controlling the affinity and density of ligand-receptor interactions at the biomaterials interface.
Directing stem cell fate by controlling the affinity and density of ligand-receptor interactions at the biomaterials interface.
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DOI：
10.1002/anie.201108746
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发表时间：
2012-05-14
影响因子：
16.6
通讯作者：
Mrksich, Milan
中科院分区：
文献类型：
--
作者：
Kilian, Kristopher A.;Mrksich, Milan
间充质干细胞（MSC）是来自骨髓和潜在的许多其他组织的粘附性多能干细胞[1]，其用作用于评估细胞外因子对干细胞分化的影响的有吸引力的模型系统。MSC已被证明致力于几个谱系，包括：骨，软骨，脂肪和平滑肌，以及转分化为骨骼肌和神经命运。[1b我们的研究小组[3]和其他人[2a，B，4]已经使用MSC来证明细胞骨架张力在谱系特化和定型过程中的重要性。例如，在坚硬的基质上培养的MSC [2b]或在促进细胞铺展或细胞骨架张力的表面上形成图案的MSC [3，4 b]都有利于依赖于肌动蛋白细胞骨架收缩性增加的成骨程序。其他报告已经证明了使用细胞粘附配体修饰的材料来促进MSC成骨;[5]我们推断粘附配体的分子特征-包括亲和力和密度-会影响细胞的细胞骨架，因此可能有助于指导粘附MSC的分化途径。在这里，我们报告说，细胞和它们的基板之间的生物分子相互作用，可以调整，以促进成骨，肌生成，或神经发生培养的骨髓间充质干细胞。这项工作提供了使用分子工程来控制材料在调节细胞功能中的影响的一个例子。我们使用了烷基硫醇盐在金表面的自组装单分子膜（通过巯基锚定）作为模型底物，因为这些表面允许对介导细胞粘附的配体-受体相互作用的极好控制，部分地，因为它们在结构上是明确的，部分地，因为使用以寡聚物封端的单层（乙二醇）基团在防止蛋白质的非特异性吸附方面非常有效。[6]固定有短肽粘附配体的单层已被用于研究细胞粘附的几个方面，包括胚胎和间充质干细胞的粘附，并且是这些应用的已建立的模型。[7]我们通过将线性肽GRGDSC（linRGD）或环状肽RGDfC（cycRGD，其中f表示具有d构型的F残基）固定到单层上来制备底物，所述单层以1%（高密度）或0.1%（低密度）的密度呈现马来酰亚胺基团，相对于三（乙二醇）基团的背景（图1a）。[8]与线性肽相比，环状肽对αvβ3整联蛋白的亲和力大约高两个数量级，α vβ3整联蛋白是MSC粘附和成骨中的一种重要受体[9]。[10]我们使用自组装单层解吸电离（SAMDI）质谱法确认肽固定在马来酰亚胺基团上（支持性信息，图S1）。我们在标准生长条件（参见支持信息）下在具有裸金膜、纤连蛋白包被的金膜（Fn）的基底上或在呈递linRGD、cycRGD或我们已证明无活性的线性肽的乱序形式（KRDGVC）的单层上培养MSC十天。[11]对于单层，肽以相对于总烷硫醇盐的1%（高密度）或0.1%（低密度）的密度存在。然后，我们固定并染色细胞，观察碱性磷酸酶（AP）的表达，这是骨生成的早期标志物。我们检测到纤连蛋白（AP染色细胞的48%）和cycRGD底物（高密度44%，低密度30%）上细胞AP表达升高。
Mesenchymal stem cells (MSCs) are adherent multipotent stem cells from bone marrow and potentially numerous other tissues [1] that serve as an attractive model system for evaluating the influence of extracellular cues on stem cell differentiation. MSCs have been shown to commit to several lineages including: bone, cartilage, fat, and smooth muscle, as well as transdifferentiation to skeletal muscle and neural fates.[1b, 2] Our research group [3] and others [2a, b, 4] have used MSCs to demonstrate the importance of cytoskeletal tension during lineage specification and commitment. For example, MSCs that were cultured either on stiff substrates [2b] or patterned on surfaces that promote cell spreading or cytoskeletal tension [3, 4b] all favored an osteogenic program that depended on increased contractility of the actomysoin cytoskeleton. Other reports have demonstrated the use of materials that are modified with cell adhesion ligands to promote MSC osteogenesis;[5] we reasoned that the molecular characteristics of the adhesion ligands—including the affinity and density—would influence the cytoskeleton of the cell and may, therefore, serve to direct the differentiation pathways of adherent MSCs. Herein we report that the biomolecular interactions between cells and their substrates can be tuned to promote osteogenesis, myogenesis, or neurogenesis of cultured MSCs. This work provides an example of the use of molecular engineering to control the influence that materials have in regulating cell function. We used self-assembled monolayers (SAMs) of alkanethiolates on gold (anchored through the thiol group) as model substrates, because these surfaces allow excellent control over the ligand–receptor interactions that mediate cell adhesion, in part, because they are structurally well-defined and, in part, because the use of monolayers that are terminated with an oligo (ethylene glycol) group are highly effective at preventing nonspecific adsorption of proteins.[6] Monolayers, to which short peptide-adhesion ligands are immobilized, have been used to study several aspects of cell adhesion, including that of embryonic and mesenchymal stem cells, and are an established model for these applications.[7] We prepared substrates by immobilizing either the linear peptide GRGDSC (linRGD) or the cyclic peptide RGDfC (cycRGD, where f denotes an F residue having the d configuration) to monolayers presenting a maleimide group at a density of 1%(high density) or 0.1%(low density) against a background of tri (ethylene glycol) groups (Figure1a).[8] The cyclic peptide has approximately two orders of magnitude higher affinity for the αvβ3 integrin—an important receptor in the adhesion and osteogenesis of MSCs [9]—than does the linear peptide.[10] We used self-assembled monolayer desorption ionization (SAMDI) mass spectrometry to confirm immobilization of the peptides to the maleimide group (Supporting Information, Figure S1). We cultured MSCs under standard growth conditions (see Supporting Information) for ten days on substrates having a bare gold film, a fibronectin-coated gold film (Fn), or on monolayers presenting linRGD, cycRGD, or a scrambled form of the linear peptide that we have demonstrated to be inactive (KRDGVC).[11] For the monolayers, peptides were present at a density of 1% relative to total alkanethiolate (high density) or 0.1%(low density). We then fixed and stained the cells to observe alkaline phosphatase (AP) expression, which is an early marker for osteogenesis. We detected elevated AP expression for cells on the fibronectin (48% of cells stained for AP) and cycRGD substrates (44% on high density, 30% on low density …
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影响因子：
15
作者：
Luo, Wei;Chan, Eugene W. L.;Yousaf, Muhammad N.
通讯作者：
Yousaf, Muhammad N.
使用自组装的单层来理解肾上腺素素中对RGD和FEI基序的α8β1介导的细胞粘附。
影响因子：
4
作者：
Sanchez-Cortes, Juan;Mrksich, Milan
通讯作者：
Mrksich, Milan
影响因子：
14
作者：
Martino, Mikael M.;Mochizuki, Mayumi;Rothenfluh, Dominique A.;Rempel, Sandra A.;Hubbell, Jeffrey A.;Barker, Thomas H.
通讯作者：
Barker, Thomas H.
DOI：
10.1021/la804077t
发表时间：
2009-05-19
期刊：
Langmuir : the ACS journal of surfaces and colloids
影响因子：
--
作者：
Hudalla GA;Murphy WL
通讯作者：
Murphy WL
影响因子：
10.8
作者：
Park, Jung;Bauer, Sebastian;Schmuki, Patrik
通讯作者：
Schmuki, Patrik