Stem Cell Differentiation & Genomic Processes in Response to Bioactive Nanotopography

干细胞分化

• 批准号: BB/G006970/1
• 负责人: Richard Oreffo
• 金额: $ 41.69万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2009
• 资助国家: 英国
• 起止时间: 2009 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=BB%2FG006970%2F1
• 关键词: Stem; Cell; Differentiation; Genomic; Processes

With an increasing ageing population the clinical requirement to replace degenerated tissues, such as musculoskeletal tissue, is a major socio-economic requirement. A key issue is an understanding of stem cell activity on different materials, specifically a need to understand how stem cells behave on a material surface. We have generated novel data that shows small changes in the shape of a material can relate to large changes in cell behaviour when they are grown on the material surface. These changes in material shape can be at the nanoscale (1 x 10-9 meters); for examples pits, pillars and grooves with widths and heights of under 100 nm can cause cell alignment, increases in adhesion and even cause total non-adhesion (non-contact) through adjustments of spacing and aspect ratio. Other effects nanoscale designs can have on cells are changes in cytoskeleton (proteins involved in cell adhesion, spreading, metabolism and signalling), cell growth and the function of the cell (differentiation). Stem cells are immature cells that have the ability to differentiate into a number of mature cell types. For example, stem cells from bone can differentiate into cells for bone formation and maintenance (osteoblasts and osteocytes) or cells for cartilage formation and maintenance (chondroblasts and chondrocytes), ligament and tendon formation (fibroblasts) and a number of other cell types (fat, endothelial, epithelial). The understanding of the environmental cues allowing cells to chose one type (bone or fat - referred to as lineage) over another would be of great advantage for stem cell biologists and subsequently for materials researchers and tissue engineers could then optimise material design for e.g. hip and knee replacements. In the replacements of load bearing implants for bone (such as the knee and hip), once the material is implanted, bone stem cells in the bone marrow (called mesenchymal or skeletal stem cells) differentiate to become fibroblasts due to lack of appropriate cues from the material. Thus, the material is surrounded by soft tissue rather than hard bone. Over time this causes implant failure leading to older patients undergoing complicated secondary (revision) surgery. Here, we plan to investigate how materials can pass nanoscale mechanical signals to the cell nucleus and how this leads to changes in DNA organisation and subsequent cell differentiation - a process known as direct mechanotransduction. We would view changes in structural proteins of the nucleus (nucleoskeleton) with changes in cell spreading on nanomaterials. These changes could then be related to changes in DNA positioning and gene regulation alongside studies of differentiation. Very little is know about what in their environment triggers stem cell differentiation, we believe that surface shape, also known as topography (like a mountain surface can be flat, rugged, smooth and bumpy), is important. If we can understand these processes we can produce better materials (informed design) that will encourage direct bone bonding (apposition) to an implant, thus removing the need for revision surgery. This would save patient worry, surgical time and the NHS millions of pounds.

随着人口老龄化的增加，临床需要更换退化的组织，如肌肉骨骼组织，这是一项主要的社会经济需求。一个关键问题是了解干细胞在不同材料上的活性，特别是需要了解干细胞在材料表面的行为。我们已经产生了新的数据，表明当材料生长在材料表面时，材料形状的微小变化可以与细胞行为的巨大变化相关。材料形状的这些变化可以是纳米级的(1 x 10-9米)；例如，宽度和高度在100 nm以下的凹坑、柱子和沟槽可以导致电池排列，增加粘附性，甚至通过调整间距和纵横比导致完全不粘连(非接触)。纳米设计对细胞的其他影响包括细胞骨架(参与细胞黏附、扩散、新陈代谢和信号传递的蛋白质)、细胞生长和细胞功能(分化)的变化。干细胞是一种未成熟细胞，具有分化为多种成熟细胞类型的能力。例如，骨干细胞可以分化为骨形成和维持的细胞(成骨细胞和骨细胞)或软骨形成和维持的细胞(软骨母细胞和软骨细胞)、韧带和肌腱形成(成纤维细胞)和许多其他类型的细胞(脂肪、内皮、上皮细胞)。了解允许细胞选择一种类型(骨骼或脂肪--称为谱系)而不是另一种类型的环境线索将对干细胞生物学家非常有利，随后材料研究人员和组织工程师可以优化材料设计，例如髋关节和膝盖置换。在替代骨(如膝盖和髋关节)的承重植入物时，一旦植入材料，由于缺乏材料的适当提示，骨髓中的骨干细胞(称为间充质干细胞或骨骼干细胞)会分化为成纤维细胞。因此，材料周围是软组织，而不是硬骨。随着时间的推移，这会导致植入失败，导致老年患者接受复杂的二次(翻修)手术。在这里，我们计划研究材料如何将纳米级的机械信号传递到细胞核，以及这如何导致DNA组织和随后的细胞分化的变化--这一过程被称为直接机械转导。我们认为，随着细胞在纳米材料上扩散的变化，细胞核(核骨架)的结构蛋白也会发生变化。这些变化可能与DNA定位和基因调控的变化以及对分化的研究有关。我们对其环境中触发干细胞分化的因素知之甚少，但我们认为表面形状，也就是众所周知的地形(就像山脉的表面可以是平的、崎岖的、光滑的和凹凸不平的)很重要。如果我们能够了解这些过程，我们就可以生产出更好的材料(知情设计)，鼓励直接将骨结合到植入物上，从而消除了翻修手术的需要。这将为患者节省担忧，节省手术时间，并为NHS节省数百万英镑。

项目成果

Effects of a surface topography composite with puerariae radix on human STRO-1-positive stem cells.

• DOI: 10.1016/j.actbio.2010.02.038
• 发表时间: 2010-09
• 期刊: Acta biomaterialia
• 影响因子: 9.7
• 作者: Fahsai Kantawong;Karl E. V. Burgess;Kamburapola Jayawardena;A. Hart;M. Riehle;R. Oreffo;M. Dalby;R. Burchmore

Embryonic and induced pluripotent stem cells: understanding, creating, and exploiting the nano-niche for regenerative medicine.

• DOI: 10.1021/nn3037094
• 发表时间: 2013-03-26
• 期刊: ACS NANO
• 影响因子: 17.1
• 作者: Kingham, Emmajayne;Oreffo, Richard O. C.
• 通讯作者: Oreffo, Richard O. C.

Hypoxia inducible factors regulate pluripotency and proliferation in human embryonic stem cells cultured at reduced oxygen tensions.

• DOI: 10.1530/rep-09-0300
• 发表时间: 2010-01
• 期刊: Reproduction (Cambridge, England)
• 作者: Forristal CE;Wright KL;Hanley NA;Oreffo RO;Houghton FD
• 通讯作者: Houghton FD

Osteogenic lineage restriction by osteoprogenitors cultured on nanometric grooved surfaces: the role of focal adhesion maturation.

• DOI: 10.1016/j.actbio.2013.11.008
• 发表时间: 2014-02
• 期刊: ACTA BIOMATERIALIA
• 影响因子: 9.7
• 作者: Cassidy, John W.;Roberts, Jemma N.;Smith, Carol-Anne;Robertson, Mary;White, Kate;Biggs, Manus J.;Oreffo, Richard O. C.;Dalby, Matthew J.
• 通讯作者: Dalby, Matthew J.

Protein Expression of STRO-1 Cells in Response to Different Topographic Features.

STRO-1 细胞响应不同地形特征的蛋白质表达。

• DOI: 10.4061/2011/534603
• 发表时间: 2011
• 期刊: Journal of tissue engineering
• 影响因子: 8.2
• 作者: Kantawong F