Beating mesenchymal stem cell senescence with materials that organise growth factors.

骨髓间充质干细胞（Mesenchymal stem cells，MSCs）是从成人骨髓中分离出来的一种具有生物学活性的细胞，可分化为支持骨软骨、韧带、肌腱等组织再生的细胞。它们还具有免疫调节特性，因此在移植过程中越来越广泛地用作“药物”，以帮助预防排斥反应，例如在胰岛移植和移植物抗宿主病中。此外，它们可以支持骨髓造血干细胞的生长，并可以在帮助血液疾病如白血病方面发挥再生作用。因此，我们认为，它们有潜力在支持广泛的下一代疾病治疗的策略中发挥关键作用。从骨髓中分离出的MSC数量很少（1000）然而，细胞疗法将需要每剂量数千万个MSC，并且形成提供疗法的公司将需要生产数十亿个细胞的能力，以满足医疗保健供应商的需求。随着MSC在培养物中生长，在骨髓的调节下，它们改变表型（分化）和年龄（导致生长停止-衰老）。为了提供MSC疗法，这两个障碍都需要克服。我们已经开发出聚合物，可以控制细胞外基质（ECM）蛋白的呈递，MSC在骨髓中以允许更好的MSC生长的方式相互作用。ECM蛋白含有隐藏的肽序列，当暴露时，允许细胞粘附到它们，并允许信号蛋白，如生长因子，结合到它们，从而更好地控制细胞signaling.In这个项目中，我们将研究原代人MSC生长的ECM蛋白与生长因子的生物呈递关系，以优化MSC体外生长。我们将使用生物学（PCR，流式细胞术，qPCR，显微镜）和生物力学（机械细胞术，纳米压痕和布里渊显微镜）来寻找保存的MSC表型和衰老（例如细胞核硬化）的标志物。我们还将利用转录组学（RNAseq）和代谢组学来寻找我们可以抑制的信号靶点作为药物靶点，以进一步防止MSC老化，同时促进MSC扩增。该项目与工业合作伙伴QKine合作，开发用于干细胞的无动物产品生长因子。

Mesenchymal stem cells (MSCs) from the adult bone marrow can differentiate into cells that support the regeneration of tissues such as bone cartilage, ligament and tendon. They also have immunomodulatory properties and so are becoming more widely used as 'drugs' in transplant procedures to help prevent rejection e.g. in islet transplants and in graft vs host disease. Further, they can support the growth of the blood-forming stem cells of the bone marrow and can have regenerative roles in helping in blood diseases such as leukaemias. Therefore, they have the potential to provide a key role in strategies to underpin a wide range of next-generation disease therapies.MSCs are isolated from the bone marrow in low numbers (1000s) and yet a cell therapy would require tens of millions of MSCs per dose and forming a company to supply the therapies would require the ability to produce billions of cells in order to meet the demand of healthcare suppliers at a cost that can be justified.As MSCs grow in culture, out of the regulation of the bone marrow, they change phenotype (differentiate) and age (leading to the stopping of growth - senescence). To provide MSC therapies, both of these hurdles need to be overcome.We have developed polymers that can control the presentation of extracellular matrix (ECM) proteins that MSCs interact with in the bone marrow in ways that allow for better MSC growth. ECM proteins contain cryptic peptide sequences that, when exposed, allow cell adhesion to them and allow signalling proteins, such as growth factors, to bind to them allowing better control of cell signalling.In this project, we will study primary human MSC growth in relation to the biological presentation of the ECM proteins with growth factors in order to optimise MSC growth in vitro. We will use both biological (PCR, flow cytometry, qPCR, microscopy) and biomechanical (mechanical cytometry, nanoindentation and Brillouin microscopy) to look for markers of preserved MSC phenotype and senescence (eg stiffening of the cell nucleus). We will also employ transcriptomics (RNAseq) and metabolomics to look for signalling targets that we can inhibit as drug targets to further prevent MSC ageing while promoting MSC expansion.The project is in collaboration with the industrial partner QKine who develop animal-product free growth factors for stem cells.