Rejuvenating the aged cell through epigenetic modulation: defining culture conditions to reverse mesenchymal stromal cell (MSC) ageing

项目理由和重要性：我们最近发现了可能与MSC老化有关的表观遗传调节因子。我们使用针对398种表观遗传酶的短发夹状RNA(ShRNA)文库未发表的数据表明，沉默老年/非增殖期的人骨髓间充质干细胞(HMSCs)中特定的表观遗传酶具有逆转生长停滞和重建细胞增殖的能力。有趣的是，很大一部分已确定的表观遗传酶具有相关的小分子(化学/化合物)调节剂，这为开发具有逆转hMSC衰老能力的体外培养条件提供了独特的机会。事实上，体细胞重新编程为多能细胞告诉我们，在细胞水平上，将年龄重新设置为“基态”是可能的。对表观遗传状态的谨慎操作也可能使细胞在不抹去其身份的情况下再次年轻(4)。这将最终导致对如何逆转细胞衰老和/或保持细胞年轻状态的新见解，这将在再生医学中具有重要的影响和应用。目的和目的：本研究将明确表观遗传学在hMSCs衰老过程中的作用，并在建立体外培养条件以逆转细胞体外衰老方面取得新的技术进展。目的1建立基于表观遗传酶活性控制的体外条件，以改变hMSC的衰老。目的2从机制上理解hMSC衰老的表观遗传控制，从而确定骨骼抗衰老的靶点。目的了解单细胞核糖核酸序列(ScRNASeq)表观遗传调控逆转年龄反应的异质性。

Project rationale and importance: We have recently discovered epigenetic regulators that may be involved in MSC ageing. Our unpublished data using a short hairpin RNA (shRNA) library targeting 398 epigenetic enzymes indicates that silencing of specific epigenetic enzymes in aged/non-proliferating human MSCs (hMSCs) has the capacity to reverse growth arrest and re-establish cell proliferation. Interestingly, a large proportion of the identified epigenetic enzymes have associated small molecule (chemical/compound) modulators, which presents a unique opportunity to develop in vitro culture conditions that have the capacity to reverse hMSC ageing. Indeed, the reprogramming of somatic cells to pluripotency has taught us that at the cellular level it is possible to reset age to a 'ground state'. Careful manipulation of epigenetic state is also likely to make cells 'young again' without erasing their identity(4). This will ultimately lead to novel insights in how to reverse cell ageing and/or maintain cells in a youthful state, which will have significant impact and applications in regenerative medicine.Aim and objectives: This studentship will define the role of epigenetics in the ageing process of hMSCs, and create new technological advances towards the establishment of culture conditions to reverse cell ageing in vitro.Objective 1 To develop in vitro conditions with the capacity to modify hMSC ageing based on the control of epigenetic enzyme activity. Objective 2 To deliver a mechanistic understanding of the epigenetic control of hMSC ageing, hence identifying skeletal anti-ageing targets. Objective 3 To understand the heterogeneity of response to age reversal through epigenetic modulation by single cell RNA sequencing (scRNASeq).