Abstract：
It is important to understand whether endothelial cells are epigenetically affected by titanium-enriched media when angiogenesis is required during bone development and it is expected to be recapitulated during osseointegration of biomaterials. To better address this issue, titanium-enriched medium was obtained from incubation of titanium discs for up to 24 h as recommended by ISO 10993-5:2016, and further used to expose human umbilical vein endothelial cells (HUVECs) for up to 72 h, when the samples were properly harvested to allow molecular analysis and epigenetics. In general, our data show an important repertoire of epigenetic players in endothelial cells responding to titanium, reinforcing protein related to the metabolism of acetyl and methyl groups, as follows: Histone deacetylases (HDACs) and NAD-dependent deacetylase sirtuin-1 (Sirt1), DNA methyltransferases (DNMTs) and ten-eleven translocation (TET) methylcytosine dioxygenases, which in conjunction culminate in driving chromatin condensation and the methylation profile of DNA strands, respectively. Taking our data into consideration, HDAC6 emerges as important player of this environment-induced epigenetic mechanism in endothelial cells, while Sirt1 is required in response to stimulation of reactive oxygen species (ROS) production, as its modulation is relevant to vasculature surrounding implanted devices. Collectively, all these findings support the hypothesis that titanium keeps the surrounding microenvironment dynamically active and so affects the performance of endothelial cells by modulating epigenetics. Specifically, this study shows the relevance of HDAC6 as a player in this process, possibly correlated with the cytoskeleton rearrangement of those cells. Furthermore, as those enzymes are druggable, it opens new perspectives to consider the use of small molecules to modulate their activities as a biotechnological tool in order to improve angiogenesis and accelerate bone growth with benefits of a fast recovery time for patients.
摘要：
重要的是要了解在骨骼发育过程中需要血管生成时，内皮细胞是否会受到富钛介质的表观遗传影响，并且有望在生物材料的骨整合过程中进行概述。为了更好地解决这个问题，根据ISO10993-5：2016的建议，从钛圆盘孵育长达24小时获得富含钛的培养基，并进一步用于暴露人脐静脉内皮细胞（HUVEC）长达72小时，当样品被正确收集以允许分子分析和表观遗传学。总的来说,我们的数据显示内皮细胞对钛有重要的表观遗传因素，与乙酰基和甲基代谢有关的增强蛋白，如下：组蛋白脱乙酰酶（HDAC）和NAD依赖性脱乙酰酶sirtuin-1（Sirt1），DNA甲基转移酶（DNMT）和十11易位（TET）甲基胞嘧啶双加氧酶，最终导致染色质凝聚和DNA链的甲基化，分别。考虑到我们的数据，HDAC6在内皮细胞中作为这种环境诱导的表观遗传机制的重要参与者，而Sirt1是响应活性氧（ROS）产生的刺激所必需的，因为它的调制与植入装置周围的脉管系统有关。总的来说，所有这些发现都支持以下假设：钛保持周围微环境的动态活性，从而通过调节表观遗传学影响内皮细胞的性能。具体来说,这项研究显示了HDAC6作为玩家在这个过程中的相关性，可能与这些细胞的细胞骨架重排有关。此外，因为这些酶是可以下药的，它为考虑使用小分子作为生物技术工具来调节其活性开辟了新的视角，以改善血管生成和加速骨骼生长，并为患者提供快速恢复时间。
