PKC/HDAC5信号参与材料纳米形貌调控巨噬细胞极化促进牙周再生的基础研究

材料纳米形貌与巨噬细胞（Mφ）极化和功能调控关系密切，但机理不清。课题组前期研究证实纳米纤维形貌可抑制Mφ促炎反应，且伴有蛋白激酶C（PKC）表达下降和组蛋白去乙酰基酶5（HDAC5）表达升高，提示PKC/HDAC5在材料形貌调控Mφ极性转换中扮演重要角色。基于明胶纳米纤维形貌，本项目拟建立二维、三维培养体系，总结纳米纤维形貌调控Mφ表型和功能的一般规律；通过ChIP-seq从组蛋白乙酰化水平变化的角度，明确培养体系中Mφ极化受控的关键促炎/抑炎基因；通过基因转染等技术阐释PKC-HDAC5信号轴如何影响Mφ关键促炎/抑炎基因转录，从而建立材料形貌调控Mφ极性转换的分子网络；最后通过Mφ极化受控小鼠牙周缺损模型，观察Hdac5敲除对材料纳米纤维形貌调控Mφ和促进组织再生的影响。本项目从表观遗传角度解析材料物理性能对Mφ表型和功能的影响，为新型免疫调节型再生生物材料设计提供新思路。

Biomaterial nanotopography plays an important role in modulating the macrophage polarization and function across the cascade of tissue regeneration, but the underlying molecular mechanism remains unclear. Our preliminary study suggests that the nanofibrous topography of gelatin scaffolds can inhibit the pro-inflammatory responses of macrophages, accompanied by a decrease in the protein kinase C (PKC) expression and an increase in the histone deacetylase 5 (HDAC5) expression. Considering PKC modulates the nuclear export of HDAC5, it is reasonable to propose that PKC/HDAC5 may play an important role in the phenotype transition of macrophages on the surface of nanofiber materials. In this project, we will clarify the general patterns of nanofibrous topography-based modulation of macrophage polarization in both two- and three-dimensional culture system. With the help of ChIP-seq, gene transfection, RNAi technology and such, we will screen out the critical genes in nanofibrous topography-based modulation of macrophage polarization from histone acetylation level changes, figure out how the PKC/HDAC5 axis regulates the transcription of those critical pro/anti-inflammatory genes, and then build up the molecular network by which topography modulates macrophage phenotype transition. In the transgenic mice with periodontal defects, we will observe how Hdac5 knockout affects the interplay between nanofibrous topography and macrophage regulation, and indeed the outcome of periodontal tissue regeneration. From the epigenetic perspective, this project for the first time explores how the physical properties of biomaterials may influence macrophage phenotype and function, which will provide novel ideas for the design of immunomodulating biomaterials for regenerative medicine.