PDGF-D通过PDGFR-β通路调控周细胞的成血管作用促进脂肪移植早期微血管形成的机制研究

How to reduce fat absorption caused by lack of capillary formation after fat transplantation is a hot topic in the field of plastic surgery. And pericyte acts as a leading role in early phase of capillary formation. Literatures and our preliminary data indicated that Platelet-derived Growth Factor-D (PDGF-D), as a positive regulator of capillary formation, could play an important role in regulating the angiogenesis effect of pericyte by activating Platelet-derived Growth Factor Receptor-β (PDGFR-β) pathway. We first evaluate the correlation of PDGF-D and PDGFR-β pathway and the effect of PDGF-D on pericyte by in vitro experiment. Subsequently, the mechanism of PDGF-D regulates the angiogenesis effect of pericyte will explored by molecular experiments through intervening the key molecules of PDGFR-β pathway. Finally, local fat transplantation into rabbit's ears will be performed, and the effects of PDGF-D on promoting angiogenesis and improve the survival rate of fat transplantation through PDGFR-β pathway will be evaluated. In summary, we solve the problem of whether PDGF-D could regulate the angiogenesis effect of pericyte through PDGFR-β pathway and then reduce fat absorption after transplantation systematically by in vitro experiment, molecular mechanism research and animal experiment. These results could also provide more evidence to improve the survival rate of fat after transplantation in clinical.

改善脂肪移植术后因早期微血管形成不足所导致的吸收问题是整形医学领域的研究热点，其中周细胞在微血管形成的早期具有主导作用。文献报道和我们前期研究表明，PDGF-D作为促血管形成因子，可能通过PDGFR-β通路调控周细胞的增殖、迁移和分泌等成血管作用。本项目首先通过体外细胞实验初步判断PDGF-D与PDGFR-β通路的相关性及其对周细胞成血管作用的影响。随后通过干预PDGFR-β通路中的关键分子，在分子水平研究PDGF-D调控周细胞成血管作用的机制。最后借助兔耳脂肪移植模型，验证PDGF-D通过PDGFR-β通路促进脂肪移植早期血管化并提高远期存留率的效果。从体外细胞实验、分子机制研究和动物实验验证三个层面系统的解决PDGF-D能否通过PDGFR-β通路调控的周细胞的成血管作用从而改善脂肪移植术后的吸收问题，为临床提高脂肪移植远期存留率提供依据。

改善脂肪移植术后因早期微血管形成不足所导致的吸收问题是整形医学领域的研究热点。其中周细胞在微血管形成的早期具有主导作用，然而其对微血管形成的作用机制及促进脂肪移植后体积存留的能力尚不完全清楚。因此，本项目首先利用周细胞，借助影像学、细胞学等手段，明确了不同浓度的PDGF-D和PDGFR-β阻断剂对周细胞的存活、增殖、迁移等影响。结果显示：①PDGFR-β阻断剂可促进细胞增殖，对细胞迁移无影响；②低浓度的PDGF-D对周细胞的增殖无影响，高浓度的PDGF-D抑制周细胞的增殖；③PDGF-D的浓度升高可促进周细胞的迁移，当PDGF-D的浓度为20ng/ml时，周细胞的迁移效果最佳。随后利用人体皮下脂肪，借助细胞学、组织学等手段，优化了震荡法提取脂肪中SVF的效果，比较了不同制备方法对SVF的影响。结果显示：①30Hz的震荡频率和15min的震荡时间为震荡法提取SVF的最优参数；②震荡法获得的SVF的状态最好，其细胞存活、增殖和成脂分化能力均高于其他组。接着构建了裸鼠背部皮下注射模型，借助大体观察、组织学染色等方法，验证了脂肪颗粒+周细胞+PDGF-D的脂肪移植效果最佳，提示PDGF-D可通过PDGFR-β通路调控周细胞的成血管作用，进而促进脂肪移植的远期效果。最后构建了兔耳皮下注射模型，借助大体观察、超声检测、组织学染色等方法验证了震荡法提取的SVF对脂肪移植后的血管形成与体积存留的有效性。本项目研究内容进展顺利，已发表SCI论文2篇、中文核心论文接收1篇；授权国家发明专利1项、实用新型专利1项；获得科技奖励1项；参编专著2部；参加国际国内学术会议4次，其中2次国际大会发言、2次壁报获奖；培养博士2人、硕士4人。