基于CHI3L1调控notch与smad通路crosstalk研究柚皮素对慢性骨髓炎骨缺损的修复机制

Chronic osteomyelitis is often difficult to cure in clinic, and its core pathological changes is the bone defects, which is challenge for orthopedic surgeons and. It has a long history of traditional Chinese medicine (TCM) treatment to chronic osteomyelitis, and achieved good results, but the molecular mechanism is still unclear. Our initial study found that anti-inflammatory effects of naringenin may play a key role in the TCM treatment of chronic osteomyelitis. S.aureus can inhibit the proliferation and differentiation of osteoblast in mice, and in the detection of angiogenesis and bone related genes, we found CHI3L1 may play an important role in the bone defect repair mediated by anti-inflammatory effects of naringenin. Based on these studies, this project intends to collect clinical samples to confirm the relationship between CHI3L1 and the occurrence and development of chronic osteomyelitis, Then use S.aureus to establish the rabbit model of chronic osteomyelitis tibia bone defect to study the bone defect repair mechanism of chronic osteomyelitis mediated by naringenin and CHI3L1. At the same time, we establish co-culture system of osteoblast and vascular endothelial cells to further study on the molecular mechanism of CHI3L1 on osteogenesis and angiogenesis. This study can further clarify the bone defect repair mechanisms of naringenin and CHI3L1 on chronic osteomyelitis, and research results will help to reduce the incidence of chronic osteomyelitis and provide a new method for the treatment of chronic osteomyelitis.

慢性骨髓炎临床通常难以治愈，其核心病理变化是骨缺损，对骨科医师来说是一大难题与挑战。中医治疗该病有着悠久的历史，且取得良好的效果，但其中的分子机制还不清楚。前期在小鼠成骨细胞-金黄色葡萄球菌（S.aureus）共培养体系中，研究发现中草药的活性成分柚皮素抗炎作用可能在慢性骨髓炎的中医药治疗中发挥关键介导作用。S.aureus能够抑制小鼠成骨细胞增殖分化，在血管生成或骨相关基因检测中，发现CHI3L1可能在柚皮素的抗炎作用及骨缺损修复中扮演了重要角色。在这些研究的基础上，本项目拟收集临床样本，确认CHI3L1与慢性骨髓炎发生发展的关系，继而利用S.aureus建立兔慢性骨髓炎胫骨骨缺损模型，研究柚皮素和CHI3L1对慢性骨髓炎骨缺损的修复机制，同时建立成骨细胞-血管内皮细胞共培养体系，进一步研究CHI3L1在成骨-成血管中的分子机制。本研究能进一步阐明柚皮素和CHI3L1对慢性骨髓炎骨缺损的修复机制，研究成果将有助于降低慢性骨髓炎的发病率，并为慢性骨髓炎的治疗提供新的思路。

慢性骨髓炎是由化脓性细菌感染引起的骨组织的慢性炎症，病变可涉及骨髓、骨质、骨膜及周围软组织。危及生命的重症患者有时不得已需要采取截肢保命的应急办法，往往给患者精神上、经济上带来难以承受的负担。慢性骨髓炎的主要致病菌为金黄色葡萄球菌。慢性骨髓炎的外治是中医药的特色之一。柚皮素是中草药中枳实、枳壳、橘红等的主要有效成分。研究表明柚皮素具有较强的抗菌、抗炎、抗氧化、细胞保护等作用。课题组开发了金黄色葡萄球菌诱导的骨髓炎小鼠模型。课题组还发现柚皮素能够显著抑制金黄色葡萄球菌诱导的炎症因子的分泌，而且能有效抑制CHI3L1的表达，而抑制CHI3L1可以降低金黄色葡萄球菌在小鼠骨髓炎模型中的衰弱作用说明了柚皮素能有效的抑制骨髓炎进程。并且柚皮素通过Notch与Smad信号通路crosstalk影响骨髓炎进程。课题组还证明了circ_0080425通过使miR-24海绵化并靶向CHI3L1来调控小鼠骨髓炎。此项研究首次探明了CHI3L1慢性骨髓炎骨缺损修复中作用及其机制，从新的角度探讨成骨细胞‐血管内皮细胞在慢性骨髓炎中的成骨‐成血管能力，并且首次探讨了 Notch 和 Smad 信号通路在慢性骨髓中的交叉对话。