Integrated Analyses on adaptation and control mechanisms in remodeling of the extracellular matrix in the in situ frozen-thawed anterior cruciate ligament

1.本研究从生长因子调控胶原合成和代谢的角度，采用原位冻融处理方法和我们自行开发的几种独特的动物模型，从生物力学和分子生物学角度阐明髌腱（PT）和前交叉韧带（ACL）组织的重塑现象。结果表明：（1）内源性成纤维细胞坏死对PT的力学性能无明显影响，至少在6周内，外源性成纤维细胞浸润对PT的力学性能有影响。此外，无论是应力剥夺和增强显着恶化的机械性能，在原位冷冻ACL。(2)在原位冷冻PT中，在6和12周时，III型前胶原mRNA在外源性细胞中过表达，并且III型胶原在外源性细胞周围表达。(3)应用IL-1 β和PDGF-BB促进体外培养的成纤维细胞胶原酶mRNA的表达 ...更多信息 （4）肌腱组织中的应力剥夺不仅诱导成纤维细胞中IL-1 β和TGF-β的过度表达，而且还导致细胞外基质的机械性能降低。(5)低剂量TGF-β1和EGF在冻融前交叉韧带0周和3周时均能抑制冻融后材料的降解，而6周时不能抑制冻融后材料的降解，高剂量时不能抑制冻融后材料的降解。(6)TGF-β的应用改善了损伤ACL中愈合组织的材料性质，但PDGF-BB的应用没有任何效果。此外，本研究还建立了一个新的综合分析体系，从生物力学和分子生物学的角度阐明肌腱和韧带组织改建的适应和控制机制。至于临床相关性，本研究证明了治疗试验的基本原则，以抑制移植肌腱和韧带组织的材料性能恶化，这是目前的一个重要临床问题。我们相信，这一原理将有助于发展基因治疗和组织工程为基础的治疗损伤的肌腱和韧带组织在骨科手术和运动医学领域。少

1. This study biomechanically and molecular-biologically clarified the remodeling phenomenon of the patellar tendon (PT) and anterior cruciate ligament (ACL) tissues from the viewpoint of collagen synthesis and metabolism controlled by growth factors, using the in situ freeze-thaw treatment and several unique animal models which were originally developed by us. The results were shown as follows : (1) Intrinsic fibroblast necrosis did not significantly affect the mechanical properties of the PT, at least, for 6 weeks, but extrinsic fibroblast infiltration affected them. In addition, both stress deprivation and enhancement significantly deteriorated the mechanical properties of the in situ frozen ACL. (2) In the situ frozen PT, type-III procollagen mRNA was overexpressed in the extrinsic cells at 6 and 12 weeks, and type-III collagen was expressed around the extrinsic cells. (3) Application of IL-1beta and PDGF-BB enhanced expression of the collagenase mRNA in the extrinsic fibroblasts i … More n the frozen PT, while application of TGF-beta inhibited it. (4) Stress deprivation in the tendon tissue simultaneously induced not only overexpression of IL-1beta and TGF-beta-in fibroblasts but also reduction of the mechanical properties of the extracellular matrix. (5) A low-dose of TGF-β1 and EGF applied to the frozen-thawed ACL at 0 and 3 weeks inhibitd the material deterioration caused by freezing, but the same dose application at 6 weeks did not inhibit it. A high dose application did not inhibit it at each period. (6) Application of TGF-beta improves the material properties of healing tissue in the injured ACL, but application of the PDGF-BB does not have any effects.2. In addition, this study established a new integrated analysis system to clarify adaptation and control mechanisms in remodeling of the tendon and ligament tissue, using the biomechanical and molecular-biological methods. As to clinical relevance, this study demonstrated a basic principle of therapeutic trials to inhibit the deterioration of the material properties of the grafted tendon and ligament tissues, which is a significant clinical problem at the present time. We believe that this principle will contribute development of gene therapy and tissue engineering-based treatment for the injured tendon and ligament tissues in the field of orthopaedic surgery and sports medicine. Less