Regenerative Engineering Laboratory, Section for Oral and Maxillofacial Surgery, College of Dental Medicine, Columbia University, 630 W. 168 St. - VC12-230, New York, NY 10032, United States.
Regenerative Engineering Laboratory, Section for Oral and Maxillofacial Surgery, College of Dental Medicine, Columbia University, 630 W. 168 St. - VC12-230, New York, NY 10032, United States.
Arch Oral Biol. 2018 Feb;86:1-6. doi: 10.1016/j.archoralbio.2017.11.002. Epub 2017 Nov 8.
To determine the regionally variant quality of collagen alignment in human TMJ discs and its statistical correlation with viscoelastic properties.
For quantitative analysis of the quality of collagen alignment, horizontal sections of human TMJ discs with Pricrosirius Red staining were imaged under circularly polarized microscopy. Mean angle and angular deviation of collagen fibers in each region were analyzed using a well-established automated image-processing for angular gradient. Instantaneous and relaxation moduli of each disc region were measured under stress-relaxation test both in tensile and compression. Then Spearman correlation analysis was performed between the angular deviation and the moduli. To understand the effect of glycosaminoglycans on the correlation, TMJ disc samples were treated by chondroitinase ABC (C-ABC).
Our imaging processing analysis showed the region-variant direction of collagen alignment, consistently with previous findings. Interestingly, the quality of collagen alignment, not only the directions, was significantly different in between the regions. The angular deviation of fiber alignment in the anterior and intermediate regions were significantly smaller than the posterior region. Medial and lateral regions showed significantly bigger angular deviation than all the other regions. The regionally variant angular deviation values showed statistically significant correlation with the tensile instantaneous modulus and the relaxation modulus, partially dependent on C-ABC treatment.
Our findings suggest the region-variant degree of collagen fiber alignment is likely attributed to the heterogeneous viscoelastic properties of TMJ disc that may have significant implications in development of regenerative therapy for TMJ disc.
确定人类颞下颌关节盘胶原纤维排列的区域性差异质量及其与黏弹性特性的统计相关性。
为了定量分析胶原纤维排列质量，对经苦味酸天狼星红染色的人类颞下颌关节盘的水平切片进行圆形偏振显微镜成像。使用成熟的自动图像处理技术对每个区域的胶原纤维的平均角度和角度偏差进行分析。在拉伸和压缩的应力松弛试验下，测量每个盘区的瞬时和松弛模量。然后对角度偏差和模量进行 Spearman 相关分析。为了了解糖胺聚糖对相关性的影响，用软骨素酶 ABC（C-ABC）处理颞下颌关节盘样本。
我们的成像处理分析显示了胶原纤维排列的区域性方向，与之前的发现一致。有趣的是，不仅是方向，纤维排列的质量在区域之间也有明显的差异。前区和中区纤维排列的角度偏差明显小于后区。内侧和外侧区域的角度偏差明显大于所有其他区域。纤维排列的区域性角度偏差值与拉伸瞬时模量和松弛模量呈统计学显著相关，部分取决于 C-ABC 处理。
我们的研究结果表明，胶原纤维排列的区域差异程度可能归因于颞下颌关节盘的异质黏弹性特性，这可能对颞下颌关节盘再生治疗的发展具有重要意义。
