Chronic inflammation deteriorates structure and function of collagen fibril in rat temporomandibular joint disc  

作　　者：Shengjie Cui Yu Fu Yan Liu Xiaoxing Kou Jieni Zhang Yehua Gan Yanheng Zhou Xuedong Wang 

机构地区：[1]Department of Orthodontics, Peking University School and Hospital of Stomatology [2]Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology [3]Center for Temporomandibular Disorders and Orofacial Pain, Peking University School and Hospital of Stomatology

出　　处：《International Journal of Oral Science》2019年第1期42-49,共8页国际口腔科学杂志（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 81671015, 81571815, 81470717);Beijing Municipal Science and Technology Commission (Grant No. Z171100001017128)

摘　　要：Collagen is the building component of temporomandibular joint(TMJ) discs and is often affected by inflammation in temporomandibular disorders. The macromechanical properties of collagen are deteriorated by chronic inflammation. However,the mechanism by which inflammation influences disc function remains unknown. The relationship between the ultrastructure and nanomechanical properties of collagen in inflamed discs should be clarified. Seven-week-old female Sprague–Dawley rats were randomly divided into two groups. Chronic TMJ inflammation was induced by intra-articular injection of complete Freund's adjuvant, and samples were harvested after 5 weeks. Picrosirius staining revealed multiple colours under polarized light, which represented alternative collagen bundles in inflamed discs. Using atomic force microscopy scanning, the magnitude of Young's modulus was reduced significantly accompanied with disordered collagen fibril arrangement with porous architecture of inflamed discs. Transmission electron microscopy scanning revealed a non-uniform distribution of collagen fibres, and oversized collagen fibrils were observed in inflamed discs. Fourier transform infrared microspectroscopy revealed a decrease in 1 338 cm^(-1)/amide II area ratio of collagen in different regions. The peak positions of amide I and amide II bands were altered in inflamed discs,indicating collagen unfolding. Our results suggest that sustained inflammation deteriorates collagen structures, resulting in the deterioration of the ultrastructure and nanomechanical properties of rat TMJ discs.Collagen is the building component of temporomandibular joint(TMJ) discs and is often affected by inflammation in temporomandibular disorders. The macromechanical properties of collagen are deteriorated by chronic inflammation. However,the mechanism by which inflammation influences disc function remains unknown. The relationship between the ultrastructure and nanomechanical properties of collagen in inflamed discs should be clarified. Seven-week-old female Sprague–Dawley rats were randomly divided into two groups. Chronic TMJ inflammation was induced by intra-articular injection of complete Freund's adjuvant, and samples were harvested after 5 weeks. Picrosirius staining revealed multiple colours under polarized light, which represented alternative collagen bundles in inflamed discs. Using atomic force microscopy scanning, the magnitude of Young's modulus was reduced significantly accompanied with disordered collagen fibril arrangement with porous architecture of inflamed discs. Transmission electron microscopy scanning revealed a non-uniform distribution of collagen fibres, and oversized collagen fibrils were observed in inflamed discs. Fourier transform infrared microspectroscopy revealed a decrease in 1 338 cm^(-1)/amide II area ratio of collagen in different regions. The peak positions of amide I and amide II bands were altered in inflamed discs,indicating collagen unfolding. Our results suggest that sustained inflammation deteriorates collagen structures, resulting in the deterioration of the ultrastructure and nanomechanical properties of rat TMJ discs.

关 键 词：TEMPOROMANDIBULAR joint(TMJ FEMALE SPRAGUE-DAWLEY 

分 类 号：R[医药卫生]