Shapiro Frederic, Mulhern Howard, Weis Mary Ann, Eyre David
Department of Orthopaedic Surgery, Children's Hospital Boston, 300 Longwood Avenue, Boston, MA 02115, USA.
Ultrastruct Pathol. 2006 Sep-Oct;30(5):393-400. doi: 10.1080/01913120600967004.
Iliac crest growth cartilage biopsy in spondyloepimetaphyseal dysplasia (SEMD) showed an endoplasmic reticulum storage disorder of epiphyseal and physeal chondrocytes. Biochemical analyses of iliac crest cartilage extracellular matrix showed no signs of deficits in any of the structural collagens types II, IX, or XI. The physis was abnormal by light microscopy with chondrocyte columnation replaced by clone-like cell accumulations surrounded by widened acellular cartilage septae. The rough endoplasmic reticulum (RER) of most chondrocytes was dilated. In some cells the RER contained homogeneous material but in most there were abnormal electron-dense accumulations. In some the material was seen in small amounts adjacent to the edge of the RER. In others, increasingly large amounts were seen that were randomly oriented and diffusely marginated. In many cells, assembly had progressed to well-marginated collections of wavy rod-like structures with a circular orientation parallel to the outer edges of the RER. The electron-dense accumulations measured from 34 to 40 nm in diameter. Mutations have prevented normal processing of collagen such that exit from the RER is abnormally slowed and abnormal self-assembly occurs within the dilated cisternae.
脊椎骨骺发育异常（SEMD）患者的髂嵴生长软骨活检显示，骨骺和生长板软骨细胞存在内质网储存障碍。髂嵴软骨细胞外基质的生化分析表明，II型、IX型或XI型结构胶原均无缺乏迹象。光镜下可见生长板异常，软骨细胞柱被克隆样细胞聚集取代，周围是增宽的无细胞软骨间隔。大多数软骨细胞的粗面内质网（RER）扩张。在一些细胞中，RER含有均匀物质，但在大多数细胞中存在异常的电子致密聚集物。在一些细胞中，可见少量物质靠近RER边缘。在其他细胞中，可见越来越多随机排列且边缘弥散的物质。在许多细胞中，组装已发展为形成排列良好的波浪状杆状结构集合，呈与RER外边缘平行的圆形排列。电子致密聚集物直径为34至40纳米。突变阻止了胶原蛋白的正常加工，使得从RER的输出异常减慢，并且在扩张的池内发生异常的自我组装。
