Morphologic characteristics of processes of nucleus pulposus cells in adult human intervertebral disc

Abstract

To explore morphologic characterizatics of cellular processes from adult human nucleus pulposus cells, the nucleus pulposus of adult human intervertebral disc were obtained from 8 patients (Thompson's grade I~II) and then the tissues specimens were carried out by frozen section and electron microscopic section as well as cell isolation and cultured, processes of nucleus pulposus cells were examined using light microscopy, laser scanning confocal microscopy and transmission electron microscopy. When examined at both the confocal and electron microscope level, all the cells possessed the processes and adjacent nucleus pulposus cells processes possessed a gap junction. But elongated and round cells can be examined when NP cells were monolayer cultured. The rate of elongated cells to round cells is 2.3 to 1. The elongated cells protrude along with the long axis of cell body without second processes. Dendritic processes of round cells protrude to all directions from the cell body with multiple-level processes. Processes are one of the morphologic characteristics of intervertebral disc cells which are different from articular cartilage chondrocytes. The research on processes functions will be helpful to understand pathomechanism of intervertebral disc degradation and open a new approach for cytobiology treatment of the intervertebral disc diseases.