Autophagy expression and its significance in chondrocytes from a degenerate model of human cervical endplate

Abstract

To explore the autophagy expression and examine its significance in chondrocytes in a degenerate model of human cervical vertebrae endplate. Cartilage endplates were obtained from 48 hospitalized patients with cervical vertebral fracture or dislocation at our hospital between February 2012 to August 2012. They were divided into cervical spondylosis group with cervical spondylotic myelopathy (n = 31) and control group (n = 17).Endplate chondrocytes were isolated by enzyme digestion and cultured in vitro. The cells were stained with toluidine blue and hematoxylin and eosin; laser scanning confocal microscope and monodansylcadaverine (MDC) were used to observe autophagy in endplate chondrocytes; reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the mRNA expression of typeIIcollagen and aggrecan and Western blot for the protein of LC3. A degenerative cell model of human cervical endplate chondrocytes was established successfully in vitro. Compared with the common group, the cellular morphologies of degenerative group showed spindle changes. Autophagic body was stained with MDC.Intracellular and perinuclear LC3 protein was detected by laser confocal microscopy. Compared with the control group, the mRNA expressions of aggrecan (0.715 ± 0.194) and typeII collagen (0.628 ± 0.254) markedly decreased (0.845 ± 0.186,0.913 ± 0.254, P < 0.05) and LC3-II/LC3-I declined in cervical spondylosis group. Autophagy plays an important pathogenic role in the process of human cervical disc degeneration. And regulating its expression may improve disc degeneration in endplate cartilage cells.