Βeta2 Microglobulin Amyloid Deposition in Degenerative Disc Tissues in Patients Undergoing Dialysis and in Rat Nucleus Pulposus Cells

Background: The prevalence and incidence of end-stage renal disease (ESRD) have been increased worldwide, and it has become a public health problem resulting in high economic and social costs. Especially in Taiwan, the number of patients receiving dialysis therapy has rapidly increased and has been at the top of list. A large proportion of dialysis patients are diabetic and aging populations, at the same time, these selected populations also suffer degenerative disc disease. Disc degeneration is a common problem in the spine. A healthy disc contains a great deal of water in the nucleus pulposus (NP), which gives it a spongy quality to absorb spinal stress. Beta-2 microglobulin (β2M) amyloidosis is an unpleasant condition that may occur in patients undergoing long-term hemodialysis. The accumulation of β2M amyloid fibrils in the body, particular in bone, joint, and tendons possibly lead to bone disease and chronic arthritis. β2M amyloid deposition in injured discs can develop dialysis amyloid spondyloarthropathy, which is often misdiagnosed with non-infective destructive spondyloarthropathy by medical imaging. Objective: The aim of this study is to examine the association between β2M amyloid deposit and disc degeneration in dialysis patients, and also investigate the effect of β2M amyloid deposit in rat nucleus pulposus cells. Since we have previously studied the association of advanced glycation end products, diabetes and disc degeneration, and published in Journal of Orthopaedic Research, the study is designed in hope to achieve our objective. Materials and Methods: The clinical charts of all dialysis-dependent patients who underwent spinal surgery are reviewed, and the demographic and clinical data are collected for statistical analysis. For the enrolled patients, formalin fixed paraffin wax embedded disc tissue samples are obtained from Tissue Bank of our institution. Congo red stain and Thioflavin stain are performed to assess the presence of amyloid deposit. In addition, intervertebral disc tissues are surgically harvested from patients with and without dialysis treatment, and NP cells were isolated and cultured for comparing the expression of β2M by Congo red kit. NP cells from Spargue-Dawley male rat discs are treated with different concentrations of β2M for different time-periods, and the expressions of MMP2, POSTN and SULF1 are compared using RT-PCR, real-time PCR, western blot and histological analyses.

Project ID:PC10408-1257
External Project ID:MOST104-2314-B182-012-MY2