MURINE NUCLEUS PULPOSUS-DERIVED CELLS SECRETE INTERLEUKIN-1-BETA, INTERLEUKIN-6, AND INTERLEUKIN-10 AND GRANULOCYTE-MACROPHAGE COLONY-STIMULATING FACTOR IN CELL-CULTURE

Study Design. Cultures established from murine disc-derived cells were stimulated by lipopolysaccharide. The cells' capacity to secrete proi nflammaton/cytokines and interleukin-10 with and without lipopolysacch aride stimulation was determined using enzyme-linked immunosorbent ass ays. Objectives. To determine the capacity of disc-derived cells to se crete proinflammatory cytokines, and the effect of lipopolysaccharide stimulation on such secretion. Summary of Background Data. The pathoph ysiology of compressive radiculopathy is unclear. Inflammation is a po ssible explanation. Proinflammatory cytokine secretion was demonstrate d in herniated nucleus pulposus. It is unknown whether these cytokines are secreted from disc-derived cells or from infiltrating inflammator y cells in the herniated nucleus pulposus. Methods. Discs were microsu rgically harvested from inbred mice and cut to allow the nucleus pulpo sus to establish cell culture. A study group was exposed to lipopolysa ccharide stimulation. Media were harvested from the study and control groups 24 hours later. Secretion of interleukins-1-, -6, and -10, gran ulocyte-macrophage colony-stimulating factor, and tumor necrosis facto r-alpha were determined using enzyme-linked immunosorbent-assays. Resu lts. Basal secretion of inlerleukins-6 and -10, but no basal secretion of interleukin-1-, granulocyte-macrophage colony-stimulating factor, or tumor necrosis factor-alpha was detected. Secretion of interleukin- 1-rose from zero to 27.69 pg/10(5) cells, and granulocyte-macrophage c olony-stimulating factor secretion rose from zero to 9.77 pg/10(5) cel ls after lipopolysaccharide stimulation. A 75-fold increase in interle ukin-6 secretion and a 150-fold increase in interleukin-10 secretion w ere detected after stimulation with lipopolysaccharide. No tumor necro sis factor-a secretion was detectable. All result had high statistical significance (all P < 0.001). Conclusions. Cultured murine disc-deriv ed cells have the capacity to secrete proinflammatory cytokines and in terleukin-10 in the absence of inflammatory cells. This finding suppor ts the hypothesis that disc-derived cells are capable of initiating or amplifying an inflammatory process. Results. Basal secretion of inter leukins-6 and -10, but no basal secretion of interleukin-1-, granulocy te-macrophage colony-stimulating factor, or tumor necrosis factor-a: w as detected. Secretion of interleukin-1-rose from zero to 27.69 pg/10( 5) cells, and granulocyte-macrophage colony-stimulating factor secreti on rose from zero to 9.77 pg/10(5) cells after lipopolysaccharide stim ulation. A 75-fold increase in interleukin-6 secretion and a 150-fold increase in interleukin-10 secretion were detected after stimulation w ith lipopolysaccharide. No tumor necrosis factor-alpha secretion was d etectable. All result had high statistical significance (all P < 0.001 ).