TgA86 Mice overexpressing transmembrane TNF display an unexpected absence of thoracolumbar disc degeneration

Abstract Objective. This study evaluated the relevance of TgA86 mice, which overexpress transmembrane TNF (tmTNF), as a model for intervertebral disc degeneration (IVDD). Six middle-aged, skeletally mature, transgenic TgA86 mice were included in this study alongside three control littermates. Histopathological scoring was performed on sections of the lumbar and thoracic segments of the spine to evaluate the extent of IVDD. Results. Despite preexisting cues predicting a degenerated disc phenotype, degeneration scores were comparable between TgA86 and wild-type mice, with no evidence of any genotype-specific effects. This first report of a detailed histopathological characterization of TgA86 mice thoracolumbar intervertebral discs suggest that transmembrane TNF (tmTNF)-driven inflammation alone does not induce IVDD, limiting their utility as a model for studying disc degeneration.