Sod2 and catalase improve pathological conditions of intervertebral disc degeneration by modifying human adipose-derived mesenchymal stem cells

•Ad-Sod2 and Ad-Cat upregulated SOX9, ACAN and COL2 in hADSCs.•Ad-Sod2-hADSCs and Ad-Cat-hADSCs increased the disc height index of mice with IVD.•Ad-Sod2/Cat-hADSCs improved the structure and water content of the nucleus pulposus.•Modification of hADSCs by Sod2 and Cat upregulated GAG and COL2 in mice with IVD.•Ad-Sod2-hADSCs and Ad-Cat-hADSCs reduced proinflammatory factors in the intervertebral discs of mice with IVD.