Effect of TUG1 on proliferation, apoptosis and ECM degradation of human degenerated intervertebral disc NPCs. A. The expression of TUG1 was assessed by qRT-PCR in NPCs of LVF group and IDD group. *P<0.05, **P<0.01. After isolated from human degenerative disc nucleus pulposus, the NPCs were transfected with pcDNA, pcDNA-TUG1, si-NC or si-TUG1. B. After transfection for 48 h, TUG1 expression was detected by qRT-PCR. C. Cell viability of human degenerated intervertebral disc NPCs transfected for 48 h was detected by EdU assay. Bar =100 μm. D. Cell apoptosis of human degenerated intervertebral disc NPCs transfected for 48 h was analyzed by flow cytometry using Annexin V/PI staining assay kit. E. Apoptosis-related proteins Bcl-2, Bax and cleaved caspase-3 expression were detected by western blot assay in human degenerated intervertebral disc NPCs transfected for 48 h. The original images are available in Figure S3. F. ECM degradation-related proteins collagen II, aggrecan, MMP-3 and MMP-13 expression were detected by western blot assay in human degenerated intervertebral disc NPCs transfected for 48 h. The original images are available in Figure S4. *P<0.05, **P<0.01.