Figure 2. Analysis of SIRT6 and telomerase activity in human ligamentum flavum samples. (A) TERT, TPP1, POT1, and SIRT6 levels in non-hypertrophic and hypertrophic ligamentum flavum (LFH and LFN, respectively) tissue samples were assessed via immunohistochemistry (IHC). Scale bar = 200 μm or 50 μm. (B–E) Quantitative analysis of the percent area positive TERT (B), TPP1 (C), POT1 (D) and SIRT6 (E) staining area. (F) Telomerase activity in LFH and LFN tissue samples as represented by telomerase signal (optical density). n = 30. *p<0.05, **p<0.01 vs. LFN.