Figure 1.

Ectopic TERT but not TERT-HA expression suppresses extracellular citrate levels in parallel with senescence bypass. (A, B) The effect of ectopic TERT expression on citrate levels in (A) BJ cells and (B) NHOF-1 oral fibroblasts (n = 3). Data are means ± standard deviation. *p < .05; 
***p < .001; ****p < .0001. (C, D) The percentage of senescent cells in (A) and (B) as assessed by (C) SA-βGal (n =3) and (D) is derived from 1 experiment. Symbols are the same as for (A) and (B). (E) Typical images of late passage SA-βGal-stained BJ cells transduced with the empty PURO vector, the TERT-HA construct (extrachromosomal TERT functions only), and TERT; black scale bar = 100 μm. (F, G) The telomere lengths of the cells analyzed in (A) and (B) at the point of senescence showing a clear increase in telomere length in NHOF-1 cells expressing TERT. Data are from 2 replicate runs of the same samples. (H, I) TERT mRNA levels in the cells from (A) and (B) at the point of senescence. Showing high levels of TERT and TERT-HA mRNA in both BJ and NHOF-1 cells. PC3 mRNA is the positive control. (J) Telomerase activity in the BJ cells from (A). The data are derived from 1 experiment in (A). PC3 is the positive control and heat-treated PC3 extract is the negative control. (K) IL-6 levels in the BJ cells from (A, n = 3). Data are means ± standard deviation. *p < .05; **p < .01.