Fig. 2.

Reduced telomerase activity and telomere length is associated with elevated expression of markers of telomere-induced senescence in FGR placenta samples. Fresh placental biopsies near the umbilical cord were obtained for 4 idiopathic FGR and 4 control newborns of similar gestational age (38-40 weeks), and telomerase extracts, RNA and DNA were obtained as described (Materials and Methods). A. Telomerase activity was assessed using the TRAP assay. A typical blot for all samples is shown. NC-negative control. The internal control for PCR efficiency in the TRAP assay is indicated at the side (arrow). B. Quantification of TRAP analysis of telomerase activity for samples shown in panel A. Results represent 4 or more measurements of telomerase activity for each sample. The P value (student's t-test) is shown. C. Quantitative analysis of telomere length (mean TRF length) for all placental and CB DNA samples. Results represent 4 or more measurements of mean TRF length for each sample. D. Real time PCR analysis of the expression levels of 3 markers of telomere-induced senescence (p16, p21 and EF-1α) for all placental RNA samples. Expression levels are shown relative to GAPDH. Similar results were also observed using an 18S RNA reference control (not shown). For each gene, results represent 6 or more measurements of relative expression levels per sample. For all quantitative analyses, error bars represent standard deviation.