Research Paper Volume 3, Issue 4 pp 407—416

Figure 2. Senescent fibroblasts accumulate in geriatric dermis in vivo. Biopsies of sun-protected skin were obtained from six young adult (20-28 years old) and six geriatric (>65 years old) volunteers. (A) Sections of skin were stained with antibodies to 53BP1 and γH2AX. Positive nuclei are indicated by white arrows; dashed line specifies the location of the basement membrane; bar = 25 µm. (B) Quantitative PCR analysis of mRNA isolated from skin biopsies, normalized to actin expression. Asterisk indicate statistical significance from young adult values (IGF-1 p = 0.005, COL1 p = 0.091; two-tailed t-test). (C) The number of senescent fibroblasts (based on circular or elliptical nuclear morphology as determined using Nikon Elements Image Analysis software) was counted in the papillary dermis. Asterisk indicates statistical significance from young adult values (p = 0.001; two-tailed t-test). (D) The area of the epidermis and papillary dermis were calculated from 3mm punch biopsies using Nikon Elements image analysis software. Asterisk indicates statistical significance from young adult values (Epidermis p = 0.0577, Papillary dermis p = 0.022; two-tailed t-test).