Fig. 1: Increased Glb1 mRNA and protein levels in cell and tissue aging.

Increased SAβ-gal with quantification of percent positive cells (bottom panel, over 100 cells per group were counted) and enlarged cell morphology (a), elevated mRNA levels of Glb1, p16^Ink4a, and p21^Wif1 (b), and upregulated protein levels of GLB1 and p16^Ink4a (c) in mouse embryonic fibroblasts (MEFs, from n = 3 embryos of wild-type C57BL6 mice) during replicative senescence. Scale bar, 100 µm. Representative images showing co-staining of GLB1 (red) and p16^Ink4a (green) (d, quantification of correlation between two signals in lower panel, over 80 cells per group were counted), and co-staining of GLB1 (red) and p21^Wif1 (green) (e, quantification of correlation between two signals in lower panel, over 100 cells per group were counted) in MEFs during replicative senescence. Scale bar, 50 µm. The mRNA (f) and protein (g) levels of Glb1, p16^Ink4a, and p21^Wif1 in indicated tissues isolated from young (3 months, male, n = 3) and old (24 months, male, n = 3) mice. h Quantification of GLB1 band intensity in g. i SAβ-gal staining in brain, kidney, and liver tissues from young (3 months, male, n = 3) and old (24 months, male, n = 3) mice. Scale bar, 50 µm. Cell passage (P) numbers are indicated. “n” represents number of biological replicates. Data represent the means ± s.e.m. p value was calculated by Student’s t test (two-sided).