Figure 2.

Aging-related phenotypes and upregulation of p16^Ink4A, p19^Arf and p21^CIP expression in Auf1^-/- mice. (a) Representative images of kyphosis (hunchback) (arrow), presence (top panel) and absence (bottom panel) of subcutaneous body fat (arrows), and atrophied gonads typically observed in 12-month-old Auf1^-/- (KO) mice but not in WT littermates. Images shown represent the majority of KO animals surveyed (>60%, kyphosis; >90%, reduced body fat; >90%, gonadal atrophy). (b) Increased relative expression of p16^Ink4a, p19^Arf and p21^CIP mRNAs in tissues and organs from 12-month-old KO mice compared to WT littermates, determined by qRT-PCR. (c) Immunohistochemical staining for p16^Ink4a and p21^CIP (brown, arrows) in organ sections from 12-month-old KO mice compared to WT littermates. Sections counter-stained by H&E. (d) Decay plots of p16^Ink4a, p19^Arf and p21^CIP mRNAs in MEFs from G2 embryos. Transcription was blocked with actinomycin D, cells were collected at indicated time points, RNA was extracted and mRNA levels were quantified by qRT-PCR. Plots are the mean of three independent experiments with calculated half-lives shown. (e) Decay plots showing recovery of p16^Ink4a mRNA destabilization by individual isoforms of AUF1 in KO MEFs. Plot shown is an average of three independent experiments.