Figure 5. VCPIP1 is critical for DPC repair, genomic stability and healthy aging.

(A) Survival assays for Vcpip1^+/+ and Vcpip1^−/− MEFs exposed to formaldehyde (FA), camptothecin (CPT) and cisplatin (Cis). Error bars indicate mean ± SD of three independent experiments (* p<0.05; ** p<0.01). The expression level of VCPIP1 was assessed by Western blot (top left).

(B-C) Vcpip1^+/+ or Vcpip1^−/− MEFs were treated with CPT (1 μM, 30 min) and Top1cc signals were detected by immunofluorescence. Nuclei were visualized with DAPI (blue). Representative images are shown in (B). Quantification of foci signals is shown in (C) (** p<0.01). Scale bars, 10 μm.

(D) Vcpip1^+/+ or Vcpip1^−/− MEFs were treated with FA (250 μM, 1 h) and DPCs were measured as the ratio of crosslinked DNA compared to total DNA (* p<0.05).

(E-F) Vcpip1^−/− cells showed genomic instability. (E) Representative images of metaphases prepared from Vcpip1^+/+ and Vcpip1^−/− MEFs. Arrows indicate chromosomal abnormalities. (F) Quantification of the percentage of chromosomal abnormalities. Metaphase spreads (50) were evaluated for each genotype. Scale bars, 10 μm.

(G) Quantification of micronucleated normochromic erythrocytes from Vcpip1^+/+ and Vcpip1^−/− mice blood (** p<0.01).

(H-I) Immunohistochemistry of Top1cc signals from the livers of 4-month-old Vcpip1^+/+ and Vcpip1^−/− mice. Nuclei were visualized with Hoechst (blue). Representative images are shown in (H). Quantification of foci signals is shown in (I) (** p<0.01). Scale bars, 10 μm.

(J) Representative images of the eyes of female Vcpip1^+/+ and Vcpip1^−/− mice. Note cataract in Vcpip1^−/− mice.

(K) Incidence of cataract formation over time in Vcpip1^+/+ (n=29) and Vcpip1^−/− (n=22) mice (** p<0.01).

(L) Representative images of 6-month-old female Vcpip1^+/+ and Vcpip1^−/− mice. Note lordokyphosis in the Vcpip1^−/− mouse as indicted by the dotted red line.

(M) Incidence of lordokyphosis in Vcpip1^+/+ (n=29) and Vcpip1^−/− (n=22) mice (* p<0.05).

(N) Inguinal adipose tissue (IAT) from 6-month-old Vcpip1^+/+ or Vcpip1^−/− mice (n=3) were analyzed by SA-β-Gal staining.

(O) Body weight analysis of female Vcpip1^+/+ and Vcpip1^−/− mice (n=4) (** p<0.01).

(P) Overall survival curves for Vcpip1^+/+ (n=29) and Vcpip1^−/− (n=22) mice (* p<0.05).

See also Figure S5.