PMC

Induction of DNase I-like endonucleases in EndoG-overexpressing cells. (A) Western blotting for DNase I, DNase X (both at 8 h), DNase 1-like 2, DNase γ (both at 12 h), caspase-activated DNase (CAD) (at 8 h post-transfection), and GAPDH (as a loading control) in NRK-52E cells overexpressing EndoG. (B–F) Quantification of DNase I, DNase X, DNase 1-like 2, DNase γ, and CAD by densitometric analysis of band mean optical densities (n=4, *p≤0.05 vs. pECFP transfected NRK-52E cells). CAD, caspase-activated DNase; GAPDH, glyceraldehyde-3-phosphate dehydrogenase.

Identification of CpG island only in promoter and exon 1 regions of EndoG gene among all known human cell death endonucleases including sequence variants. The criteria for CpG island identification were: length > 500bp, GC > 55%, observed/expected ratio > 0.65). DNase 1 (GenBank accession # NM 005223.3), DNase 1L1 variants 1 (NM 006730.2), 2 (NM 001009932.1), 3 (NM 001009933.1) and 4 (NM 001009934.1), DNase 1L2 (NM 001374.2), DNase 1L3 (DNase γ) (NM 004944.2), DNase 2α (NM 001375.2), DNase 2β variants 1 (NM 021233.2) and 2 (NM 058248.1), L-DNase II (LEI) (NM 030666.2), caspase-activated DNase (CAD) (NM 004402.2) and EndoG (NM 004435.2). CpG island in EndoG promoter/exon 1 is shown in solid black color.

CAD knockout alleviates development of atherosclerosis. A, Loss of CAD expression was confirmed by immunoblotting. B, Representative images of en face with Oil Red O staining of aortas of NC or HFD‐fed CAD ^−/−ApoE^−/− and ApoE^−/− littermates are shown in the left panel. Lesion occupation on the whole aorta was quantified (Right panel). n=10. *P<0.05 versus ApoE^−/− HF group; NS, no significance. C through E, (Left) Representative images of hematoxylin and eosin–stained cross‐sections of aortic roots (n=10) (C), brachiocephalic arteries (n=4) (D), and aortic arches (n=3) (E). Scale bar=100 μm. (Right) Quantification of areas of atheromatous plagues. *P<0.05 versus ApoE^−/− mice. CAD indicates caspase‐activated DNase; HF, high‐fat; HFD, high‐fat diet; NC, normal controls.

Sublethal engagement of apoptotic pathways can promote mutations in surviving cells. Cells subjected to sublethal stress or death receptor ligation can activate low (nonlethal) levels of executioner caspases and activated caspase-activated DNase (CAD). CAD cuts DNA, and error-prone DNA repair of the damage can lead to mutations that promote cancer.