LIF deficiency causes resistance against hyperoxic insult and increased extraretinal neovascularization in the OIR model.
(A–F) Double IHC of PECAM-1 (green in A and C; white in E and F) and GFAP (red in B and D) in P12 retinas after 3 days of hyperoxygen insult. Note the obliterated vein typically observed in Lif+/+ mice (open arrowheads), which was preserved in Lif–/– mice. Also note the entirely decreased area of vaso-obliteration (yellow outlines in E and F) in Lif–/– mice. (G–J) ISH for VEGF combined with isolectin staining in P12 retinas in the OIR model. Note the increased VEGF-expressing cells in Lif–/– mice were detected in the area resistant against hyperoxygen insult (above dotted lines). (K) Quantification of the vaso-obliterated area. Data represent quantification of the entire retina (n = 6). (L) Quantitative RT-PCR of vegfa for RNA isolated from P12 retina in the OIR model (n = 5). (M–P) Double IHC of PECAM-1 and GFAP in P17 retinas in the OIR model. (Q and R) Higher-magnification images of the boxed regions in M and O, respectively. (S and T) Three-dimensional confocal images of IHC for PECAM-1 in the NVT area. (U and V) Bright-field images of P17 retinas of Lif+/+ and Lif–/– mice in the OIR model. Note the severe bleeding in the NVT area of Lif–/– retina. (W) Quantification of the NVT area. Data represent quantification of the entire retina (n = 7). (X) Quantitative RT-PCR of vegfa for RNA isolated from P17 retina in the OIR model (n = 5). (Y) Western blotting of VEGF proteins from P17 retina in the OIR model. Numbers indicate VEGF120, VEGF164, and VEGF188 isoforms, respectively. a, artery; v, vein. Scale bars: 50 μm. *P < 0.03, **P < 0.01 versus Lif+/+.