Fig 1: Elevated Gremlin1 expression in vitreous fluid of patients with PDR and in mouse models. (A) Quantification of Gremlin1 protein levels by multiplex liquid-chip assay analysis (n=10 for control subjects, n=9 for PDR patients). (B) Quantification of Grem1 mRNA (n=7-8, Gapdh was used as the internal control) and Gremlin1 protein expression levels (n=6, β-actin was used as the internal control) in the retinae of OIR and control groups. Student's t test was used to compare differences. (C) Quantification of Grem1 mRNA (n=7-9, Gapdh was used as the internal control) and Gremlin1 protein expression levels (n=6, β-actin was used as the internal control) in CNV mice model. Student's t test was used to compare differences. One-way ANOVA was used to compare the difference. (D) Representative images of fluorescence in situ hybridization of Grem1(green) in the retinae with GS (red) and DAPI (blue). All three channels were merged. Scale bar, 50 μm. (E) Analysis of Grem1 mRNA (n=4, Gapdh was used as the internal control) and Gremlin1 protein levels (n=3, β-actin was used as the internal control) in Müller cells treated as indicated. NO, normal oxygen. Student's t test was used to compare differences. (F) RT-PCR analysis assessed the Grem1 mRNA levels (n=3-4, Gapdh was used as the internal control). Gremlin1 protein levels were quantified by Western blotting analysis (n=3, β-actin was used as the internal control). NG, normal glucose (5.5 mM). One-way ANOVA was used to compare the difference. (G) Level of soluble Gremlin1 in the Müller cells culture medium after high glucose treatment (n=5). NG, normal glucose (5.5 mM). One-way ANOVA was used to compare the difference. *P < 0.05, **P<0.01, ****P<0.0001 compared with control group.