Fig 2: a HRMECs were subjected to hypoxia for 24 h. DNMT3A and HIF-1α levels in HRMECs were measured via WB in the control and hypoxic groups (n = 3 per group). *p < 0.05 and ***p < 0.001. b HRMECs were treated with L-lactate (20 mM). DNMT3A and HIF-1α levels in HRMECs were measured via WB in the control and L-lactate groups (n = 3 per group). N, no significance; *p < 0.05. c HRMECs treated with AZD3965 (8 nM) under hypoxic conditions. DNMT3A and HIF-1α levels in HRMECs were measured via WB in the control and L-lactate groups (n = 3 per group). N, no significance; *p < 0.05. d Hypoxia increases HIF-1α lactylation. HIF-1α lactylation in control or hypoxic HRMECs was detected using the Pan anti-Kla antibody (n = 3 per group). *p < 0.05. e L-lactate increases HIF-1α lactylation. HIF-1α lactylation in control or L-lactate-treated HRMECs was detected using the Pan anti-Kla antibody (n = 3 per group). *p < 0.05. f AZD3965 decreases HIF-1α lactylation. HIF-1α lactylation in control or AZD3965-treated HRMECs was detected using the Pan anti-Kla antibody (n = 3 per group). ***p < 0.001

Fig 3: a Representative images of CD31 co-stained with VEGFA in retina samples. The relative fluorescence intensity was calculated and measured by Image J (n = 4 images per group); Scale bar, left, 500 μm, right, 50 μm. ****p < 0.0001. b Representative images of CD31 co-stained with Pan-Kla in retina samples. The relative fluorescence intensity was calculated and measured by Image J (n = 4 images per group); Scale bar, left, 500 μm, right, 50 μm. ****p < 0.0001. c Representative images of HIF-1α co-stained with Pan-Kla in retina samples. The relative fluorescence intensity was calculated and measured by Image J (n = 4 images per group); Scale bar, left, 500 μm, right, 50 μm. ***p < 0.001. d Representative images of CD31 co-stained with DNMT3A in retina samples. The relative fluorescence intensity was calculated and measured by Image J (n = 4 images per group); Scale bar, left, 500 μm, right, 50 μm. **p < 0.01. e Representative images of CD31 co-stained with VEGFA in retina samples. The relative fluorescence intensity was calculated and measured by Image J (n = 4 images per group); Scale bar, left, 500 μm, right, 50 μm. ***p < 0.001. f Representative images of CD31 co-stained with Pan-Kla in retina samples. The relative fluorescence intensity was calculated and measured by Image J (n = 4 images per group); Scale bar, left, 500 μm, right, 50 μm. ****p < 0.0001. g Representative images of HIF-1α co-stained with Pan-Kla in retina samples. The relative fluorescence intensity was calculated and measured by Image J (n = 4 images per group); Scale bar, left, 500 μm, right, 50 μm. ***p < 0.001. h Representative images of CD31 co-stained with DNMT3A in retina samples. The relative fluorescence intensity was calculated and measured by Image J (n = 4 images per group); Scale bar, left, 500 μm, right, 50 μm. **p < 0.01

Fig 4: a HIF-1α, DNMT3A, and VEGFA levels in DNMT3A-overexpressing HRMECs (n = 3 per group). N, no significance; *p < 0.05 and **p < 0.01. b HIF-1α, DNMT3A, and VEGFA levels in DNMT3A-knockdown HRMECs (n = 3 per group). N, no significance; **p < 0.01, ***p < 0.001. c Lactylation levels in HRMECs in the overexpressing (oe)-control and oe-DNMT3A groups were measured via WB. d Lactylation levels in HRMECs in the silencing (sh)-control and sh-DNMT3A groups were measured using WB. e Oe-DNMT3A increased HIF-1α lactylation, whereas sh-DNMT3A decreased HIF-1α lactylation (n = 3 per group). *p < 0.05. f Representative images of sprouting in the control and DNMT3A overexpression/knockdown groups after L-lactate treatment (n = 3 independent experiments, 3 images for each group); Scale bar: 50 µm. *p < 0.05, **p < 0.01. g Representative images of sprouting in the control and DNMT3A overexpression/knockdown groups after AZD3965 treatment (n = 3 independent experiments, 3 images for each group); N, no significance; Scale bar: 50 µm. h Representative images of cell migration in the control and DNMT3A overexpression/knockdown groups after L-lactate treatment (n = 3 independent experiments, 3 images for each group); Scale bar: 50 µm. **p < 0.01, ***p < 0.001. i Representative images of migration in the control and DNMT3A overexpression/knockdown groups after AZD3965 treatment (n = 3 independent experiments, 3 images for each group); N, no significance; Scale bar: 50 µm. j Representative images of proliferation in the control and DNMT3A overexpression/knockdown groups after L-lactate treatment (n = 3 independent experiments, 3 images for each group); Scale bar: 100 µm. *p < 0.05. k Representative images of proliferation in the control and DNMT3A overexpression/knockdown groups after AZD3965 treatment (n = 3 independent experiments, 3 images for each group); N, no significance; Scale bar: 100 µm

Fig 5: Schematic illustrating the molecular mechanism by which lactate-DNMT3A in HRMECs contributes to angiogenesis. Under hypoxic conditions, lactate-DNMT3A is upregulated in HRMECs in response to hypoxia. HIF-1ɑ lactylation promotes VEGFA levels and contributes to NV