VEGF诱导血管内皮细胞产生H2O2及其促增殖作用

目的： 研究VEGF诱导血管内皮细胞产生细胞外H₂O₂及其在VEGF促血管内皮细胞增殖功能中的作用。方法: ① 以H₂DCFDA为H₂O₂指示剂，检测 500 μg/L VEGF刺激下，血管内皮细胞H₂O₂的产生；② 以MTT法检测3×10⁶ U/L过氧化氢酶（CAT），及外源性加入5-20 mmol/L H₂O₂对VEGF促增殖功能的影响。结果: ① 在VEGF刺激血管内皮细胞 15 min 后，细胞内开始出现逐渐增强的荧光，且随时间逐渐增强，至 45 min 左右最强，随后逐渐减弱；而同时加入过氧化氢酶组的细胞则仅有微弱荧光产生，且荧光强度不随时间变化；② 3×10⁶ U/L过氧化氢酶对VEGF的促增殖功能有明显的抑制作用（P<0.01）；③ 外源性加入5-10 mmol/L H₂O₂ 时对血管内皮细胞有明显促增殖作用（P<0.01），但其对VEGF的促增殖功能却有显著抑制作用（P<0.01）。结论: VEGF可刺激血管内皮细胞产生细胞外H₂O₂，在促细胞增殖中可能具有重要作用。而外源性H₂O₂对VEGF的生理功能可能具有抑制作用。

VEGF induces HUVECs to produce extracellular H2O2 and its proliferation role

AIM:To study the effect of VEGF on extracellular H₂O₂ production in HUVECs and the role of H₂O₂ in the VEGF-induced proliferation. METHODS:HUVECs was stimulated with 500 μg/L VEGF. Products of extracellular H₂O₂ was detected by H₂DCFDA staining. MTT method was used to value the influences of 3×10⁶ U/L catalase and 5-20 mmol/L H₂O₂ to VEGF function. RESULTS:After treatment for 15 min with VEGF, HUVECs appeared fluorescence, and continued to become stronger, peaked at 45 min then decreased. HUVECs, which was treated simultaneity with VEGF and 3×10⁶ U/L catalase, only appeared very faint fluorescence. The proliferation of HUVECs by VEGF was restrained when treated with 3×10⁶ U/L catalase. The extrinsic H₂O₂ at concentration of 5-10 mmol/L promoted the proliferation of HUVECs but inhibited the proliferation effect of VEGF on HUVECs (P<0.01). CONCLUSION:These findings indicate that VEGF induces HUVECs to produce extracellular H₂O₂ and plays role in proliferation, but extrinsic H₂O₂ restrains VEGF function.