Usui Tomohiko, Ishida Susumu, Yamashiro Kenji, Kaji Yuichi, Poulaki Vasiliki, Moore Johnny, Moore Tara, Amano Shiro, Horikawa Yoshitaka, Dartt Darlene, Golding Matthew, Shima David T, Adamis Anthony P
Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA.
Invest Ophthalmol Vis Sci. 2004 Feb;45(2):368-74. doi: 10.1167/iovs.03-0106.
Vascular endothelial growth factor (VEGF) induces angiogenesis and vascular permeability and is thought to be operative in several ocular vascular diseases. The VEGF isoforms are highly conserved among species; however, little is known about their differential biological functions in adult tissue. In the current study, the inflammatory potential of two prevalent VEGF isoform splice variants, VEGF(120(121)) and VEGF(164(165)), was studied in the transparent and avascular adult mouse cornea.
Controlled-release pellets containing equimolar amounts of VEGF(120) and VEGF(164) were implanted in corneas. The mechanisms underlying this differential response of VEGF isoforms were explored. The response of VEGF in cultured endothelial cells was determined by Western blot analysis. The response of VEGF isoforms in leukocytes was also investigated.
VEGF(164) was found to be significantly more potent at inducing inflammation. In vivo blockade of VEGF receptor (VEGFR)-1 significantly suppressed VEGF(164)-induced corneal inflammation. In vitro, VEGF(165) more potently stimulated intracellular adhesion molecule (ICAM)-1 expression on endothelial cells, an effect that was mediated by VEGFR2. VEGF(164) was also more potent at inducing the chemotaxis of monocytes, an effect that was mediated by VEGFR1. In an immortalized human leukocyte cell line, VEGF(165) was found to induce tyrosine phosphorylation of VEGFR1 more efficiently.
Taken together, these data identify VEGF(164(165)) as a proinflammatory isoform and identify multiple mechanisms underlying its proinflammatory biology.
血管内皮生长因子（VEGF）可诱导血管生成和血管通透性，被认为在多种眼部血管疾病中起作用。VEGF异构体在物种间高度保守；然而，关于它们在成体组织中的不同生物学功能知之甚少。在本研究中，我们在透明且无血管的成年小鼠角膜中研究了两种常见的VEGF异构体剪接变体VEGF(120(121))和VEGF(164(165))的炎症潜能。
将含有等摩尔量VEGF(120)和VEGF(164)的控释微丸植入角膜。探讨了VEGF异构体这种差异反应的潜在机制。通过蛋白质免疫印迹分析确定培养的内皮细胞中VEGF的反应。还研究了白细胞中VEGF异构体的反应。
发现VEGF(164)在诱导炎症方面明显更有效。体内阻断VEGF受体（VEGFR）-1可显著抑制VEGF(164)诱导的角膜炎症。在体外，VEGF(165)更有效地刺激内皮细胞上细胞间黏附分子（ICAM）-1的表达，这一效应由VEGFR2介导。VEGF(164)在诱导单核细胞趋化方面也更有效，这一效应由VEGFR1介导。在永生化的人类白细胞细胞系中，发现VEGF(165)能更有效地诱导VEGFR1的酪氨酸磷酸化。
综上所述，这些数据确定VEGF(164(165))为促炎异构体，并确定了其促炎生物学的多种潜在机制。
