Lazarous D F, Shou M, Stiber J A, Hodge E, Thirumurti V, Gonçalves L, Unger E F
Experimental Physiology and Pharmacology Section, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Cardiovasc Res. 1999 Nov;44(2):294-302. doi: 10.1016/s0008-6363(99)00203-5.
Angiogenic peptides like VEGF (vascular endothelial growth factor) and bFGF (basic fibroblast growth factor) have entered clinical trials for coronary artery disease. Attempts are being made to devise clinically relevant means of delivery and to effect site-specific delivery of these peptides to the cardiac tissue, in order to limit systemic side-effects. We characterized the response of the pericardium to delivery of a replication-deficient adenovirus carrying the cDNA for AdCMV.VEGF165, and assessed the effect of pericardial VEGF165 on myocardial collateral development in a canine model of progressive coronary occlusion.
Ameroid constrictors were placed on the proximal left circumflex coronary artery of mongrel dogs. Ten days later, 6 x 10(9) pfu AdCMV.VEGF165 (n = 9). AdRSV.beta-gal (n = 9), or saline (n = 7) were injected through an indwelling pericardial catheter. Transfection efficiency was assessed by X-gal staining. Pericardial and serum VEGF levels were measured serially by ELISA. Maximal myocardial collateral perfusion was quantified with radiolabeled or fluorescent microspheres 28 days after treatment.
In AdRSV.beta-gal-treated dogs, there was extensive beta-gal staining in the pericardium and epicardium, with minimal beta-gal staining in the mid-myocardium and endocardium. Pericardial delivery of AdCMV.VEGF165 resulted in sustained (8-14 day) pericardial transgene expression, with VEGF levels peaking 3 days after infection (> 200 ng/ml) and decreasing thereafter. There was no detectable increase in serum VEGF levels. Maximal collateral perfusion, a principal correlate of collateral development and angiogenesis, was equivalent in all groups.
Adenoviral-mediated gene transfer is capable of inducing sustained VEGF165 expression in the pericardium; however, locally targeted pericardial VEGF delivery failed to improve myocardial collateral perfusion in this model.
血管生成肽如血管内皮生长因子（VEGF）和碱性成纤维细胞生长因子（bFGF）已进入冠心病的临床试验。人们正在尝试设计与临床相关的递送方法，并将这些肽特异性地递送至心脏组织，以限制全身副作用。我们对携带AdCMV.VEGF165 cDNA的复制缺陷型腺病毒递送至心包后的反应进行了表征，并评估了心包内VEGF165对犬进行性冠状动脉闭塞模型中心肌侧支血管发育的影响。
在杂种犬的左回旋支冠状动脉近端放置Ameroid缩窄环。10天后，通过留置的心包导管注射6×10⁹ pfu的AdCMV.VEGF165（n = 9）、AdRSV.β-半乳糖苷酶（n = 9）或生理盐水（n = 7）。通过X-半乳糖苷染色评估转染效率。通过ELISA连续测量心包和血清中的VEGF水平。治疗28天后，用放射性标记或荧光微球对最大心肌侧支灌注进行定量。
在AdRSV.β-半乳糖苷酶治疗的犬中，心包和心外膜有广泛的β-半乳糖苷染色，心肌中层和心内膜的β-半乳糖苷染色极少。AdCMV.VEGF165的心包递送导致心包转基因持续表达（8 - 14天），VEGF水平在感染后3天达到峰值（> 200 ng/ml），此后下降。血清VEGF水平没有可检测到的升高。最大侧支灌注是侧支血管发育和血管生成的主要相关指标，在所有组中相当。
腺病毒介导的基因转移能够在心包中诱导VEGF165持续表达；然而，在该模型中，局部靶向的心包VEGF递送未能改善心肌侧支灌注。
