Jeschke M G, Barrow R E, Hawkins H K, Yang K, Hayes R L, Lichtenbelt B J, Perez-Polo J R, Herndon D N
Shriners Hospital for Children, University of Texas Medical Branch, Galveston, Texas 77550, USA.
Gene Ther. 1999 Jun;6(6):1015-20. doi: 10.1038/sj.gt.3300923.
Exogenous insulin-like growth factor-I (IGF-I) is known to improve the pathophysiology of a thermal injury, however, deleterious side-effects have limited its utility. Cholesterol-containing cationic liposomes that encapsulate complementary DNA (cDNA) are nonviral carriers used for in vivo gene transfection. We propose that liposome IGF-I gene transfer will accelerate wound healing in burned rats and attenuate deleterious side-effects associated with high levels of IGF-I. To test this hypothesis IGF-I gene constructs, encapsulated in liposomes, were studied for their efficacy in modulating the thermal injury response. Thirty adult male Sprague-Dawley rats were given a 60% TBSA scald burn and randomly divided into three groups to receive weekly subcutaneous injections of liposomes plus the lacZ gene coding for beta-galactosidase, liposomes plus cDNA for IGF-I and beta-galactosidase or liposomes plus the rhIGF-I protein. Body weights and wound healing were measured. Muscle and liver dry/wet weights and IGF-I concentrations in serum, skin and liver were measured by radioimmunoassay. Transfection was confirmed by histochemical staining for beta-galactosidase. Rats receiving the IGF-I cDNA constructs exhibited the most rapid wound re-epithelialization and greatest increase in body weight and gastrocnemius muscle protein content (P < 0.05). Local IGF-I protein concentrations in the skin were higher when compared to liposomes containing only the lacZ gene (P < 0.05) Transfection was apparent in the cytoplasm of myofibroblasts, endothelial cells and macrophages of the granulation tissue. Liposomes containing the IGF-I gene constructs proved effective in preventing muscle protein wasting and preserving total body weight after a severe thermal injury.
已知外源性胰岛素样生长因子-I（IGF-I）可改善热损伤的病理生理过程，然而，其有害的副作用限制了它的应用。包裹互补DNA（cDNA）的含胆固醇阳离子脂质体是非病毒载体，用于体内基因转染。我们提出脂质体IGF-I基因转移将加速烧伤大鼠的伤口愈合，并减轻与高水平IGF-I相关的有害副作用。为了验证这一假设，对包裹在脂质体中的IGF-I基因构建体调节热损伤反应的功效进行了研究。30只成年雄性Sprague-Dawley大鼠给予60%体表面积的烫伤，随机分为三组，分别每周皮下注射脂质体加编码β-半乳糖苷酶的lacZ基因、脂质体加IGF-I和β-半乳糖苷酶的cDNA或脂质体加重组人IGF-I蛋白。测量体重和伤口愈合情况。通过放射免疫分析法测量肌肉和肝脏的干/湿重以及血清、皮肤和肝脏中的IGF-I浓度。通过β-半乳糖苷酶的组织化学染色确认转染情况。接受IGF-I cDNA构建体的大鼠伤口再上皮化最快，体重和腓肠肌蛋白含量增加最多（P<0.05）。与仅含lacZ基因的脂质体相比，皮肤中局部IGF-I蛋白浓度更高（P<0.05）。在肉芽组织的肌成纤维细胞、内皮细胞和巨噬细胞的细胞质中可见转染现象。含有IGF-I基因构建体的脂质体被证明可有效防止严重热损伤后肌肉蛋白消耗并维持总体重。
