Mislick K A, Baldeschwieler J D
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena 91125, USA.
Proc Natl Acad Sci U S A. 1996 Oct 29;93(22):12349-54. doi: 10.1073/pnas.93.22.12349.
We report evidence that gene complexes, consisting of polycations and plasmid DNA enter cells via binding to membrane-associated proteoglycans. Treatment of HeLa cells with sodium chlorate, a potent inhibitor of proteoglycan sulfation, reduced luciferase expression by 69%. Cellular treatment with heparinase and chondroitinase ABC inhibited expression by 78% and 20% with respect to control cells. Transfection was dramatically inhibited by heparin and heparan sulfate and to a smaller extent by chondroitan sulfate B. Transfection of mutant, proteoglycan deficient Chinese hamster ovary cells was 53 x lower than of wild-type cells. For each of these assays, the intracellular uptake of DNA at 37 degrees C and the binding of DNA to the cell membrane at 4 degrees C was impaired. Preliminary transfection experiments conducted in mutant and wild-type Chinese hamster ovary cells suggest that transfection by some cationic lipids is also proteoglycan dependent. The variable distribution of proteoglycans among tissues may explain why some cell types are more susceptible to transfection than others.
由聚阳离子和质粒DNA组成的基因复合物通过与膜相关蛋白聚糖结合进入细胞。用氯酸钠（一种有效的蛋白聚糖硫酸化抑制剂）处理HeLa细胞，可使荧光素酶表达降低69%。用肝素酶和软骨素酶ABC处理细胞，相对于对照细胞，表达分别抑制了78%和20%。肝素和硫酸乙酰肝素显著抑制转染，硫酸软骨素B的抑制作用较小。突变的、缺乏蛋白聚糖的中国仓鼠卵巢细胞的转染率比野生型细胞低53倍。对于这些实验中的每一个，37℃时DNA的细胞内摄取以及4℃时DNA与细胞膜的结合均受损。在突变型和野生型中国仓鼠卵巢细胞中进行的初步转染实验表明，某些阳离子脂质的转染也依赖于蛋白聚糖。蛋白聚糖在组织间的分布差异可能解释了为什么某些细胞类型比其他细胞类型更容易被转染。
