人上皮细胞角蛋白纤维结构转化的分析

ANALYSIS OF KERATIN FILAMENT STRUCTURAL TRANSFORMATION IN HUMAN EPITHELIAL CELLS

用0℃冷冻处理2—3 h,一些PcaSE-1和BEL-7404细胞的角蛋白纤维能部分地转化成凝聚颗粒,但在HeLa 和CNE 细胞中不发生这种角蛋白纤维结构转化。当回复温度到37℃15—30 min 时,PcaSE-1 和BEL-7404细胞的这种结构转化能快速回复。相反,在HeLa 和CNE 细胞有丝分裂时,角蛋白纤维能转化成凝聚颗粒,但PcaSE-1细胞和BEL-7404细胞的角蛋白纤维网始终维持纤维状态,且围绕纺锤体分布。上述结果表明:两类上皮细胞角蛋白纤维结构的转化似由不同因子所引起。我们的结果还指出:(1)单用秋水仙素或用秋水仙素和细胞松弛素D 合并处理PcaSE-1细胞不能引起角蛋白纤维凝聚。但经秋水仙素解聚微管后,会增强细胞对冷处理的凝聚反应。(2)冷处理时角蛋白纤维凝聚的形成与细胞是否具有两套不同的中间纤维无关。(3)予先用TritonX-100抽提细胞,角蛋白纤维在冷冻后不能转化成凝聚颗粒。(4)冷冻处理引起的结构转化可能是某些上皮细胞系的角蛋白纤维的一种特殊性质。

Upon 2—3 hours cold treatment(0℃),the keratin filaments of some PeaSE-1 ce-lls and BEL-7404 cells are partly trans-formed into granular aggregates,But suchstructural transformation does not occur inHeLa cells and CNE cells.By rewarming(37℃)cells within 15—30 minutes,thisstructural changes of keratin filaments inPcaSE-1 cells and BEL-7404 cells are rea-dily reversed.In contrast,in HeLa cellsand CNE cells,keratin filaments are tran-sformed into granula aggregates during mi-tosis,but the keratin filament network inPeaSE-1 cells and BEL-7404 cells remain-ed intact and encircled the developing mi-totic spindle as the cells entered mitosis.Results suggest that the above two typesof keratin filament structural transforma-tion might be induced by different factors.Our results also indicate that:(1)PcaSE-1 cells treated with colchicine alone orwith combination of colchicine and cyto-chalasin D does not cause granular aggre-gates of keratin filaments.However,afterdepolymerization of microtubules with col-chicine,the response of the cells to coldtreatment is intensified.(2)The aggrega-te formation during cold treatment is un-related to whether epithelial cells containtwo different type intermediate filamentsor not.(3)Epithelial cells preextractedwith Triton X-100 do not induce granularaggreagte formation of keratin filamentsupon cold treatment.(4)The structuraltransformation upon cold treatment maybe a characteristic of keratin filaments ofcertain epithelial cell lines.