Stege G J, Li G C, Li L, Kampinga H H, Konings A W
Department of Radiobiology, University of Groningen, The Netherlands.
Int J Hyperthermia. 1994 Sep-Oct;10(5):659-74. doi: 10.3109/02656739409022446.
Heat treatment of cells results in an increased protein content of nuclei and nuclear matrices when isolated after the heat treatment. This increase of TX-100 insoluble protein is interpreted as being the result of protein denaturation and subsequent aggregation. After the heat treatment cells can (partly) recover from these aggregates. Recent data suggest that heat shock proteins (hsps) might be involved in the recovery (disaggregation) from these heat-induced insoluble protein complexes. In this report, the role of hsp72 in the process of aggregation and disaggregation was investigated using: non-tolerant rat-1 cells, thermotolerant rat-1 cells (rat-1 TT), and transfected rat-1 cells constitutively expressing the human inducible hsp72 gene (HR-24 cells). After heating the various cells, it was observed that the expression of the human hsp72 confers heat resistance (43-45 degrees C). Heat-induced intranuclear protein aggregation was less in HR and rat-1 TT cells as compared to nontolerant rat-1 cells. After heat treatments leading to the same initial intranuclear protein aggregation, rat-1 TT cells recovered more rapidly from these aggregates, while HR cells recovered at the same rate as nontolerant rat-1 cells. Our data suggest that increased levels of hsp72 can confer heat resistance at the level of initial (nuclear) heat damage. Elevated levels of hsp72 alone, however, do not enable cells to recover more rapidly from heat-induced intranuclear protein aggregates.
对细胞进行热处理后，若在热处理后分离细胞核和核基质，其蛋白质含量会增加。TX - 100不溶性蛋白质的这种增加被解释为蛋白质变性及随后聚集的结果。热处理后细胞能够（部分地）从这些聚集体中恢复。最近的数据表明，热休克蛋白（hsps）可能参与了从这些热诱导的不溶性蛋白质复合物中的恢复（解聚）过程。在本报告中，使用以下细胞研究了hsp72在聚集和解聚过程中的作用：不耐热的大鼠 - 1细胞、耐热的大鼠 - 1细胞（大鼠 - 1 TT）以及组成性表达人诱导型hsp72基因的转染大鼠 - 1细胞（HR - 24细胞）。对各种细胞进行加热后，观察到人类hsp72的表达赋予了耐热性（43 - 45摄氏度）。与不耐热的大鼠 - 1细胞相比，HR和大鼠 - 1 TT细胞中热诱导的核内蛋白质聚集较少。在导致相同初始核内蛋白质聚集的热处理后，大鼠 - 1 TT细胞从这些聚集体中恢复得更快，而HR细胞与不耐热的大鼠 - 1细胞以相同的速率恢复。我们的数据表明，hsp72水平的升高可以在初始（核）热损伤水平赋予耐热性。然而，仅hsp72水平的升高并不能使细胞从热诱导的核内蛋白质聚集体中更快地恢复。
