Sakakibara Y, Shimada Y, Masuda A, Ohtsuka K
Department of Anesthesiology, Nagoya University School of Medicine, Japan.
Int J Hyperthermia. 1992 May-Jun;8(3):329-40. doi: 10.3109/02656739209021788.
We investigated the relation between the synthesis of inducible form of heat-shock protein 70 (hsp70) and the development of thermotolerance using NRK (normal rat kidney) cells and their mutant cell line (39-1 cells). In NRK cells, hsp70 was clearly induced by conditioning treatments (42 degrees C for 2 h, 45 degrees C for 15 min or 100 microM sodium arsenite for 1 h). On the other hand, the induction of hsp70 in 39-1 cells was very low or not detectable by these treatments. Other high molecular weight hsps, hsc70 (constitutive form), hsp90 and hsp110 were induced in both cell lines. However, thermotolerance as defined by clonogenic survival was induced in both cell lines to a similar extent by the conditioning treatments. When cells were made thermotolerant by conditioning heating at 45 degrees C for 15 min, the inhibition of protein synthesis after challenge (second) heating was less in NRK cells than in 39-1 cells. This indicated that the extent of 'translational thermotolerance' was much higher in NRK cells than in 39-1 cells. From these results, it is suggested that the synthesis of inducible hsp70 is involved in the translational thermotolerance rather than the development of thermotolerance as defined by clonogenic survival.
我们利用NRK（正常大鼠肾）细胞及其突变细胞系（39 - 1细胞）研究了热休克蛋白70（hsp70）诱导型的合成与热耐受性发展之间的关系。在NRK细胞中，通过预处理（42℃处理2小时、45℃处理15分钟或100微摩尔亚砷酸钠处理1小时）可明显诱导hsp70的产生。另一方面，这些处理在39 - 1细胞中对hsp70的诱导作用非常低或无法检测到。其他高分子量热休克蛋白，即hsc70（组成型）、hsp90和hsp110在两种细胞系中均有诱导产生。然而，通过预处理，两种细胞系中由克隆形成存活率定义的热耐受性均被诱导到相似程度。当细胞通过在45℃预处理加热15分钟而获得热耐受性后，在再次加热（激发）后，NRK细胞中蛋白质合成的抑制程度低于39 - 1细胞。这表明NRK细胞中“翻译性热耐受性”的程度远高于39 - 1细胞。从这些结果推测，诱导型hsp70的合成参与了翻译性热耐受性，而非由克隆形成存活率定义的热耐受性的发展。
