Blackburn R, Galoforo S, Berns C M, Ireland M, Cho J M, Corry P M, Lee Y J
Department of Radiation Oncology, William Beaumont Hospital, Royal Oak, Michigan 48073, USA.
Mol Cell Biochem. 1996 Feb 9;155(1):51-60. doi: 10.1007/BF00714333.
We investigated the role of alpha B-crystallin expression in the development of thermotolerance in murine L929 cells. An initial heat-shock of 10 min at 45 degrees C induced thermotolerance in these cells to a heat challenge at 45 degrees C administered 24 h later. The thermotolerance ratio at 10(-1) isosurvival was 1.7. Expression of alpha B-crystallin gene was not detected during the 24 h incubation at 37 degrees C following heat shock by either northern or western blots. In contrast, inducible HSP70 synthesis was observed during this time period. Thus, this cell line provided an unique system in which to examine the effects of transfected alpha B-crystallin on thermoresistance and thermotolerance. Cells stably transfected with alpha B-crystallin under the control of an inducible promoter did not show a significant increase in the ability to develop thermotolerance. However, a stably transfected L929 clone expressing high levels of constitutive alpha B-crystallin exhibited an approximately 50% increase in thermal resistance over parental and control cells. Though expression of alpha B-crystallin is not requisite for the development of thermotolerance in L929 cells, overexpression of transfected alpha B-crystallin can contribute to increased thermoresistance.
我们研究了αB-晶状体蛋白表达在小鼠L929细胞耐热性形成中的作用。在45℃进行10分钟的初始热休克可诱导这些细胞对24小时后施加的45℃热刺激产生耐热性。10^(-1)等存活度下的耐热比为1.7。热休克后在37℃孵育的24小时内，通过Northern印迹或Western印迹均未检测到αB-晶状体蛋白基因的表达。相反，在此时间段内观察到了诱导型HSP70的合成。因此，该细胞系提供了一个独特的系统，可用于研究转染的αB-晶状体蛋白对热抗性和耐热性的影响。在可诱导启动子控制下稳定转染αB-晶状体蛋白的细胞在形成耐热性的能力上未显示出显著增加。然而，一个稳定转染的L929克隆表达高水平的组成型αB-晶状体蛋白，其热抗性比亲本细胞和对照细胞提高了约50%。虽然αB-晶状体蛋白的表达对于L929细胞耐热性的形成并非必需，但转染的αB-晶状体蛋白的过表达可有助于提高热抗性。
