Merchant F A, Holmes W H, Capelli-Schellpfeffer M, Lee R C, Toner M
Center for Engineering in Medicine and Surgical Services, Massachusetts General Hospital, Boston, USA.
J Surg Res. 1998 Feb 1;74(2):131-40. doi: 10.1006/jsre.1997.5252.
Damage to the cell membrane has been implicated as the primary event in the pathogenesis of heat shock, generally resulting in loss of cellular homeostasis and cell death. Thus a promising mode of therapy would involve the restoration of cell membrane integrity. Surfactant molecules, specifically triblock polymers such as Poloxamer 188 (P-188), possess the ability to self-aggregate into membrane-like structures in aqueous solutions and have been shown to restore membrane integrity. The objective of this study was to develop functional and morphological assays to determine whether treatment with P-188 after heat shock enhances the recovery of thermally damaged cells. Human foreskin fibroblasts were placed in sterile vials and heated by immersion in a calibrated water bath for various lengths of time at predefined temperatures. Cell recovery after heat shock was assessed using a functional assay based on the ability of the cells to contract fibroblast populated collagen lattices (FPCLs). Subsequent to heating, collagen lattices were prepared with control (no heat, no P-188) and heat shocked cells (with and without P-188). Our results indicate that treatment with low concentrations of P-188 after heat shock was effective in ameliorating both the morphological integrity and the contractile function of thermally damaged cells. Further, we observed that P-188 was most effective in improving the contractile ability of cells heat shocked at 45 degrees C; however, it had no influence on the contractility of cells exposed to higher temperatures. Our results suggest that there exists a threshold of thermal stress (45 degrees C for 20-60 min) beyond which treatment with low concentrations of P-188 (0.5 mg/ml) is ineffective in minimizing cell damage. Moreover, the results of our morphological assays indicate that cells treated with P-188 after heat shock maintain their cytoskeletal organization, whereas untreated cells exhibit filamentous actin depolymerization.
细胞膜损伤被认为是热休克发病机制中的主要事件，通常会导致细胞内稳态丧失和细胞死亡。因此，一种有前景的治疗方式将涉及恢复细胞膜的完整性。表面活性剂分子，特别是三嵌段聚合物，如泊洛沙姆188（P - 188），具有在水溶液中自聚集形成膜状结构的能力，并已被证明能恢复膜的完整性。本研究的目的是开发功能和形态学检测方法，以确定热休克后用P - 188治疗是否能增强热损伤细胞的恢复。将人包皮成纤维细胞置于无菌小瓶中，通过浸入校准水浴中在预定温度下加热不同时间。热休克后细胞的恢复通过基于细胞收缩成纤维细胞填充胶原晶格（FPCL）能力的功能检测来评估。加热后，用对照（无热，无P - 188）和热休克细胞（有和无P - 188）制备胶原晶格。我们的结果表明，热休克后用低浓度的P - 188治疗可有效改善热损伤细胞的形态完整性和收缩功能。此外，我们观察到P - 188在改善45℃热休克细胞的收缩能力方面最有效；然而，它对暴露于更高温度的细胞的收缩性没有影响。我们的结果表明存在一个热应激阈值（45℃持续20 - 60分钟），超过该阈值，用低浓度的P - 188（0.5mg/ml）治疗在最小化细胞损伤方面无效。此外，我们形态学检测的结果表明，热休克后用P - 188处理的细胞保持其细胞骨架组织，而未处理的细胞表现出丝状肌动蛋白解聚。
