Superoxide: A Major Factor for Stress Protein Induction in Reoxygenation Injury in the Intestinal Cell Line Caco-2

Abstract

Background/Aims: Acute intestinal ischemia is followed by cellular destruction and loss of mucosal barrier function. Posthypoxic injury of cellular proteins leads to the synthesis of heat shock proteins. The role of oxygen radicals in this process, however, is not fully established. Methods: In the present study, using the intestinal cell line Caco-2, we investigated the relationship between the synthesis of the heat shock protein HSP70, detected by Western blot and oxygen radicals as well as lactate dehydrogenase (LDH) release, as measured in photometrical tests. Results: Various periods of hypoxia and 30 min of reoxygenation resulted in an increased generation of superoxide as measured by the tetrazolium base 3-(4,5-dimethylthiazol-2-yl)2,5-diphenyltetrazoliumbromide. The inhibitor of superoxide dismutase (SOD), diethyldithiocarbamate (DDC) increased and addition of SOD decreased intracellular superoxide levels. HSP70 synthesis was detectable after 2 h of hypoxia. Similar to superoxide production, DDC increased and SOD reduced the HSP70 synthesis. In contrast, the increased LDH release from the cells observed after hypoxia was not significantly altered by DDC and SOD. Conclusion: The production of superoxide correlates with HSP70 induction, but not with LDH release. We conclude that hypoxia/reoxygenation induces heat shock protein production, a result of protein damage, by increased superoxide generation, whereas superoxide does not correlate with membrane damage in Caco-2 cells.

Serum heat shock protein 70 and oxidized LDL in patients with type 2 diabetes: does sex matter?

“…Increase in superoxide production and a reduced level of NO are also reported in the postmenopausal state (White et al 2010). Both thee mechanisms are associated with HSP70 induction (Gebhardt et al 1999;Wang et al 1996). Consistent with our presumptions, Molvarec et al (2007bMolvarec et al ( , 2010 demonstrated that serum HSP70 concentrations are decreased in normal human pregnancy, which is associated with down regulation of the immune system.…”

Expression analysis of heat shock protein genes during Aeromonas hydrophila infection in rohu, Labeo rohita, with special reference to molecular characterization of Grp78

“…However, excessive production of these ROS may lead to oxidative stress in fish. Over-expression of Hsc70 protects cells from oxidative stress (Dastoor and Dreyer 2000;Gebhardt et al 1999). Up-regulation of Hsc70 gene in A. hydrophila-infected liver and spleen tissues of rohu during 3 to 12 and 3 to 72 hpc, respectively, signifies the protective mechanism of the host cell from infection-related oxidative stress.…”

Natural annual cycle of heat shock protein expression in land snails: desertversusMediterranean species ofSphincterochila

“…The resulting rise in the rates of oxyradical production might increase oxidative stress and thus the need for HSPs for cytoprotection. Previous studies demonstrated the induction of Hsp70 and sHSPs in a number of conditions leading to oxidative stress, including renal ischemia, intestinal hypoxiareoxygenation experiments (Gebhardt et al, 1999;Smoyer et al, 2000) and hypoxia exposure in Lymnaea stagnalis snails (Fei et al, 2007). In the surf clam Donax variabilis, hyperoxia induced the expression of Hsp70, whereas sulfide-induced oxidative damage induced the expression of sHSPs (Joyner-Matos et al, 2006).…”