Heat shock response for ischemic kidney preservation and transplantation

Abstract

The heat shock response (HSR) is a form of stress conditioning during which reversible changes in cellular metabolism are rapidly induced by brief exposure to supra-physiologic levels of heat. The nature of these adaptive adjustments has been widely investigated and has received much attention in molecular biology and cancer research. Recent evidence indicates that a basic form of this stress response exists at the cellular level of virtually every organism. Although the physiological phenomenon of HSR is complex, it is well known that it can induce specific proteins, known as heat shock proteins (HSP's), which are not normally synthesized. HSP's become the major proteins synthesized during the heat shock response while normal protein synthesis is suppressed. In addition, the HSR has been demonstrated to confer a transient resistance to the organism to subsequent episodes of stress. Recently it has been reported that the HSR confers protection against cold ischemic injury and extends the cold preservation time of the rat kidney to 48 hours. In this study, we have applied the concept of HSR to the preservation, and transplantation of warm ischemically injured pig kidneys. Since there is a serious shortage of cadaver kidneys available for transplantation worldwide, this number would increase if warm ischemic kidneys could be utilized. However with present methods of organ recovery and preservation, such kidneys are not likely to function after transplantation even if they were removed. We hypothesized that the application of a thermal stress to pig kidneys prior to organ procurement and preservation will enhance the organs' ability to function after warm ischemic injury.