Increased immunogenicity is an integral part of the heat shock response following renal ischemia.

Renal ischemia increases tubular immunogenicity predisposing to increased risk of kidney allograft rejection. Ischemia-reperfusion not only disrupts cellular homeostasis but also induces the cytoprotective heat shock response that also plays a major role in cellular immune and defense processes. This study therefore tested the hypothesis that upregulation of renal tubular immunogenicity is an integral part of the heat shock response after renal ischemia.

HSP-mediated cytoprotection of mesothelial cells in experimental acute peritoneal dialysis.

Background: Low biocompatibility of peritoneal dialysis solution (PDS) injures mesothelial cells but also induces heat shock proteins (HSP), the main effectors of the cellular stress response. This study investigated whether overexpression of HSP upon pharmacologic induction results in cytoprotection of mesothelial cells in experimental PD.

Methods: Stress response of mesothelial cells upon exposure to PDS was pharmacologically manipulated using glutamine as a co-inducer.

Evidence for HSP-mediated cytoskeletal stabilization in mesothelial cells during acute experimental peritoneal dialysis.

Low biocompatibility of peritoneal dialysis fluid (PDF) injures mesothelial cells and activates their stress response. In this study, we investigated the role of heat shock proteins (HSP), the main cytoprotective effectors of the stress response, in cytoskeletal stabilization of mesothelial cells in experimental peritoneal dialysis. In cultured human mesothelial cells, cytoskeletal integrity was assessed by detergent extractability of marker proteins following in vitro PDF exposure.

Overexpression of HSP-72 confers cytoprotection in experimental peritoneal dialysis.

Background: Peritoneal dialysis is complicated by mesothelial cell injury due to low biocompatibility of peritoneal dialysis fluid (PDF). We have previously demonstrated that heat shock protein (HSP)-72 is potently up-regulated in response to PDF exposure of mesothelial cells in in vitro and in vivo models of peritoneal dialysis. The aim of this study was to evaluate potential cytoprotective effects of overexpression of HSP-72.

Urinary heat shock protein-72 excretion in clinical and experimental renal ischemia.

Renal ischemia not only causes injury but also induces repair mechanisms, such as the cellular induction of the 72-kilodalton heat shock protein HSP-72. The aim of this study was to determine whether HSP-72 is excreted in urine after ischemic renal injury. The first urine of six pediatric allograft recipients was examined for proteinuria and urinary HSP-72 excretion.

Developmental expression of HSP-72 and ischemic tolerance of the immature kidney.

The resistance of the immature kidney to ischemic injury is well documented, but the mechanisms involved in this tolerance have been elusive. Previous studies have demonstrated that tubules obtained from immature rats exhibit a bigger stress response than mature tubules. Consequently, we evaluated the developmental expression of HSP-72 in the postnatal kidney and determined whether or not that pattern of expression was correlated with the previously known tolerance of the immature kidney to injury.

HSP-25 and HSP-90 stabilize Na,K-ATPase in cytoskeletal fractions of ischemic rat renal cortex.

Background: We recently designed an in vitro system based on differential Triton-extractability of Na,K-ATPase from the cytoskeletal protein fraction isolated from rat renal cortex after renal ischemia. In the present study, we hypothesized that heat shock protein (HSP)-70, HSP-25 and HSP-90 work synergistically to stabilize the cytoskeletal anchorage of Na,K-ATPase.

Methods: Cellular proteins were fractionated by differential centrifugation into cytoskeletal pellets (I-PEL) obtained early (exhibiting abnormally high Triton extractability of Na,K-ATPase) and non-cytoskeletal supernatants (R-SUP) obtained late (exhibiting high abundance of HSP) after renal ischemia.

Ischemic conditioning prevents Na,K-ATPase dissociation from the cytoskeletal cellular fraction after repeat renal ischemia in rats.

Recent studies have suggested that heat shock proteins (HSPs) are involved in the restoration of the cytoskeletal anchorage of Na,K-ATPase after renal ischemia. To determine their role in ischemic conditioning, we investigated whether cytoskeletal Na,K-ATPase was stabilized during repeat ischemia concurrent with 25-kD and 70-kD HSPs induction. Anesthetized rats either underwent single unilateral renal ischemia or were conditioned with bilateral renal ischemia and, after 18 h of reflow, were then subjected to repeat unilateral renal ischemia.