thapsigargin and Kidney-Diseases

Fibrosis is a common final pathway of chronic kidney disease, which is a major incurable disease. Although fibrosis has an irreversible pathophysiology, the molecular and cellular mechanisms responsible remain unclear and no specific treatment is available to halt the progress of renal fibrosis. Thus, an improved understanding of the cellular mechanism involved and a novel therapeutic approach are urgently required for end-stage renal disease (ESRD). We investigated the role played by interleukin-10 (IL-10, a potent anti-inflammatory cytokine) in kidney fibrosis and the mechanisms involved using

Topics: Animals; Apoptosis; Brefeldin A; Disease Models, Animal; Endoplasmic Reticulum Stress; Fibrosis; Interleukin-10; Kidney; Kidney Diseases; Mice; Renal Insufficiency, Chronic; RNA, Small Interfering; Thapsigargin; Tunicamycin; Ureteral Obstruction

Topics: Cell Death; Colforsin; Humans; Indenes; Kidney Diseases; MAP Kinase Signaling System; Podocytes; Pyrazoles; Signal Transduction; Thapsigargin

Although renal ischemia-reperfusion is known to activate the unfolded protein response, the renal site and role of activation of this response following the insult in vivo remains largely unknown. Here we studied the renal spatio-temporal expression pattern of glucose-regulated protein (GRP) 78, a central regulator of the unfolded protein response network, following renal ischemia-reperfusion and the effects of the specific chemical unfolded protein response inducers, tunicamycin and thapsigargin, on renal ischemia-reperfusion injury in mice. Renal ischemia-reperfusion resulted in expression of the spliced form of the X-box binding protein-1 (XBP-1s) transcript, an unfolded protein response target, at 1 and 2 h after the insult. This response was followed by an increase in the GRP78 transcript and protein. The increased amount of GRP78 protein after ischemia-reperfusion was largely localized in proximal tubule cells. Pretreatment with tunicamycin or thapsigargin significantly ameliorated renal dysfunction and injury after ischemia-reperfusion. Taken together with these results, the unfolded protein response was activated following renal ischemia-reperfusion at sites that are susceptible to ischemia-reperfusion injury, and this activation had a protective effect against renal ischemia-reperfusion injury in vivo. Molecules involved in the unfolded protein response may offer new opportunities for pharmacological intervention against renal ischemia-reperfusion injury, which is an important cause of acute kidney injury.

Topics: Animals; Blotting, Western; DNA-Binding Proteins; Endoplasmic Reticulum Chaperone BiP; Enzyme Inhibitors; Heat-Shock Proteins; Kidney; Kidney Diseases; Kidney Function Tests; Male; Mice; Molecular Chaperones; Protein Folding; Regulatory Factor X Transcription Factors; Renal Circulation; Reperfusion Injury; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Thapsigargin; Transcription Factors; Tunicamycin; X-Box Binding Protein 1

The cytoprotection of LLC-PK1 cells afforded by endoplasmic reticulum (ER) stress preconditioning suggests that the ER plays an important role during drug-induced renal toxicity. However, in vitro studies have been largely limited to LLC-PK1 cells and model toxins. Therefore, we tested the hypothesis that cytoprotection following ER stress preconditioning is a common property of renal cell lines (LLC-PK1 (pig), NRK-52E (rat), HEK293 (human), MDCK (dog)) and extends to clinically relevant nephrotoxins. ER stress inducers (tunicamycin, thapsigargin and oxidized dithiothreitol (DTTox)) resulted in a dose-dependent increase in GRP78 and GRP94 stress protein expression, but the magnitude of induction was cell line- and inducer-dependent. Toxicity of the model toxins iodoacetamide and tert-butylhydroperoxide was modified by preconditioning. DTTox was effective in decreasing the toxicity in all cell lines, but protection was variable with tunicamycin and thapsigargin. Toxicity of clinically relevant drugs (cisplatin, gentamicin, glyoxylate, cyclosporine A, p-aminophenol) was significantly decreased in cells preconditioned by tunicamycin or DTTox. These results demonstrate that ER stress preconditioning offers cytoprotection against clinically relevant nephrotoxins in renal cell lines from multiple species, although there were qualitative and quantitative differences between the cell lines. These results support the hypothesis that ER is involved in drug-induced renal toxicity.

Topics: Animals; Dithiothreitol; Dogs; Endoplasmic Reticulum; Endoplasmic Reticulum Chaperone BiP; Heat-Shock Proteins; Humans; Iodoacetamide; Kidney; Kidney Diseases; L-Lactate Dehydrogenase; LLC-PK1 Cells; Oxidative Stress; Rats; Swine; Thapsigargin; Tunicamycin

Nifedipine and verapamil have been shown previously to protect against renal function alterations induced by shock wave lithotripsy (SWL) in humans and rats; however, the mechanism is unclear. This study was aimed to examine whether these drugs could protect cultured kidney cells following shock wave exposure (SWE). The effect of nifedipine, verapamil and diltiazem on Madin Darby canine kidney (MDCK) cells following SWE was examined by determining the release of glutamate oxalactate transferase (GOT) and lactate dehydrogenase (LDH) in cell suspensions; and also cytosolic Ca2+ concentration ([Ca2+]i). Immediately after SWE, there was a transient release of GOT and LDH (16% and 4 fold, respectively). In contrast, [Ca2+]i measured within 1-6 hr after SWE gradually increased by 15-156%. The Ca2+ entry blockers (1 or 10 microM) failed to inhibit the enzyme release; however, they abolished the progressive rises in [Ca2+]i. The Ca2+ entry blockers may protect the cells from damage of SWE via maintaining a low resting [Ca2+]i.

Topics: Adenosine Triphosphate; Animals; Aspartate Aminotransferases; Bradykinin; Calcium; Calcium Channel Blockers; Cell Line; Cytosol; Diltiazem; Dogs; Enzyme Inhibitors; Fluorescent Dyes; Fura-2; Kidney Diseases; Kidney Tubules; L-Lactate Dehydrogenase; Lithotripsy; Nifedipine; Thapsigargin; Verapamil