fr-167653 and Proteinuria

Acute tubular necrosis (ATN) secondary to induced warm ischemia (WI) results in inflammatory and delayed fibrotic processes and remains a common clinical problem with serious consequences. Because tumor necrosis factor-alpha (TNF-alpha) is a prominent proinflammatory factor implicated in the pathophysiology of acute renal ischemia reperfusion injury (IRI), we hypothesized that FR167653 (FR), a potent inhibitor of TNF-alpha and interleukin-1beta production, may reduce IRI.. IRI was induced in male pigs by bilateral clamping of the renal pedicle for 90 minutes (WI90), or unilateral renal clamping (90 minutes) after contralateral nephrectomy (1/2Nx90), or unilateral renal clamping without contralateral nephrectomy (WIuni90). FR was administered intravenously 60 minutes before WI (1 mg/kg/h), during WI, and continuously for 3 hours (1 mg/kg/h) during reperfusion in treated groups (FRWI90, FR1/2Nx90, or FRWIuni90). Blood and urine samples were collected between day 1 and 3 months after reperfusion for assessment of renal function. Kidneys were excised and renal tissues were collected at 3 months for morphologic and inflammation evaluation and protein analysis. Experimental groups were compared with sham operated (control) and heminephrectomized (Unif) groups without renal ischemia.. Three WI90 animals (43%) and five 1/2Nx90 (70%) were euthanized and necropsied at day 7 because of no urine production or poor conditions. Mortality was significantly improved after FR treatment. Survival was 100% in the control, Unif, WIuni90, and FR groups. In Unif groups, FR significantly reduced renal failure and bilateral renal ischemia (P < .05). At 3 months, proteinuria was significantly reduced in FR-treated groups (P < .01). Inflammatory cells count was also dramatically diminished in FR-treated pigs (P < .01 for CD3-positive cells). The second aspect of transient ischemia is the fibrotic process determined at 3 months. FR treatment was characterized by a reduction of renal fibrosis, particularly in Unif groups. TNF-alpha protein expression was diminished in FR-treated groups.. This is the first evidence that FR reduced the early and long-term effect of WI in the severe ischemia model. This effect was particularly marked against fibrosis and inflammation, which would contribute to deterioration of a patient's renal function.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Constriction; Disease Models, Animal; Fibrosis; Inflammation; Infusions, Intravenous; Interleukin-1; Kidney; Kidney Function Tests; Male; Necrosis; Nephrectomy; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Proteinuria; Pyrazoles; Pyridines; Recovery of Function; Renal Insufficiency; Reperfusion Injury; Swine; Time Factors; Tumor Necrosis Factor-alpha; Warm Ischemia

Chronic allograft nephropathy (CAN) remains a challenge for transplant clinicians. Some novel intervention strategies may shed new light on its treatment.. An orthotopic kidney transplant model in Fisher-to-Lewis rats was used with administration of cyclosporine alone or in combination with FR167653 (30 mg/kg/d subcuntaneously) to recipients. We analyzed renal function and urinary protein excretion. Animals were sacrificed at 30 weeks posttransplantation for histological and immunohistochemical studies.. Renal function among vehicle-treated rats deteriorated progressively with substantial proteinuria compared with FR167653-treated rats. FR167653 administration significantly prevented the morphlogical features of CAN and prolonged rat survivals. p38 mitogen-activated protein kinase (MAPK) expression was markedly reduced by FR167653 treatment. Meanwhile, transforming growth factor-beta1 and monocyte chemotactic protein-1 expression were significantly down-regulated among FR167653-treated hosts.. p38 MAPK phosphorylation correlated with CAN progression and inhibition of p38 MAPK by FR167653 may provide a potent novel therapeutic target for its prevention.

Topics: Animals; Chronic Disease; Creatinine; Cyclosporine; Immunosuppressive Agents; Kidney Transplantation; Male; p38 Mitogen-Activated Protein Kinases; Proteinuria; Pyrazoles; Pyridines; Rats; Rats, Inbred F344; Rats, Inbred Lew; Transplantation, Homologous

The phosphorylation of p38 mitogen-activated protein kinase (MAPK) is responsible for the production and signal transduction of cytokines and chemokines. This study hypothesized that p38 MAPK activation is required for spontaneous autoimmune renal injury in MRL-Fas(lpr) mice, resembling human lupus erythematosus. FR167653, a specific inhibitor of p38 MAPK, is orally administrated from 3 or 4 mo of age in MRL-Fas(lpr) mice (at doses of 10 or 32mg/kg per day) until 6 mo of age. The phosphorylated p38 MAPK in kidneys of MRL-Fas(lpr) mice was evaluated. The number of phosphorylated p38 MAPK-positive cells was increased in diseased kidneys. The daily oral administration of FR167653 decreased p38 MAPK phosphorylation in kidneys, especially in a group of mice administered FR167653 (32 mg/kg per day) daily from 3 to 6 mo of age. FR167653 reduced the accumulation of macrophages and T cell and prevented kidney pathology, resulting in prolonged survival. In addition, FR167653 reduced expression of MCP-1 and TNF-alpha in the diseased kidneys and cultured tubular epithelial cells. Furthermore, FR167653 decreased IgG levels in the diseased kidneys and circulation. These results suggest that the phosphorylation of p38 MAPK is required for the pathogenesis of renal injury in MRL-Fas(lpr) mice followed by subsequent expression of renal cytokine/chemokine and IgG production. This study provides evidence that the regulation of p38 MAPK is a novel target for the therapy of renal injury in systemic lupus erythematosus.

Topics: Animals; Antibodies, Antinuclear; Autoimmunity; Cells, Cultured; Chemokine CCL2; DNA; fas Receptor; Immunoglobulin G; Immunosuppressive Agents; Kidney; Kidney Glomerulus; Kidney Tubules, Proximal; Lupus Erythematosus, Systemic; Lymphatic Diseases; Mice; Mice, Inbred MRL lpr; Mitogen-Activated Protein Kinases; Neuropeptides; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Proteinuria; Pyrazoles; Pyridines; Receptors, Tumor Necrosis Factor; RNA, Messenger; Tumor Necrosis Factor-alpha

In the passive Heymann nephritis (PHN) model of rat membranous nephropathy, complement C5b-9 causes sublytic injury of glomerular epithelial cells (GEC). We previously showed that sublytic concentration of C5b-9 triggers a variety of biological events in GEC. In the current study, we demonstrate that complement activates p38 MAPK in GEC and address the role of p38 in complement-mediated cell injury. When cultured rat GEC were stimulated with complement, p38 kinase activity and phosphorylation were increased by approximately 2.4-fold, compared with control. Treatment with p38 inhibitors significantly augmented complement-mediated cytotoxicity. In contrast, when the constitutively active mutant of transforming growth factor-beta-activated kinase 1 (TAK1), a kinase upstream of p38, was expressed in GEC in an inducible manner, cytotoxicity was significantly reduced, compared with uninduced cells. p38 inhibitors abolished the protective effect of TAK1 expression. By analogy to cultured cells, p38 activity was also increased in glomeruli from rats with PHN and treatment with the p38 inhibitor FR-167653 increased proteinuria. Complement induced phosphorylation of MAPK-associated protein kinase-2 (MAPKAPK-2), a kinase downstream of p38 in GEC. Heat shock protein (HSP27) is a cytoskeleton-interacting substrate of MAPKAPK-2. Overexpression of the wild-type HSP27, but not a non-phosphorylatable mutant, markedly reduced complement-mediated GEC injury. In summary, complement activates p38 MAPK in GEC in vitro and in glomeruli from rats with PHN. The activation of p38 MAPK appears to be cytoprotective for GEC against complement-mediated GEC injury. Phosphorylation of HSP27 may mediate this cytoprotection.

Topics: Animals; Arachidonic Acid; Cells, Cultured; Complement Membrane Attack Complex; Cytoprotection; Enzyme Activation; Enzyme Inhibitors; Epithelial Cells; Glomerulonephritis; Heat-Shock Proteins; HSP27 Heat-Shock Proteins; Kidney Glomerulus; Mitogen-Activated Protein Kinases; Neoplasm Proteins; p38 Mitogen-Activated Protein Kinases; Proteinuria; Pyrazoles; Pyridines; Rats; Reactive Oxygen Species

p38 Mitogen-activated protein kinase (MAPK) is involved in the production and signal transduction of interleukin-1beta (IL-1beta), tumor necrosis factor-alpha, and chemokines in vitro. However, the crucial role of p38 MAPK in the inflammatory processes of crescentic glomerulonephritis in vivo remains to be investigated. We showed a dramatic decrease in IL-1beta-induced phosphorylation of p38 MAPK, not extracellular signal-regulated kinases 1/2 or jun NH2-terminal kinase, in rat cultured mesangial cells by FR167653. We explored the effects of FR167653 as a specific inhibitor of p38 MAPK on renal injury and subsequent renal expression of chemokines in a progressive experimental crescentic glomerulonephritis model in Wistar-Kyoto rats. Rats developed crescentic glomerulonephritis leading to glomerulosclerosis and interstitial fibrosis by 56 days after the administration of nephrotoxic sera. The number of phosphorylated p38 MAPK-positive cells, detected mainly in crescents, correlated well with the percentage of crescents and number of ED-1-positive cells. Phosphorylated p38 MAPK-positive cells were downregulated in glomeruli in rats with the daily subcutaneous administration of FR167653 for 6 days. Concomitantly, renal expression of macrophage inflammatory protein-1alpha and monocyte chemoattractant protein-1/monocyte chemotactic and activating factor was markedly reduced by day 6. The severity of glomerulosclerosis and interstitial fibrosis significantly decreased by day 56, and renal function was preserved. These results suggest that p38 MAPK phosphorylation is pivotal for crescentic glomerulonephritis, followed by the subsequent expression of renal chemokines. This study provides evidence that regulation of p38 MAPK is a novel appealing therapeutic target for crescentic glomerulonephritis.

Topics: Animals; Carrier Proteins; Cells, Cultured; Chemokine CCL2; Chemokine CCL4; Glomerulonephritis; Macrophage Inflammatory Proteins; Male; Mitogen-Activated Protein Kinases; p38 Mitogen-Activated Protein Kinases; Phosphorylation; Proteinuria; Pyrazoles; Pyridines; Rats; Rats, Inbred WKY; Rats, Sprague-Dawley

The pathophysiologic effects of FR167653 were investigated in a model of crescentic glomerulonephritis induced by a small dose of nephrotoxic serum in Wistar-Kyoto rats. The rats developed crescentic glomerulonephritis by 6 d after the administration of serum. The subcutaneous administration of FR167653 (32 mg/kg) markedly decreased the severity of the renal damage. In a group of rats treated with FR167653 daily from day 0 to day 6, glomerular damage, including crescent formation and proteinuria, was virtually absent. FR167653 markedly decreased urinary levels of monocyte chemoattractant protein-1 (MCP-1). In addition, FR167653 reduced production of MCP-1 protein and transcripts in the diseased kidneys. In a group of rats for which treatment was initiated on day 3, shortly after the appearance of glomerular abnormalities, the progression of renal disease was appreciably retarded, with partial inhibition of MCP-1. In contrast, when rats were treated only on the first day, no beneficial effects were observed and severe proliferative and necrotizing glomerulonephritis, with crescent formation, was induced by day 6, with the upregulation of MCP-1. These results suggest that FR167653 may be effective against crescentic glomerulonephritis, possibly via the inhibition of MCP-1. In addition, there was marked reduction in renal injury even when FR167653 treatment was initiated after glomerular inflammation was established, suggesting that the therapeutic application of FR167653 may be clinically useful for human renal diseases.

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Chemokine CCL2; Glomerulonephritis; Male; Proteinuria; Pyrazoles; Pyridines; Rats; Rats, Inbred WKY; RNA, Messenger