Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0920646 (renal ischemia)
 2,515 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study investigated whether the renal regeneration occurring in the recovery phase of kidney ischemia-reperfusion (I/R) is mediated by endogenously generated lipocalin-2 (Lcn2). A second objective was to examine whether Lcn2-mediated cell effects could be regulated by the inflammatory cytokines in the environment through their action on Lcn2 receptors (Lcn2R and megalin). Male Swiss mice were subjected to 30 min of renal ischemia with a reperfusion period of 24 h (early reperfusion, expected time for maximum inflammation) and 96 h (late reperfusion, expected time for maximum regeneration). Different experimental groups underwent I/R, I/R with iv anti-mouse Lcn2 monoclonal antibody injected during the early/inflammatory or late/recovery phase, and I/R with proinflammatory cytokine cocktail administration (recombinant mouse IL-1beta, TNF-alpha, and IFN-gamma). Compared with control nonischemic mice, the expression of three proliferation markers (stathmin, PCNA, and Ki-67, analyzed by quantitative RT-PCR) increased significantly in the I/R-treated animals. Blockade of Lcn2 by addition of anti-Lcn2 antibody significantly decreased the expression of these three proliferation markers when administered in the late/reparative phase, but had the opposite effect when administered in the early/inflammatory phase. Proinflammatory cytokine cocktail administration reduced the proliferative effects of Lcn2, and repressed Lcn2R and megalin expression. In conclusion, endogenously generated Lcn2 induces renal cell regeneration depending on the inflammatory cytokines in kidney I/R.
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PMID:Lipocalin-2-induced renal regeneration depends on cytokines. 1881 20

Severe sepsis is often accompanied by acute renal failure with renal tubular dysfunction. Albuminuria is a common finding in septic patients and we studied whether it was due to an impairment of proximal tubular endocytosis of filtered albumin. We studied the regulation of megalin and cubilin, the two critical multiligand receptors responsible for albumin absorption, during severe experimental endotoxemia. Lipopolysaccharide (LPS) caused a time- and dose-dependent suppression of megalin and cubilin expression that was paralleled by a decrease in plasma albumin levels and an increase in the urine concentration of albumin in mice. Incubation of rat renal cortical slices with LPS also reduced the mRNA expression of megalin and cubilin. Further, LPS suppressed megalin and cubilin mRNA expression in murine primary proximal tubule cells and decreased the uptake of FITC albumin in these cells. In addition, the increase in urine levels of albumin in response to ischemia/reperfusion-induced acute renal failure was paralleled by a decrease in the expression of megalin and cubilin. Thus, our data indicate that the expression of megalin and cubilin is decreased during experimental endotoxemia and in response to renal ischemia/reperfusion injury. This downregulation may contribute, in part, to an increase in urine levels of albumin during acute renal failure.
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PMID:Acute endotoxemia in mice induces downregulation of megalin and cubilin in the kidney. 2243 17

In order to develop a novel kidney-targeted drug delivery system, we synthesized prednisolone carbamate-glucosamine conjugate (PCG) using 2-glucosamine as a ligand, and investigated its potential targeting efficacy. In vitro studies demonstrated that PCG could remarkably improve the uptake of drug by kidney cells. And the specific uptake of PCG could be largely reduced by the inhibitors of megalin receptor. More importantly, PCG showed an excellent kidney targeting property in vivo, and the concentration of the conjugate in the kidney was 8.1-fold higher than that of prednisolone group at 60 min after intravenous injection. Besides, PCG could significantly reverse the disease progression in renal ischemia-reperfusion (I/R) injury animal models. Furthermore, PCG presented no adverse effect on bone density while prednisolone resulted in severe osteoporosis. Thus, it indicated that 2-glucosamine could be a potential ligand for kidney-targeted delivery of prednisolone.
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PMID:Targeted drug delivery to renal proximal tubule epithelial cells mediated by 2-glucosamine. 2341 93

Triptolide (TP), a naturally derived compound, is proven effective in the treatment of nephritis and chronic allograft nephropathy. However, the severe multiorgan toxicity greatly limited it from further clinic use. 2-Glucosamine was demonstrated as a potential targeting ligand that could specifically interact with megalin receptors highly expressed in renal proximal tubules. In this study, 2-glucosamine was employed as a glycosyl donor while triptolide the acceptor to afford a nonhydrolyzable triptolide derivative-triptolide aminoglycoside (TPAG). The kidney-targeting efficiency, pharmacodynamic properties and safety of TPAG were thus evaluated. TPAG displayed 6.94-fold of AUC(0-t, kidney) and 13.96-fold of MRT(0-t, kidney) compared to TP. Additionally, TPAG presented improved protective effect against renal ischemia/reperfusion injury. Compared to TP's multiorgan toxicity, TPAG showed minimum toxicity toward the kidney and genital systems, and greatly lowered toxicity in the liver and immune systems. In sum, our study presented an alternative structure modification of triptolide with improved safety and efficacy profiles.
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PMID:A renal-targeted triptolide aminoglycoside (TPAG) conjugate for lowering systemic toxicities of triptolide. 2586 48