phenanthrenes and Nephritis

To observe the clinical efficacy of the Chinese herb, Triptolide, in children with moderately severe Henoch-Schönlein purpura nephritis (HSPN).. From January 2007 to December 2011, 56 HSPN children manifested by nephrotic range proteinuria with normal kidney function and <50% crescents or sclerosing lesions on biopsy were hospitalized in the Children's Hospital of Zhejiang University School of Medicine. They were divided into two groups: the treatment group (n = 42; Triptolide at a dosage of 1 mg/kg · d, combined with prednisone at a dosage of 2 mg/kg · d, within a course of medium-to-long-term therapy of 6 to 9 months) and the control group (n = 14; prednisone alone, with the same procedure).. Short-term remission was observed in 95% of patients from treatment group and in 72% of patients from control group, respectively. There was a significant difference between both groups (χ(2) = 6.222, P = 0.029) for short-term effects. Meanwhile, no significant difference, as proteinuria, hematuria, hypertension, and decreased eGFR, was observed between the two groups in long-term followup (χ(2) = 3.111, P = 0.097). The Kaplan-Meier plot analysis also revealed no significant difference (χ(2) = 2.633, P = 0.105).. Triptolide is effective in relieving short-term symptoms for moderately severe HSPN children, though its long-term effects need to be observed further.

Topics: Biopsy; Child; Child, Preschool; China; Diterpenes; Drugs, Chinese Herbal; Epoxy Compounds; Female; Humans; IgA Vasculitis; Kaplan-Meier Estimate; Male; Nephritis; Phenanthrenes; Proteinuria

Apoptosis, necrosis, and inflammation are hallmarks of cisplatin nephrotoxicity; however, the role and mechanisms of necrosis and inflammation remains undefined. As poly(ADP-ribose) polymerase 1 (PARP1) inhibition or its gene deletion is renoprotective in several renal disease models, we tested whether its activation may be involved in cisplatin nephrotoxicity. Parp1 deficiency was found to reduce cisplatin-induced kidney dysfunction, oxidative stress, and tubular necrosis, but not apoptosis. Moreover, neutrophil infiltration, activation of nuclear factor-κB, c-Jun N-terminal kinases, p38 mitogen-activated protein kinase, and upregulation of proinflammatory genes were all abrogated by Parp1 deficiency. Using proximal tubule epithelial cells isolated from Parp1-deficient and wild-type mice and pharmacological inhibitors, we found evidence for a PARP1/Toll-like receptor 4/p38/tumor necrosis factor-α axis following cisplatin injury. Furthermore, pharmacological inhibition of PARP1 protected against cisplatin-induced kidney structural/functional damage and inflammation. Thus, our findings suggest that PARP1 activation is a primary signal and its inhibition/loss protects against cisplatin-induced nephrotoxicity. Targeting PARP1 may offer a potential therapeutic strategy for cisplatin nephrotoxicity.

Topics: Acute Kidney Injury; Animals; Antineoplastic Agents; Apoptosis; Cells, Cultured; Cisplatin; Disease Models, Animal; Enzyme Activation; Enzyme Inhibitors; Gene Expression Regulation; Inflammation Mediators; JNK Mitogen-Activated Protein Kinases; Kidney Tubules; Male; Mice; Mice, Knockout; Necrosis; Nephritis; Neutrophil Infiltration; NF-kappa B; Oxidative Stress; p38 Mitogen-Activated Protein Kinases; Phenanthrenes; Poly (ADP-Ribose) Polymerase-1; Poly(ADP-ribose) Polymerase Inhibitors; Poly(ADP-ribose) Polymerases; Signal Transduction; Time Factors; Toll-Like Receptor 4; Tumor Necrosis Factor-alpha

Henoch-Schönlein purpura (HSP) is one of the most common causes of systemic vasculitis in children. The incidence of HSP nephritis (HSPN) among HSP patients has been reported to be 15-62%. Even so, what constitutes severe HSPN is controversial. In the study reported here, we retrospectively reviewed the clinical features and prognosis of 101 children with HSPN, ISKDC grade IIIa/IIIb, from January 1992 to November 2008. Patients with isolated hematuria and/or proteinuria <50 mg/kg/day received triptolide alone, and those with nephrotic range proteinuria received a combination therapy of prednisone and triptolide. Nephrotic syndrome was the most common clinical manifestation (45.5%). There were no significant differences in the clinical features (χ(2) = 2.756, P = 0.252), the side effects related to treatment (χ(2) = 2.259, P = 0.894), prognosis between IIIa and IIIb (χ(2) = 3.013, P = 0.222), or prognosis in grade IIIa patients receiving triptolide alone or triptolide and prednisone (χ(2) = 1.207, P = 0.272) and grade IIIb patients (χ(2) = 1.158, P = 0.282). No significant difference in clinical manifestations and long-term prognosis of our HSPN patients with grade IIIa or grade IIIb were found, implying that our patients with International Study and Kidney Disease in Children (ISKDC) grade IIIb were not the most severe cases of HSPN. Our results may also suggest that treatment with steroid may not alter the clinical outcome of such grade IIIa or IIIb patients.

Topics: Adolescent; Biopsy; Chi-Square Distribution; Child; Child, Preschool; China; Diterpenes; Drug Therapy, Combination; Epoxy Compounds; Female; Hematuria; Humans; IgA Vasculitis; Immunosuppressive Agents; Male; Nephritis; Nephrotic Syndrome; Phenanthrenes; Prednisone; Proteinuria; Retrospective Studies; Risk Assessment; Risk Factors; Severity of Illness Index; Time Factors; Treatment Outcome

Aristolochic acid (AA), a naturally occurring nephrotoxin and rodent carcinogen, has recently been associated with the development of urothelial cancer in humans. Understanding which enzymes are involved in AA activation and/or detoxication is important in the assessment of an individual susceptibility to this natural carcinogen. We examined the ability of enzymes of rat renal and hepatic cytosolic fractions to activate AA to metabolites forming DNA adducts by the nuclease P1-enhanced version of the (32)P-postlabeling assay. Cytosolic fractions of both these organs generated AA-DNA adduct patterns reproducing those found in renal tissues from humans exposed to AA. 7-(Deoxyadenosin-N(6)-yl)aristolactam I, 7-(deoxyguanosin-N(2)-yl)aristolactam I and 7-(deoxyadenosin-N(6)-yl)aristolactam II were identified as AA-DNA adducts formed from AAI and 7-(deoxyguanosin-N(2)-yl)aristolactam II and 7-(deoxyadenosin-N(6)-yl)aristolactam II were generated from AAII by hepatic cytosol. Qualitatively the same AA-DNA adduct patterns were observed, although at lower levels, upon incubation of AAs with renal cytosol. To define the role of cytosolic reductases in the reductive activation of AA, we investigated the modulation of AA-DNA adduct formation by cofactors, specific inducers or selective inhibitors of the cytosolic reductases, DT-diaphorase, xanthine oxidase (XO) and aldehyde oxidase. The role of the enzymes in AA activation was also investigated by correlating the DT-diaphorase- and XO-dependent catalytic activities in cytosolic sample with the levels of AA-DNA adducts formed by the same cytosolic sample. On the basis of these studies, we attribute most of the cytosolic activation of AA to DT-diaphorase, although a role of cytosolic XO cannot be ruled out. With purified DT-diaphorase, the participation of this enzyme in the formation of AA-DNA adducts was confirmed. The binding orientation of AAI in the active site of DT-diaphorase was predicted by computer modeling based on published X-ray structures. The results presented here are the first report demonstrating a reductive activation of carcinogenic AAs by DT-diaphorase.

Topics: Aldehyde Oxidase; Aldehyde Oxidoreductases; Animals; Antineoplastic Agents; Aristolochic Acids; Carcinogens; Cell Nucleus; Chromatography, High Pressure Liquid; Cytosol; DNA; DNA Adducts; DNA, Complementary; Dose-Response Relationship, Drug; Drugs, Chinese Herbal; Enzyme Activation; Liver; Models, Chemical; Models, Molecular; NAD(P)H Dehydrogenase (Quinone); Nephritis; Phenanthrenes; Rats; Rats, Wistar; Thymus Gland; Time Factors; Xanthine Oxidase

We have studied interleukin-1 (IL-1)-stimulated signals and gene expression in mesangial cells (MCs) to identify molecular mechanisms of MC activation, a process characteristic of glomerular inflammation. The JNK1 pathway has been implicated in cell fate decisions, and IL-1 stimulates the Jun N-terminal/stress-activated protein kinases (JNK1/SAPK). However, early postreceptor mechanisms by which IL-1 activates these enzymes remain unclear. Free arachidonic acid (AA) activates several protein kinases, and because IL-1 rapidly stimulates phospholipase A2 (PLA2) activity release AA, IL-1-induced activation of JNK1/SAPK may be mediated by AA release.. MCs were grown from collagenase-treated glomeruli, and JNK/SAPK activity in MC lysates was determined using an immunocomplex kinase assay.. Treatment of MCs with IL-1 alpha induced a time-dependent increase in JNK1/SAPK kinase activity, assessed by phosphorylation of the activating transcription factor-2 (ATF-2). Using similar incubation conditions, IL-1 also increased [3H]AA release from MCs. Pretreatment of MCs with aristolochic acid, a PLA2 inhibitor, concordantly reduced IL-1-regulated [3H]AA release and JNK1/SAPK activity, suggesting that cytosolic AA in part mediates IL-1-induced JNK1/SAPK activation. Addition of AA stimulated JNK1/SAPK activity in a time- and concentration-dependent manner. This effect was AA specific, as only AA and its precursor linoleic acid stimulated JNK1/SAPK activity. Other fatty acids failed to activate JNK1/SAPK. Pretreatment of MCs with specific inhibitors of AA oxidation by cyclooxygenase, lipoxygenase, and cytochrome P-450 epoxygenase had no effect on either IL-1- or AA-induced JNK1/SAPK activation. Furthermore, stimulation of MCs with the exogenous cyclooxygenase-, lipoxygenase-, phosphodiesterase-, and epoxygenase-derived arachidonate metabolites, in contrast to AA itself, did not activate JNK1/SAPK.. We conclude that IL-1-stimulated AA release, in part, mediates stimulation of JNK1/SAPK activity and that AA activates JNK1/SAPK by a mechanism that does not require enzymatic oxygenation. JNK1 signaling pathway components may provide molecular switches that mediate structural rearrangements and biochemical processes characteristic of MC activation and could provide a novel target(s) for therapeutic intervention.

Topics: 15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; 8,11,14-Eicosatrienoic Acid; Animals; Arachidonic Acid; Aristolochic Acids; Calcium-Calmodulin-Dependent Protein Kinases; Cells, Cultured; Dinoprostone; Enzyme Activation; Enzyme Inhibitors; Fatty Acids, Unsaturated; Glomerular Mesangium; Interleukin-1; JNK Mitogen-Activated Protein Kinases; Leukotrienes; Lipid Peroxides; Mitogen-Activated Protein Kinases; Nephritis; Phenanthrenes; Phosphodiesterase Inhibitors; Phospholipases A; Phospholipases A2; Rats; Signal Transduction; Stearic Acids; Tritium; Vasoconstrictor Agents