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Diabetic nephropathy (DN) is a leading cause of end-stage renal disease (ESRD). Hypertension increases kidney stress, which deteriorates function, and leads to peripheral renal vascular resistance. Long-term hypoperfusion promotes interstitial fibrosis and glomerular sclerosis, resulting in nephrosclerosis. Although hypertension and DN are frequent ESRD complications, relevant animal models remain unavailable. We generated a deoxycorticosterone acetate (DOCA)-salt hypertensive uni-nephrectomized (UNx) KKA y mouse model demonstrating hypertension, hyperglycemia, cardiac hypertrophy, kidney failure, increased urinary albumin creatinine ratio (UACR), and increased renal PDE4D and cardiac PDE5A mRNA levels. We hypothesized that the novel PDE4 selective inhibitor, compound A, and PDE5 inhibitor, sildenafil, exhibit nephroprotective, and cardioprotective effects in this new model. Compound A, sildenafil, and the angiotensin II receptor blocker, irbesartan, significantly reduced ventricular hypertrophy and pleural effusion volume. Meanwhile, compound A and sildenafil significantly suppressed the UACR, urinary kidney injury molecule-1, and monocyte chemoattractant protein-1 levels, as well as that of renal pro-fibrotic marker mRNAs, including collagen 1A1, fibronectin, and transforming growth factor-beta (TGF-β). Moreover, compound A significantly suppressed TGF-β-induced pro-fibrotic mRNA expression in vitro in all major kidney lesions, including within the glomerular mesangial region, podocytes, and epithelial region. Hence, PDE4 and PDE5 inhibitors may be promising treatments, in combination with irbesartan, for DN with hypertension as they demonstrate complementary mechanisms., (© 2020 Federation of American Societies for Experimental Biology.)

Neprilysin (NEP) is an endogenously induced peptidase for modulating production and degradation of various peptides in humans. It is most abundantly present in kidney and regulates the intrinsic renal homeostatic mechanism. Recently, drugs inhibiting NEP have been approved for the use in heart failure. In the context of increased prevalence of ischemia associated renal failure, NEP could be an attractive target for treating kidney failure. In the kidney, targeting NEP may possess potential benefits as well as adverse consequences. The unfavorable outcomes of NEP are mainly attributed to the degradation of the natriuretic peptides (NPs). NPs are involved in the inhibition of the renin-angiotensin-aldosterone system (RAAS) and activation of the sympathetic system contributing to the tubular and glomerular injury. In contrary, NEP exerts the beneficial effect by converting angiotensin-1 (Ang I) to angiotensin-(1-7) (Ang-(1-7)), thus activating MAS-related G-protein coupled receptor. MAS receptor antagonizes angiotensin type I receptor (AT-1R), reduces reactive oxygen species (ROS) and inflammation, thus ameliorating renal injury. However, the association of NEP with complex cascades of renal ischemia remains vague. Therefore, there is a need to evaluate the putative mechanism of NEP and its overlap with other signaling cascades in conditions of renal ischemia.

Kidney failure is common in haematologic malignancies. However, the nephrotoxic effect of lysozyme is seldom recognized. We present a 78-year-old male with chronic myelomonocytic leukaemia who developed progressive kidney failure due to increased production of lysozyme.

Background: Chronic Kidney Disease (CKD), a global public health problem, affects numerous people worldwide, and the prevalence is rising. Results from animal experiments and clinical investigations have demonstrated that drug metabolic enzymes and transporters-mediated non-renal clearance are dramatically impaired in CKD, co-respondent with alterations in the elimination of metabolized drugs. Accumulated uremic toxins may downregulate or directly inhibit the activity and/or the expression of drug metabolic enzymes and transporters, which may result in unintended alterations of drug exposure and response in cases when drugs dose are not adjusted for the renal dysfunction., Method: The aim of this review is to highlight the impact of CKD on non-renal drug clearance involving metabolism enzyme system and transport pathways, and to provide insight into the impact of non-renal drug clearance on drug metabolism and distribution in CKD patients., Results: Metabolic enzyme system and transport pathways are dysregulated in both rats and humans with renal failure., Conclusion: The alterations of drug metabolic enzymes and transporters in the kidney, liver, and intestine play an important role in their pharmacokinetic changes, and thus, the metabolism and transportation of many medications used to treat CKD patients may be affected., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Glutathione S-transferase mu 1 ( GSTM1) encodes an enzyme that catalyzes the conjugation of electrophilic compounds with glutathione to facilitate their degradation or excretion. The loss of one or both copies of GSTM1 is common in many populations and has been associated with CKD progression. With the hypothesis that the loss of GSTM1 is also associated with incident kidney failure and heart failure, we estimated GSTM1 copy number using exome sequencing reads in the Atherosclerosis Risk in Communities (ARIC) Study, a community-based prospective cohort of white and black participants. Overall, 51.2% and 39.8% of white participants and 25.6% and 48.5% of black participants had zero or one copy of GSTM1 , respectively. Over a median follow-up of 24.6 years, 256 kidney failure events occurred in 5715 participants without prevalent kidney failure, and 1028 heart failure events occurred in 5368 participants without prevalent heart failure. In analysis adjusted for demographics, diabetes, and hypertension, having zero or one copy of GSTM1 associated with higher risk of kidney failure and heart failure (adjusted hazard ratio [95% confidence interval] for zero or one versus two copies of GSTM1 : kidney failure, 1.66 [1.27 to 2.17]; heart failure, 1.16 [1.04 to 1.29]). Risk did not differ significantly between participants with zero and one copy of GSTM1 ( P >0.10). In summary, the loss of GSTM1 was significantly associated with incident kidney and heart failure, independent of traditional risk factors. These results suggest GSTM1 function is a potential treatment target for the prevention of kidney and heart failure., (Copyright © 2017 by the American Society of Nephrology.)

Objectives: Preoperative liver dysfunction is a well-known risk factor for adverse events after major surgery. However, there is only little data regarding the precise role of the Model of End-Stage Liver Disease (MELD) score and the De Ritis ratio (DRR, alanine transaminase/aspartate aminotransferase) as a predictor for outcome after left ventricular assist device (LVAD) implantation., Methods: A retrospective analysis of all patients undergoing LVAD implantation at our institution between January 2012 and August 2014 was performed. The primary outcome was survival at 180 days after surgery., Results: During the observation period, 63 patients underwent LVAD implantation (mean age 59.9 ± 8.3 years, 50% male). Mean preoperative ejection fraction was 16.3 ± 7.7, 13 patients required preoperative renal replacement therapy and 9 patients were on extracorporeal life support. Mean Interagency Registry for Mechanically Assisted Circulatory Support level was 2.8 ± 1.3, mean preoperative MELD was 12.7 ± 7.2, mean preoperative DRR was 2.01 ± 4.4. Aspartate aminotransferase (102 ± 220.8 vs 57.8 ± 123.4 U/l, P = 0.041), MELD score (16.1 ± 8.8 vs 11.4 ± 6.1, P = 0.017) and DRR (4.2 ± 7.8 vs 1.1 ± 1.1, P = 0.001) were significantly higher in non-survivors than in survivors after 180 days. Using logistic regression analyses, a DRR >1.37 was an independent predictor for 30-day mortality [odds ratio (OR) 4.5] and 180-day mortality (OR 4.1). In addition, the DRR was associated with postoperative acute kidney injury with need for renal replacement therapy (OR 4.2) and prolonged postoperative ventilation time >72 h (OR 3.8). Using receiver operator characteristics analyses, DRR showed a sensitivity of 0.80 and a specificity of 0.81 (area under the curve 0.834, cut-off 1.37) for 180-day mortality., Conclusions: The DRR is predictive of early and mid-term mortality as well as relevant morbidities in patients undergoing LVAD implantation. Therefore, the DRR should be considered within the preoperative risk stratification and patient selection for LVAD implantation., (© The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)

Inappropriate activation of the Wnt/β-catenin pathway has been indicated in podocyte dysfunction and injury, and shown to contribute to the development and progression of nephropathy. Tankyrases, multifunctional poly(ADP-ribose) polymerase (PARP) superfamily members with features of both signaling and cytoskeletal proteins, antagonize Wnt/β-catenin signaling. We found that tankyrases interact with CD2-associated protein (CD2AP), a protein essential for kidney ultrafiltration as CD2AP-knockout (CD2AP-/-) mice die of kidney failure at the age of 6-7 weeks. We further observed that tankyrase-mediated total poly-(ADP-ribosyl)ation (PARylation), a post-translational modification implicated in kidney injury, was increased in mouse kidneys and cultured podocytes in the absence of CD2AP. The data revealed increased activity of β-catenin, and upregulation of lymphoid enhancer factor 1 (LEF1) (mediator of Wnt/β-catenin pathway) and fibronectin (downstream target of Wnt/β-catenin) in CD2AP-/- podocytes. Total PARylation and active β-catenin were reduced in CD2AP-/- podocytes by tankyrase inhibitor XAV939 treatment. However, instead of ameliorating podocyte injury, XAV939 further upregulated LEF1, failed to downregulate fibronectin and induced plasminogen activator inhibitor-1 (PAI-1) that associates with podocyte injury. In zebrafish, administration of XAV939 to CD2AP-depleted larvae aggravated kidney injury and increased mortality. Collectively, the data reveal sustained activation of the Wnt/β-catenin pathway in CD2AP-/- podocytes, contributing to podocyte injury. However, we observed that inhibition of the PARylation activity of tankyrases in the absence of CD2AP was deleterious to kidney function. This indicates that balance of the PARylation activity of tankyrases, maintained by CD2AP, is essential for normal kidney function. Furthermore, the data reveal that careful contemplation is required when targeting Wnt/β-catenin pathway to treat proteinuric kidney diseases associated with impaired CD2AP.

Purpose: The aim of this work is to demonstrate if urinary excretion of glutamyl aminopeptidase (GluAp) can be quantified by immunological methods., Experimental Design: Urine samples from control and cisplatin-treated rats (n = 10 each group) were obtained at 1, 8, and 15 days after cisplatin injection. GluAp was analyzed by kinetic fluorimetry, ELISA, and immunoblotting. Sensitivity and specificity was studied for fluorimetric activity and ELISA 24 h after cisplatin injection. We also analyzed the predictive value over renal dysfunction at the end of the experiment., Results: GluAp was easily detected by immunoblotting and ELISA, and its urinary excretion was increased in cisplatin-treated rats (p < 0.01). Results obtained with ELISA were strongly correlated (r = 0.8186; p < 0.0001) with fluorimetric activity. Kinetic fluorimetry was the method with the highest AUC (AUC = 1) and the highest predictive value over serum creatinine (r = 0.7630; p = 0.0001) and body weight increase (r = -0.8721; p < 0.0001)., Conclusions and Clinical Relevance: GluAp can be detected in urine samples with immunological methods, making possible the development of an antibody-based kit for its determination. Its excretion correlates with the extent of renal dysfunction in cisplatin-treated rats, confirming its value as an early marker of renal damage that can be a diagnostic aid in renal diseases., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Telomerase is involved in the elongation of telomeres. It remains active in very few types of cell in mature organisms. One such cell type is the lymphocytes. In this study, we investigated the activity and expression of telomerase in lymphocytes from renal failure patients and compared it to that for normal controls. Inflammation status was determined at the same time. The enzyme activity was measured using PCR-ELISA with peripheral blood mononuclear cells (PBMCs) from three groups: 53 healthy individuals, 50 patients with chronic kidney disease (CKD) and 50 dialysis patients. In the same cell populations, the expression of the reverse transcriptase of the human telomerase gene (hTERT) was measured via real-time PCR. The inflammationstatus of these individuals was determined by calculating the interleukin 6 (IL-6), IL-10, C-reactive protein (CRP) and tumor necrosis factor alpha (TNF-a) serum concentrations via ELISA. The lowest levels of telomerase activity were detected in CKD, and this group had the highest IL-6 and CRP values and the lowest hTERT expression. The dialysis group showed significant differences in comparison to the normal subjects and to the CKD patients. Further studies are warranted in order to explore the way inflammation influences telomerase activity and hTERT expression.

Background: Renal failure is a frequent and serious complication in patients with decompensated cirrhosis., Objectives: We aimed to evaluate the renal oxidative stress, cell damage and impaired cell function in animal model of cirrhosis., Methods: Secondary biliary cirrhosis was induced in rats by ligation of the common bile duct. We measured TBARS, ROS and mitochondrial membrane potential in kidney as markers of oxidative stress, and activities of the antioxidant enzymes. Relative cell viability was determined by trypan blue dye-exclusion assay. Annexin V-PE was used with a vital dye, 7-AAD, to distinguish apoptotic from necrotic cells and comet assay was used for determined DNA integrity in single cells., Results: In bile duct ligation animals there was significant increase in the kidney lipoperoxidation and an increase of the level of intracellular ROS. There was too an increase in the activity of all antioxidant enzymes evaluated in the kidney. The percentage viability was above 90% in the control group and in bile duct ligation was 64.66% and the dominant cell death type was apoptosis. DNA damage was observed in the bile duct ligation. There was a decreased in the mitochondrial membrane potential from 71.40% ± 6.35% to 34.48% ± 11.40% in bile duct ligation., Conclusions: These results indicate that intracellular increase of ROS cause damage in the DNA and apoptosis getting worse the renal function in cirrhosis.

Acute rejection is a major risk factor for chronic allograft injury (CAI). Blood leukocytes interacting with allograft endothelial cells during acute rejection were suggested to contribute to the still enigmatic pathogenesis of CAI. We hypothesize that tissue transglutaminase (Tgm2), a multifunctional protein and established marker of M2 macrophages, is involved in acute and chronic graft rejection. We focus on leukocytes accumulating in blood vessels of rat renal allografts (Fischer-344 to Lewis), an established model for reversible acute rejection and CAI. Monocytes in graft blood vessels overexpress Tgm2 when acute rejection peaks on day 9 after transplantation. Concomitantly, caspase-3 is activated, suggesting that Tgm2 expression is linked to apoptosis. After resolution of acute rejection on day 42, leukocytic Tgm2 levels are lower and activated caspase-3 does not differ among isografts and allografts. Cystamine was applied for 4 weeks after transplantation to inhibit extracellular transglutaminase activity, which did, however, not reduce CAI in the long run. In conclusion, this is the first report on Tgm2 expression by monocytes in vivo. Tgm2 may be involved in leukocytic apoptosis and thus in reversion of acute rejection. However, our data do not support a role of extracellular transglutaminase activity as a factor triggering CAI during self-limiting acute rejection.

Orteronel is a nonsteroidal, selective inhibitor of 17,20-lyase that was recently in phase 3 clinical development as a treatment for castration-resistant prostate cancer. In humans, the primary clearance route for orteronel is renal excretion. Human liver microsomal studies indicated that orteronel weakly inhibits CYP1A2, 2C8, 2C9 and 2C19, with IC50 values of 17.8, 27.7, 30.8 and 38.8 µm, respectively, whereas orteronel does not inhibit CYP2B6, 2D6 or 3A4/5 (IC50  > 100 µm). Orteronel also does not exhibit time-dependent inhibition of CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6 or 3A4/5. The results of a static model indicated an [I]/Ki ratio >0.1 for CYP1A2, 2C8, 2C9 and 2C19. Therefore, a physiologically based pharmacokinetic (PBPK) model was developed to assess the potential for drug-drug interactions (DDIs) between orteronel and theophylline, repaglinide, (S)-warfarin and omeprazole, which are sensitive substrates of CYP1A2, 2C8, 2C9 and 2C19, respectively. Simulation of the area under the plasma concentration-time curve (AUC) of these four CYP substrates in the presence and absence of orteronel revealed geometric mean AUC ratios <1.25. Therefore, in accordance with the 2012 US FDA Draft Guidance on DDIs, orteronel can be labeled a 'non-inhibitor' and further clinical DDI evaluation is not required. In PBPK models of moderate and severe renal impairment, the AUC of orteronel was predicted to increase by 52% and 83%, respectively. These results are in agreement with those of a clinical trial in which AUC increases of 38% and 87% were observed in patients with moderate and severe renal impairment, respectively., (Copyright © 2014 John Wiley & Sons, Ltd.)

Background: The present study was conducted to elucidate the protective role of Withania somnifera against bromobenzene induced nephrotoxicity and mitochondrial dysfunction in rats., Methods: In this study, Wistar albino rats of either sex were divided into six groups consisting of six animals each. The first one was control, those in group II received bromobenzene (10 mmol/kg, intragastric intubation) once, but group III and IV animals received W. somnifera (250 and 500 mg/kg, orally), respectively for 8 days followed by bromobenzene once on the 8th day and silymarin (100 mg/kg, orally) was given for 8 days to group V animals and then bromobenzene on the last day. Group VI animals received only W. somnifera (500 mg/kg) for 8 days., Results: The levels of renal lipid peroxidation, lysosomal enzymes and glycoprotein were increased significantly (p<0.05) in the bromobenzene alone treated rats and antioxidant status and mitochondrial enzymes were found to be decreased, when compared to the control group. The levels of kidney functional markers (urea, uric acid and creatinine) were also found to be abnormal in serum of bromobenzene alone treated rats. On the other hand, administration of W. somnifera (250 and 500 mg/kg) along with bromobenzene offered a significant dose-dependent protection to the biochemical alterations as observed in the bromobenzene alone treated rats, which was also evidenced by histopathology., Conclusion: Thus, the oral administration of W. somnifera significantly protected against the bromobenzene induced nephrotoxicity and renal mitochondrial dysfunction in rats.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) belongs to toxicologically important class of poly halogenated aromatic hydrocarbons and produce wide variety of adverse effects in humans. The present study investigated the protective effect of ellagic acid, a natural polyphenolic compound against TCDD-induced nephrotoxicity in Wistar rats. TCDD-induced nephrotoxicity was reflected in marked changes in the histology of kidney, increase in levels of kidney markers (serum urea, serum creatinine) and lipid peroxides. A significant increase in activity of phase I enzyme CYP1A1 with concomitant decline in the activities of phase II enzymes [non-enzymic antioxidant and various enzymic antioxidants such as superoxide dismutase, catalase, glutathione peroxidase, glutathione-s-transferase] was also observed. In addition, TCDD treated rats showed alterations in ATPase enzyme activities such as Na(+) K(+)-ATPase, Mg(2+) ATPase and Ca(2+) ATPase. Oral pre-treatment with ellagic acid prevented TCDD-induced alterations in levels of kidney markers. Ellagic acid pre-treatment significantly counteracted TCDD-induced oxidative stress by decreasing CYP1A1 activity and enhancing the antioxidant status. Furthermore, ellagic acid restored TCDD-induced histopathological changes and alterations in ATPase enzyme activities. The results of the present study show that significant protective effect rendered by ellagic acid against TCDD-induced nephrotoxicity might be attributed to its antioxidant potential.

Arthrogryposis, renal dysfunction and cholestasis (ARC) syndrome (OMIM 208085) is an autosomal recessive disorder that is caused by mutations in 2 interacting genes VPS33B and VIPAS39. Mutations in VPS33B gene account for most cases of ARC. As low or normal gamma-glutamyl transpeptidase (GGT) activity has been described in all patients with ARC syndrome identified so far, ARC syndrome is a possible diagnosis for low GGT cholestasis. Here we describe a Chinese patient with neonatal cholestasis and a high GGT level in three consecutive tests. She had other typical manifestations of ARC syndrome, including arthrogryposis multiplex congenita, renal involvement and ichthyosis. Genetic study of the VPS33B gene further confirmed the diagnosis by identification of compound heterozygosity of two known disease-causing mutations, c.403+2T > A and c.1509-1510insG. The mechanism of high GGT in this patient is unclear. Nevertheless, this case indicates that ARC syndrome cannot be excluded from the differential diagnosis of neonatal cholestasis even if high GGT activity is found.

Renal toxicity constitutes a dose-limiting side effect of anticancer therapies targeting vascular endothelial growth factor (VEGF). In order to study this further, we followed up 29 patients receiving this treatment, who experienced proteinuria, hypertension, and/or renal insufficiency. Eight developed minimal change nephropathy/focal segmental glomerulopathy (MCN/FSG)-like lesions and 13 developed thrombotic microangiopathy (TMA). Patients receiving receptor tyrosine kinase inhibitors (RTKIs) mainly developed MCN/FSG-like lesions, whereas TMA complicated anti-VEGF therapy. There were no mutations in factor H, factor I, or membrane cofactor protein of the complement alternative pathway, while plasma ADAMTS13 activity persisted and anti-ADAMTS13 antibodies were undetectable in patients with TMA. Glomerular VEGF expression was undetectable in TMA and decreased in MCN/FSG. Glomeruli from patients with TMA displayed a high abundance of RelA in endothelial cells and in the podocyte nuclei, but c-mip was not detected. Conversely, MCN/FSG-like lesions exhibited a high abundance of c-mip, whereas RelA was scarcely detected. RelA binds in vivo to the c-mip promoter and prevents its transcriptional activation, whereas RelA knockdown releases c-mip activation. The RTKI sorafenib inhibited RelA activity, which then promoted c-mip expression. Thus, our results suggest that c-mip and RelA define two distinct types of renal damage associated with VEGF-targeted therapies.

Podocytes are highly specialized epithelial cells with complex actin cytoskeletal architecture crucial for maintenance of the glomerular filtration barrier. The mammalian Rho GTPases Rac1 and Cdc42 are molecular switches that control many cellular processes, but are best known for their roles in the regulation of actin cytoskeleton dynamics. Here, we employed podocyte-specific Cre-lox technology and found that mice with deletion of Rac1 display normal podocyte morphology without glomerular dysfunction well into adulthood. Using the protamine sulfate model of acute podocyte injury, podocyte-specific deletion of Rac1 prevented foot process effacement. In a long-term model of chronic hypertensive glomerular damage, however, loss of Rac1 led to an exacerbation of albuminuria and glomerulosclerosis. In contrast, mice with podocyte-specific deletion of Cdc42 had severe proteinuria, podocyte foot process effacement, and glomerulosclerosis beginning as early as 10 days of age. In addition, slit diaphragm proteins nephrin and podocin were redistributed, and cofilin was dephosphorylated. Cdc42 is necessary for the maintenance of podocyte structure and function, but Rac1 is entirely dispensable in physiological steady state. However, Rac1 has either beneficial or deleterious effects depending on the context of podocyte impairment. Thus, our study highlights the divergent roles of Rac1 and Cdc42 function in podocyte maintenance and injury.

Tissue methylmalonic acid (MMA) accumulation is the biochemical hallmark of methylmalonic acidemia. Clinically, the disease is characterized by progressive neurological deterioration and renal failure, whose pathophysiology is still undefined. In the present study we investigated the effect of acute MMA administration on some important parameters of brain neurotransmission in cerebral cortex of rats, namely Na(+), K(+)-ATPase, ouabain-insensitive ATPases and acetylcholinesterase activities, in the presence or absence of kidney injury induced by gentamicin administration. Initially, thirty-day old Wistar rats received one intraperitoneal injection of saline or gentamicin (70 mg/kg). One hour after, the animals received three consecutive subcutaneous injections of MMA (1.67 μmol/g) or saline, with an 11 h interval between each injection. One hour after the last injection the animals were killed and the cerebral cortex isolated. MMA administration by itself was not able to modify Na(+), K(+)-ATPase, ATPases ouabain-insensitive or acetylcholinesterase activities in cerebral cortex of young rats. In rats receiving gentamicin simultaneously with MMA, it was observed an increase in the activity of acetylcholinesterase activity in cerebral cortex, without any alteration in the activity of the other studied enzymes. Therefore, it may be speculated that cholinergic imbalance may play a role in the pathogenesis of the brain damage. Furthermore, the pathophysiology of tissue damage cannot be exclusively attributed to MMA toxicity, and control of kidney function should be considered as a priority in the management of these patients, specifically during episodes of metabolic decompensation when MMA levels are higher.

Although cisplatin is widely used as an anti-cancer agent, its use is significantly limited because of its tendency to induce nephrotoxicity through poorly understood mechanisms. NAD(P)H:quinone oxidoreductase 1 (NQO1) is well known to regulate ROS generation. The purpose of this study was to investigate whether NQO1 modulates cisplatin-induced renal failure associated with NADPH oxidase (NOX)-derived ROS production in an animal model. NQO1-/- mice were treated with cisplatin (18 mg/kg) and renal function, oxidative stress, and tubular apoptosis were assessed. NQO1-/- mice showed increased blood urea nitrogen and creatinine levels, tubular damage, oxidative stress, and apoptosis. In accordance with these results, the cellular NADPH/NADP ratio and NOX activity were markedly increased in the kidneys of NQO1-/- mice compared to NQO1+/+ mice. In addition, activation of NQO1 by βL treatment significantly improved renal dysfunction and reduced tubular cell damage, oxidative stress, and apoptosis. This study demonstrates that NQO1 protects cells against renal failure induced by cisplatin, and that this effect is mediated by decreased NOX activity via cellular NADPH/NADP modulation. These results provide convincing evidence that NQO1 might be beneficial for ameliorating renal failure induced by cisplatin., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Background: Chronic renal failure (CRF) is associated with increased cardiovascular mortality, and medial vascular smooth muscle cell (VSMC) hypertrophy, proliferation, and calcification play a pivotal role in uremic vasculopathy. Glucose transporter-1 (GLUT1) facilitates the transport of glucose into VSMCs, and GLUT1 overexpression associated with high glucose influx leads to a stimulation of VSMC proliferation. However, the role of GLUT1 in uremic vasculopathy remains unclear. This study aimed to identify changes in the expression of GLUT1 in VSMCs in the setting of experimental uremia and investigate whether Akt/tuberous sclerosis complex subunit 2 (TSC2)/mammalian target of rapamycin (mTOR)/ribosomal S6 protein kinase (S6K) signaling, which plays a crucial role in VSMC proliferation and glucose metabolism, is involved in the regulation of GLUT1 expression., Methods: In vivo experimental CRF was induced in Wistar rats by 5/6 nephrectomy, and the GLUT1 expression in aortic tissue was determined by the reverse transcriptase-polymerase chain reaction, immunoblotting, and immunohistochemical staining. Indoxyl sulfate (IS) is a uremic retention solute proven with pro-proliferative effect on rat VSMCs, and we further studied the expression of GLUT1 in rat A7r5 rat embryonic aortic cells stimulated by IS in the presence or absence of phloretin, a GLUT1 inhibitor, to explore the pathogenic role of GLUT1 in uremic vasculopathy. The contribution of Akt/TSC2/mTOR/S6K signaling in modifying the GLUT1 expression was also assessed., Results: Eight weeks after 5/6 nephrectomy, aortic tissue obtained from CRF rats exhibited increased wall thickness and VSMC hypertrophy, hyperplasia, and degeneration. Compared with the sham-operated control group, the messenger (m)RNA and protein abundance of GLUT1 were both markedly increased in CRF rats. In vitro, IS induced a significant increase in expression of GLUT1 protein as well as pro-proliferative cyclin D1 and p21 mRNA and a modest increase in expression of antiapoptotic p53 mRNA in A7r5 cells, whereas inhibition of GLUT1 mediated glucose influx reduced the pro-proliferative and antiapoptotic effects of IS. In addition to increased GLUT1 expression, IS significantly suppressed Akt and TSC2 phosphorylation after 6-hour and 12-hour treatment, but increased S6K phosphorylation after 3-hour treatment. Inactivation of mTOR downstream signaling by rapamycin treatment inhibited S6K phosphorylation and abolished the stimulatory effect of IS on GLUT1 expression., Conclusions: In vivo and in vitro experimental CRF displayed prominent GLUT1 upregulation in VSMCs. The uremic toxin IS stimulated proliferation of VSMCs possibly through induction of GLUT1 expression. The Akt/TSC/mTOR/S6K signaling pathway may be one of the mechanisms underlying the upregulation of GLUT1 expression in uremic VSMCs., (Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Paraoxonase lactonase activity protects against homocysteinylation; therefore, it can be a potential contributing factor to prevent atherosclerosis. We aimed to determine paraoxonase and HTLase activities and to clarify the relationship between HTLase activity and some cardiovascular risk factors, such as homocysteine, cystatin C asymmetric dimethylarginine (ADMA), and adipokines both in hemo dialyzed and transplanted patients. Among 114 hemodialyzed, 80 transplanted and 64 healthy control subjects, we investigated body mass index (BMI) as well as fasting serum contents of urea, uric acid, creatinine, cystatin C, homocysteine, glucose, lipids, total protein and albumin. Serum paraoxonase (PON 1) and HTLase activities were measured spectrophotometrically. ADMA, ADPN adiponectin, leptin (LEP) levels was determined with a sandwich enzyme-linked immunosorbent assay method. Dyslipidemic patients showed hypercholesterolemia, and high low-density lipoprotein (LDL); parallel with improved renal function, they displayed decreased cystatin C and homocysteine levels (P < .001). There was a significant negative correlation between PON 1 activity and cystatin C and homocysteine concentrations (P < .05). Obese patients revealed significantly higher LDL (P < .05) and leptin concentrations (P < .01). There was a significant positive correlation between PON 1 activity and adiponectin levels (P = .0276). Both dialyzed and transplanted patients displayed significantly lower HTLase activities compared to the control group (P < .001), particularly lower HTLase and PON 1 activities in dialyzed subjects compared with the transplanted group (P < .05). HTLase activity showed significant negative correlations with ADMA levels among the whole study population (P < .001), whereas positive associations were noted between PON 1 and HTLase activities (P < .001). HTLase activity may be a new predictor of cardiovascular risk in renal failure although it is modulated by other risk factors., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Cyclooxygenase (COX)-dependent prostaglandins are necessary for normal kidney function. These prostaglandins are associated with inflammation, maintenance of sodium and water homeostasis, control of renin release, renal vasodilation, vasoconstriction attenuation, and prenatal renal development. COX-2 expression is regulated by the renin-angiotensin system, glucocorticoids or mineralcorticoids, and aldosterone, supporting a role for COX-2 in kidney function. Indeed, COX-2 mRNA and protein levels as well as enzyme activity are increased, along with PGE2, during kidney failure. In addition, changes in COX-2 expression are associated with increased blood pressure, urinary volume, sodium and protein and decreased urinary osmolarity. Intrarenal mechanisms such as angiotensin II (Ang II) production, increased sodium delivery, glomerular hypertension, and renal tubular inflammation have been suggested to be responsible for the increase in COX-2 expression. Although, specific COX-2 pharmacological inhibition has been related to the prevention of kidney damage, clinical studies have reported that COX-2 inhibition may cause side effects such as edema or a modest elevation in blood pressure and could possibly interfere with antihypertensive drugs and increase the risk of cardiovascular complications. Thus, administration of COX-2 inhibitors requires caution, especially in the presence of underlying cardiovascular disease., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Diabetes and renal insufficiency are interrelated metabolic disorders closely associated with redox homeostasis disturbances. The aim of this study was to compare the activity of copper zinc superoxide dismutase (CuZnSOD) in the erythrocytes of hypertensive diabetic patients with or without renal insufficiency with normal healthy control subjects. In both groups of diabetic patients, blood glucose level and the content of glycosylated hemoglobin (HbA1c) were higher than in the control group. However, CuZnSOD activity was significantly higher than control only in hypertensive diabetic patients with renal insufficiency. Our results suggest that disturbances in superoxide homeostasis do correlate with long-term complication in diabetes, i.e. diabetic renal insufficiency and hypertension.

Previously, we showed that curcumin prevents chronic kidney disease (CKD) development in &frac56; nephrectomized (Nx) rats when given within 1 wk after Nx (Ghosh SS, Massey HD, Krieg R, Fazelbhoy ZA, Ghosh S, Sica DA, Fakhry I, Gehr TW. Am J Physiol Renal Physiol 296: F1146-F1157, 2009). To better mimic the scenario for renal disease in humans, we began curcumin and enalapril therapy when proteinuria was already established. We hypothesized that curcumin, by blocking the inflammatory mediators TNF-α and IL-1β, could also reduce cyclooxygenase (COX) and phospholipase expression in the kidney. Nx animals were divided into untreated Nx, curcumin-treated, and enalapril-treated groups. Curcumin (75 mg/kg) and enalapril (10 mg/kg) were administered for 10 wk. Renal dysfunction in the Nx group, as evidenced by elevated blood urea nitrogen, plasma creatinine, proteinuria, segmental sclerosis, and tubular dilatation, was comparably reduced by curcumin and enalapril, with only enalapril significantly lowering blood pressure. Compared with controls, Nx animals had higher plasma/kidney TNF-α and IL-1β, which were reduced by curcumin and enalapril treatment. Nx animals had significantly elevated kidney levels of cytosolic PLA(2), calcium-independent intracellular PLA(2), COX 1, and COX 2, which were comparably reduced by curcumin and enalapril. Studies in mesangial cells and macrophages were carried out to establish that the in vivo increase in PLA(2) and COX were mediated by TNF-α and IL-1β and that curcumin, by antagonizing the cytokines, could significantly reduce both PLA(2) and COX. We conclude that curcumin ameliorates CKD by blocking inflammatory signals even if it is given at a later stage of the disease.

Chronic kidney disease is a long-term complication in acute intermittent porphyria (AIP). The pathophysiological significance of hepatic overproduction of the porphyrin precursors aminolevulinate acid (ALA) and porphobilinogen (PBG) in chronic kidney disease is unclear. We have investigated the effect of repetitive acute attacks on renal function and the effect of total or five-sixth nephrectomy causing renal insufficiency on hepatic heme synthesis in the porphobilinogen deaminase (PBGD)-deficient (AIP) mouse. Phenobarbital challenge in the AIP-mice increased urinary porphyrin precursor excretion. Successive attacks throughout 14 weeks led to minor renal lesions with no impact on renal function. In the liver of wild type and AIP mice, 5/6 nephrectomy enhanced transcription of the first and rate-limiting ALA synthase. As a consequence, urinary PBG excretion increased in AIP mice. The PBG/ALA ratio increased from 1 in sham operated AIP animals to over 5 (males) and over 13 (females) in the 5/6 nephrectomized mice. Total nephrectomy caused a rapid decrease in PBGD activity without changes in enzyme protein level in the AIP mice but not in the wild type animals. In conclusion, high concentration of porphyrin precursors had little impact on renal function. However, progressive renal insufficiency aggravates porphyria attacks and increases the PBG/ALA ratio, which should be considered a warning sign for potentially life-threatening impairment in AIP patients with signs of renal failure.

Background: The severity of renal dysfunction correlates with fatal outcome after hemorrhagic shock. However, the precise mechanism for increasing renal dysfunction in response to the degree and the progression of hemorrhagic shock has not been clearly demonstrated. In this study, we examined the role of p38 mitogen-activated protein kinase (MAPK) activation on the progression of renal dysfunction by studying the differential severity of bleeding., Methods: Hemorrhagic shock was studied by quantitatively grading four groups of hemorrhaging rats: not hemorrhaged (Sham group); hemorrhaged up to 16.7% of their total body blood volume (16.7% group); hemorrhaged up to 25% (25% group); and hemorrhaged up to 33% (33% group). Mean arterial blood pressure and renal blood flow were recorded up to 5 hours after the bleeding. Kidneys were excised for assays of p38 MAPK and mRNA of the proinflammatory cytokines, such as tumor necrosis factor-α and interleukin-1β, and for histopathological study. The levels the cytokines and creatinine were measured in the renal venous blood., Results: As the amount of bleeding increased, the initial activation of p38 MAPK and the expression of renal cytokines were progressively enhanced. The severity of renal dysfunction, manifested by serum creatinine concentration, histologic damage score, and neutrophil accumulation in the kidney, was well correlated with the degree of initial p38 MAPK activation., Conclusions: The increase of initial p38 MAPK activation after hemorrhagic shock quantitatively enhanced the ensuing renal dysfunction in response to the degree and the progression of hemorrhagic shock.

Hepatic metabolizing enzymes of diethylene glycol (DEG) are impaired in liver diseases. Thus, the purpose of this study was to increase our understandings in metabolism and toxicology of DEG by clarifying the influences of pre-existing liver disease. Forty Sprague-Dawley rats with carbon tetrachloride-induced liver cirrhosis and 20 control rats were intraperitoneally administered a single dose of DEG, and randomly killed 1, 2, 5 or 8 days following exposure. Compared with control rats, the model rats had significantly higher blood CO(2)-combining power, lower blood urine nitrogen, serum creatinine and alanine aminotransferase levels on the second day and a lower mortality rate on the eighth day following DEG exposure. Enlargements of liver and kidneys and degeneration and necrosis of hepatocytes and renal tubules in the model rats was also less serious than in the control rats. Urine DEG levels were significantly higher on the first day in the model rats than the control rats (46.65 ± 8.79 mg vs 18.88 ± 6.18 mg, p < 0.01), but DEG concentrations in the blood, liver and kidneys were lower. Hepatic alcohol dehydrogenase (ADH) activity in the model rats was significantly lower than that in the control rats, which was positively related to renal damage. The toxic effects of DEG in rats with pre-existing liver cirrhosis are significantly reduced, which may be due to the decreased hepatic ADH activity. It suggests that the metabolite of ADH is responsible for DEG poisoning, and this toxic metabolite may mainly originate in the liver.

Autosomal dominant polycystic kidney disease (ADPKD) caused by mutations in either the PKD1 or PKD2 gene is a major cause of end-stage renal failure. A number of compounds targeting specific signaling pathways were able to inhibit cystogenesis in rodent models and are currently being tested in clinical trials. However, given the complex signaling in ADPKD, an ideal therapy would likely have to comprise several pathways at once. Therefore, multitarget compounds may provide promising therapeutic interventions for the treatment of ADPKD. To test this hypothesis, we treated Pkd1-deletion mice with diferuloylmethane (curcumin), a compound without appreciable side effects and known to modulate several pathways that are also altered in ADPKD, e.g., mammalian target of rapamycin (mTOR) and Wnt signaling. After conditional inactivation of Pkd1, mTOR signaling was indeed elevated in cystic kidneys. Interestingly, also activation of signal transducers and activator of transcription 3 (STAT3) strongly correlated with cyst progression. Both pathways were effectively inhibited in vitro by curcumin. Importantly, Pkd1-deletion mice that were treated with curcumin and killed at an early stage of PKD displayed improved renal histology and reduced STAT3 activation, proliferation index, cystic index, and kidney weight/body weight ratios. In addition, renal failure was significantly postponed in mice with severe PKD. These data suggest that multitarget compounds hold promising potential for safe and effective treatment of ADPKD.

ACE (angiotensin-converting enzyme) 2 is expressed in the heart and kidney and metabolizes Ang (angiotensin) II to Ang-(1-7) a peptide that acts via the Ang-(1-7) or mas receptor. The aim of the present study was to assess the effect of Ang-(1-7) on blood pressure and cardiac remodelling in a rat model of renal mass ablation. Male SD (Sprague-Dawley) rats underwent STNx (subtotal nephrectomy) and were treated for 10 days with vehicle, the ACE inhibitor ramipril (oral 1 mg·kg(-1) of body weight·day(-1)) or Ang-(1-7) (subcutaneous 24 μg·kg(-1) of body weight·h(-1)) (all n = 15 per group). A control group (n = 10) of sham-operated rats were also studied. STNx rats were hypertensive (P<0.01) with renal impairment (P<0.001), cardiac hypertrophy (P<0.001) and fibrosis (P<0.05), and increased cardiac ACE (P<0.001) and ACE2 activity (P<0.05). Ramipril reduced blood pressure (P<0.01), improved cardiac hypertrophy (P<0.001) and inhibited cardiac ACE (P<0.001). By contrast, Ang-(1-7) infusion in STNx was associated with further increases in blood pressure (P<0.05), cardiac hypertrophy (P<0.05) and fibrosis (P<0.01). Ang-(1-7) infusion also increased cardiac ACE activity (P<0.001) and reduced cardiac ACE2 activity (P<0.05) compared with STNx-vehicle rats. Our results add to the increasing evidence that Ang-(1-7) may have deleterious cardiovascular effects in kidney failure and highlight the need for further in vivo studies of the ACE2/Ang-(1-7)/mas receptor axis in kidney disease.

Background: pre-clinical studies showed that carnosine may have a beneficial cardiovascular effect. We studied the effect of tri-nucleotide repeat (CTGs) polymorphisms in exon 2 of the CNDP1 gene, which codes for carnosinase and is responsible for the degradation of carnosine, on the clinical outcome of Chinese peritoneal dialysis (PD) patients., Methods: we studied 442 PD subjects. Genotyping was done by direct sequencing of genomic DNA. Patients were followed for 43.5 ± 16.2 months., Results: the prevalence of 6-6, 5-6, 5-5 and 4-6 CTGs genotypes was 80.3%, 18.6%, 0.9% and 0.2%, respectively. A total of 270 patients (61.1%) developed the primary composite end point during follow-up. The 5-year event-free survival of the 6-6 CTGs and non 6-6 group was 37.1% and 21.3%, respectively (log rank test, p = 0.3)., Conclusion: the CTGs polymorphism of the CNDP1 gene does not affect survival of Chinese PD subjects. The role of carnosine and CNDP1 gene polymorphism in the pathogenesis of cardiovascular disease requires further study.

Objective: Epidemiological and experimental studies indicate that kidney disease is associated with increased oxidative stress. Our aim was to determine whether paraoxonase 1 (PON1) activity is altered in patients with moderately decreased glomerular filtration rates (GFRs) compared to healthy controls., Material and Methods: Forty-eight patients showing relatively low GFRs upon renal scintigraphy with (99m)Tc-DTPA were compared to 40 age-matched healthy subjects. Serum PON1 activity was measured spectrophotometrically. Lipid hydroperoxide levels were measured via iodometric assay., Results: The mean ages of the patient and control groups were 32.09 +/- 6.10 (range 23-50) and 31.30 +/- 5.30 (range 20-46) years, respectively. Serum PON1 (p= 0.949) and high-density lipoprotein (p= 0.473) levels did not differ between groups. Significant differences were detected between groups in terms of mean triglyceride (p= 0.009), very-low-density lipoprotein (p = 0.010), lipid hydroperoxide (p = 0.026), urea (p = 0.012), and creatinine (p = 0.001) levels, whereas total cholesterol (p = 0.520) and low-density lipoprotein (p = 0.161) were similar between groups. Mean GFR was significantly lower in the low GFR group compared to the control (p = 0.000)., Conclusion: Our results indicate that PON1 activity and high-density lipoprotein levels may not be determining factors in premature vascular aging in patients with moderately decreased GFRs. Instead, some other undetermined factor(s) may be involved in modulating enzymatic activity.

While erudite cell biologists have for many decades described singular immotile appendages known as primary cilia to be present on most cells in our bodies, cilial function(s) long remained an enigma. Driven largely by an ever increasing number of discoveries of genetic defects in primary cilia during the past decade, cilia were catapulted from a long lasting existence in obscurity into the bright spotlight in cell biology and medicine. The study by O'Toole et al. in this issue of the JCI adds a novel "enzymatic" facet to the rapidly growing information about these little cellular tails, by demonstrating that defects in the XPNPEP3 gene, which encodes mitochondrial and cytosolic splice variants of X-prolyl aminopeptidase 3, can cause nephronophthisis-like ciliopathy. Future studies are in order now to elucidate the cystogenic pathways affected by disrupted enzymatic function of XPNPEP3 in cilia-related cystogenic diseases.

The autosomal recessive kidney disease nephronophthisis (NPHP) constitutes the most frequent genetic cause of terminal renal failure in the first 3 decades of life. Ten causative genes (NPHP1-NPHP9 and NPHP11), whose products localize to the primary cilia-centrosome complex, support the unifying concept that cystic kidney diseases are "ciliopathies". Using genome-wide homozygosity mapping, we report here what we believe to be a new locus (NPHP-like 1 [NPHPL1]) for an NPHP-like nephropathy. In 2 families with an NPHP-like phenotype, we detected homozygous frameshift and splice-site mutations, respectively, in the X-prolyl aminopeptidase 3 (XPNPEP3) gene. In contrast to all known NPHP proteins, XPNPEP3 localizes to mitochondria of renal cells. However, in vivo analyses also revealed a likely cilia-related function; suppression of zebrafish xpnpep3 phenocopied the developmental phenotypes of ciliopathy morphants, and this effect was rescued by human XPNPEP3 that was devoid of a mitochondrial localization signal. Consistent with a role for XPNPEP3 in ciliary function, several ciliary cystogenic proteins were found to be XPNPEP3 substrates, for which resistance to N-terminal proline cleavage resulted in attenuated protein function in vivo in zebrafish. Our data highlight an emerging link between mitochondria and ciliary dysfunction, and suggest that further understanding the enzymatic activity and substrates of XPNPEP3 will illuminate novel cystogenic pathways.

Isolated complex I deficiency is the most commonly reported enzyme defect in paediatric mitochondrial disorders, and may arise due to mutations in nuclear-encoded structural or assembly genes, or the mitochondrial genome. We present the clinical, biochemical and molecular genetic data in a young girl whose clinical picture is dominated by chronic renal failure, myopathy and persistent lactic acidosis. An isolated complex I deficiency in muscle was identified due to a novel mutation (m.12425delA) in the MTND5 gene. This single nucleotide deletion is heteroplasmic and detectable in several tissues from the proband but not her mother, suggesting a de novo mutation event. The description of the first frameshift mutation in a mitochondrial complex I gene affirms mitochondrial DNA mutations as an important cause of isolated complex I deficiency in children and the importance of whole mitochondrial genome sequencing in the diagnostic work-up to elucidate the underlying molecular genetic abnormality and provide important genetic advice., (Copyright 2009 Elsevier B.V. All rights reserved.)

Aldose reductase enzyme (ALR2) of the polyol metabolic pathway, apart from its role as detoxifying enzyme towards toxic aldehydes, osmoregulator in the kidney and regulator of sperm maturation, was first found to be implicated in the etiology of the long term diabetic complications. However, to date, emerging reports have suggested that under normal glucose concentration, ALR2 may be up-regulated by factors other than hyperglycemia and therefore be involved also in other pathological processes that have become major threats to human health in the 21(st) century. Such pathologies are a number of cardiac disorders, inflammation, mood disorders, renal insufficiency and ovarian abnormalities. In addition, ALR2 was found to be over-expressed in different human cancers such as liver, breast, ovarian, cervical and rectal cancers. Although several aldose reductase inhibitors (ARIs) have progressed to the clinical level, only one is currently on the market. Thus, attention is currently targeted to discover ARIs of distinct chemical structures, being neither hydantoin nor carboxylic acid derivatives. The present review focuses on the molecular mechanisms by which ALR2 is implicated in a number of pathologies, on various aspects concerning its catalytic mechanism and its active site, and on the main classes of ARIs that have been developed to date, as well as on reported (quantitive) structure-activity relationships. The presented data aim to support the notion that ARIs are of pharmacotherapeutic interest for the pharmaceutical community and highlight essential aspects for the development of efficient and potent ARIs.

Objectives: There is little information on the prevalence of increased serum lipase levels and its determinants from population-based studies. The present study was performed to provide such information., Methods: We used data from the 4275 subjects aged 20 to 79 years who were recruited for the population-based Study of Health in Pomerania. Serum lipase levels were determined colorimetrically; levels > or =3.17 micromol/s x l were considered increased., Results: The prevalence of increased serum lipase levels was 3.4%. The prevalence of self-reported chronic pancreatitis in this population was 0.7%. Subjects with and without increased serum lipase levels did not differ with respect to symptoms indicative of pancreatitis including abdominal feeling of fullness, abdominal pain, nausea, and loss of weight. High serum lipase levels correlated with advanced age, increased serum creatinine levels, and use of steroids or enalapril., Conclusions: Increased serum lipase levels are unrelated to pancreatitis-related symptoms. Renal insufficiency and prevalent pancreatitis explain increased serum lipase levels in a minority of subjects. In clinical practice, drugs including steroids and enalapril should be excluded as cause of increased serum lipase levels. The predictive roleof lipase measurements with respect to other pancreatic or extrapancreatic disorders has to be investigated in cohort studies.

Matrix metalloproteinases (MMPs) are classically associated with the turnover of secreted structural and functional proteins. Although MMPs have been shown to process also a kaleidoscope of membrane-associated substrates, little is known about the processing of intracellular proteins by MMPs. Physiological and pathological cell apoptosis, necrosis and tumor lysis by chemotherapy, radiotherapy or immunological cytotoxicity, are examples of conditions in which an overload of intracellular proteins becomes accessible to the action of MMPs. We used a model system of dying human myelomonocytic cells to study the processing of intracellular protein substrates by gelatinase B/MMP-9 in vitro. Adenylyl cyclase-associated protein-1 or CAP1 was identified as a novel and most efficient substrate of gelatinase B/MMP-9. The presence of CAP1 in the extracellular milieu in vivo was documented by analysis of urine of patients with systemic autoimmune diseases. Whereas no active MMP-9 could be detected in urines of healthy controls, all urine samples of patients with clinical parameters of renal failure contained activated MMP-9 and/or MMP-2. In addition, in some of these patients indications of CAP1 cleavage are observed, implying CAP1 degradation in vivo. The high turnover rate of CAP1 by MMP-9, comparable to that of gelatin as the natural extracellular substrate of this enzyme, may be critical to prevent pathological conditions associated with considerable cytolysis.

Vascular calcification is associated with increased cardiovascular morbidity and mortality. A number of calcification inhibitors have been defined recently, including inorganic pyrophosphate (PP(i)), an important physicochemical inhibitor of hydroxyapatite crystal growth. Increased hydrolysis of PP(i) by tissue-nonspecific alkaline phosphatase (TNAP) may occur in renal failure and act to enhance mineralization of vessels.

Objectives: To determine whether high levels of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) are associated with prevalent cardiovascular disease (CVD) and to evaluate factors most influencing Lp-PLA(2) levels in a community-based cohort of older adults., Design: Cross-sectional., Setting: The Cardiovascular Health Study (CHS), a population-based cohort study of men and women aged 65 and older., Participants: Five thousand five hundred thirty-one CHS participants., Measurements: Levels of Lp-PLA(2) activity were determined using stored blood samples from the baseline examination., Results: Mean Lp-PLA(2) was higher in participants with electrocardiographically determined ventricular conduction defect and major Q-wave abnormality and was positively correlated with left ventricular (LV) mass. It was high in those with echocardiographically determined abnormal LV ejection fraction, which persisted after adjustment. Mean Lp-PLA(2) was also higher in participants with mild renal insufficiency and kidney disease. After multivariable adjustment, there was a modest but significant 27% greater risk of prevalent CHF per standard deviation increment of Lp-PLA(2) and a modest but significant 12% greater risk of prevalent myocardial infarction. Lp-PLA(2) was weakly but mainly most strongly correlated with cholesterol and lipoproteins, but those correlations were not especially strong. Lp-PLA(2) was weakly positively correlated with soluble intercellular adhesion molecule-1 but not interleukin-6. In total, all factors considered could explain only 29% of Lp-PLA(2) activity., Conclusion: Novel findings in the study are the associations, in those aged 65 and older, between Lp-PLA(2) activity and LV dysfunction, CHF, and renal disease. CVD risk factors only minimally explain levels of Lp-PLA(2).

Objectives: To test the association between angiotensin-converting enzyme (ACE) insertion or deletion (I/D) polymorphism and decline of renal function in people aged 60 and older., Design: Population-based prospective study with 4-year follow-up., Setting: Department of Internal Medicine and Family Medicine, Kaohsiung Medical University (KMU) Hospital and Graduate Institute of Medicine and Public Health, KMU., Participants: Of 1,500 people screened, 193 subjects were enrolled, and 144 completed 4 years of follow-up, 112 non-diabetic normotensive elderly people were analyzed., Measurements: Subjects received biochemistry examination at baseline and at 2- and 4-year follow-ups. Serum creatinine and calculated renal parameters, including the Cockroft-Gault (CG) formula, the Jelliffe formula, and the Modification of Diet in Renal Disease (MDRD) Study equation, were used. Genetic polymorphism was analyzed according to the polymerase chain reaction., Results: The mean age+/-standard deviation of the subjects was 71.9+/-3.7 (range 60-81). Serum creatinine, CG creatinine clearance (CrCl), Jelliffe CrCl, and MDRD glomerular filtration rate (GFR) were significantly lower at the 2- and 4-year follow-ups (all P < or = .001). At the 4-year follow-up, the magnitude of declines of the above four renal parameters was significantly higher in subjects with the ACE D allele than in the non-D-allele carriers (P = .01, .01, .04, and .01 for creatinine, CG CrCl, Jelliffe CrCl, and MDRD GFR, respectively). This association was still significant in multivariate analyses (P < or = .02 for all parameters)., Conclusion: This longitudinal study showed the ACE I/D gene polymorphism might modulate renal function decline in elderly Chinese. This provides further knowledge essential in the assessment of renal disease and determination of renal function in older Chinese.

Nephrogenic systemic fibrosis (NSF), also known as nephrogenic fibrosing dermopathy (NFD), occurs in renal failure patients after gadolinium contrast exposure. The fibrosis of the dermis and subcutaneous septae accompanies fibrosis of other organs, including the heart, liver, lungs, and muscle. The fibrotic skin demonstrates increased dermal collagen, fibroblasts, and mucin. The mechanism by which gadolinium is associated with fibrosis is not known. We tested the hypothesis that upregulation of transglutaminases contributes to the fibrosis seen in the organs, including skin, of renal failure patients exposed to gadolinium contrast. We performed immunohistochemical studies using antibodies to transglutaminase-2, factor XIIIa, transglutaminase isopeptide, and the histiocyte marker CD68 on five archived skin biopsies of NSF. The results indicate that the dermal fibroblasts and histiocytes of NSF express transglutaminase-2, CD68, factor XIIIa, and transglutaminase isopeptide, indicating increased expression and/or activation of transglutaminases in NSF. We recommend further research into the use of transglutaminase inhibitors in the treatment and prevention of NSF.

Diagnosis of heterozygous Fabry patients is difficult because of its variable clinical manifestations and overlapping serum alpha-galactosidase A (AGA) activity between carriers and non-carriers. We tried to facilitate diagnosis of heterozygous Fabry patients by detailed clinical examination. We analyzed clinical presentations, biochemical, electrophysiological and genetic characteristics of 16 patients with Fabry disease in a large Chinese family. Male patients demonstrated significantly higher pain scores, poorer renal function, and higher frequency of hypohidrosis and corpora angiokeratomas than female patients. Interestingly, all the males and females had corneal verticilata by slit lamp examination. However, there was no association of serum AGA activity with renal function or pain symptom scores. The results indicated that detailed ocular and neurological examination might provide an alternative way of detecting heterozygous patients. We also report a novel large deletion spanning across the joint of Alu repetitive elements in introns 1 and 2 with resultant exon 2 deletion in a Chinese family with Fabry disease.

Beta4 galactosylation of glycoproteins plays important roles in protein conformation, stability, transport, and clearance from the circulation. Recent studies have revealed that aberrant glycosylation causes various human diseases. Here we report that mice lacking beta-1,4-galactosyltransferase (beta4GalT)-I, which transfers galactose to the terminal N-acetylglucosamine of N- and O-linked glycans in a beta-1,4 linkage, spontaneously developed human immunoglobulin A nephropathy (IgAN)-like glomerular lesions with IgA deposition and expanded mesangial matrix. beta4GalT-I-deficient mice also showed high serum IgA levels with increased polymeric forms as in human IgAN. IgAN is the most common form of glomerulonephritis, and a significant proportion of patients progress to renal failure. However, pathological molecular mechanisms of IgAN are poorly understood. In humans, abnormal character of serum IgA, especially serum IgA1 with aberrant galactosylation and sialylation of O-glycans in its hinge region is thought to contribute to the pathogenesis of IgAN. Mouse IgA has N-glycans but not O-glycans, and beta4-galactosylation and sialylation of the N-glycans on the serum IgA from beta4GalT-I-deficient mice was completely absent. This is the first report demonstrating that genetic remodeling of protein glycosylation causes IgAN. We propose that carbohydrates of serum IgA are involved in the development of IgAN, whether the carbohydrates are O-glycans or N-glycans.

Objective: To determine the type of mutation in a patient with clinical diagnosis of suspected APRT deficiency., Design and Methods: A 51-year-old male patient, with a clinical history of two prior episodes of renal colic with urinary stone excretion (reported as uric acid stones in the first episode and as calcium oxalate stones in the second), was admitted to the hospital with severe non-oliguric renal failure (1.06 mmol/L serum creatinine), severe hyponatremia (114 mmol/L Na(+)), metabolic acidosis (14 mmol/L HCO(3)(-)) and uricemia in the normal range. Abnormalities at renal scan and persistency of severe renal failure required to start haemodialysis. Results of renal biopsy prompted us to undertake a biochemical and molecular biological evaluation of the patient for suspected adenine phosphoribosyltransferase (APRT) deficiency., Results: HPLC analysis of serum and urine, for determining purine derivative profile, showed the pathological presence of adenine in both biological fluids (3.57 micromol/L and 7.11 micromol/mmol creatinine in serum and urine, respectively; not detectable in both fluids in healthy controls). APRT assay in a sample of patient hemolysate showed no detectable activity of the enzyme (25.56+/-9.55 U/L red blood cells in control healthy subjects). Molecular biological analysis of the amplified APRT gene revealed that the patient harboured in exon 3 a homozygous 254 bp deletion-8 bp insertion, previously described only once in a compound heterozygote. Analysis of the patient family showed that heterozygotes for this APRT gene mutation, in spite of a 69% lower APRT enzymatic activity than that of healthy subjects, had no detectable adenine concentrations in both serum and urine., Conclusions: Results of the first patient harbouring the homozygous 254 bp deletion-8 bp insertion of the APRT gene strongly indicated that definitive diagnosis of APRT deficiency (often under or misdiagnosed) would require a combined clinical, biochemical and molecular biological evaluation.

Purpose: The purpose of this study was to see if there is a significant association between calcium-phosphorus product (CPP) and initial troponin-T values in patients with renal insufficiency., Basic Procedures: A retrospective study over 4 months from the laboratory database of all patients with serum creatinine values greater than 3 mg/dL who had concomitant troponin T and creatine kinase isoenzymes measured was conducted. The most recent calcium and phosphorus values were also abstracted., Results: There were 87 patients with a mean age of 59 years, a median creatinine value of 51 mg/dL, a mean CPP of 47, and a median initial troponin-T value of 0.18 ng/mL. The troponin level was elevated (>0.05 ng/mL) in 74% of the patients. The CPP was higher than 55 in 28% of the patients. When comparing the troponin values with the CPP, there was no association noted (P = .72)., Conclusions: Although both elevated CPP and troponin values are associated with increased cardiovascular mortality in the intermediate term, we could not demonstrate a useful relationship between the 2 values that would indicate causality or help with the interpretation of the initial troponin level when patients with renal insufficiency present with suspected acute myocardial infarction.

Gentamicin (GM) is one of the most important of the aminoglycoside antibiotics used widely for the treatment of serious and life-threatening infections and whose clinical use is limited by its nephrotoxicity. As the pathogenesis of GM-induced renal dysfunction and injury involves reactive oxygen species, the polyphenolic constituents of soybean with antioxidant property may protect against GM-induced renal toxicity. We therefore tested this hypothesis using phenolic extract of soybean (PESB) on GM-induced nephrotoxicity rat model. Administration of GM (80 mg/kg, s.c.) for 12 days to rats induced marked renal failure, characterized by a significantly increased plasma creatinine, urea and Na(+) ions levels, with K(+) depletion. This was also associated with decreases in the activity of the renal antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), glutathione-S-transferase (GST)] measured and depletion of both blood and renal reduced glutathione (GSH) levels. The activities of membrane-bound glucose-6-phosphatase (G6Pase) and 5(1)-nucleotidase (5(1)-NTD) enzymes as well as gamma-glutamyltransferase (gamma-GT) and aspartate aminotransferase (AST) (enzymes that are located in the proximal tubule) were decreased. Renal histology examination further confirmed the damage to the kidney as it reveals severe necrosis of the proximal renal tubules with deposition of colloid casts. These alterations were ameliorated in rats pretreated with PESB. The decrease in the activities of SOD, CAT, GST as well as GSH depletion observed in GM-treated rats was prevented in the rats pretreated with PESB. The activities of gamma-GT, AST and G6Pase were also increased in the kidney. These protective effects were dose dependent except for G6Pase activity and GSH levels that were preserved only at 500 mg/kg dose of PESB, and 5'-NTD activity that was dose dependently decreased. Furthermore, the extent of tubular damage induced by GM was reduced in rats that also received PESB. The lower dose (500 mg/kg) of the extract, however, appeared to provide better histological protection. These results suggest that the PESB has protective effects on GM-mediated nephropathy and this may be related to the action of the antioxidant polyphenolic content of the soybean.

Background: Calcineurin inhibitor (CI)-based immunosuppression has prolonged the survival of heart transplant recipients. However, CI-induced renal injury remains as a major problem in these patients. Sirolimus is an immunosuppressant with no significant impact on renal function. A limited number of recent papers have showed that the switch from CI to sirolimus improved renal function in late follow-up of heart transplant patients with CI-related nephrotoxicity., Methods: Ten heart transplant recipients with CI-induced nephrotoxicity (creatinine 3.9+/-1.8 mg/dl) at a median of 701 (465 to 1325) days posttransplant had CI switched to sirolimus (target though levels 10 to 14 ng/ml) while mycophenolate mofetil (MMF, 3g/day) was maintained and adjusted according to white blood cell count., Results: This maneuver caused a marked decrease in serum creatinine (P<0.00001) at 30 (1.2+/-0.4 mg/dl), 90 (1.3+/-0.4 mg/dl) and 180 (1.3+/-0.4 mg/dl) days post-conversion and a significant decrease in serum potassium levels (5.1+/-0.5 at baseline vs. 3.9+/-0.3 at 180 days, P<0.00005). After the drugs switch no changes in hemoglobin levels, white blood cell count, platelets count, blood glucose and glutamic oxaloacetic transaminase plasma levels were observed. Total cholesterol increased from 242+/-28 to 290+/-117 mg/dl (P>0.05) after 90 days and decreased to 216+/-58 mg/dl at day 180 (P>0.05) after statins dose adjustment. Rejection and infection rates were not modified by sirolimus., Conclusions: Conversion to a sirolimus-based immunosuppression regimen associated with MMF allowed striking renal function recovery in heart transplant recipients with calcineurin inhibitor-induced renal impairment at midterm follow-up.